title: Enhanced susceptibility of cyclin kinase inhibitor p21 knockout mice to high fat diet induced atherosclerosis.
abstract: Cyclin kinase inhibitor p21 is one of the most potent inhibitors of aortic smooth muscle cell proliferation, a key mediator of atherosclerosis. This study tests if p2l deficiency will result in severe atherosclerosis in a mouse model. p21-/- and strain matched wild type mice were fed with high fat diet for 21 weeks. Analysis for biochemical parameters (cholesterol, triglycerides) in serum and mRNA expression of CD36, HO-1, TGF-beta, IFN-gamma, TNF-alpha, PPAR-gamma and NADPH oxidase components (p22phox, NOX-1 and Rac-1) was performed in aortic tissues by Real Time PCR. p21-/- mice gained significantly (p < 0.01) more weight than wild type mice, triglycerides (p < 0.05) and cholesterol levels (p < 0.01) were more pronounced in the sera of p21-/- compared to wild type mice fed with high fat diet. High fat diet resulted in significantly decreased TGF-beta (p < 0.02), HO-l (p < 0.02) and increased CD36 (p < 0.03) mRNA expression in aortic tissues of p21-/- mice compared to animal fed with regular diet. IFN-gamma mRNA expression (235 +/- 11 folds) increased significantly in high fat diet fed p21-/- mice and a multifold modulation of PPAR-gamma(136 +/- 7), p22phox, NOX-1 and Rac-1 (15-35-folds) mRNA in aortic tissues from p21-/- mice compared to the wild type mice. Severity of atherosclerotic lesions was significantly higher in p21-/- compared to wild type mice. The results demonstrate that the deficiency of p21 leads to altered expression of pro-atherogenic genes, and severe atherosclerosis in mice fed with high fat diet. This opens the possibility of p21 protein as a therapeutic tool to control progression of atherosclerosis.
authors: Department of Medicine (Cardiology), University of Maryland, Baltimore, USA. akhanna@medicine.umaryland.edu
authors: Ashwani K
authors: AK
authors: Khanna
mesh_terms: D000821:Animal Feed; D000818:Animals; D001011:Aorta / Q000378:metabolism; D050197:Atherosclerosis / Q000209:etiology / Q000235:genetics*; D018955:CD36 Antigens / Q000096:biosynthesis; D049109:Cell Proliferation; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D051547:Heme Oxygenase-1 / Q000096:biosynthesis; D008055:Lipids / Q000737:chemistry; D008565:Membrane Proteins / Q000096:biosynthesis; D051379:Mice; D018345:Mice, Knockout; D019255:NADPH Oxidases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors
chemical_list: D018955:CD36 Antigens; D050759:Cyclin-Dependent Kinase Inhibitor p21; D008055:Lipids; D008565:Membrane Proteins; D012333:RNA, Messenger; D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse; D019255:NADPH Oxidases