Evidence that MMP-2 and TIMP-2 are at play in the FSH-induced changes in Sertoli cells.

FSH has been shown to elicit in vitro changes in the Sertoli cell cytoskeleton through involving proteases, and cytochalasin-D mimics FSH. Testis extracts were screened (RT-PCR) for various metalloproteinases (MMPs), 20-day-old rat Sertoli cells were purified, cultured and treated with FSH, cytochalasin D and TNFalpha (to antagonize FSH action). Cell shape (phase-contrast microscopy) and levels for MMP-2 (gelatin zymography) and its inhibitor TIMP-2 (Northern and Western blot) were monitored. TNFalpha-treated cells spread readily and grew larger than FSH-treated cells. Cytochalasin-D mimicked FSH, and MMP-2 production and TIMP-2 gene expression were augmented. Interestingly, TNFalpha reversed FSH- and cytochalasin D-induced effects both on cell shape and on MMP-2 and TIMP-2. These effects occurred during the first 48 h of culture, when Sertoli cells migrated from the freshly dispersed aggregates, but not once cells were organized in monolayers. MMP-2 and TIMP-2 are likely involved in the FSH-induced changes in Sertoli cells.