CEDIE   05498
CENTRO DE INVESTIGACIONES ENDOCRINOLOGICAS "DR. CESAR BERGADA"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Immaturity Cell Markers in Sertoli Cells: Regulation of Cyp26b1 (Retinoic Acid (RA)-Degrading Enzyme) and Anti-Müllerian Hormone (AMH) Expression by Androgens
Autor/es:
REY, R.; SCHTEINGART, H.F.; EDELSZTEIN, N.
Lugar:
Mar del Plata
Reunión:
Congreso; LXI Reunion Anual de la Sociedad Argentina de Investigación Clínica; 2016
Institución organizadora:
Sociedad Argentina de Investigación Clínica
Resumen:
RA-signaling responsible for meiosis initiation is temporarily blocked in fetal testis by CYP26B1. AMH expression in Sertoli cells is inhibited by androgens at the onset of puberty. Little is known about these two phenomena. We sought to test if androgens have a direct effect on AMH and Cyp26b1 promoter activity through luciferase assays in prepubertal Sertoli cells (SMAT1) co-transfected with the androgen receptor (AR) and mutants of AMH or length variants of Cyp26b1 promoter. Results, expressed as percentage (mean±SEM), are compared against basal activity (theoretical value: 100%) using a one sample t-test. We have already shown the role of the proximal AMH promoter and SF1 recognition sequences in the inhibition caused by DHT (10-7M) (Edelsztein et al., SAIC 2015). Here, we show that DHT inhibition is reversed by treatment with the anti-androgen enzalutamide/MDV3100 (10-5M) (90.7±5.3%;P=0.178, n=4), reaffirming the role of the AR in this inhibition. We further analyzed the inhibitory effect on AMH promoter activity by mutating the SF1 sites independently. Inhibition persisted, whether the site at -92b (49.3±5.3%;P=0.001, n=5) or -218b (54.8±6.4%;P=0.019, n=3) was mutated, indicating that annulment of both SF1 sites present in the AMH promoter is necessary to abrogate the inhibitory effect of androgens. Regarding Cyp26b1, a significant increase in promoter activity was observed only when cells were co-transfected with the AR and a Cyp26b1 construct containing ~9kb 5´-upstream of the first ATG (806.2±141.5;P=0.016, n=3) or 3kb (258.0±19.0;P=0.004, n=3), 2.2kb (356.8±66.7;P=0.031, n=3), 1.3kb (164.0±14.54;P=0.022, n=3) or 0.6kb (135.5±5.0;P=0.019, n=3) regions 5?-upstream of Cyp26b1 promoter; unveiling a regulation of Cyp26b1 by androgens. DHT treatment is able to alter Cyp26b1 and inhibit AMH promoter activity through the AR in SMAT1 cells. The latter requires at least one intact SF1 recognition sequence present in the proximal region of the AMH promoter to occur.