Hydrogen sulfide attenuates paraquat-induced epithelial-mesenchymal transition of human alveolar epithelial cells through regulating transforming growth factor-ß1/Smad2/3 signaling pathway.

Exogenous H2 S donor, sodium hydrosulfide (NaHS), can influence the bleomycin-induced pulmonary fibrosis by attenuating the epithelial-mesenchymal transition (EMT) of alveolar epithelial cells, but whether NaHS affects paraquat (PQ)-induced EMT and the molecular mechanisms remain unclarified. The aim of the present study is to examine the effect of exogenous NaHS on PQ-induced EMT in human alveolar epithelial cells (A549 cells) and assess if this effect occurs through regulating transforming growth factor (TGF)-ß1/Smad2/3 signaling pathway. The expressions of endogenous H2 S producing enzymes, namely cystathionine ß-synthase, cystathionine γ-lyase and 3-mercaptopyruvate sulfur transferase, were detected by reverse transcription-polymerase chain reaction and western blotting. The induced EMT was assessed by morphological and phenotypic characterizations, and the protein level of E-cadherin and vimentin were detected by western blotting. To investigate the effect of NaHS on PQ-induced EMT and potential mechanism, A549 cells were pretreated with NaHS before incubating with PQ and then evaluated by morphological changes, cell migration ability, the expression of EMT markers and TGF-ß1/Smad2/3 signaling pathway related proteins. PQ significantly downregulated the expression levels of cystathionine ß-synthase and cystathionine γ-lyase, but not 3-mercaptopyruvate sulfur transferase, in a time-dependent manner in A549 cells. Exogenous NaHS could significantly retard PQ-induced morphological changes and cell migration ability. Furthermore, exogenous NaHS significantly upregulated the expression of E-cadherin, whereas it downregulated the expression of vimentin. In addition, exogenous NaHS could also significantly attenuates PQ-induced TGF-ß1, phosphorylated Smad2/3 proteins expression, which induced by PQ in a time-dependent manner. This study provides the first evidence that exogenous NaHS attenuates PQ-induced EMT and migration of human alveolar epithelial cells through regulating the TGF-ß1/Smad2/3 signaling pathway.

Viral mimic polyinosine-polycytidylic acid potentiates liver injury in trichloroethylene-sensitized mice - Viral-chemical interaction as a novel mechanism.

Occupational trichloroethylene (TCE) exposure can induce hypersensitivity dermatitis and severe liver injury. Recently, several clinical investigations indicate that viral infection, such as human herpesvirus-6, is associated with hepatic dysfunction in patients with TCE-related generalized skin disorders. However, whether viral infection potentiates TCE-induced liver injury remains unknown. This study aimed to explore the contribution of viral infection to the development of TCE-sensitization-induced liver injury in BALB/c mice. Female BALB/c mice were randomly assigned into four groups: solvent control group (n = 20), TCE group (n = 80), poly(I:C) group (n = 20) and combination of TCE and poly(I:C) (poly(I:C)+TCE) group (n = 80). Poly(I:C) (50 µg) was i.p. administrated. TCE and poly(I:C)+TCE groups were further divided into sensitization and non-sensitization subgroup. Complement 3 and C3a protein levels, and complement factors were measured. Combination treatment significantly enhanced TCE-induced liver injury, decreased complement 3, but increased C3a in serum and liver tissues in sensitization group. These changes were not correlated with the hepatic complement 3 transcription. Moreover, combination treatment specifically promoted complement factor B, but not factor D and factor H expressions. These data provide first evidence that poly(I:C) potentiates liver injury in BALB/c mouse model of TCE-sensitization. Upregulated C3a and factor B contributes to the poly(I:C) action in TCE-induced liver injury. This new mode of action may explain increased risk of chemical-sensitization induced tissue damage by viral infection.

Prognostic value of hematological parameters in patients with paraquat poisoning.

Paraquat (PQ) is a non-selective contact herbicide, and acute PQ poisoning has a high mortality. The aim of the present study is to evaluate the prognostic value of hematological parameters in patients with acute PQ poisoning. We retrospectively reviewed the records of patients with acute PQ poisoning from January 2010 to December 2015 at the First Affiliated Hospital, Anhui Medical University (Hefei, China). A total of 202 patients were included in the study, and the 30-day mortality was 51.98%. Leukocyte, neutrophil counts and neutrophil-lymphocyte ratio (NLR) were significantly higher in non-survivors than in survivors. In the receiver operating characteristic (ROC) curve analysis, the NLR had an area of 0.916(95%CI, 0.877-0.954) and the optimal cut-off value was 10.57 (sensitivity, 86.70%; specificity, 83.51%; Youden's index, 0.702). The leukocyte counts had an area of 0.849(95%CI, 0.796-0.902) and the optimal cut-off value was 13.15 × 103/mm3 (sensitivity, 77.10%; specificity, 83.50%; Youden's index, 0.606). The neutrophil counts had an area of 0.878(95%CI, 0.830-0.925) and the optimal cut-off value was 10.10 × 103/mm3 (sensitivity, 83.80%; specificity, 79.38%; Youden's index, 0.632). NLR, leukocyte and neutrophil counts are associated with the 30-day mortality, which may be useful and simple parameters in predicting the prognosis of PQ poisoning.

Association of glutathione S-transferase pi (GSTP1) Ile105Val polymorphism with the risk of skin cancer: a meta-analysis.

Numerous epidemiological studies have evaluated the association of Glutathione S-transferase P1 (GSTP1) Ile105Val polymorphism with the risk of skin cancer. However, the results remain inconclusive. To derive a more precise estimation of the association between the GSTP1 Ile105Val polymorphism and skin cancer risk, a meta-analysis was performed. A comprehensive search was conducted to identify the eligible studies. We used odds ratios (ORs) with 95 % confidence intervals (CIs) to assess the association of GSTP1 Ile105Val polymorphism with skin cancer risk. Thirteen case-control studies in nine articles, which included a total of 1504 cases and 2243 controls. Overall, we found that GSTP1 Ile105Val polymorphism was not associated with skin cancer risk. Furthermore, subgroup analysis by histological types showed that GSTP1 Ile105Val polymorphism was associated with risks of malignant melanoma under the dominant model (Val/Val + Val/Ile vs. Ile/Ile: OR 1.230, 95 % CI 1.017-1.488, P = 0.033). However, lack of association between GSTP1 Ile105Val polymorphism and BCC and SCC risk in all genetic models. Our meta-analysis suggested that the GSTP1 Ile105Val polymorphism might be associated with increased risk of malignant melanoma in Caucasian population.

Association of a disintegrin and metalloprotease 33 (ADAM33) gene polymorphisms with the risk of COPD: an updated meta-analysis of 2,644 cases and 4,804 controls.

A series of observational studies have been made to investigate the association of the ADAM33 gene polymorphisms with the risk of COPD, but their results were conflicting. Therefore, we performed an updated meta-analysis to quantitatively summarize the associations of ADAM33 gene polymorphisms with the risk of COPD. Thirteen case-control studies referring to nine SNPs were identified: V4 (rs2787094), T+1 (rs2280089), T2 (rs2280090), T1 (rs2280091), S2 (rs528557), S1 (rs3918396), Q-1 (rs612709), F+1 (rs511898) and ST+5 (rs597980). A dominant model (AA+Aa vs. aa), recessive model (AA vs. Aa+aa), additive model (AA vs. aa) and allelic model (A vs. a) were used to evaluate the association of ADAM33 polymorphism with the risk of COPD. The results indicated that significant associations were found for ADAM33 T1, T2, S1, Q-1, F+1 and ST+5 polymorphisms associated with the risk of COPD in different populations. However, no significant associations were found for V4, T+1 and S2 polymorphisms with the risk of COPD in all genetic models, even in the subgroup analysis by ethnicity. This meta-analysis provided evidence that the ADAM33 T1, T2, S1, Q-1, F+1 and ST+5 six locus polymorphisms association with the risk of COPD. Furthermore, T2, Q-1 and ST+5 indicated an association with the risk of COPD in the European populations, whereas T1, T2, S1, F+1 and Q-1 indicated an association with the risk of COPD in the Asian populations.

Bleomycin-induced epithelial-mesenchymal transition in sclerotic skin of mice: possible role of oxidative stress in the pathogenesis.

Epithelial-mesenchymal transition (EMT) derived myofibroblasts are partly responsible for the increased collagen synthesis and deposition that occur in tissue fibrosis; however EMT occurrence in skin fibrosis and its mechanism remain unknown. The aim of this study was to investigate whether epithelial cells undergo EMT and determine the role of oxidative stress in this process. BALB/c mice were subcutaneously injected with bleomycin (BLM) or phosphate buffer saline (PBS) into the shaved back daily for 2, 3, and 4weeks. Skin collagen deposition was evaluated by histopathology and Western blotting. EMT characteristics in the skin were determined by histopathology and immunofluorescent staining for E-cadherin and vimentin, which were further evaluated by Western blotting and reverse transcriptase polymerase chain reaction (RT-PCR). To investigate the role of oxidative stress in EMT, the antioxidant N-acetylcysteine (NAC) was intraperitoneally (100mg/kg body weight/day) injected daily for 3weeks. The epithelial suprabasal cells were detached from the basement membrane zone (BMZ) in the sclerotic skin treated with BLM. Immunofluorescent staining indicated vimentin-positive epithelial cells frequently occurring in the thickened epidermis of BLM-treated mice. Western blotting and RT-PCR showed that the expression of E-cadherin was significantly decreased but that of vimentin significantly increased in the skin treated with BLM. NAC attenuated BLM induced oxidative damage, changes in E-cadherin and vimentin expressions and collagen deposition in the sclerotic skin of mice. This study provides the first evidence that BLM induces the EMT of the epithelial cells superficial to the basement membrane zone in the skin fibrosis. Oxidative stress may contribute, at least in part, to BLM induced EMT and skin fibrosis in mice.

Possible role of complement activation in renal impairment in trichloroethylene-sensitized guinea pigs.

Recent studies have revealed that trichloroethylene (TCE) can induce occupational medicamentosa-like dermatitis (OMLD) with multi-system injuries, including liver, kidney and skin injuries, which can subsequently cause multiple organ failure later. But the mechanism of immune dysfunction leading to organ injury was rarely clarified. The present study was initiated to analyze the influence of trichloroethylene on renal injury and study the relevant mechanism in guinea pigs. Guinea pig maximization test (GPMT) was carried out. Inflammation on the guinea pigs' skin was scored. Kidney function, urine protein and ultra-structural change of kidney were determined by biochemical detection and electron microscope. Deposition of complement 3 and membrane attack complex (MAC, C5b-9) were determined by immunohistochemistry. Erythema and edema of skin impairment were observed in TCE sensitized groups, and sensitization rate was 63.16%. Through electron microscope, tubular epithelial cell mitochondrial swelling, vacuolar degeneration and atrophy of microvillus were observed in TCE sensitized groups. The parameters of urease and urinary protein elevated markedly, and a high degree of C3 and MAC deposition was found in the renal tubular epithelial cells in TCE sensitized groups. By demonstrating that TCE and its metabolites can cause the deposition of C3 and MAC in renal epithelial cells, we found that activated complement system may be the mechanism of the acceleration and the development of TCE-induced kidney disease.

[Changes of nitric oxide after trichloroethylene irritation in hairless mice skin and protection of ginkgo biloba extract and vitamin E].

OBJECTIVE: To study the changes of nitric oxide (NO) in the BALB/c hairless mice skin after trichloroethylene (TCE) irritation and the protection of ginkgo biloba extract (GbE) and vitamin E (VE). METHODS: 132 BALB/c hairless mice were randomly divided into blank control group, solvent group (olive oil), TCE groups (20%TCE, 40%TCE, 80%TCE and 100%TCE), GbE groups (0.1%GbE, 1%GbE and 10%GbE) and VE groups (5%VE, 10% VE and 20% VE), with 11 animals in each group, 5 for acute irritation test and 6 for the cumulative irritation test. The skin irritation was observed, and the levels of NO in the dorsal skin of BALB/C hairless mice were detected. The kit of NO was used to detect the levels of NO in the dorsal skin of BALB/c hairless mice. RESULTS: (1) The skin presented erythema and edema after TCE irritation both in acute irritation and cumulative irritation test and the skin inflammation showed time-dose effect relationship; the mice skin was protected in GbE or VE groups. (2) In the acute stimulation test, the levels of NO in 80%TCE group (69.895 +/- 9.605 micromol/mg pro) and 100%TCE group (77.273 +/- 9.290 micromol/mg pro) were significantly different compared with blank control group and solvent control group (P < 0.05 or P < 0.01). In the protection group, the NO level were reduced, with the statistically significant differences. (3) In acute irritation test, the levels of NO in 80%TCE group (60.362 +/- 9.817 micromol/mg pro) and 100%TCE group (68.027 +/- 9.354 micromol/mg pro) were significantly different compared with blank control group and solvent control group, (P < 0.05 or P < 0.01); In the protection group, 1% GbE, 10% GbE, 10% VE and 20%VE could reduce the levels of NO, with statistically significant differences. CONCLUSION: TCE can produce the irritation on the dorsal skin of BALB/c hairless mice and induce the significant increase of the NO levels. GbE and VE can protect the skin from TCE irritation damage.

[Relationship of nitric oxide with the apoptosis of keratinocytes].

Nitric oxide (NO) is a kind of free radical, also is a signaling molecule, which universally distributed in the tissues of organism. NO play important role in the dermato-, cardia-, encephalo-, hepat- and immunological regulation on the physio- and patho- situation. Recently studying show that NO can bifunctionally regulate the apoptosis of keratinocytes, which play an important role in the occurrence and development of many skin diseases. However, the regulatory mechanism still can't be completely elucidated at present time. In this review, we are reviewing the recent investigation progress on the apoptosis of keratinocytes and some diseases of skin that related to the regulating disturbance of NO.

Kupffer cells and reactive oxygen species partially mediate lipopolysaccharide-induced downregulation of nuclear receptor pregnane x receptor and its target gene CYP3a in mouse liver.

Pregnane X receptor (PXR) is a member of the nuclear receptor superfamily that regulates target gene transcription in a ligand-dependent manner. The in vivo effects of lipopolysaccharide (LPS) on expression of PXR and its target gene cytochrome P450 3A (CYP3A) in mouse liver were investigated in this study. Mice were injected intraperitoneally with different doses of LPS (0.1-5.0 mg/kg). PXR and CYP3A11 mRNA levels were measured using reverse transcription polymerase chain reaction. Results indicate that LPS significantly inhibits the expression of PXR mRNA in a dose-dependent manner, followed by suppression of CYP3A11 mRNA in mouse liver. LPS also represses the upregulation of CYP3A11 mRNA levels and erythromycin N-demethylase (ERND) catalytic activity in mice pretreated with PXR ligands dexamethasone, rifampicin, mifepristone, and phenobarbital. LPS-induced downregulation of PXR and CYP3A11 mRNA in liver was significantly attenuated in mice pretreated with gadolinium chloride, a selective Kupffer cell toxicant. Pretreatment with a single dose of gadolinium chloride (10 mg/kg) also significantly attenuated LPS-induced downregulation of dexamethasone-, rifampicim-, mifepristone-, and phenobarbital-inducible, CYP3A11 mRNA expression and ERND activity in mouse liver. Furthermore, LPS-induced downregulation of PXR and CYP3A11 mRNA was significantly attenuated in mice pretreated with allopurinol, an inhibitor of xanthine oxidase, and diphenyleneiodonium chloride, an inhibitor of NADPH oxidase. Allopurinol and diphenyleneiodonium chloride pretreatment also attenuated the repressive effects of LPS on dexamethasone-, rifampicin-, mifepristone-, and phenobarbital-inducible CYP3A11 mRNA expression and ERND catalytic activity in mouse liver. However, aminoguanidine, a selective inhibitor of inducible nitric oxide synthase, has no effect on LPS-induced downregulation of PXR and CYP3A11 mRNA. Finally, LPS-induced downregulation of PXR and CYP3A11 mRNA was prevented in mice pretreated with either N-acetylcysteine or ascorbic acid. These antioxidants also prevented the repressive effects of LPS on dexamethasone-, rifampicin-, mifepristone-, and phenobarbital-inducible CYP3A11 mRNA expression and ERND catalytic activity in mouse liver. These results indicate that Kupffer cells contribute to LPS-induced downregulation of PXR and CYP3A in mouse liver. Reactive oxygen species, produced possibly by NADPH oxidase and perhaps by xanthine oxidase, are involved in LPS-induced downregulation of nuclear receptor PXR and its target gene CYP3A in mouse liver.