Regulatory effects of bone morphogenetic protein-4 on tumour necrosis factor-α-suppressed Runx2 and osteoprotegerin expression in cementoblasts.

TNF-α inhibited Runx2 and OPG in cementoblasts, and the p38 MAPK and NF-κB pathways acted in a negative-feedback way to attenuate the inhibitory effects. TNF-α-inhibited Runx2 and OPG could be effectively up-regulated by BMP-4; however, further investigations are needed to fully elaborate the underlying mechanisms.