Abstract
The molecular events associated with the development of pathological hypertrophy have been shown to be stimulated through G-protein-coupled receptors that activate Gq signaling pathways in neonatal cardiomyocytes and in transgenic (TG) and knockout mice. We demonstrated that CaMKII, a multifunctional Ca 2+-regulated protein kinase, was activated through G-protein-coupled receptor and inositol trisphosphate-mediated Ca 2+ release and suggested that CaMKII was a downstream mediator of Gq-coupled hypertrophic signaling. This was supported by the demonstration of CaMKII activation by pressure overload [(transverse aortic constriction (TAC)] and induction of hypertrophy by TG CaMKII expression. CaMKII also phosphorylates Ca 2+ handling proteins including the ryanodine receptor (RyR2), phosphorylation of which markedly increases sarcoplasmic reticulum Ca2+ leak. Increased RyR2 phosphorylation is associated with heart failure development in CaMKII TG mice, and mice genetically deletedfor CaMKII (KO) have attenuated RyR2 phosphorylation, sarcoplasmic reticulum Ca 2+ leak, and heart failure development after long-term TAC. Genetic ablation of CaMKII also decreases development of heart failure in Gq TG mice and decreases infarct size, while improving functional recovery in mice subject to ischemia/reperfusion and preventing adverse remodeling after coronary artery occlusion. The underlying mechanisms are currently under study.
Original language | English (US) |
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Pages (from-to) | 598-603 |
Number of pages | 6 |
Journal | Journal of Cardiovascular Pharmacology |
Volume | 56 |
Issue number | 6 |
DOIs | |
State | Published - Dec 2010 |
Keywords
- CaMKII
- GPCR
- Heart failure
- Hypertrophy
- Ischemia/ reperfusion
ASJC Scopus subject areas
- Pharmacology
- Cardiology and Cardiovascular Medicine