Coupling factors and exosomal packaging microRNAs involved in the regulation of bone remodelling

Abstract

Bone remodelling is a continuous process by which bone resorption by osteoclasts is followed by bone formation by osteoblasts to maintain skeletal homeostasis. These two forces must be tightly coordinated not only quantitatively, but also in time and space, and its malfunction leads to diseases such as osteoporosis. Recent research focusing on the cross-talk and coupling mechanisms associated with the sequential recruitment of osteoblasts to areas where osteoclasts have removed bone matrix have identified a number of osteogenic factors produced by the osteoclasts themselves. Osteoclast-derived factors and exosomal-containing microRNA (miRNA) can either enhance or inhibit osteoblast differentiation through paracrine and juxtacrine mechanisms, and therefore may have a central coupling role in bone formation. Entwined with angiocrine factors released by vessel-specific endothelial cells and perivascular cells or pericytes, these factors play a critical role in angiogenesis-osteogenesis coupling essential in bone remodelling.

Modulating calcium‐mediated NFATc1 and mitogen‐activated protein kinase deactivation underlies the inhibitory effects of kavain on osteoclastogenesis and bone resorption

“…Bone remodeling collectively refers to the processes of bone resorption and bone formation (Marie, Kornak, & Teti, ). The coupling activities between these two processes maintain normal bone homeostasis (Yang et al, ; Zhu et al, ). Bone resorption outstripping bone synthesis is the pathological feature of osteolysis and osteoporosis (Mbalaviele, Novack, Schett, & Teitelbaum, ; Rachner, Khosla, & Hofbauer, ).…”

Molecular structure and the role of high‐temperature requirement protein 1 in skeletal disorders and cancers

“…15,16 The imbalance between osteogenesis and osteoclastogenesis leads to bone diseases such as osteoporosis and osteopetrosis. 15,16 Bone formation is known to be regulated by several major signalling pathways, including BMP and TGF-β. TGF-β and BMP induce Smad-dependent signalling pathway and Smad-independent signalling cascade, such as MKK3/6.…”

MicroRNA‐92b‐5p modulates melatonin‐mediated osteogenic differentiation of bone marrow mesenchymal stem cells by targeting ICAM‐1

“…MicroRNAs (miRNAs) are a family of abundant, endogenously expressed, double‐stranded small non‐coding RNAs of about 20‐25 nucleotides . MiRNAs function as key regulators of gene expression by binding to the 3'‐UTR of their target mRNAs and play a critical role in a wide variety of biological processes, including cell proliferation, cell apoptosis, cell fate and organ development . In addition, miRNAs participate in multiple diseases, such as cancers, diabetes mellitus, heart failure, liver injury, cerebrovascular disease and glaucoma .…”