ABSTRACT
Objective To study the effect of TLR4 activation with LPS on BMP9-induced osteogenic differentiation of immortalized mouse embryonic fibroblasts ( iMEFs).Methods The activation of TLR4/NF-κB signaling path-way was detected by ICC.iMEFs were treated with LPS,BAY11-7082,Adnovirus GFP and BMP9.The early osteo-genic differentiation capability of iMEFs was detected by ALP staining and quantitative assay .The later osteogenic differentiation capability was detected by alizarin red S staining .The expression of later osteogenic differentiation marker gene OCN and OPN were detected by PCR and Western blot .The change of p-Smad1/5/8 was detected by Western blot.The expression of Runx2 and Dlx5 were detected by PCR and Western blot .Results LPS can effec-tively stimulate TLR4/NF-κB signaling pathway .TLR4 activation inhibited BMP 9-induced osteogenic differentiation . BMP9-induced osteogenic differentiation related gene and Smad 1/5/8 signaling activation were inhibited by TLR4 activation .The inhibition effect was partly reversed by BAY 11-7082 ( P<0.05 ) .Conclusions TLR4 activation with LPS can inhibit BMP9-induced osteogenic differentiation of iMEFs cells via NF-κB signaling pathway .