Bone and muscle

Abstract

Muscle and bone are anatomically integrated with each other to form the musculoskeletal system. Muscle has been considered as an endocrine organ to affect other tissues, including bone, via secreting factors within the microenvironment to modulate their biological functions. Thus muscle is essential for bone development, modeling, and remodeling. Similar to muscle, bone can also be considered an endocrine organ targeting other tissues such as muscle. Therefore, the aim of this chapter is to summarize endocrine factors derived from either bone or muscle and their potential benefits for the therapy of simultaneous bone-muscle dysfunction, such as osteoporosis and sarcopenia in the elderly population. Herein, we first describe the synchronous development of the musculoskeletal system during embryogenesis and how this close relationship between bone and muscle continues in postnatal life. Then the factors regulating both bone and muscle, including factors like myogenic regulatory factors (MRFs) and myostatin from muscle, bone-derived factors like bone morphogenetic proteins (BMPs) and prostaglandin E2 (PGE2), as well as other secretory factors, are discussed to provide a better understanding of the mechanisms underlying the parallel development of musculoskeletal system diseases. Finally, we discuss some meaningful and innovative treatment strategies, which preferentially strengthen the musculoskeletal unit as a whole.