Connexin-43: A possible mediator of heat stress effects on ram Sertoli cells

Sertoli cells are an essential group of cells in seminiferous epithelium which provide nutritional and structural supports for spermatogenic cells via cell junctions. In this study, the gene expression of connexin-43, the most abundantly distributed gap junction protein of cells, was investigated in ram Sertoli cells under mild and severe heat stresses with real-time quantitative PCR. Sertoli cells were isolated from testes of 10 lambs. After culture and 3 passages, they were treated with mild (39 ˚C) and severe (42 ˚C) heat stress for 6 hr. The results showed a significant reduction in the percentage of live cells under severe heat stress compared to the control group (32 ˚C), (p <0.05). Relative quantification analysis revealed significantly higher (3.80 fold increase) values of connexin-43 transcripts in severely heat stressed group than control group (p <0.05). It is concluded that challenging Sertoli cells with 42 ˚C heat could threaten their survival, and overexpression of connexin-43 may cause dysfunction of Sertoli cells due to heat stress. These findings can be useful to identify the molecular mechanisms involved in adverse effects of heat stress on male reproduction and enhance our understanding of its pathogenesis.