Objective To investigate the role of homocysteine(Hcy)in the pathogenesis of irritable bowel syn-drome(IBS)and its effects on intestinal motility,visceral hypersensitivity,and barrier function.Methods Clinical cohorts and animal models were combined for this study.Clinically,fifteen IBS patients meeting Rome Ⅲcriteria and 15 control individuals were enrolled to detect fecal Hcy levels and their correlation with symptoms.As for animal experiments,water avoidance stress(WAS)and 2,4,6-trinitrobenzene sulfonic acid(TNBS)chemical induction were utilized to establish IBS rat and mouse models,combined with a high-methionine diet(HMD)to simulate hyperhomocysteinemia.IBS symptoms were evaluated through fecal water content,carmine red intestinal transit time,and visceral hypersensitivity scores.Immune-fluorescence and Western blot were used to detect intes-tinal epithelial tight junction proteins.Serum and fecal Hcy concentrations were measured to assess Hcy levels.Statistical analyses included t-tests and One-way Anova.Results Fecal Hcy level in IBS patients were signifi-cantly higher than those in the healthy control group which demonstrated a positive correlation with defecation fre-quency(P＜0.01).In animal models,the combination of TNBS administration and a high-methionine diet markedly elevated serum and fecal Hcy levels in mice,while synergistically exacerbated intestinal motility disor-ders and visceral hypersensitivity.In vitro experiments showed that Hcy treatment down-regulates the expression of tight junction proteins in human colon cancer cell line(Caco-2).Conclusions Hcy plays an important role in the pathogenesis of IBS by impairing intestinal barrier function and enhancing visceral hypersensitivity,and it may serve as a potential new target for the treatment of IBS.

AIM: To explore the effect of hydrogen sulfide on the senescence of human umbilical vein endothe -lial cells (HUVECs) induced by high glucose.METHODS: Senescence model was established by treating HUVECs with33 mmol/L glucose for 48 h.The parameters were detected to demonstrate the effect of hydrogen sulfide on senescence andthe mechanism involved was also investigated .RESULTS: In the cells treated with high glucose, the proliferation was attenuatedwith a higher number of senescence -associated β-galactosidase (SA-β-Gal) positive cells, and plasminogen activatorinhibitor 1 (PAI-1) protein expression, malondialdehyde (MDA) production and NF-κB p65 activity were increasedsignificantly, but the expression of superoxide dismutase 1 (SOD1) was decreased.However, the cell number and SOD1expression were increased, and the number of SA-β-Gal positive cells, PAI-1 protein expression, MDA production and theactivity of NF-κB p65 were decreased after sodium hydrosulfide (100 and 200 μmol/L) treatment.CONCLUSION: Exogenoushydrogen sulfide prevents HUVECs against high glucose -induced senescence by suppressing oxidative stress and NF -κB p65 activity.

Objective:To explore the association of the genes GSTM1 and GSTT1 with oligozoospermia infertility.Methods:PCR technique was used to analyze the GSTM1 and GSTT1 genes polymorphisms in 75 with oligospermia infertility and 36 healthy individuals of Zhuang population from Guangxi Baise area,and then the possibility function of GSTM1 and GSTT1 genes in human oligozoospermia were studied.Results:Analyses of the polymorphisms in GSTM1 and GSTT1 genes showed that GSTM1 defect or combined defects of both GSTM1 and GSTT1 was found more frequent in patients with infertile oligospermia than in the healthy control.Conclusion:GSTM1 and GSTT1 genes may have modulating effects on human spermatogenesis,whose mechanism needs further studies.