3100-LB: Proteomic Profiling of Adipose Tissue–Derived Extracellular Vesicles Reveals Metabolic Changes along the Obesity–Diabetes Transition

Introduction and Objective: Obesity and type 2 diabetes (T2D) are closely linked metabolic disorders, yet molecular changes preceding diabetes remain incompletely understood. Adipose tissue is an active endocrine organ, and extracellular vesicles (EVs) may reflect metabolic status and disease progression. We aimed to characterize proteomic remodeling of adipose tissue-derived EVs (AT-EVs) across the obesity-diabetes continuum. Methods: EVs were isolated from adipose tissue of lean (L), lean-diabetes (LD), obese (O), and obese-diabetes (OD) individuals. A direct DIA workflow was used for EV proteome profiling. Differential expression and pathway enrichment analyses identified stage-specific and progression-related molecular signatures. Results: Distinct EV protein signatures varied across metabolic states: O vs. L (255 downregulated, 111 upregulated), OD vs. O (895 upregulated, 298 downregulated), and LD vs. L (53 upregulated, 304 downregulated). Pathway enrichment revealed that O-derived EVs were enriched in lipid metabolism related pathways, while OD-derived EVs demonstrated increased carbohydrate and glucose metabolism signatures. LD-derived EVs exhibited alterations in mitochondrial and energy metabolism pathways, suggesting early metabolic stress independent of obesity. Progressive changes across the obesity-T2D progression involved immune response, extracellular matrix organization, signal transduction, and gene expression pathways. Notably, RNA metabolism and post-transcriptional regulatory processes were consistently enriched in EVs and showed stage-dependent amplification. Validation in in vitro adipocyte differentiation models supported the proteomic findings. Conclusion: AT-EVs show dynamic proteomic remodeling from obesity to T2D. RNA related pathway enrichment suggests an EV associated mechanism of metabolic deterioration, highlighting adipose EVs as potential mediators and indicators of disease progression. Disclosure Y. Liu: None. Y. He: None. J. Fan: None. Funding National Institutes of Health (5P20GM109036-09)