[Show abstract][Hide abstract]ABSTRACT: In adipose tissue, agonists of the β3-adrenergic receptor (ADRB3) regulate lipolysis, lipid oxidation, and thermogenesis. The deficiency in the thermogenesis induced by neuroblast differentiation-associated protein AHNAK in white adipose tissue (WAT) of mice fed a high-fat diet suggests that AHNAK may stimulate energy expenditure via development of beige fat. Here, we report that AHNAK deficiency promoted browning and thermogenic gene expression in WAT but not in brown adipose tissue of mice stimulated with the ADRB3 agonist CL-316243. Consistent with the increased thermogenesis, Ahnak−/− mice exhibited an increase in energy expenditure, accompanied by elevated mitochondrial biogenesis in WAT depots in response to CL-316243. Additionally, AHNAK-deficient WAT contained more eosinophils and higher levels of type 2 cytokines (IL-4/IL-13) to promote browning of WAT in response to CL-316243. This was associated with enhanced sympathetic tone in the WAT via upregulation of adrb3 and tyrosine hydroxylase (TH) in response to β-adrenergic activation. CL-316243 activated PKA signalling and enhanced lipolysis, as evidenced by increased phosphorylation of hormone-sensitive lipase and release of free glycerol in Ahnak−/− mice compared to wild-type mice. Overall, these findings suggest an important role of AHNAK in the regulation of thermogenesis and lipolysis in WAT via β-adrenergic signalling.
[Show abstract][Hide abstract]ABSTRACT: Korean pine nut oil (PNO) has been reported to influence weight gain and lipid metabolism. We examined whether PNO replacement in a high-fat diet (HFD) can ameliorate HFD-induced hepatic steatosis. Five-week-old male C57BL mice were fed control diets containing 10% of the energy from fat from PNO or soybean oil (SBO) (PC, SC) or HFDs with 45% of the energy from fat, with 10% from PNO or SBO and 35% from lard (PHFD, SHFD), for 12 weeks. Body weight gain and amount of white adipose tissue were lower in PHFD (10% and 18% lower, respectively) compared with SHFD. Hepatic triacylglycerol (TG) level was significantly lower in PHFD than the SHFD (26% lower). PNO consumption upregulated hepatic ACADL mRNA levels. The hepatic PPARG mRNA level was lower in the PC than in the SC. Expression of the sirtuin (SIRT) 3 protein in white adipose tissue was down-regulated in the SHFD and restored in the PHFD to the level in the lean control mice. SIRT 3 was reported to be upregulated under conditions of caloric restriction (CR) and plays a role in regulating mitochondrial function. PNO consumption resulted in lower body fat and hepatic TG accumulation in HFD-induced obesity, which seemed to be associated with the CR-mimetic response.
[Show abstract][Hide abstract]ABSTRACT: Graphene, a two dimensional engineered nanomaterial, is now being used in many applications, such as electronics, biological engineering, filtration, lightweight and strong nanocomposite materials, and energy storage. However, there is a lack of information on the potential health effects of graphene in humans based on inhalation, the primary ENM exposure pathway in workplaces. Thus, an inhalation toxicology study of graphene was conducted using a nose-only inhalation system for 28 days (6 hrs/day and 5 days/week) with male Sprague-Dawley (SD) rats that were then allowed to recover for 1, 28, and 90 days post-exposure period. Animals were separated into 4 groups (control, low, moderate, and high) with 15 male rats (5 rats per time point) in each group. The measured mass concentrations for the low, moderate, and high exposure groups were 0.12, 0.47, and 1.88 mg/m(3), respectively, very close to target concentrations of 0.125, 0.5, and 2 mg/m(3). Airborne graphene exposure was monitored using several real-time instrumentation over 10 nm to 20µm for size distribution and number concentration. The total and respirable elemental carbon (EC) concentrations were also measured using filter sampling. Graphene in the air and biological media was traced using transmission electron microscopy. In addition to mortality and clinical observations, the body weights and food consumption were recorded weekly. At the end of the study, the rats were subjected to a full necropsy, blood samples were collected for blood biochemical tests, and the organ weights were measured. No dose-dependent effects were recorded for the body weights, organ weights, BAL fluid inflammatory markers, and blood biochemical parameters at 1-day post-exposure and 28-days post-exposure. The inhaled graphenes were mostly ingested by macrophages. No distinct lung pathology was observed at the 1-, 28- and 90-days post-exposure. The inhaled graphene was translocated to lung lymph nodes. The results of this 28-day graphene inhalation study suggest low toxicity and a NOAEL of no less than 1.88 mg/m(3).
[Show abstract][Hide abstract]ABSTRACT: Objective
Recent evidence has suggested that AHNAK expression is altered in obesity, although its role in adipose tissue development remains unclear. The objective of this study was to determine the molecular mechanism by which Ahnak influences adipogenesis and glucose homeostasis.
We investigated the in vitro role of AHNAK in adipogenesis using adipose-derived mesenchymal stem cells (ADSCs) and C3H10T1/2 cells. AHNAK-KO male mice were fed a high-fat diet (HFD; 60% calories from fat) and examined for glucose and insulin tolerances, for body fat compositions, and by hyperinsulinemic-euglycemic clamping. Energy expenditures were assessed using metabolic cages and by measuring the expression levels of genes involved in thermogenesis in white or brown adipose tissues.
Adipogenesis in ADSCs was impaired in AHNAK-KO mice. The loss of AHNAK led to decreased BMP4/SMAD1 signaling, resulting in the downregulation of key regulators of adipocyte differentiation (P<0.05). AHNAK directly interacted with SMAD1 on the Pparγ2 promoter. Concomitantly, HFD-fed AHNAK-KO mice displayed reduced hepatosteatosis and improved metabolic profiles, including improved glucose tolerance (P<0.001), enhanced insulin sensitivity (P<0.001), and increased energy expenditure (P<0.05), without undergoing alterations in food intake and physical activity.
AHNAK plays a crucial role in body fat accumulation by regulating adipose tissue development via interaction with the SMAD1 protein and can be involved in metabolic homeostasis.
[Show abstract][Hide abstract]ABSTRACT: Graphene is receiving increased attention due to its potential widespread applications in future. However, the health effects of graphene have not yet been well studied. Therefore, this study examined the pulmonary effects of graphene oxide using male Sprague-Dawley rats and a single 6-hour nose-only inhalation technique. Following the exposure, the rats were allowed to recover for 1 day, 7 days, or 14 days. A total of three groups were compared: control (fresh air), low concentration (
mg/m3), and high concentration (
mg/m3). The exposure to graphene oxide did not induce significant changes in the body weights, organ weights, and food consumption during the 14 days of recovery time. The microalbumin and lactate dehydrogenase levels in the bronchoalveolar lavage (BAL) fluid were not significantly changed due to the exposure. Similarly, total cell count, macrophages, polymorphonuclear leukocytes, and lymphocytes were not significantly altered in the BAL fluid. Plus, the histopathological examination of the rat lungs only showed an uptake of graphene oxide in the alveolar macrophages of the high-concentration group. Therefore, these results demonstrate that the single inhalation exposure to graphene oxide induce minimal toxic responses in rat lungs at the concentrations and time points used in the present study.
[Show abstract][Hide abstract]ABSTRACT: Supplement 1: shows food intake of rats.
Supplement 2: shows body weight of rats before and after the exposure.
Supplement 3-5: shows gross findings of rats during the recovery period.
Supplement 6-11: shows absolute and relative organ weight of rats during the recovery period.
[Show abstract][Hide abstract]ABSTRACT: Hes6 is a member of the hairy-enhancer of split homolog (Hes) family of transcription factors and interacts with other Hes family genes. During development, Hes genes are expressed in neural stem cells and progenitor cells. However, the role of Hes6 in adult hippocampal neurogenesis remains unclear. We therefore investigated the effects of Hes6 on adult hippocampal neurogenesis, by comparing Hes6 knockout and wild-type mice. To this end, we immunostained for markers of neural stem cells and progenitor cells (nestin), proliferating cells (Ki67), post-mitotic neuroblasts and immature neurons (doublecortin, DCX), mature neuronal cells (NeuN), and astrocyte (S100β). We also injected 5-bromo-2'-deoxyuridine (BrdU) to trace the fate of mitotic cells. Nestin- and Ki67-positive proliferating cells did now show any significant differences between wild and knockout groups. Hes6 knockout negatively affects neuroblast differentiation based on DCX immunohistochemistry. On the contrary, the ratio of the BrdU and NeuN double-positive cells did not show any significance, even though it was slightly higher in the knockout group. These results suggest that Hes6 is involved in the regulation of neuroblast differentiation during adult neurogenesis, but does not influence integration into mature neurons.
Article · Jun 2015 · Cellular and Molecular Neurobiology
[Show abstract][Hide abstract]ABSTRACT: Expression of the giant protein Ahnak has been reported in endothelial cells of the blood brain barrier and in non-neuronal cells including myelinating Schwann cells. However, the function of Ahnak in neurogenesis has not been determined. In the present study, we report for the first time the effects of Ahnak on adult hippocampal neurogenesis using Ahnak(-/-) mice. Proliferating cells were labeled with BrdU for a 30-day period before sacrifice. In Ahnak(-/-) mice, the incorporation of BrdU with NeuN (Neuronal Nuclei) increased significantly in both the subgranular zone and the granular cell layer of the dentate gyrus. In addition, Ahnak(-/-) mice displayed increased Doublecortin-immunoreactive neuroblasts compared with wild-type controls. Taken together, Ahnak deficiency plays a positive role for hippocampal neurogenesis in adult mice because proliferating cells were increased in Ahnak(-/-) mice and advanced to mature neurons. These findings suggest that Ahnak might be involved in modulating the differentiation of newly generated cells into neuronal or non-neuronal cells.
[Show abstract][Hide abstract]ABSTRACT: In this paper, we report cost-effective and simply achievable extended release formulations of ropinirole hydrochloride (RP) by forming coating layers with well-known polymers. The upper and bottom coating layers were composed of one of gel-forming polymers such as PEG, PVP, and HPMC, respectively, designed to control drug release profile. The core tablet is prepared by wet granulation method with RP and HPMC (150 K). The multi-layer tablet showed much slower release behavior than that of commercially available once-diary formulation (REQUIP PD®, 4 mg, GSK) in the pH 1.2 conditions regardless of coated polymers, and zero order release profiles of RP were observed in the pH 6.8 dissolution conditions, which is nearly identical to dissolution profile of REQUIP PD®. These results indicate that the formation of multi-layer tablet is one of promising strategies for extended release formulation of RP, in addition, better bioavailability is expected due to minimized dissolution profiles of RP in low pH.
Article · Apr 2015 · Journal of Pharmaceutical Investigation
[Show abstract][Hide abstract]ABSTRACT: A novel Helicobacter species was identified from the gastrointestinal tract of Korean striped field mice (Apodemus agrarius). Biochemical testing, ultrastructure characterization, and 16S rRNA gene sequence analysis suggested that this bacterium represents a distinct taxon. The bacterium was positive for urease activity, susceptible to cephalothin and nalidixic acid, and weakly positive for oxidase and catalase activity. Electron microscopy revealed that the bacterium has spirally curved rod morphology with singular bipolar nonsheathed flagella. Genotypically, the isolated bacterial strains (YMRC 000215, YMRC 000216, and YMRC 000419) were most closely related to a reference strain of Helicobacter mesocricetorum (97.25%, 97.32%, and 97.03% 16S rRNA sequence similarities, respectively). The 16S rRNA sequences of these strains were deposited into GenBank under accession numbers AF284754, AY009129, and AY009130, respectively. We propose the name Helicobacter apodemus for this novel species.
Full-text Article · Mar 2015 · Journal of veterinary science (Suwŏn-si, Korea)
[Show abstract][Hide abstract]ABSTRACT: Abstract Graphene has recently been attracting increasing attention due to its unique electronic and chemical properties and many potential applications in such fields as semiconductors, energy storage, flexible electronics, biosensors and medical imaging. However, the toxicity of graphene in the case of human exposure has not yet been clarified. Thus, a 5-day repeated inhalation toxicity study of graphene was conducted using a nose-only inhalation system for male Sprague-Dawley rats. A total of three groups (20 rats per group) were compared: (1) control (ambient air), (2) low concentration (0.68 ± 0.14 mg/m(3) graphene) and (3) high concentration (3.86 ± 0.94 mg/m(3) graphene). The rats were exposed to graphene for 6 h/day for 5 days, followed by recovery for 1, 3, 7 or 28 days. The bioaccumulation and macrophage ingestion of the graphene were evaluated in the rat lungs. The exposure to graphene did not change the body weights or organ weights of the rats after the 5-day exposure and during the recovery period. No statistically significant difference was observed in the levels of lactate dehydrogenase, protein and albumin between the exposed and control groups. However, graphene ingestion by alveolar macrophages was observed in the exposed groups. Therefore, these results suggest that the 5-day repeated exposure to graphene only had a minimal toxic effect at the concentrations and time points used in this study.
[Show abstract][Hide abstract]ABSTRACT: Coal workers' pneumoconiosis (CWP) is characterized as a chronic inflammation of the lung associated with activation of macrophages and endothelial cells in the lung. The aim of the present study was to compare the levels of serum interleukin-8 (IL-8), macrophage inflammatory protein-1α (MIP-α), and intercellular adhesion molecule-1 (ICAM-1) as biomarkers for progressive massive fibrosis (PMF) in 106 subjects (27 non-CWP and 79 CWP patients). The levels of serum IL-8 (P<0.001) and ICAM-1 (P=0.001) of subjects with PMF were higher than those of non-CWP subjects. The IL-8 levels of PMF subjects were also higher than those of simple CWP subjects (P=0.003). Among the subjects without PMF, IL-8 levels in the subjects with International Labour Organization (ILO) category II or III were higher than those in the subjects with ILO category 0 (P=0.006) and with category I (P=0.026). These results suggest that high serum levels of IL-8 and ICAM-1, which are important as neutrophil attractants and adhesion molecules, are associated with PMF.
Full-text Article · Feb 2015 · Journal of Korean Medical Science
[Show abstract][Hide abstract]ABSTRACT: While many in vivo and in vitro toxicology studies of multi-walled carbon nanotubes (MWCNTs) have already indicated that exposure to MWCNTs can potentially induce health effects in humans, the actual health effects of MWCNTs among exposed workers are not yet known. Moreover, the levels of exposure and internal doses of MWCNTs are becoming more and more important for estimating the health effects resulting from exposure to MWCNTs. However, information on biomonitoring and exposure to MWCNTs remains limited. Therefore, the authors conducted a health surveillance study in a workplace that manufactures MWCNTs, including assessment of the personal and area exposure levels to MWCNTs, a walk-through evaluation of the manufacturing process, and collection of blood and exhaled breath condensates (EBCs) from the MWCNT manufacturing and office workers. In addition, a pulmonary function test was also conducted on the MWCNT manufacturing workers (9) and office workers (4). The worker exposure to elemental carbon was found to be 6.2–9.3 μg/m3 in the personal samplings and 5.5–7.3 μg/m3 in the area samplings. Notwithstanding, the workers exhibited a normal range of hematology and blood biochemistry values and normal lung function parameters. When analyzing the EBCs, the malondialdehyde (MDA), 4-hydroxy-2-hexenal (4-HHE) and n-hexanal levels in the MWCNT manufacturing workers were significantly higher than those in the office workers. The MDA and n-hexanal levels were also significantly correlated with the blood molybdenum concentration, suggesting MDA, n-hexanal and molybdenum as useful biomarkers of MWCNT exposure.
[Show abstract][Hide abstract]ABSTRACT: Gold nanoparticles are known to be distributed to many tissues following their oral, inhalation, or intravenous exposure. Information on the biodistribution and clearance of gold nanoparticles from these tissues is, therefore, important to understand their behavior in vivo. To study the effect of size on the biodistribution of gold nanoparticles, Sprague-Dawley rats were exposed by inhalation to small gold nanoparticles (13 nm in diameter on average) at an exposure concentration of 12.8 ± 2.42 µg/m(3), and to large gold nanoparticles (105 nm in diameter on average) at an exposure concentration of 13.7 ± 1.32 µg/m(3). The experimental animals were exposed to the gold nanoparticles and the control animals to fresh air for 5 days (6 h/day), followed by a recovery period of 1, 3, and 28 days in fresh air. None of the exposed animals exhibited any toxic response to the gold nanoparticles. Despite the difference in size, both small and large gold nanoparticles deposited mainly in rat lungs. Their biodistribution from the lungs to secondary target organs was significantly higher with the small compared to the large gold nanoparticles. While the large gold nanoparticles were only found in the blood, the small gold nanoparticles were detected in the liver, spleen, brain, testes, and blood. In addition, the elimination half-life of the small gold nanoparticles from the lungs was significantly shorter than that of the large gold nanoparticles. The present data may, therefore, suggest that the smaller gold nanoparticles are able to translocate from the lungs, the primary exposure organ to extrapulmonary organs at a faster rate than the larger gold nanoparticles and thus confirming previous observations reported in the literature.
Full-text Article · Jun 2014 · Archive für Toxikologie
[Show abstract][Hide abstract]ABSTRACT: Background
Chronic obstructive pulmonary disease (COPD) is an important cause of occupational mortality in miners exposed to coal mine dust. Although the inflammatory mediators involved in COPD have not been defined, many studies have shown that inflammatory mediators such as reactive oxygen and nitrogen species are involved in orchestrating the complex inflammatory process in COPD.
To investigate the relevance of exhaled biomarkers of oxidative and nitrosative stress in participants with COPD, we determined the levels of hydrogen peroxide, malondialdehyde (MDA), and 3-nitrotyrosine (3-NT) in exhaled breath condensate (EBC) in 90 retired elderly coal miners (53 non-COPD and 37 COPD participants).
Mean levels of MDA (4.64 nM vs. 6.46 nM, p = 0.005) and 3-NT (3.51 nM vs. 5.50 nM, p = 0.039) in EBC were significantly higher in participants with COPD. The median level of MDA did show statistical difference among the COPD severities (p = 0.017), and the area under the receiver operating characteristic curve for MDA (0.67) for the diagnostic discrimination of COPD indicated the biomarker. The optimal cutoff values were 5.34 nM (64.9% sensitivity and 64.2% specificity) and 5.58 nM (62.2% sensitivity and 62.3% specificity) for MDA and 3-NT, respectively. The results suggest that high levels of MDA and 3-NT in EBC are associated with COPD in retired elderly miners.
These results showed that the elevated levels of EBC MDA and EBC 3-NT in individuals with COPD are biomarkers of oxidative or nitrosative stress.
Full-text Article · Jun 2014 · Safety and Health at Work
[Show abstract][Hide abstract]ABSTRACT: Pig pancreas may be a therapeutic resource for human diabetic patients. However, this potential is hindered by a lack of knowledge of the molecular events of pig pancreas development. In this study, the embryonic day 60, neonate and 6-month protein profiles of pig pancreas were ascertained at using two-dimensional gel electrophoresis and matrix assisted laser desorption/ionization-time of flight mass spectrometry. Twenty four proteins were differentially expressed during pig pancreas development. Among them, 12 spots increased and 7 spots decreased according to development. The expression of 5 protein were highest at birth. Expression of digestive enzymes including trypsin, pancreatic triacylglycerol lipase and pancreatic alpha-amylase was elevated in adults, whereas chymotrypsins were highly expressed in neonates. Proteins that were abundantly expressed during gestation were alpha-1-antitrypsin, alpha-fetoprotein and transferrins. Taken together, we found out that several proteins were significantly up- or down- regulated from pig pancreas based on developmental stage. This study will provide basis for understanding development of pig pancreas.
[Show abstract][Hide abstract]ABSTRACT: Abstract Despite their useful physico-chemical properties, carbon nanotubes (CNTs) continue to cause concern over occupational and human health due to their structural similarity to asbestos. Thus, to evaluate the toxic and genotoxic effect of multi-wall carbon nanotubes (MWCNTs) on lung cells in vivo, eight-week-old rats were divided into four groups (each group = 25 animals), a fresh air control (0 mg/m(3)), low (0.17 mg/m(3)), middle (0.49 mg/m(3)), and high (0.96 mg/m(3)) dose group, and exposed to MWCNTs via nose-only inhalation 6 h per day, 5 days per week for 28 days. The count median length and geometric standard deviation for the MWCNTs determined by TEM were 330.18 and 1.72 nm, respectively, and the MWCNT diameters ranged from 10 to 15 nm. Lung cells were isolated from five male and five female rats in each group on day 0, day 28 (only from males) and day 90 following the 28-day exposure. The total number of animals used was 15 male and 10 female rats for each concentration group. To determine the genotoxicity of the MWCNTs, a single cell gel electrophoresis assay (Comet assay) was conducted on the rat lung cells. As a result of the exposure, the olive tail moments were found to be significantly higher (p < 0.05) in the male and female rats from all the exposed groups when compared with the fresh air control. In addition, the high-dose exposed male and middle and high-dose exposed female rats retained DNA damage, even 90 days post-exposure (p < 0.05). To investigate the mode of genotoxicity, the intracellular reactive oxygen species (ROS) levels and inflammatory cytokine levels (TNF-α, TGF- β, IL-1, IL-2, IL-4, IL-5, IL-10, IL-12 and IFN-γ) were also measured. For the male rats, the H2O2 levels were significantly higher in the middle (0 days post-exposure) and high- (0 days and 28 days post-exposure) dose groups (p < 0.05). Conversely, the female rats showed no changes in the H2O2 levels. The inflammatory cytokine levels in the bronchoalveolar lavage (BAL) fluid did not show any statistically significant difference. Interestingly, the short-length MWCNTs deposited in the lung cells were persistent at 90 days post-exposure. Thus, exposing lung cells to MWCNTs with a short tube length may induce genotoxicity.
Full-text Article · Mar 2014 · Inhalation Toxicology
[Show abstract][Hide abstract]ABSTRACT: Various cytokines activated by the inhalation of coal dust may mediate inflammation and lead to tissue damage. Objective of this study was to examine the relationships between coal workers' pneumoconiosis (CWP) progression over a 3 yr period and the serum levels of cytokines in 85 retired coal workers. To investigate the relevance of serum cytokines in CWP, serum levels of interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-alpha), transforming growth factor-beta1 (TGF-beta 1), and monocyte chemotactic protein-1 (MCP-1) as progressive CWP biomarkers were studied in relation to the progression of pneumoconiosis over a 3 yr period in 85 patients with CWP. CWP progression was evaluated through paired comparisons of chest radiographs. Median levels of TGF-beta 1 and MCP-1 were significantly higher in subjects with progressive CWP than in those without CWP progression. The area under the ROC curve for TGF-beta 1 (0.693) and MCP-1 (0.653) indicated that these cytokines could serve as biomarkers for the progression of CWP. Serum TGF-beta 1 levels were related to the progression of CWP (beta=0.247, p=0.016). The results suggest that high serum levels of TGF-beta 1 and MCP-1 are associated with the progression of CWP.
[Show abstract][Hide abstract]ABSTRACT: Various cytokines activated by the inhalation of coal dust may mediate inflammation and lead to tissue damage. Objective of this study was to examine the relationships between coal workers' pneumoconiosis (CWP) progression over a 3-yr period and the serum levels of cytokines in 85 retired coal workers. To investigate the relevance of serum cytokines in CWP, serum levels of interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta1 (TGF-β1), and monocyte chemotactic protein-1 (MCP-1) as progressive CWP biomarkers were studied in relation to the progression of pneumoconiosis over a 3-yr period in 85 patients with CWP. CWP progression was evaluated through paired comparisons of chest radiographs. Median levels of TGF-β1 and MCP-1 were significantly higher in subjects with progressive CWP than in those without CWP progression. The area under the ROC curve for TGF-β1 (0.693) and MCP-1 (0.653) indicated that these cytokines could serve as biomarkers for the progression of CWP. Serum TGF-β1 levels were related to the progression of CWP (β=0.247, p=0.016). The results suggest that high serum levels of TGF-β1 and MCP-1 are associated with the progression of CWP.