We identified a microRNA (miRNA) profile characterizing HIV lipodystrophy and explored the downstream mechanistic implications with respect to adipocyte biology and the associated clinical phenotype. miRNA profiles were extracted from small extracellular vesicles (sEVs) of HIV-infected individuals with and without lipodystrophic changes and individuals without HIV, among whom we previously showed significant reductions in adipose Dicer expression related to HIV. miR-20a-3p was increased and miR-324-5p and miR-186 were reduced in sEVs from HIV lipodystrophic individuals. Changes in these miRNAs correlated with adipose Dicer expression and clinical markers of lipodystrophy, including fat redistribution, insulin resistance, and hypertriglyceridemia. Human preadipocytes transfected with mimic miR-20a-3p, anti–miR-324-5p, or anti–miR-186 induced consistent changes in latent transforming growth factor beta binding protein 2 (Ltbp2), Wisp2, and Nebl expression. Knockdown of Ltbp2 downregulated markers of adipocyte differentiation (Fabp4, Pparγ, C/ebpa, Fasn, adiponectin, Glut4, CD36), and Lamin C, and increased expression of genes involved in inflammation (IL1β, IL6, and Ccl20). Our studies suggest a likely unique sEV miRNA signature related to dysregulation of Dicer in adipose tissue in HIV. Enhanced miR-20a-3p or depletion of miR-186 and miR-324-5p may downregulate Ltbp2 in HIV, leading to dysregulation in adipose differentiation and inflammation, which could contribute to acquired HIV lipodystrophy and associated metabolic and inflammatory perturbations.
Suman Srinivasa, Ruben Garcia-Martin, Martin Torriani, Kathleen V. Fitch, Anna R. Carlson, C. Ronald Kahn, Steven K. Grinspoon
Hypothesized translational model of adipose dysfunction and metabolic complications in HIV lipodystrophy.