Isolation of bone marrow stromal cell-derived smooth muscle cells by a human SM22alpha promoter: in vitro differentiation of putative smooth muscle progenitor cells of bone marrow.
BACKGROUND
Bone marrow stromal cells (BMSCs) have many characteristics of mesenchymal stem cells that can differentiate into smooth muscle cells (SMCs). However, there have been few studies closely following the cell development of smooth muscle lineage among BMSCs.


RESULTS
To investigate the possible existence of a cell population committed to the SMC lineage among bone marrow adhesion cells, we tried to detect and follow the in vitro differentiation of such a cell type by using a promoter-sorting method with a human SM22alpha promoter (-480 bp)/green fluorescent protein (GFP) construct. The construct was transfected to adhesion cells that appeared 5 days after the seeding of mononuclear cells from bone marrow. GFP was first detectable 5 days after the transfection in a cell population [Ad(G) cells], which expressed PDGF-beta but neither mature (calponin) nor immature (SMemb) SMC-specific proteins at that time. However, the cells were eventually grown into individual clones that expressed SMC-specific proteins (alpha-smooth muscle actin, calponin, and SM-1), suggesting that Ad(G) cells have partly at least progenitor properties. Because early studies have reported that PDGF-beta signaling plays pivotal roles in the differentiation of mesenchymal smooth muscle progenitor cells, Ad(G) cells might be putative mesenchymal smooth muscle progenitors expressing PDGF-beta.


CONCLUSIONS
We demonstrated the presence of a cell population fated to become SMCs and followed their differentiation into SMCs among BMSCs.
Kashiwakura
Yuji
Y
Department of Cardiology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
Katoh
Youichi
Y
Tamayose
Kenji
K
Konishi
Hakuoh
H
Takaya
Norihide
N
Yuhara
Senji
S
Yamada
Masanori
M
Sugimoto
Koichi
K
Daida
Hiroyuki
H
D000818:Animals; D000906:Antibodies; D001854:Bone Marrow Cells / Q000166:cytology*; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000276:immunology; D002454:Cell Differentiation; D019070:Cell Lineage; D002478:Cells, Cultured; D002999:Clone Cells; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins / Q000032:analysis / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008840:Microfilament Proteins / Q000235:genetics*; D009124:Muscle Proteins / Q000235:genetics*; D009131:Muscle, Smooth, Vascular / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000032:analysis / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000032:analysis; D024745:Smooth Muscle Myosins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D013234:Stem Cells / Q000502:physiology*; D017154:Stromal Cells / Q000502:physiology*; D014162:Transfection; D000096985:Calponins
D000906:Antibodies; D002135:Calcium-Binding Proteins; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D008840:Microfilament Proteins; D009124:Muscle Proteins; D012333:RNA, Messenger; D020797:Receptor, Platelet-Derived Growth Factor beta; D011993:Recombinant Fusion Proteins; D024745:Smooth Muscle Myosins; D000096985:Calponins; C058992:Tagln protein, mouse; C051615:transgelin