PROJECT SUMMARY People living with HIV demonstrate increased incidence of lung inflammation and HIV is an independent risk factor development of COPD. In the era of antiretroviral therapy (ART) with markedly improved life expectancy, lung related chronic conditions like COPD and bacterial pneumonia are primarily responsible for increased morbidity and mortality in people living with HIV (PLWH). HIV patients die of non-AIDS comorbidities almost a decade earlier that their non-HIV counterparts. Identifying the pathophysiological mechanism and treatment of HIV-associated comorbidities is very complex in chronic lung diseases, even with ART. TGF-β signaling upregulated by HIV Tat, and Tat itself alters the microRNAome of the airway epithelium. MicroRNAs play important roles in lung health and diseases and their dysregulation can serve as pathological hallmarks of several lung diseases. TGF-β signaling, plays a vital role in the progression of chronic airway diseases like COPD and lung infections. This is important since we have shown that TGF-β can increase the viral burden in the airway thereby establishing a positive feedback loop mechanism. HIV Tat and TGF-β1 upregulates miR-126-3p, a microRNA known to suppress IRS-1 which leads to upregulation of ADAM17 in airway epithelial cells which leads to impaired mitophagy, senescence and lung inflammation in vitro and in vivo. The current proposal focuses on determining the pathophysiological mechanism and rescue by which HIV- associated COPD through TGF-β alter the microRNAome to mediate suppression of critical genes in mitophagy leading to defective mitophagy, senescence and inflammation. Aim 1 will identify a novel crosstalk between the defective microRNAome, IRS-1 and ADAM17 with downstream effects on mitochondrial homeostasis, senescence, and inflammation in the context of HIV and CS. We will validate this pathway using miRNA mimics and antagomiRs in vitro and in vivo on lung inflammation in air and CS-exposed SP-C Tat transgenic. Aim 2 will test therapeutic approaches given that miRNA target sites differ among different genes regulated by the same miRNA, editing the miR-126-3p target site on IRS-1 3’ UTR will preserve IRS-1 levels in the context of HIV and CS thereby restoring baseline mitophagy, senescence and mitigating inflammation in EcoHIV mouse models of HIV infection.