Genetic Interference With Endothelial PPAR-γ (Peroxisome Proliferator-Activated Receptor-γ) Augments Effects of Angiotensin II While Impairing Responses to Angiotensin 1-7. Hypertension 2017 Sep;70(3):559-565
Date
07/05/2017Pubmed ID
28674038Pubmed Central ID
PMC5552422DOI
10.1161/HYPERTENSIONAHA.117.09358Scopus ID
2-s2.0-85021825355 (requires institutional sign-in at Scopus site) 16 CitationsAbstract
Pharmacological activation of PPAR-γ (peroxisome proliferator-activated receptor-γ) protects the vasculature. Much less is known on the cell-specific impact of PPAR-γ when driven by endogenous ligands. Recently, we found that endothelial PPAR-γ protects against angiotensin II-induced endothelial dysfunction. Here, we explored that concept further examining whether effects were sex dependent along with underlying mechanisms. We studied mice expressing a human dominant-negative mutation in PPAR-γ driven by the endothelial-specific vascular cadherin promoter (E-V290M), using nontransgenic littermates as controls. Acetylcholine (an endothelium-dependent agonist) produced similar relaxation of carotid arteries from nontransgenic and E-V290M mice. Incubation of isolated arteries with angiotensin II (1 nmol/L) overnight had no effect in nontransgenic, but reduced responses to acetylcholine by about 50% in male and female E-V290M mice (P<0.05). Endothelial function in E-V290M mice was restored to normal by inhibitors of superoxide (tempol), NADPH oxidase (VAS-2870), Rho kinase (Y-27632), ROCK2 (SLX-2119), NF-κB (nuclear factor-kappa B essential modulator-binding domain peptide), or interleukin-6 (neutralizing antibody). In addition, we hypothesized that PPAR-γ may influence the angiotensin 1-7 arm of the renin-angiotensin system. In the basilar artery, dilation to angiotensin 1-7 was selectively reduced in E-V290M mice by >50% (P<0.05), an effect reversed by Y-27632. Thus, effects of angiotensin II are augmented by interference with endothelial PPAR-γ through sex-independent mechanisms, involving oxidant-inflammatory signaling and ROCK2 (Rho kinase). The study also provides the first evidence that endothelial PPAR-γ interacts with angiotensin 1-7 responses. These critical roles for endothelial PPAR-γ have implications for pathophysiology and therapeutic approaches for vascular disease.
Author List
De Silva TM, Hu C, Kinzenbaw DA, Modrick ML, Sigmund CD, Faraci FMAuthor
Curt Sigmund PhD Chair, Professor in the Physiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AmidesAngiotensin I
Angiotensin II
Animals
Animals, Genetically Modified
Carotid Arteries
Female
Interleukin-6
Male
Mice
NF-kappa B
Oxidative Stress
PPAR gamma
Peptide Fragments
Pyridines
Renin-Angiotensin System
Vascular Diseases
Vasoconstrictor Agents
Vasodilation
