The Regulatory Roles of MicroRNAs in Bone Remodeling and Perspectives as Biomarkers in Osteoporosis

Figure 1

Bone cell interactions and key signaling pathways during bone remodeling. Osteoblasts induce RANKL and regulate the differentiation of osteoclast precursors. Meanwhile, the binding of RANKL and RANK stimulates the activity of osteoclasts. OPG produced by osteoblasts competitively binds to RANKL, resulting in the inhibition of osteoclasts differentiation. FZD and LRP form a coreceptor for Wnt ligand. The combination between Wnt ligand and its receptor results in the enhancement of osteoblast differentiation. Heterodimers of Ser/The form the receptor of BMPs. BMPs are regulated by Smads and Runx2.