Studies on the Actions of Interleukin-1 on Bone Metabolism: IL-1 Stimulation of Bone Cell Proliferation, and Inhibition of IL-1 Induced Bone Resorption by Interferon-

Abstract

Partially purified human interleukin-1 (IL-1) was shown to be a potent stimulator of DNA synthesis and proliferation by cells derived from human trabecular bone. Stimulation by the factor was affected by serum concentration in the cultures, the degree of confluence of the cells, and the presence of indomethacin in the cultures The bone cell-activating factor comigrated with IL-1 over gel filtration chromatography (Mr 15000 and 30000) and isoelectnc focusing (pl 5.6 and 7.1), and was active over the same concentration range in the bone cell proliferation and lymphocyte activating factor (LAF) assays Interferon-γ (IFN-γ) was shown to completely inhibit IL-1-stimulated bone resorption at concentrations between 30 and 300 U/ml Basal bone resorption was slightly depressed.