Role of Epididymis and Testis in Nuclear Factor Erythroid 2-Related Factor 2 Signaling in Mouse Experimental Cryptorchidism

Background: Cryptorchidism is a common gonadal disease in neonates that promotes oxidative stress and reactive oxygen spices production following the presence of testicles in ectopic places. Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling could prevent oxidative stress damage through the Nrf2-driven antioxidants. Objectives: The current study aimed at evaluating the pattern of gene expressions related to this pathway in testis and epididymis of mice experimentally subjected to cryptorchidism. Methods: The current experimental study was conducted on 48 male mice randomly divided into six groups at Arak University of Medical Sciences, Arak, Iran, 2018. Cryptorchidism was induced in the left testis of mice in five experimental groups by removing the testis from the scrotum and suturing it to the muscles of the abdominal wall. One group remained intact as the control group. Sperm parameters were analyzed one day, as well as one, two, four, and eight weeks after the operation. The expression of Nrf2, NQO1, HO1, and Keap1 genes in testis and epididymis was assessed using quantitative reverse transcriptase-polymerase chain reaction. Results: Sperm analysis showed a significant decrease in sperm number, viability, normal morphology (except in the one day group), and motility in all experimental groups compared to the control group (P <= 0.05). The expression level of Nrf2 (in testis tissue), Keap1 (in both testis and epididymis), and HO1 (in testis tissue) showed no changes over the time (P > 0.05), while the expression of other genes decreased remarkably (P <= 0.05) in both testis tissue and epididymis in a time-dependent manner. Conclusions: The current study findings showed that the expression of genes involved in NRF2 systems decreased in the epididymis of cryptorchid mice more than testis and it suggested that treatment with Nrf2 inducer could decrease destructive effects of cryptorchidism on the reproductive system.