The role and mechanism of tumor necrosis factor-alpha in alcohol-induced bone loss

Abstract

Abstract Aim: It is well known that alcohol can cause bone loss and that bone mineral density has an inverse relationship with bone marrow adipocyte (BMA). However, little is known about the mechanisms that link alcohol and bone loss, and existing studies lack data on BMA in alcohol-induced bone loss. Here, wild-type (WT) and tumor necrosis factor-alpha knockout (TNF-α KO) mice were used to examine the effects of alcohol on bone metabolism. Methods: The effects of alcohol on bone metabolism were demonstrated in vivo by feeding WT and TNF-α KO mice with alcohol. The osteogenesis and adipogenesis of primary bone marrow stromal cells (BMSCs) derived from WT and TNF-α KO mice under alcohol intervention were compared in vitro. Tissue staining, cell staining, micro-CT, and quantitative RT-PCR were used to explore the potential mechanism. Results: Alcohol induced trabecular bone loss, increased BMA, and promoted the mRNA expression of Adipoq, Fabp4, visfatin， Pparg, TNF-α, IL-1β, and IL-6 in BMA in WT mice, but not in TNF-α KO mice. In addition, alcohol promoted BMSC adipogenesis and inhibited BMSC osteogenesis, while TNF-α knockout could restrain this situation. Conclusion: Our study demonstrated that alcohol may reduce bone mass by disrupting the balance of osteogenesis and adipogenesis in bone marrow, and TNF-α plays an important role in this process.