Andreas Brodehl1, Mareike Dieding2, Niklas Biere2, Andreas Unger3, Bärbel Klauke4, Volker Walhorn2, Jan Gummert4, Uwe Schulz4, Wolfgang A Linke3, Brenda Gerull5, Matthias Vorgert6, Dario Anselmetti2, Hendrik Milting7. 1. Erich and Hanna Klessmann Institute for Cardiovascular Research & Development (EHKI), Heart and Diabetes Center NRW, Ruhr University Bochum, D-32545 Bad Oeynhausen, Germany; Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, 3280 Hospital Drive NW, T2N4Z6 Calgary, AB, Canada. Electronic address: Andreas.Brodehl@web.de. 2. Experimental Biophysics and Applied Nanoscience, Faculty of Physics and Bielefeld Institute for Biophysics and Nanoscience (BINAS), Bielefeld University, D-33615 Bielefeld, Germany. 3. Department of Cardiovascular Physiology, Ruhr University Bochum, D-44780 Bochum, Germany. 4. Erich and Hanna Klessmann Institute for Cardiovascular Research & Development (EHKI), Heart and Diabetes Center NRW, Ruhr University Bochum, D-32545 Bad Oeynhausen, Germany. 5. Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, 3280 Hospital Drive NW, T2N4Z6 Calgary, AB, Canada. 6. Neurologische Klinik und Poliklinik, Universitätsklinikum Bergmannsheil, Buerkle-de-la-Camp-Platz 1, D-44789 Bochum, Germany. 7. Erich and Hanna Klessmann Institute for Cardiovascular Research & Development (EHKI), Heart and Diabetes Center NRW, Ruhr University Bochum, D-32545 Bad Oeynhausen, Germany. Electronic address: hmilting@hdz-nrw.de.
Abstract
BACKGROUND: Dilated cardiomyopathy (DCM) could be caused by mutations in more than 40 different genes. However, the pathogenic impact of specific mutations is in most cases unknown complicating the genetic counseling of affected families. Therefore, functional studies could contribute to distinguish pathogenic mutations and benign variants. Here, we present a novel heterozygous DES missense variant (c.407C>T; p.L136P) identified by next generation sequencing in a DCM patient. DES encodes the cardiac intermediate filament protein desmin, which has important functions in mechanical stabilization and linkage of the cell structures in cardiomyocytes. METHODS AND RESULTS: Cell transfection experiments and assembly assays of recombinant desmin in combination with atomic force microscopy were used to investigate the impact of this novel DES variant on filament formation. Desmin-p.L136P forms cytoplasmic aggregates indicating a severe intrinsic filament assembly defect of this mutant. Co-transfection experiments of wild-type and mutant desmin conjugated to different fluorescence proteins revealed a dominant affect of this mutant on filament assembly. These experiments were complemented by apertureless scanning near-field optical microscopy. CONCLUSION: In vitro analysis demonstrated that desmin-p.L136P is unable to form regular filaments and accumulate instead within the cytoplasm. Therefore, we classified DES-p.L136P as a likely pathogenic mutation. In conclusion, the functional characterization of DES-p.L136P might have relevance for the genetic counseling of affected families with similar DES mutations and could contribute to distinguish pathogenic mutations from benign rare variants.
BACKGROUND:Dilated cardiomyopathy (DCM) could be caused by mutations in more than 40 different genes. However, the pathogenic impact of specific mutations is in most cases unknown complicating the genetic counseling of affected families. Therefore, functional studies could contribute to distinguish pathogenic mutations and benign variants. Here, we present a novel heterozygous DES missense variant (c.407C>T; p.L136P) identified by next generation sequencing in a DCMpatient. DES encodes the cardiac intermediate filament protein desmin, which has important functions in mechanical stabilization and linkage of the cell structures in cardiomyocytes. METHODS AND RESULTS: Cell transfection experiments and assembly assays of recombinant desmin in combination with atomic force microscopy were used to investigate the impact of this novel DES variant on filament formation. Desmin-p.L136P forms cytoplasmic aggregates indicating a severe intrinsic filament assembly defect of this mutant. Co-transfection experiments of wild-type and mutant desmin conjugated to different fluorescence proteins revealed a dominant affect of this mutant on filament assembly. These experiments were complemented by apertureless scanning near-field optical microscopy. CONCLUSION: In vitro analysis demonstrated that desmin-p.L136P is unable to form regular filaments and accumulate instead within the cytoplasm. Therefore, we classified DES-p.L136P as a likely pathogenic mutation. In conclusion, the functional characterization of DES-p.L136P might have relevance for the genetic counseling of affected families with similar DES mutations and could contribute to distinguish pathogenic mutations from benign rare variants.
Authors: Andreas Brodehl; Hans Ebbinghaus; Marcus-André Deutsch; Jan Gummert; Anna Gärtner; Sandra Ratnavadivel; Hendrik Milting Journal: Int J Mol Sci Date: 2019-09-06 Impact factor: 5.923
Authors: Andreas Brodehl; Seyed Ahmad Pour Hakimi; Caroline Stanasiuk; Sandra Ratnavadivel; Doris Hendig; Anna Gaertner; Brenda Gerull; Jan Gummert; Lech Paluszkiewicz; Hendrik Milting Journal: Genes (Basel) Date: 2019-11-11 Impact factor: 4.096
Authors: Miloš Kubánek; Tereza Schimerová; Lenka Piherová; Andreas Brodehl; Alice Krebsová; Sandra Ratnavadivel; Caroline Stanasiuk; Hana Hansíková; Jiří Zeman; Tomáš Paleček; Josef Houštěk; Zdeněk Drahota; Hana Nůsková; Jana Mikešová; Josef Zámečník; Milan Macek; Petr Ridzoň; Jana Malusková; Viktor Stránecký; Vojtěch Melenovský; Hendrik Milting; Stanislav Kmoch Journal: J Clin Med Date: 2020-03-29 Impact factor: 4.241