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Mechanistic investigation of Ca(2+) alternans in human heart failure and its modulation by fibroblasts

BACKGROUND: Heart failure (HF) is characterized, among other factors, by a progressive loss of contractile function and by the formation of an arrhythmogenic substrate, both aspects partially related to intracellular Ca(2+) cycling disorders. In failing hearts both electrophysiological and structura...

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Autores principales: Mora, Maria T., Gomez, Juan F., Morley, Gregory, Ferrero, Jose M., Trenor, Beatriz
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6581251/
https://www.ncbi.nlm.nih.gov/pubmed/31211790
http://dx.doi.org/10.1371/journal.pone.0217993
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author Mora, Maria T.
Gomez, Juan F.
Morley, Gregory
Ferrero, Jose M.
Trenor, Beatriz
author_facet Mora, Maria T.
Gomez, Juan F.
Morley, Gregory
Ferrero, Jose M.
Trenor, Beatriz
author_sort Mora, Maria T.
collection PubMed
description BACKGROUND: Heart failure (HF) is characterized, among other factors, by a progressive loss of contractile function and by the formation of an arrhythmogenic substrate, both aspects partially related to intracellular Ca(2+) cycling disorders. In failing hearts both electrophysiological and structural remodeling, including fibroblast proliferation, contribute to changes in Ca(2+) handling which promote the appearance of Ca(2+) alternans (Ca-alt). Ca-alt in turn give rise to repolarization alternans, which promote dispersion of repolarization and contribute to reentrant activity. The computational analysis of the incidence of Ca(2+) and/or repolarization alternans under HF conditions in the presence of fibroblasts could provide a better understanding of the mechanisms leading to HF arrhythmias and contractile function disorders. METHODS AND FINDINGS: The goal of the present study was to investigate in silico the mechanisms leading to the formation of Ca-alt in failing human ventricular myocytes and tissues with disperse fibroblast distributions. The contribution of ionic currents variability to alternans formation at the cellular level was analyzed and the results show that in normal ventricular tissue, altered Ca(2+) dynamics lead to Ca-alt, which precede APD alternans and can be aggravated by the presence of fibroblasts. Electrophysiological remodeling of failing tissue alone is sufficient to develop alternans. The incidence of alternans is reduced when fibroblasts are present in failing tissue due to significantly depressed Ca(2+) transients. The analysis of the underlying ionic mechanisms suggests that Ca-alt are driven by Ca(2+)-handling protein and Ca(2+) cycling dysfunctions in the junctional sarcoplasmic reticulum and that their contribution to alternans occurrence depends on the cardiac remodeling conditions and on myocyte-fibroblast interactions. CONCLUSION: It can thus be concluded that fibroblasts modulate the formation of Ca-alt in human ventricular tissue subjected to heart failure-related electrophysiological remodeling. Pharmacological therapies should thus consider the extent of both the electrophysiological and structural remodeling present in the failing heart.
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spelling pubmed-65812512019-06-28 Mechanistic investigation of Ca(2+) alternans in human heart failure and its modulation by fibroblasts Mora, Maria T. Gomez, Juan F. Morley, Gregory Ferrero, Jose M. Trenor, Beatriz PLoS One Research Article BACKGROUND: Heart failure (HF) is characterized, among other factors, by a progressive loss of contractile function and by the formation of an arrhythmogenic substrate, both aspects partially related to intracellular Ca(2+) cycling disorders. In failing hearts both electrophysiological and structural remodeling, including fibroblast proliferation, contribute to changes in Ca(2+) handling which promote the appearance of Ca(2+) alternans (Ca-alt). Ca-alt in turn give rise to repolarization alternans, which promote dispersion of repolarization and contribute to reentrant activity. The computational analysis of the incidence of Ca(2+) and/or repolarization alternans under HF conditions in the presence of fibroblasts could provide a better understanding of the mechanisms leading to HF arrhythmias and contractile function disorders. METHODS AND FINDINGS: The goal of the present study was to investigate in silico the mechanisms leading to the formation of Ca-alt in failing human ventricular myocytes and tissues with disperse fibroblast distributions. The contribution of ionic currents variability to alternans formation at the cellular level was analyzed and the results show that in normal ventricular tissue, altered Ca(2+) dynamics lead to Ca-alt, which precede APD alternans and can be aggravated by the presence of fibroblasts. Electrophysiological remodeling of failing tissue alone is sufficient to develop alternans. The incidence of alternans is reduced when fibroblasts are present in failing tissue due to significantly depressed Ca(2+) transients. The analysis of the underlying ionic mechanisms suggests that Ca-alt are driven by Ca(2+)-handling protein and Ca(2+) cycling dysfunctions in the junctional sarcoplasmic reticulum and that their contribution to alternans occurrence depends on the cardiac remodeling conditions and on myocyte-fibroblast interactions. CONCLUSION: It can thus be concluded that fibroblasts modulate the formation of Ca-alt in human ventricular tissue subjected to heart failure-related electrophysiological remodeling. Pharmacological therapies should thus consider the extent of both the electrophysiological and structural remodeling present in the failing heart. Public Library of Science 2019-06-18 /pmc/articles/PMC6581251/ /pubmed/31211790 http://dx.doi.org/10.1371/journal.pone.0217993 Text en © 2019 Mora et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Mora, Maria T.
Gomez, Juan F.
Morley, Gregory
Ferrero, Jose M.
Trenor, Beatriz
Mechanistic investigation of Ca(2+) alternans in human heart failure and its modulation by fibroblasts
title Mechanistic investigation of Ca(2+) alternans in human heart failure and its modulation by fibroblasts
title_full Mechanistic investigation of Ca(2+) alternans in human heart failure and its modulation by fibroblasts
title_fullStr Mechanistic investigation of Ca(2+) alternans in human heart failure and its modulation by fibroblasts
title_full_unstemmed Mechanistic investigation of Ca(2+) alternans in human heart failure and its modulation by fibroblasts
title_short Mechanistic investigation of Ca(2+) alternans in human heart failure and its modulation by fibroblasts
title_sort mechanistic investigation of ca(2+) alternans in human heart failure and its modulation by fibroblasts
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6581251/
https://www.ncbi.nlm.nih.gov/pubmed/31211790
http://dx.doi.org/10.1371/journal.pone.0217993
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