Trilobatin alleviates polycystic ovary syndrome in rats by targeting SIRT2-Mediated PKM2 acetylation in glycolysis and mitochondrial function

초록

Background: Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder that severely impacts female fertility. The natural dihydrochalcone trilobatin (TLB) has shown potential in managing metabolic diseases; however, its therapeutic effect on PCOS and the underlying mechanisms remain unexplored. Purpose: To investigate the therapeutic potential of TLB for PCOS and to elucidate the mechanistic basis, focusing on glycolytic metabolism and mitochondrial function in granulosa cells (GCs). Methods: A dehydroepiandrosterone (DHEA) -induced PCOS rat model was established and treated with two different doses of TLB or metformin.Therapeutic effects were assessed based on estrous cyclicity, ovarian morphology, serum hormone levels, and the HOMA-IR index. Key targets were identified through integrated metabolomics and bioinformatics analyses. The mechanism was further validated in vitro using dihydrotestosterone (DHT)-induced primary rat GCs, combined with molecular docking, cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS) assay, co-immunoprecipitation (CO-IP), and Seahorse metabolic analysis. Results: TLB administration alleviated estrous cycle disruption, improved ovarian morphology, and normalized serum testosterone, luteinizing hormone, and HOMA-IR index in PCOS rats. Metabolomics and bioinformatics analyses identified SIRT2 as a primary target of TLB. Mechanistically, TLB targets SIRT2, promoting the deacetylation of pyruvate kinase M2 (PKM2) at the K305 site. This deacetylation enhanced PKM2 tetramerization and enzymatic activity, thereby ameliorating the glycolytic imbalance in GCs, as evidenced by reduced pyruvate accumulation and restored lactate production. Furthermore, TLB, via the SIRT2/PKM2 axis, improved mitochondrial function, supported by the recovery of ATP production, mitochondrial membrane potential, and mitochondrial permeability transition pore integrity, ultimately suppressing GC apoptosis. Conclusion: Our findings demonstrate that TLB alleviates ovarian PCOS phenotypes by targeting SIRT2 to promote PKM2 deacetylation at K305, which effectively corrects glycolytic flux and restores mitochondrial function in GCs.

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