title: Critical role for FoxO3a-dependent regulation of p21CIP1/WAF1 in response to statin signaling in cardiac myocytes.
abstract: Statins are widely used clinical drugs that exert beneficial growth-suppressive effects in patients with cardiac hypertrophy. We investigated the role of the cell cycle inhibitor p21(CIP1/WAF1) (p21) in statin-dependent inhibition of hypertrophic growth in postmitotic cardiomyocytes. We demonstrate that lovastatin fails to inhibit cardiac hypertrophy to angiotensin II in p21(-/-) mice and that reconstitution of p21 function by TAT.p21 protein transduction can rescue statin action in these otherwise normally developed animals. Lovastatin specifically recruits the forkhead box FoxO3a transcription factor to the p21 promoter, mediating transcriptional transactivation of the p21 gene as analyzed in isolated primary cardiomyocytes. Lovastatin also stimulates protein kinase B/Akt kinase activity, and Akt-dependent phosphorylation forces p21 in the cytoplasm, where it inhibits Rho-kinases contributing to the suppression of cardiomyocyte hypertrophy. Loss of p21 or FoxO3a by RNA interference causes a general inhibition of lovastatin signal transduction. These results suggest that p21 functions as FoxO3a downstream target to mediate an statin-derived anti-hypertrophic response. Taken together, our genetic and biochemical data delineate an essential function of p21 for statin-dependent inhibition of cardiac myocyte hypertrophy.
authors.affiliation: University Health Network, MaRS 3-908, 200 Elizabeth St, Toronto, Ontario M5G 2C4, Canada.
authors.forename: Ludger
authors.initials: L
authors.lastname: Hauck
authors.forename: Christoph
authors.initials: C
authors.lastname: Harms
authors.forename: Daniela
authors.initials: D
authors.lastname: Grothe
authors.forename: Junfeng
authors.initials: J
authors.lastname: An
authors.forename: Karen
authors.initials: K
authors.lastname: Gertz
authors.forename: Golo
authors.initials: G
authors.lastname: Kronenberg
authors.forename: Rainer
authors.initials: R
authors.lastname: Dietz
authors.forename: Matthias
authors.initials: M
authors.lastname: Endres
authors.forename: Rüdiger
authors.initials: R
authors.lastname: von Harsdorf
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000378:metabolism* / Q000494:pharmacology; D006984:Hypertrophy / Q000517:prevention & control; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors; D008148:Lovastatin / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D051057:Proto-Oncogene Proteins c-akt / Q000502:physiology; D034622:RNA Interference; D051381:Rats; D015398:Signal Transduction; D014158:Transcription, Genetic / Q000502:physiology; D054460:rho-Associated Kinases
chemical_list: C493957:Cdkn1a protein, mouse; C493958:Cdkn1a protein, rat; D050759:Cyclin-Dependent Kinase Inhibitor p21; C499515:FOXO3 protein, rat; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D008148:Lovastatin; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D054460:rho-Associated Kinases