Protective effect and mechanism of alpha-lipoic acid on lead-induced Sertoli cell damage in rooster testes

Objective: To investigate the protective effect of alpha-lipoic acid on lead-induced Sertoli cell injury and its potential molecular mechanisms using primary Sertoli cells from rooster testes. Methods: Primary Sertoli cells from 6-week-old rooster testes were divided into four goups. They were treated with serum-free DMEM-F12 medium (the control group), 40 μM lead acetate, 100 μM alpha-lipoic acid, or 40 μM lead acetate plus 100 μM alpha-lipoic acid for 24 h, respectively. Cell viability, reactive oxygen species levels (DCFH-DA), antioxidant enzyme activities (catalase, superoxide dismutase), blood-testis barrier-related proteins, nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway components, proliferation/apoptosis markers (Western blot), and related gene expression (qPCR) were analyzed. Results: Alpha-lipoic acid treatment significantly reduced lead-induced reactive oxygen species (ROS) production by 58.3% compared to the lead acetate group ( P <0.05), enhanced catalase activity by 35.8% ( P <0.05), and elevated lead-reduced PCNA expression by 47.2% ( P <0.05). Lead acetate 40 μM plus 100 μM alpha-lipoic acid significantly increased Nrf2 expression by 78.9% and HO1/NQO1 expression by 97.5% and 89.4%, respectively ( P <0.05), significantly upregulated the expression of Bcl2 protein and significantly downregulated Bax protein expression ( P <0.05). Conclusions: Alpha-lipoic acid enhances the antioxidant properties of Sertoli cells by activating the Nrf2 pathway, restores lead-induced excessive autophagy, and inhibits apoptosis, thus alleviating the damage caused by lead in Sertoli cells.