CCL7 Is a Protective Factor Secreted by Mechanically Loaded Osteocytes

摘要: In a search for factors up-regulated by mechanical strain in osteocytes, we discovered that chemokine (C-C motif) ligand 7 (CCL7), chemotactic myokine, was highly expressed MLO-Y4 osteocyte-like cells. Although cells secrete potent osteoclast precursors, CCL7 not responsible this activity. increased osteocytes response to tooth movement vivo. Since loading plays crucial role maintaining osteocyte viability, tested protective activity and found be against cell death induced dexamethasone etoposide. specific antibody partially, but combination with indomethacin, completely abrogated the effects of fluid flow shear stress dexamethasone-induced death. activated β-catenin pathway through phosphorylation glycogen synthase kinase 3 (GSK-3), suggesting is observed effects. A related cytokine, CCL2, also produced regulated loading, proved more protected only dexamethasone, Tumor Necrosis Factor α (TNFα). Whereas may produce CCL2 constitutively low levels, major function mechanically selectively protect an autocrine manner glucocorticoid-induced