Integrin receptors (hard tissue lineage) (Integrin)

Integrin receptors on hard tissue lineage cells, including osteoblasts, osteoclasts, and osteocytes, are a family of heterodimeric transmembrane glycoproteins that mediate critical interactions between these cells and the bone extracellular matrix (ECM) [PMID: 24508218]. The most prominent members include the vitronectin receptor (alpha-V beta-3), which is highly expressed on osteoclasts and is essential for the formation of the sealing zone during bone resorption [PMID: 8429013]. On osteoblasts, integrins such as alpha-1 beta-1, alpha-2 beta-1, and alpha-5 beta-1 facilitate adhesion to collagen and fibronectin, triggering intracellular signaling pathways like the FAK/MAPK cascade that drive osteoblast differentiation and mineralization [PMID: 8930148]. These receptors also function as mechanosensors, allowing bone cells to respond to physical loads, which is vital for maintaining bone density [PMID: 15555913]. In pathological states like osteoporosis and bone metastasis, integrin signaling is often dysregulated, contributing to excessive bone loss or the establishment of secondary tumors [PMID: 17652496]. Consequently, these receptors are targeted by various therapeutic agents, including RGD-mimetic small molecules and monoclonal antibodies, to modulate bone remodeling and treat skeletal diseases [PMID: 21834709].

Other names

Bone cell integrinsOsteoblast integrinsOsteoclast integrinsVitronectin receptorCollagen receptorFibronectin receptor

Competitive antagonism of the RGD (Arg-Gly-Asp) binding site on integrin heterodimers, preventing interaction with extracellular matrix proteins and inhibiting downstream signaling and cell adhesion.