Expression of Hsp70 and Hsp27 in lens epithelial cells incontused eye of rat modulated by thermotolerance or quercetin

摘要

Purpose: To investigate the dynamic expression of heat shock protein(Hsp)70 and Hsp27 in lens epithelial cells (LECs) of contused eyes andthe effects of heat shock and quercetin.Methods: Rat eyes were randomized into three groups: contusion, heatshock, and quercetin. Eye contusions were induced by dropping a 20 gsteel ball from a height of 20 cm for 100 times. Heat shock was inducedby raising the core body temperature to 40.5-41.5 °C for 8 min, 2-3h before eye contusion. Quercetin, an inhibitor of Hsp expression, wasgiven via gavage (100 mg/kg) 2-3 h before eye contusion. Experimentaleyes were enucleated at 0, 1, 3, 6, and 24 h following each grouptreatment for the detection of Hsp70 and Hsp27 expression in LECs usingRT-PCR. Lens sections were examined by immunohistochemistry withantibodies to Hsp70.Results: Basic expression of Hsp70 and Hsp27 was observed in LECs.Expression of Hsp70 in LECs was increased after contusion in atime-dependent manner. Preconditioning hyperthemia (45 °C, 8 min)resulted in a significant increase of Hsp70 expression compared to thebase level, and enhanced the expression in each subgroup in contrast tothe corresponding subgroup in the contusion group. However, Hsp70 levelsin the 1-6 h subgroup in the quercetin group was significantly lower.There was no notable change of expression of Hsp27 between each group.Immunostaining of Hsp70 was prominent in LECs of contusion eyes and heatshock eyes compared with those in normal eyes. Immunostaining of Hsp70was faint in LECs of quercetin eyes.Conclusions: Increased expression of Hsp70 in LECs of contused eyesmay play a protective role against degeneration of lens protein. Thermalpreconditioning possibly protects against lens injury by increasing theexpression of Hsp70. Endogenous protective mechanisms may be importantin eye contusion.