Identification of Muscle Strength-Related Gut Microbes through Human Fecal Microbiome Transplantation.

The gut microbiome is well known for its influence on human physiology and aging. Therefore, we speculate that the gut microbiome may affect muscle strength in the same way as the host's own genes. To demonstrate candidates for gut microbes affecting muscle strength, we remodeled the original gut microbiome of mice into human intestinal microbiome through fecal microbiome transplantation (FMT), using human feces and compared the changes in muscle strength in the same mice before and three months after FMT. After comparing before and after FMT, the mice were divided into three groups based on the observed changes in muscle strength: positive, none, and negative changes in muscle strength. As a result of analyzing the α-diversity, ß-diversity, and co-occurrence network of the intestinal microbial community before and after FMT, it was observed that a more diverse intestinal microbial community was established after FMT in all groups. In particular, the group with increased muscle strength had more gut microbiome species and communities than the other groups. Fold-change comparison showed that Eisenbergiella massiliensis and Anaeroplasma abactoclasticum from the gut microbiome had positive contributions to muscle strength, while Ileibacterium valens and Ethanoligenens harbinense had negative effects. This study identifies candidates for the gut microbiome that contribute positively and those that contribute negatively to muscle strength.

Performance Comparison Between Fourier-Transform Infrared Spectroscopy-based IR Biotyper and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry for Strain Diversity.

Background: Development of an accessible method to routinely evaluate the clonality of strains is needed in microbiology laboratories. We compared the discriminatory power of the Fourier-transform infrared (FTIR) spectroscopy-based IR Biotyper (Bruker Daltonics GmbH, Bremen, Germany) to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), using whole-genome sequencing (WGS) as the reference method. Methods: Eighty-three extended-spectrum ß-lactamase-producing Escherichia coli isolates were tested using WGS, MALDI-TOF MS, and IR Biotyper. Simpson's diversity index (SDI), a statistical analysis for testing the homogeneity of a dendrogram, and the adjusted Rand index (aRI) were used to compare the discriminatory ability between typing tests. Results: The SDI (95% confidence interval) was 0.969 (0.952-0.985) for WGS, 0.865 (0.807-0.924) for MALDI-TOF MS, and 0.974 (0.965-0.983) for IR Biotyper. Compared with WGS, IR Biotyper showed compatible diversity, whereas MALDI-TOF MS did not. The concordance and aRI improved from 66.3% to 84.3% and from 0.173 to 0.538, respectively, for IR Biotyper versus MALDI-TOF MS with WGS as the reference method. IR Biotyper showed substantially improved performance in strain typing compared with MALDI-TOF MS. Conclusions: IR Biotyper is useful for diversity analysis with improved discriminatory power over MALDI-TOF MS in comparison with WGS as a reference method. IR Biotyper is an accessible method to evaluate the clonality of strains and could be applied in epidemiological analysis during an outbreak of a health care facility, as well as for research on the transmission of resistant bacteria in community settings.

Nephrotoxicity evaluation and proteomic analysis in kidneys of rats exposed to thioacetamide.

Thioacetamide (TAA) was administered orally at 0, 10, and 30 mg/kg body weight (BW) daily to Sprague-Dawley rats aged 6-7 weeks for 28 consecutive days. Nephrotoxicity and proteomics were evaluated in the kidneys of rats exposed to TAA. The BW decreased, however, the relative kidneys weight increased. No significant histopathologic abnormalities were found in the kidneys. The numbers of monocytes and platelets were significantly increased. However, the mean corpuscular volume and hematocrit values were decreased significantly in rats exposed to 30 mg/kg BW TAA. The expression levels of Kim-1 and NGAL were increased 4 to 5-fold in the kidneys, resulting in significant nephrotoxicity. Proteomic analysis was conducted and a total of 5221 proteins spots were resolved. Of these, 3 and 21 protein spots were up- and downregulated, respectively. The validation of seven proteins was performed by Western blot analysis. The expression level of ASAP2 was significantly upregulated, whereas RGS14, MAP7Dl, IL-3Rα, Tmod1, NQO2, and MUP were reduced. Sixteen isoforms of MUP were found by the 2DE immunoblot assay and were significantly downregulated with increasing exposure to TAA. MUP isoforms were compared in the liver, kidneys, and urine of untreated rats and a total of 43 isoforms were found.

Protective effects of sciadopitysin against methylglyoxal-induced degeneration in neuronal SK-N-MC cells.

The accumulation of advanced glycation end products (AGEs) causes metabolic dysfunction and neuronal cell damage. Methylglyoxal (MG) is a major glycating agent that reacts with basic residues present in proteins and promotes the formation of AGEs. Sciadopitysin, a type of biflavonoid, exerts protective effects against neuronal cell damage; however, the underlying mechanisms have not been studied. This study aimed to investigate the mechanisms underlying the protective effects of sciadopitysin against MG-mediated cytotoxicity in SK-N-MC neuroblastoma cells. Our results demonstrated that pretreatment of SK-N-MC cells with sciadopitysin improved the cell viability that was inhibited by MG and inhibited the apoptosis induced by MG. Sciadopitysin attenuated intracellular Ca2+ , NOX4 levels, oxidative stress, and MG-protein adduct levels, and increased nuclear Nrf2 and glyoxalase 1 levels in the presence of MG. These results suggest that sciadopitysin exerts neuroprotective effects against MG-induced death of human SK-N-MC cells via its antioxidative action. This study highlights sciadopitysin as a promising candidate for antioxidant therapy and designing natural drugs against AGE-induced neurodegenerative disorders.

Spironolactone Attenuates Methylglyoxal-induced Cellular Dysfunction in MC3T3-E1 Osteoblastic Cells.

BACKGROUND: Methylglyoxal (MG) is associated with the pathogenesis of age- and diabetes-related complications. Spironolactone is a competitive antagonist of aldosterone that is widely employed in the treatment of hypertension and heart failure. This study examined the effects of spironolactone on MG-induced cellular dysfunction in MC3T3-E1 osteoblastic cells. METHODS: MC3T3-E1 cells were treated with spironolactone in the presence of MG. The mitochondrial function, bone formation activity, oxidative damage, inflammatory cytokines, glyoxalase I activity, and glutathione (GSH) were measured. RESULTS: Pretreatment of MC3T3-E1 osteoblastic cells with spironolactone prevented MG-induced cell death, and improved bone formation activity. Spironolactone reduced MG-induced endoplasmic reticulum stress, production of intracellular reactive oxygen species, mitochondrial superoxides, cardiolipin peroxidation, and inflammatory cytokines. Pretreatment with spironolactone also increased the level of reduced GSH and the activity of glyoxalase I. MG induced mitochondrial dysfunction, but markers of mitochondrial biogenesis such as mitochondrial membrane potential, adenosine triphosphate, proliferator-activated receptor gamma coactivator 1α, and nitric oxide were significantly improved by treatment of spironolactone. CONCLUSION: Spironolactone could prevent MG-induced cytotoxicity in MC3T3-E1 osteoblastic cells by reduction of oxidative stress. The oxidative stress reduction was explained by spironolactone's inhibition of advanced glycation end-product formation, restoring mitochondrial dysfunction, and anti-inflammatory effect.

Catalpol protects against 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced cytotoxicity in osteoblastic MC3T3-E1 cells.

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a well-known environmental contaminant that produces a wide variety of adverse effects in humans. Catalpol, a major bioactive compound enriched in the dried root of Rehmannia glutinosa, is a major iridoid glycoside that alleviates bone loss. However, the detailed mechanisms underlying the effects of catalpol remain unclear. The present study evaluated the effects of catalpol on TCDD-induced cytotoxicity in osteoblastic MC3T3-E1 cells. Catalpol inhibited TCDD-induced reduction in cell viability and increases in apoptosis and autophagic activity in osteoblastic MC3T3-E1 cells. Additionally, pretreatment with catalpol significantly decreased the nitric oxide and nitrite levels compared with a control in TCDD-treated cells and significantly inhibited TCDD-induced increases in the levels of cytochrome P450 1A1 and extracellular signal-regulated kinase. Pretreatment with catalpol also effectively restored the expression of superoxide dismutase and extracellular signal-regulated kinase 1 and significantly enhanced the expression of glutathione peroxidase 4 and osteoblast differentiation markers, including alkaline phosphatase and osterix. Taken together, these findings demonstrate that catalpol has preventive effects against TCDD-induced damage in MC3T3-E1 osteoblastic cells.

Effect of bergenin on RANKL-induced osteoclast differentiation in the presence of methylglyoxal.

Methylglyoxal (MG), a highly reactive dicarbonyl compound, is a major precursor in the formation of advanced glycation end products, which are associated with diabetes-related diseases. Bergenin, an active constituent of plants of the genus Bergenia, exhibits multiple biological activities. This study evaluated the effect of bergenin on osteoclast differentiation and determined its mechanism of action. Bergenin reversed MG-inhibited tartrate-resistant acid phosphatase (TRAP) activity and decreased the bone resorption activity of osteoclasts. Quantitative RT-PCR revealed that bergenin decreased the expression of ERK1, Akt2, MMP-9, and OSTM1 genes in the presence of MG. Bergenin pretreatment yielded significant increases in intracellular calcium concentration, mitochondrial mass, mitochondrial membrane potential, and glyoxalase I reduced by MG. Additionally, bergenin decreased the formation of mitochondrial superoxide induced by MG. Detoxification of MG by bergenin may be a viable treatment for bone disorders in patients with diabetes.

Pathogenetic implications of early growth response 1 in Ewing sarcoma.

Ewing sarcoma (ES) is the second most common primary malignant bone tumour, mainly occurs in children and adolescents, and has an overwhelming mortality. Despite extensive studies, few effective oncogenic signals have been described. Therefore, it is crucial to exploit novel pathognomonic factors and targetable biomarkers for ES patients. Based on previous studies, we speculate that insulin-like growth factor 1 receptor (IGF1R), which is upregulated by early growth response 1 (EGR1), may play a pivotal role in strengthening the downward transmission of IGF1 cascades. Therefore, in this study, we concentrated on determining the pathogenetic contribution of EGR1 in diverse ES cells. This report is the first to study the pathogenic role of EGR1 in ES. ES cells were cultured and transfected with Stealth RNAi human EGR1 small interfering RNA (siRNA) or negative control. Cell proliferation and invasion potential were measured. mRNA and protein expression of EGR1, IGF1R, and EWS-FLI1 also were assessed. In all EGR1 siRNA-transfected cells (SK-ES-1, RD-ES, and HS863.T), cell proliferation and invasive potential decreased significantly in EGR1 siRNA-transfected ES cells. mRNA and protein expression for EGR1, IGF1R, and EWS-FLI1 were also significantly reduced. In conclusion, EGR1 upregulated IGF1R expression and enhanced the expression of the oncogenic fusion protein EWS-FLI1. The EWS-FLI1/EGR1/IGF1R cascade combined with the previously confirmed pathways can form a speculative circuit, implicating positive feedback for tumourigenesis in ES. Therefore, EGR1 inhibitors are expected to be useful for the treatment of ES by preventing oncogenic IGF1/IGF1R expression.

Crocin attenuates methylglyoxal-induced osteoclast dysfunction by regulating glyoxalase, oxidative stress, and mitochondrial function.

Methylglyoxal (MG), a highly reactive dicarbonyl compound, is a major cell-permeant precursor of advanced glycation end-products, which are associated with several conditions, including diabetes and degenerative diseases. Crocin, a constituent of saffron, is involved in many pharmacological activities. Recent studies have reported that crocin exerts protective effects against bone diseases. Osteoclasts are multinucleated cells derived from hematopoietic stem cells that are responsible for bone resorption. The up- or down-regulation of their proliferation and differentiation is often associated with many bone-related diseases. The present study aimed to investigate the effects of crocin on osteoclast differentiation and to clarify its mechanism of action in the presence of MG. We demonstrated that crocin reversed MG-induced inhibition of tartrate-resistant acid phosphatase activity and bone resorption activity in osteoclasts. Quantitative reverse transcription-polymerase chain reaction analysis indicated that crocin treatment decreased the expression of TNF receptor-associated factor-6 (TRAF6), Akt2, extracellular-signal-regulated kinase-1 (ERK1), osteopetrosis-associated transmembrane protein 1 (OSTM1), and matrix metalloproteinase 9 (MMP-9) genes in the presence of MG. Crocin pretreatment also reversed MG-induced changes in mitochondrial mass, mitochondrial membrane potential, mitochondrial superoxide, and glyoxalase I levels. Taken together, our data suggest that crocin may be a useful therapeutic agent for the treatment of diabetic bone disorders.

Effects of methylglyoxal on RANKL-induced osteoclast differentiation in RAW264.7 cells.

Methylglyoxal (MG) is a reactive dicarbonyl compound produced by glycolytic processing, which has been identified as a precursor of advanced glycation end products. Elevated MG levels in patients with diabetes are believed to contribute to diabetic complications, including bone defects. The objective of this study was to evaluate the effect of MG on RANKL-induced osteoclast differentiation in RAW264.7 cells, a murine macrophage cell line. RAW264.7 cells were cultured in medium containing 50 ng/mL RANKL and different concentrations of MG. Tartrate-resistant acid phosphatase (TRAP) activity and osteoclast bone resorbing activity were assessed and changes in intracellular calcium concentration, mitochondrial mass, mitochondrial membrane potential, and glyoxalase I level were examined. In addition, real-time RT-PCR assay was used to analyse osteoclast-associated genes. MG markedly inhibited RANKL-induced TRAP activity. MG treatment resulted in a significant decrease in intracellular calcium concentration, mitochondrial mass, mitochondrial membrane potential, and glyoxalase I level during osteoclastogenesis. In addition, MG increased the formation of mitochondrial superoxide. Quantitative reverse transcriptase-polymerase chain reaction revealed increased expression of the TRAF6, GAB2, ERK1, c-Fos, NFATc1, CLCN7, and OSTM1 genes, decreased expression of TCIRG and carbonic anhydrase II, and unchanged expression of cathepsin K and MMP-9 upon MG treatment. MG had no effect on the bone resorbing activity of osteoclasts. Our findings indicate that MG inhibits TRAP and glyoxalase I activity and impairs mitochondrial function in osteoclasts. Further validation of the underlying pathway is necessary.

Glabridin attenuates antiadipogenic activity induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in murine 3T3-L1 adipocytes.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has various toxicological effects in adipose tissue. Evidence is accumulating that glabridin, a flavonoid extracted from licorice, has beneficial effects on the regulation of glucose homeostasis. In this study, we investigated whether glabridin suppresses TCDD-induced loss of adipogenic action using 3T3-L1 adipocytes as a cell culture model of wasting syndrome. Glabridin effectively suppressed TCDD-induced loss of lipid accumulation in this model. Pretreating cells with glabridin increased the gene expression of not only the adipogenesis-associated key transcription factors peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer binding protein alpha, but also lipoprotein lipase in the presence of TCDD. TCDD decreased insulin-stimulated glucose uptake, which was effectively restored by pretreatment with glabridin. Glabridin also inhibited the TCDD-driven decreased production of insulin receptor substrate 1 and glucose transporter 4. TCDD increased the production of mitochondrial superoxides, prostaglandin E2 , phospholipase A2 , cyclooxygenase-1 and intracellular calcium concentrations, while reducing the production of PPARγ coactivator 1 alpha and glycolysis. However, glabridin treatment reduced these TCDD-induced effects. We conclude that glabridin suppresses the TCDD-induced loss of lipid accumulation in 3T3-L1 adipocytes by regulating the levels of PPARγ, CCAAT/enhancer binding protein alpha, lipoprotein lipase, glucose uptake, prostaglandin E2 and energy metabolism. These results also provide in vitro evidence of the effects of glabridin on adipocyte metabolism, which suggests a protective effect against dioxin exposure in the development of insulin resistance and diabetes.

27-Deoxyactein prevents 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced cellular damage in MC3T3-E1 osteoblastic cells.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a well-known environmental contaminant that exerts its toxicity through a variety of signaling mechanisms. The present study evaluated the effects of 27-deoxyactein, one of the major constituents isolated from Cimicifuga racemosa, on TCDD-induced toxicity in osteoblastic MC3T3-E1 cells. TCDD reduced cell survival, markedly increased apoptosis, and enhanced autophagy activity. However, pre-treatment with 27-deoxyactein attenuated all TCDD-induced effects and significantly decreased intracellular calcium (Ca2+) concentrations, the collapse of the mitochondrial membrane potential (MMP), the level of reactive oxygen species (ROS), and cardiolipin peroxidation compared to the TCDD-treated controls. Additionally, TCDD-induced increases in the levels of aryl hydrocarbon receptor (AhR), cytochrome P450 1A1 (CYP1A1), and extracellular signal-regulated kinase (ERK) were significantly inhibited by 27-deoxyactein. The mRNA levels of superoxide dismutase (SOD), ERK1, and nuclear factor kappa B (NF-κB) were also effectively restored by pre-treatment with 27-deoxyactein. Furthermore, 27-deoxyactein significantly increased the expressions of genes associated with osteoblast differentiation, including alkaline phosphatase (ALP), osteocalcin, bone sialoprotein (BSP), and osterix. Taken together, the present findings demonstrate the preventive effects of 27-deoxyactein on TCDD-induced damage in osteoblasts.

Characterization of Clostridium difficile Strains Isolated from Patients with C. difficile-associated Disease in Korea.

OBJECTIVES: Studies on Clostridium difficile are rare in Korea. We investigated the epidemiological characteristics of C. difficile isolates from patients with C. difficile-associated disease (CDAD) in Korea. METHODS: Multiplex polymerase chain reaction was performed to detect the presence of tcdA and tcdB toxin genes. Antimicrobial susceptibility test was carried out by the disk-dilution method. C. difficile strains were subtyped by automated repetitive-element palindromic PCR (rep-PCR). RESULTS: Among patients with CDAD, 73 (25.8%), 32 (11.3%), 32 (11.3%), and 26 (9.2%) suffered from pneumonia, cancer or neoplasm, diabetes, and colitis, respectively. Of all stool samples, 43 samples (15.2%) were positive for C. difficile strains. We observed two expression patterns of toxin genes: tcdA+/tcdB+ (86% isolates) and tcdA-/tcdB+ (14% isolates), with all isolates expressing tcdB. Furthermore, some isolates were resistant to clindamycin (65%), ampicillin (56%), and cefazolin (40%), but all were susceptible to vancomycin and metronidazole. The tested samples were classified into diverse clusters using automated rep-PCR. CONCLUSION: Our findings revealed the characteristics and antibiotic resistance of C. difficile isolates from patients in Korea. The epidemiological data may provide valuable insight into development of treatment strategies for C. difficile infections in Korea.

Magnolol protects pancreatic ß-cells against methylglyoxal-induced cellular dysfunction.

Chronic hyperglycemia aggravates insulin resistance, in part due to increased formation of advanced glycation end-products (AGEs). Methylglyoxal (MG), a major precursor of AGEs, accumulates abnormally in various tissues and organs and participates in oxidative damage. We investigated the insulinotropic benefits of magnolol, a hydroxylated biphenyl compound isolated from Magnolia officinalis, in pancreatic ß-cells exposed to MG in vitro. When exposed to cytotoxic levels of MG for 48 h, RIN-m5F ß-cells exhibited a significant loss of viability and impaired insulin secretion, whereas pretreatment with magnolol protected against MG-induced cell death and decreased insulin secretion. Moreover, magnolol increased the expression of genes involved in ß-cell survival and function, including Ins2 and PDX1. Furthermore, magnolol increased the levels of AMPK phosphorylation, SIRT1, and PGC1α in RIN-5F ß-cells. In addition, magnolol increased the activity of glyoxalase I and decreased the levels of MG-modified protein adducts, which suggests that magnolol protects against MG-induced protein glycation. Taken together, the results indicate the potential application of magnolol as an intervention against MG-induced hyperglycemia.

Actein alleviates 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated cellular dysfunction in osteoblastic MC3T3-E1 cells.

The environmental pollutant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is known to affect bone metabolism. We evaluated the protective effects of the triterpene glycoside actein from the herb black cohosh against TCDD-induced toxicity in MC3T3-E1 osteoblastic cells. We found that TCDD significantly reduced cell viability and increased apoptosis and autophagy in MC3T3-E1 osteoblastic cells (P < .05). In addition, TCDD treatment resulted in a significant increase in intracellular calcium concentration, mitochondrial membrane potential collapse, reactive oxygen species (ROS) production, and cardiolipin peroxidation, whereas pretreatment with actein significantly mitigated these effects (P < .05). The effects of TCDD on extracellular signal-related kinase (ERK), aryl hydrocarbon receptor, aryl hydrocarbon receptor repressor, and cytochrome P450 1A1 levels in MC3T3-E1 cells were significantly inhibited by actein. The levels of superoxide dismutase, ERK1, and nuclear factor kappa B mRNA were also effectively restored by pretreatment with actein. Furthermore, actein treatment resulted in a significant increase in alkaline phosphatase (ALP) activity and collagen content, as well as in the expression of genes associated with osteoblastic differentiation (ALP, type I collagen, osteoprotegerin, bone sialoprotein, and osterix). This study demonstrates the underlying molecular mechanisms of cytoprotection exerted by actein against TCDD-induced oxidative stress and osteoblast damage.

Deoxyactein protects pancreatic ß-cells against methylglyoxal-induced oxidative cell damage by the upregulation of mitochondrial biogenesis.

Methylglyoxal (MG) is one of the major precursors of advanced glycation end products (AGEs), which are considered to be one of the causes of diabetes and its complications. The root and rhizomes of black cohosh (Cimicifuga racemosa) have long been used medicinally, and deoxyactein is one of its major constituents. In the present study, the protective effects of deoxyactein against MG-induced oxidative cell damage were investigated in insulin-producing pancreatic ß-cells. We found that deoxyactein protected the pancreatic ß-cells against MG-induced cell death. Pre-treatment with deoxyactein significantly reduced the levels of intracellular reactive oxygen species (ROS), interleukin-1ß (IL-1ß), cardiolipin peroxidation, and protein adduct accumulation induced by MG. Pre-treatment of the cells with deoxyactein restored glyoxalase I activity and insulin secretion which were reduced by MG, and increased the mRNA expression of insulin 2 (INS2) and pancreatic and duodenal homeobox protein-1 (PDX-1). It also increased the levels of endogenous antioxidant enzymes, including superoxide dismutase (SOD) and glutathione peroxidase (GPX). Furthermore, treatment with deoxyactein increased the levels of sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor-γ co-activator-1α (PGC-1α). These findings indicate that deoxyactein may exert beneficial effects on pancreatic ß-cells via the upregulation of mitochondrial biogenesis. Taken together, these results suggest that deoxyactein may be used for the prevention of pancreatic ß-cell damage.

Clinicopathological implications of GNAS in Ewing sarcoma.

The objective of the present study was to determine whether guanine nucleotide-binding protein α stimulating (GNAS) gene expression correlates with pathognomonic signs by analyzing the mutations, methylation status and G-protein α subunit (Gsα) expression of GNAS in Ewing sarcoma (ES). Formalin-fixed paraffin-embedded tissue samples from 77 patients with primary ES were obtained in South Korea, Argentina and Brazil, and were studied via methylation chip assay and direct sequencing of the GNAS gene and immunohistochemical analysis of Gsα. The mutation and methylation statuses of the GNAS gene were examined. Immunohistochemical results were measured with respect to proportion and staining intensity. The results revealed that GNAS genes in ES tumor samples were less methylated compared with normal controls. No mutations were detected at exons 8 or 9 of the GNAS locus complex on chromosome 20q13.3, indicating that the pathogenesis of ES was not associated with GNAS mutation. Gsα expression correlated well with the methylation status of the GNAS gene. Notably, high Gsα expression was detected more frequently in samples from living patients than from decedents, although this was not statistically significant (P=0.055). In conclusion, GNAS mutation is not associated with the pathogenesis of ES tumors. This finding may be used to differentiate ES tumors from metastatic bone lesions with morphological similarity to ES tumors. Analysis of the methylation status of the GNAS gene and immunohistochemical Gsα expression suggests that hypermethylated GNAS (low Gsα expression) in ES may be associated with unfavorable progression with a non-significant trend.

Evaluation of toxicological biomarkers in secreted proteins of HepG2 cells exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin and their expressions in the plasma of rats and incineration workers.

Toxicological biomarkers of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) were investigated in proteins secreted by HepG2 cells and their expression levels were determined in the plasma of rats exposed to 2,3,7,8-TCDD and in the plasma of incineration workers exposed to dioxins. HepG2 cells were treated with various concentrations of 2,3,7,8-TCDD (0, 0.25, 0.5, 1, 2.5, 5, 10, 25 nM) for 24 or 48 h. MTT and Comet assays were performed to determine cytotoxicities and genotoxicities to select exposure concentrations for the proteomic analysis of proteins secreted by 2,3,7,8-TCDD-treated cells. In the proteomic analysis, dose- and time-dependent toxicological biomarkers were evaluated using two pI ranges (4-7 and 6-9) using a large gel 2-DE system. Fifteen secreted proteins were identified by a nano-LC-ESI-MS/MS and nano-ESI on a Q-TOF2 MS and the identities of eight secreted proteins including glyoxalase 1 (GLO 1), homogentisate dioxygenase (HGD), peroxiredoxin 1 (PRX 1), proteasome subunit beta type (PSMB) 5 and 6, UDP-glucose 6-dehydrogenase (UDP-GlcDH), hydroxyacyl-coenzyme A dehydrogenase (HADH) and serotransferrin (STF) were confirmed by western blotting. Of these, PSMB 5 and PRX 1 were also found in the plasma of rats exposed to 2,3,7,8-TCDD, whereas GLO 1, HGD, PSMB 6 and PRX 1 were found in the plasma of incineration workers exposed to dioxins.

Effects of PRELI in Oxidative-Stressed HepG2 Cells.

Protein of relevant evolutionary and lymphoid interest (PRELI) is known for preventing apoptosis by mediating intramitochondrial transport of phosphatidic acid. However, the role of PRELI remains unclear. This study has demonstrated functions of PRELI through PRELI-knockdown in hepatocellular carcinoma (HepG2) cells exposed to oxidative stress by hydrogen peroxide. Results show that PRELI has three functions in HepG2 cells with regard to oxidative stress. First, PRELI affects expressional regulation of SOD-1 and caspase-3 genes in HepG2 cells. PRELI knockdown HepG2 cells have shown up-regulation of caspase-3 and down-regulation of SOD-1. Second, PRELI suppresses mitochondrial apoptosis in HepG2 cells. Fluorescence intensity related to mitochondrial apoptosis in PRELI-knockdown HepG2 cells increased more than two-fold compared to normal HepG2 cells. Third, PRELI suppresses senescence of HepG2 cells with oxidative stress. PRELI knockdown HepG2 cells showed higher levels of senescence than normal HepG2 cells. These results suggest that PRELI is a crucial protein in the suppression of apoptosis in HepG2 cells in response to oxidative stress.

The ORF3 protein of porcine circovirus type 2 promotes secretion of IL-6 and IL-8 in porcine epithelial cells by facilitating proteasomal degradation of regulator of G protein signalling 16 through physical interaction.

Porcine circovirus type 2 (PCV2) is the main aetiological agent of postweaning multisystemic wasting syndrome. The mechanism of pathogenicity associated with PCV2 infection is still not fully understood. Nevertheless, the fact that large amounts of proinflammatory cytokines within lymphoid tissues are released during the early stage of PCV2 infection may induce chronic inflammatory responses followed by the destruction of lymphoid tissues. However, how PCV2 infection causes an excessive inflammatory response in the host immune system during the early stage of PCV2 infection has still not been elucidated. In this study, we show that direct interaction between the PCV2 ORF3 and regulator of G protein signalling 16 (RGS16) within the cytoplasm of host cells leads to ubiquitin-mediated proteasomal degradation of RGS16. Facilitated degradation of the RGS16 by PCV2 ORF3 further enhances NFκB translocation into the nucleus through the ERK1/2 signalling pathway and increased IL-6 and IL-8 mRNA transcripts. Consequently, more severe inflammatory responses and leukocyte infiltration occur around host cells. This evidence may be the first clue explaining the molecular basis of how excessive amounts of proinflammatory cytokines within lymphoid tissues are released during the early stage of PCV2 infection.