Role of Mac-1 in osteoclast differentiation / 中国病理生理杂志

ABSTRACT

AIM:To investigate the function of macrophage differentiation antigen-1 (Mac-1) in receptor acti-vator of nuclear factor-κB ligand ( RANKL )-induced osteoclast differentiation and the mechanisms .METHODS: The spleen cells were isolated from 4-week-old C57BL/6J mice, and cultured with RANKL, macrophage colony-stimulating fac-tor and CD11b and CD18 antibodies for 1 week.The actin bundles were stained with rhodamine-labeled phalloidin, and nu-clei were stained with DAPI.CD11b and CD18 antibodies, lentivirus with interfering vector plasmid of target gene Itgam (encoding CD11b) and empty virus (control virus) were used to treat osteoclasts for 1 week, and then immunofluorescence staining was performed.CD11b antibody, lentivirus and control virus were used to treat osteoclasts for 1 week, and total protein was taken for Western blot .RESULTS:Lower multinuclear positive rates in the groups treated with CD 11b anti-body were observed than that in the groups treated with CD 18 antibody and control group .Lower immunofluorescence inten-sity of Syk, CD11b and NFATc1 was found in CD11b antibody group than that in control group .Lower Syk, CD11b and NFATc1 immunofluorescence intensity was also observed in lentivirus group than that in control virus group .The results of Western blot analysis showed that the protein levels of CD 11b, Syk, NFATc1, c-Fos and p-ERK/ERK in CD11b antibody group were decreased as compared control group .Compared with control virus group , the protein levels of CD11b, Syk, NFATc1, c-Fos and p-ERK/ERK in lentivirus group were also decreased .CONCLUSION:CD11b subunit of Mac-1 pro-motes osteoclast differentiation by up-regulating c-Fos, ERK activity and NFATc1.