Matrix metalloproteinases and tissue inhibitors of metalloproteinases in human fetal testis and ovary.

Matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) are major regulators of tissue remodelling of the extracellular matrix (ECM) and may also be involved in the control of growth factor availability. We have investigated their production and localization in the developing human gonad during mid-gestation using zymographic techniques and immunohistochemistry. The secretion of MMP-2, MMP-9 and all four TIMP was demonstrated from both testis and ovary, with the predominant gelatinase produced by both being MMP-2. In the testis, MMP-1, MMP-2, MMP-9 and all TIMP family members were localized to the interstitium and to varying degrees within the tubules. MMP-9 and TIMP-4 were abundant in both Sertoli cells and gonocytes and MMP-1 and TIMP-1 were localized in particular to Sertoli cells. In the ovary, all TIMP and MMP-1, MMP-2 and MMP-9 were localized to the oogonium/oocyte cytoplasm with varying intensities and MMP-1, TIMP-2 and TIMP-3 were also detected in the ovarian stroma. This study demonstrates that MMP-1, MMP-2, MMP-9 and all TIMP family members are secreted by the developing ovary and testis and are localized to specific cell and tissue sites. MMP and TIMP are likely to play a role in ECM remodelling during gonadal development and also in the cell and matrix interactions that control a range of cellular functions.