Effect Of Interleukin-18 In Monocytes And Macrophages On The Temporomandibular Joint Arthritis

ObjectiveTo elucidate the potentital roles of IL-18 in temporomandibular joint arthritis by detecting expressions of IL-18 R on monocytes and macrophages.MethodsThirty male BALB/c mice(SPF grade)were randomly divided into A,B,C,D and E groups,each with six mice.A different treatment protocol was used for each group.Group A was only injected with 0.9% sodium chloride injection(NS),group B was injected with type ? collagenase and NS,group C was injected with type ? collagenase and IL-18,group D was injected with type ?collagenase and IL-18 binding protein(IL-18BP),and group E was injected with type ? collagenase,IL-18 BP and IL-18,respectively.Group B,C,D,E were injected with 100?l of type ? collagen(2g/ml)on the 1st day and the 21 st day,respectively.Group C,D,E were injected with 100 ?l of IL-18/IL-18BP(10 ng/ml)once every three days.On the 25 th day,all the mice of peripheral blood and tissue lavage fluid in each group were collected.The expression of IL-18receptor(IL-18R)in monocytes and macrophages was demonstrated by flow cytometry(FCM)and the levels of tumor necrosis factor-?(TNF-?)and IL-1? in supernatant of plasma and joint tissue were measured by Enzyme-linked Immunosorbent Assay(ELISA).Results1.FCM analysis demonstrated that the positive expression rate of IL-18 R in peripheral blood monocytes and temporomandibular lavage fluid macrophages in group B,C,D,E was significantly higher than that in group A(p <0.001).Theexpression of IL-18 R in monocytes and macrophages was significantly higher in group C than that in group B,D,E(p<0.001).2.ELISA results demonstrated that the levels of TNF-? and IL-1? in the plasma and temporomandibular joint fluid lavage fluid in group B,C,D,E were higher than those in group A(p<0.001).The levels of TNF-? and IL-1? in group C were significantly higher than those in group B,D,E(p<0.001).ConclusionsUpregulated expressions of IL-18 R in monocytes and macrophages of mice with temporomandibular arthritis,IL-18 induced expressions of IL-18 R and pro-inflammatory cytokines,suggesting the interaction between IL-18 and IL-18 R might be involved in temporomandibular arthritis.Il-18 BP could inhibit IL-18 induced-expressions of IL-18 R and cytokines,indicating IL-18 might be the potential target of temporomandibular arthritis treatment.