Adipocyte Extracellular Vesicles (Adevs) Promote a Proinflammatory and Profibrotic Profile in Human Renal and Endothelial Cells in Vitro

In obesity,white adipose tissue (WAT) undergoes hypertrophic and hyperplastic changes that are driven by phenotypical changes in preadipocytes and adipocytes. WAT also causes a chronic inflammatory state that modifies gene expression and the secretome, including the shedding of adipose-derived extracellular vesicles (AdEVs) into the circulation, with these AdEVs affecting other cell types and potentially modifying their phenotypes. Aim: To evaluate the effects of AdEVs on renal and endothelial cells and their impacts on gene expression associated with inflammation, fibrosis, and endothelial function. Methods: Human SW872 adipocytes were differentiated from preadipocytes and further characterized. AdEVs were isolated via ultracentrifugation and characterized according to ISEV guidelines. AdEVs were added to either human renal (HCD) or endothelial cells (EA.hy926) for 24 hours. Adipokine, cytokine (IL-6 and IL-1B), fibrosis-related, NGAL, and eNOS gene expression wasevaluated via RT-qPCR and western blotting. Results: SW872 cells exhibited classical adipocyte morphologies and a significant accumulation of lipid droplets. Isolated AdEVs exhibited a donut-shaped morphology, a characteristic size, and both CD9 and TSG101 markers, which are compatible with EV features. Both renal and endothelial cells that were challenged with AdEVs were able to (1) incorporate AdEV-PKH67 (a fluorescent dye) and (2) induce high expression of IL-6 and IL-1B (p<0.05). A decrease in eNOS expression was detected in endothelial cells treated with AdEVs (p<0.05). Conclusion: AdEVs induced a proinflammatory profile in renal and endothelial cells (HCD and EA.hy926) in vitro , and a decrease of eNOS expression in EA.hy926 cells. These results support that EVs from mature adipocytes could increase the inflammation and vascular dysfunction in obesity.