Background: Polycystic ovarian syndrome (PCOS) is an endocrine disorder characterized by abnormal proliferation and apoptosis of ovarian granulosa cells (GCs), which contribute to follicular dysfunction and impaired ovulation. Although astragaloside IV (AS-IV) has shown anti-proliferative effects, its underlying mechanism remains unclear. This study aims to explore how AS-IV regulates the growth and apoptosis of human ovarian granulosa cell tumor (KGN) cells via glycolysis.

Methods: In this study, the human ovarian granulosa cell tumor line KGN was used as an in vitro model. AS-IV treatment was combined with genetic manipulations, including short hairpin RNA (shRNA)-mediated knockdown of G protein subunit beta 2 (GNB2) and overexpression of peroxisome proliferator-activated receptor gamma (PPARγ) and GNB2, to dissect their roles in AS-IV-mediated effects. The effects of AS-IV on KGN cell proliferation, apoptosis, lactate, pyruvate, and pyruvate kinase m2 (PKM2) levels via the PPARγ/GNB2 were evaluated. Chromatin immunoprecipitation and dual-luciferase reporter assays were used to study PPARγ's transcriptional regulation of GNB2. Ubiquitination and degradation of PKM2 by GNB2 were examined using immunoprecipitation.

Results: AS-IV induced apoptosis and lowered KGN cell growth (p < 0.01). Knockdown of GNB2 expression partially reversed the anti-proliferative and pro-apoptotic effects of AS-IV, indicating that GNB2 mediates AS-IV activity (p < 0.05). PPARγ transcriptionally regulated GNB2 expression, thereby enhancing the effect of AS-IV (p < 0.05). AS-IV upregulated the PPARγ/GNB2, inhibited PKM2 expression, and promoted PKM2 ubiquitination and degradation, further modulating glycolysis (p < 0.05).

Conclusion: This study reveals that AS-IV regulates KGN cell proliferation and apoptosis via the PPARγ/GNB2/PKM2 axis by inhibiting glycolysis. This study provides novel mechanistic insights into the therapeutic potential of AS-IV for PCOS by targeting granulosa cell metabolism and survival.