Open AccessTwo Different Roles of Purified CD45 + c‐Kit + Sca‐1 + Lin − Cells After Transplantation in Muscles
Author(s) -
Yoshimoto Momoko,
Chang Hsi,
Shiota Mitsutaka,
Kobayashi Hirohiko,
Umeda Katsutsugu,
Kawakami Atsushi,
Heike Toshio,
Nakahata Tatsutoshi
Publication year - 2005
Publication title -
stem cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.159
H-Index - 229
eISSN - 1549-4918
pISSN - 1066-5099
DOI - 10.1634/stemcells.2004-0220
Subject(s) - green fluorescent protein , biology , myod , microbiology and biotechnology , myosin , myf5 , transplantation , myocyte , myogenesis , biochemistry , medicine , surgery , gene
Recent studies have indicated that bone marrow cells can regenerate damaged muscles and that they can adopt phenotypes of other cells by cell fusion. Our direct visualization system gave evidence of massive muscle regeneration by green fluorescent protein (GFP)–labeled CD45 + c‐Kit + Sca‐1 + Lin − cells (KSL cells), and we investigated the role of KSL cells in muscle regeneration after transplantation with or without lethal irradiation. In the early phase, GFP signals were clearly observed in all the muscles of only irradiated mice. Transverse cryostat sections showed GFP + myosin + muscle fibers, along with numerous GFP + hematopoietic cells in damaged muscle. These phenomena were temporary, and GFP signals had dramatically reduced 30 days after transplantation. After 6 months, GFP + fibers could hardly be detected, but GFP + c‐Met + mononuclear cells were located beneath the basal lamina where satellite cells usually exist in both conditioned mice. Immunostaining of isolated single fibers revealed GFP + PAX7 + , GFP + MyoD + , and GFP + Myf5 + satellite‐like cells on the fibers. Single‐fiber cultures from these mice showed proliferation of GFP + fibers. These results indicate two different roles of KSL cells: one leading to regeneration of damaged muscles in the early phase and the other to conversion into satellite cells in the late phase.