Effect of hydrogen on endotoxin-induced expression of zonula occludens-1 in human colon epithelial cells / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of hydrogen on endotoxin-induced expression of zonula occludens-1 (ZO-1) in human colon epithelial cells (Caco-2 cells).Methods Caco-2 cells were cultured routinely,seeded in Transwell chambers or wells,and randomly divided into 4 groups (n =45 each) using a random number tablecontrol group (group C);hydrogen-rich culture medium group (group H);endotoxin group (group E);hydrogen-rich culture medium + endotoxin group (group HE).The cells were cultured in high-glucose DMEM culture medium in group C.The cells were incubated in hydrogen-rich culture medium containing hydrogen 0.6 mmol/L in group H.The cells were incubated in highglucose DMEM culture medium containing 50 μg/ml lipopolysaccharide in group E.The cells were incubated in hydrogen-rich culture medium containing 50 μg/ml lipopolysaccharide and 0.6 mmol/L hydrogen in group HE.Transepithelial electrical resistance (TEER) was measured before incubation or culture,and at 6,12 and 24 h of incubation or culture.The viability of Caco-2 cells was measured by methyl thiazolyl tetrazolium assay at 24 h of incubation or culture.The expression of ZO-1 mRNA in Caco-2 cells was determined using real-time reverse transcriptase polymerase chain reaction at 6,12 and 24 h of incubation or culture.The distribution of ZO-1 in Caco-2 cells was observed by immunofluorescence at 24 of incubation or culture.Results Compared with group C,TEER was significantly decreased at 6,12 and 24 h of incubation or culture,and the expression of ZO-1 mRNA was significantly down-regulated in E and HE groups (P＜0.05),and no significant change was found in the parameters mentioned above in group H (P＞0.05).Compared with group E,TEER was significantly increased at 6,12 and 24 h of incubation or culture,and the expression of ZO-1 mRNA was significantly up-regulated in group HE (P＜0.05).The distribution of ZO-1 protein in cell membrane became discontinuous,and the distribution of ZO-1 protein in cytoplasm was significantly increased in group E.Compared with group E,the distribution of ZO-1 protein in cell membrane was significantly increased and gradually became continuous,and the distribution of ZO-1 protein in cytoplasm was significantly decreased in group HE.Conclusion The mechanism by which hydrogen reduces the damage to human colon epithelial cell barrier is related to up-regulation of ZO-1 expression and improvement in the redistribution of ZO-1 protein.