Reduced IL10 expression in diminished ovarian reserve and receptor-dependent IL-10 responses in granulosa cell models

Objective Diminished ovarian reserve (DOR) is increasingly linked to chronic low-grade inflammation, yet how systemic immune tone is associated with dysfunction of granulosa cells (GCs) remains unclear. We integrated population epidemiology, granulosa-cell transcriptomics, and mechanistic in vitro studies to interrogate a receptor-limited IL-10/IL-10R axis as a potential immunometabolic regulator of ovarian stress resilience. Methods Women aged 20–40 years from the NHANES 2017–March 2020 pre-pandemic sample were analyzed (n = 1191). DOR was operationally defined as anti-Müllerian hormone (AMH) < 1.1 ng/mL and/or follicle-stimulating hormone (FSH) > 10 mIU/mL. Age-based overlap weighting was used for descriptive comparisons, whereas associations of neutrophil count (NC) and neutrophil-to-lymphocyte ratio (NLR) with DOR were evaluated using survey-weighted logistic regression. Transcriptomic alterations were examined in six DOR and six normal ovarian reserve (NOR) mural GC samples from GSE232306 using DESeq2, apeglm effect-size shrinkage, and functional enrichment analysis. In vitro, IL10RA was reconstituted in KGN and COV434 cells to evaluate IL-10–induced STAT3/SOCS3 signaling, modulation by IFN-γ and estradiol, oxidative-stress responses, and neutral lipid accumulation. Results Among 1191 women, 314 met the operational DOR definition and 877 were classified as NOR. In age-overlap-weighted comparisons, women with DOR had higher NC (4.67 ± 1.82 vs. 4.31 ± 1.72 ×10 ³ cells/μL; P = 0.003) and NLR (2.13 ± 1.11 vs. 1.97 ± 0.90; P = 0.027). In fully adjusted survey-weighted models, each 1 × 10 ³ cells/μL increase in NC was associated with 17% higher odds of DOR (OR 1.17, 95% CI 1.04–1.32; P = 0.014), and each one-unit increase in NLR was associated with 28% higher odds (OR 1.28, 95% CI 1.05–1.55; P = 0.019). In GSE232306, IL10 expression was significantly reduced in DOR granulosa cells (unshrunken DESeq2 log2FC = −2.04; apeglm-shrunken log2FC = −1.48; adjusted P = 0.022), whereas IL10RA and IL10RB were not significantly altered in the complete dataset. In KGN and COV434 cells, IL10RA reconstitution restored IL-10-induced STAT3/SOCS3 signaling, whereas IFN-γ and estradiol increased IL10RA expression and cell-surface IL-10Rα abundance. Functionally, IL-10 reduced oxidative-stress–induced ROS and decreased PA/OA-driven neutral lipid accumulation in an IL-10R–dependent manner. Conclusion DOR was associated with modest elevations in neutrophil-related systemic inflammatory indices and with reduced IL10 expression and immunometabolic transcriptional remodeling in GCs. The transcriptomic data did not independently demonstrate reduced IL-10 receptor expression in primary DOR GCs; however, cell-line experiments showed that receptor availability determines IL-10 responsiveness and its effects on oxidative stress and lipid handling. These findings identify the IL-10/IL-10R axis as a candidate regulatory pathway requiring validation in primary GCs and prospective DOR models.