title: Clonal differentiation of skeletal muscle-derived CD34(-)/45(-) stem cells into cardiomyocytes in vivo.
abstract: The differentiation and/or therapeutic potential of skeletal muscle-derived stem cells for cardiac infarction have been studied extensively for use in cellular cardiomyoplasty, as injured cardiomyocytes exhibit limited regenerative capacity. We previously reported cardio-myogenic differentiation of skeletal muscle-derived CD34+/45(-) (Sk-34) stem cells after therapeutic transplantation. However, the clonal differentiation potential of these cells remains unknown. Here, we show that skeletal muscle-derived CD34(-)/45(-) (Sk-DN) stem cells, which are situated upstream of Sk-34 cells in the same lineage, exhibit clonal differentiation into cardiomyocytes after single cell-derived single-sphere implantation into myocardium. Sk-DN cells were enzymatically isolated from green fluorescent protein (GFP) transgenic mice and purified by flow cytometry, and were then clonally cultured in collagen-based medium with bFGF and EGF after clonal cell sorting. Single cell-derived single-sphere colonies of Sk-DN cells were directly implanted into the wild-type mouse myocardium. At 4 weeks after implantation, donor cells exhibited typical cardiomyocyte structure with the formation of gap-junctions between donor and recipient cells. Expression of specific mRNAs for cardiomyocytes, such as cardiac actin and GATA-4, Nkx2-5, Isl-1, Mef2, and Hand2, were also seen in clonal cell cultures of Sk-DN cells. Cell fusion-independent differentiation was also confirmed by bulk cell transplantation using Cre- and loxP (enhanced GFP)-mice. We conclude that Sk-DN cells can give rise to cardiac muscle cells clonally, and that skeletal muscle includes a practical cell source for cellular cardiomyoplasty.
authors.affiliation: Muscle Physiology and Cell Biology Unit, Tokai University School of Medicine, Shimokasuya, Isehara, Kanagawa, Japan. tamaki@is.icc.u-tokai.ac.jp
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Tamaki
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Uchiyama
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Okada
authors.forename: Kayoko
authors.initials: K
authors.lastname: Tono
authors.forename: Maki
authors.initials: M
authors.lastname: Masuda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nitta
authors.forename: Akio
authors.initials: A
authors.lastname: Hoshi
authors.forename: Akira
authors.initials: A
authors.lastname: Akatsuka
mesh_terms: D000199:Actins / Q000235:genetics; D000818:Animals; D018952:Antigens, CD34; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics; D015415:Biomarkers; D002454:Cell Differentiation; D002478:Cells, Cultured; D050991:GATA4 Transcription Factor / Q000235:genetics; D017629:Gap Junctions; D015870:Gene Expression; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000235:genetics; D060850:LIM-Homeodomain Proteins; D017493:Leukocyte Common Antigens; D051379:Mice; D008822:Mice, Transgenic; D018485:Muscle Fibers, Skeletal / Q000166:cytology* / Q000378:metabolism; D009203:Myocardial Infarction / Q000628:therapy; D009206:Myocardium / Q000378:metabolism / Q000648:ultrastructure; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism; D018006:Myogenic Regulatory Factors / Q000235:genetics; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D014157:Transcription Factors
chemical_list: D000199:Actins; D018952:Antigens, CD34; D051792:Basic Helix-Loop-Helix Proteins; D015415:Biomarkers; D050991:GATA4 Transcription Factor; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D017493:Leukocyte Common Antigens; D018006:Myogenic Regulatory Factors; D014157:Transcription Factors; C498766:Hand2 protein, mouse; C484469:Nkx2-5 protein, mouse; C063843:insulin gene enhancer binding protein Isl-1