Opposing Cardioprotective Actions and Parallel Hypertrophic Effects of δPKC and εPKC

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 98; no. 20; pp. 11114 - 11119
• Main Authors: Chen, Leon, Hahn, Harvey, Wu, Guangyu, Chen, Che-Hong, Liron, Tamar, Schechtman, Deborah, Cavallaro, Gabriele, Banci, Lucia, Guo, Yiru, Bolli, Roberto, Dorn, Gerald W., Mochly-Rosen, Daria
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 25.09.2001
• Subjects: Amino Acid Sequence; Amino acids; Animals; Biological Sciences; Cardiomegaly; Cardiomegaly - physiopathology; Cells, Cultured; Enzyme Activation; Heart; Heart - drug effects; Heart - physiology; Heart - physiopathology; Hemodynamics - drug effects; Hemodynamics - physiology; Hypertrophy; In Vitro Techniques; Ischemia; Isoenzymes - chemistry; Isoenzymes - metabolism; Male; Mice; Mice, Transgenic; Models, Molecular; Molecular Sequence Data; Myocardial Contraction - drug effects; Myocardial Contraction - physiology; Myocardial Ischemia - physiopathology; Myocardium; Peptide Fragments - chemical synthesis; Peptide Fragments - chemistry; Peptide Fragments - pharmacology; Peptides - chemical synthesis; Peptides - chemistry; Peptides - pharmacology; Perfusion; Protein Conformation; Protein Kinase C - chemistry; Protein Kinase C - metabolism; Protein Kinase C-delta; Protein Kinase C-epsilon; Rats; Rats, Wistar; Reperfusion; Sequence Alignment; Sequence Homology, Amino Acid; Transgenic animals
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.191369098

Conflicting roles for protein kinase C (PKC) isozymes in cardiac disease have been reported. Here, δPKC-selective activator and inhibitor peptides were designed rationally, based on molecular modeling and structural homology analyses. Together with previously identified activator and inhibitor peptides of εPKC, δPKC peptides were used to identify cardiac functions of these isozymes. In isolated cardiomyocytes, perfused hearts, and transgenic mice, δPKC and εPKC had opposing actions on protection from ischemia-induced damage. Specifically, activation of εPKC caused cardioprotection whereas activation of δPKC increased damage induced by ischemia in vitro and in vivo. In contrast, δPKC and εPKC caused identical nonpathological cardiac hypertrophy; activation of either isozyme caused nonpathological hypertrophy of the heart. These results demonstrate that two related PKC isozymes have both parallel and opposing effects in the heart, indicating the danger in the use of therapeutics with nonselective isozyme inhibitors and activators. Moreover, reduction in cardiac damage caused by ischemia by perfusion of selective regulator peptides of PKC through the coronary arteries constitutes a major step toward developing a therapeutic agent for acute cardiac ischemia.