Effects Of IL-17 On The Expressions Of MMP-9 In Osteoclasts

Objective: To explore the effects of interleukin-17(IL-17) on the expressions of matrix metalloproteinase-9(MMP-9) in osteoclasts, and to provide references for the study of IL-17 in orthodontic force induced root resorption.Methods: Induced the mouse monocyte/macrophage cell line RAW264.7 forming osteoclasts, and to identify a successful induction of osteoclasts by TRAP staining. Added to the culture medium of experimental groups in a gradient concentration of 0.1, 1.0, 10 and 100ng/m L IL-17, and set as group a, group b, group c, group d in turn, the control group without IL-17. ELISA method was used to test the expression levels of MMP-9 proteins when osteoclasts induced 3, 4, and 5 days, RT-PCR method was used to test the expression levels of MMP-9 m RNA when osteoclasts induced 3, 4 and 5 days.Results: 1、TRAP staining of osteoclasts:When RAW264.7 cells induced 3-5 days, TRAP staining positive cells were found, which have large volume, and large number of nuclei(nuclei≥3), the nuclei are purplish blue, tartrate resistant acid phosphatase in the cytoplasm active site is purple particles. 2、ELISA detection:The expression levels of MMP-9 proteins were increased in group d compared with control group when osteoclasts induced 3 days, there were significant differences(P<0.05); the expression levels of MMP-9 proteins were increased in group b, group c and group d compared with control group when osteoclasts induced 4 and 5 days, there were significant differences(P<0.05). The group b and group c, group c and group d were compared with statistical difference(P<0.05). 3、RT-PCR detection:The expression levels of MMP-9 m RNA were increased in group a, group b, group c and group d compared with control group when osteoclasts induced 3, 4 and 5 days, there were significant differences(P<0.01). Any two experimental groups were compared with statistical significance at the same time(P<0.05). The expression levels of MMP-9 m RNA in each group when osteoclasts induced 5 days were higher than 3 and 4 days, there were significant differences(P<0.05).Conclusion: IL-17 promoted the expressions of MMP-9 in osteoclasts, and the promoting effect is enhanced with the increasing of IL-17 concentration. Suggests that the role of IL-17 on osteoclasts in addition to promote osteoclasts differentiation directly and as an inducer of nuclear factor kappa B receptor activation factor ligand, may also promote the expression of MMP-9, then affect osteoclasts migration and enhance the ability of the degradation of bone matrix.