Jiawei Buzhong Yiqi decoction ameliorates polycystic ovary syndrome via oocyte-granulosa cell communication

Ethnopharmacological relevance: Jiawei Buzhong Yiqi Decoction (JWBZYQ), from records of Fuqingzhu Nvke, is a classical formula for treating obese women related infertility. JWBZYQ has been shown to be effective in treating polycystic ovary syndrome (PCOS) in both clinical studies and practical practice, with the pharmacological mechanism remaining unknown. Aim of the study: To explore the potential therapeutic effects and mechanistic insights of JWBZYQ in PCOS. Materials and methods: An overweight PCOS rat model was established via testosterone propionate (TP) injection and 45% high-fat diet (HFD). Then they were categorized into five distinct groups: Control group, Model group, low-dose of JWBZYQ (JWBZYQ1) group, high-dose of JWBZYQ (JWBZYQ2) group, and metformin (Met) group. Body weight, estrous cycle, and sex hormone levels were observed. Hematoxylin-Eosin staining was employed to investigate the histological characteristics of the ovaries. To identify the pathways that changed significantly, transcriptome analysis was performed. The protein and mRNA levels of key molecules in ovarian zona pellucida (ZP) organization, transzonal projections (TZPs) assembly, steroid hormone receptors, and steroidogenesis were assessed using phalloidin staining, immunohistochemistry, Western blot, and polymerase chain reaction. Results: RNA-seq analysis demonstrated that regulation of hormone secretion, cilium assembly, cell projection assembly, and ZP production may all have crucial impact on the etiology of PCOS and therapeutic effect of JWBZYQ. In particular, PCOS rats exhibited elevated expressions of ZP1-3, which can be reversed by JWBZYQ2 particularly. Simultaneously, TZPs assembly was totally disrupted in PCOS rats, evidenced by the phalloidin staining, upregulated calcium-/calmodulin-dependent protein kinase II beta (CaMKII beta), and deficient p-CaMKII beta, myosin X (MYO10), proline-rich tyrosine kinase 2 (PTK2), and Fascin. Nonetheless, JWBZYQ or metformin treatment revived the disturbance, repairing the oocyte-granulosa cell communication, regulating steroidogenesis in PCOS rats. In this way, JWBZYQ and metformin exerted remarkable effects in alleviating altered ovarian morphology and function in PCOS rats, with JWBZYQ2 revealing the best effect. Conclusions: JWBZYQ restored the altered ovarian morphology and function by regulating the oocyte-granulosa cell communication, which was related with ZP organization and TZPs assembly in the ovary.