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 ra t seminiferous epithelial cycle. We investigated FSH regulation of CP- 2 mRNA expression and its cellular localization in isolated staged sem iniferous tubular segments. FSH induced a significant increase of CP-2 mRNA levels in stages IX-I, whereas ill stages II-VIII, the levels of CP-2 mRNA were reduced. A similar effect was produced by two cAMP ana logs, dbcAMP (0.2 mM) and Sp cAMP (20 mu M). FSH and cAMP did not affe ct on the levels of SGP-2 mRNA during the seminiferous epithelial cycl e. The magnitude of the response was time- and dose-dependent; the max imum was obtained with 100 ng/ml of FSH. It is likely that FSH regulat es CP-2 gene transcription, since de novo RNA synthesis was required f or the stimulatory FSH effect on CP-2 mRNA levels, while ongoing prote in synthesis was not. In conclusion, the data suggest that FSH, via cA MP-mediated pathway, regulates CP-2/cathepsin L gene transcription in rat Sertoli cells and modulated the stage-specific expression pattern.