Effect of H2O2,extracellular matrix and out segment of photoreceptor on expression of focal adhesion kinase in RPE cell / 中华实验眼科杂志

ABSTRACT

Background The underlying mechanism of choroidal neovascularization(CNV) is multifactorial and complex.Focal adhesion kinase(FAK) plays a crucial role in controlling essential cellular processes and influencing distinct steps of the angiogenic response.But to our knowledge,seldom study on the effect of FAK on CNV formation has been reported previously.Objective In this study,the effect of several CNV risk factors on the expression of FAK in cultured retinal pigment epithelium(RPE) cells was investigated to illuminate effect of FAK on CNV.Methods Human RPE cells were isolated from donor eyes and exposed to H2O2,swallow of outer segment of photoreceptors(POS) and extracellular matrix(ECM) separately with the treating as follows:RPE cells were co-cultured with 10,20,50 and 100μmol/L H2O2 for 20 days;POS(1×106/ml) were co-cultivated with RPE cells for 20 days(setting control group,POS group,hypoxia group with 200μmol/L CoCl2,and POS+hyoxia group);RPE cells were cultured on the plates coated with 100mg/L fibronectin(FN),laminin(LN) or collagen typeⅠfor 30minutes or 1 hour.The expression of FAK and pFAK in RPE cells were examined by Western blot analysis.Results FAK was highly expressed in the 20μmol/L and 50μmol/L H2O2 groups compared with control group(P＜0.01);while he expression level of pFAK was reduced after treated with H2O2 in comparison with the control group(P＜0.01).After cultured with POS for 20 days,the undigested lysosome could be observed in RPE cells.The expressions of FAK and pFAK in RPE cells were not significantly changed between control group and POS groups(P＞0.05),but those in hypoxia group were significantly up-regulated in comparison with control group(P＜0.01).Compared with the hypoxia group,the expression amount of pFAK was elevated in POS+hyoxia group(P＜0.01).In comparison with control group,the increased pFAK expression was seen in FN,LN and collagen typeⅠtreating for 1-hour groups(P＜0.05,P＜0.01).Conclusion FAK pathway participates in several CNV-initiated signaling,such as H2O2,POS and ECM,in cultured RPE cells.It is reasonable to believe that FAK potentially plays an important role in CNV-dependent disorder.