ABSTRACT
Background: Disruption of tight junctions between intestinal epithelial cells followed by loss of barrier function is crucial for the pathogenesis and progression of a variety of gastrointestinal disorders.Aims: To investigate the protective effect of ulinastatin on hydrogen peroxide (H2O2)-induced intestinal epithelial barrier disruption.Methods: Model of intestinal epithelial monolayer barrier was established with Caco-2 cells in vitro,and then divided into four groups: blank control group (without any intervention),H2O2 group (500 μmol/L H2O2),low-dose (500 U/mL) and high-dose (3 000 U/mL) ulinastatin groups (ulinastatin + H2O2).Level of malondialdehyde (MDA) and activity of superoxide dismutase (SOD) were detected;transepithelial electrical resistance (TEER) and flux of sodium fluorescein were measured to assess the barrier function;expression and localization of two tight junction proteins,ZO-1 and occludin were evaluated by Western blotting and immunofluorescence;ultrastructure of tight junctions was observed by transmission electron microscopy (TEM).Results: Compared with the blank control group,treatment of Caco-2 cell monolayers with H2O2 resulted in increase in level of MDA,flux of sodium fluorescein and decrease in activity of SOD,TEER and expressions of ZO-1 and occludin (P all ＜0.05).TEM and immunofluorescence showed that the brusher border of Caco-2 cells in H2O2 group was destroyed,the cell-cell junction was vague and the localization of ZO-1 and occludin was discontinuous and the fluorescence intensity was extremely low.While in ulinastatin groups,especially the high-dose group,all the indices above-mentioned were significantly improved (P all ＜0.05).Conclusions: Ulinastatin protects intestinal epithelial monolayer barrier against H2O2-induced disruption at least partially by its antioxidant activity and modulating expression and localization of tight junction proteins.
ABSTRACT
Objective To study the significance of level changes of serum hydrogen sulfide(H2 S) and interleukin-6(IL-6)in children with hand,foot and mouth disease(HFMD).Methods Nity-two cases with HFMD were enrolled and divided into severe HFMD group(48 cases)and common HFMD group(44 cases).Forty-six healthy children were enrolled as healthy control group.The serum H2 S and IL-6 were detected.Results Acute phase:compared to the healthy control group[H2 S(55.76 ±7.80)μmol /L,IL-6 (61.31 ±13.43)ng /L],the level of serum H2 S significantly reduced and the level of IL-6 significantly increased in severe HFMD group[H2 S(21.72 ±7.52)μmol /L;IL-6(131.33 ±17.82)ng /L]and common HFMD group[H2 S(31.86 ±8.41 )μmol /L;IL-6(95.48 ±15.07)ng /L](P ﹤0.01 ),and there was signifi-cantly difference between the severe HFMD group and common HFMD group(P ﹤0.01 ).Recovery phase:compared to the healthy control group,the serum H2 S level[(34.54 ±13.21 )μmol /L]was lower and IL-6 [(92.73 ±15.25)ng /L]was higher in severe HFMD group(P ﹤0.01 ).The serum H2 S level was negatively correlated with IL-6 in severe HFMD group and common HFMD group(r =-0.31 ,P ﹤0.01 ;r =-0.45, P ﹤0.01 ).Conclusion The serum H2 S and IL-6 participate in the pathological process of HFMD,and the level change can be used as one of indicators of early diagnosis.