Calcium regulation in cardiac myocytes is central to excitation-contraction coupling (ECC) and is also involved in hypertrophic nuclear signaling. Two important and ubiquitous Ca regulatory systems, Ca-calmodulin dependent protein kinase II (CaMKII) and inositol (1,4,5)P3 receptors (InsP3R) are present in myocytes, and have been implicated in altering ECC, arrhythmogenesis and nuclear signaling. However, surprisingly littlie is known about how these effects occur. Ca-dependent pathways implicated in regulating transcription in hypertrophy (Hyp) and heart failure (HF) include CaMKII &calcineurin (CaN) and these may function via nuclear translocation of key factors (NFAT &HDAC) which alter transcription. Overall goals here are to understand better how CaMKII and InsP3R function in cardiac myocytes with respect to acute Ca signaling (ECC &arrhythmogenesis) and in nuclear signaling (via NFAT &HDAC) in hypertrophy &HF. Four highly synergistic multidisciplinary projects are planned. Project I (Bers) focuses on cellular aspects of CaMKII in 3 aims concerning: 1) acute CaMKII effects on ECC, 2) Ca-dependent nuclear signaling via a proposed lnsP3R-CaMKII-HDAC pathway, &3) altered CaMKII signaling in Hyp &HF (regarding ECC, arrhythmias &HDAC activation). Project II (Blatter) focuses on cellular aspects of IP3Rs in 3 aims (all qHyp &HF) concerning: 1) acute IP3R-mediated effects on ECC, 2) the role of InsP3R in arrhythmogenesis and how CaMKII modulates lnsP3R function, and 3) Ca coding and IP3R involvement in NFAT signaling to the nucleus. Project III (Miqnery) focuses on molecular characterization of 1) the direction that nuclear InsP3Rs face and their physical interactions with CaMKII (&CaM &CaN), 2) CaMKII-dependent phosphorylation of InsP3R and modulation of function, 3) manipulation of InsP3R-CaMKII interaction, 4) InsP3R isoform expression &localization in atrial &ventricular myocytes (Hyp &HF), 5) generating novel fluorescent [InsP3] sensors (FIREs). Project IV (Brown) focuses on CaMKII and InsP3R regulation at in vivo and biochemical levels concerning: 1) development of Hyp &HF in knockout mice lacking cardiac lnsP3R2 or CaMKIIlambda (the dominant myocyte isoforms), 2) differential activation of cytosolic vs. nuclear CaMKII, plus development of a fluorescent CaMK activity sensor (CaMKAR), 3) differential target phosphorylation by CaMKII isoforms, &4) cardiac InsP3 formation and regulation by CaMKII. Three scientific cores will support these aims. Core B (Myocytes &HF Rabbits) will isolate myocytes from mice and rabbits (including Hyp mice and HF rabbits). Core C (Fluorescence Imaging) will provide instrumentation and expertise for fluorescent imaging. Core D (Genetic Mouse &Adenovirus) will develop unique mouse models (e.g. lnsPaR2- &CaMKIIlambda-KO) and adenoviral vectors for myocyte studies. The proposed work integrates experienced investigators with highly complementary expertise and perspective to tackle these questions in a highly interactive multidisciplinary approach. The results will greatly increase our understanding of the roles of CaMKII and InsP3R in cardiac myocytes during ECC, arrhythmogenesis and nuclear signaling in normal, Hyp and HF cardiac myocytes.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL080101-05
Application #
7784525
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Program Officer
Przywara, Dennis
Project Start
2006-01-01
Project End
2011-06-30
Budget Start
2009-12-01
Budget End
2011-06-30
Support Year
5
Fiscal Year
2010
Total Cost
$2,406,469
Indirect Cost
Name
University of California Davis
Department
Pharmacology
Type
Schools of Medicine
DUNS #
047120084
City
Davis
State
CA
Country
United States
Zip Code
95618
Yuen, Garrick K; Galice, Samuel; Bers, Donald M (2017) Subcellular localization of Na/K-ATPase isoforms in ventricular myocytes. J Mol Cell Cardiol 108:158-169
Burel, Sophie; Coyan, Fabien C; Lorenzini, Maxime et al. (2017) C-terminal phosphorylation of NaV1.5 impairs FGF13-dependent regulation of channel inactivation. J Biol Chem 292:17431-17448
Kanaporis, Giedrius; Blatter, Lothar A (2017) Membrane potential determines calcium alternans through modulation of SR Ca2+ load and L-type Ca2+ current. J Mol Cell Cardiol 105:49-58
Bovo, Elisa; Huke, Sabine; Blatter, Lothar A et al. (2017) The effect of PKA-mediated phosphorylation of ryanodine receptor on SR Ca2+ leak in ventricular myocytes. J Mol Cell Cardiol 104:9-16
Bers, Donald M (2017) CALMing Down Arrhythmogenic Calmodulinopathies via a Precision Medicine Approach. Circ Res 120:3-4
Lang, Di; Sato, Daisuke; Jiang, Yanyan et al. (2017) Calcium-Dependent Arrhythmogenic Foci Created by Weakly Coupled Myocytes in the Failing Heart. Circ Res 121:1379-1391
Ma, Xiaolong; Chen, Chao; Veevers, Jennifer et al. (2017) CRISPR/Cas9-mediated gene manipulation to create single-amino-acid-substituted and floxed mice with a cloning-free method. Sci Rep 7:42244
Dewenter, Matthias; Neef, Stefan; Vettel, Christiane et al. (2017) Calcium/Calmodulin-Dependent Protein Kinase II Activity Persists During Chronic ?-Adrenoceptor Blockade in Experimental and Human Heart Failure. Circ Heart Fail 10:e003840
Pereira, Laƫtitia; Bare, Dan J; Galice, Samuel et al. (2017) ?-Adrenergic induced SR Ca2+ leak is mediated by an Epac-NOS pathway. J Mol Cell Cardiol 108:8-16
Blatter, Lothar A (2017) The intricacies of atrial calcium cycling during excitation-contraction coupling. J Gen Physiol 149:857-865

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