Promotion of CHIP-Mediated p53 Degradation Protects the Heart From Ischemic Injury

• Published in: Circulation research 2010-06, Vol.106 (11), p.1692-1702
• Main Authors: Naito, Atsuhiko T, Okada, Sho, Minamino, Tohru, Iwanaga, Koji, Liu, Mei-Lan, Sumida, Tomokazu, Nomura, Seitaro, Sahara, Naruhiko, Mizoroki, Tatsuya, Takashima, Akihiko, Akazawa, Hiroshi, Nagai, Toshio, Shiojima, Ichiro, Komuro, Issei
• Format: Article
• Language: English
• Subjects: Animals; Animals, Newborn; Apoptosis; Base Sequence; Benzoquinones - pharmacology; Biological and medical sciences; Cardiology. Vascular system; Cell Hypoxia; Chlorocebus aethiops; Coronary heart disease; COS Cells; Disease Models, Animal; Fundamental and applied biological sciences. Psychology; Genetic Therapy - methods; Heart; HSP90 Heat-Shock Proteins - antagonists & inhibitors; HSP90 Heat-Shock Proteins - metabolism; Humans; Hypoxia-Inducible Factor 1, alpha Subunit - genetics; Hypoxia-Inducible Factor 1, alpha Subunit - metabolism; Lactams, Macrocyclic - pharmacology; Male; Medical sciences; Mice; Mice, Inbred C57BL; Mice, Knockout; Molecular Sequence Data; Mutation; Myocardial Infarction - enzymology; Myocardial Infarction - genetics; Myocardial Infarction - physiopathology; Myocardial Infarction - therapy; Myocarditis. Cardiomyopathies; Myocytes, Cardiac - drug effects; Myocytes, Cardiac - enzymology; Myocytes, Cardiac - pathology; Promoter Regions, Genetic; Proteasome Endopeptidase Complex - metabolism; Protein Processing, Post-Translational - drug effects; Protein Processing, Post-Translational - genetics; Rats; Rats, Wistar; RNA Interference; Transcriptional Activation; Tumor Suppressor Protein p53 - metabolism; Ubiquitin-Protein Ligases - deficiency; Ubiquitin-Protein Ligases - genetics; Ubiquitin-Protein Ligases - metabolism; Ubiquitination; Ventricular Remodeling; Vertebrates: cardiovascular system
• ISSN: 0009-7330; 1524-4571
• DOI: 10.1161/CIRCRESAHA.109.214346

RATIONALE:The number of patients with coronary heart disease, including myocardial infarction, is increasing and novel therapeutic strategy is awaited. Tumor suppressor protein p53 accumulates in the myocardium after myocardial infarction, causes apoptosis of cardiomyocytes, and plays an important role in the progression into heart failure. OBJECTIVES:We investigated the molecular mechanisms of p53 accumulation in the heart after myocardial infarction and tested whether anti-p53 approach would be effective against myocardial infarction. METHODS AND RESULTS:Through expression screening, we found that CHIP (carboxyl terminus of Hsp70-interacting protein) is an endogenous p53 antagonist in the heart. CHIP suppressed p53 level by ubiquitinating and inducing proteasomal degradation. CHIP transcription was downregulated after hypoxic stress and restoration of CHIP protein level prevented p53 accumulation after hypoxic stress. CHIP overexpression in vivo prevented p53 accumulation and cardiomyocyte apoptosis after myocardial infarction. Promotion of CHIP function by heat shock protein (Hsp)90 inhibitor, 17-allylamino-17-demethoxy geldanamycin (17-AAG), also prevented p53 accumulation and cardiomyocyte apoptosis both in vitro and in vivo. CHIP-mediated p53 degradation was at least one of the cardioprotective effects of 17-AAG. CONCLUSIONS:We found that downregulation of CHIP level by hypoxia was responsible for p53 accumulation in the heart after myocardial infarction. Decreasing the amount of p53 prevented myocardial apoptosis and ameliorated ventricular remodeling after myocardial infarction. We conclude that anti-p53 approach would be effective to treat myocardial infarction.