Ethanol may suppress Wnt/β-catenin signaling on human bone marrow stroma cells

Ethanol and glucocorticoids are risk factors associated with osteonecrosis. Previous reports suggest ethanol and glucocorticoids induce adipogenesis, decrease osteogenesis in bone marrow stroma cells, and produce intracellular lipid deposits resulting in death of osteocytes. The Wnt/beta-catenin signal pathway is involved in the regulation of homeostasis of bone and we presume glucocorticoids and ethanol may induce osteonecrosis in humans through a similar mechanism as in rodents. We hypothesized (1) ethanol, like glucocorticoids, decreases osteogenesis and increases adipogenesis through the Wnt/beta-catenin signaling pathway in human bone marrow stromal cells; and (2) ethanol decreases intranuclear translocation of beta-catenin. We found both dexamethasone and ethanol decrease the gene and protein expression of osteogenesis and increase that of adipogenesis through Wnt signaling-related genes by semiquantitative and quantitative polymerase chain reaction and Western blot. Ethanol hampered intranuclear translocation of beta-catenin by immunofluorescence analysis. The data suggest the Wnt/beta-catenin signaling pathway may be associated with ethanol-induced osteonecrosis.