Pioglitazone Reverses Alcohol-induced HIV Replication and IL-1β Expression in Alveolar Macrophages.

Abstract

Approximately 50% of people living with HIV (PWH) in the United States misuse alcohol, and they are at increased risk of chronic lung inflammation despite antiretroviral therapy. Acetaldehyde, a metabolite of alcohol, circulates systemically and directly impacts alveolar macrophages (AMs), the primary reservoir of HIV in the lungs. Acetaldehyde promotes AM HIV replication and triggers interleukin (IL)-1β release. We explored the mechanisms by which alcohol-derived acetaldehyde drives HIV replication and IL-1β release in AMs. Further, we tested if the transcription factor peroxisome proliferator-activated receptor (PPAR)γ agonist, pioglitazone, attenuates AM HIV replication and IL-1β release. Primary mouse AMs (mAMs), MH-S cells (an AM cell line), and THP-1 (human monocyte cell line)-derived macrophages were treated with alcohol-derived acetaldehyde (acetaldehyde generating system, AGS), HIV 1_ADA, and EcoHIV, a chimeric HIV that infects murine cells. HIV expression was confirmed by HIV gag RNA (qRT-PCR) and p24 release (ELISA). IL-1β was measured by qRT-PCR and ELISA. Extracellular hydrogen peroxide (H₂O₂) release was quantified by Amplex Red assay. Further, immunoblot analysis of ERK1/2, PPARγ, and nuclear factor (NF)-ĸB/p65 (p65) was used to identify how acetaldehyde potentiates HIV replication and IL-1β activation in AMs. AGS increased H₂O₂, leading to ERK1/2 phosphorylation, which deactivated PPARγ. AGS drove nuclear p65 translocation in HIV-infected cells, which enhanced HIV replication and IL-1β release. Treatment with pioglitazone decreased nuclear p65, attenuating AGS-induced HIV replication and IL-1β activation in AMs. We identified mechanisms underlying acetaldehyde-induced inflammatory activation and potentiation of HIV replication in AMs, which could be therapeutically targeted with pioglitazone to decrease HIV-related respiratory comorbidities among PWH who misuse alcohol.