Effect of silencing HIF-1α gene on testicle spermatogenesis function in varicocele rats

This study uses the CRISPR/Cas9 gene editing technique to silence the expression of hypoxia-inducible factor-1α (HIF-1α) gene and investigate its effect on testicle spermatogenesis function in varicocele (VC) rats. Sprague Dawley rats were divided into four groups; the control, VC model, VC+HIF-1α-lentivirus and VC+Luciferase-lentivirus group. The sperm count and survival rate were analyzed using computer-aided sperm analysis. The morphological changes of seminiferous tubules were observed by a microscope. Expressions of HIF-1α, Bax, cleaved caspase-3 and Bcl-2 were detected via Western blot, immunofluorescence and real-time polymerase chain reaction methods. One-way ANOVA was used to analyze the differences between groups. The sperm count and survival rate were significantly lower (p < 0.05) and the seminiferous epithelium was more disordered in the VC group than that in the control group. The expression of Bax and cleaved caspase-3 were increased and Bcl-2 was reduced in the VC group than the control group. Compared with the VC group, sperm count and survival rate noticeably increased (p < 0.05), seminiferous epithelium was inordered arrangement and fewer spermatogenic cells were injured in the VC+HIF-1α-lentivirus group. Expression of Bax and cleaved caspase-3 were decreased significantly in the VC+HIF-1α-lentivirus group compared with the VC group and VC+Luciferase-lentivirus group (p < 0.05), whereas the expression of Bcl-2 was increased (p < 0.05). No significant difference was observed between the control group and the VC+HIF-1α-lentivirus group (p > 0.05). Results show that the apoptosis of spermatogenic cells was decreased and the testicle spermatogenesis function was significantly improved after silencing HIF-1α gene in testis of VC rats. HIF-1α may play a crucial role during spermatogenesis in VC inducing male infertility.