Gossypol repressed the gap junctional intercellular communication between Sertoli cells by decreasing the expression of Connexin43.

Previous studies showed that gossypol could block the gap junctional intercellular communication (GJIC) between cultured cells. The present study was designed to investigate the effects of gossypol on the GJIC and the expression of connexin43 (Cx43) in the cultured cells. A Sertoli cell line, TM4, was treated with different concentrations of gossypol 1.25, 2.5, 5, and 10micromol/L for 6, 12, 24, and 48h. Cell viability was assessed with CCK-8 assay. GJIC in the cells was determined using the scrape loading and dye transfer (SLDT) assay; the expression of Cx43 was detected by RT-PCR, immunofluorescence and Western blot analysis. The SLDT assay showed gossypol significantly decreased GJIC between adjacent cells. RT-PCR, immunofluorescence and Western blot analyses demonstrated the expression of Cx43 in TM4 cells. The expression of Cx43 was gradually decreased with the increasing concentrations of gossypol, and the effect occurred as early as 6h after the treatment and continued until 48h. These results suggested that gossypol impaired GJIC by decrease of Cx43 expression in the cells, which is important for Sertoli cells to regulate spermatogenesis.