Identification of myogenic-endothelial progenitor cells in the interstitial spaces of skeletal muscle.
Putative myogenic and endothelial (myo-endothelial) cell progenitors were identified in the interstitial spaces of murine skeletal muscle by immunohistochemistry and immunoelectron microscopy using CD34 antigen. Enzymatically isolated cells were characterized by fluorescence-activated cell sorting on the basis of cell surface antigen expression, and were sorted as a CD34+ and CD45- fraction. Cells in this fraction were approximately 94% positive for Sca-1, and mostly negative (<3% positive) for CD14, 31, 49, 144, c-kit, and FLK-1. The CD34+/45- cells formed colonies in clonal cell cultures and colony-forming units displayed the potential to differentiate into adipocytes, endothelial, and myogenic cells. The CD34+/45- cells fully differentiated into vascular endothelial cells and skeletal muscle fibers in vivo after transplantation. Immediately after sorting, CD34+/45- cells expressed only c-met mRNA, and did not express any other myogenic cell-related markers such as MyoD, myf-5, myf-6, myogenin, M-cadherin, Pax-3, and Pax-7. However, after 3 d of culture, these cells expressed mRNA for all myogenic markers. CD34+/45- cells were distinct from satellite cells, as they expressed Bcrp1/ABCG2 gene mRNA (Zhou et al., 2001). These findings suggest that myo-endothelial progenitors reside in the interstitial spaces of mammalian skeletal muscles, and that they can potentially contribute to postnatal skeletal muscle growth.
Tamaki
Tetsuro
T
Department of Physiology, Division of Human Structure and Function, Tokai University School of Medicine, Isehara, Kanagawa, Japan. tamaki@is.icc.u-tokai.ac.jp
Akatsuka
Akira
A
Ando
Kiyoshi
K
Nakamura
Yoshihiko
Y
Matsuzawa
Hideyuki
H
Hotta
Tomomitsu
T
Roy
Roland R
RR
Edgerton
V Reggie
VR
D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D000954:Antigens, Surface / Q000378:metabolism; D015415:Biomarkers; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure; D005110:Extracellular Space / Q000378:metabolism*; D005434:Flow Cytometry; D007150:Immunohistochemistry; D017493:Leukocyte Common Antigens / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008854:Microscopy, Electron; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure; D009363:Neoplasm Proteins; D019859:Proto-Oncogene Proteins c-met / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism* / Q000648:ultrastructure
C116614:ABCG2 protein, human; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D018952:Antigens, CD34; D000954:Antigens, Surface; D015415:Biomarkers; D009124:Muscle Proteins; D009363:Neoplasm Proteins; D019859:Proto-Oncogene Proteins c-met; D017493:Leukocyte Common Antigens