| The circadian rhythm is a biological characteristic of living organisms in order to adapt to the natural environment. The clock genes such as Bmal1, Clock, PERs, CRYs, Rev-erbα and clock control genes exert vital function. The interaction between immune cells and bone cells regulates the balance of bone metabolism through the interaction of common cytokines and signaling pathways, and immune disorders could cause abnormal bone metabolism. The birth of osteoimmunology is beneficial to the further study of the interaction between skeletal system and immune system, and osteoimmunology is involved in the occurrence and progression of many orthopedic diseases and immune diseases. In the physiological state, clock genes play an important role in maintaining the balance of osteoimmunology by regulating the circadian rhythm of skeletal system and immune system. However, in the pathological state, clock genes malfunction not only causes the disorders of circadian rhythm of the skeletal system and the immune system, it further leads to loss of bone mass and immuno-inflammatory reactions. It also exerts effects on bone metabolism through osteoimmunology related factors such as IL-1, IL-6, TNF-α and RANKL. The immuno-inflammatory reactions also affect the normal function of clock genes, which in turn affects bone metabolism. According to the characteristics of clock genes and bone metabolism, understanding the interaction between clock genes and osteoimmunology under physiological and pathological conditions will have certain guiding significance for the prevention and treatment of skeletal system diseases and immune system diseases. |