Tomoko Miyashita

Inhibition of the insulin-like growth factor system is a potential therapy for rheumatoid arthritis

Abstract Objective: We have shown that connective tissue growth factor (CTGF) plays an important role in the pathogenesis of rheumatoid arthritis (RA). Insulin-like growth factor binding proteins (IGFBPs) are modules of CTGF. IGFBPs bind IGF-I and IGF-II. IGF-I plays a role in the regulation of immunity, bone metabolism and inflammation. Therefore, we investigated how the IGF system is associated with RA disease progression. Methods: Serum samples were collected from RA patients. IGF-I and IGFBP-3 production were evaluated by enzyme-linked immunosorbent assay, real-time RT-PCR and indirect immunofluorescence microscopy. Osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase staining, a bone resorption assay and osteoclast-specific enzyme production. Angiogenesis was examined by a tube formation assay using human umbilical vein endothelial cells. Results: The serum concentrations of IGFBP-3 in RA patients were greater than those in normal controls. IGF-I and IGFBP-3 were produced primarily by macrophages in the RA synovium. Furthermore, tumor necrosis factor-α could induce aberrant IGF-I and IGFBP-3 production in synovial fibroblasts. IGF-I and IGFBP-3 promoted the induction of osteoclast generation and morphological changes, in combination with M-colony stimulating factor and the receptor activator of NF-κB ligand. In addition, IGF-I and IGFBP-3 induced angiogenesis, as determined by the tube formation assay. These effects were neutralized by anti-IGF-IR monoclonal antibody (mAb). Conclusions: These results indicate that aberrant IGF-I and IGFBP-3 production plays a role in abnormal osteoclastic activation and angiogenesis in RA. This work supports future clinical exploration of anti-IGF-IR mAb in drug repositioning as a new treatment for RA.

Inhibition of each module of connective tissue growth factor as a potential therapeutic target for rheumatoid arthritis.

Abstract We previously reported the importance of connective tissue growth factor (CTGF) in rheumatoid arthritis (RA). CTGF contains four distinct modules connected in tandem, namely insulin-like growth factor-binding protein (IGFBP)-like, von Willebrand factor (vWF) type C repeat, thrombospondin type 1 (TSP-1) repeat, and carboxyl-terminal (CT) modules. The relationships between each of these modules of CTGF and RA remain unknown. Here, we analyzed how inhibition of each CTGF module affects the pathophysiology of RA. We conducted stimulation and suppression experiments on synovial cells (MH7A) obtained from patients with RA. Moreover, we examined angiogenesis by means of a tube-formation assay performed using human umbilical vein endothelial cells (HUVECs), and we used tartrate-resistant acid phosphatase (TRAP) staining to analyze osteoclastogenesis. Our results showed that M-CSF/RANKL-mediated osteoclastogenesis was enhanced when CTGF was added, but the effect of CTGF was neutralized by mAbs against CTGF modules 1–4. Furthermore, CTGF treatment of HUVECs induced formation of tubular networks, which resulted in acceleration of the angiogenesis of RA synoviocytes, and quantification showed that this tubular-network formation was also disrupted by anti-CTGF module 1–4 mAbs. Lastly, TNF-α enhanced the expression of CTGF and matrix metalloproteinase-3 (MMP3) in MH7A cells, and this enhancement was potently neutralized by mAbs against CTGF modules 1, 3 and 4. Thus, our results indicate that not only a mAb against CTGF but also mAbs against each specific module of CTGF might serve as potential therapeutic agents in the treatment of RA.

JAK inhibitor has the amelioration effect in lupus-prone mice: the involvement of IFN signature gene downregulation

BackgroundWe previously reported that JAK–STAT-pathway mediated regulation of IFN-regulatory factor genes could play an important role in SLE pathogenesis. Here, we evaluated the efficacy of the JAK inhibitor tofacitinib (TOFA) for controlling IFN signalling via the JAK–STAT pathway and as a therapeutic for SLE.ResultsWe treated NZB/NZW F1 mice with TOFA and assessed alterations in their disease, pathological, and immunological conditions. Gene-expression results obtained from CD4+ T cells (SLE mice) and CD3+ T cells (human SLE patients) were measured by DNA microarray and qRT-PCR. TOFA treatment resulted in reduced levels of anti-dsDNA antibodies, decreased proteinuria, and amelioration of nephritis as compared with those observed in control animals. Moreover, we observed the rebalance in the populations of naïve CD4+ T cells and effector/memory cells in TOFA-treated mice; however, treatment with a combination of TOFA and dexamethasone (DEXA) elicited a stronger inhibitory effect toward the effector/memory cells than did TOFA or DEXA monotherapy. We also detected decreased expression of several IFN-signature genes Ifit3 and Isg15 in CD4+ from SLE-prone mice following TOFA and DEXA treatment, and IFIT3 in CD3+ T cells from human patients following immunosuppressant therapy including steroid, respectively.ConclusionModulation of type I IFN signalling via JAK–STAT inhibition may exert a beneficial effect in SLE patients, and our results suggest that TOFA could be utilised for the development of new SLE-specific therapeutic strategies.

Kinase inhibitors of the IGF-1R as a potential therapeutic agent for rheumatoid arthritis

Abstract We have previously shown that the inhibition of connective tissue growth factor (CTGF) is a potential therapeutic strategy against rheumatoid arthritis (RA). CTGF consists of four distinct modules, including the insulin-like growth factor binding protein (IGFBP). In serum, insulin-like growth factors (IGFs) bind IGFBPs, interact with the IGF-1 receptor (IGF-1 R), and regulate anabolic effects and bone metabolism. We investigated the correlation between IGF-1 and the pathogenesis of RA, and the inhibitory effect on osteoclastogenesis and angiogenesis of the small molecular weight kinase inhibitor of the IGF-1 R, NVP-AEW541, against pathogenesis of RA in vitro. Cell proliferation was evaluated by cell count and immunoblotting. The expression of IGF-1 and IGF-1 R was evaluated by RT-PCR. Osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase staining, a bone resorption assay, and osteoclast-specific enzyme production. Angiogenesis was evaluated by a tube formation assay using human umbilical vein endothelial cells (HUVECs). The proliferation of MH7A cells was found to be inhibited in the presence of NVP-AEW541, and the phosphorylation of extracellular signal-regulated kinase (ERK) and Akt was downregulated in MH7A cells. IGF-1 and IGF-1 R mRNA expression levels were upregulated during formation of M-colony stimulating factor (M-CSF) and receptor activator of NF-κB ligand (RANKL)-mediated osteoclast formation. Moreover, osteoclastogenesis was suppressed in the presence of NVP-AEW541. The formation of the tubular network was enhanced by IGF-1, and this effect was neutralized by NVP-ARE541. Our findings suggest that NVP-AEW541 may be utilized as a potential therapeutic agent in the treatment of RA.

A Case of Sarcoidosis with Unusual Radiographic Findings that Developed 5 Years after Silicone Augmentation Mammoplasty Complicated by Miliary Tuberculosis during Corticosteroid Treatment

A 54-year-old woman with a past history of silicone augmentation mammoplasty was admitted with fever and dyspnea with diffuse interstitial shadows on computed tomography (CT). Although radiological findings were atypical, we diagnosed sarcoidosis by laboratory, microbiological, and bronchoalveolar lavage fluid analysis. Corticosteroids ameliorated the condition, but she had recurrent of fever and CT revealed miliary nodules while interstitial shadows disappeared. Liver biopsy showed that noncaseating granuloma and Ziehl-Neelsen stain was positive. We diagnosed miliary tuberculosis which developed during corticosteroid therapy. Antituberculotic therapy resulted in favorable outcome. Possibility exists that onset of sarcoidosis was induced by mammoplasty, namely, human adjuvant disease.

Aortic Aneurysm as a Complication of Granulomatosis with Polyangiitis Successfully Treated with Prednisolone and Cyclophosphamide: A Case Report and Review of the Literature

A 57-year-old Japanese man was admitted to the hospital with back pain and fever, multiple lung nodules, and abdominal aortic aneurysm (AAA). Laboratory tests performed at admission showed an increased proteinase 3 anti-neutrophil cytoplasmic antibody (PR3-ANCA) level. Video-associated thoracoscopic lung biopsy was performed; pathologic examination showed granulation tissue with necrosis and multinucleated giant cells. The diagnosis of granulomatosis with polyangiitis (GPA) was confirmed on the basis of the clinical presentation, laboratory findings, and lung biopsy. All symptoms were ameliorated, and the serum level of PR3-ANCA declined following treatment with prednisolone and cyclophosphamide. Although the association of GPA with AAA is rare, GPA may be included among the large vessel vasculitides that can give rise to aortic aneurysm.

Connective Tissue Growth Factor Neutralization Aggravates the Psoriasis Skin Lesion: The Analysis of Psoriasis Model Mice and Patients

Background Connective tissue growth factor (CTGF) is a multifunctional cellular protein and playing a role as a central mediator in tissue remodeling and fibrosis. The physiological function of CTGF in psoriasis is unknown. Objective The purpose of this study was to investigate the function of CTGF in psoriasis using the established imiquimod (IMQ)-induced psoriasis murine model and psoriasis patients. Methods Anti-CTGF monoclonal antibody was applied to IMQ induced psoriasis mice and those skin were clinically, pathologically and immunologically analyzed. Additionally, CTGF expression was analyzes using skin samples and plasma from psoriasis patients. Results CTGF expression was observed in the dermis from both IMQ-induced psoriatic mice and psoriasis patients. CTGF inhibition using an anti-CTGF antibody slightly worsened IMQ-induced dermatitis. In addition, the increase of CTGF showed tendency to suppress the psoriatic dermatitis through inhibition of suprabasal cells proliferation and macrophage infiltration in the skin. CTGF was also detected significantly higher in plasma from psoriasis patients comparing with healthy control. Conclusion Our findings suggest that CTGF could contribute to the healing rather than the worsening of psoriasis skin lesions.

Mizoribine Synchronized Methotrexate Therapy should be Considered when Treating Rheumatoid Arthritis Patients with an Inadequate Response to Various Combination Therapies

Objective The objective of this study was to confirm the efficacy of low-dose mizoribine (MZR), an inhibitor of inosine monophosphate dehydrogenase, as part of synchronized methotrexate (MTX) therapy for rheumatoid arthritis (RA) patients with an inadequate response to various combination therapies of MTX, other synthetic disease-modifying anti-rheumatic drugs (DMARDs) and biological DMARDs. Methods Low-dose MZR was administered to 56 uncontrolled RA patients being treated with MTX and various biological DMARDs. The observation period was 12 months, and the disease activity was evaluated based on the Disease Activity Score in 28 joints (DAS28)-ESR, Simplified Disease Activity Index (SDAI) and serum MMP-3 level. Results All of the disease activity indices were significantly improved within three months, and the serum MMP-3 levels were also significantly decreased around four months after starting low-dose MZR therapy. No patients experienced any adverse effects. Conclusion The present preliminary findings suggest that low-dose MZR therapy with MTX should be considered for the treatment of RA patients with an inadequate response to various combination therapies including MTX, other synthetic DMARDs and biological DMARDs or in whom increasing the dose of MTX is difficult for reasons such as adverse effects and complications.

Development of various arrhythmias and conduction disturbances following corticosteroid therapy for systemic lupus erythematosus with antiphospholipid syndrome

A 45-year-old Chinese woman with active systemic lupus erythematosus, lupus anticoagulant positive, was admitted to our hospital. Electrocardiography on admission was normal. Though anti-Sjögren’s syndrome A (anti SS-A/Ro) antibodies were negative and ultrasound cardiographic findings were normal, she developed various arrhythmias/conduction disturbances shortly after starting corticosteroid. Nearly all were resolved with continuous corticosteroid and aspirin therapy before discharge. Vasculitis, the presence of antiphospholipid antibodies, and platelet aggregation due to corticosteroid were possible mechanisms underlying the arrhythmias/conduction disturbances.