#324 : Gasdermin D-Mediated Pyroptosis Underlies Dehydroepiandrosterone-Induced Polycystic Ovary Syndrome

Background and Aims: Intestinal microflora disturbance is one of the important etiologies of polycystic ovary syndrome (PCOS). The purpose of this study was to investigate the mechanism of macrophage pyroptosis induced by intestinal microbiota disturbance in PCOS. Method: The PCOS mouse model was established using dehydroepiandrosterone, and was studied by 16S rDNA sequencing, western blot, ELISA, GSDMD gene knockout/oral pyroptotic inhibitors, single cell transcriptomics and translatomics analysis. Results: PCOS mice showed abnormal estrous cycle, elevated serum testosterone and polycystic ovaries. Fecal 16S rDNA sequencing showed that Muribaculacea (26.76%), and Lactobacillus (40.98%) were the most abundant microbe in the intestinal tracts of control mice and PCOS mice, respectively. Difference analysis showed a significant decrease in the abundance of intestinal probiotics Akkermansia and a significant increase in Gram-negative bacteria (Desulfovibrio and Burkholderia) in PCOS mice. Intestinal microbial disturbance in PCOS mice was associated with increased serum lipopolysaccharide (LPS). LPS intraperitoneal injection can induce pyroptosis of ovarian macrophages, which also exists in the ovaries of PCOS mice. The cleavage of GSDMD protein is the final key step in pyroptosis of macrophages. GSDMD knockout ameliorated PCOS in mice. Oral administration of pyroptotic inhibitors disulfiram and metformin can increase the abundance of intestinal Akkermansia, inhibit pyroptosis of ovarian macrophages and ameliorated PCOS in PCOS group mice. Mechanically, transcriptome and translatome sequencing of primary granulosa cells showed that pyroptosis of macrophages disrupted estrogen production and promoted granulosa cell apoptosis. Conclusion: This study revealed that macrophage pyroptosis induced by intestinal flora disorder can lead to the occurrence of PCOS through granulosa cell apoptosis and estrogen synthesis dysfunction. Macrophage pyroptotic inhibitors may be a potential therapeutic strategy for PCOS.