| When cells are affected by factors such as inflammation, gene mutations, hypoxia, etc., endoplasmic reticulum (ER) stress will be caused. Cells will initiate an adaptive regulation of unfolded protein response (UPR) in order to restore the normal structure and function of the ER, in order to process unfolded or misfolded proteins. If the ER stress state persists, it will cause a prolongation of the UPR time limit, which will eventually induce apoptosis. In this paper, we summarize the mechanism of the three UPR pathways in regulating the differentiation of osteoblasts and osteoclasts, especially the important targets and mechanisms of the protein kinase RNA-like ER kinase pathway in the treatment of osteoporosis, and explore the effect of UPR on the mechanism of bone homeostasis, aiming to provide relevant information for the treatment of osteoporosis. |