Morphometric Characterization of Extracellular Vesicles and Their Contents of miRNA-145 in Adults with and Without Obesity (P18-127-19)

The aim was to characterize populations of extracellular vesicles (EVs) and their content of miRNA-145, in adults with obesity and normal weight. Study design was cross-sectional and subjects were assigned to: group A (n = 10) which included participants with obesity (Body Mass Index (BMI) > 30 kg/m2), and group B (n = 10) included subjects with normal weight (BMI 18 - < 25 kg/m2). Subjects were free of co-morbidities. Weight, height, electrical bioimpedance, and serum lipids were evaluated. EVs were isolated from blood plasma using Invitrogen total exosome isolation reagent. Isolation was later corroborated by detecting the expression of the marker ALIX, an EV-associated protein by Western blot (WB), and the particle size was assessed using Zetasizer Nano ZS. The isolated EVs were also analyzed by transmission electron microscopy (TEM) and, finally, the expression of miRNA-145 was determined in the EVs by real-time PCR. We identified two sizes of EVs, that were later classified as exosomes and microvesicles. The characterization of EVs was confirmed with the expression of ALIX and the images of TEM. In subjects from group A, EVs size (65.9 ± 16.1 nm) was larger than in those subjects without obesity (42.3 ± 10.7 nm), but this was not statistically significant. Body weight and tryglycerides concentration were positively associated (P < 0.05) with EVs’ size. The variability in the size of EVs between groups could reflect different composition or maturation level of EVs. Analysis of miRNA-145 content in the EVs, showed that it was 1.15 times higher in group A vs B, and therefore it was possible to identify a differential expression associated with higher levels of risk for subjects with obesity compared to the normal weight group. The size of EVs is related with state of obesity, also its content could reflect higher risk of developing comorbidities associated with excess weight and nutritional status. The project was funded by CIAD and MAH received a scholarship from CONACYT.