2-hydroxyoestradiol and 2-methoxyoestradiol, two endogenous oestradiol metabolites, induce DNA fragmentation in Sertoli cells

摘要

Elevated intratesticular levels of hydroxyoestradiols and methoxyoestradiols, two classes of endogenous oestradiol metabolites, have been associated with male infertility. The aim of this study was to explore the effects of 2-hydroxyoestradiol (2OHE(2)), 4-hydroxyoestradiol (4OHE(2)), 2-methoxyoestradiol (2ME(2)) and 4-methoxyoestradiol (4ME(2)) on Sertoli cell viability. For this, TM4 cells were incubated with different concentrations of these metabolites for 24 h to then evaluate the viability and DNA integrity by MTS and TUNEL assay respectively. The participation of classical oestrogen receptors and the involvement of oxidative stress and apoptotic mechanisms were also evaluated co-incubating TM4 cells with these estradiol metabolites and with the drugs ICI182780, N-acetylcysteine and Z-VAD-FMK respectively. Only high concentrations of 2OHE(2) and 2ME(2) decreased cell viability inducing DNA fragmentation. In addition, ICI182780 did not block the effect of 2OHE(2) and 2ME(2), while N-Acetylcysteine and Z-VAD-FMK only blocked the effect of 2OHE(2). Moreover, 2OHE(2) but not 2ME(2) induced PARP and caspase-3 cleavage. Finally, lower 2OHE(2) and 2ME(2) concentrations (0.01-0.1-1.0 mu mol l(-1)) decreased Sertoli cell viability 48 h post-treatment. Our results support the hypothesis that elevated intratesticular 2OHE(2) or 2ME(2) concentrations could be related to male infertility since 2OHE(2) by apoptosis and 2ME(2) by undetermined mechanisms induce DNA fragmentation in Sertoli cells.