| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Integrative Physiology |
From the Genetics Graduate Program (A.M.B., C.M.H.), the Department of Internal Medicine (W.J.d.L., M.L.M., H.L.K., F.M.F., C.D.S.), the Department of Pharmacology (F.M.F.), the Department of Molecular Physiology and Biophysics (C.D.S.), and the Center on Functional Genomics of Hypertension (C.D.S.), Cardiovascular Center, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa.
Correspondence to Curt D. Sigmund, PhD, Departments of Internal Medicine and Molecular Physiology & Biophysics, 3181B MERF, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242. E-mail curt-sigmund{at}uiowa.edu
The ligand-activated transcription factor peroxisome proliferator activated receptor gamma (PPAR
) is expressed in vascular endothelium where it exerts anti-inflammatory and antioxidant effects. However, its role in regulating vascular function remains undefined. We examined endothelial function in transgenic mice expressing dominant-negative mutants of PPAR
under the control of an endothelial-specific promoter to test the hypothesis that endothelial PPAR
plays a protective role in the vasculature. Under baseline conditions, responses to the endothelium-dependent agonist acetylcholine were not affected in either aorta or the basilar artery in vitro. In response to feeding a high-fat diet for 12 weeks, acetylcholine produced dilation that was markedly impaired in the basilar artery of mice expressing dominant-negative mutants, but not in mice expressing wild-type PPAR
controlled by the same promoter. Unlike basilar artery, 12 weeks of a high-fat diet was not sufficient to cause endothelial dysfunction in the aorta of mice expressing dominant-negative PPAR
, although aortic dysfunction became evident after 25 weeks. The responses to acetylcholine in basilar artery were restored to normal after treatment with a scavenger of superoxide. Baseline blood pressure was only slightly elevated in the transgenic mice, but the pressor response to angiotensin II was augmented. Thus, interference with PPAR
in the endothelium produces endothelial dysfunction in the cerebral circulation through a mechanism involving oxidative stress. Consistent with its role as a fatty acid sensor, these findings provide genetic evidence that endothelial PPAR
plays a critical role in protecting blood vessels in response to a high-fat diet.
Key Words: endothelium oxidative stress transcription transgenic animals vascular
This article has been cited by other articles:
![]() |
F.-I Hsieh, W.-C. Lo, H.-J. Lin, Y.-C. Hsieh, L.-M. Lien, C.-H. Bai, H.-P. Tseng, and H.-Y. Chiou Significant Synergistic Effect of Peroxisome Proliferator-Activated Receptor {gamma} C-2821T and Diabetes on the Risk of Ischemic Stroke Diabetes Care, November 1, 2009; 32(11): 2033 - 2035. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Kleinhenz, D. J. Kleinhenz, S. You, J. D. Ritzenthaler, J. M. Hansen, D. R. Archer, R. L. Sutliff, and C. M. Hart Disruption of endothelial peroxisome proliferator-activated receptor-{gamma} reduces vascular nitric oxide production Am J Physiol Heart Circ Physiol, November 1, 2009; 297(5): H1647 - H1654. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Tsukuda, M. Mogi, J. Iwanami, L.-J. Min, A. Sakata, F. Jing, M. Iwai, and M. Horiuchi Cognitive Deficit in Amyloid-{beta}-Injected Mice Was Improved by Pretreatment With a Low Dose of Telmisartan Partly Because of Peroxisome Proliferator-Activated Receptor-{gamma} Activation Hypertension, October 1, 2009; 54(4): 782 - 787. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Chang, L. Villacorta, J. Zhang, M. T. Garcia-Barrio, K. Yang, M. Hamblin, S. E. Whitesall, L. G. D'Alecy, and Y. E. Chen Vascular Smooth Muscle Cell-Selective Peroxisome Proliferator-Activated Receptor-{gamma} Deletion Leads to Hypotension Circulation, April 28, 2009; 119(16): 2161 - 2169. [Abstract] [Full Text] [PDF] |
||||
|
Circulation Research Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 2008 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |