Abstract 14015: Extracellular Vesicle-Associated microRNAs From the Plasma of HIV-Positive Individuals Enhance Atherosclerosis Burden

Abstract

Introduction: People living with HIV (PLHIV) have a higher risk of cardiovascular diseases (CVD) compared to HIV negative (HIV - ) individuals. The molecular mechanisms underlying the increased CVD risk remain elusive. Extracellular vesicles (EVs) mediate cell-to-cell communication through cargo transfer, including microRNAs (EV-miRs). Hypothesis: HIV infection results in modification of plasma EVs cargo and these HIV positive EVs (HIV posEVs ), specifically EV-miRs, recapitulate the effects of HIV infection on CVD development. Methods: Atherosclerosis burden was assessed by carotid ultrasound in 74 PLHIV treated with antiretroviral therapy (ART) with viral loads <50 c/ml and 23 HIV - subjects. Circulating endothelial progenitor cell (EPC) levels were measured by colony forming unit (CFU) assay. PLHIV plasma was fractionated into plasma EVs (HIV posEVs ) and plasma-depleted of EVs (HIV plasmadepEVs ). These fractions, EVs from HIV - subjects (HIV negEVs ) and PBS were injected weekly into apoE -/- mice via tail vein for three months. Atherosclerosis burden (H&E and Oil Red O staining), bone marrow (BM) EPC senescence (β-galactosidase staining), proliferation (MTT assay) and migration (“scratch” assay) were examined. RNASeq was used to identify EV-miRs that mediated the effects of HIV posEVs . Tailored EVs (TEVs) loaded with antagomirs for top EV-miRs were generated to determine their capacity to reverse the adverse effects of HIV posEVs in mouse EPCs in vitro . Results: PLHIV had higher atherosclerosis burden and lower circulating EPC numbers. Mice treated with HIV posEVs showed increased atherosclerotic burden, higher BM EPC senescence and lower functionality. HIV posEVs also negatively affected mouse BM EPC senescence in vitro . RNAseq identified four top candidate EV-miRs upregulated in HIV posEVs : let-7b-5p, miR-16-5p, miR-423-5p, and miR-103a-2. TEVs loaded with the antagomirs for let-7b and miR103a-2 counteracted the effects of HIV posEVs on the accelerated senescence of mouse BM EPCs. Conclusion: 1) Plasma EVs from PLHIV reconstitute the effects of HIV infection on accelerated atherosclerosis via negatively affects EPC functionality; and 2) TEVs, targeting candidate EV-miRs counteracts the effects of HIV infection on EPCs.