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.
ABSTRACT
As a Y-box transcdption factor,ZONAB performs biological functions of promoting the proliferation and inhibiting the differentiation of epithelial cells,regulating the function of tight junctions,as well as promoting the epithelial-mesenchymal transition.ZONAB plays its transcriptional activity by interacting with other tight junction elements and genes,proteins,enzymes and transcription factors which are enrolled in the cell cycle.Meanwhile,its transcriptional activity is also regulated by many other factors.ZONAB takes part in the proliferation,differentiation of epithelial cells,stress reaction,organogenesis and oncogenesis progress,which has been proved to be associated with the genesis and development of many diseases.The regulation mechanism and clinical significance of ZONAB has been the focus at home and abroad.