Leptin Replacement Therapy Improves Endothelial Function and Vascular Inflammation in a Mouse Model of Acquired Lipodystrophy Associated with Antiretroviral Treatment by Regulating Nox1‐Derived ROS and C‐C Chemokine Receptor Type 5

Abstract

Highly active antiretroviral therapy (HAART) has been used at suppressing HIV replication, as a side effect HAART promotes lipodystrophy, which is a metabolic disorder characterized by an abnormal adipose tissue distribution, reduced leptin plasma levels and vascular complications. Leptin replacement therapy (LRT) is currently used to treat metabolic dysfunctions in patients diagnosed with congenital lipodystrophy. Here, we sought to investigate whether LRT restores vascular function and reduces inflammation in mice treated with the antiretroviral agent, ritonavir. Four weeks of ritonavir reduced body weight [control (C): 28.4±0.5 vs. Rit: 24.4 ± 0.2g*, *P<0.05], fat mass (C: 10 ± 0.4 vs. Rit: 4.5 ± 0.9 %*, *P<0.05) and leptin plasma levels (C: 4.7 ± 0.05 vs. Rit: 2.0 ± 0.36 ng/mL*, *P<0.05) confirming that it induces acquired lipodystrophy. Acquired lipodystrophy impaired endothelial function, increased plasma lipid peroxidation and vascular H2O2, and ROS producing enzymes (Nox1 and NoxA1). Furthermore, acquired lipodystrophy was associated with vascular inflammation characterized by elevation of NLRP3, Caspase‐1, IL‐1β, MCP‐1, F4/80, CCR5 and CCL5 gene expression. ROS scavenging via tempol (SOD mimetic, 100 μmol/l) or GKT771 (Nox1 inhibitor, 10 μmol/l) restored endothelial function. LRT (10μg/day/7 days, osmotic mini‐pump), at the end of the 3‐week ritonavir, restored endothelial function, reduced vascular oxidative stress and Nox1 and NOXA1 gene expression and vascular inflammation. Nox1 deficiency (Nox1−/−) protected mice from acquired lipodystrophy‐induced endothelial dysfunction and reduced inflammatory markers including CCR5 and CCL5. In order to analyze whether vascular inflammation is occurring via CCR5/CCL5, we induced lipodystrophy in CCR5 deficient mice (CCR5−/−). These mice were protected from acquired lipodystrophy‐induced endothelial dysfunction and vascular inflammation. Moreover, deleting endothelial leptin signaling via specific deletion of leptin receptor (LepR) in endothelial cells (LepR−/−EC mice) promoted endothelial dysfunction, which was reverted by pre‐incubating aortic rings with Nox1 inhibitor (GKT771) in vitro and increased inflammatory markers. Furthermore, LepR−/−EC mice were resistant to the vascular protective effects of LRT. Taken all together, LRT restores endothelial function and reduces vascular inflammation in acquired lipodystrophy associated with HAART via endothelium dependent reduction in Nox1‐derived ROS and CCR5/CCL5. Taken together these data support a key role for endothelial leptin signaling in the control of vascular tone and inflammation and suggest that LRT could represent a potential new avenue for the treatment of vascular diseases associated with acquired lipodystrophy.Support or Funding InformationWork supported by 17POST33410363 and 1K99HL140139‐01A1 to TBN and 1R01HL13030101 to EJ.BdC.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.