Follicle-stimulating hormone regulates the expression of cyclic protein-2/cathepsin L messenger ribonucleic acid in rat Sertoli cells in a stage-specific manner

Cyclic protein-2/cathepsin L (CP-2) is secreted by Sertoli cells in a highly stage-specific manner, maximally during stages VI–VII of the rat seminiferous epithelial cycle. We investigated FSH regulation of CP-2 mRNA expression and its cellular localization in isolated staged seminiferous tubular segments. FSH induced a significant increase of CP-2 mRNA levels in stages IX-I, whereas in stages II–VIII, the levels of CP-2 mRNA were reduced. A similar effect was produced by two cAMP analogs, dbcAMP (0.2 mM) and Sp cAMP (20 μM). FSH and cAMP did not affect on the levels of SGP-2 mRNA during the seminiferous epithelial cycle. The magnitude of the response was time- and dose-dependent; the maximum was obtained with 100 ng/ml of FSH. It is likely that FSH regulates CP-2 gene transcription, since de novo RNA synthesis was required for the stimulatory FSH effect on CP-2 mRNA levels, while ongoing protein synthesis was not. In conclusion, the data suggest that FSH, via cAMP-mediated pathway, regulates CP-2/cathepsin L gene transcription in rat Sertoli cells and modulated the stage-specific expression pattern.