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.

Associations between Apolipoprotein E Gene Polymorphisms and Cardiovascular Complications of Uremic Patients on Maintenance Hemodialysis.

This study is to investigate the associations between apolipoprotein E (ApoE) gene polymorphisms and cardiovascular complications of uremic patients on maintenance hemodialysis (MHD). Uremic patients on MHD (189, case group) and healthy people (165, control group) were recruited. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to test ApoE gene polymorphisms. Indicators of MHD and cardiovascular complications were observed. Compared with the control group, the case group had decreased frequency of ε3/3 genotype and ε3 allele and increased ε4/3 genotype and ε4 allele. The ε4 group had elevated adiponectin, serum creatinine, blood urea nitrogen, and total cholesterol but decreased HDL-C compared with other groups. The ε3 group had reduced complications. ApoE ε3 and ε4 alleles were related with cardiovascular complications of the uremic patients on MHD. We concluded that ApoE gene polymorphisms were associated with susceptibility to infections in uremia, and that ApoE ε3 and ε4 alleles might correlate with cardiovascular complications of uremic patients on MHD.