Cardiac hypertrophy is the primary compensatory response of the heart to chronic stress. Accordingly, left ventricular hypertrophy is a major risk factor for the development of dilated cardiomyopathy and heart failure. The Ca2+/calmodulin-dependent protein phosphatase Calcineurin (CaN) is a key signaling protein regulating pathological remodeling, and manipulation of CaN activity has been proposed as a therapeutic strategy. However, classical inhibitors of CaN are immunosuppressants and have adverse side effects, making this drug option unfeasible for long-term treatment of cardiac disease. We propose that targeting specific microdomains of CaN via disrupting CaN localization will open up new avenues of drug design for the treatment of hypertrophy. In particular, we have shown that the scaffolding protein mAKAP? binds both CaN and its downstream substrate MEF2D, hence creating a microdomain of CaN signaling. Additionally, mAKAP? expression is required in vivo for the induction of pathological remodeling in response to pressure overload. Our central hypothesis states that specific pools of CaN confined to select intracellular compartments such as that organized by mAKAP? provides the molecular basis for both localized activation and definition of substrate. Our three specific aims will test whether mAKAP?-bound CaN is regulated by a perinuclear Ca2+ compartment (Aim 1) that controls MEF2D gene transcription (Aim 2) and that may be selectively targeted for drug therapy for heart failure (Aim 3).

Public Health Relevance

Heart failure is a syndrome of major public heath significance accountable for nearly 300,000 deaths each year. It is estimated that 5.1 million US citizens suffer from heart failure, with nearly 825,000 new cases diagnosed annually. A better understanding of the cellular mechanisms that control cardiac remodeling, including myocyte hypertrophy, may yield better therapeutic regimens with decreased mortality.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL126825-01A1
Application #
9022960
Study Section
Molecular and Integrative Signal Transduction Study Section (MIST)
Program Officer
Schwartz, Lisa
Project Start
2016-02-01
Project End
2020-01-31
Budget Start
2016-02-01
Budget End
2017-01-31
Support Year
1
Fiscal Year
2016
Total Cost
Indirect Cost
Name
University of Connecticut
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
022254226
City
Farmington
State
CT
Country
United States
Zip Code
Li, Jinliang; Aponte Paris, Shania; Thakur, Hrishikesh et al. (2018) Muscle A-kinase-anchoring protein-?-bound calcineurin toggles active and repressive transcriptional complexes of myocyte enhancer factor 2D. J Biol Chem :
Bedioune, Ibrahim; Lefebvre, Florence; LechĂȘne, Patrick et al. (2018) PDE4 and mAKAP? are nodal organizers of ?2-ARs nuclear PKA signalling in cardiac myocytes. Cardiovasc Res 114:1499-1511
Dodge-Kafka, Kimberly L; Gildart, Moriah; Li, Jinliang et al. (2018) Bidirectional regulation of HDAC5 by mAKAP? signalosomes in cardiac myocytes. J Mol Cell Cardiol 118:13-25
Gildart, Moriah; Kapiloff, Michael S; Dodge-Kafka, Kimberly L (2018) Calcineurin-AKAP interactions: therapeutic targeting of a pleiotropic enzyme with a little help from its friends. J Physiol :