Genomes and Genes
Ryanodine receptor in cardiac hypertrophy and heart failure
Principal Investigator: GERHARD W MEISSNER
Abstract: The goal of our proposed research is to understand how the cardiac Ca2+ release channel (ryanodine receptor, RyR2) regulates cardiac function. The RyR2s are 2,200 kDa ion channels that release Ca2+ ions in response to an action potential from the sarcoplasmic reticulum. The RyR2 ion channel is composed of four RyR2 560 kDa subunits that bind calmodulin (CaM), and four small 12.6 kDa FK506 binding proteins. Our proposed studies make use of genetically modified mice with mutations in the CaM binding domain of RyR2 to elucidate signaling mechanisms associated with cardiac hypertrophy. Homozygous mice expressing a mutant form of RyR2 (RyR2-W3587A/L3591D/F3603A or RyR2ADA), that is not inhibited by CaM at diastolic and systolic Ca2+ concentrations, show signs of cardiac hypertrophy as early as 1 day after birth. There is up- regulation of genes and proteins associated with class II histone deacetylase(HDAC)/myocyte enhancer factor- 2(MEF2) and calcineurin signaling pathways, and the homozygous mutant mice die within two weeks of birth. Genetically modified mice deficient in CaM regulation of RyR2 by CaM at diastolic or diastolic and systolic Ca2+ concentrations will be used to test the hypothesis that a defective sarcoplasmic reticulum Ca2+ release activates signaling mechanisms in the embryonic heart, and ensuing major alterations in signaling and Ca2+ handling proteins contribute to the rapid progression of cardiac hypertrophy in newborn mice. We will determine heart and cardiomyocyte function and morphology, and temporal changes in relative abundance and activity of signaling molecules by microarray, quantitative RT-PCR, immunoblot and enzymatic analysis. The functional significance of class II HDAC/MEF2 and calcineurin signaling will be probed using class II HDAC mutants, and by crossing mice impaired in CaM regulation of RyR2 with mice deficient in calcineurin A2, and with mice that carry the luciferase transgene driven by NFAT-dependent promoter. Ca2+ handling by wild type and mutant mice will be assessed using whole cell patch clamp techniques, Ca2+ imaging, cell homogenates and membrane preparations. PUBLIC HEALTH RELEVANCE The proposed research will make use of genetically modified mice with mutations in the calmodulin binding domain of the cardiac sarcoplasmic reticulum Ca2+ release channel to reveal new regulatory mechanisms in cardiac hypertrophy. Our studies will provide new approaches to minimize the risks of cardiac hypertrophy and heart failure, one of the most frequent causes of death in humans.
Funding Period: 2003-04-15 - 2014-12-31
more information: NIH RePORT
- Knocking down type 2 but not type 1 calsequestrin reduces calcium sequestration and release in C2C12 skeletal muscle myotubesYing Wang
Department of Biochemistry and Biophysics, Gene Therapy Center, University of North Carolina, Chapel Hill, North Carolina 27599 7260, USA
J Biol Chem 281:15572-81. 2006..Taken together, our data suggest that knocking down CSQ2, but not CSQ1, leads to reduced Ca2+ storage and release in C2C12 myotubes...
- Cardiac hypertrophy associated with impaired regulation of cardiac ryanodine receptor by calmodulin and S100A1Naohiro Yamaguchi
Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
Am J Physiol Heart Circ Physiol 305:H86-94. 2013..They further suggest that CaM inhibition of RyR2 at systolic Ca²⁺ is important for maintaining normal cardiac function...
- Detection of calcium release via ryanodine receptorsJerry P Eu
Department of Medicine, Division of Pulmonary, Allergy and Critical Care, Duke University, Durham, NC, USA
Methods Mol Biol 798:373-82. 2012....
- Dysfunctional ryanodine receptor and cardiac hypertrophy: role of signaling moleculesNaohiro Yamaguchi
Dept of Biochemistry and Biophysics, Univ of North Carolina, Chapel Hill, NC 27599 7260, USA
Am J Physiol Heart Circ Physiol 300:H2187-95. 2011..5 hearts; rather increased Erk1/2 and p90RSK phosphorylation levels likely leading to reduced GSK-3β activity were found to precede development of cardiac hypertrophy in mice expressing dysfunctional ryanodine receptor ion channel...
- A structural model of the pore-forming region of the skeletal muscle ryanodine receptor (RyR1)Srinivas Ramachandran
Department of Biochemistry and Biophysics, University of North Carolina Chapel Hill, Chapel Hill, North Carolina, USA
PLoS Comput Biol 5:e1000367. 2009..Together, the computational and experimental results shed light on ion conductance and selectivity of RyR1 at an atomistic level...
- Regulation of the cardiac muscle ryanodine receptor by O(2) tension and S-nitrosoglutathioneJunhui Sun
Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, USA
Biochemistry 47:13985-90. 2008..Our results indicate that both RyR1 and RyR2 are pO(2)-responsive yet point to different mechanisms by which NO and S-nitrosoglutathione influence cardiac and skeletal muscle sarcoplasmic reticulum Ca(2+) release...
- Thermodynamics of calmodulin binding to cardiac and skeletal muscle ryanodine receptor ion channelsGerhard Meissner
Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599 7260, USA
Proteins 74:207-11. 2009..15 microM Ca(2+) the rate from RyR2 was little affected. The results suggest major differences in the energetics of CaM binding to and dissociation from RyR1 and RyR2...
- Early cardiac hypertrophy in mice with impaired calmodulin regulation of cardiac muscle Ca release channelNaohiro Yamaguchi
Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
J Clin Invest 117:1344-53. 2007..Taken together, the data indicate that impaired CaM inhibition of RyR2, associated with defective sarcoplasmic reticulum Ca(2+) release and altered gene expression, leads to cardiac hypertrophy and early death...
- Does Ca2+/calmodulin-dependent protein kinase deltac activate or inhibit the cardiac ryanodine receptor ion channel?Naohiro Yamaguchi
Circ Res 100:293-5. 2007
- Cardiac myocyte Z-line calmodulin is mainly RyR2-bound, and reduction is arrhythmogenic and occurs in heart failureYi Yang
From the Department of Pharmacology Y Y, T G, T O, H U, A A K, D M B, and Molecular and Cellular Cardiology Division, Department of Medicine L C, A A K, University of California, Davis, CA Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC A C, G M and Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN B R F, R L C
Circ Res 114:295-306. 2014..Defective CaM-RyR2 interaction may occur in heart failure, cardiac hypertrophy, and catecholaminergic polymorphic ventricular tachycardia. However, the in situ binding properties for CaM-RyR2 are unknown...
- Connexin Distribution in Physiological Versus Pathological Cardiac HypertrophyMichael R Zile; Fiscal Year: 2013..pathological hypertrophy, with ex- tensively characterized cytoskeletal properties in each setting. ..
- Ca-Calmodulin Activated Phosphorylation Signaling Pathways in the HeartCOURTNEY BLAKE NICHOLS; Fiscal Year: 2013..This will help to identify novel signaling cascades and thereby identify new therapeutic targets for the treatment of heart failure. ..
- CARDIOVASCULAR DYNAMICS AND THEIR CONTROLJohn E Hall; Fiscal Year: 2013..End of Abstract) ..