[The effect of growth/differentiation factor-5 (GDF-5) on genotype and phenotype in human adult mesenchymal stem cells].
OBJECTIVE
To evaluate the effects of GDF-5 on genotype and phenotype of human mesenchymal stem cells (hMSC).


OBJECTIVE
GDF-5 leads to up-regulation of the Type I-collagen (Col) gene without altering bone marker genes or alkaline phosphatase activity.


METHODS
To test our hypothesis hMSC were treated with rmGDF-5. Using quantitative real-time PCR we analyzed mRNA for Col, Runx2 and Osterix (Osx). Furthermore, we analyzed alkaline phosphatase activity (ALP) as a phenotypical bone marker. ANOVA and post hoc statistical analyses were used to determine differences among treatments (p < 0.05).


RESULTS
HMSC showed a biphasic response in both Col and Runx2 after rmGDF-5. Initial up-regulation was followed by a significant down-regulation below controls. Interestingly, the controls presented with changes for Col and Runx2 over time. There was no Osx expression in either treated hMSC or controls. No significant differences could be detected in ALP.


CONCLUSIONS
Increased expression of Col and Runx2 might indicate differentiation towards both osteoblast and fibroblast lineage. However, no Osx expression and no change in ALP support the assumption that rmGDF-5 does not lead to an osteoblast phenotype in hMSC. Our in vitro studies confirm a possible therapeutic benefit of GDF-5 in the treatment of tendon and ligament injuries and tissue engineering approaches. Further research is necessary to prove its clinical value.
Koch
H
H
Klinik für Orthopädie und orthopädische Chirurgie, Universität Greifswald. hannjoerg.koch@uni-greifswald.de
Jadlowiec
J A
JA
Fu
F H
FH
Nonn
J
J
Merk
H R
HR
Hollinger
J O
JO
Campbell
P G
PG
D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects* / Q000235:genetics*; D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D050659:Core Binding Factor Alpha 1 Subunit; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000235:genetics; D055428:Growth Differentiation Factor 5; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010641:Phenotype; D016133:Polymerase Chain Reaction; D000076182:Sp7 Transcription Factor; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D019485:Bone Morphogenetic Proteins; D024042:Collagen Type I; D050659:Core Binding Factor Alpha 1 Subunit; C525893:GDF5 protein, human; D055428:Growth Differentiation Factor 5; D009363:Neoplasm Proteins; D000076182:Sp7 Transcription Factor; C478163:SP7 protein, human; D014157:Transcription Factors; D000469:Alkaline Phosphatase