Bisphenol S stimulates Leydig cell proliferation but inhibits differentiation in pubertal male rats through multiple mechanisms

Abstract Bisphenol S (BPS) is a novel bisphenol A (BPA) analogue, a ubiquitous environmental pollutant that disrupts male reproductive system. Whether BPS affects Leydig cell maturation in male puberty remains unclear. Male Sprague–Dawley rats (age of 35 days) were daily gavaged to 0, 1, 10, 100, and 200 mg/kg/day from postnatal days 35–56. BPS at 1–10 mg/kg/day and higher doses markedly reduced serum testosterone and progesterone levels but it at 200 mg/kg/day significantly increased estradiol level. BPS at 100 and 200 mg/kg/day significantly elevated serum luteinizing hormone (LH) levels. BPS at 1–10 mg/kg/day and higher doses significantly reduced inhibin A and inhibin B levels. BPS at 100 and 200 mg/kg/day markedly increased CYP11A1 + Leydig cell number, but did not affect HSD11B1 + (a mature Leydig cell marker) cell number. BPS at 10 mg/kg/day and higher doses significantly downregulated the expression of Cyp11a1 and at 100 and 200 mg/kg/d significantly lowered Cyp17a1 , Hsd11b1 , and Nr5a1 in the testes. BPS at 100 and/or 200 mg/kg/day significantly elevated Lhb in the pituitary. BPS at 100 and 200 mg/kg/day significantly increased the phosphorylation of AKT1, AKT2, and CREB without affecting total AKT1, AKT2, and CREB levels. BPS at 1–100 μM significantly suppressed testosterone production and induced proliferation of primary immature Leydig cells after 24 h of treatment and these actions were reversed by estrogen receptor α antagonist, ICI 182780, and partially reversed by vitamin E. BPS at 0.1–10 μM significantly increased oxidative stress of Leydig cells in vitro. BPS also directly inhibited 17β‐hydroxysteroid dehydrogenase 3 activity at 10–100 μM. In conclusion, BPS causes hypergonadotropic androgen deficiency in male rats during pubertal exposure via activating ESR1 and inducing ROS in immature Leydig cells and directly inhibiting 17β‐hydroxysteroid dehydrogenase 3 activity.