Effects of bradykinin on the proliferation of rabbit corneal endothelial cells and the expression of tight junction-related proteins ZO-1 and ZONAB / 眼科新进展

ABSTRACT

Objective To investigate the effects of bradykinin (BK) on the proliferation of rabbit corneal endothehal ceils (RCECs) and the expression of tight junction-related proteins zonula occludens-1 (ZO-1) and zonula occludens-1-associated nucleic-acid-binding protein (ZONAB),and to explore the underlying mechanisms of BK on cell proliferation in corneal endothelium.Methods RCECs at logarithmic growth phase were treated with different concentrations of BK (0.01,0.1,1,10 μmol · L-1) BK group,with the controls left untreated.Morphological changes of cells in each group were examined under phase-contrast microscope,and MTT assays were used to detect cell proliferation at 24 h,48 h,72 h,96 h after BK treatment.And,at 72 h,the expression levels of ZO-1 and ZONAB protein were determined by Western blot.Results After 72 h of treatment,the cells in each group were fused into pieces and closely linked into a monolayer;but after 96 h,the growth of the cells was restricted,with the intercellular space become larger and the cells exfoliated.Compared with the control group,BK induced a significant increase of absorbance value and cell viability,and the differences were statistically significant (all P ＜ 0.001),and the promoting effects showed a concentration-dependent manner,and 1 μmol · L-1 BK demonstrated the strongest regulative effect (P ＜ 0.001).Western blot results showed that BK upregulated the expression of ZO-1 and ZONAB protein in a concentration-dependent manner.Conclusion BK can stimulate the proliferation of RCECs in a time-and concentration-dependent manner,and the mechanisms are probably associated with ZO-1/ZONAB-mediated signaling pathway.