Abstract:

BACKGROUND: Special anatomical location makes eye lens expose to stressful situation in a long term. Whether the environmental stress can up-regulate the expression of heat shock proteins in human lens epithelial cells? Whether the synthesis increase occurs in the level of transcription or translation, remains unclear.
OBJECTIVE: To observe the expression and location of heat shock protein 27 (HSP27) in human lens epithelial cells under the conditions of high temperature and oxidative stress, and to investigate the pathogenesis of the cataract.
METHODS: Human lens epithelial cells cultured in vitro were exposed to heat (45 ℃) and oxidative stress (50 mmol/L H2O2) for 30 minutes, respectively, then allowed to recover normal conditions. At different intervals (0, 2, 4, 6, 16, 24 hours), immunocytochemistry and reverse transcription polymerase chain reaction were used to determine the expression and localization of HSP27.
RESULTS AND CONCLUSION: HSP27 was shown to express in both physiological and stressful conditions. The expressions of HSP27 mRNA and protein were remarkably increased at 2 hours following heat and oxidative stress, and reached the peak at 6 hours. HSP27 could maintain a high level for 16 hours. The stress-induced HSP27 protein positive particles transferred from the cytoplasm to the nucleus, and gradually shift back to the cytoplasm along time. It is proved that HSP27 exists in lens epithelial cells and can be increased after stress. The data suggested it may play an important protective role in lens epithelial cells in respond to cellular stress.