Osteoblast-Osteoclast Interactions

Abstract

Bone homeostasis depends on the resorption of bone by osteoclasts and formation of bone by osteoblasts. Imbalance of this tightly coupled process can cause diseases such as osteoporosis. Thus, the mechanisms that regulate communication between osteoclasts and osteoblasts are critical to bone cell biology. It has been shown that osteoblasts and osteoclasts can communicate with each other through direct cell-cell contact, cytokines and extracellular matrix interaction. Osteoblasts can affect osteoclast formation, differentiation or apoptosis through several pathways, such as OPG/RANKL/RANK, LGR4/RANKL/RANK, Ephrin2/ephB4 and Fas/FasL pathways. Conversely, osteoclasts also influence formation of bone by osteoblasts via the d2 isoform of vacuolar (H+) ATPase (v-ATPase) V0 domain (Atp6v0d2), complement component 3a, semaphorin 4D or microRNAs. In addition, cytokine released from the resorbed bone matrix, such as TGF-β and IGF-1 also affects the activity of osteoblasts. Several reviews have been performed on the osteoblasts-osteoclasts communication. However, few reviews have shown the research advances in the recent years. In this review we summarized the current knowledge on osteoblast-osteoclast communication.