Impact of obesity on proteomic profiles of follicular fluid-derived small extracellular vesicles: A comparison between PCOS and non-PCOS women.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by ovulatory dysfunction, hyperandrogenism, and polycystic ovaries, significantly impacting reproductive health. Obesity, prevalent in 50-80% of PCOS patients, exacerbates metabolic disturbances and negatively influences assisted reproductive technology outcomes. This study investigates how obesity alters the proteomic profile of follicular fluid-derived small extracellular vesicles (FF-sEVs), aiming to elucidate mechanisms underlying reproductive impairments in this population. METHODS: This study included women undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), categorized into PCOS and non-PCOS control groups, further divided by BMI. Follicular fluid was collected, and sEVs isolated via ultracentrifugation. Proteomic analysis utilized data-independent acquisition (DIA) technology, with bioinformatics tools applied for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, along with protein-protein interaction (PPI) analysis. Statistical comparisons were performed using Analysis of variance (ANOVA) and t-tests to identify differentially expressed proteins. Correlation analysis assessed relationships between sEV protein profiles and reproductive outcomes, employing the Pearson correlation coefficient. RESULTS: Proteomic profiling of sEVs revealed that the overweight/obese PCOS group had 180 upregulated and 256 downregulated proteins compared to lean counterparts. Additionally, differential functional analysis and PPI analysis indicated significant pathway and key proteins alterations in the PCOS group related to inflammation, while non-PCOS women demonstrated metabolic reprogramming and anti-inflammatory responses, suggesting a differential response to obesity that may preserve oocyte quality. Correlation analysis revealed significant associations between specific differentially expressed proteins and IVF/ICSI outcomes, while a protective role for Heat Shock Protein 90 Beta Family Member 1 (HSP90B1) protein was observed in the non-PCOS group. Lastly, validation through Western blot confirmed critical protein expression changes, particularly for S100 Calcium-binding Protein A8 (S100A8), emphasizing the impact of obesity on reproductive health outcomes in PCOS patients. CONCLUSIONS: In conclusion, our findings indicate that obesity exacerbates inflammation and oxidative stress in PCOS women, adversely affecting oocyte development and IVF/ICSI outcomes. In contrast, non-PCOS women exhibit protective metabolic and inflammatory adaptations. These insights underscore the necessity for tailored fertility management approaches, including weight loss strategies and specific interventions for PCOS patients, to optimize reproductive outcomes and enhance pregnancy success rates.