ALPK3-deficient cardiomyocytes generated from patient-derived induced pluripotent stem cells and mutant human embryonic stem cells display abnormal calcium handling and establish that ALPK3 deficiency underlies familial cardiomyopathy
Journal Title
Eur Heart J
Publication Type
Journal Article in press
Abstract
AIMS: We identified a novel homozygous truncating mutation in the gene encoding alpha kinase 3 (ALPK3) in a family presenting with paediatric cardiomyopathy. A recent study identified biallelic truncating mutations of ALPK3 in three unrelated families; therefore, there is strong genetic evidence that ALPK3 mutation causes cardiomyopathy. This study aimed to clarify the mutation mechanism and investigate the molecular and cellular pathogenesis underlying ALPK3-mediated cardiomyopathy. METHODS AND RESULTS: We performed detailed clinical and genetic analyses of a consanguineous family, identifying a new ALPK3 mutation (c.3792G>A, p.W1264X) which undergoes nonsense-mediated decay in ex vivo and in vivo tissues. Ultra-structural analysis of cardiomyocytes derived from patient-specific and human ESC-derived stem cell lines lacking ALPK3 revealed disordered sarcomeres and intercalated discs. Multi-electrode array analysis and calcium imaging demonstrated an extended field potential duration and abnormal calcium handling in mutant contractile cultures. CONCLUSIONS: This study validates the genetic evidence, suggesting that mutations in ALPK3 can cause familial cardiomyopathy and demonstrates loss of function as the underlying genetic mechanism. We show that ALPK3-deficient cardiomyocytes derived from pluripotent stem cell models recapitulate the ultrastructural and electrophysiological defects observed in vivo. Analysis of differentiated contractile cultures identified abnormal calcium handling as a potential feature of cardiomyocytes lacking ALPK3, providing functional insights into the molecular mechanisms underlying ALPK3-mediated cardiomyopathy.
Publisher
OUP
WEHI Research Division(s)
Population Health And Immunity
PubMed ID
27106955
NHMRC Grants
NHMRC/1002098 NHMRC/1054618
Rights Notice
Refer to copyright notice on published article.


Creation Date: 2016-05-02 10:21:21
Last Modified: 2016-05-05 11:39:26
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