Cilengitide inhibits osteoclast adhesion through blocking the αvβ3-mediated FAK/Src signaling pathway
Dan‐Yang Guo, Zhong-Hua Chen, Yi-Fei Fu, Yueyue Li, Meng-Nan Chen, Jun‐Jie Wu, Zheng‐Dong Yuan, Junxing Ye, Xia Li, Feng‐Lai Yuan
Abstract
The remodeling of actin cytoskeleton of osteoclasts on the bone matrix is essential for osteoclastic resorption activity. A specific regulator of the osteoclast cytoskeleton, integrin α v β 3 , is known to provide a key role in the degradation of mineralized bone matrixes. Cilengitide is a potent inhibitor of integrins and is capable of affecting α v β 3 receptors, and has anti-tumor and anti-angiogenic and apoptosis-inducing effects. However, its function on osteoclasts is not fully understood. Here, the cilengitide role on nuclear factor κB ligand-receptor activator (RANKL)-induced osteoclasts was explored. Cells were cultured with varying concentrations of cilengitide (0,0.002,0.2 and 20 μM) for 7 days, followed by detected via Cell Counting Kit-8, staining for tartrate resistant acid phosphatase (TRAP), F-actin ring formation, bone resorption assays, adhesion assays, immunoblotting assays, and real-time fluorescent quantitative PCR. Results demonstrated that cilengitide effectively restrained the functionality and formation of osteoclasts in a concentration-dependent manner, without causing any cytotoxic effects. Mechanistically, cilengitide inhibited osteoclast-relevant genes expression; meanwhile, cilengitide downregulated the expression of key signaling molecules associated with the osteoclast cytoskeleton, including focal adhesion kinase (FAK), integrin α v β 3 and c-Src. Therefore, this results have confirmed that cilengitide regulates osteoclast activity by blocking the integrin α v β 3 signal pathway resulting in diminished adhesion and bone resorption of osteoclasts.