title: Alteration of cardiac progenitor cell potency in GRMD dogs.
abstract: Among the animal models of Duchenne muscular dystrophy (DMD), the Golden Retriever muscular dystrophy (GRMD) dog is considered the best model in terms of size and pathological onset of the disease. As in human patients presenting with DMD or Becker muscular dystrophies (BMD), the GRMD  is related to a spontaneous X-linked mutation of dystrophin and is characterized by myocardial lesions. In this respect, GRMD is a useful model to explore cardiac pathogenesis and for the development of therapeutic protocols. To investigate whether cardiac progenitor cells (CPCs) isolated  from healthy and GRMD dogs may differentiate into myocardial cell types and to test the feasibility of cell therapy for cardiomyopathies in a preclinical model of DMD, CPCs were isolated from cardiac biopsies of healthy and GRMD dogs. Gene profile analysis revealed an active cardiac transcription  network in both healthy and GRMD CPCs. However, GRMD CPCs showed impaired self-renewal and cardiac differentiation. Population doubling and telomerase analyses highlighted earlier senescence and proliferation impairment in progenitors isolated from GRMD cardiac biopsies. Immunofluorescence  analysis revealed that only wt CPCs showed efficient although not terminal cardiac differentiation, consistent with the upregulation of cardiac-specific proteins and microRNAs. Thus, the pathological condition adversely influences the cardiomyogenic differentiation potential of cardiac progenitors.  Using PiggyBac transposon technology we marked CPCs for nuclear dsRed expression, providing a stable nonviral gene marking method for in vivo tracing of CPCs. Xenotransplantation experiments in neonatal immunodeficient mice revealed a valuable contribution of CPCs to cardiomyogenesis with  homing differences between wt and dystrophic progenitors. These results suggest that cardiac degeneration in dystrophinopathies may account for the progressive exhaustion of local cardiac progenitors and shed light on cardiac stemness in physiological and pathological conditions. Furthermore,  we provide essential information that canine CPCs may be used to alleviate cardiac involvement in a large preclinical model of DMD.
authors.affiliation: Laboratory of Translational Cardiomyology, Stem Cell Institute, Department of Development and Regeneration, University of Leuven (KU Leuven), Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Cassano
authors.forename: E
authors.initials: E
authors.lastname: Berardi
authors.forename: S
authors.initials: S
authors.lastname: Crippa
authors.forename: J
authors.initials: J
authors.lastname: Toelen
authors.forename: I
authors.initials: I
authors.lastname: Barthelemy
authors.forename: R
authors.initials: R
authors.lastname: Micheletti
authors.forename: M
authors.initials: M
authors.lastname: Chuah
authors.forename: T
authors.initials: T
authors.lastname: Vandendriessche
authors.forename: Z
authors.initials: Z
authors.lastname: Debyser
authors.forename: S
authors.initials: S
authors.lastname: Blot
authors.forename: M
authors.initials: M
authors.lastname: Sampaolesi
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D051379:Mice; D016513:Mice, SCID; D009137:Muscular Dystrophy, Animal / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D009206:Myocardium / Q000166:cytology* / Q000378:metabolism / Q000473:pathology*; D051381:Rats; D013234:Stem Cells / Q000378:metabolism / Q000473:pathology*; D059467:Transcriptome