Proteins and peptides responsible for bone remodeling

Bones are living tissues that are periodically renewed through the bone remodeling process. It starts when monocyte-macrophage-type cells begin to proliferate and recruit into the bone tissue due to the action of various proteins. The proteins are generated by the body in response to a lack of calcium in the blood or a damaged bone tissue. Then, other chemical signals promote the differentiation of monocyte-macrophage-type cells into osteoclasts. Finally, osteoclasts carry out a process known as bone resorption in which they degrade bone tissue. After, bone resorption a process known as osteogenesis takes place. In osteogenesis, pluripotent mesenchymal stem cells proliferate and recruit in the bone damaged by bone resorption in response to the action of different compounds. Then, pluripotent mesenchymal stem cells differentiate into osteoblasts due to the effect of specific proteins. Finally, osteoblasts generate new bone tissue, completing the bone remodeling process. This review aims to summarize and provide recent findings of the proteins and chemical signals involved in osteoclast and osteoblast proliferation, recruitment and maturation during the bone resorption and osteogenesis processes. The information found about these molecules could help to better understand all the complex mechanisms that directly or indirectly influence the bone remodeling process. In this sense, the mechanisms of different bone disorders and diseases could be elucidated in a better way, leading to the generation of efficient and specific treatments for each of them in the future.