The expression and function of microRNAs in bone homeostasis.

microRNAs (miRNAs) are a class of small, endogenous, non-coding single strand RNAs. miRNAs are involve in multiple developmental events during embryogenesis and adult tissue homeostasis. miRNAs regulate epigenetic regulating genes through post-transcriptional regulation and that epigenetic factors mediate the regulation of miRNA. Bone tissue homeostasis is maintained through the dynamic balance between osteoclastic bone resorption and osteoblastic bone formation. And miRNAs are important regulators of bone resorbing activity mediated by osteoclasts, as well as osteoblast proliferation and differentiation. This review summarizes recent studies bone-regulating miRNAs, which are divided into two major branches: the osteogenesis regulator and the osteoclastogenesis regulator. miRNAs can positively or negatively regulate osteogenesis and osteoclastogenesis. This review also discusses how miRNAs, target genes, intracellular effectors and transcription factors affect both the bone homeostasis and bone homeostasis processes. Disrupted the function of miRNAs is related to some bone diseases, such as osteoporosis. Studying the mechanisms underlying the role of miRNAs in the bone and mineral field may reveal potential therapeutic targets for treating metabolic bone disorders, bone loss and bone diseases.