title: A regulatory pathway involving Notch1/beta-catenin/Isl1 determines cardiac progenitor cell fate.
abstract: Regulation of multipotent cardiac progenitor cell (CPC) expansion and subsequent differentiation into cardiomyocytes, smooth muscle or endothelial cells is a fundamental aspect of basic cardiovascular biology and cardiac regenerative medicine. However, the mechanisms governing these decisions remain unclear. Here, we show that Wnt/beta-catenin signalling, which promotes expansion of CPCs, is negatively regulated by Notch1-mediated control of phosphorylated beta-catenin accumulation within CPCs, and that Notch1 activity in CPCs is required for their differentiation. Notch1 positively, and beta-catenin negatively, regulated expression of the cardiac transcription factors, Isl1, Myocd and Smyd1. Surprisingly, disruption of Isl1, normally expressed transiently in CPCs before their differentiation, resulted in expansion of CPCs in vivo and in an embryonic stem (ES) cell system. Furthermore, Isl1 was required for CPC differentiation into cardiomyocyte and smooth muscle cells, but not endothelial cells. These findings reveal a regulatory network controlling CPC expansion and cell fate that involves unanticipated functions of beta-catenin, Notch1 and Isl1 that may be leveraged for regenerative approaches involving CPCs.
authors.affiliation: Gladstone Institute of Cardiovascular Disease and Departments of Pediatrics and Biochemistry & Biophysics, University of California, San Francisco, 1650 Owens Street, San Francisco, CA 94158, USA. ckwon@gladstone.ucsf.edu
authors.forename: Chulan
authors.initials: C
authors.lastname: Kwon
authors.forename: Li
authors.initials: L
authors.lastname: Qian
authors.forename: Paul
authors.initials: P
authors.lastname: Cheng
authors.forename: Vishal
authors.initials: V
authors.lastname: Nigam
authors.forename: Joshua
authors.initials: J
authors.lastname: Arnold
authors.forename: Deepak
authors.initials: D
authors.lastname: Srivastava
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004622:Embryo, Mammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D060850:LIM-Homeodomain Proteins; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D034622:RNA Interference; D051881:Receptor, Notch1 / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*; D000099251:Myocardin
chemical_list: D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D009124:Muscle Proteins; D009687:Nuclear Proteins; D051881:Receptor, Notch1; D015534:Trans-Activators; D014157:Transcription Factors; D051176:beta Catenin; D000099251:Myocardin; C497762:Notch1 protein, mouse; C096485:Smyd1 protein, mouse; C063843:insulin gene enhancer binding protein Isl-1