Effects of interleukin-6 in wound healing of human biliary epithelial cells

Abstract

Objective To investigate the mechanism of interlekin-6 (IL-6) in wound healing of human biliary epithelial cells ( BECs ).Methods BECs were cultured in IL-6 at different concentrations:0 ng/L(0 ng/L group),10 ng/L (10 ng/L group),50 ng/L (50 ng/L group),100 ng/L (100 ng/L group),1000 ng/L ( 1000 ng/L group).The effects of IL-6 on the phosphorylation of signal transducer and activator of transcription 3( STAT3 ) and the expression of trefoil family factors 3 (TFF3) were detected.BECs were divided into untreated group,STAT3-RNAi group (BECs transfected with STAT3 RNAi adenovirus) and Control-RNAi group (BECs transfected with vacant RNAi adenovirus).The effects of IL-6 on the expression of TFF3 were detected after RNAi of STAT3.In vitro wound models were constructed for the untreated group,STAT3-RNAi group and Control-RNAi group,and the effects of IL-6 and TFF3 on BECs of the 3 groups were detected.All data were analyzed by using the Student's t test,analysis of variance or Sidak test.Results The expressions of phosphorylated STAT3 in the 50 ng/L group,100 ng/L group and 1000 ng/L group were 0.240 ± 0.052,0.714 ± 0.124,0.327 ± 0.069,respectively,which were significantly higher than 0.033 ± 0.011 of the 0 ng/L group (q =5.246,17.260,7.451,P ＜ 0.05 ).The contents of mRNA and protein of TFF3 increased as the increase of IL-6 concentration (q =12.045,9.889,P ＜ 0.05).After RNAi of STAT3 of the BECs,the expression of TFF3 decreased when the concentration of IL-6 was 1000 ng/L.The expression of TFF3 of the STAT3-RNAi group was 0.037 ± 0.005,which was significantly lower than 0.267 ± 0.038 of the Control-RNAi group and 0.301 ± 0.042 in the untreated group ( q =12.135,13.929,P ＜ 0.05 ).In the in vitro wound model,the speed of BECs migration in the STAT3-RNAi group was (9.1 ± 1.5 ) μm/h,which was slower than (25.1 ± 3.8 ) μm/h of the Control-RNAi group after 12 hours of interference with IL-6 (q =7.737,P ＜ 0.05 ).The speed of BECs migration of STAT3-RNAi group was (39.2 ± 4.7) μm/h after adding 1 g/L of recombinant TFF,which was significantly faster than that of the Control-RNAi group (q =14.507,P ＜0.05).Conclusion IL-6 promotes cell migration and wound healing by activating STAT3 and up-regulating TFF3 expression. Key words: Biliary epithelial cells; Wound healing; Interleukin-6; Signal transducer and activator of transcription 3; Trefoil family factor 3