A homozygous DSC2 deletion associated with arrhythmogenic cardiomyopathy is caused by uniparental isodisomy
| Autor: | Hendrik Milting, Hans Ebbinghaus, Marcus-André Deutsch, Brenda Gerull, Jens Tiesmeier, Andreas Peterschröder, Caroline Stanasiuk, Anna Gärtner, Jan Gummert, Henrik Fox, Bärbel Klauke, Thorsten Laser, Lech Paluszkiewicz, Jana Davina Debus, Jördis Bax, Jürgen Weiss, Andreas Brodehl |
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| Rok vydání: | 2020 |
| Předmět: |
Male
0301 basic medicine Nonsense-mediated decay 030204 cardiovascular system & hematology Biology Frameshift mutation Loss of heterozygosity 03 medical and health sciences 0302 clinical medicine Western blot Chromosome 18 Cell Line Tumor medicine Humans Myocytes Cardiac Amino Acid Sequence Molecular Biology Desmocollins DSC2 Base Sequence medicine.diagnostic_test Myocardium Homozygote Arrhythmias Cardiac Middle Aged Uniparental Disomy Molecular biology Pedigree 030104 developmental biology medicine.anatomical_structure Uniparental Isodisomy Mutation Female Cardiomyopathies Cardiology and Cardiovascular Medicine Intercalated disc Gene Deletion |
| Zdroj: | Journal of Molecular and Cellular Cardiology. 141:17-29 |
| ISSN: | 0022-2828 |
| DOI: | 10.1016/j.yjmcc.2020.03.006 |
| Popis: | Aims We aimed to unravel the genetic, molecular and cellular pathomechanisms of DSC2 truncation variants leading to arrhythmogenic cardiomyopathy (ACM). Methods and results We report a homozygous 4-bp DSC2 deletion variant c.1913_1916delAGAA, p.Q638LfsX647hom causing a frameshift carried by an ACM patient. Whole exome sequencing and comparative genomic hybridization analysis support a loss of heterozygosity in a large segment of chromosome 18 indicating segmental interstitial uniparental isodisomy (UPD). Ultrastructural analysis of the explanted myocardium from a mutation carrier using transmission electron microscopy revealed a partially widening of the intercalated disc. Using qRT-PCR we demonstrated that DSC2 mRNA expression was substantially decreased in the explanted myocardial tissue of the homozygous carrier compared to controls. Western blot analysis revealed absence of both full-length desmocollin-2 isoforms. Only a weak expression of the truncated form of desmocollin-2 was detectable. Immunohistochemistry showed that the truncated form of desmocollin-2 did not localize at the intercalated discs. In vitro, transfection experiments using induced pluripotent stem cell derived cardiomyocytes and HT-1080 cells demonstrated an obvious absence of the mutant truncated desmocollin-2 at the plasma membrane. Immunoprecipitation in combination with fluorescence measurements and Western blot analyses revealed an abnormal secretion of the truncated desmocollin-2. Conclusion In summary, we unraveled segmental UPD as the likely genetic reason for a small homozygous DSC2 deletion. We conclude that a combination of nonsense mediated mRNA decay and extracellular secretion is involved in DSC2 related ACM. |
| Databáze: | OpenAIRE |
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