Notch signaling enhances osteogenic differentiation while inhibiting adipogenesis in primary human bone marrow stromal cells.
OBJECTIVE
The Notch signaling pathway has been shown to play a role in bone marrow-derived stromal cell differentiation, however, the precise outcome of Notch activation remains controversial. The aim of this study was to evaluate the effect of Notch signaling in primary human bone marrow-derived stromal cells (hBMSCs).


METHODS
hBMSCs were transduced to >90% with lentiviral vectors containing either human notch1 intracellular domain (NICD), jagged1, or dominant negative mastermind1. Cells were exposed to adipogenic and osteogenic differentiation stimuli and differentiation was quantified by oil red or alizarin red staining, alkaline phosphatase liver/bone/kidney (ALPL) activity and expression of adipogenic or osteogenic marker genes.


RESULTS
NICD and jagged1 transgene-expressing hBMSCs demonstrated enhanced mineralization, nodule formation, and ALPL activity in osteogenic differentiation media. These findings correlated with increased gene expression of bone morphogenetic protein 2 and ALPL. In contrast, NICD or jagged1 transgene expression strongly inhibited adipocyte formation and reduced peroxisome proliferator-activated receptor-gamma, fatty acid binding protein 4, and adiponectin precursor gene expression. Co-overexpression of dominant negative mastermind1 and NICD or jagged1 led to a partial rescue of the differentiation phenotypes. In addition, high endogenous jagged1 expression levels were observed in hBMSCs samples with strong ALPL activity compared to a group of samples with low ALPL activity.


CONCLUSIONS
In summary, our data suggest that induction of Notch signaling enhances the osteogenic differentiation of hBMSCs while inhibiting the adipogenic fate.
Ugarte
Fernando
F
Department of Pediatrics, University Clinic Dresden, Dresden, Germany.
Ryser
Martin
M
Thieme
Sebastian
S
Fierro
Fernando A
FA
Navratiel
Katrin
K
Bornhäuser
Martin
M
Brenner
Sebastian
S
D017667:Adipocytes / Q000166:cytology*; D000469:Alkaline Phosphatase / Q000378:metabolism; D001483:Base Sequence; D001854:Bone Marrow Cells / Q000166:cytology* / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000235:genetics; D002454:Cell Differentiation; D002478:Cells, Cultured; D017931:DNA Primers; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics; D000072100:Jagged-1 Protein; D008565:Membrane Proteins / Q000235:genetics; D051880:Receptors, Notch / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000072099:Serrate-Jagged Proteins; D015398:Signal Transduction; D017154:Stromal Cells / Q000166:cytology* / Q000378:metabolism
D002135:Calcium-Binding Proteins; D017931:DNA Primers; D036341:Intercellular Signaling Peptides and Proteins; C000606273:JAG1 protein, human; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; D051880:Receptors, Notch; D000072099:Serrate-Jagged Proteins; D000469:Alkaline Phosphatase