Inflammatory bone loss: pathogenesis and therapeutic intervention

Bone continuously undergoes building and degradation — a process known as bone remodelling. This tightly controlled process can be dysregulated by chronic inflammation, and bone loss is commonly associated with inflammatory diseases. Here, Redlich and Smolen discuss the molecular mechanisms mediating the inflammatory loss of bone and present strategies and agents for therapeutic intervention. Bone is a tissue undergoing continuous building and degradation. This remodelling is a tightly regulated process that can be disturbed by many factors, particularly hormonal changes. Chronic inflammation can also perturb bone metabolism and promote increased bone loss. Inflammatory diseases can arise all over the body, including in the musculoskeletal system (for example, rheumatoid arthritis), the intestine (for example, inflammatory bowel disease), the oral cavity (for example, periodontitis) and the lung (for example, cystic fibrosis). Wherever inflammatory diseases occur, systemic effects on bone will ensue, as well as increased fracture risk. Here, we discuss the cellular and signalling pathways underlying, and strategies for therapeutically interfering with, the inflammatory loss of bone.