Androgens alter the promoter activity of anti-Müllerian hormone (AMH) and Cyp26b1 genes in prepubertal Sertoli cells

SCHTEINGART, H.; EDELSZTEIN, N.; REY, R.

Boston

Congreso; Society for Developmental Biology 75th Annual Meeting | International Society of Differentiation 19th International Conference; 2016

Society for Developmental Biology & International Society of Differentiation

Inthe testis, pubertal Sertoli cell maturation is characterized by a decrease inAMH expression at the time when germ cells enter meiosis induced by retinoicacid (RA). In earlier stages of development, RA action is blocked by CYP26B1 expressedin peritubular and Sertoli cells. Since AMH inhibition and meiosis initiationare simultaneous, we sought to test if androgens could have an inhibitoryeffect on both AMH and Cyp26b1 gene regulation.To test androgen effect on AMH promoter activity, a prepubertalSertoli cell line (SMAT1) was transiently co-transfected with the androgenreceptor (AR) and AMHpromoter-luciferase constructs. Treatment with dihydrotestosterone (DHT, 10-7M) resulted in a significant decrease in the activity of a (-3068 to -1)bp- anda (-423 to -1)bp-AMH promoter,but not of a (-3068 to -1916)bp promoter, suggesting that the proximal regionof the AMH promoter is involvedin the inhibition. Since this region lacks known androgen response elements, wetested if inhibition could be due to interaction of the AR with AMH-transactivating factors. DHTinhibition persisted when GATA4- and AP1-, but not SF1-, sites were mutated.Regarding androgen effect on the Cyp26b1 promoter, in conflict with ourhypothesis, a significant increase in promoter activity was seen for theconstructs including ~9kb 5´-upstream of the first ATG or 3kb, 2.2kb, 1.3kb or0.6 kb 5?-upstream of Cyp26b1promoter, showing a positive regulation of Cyp26b1by androgens.DHT treatment inhibits AMH but increases Cyp26b1 promoter activity in presence ofthe AR in SMAT1 cells. AMH inhibition by androgens requires intact SF1sequences in the proximal region of the AMHpromoter.