Metabolomic Analysis Identifies Betaine as a Key Mediator of -Induced Ferroptosis in Ovarian Granulosa Cells.

Granulosa cells (GCs) are essential for follicular growth and development, and their functional state critically impacts folliculogenesis. , a transcriptionally active isoform of the gene, is crucial for maintaining follicular integrity. In this study, we demonstrate that overexpression promotes ferroptosis in bovine GCs by downregulating , depleting intracellular glutathione (GSH), and enhancing lipid peroxidation, particularly under Erastin treatment. By contrast, knockdown restores antioxidant capacity, elevates GSH levels, and attenuates ferroptosis. To elucidate the underlying mechanism, untargeted metabolomic profiling revealed that overexpression significantly altered the metabolic landscape of GCs, with marked enrichment in the glutathione metabolism pathway. Notably, betaine-a metabolite closely linked to redox homeostasis-was markedly downregulated. Functional assays confirmed that exogenous betaine supplementation restored expression, increased GSH levels, and alleviated oxidative damage induced by either HO or overexpression. Moreover, betaine co-treatment effectively reversed lipid peroxide accumulation and mitigated -induced ferroptosis. Collectively, our findings identify a novel mechanism by which promotes ferroptosis in granulosa cells through the suppression of betaine and glutathione metabolism, highlighting betaine as a key metabolic modulator with promising protective potential.