[Expression of heat shock protein 70 and heat shock protein 27 in lens epithelial cells induced by contusion and thermotolerance in rat model].

OBJECTIVE: To study the dynamic expression of heat shock protein (HSP) 70 and HSP27 in lens epithelial cells (LECs) in contused eyes of rat model and to detect the dynamic change of the expression of HSP70 and HSP27 after thermotolerance.

METHODS: Forty-eight Sprague-Dawley (SD) rats were randomized into two groups: contusion group and thermotolerance group. Contusion eyes were induced by dropping a steel ball of 20 g from the height of 20 cm for 100 times. Thermotolerance was induced by raising the core body temperature of rat to 40.5-41.5 degrees C for 8 min, 2-3 h before eyes contusion. HSP70 and HSP27 expression in the LEC were measured using one-tube RT-PCR.

RESULTS: Contusion of eyes resulted in increase of HSP70 expression. Expression of HSP70 increased to 4.59 +/- 0.12 at 1 h after contusion, reached the highest level of 7.72 +/- 0.27 at 3 h after contusion, and reduced to the normal level of 1.32 +/- 0.14 at 24 h after contusion. Preconditioning hyperthermia resulted in significantly increase of HSP70 expression. There was no significant change of HSP27 expression in both groups.

CONCLUSIONS: Increased expression of HSP70 in LECs of contused eyes possibly protects the proteins of lens against degeneration. Thermal preconditioning might suppress lens injury induced by contusion via increasing the expression of HSP70.