Expression profile of osteoblast lineage at defined stages of differentiation.
The inherent heterogeneity of bone cells complicates the interpretation of microarray studies designed to identify genes highly associated with osteoblast differentiation. To overcome this problem, we have utilized Col1a1 promoter-green fluorescent protein transgenic mouse lines to isolate bone cells at distinct stages of osteoprogenitor maturation. Comparison of gene expression patterns from unsorted or isolated sorted bone cell populations at days 7 and 17 of calvarial cultures revealed an increased specificity regarding which genes are selectively expressed in a subset of bone cell types during differentiation. Furthermore, distinctly different patterns of gene expression associated with major signaling pathways (Igf1, Bmp, and Wnt) were observed at different levels of maturation. Some of our data differ from current models of osteoprogenitor cell differentiation and emphasize components of the pathways that were not revealed in studies based on a total cell population. Thus, applying methods to generate more homogeneous populations of cells at a defined level of cellular differentiation from a primary osteogenic culture is feasible and leads to a novel interpretation of the gene expression associated with increasing levels of osteoprogenitor maturation.
Kalajzic
Ivo
I
Department of Genetics and Developmental Biology, University of Connecticut Health Center, Farmington, Connecticut 06053, USA.
Staal
Ada
A
Yang
Wen-Pin
WP
Wu
Yuli
Y
Johnson
Susan E
SE
Feyen
Jean H M
JH
Krueger
Winfried
W
Maye
Peter
P
Yu
Fang
F
Zhao
Yifang
Y
Kuo
Lynn
L
Gupta
Rishi R
RR
Achenie
Luke E K
LE
Wang
Hsin-Wei
HW
Shin
Dong-Guk
DG
Rowe
David W
DW
D000818:Animals; D015152:Blotting, Northern; D002454:Cell Differentiation; D019070:Cell Lineage; D002478:Cells, Cultured; D020869:Gene Expression Profiling / Q000379:methods; D005786:Gene Expression Regulation; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D020411:Oligonucleotide Array Sequence Analysis; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology; D010012:Osteogenesis / Q000502:physiology; D011401:Promoter Regions, Genetic; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors
D012333:RNA, Messenger; D049452:Green Fluorescent Proteins; D012313:RNA