SPRY4 regulates ERK1/2 phosphorylation to affect oxidative stress and steroidogenesis in polycystic ovary syndrome

•SPRY4 level is upregulated in the ovarian tissue of PCOS mice.•SPRY4 knockdown reduces PCOS symptoms and pathological changes.•SPRY4 knockdown reduces oxidative stress and steroid disorders in the ovarian tissue.•SPRY4 and ERK1/2 phosphorylation affects ovarian granulosa cell function.•ERK1/2 phosphorylation reverses the effects of SPRY4 knockdown. Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder in women of childbearing age. The role of Sprouty RTK Signaling Antagonist 4 (SPRY4) in ovarian function in PCOS was investigated herein, focusing on its regulation of ERK1/2 phosphorylation. PCOS models were established in mice using dehydroepiandrosterone (DHEA). The expression levels of SPRY4 in ovarian tissues were analyzed through RT-qPCR and immunohistochemistry. SPRY4 knockdown was achieved via lentivirus, and its effects on endocrine function, ovarian morphology, oxidative stress, and ERK1/2 phosphorylation were evaluated. Afterwards, granulosa cells were isolated and treated with DHEA and ERK2 agonist tert-Butylhydroquinone. The impacts of ERK2 activation on the regulation of SPRY4 knockdown were assessed using ELISA, fluorescent probes, western blotting, and biochemical assays. SPRY4 knockdown normalized the estrous cycle, reduced serum levels of testosterone, anti-Müllerian hormone, and luteinizing hormone/follicle-stimulating hormone ratio, and improved ovarian morphology. Additionally, SPRY4 knockdown alleviated oxidative stress by decreasing reactive oxygen species and malondialdehyde levels while increasing superoxide dismutase activity. It also restored steroidogenic enzyme expression, which were disrupted by DHEA induction. In vitro, SPRY4 knockdown enhanced granulosa cell viability and reduced ERK1/2 phosphorylation, with tert-Butylhydroquinone reversing these effects and restoring oxidative stress and steroidogenesis disruptions. Together, SPRY4 modulates ERK1/2 phosphorylation to influence oxidative stress and steroidogenesis in PCOS. Targeting SPRY4 may provide novel therapeutic avenues for improving ovarian function and managing PCOS.