Inactivation of NF-kappa B involved in osteoblast development through interleukin-6

Osteoblasts undergo a process of proliferation and differentiation and are responsible for hone formation. In this study, we examined the relation bet ween NF-kappaB, a key transcription factor in bone metabolism, and osteobla st maturation. NF-kappaB activity and expression of p50, a subunit of NF-ka ppaB, decreased during development of osteoblastic MC3T3-E1 cells. The secr etion of IL-6 by osteoblast, which in combination with soluble IL-6 recepto r induces conversion of fibroblasts to alkaline phosphatase-positive cells, also increased. p50 antisense oligonucleotide increased IL-6 mRNA expressi on. These results suggest that p50 regulates transcription of IL-6 and indi rectly controls osteoblast maturation. (C) 2001 Academic Press.