Receptor activator of NF-kappaB ligand induces the expression of carbonic anhydrase II, cathepsin K, and matrix metalloproteinase-9 in osteoclast precursor RAW264.7 cells.

Interleukin-1 (IL-1) is a proinflammatory cytokine that is a potent stimulator of bone resorption and an inhibitor of bone formation, whereas macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-kappaB (RANK) ligand (RANKL) are essential and sufficient for osteoclast differentiation. Recently, we showed that IL-1alpha affects mineralized nodule formation in vitro and halts bone matrix turnover. We also showed that IL-1alpha stimulates osteoclast formation via the interaction of RANKL with RANK by increasing M-CSF and prostaglandin E(2) and decreasing osteoprotegerin.

The effect of IL-1alpha on the expression of matrix metalloproteinases, plasminogen activators, and their inhibitors in osteoblastic ROS 17/2.8 cells.

Interleukin-1 (IL-1) plays key roles in altering bone matrix turnover. This turnover is regulated by matrix metalloproteinases (MMPs), tissue inhibitor of matrix metalloproteinases (TIMPs), and the plasminogen activation system, including tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA) , and plasminogen activator inhibitor type-1 (PAI-1). In this study, we examined the effect of IL-1alpha on the expression of the MMPs, TIMPs, tPA, uPA, and PAI-1 genes in osteoblasts derived from the rat osteosarcoma cell line ROS 17/2.

IL-1 alpha stimulates the formation of osteoclast-like cells by increasing M-CSF and PGE2 production and decreasing OPG production by osteoblasts.

Interleukin-1alpha (IL-1alpha) is one of the most potent bone-resorbing factors involved in the bone loss that is associated with inflammation. We examined the effect of the inflammatory mediator IL-1alpha on the expression of macrophage colony-stimulating factor (M-CSF), osteoprotegerin (OPG), and prostaglandin E2 (PGE2) in rat osteoblasts, and the indirect effect of IL-1alpha on the formation of osteoclast-like cells. Osteoblasts were cultured in alpha-minimum essential medium containing 10% fetal bovine serum with or without 100 units/ml of IL-1alpha for up to 14 days.