Gene expression profiling of human mesenchymal stem cells derived from bone marrow during expansion and osteoblast differentiation.
BACKGROUND
Human mesenchymal stem cells (MSC) with the capacity to differentiate into osteoblasts provide potential for the development of novel treatment strategies, such as improved healing of large bone defects. However, their low frequency in bone marrow necessitate ex vivo expansion for further clinical application. In this study we asked if MSC are developing in an aberrant or unwanted way during ex vivo long-term cultivation and if artificial cultivation conditions exert any influence on their stem cell maintenance. To address this question we first developed human oligonucleotide microarrays with 30.000 elements and then performed large-scale expression profiling of long-term expanded MSC and MSC during differentiation into osteoblasts.


RESULTS
The results showed that MSC did not alter their osteogenic differentiation capacity, surface marker profile, and the expression profiles of MSC during expansion. Microarray analysis of MSC during osteogenic differentiation identified three candidate genes for further examination and functional analysis: ID4, CRYAB, and SORT1. Additionally, we were able to reconstruct the three developmental phases during osteoblast differentiation: proliferation, matrix maturation, and mineralization, and illustrate the activation of the SMAD signaling pathways by TGF-beta2 and BMPs.


CONCLUSIONS
With a variety of assays we could show that MSC represent a cell population which can be expanded for therapeutic applications.
Kulterer
Birgit
B
Institute for Genomics and Bioinformatics and Christian-Doppler Laboratory for Genomics and Bioinformatics, Graz University of Technology, Graz, Austria. birgit.kulterer@gmx.at <birgit.kulterer@gmx.at>
Friedl
Gerald
G
Jandrositz
Anita
A
Sanchez-Cabo
Fatima
F
Prokesch
Andreas
A
Paar
Christine
C
Scheideler
Marcel
M
Windhager
Reinhard
R
Preisegger
Karl-Heinz
KH
Trajanoski
Zlatko
Z
D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics*; D016000:Cluster Analysis; D003114:Colony-Forming Units Assay; D020869:Gene Expression Profiling / Q000379:methods*; D006801:Humans; D051796:Inhibitor of Differentiation Proteins / Q000235:genetics; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D010012:Osteogenesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D038203:alpha-Crystallin B Chain / Q000235:genetics
C059215:CRYAB protein, human; C490128:ID4 protein, human; D051796:Inhibitor of Differentiation Proteins; D038203:alpha-Crystallin B Chain