Expression of heat shock protein 60 and its correlation with germ cells apoptosis in testis of rats with varicocele

Abstract

Objective To investigate the expression of heat shock protein 60 (HSP60) and apoptosis related protein caspase 3 in testis of rat varicocele (VC) , and the role of HSP60 in apoptosis of testicular germ cells in rats. Methods Thirty-two SD rats were randomly divided into the control group (n= 8) , sham operation group (n=8) and VC model group (n=16). VC rat models were prepared by ligation of the left renal vein. Real-time quantitative PCR and Western blot assay were used to determine the mRNA and protein expression levels of HSP60 in testicular tissues of VC rats; immunoblot assay was used to determine the expression of caspase 3 (activated type) in VC rat testis. We analyzed the relationship between HSP60 and caspase 3 expressions in VC rat testis. Results Compared with the control group and the sham operation group, VC rats had increased testis mRNA and protein levels of HSP60 and caspase 3 (HSP60 mRNA: 2.67±0.42 vs 1.18±0.30, 0.98±0.16, HSP60 protein: 12.02±1.78 vs 2.31±0.34, 3.15±0.60; caspase 3 mRNA: 4.28±0.47 vs 1.45±0.17, 1.38±0.24, caspase 3 protein: 5.44±2.06 vs 1.32±0.84, 1.16±0.76, all P 0.05). In the VC model group, HSP60 and cleaved caspase 3 expression in rat testis tissue were positively correlated (R=0.95, P<0.05). Conclusion HSP60 expression is increased in testis of VC rats, and may be involved in testicular germ cell apoptosis, which in turn essentially contributes to male infertility in VC. Key words: Varicocele; Heat shock protein 60; Testis; Apoptosis