Main content area

Crosstalk between tyrosine kinase receptors, GSK3 and BMP2 signaling during osteoblastic differentiation of human mesenchymal stem cells

Biver, Emmanuel, Thouverey, Cyril, Magne, David, Caverzasio, Joseph
Molecular and Cellular Endocrinology 2014 v.382 pp. 120-130
alkaline phosphatase, bone formation, calcification, fibroblast growth factor receptors, fibroblast growth factors, humans, mitogen-activated protein kinase, receptors, signal transduction, stem cells, tyrosine
Bone morphogenic proteins (BMPs) promote mesenchymal stem cell (MSC) osteogenic differentiation, whereas platelet derived growth factor (PDGF) and fibroblast growth factor (FGF) activate their proliferation through receptors tyrosine kinase (RTK). The effects of PDGF or FGF receptor signaling pathway on BMP2-induced osteoblastic differentiation was investigated in human MSC (HMSC). Inhibition of PDGF or/and FGF receptors enhanced BMP2-induced alkaline phosphatase (ALP) activity, expression of Osterix, ALP and Bone sialoprotein, and matrix calcification. These effects were associated with increased Smad-1 activity, indicating that mitogenic factors interfere with Smad signaling in HMSC differentiation. RTK activate MAPK and inhibit GSK3 through the PI3K/Akt pathway. Biochemical analysis indicated that MAPK JNK and GSK3 especially are potential signaling molecules regulating BMP-induced osteoblastic HMSC differentiation. These observations highlight that the osteogenic effects of BMP2 are modulated by mitogenic factors acting through RTK.