Interleukin-1 beta enhances and tumor necrosis factor-alpha inhibits bone morphogenetic protein-2-induced alkaline phosphatase activity in MC3T3-E1 osteoblastic cells.

The modulatory effects of interleukin (IL)-1 beta and tumor necrosis factor (TNF)-alpha on bone morphogenetic protein (BMP)-2- and -4-induced alkaline phosphatase (ALP) activity were examined in cultures of mouse MC3T3-E1 osteoblastic cells. Both BMP-2 and -4 significantly induced ALP in these cells. IL-1 beta alone had no effect on ALP activity, but it significantly enhanced BMP-2- and -4-induced ALP activity. TNF-alpha suppressed the induction of ALP by BMP-2 or -4. The results suggest that the action of BMP on osteogenic differentiation may be regulated by such immuno/inflammatory cytokines as IL-1 beta and TNF-alpha.