Bone-muscle crosstalk under physiological and pathological conditions.

Anatomically connected bones and muscles determine movement of the body. Forces exerted on muscles are then turned to bones to promote osteogenesis. The crosstalk between muscle and bone has been identified as mechanotransduction previously. In addition to the mechanical features, bones and muscles are also secretory organs which interact closely with one another through producing myokines and osteokines. Moreover, besides the mechanical features, other factors, such as nutrition metabolism, physiological rhythm, age, etc., also affect bone-muscle crosstalk. What's more, osteogenesis and myogenesis within motor system occur almost in parallel. Pathologically, defective muscles are always detected in bone associated diseases and induce the osteopenia, inflammation and abnormal bone metabolism, etc., through biomechanical or biochemical coupling. Hence, we summarize the study findings of bone-muscle crosstalk and propose potential strategies to improve the skeletal or muscular symptoms of certain diseases. Altogether, functional improvement of bones or muscles is beneficial to each other within motor system. Key points: • Bone-muscle crosstalk is established by various osteokines and myokines. • Bone-muscle crosstalk is subjected to diseases not only defined in motor system. • MSCs secret exosomes rich in noncoding RNAs to function on muscles. • Bone metastasis of breast cancer is also harmful to muscles. [ABSTRACT FROM AUTHOR]