title: The role of notch 1 activation in cardiosphere derived cell differentiation.
abstract: Cardiosphere derived cells (CDC) are present in the human heart and include heterogeneous cell populations of cardiac progenitor cells, multipotent progenitors that play critical roles in the physiological and pathological turnover of heart tissue. Little is known about the molecular pathways that control the differentiation of CDC. In this study, we examined the role of Notch 1/J kappa-recombining binding protein (RBPJ) signaling, a critical cell-fate decision pathway, in CDC differentiation. We isolated CDC from mouse cardiospheres and analyzed the differentiation of transduced cells expressing the Notch1 intracellular domain (N1-ICD), the active form of Notch1, using a terminal differentiation marker polymerase chain reaction (PCR) array. We found that Notch1 primarily supported the differentiation of CDC into smooth muscle cells (SMC), as demonstrated by the upreguation of key SMC proteins, including smooth muscle myosin heavy chain (Myh11) and SM22α (Tagln), in N1-ICD expressing CDC. Conversely, genetic ablation of RBPJ in CDC diminished the expression of SMC differentiation markers, confirming that SMC differentiation CDC is dependent on RBPJ. Finally, in vivo experiments demonstrate enhanced numbers of smooth muscle actin-expressing implanted cells after an injection of N1-ICD-expressing CDC into ischemic myocardium (44±8/high power field (hpf) vs. 11±4/high power field (hpf), n=7 sections, P<0.05). Taken together, these results provide strong evidence that Notch1 promotes SMC differentiation of CDC through an RBPJ-dependent signaling pathway in vitro, which may have important implications for progenitor cell-mediated angiogenesis.
authors.affiliation: Division of Cardiovascular Disease, Department of Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati, Ohio 45243, USA.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Chen
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ashraf
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Wang
authors.forename: Mi
authors.initials: M
authors.lastname: Zhou
authors.forename: John
authors.initials: J
authors.lastname: Zhang
authors.forename: Gangjian
authors.initials: G
authors.lastname: Qin
authors.forename: Jack
authors.initials: J
authors.lastname: Rubinstein
authors.forename: Neal L
authors.initials: NL
authors.lastname: Weintraub
authors.forename: Yaoliang
authors.initials: Y
authors.lastname: Tang
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D006801:Humans; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D009203:Myocardial Infarction / Q000628:therapy; D009206:Myocardium / Q000473:pathology*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D051881:Receptor, Notch1 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D015398:Signal Transduction; D018874:Spheroids, Cellular / Q000166:cytology*; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000378:metabolism / Q000502:physiology*; D059467:Transcriptome
chemical_list: D000943:Antigens, Differentiation; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D008840:Microfilament Proteins; D009124:Muscle Proteins; C497762:Notch1 protein, mouse; C497571:Rbpj protein, mouse; D051881:Receptor, Notch1; D011994:Recombinant Proteins; C058992:Tagln protein, mouse; C573943:myosin 11, mouse; D018995:Myosin Heavy Chains