Genetic Fate Mapping Identifies Second Heart Field Progenitor Cells As a Source of Adipocytes in Arrhythmogenic Right Ventricular Cardiomyopathy

The phenotypic hallmark of arrhythmogenic right ventricular cardiomyopathy, a genetic disease of desmosomal proteins, is fibroadipocytic replacement of the right ventricle. Cellular origin of excess adipocytes, the responsible mechanism(s) and the basis for predominant involvement of the right ventricle are unknown. We generated 3 sets of lineage tracer mice regulated by cardiac lineage promoters &agr;-myosin heavy chain (&agr;MyHC), Nkx2.5, or Mef2C. We conditionally expressed the reporter enhanced yellow fluorescent protein while concomitantly deleting the desmosomal protein desmoplakin in cardiac myocyte lineages using the Cre-LoxP technique. Lineage tracer mice showed excess fibroadiposis and increased numbers of adipocytes in the hearts. Few adipocytes in the hearts of &agr;MyHC-regulated lineage tracer mice, but the majority of adipocytes in the hearts of Nkx2.5- and Mef2C-regulated lineage tracer mice, expressed enhanced yellow fluorescent protein. In addition, rare cells coexpressed adipogenic transcription factors and the second heart field markers Isl1 and Mef2C in the lineage tracer mouse hearts and in human myocardium from patients with arrhythmogenic right ventricular cardiomyopathy. To delineate the responsible mechanism, we generated transgenic mice expressing desmosomal protein plakoglobin in myocyte lineages. Transgene plakoglobin translocated to nucleus, detected by immunoblotting and immunofluorescence staining and coimmunoprecipitated with Tcf7l2, a canonical Wnt signaling transcription factor. Expression levels of canonical Wnt/Tcf7l2 targets bone morphogenetic protein 7 and Wnt5b, which promote adipogenesis, were increased and expression level of connective tissue growth factor, an inhibitor of adipogenesis, was decreased. We conclude adipocytes in arrhythmogenic right ventricular cardiomyopathy originate from the second heart field cardiac progenitors, which switch to an adipogenic fate because of suppressed canonical Wnt signaling by nuclear plakoglobin.

[1]  I. Efimov,et al.  Resolution of Established Cardiac Hypertrophy and Fibrosis and Prevention of Systolic Dysfunction in a Transgenic Rabbit Model of Human Cardiomyopathy Through Thiol-Sensitive Mechanisms , 2009, Circulation.

[2]  S. Twigg,et al.  Connective tissue growth factor inhibits adipocyte differentiation. , 2008, American journal of physiology. Cell physiology.

[3]  B. Spiegelman,et al.  PRDM16 controls a brown fat/skeletal muscle switch , 2008, Nature.

[4]  C. Kahn,et al.  New role of bone morphogenetic protein 7 in brown adipogenesis and energy expenditure , 2008, Nature.

[5]  A. Marian,et al.  Differential interactions of thin filament proteins in two cardiac troponin T mouse models of hypertrophic and dilated cardiomyopathies. , 2008, Cardiovascular research.

[6]  H. Calkins,et al.  Mechanisms of Disease: molecular genetics of arrhythmogenic right ventricular dysplasia/cardiomyopathy , 2008, Nature Clinical Practice Cardiovascular Medicine.

[7]  W. Birchmeier,et al.  Distinct roles of Wnt/β-catenin and Bmp signaling during early cardiogenesis , 2007, Proceedings of the National Academy of Sciences.

[8]  M. Lu,et al.  Wnt/beta-catenin signaling promotes expansion of Isl-1-positive cardiac progenitor cells through regulation of FGF signaling. , 2007, The Journal of clinical investigation.

[9]  A. Baldini,et al.  Canonical Wnt signaling functions in second heart field to promote right ventricular growth , 2007, Proceedings of the National Academy of Sciences.

[10]  P. Ellinor,et al.  Mutant desmocollin-2 causes arrhythmogenic right ventricular cardiomyopathy. , 2006, American journal of human genetics.

[11]  A. Emili,et al.  Tissue subcellular fractionation and protein extraction for use in mass-spectrometry-based proteomics , 2006, Nature Protocols.

[12]  P. Syrris,et al.  Arrhythmogenic right ventricular dysplasia/cardiomyopathy associated with mutations in the desmosomal gene desmocollin-2. , 2006, American journal of human genetics.

[13]  Michael D. Schneider,et al.  Suppression of canonical Wnt/beta-catenin signaling by nuclear plakoglobin recapitulates phenotype of arrhythmogenic right ventricular cardiomyopathy. , 2006, The Journal of clinical investigation.

[14]  M. Simpson,et al.  Novel Mutation in Desmoplakin Causes Arrhythmogenic Left Ventricular Cardiomyopathy , 2005, Circulation.

[15]  G. Danieli,et al.  Clinical profile of four families with arrhythmogenic right ventricular cardiomyopathy caused by dominant desmoplakin mutations. , 2005, European heart journal.

[16]  S. Maeda,et al.  Wnt5b partially inhibits canonical Wnt/beta-catenin signaling pathway and promotes adipogenesis in 3T3-L1 preadipocytes. , 2005, Biochemical and biophysical research communications.

[17]  Karl-Ludwig Laugwitz,et al.  Postnatal isl1+ cardioblasts enter fully differentiated cardiomyocyte lineages , 2005, Nature.

[18]  A. Marian,et al.  Induction and reversal of cardiac phenotype of human hypertrophic cardiomyopathy mutation cardiac troponin T-Q92 in switch on-switch off bigenic mice. , 2004, Journal of the American College of Cardiology.

[19]  Walter Birchmeier,et al.  Mutations in the desmosomal protein plakophilin-2 are common in arrhythmogenic right ventricular cardiomyopathy , 2004, Nature Genetics.

[20]  M. Entman,et al.  Aldosterone, Through Novel Signaling Proteins, Is a Fundamental Molecular Bridge Between the Genetic Defect and the Cardiac Phenotype of Hypertrophic Cardiomyopathy , 2004, Circulation.

[21]  Yunqing Shi,et al.  Isl1 identifies a cardiac progenitor population that proliferates prior to differentiation and contributes a majority of cells to the heart. , 2003, Developmental cell.

[22]  S. Rosenheck,et al.  Arrhythmogenic Right Ventricular Dysplasia A Recessive Mutation in Desmoplakin Causes Arrhythmogenic Right Ventricular Dysplasia, Skin Disorder, and Woolly Hair , 2003 .

[23]  G. Danieli,et al.  Mutation in human desmoplakin domain binding to plakoglobin causes a dominant form of arrhythmogenic right ventricular cardiomyopathy. , 2002, American journal of human genetics.

[24]  F. Miró,et al.  The Transcriptional Factor Tcf-4 Contains Different Binding Sites for β-Catenin and Plakoglobin* , 2002, The Journal of Biological Chemistry.

[25]  R. Schwartz,et al.  Embryonic expression of an Nkx2‐5/Cre gene using ROSA26 reporter mice , 2001, Genesis.

[26]  M. Buckingham,et al.  The arterial pole of the mouse heart forms from Fgf10-expressing cells in pharyngeal mesoderm. , 2001, Developmental cell.

[27]  Shankar Srinivas,et al.  Cre reporter strains produced by targeted insertion of EYFP and ECFP into the ROSA26 locus , 2001, BMC Developmental Biology.

[28]  D. Kelsell,et al.  Recessive mutation in desmoplakin disrupts desmoplakin-intermediate filament interactions and causes dilated cardiomyopathy, woolly hair and keratoderma. , 2000, Human molecular genetics.

[29]  A. Crosby,et al.  Identification of a deletion in plakoglobin in arrhythmogenic right ventricular cardiomyopathy with palmoplantar keratoderma and woolly hair (Naxos disease) , 2000, The Lancet.

[30]  Michael Shtutman,et al.  Differential Mechanisms of LEF/TCF Family-Dependent Transcriptional Activation by β-Catenin and Plakoglobin , 2000, Molecular and Cellular Biology.

[31]  E. Fuchs,et al.  Desmoplakin Is Required Early in Development for Assembly of Desmosomes and Cytoskeletal Linkage , 1998, The Journal of cell biology.

[32]  Sujata Roy,et al.  Regulation of (cid:98) -Catenin Levels and Localization by Overexpression of Plakoglobin and Inhibition of the Ubiquitin-Proteasome System , 2022 .

[33]  M. Davies,et al.  Spectrum of clinicopathologic manifestations of arrhythmogenic right ventricular cardiomyopathy/dysplasia: a multicenter study. , 1997, Journal of the American College of Cardiology.

[34]  B. A. French,et al.  Gene recombination in postmitotic cells. Targeted expression of Cre recombinase provokes cardiac-restricted, site-specific rearrangement in adult ventricular muscle in vivo. , 1997, The Journal of clinical investigation.

[35]  D. Corrado,et al.  Right ventricular cardiomyopathy and sudden death in young people. , 1988, The New England journal of medicine.

[36]  Walter Birchmeier,et al.  Distinct roles of Wnt/beta-catenin and Bmp signaling during early cardiogenesis. , 2007, Proceedings of the National Academy of Sciences of the United States of America.

[37]  D. Garrod,et al.  Desmoplakin is essential for epidermal sheet formation. , 2007, The Journal of investigative dermatology.

[38]  P. Anversa,et al.  Cardiac regeneration. , 2006, Journal of the American College of Cardiology.

[39]  G. Thiene,et al.  Structural and molecular pathology of the heart in Carvajal syndrome. , 2004, Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology.

[40]  D. Corrado,et al.  CARDIOMYOPATHY Arrhythmogenic right ventricular cardiomyopathy: diagnosis, prognosis, and treatment , 2022 .