Decoding Epigenetic Switches: How Histone Acetylation/Deacetylation Regulates Mononuclear/Macrophage Fate in Bone Disorders.

Monocyte-macrophage plays a central role in innate immunity, tissue homeostasis maintenance, and disease progression. These phagocytes, which originate from blood monocytes or embryonic sources, are imperative for inflammatory responses, tissue repair, and bone remodeling. In orthopedic diseases, including osteoarthritis, rheumatoid arthritis, osteoporosis, and fractures, changes in histone acetylation are key to regulating macrophage gene expression, polarization, differentiation into osteoclasts, and pathological bone remodeling. Histone acetylation (mediated by histone acetylases) and deacetylation (mediated by histone deacetylases) directly influence important transcription factors in the monocyte-macrophage system by dynamically modulating chromatin accessibility. This review systematically examines the epigenetic network involving histone acetylation and deacetylation monocyte-macrophage, exploring its translational potential in bone-related diseases.