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Radiation Proteomics: A Brief Overview.
Abstract
Acute biological effects caused by the exposure to high doses of radiation, either ionizing or non-ionizing, are relatively well known but the delayed effects, occurring decades after exposure, are difficult to predict. The knowledge of the acute and delayed effects of the low doses of ionizing radiation (e.g. bystander effect) or non-ionizing radiation (e.g. radiation emitted by wireless communication devices) is not yet reliably established. Often the acute effects of low doses are small and difficult to discover and replicate in scientific studies. Chronic effects of prolonged exposures to low-dose radiation for decades are virtually unknown and often not possible to predict on the basis of the knowledge gained from acute exposures to high doses of radiation. Physiological significance of the biological effects induced by low doses of radiation is not known. The same lack of predictability of outcomes applies to the delayed effects of high-dose radiation exposures. Proteomics, supplemented with other "omics" techniques, might be the best way forward to find out the target molecules of radiation, the biomarkers of radiation exposure and the physiological and health significance of the acute and delayed biological effects caused by the exposures to high and low-dose radiation. However, the currently available database of radiation effects on proteomes is far too small to be useful in formulation of new hypotheses concerning health consequences of radiation exposures. This article is protected by copyright. All rights reserved.
... For decades, the chronic effects of prolonged exposures to low-dose radiation practically, and usually not possible to predict on the basis of the knowledge gained from acute exposures to high doses of radiation is not known the physiological significance of the biological effects induced by low doses of radiation [15]. Chronic ionizing radiation exposure can affect human health and ecosystem functioning [16]. ...
... and data presented in Figure (4-12). The MCHC of the control group is compared with other values of the irradiated groups, as in tables (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). The increase in red blood cell volume refers to variations in morphology and deformability of RBCs, which confirmed by a lightly increase in RDW (%). ...
... And data presented in Figure (4-13). The RDW% of the control group is compared with other values of the irradiated groups, as in tables (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). Table (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) Multiple comparisons between the RDW counts of the control group and the irradiated groups ...
The exposure of living organisms to low doses of ionizing radiation
continuously poses a high risk to their cells depends on the amount of absorbed
dose and the duration of exposure, used in this study thirty-six male mice of the
Bulb-C strain were divided into six groups of six mice of each group. The first
group (control group) did not receive any radiation; while irradiated the other
groups of mice with different doses of gamma radiation emitted from cesium-137
source of 100μci activity, with the external dose rate (11.883μGy/h), by changing
the time of irradiation of each group respectively. Pulling blood by puncture heart
in the mice and the organs were extracted (liver, kidney and spleen) to study the
hematological and histopathological changes.
The results complete blood count showed a significant decrease (P<0.05) in
the White blood cells, Red blood cell ,Hematocrit, Eosinophil, and Mean
Corpuscular Hemoglobin Concentration, and a highly significant decrease
(P<0.01) in the Monocytes and red cell distribution width compared with control
group, and non-significant difference (P<0.05) in the mean of Hemoglobin,
Platelets count, Neutrophils, Lymphocyte, Mean cell volume and Mean cell
hemoglobin compared with control group.
The results of the blood film analysis after 6 days of irradiation RBCs
appear as clear cell with on nuclei low stain density (Microcytic Hypochromic) and
showed Burr cells, after 12 days RBCs showed Microcytic Normochromic appear
as light dote due to gradually loss of normal stain also unequal in size
(Anisocytosis). After 18 days RBCs which appeared microcytic hypochromic with
different in shapes and sizes (Anisopikilocytosis). After 24 days the RBCs
appeared microcytic hypochromic, mild (Anisopikilocytosis) is detection loss
normal size (Enlargments). After 32 days, RBCs appeared as empty vacuole due to
Abstract
loss of Chromatin material (Death), also some cells appeared like Drop,
Elliptocytes and Rouleaux in shape, WBCs showed marked Leucopenia.
histopathological examination:
a- Histological changes in liver after the end of the irradiation period showed
vaculation and enlargement of hepatocytes, absence of sinusoids , increase in
the number of kupffer cells with infiltration of inflammatory cells, extansion of
centeral vein, large necrotic area appear surrounded by the inflammatory zone.
focal aggregation of infiltration cells and granuloma.
b- Histological changes in kidney after the end of the irradiation period showed a
congestion, mild hemorrhage vaculation of epithelial lining urinary tubules
appeared with sloughing of some of cell, expinsion glomerular tuft, appear cast
in urinary tubules, severes hemorrhage with infiltration of inflammatory cells
and atrophy of glomerular tuft.
c- Histological changes in spleen after the end of the irradiation period showed
depletion of white pulp ,increase in number of megakaryocyte, depletion of
lymphoid, congestion in central artioles and vessels, destruction of spleen
parenchyma and trabeculae, deposition of amyloid-like substances more clearly
around lymphoid .
The study also includes complete blood count test for a number of workers
in the Radiation Therapy Center in Baghdad, who exposed to low-dose of ionizing
radiation because of their work, and compare the results with a control group
(population).The results showed a significant decrease (P <0.05) in RBCs, and
highly significant decrease (P <0.01) in Neu, Lymph, Mono,and MCHC, and Nonsignificant
difference in (WBCs, Hg, Hct, MCV, MCH and RDW) compared with
the control group. The study also recommended a periodic complete blood test for
radiation workers to ensure the safety of workers.
... The complex puzzle of the interaction of radiation in tissue is not yet fully solved and the need for radiobiology studies in radionuclide therapy are especially great [15,16]. Profiling of the proteomic and transcriptomic response to radiation has the potential to broaden our understanding of the mechanisms that lead to radiation-induced damage and can be a useful tool to identify biomarkers [17,18]. To the best of our knowledge, only a handful of studies have addressed the genomic or proteomic response in the kidneys after internal irradiation, including exposure to 177 Luoctreotate [19][20][21][22][23][24]. ...
... HP has previously been found to be over expressed in bone marrow after irradiation [40,44,45]. Nevertheless, since HP was only found to be upregulated in the combination group and not in the irradiation only group, the 18 change in HP levels are not likely to be a response to irradiation only, but rather a response to a combination of radiation and A1M in irradiated tissue. A1M and HP both play an important role in the defense against toxic levels of hemoglobin (Hb) and heme [46,47]. ...
Recombinant α1-microglobulin (A1M) is proposed as protector during 177Lu-octreotate treatment of neuroendocrine tumors, which is currently limited by bone marrow and renal toxicity. Co-administration of 177Lu-octreotate and A1M could result in a more effective treatment by protecting healthy tissue, but, the radioprotecting action of A1M is not fully understood. The aim of this study was to examine the proteomic response of kidneys and bone marrow early after 177Lu-octreotate and/or A1M administration. Mice were injected with 177Lu-octreotate and/or A1M, while control mice received saline or A1M vehicle solution. Bone marrow, kidney medulla, and kidney cortex were sampled after 24 hours or 7 days. Differential protein expression was analyzed with tandem mass spectrometry. Dosimetric estimation was based on 177Lu activity in kidney. PHLDA3 was the most prominent radiation responsive protein in kidney tissue. In general, no statistically significant difference in expression of radiation-related proteins was observed between the irradiated groups. Most canonical pathways were identified in bone marrow from the 177Lu-octreotate+A1M group. Altogether, tissue-dependent proteomic response followed exposure to 177Lu-octreotate alone or together with A1M. Combining 177Lu-octreotate with A1M did not inhibit the radiation induced protein expression early after exposure, and late effects should be further studied.
... It has been well realized that cellular changes and protein modifications like carbonylation, nitrosylation and acetylation (Barjaktarovic et al. 2016) following radiation exposure can be screened effectively using a proteomics approach (Guipaud and Benderitter 2009). This technique is also beneficial in discovering biomarkers that can be used to assess the time and dose of radiation exposed and may further help in the development of radiation counter measures (Bo et al. 2005;Miura et al. 2007;Guipaud 2013;Sharma and Moulder 2013;Leszczynski 2014). Additionally, investigators have also tried to explore this approach for the development of clinical biomarkers of radiotherapy (Hosseinimehr 2007) and for cellular protein alterations in various diseases, ageing, oxidative stress and radiation effects (Miura et al. 2007). ...
... It has been established as a weapon for occupational purpose (Sudhakar 2009). Irrespective of its medicinal importance and known effect on biochemical changes, the information on the effect of radiation on changes in protein profiles of different radiosensitive tissues of mice are very limited (Hutchinson 1963;Dattilo et al. 2015;Leszczynski 2014). Identification of differentially expressed proteins in radiosensitive organs may also support in the management of radiation emergencies and allow medical personnel to make critical triage decisions. ...
Purpose:
Exposure to radiation causes severe alterations of protein expression level inside the cell, thus it may influence the biological events and stress response. In the present investigation, we have demonstrated the effect of radiation on mice lung tissues.
Materials and methods:
Two-dimensional gel electrophoresis (2-DE) coupled with MALDI-TOF/TOF was used to check the expression changes in lung proteome profile of strain 'A' female mice after exposure to lethal doses of gamma irradiation at different time periods (24 and 48 h). Identified proteins were analysed for their altered expression and were further validated by Western blotting and enzyme-linked immunosorbent assay (ELISA).
Results:
Nine significant differentially expressed proteins were identified from irradiated lungs tissues. The expression level of zinc finger protein was found to be up regulated at 24 h irradiation in comparison to 48 h irradiation.
Conclusions:
Zinc finger protein may be considered as a radiation responsive protein. Alteration in its expression pattern may primarily affect binding specificity of the protein that can further result in the interference in transcriptional control of multiple stress responsive genes.
... Proteomic studies are important for uncovering the complex biological pathways and molecular networks related to physiological or pathological status or environmental stresses, including ionizing radiation. Interest in proteomic investigations of radiation biology is increasing [13] following the broad application of genomic technology and bioinformatics to studies of the effects of radiation, including dose and dose-rate effects [14,15], differential end points of cancer and normal tissue [16][17][18][19][20], individual radiation sensitivity, and biomarker identification [20,21] for radiation biodosimeters or risk assessment. A comprehensive combination of comparative proteomics and advanced bioinformatics would provide valuable insights into the complex biological networks that are influenced by radiation exposure [13,[22][23][24]. ...
... Interest in proteomic investigations of radiation biology is increasing [13] following the broad application of genomic technology and bioinformatics to studies of the effects of radiation, including dose and dose-rate effects [14,15], differential end points of cancer and normal tissue [16][17][18][19][20], individual radiation sensitivity, and biomarker identification [20,21] for radiation biodosimeters or risk assessment. A comprehensive combination of comparative proteomics and advanced bioinformatics would provide valuable insights into the complex biological networks that are influenced by radiation exposure [13,[22][23][24]. A number of proteomic studies of heavy-ion effects have also been performed recently [25][26][27]. ...
Radiotherapy with heavy ions is considered advantageous compared to irradiation with photons due to the characteristics of the Braggs peak and the high linear energy transfer (LET) value. To understand the mechanisms of cellular responses to different LET values and dosages of heavy ion radiation, we analyzed the proteomic profiles of mouse embryo fibroblast MEF cells exposed to two doses from different LET values of heavy ion ¹²C. Total proteins were extracted from these cells and examined by Q Exactive with Liquid Chromatography (LC)—Electrospray Ionization (ESI) Tandem MS (MS/MS). Using bioinformatics approaches, differentially expressed proteins with 1.5 or 2.0-fold changes between different dosages of exposure were compared. With the higher the dosage and/or LET of ion irradiation, the worse response the cells were in terms of protein expression. For instance, compared to the control (0 Gy), 771 (20.2%) proteins in cells irradiated at 0.2 Gy of carbon-ion radiation with 12.6 keV/μm, 313 proteins (8.2%) in cells irradiated at 2 Gy of carbon-ion radiation with 12.6 keV/μm, and 243 proteins (6.4%) in cells irradiated at 2 Gy of carbon-ion radiation with 31.5 keV/μm exhibited changes of 1.5-fold or greater. Gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, Munich Information Center for Protein Sequences (MIPS) analysis, and BioCarta analysis all indicated that RNA metabolic processes (RNA splicing, destabilization and deadenylation) and proteasome pathways may play key roles in the cellular response to heavy-ion irradiation. Proteasome pathways ranked highest among all biological processes associated with heavy carbon-ion irradiation. In addition, network analysis revealed that cellular pathways involving proteins such as Col1a1 and Fn1 continued to respond to high dosages of heavy-ion irradiation, suggesting that these pathways still protect cells against damage. However, pathways such as those involving Ikbkg1 responded better at lower dosages than at higher dosages, implying that cell damage would occur when the networks involving these proteins stop responding. Our investigation provides valuable proteomic information for elucidating the mechanism of biological effects induced by carbon ions in general.
... For the past several decades, understanding cellular and biological effects of low dose radiation exposures, and to quantify risks from such exposures, has remained a scientific challenge. Biological effects at high doses of ionizing radiation, which are well above the low dose range for environmental or therapeutic radiation exposures (>1 Gy) have been clearly documented [1][2][3]. In recent times, due to more and more technological advances, the human genome has been increasingly threatened by low dose low-linear energy transfer radiation from environmental, medical, and in many cases, occupational sources. ...
... The authors reported down-regulation or complete "turn off" of many of the tissue-enriched genes in the corresponding cell lines of the normal tissues [16]. The variation in the experimental conditions and methods used for analysis in multiple studies, further limits this extrapolation [2]. Application of proteome profiling for radiation research has also been limited by lack of data on the time-and dose-dependent variation of protein expression. ...
Humans are continually exposed to ionizing radiation from natural as well as anthropogenic sources. Though biological effects of high dose radiation exposures have been well accepted, studies on low-to-moderate dose exposures (in the range of 50-500mGy) have been strongly debated even as researchers continue to search for elusive ‘radiation signatures’ in humans. Proteins are considered as dynamic functional players that drive cellular responses. However, there is little proteomic information available in context of human exposure to ionizing radiation. In this study, we determined differential expressed proteins in G0 peripheral blood mononuclear cells (PBMCs) from healthy individuals 1 h and 4 h after ‘ex vivo’ exposure with two radiation doses (300 mGy and 1 Gy). Twenty-three proteins were found to be significantly altered in irradiated cells when compared to sham irradiated cells with fold change ±1.5-fold (p ≤ 0.05), with only three proteins showing ≥2.5-fold change, either with dose or with time. Mass spectrometry analyses identified redox sensor protein, chloride intracellular channel protein 1 (CLIC-1), the antioxidant protein, peroxiredoxin-6 and the pro-survival molecular chaperone 78KDa glucose regulated protein (GRP78) among the 23 modulated proteins. The mean coefficient of variation (CV) for the twenty-three radiation responsive protein spots was found to be 33.7% for 300 mGy and 48.3% for 1 Gy. We thus, conclude that the radiation proteomic response of G0 human PBMCs, which are in the resting stage of the cell cycle, involves moderate upregulation of protective mechanisms, with low inter-individual variability. This study will help further our understanding of cellular effects of low dose acute radiation in humans and contribute towards differential biomarker discovery.
... New assays allowing for rapid identification of exposed subjects are therefore required. Several candidates for new biological dosimetry methods have been proposed, including premature chromosome condensation assay (PCC) (Lindholm et al. 2010), c-H2AX foci assay (Rothkamm and Horn 2009), electron paramagnetic resonance (EPR)-based assays (Swartz et al. 2007), and methods based on protein or metabolic biomarkers (Coy et al. 2011;Leszczynski 2014). One of the most encouraging new biodosimetry methods is the analysis of gene expression in blood cells at the mRNA level (Amundson et al. 2004;Badie et al. 2013;Chaudhry et al. 2012;Joiner et al. 2011;Kabacik et al. 2011a;Tucker et al. 2012). ...
... In our experimental setup, the commonly used reference genes, such as ACTB, GAPDH, or HPRT1, were not the best choice for the analysis of gene expression in blood cells in response to ionizing radiation. Genes ITFG1 and DPM1 previously used by Tucker et al. (2012;2014) and Joiner et al. (2011) showed a lower variability in expression than ACTB, GAPDH, and HPRT1 and therefore were used for normalization in our study. A very interesting approach to the problem of normalization of mRNA level was proposed by Forrester and Sprung (2014), who normalized the mRNA level of radiation-modulated transcripts to the level of radiation-independent transcripts from the same gene. ...
The most frequently used and the best established method of biological dosimetry at present is the dicentric chromosome assay, which is poorly suitable for a mass casualties scenario. This gives rise to the need for the development of new, high-throughput assays for rapid identification of the subjects exposed to ionizing radiation. In the present study, we tested the usefulness of gene expression analysis in blood cells for biological dosimetry. Human peripheral blood from three healthy donors was X-irradiated with doses of 0 (control), 0.6, and 2 Gy. The mRNA level of 16 genes (ATF3, BAX, BBC3, BCL2, CDKN1A, DDB2, FDXR, GADD45A, GDF15, MDM2, PLK3, SERPINE1, SESN2, TNFRSF10B, TNFSF4, and VWCE) was assessed by reverse transcription quantitative PCR 6, 12, 24, and 48 h after exposure with ITFG1 and DPM1 used as a reference genes. The panel of radiation-responsive genes was selected comprising GADD45A, CDKN1A, BAX, BBC3, DDB2, TNFSF4, GDF15, and FDXR. Cluster analysis showed that ΔCt values of the selected genes contained sufficient information to allow discrimination between irradiated and non-irradiated blood samples. The samples were clearly grouped according to the absorbed doses of radiation and not to the time interval after irradiation or to the blood donor.
Electronic supplementary material
The online version of this article (doi:10.1007/s00411-015-0603-8) contains supplementary material, which is available to authorized users.
... Indeed radiation proteomics is an active field. Recent reviews collectively provide a comprehensive account of prior studies [67,68]. ...
... Prior studies suggest that low doses of IR (0.2-1 Gy) may yield proteomic responses that are sensitive to experimental design and chance variation and are often contradictory [68]. The following sections focus on studies that use higher doses (two or more Gy per fraction on cultured cells, for example) that are considered more clinically relevant. ...
In this review, we will summarize the data from different model systems that illustrate the need for proteome-wide analyses of the biological consequences of ionizing radiation (IR). IR remains one of three main therapy choices for oncology, the others being surgery and chemotherapy. Understanding how cells and tissues respond to IR is essential for improving therapeutic regimes against cancer. Numerous studies demonstrating the changes in the transcriptome following exposure to IR, in diverse systems, can be found in the scientific literature. However, the limitation of our knowledge is illustrated by the fact that the number of transcripts that change after IR exposure is approximately an order of magnitude lower than the number of transcripts that re-localize to or from ribosomes under similar conditions. Furthermore, changes in the post-translational modifications of proteins (phosphorylation, acetylation as well as degradation) are profoundly important for the cellular response to IR. These considerations make proteomics a highly suitable tool for mechanistic studies of the effect of IR. Strikingly such studies remain outnumbered by those utilizing proteomics for diagnostic purposes such as the identification of biomarkers for the outcome of radiation therapy. Here we will discuss the role of the ribosome and translational regulation in the survival and preservation of cells and tissues after exposure to ionizing radiation. In doing so we hope to provide a strong incentive for the study of proteome-wide changes following IR exposure.
... Multiple transcriptomic studies, including those on human skin in vivo and in vitro [8][9][10][11], have demonstrated that LD-IR has significant effects at the level of mRNA. However, there is scant global proteomic data available to assess LD-IR effects in a complex tissue at the protein level [12]. One study utilized an endothelial cell line exposed to a dose of 20 cGy and identified 15 altered proteins [13], while an additional study identified a handful of proteins affected by low-dose radiation (0.01 and 0.1 Gy) given alone or in conjunction with low doses of arsenic [14]. ...
... These findings highlight the importance of protein-based studies that add additional levels of information compared to transcriptomic analyses alone. However, as noted in several recent reviews on radiation proteomics [12,46,47], only a small number of ionizing radiation-affected proteins have been identified to date, and much more work is needed in this area to validate or challenge current paradigms relating to the health consequences of low-dose exposures. Most radiation proteomic studies performed to date have used higher doses and were done on cell monocultures, making it difficult to directly compare our data to these studies. ...
To assess responses to low-dose ionizing radiation (LD-IR) exposures potentially encountered during medical diagnostic procedures, nuclear accidents or terrorist acts, a quantitative proteomic approach was used to identify changes in protein abundance in a reconstituted human skin tissue model treated with 0.1 Gy of ionizing radiation. To improve the dynamic range of the assay, subcellular fractionation was employed to remove highly abundant structural proteins and to provide insight into radiation-induced alterations in protein localization. Relative peptide quantification across cellular fractions, control and irradiated samples was performing using 8-plex iTRAQ labeling followed by online two-dimensional nano-scale liquid chromatography and high resolution MS/MS analysis. A total of 107 proteins were detected with statistically significant radiation-induced change in abundance (>1.5 fold) and/or subcellular localization compared to controls. The top biological pathways identified using bioinformatics include organ development, anatomical structure formation and the regulation of actin cytoskeleton. From the proteomic data, a change in proteolytic processing and subcellular localization of the skin barrier protein, filaggrin, was identified, and the results were confirmed by western blotting. This data indicate post-transcriptional regulation of protein abundance, localization and proteolytic processing playing an important role in regulating radiation response in human tissues.
... Molecular pathways are commonly characterized by changes in gene-products through methods that assay RNA expression (Osman et al., 2020;Lee et al., 2022;Li et al., 2015). Consequently, little is known regarding effects of sex, microglia signaling, and radiation exposure on the brain proteome compared to the transcriptome (Wingo et al., 2023;Leszczynski, 2014). mRNA expression levels do not always correspond with protein levels because mRNA gene products undergo post-transcriptional and translational regulation, and there are different rates of degradation between mRNA and proteins (Wingo et al., 2023;Maier et al., 2009;Jung et al., 2017;Vogel et al., 2012;Sharma et al., 2015). ...
Patients receiving cranial radiation therapy experience tissue damage and cognitive deficits that severely decrease their quality of life. Experiments in rodent models show that these adverse neurological effects are in part due to functional changes in microglia, the resident immune cells of the central nervous system. Increasing evidence suggests that experimental manipulation of microglial signaling can regulate radiation-induced changes in the brain and behavior. Furthermore, many studies show sex-dependent neurological effects of radiation exposure. Despite this, few studies have used both males and females to explore how sex and microglial function interact to influence radiation effects on the brain. Here, we used a system levels approach to examine how deficiencies in purinergic and fractalkine signaling, two important microglial signaling pathways, impact brain proteomic and behavioral profiles in irradiated and control male and female mice. We performed a comprehensive analysis of the cortical proteomes from irradiated and control C57BL/6J, P2Y12−/−, and CX3CR1−/− mice of both sexes using multiple bioinformatics methods. We identified distinct proteins and biological processes, as well as behavioral profiles, regulated by sex, genotype, radiation exposure, and their interactions. Disrupting microglial signaling, had the greatest impact on proteomic expression, with CX3CR1−/− mice showing the most distinct proteomic profile characterized by upregulation of CX3CL1. Surprisingly, radiation exposure caused relatively smaller proteomic changes in glial and synaptic proteins, including Rgs10, Crybb1, C1qa, and Hexb. While we observed some radiation effects on locomotor behavior, biological sex as well as loss of P2Y12 and CX3CR1 signaling had a stronger influence on locomotor outcomes in our model. Lastly, loss of P2Y12 and CX3CR1 strongly regulated exploratory behaviors. Overall, our findings provide novel insights into the molecular pathways and proteins that are linked to P2Y12 and CX3CR1 signaling, biological sex, radiation exposure, and their interactions.
... HSPs are molecular chaperones that help protect cells from damage caused by environmental stressors, including heat and radiation. The activation of HSPs in response to non-ionizing radiation, however, is typically associated with much higher levels of exposure than those emitted by cell towers (Leszczynski, 2014). Impact on DNA and Genetic Material: There is limited evidence suggesting that RF radiation might induce genotoxic effects (i.e., damage to genetic material). ...
The proliferation of cellular communication towers, driven by the rapid advancement of wireless technologies like 4G and 5G, has raised significant public health concerns regarding the potential effects of long-term exposure to radiofrequency (RF) electromagnetic radiation (EMR). This review explores the implications of RF radiation emitted by these towers, which is classified as non-ionizing and typically associated with thermal effects, albeit at levels considered safe by major health organizations such as the World Health Organization (WHO) and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Key topics addressed include the mechanisms of RF radiation interaction with biological systems, public concerns about health effects including cancer risks, neurological impacts, reproductive health, and the controversial condition known as electromagnetic hypersensitivity (EHS). While numerous studies suggest that RF exposure does not lead to significant adverse health outcomes at permissible levels, evidence regarding potential non-thermal effects, such as oxidative stress and changes in cell signaling, remains inconclusive. The review emphasizes the need for further research into the long-term effects of RF radiation, particularly with the expansion of 5G technology, and considers the regulatory frameworks established to ensure public safety. The conclusion highlights a cautious approach, advocating for ongoing scientific inquiry and the application of the precautionary principle, especially concerning vulnerable populations like children and pregnant women.
... The complex puzzle of the interaction of radiation and tissue is not yet fully solved, and the need for radiobiology studies in radionuclide therapy is especially great [15,16]. Profiling of the proteomic and transcriptomic response to radiation has the potential to broaden our understanding of the mechanisms that lead to radiation-induced damage and can be a useful tool to identify biomarkers [17,18]. To the best of our knowledge, only a handful of studies have addressed the genomic or proteomic response in the kidneys after internal irradiation, including exposure to 177 Lu-octreotate [19][20][21][22][23]. ...
Recombinant α1-microglobulin (A1M) is proposed as a protector during 177Lu-octreotate treatment of neuroendocrine tumors, which is currently limited by bone marrow and renal toxicity. Co-administration of 177Lu-octreotate and A1M could result in a more effective treatment by protecting healthy tissue, but the radioprotective action of A1M is not fully understood. The aim of this study was to examine the proteomic response of kidneys and bone marrow early after 177Lu-octreotate and/or A1M administration. Mice were injected with 177Lu-octreotate and/or A1M, while control mice received saline or A1M vehicle solution. Bone marrow, kidney medulla, and kidney cortex were sampled after 24 h or 7 d. The differential protein expression was analyzed with tandem mass spectrometry. The dosimetric estimation was based on 177Lu activity in the kidney. PHLDA3 was the most prominent radiation-responsive protein in kidney tissue. In general, no statistically significant difference in the expression of radiation-related proteins was observed between the irradiated groups. Most canonical pathways were identified in bone marrow from the 177Lu-octreotate+A1M group. Altogether, a tissue-dependent proteomic response followed exposure to 177Lu-octreotate alone or together with A1M. Combining 177Lu-octreotate with A1M did not inhibit the radiation-induced protein expression early after exposure, and late effects should be further studied.
... Other IR includes alpha and beta particles with undetectable wavelengths and high penetrating ability (Griffiths, 2020;Chaudhary and Kumar, 2023). Non-IR does not result in the formation of ions but includes ultraviolet radiation (UVR), whose wavelengths fall between 100 and 400 nm (Mba et al., 2012;Leszczynski, 2014). These Rr bacteria of desiccated soil evolved in response to photo-irradiation and can survive with exposure to radiation environments. ...
A rich diversity of radiation-resistant (Rr) and desiccation-resistant (Dr) bacteria has been found in arid habitats of the world. Evidence from scientific research has linked their origin to reactive oxygen species (ROS) intermediates. Rr and Dr. bacteria of arid regions have the potential to regulate imbalance radicals and evade a higher dose of radiation and oxidation than bacterial species of non-arid regions. Photochemical-activated ROS in Rr bacteria is run through photo-induction of electron transfer. A hypothetical model of the biogeochemical cycle based on solar radiation and desiccation. These selective stresses generate oxidative radicals for a short span with strong reactivity and toxic effects. Desert-inhibiting Rr bacteria efficiently evade ROS toxicity with an evolved antioxidant system and other defensive pathways. The imbalanced radicals in physiological disorders, cancer, and lung diseases could be neutralized by a self-sustaining evolved Rr bacteria antioxidant system. The direct link of evolved antioxidant system with intermediate ROS and indirect influence of radiation and desiccation provide useful insight into richness, ecological diversity, and origin of Rr bacteria capabilities. The distinguishing features of Rr bacteria in deserts present a fertile research area with promising applications in the pharmaceutical industry, genetic engineering, biological therapy, biological transformation, bioremediation, industrial biotechnology, and astrobiology.
... Another effect is significant long-term alterations in lipid metabolism in the liver of the tested animals. 4,5 Genomics is used to detect the molecular mechanism of chronic LDIR. Based on genomics findings, dissimilar appearances of LDIR-induced cellular responses may have diverse signal transduction pathways. ...
Introduction: Understanding the molecular mechanism of chronic low-dose ionizing radiation (LDIR) effects on the human body is the subject of many research studies. Several aspects of cell function such as cell proliferation, apoptosis, inflammation, and tumorigenesis are affected by LDIR. Detection of the main biological process that is targeted by LIDR via network analysis is the main aim of this study. Methods: GSE66720 consisting of gene expression profiles of human umbilical vein endothelial cells (HUVECs) (a suitable cell line to be investigated), including irradiated and control cells, was downloaded from Gene Expression Omnibus (GEO). The significant differentially expressed genes (DEGs) were determined and analyzed via protein-protein interaction (PPI) network analysis to find the central individuals. The main cell function which was related to the central nodes was introduced. Results: Among 64 queried DEGs, 48 genes were recognized by the STRING database. C-X-C motif chemokine ligand 8 (CXCL8), intercellular adhesion molecule 1 (ICAM1), Melanoma growth-stimulatory activity/growth-regulated protein α (CXCL1), vascular cell adhesion molecule 1 (VCAM-1), and nerve growth factor (NGF) were introduced as hub nodes. Conclusion: Findings indicate that inflammation is the main initial target of LDIR at the cellular level which is associated with alteration in the other essential functions of the irradiated cells.
... The application of proteomics approaches in radiation research is well acknowledged [70][71][72]. The proteome profiling offers a comprehensive platform to investigate the cellular response of cancer and normal tissue to radiation exposure [73,74]. ...
Archival formalin-fixed, paraffin-embedded (FFPE) tissues and their related diagnostic records are an invaluable source of biological information. The archival samples can be used for retrospective investigation of molecular fingerprints and biomarkers of diseases and susceptibility. Radiobiological archives were set up not only following clinical performance such as cancer diagnosis and therapy but also after accidental and occupational radiation exposure events where autopsies or cancer biopsies were sampled. These biobanks provide unique and often irreplaceable materials for the understanding of molecular mechanisms underlying radiation-related biological effects. In recent years, the application of rapidly evolving “omics” platforms, including transcriptomics, genomics, proteomics, metabolomics and sequencing, to FFPE tissues has gained increasing interest as an alternative to fresh/frozen tissue. However, omics profiling of FFPE samples remains a challenge mainly due to the condition and duration of tissue fixation and storage, and the extraction methods of biomolecules. Although biobanking has a long history in radiation research, the application of omics to profile FFPE samples available in radiobiological archives is still young. Application of the advanced omics technologies on archival materials provides a new opportunity to understand and quantify the biological effects of radiation exposure. These newly generated omics data can be well integrated into results obtained from earlier experimental and epidemiological analyses to shape a powerful strategy for modelling and evaluating radiation effects on health outcomes. This review aims to give an overview of the unique properties of radiation biobanks and their potential impact on radiation biology studies. Studies recently performed on FFPE samples from radiobiology archives using advanced omics are summarized. Furthermore, the compatibility of archived FFPE tissues for omics analysis and the major challenges that lie ahead are discussed.
... Radiation proteomics is an interesting field to discover molecules of radiation, biomarkers, acute and chronic physiological and health effects under different levels of exposure [111]. They have identified that ionizing gamma radiation could deregulate numerous proteins. ...
Lipid synthesis pathways of toothed whales have evolved since their movement from the terrestrial to marine environment. The synthesis and function of these endogenous lipids and affecting factors are still little understood. In this review, we focused on different omics approaches and techniques to investigate lipid metabolism and radiation impacts on lipids in toothed whales. The selected literature was screened, and capacities, possibilities, and future approaches for identifying unusual lipid synthesis pathways by omics were evaluated. Omics approaches were categorized into the four major disciplines: lipidomics, transcriptomics, genomics, and proteomics. Genomics and transcriptomics can together identify genes related to unique lipid synthesis. As lipids interact with proteins in the animal body, lipidomics, and proteomics can correlate by creating lipid-binding proteome maps to elucidate metabolism pathways. In lipidomics studies, recent mass spectroscopic methods can address lipid profiles; however, the determination of structures of lipids are challenging. As an environmental stress, the acoustic radiation has a significant effect on the alteration of lipid profiles. Radiation studies in different omics approaches revealed the necessity of multi-omics applications. This review concluded that a combination of many of the omics areas may elucidate the metabolism of lipids and possible hazards on lipids in toothed whales by radiation.
... Differences in protein levels can occur between radioresistant and radiosensitive individuals, and therefore protein signatures might also have a predictive value (Chaze et al. 2013). Recent advances in proteomics might allow the identification of proteins associated with radiosensitivity (Leszczynski 2014;Smith et al. 2009;Turtoi et al. 2011). ...
Unlike individuals on Earth who are protected against most types of ionizing radiation by the shielding characteristics of the atmosphere and the electromagnetic field, astronauts aboard a spaceship or on the surface of the moon or another planet are exposed to much higher doses of ionizing radiation. Besides this, the radiation spectrum present in space is very different from that on Earth (see Chap. 20). Terrestrial radiation mainly consists of low-LET radiation such as X- and gamma rays. Space radiation on the other hand is made up of (1) radiation from the solar wind which is trapped in the Earth’s magnetic field (Van Allen belts), (2) galactic cosmic radiation comprised of high-energy protons and heavy ions, and (3) solar particle events mainly consisting of low-energy protons. Recent estimations of the dose equivalent for a round trip to Mars were in the order of 0.66 Sv, which is well beyond the limitations for nuclear workers. Therefore, for manned spaceflight, the biological response to space radiation is of critical concern for risk assessment for astronauts, especially since space agencies like NASA limit the risk of radiation exposure-induced death due to cancer to only 3% (at 95% confidence level). Based on findings from early NASA astronauts, some of whom traveled beyond Low Earth Orbit, no association was found between radiation dose and mortality from cardiovascular disease or cancer risk using a logistic regression model. Nevertheless, for long-duration interplanetary manned missions the uncertainty about the health risks of radiation exposure remains one of the most important limiting factors. For this reason, the identification of (predictive) biomarkers to determine both the received radiation dose (biodosimetry) as well as the radiosensitivity of individuals may be an important aspect for future crew selection. This chapter reviews some of the most frequently used assays for these purposes.
... It is undeniable that the use of ionizing radiation in industry, medicine, and agriculture has been dramatically increased; nonetheless, its harmful effects cannot be overlooked. Over the course of the past century, studies have identified and quantified the unfavorable effects of radiation and its biological effects, especially at high radiation doses (Leszczynski, 2014;Azimzadeh et al., 2014). Many studies indicate that ionization radiation in low doses can induce various disease especially many kinds of cancers (Brooks et al., 2016;Brenner et al., 2003;Cardis et al., 2005). ...
The aim of this paper is to study the effect of very low dose gamma radiation exposure on the plasmonic behavior of gold nanoparticles. For this purpose, gold nanoparticles were exposed to three different dose rates of radiation, with the absorbed doses of 0.33, 0.56 and 0.75 milligray. Subsequently, the effect of radiation exposure on the color of the solution, which is due to the accumulation of nanoparticles in the presence of salt, was investigated using visible spectroscopy. The results show that the presence of radiation can change the behavior of gold nanoparticles in the presence of salt for a specified period, in a way that the spectrum is similar to the spectrum of nanoparticles in the absence of salt. Based on these observations, a simple way of detecting ionizing radiation is introduced.
... It is undeniable that the use of ionizing radiation in industry, medicine, and agriculture has been dramatically increased; nonetheless, its harmful effects cannot be overlooked. Over the course of the past century, studies have identified and quantified the unfavorable effects of radiation and its biological effects, especially at high radiation doses (Leszczynski, 2014;Azimzadeh et al., 2014). Many studies indicate that ionization radiation in low doses can induce various disease especially many kinds of cancers (Brooks et al., 2016;Brenner et al., 2003;Cardis et al., 2005). ...
... The activation of cellular stress response might affect variety of physiological processes, like brain tumor development and blood brain barrier permeability and is induced by of mobile phone radiations. The study showed that the mobile phone radiation exposure of cell for 1 hour, leads to increase in the expression of hsp27 (Leszczynski, 2014). However, in case of the normal cell, even the incubation Int. ...
... Data collated from earlier published study (Sankhwar et biochemical changes such as lipid, protein, and nucleic acid, profile of GI radiosensitive tissues cannot be ignored. [32] Though cancer treatment via radiotherapy has advanced by each passing year, still there are limitations in safe dose delivery. [33] While radiotherapy procedure in treating cancer in pelvic, bladder, and prostate region, the exposure to various areas in GI tract resulting in radiation-induced GI toxicity has been inevitable. ...
... This has resulted in an increase of exposure to extremely low frequency (ELF) and radio frequency (RF) electromagnetic fields (EMFs). There has been a long-running debate on the health effect of these non-ionizing EMFs [1]. However, prior to formulating useful and testable hypotheses on the potential adverse or beneficial influence of EMF exposure on human health it is imperative that the biological effects on the cells are detected unambiguously [2][3][4][5]. ...
The potential effects of non-ionizing electromagnetic fields (EMFs), such as those emitted by power-lines (in extremely low frequency range), mobile cellular systems and wireless networking devices (in radio frequency range) on human health have been intensively researched and debated. However, how exposure to these EMFs may lead to biological changes underlying possible health effects is still unclear. To reveal EMF-induced molecular changes, unbiased experiments (without a priori focusing on specific biological processes) with sensitive readouts are required. We present the first proteome-wide semi-quantitative mass spectrometry analysis of human fibroblasts, osteosarcomas and mouse embryonic stem cells exposed to three types of non-ionizing EMFs (ELF 50 Hz, UMTS 2.1 GHz and WiFi 5.8 GHz). We performed controlled in vitro EMF exposures of metabolically labeled mammalian cells followed by reliable statistical analyses of differential protein- and pathway-level regulations using an array of established bioinformatics methods. Our results indicate that less than 1% of the quantitated human or mouse proteome responds to the EMFs by small changes in protein abundance. Further network-based analysis of the differentially regulated proteins did not detect significantly perturbed cellular processes or pathways in human and mouse cells in response to ELF, UMTS or WiFi exposure. In conclusion, our extensive bioinformatics analyses of semi-quantitative mass spectrometry data do not support the notion that the short-time exposures to non-ionizing EMFs have a consistent biologically significant bearing on mammalian cells in culture.
... Analyses of protein expression in direct connection with biological functions provide useful information on health effects. Radiation effects on protein expression have been investigated in some systems [6][7][8]. Effects of lowdose radiation or low-dose-rate irradiation on protein expression have also been investigated in order to understand environmental or medical low-dose radiation [9,10]. We previously reported changes in protein expression in the livers of mice irradiated at low dose rates over the long term [10]. ...
Molecular mechanisms of radiation dose-rate effects are not well understood. Among many possibilities, long-lasting sustained alterations in protein levels would provide critical information. To evaluate sustained effects after acute and chronic radiation exposure, we analyzed alterations in protein expression in the livers of mice. Acute exposure consisted of a lethal dose of 8 Gy and a sublethal dose of 4 Gy, with analysis conducted 6 days and 3 months after irradiation, respectively. Chronic irradiation consisted of a total dose of 8 Gy delivered over 400 days (20 mGy/day). Analyses following chronic irradiation were done immediately and at 3 months after the end of the exposure. Based on antibody arrays of protein expression following both acute lethal and sublethal dose exposures, common alterations in the expression of two proteins were detected. In the sublethal dose exposure, the expression of additional proteins was altered 3 months after irradiation. Immunohistochemical analysis showed that the increase in one of the two commonly altered proteins, MyD88, was observed around blood vessels in the liver. The alterations in protein expression after chronic radiation exposure were different from those caused by acute radiation exposures. Alterations in the expression of proteins related to inflammation and apoptosis, such as caspase 12, were observed even at 3 months after the end of the chronic radiation exposure. The alterations in protein expression depended on the dose, the dose rate, and the passage of time after irradiation. These changes could be involved in long-term effects of radiation in the liver. © 2017 The Author. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.
... Informatics and modeling-based approaches that are capable of exploiting new and existing datasets can be used to define low-dose effects in a more sensitive way because of the large volumes of data that can be used. There remain in the U.S. perhaps a few investigators who are involved in OMCIS research related to radiation biology, most through NASA-funded programs or focused on low and high doses of radiation both (Hyduke et al. 2013;Leszczynski, 2014;Reisz et al. 2014). While these researchers developed ingenious approaches for data analysis, and in the process made significant contributions to initiation of 'big data research', most of this work is becoming more and more constricted with the data input(s) becoming more limited, again, mostly due to the lack of foresight by the U.S. funding agencies. ...
Purposes: Human beings encounter radiation in many different situations; from proximity to radioactive waste sites to participation in medical procedures using X-rays etc. Limits for radiation exposures are legally regulated, however, current radiation protection policy does not explicitly acknowledge that biological, cellular and molecular effects of low doses and low dose rates of radiation differ from effects induced by medium and high dose radiation exposures. Recent technical developments in biology and medicine, from single cell techniques to big data computational research, have enabled new approaches for study of biology of low doses of radiation. Results of the work done so far support the idea that low doses of radiation have effects that differ from those associated with high dose exposures; this work, however, is far from sufficient for development of new theoretical framework needed for understanding of low dose radiation exposures.
Conclusions: Mechanistic understanding of radiation effects at low doses is necessary in order to develop better radiation protection policy.
... Diverse omics technologies have indicated a complex response of biological systems after different radiation exposure events. These include various radiation qualities, doses, and dose rates [61][62][63]. The harmful impact includes primary effects such as genetic instability, impairment of synaptic plasticity, and cell survival and apoptosis, but also secondary effects such as increased oxidative stress and inflammation [64][65][66][67][68][69][70]. ...
Epidemiological studies on the atomic-bomb survivors, cancer survivors and occupational cohorts
provide strong evidence for multifaceted damage to brain after ionizing radiation. Radiation-induced late
effects may manifest as brain tumors or cognitive impairment. Decreased neurogenesis and
differentiation, alteration in neural structure and synaptic plasticity as well as increased oxidative
stress and inflammation are suggested to contribute to adverse effects in the brain. In addition to neural
stems cells, several brain-specific mature cell types including endothelial and glial cells are negatively
affected by ionizing radiation. Radiation-induced enhancement of endothelial cell apoptosis results in
disruption of the vascular system and the blood brain barrier. Activated microglia create inflammatory
environment that negatively affects neuronal structures and results in decreased synaptic plasticity.
Although the molecular mechanisms involved in radiation-induced brain injury remain elusive,
first
strategies for prevention and amelioration are being developed. Drug-based prevention and treatment
focus mainly on the inhibition of oxidative stress and inflammation. Cell replacement therapy holds great
promise as
first animal studies using transplantation of neural stem cells to irradiated brain have been
successful in restoring memory and cognition deficits. This review summarizes the epidemiological and
biological data on radiation-induced brain damage and describes prevention and therapy methods to
avoid and ameliorate these adverse effects, respectively.
... Diverse omics technologies have indicated a complex response of biological systems after different radiation exposure events. These include various radiation qualities, doses, and dose rates [61][62][63]. The harmful impact includes primary effects such as genetic instability, impairment of synaptic plasticity, and cell survival and apoptosis, but also secondary effects such as increased oxidative stress and inflammation [64][65][66][67][68][69][70]. ...
Epidemiological studies on the atomic-bomb survivors, cancer survivors and occupational cohorts provide strong evidence for multifaceted damage to brain after ionizing radiation. Radiation-induced late effects may manifest as brain tumors or cognitive impairment. Decreased neurogenesis and differentiation, alteration in neural structure and synaptic plasticity as well as increased oxidative stress and inflammation are suggested to contribute to adverse effects in the brain. In addition to neural stems cells, several brain-specific mature cell types including endothelial and glial cells are negatively affected by ionizing radiation. Radiation-induced enhancement of endothelial cell apoptosis results in disruption of the vascular system and the blood brain barrier. Activated microglia create inflammatory environment that negatively affects neuronal structures and results in decreased synaptic plasticity. Although the molecular mechanisms involved in radiation-induced brain injury remain elusive, first strategies for prevention and amelioration are being developed. Drug-based prevention and treatment focus mainly on the inhibition of oxidative stress and inflammation. Cell replacement therapy holds great promise as first animal studies using transplantation of neural stem cells to irradiated brain have been successful in restoring memory and cognition deficits. This review summarizes the epidemiological and biological data on radiation-induced brain damage and describes prevention and therapy methods to avoid and ameliorate these adverse effects, respectively.
... Type I systems biology is a term used to describe collecting large amounts of data and analyzing the data together (73). In practice, principles of Type I systems biology is already being applied to radiation biology: although beyond the scope of this review, studies of the consequences of radiation on the genome or transcriptome (74,75) and proteome (76,77) are reported in the literature. Although technology seems to have advanced enough to generate broad Type I systems biology-level profiling of patients at many molecular and phenotypic levels, such in-depth profiling in the clinic has yet to be greatly applied in radiation research, or in any other field. ...
Human exposure to ionizing radiation disrupts normal metabolic processes in cells and organs by inducing complex biological responses that interfere with gene and protein expression. Conventional dosimetry, monitoring of prodromal symptoms and peripheral lymphocyte counts are of limited value as organ and tissue specific biomarkers for personnel exposed to radiation, particularly, weeks or months after exposure. Analysis of metabolites generated in known stress-responsive pathways by molecular profiling helps to predict the physiological status of an individual in response to environmental or genetic perturbations. Thus, a multi-metabolite profile obtained from a high resolution mass spectrometry-based metabolomics platform offers potential for identification of robust biomarkers to predict radiation toxicity of organs and tissues resulting from exposures to therapeutic or non-therapeutic ionizing radiation. Here, we review the status of radiation metabolomics and explore applications as a standalone technology, as well as its integration in systems biology, to facilitate a better understanding of the molecular basis of radiation response. Finally, we draw attention to the identification of specific pathways that can be targeted for the development of therapeutics to alleviate or mitigate harmful effects of radiation exposure.
... In radiobiology there is an increasing interest in proteomics nowadays [1][2][3]. The response for radiation was often studied on the genome level. ...
This is the first study of changes in protein glycosylation due to exposure of human subjects to ionizing radiation. Site specific glycosylation patterns of 7 major plasma proteins were analyzed; 171 glycoforms were identified; and the abundance of 99 of these was followed in the course of cancer radiotherapy in 10 individual patients. It was found that glycosylation of plasma proteins does change in response to partial body irradiation (∼60Gy), and the effects last during follow-up; the abundance of some glycoforms changed more than twofold. Both the degree of changes and their time-evolution showed large inter-individual variability.
... Therefore, the complementation of expression studies with proteomics can provide new insight into molecular mechanisms of plant growth in radio-contaminated environments. Indeed, proteome alterations induced by IR are the subject of increased research interest, especially in mammalian systems (Azimzadeh et al., 2014;Leszczynski, 2014). In plants, this is also appears to be the case, as differential abundances of proteins associated with defense and stress responses were detected in leaves harvested from rice grown in the soil taken around Chernobyl reactor site (Rakwal et al., 2009). ...
Plants have the ability to grow and successfully reproduce in radio-contaminated environments, which has been highlighted by nuclear accidents at Chernobyl (1986) and Fukushima (2011). The main aim of this article is to summarize the advances of the Chernobyl seed project which has the purpose to provide proteomic characterization of plants grown in the Chernobyl area. We present a summary of comparative proteomic studies on soybean and flax seeds harvested from radio-contaminated Chernobyl areas during two successive generations. Using experimental design developed for radio-contaminated areas, altered abundances of glycine betaine, seed storage proteins, and proteins associated with carbon assimilation into fatty acids were detected. Similar studies in Fukushima radio-contaminated areas might complement these data. The results from these Chernobyl experiments can be viewed in a user-friendly format at a dedicated web-based database freely available at http://www.chernobylproteomics.sav.sk.
Long-term low-dose ionizing radiation (LLIR) widely exists in human life and has been confirmed to have potential pathogenic effects on cancer and cardiovascular diseases. However, it is technically and ethically unfeasible to explore LLIR-induced phenotypic changes in the human cohort, leading to slow progress in revealing the pathogenesis of LLIR. In this work, we recruited 32 radiation workers and 18 healthy non-radiation workers from the same city with the same eating habits for radiation damage evaluation and metabolomics profiling. It was found that clear metabolic phenotypic differences existed between LLIR and non-LLIR exposed participants. Moreover, LLIR exposed workers can be further divided into two types of metabolic phenotypes, corresponding to high and low damage types respectively. 3-hydroxypropanoate and glycolaldehyde were identified as sensitive indicators to radiation damage, which specific response to the chromosomal aberration of workers and may be potential monitoring markers for LLIR protection. Taurine metabolism-related pathways were identified as the main differential metabolic pathway under LLIR inducing, which had been confirmed to have a response to acute or chronic radiation exposure. We expect our study can be helpful to LLIR damage monitoring and symptomatic intervention in the future.
Fundamental responses to any stimulus are mediated through the expression of exclusive and specific protein arrays, inside or outside the cellular milieu. Understanding these specific arrays of proteins could lead to a way to ameliorate the situations raised by such insults. For the past few decades and with the advancement of molecular tools, the radiation-affected proteome has been a focus of research. These protein biomarkers have provided insights to develop biodosimetry and diagnostic approaches, and to determine the response of tumors versus normal cells to different radiations to improve radiation therapy (RT). In this review, we elaborate on radiation proteomic studies and their possible role in the development of modalities for radiation countermeasures, radiation biodosimetry, and carcinogenesis applications.
Purpose:
The thrombopoietin receptor agonist romiplostim (RP) is a therapeutic agent for immune thrombocytopenia that can achieve complete survival in mice exposed to a lethal dose of ionizing radiation. The estimated mechanism of the radio-protective/mitigative effects of RP has been proposed; however, the detailed mechanism of action remains unclear. This study aimed to elucidate the mechanism of the radio-protective/mitigative effects of RP, the fluctuation of protein in the blood was analyzed by proteomics.
Materials and methods:
Eight-week-old female C57BL/6J mice were randomly divided into 5 groups; control at day 0, total-body irradiation (TBI) groups at day 10 and day 18, and TBI plus RP groups at day 10 and day18, consisting of 3 mice per group, and subjected to TBI with 7 Gy of 137Cs γ-rays at a dose rate of 0.74 Gy/min. RP was administered intraperitoneally to mice at a dose of 50 µg/kg once daily for 3 days starting 2 hours after TBI. On day 10 and day 18 after TBI, serum collected from each mouse was analyzed by liquid chromatography tandem mass spectrometry.
Results:
Nine proteins were identified by proteomics methods from 269 analyzed proteins detected in mice exposed to a lethal dose of TBI: keratin, type II cytoskeletal 1 (KRT1), fructose-1, 6-bisphosphatase (FBP1), cytosolic 10-formyltetrahydrofolate dehydrogenase (ALDH1L1), peptidyl-prolyl cis-trans isomerase A (PPIA), glycine N-methyltransferase (GNMT), glutathione S-transferase Mu 1 (GSTM1), regucalcin (RGN), fructose-bisphosphate aldolase B (ALDOB) and betain-homocysteine S-methyltransferase 1 (BHMT). On the 10th day after TBI, KRT1 was significantly increased (p < 0.05) by 4.26-fold compared to the control group in the TBI group and significantly inhibited in the TBI plus RP group (p < 0.05). Similarly, the expression levels of other 8 proteins detected at 18th day after TBI were significantly increased by 4.29 to 27.44-fold in the TBI group, but significantly decreased in the TBI plus RP group compared to the TBI group, respectively.
Conclusion:
Nine proteins were identified by proteomics methods from 269 analyzed proteins detected in mice exposed to a lethal dose of TBI. These proteins are also expected to be indicators of the damage induced by high-dose radiation.
Purpose:
Potential acute exposure to ionizing radiation in nuclear or radiological accidents presents complex mass casualty scenarios that demand prompt triage and treatment decisions. Due to delayed symptoms and varied response of radiation victims, there is an urgent need to develop robust biomarkers to assess the extent of injuries in individuals.
Experimental design:
The transcription factor Nrf2 is the master of redox homeostasis and there was transcriptional evidence of Nrf2-dependent antioxidant response activation upon radiation. We investigated the biomarker potential of Nrf2-dependent downstream target enzymes by measuring their response in bone marrow extracted from C57Bl/6 and C3H mice of both genders for up to 4 days following 6 Gy total body irradiation using targeted mass spectrometry.
Results:
Overall, C57Bl/6 mice have a stronger proteomic response than C3H mice. In both strains, male mice have more occurrences of upregulation in antioxidant enzymes than female mice. For C57Bl/6 male mice, 3 proteins showed elevated abundances after radiation exposure: catalase, superoxide dismutase 1, and heme oxygenase 1. Across both strains and genders, glutathione S-transferase Mu 1 was consistently decreased.
Conclusions and clinical relevance:
This study provides the basis for future development of organ-specific protein biomarkers used in diagnostic blood test for radiation injury. This article is protected by copyright. All rights reserved.
Exposure to ionizing radiation is ubiquitous, and it is well established that moderate and high doses cause ill-health and can be lethal. The health effects of low doses or low dose-rates of ionizing radiation are not so clear. This paper describes a project which sets out to summarize, as a restatement, the natural science evidence base concerning the human health effects of exposure to low-level ionizing radiation. A novel feature, compared to other reviews, is that a series of statements are listed and categorized according to the nature and strength of the evidence that underpins them. The purpose of this restatement is to provide a concise entrée into this vibrant field, pointing the interested reader deeper into the literature when more detail is needed. It is not our purpose to reach conclusions on whether the legal limits on radiation exposures are too high, too low or just right. Our aim is to provide an introduction so that non-specialist individuals in this area (be they policy-makers, disputers of policy, health professionals or students) have a straightforward place to start. The summary restatement of the evidence and an extensively annotated bibliography are provided as appendices in the electronic supplementary material.
Three new complexes bearing the tridentate hydrazone-based ligand 2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)pyridine (L) were synthesized and structurally characterized. Biological tests indicate that the Zn(ii) complex [ZnCl2(L)] is of low cytotoxicity against the hepatocellular carcinoma cell line HepG2. In contrast, the Cu(ii) and Mn(ii) complexes [CuCl2(L)] and [MnCl2(L)] are highly cytotoxic with EC50 values of 1.25 ± 0.01 μM and 20 ± 1 μM, respectively. A quantitative proteome analysis reveals that treatment of the cells with the Cu(ii) complex leads to a significantly altered abundance of 102 apoptosis-related proteins, whereas 38 proteins were up- or down-regulated by the Mn(ii) complex. A closer inspection of those proteins regulated only by the Cu(ii) complex suggests that the superior cytotoxic activity of this complex is likely to be related to an initiation of the caspase-independent cell death (CICD). In addition, an increased generation of reactive oxygen species (ROS) and a strong up-regulation of proteins responsive to oxidative stress suggest that alterations of the cellular redox metabolism likely contribute to the cytotoxicity of the Cu(ii) complex.
Unlabelled:
Recent advances in the field of biodosimetry have shown that the response of biological systems to ionizing radiation is complex and depends on the type and dose of radiation, the tissue(s) exposed, and the time lapsed after exposure. The biological effects of low dose radiation on learning and memory are not well understood. An ion mobility-enhanced data-independent acquisition (MS(E)) approach in conjunction with the ISOQuant software tool was utilized for label-free quantification of hippocampal proteins with the goal of determining protein alteration associated with low-dose whole body ionizing radiation (X-rays, 1Gy) of 5.5-month-old male C57BL/6J mice post contextual fear conditioning training. Global proteome analysis revealed deregulation of 73 proteins (out of 399 proteins). Deregulated proteins indicated adverse effects of irradiation on myelination and perturbation of energy metabolism pathways involving a shift from the TCA cycle to glutamate oxidation. Our findings also indicate that proteins associated with synaptic activity, including vesicle recycling and neurotransmission, were altered in the irradiated mice. The elevated LTP and decreased LTD suggest improved synaptic transmission and enhanced efficiency of neurotransmitter release which would be consistent with the observed comparable contextual fear memory performance of the mice following post-training whole body or sham-irradiation.
Significance:
This study is significant because the biological consequences of low dose radiation on learning and memory are complex and not yet well understood. We conducted a IMS-enhanced MS(E)-based label-free quantitative proteomic analysis of hippocampal tissue with the goal of determining protein alteration associated with low-dose whole body ionizing radiation (X-ray, 1Gy) of 5.5-month-old male C57BL/6J mice post contextual fear conditioning training. The IMS-enhanced MS(E) approach in conjunction with ISOQuant software was robust and accurate with low median CV values of 0.99% for the technical replicates of samples from both the sham and irradiated group. The biological variance was as low as 1.61% for the sham group and 1.31% for the irradiated group. The applied data generation and processing workflow allowed the quantitative evaluation of 399 proteins. The current proteomic analysis indicates that myelination is sensitive to low dose radiation. The observed protein level changes imply modulation of energy metabolism pathways in the radiation exposed group, specifically changes in protein abundance levels suggest a shift from TCA cycle to glutamate oxidation to satisfy energy demands. Most significantly, our study reveals deregulation of proteins involved in processes that govern synaptic activity including enhanced synaptic vesicle cycling, and altered long-term potentiation (LTP) and depression (LTD). An elevated LTP and decreased LTD suggest improved synaptic transmission and enhanced efficiency of neurotransmitter release which is consistent with the observed comparable contextual fear memory performance of the mice following post-training whole body or sham-irradiation. Overall, our results underscore the importance of low dose radiation experiments for illuminating the sensitivity of biochemical pathways to radiation, and the modulation of potential repair and compensatory response mechanisms. This kind of studies and associated findings may ultimately lead to the design of strategies for ameliorating hippocampal and CNS injury following radiation exposure as part of medical therapies or as a consequence of occupational hazards.
Purpose:
Protein oxidation in response to radiation results in DNA damage, endoplasmic reticulum stress/unfolded protein response, cell cycle arrest, cell death and senescence. The liver, a relatively radiosensitive organ, undergoes measurable alterations in metabolic functions following irradiation. Accordingly, we investigated radiation-induced changes in liver metabolism and alterations in protein oxidation.
Materials and methods:
C57BL/6 mice were sham irradiated or exposed to 8.5 Gy (60)Co (0.6 Gy/min) total body irradiation. Metabolites and metabolic enzymes in the blood and liver tissue were analyzed. Two-dimensional gel electrophoresis and OxyBlot™ were used to detect carbonylated proteins that were then identified by peptide mass fingerprinting.
Results:
Analysis of serum metabolites revealed elevated glucose, bilirubin, lactate dehydrogenase (LDH), high-density lipoprotein, and aspartate aminotransferase within 24-72 h post irradiation. Liver tissue LDH and alkaline phosphatase activities were elevated 24-72 h post irradiation. OxyBlotting revealed that the hepatic proteome contains baseline protein carbonylation. Radiation exposure increased carbonylation of specific liver proteins including carbonic anhydrase 1, α-enolase, and regucalcin.
Conclusions:
8.5 Gy irradiation resulted in distinct metabolic alterations in hepatic functions. Coincident with these changes, radiation induced the carbonylation of specific liver enzymes. The oxidation of liver enzymes may underlie some radiation-induced alterations in hepatic function.
Ataxia telangiectasia (AT) is a human genetic disease characterized by radiation sensitivity, impaired neuronal development and predisposition to cancer. Using a genetically defined model cell system consisting of cells expressing a kinase dead or a kinase proficient ATM gene product, we previously reported systemic alterations in major metabolic pathways that translate at the gene expression, protein and small molecule metabolite levels. Here, we report ionizing radiation induced stress response signaling arising from perturbations in the ATM gene, by employing a functional proteomics approach. Functional pathway analysis shows robust translational and post-translational responses under ATM proficient conditions, which include enrichment of proteins in the Ephrin receptor and axonal guidance signaling pathways. These molecular networks offer a hypothesis generating function for further investigations of cellular stress responses.
All tissues can be damaged by ionizing radiation. Early biomarkers of radiation injury are critical for triage, treatment and follow-up of large numbers of people exposed to ionizing radiation after terrorist attacks or radiological accident, and for prediction of normal tissue toxicity before, during and after a treatment by radiotherapy. The comparative proteomic approach is a promising and powerful tool for the discovery of new radiation biomarkers. In association with multivariate statistics, proteomics enables measurement of the level of hundreds or thousands of proteins at the same time and identifies set of proteins that can discriminate between different groups of individuals. Human serum and plasma are the preferred samples for the study of normal and disease-associated proteins. Extreme complexity, extensive dynamic range, genetic and physiological variations, protein modifications and incompleteness of sampling by two-dimensional electrophoresis and mass spectrometry represent key challenges to reproducible, high-resolution, and high-throughput analyses of serum and plasma proteomes. The future of radiation research will possibly lie in molecular networks that link genome, transcriptome, proteome and metabolome variations to radiation pathophysiology and serve as sensors of radiation disease. This chapter reviews recent advances in proteome analysis of serum and plasma as well as its applications to radiation biology and radiation biomarker discovery for both radiation exposure and radiation tissue toxicity.
This chapter will review the proteome alterations induced by ionizing radiation in cellular systems or using animal models with whole body or localised exposure. The recent developments in qualitative and quantitative proteome analysis using formalin-fixed paraffin-embedded material from radiobiology archives will be illustrated. The development of promising protein targets to be used as radiation biomarkers in future molecular epidemiology studies is described.
The nucleolus is a nuclear organelle that coordinates rRNA transcription and ribosome subunit biogenesis. Recent proteomic analyses have shown that the nucleolus contains proteins involved in cell cycle control, DNA processing and DNA damage response and repair, in addition to the many proteins connected with ribosome subunit production. Here we study the dynamics of nucleolar protein responses in cells exposed to stress and DNA damage caused by ionizing and ultraviolet (UV) radiation in diploid human fibroblasts. We show using a combination of imaging and quantitative proteomics methods that nucleolar substructure and the nucleolar proteome undergo selective reorganization in response to UV damage. The proteomic responses to UV include alterations of functional protein complexes such as the SSU processome and exosome, and paraspeckle proteins, involving both decreases and increases in steady state protein ratios, respectively. Several nonhomologous end-joining proteins (NHEJ), such as Ku70/80, display similar fast responses to UV. In contrast, nucleolar proteomic responses to IR are both temporally and spatially distinct from those caused by UV, and more limited in terms of magnitude. With the exception of the NHEJ and paraspeckle proteins, where IR induces rapid and transient changes within 15 min of the damage, IR does not alter the ratios of most other functional nucleolar protein complexes. The rapid transient decrease of NHEJ proteins in the nucleolus indicates that it may reflect a response to DNA damage. Our results underline that the nucleolus is a specific stress response organelle that responds to different damage and stress agents in a unique, damage-specific manner.
High doses of ionising radiation damage the heart by an as yet unknown mechanism. A concern for radiological protection is the recent epidemiological data indicating that doses as low as 100-500 mGy may induce cardiac damage. The aim of this study was to identify potential molecular targets and/or mechanisms involved in the pathogenesis of low-dose radiation-induced cardiovascular disease. The vascular endothelium plays a pivotal role in the regulation of cardiac function and is therefore a potential target tissue. We report here that low-dose radiation induced rapid and time-dependent changes in the cytoplasmic proteome of the human endothelial cell line EA.hy926. The proteomes were investigated at 4 and 24 h after irradiation at two different dose rates (Co-60 gamma ray total dose 200 mGy; 20 mGy/min and 190 mGy/min) using 2D-DIGE technology. Differentially expressed proteins were identified, after in-gel trypsin digestion, by MALDI-TOF/TOF tandem mass spectrometry, and peptide mass fingerprint analyses. We identified 15 significantly differentially expressed proteins, of which 10 were up-regulated and 5 down-regulated, with more than ±1.5-fold difference compared with unexposed cells. Pathways influenced by the low-dose exposures included the Ran and RhoA pathways, fatty acid metabolism and stress response.
Use of mobile phones has widely increased over the past decade. However, in spite of the extensive research, the question of potential health effects of the mobile phone radiation remains unanswered. We have earlier proposed, and applied, proteomics as a tool to study biological effects of the mobile phone radiation, using as a model human endothelial cell line EA.hy926. Exposure of EA.hy926 cells to 900 MHz GSM radiation has caused statistically significant changes in expression of numerous proteins. However, exposure of EA.hy926 cells to 1800 MHz GSM signal had only very small effect on cell proteome, as compared with 900 MHz GSM exposure. In the present study, using as model human primary endothelial cells, we have examined whether exposure to 1800 MHz GSM mobile phone radiation can affect cell proteome.
Primary human umbilical vein endothelial cells and primary human brain microvascular endothelial cells were exposed for 1 hour to 1800 MHz GSM mobile phone radiation at an average specific absorption rate of 2.0 W/kg. The cells were harvested immediately after the exposure and the protein expression patterns of the sham-exposed and radiation-exposed cells were examined using two dimensional difference gel electrophoresis-based proteomics (2DE-DIGE). There were observed numerous differences between the proteomes of human umbilical vein endothelial cells and human brain microvascular endothelial cells (both sham-exposed). These differences are most likely representing physiological differences between endothelia in different vascular beds. However, the exposure of both types of primary endothelial cells to mobile phone radiation did not cause any statistically significant changes in protein expression.
Exposure of primary human endothelial cells to the mobile phone radiation, 1800 MHz GSM signal for 1 hour at an average specific absorption rate of 2.0 W/kg, does not affect protein expression, when the proteomes were examined immediately after the end of the exposure and when the false discovery rate correction was applied to analysis. This observation agrees with our earlier study showing that the 1800 MHz GSM radiation exposure had only very limited effect on the proteome of human endothelial cell line EA.hy926, as compared with the effect of 900 MHz GSM radiation.
Quantitative evaluation of early response proteins (ERPRO) and early response genes (ERG) following γ-irradiation of human lymphocytes; identification of specific proteins and genes as candidate biomarkers for the development of a novel biodosimeter.
Human peripheral blood lymphocytes were exposed to clinically relevant doses (1, 2 and 4 Gy) of γ-radiation ex-vivo. Analyses of protein and gene expression modulation were conducted 2 h post-irradiation. Global modulations were monitored using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and DNA microarray analyses of the samples originating from one human donor. On the proteome level, both phosphorylated and non-phosphorylated proteins were considered. Proteins and genes of specific interest were further targeted using Western blot (WB) and real-time quantitative polymerase chain reaction (RT-qPCR) techniques, employing samples from several human donors (n=3).
A set of ERPRO and ERG showing significant alterations 2 h post-γ-irradiation have been identified in human lymphocytes. The most radiation responsive genes and proteins indicated alterations of cellular structure (ß-actin, talin-1 [TLN1], talin-2, zyxin-2), immune and defence reactions (major histocompatibility complex binding protein-2 [MBP2], interleukin-17E and interferon-γ), cell cycle control (cyclin-dependent kinase inhibitor-1A [CDKN1A], mouse double minute-2, annexin-A6 [ANXA6], growth arrest and DNA-damage-inducible protein-α [GADD45A], proliferating cell nuclear antigen [PCNA], dual specificity phosphatase-2 and 8 [DUSP8]) as well as detoxification processes (peroxin-1) and apoptosis (B-cell lymphoma-2 binding component-3 [BBC3]).
The estimations of protein concentration modulation of TLN1 and CDKN1A, phosphorylation status of ANXA6 (dose range 0-2 Gy) and MBP2 as well as the alterations in the level of gene expressions of BBC3, DUSP8, GADD45A and PCNA appears to be of potential value for future biodosimetric applications.
Repeated exposures to UVB of human keratinocytes lacking functional p16(INK-4a) and able to differentiate induce an alternative state of differentiation rather than stress-induced premature senescence.
A 2D-DIGE proteomic profiling of this alternative state of differentiation was performed herein at various times after the exposures to UVB. Sixty-nine differentially abundant protein species were identified by mass spectrometry, many of which are involved in keratinocyte differentiation and survival. Among these protein species was TRIpartite Motif Protein 29 (TRIM29). Increased abundance of TRIM29 following UVB exposures was validated by Western blot using specific antibody and was also further analysed by immunochemistry and by RT-PCR. TRIM29 was found very abundant in keratinocytes and reconstructed epidermis. Knocking down the expression of TRIM29 by short-hairpin RNA interference decreased the viability of keratinocytes after UVB exposure. The abundance of involucrin mRNA, a marker of late differentiation, increased concomitantly. In TRIM29-knocked down reconstructed epidermis, the presence of picnotic cells revealed cell injury. Increased abundance of TRIM29 was also observed upon exposure to DNA damaging agents and PKC activation. The UVB-induced increase of TRIM29 abundance was dependent on a PKC signaling pathway, likely PKCdelta.
These findings suggest that TRIM29 allows keratinocytes to enter a protective alternative differentiation process rather than die massively after stress.
To investigate whether or not low intensity radio frequency electromagnetic field exposure (RF-EME) associated with mobile phone use can affect human cells, we used a sensitive proteome analysis method to study changes in protein synthesis in cultured human cells.
Four different cell kinds were exposed to 2 W/kg specific absorption rate in medium containing 35S-methionine/cysteine, and autoradiography of 2D gel spots was used to measure the increased synthesis of individual proteins.
While short-term RF-EME did not significantly alter the proteome, an 8-h exposure caused a significant increase in protein synthesis in Jurkat T-cells and human fibroblasts, and to a lesser extent in activated primary human mononuclear cells. Quiescent (metabolically inactive) mononuclear cells, did not detectably respond to RF-EME. Since RF exposure induced a temperature increase of less than 0.15 degrees C, we suggest that the observed cellular response is a so called "athermal" effect of RF-EME.
Our finding of an association between metabolic activity and the observed cellular reaction to low intensity RF-EME may reconcile conflicting results of previous studies. We further postulate that the observed increased protein synthesis reflects an increased rate of protein turnover stemming from protein folding problems caused by the interference of radio-frequency electromagnetic fields with hydrogen bonds. Our observations do not directly imply a health risk. However, vis-a-vis a synopsis of reports on cells stress and DNA breaks, after short and longer exposure, on active and inactive cells, our findings may contribute to the re-evaluation of previous reports.
Background: We have earlier shown that exposure of human endothelial cell line EA.hy926 to 900 MHz GSM mobile phone radiation causes changes in the expression of numerous proteins. Here, we have examined the effects of 1800 MHz GSM mobile phone signal on the proteomeof the same cell line.
Results: EA.hy926 cells were exposed for one hour to 1800 MHz GSM signal, simulating mobile phone talking conditions, at an average specific absorption rate (SAR) of 2.0 W/kg at 37±0.3°C. Sham samples were produced simultaneously in the same conditions but without theradiation exposure. Cells were harvested immediately after 1-hour exposure to the radiation, and proteins were extracted and separated using 2-dimensional electrophoresis (2DE). In total, 10 experimental replicates were generated from both exposed and sham samples. About 900 protein spots were detected in the 2DE-gels using PDQuest software and eight of them were found to be differentially expressed in exposed cells (p<0.05, t-test). Three out of these eight proteins were identified using Maldi-ToF mass spectrometry (MS). These proteins are: spermidine synthase (SRM), 78 kDa glucose-regulated protein (55 kDa fragment) (GRP78) and proteasome subunit alpha type 1 (PSA1). Due to the lack of the availability of commercial antibodies we were able to further examine expression of only GRP78. Using SDSPAGE and western blot method we were not able to confirm the result obtained for GRP78 using 2DE. Additionally, we have not seen any effect of 1800GSM exposure on the expression of vimentin and Hsp27 - proteins that were affected by the 900 MHz GSM exposure in our earlier studies.
Conclusions: Our results suggest that the 900GSM and 1800GSM exposures might affect the expression of some proteins in the EA.hy926 cell line. The observed here discrepancy between the expression changes of GRP78 detected with 1DE and 2DE confirms the importance of validation of the results obtained with 2DE using othermethods, e.g. western blot.
We aimed to identify putative predictive protein biomarkers of radioresistance.
Three breast cancer cell lines (MCF7, MDA-MB-231, and T47D) were used as in vitro models to study radioresistance. Inherent radiosensitivities were examined using a clonogenic survival assay. It was revealed that each cell line differed in their response to radiotherapy. These parental breast cancer cell lines were used to establish novel derivatives (MCF7RR, MDA-MB-231RR, and T47DRR) displaying significant resistance to ionizing radiation. Derivative cells were compared with parental cells to identify putative biomarkers associated with the radioresistant phenotype. To identify these biomarkers, complementary proteomic screening approaches were exploited encompassing two-dimensional gel electrophoresis in combination with mass spectrometry, liquid chromatography coupled with tandem mass spectrometry and quantitative proteomics using iTRAQ technology.
A large number of potential biomarkers were identified, and several of these were confirmed using Western blot analysis. In particular, a decrease in the expression of the 26S proteasome was found in all radioresistant derivatives when compared with the respective parent cells. Decreased expression of this target was also found to be associated with radioresistant laryngeal tumors (P = .05) in a small pilot immunohistochemical study.
These findings suggest that the 26S proteasome may provide a general predictive biomarker for radiotherapy outcome.
There is considerable public concern regarding the health effects of exposure to low-frequency electromagnetic fields. In addition, the association between exposure and disease incidence or the possible biological effects of exposure are unclear. Using 2D-DIGE and MS in a blind study, we have investigated the effects of static and oscillating extremely low-frequency electromagnetic fields (ELF EMFs) on the proteomes of wild type Schizosaccharomyces pombe and a Sty1p deletion mutant which displays increased sensitivity to a variety of cellular stresses. Whilst this study identifies a number of protein isoforms that display significant differential expression across experimental conditions, there was no correlation between their patterns of expression and the ELF EMF exposure regimen. We conclude that there are no significant effects of either static or oscillating EMF on the yeast proteome at the sensitivity afforded by 2D-DIGE. We hypothesise that the proteins identified must be sensitive to subtle changes in culture and/or handling conditions, and that the identification of these proteins in other proteomic studies should be treated with some caution when the results of such studies are interpreted in a biological context.
Proteomics is widely used in search of biomarkers, pharmacology, clinical research and toxicology. With the help of proteomics large amount of information about the physiology of living cells can be obtained in a single experiment. Combining this information with data from genomics and other high-throughput screening techniques like transcriptomics and metabolomics allows gaining new insights into physiology of life and diseases.
The area of research that is still waiting for the proteomics “boom” is the search for the biological effects of radiation. It is relatively much known about the effects of high doses of radiation, both ionizing and non-ionizing. However, much less is known about the effects of low or very low doses of radiation, to which people are often exposed in their every day life. The effects of the low doses of ionizing radiation (e.g. bystander effect) or low doses of non-ionizing radiation (e.g. effect of radiation emitted by wireless communication devices) are not yet reliably established. Often these effects are small and difficult to discover and to replicate. One of the limiting factors in the research of low dose radiation effects is often the lack of the knowledge of the cellular target molecules.
Proteomics, the high-throughput screening of expression and activity of proteins is very well suited for the research aiming at discovery of molecular targets of low dose radiation. Proteomics approach seems to be particularly well suited for studying biological effects of low dose radiation because it might reveal effects that are not possible to predict based on the presently available knowledge concerning the effects of the high doses of radiation.
Search through the published scientific literature shows that to date was published only a very limited number of proteomics studies examining effects of radiation. This book, Radiation Proteomics, presents the current status the research of radiation effects using proteomics approach. The book begins with the review of current status and the future direction in the development of proteomics methods. This is followed by chapters dealing with the effects of ionizing and non-ionizing radiation on cells, tissues and body fluids.
The editor of the book, Research Professor Dariusz Leszczynski, is known for studies that introduced, some 10 years ago, the high-throughput screening techniques of proteomics and transcriptomics into the main stream of the research on the biological effects of the non-ionizing radiation emitted by the wireless communication devices. In recent years he has also done studies examining effects of low-dose ionizing radiation on cellular proteome.
Extremely Low Frequency Magnetic Fields (ELF MF) has been considered as a “possible human carcinogen” by International Agency for Research on Cancer (IARC) while credible mechanisms of its carcinogenicity remain unknown. In this study, a proteomics approach was employed to investigate the changes of protein expression profile induced by ELF MF in human breast cancer cell line MCF7, in order to determine ELF MF-responsive proteins. MCF7 cells were exposed to 50 Hz, 0.4 mT ELF MF for 24 h and the changes of protein profile were examined using two dimensional electrophoresis. Up to 6 spots have been statistically significantly altered (their expression levels were changed at least 5 fold up or down) compared with sham-exposed group. 19 ones were only detected in exposure group while 19 ones were missing. Three proteins were identified by LC-IT Tandem MS as RNA binding protein regulatory subunit Proteasome subunit beta type 7 precursor and Translationally Controlled Tumor Protein. Our finding showed that 50 Hz, 0.4 mT ELF MF alternates the protein profile of MCF7 cell and may affect many physiological functions of normal cell and 2-DE coupled with MS is a promising approach to elucidating cellular effects of electromagnetic fields.
Epidemiological studies have shown that moderate and low radiation doses to the heart area may result in an increase in cardiovascular mortality. It has been suggested that cardiovascular endothelium could be one of the targets for the ionising radiation-induced heart injury. We have used human endothelial cells as an in vitro model to study immediate effects of ionising radiation on endothelium. Cells were exposed to low and
moderate doses of γ-radiation, and short-term protein expression profiles were examined. Proteomics analysis did not show significant changes in the examined protein expression profiles after the γ-irradiation in any of the examined conditions. The molecular level cellular damage was verified by examining phosphorylation of tumour suppressor p53 binding protein 1, which was dose- and time-dependent. Further examination of cellular proteome and phosphoproteome, using more sensitive quantification and detection
techniques, is warranted and might reveal changes, which were not detected in this study.
Purpose:
Combined hormone and radiation therapy (CHRT) is one of the principle curative regimes for localised prostate cancer (PCa). Following treatment, many patients subsequently experience disease recurrence however; current diagnostics tests fail to predict the onset of disease recurrence. Biomarkers that address this issue would be of significant advantage.
Experimental design:
Label-free LC-MS/MS for protein biomarker discovery and MRM for targeted confirmation were applied to patient serum samples accrued in a non-interventional clinical trial of CHRT.
Results:
Analysis of time-matched patient samples from a patient with disease recurrence compared with a time match disease-free individual supported the identification of 287 proteins. Of these, 141 proteins were quantified, 95 proteins changed in their expression (P ≤ 0.05 and ≥1.5-fold change) and of these 16 were selected for MRM confirmation. The protein expression changes observed in the label-free LC-MS/MS and MRM analysis were found to be highly correlated (R(2) = 0.85).
Conclusions and clinical relevance:
The establishment of a clinical trial to support the acquisition of samples and development of a pipeline for MS-based biomarker discovery and validation should contribute to the identification of a serum protein signature to predict or monitor the outcome of treatment of patients with PCa.
To be highly successful, a radiotherapeutic dose must be sufficiently large to destroy radioresistant tumors, yet avoid injuring the surrounding healthy tissue. However, many patients exhibit high radiosensitivity and may develop radiation-induced early and late side effects. Because the identification of these radiosensitive patients remains largely problematic, general radiotherapy protocols currently limit the dose given, which risks delivering an insufficient dose to a significant number of less sensitive patients. Therefore, one of the main current challenges of radiobiology is to predict a patient's tumor radioresistance and normal tissue radiosensitivity to tailor a personalized treatment to that individual. Although predictive assays exist, none has demonstrated highly significant results that would be useful in a clinical setting. Therefore, proteomics represents a promising approach for identifying new relevant predictive biomarkers. In this review, the authors first explain the main characteristics of tumor radioresistance and normal tissue radiosensitivity. The authors next describe the existing predictive assays. Finally, the proteomics studies performed to date to identify new biomarkers that probably predicts radiotherapy outcomes are discussed.
Ultraviolet (UV) radiation is known to cause both positive and negative health effects for humans. The synthesis of vitamin D is one of the rare beneficial effects of UV. The negative effects, such as sunburn and premature photoaging of the skin, increase the risk of skin cancer, which is the most detrimental health consequence of UV radiation. Although proteomics has been extensively applied in various areas of the biomedical field, this technique has not been commonly used in the cutaneous biology. Proteome maps of human keratinocytes and of murine skin have been established to characterize the cutaneous responses and the age-related differences. There are very few publications, in which proteomic techniques have been utilized in photobiology and hence there is no systematic research data available of the UV effects on the skin proteome. The proteomic studies have mainly focused on the UV-induced photoaging, which is the consequence of the long-term chronic UV exposure. Since the use of proteomics has been very narrow in the photobiology, there is room for new studies. Proteomics would offer a cost-effective way to large-scale screen the possible target molecules involved in the UV-derived photodamage, especially what the large-scale effects are after the acute and chronic exposure on the different skin cell populations.
Proteomic studies to date have had limited use as an investigative tool in the skin's response to UV radiation. These studies used cell lines and reconstructed skin and have shown evidence of cell injury with oxidative damage and stress induced heat shock proteins. Others changes included altered cytokeratin and cytoskeletal proteins with enhanced expression of TRIM29 as the keratinocytes regenerate. The associated DNA repair requires polη, Rad18/Rad16 and Rev1. In the whole animal these events would be associated with inflammation, remodelling of the epidermis and modulation of the immune response. Longer term changes include ageing and skin cancers such as melanoma, squamous cell carcinoma and basal cell carcinoma. In the future proteomics will be used to explore these important aspects of photobiology. Better characterisation of the proteins involved should lead to a greater understanding of the skin's response to UV radiation.
Daily exposure to extremely low frequency magnetic fields (ELF MF) in the environment has raised public concerns on human health. Epidemiological studies suggest that exposure to ELF MF might associate with an elevated risk of cancer and other diseases in humans. To explain and/or support epidemiological observations, many laboratory studies have been conducted to elucidate the biological effects of ELF MF exposure and the underlying mechanisms of action. In order to reveal the global effects of ELF MF on protein expression, the proteomics approaches has been employed in this research field. In 2005, WHO organized a Workshop on Application of Proteomics and Transcriptomics in electromagnetic fields (EMF) Research in Helsinki, Finland to discuss the related problems and solutions. Later the journal Proteomics published a special issue devoted to the application of proteomics to EMF research. This chapter aims to summarize the current research progress and discuss the applicability of proteomics approaches in studying on ELF MF induced biological effects and the underlying mechanisms.
Proteomics, the science that examines the repertoire of proteins present in an organism using both high-throughput and low-throughput techniques, might give a better understanding of the functional processes ongoing in cells than genomics or transcriptomics, because proteins are the molecules that directly regulate physiological processes. Not all changes in gene expression are necessarily reflected in the proteome. Therefore, using proteomics approaches to study the effects of RF-EMF might provide information about potential biological and health effects. Especially that the RF-EMF used in wireless communication devices has very low energy and is unable to directly induce gene mutations.
The global rise in terrorism has increased the risk of radiological events aimed at creating chaos and destabilization, although they may cause relatively limited number of immediate casualties. We have proposed that a self-administered test would be valuable for initial triage following terrorist use of nuclear/radiological devices. The urine proteome may be a useful source of the biomarkers required for developing such a test. We have developed and extensively used a rat model to study the acute and late effect of total body (TBI) and partial body irradiation on critical organ systems. This model has proven valuable for correlating the structural and functional effects of radiation with molecular changes. Results show that nephron segments differ with regard to their sensitivity and response to ionizing radiation. The urine proteome was analyzed using LC-MS/MS at 24 h after TBI or local kidney irradiation using a 10 Gy single dose of X rays. LC-MS/MS data were analyzed and grouped under Gene Ontology categories Cellular Localization, Molecular Function and Biological Process. We observed a decrease in urine protein/creatinine ratio that corroborated with decreased spectral counts for urinary albumin and other major serum proteins. Interestingly, TBI caused greater decline in urinary albumin than local kidney irradiation. Analysis of acute-phase response proteins and markers of acute kidney injury showed increased urinary levels of cystatin superfamily proteins and alpha-1-acid glycoprotein. Among proteases and protease inhibitors, levels of Kallikrein 1-related peptidase b24, precursor and products of chymotrypsin-like activity, were noticeably increased. Among the amino acids that are susceptible to oxidation by free radicals, oxidized histidine levels were increased following irradiation. Our results suggest that proteomic analysis of early changes in urinary proteins will identify biomarkers for developing a self-administered test for radiation biodosimetry.
Exposure of tumourous tissue to ionizing radiation initiates a wound-healing response involving remodelling of the extracellular microenvironment. The initial reaction involves direct damage to the matrix proteins and the secretion and activation of proteolytic enzymes that lead to local destruction of the extracellular matrix. Subsequently the wounded area may undergo complete repair, may enter a prolonged period of heightened proteolysis, or may overproduce matrix proteins leading to fibrosis. The source of matrix degrading enzymatic activity may be the tumour cells and the tumour stroma. Additional complexity is provided by proteolytic activity released from tissue macrophages, mast cells and by invading inflammatory cells. The local production of growth factors, including VEGF and TGF-β play a key role in coordinating the response. It is anticipated that the application of modern proteomic technologies will reveal hitherto unrecognised levels of complexity in these processes. Hopefully this will lead to the development of new therapeutic strategies to prevent long-term health implications of radiation exposure.
As the main catalytic and structural molecules within living systems, proteins are the most likely biomolecules to be affected by radiation exposure. Proteomics, the comprehensive characterization of proteins within complex biological samples, is therefore a research approach ideally suited to assess the effects of radiation exposure on cells and tissues. For comprehensive characterization of proteomes, an analytical platform capable of quantifying protein abundance, identifying post-translation modifications and revealing members of protein complexes on a system-wide level is necessary. Mass spectrometry (MS), coupled with technologies for sample fractionation and automated data analysis, provides such a versatile and powerful platform. In this chapter we offer a view on the current state of MS-proteomics, and focus on emerging technologies within three areas: (1) New instrumental methods; (2) New computational methods for peptide identification; and (3) Label-free quantification. These emerging technologies should be valuable for researchers seeking to better understand biological effects of radiation on living systems.
Tumorigenesis is always concomitant with microenvironmental alterations. The tumor microenvironment is a heterogeneous and complex milieu, which exerts a variety of stresses on tumor cells for proliferation, survival, or death. Recently, accumulated evidence revealed that metabolic and oxidative stresses both play significant roles in tumor development and progression that converge on a common autophagic pathway. Tumor cells display increased metabolic autonomy, and the hallmark is the exploitation of aerobic glycolysis (termed Warburg effect), which increased glucose consumption and decreased oxidative phosphorylation to support growth and proliferation. This characteristic renders cancer cells more aggressive; they devour tremendous amounts of nutrients from microenvironment to result in an ever-growing appetite for new tumor vessel formation and the release of more "waste," including key determinants of cell fate like lactate and reactive oxygen species (ROS). The intracellular ROS level of cancer cells can also be modulated by a variety of stimuli in the tumor microenvironment, such as pro-growth and pro-inflammatory factors. The intracellular redox state serves as a double-edged sword in tumor development and progression: ROS overproduction results in cytotoxic effects and might lead to apoptotic cell death, whereas certain level of ROS can act as a second-messenger for regulation of such cellular processes as cell survival, proliferation, and metastasis. The molecular mechanisms for cancer cell responses to metabolic and oxidative stresses are complex and are likely to involve multiple molecules or signaling pathways. In addition, the expression and modification of these proteins after metabolic or oxidative stress challenge are diverse in different cancer cells and endow them with different functions. Therefore, MS-based high-throughput platforms, such as proteomics, are indispensable in the global analysis of cancer cell responses to metabolic and oxidative stress. Herein, we highlight recent advances in the understanding of the metabolic and oxidative stresses associated with tumor progression with proteomics-based systems biology approaches. © 2012 Wiley Periodicals, Inc. Mass Spec Rev.
The human skin is the only line of defense against UV radiation. A series of responses to protect the skin are induced by UV radiation. In this study, a proteomic approach was used to study these responses. We have performed high-resolution two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) analysis of (solar simulated) UV-exposed reconstructed skin equivalents as well as native skin. Differentially expressed proteins were processed for mass spectrometric analysis, when consistent differences were observed in all individual human skin equivalents. In addition to proteins known to be involved in UV responses (HSP27, MnSOD, and PDX-2), we identified two novel proteins that were downregulated following UV exposure. Further analysis revealed that these proteins were the phosphorylated forms of the actin cytoskeleton modulators cofilin-1 and destrin. The de-phosphorylation of cofilin-1 was confirmed using western blotting of UV-exposed skin equivalents and ex vivo skin protein extracts. In conclusion, our study indicates the potency of a proteomic approach to study UV-induced changes in a tissue culture system mimicking human skin as well as excised human skin.Keywords: cofilin-1, destrin, human skin equivalents, proteomics, UV
Epidemiological data show that ionising radiation increases the risk of cardiovascular disease. The endothelium is one of the main targets of radiation-induced damage. Rapid radiation-induced alterations in the biological processes were investigated after exposure to a clinically relevant radiation dose (2.5 Gy gamma radiation). The changes in protein expression were determined using the human endothelial cell line EA.hy926 as a model. Two complementary proteomic approaches, SILAC (Stable Isotope Labelling with Amino acids in Cell culture) and 2D-DIGE (Two Dimensional Difference-in-Gel-Electrophoresis) were used. The proteomes of the endothelial cells were analysed 4h and 24h after irradiation. Differentially expressed proteins were identified and quantified by MALDI-TOF/TOF and LTQ Orbitrap tandem mass spectrometry. The deregulated proteins were mainly categorised in four key pathways: (i) glycolysis/gluconeogenesis and synthesis/degradation of ketone bodies, (ii) oxidative phosphorylation, (iii) Rho-mediated cell motility and (iv) non-homologous end joining. We suggest that these alterations facilitate the repair processes needed to overcome the stress caused by irradiation and are indicative of the vascular damage leading to radiation-induced cardio- and cerebrovascular impairment.
The objective of this study was to investigate the effects of two sources of electromagnetic fields (EMFs) on the proteome of cerebellum, hippocampus, and frontal lobe in Balb/c mice following long-term whole body irradiation. Three equally divided groups of animals (6 animals/group) were used; the first group was exposed to a typical mobile phone, at a SAR level range of 0.17-0.37 W/kg for 3 h daily for 8 months, the second group was exposed to a wireless DECT base (Digital Enhanced Cordless Telecommunications/Telephone) at a SAR level range of 0.012-0.028 W/kg for 8 h/day also for 8 months and the third group comprised the sham-exposed animals. Comparative proteomics analysis revealed that long-term irradiation from both EMF sources altered significantly (p < 0.05) the expression of 143 proteins in total (as low as 0.003 fold downregulation up to 114 fold overexpression). Several neural function related proteins (i.e., Glial Fibrillary Acidic Protein (GFAP), Alpha-synuclein, Glia Maturation Factor beta (GMF), and apolipoprotein E (apoE)), heat shock proteins, and cytoskeletal proteins (i.e., Neurofilaments and tropomodulin) are included in this list as well as proteins of the brain metabolism (i.e., Aspartate aminotransferase, Glutamate dehydrogenase) to nearly all brain regions studied. Western blot analysis on selected proteins confirmed the proteomics data. The observed protein expression changes may be related to brain plasticity alterations, indicative of oxidative stress in the nervous system or involved in apoptosis and might potentially explain human health hazards reported so far, such as headaches, sleep disturbance, fatigue, memory deficits, and brain tumor long-term induction under similar exposure conditions.
Extremely low-frequency magnetic fields (ELF-MFs) may affect human health because of the possible associations with leukemia but also with cancer, cardiovascular, and neurological disorders. In the present work, human SH-SY5Y neuroblastoma cells were exposed to a 50 Hz, 1 mT sinusoidal ELF-MF at three different times, that is, 5 days (T5), 10 days (T10), and 15 days (T15) and then the effects of ELF-MF on proteome expression and biological behavior were investigated. Through comparative analysis between treated and control samples, we analyzed the proteome changes induced by ELF-MF exposure. Nine new proteins resolved in sample after a 15-day treatment were involved in a cellular defense mechanism and/or in cellular organization and proliferation such as peroxiredoxin isoenzymes (2, 3, and 6), 3-mercaptopyruvate sulfurtransferase, actin cytoplasmatic 2, t-complex protein subunit beta, ropporin-1A, and profilin-2 and spindlin-1. Our results indicated that ELF-MFs exposure altered the proliferative status and other important cell biology-related parameters, such as cell growth pattern, and cytoskeletal organization. These findings support our hypothesis that ELF radiation could trigger a shift toward a more invasive phenotype.
Accidental nuclear scenarios lead to environmental contamination of unknown level. Immediate radiation-induced biological responses that trigger processes leading to adverse health effects decades later are not well understood. A comprehensive proteomic analysis provides a promising means to identify and quantify the initial damage after radiation exposure. Early changes in the cardiac tissue of C57BL/6 mice exposed to total body irradiation were studied, using a dose relevant to both intentional and accidental exposure (3 Gy gamma ray). Heart tissue protein lysates were analyzed 5 and 24 h after the exposure using isotope-coded protein labeling (ICPL) and 2-dimensional difference-in-gel-electrophoresis (2-D DIGE) proteomics approaches. The differentially expressed proteins were identified by LC-ESI-MS-MS. Both techniques showed similar functional groups of proteins to be involved in the initial injury. Pathway analyses indicated that total body irradiation immediately induced biological responses such as inflammation, antioxidative defense, and reorganization of structural proteins. Mitochondrial proteins represented the protein class most sensitive to ionizing radiation. The proteins involved in the initial damage processes map to several functional categories involving cardiotoxicity. This prompts us to propose that these early changes are indicative of the processes that lead to an increased risk of cardiovascular disease after radiation exposure.
Widespread utilization of proteomics analysis for biomarkers discovery in oncology is impeded by prohibitive sample size requirements. In this work, we propose a novel graph-based scoring function to rank and identify the most robust biomarkers from limited proteomics data. The methodology is demonstrated for identifying biomarkers for radiation pneumonitis in lung cancer patients. Our preliminary results suggest that the proposed approach is promising for biomarker identification in sample-limited clinical applications.
Ultraviolet-B (UVB) radiation can result in acute photodamage, photoaging and skin cancer through the induction of reactive oxygen species, DNA damage, activation of signaling pathways, and regulation of gene expression. In this study, we investigated UVB-induced alterations in protein expression in human dermal fibroblasts.
Skin fibroblasts were irradiated with 100 mJ/cm² UVB, and cell viability was monitored by the 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide assay. Two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectroscopy were used to identify differentially expressed proteins. The mRNA and levels of identified proteins were detected using a quantitative real-time polymerase chain reaction assay and Western blot.
UVB decreased the viability of skin fibroblasts. In UVB-treated cells, eighteen differentially expressed proteins were identified. Among these proteins, the amounts of receptor-interacting protein (RIP) and vimentin were significantly up-regulated. However, their mRNA levels decreased and remained relatively stable, respectively.
The differential expression of RIP and vimentin was validated in UVB-irradiated fibroblasts. RIP may promote cell injury, and vimentin may contribute to the resistance of cells to UVB-induced damage.
Solar UVA exposure plays a causative role in skin photoaging and photocarcinogenesis. Here, we describe the proteomic identification of novel UVA-targets in human dermal fibroblasts following a two-dimensional-difference-gel-electrophoresis (2D-DIGE) approach. Fibroblasts were exposed to noncytotoxic doses of UVA or left untreated, and total protein extracts underwent CyDye-labeling followed by 2D-DIGE/mass-spectrometric identification of differentially expressed proteins, confirmed independently by immunodetection. The protein displaying the most pronounced UVA-induced upregulation was identified as the nucleolar protein nucleophosmin. The protein undergoing the most pronounced UVA-induced downregulation was identified as cathepsin B, a lysosomal cysteine-protease displaying loss of enzymatic activity and altered maturation after cellular UVA exposure. Extensive lysosomal accumulation of lipofuscin-like autofluorescence and osmiophilic material occurred in UVA-exposed fibroblasts as detected by confocal fluorescence microscopy and transmission electron microscopy, respectively. Array analysis indicated UVA-induced upregulation of oxidative stress response gene expression, and UVA-induced loss of cathepsin B enzymatic activity in fibroblasts was suppressed by antioxidant intervention. Pharmacological cathepsin B inhibition using CA074Me mimicked UVA-induced accumulation of lysosomal autofluorescence and deficient cathepsin B maturation. Taken together, these data support the hypothesis that cathepsin B is a crucial target of UVA-induced photo-oxidative stress causatively involved in dermal photodamage through the impairment of lysosomal removal of lipofuscin.
Radiotherapy is the primary treatment for nasopharyngeal cancer (NPC), but radioresistance remains a serious obstacle to successful treatment in many cases. To identify the proteins involved in this resistance and to evaluate their potential for predicting NPC response to radiotherapy, we first established a radioresistant subclone cell line (CNE2-IR) derived from NPC cell line CNE2 by treating the cells with five rounds of sublethal ionizing radiation. Proteomics was then performed to compare the protein profiles of CNE2-IR and CNE2, and a total of 34 differential proteins were identified. Among them, 14-3-3sigma and Maspin were downregulated and GRP78 and Mn-SOD were upregulated in the radioresistant CNE2-IR compared with control CNE2, which was conformed by Western blot. Immunohistochemistry was performed to detect the expression of the four validated proteins in the 39 radioresistant and 51 radiosensitive NPC tissues and their value for predicting NPC response to radiotherapy were evaluated by receiver operating characteristic analysis. The results showed that the downregulation of 14-3-3sigma and Maspin and the upregulation of GRP78 and Mn-SOD were significantly correlated with NPC radioresistance and the combination of the four proteins achieved a sensitivity of 90% and a specificity of 88% in discriminating radiosensitive from radiaoresistant NPC. Furthermore, the resistance to ionizing radiation can be partially reversed by the overexpression of 14-3-3sigma in the CNE2-IR. The data suggest that 14-3-3sigma, Maspin, GRP78, and Mn-SOD are potential biomarkers for predicting NPC response to radiotherapy and their dysregulation may be involved in the radioresistance of NPC.
Although many in vitro studies have previously been conducted to elucidate the biological effects of radio frequency (RF) radiation over the past decades, the existence and nature of any effects is still inconclusive. In an effort to further elucidate this question, we have monitored changes in protein expression profiles in RF-exposed MCF7 human breast cancer cells using two-dimensional gel electrophoresis. MCF7 cells were exposed to 849 MHz RF radiation for 1 h per day for three consecutive days at specific absorption rates (SARs) of either 2 W/Kg or 10 W/kg. During exposure, the temperature in the exposure chamber was kept in an isothermal condition. Twenty-four hours after the final RF exposure, the protein lysates from MCF cells were prepared and two-dimensional electrophoretic analyses were conducted. The protein expression profiles of the MCF cells were not significantly altered as the result of RF exposure. None of the protein spots on the two-dimensional electrophoretic gels showed reproducible changes in three independent experiments. To determine effect of RF radiation on protein expression profiles more clearly, three spots showing altered expression without reproducibility were identified using electrospray ionization tandem mass spectrometry analysis and their expressions were examined with RT-PCR and Western blot assays. There was no alteration in their mRNA and protein levels. As we were unable to observe any significant and reproducible changes in the protein expression profiles of the RF radiation-exposed MCF7 cells using high throughput and non-high throughput techniques, it seems unlikely that RF exposure modulates the protein expression profile.
Chronic ultraviolet (UV) exposure induces photoaging and oxidative stress in the skin. We investigated whether Machilus thunbergii Sieb et Zucc (M. thunbergii) could reduce UV-induced photoaging and oxidative stress in hairless mice. The dorsal skin of hairless mice was treated topically with M. thunbergii for 2 h prior to UV irradiation. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were then measured in skin and/or serum samples. Histological changes in the skin were assessed by hematoxylin-eosin (HE) staining. In addition, proteomes from the skin of hairless mice in each group were analyzed. The thickness of the dorsal skin and epidermis was significantly decreased by M. thunbergii treatment. We also found that MDA levels decreased after M. thunbergii treatment and the SOD levels were increased by M. thunbergii compared with those in the UV-only treated group. Proteomic analysis revealed 17 proteins associated with photoaging. These data indicate that M. thunbergii might have antiphotoaging effects.
Escherichia coli K12 was used as a model system to determine whether ELF magnetic fields (MFs) are a general stress factor. The cells were exposed to ELF MFs (5-100 Hz) at a maximum intensity of 14 mT r. m.s. for circularly polarized MFs and 10 mT r.m.s. for vertically polarized MFs. The response of the cells to the MFs was estimated from the change in protein synthesis by using 2D PAGE. Approximately 1,000 proteins were separated on the 2D gels. The stress-responsive proteins such as CH10, DNAK, CH60, RECA, USPA, K6P1 and SODM were identified from the SWISS-2DPAGE database on the 2D gels. These proteins respond to most stress factors, including temperature change, chemical compounds, heavy metals, and nutrients. When the bacterial cells were exposed to each MF at 5-100 Hz under aerobic conditions (6.5 h) or at 50 Hz under anaerobic conditions (16 h) at the maximum intensity (7.8 to 14 mT r.m.s.), no reproducible changes were observed in the 2D gels. Changes in protein synthesis were detected by 2D PAGE with exposure to heat shock (50 degrees C for 30 min) or under anaerobic conditions (no bubbling for 16 h). Increases in the levels of synthesis of the stress proteins were observed in heat-shocked cells (CH60, CH10, HTPG, DNAK, HSLV, IBPA and some unidentified proteins) and in cells grown under anaerobic conditions (DNAK, PFLB, RECA, USPA and many unidentified proteins). These results suggest that 2D PAGE is sufficient to detect cell responses to environmental stress. The high-intensity ELF MFs (14 mT at power frequency) did not act as a general stress factor.
We have examined whether non-thermal exposures of cultures of the human endothelial cell line EA.hy926 to 900 MHz GSM mobile phone microwave radiation could activate stress response. Results obtained demonstrate that 1-hour non-thermal exposure of EA.hy926 cells changes the phosphorylation status of numerous, yet largely unidentified, proteins. One of the affected proteins was identified as heat shock protein-27 (hsp27). Mobile phone exposure caused a transient increase in phosphorylation of hsp27, an effect which was prevented by SB203580, a specific inhibitor of p38 mitogen-activated protein kinase (p38MAPK). Also, mobile phone exposure caused transient changes in the protein expression levels of hsp27 and p38MAPK. All these changes were non-thermal effects because, as determined using temperature probes, irradiation did not alter the temperature of cell cultures, which remained throughout the irradiation period at 37 +/- 0.3 degrees C. Changes in the overall pattern of protein phosphorylation suggest that mobile phone radiation activates a variety of cellular signal transduction pathways, among them the hsp27/p38MAPK stress response pathway. Based on the known functions of hsp27, we put forward the hypothesis that mobile phone radiation-induced activation of hsp27 may (i) facilitate the development of brain cancer by inhibiting the cytochrome c/caspase-3 apoptotic pathway and (ii) cause an increase in blood-brain barrier permeability through stabilization of endothelial cell stress fibers. We postulate that these events, when occurring repeatedly over a long period of time, might become a health hazard because of the possible accumulation of brain tissue damage. Furthermore, our hypothesis suggests that other brain damaging factors may co-participate in mobile phone radiation-induced effects.
To estimate the effect of 50 Hz magnetic-field exposure on genome-wide gene expression, the yeast Saccharomyces cerevisiae was used as a model for eukaryotes. 2D PAGE (about 1,000 spots) for protein and cDNA microarray (about 5,900 genes) analysis for mRNA were performed. The cells were exposed to 50 Hz vertical magnetic fields at 10, 150 or 300 mT r.m.s. for 24 h. As positive controls, the cells were exposed to aerobic conditions, heat (40 degrees C) or minimal medium. The 2D PAGE and microarray analyses for the positive controls showed high-confidence differential expression of many genes including those for known or unknown proteins and mRNAs. For magnetic-field exposure, no high-confidence changes in expression were observed for proteins or genes that were related to heat-shock response, DNA repair, respiration, protein synthesis and the cell cycle. Principal component analysis showed no statistically significant difference in principal components, with only insignificant differences between the magnetic-field intensities studied. In contrast, the principal components for the positive controls were significantly different. The results indicate that a 50 Hz magnetic field below 300 mT did not act as a general stress factor like heat shock or DNA damage, as had been reported previously by others. This study failed to find a plausible differential gene expression that would point to a possible mechanism of an effect of magnetic fields. The findings provide no evidence that the magnetic-field exposure alters the fundamental mechanism of translation and transcription in eukaryotic cells.
The human endothelial cell line EA.hy926 was exposed to mobile phone radiation and the effect on protein expression was examined using two-dimensional electrophoresis (2-DE). Up to 38 various proteins have statistically significantly altered their expression levels following the irradiation. Four proteins were identified with matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). Two of the affected proteins were determined to be isoforms of cytoskeletal vimentin. This finding supports our earlier presented working hypothesis which indicated that the mobile phone radiation might affect the cytoskeleton and might have an effect on the physiological functions that are regulated by the cytoskeleton.
The microenvironmental physiology of tumors is uniquely different from that of normal tissues. It is characterized, inter alia, by O(2) depletion (hypoxia, anoxia), glucose and energy deprivation, high lactate levels, and extracellular acidosis, parameters that are anisotropically distributed within the tumor mass. This hostile microenvironment is largely dictated by the abnormal tumor vasculature and heterogeneous microcirculation. Hypoxia and other hostile microenvironmental parameters are known to directly or indirectly confer resistance to irradiation leading to treatment failure. Hypoxia directly leads to a reduced "fixation" of radiation-induced DNA damage. Indirect mechanisms include a restrained proliferation, changes in gene expression and alterations of the proteome (eg, elevated activity of DNA-repair enzymes and resistance-related proteins, increased transcription of growth factors), and genomic changes (genomic instability leading to clonal heterogeneity and selection of resistant clonal variants). These changes, caused by the hostile microenvironment, can favor tumor progression and acquired treatment resistance, both resulting in poor clinical outcome and prognosis. Pretreatment assessment of critical microenvironmental parameters is therefore needed to allow the selection of patients who could benefit from special treatment approaches (eg, hypoxia-targeting therapy). Because of a relatively high risk of local relapse or distant metastasis, patients with hypoxic and/or "high-lactate" tumors should undergo close surveillance.
Extremely Low Frequency Magnetic Fields (ELF MF) has been considered as a "possible human carcinogen" by International Agency for Research on Cancer (IARC) while credible mechanisms of its carcinogenicity remain unknown. In this study, a proteomics approach was employed to investigate the changes of protein expression profile induced by ELF MF in human breast cancer cell line MCF7, in order to determine ELF MF-responsive proteins. MCF7 cells were exposed to 50 Hz, 0.4 mT ELF MF for 24 h and the changes of protein profile were examined using two dimensional electrophoresis. Up to 6 spots have been statistically significantly altered (their expression levels were changed at least 5 fold up or down) compared with sham-exposed group. 19 ones were only detected in exposure group while 19 ones were missing. Three proteins were identified by LC-IT Tandem MS as RNA binding protein regulatory subunit, Proteasome subunit beta type 7 precursor and Translationally Controlled Tumor Protein. Our finding showed that 50 Hz, 0.4 mT ELF MF alternates the protein profile of MCF7 cell and may affect many physiological functions of normal cell and 2-DE coupled with MS is a promising approach to elucidating cellular effects of electromagnetic fields.
The administration of chemotherapy either alone or in combination with radiotherapy is an important factor in reducing the mortality and morbidity of cancer patients. Resistance to both chemotherapy and radiotherapy represents a major obstacle to a successful outcome. The identification of novel biomarkers that can be used to predict treatment response would allow therapy to be tailored on an individual patient basis. Although the mechanisms are unclear, it is accepted that development of therapy resistance is a multifactorial phenomenon involving alterations in several cellular pathways. Proteome analysis methods are powerful tools for identifying factors associated with resistance to anticancer therapy because they facilitate the simultaneous analysis of whole proteomes. The current review describes the plethora of existing proteomic approaches and details the studies that have identified biomarkers that may be useful in the prediction of clinical response to anticancer therapy.
DNA polymerase eta (Poleta) is responsible for efficient translesion synthesis (TLS) past cis-syn cyclobutane thymine dimers (TT dimers), the major DNA lesions induced by UV irradiation. Loss of human Poleta leads to xeroderma pigmentosum variant syndrome, clearly indicating that Poleta plays a vital role in preventing skin cancer caused by exposure to sunlight. To further examine Poleta functions and the mechanisms that regulate this important protein, Poleta complexes were purified from HeLa cells over-expressing epitope-tagged Poleta, and polypeptides associated with Poleta, including Rad18, Rad6 and Rev1, were identified by a combination of mass spectrometry and Western blot analysis. The chromatin-bound fractions of cells subjected to UV irradiation, S phase synchronization, or S phase arrest were specifically enriched in such complexes. These results suggest that arrested replication forks strengthen interactions among Poleta, Rad18/Rad6 and Rev1, consistent with the requirement for effective TLS by Poleta at sites of DNA lesions.
We have examined in vitro cell response to mobile phone radiation (900 MHz GSM signal) using two variants of human endothelial cell line: EA.hy926 and EA.hy926v1. Gene expression changes were examined in three experiments using cDNA Expression Arrays and protein expression changes were examined in ten experiments using 2-DE and PDQuest software. Obtained results show that gene and protein expression were altered, in both examined cell lines, in response to one hour mobile phone radiation exposure at an average specific absorption rate of 2.8 W/kg. However, the same genes and proteins were differently affected by the exposure in each of the cell lines. This suggests that the cell response to mobile phone radiation might be genome- and proteome-dependent. Therefore, it is likely that different types of cells and from different species might respond differently to mobile phone radiation or might have different sensitivity to this weak stimulus. Our findings might also explain, at least in part, the origin of discrepancies in replication studies between different laboratories.
The applicability of high-throughput screening techniques of transcriptomics, proteomics and metabolomics in the search for biological and health effects of electromagnetic fields is a hotly debated issue. On the one hand, use of these modern screening technologies speeds up the discovery process and gives broader insight into biochemical events that follow the exposure to electromagnetic fields. On the other hand these modern screening technologies have the problem of reproducibility and variability between experiments and are prone to produce false positive results. These and other issues concerning the applicability of modern screening technologies were the topic of a workshop held at STUK in 2005 (30 October to 1 November) in Helsinki, Finland, and this Report summarizes the discussions at this workshop.