CaMKII activation participates in doxorubicin cardiotoxicity and is attenuated by moderate GRP78 overexpression

PLoS One. 2019 Apr 29;14(4):e0215992. doi: 10.1371/journal.pone.0215992. eCollection 2019.

Abstract

The clinical use of the chemotherapeutic doxorubicin (Dox) is limited by cardiotoxic side-effects. One of the early Dox effects is induction of a sarcoplasmic reticulum (SR) Ca2+ leak. The chaperone Glucose regulated protein 78 (GRP78) is important for Ca2+ homeostasis in the endoplasmic reticulum (ER)-the organelle corresponding to the SR in non-cardiomyocytes-and has been shown to convey resistance to Dox in certain tumors. Our aim was to investigate the effect of cardiac GRP78 gene transfer on Ca2+ dependent signaling, cell death, cardiac function and survival in clinically relevant in vitro and in vivo models for Dox cardiotoxicity.By using neonatal cardiomyocytes we could demonstrate that Dox induced Ca2+ dependent Ca2+ /calmodulin-dependent protein kinase II (CaMKII) activation is one of the factors involved in Dox cardiotoxicity by promoting apoptosis. Furthermore, we found that adeno-associated virus (AAV) mediated GRP78 overexpression partly protects neonatal cardiomyocytes from Dox induced cell death by modulating Ca2+ dependent pathways like the activation of CaMKII, phospholamban (PLN) and p53 accumulation. Most importantly, cardiac GRP78 gene therapy in mice treated with Dox revealed improved diastolic function (dP/dtmin) and survival after Dox treatment. In conclusion, our results demonstrate for the first time that Ca2+ dependent CaMKII activation fosters Dox cardiomyopathy and provide additional insight into possible mechanisms by which GRP78 overexpression protects cardiomyocytes from Doxorubicin toxicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Calcium / metabolism
  • Calcium Signaling / drug effects
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2 / metabolism*
  • Cardiotoxicity / enzymology*
  • Cardiotoxicity / pathology*
  • Cardiotoxicity / physiopathology
  • Doxorubicin / toxicity*
  • Endoplasmic Reticulum Chaperone BiP
  • Enzyme Activation / drug effects
  • Heat-Shock Proteins / metabolism*
  • Homeostasis
  • Male
  • Mice, Inbred C57BL
  • Myocytes, Cardiac / metabolism
  • Phosphorylation
  • Rats
  • Sarcoplasmic Reticulum / drug effects
  • Sarcoplasmic Reticulum / metabolism

Substances

  • Endoplasmic Reticulum Chaperone BiP
  • Heat-Shock Proteins
  • Hspa5 protein, mouse
  • Doxorubicin
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2
  • Calcium

Grants and funding

This work was supported in part by grants from the Deutsche Forschungsgemeinschaft (http://www.dfg.de/; RA 1668/3-1 and RA 1668/6-1) to PWR and by the excellence initiative "Heart and Cancer" funded by the state of Baden-Württemberg, Germany (https://mwk.baden-wuerttemberg.de/de/forschung/forschungsfoerderung/exzellenzinitiative/) to PWR. LHL is recipient of the clinician scientist program of the German Society of Cardiology (DGK) (https://dgk.org/preise-und-stipendien/stipendien/dgk-clinician-scientist-programm-csp/). We acknowledge financial support by Deutsche Forschungsgemeinschaft within the funding program Open Access Publishing, by the Baden-Württemberg Ministry of Science, Research and the Arts and by Ruprecht-Karls-Universität Heidelberg. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.