Additive effect of Bisphenol A and Pefluoro-sulphoctanoic acid exposure at subacute toxic levels, on a murine model of sertoli cell

Endocrine disruptors (EDs) interfere with the endocrine system leading to health consquences and reproductive derangements. Most EDs are environmental pollutants whose risk evaluation is hampered by the simultaneous exposure to a number of chemicals. Here we investigated the possible mechanistic involvement of Sertoli cells, the nurse cell population in the seminiferous tubule, in the reproductive toxicity of Bisphenol A (BPA) and perfluoro-octane sulphonate (PFOS), two acknowledged EDs, at recognized subacute toxic levels.

Mouse Sertoli cell line TM4 were exposed for 24 h to 40 ng/mL BPA or 30 ng/mL PFOS or their association. Cell proliferation was measuerd by MTT assay. Cell apoptosis was evaluated with Annexin-V/propidium iodide staining. Protein expression analysis was peformed by western blotting.

Compared to unexposed controls (100.0 ± 3.5%), cells exposed to BPA (79.5 ± 3.5%) or PFOS (76.0 ± 7.9%) showed reduced survival rate (P < 0.001 vs control). The exposure to the mixture of BPA and PFOS was associated with a further reduction of cell survival (63.9 ± 7.2%, P < 0.001 vs control) and an increase of the percentage of apoptotic cells (13.7 ± 4.6% control, 40.3 ± 13.5% BPA, PFOS 28.7 ± 5.6%, 67.1 ± 19.6% BPA + PFOS P = 0.001 vs control; P = 0.022 vs BPA). The exposure to the combination of BPA and PFOS was associated with Akt-signaling pathway activation and with the downstream caspase 3 cleavage. In addition, the exposure to the combination of BPA and PFOS was associated with NF-κB activation and increased expression of FasL.

Subacute toxic levels of BPA and PFOS display additive effects on Sertoli cell apoptosis with the possible involvement of FasL-dependent germ cell apoptosis.