Atheroma development in apolipoprotein E-null mice is not regulated by phosphorylation of p27Kip1 on threonine 187
Article first published online: 14 OCT 2005
Copyright © 2005 Wiley-Liss, Inc.
Journal of Cellular Biochemistry
Volume 97, Issue 4, pages 735–743, 1 March 2006
How to Cite
Sanz-González, S. M., Melero-Fernández de Mera, R., Malek, N. P. and Andrés, V. (2006), Atheroma development in apolipoprotein E-null mice is not regulated by phosphorylation of p27Kip1 on threonine 187. J. Cell. Biochem., 97: 735–743. doi: 10.1002/jcb.20680
- Issue published online: 30 JAN 2006
- Article first published online: 14 OCT 2005
- Manuscript Accepted: 9 SEP 2005
- Manuscript Received: 27 JUL 2005
- Instituto de Salud Carlos III (Red de Centros RECAVA, C03/01)
- Regional Government of Valencia. Grant Number: GV04B-288
- Spanish Ministry of Education and Science and Fondo Europeo de Desarrollo Regional. Grant Number: SAF2004-03057
- BEFI Fellowship (from the Spanish Ministry of Health to S.M.S.-G).
- transgenic animal models;
- protein phosphorylation;
- cell cycle control
Excessive cellular proliferation is thought to contribute to neointimal lesion development during atherosclerosis and restenosis after angioplasty. Inhibition of cyclin-dependent kinase (CDK) activity by p27 inhibits mammalian cell growth. Mounting evidence indicates that p27 negatively regulates neointimal thickening in animal models of restenosis and atherosclerosis, and its expression in human neointimal lesions is consistent with such a protective role. Cell cycle progression is facilitated by cyclinE/CDK2-dependent phosphorylation of p27 on threonine 187 (T187) during late G1. The purpose of this study was to assess whether this phosphorylation event plays a role during atherosclerosis. To this end, we generated apolipoprotein E-null mice with both p27 alleles replaced by a mutated form non-phosphorylatable at T187 (apoE−/−p27T187A mice) and investigated the kinetics of atheroma development in these animals compared to apoE−/− controls with an intact p27 gene. Fat feeding resulted in comparable level of hypercholesterolemia in both groups of mice. Surprisingly, aortic p27 expression was not increased in fat-fed apoE−/−p27T187A mice compared with apoE−/− controls. Moreover, atheroma size, lesion cellularity, proliferation, and apoptotic rates were undistinguishable in both groups of fat-fed mice. Thus, in contrast to previous studies that highlight the importance of p27 phosphorylation at T187 on the control of p27 expression and function in different tissues and pathophysiological scenarios, our findings demonstrate that this phosphorylation event is not implicated in the control of aortic p27 expression and atheroma progression in hypercholesterolemic mice. J. Cell. Biochem. 97: 735–743, 2006. © 2005 Wiley-Liss, Inc.