Differential subcutaneous adipose tissue gene expression patterns in a randomized clinical trial of efavirenz or lopinavir-ritonavir in antiretroviral-naive patients

Abstract

Gene expression studies of subcutaneous adipose tissue may help to better understand the mechanisms behind body fat changes in HIV-infected patients who initiate antiretroviral therapy (ART). Here, we evaluated early changes in adipose tissue gene expression and their relationship to fat changes in ART-naive HIV-infected patients randomly assigned to initiate therapy with emtricitabine/tenofovir plus efavirenz (EFV) or ritonavir-boosted lopinavir (LPV/r). Patients had abdominal subcutaneous adipose tissue biopsies at baseline and week 16 and dual-energy-X-ray absorptiometry at baseline and weeks 16 and 48. mRNA changes of 11 genes involved in adipogenesis, lipid and glucose metabolism, mitochondrial energy, and inflammation were assessed through reverse transcription-quantitative PCR (RT-qPCR). Additionally, correlations between gene expression changes and fat changes were evaluated. Fat increased preferentially in the trunk with EFV and in the limbs with LPV/r (P < 0.05). After 16 weeks of exposure to the drug regimen, transcripts of CEBP/A, ADIPOQ, GLUT4, LPL, and COXIV were significantly downregulated in the EFV arm compared to the LPV/r arm (P < 0.05). Significant correlations were observed between LPL expression change and trunk fat change at week 16 in both arms and between CEBP/A or COXIV change and trunk fat change at the same time point only in the EFV arm and not in the LPV/r arm. When combined with emtricitabine/tenofovir as standard backbone therapy, EFV and LPV/r induced differential early expression of genes involved in adipogenesis and energy metabolism. Moreover, these mRNA expression changes correlated with trunk fat change in the EFV arm. (This was a substudy of a randomized clinical trial [LIPOTAR study] registered at ClinicalTrials.gov under identifier NCT00759070.).