Effects of β2 Integrins on Osteoclasts, Macrophages, Chondrocytes, and Synovial Fibroblasts in Osteoarthritis

β2 integrins are transmembrane receptors that exist widely in human immune cells and participate in pathological processes such as chronic inflammation, thrombosis, and malignant tumor formation. They mainly mediate intercellular adhesion, coordinate the ingestion of extracellular matrix components, and regulate cytoskeleton formation, thereby regulating cell signaling. Osteoarthritis (OA) is a chronic joint disease that causes joint pain and increases disease burden; it has a high prevalence among populations worldwide. Previous studies have reported that β2 integrins are overexpressed in OA and may play an essential role in the occurrence of OA. The important roles of β2 integrins in the maturation and differentiation of osteoclasts, the regulation of bone homeostasis, and the polarization and migration of macrophages have also been reported. The present review aims to highlight the role of β2 integrins in OA pathogenesis and outline their potential for serving as therapeutic targets.