RESUMEN
Anti-Müllerian hormone (AMH) production by testicular Sertoli cells is high before puberty and can be further induced by FSH. Our objective was to delineate the mechanisms by which FSH stimulates AMH production. Assay of serum AMH levels and histological morphometric analysis in prepubertal FSH-deficient transgenic mice showed that serum AMH and testicular mass were decreased owing to reduced Sertoli cell number. All parameters resumed normal values in mice treated with recombinant FSH. We also analyzed the ability of FSH and the factors involved in its signaling pathway to activate AMH transcription by transfecting AMH promoter-luc reporter constructs of different lengths in a prepubertal Sertoli cell line. Our results showed that FSH activates AMH transcription via adenylate cyclase, cAMP, and protein kinase A but involving a nonclassical cAMP-response pathway requiring nuclear factor-kappaB and activating protein 2 binding sites, which lie more than 1.9 kb upstream of the AMH transcription start site. This is the first report showing the importance of distant sequences in the regulation of AMH expression. We conclude that prepubertal testicular AMH production is increased by FSH stimulation through Sertoli cell proliferation and an enhancement of AMH gene transcription.