Hiroyuki Komamura, Akira Nakajima*, Remi Sano and Mitsuru Motoyoshi
The aim of this study was to investigate the effects of bone formation on the Smad-independent signaling pathways in MC3T3-E1 cells stimulated with recombinant human TGF-β2 (rhTGF-β2). The concentration of TGF-β2 in cells subjected to an optimal compressive force of 1.0 g/cm2 (simulate as orthodontic force) was determined using an ELISA. After cell stimulation with 2.5 ng/mL rhTGF-β2 for 3 h, the expression of Smad-independent signaling factors (ERK1/2, TAK1, p38, and JNK) and the expression of osteogenic transcriptional factors (Msx2 and Dlx5) were determined. The expression levels of phosphorylated Smad-independent signaling and transcription factors were also significantly increased by rhTGF-β2 stimulation. These increased expression levels were significantly decreased by LY2109761, an inhibitor of TGF-β receptors. Our new findings suggest that the Smad-independent pathway defines cellular-specific responses to TGF-β2. In addition, rhTGF-β2 stimulation induces the osteogenic transcription factors, Msx2 and Dlx5, via MAPK phosphorylation in the Smad-independent signaling pathway in osteoblasts.
Published Date: 2022-07-29; Received Date: 2022-07-01
