[Show abstract][Hide abstract] ABSTRACT: Although protein ubiquitination has been shown to regulate multiple processes during host response to Salmonella enterica serovar Typhimurium infection, specific functions of host deubiquitinating enzymes remain unknown in this bacterial infection. By using chemical proteomics approach, in which deubiquitinating enzymes were labeled by an active-site probe and analyzed by quantitative proteomics, we identified novel deubiquitinases in chicken macrophages based on their reactivity with the probe. Also, we detected down-regulation of UCH-L3, and USP4 as well as up-regulation of USP5 and UCH-L5 deubiquitinating enzymes in macrophages infected with Salmonella Typhimurium. We showed that decrease in either UCH-L5 activity, or in UCH-L5 protein amount in chicken and human macrophages infected or stimulated with LPS/nigericin, led to decreased IL-1β release. These data point towards a putative role of UCH-L5 in inflammasome regulation during Salmonella infection. Because inflammasome activation is important in innate resistance to these bacteria, one would expect that naturally occurring or therapeutically induced alteration in UCH-L5 activation would influence disease outcome and could represent a target for new therapeutic approaches.
PLoS ONE 08/2015; 10(8):e0135531. DOI:10.1371/journal.pone.0135531 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: A systems toxicology investigation comparing and integrating transcriptomic and proteomic results was conducted to develop holistic effects characterizations for the wildlife bird model, Northern bobwhite (Colinus virginianus) dosed with the explosives degradation product 2-amino-4,6-dinitrotoluene (2A-DNT). A subchronic 60d toxicology bioassay was leveraged where both sexes were dosed via daily gavage with 0, 3, 14, or 30 mg/kg-d 2A-DNT. Effects on global transcript expression were investigated in liver and kidney tissue using custom microarrays for C. virginianus in both sexes at all doses, while effects on proteome expression were investigated in liver for both sexes and kidney in males, at 30 mg/kg-d.
Results: As expected, transcript expression was not directly indicative of protein expression in response to 2A-DNT. However, a high degree of correspondence was observed among gene and protein expression when investigating higher-order functional responses including statistically enriched gene networks and canonical pathways, especially when connected to toxicological outcomes of 2A-DNT exposure. Analysis of networks statistically enriched for both transcripts and proteins demonstrated common responses including inhibition of programmed cell death and arrest of cell cycle in liver tissues at 2A-DNT doses that caused liver necrosis and death in females. Additionally, both transcript and protein expression in liver tissue was indicative of induced phase I and II xenobiotic metabolism potentially as a mechanism to detoxify and excrete 2A-DNT. Nuclear signaling assays, transcript expression and protein expression each implicated peroxisome proliferator-activated receptor (PPAR) nuclear signaling as a primary molecular target in the 2A-DNT exposure with significant downstream enrichment of PPAR-regulated pathways including lipid metabolic pathways and gluconeogenesis suggesting impaired bioenergetic potential.
Conclusion: Although the differential expression of transcripts and proteins was largely unique, the consensus of functional pathways and gene networks enriched among transcriptomic and proteomic datasets provided the identification of many critical metabolic functions underlying 2A-DNT toxicity as well as impaired PPAR signaling, a key molecular initiating event known to be affected in di- and trinitrotoluene exposures.
[Show abstract][Hide abstract] ABSTRACT: Whether your interests lie in scientific arenas, the corporate world, or in government, you have certainly heard the praises of big data: Big data will give you new insights, allow you to become more efficient, and/or will solve your problems. While big data has had some outstanding successes, many are now beginning to see that it is not the Silver Bullet that it has been touted to be. Here our main concern is the overall impact of big data; the current manifestation of big data is constructing a Maginot Line in science in the 21st century. Big data is not "lots of data" as a phenomena anymore; The big data paradigm is putting the spirit of the Maginot Line into lots of data. Big data overall is disconnecting researchers and science challenges. We propose No-Boundary Thinking (NBT), applying no-boundary thinking in problem defining to address science challenges.
[Show abstract][Hide abstract] ABSTRACT: Community annotation of biological entities with concepts from multiple
bio-ontologies has created large and growing repositories of ontology-based
annotation data with embedded implicit relationships among orthogonal
ontologies. Development of efficient data mining methods and metrics to mine
and assess the quality of the mined relationships has not kept pace with the
growth of annotation data. In this study, we present a data mining method that
uses ontology-guided generalization to discover relationships across ontologies
along with a new interestingness metric based on information theory. We apply
our data mining algorithm and interestingness measures to gene expression
datasets from the Gene Expression Database at the Mouse Genomics Institute as a
preliminary proof of concept to mine relationships between developmental stages
in the mouse anatomy ontology and Gene Ontology concepts (biological process,
molecular function and cellular component). In addition, we present a
comparison of our interestingness metric to four existing metrics.
Ontology-based annotation datasets provide a valuable resource for discovery of
relationships across ontologies. The use of efficient data mining methods and
appropriate interestingness metrics enables the identification of high quality
[Show abstract][Hide abstract] ABSTRACT: We describe the organization of a nascent international effort, the Functional Annotation of Animal Genomes (FAANG) project, whose aim is to produce comprehensive maps of functional elements in the genomes of domesticated animal species.
[Show abstract][Hide abstract] ABSTRACT: Copper (II) oxide (CuO) nanoparticles (NP) are widely used in industry and medicine. In our study we evaluated the response of BEAS-2B human lung cells to CuO NP, using Stable isotope labeling by amino acids in cell culture (SILAC)-based proteomics and phosphoproteomics. Pathway modeling of the protein differential expression showed that CuO NP affect proteins relevant in cellular function and maintenance, protein synthesis, cell death and survival, cell cycle and cell morphology. Some of the signaling pathways represented by BEAS-2B proteins responsive to the NP included mTOR signaling, protein ubiquitination pathway, actin cytoskeleton signaling and epithelial adherens junction signaling. Follow-up experiments showed that CuO NP altered actin cytoskeleton, protein phosphorylation and protein ubiquitination level.
PLoS ONE 12/2014; 9(12):e114390. DOI:10.1371/journal.pone.0114390 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Listeria monocytogenes is a gram-positive, foodborne pathogen responsible for approximately 28% of all food-related deaths each year in the United States. L. monocytogenes infections are linked to the consumption of minimally processed ready-to-eat (RTE) products such as cheese, deli meats, and cold-smoked finfish products. L. monocytogenes is resistant to stresses commonly encountered in the food-processing environment, including low pH, high salinity, oxygen content, and various temperatures. The purpose of this study was to determine if cells cultured at low temperatures would result in cross-protective effects against osmotic stress. We found that cells exposed to refrigerated temperatures prior to a mild salt stress treatment had increased survival in NaCl concentrations of 3%. Additionally, the longer the cells were pre-exposed to cold temperatures, the greater the increase in survival in 3% NaCl. A proteomics analysis was performed in triplicate in order to elucidate mechanisms involved in cold-stress induced cross-protection against osmotic stress. Proteins involved in maintenance of the cell wall and cellular processes, such as penicillin binding proteins and osmolyte transporters, and processes involving amino acid metabolism, such as osmolyte synthesis, transport and lipid biosynthesis, had the greatest increase in expression when cells were exposed to cold temperatures prior to salt. By gaining a better understanding of how this pathogen adapts physiologically to various environmental conditions, improvements can be made in detection and mitigation strategies.
Journal of Proteome Research 02/2014; 13(4). DOI:10.1021/pr401004a · 5.00 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Lysine acetylation is a reversible, dynamic protein modification regulated by lysine acetyltransferases and deacetylases. Recent advances in high-throughput proteomics have greatly contributed to the success of global analysis of lysine acetylation. A large number of proteins of diverse biological functions have been shown to be acetylated in several reports in human cells, E.coli, and dicot plants. However, the extent of lysine acetylation in non-histone proteins remains largely unknown in monocots, particularly in the cereal crops. Here we report the mass spectrometric examination of lysine acetylation in rice (Oryza sativa). We identified 60 lysine acetylated sites on 44 proteins of diverse biological functions. Immunoblot studies further validated the presence of a large number of acetylated non-histone proteins. Examination of the amino acid composition revealed substantial amino acid bias around the acetylation sites and the amino acid preference is conserved among different organisms. Gene ontology analysis demonstrates that lysine acetylation occurs in diverse cytoplasmic, chloroplast and mitochondrial proteins in addition to the histone modifications. Our results suggest that lysine acetylation might constitute a regulatory mechanism for many proteins, including both histones and non-histone proteins of diverse biological functions.
PLoS ONE 02/2014; 9(2):e89283. DOI:10.1371/journal.pone.0089283 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Currently there are definitions from many agencies and research societies defining "bioinformatics" as deriving knowledge from computational analysis of large volumes of biological and biomedical data. Should this be the bioinformatics research focus? We will discuss this issue in this review article. We would like to promote the idea of supporting human-infrastructure (HI) with no-boundary thinking (NT) in bioinformatics (HINT).
[Show abstract][Hide abstract] ABSTRACT: Iron is a critical cofactor for many enzymes and is known to regulate gene expression in many bacterial pathogens. Streptococcus pneumoniae normally inhabits the upper respiratory mucosa but can also invade and replicate in lungs and blood. These anatomic sites vary considerably in both the quantity and form of available iron. The genome of serotype 4 pneumococcal strain TIGR4 encodes a putative iron-dependent transcriptional regulator (IDTR). A mutant deleted at idtr (Δidtr) exhibited growth kinetics similar to parent strain TIGR4 in vitro and in mouse blood for up to 48 hours following infection. However, Δidtr was significantly attenuated in a murine model of sepsis. IDTR down-regulates the expression of ten characterized and putative virulence genes in nasopharyngeal colonization and pneumonia. The host cytokine response was significantly suppressed in sepsis with Δidtr. Since an exaggerated inflammatory response is associated with a poor prognosis in sepsis, the decreased inflammatory response could explain the increased survival with Δidtr. Our results suggest that IDTR, which is dispensable for pneumococcal growth in vitro, is associated with regulation of pneumococcal virulence in specific host environments. Additionally, IDTR ultimately modulates the host cytokine response and systemic inflammation that contributes to morbidity and mortality of invasive pneumococcal disease.
PLoS ONE 10/2013; 8(2):e55157. DOI:10.1371/journal.pone.0055157 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Mapping RNA sequences to a reference genome often results in high percentages of short reads assigned to multiple locations within the genome. These mappings are known as "ambiguous mappings" and are often discarded by sequence mapping tools and pipelines. The number of ambiguous mappings within these data sets can sometimes be significantly large, occupying in certain cases as much as one third of the mapped sequences. We are developing task specific computer programs that utilize statistical methods as an alternative solution for the problem. This statistical approach is based upon identifying significantly expressed genomic locations. We handle ambiguous data through a multi-step process starting with a standard short read alignment tool to identify all the possible mappings within the genome for each sequence read. Custom programs are then used to identify expressed genomic locations by statistical methods. That is, we compare gene expression in the regions of interest with a number of randomly-selected genomic locations. Using these comparisons will help us in establishing a value at which a gene is significantly expressed and determine the locations that are most likely to be the best mapping for each ambiguous sequence.
Proceedings of the International Conference on Bioinformatics, Computational Biology and Biomedical Informatics; 09/2013
[Show abstract][Hide abstract] ABSTRACT: Sodium methyldithiocarbamate (SMD) is one of the most abundantly used conventional pesticides in the U.S. At dosages relevant to occupational exposure, it causes major effects on the immune system in mice, including a decreased resistance to sepsis. This lab has identified some of the mechanisms of action of this compound and some of the immunological parameters affected, but the global effects have not previously been assessed. The purpose of the present study was to conduct transcriptomic analysis of the effects of SMD on lipopolysaccharide-induced expression of mediators important in innate immunity and inflammation. The results revealed broad effects on expression of transcription factors in both branches of TLR4 signaling (MyD88 and TRIF). However, TLR3 and interferon signaling pathways were decreased to a greater extent, and assessment of the effects of SMD on polyinosinic polycytidylic acid-induced cytokine and chemokine production revealed that these responses mediated by TLR3 were indeed sensitive to the effects of SMD, with inhibition occurring at lower dosages than required to inhibit responses to other immunological stimuli tested in our previous studies. In the downstream signaling pathways of these TLRs, functional analysis also revealed that NF-κB activation was inhibited by SMD, as indicated by gene expression analysis and a reporter construct in mice. A previously unreported effect on luteinizing hormone and follicle stimulating hormone pathways was also observed.
[Show abstract][Hide abstract] ABSTRACT: As the use of laparoscopic surgery has become more widespread in recent years, the need has increased for minimally-invasive surgical devices that effectively cut and coagulate tissue with reduced tissue trauma. Although electrosurgery (ES) has been used for many generations, newly-developed ultrasonic devices (HARMONIC® Blade, HB) have been shown at a macroscopic level to offer better coagulation with less thermally-induced tissue damage. We sought to understand the differences between ES and HB at a microscopic level by comparing mRNA transcript and protein responses at the 3-day timepoint to incisions made by the devices in subcutaneous fat tissue in a porcine model. Samples were also assessed via histological examination. ES-incised tissue had more than twice as many differentially-expressed genes as HB (2,548 vs 1,264 respectively), and more differentially-expressed proteins (508 vs 432) compared to control (untreated) tissue. Evaluation of molecular functions using Gene Ontology showed that gene expression changes for the energized devices reflected the start of wound healing, including immune response and inflammation, while protein expression showed a slightly earlier stage, with some remnants of hemostasis. For both transcripts and proteins, ES exhibited a greater response than HB, especially in inflammatory mediators. These findings were in qualitative agreement with histological results. This study has shown that transcriptomics and proteomics can monitor the wound healing response following surgery and can differentiate between surgical devices. In agreement with clinical observations, electrosurgery was shown to incur a greater inflammatory immune response than an ultrasonic device during initial iatrogenic wound healing.
PLoS ONE 09/2013; 8(9):e73032. DOI:10.1371/journal.pone.0073032 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Deubiquitinating enzymes (DUBs) remove ubiquitin and ubiquitin-like modifications from proteins and they have been known to contribute to processes relevant in microbial infection, such as immune responses pathways. Numerous viral and bacterial DUBs have been identified, and activities of several host DUBs are known to be modulated during the infection process, either by a pathogen or by a host. Recently there have been attempts to take advantage of this feature and design therapeutic inhibitors of DUBs that can be used to limit the spread of infection. This review is focused on exploring the potential of DUBs in the treatment of infectious diseases.
Current pharmaceutical design 11/2012; 19(18). DOI:10.2174/1381612811319180008 · 3.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
The events leading to sepsis start with an invasive infection of a primary organ of the body followed by an overwhelming systemic response. Intra-abdominal infections are the second most common cause of sepsis. Peritoneal fluid is the primary site of infection in these cases. A microarray-based approach was used to study the temporal changes in cells from the peritoneal cavity of septic mice and to identify potential biomarkers and therapeutic targets for this subset of sepsis patients.
We conducted microarray analysis of the peritoneal cells of mice infected with a non-pathogenic strain of Escherichia coli. Differentially expressed genes were identified at two early (1 h, 2 h) and one late time point (18 h). A multiplexed bead array analysis was used to confirm protein expression for several cytokines which showed differential expression at different time points based on the microarray data. Gene Ontology based hypothesis testing identified a positive bias of differentially expressed genes associated with cellular development and cell death at 2 h and 18 h respectively. Most differentially expressed genes common to all 3 time points had an immune response related function, consistent with the observation that a few bacteria are still present at 18 h.
Transcriptional regulators like PLAGL2, EBF1, TCF7, KLF10 and SBNO2, previously not described in sepsis, are differentially expressed at early and late time points. Expression pattern for key biomarkers in this study is similar to that reported in human sepsis, indicating the suitability of this model for future studies of sepsis, and the observed differences in gene expression suggest species differences or differences in the response of blood leukocytes and peritoneal leukocytes.
[Show abstract][Hide abstract] ABSTRACT: Listeria monocytogenes is a food-borne pathogen responsible for the disease listeriosis. The infectious process depends upon survival in high bile salt conditions encountered throughout the gastrointestinal tract, including the gallbladder. However, it is not clear how bile salt resistance mechanisms are induced, especially under physiologically relevant conditions. This study sought to determine how the L. monocytogenes strains EGDe (serovar 1/2a), F2365 (serovar 4a), and HCC23 (serovar 4b) respond to bile salts under anaerobic conditions. Changes in the expressed proteome were analyzed using multidimensional protein identification technology coupled with electrospray ionization tandem mass spectrometry. In general, the response to bile salts among the strains tested involved significant alterations in the presence of cell wall associated proteins, DNA repair proteins, protein folding chaperones and oxidative stress response proteins. Strain viability correlated with an initial osmotic stress response, yet continued survival for EGDe and F2365 involved different mechanisms. Specifically, proteins associated with biofilm formation in EGDe and transmembrane efflux pumps in F2365 were expressed, suggesting variations exist in how virulent strains respond and adapt to high bile salt environments. These results indicate that the bile salt response varies among these serovars and that further research is needed to elucidate how the response to bile salts correlates with colonization potential in vivo.
Journal of Medical Microbiology 09/2012; 62(Pt_1). DOI:10.1099/jmm.0.049742-0 · 2.27 Impact Factor