Germ cell apoptosis induced by experimental cryptorchidism is mediated by molecular pathways in mouse testis

The aim of the study was to characterise the alterations in expression of some apoptosis regulators in unilaterally and bilaterally heat-treated mouse testes at different time intervals to 42 days after surgery. Cryptorchidism was induced in immature mice by returning the testis to the abdominal cavity via a surgical procedure. Transcript levels of Bax, Bcl-2 proper, p53 and survivin mRNA and protein were determined in normal and cryptorchid testes using reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. RT-PCR data verified the elevation of p53 expression and decrease of Bax and Bcl-2 proper mRNA in the cryptorchid testis in a time-dependent manner. The expression of survivin 140 and 40 variants strongly decreased in the bilateral groups compared with unilateral and control groups. These changes were significantly different in the bilateral groups in comparison with the unilateral groups. Immunohistochemistry data showed that the intensity of p53 and Bax expression mainly increased in the remainder cells in the cryptorchid testis and the rates of Bcl-2 proper and survivin expression decreased mainly in the bilateral groups. These observations suggest that multiple molecular pathways participate in the germ cell apoptosis induced by cryptorchidism.