Both Sertoli and peritubular cells respond to androgens with increased expression of an androgen response element reporter.

To explore the ability of androgens to affect gene expression in Sertoli and peritubular cells in vitro, constitutively expressed pSV2-Luc and a regulated reporter containing an androgen response element (MMTV-Luc) were transiently transfected into these cells. Reporter expression was markedly affected by cell density and maturational age. Mibolerone-stimulated MMTV-Luc expression increased in Sertoli cells with animal age between 15 and 25 days, consistent with the developmental increase in androgen receptor concentration, but was not markedly age-dependent in peritubular cells. The antiandrogen hydroxyflutamide inhibited stimulation of MMTV-Luc expression by 1 and 10 nM testosterone in both Sertoli and peritubular cells, consistent with an androgen receptor-mediated event. In contrast, dexamethasone at 1 and 10 nM elicited no effect in Sertoli cells, but stimulated MMTV-Luc expression in peritubular cells. In this study, the androgen receptor/glucocorticoid receptor ratio was 2.4 and 0.06 in Sertoli and peritubular cells, respectively. Cotransfection of Sertoli and peritubular cells with a plasmid expressing the rat androgen receptor further increased the androgen-stimulated expression of MMTV-Luc. These data demonstrate the functionality of the androgen receptors in both Sertoli and peritubular cells in culture. Receptor expression appears to be a limiting factor in the response. The data are consistent with potential roles for both Sertoli and peritubular cells in androgen-mediated transcriptional events in the testis.