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Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy caused by plakophilin-2 mutations

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disorder of cardiomyocyte intercalated disk proteins causing sudden death. Heterozygous mutations of the desmosomal protein plakophilin-2 (PKP-2) are the commonest genetic cause of ARVC. Abnormal gap junction connexin43 expression has been...

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Autores principales: Fidler, Lee M, Wilson, Gregory J, Liu, Fanfan, Cui, Xuezhi, Scherer, Stephen W, Taylor, Glenn P, Hamilton, Robert M
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley & Sons, Ltd 2009
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4496128/
https://www.ncbi.nlm.nih.gov/pubmed/18662195
http://dx.doi.org/10.1111/j.1582-4934.2008.00438.x
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author Fidler, Lee M
Wilson, Gregory J
Liu, Fanfan
Cui, Xuezhi
Scherer, Stephen W
Taylor, Glenn P
Hamilton, Robert M
author_facet Fidler, Lee M
Wilson, Gregory J
Liu, Fanfan
Cui, Xuezhi
Scherer, Stephen W
Taylor, Glenn P
Hamilton, Robert M
author_sort Fidler, Lee M
collection PubMed
description Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disorder of cardiomyocyte intercalated disk proteins causing sudden death. Heterozygous mutations of the desmosomal protein plakophilin-2 (PKP-2) are the commonest genetic cause of ARVC. Abnormal gap junction connexin43 expression has been reported in autosomal dominant forms of ARVC (Naxos and Carvajal disease) caused by homozygous mutations of desmosomal plakoglobin and desmoplakin. In tissue culture, suppression of PKP-2 results in decreased expression of connexin43. We sought to characterize the expression and localization of connexin43 in patients with ARVC secondary to heterozygous PKP-2 mutations. Complete PKP-2 gene sequencing of 27 ARVC patients was utilized to identify mutant genotypes. Endomyocardial biopsies of identified carriers were then assessed by immunofluorescence to visualize intercalated disk proteins. N-cadherin was targeted to highlight intercalated disks, followed by counterstaining for PKP-2 or connexin43 using confocal double immunofluorescence microscopy. Immunofluorescence was quantified using an Adobe® Photoshop protocol, and colocalization coefficients were determined. PKP-2 siRNA experiments were performed in mouse cardiomyocyte (HL1) cell culture with Western blot analysis to assess connexin43 expression following PKP-2 suppression. Missense and frameshift mutations of the PKP-2 gene were found in four patients with biopsy material available for analysis. Immunofluorescent studies showed PKP-2 localization to the intercalated disk despite mutations, but associated with decreased connexin43 expression and abnormal colocalization. PKP-2 siRNA in HL1 culture confirmed decreased connexin43 expression. Reduced connexin43 expression and localization to the intercalated disk occurs in heterozygous human PKP-2 mutations, potentially explaining the delayed conduction and propensity to develop arrhythmias seen in this disease.
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spelling pubmed-44961282015-07-13 Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy caused by plakophilin-2 mutations Fidler, Lee M Wilson, Gregory J Liu, Fanfan Cui, Xuezhi Scherer, Stephen W Taylor, Glenn P Hamilton, Robert M J Cell Mol Med Articles Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disorder of cardiomyocyte intercalated disk proteins causing sudden death. Heterozygous mutations of the desmosomal protein plakophilin-2 (PKP-2) are the commonest genetic cause of ARVC. Abnormal gap junction connexin43 expression has been reported in autosomal dominant forms of ARVC (Naxos and Carvajal disease) caused by homozygous mutations of desmosomal plakoglobin and desmoplakin. In tissue culture, suppression of PKP-2 results in decreased expression of connexin43. We sought to characterize the expression and localization of connexin43 in patients with ARVC secondary to heterozygous PKP-2 mutations. Complete PKP-2 gene sequencing of 27 ARVC patients was utilized to identify mutant genotypes. Endomyocardial biopsies of identified carriers were then assessed by immunofluorescence to visualize intercalated disk proteins. N-cadherin was targeted to highlight intercalated disks, followed by counterstaining for PKP-2 or connexin43 using confocal double immunofluorescence microscopy. Immunofluorescence was quantified using an Adobe® Photoshop protocol, and colocalization coefficients were determined. PKP-2 siRNA experiments were performed in mouse cardiomyocyte (HL1) cell culture with Western blot analysis to assess connexin43 expression following PKP-2 suppression. Missense and frameshift mutations of the PKP-2 gene were found in four patients with biopsy material available for analysis. Immunofluorescent studies showed PKP-2 localization to the intercalated disk despite mutations, but associated with decreased connexin43 expression and abnormal colocalization. PKP-2 siRNA in HL1 culture confirmed decreased connexin43 expression. Reduced connexin43 expression and localization to the intercalated disk occurs in heterozygous human PKP-2 mutations, potentially explaining the delayed conduction and propensity to develop arrhythmias seen in this disease. John Wiley & Sons, Ltd 2009-10 2008-07-26 /pmc/articles/PMC4496128/ /pubmed/18662195 http://dx.doi.org/10.1111/j.1582-4934.2008.00438.x Text en © 2008 The Authors Journal compilation © 2009 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd
spellingShingle Articles
Fidler, Lee M
Wilson, Gregory J
Liu, Fanfan
Cui, Xuezhi
Scherer, Stephen W
Taylor, Glenn P
Hamilton, Robert M
Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy caused by plakophilin-2 mutations
title Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy caused by plakophilin-2 mutations
title_full Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy caused by plakophilin-2 mutations
title_fullStr Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy caused by plakophilin-2 mutations
title_full_unstemmed Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy caused by plakophilin-2 mutations
title_short Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy caused by plakophilin-2 mutations
title_sort abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy caused by plakophilin-2 mutations
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4496128/
https://www.ncbi.nlm.nih.gov/pubmed/18662195
http://dx.doi.org/10.1111/j.1582-4934.2008.00438.x
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