Estrogens Are Involved in the Activation of Anti-Müllerian Hormone (AMH) Promoter through an Estrogen Response Element Hemi-Palindrome Present at -1772bp

SCHTEINGART, HELENA; VALERI, CLARA; EDELSZTEIN, NADIA; RIGGIO, MARINA; GIULIANELLI, SEBASTIáN; LANARI, CLAUDIA; REY, RODOLFO

San Diego

Congreso; 97th Annual Meeting of the Endocrine Society. ENDO 2015; 2015

Endocrine Society

AMH is expressed at high levels in prepubertal Sertoli cells of the testis. FSH increases, whereas androgens inhibit, testicular AMH production. In patients with Androgen Insensitivity Syndrome or with Peutz-Jeghers Syndrome, AMH testicular production is increased, concomitantly with estradiol. The AMH promoter contains an estrogen response element hemi-palindrome (½-ERE) at position -1772. In this work we assessed whether estrogens are involved in the increase of the AMH promoter activity in a prepubertal Sertoli cell line, SMAT1.Methods and Results: Reporter assays were performed in SMAT1 cells co-transfected with AMH promoter-luciferase plasmids and expression vectors for human estrogen receptor a (ERa) and/or b (ERb), and incubated with 17b-estradiol (E2) at concentrations ranging from 10-12 to 10-6 M and/or the antiestrogen ICI 182,780 (10-6 M) for 24 h. Luciferase activity was used to estimate the AMH promoter activity, and results were expressed as % of the respective control (mean ± SEM). One sample t-tests were used to compare the results of the stimulated conditions to a 100% value corresponding to the basal activity.The expression of ERa and ERb was ascertained in transfected SMAT1 cells by immunofluorescence and Western blotting. Maximum AMH promoter activity in ERa-transfected cells was observed with E2 between 10-10 and 10-8 M; subsequent experiments were performed with E2 10-9 M since it is a physiologic concentration within the testis. In ERa-transfected cells, E2 induced a significant increase of the AMH-3068-1 promoter activity (263.5 ± 12.5%, P<0.001). Conversely, in ERb-transfected cells no significant changes were observed (96.4 ±14.2%, P=0.405). In cells co-transfected with both ERs, E2 induced a similar activation in the AMH-3068-1 promoter as that observed in cells transfected only with ERa. E2 effect was abolished in presence of ICI 182,780 (118.8 ± 24.2%, P=0.260). To verify that the effect was mediated by the ½-ERE at -1772, luciferase vectors with different AMH promoters were used. E2 increased the activity of another AMH promoter (-1916-1) containing the ½-ERE (160.4 ± 21.1%, P=0.032), but not that of promoters lacking the ½-ERE (AMH-3068-1916: 63.4 ± 47.7%, P=0.089; AMH-2580-1916: 75.01 ± 6.2%, P=0.077; AMH-423-1: 111.4 ± 24.1%, P=0.331 and mutated ½-ERE at -1772: 105.3 ± 47.7%, P=0.465).Conclusions and Discussion: E2 stimulates the transcriptional activity of the AMH promoter in SMAT1 cells in the presence of ERa, but not ERb. The effect is abolished by the antiestrogen ICI 182,780 and by the absence of the normal ½-ERE present at -1772 of the AMH promoter. These results indicate that estrogens are involved in the activation of the AMH promoter in SMAT1 cells, at least in part through the ½-ERE present at -1772. This mechanism may be involved in the increase of AMH in conditions like androgen insensitivity and Peutz-Jeghers Syndrome.