プロスタグランディン E_2 存在下での破骨細胞の新生過程における lipopolysaccharide とインターロイキン 1 の作用

Abstract

Prostaglandin E_2 (PGE_2), interleukin-1 (IL-1), and lipopolysaccharide (LPS) are the candidates for the inducers of osteoclastic bone resorption accompanied with periodontal disease. The purpose of this paper is to show the effect of these substances on osteoclast formation in cell culture. Mouse bone marrow cells were prepared, and the cells were cultured with IL-1 and LPS in the presence of PGE_2. After the culture, tartrate-resistant acid phosphatase positive cells were scored as osteoclasts. The results obtained were as follows : 1. IL-1 increased the multinuclear osteoclast formation in the culture in the presence of 0.1μM PGE_2. 2. The multinuclear osteoclast formation was increased in the culture with IL-1 added in the second half culture period as much as in the culture with the addition throughout the culture period. The multinuclear osteoclast formation decreased in the culture with IL-1 added in the first half culture period. 3. Mononuclear osteoclast formation was increased in the culture with LPS added in the first half period of the culture with 0.1μM PGE_2. Multinuclear osteoclast formation was increased by LPS added in the second half period with 0.1μM PGE_2. 4. Mean nuclear number of multinuclear osteoclasts formed by IL-1 or LPS in the presence of 0.1μM PGE_2 was much higher than that by 0.1μM PGE_2 alone. Mean nuclear number of multinuclear osteoclasts by 1μM PGE_2 alone was much less than that by 0.1μM PGE_2. These results show that osteoclasts are formed by IL-1 and LPS in the presence of low concentration of PGE_2. This suggests the possibility that PGE_2, IL-1 and LPS induce or enhance bone resorption, through osteoclast formation, accompanied with periodontal disease.