Expression Of Heat Shock Protein 70 And 27 In The Epithelial Cells Of Common Cataract Lens

Objective: Recent studies have shown that a wide variety of stress including ischemia, variation, hypoxia, oxidative stress, pH extremes, nutrient limitation, osmotic agents and notorious chemicals , can rapidly induce the expression of the gens for HSP, subsequent induce endogenous protective mechanisms. In mammalian cells, HSPs are commonly classified according to their size, for example, HSP90, HSP70, HSP60, HSP20 to HSP30 KDa(small HSP). In the mammalian lens there are three small molecules grams of protein: HSP27, crystalline-αA and crystalline-αB. Regardless of the size of the small variance, small HSPs in all mammals, except crystalline-αA and crystalline-αB, are known as HSP27. Research has found that there is not vascular and nerve supply in the lens, and its unique anatomical structure is easy to be damaged by the various stimulating factors, for example, the growth of age or exposed in the long-term UV irradiation, molecular chaperone role of crystalline-αand the human HSP is significantly decreased, which caused enzyme activity that can keep the metabolism of crystalline and resist the oxidation deprived, the lens transparency declining, leading to the occurrence of cataract. Most of HSPs are constructive proteins, only parts of them can be induced by stress, such as HSP70 and HSP27.This study was designed to investigate the expression of HSP70 and HSP27 in lens epithelial cells (LECs) in congenial cataract, cortical cataract and traumatic cataract, to determine the effects of HSP70 and HSP27 in the cause of cataract.Method: The expression of HSP70 and HSP27 in human epithelial cells is assayed using immunohistochemical streptavidin-peroxidases(S-P) method on total 46 cases including senile cortical cataract 20 cases, the traumatic cataract lens 12 cases, congenital cataract lens 10 cases and 6 normal LECs. Then positive cells of the human LECs are counted and the positive expression of regional integral optical density (IOD)is calculated. Results: Through immunohistochemical method, HSP70 and HSP27 in each group of LECs can be expressed in both the normal and cataract LECs. The expression of cataract groups is higher than that of normal control group, and there is a statistically significant difference (P <0.05).Traumatic group expression of HSP27 and HSP70 is highest in all the groups. In addition, The expression of HSP27 in the LECs is not significant than that of HSP70 (P <0.05).Conclusion: HSP70 and HSP27 may play a critical role during the development and formation of human congenial cataract, cortical cataract and traumatic cataract;and there is a different influence in pathogenesis among cortical cataract, congenial cataract and traumatic cataract.