Single-cell Analysis of Subcutaneous Fat Reveals Pro-fibrotic Cells that Correlate with Visceral Adiposity in HIV
Cardiometabolic diseases are common in persons with HIV (PWH) on antiretroviral therapy (ART), which has been attributed to preferential lipid storage in visceral adipose tissue (VAT) compared with subcutaneous adipose tissue (SAT). However, the relationship of SAT-specific cellular and molecular programs with VAT volume is poorly understood in PWH. We characterized SAT cell-type specific composition and transcriptional programs that are associated with greater VAT volume in PWH on contemporary ART. We enrolled PWH on long-term ART with a spectrum of metabolic health.We enrolled PWH on long-term ART with a spectrum of metabolic health. Ninety-two participants underwent SAT biopsy for bulk RNA sequencing and 43 had single-cell RNA sequencing. Computed tomography quantified VAT volume and insulin resistance was calculated using HOMA2-IR. VAT volume was associated with HOMA2-IR (p<0.001). Higher proportions of SAT intermediate macrophages (IMs), myofibroblasts, and MYOC+ fibroblasts were associated with greater VAT volume using partial Spearman's correlation adjusting for age, sex, and body mass index (r =0.34-0.49, p<0.05 for all). Whole SAT transcriptomics showed PWH with greater VAT volume have increased expression of extracellular matrix (ECM)- and inflammation-associated genes, and reduced expression of lipolysis- and fatty acid metabolism-associated genes. In PWH, greater VAT volume is associated with higher proportion of SAT IMs and fibroblasts, and a SAT ECM and inflammatory transcriptome, which is similar to findings in HIV-negative persons with obesity. These data identify SAT cell-type specific changes associated with VAT volume in PWH that could underlie the high rates of cardiometabolic diseases in PWH, though additional longitudinal studies are needed to define directionality and mechanisms. Overall design: To investigate the relationship of subcutaneous adipose tissue gene expression and visceral adipose tissue volume in persons with HIV, we performed subcutaneous adipose tissue biopsy and bulk RNA-sequencing. We then performed differential gene expression between individuals with high visceral adipose tissue volume compared with individuals with low visceral adipose tissue volume using DESeq2.