The Ca2+ transient as a feedback sensor controlling cardiomyocyte ionic conductances in mouse populations

Abstract
Data availability
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Abstract

Conductances of ion channels and transporters controlling cardiac excitation may vary in a population of subjects with different cardiac gene expression patterns. However, the amount of variability and its origin are not quantitatively known. We propose a new conceptual approach to predict this variability that consists of finding combinations of conductances generating a normal intracellular Ca²⁺ transient without any constraint on the action potential. Furthermore, we validate experimentally its predictions using the Hybrid Mouse Diversity Panel, a model system of genetically diverse mouse strains that allows us to quantify inter-subject versus intra-subject variability. The method predicts that conductances of inward Ca²⁺ and outward K⁺ currents compensate each other to generate a normal Ca²⁺ transient in good quantitative agreement with current measurements in ventricular myocytes from hearts of different isogenic strains. Our results suggest that a feedback mechanism sensing the aggregate Ca²⁺ transient of the heart suffices to regulate ionic conductances.

Data availability

Gene expression data has been deposited in GEO under accession code GSE48760

The following previously published data sets were used

1. Rau CD
2. Wang J
3. Wang Y
4. Lusis AJ
(2013) Transcriptomes of the hybrid mouse diversity panel subjected to Isoproterenol challenge
Publicly available at the NCBI Gene Expression Omnibus (accession no: GSE48760).

https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE48760

Article and author information

Author details

Colin M Rees

Physics Department, Northeastern University, Boston, United States

Competing interests
The authors declare that no competing interests exist.
Jun-Hai Yang

Department of Medicine, University of California, Los Angeles, Los Angeles, United States

Competing interests
The authors declare that no competing interests exist.
Marc Santolini

Physics Department, Northeastern University, Boston, United States

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0003-1491-0120
Aldons J Lusis

Department of Medicine, University of California, Los Angeles, Los Angeles, United States

Competing interests
The authors declare that no competing interests exist.
James N Weiss

Department of Medicine, University of California, Los Angeles, Los Angeles, United States

Competing interests
The authors declare that no competing interests exist.
Alain Karma

Physics Department, Northeastern University, Boston, United States

For correspondence
a.karma@northeastern.edu

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0001-7032-9862

Funding

National Heart, Lung, and Blood Institute

Colin M Rees
Jun-Hai Yang
Marc Santolini
Aldons J Lusis
James N Weiss
Alain Karma

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: This study was approved by the UCLA Chancellor's Animal Research Committee (ARC 2003-063-23B) and performed in accordance with the Guide for the Care and Use of Laboratory Animals published by the United States National Institutes of Health (NIH Publication No. 85-23, revised 1996) and with UCLA Policy 990 on the Use of Laboratory Animal Subjects in Research (revised 2010).

Copyright

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.