Lysyl oxidase and MMP-2 expression in dehydroepiandrosterone-induced polycystic ovary in rats

Polycystic ovary syndrome (PCOS) is characterized by cystogenesis; however, the cause of this cystogenesis is unknown. At ovulation, preovulatory coll agenolytic activities in the ovarian follicles increase and various protein ases are needed to degrade the tissues surrounding the follicles, To clarif y the roles of enzymes in collagen degradation of the follicular wall of po lycystic ovary (PCO) in relation to the cystogenesis, we examined expressio n of lysyl oxidase (LOX), which initiates cross-link formation of the colla gen and elastin in the extracellular matrix, and expression of matrix metal loproteinases (MMPs) in ovaries of model rats with PCO induced by dehydroep iandrosterone (DHEA) compared with MMP expression in control rats. DHEA tre atment increased LOX mRNA expression to more than three times the control v alue (P < 0.01). MMP-2 mRNA expression in control rats was threefold greate r than that in the DHEA-induced group (P < 0,05), Expression of both latent and active forms of MMP-2 in controls was more than twice that in the DHEA -induced group (P < 0.05) as shown by Western blotting, and expression of t he active form of MMP-2 was also twice as high in the controls as in the DH EA-treated group (P < 0.05) as shown by zymography. Our results suggest tha t depression of MMP-2 activity and increased LOX expression may be one of t he causes of the cystogenesis of PCO.