The Mechanism Of Kistrin's Regulations On Collagen Metabolism Of LECs On PCO Models Of Normal And Diabetic Rabbits

OBJECTIVE:It is confirmed that kinstrin can inhibit the proliferation, adhesion and migration of human lens epithelial cells (LECs) in vitro in previous studies. We applied rabbit's posterior capsular opacification (PCO) model to investigate the changes and the relationships of the gene expression of collagen IV in the extracellular matrix(ECM), matrix metalloproteinases 2(MMP-2) and tissue inhibitor of metalloproteinase 2(TIMPs), for MMP-2 is the regulation factor of ECM while TIMPs is the inhibitor of MMP-2; Another aim of this study is to explore the effect of Kistrin on the expression of focal adhesion kinase(FAK) and its downstream genes which is the key signal factor in intracellular signal transduction pathways. In total, approaching the molecular mechanism of Kistrin's regulations on collagen metabolism of LECs on PCO models of normal and diabetic Rabbits and providing a strong theoretical basis of prevention and treatment of PCO by using disintegrin is the major objective of this study.METHOD:①Different concentrations (0,40,80,160ng/ml) of Kistrin were injected into the anterior chamber of the rabbits PCO models at the end of the operations. The occurrence and morphology of PCO were observed by slit- lamp microscope. Then the eyeballs were removed at 14 days and 3 months to detect the expression of proliferating cell nuclear antigen (PCNA) in LECs. The toxic affect on cornea and retina were evaluated to definite the safe concentration of Kistrin.②PCO models of diabetic rabbits were made. All PCO models were divided into group A,B,C,D which represented control group of normal blood sugar, Kistrin experimental group of normal blood sugar, control group of high blood sugar and Kistrin experimental group of high blood sugar, respectively,. The expressions of PCNA, connexin43 and collagen IV in LECs of rabbits at 14 days were evaluated in all groups.③PCO models were divided into blank control group, negative control group and Kistrin experimental group. And the expression levels of MMP-2, TIMP-2, FAK, ERK2 gene of LECs were evaluated at 14 days.RESULTS:①Kistrin with concentration of 80ng·ml-1 could significantly inhibit the proliferation of LECs and the toxic affect on cornea and retina cells were not detected at 14 days and 3 months.②Compared with(去掉了that in) group A, the expression of PCNA and collagen IV in group B were significantly reduced at both time points. The expression of Cx-43 in group B was significantly reduced in early time (14 days). The expressions of PCNA and Cx-43 in group C were significantly higher than those in group A at 14 days, and it significantly reduced in group D but was still higher than that in group B.③In normal blood sugar group, the mRNA expressions of MMP-2 and TIMP-2 in negative control group were significantly higher than those in the blank control group (p<0.05). The gene expressions of FAK and ERK had no change (p> 0.05). Compared with the negative control group, the mRNA expression of MMP-2 in Kistrin experimental group was significantly lower (p<0.05), while the mRNA expression of TIMP-2 un-change (p>0.05). There was no change of the mRNA expression of FAK or ERK between them.CONCLUSION:Disintegrin Kistrin can effectively inhibit the formation of PCO. Its mechanism is related to the change of the ratio of MMP-2/TIMP-2, but may be unrelated to MAPK signaling pathway. The incidence of PCO in diabetic rabbits are significantly higher than that in normal blood glucose rabbit, Kistrin can also reduce the formation of PCO in diabetic rabbit.