CD147 up-regulates calcium-induced chemotaxis, adhesion ability and invasiveness of human neutrophils via a TRPM-7-mediated mechanism.

OBJECTIVES: We aimed to investigate whether CD147 can up-regulate the chemotactic, adhesive and invasive properties of human neutrophils and to determine the mechanism underlying this process. METHODS: Human promyelocytic leukaemia cells (HL-60) cells and peripheral blood or synovial fluid neutrophils were isolated from RA patients. Under cyclophilin A (CypA) stimulation, chemotaxis, adhesion potential and invasion ability were assessed using chemotaxis, adhesion and invasiveness assays. Lipid raft isolation and western blot were used to determine the mechanism underlying the effects of CypA stimulation. RESULTS: CD147 up-regulates the calcium-induced chemotaxis, adhesion ability and invasiveness of human neutrophils in RA patients. Transient receptor potential melastatin 7 may be responsible for this phenomenon. CONCLUSION: These findings suggest that in RA patients, abundant CypA up-regulates the calcium-induced chemotactic, adhesive and invasive properties of neutrophils via direct binding to CD147. Cyclophilin-CD147 interactions might contribute to the destruction of cartilage and bone in RA.

Performance of ultrasound to monitor Achilles enthesitis in patients with ankylosing spondylitis during TNF-a antagonist therapy.

Enthesitis is considered as the primary anatomical lesion in ankylosing spondylitis (AS). We aimed to investigate the potential of ultrasound to detect early changes after TNF-a antagonist therapy of Achilles enthesitis of AS patients. One hundred AS patients with active disease, requiring TNF-a antagonist therapy, were included (etanercept n = 25, infliximab n = 25, adalimumab n = 25, non-biologic disease-modifying antirheumatic drugs (DMARDs) n = 25). Physical examination was performed to evaluate disease activity and detect Achilles enthesitis and/or retrocalcaneal bursitis. Ultrasound of the Achilles enthesitis was performed bilaterally. Follow-up examinations were performed 3 months after the initiation of therapy. Gray scale (GS) scores, Power Doppler (PD) scores, and total additive scores (TS) decreased significantly during TNF-a antagonist therapy but not in traditional non-biologic traditional DMARDs group. The bath ankylosing spondylitis disease activity index (BASDAI), bath ankylosing spondylitis metrology index (BASMI), bath ankylosing spondylitis functional index (BASFI), and Maastricht ankylosing spondylitis enthesitis score (MASES) all showed significant improvements. When three different TNF-a antagonists were analyzed separately, no significant difference was observed in GS, PD, and total scores. Subclinical Achilles enthesitis, detected only with GS ultrasound, is present in a subset of AS patients and a significant improvement can be demonstrated after 3 months of TNF-a antagonist therapy. Doppler ultrasound provides a reliable estimation to monitor the therapeutic response to TNF antagonists in AS patients with Achilles enthesitis. TNF-a antagonists have been shown to be effective in decreasing ultrasound signs of enthesitis after 3 months of therapy in AS patients.

Platelets induce a proinflammatory phenotype in monocytes via the CD147 pathway in rheumatoid arthritis.

INTRODUCTION: Activated platelets exert a proinflammatory action that can be largely ascribed to their ability to interact with monocytes. However, the mechanisms that promote dynamic changes in monocyte subsets in rheumatoid arthritis (RA) have not been clearly identified. The aim of this study was to determine whether platelet activation and the consequent formation of monocyte-platelet aggregates (MPA) might induce a proinflammatory phenotype in circulating monocytes in RA. METHODS: The surface phenotype of platelets and the frequencies of monocyte subpopulations in the peripheral blood of RA patients were determined using flow cytometry. Platelets were sorted and co-cultured with monocytes. In addition, monocyte activation was assessed by measuring the nuclear factor κB (NF-κB) pathway. The disease activity was evaluated using the 28-joint disease activity score. RESULTS: Platelet activation, circulating intermediate monocytes (Mon2) and MPA formation were significantly elevated in RA, especially in those with active disease status. Furthermore, Mon2 monocytes showed higher CD147 expression and responded to direct cell contact with activated platelets with higher cytokine production and matrix metallopeptidase 9 (MMP-9) secretion, which increased the expression of CD147. After the addition of specific antibodies for CD147, those effects were abolished. Furthermore, the NF-κB-driven inflammatory pathway may be involved in this process. CONCLUSION: These findings indicate an important role of platelet activation and the consequent formation of MPA in the generation of the proinflammatory cytokine milieu and for the promotion and maintenance of the pathogenically relevant Mon2 monocyte compartment in RA, which is likely to play an important role in the pathogenesis of autoimmunity.

[Effect of cyclophilin A on monocyte-derived foam cells].

AIM: To observe whether cyclophilin A (CypA)has an effect on macrophage-derived foam cells, and to investigate the involvement of CypA in the development of atherosclerosis. METHODS: The foam cell model was established through incubating the human monocyte line (THP-1 cells) with oxidized low density lipoproteins (ox-LDL). The cells were stained with fresh oil red O to study the morphology of the macrophage-derived foam cells. The cell adhesion, invasion and the production of matrix metalloproteinase (MMPs) of the macrophage-derived foam cells were detected by adhesion assay, invasion assay and gelatin zymography respectively both in the absence or presence of different concentrations of purified CypA (50, 100, 200 µg/L). Then the foam cells were respectively pre-treated with CsA, c7b8f10, HAb18 mAb, and dual treatment of c7b8f10 and HAb18 mAb respectively, to investigate the inhibitory effect on macrophage-derived foam cells. RESULTS: The adhesion, invasion and the production of MMP-9 and MMP-2 were enhanced during the differentiation of monocytes into macrophages (P<0.05). CypA, especially in the concentration of 100 ng/mL, significantly promoted the function of macrophage-derived foam cells (P<0.05). CsA, c7b8f10, HAb18 mAb, and c7b8f10- HAb18 mAb combination dramatically inhibited the function of macrophage-derived foam cells both in the absence or presence of CypA (P<0.05). The c7b8f10- HAb18 mAb combination pretreatment had the most obviously suppressive effect on macrophage-derived foam cells (P<0.05). CONCLUSION: These findings suggest that CypA up regulates the adhesion, the invasion and the expressions of MMP-2 and MMP-9 in macrophage-derived foam cells. The CypA effect is blocked by the pretreatment of the different antagonists. This research might suggest the correlation between atherosclerosis pathogenesis and the vulnerability of atherosclerotic plaques, and thus give us some good ideas for atherosclerosis therapy in future.