NAD+ rescues Phosphatidylinositol-induced granulosa cell Pyroptosis to restore follicular development in PCOS

Polycystic ovary syndrome (PCOS) is a systemic endocrine metabolic disorder that seriously affects women's reproductive health. This study aimed to investigate the mechanism by which NAD⁺ precursors inhibits granulosa cell (GCs) pyroptosis induced by increased phosphatidylinositol (PI) levels in PCOS. Metabolomic profiling of PCOS patients demonstrated significant lipid metabolic disturbances, with differentially metabolites significantly enriched in phosphatidylinositol signaling, pyroptosis and inflammatory pathways (p < 0.05). Furthermore, PI levels were higher in the follicular fluid of PCOS patients compared to controls. In the letrozole/high-fat diet-induced PCOS rat model, intervention with NAD⁺ precursors significantly reduced androgen levels and alleviated abnormal accumulation of PI and improved ovarian dysplasia. Notably, co-analysis metabolomics and transcriptomics showed that PI levels were positively correlated with pyroptosis factors such as NLRP3, IL-1β, IL-18. Subsequently, In vitro excess PI promotes KGN cell pyroptosis, as evidenced by increased membrane permeability and membrane rupture (by TEM), increased LDH release and increased secretion of IL-1β and IL-18. Importantly, supplementation with NAD⁺ inhibits the aberrant accumulation of PI, thereby ameliorating GCs pyroptosis. In this study, we found that PI levels accumulate abnormally in PCOS ovary and that NAD⁺ ameliorates GCs pyroptosis induced by increased PI. Collectively, PI represents a candidate PCOS biomarker, and NAD⁺ may thereby offer a targeted therapeutic approach.