The current proposal is an extension of our studies conducted over the previous grant period and is aimed to investigate the contribution of arachidonic acid (AA) metabolites generated via CYP1B1 and the underlying mechanism involved in Ang II-induced neointimal growth caused by vascular injury and atherosclerosis. It is based on our novel preliminary data that: a) the selective CYP1B1 inhibitor 2,4,32,52-tetramethoxystilbene (TMS) or adenovirus CYP1B1 shRNA (CYP1B1 shRNA) prevents Ang II-stimulated neointimal growth caused by balloon injury of rat carotid artery;b) Ang II increases neointimal growth in wire-injured carotid artery of wild type (Cyp1b1+/+),but not CYP1B1 deficient (Cyp1b1-/-), mice;c) treatment with TMS inhibits generation of fatty streak areas and their acceleration by Ang II in Apo E knockout (apoE-/-) mice fed a high fat diet (HFD);and d) Ang II and AA-induced NADPH oxidase activation in rat VSMCs is prevented by TMS or CYP1B1 shRNA, and in VSMC from Cyp1b1-/-, but not Cyp1b1+/+, mice. These findings have led us to the following central hypothesis: CYP1B1, through AA metabolites/lipid peroxides, results in activation of NADPH oxidase and production of ROS, which, by activating one or more signaling molecules, contribute to the pathogenesis of restenosis caused by Ang II during vascular injury and to atherosclerosis produced by hypercholesterolemia and its acceleration by Ang II. To test this hypothesis, we will address the following specific aims:
Aim 1. Determine the contribution of CYP1B1 to neointimal growth stimulated by Ang II in balloon-injured rat and wire- injured mouse carotid artery;
Aim 2 a) Investigate the contribution of CYP1B1 to atherosclerosis and neointimal growth after wire injury of mouse carotid artery;
Aim 2 b) Examine the contribution of CYP1B1 to Ang II-induced acceleration of atherosclerosis, aneurysm, and neointimal growth;
Aim. 3. Investigate the mechanism of CYP1B1-dependent Ang II- and AA-induced NADPH oxidase and ROS production in VSMCs from hypercholesterolemia in mice. To address these aims, we plan to use numerous state-of-the-art in vitro and in vivo cellular and molecular biology techniques and transgenic mice. These include using 1) adenovirus CYP1B1 shRNA;2) apoE-/-/Cyp1b1+/+ and double knockout-apoE-/-/Cyp1b1-/- and knockin-apoE+/+/CYp1b1+/+ mice that we have generated in our laboratory;3) isolated VSMCs from these transgenic animals;4) morphological, histological, immunohistochemical and fluorescence, and biochemical techniques, and 5) HPLC-LC-ESI-MS for the identification of AA metabolites. The proposed studies should advance our current knowledge of the cellular and molecular mechanisms involved in the pathogenesis of restenosis and atherosclerosis and allow us to demonstrate CYP1B1 as a potential novel target for the development of more effective therapeutic drugs such as TMS for treating Ang II-induced restenosis caused by vascular injury and atherosclerosis by hypercholesterolemia.

Public Health Relevance

The proposed studies are designed to investigate the contribution of cytochrome P450 1B1 to the action of angiotensin II to promote restenosis caused by vascular injury and aortic atherosclerotic lesions and aneurysms produced by hypercholesterolemia. They should advance our current knowledge of the mechanisms involved in the pathogenesis of this vascular disease. Moreover, they should allow us to demonstrate cytochrome P450 1B1 as a potential novel target for the development of more effective drugs such as tetramethoxystilbene for treating the pathogenesis of restenosis caused by vascular injury and atherosclerosis.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL079109-06
Application #
8238737
Study Section
Vascular Cell and Molecular Biology Study Section (VCMB)
Program Officer
Maric-Bilkan, Christine
Project Start
2005-01-01
Project End
2015-11-30
Budget Start
2011-12-01
Budget End
2012-11-30
Support Year
6
Fiscal Year
2012
Total Cost
$399,162
Indirect Cost
$128,213
Name
University of Tennessee Health Science Center
Department
Pharmacology
Type
Schools of Medicine
DUNS #
941884009
City
Memphis
State
TN
Country
United States
Zip Code
38163
Lavrentyev, Eduard N; Malik, Kafait U (2009) High glucose-induced Nox1-derived superoxides downregulate PKC-betaII, which subsequently decreases ACE2 expression and ANG(1-7) formation in rat VSMCs. Am J Physiol Heart Circ Physiol 296:H106-18
Yaghini, Fariborz A; Li, Fang; Malik, Kafait U (2007) Expression and mechanism of spleen tyrosine kinase activation by angiotensin II and its implication in protein synthesis in rat vascular smooth muscle cells. J Biol Chem 282:16878-90
Parmentier, Jean-Hugues; Zhang, Chunxiang; Estes, Anne et al. (2006) Essential role of PKC-zeta in normal and angiotensin II-accelerated neointimal growth after vascular injury. Am J Physiol Heart Circ Physiol 291:H1602-13
Yaghini, Fariborz A; Zhang, Chunxiang; Parmentier, Jean-Hugues et al. (2005) Contribution of arachidonic acid metabolites derived via cytochrome P4504A to angiotensin II-induced neointimal growth. Hypertension 45:1182-7