Genetic deletion of calcium/calmodulin-dependent protein kinase type II delta does not mitigate adverse myocardial remodeling in volume-overloaded hearts

Sci Rep. 2019 Jul 8;9(1):9889. doi: 10.1038/s41598-019-46332-3.

Abstract

Calcium/calmodulin-dependent protein kinase type II delta (CaMKIIδ), the predominant CaMKII isoform expressed in the heart, has been implicated in the progression of myocardial infarction- and pressure overload-induced pathological remodeling. However, the role of CaMKIIδ in volume overload (VO) has not been explored. We have previously reported an activation of CaMKII during transition to HF in long-term VO. Here, we address whether CaMKIIδ is critically involved in the mortality, myocardial remodeling, and heart failure (HF) progression in response to VO. CaMKIIδ knockout (δ-KO) and wild-type (WT) littermates were exposed to aortocaval shunt-induced VO, and the progression of adverse myocardial remodeling was assessed by serial echocardiography, histological and molecular analyses. The mortality rates during 10 weeks of VO were similar in δ-KO and WT mice. Both genotypes displayed comparable eccentric myocardial hypertrophy, altered left ventricle geometry, perturbed systolic and diastolic functions after shunt. Additionally, cardiomyocytes hypertrophy, augmented myocyte apoptosis, and up-regulation of hypertrophic genes were also not significantly different in δ-KO versus WT hearts after shunt. Therefore, CaMKIIδ signaling seems to be dispensable for the progression of VO-induced maladaptive cardiac remodeling. Accordingly, we hypothesize that CaMKIIδ-inhibition as a therapeutic approach might not be helpful in the context of VO-triggered HF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / genetics
  • Calcium / metabolism*
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2 / genetics*
  • Cardiomegaly / genetics
  • Female
  • Gene Deletion
  • Heart Failure / genetics
  • Heart Failure / metabolism
  • Heart Ventricles / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mice, Transgenic
  • Myocardial Infarction / genetics
  • Myocardial Infarction / metabolism
  • Myocardium / metabolism*
  • Myocytes, Cardiac / metabolism
  • Phosphorylation / genetics
  • Signal Transduction / genetics
  • Up-Regulation / genetics

Substances

  • Calcium-Calmodulin-Dependent Protein Kinase Type 2
  • Calcium