11 The effect of methyl-β-cyclodextrin on the differentiation of RAW 264 cells into osteoclasts

Abstract

Deviation from normal bone resorption may result in bone diseases. Lipid rafts are specialized plasma membrane microdomains enriched with glycosphingolipids, sphingomyelin and cholesterol. In order to investigate the role of lipid rafts in RAW 264 cell signaling, the lipid rafts were disrupted by depleting cholesterol with methyl-β-cyclodextrin (MβCD). We found that receptor activator of nuclear factor κB ligand (RANKL)-induced differentiation into osteoclasts was markedly inhibited by MβCD, which enhanced the phosphorylation of ERK 1/2 MAP kinase. In contrast, MβCD blocked the phosphorylation of IκB kinase. These data suggest a crucial role for cholesterol in the regulation of the RANKL-mediated signaling pathway and osteoclast differentiation in RAW 264 cells.