SERTOLI CELL-GERM CELL-INTERACTIONS AND TGF-BETA-1 EXPRESSION AND SECRETION IN-VITRO

Transforming growth factor beta(1) (TGF beta(1)) has been reported to be secreted and to act within the somatic cells of the testis. We exam ined whether the TGF beta(1) expression is present at mRNA and protein levels in purified rat Sertoli cells (SC), purified pachytene spermat ocytes (SPC), and early spermatids (SPT) cultured alone or together. S C expressed a single TGF beta(1) transcript of 2.5 kb, but no TGF beta (1) protein could be detected in SC conditioned medium indicating that , if at all, SC secreted less than 10 pg/10(6) cells/24 h. Neither TGF beta(1) mRNA nor protein could be detected in either SPC or SPT. Cocu lture of SC with either SPC or SPT resulted in a a-fold increase of TG F beta(1) mRNA and more importantly in the secretion of TGF beta(1) pr otein. These findings demonstrate that Sertoli cell-germ cell interact ions regulate TGF beta(1) expression and secretion and indicate that T GF beta(1) may be involved in spermatogenesis. (C) 1997 Academic Press .