Hypoxia reduces the proliferation and occludin expression of primary Sertoli cells

Objective: To investigate the effect of hypoxia on the proliferation and occludin expression of primary rat Sertoli cells.Methods: We constructed a primary Sertoli cell system by two-step enzymatic digestion in 18-22 days old Wistar rats and identified it by oil red O and immunofluorescence methods.We randomly divided the Sertoli cells into five groups to be cultured in oxygen at the concentrations of 20%,15%,10%,5% and 1%,respectively,for 6,12,24,48 and 72 hours.We detected the proliferation of the Sertoli cells by CCK-8 assay,determined the expression of occludin by Western blot,and analyzed the differences among the five groups.Results: Oil red O staining revealed red lipid droplets in the cytoplasm of the Sertoli cells,and immunofluorescence showed the positive expression of the FasL protein,with the purity of Sertoli cells over 95% in vitro.Compared with the 20% normoxic group,the proliferation of the Sertoli cells was gradually reduced in the 15% and 10% hypoxia groups,and significantly declined in the 5% and 1% groups(P0.01).At 12 hours,the expression of occludin began to decrease with the prolonging of time and reduction of oxygen concentration(P0.01).Conclusion: Hypoxia suppresses the proliferation of Sertoli cells and reduces the expression of occludin.It could be inferred that hypoxia could damage the integrity of blood-testis barrier and spermatogenesis of the testis.