Journal Article

c-kit Haploinsufficiency impairs adult cardiac stem cell growth, myogenicity and myocardial regeneration

Aquila, Iolanda, Mancuso, Teresa, Ellison-Hughes, Georgina M., Scalise, Mariangela, Urbanek, Konrad, De Angelis, Antonella, Nadal-Ginard, Bernardo, Cappetta, Donato, Torella, Daniele, Filardo, Andrea, Smith, Andrew J., Marino, Fabiola, Isidori, Andrea M., Torella, Michele, Agosti, Valter, Viglietto, Giuseppe, Cianflone, Eleonora

2019

Overview

An overdose of Isoproterenol (ISO) causes acute cardiomyocyte (CM) dropout and activates the resident cardiac c-kit pos stem/progenitor cells (CSCs) generating a burst of new CM formation that replaces those lost to ISO. Recently, unsuccessful attempts to reproduce these findings using c-kit Cre knock-in (KI) mouse models were reported. We tested whether c-kit haploinsufficiency in c-kit Cre KI mice was the cause of the discrepant results in response to ISO. Male C57BL/6J wild-type (wt) mice and c-kit Cre KI mice were given a single dose of ISO (200 and/or 400 mg/Kg s.c.). CM formation was measured with different doses and duration of BrdU or EdU. We compared the myogenic and regenerative potential of the c-kit Cre CSCs with wtCSCs. Acute ISO overdose causes LV dysfunction with dose-dependent CM death by necrosis and apoptosis, whose intensity follows a basal-apical and epicardium to sub-endocardium gradient, with the most severe damage confined to the apical sub-endocardium. The damage triggers significant new CM formation mainly in the apical sub-endocardial layer. c-kit haploinsufficiency caused by c-kit Cre KIs severely affects CSCs myogenic potential. c-kit Cre KI mice post-ISO fail to respond with CSC activation and show reduced CM formation and suffer chronic cardiac dysfunction. Transplantation of wtCSCs rescued the defective regenerative cardiac phenotype of c-kit Cre KI mice. Furthermore, BAC-mediated transgenesis of a single c-kit gene copy normalized the functional diploid c-kit content of c-kit Cre KI CSCs and fully restored their regenerative competence. Overall, these data show that c-kit haploinsufficiency impairs the endogenous cardioregenerative response after injury affecting CSC activation and CM replacement. Repopulation of c-kit haploinsufficient myocardial tissue with wtCSCs as well c-kit gene deficit correction of haploinsufficient CSCs restores CM replacement and functional cardiac repair. Thus, adult neo-cardiomyogenesis depends on and requires a diploid level of c-kit.

• Publisher: Nature Publishing Group UK,Springer Nature B.V
• Subject: Adult Stem Cells - metabolism / Adult Stem Cells - physiology / Animal models / Animals / Antibodies / Apoptosis / Apoptosis - drug effects / Biochemistry / Biomedical and Life Sciences / c-Kit protein / Cardiomyocytes / Cell Biology / Cell Culture / Cell Differentiation - genetics / Cell growth / Cell Proliferation - genetics / Cells, Cultured / Diploids / Haploinsufficiency / Heart Ventricles - drug effects / Heart Ventricles - metabolism / Heart Ventricles - pathology / Immunology / Isoproterenol / Isoproterenol - administration & dosage / Isoproterenol - toxicity / KIT protein / Laboratory animals / Life Sciences / Male / Mice / Mice, Inbred C57BL / Mice, Knockout / Muscle Development - genetics / Myocytes, Cardiac - drug effects / Myocytes, Cardiac - metabolism / Myocytes, Cardiac - physiology / Necrosis / Overdose / Phenotypes / Progenitor cells / Proto-Oncogene Proteins c-kit - genetics / Proto-Oncogene Proteins c-kit - metabolism / Regeneration - genetics / Stem cell transplantation / Stem cells / Wound Healing - genetics