Human purified interleukin‐1 inhibits DNA synthesis and cell growth of osteoblastic cell line (MC3T3‐E1), but enhances alkaline phosphatase activity in the cells

Abstract

We examined the effects of human purified interleukin-1 (IL-1) on DNA synthesis, cell growth, and alkaline phosphatase activity in the osteoblastic cell line MC3T3-E1 under both preconfluent and confluent culture conditions. Addition of IL-1 to the cells markedly inhibited their DNA synthesis and growth over the range 1-10 U/ml. Such significant inhibitory effects were observed in cells cultivated in 1 or 5% fetal calf serum (FCS)-containing alpha modification Eagle's medium (alpha-MEM), but not in alpha-MEM containing 10% FCS. In contrast, alkaline phosphatase activity was enhanced significantly by IL-1 in the cell line cultivated in 1% FCS-containing alpha-MEM. These results demonstrate that human purified IL-1 is effective in inducing the differentiation of osteoblastic cell MC3T3-E1.