1 Effect of long-acting nitric oxide donor on osteoclast differentiation

Abstract

It is well established that osteoclast differentiation/activation is involved in orthodontic tooth movement at compression sites. However, the mechanism of osteoclast differentiation/activation in orthodontic tooth movement remains unclear. Nitric oxide (NO) has been reported to play a crucial role in bone remodeling induced by mechanical loading, and several reports have shown that inhibition of NO syntheses prevents orthodontic tooth movement in animal models. We investigated whether osteoclast differentiation can be induced by NO in vitro. We found that sustained release of NO by NOC-18 induces osteoclast differentiation of not only RAW264 cells but also bone marrow macrophages, and that the inhibition of ERK and activation of p38 MAPK may be involved in NOC-18-induced osteoclast differentiation.