Jun Kishi

Immunoglobulin G4-related lung disease: Clinicoradiological and pathological features

Immunoglobulin G4 (IgG4)‐related disease is a multi‐organ disorder that can include the lungs. IgG4‐related lung disease can present in various forms; the clinical, radiological and pathological features of patients with this disease have been assessed.

CXCL9 and 11 in patients with pulmonary sarcoidosis: a role of alveolar macrophages

Interferon‐inducible protein‐10 (IP‐10)/CXCL10, which is a ligand for CXC chemokine receptor 3 (CXCR3), is known to be involved in the pathogenesis of pulmonary sarcoidosis. However, the roles of monokine induced by interferon γ (Mig)/CXCL9 and interferon‐inducible T cell α chemoattractant (I‐TAC)/CXCL11, which are also CXCR3 ligands, remain unclear. Mig/CXCL9, IP‐10/CXCL10 and I‐TAC/CXCL11 in both bronchoalveolar lavage fluid (BALF) and serum in patients with pulmonary sarcoidosis were measured by enzyme‐linked immunosorbent assay (ELISA). The expression of these chemokines in alveolar macrophages was examined using ELISA, quantitative real‐time polymerase chain reaction and immunostaining. In BALF, Mig/CXCL9 and IP‐10/CXCL10 were significantly elevated in stage II sarcoidosis as compared with the levels in healthy volunteers. In serum, Mig/CXCL9 and I‐TAC/CXCL11 were increased in stage II of the disease. The levels of all CXCR3 ligands in BALF were correlated with the numbers of both total and CD4+ lymphocytes. Alveolar macrophages were stained positive for all CXCR3 ligands and produced increased amounts of these chemokines. Positive staining of the three chemokines was also observed in the epithelioid and giant cells in the sarcoid lungs. These findings suggest that Mig/CXCL9 and I‐TAC/CXCL11 as well as IP‐10/CXCL10 play important roles in the accumulation of Th1 lymphocytes in sarcoid lungs.

Role of Platelet-Derived Growth Factor/Platelet-Derived Growth Factor Receptor Axis in the Trafficking of Circulating Fibrocytes in Pulmonary Fibrosis

Circulating fibrocytes have been reported to migrate into the injured lungs, and contribute to fibrogenesis via CXCL12-CXCR4 axis. In contrast, we report that imatinib mesylate prevented bleomycin (BLM)-induced pulmonary fibrosis in mice by inhibiting platelet-derived growth factor receptor (PDGFR), even when it was administered only in the early phase. The goal of this study was to test the hypothesis that platelet-derived growth factor (PDGF) might directly contribute to the migration of fibrocytes to the injured lungs. PDGFR expression in fibrocytes was examined by flow cytometry and RT-PCR. The migration of fibrocytes was evaluated by using a chemotaxis assay for human fibrocytes isolated from peripheral blood. The numbers of fibrocytes triple-stained for CD45, collagen-1, and CXCR4 were also examined in lung digests of BLM-treated mice. PDGFR mRNA levels in fibrocytes isolated from patients with idiopathic pulmonary fibrosis were investigated by real-time PCR. Fibrocytes expressed both PDGFR-α and -β, and migrated in response to PDGFs. PDGFR inhibitors (imatinib, PDGFR-blocking antibodies) suppressed fibrocyte migration in vitro, and reduced the number of fibrocytes in the lungs of BLM-treated mice. PDGF-BB was a stronger chemoattractant than the other PDGFs in vitro, and anti-PDGFR-β-blocking antibody decreased the numbers of fibrocytes in the lungs compared with anti-PDGFR-α antibody in vivo. Marked expression of PDGFR-β was observed in fibrocytes from patients with idiopathic pulmonary fibrosis compared with healthy subjects. These results suggest that PDGF directly functions as a strong chemoattractant for fibrocytes. In particular, the PDGF-BB-PDGFR-β biological axis might play a critical role in fibrocyte migration into the fibrotic lungs.

Expression of Soluble Vascular Endothelial Growth Factor Receptor-1 in Human Monocyte-Derived Mature Dendritic Cells Contributes to Their Antiangiogenic Property

The soluble form of vascular endothelial growth factor receptor-1 (sVEGFR-1) is produced from endothelial cells by alternative splicing of VEGFR-1 mRNA, and can inhibit angiogenesis by blocking the biological effects of VEGF. In this study, we show the expression of a large amount of sVEGFR-1 in human monocyte-derived mature dendritic cells (mDCs). As compared with monocytes and immature DCs, mDCs generated by TNF-α or soluble CD40L with IFN-γ, but not LPS or other stimuli, preferentially produce sVEGFR-1. We also detected the mRNA of sVEGFR-1 generated by alternative splicing of VEGFR-1 mRNA in mDCs induced by TNF-α. The production of sVEGFR-1 showed a distinct contrast to those of VEGF in each DC matured with various stimuli. The supernatant of DCs matured with TNF-α or soluble CD40L with IFN-γ showed inhibition of the tube formation of HUVECs, which was neutralized by anti-VEGFR-1 Ab, indicating that sVEGFR-1 secreted from mDCs was biologically active. Interestingly, the supernatant of mDCs generated with LPS increased HUVEC capillary-like formation in vitro. The ratio of sVEGFR-1 to VEGF clearly reflected the net angiogenic property of mDCs. Administration of mDCs induced by TNF-α into the s.c. tumor of PC-14 cells implanted in SCID mice demonstrated the inhibition of tumor growth via reduction of the number of CD31-positive vessels, indicating their in vivo antiangiogenic potential. These results suggest that sVEGFR-1 produced by mDCs contribute to their antiangiogenic property, and the ratio of sVEGFR-1 to VEGF might be a useful tool for evaluating their ability to regulate angiogenesis mediated by VEGF.

Antifibrotic Effects of Focal Adhesion Kinase Inhibitor in Bleomycin-Induced Pulmonary Fibrosis in Mice

Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase involved in various biological functions, including cell survival, proliferation, migration, and adhesion. FAK is an essential factor for transforming growth factor β to induce myofibroblast differentiation. In the present study, we investigated whether the targeted inhibition of FAK by using a specific inhibitor, TAE226, has the potential to regulate pulmonary fibrosis. TAE226 showed inhibitory activity of autophosphorylation of FAK at tyrosine 397 in lung fibroblasts. The addition of TAE226 inhibited the proliferation of lung fibroblasts in response to various growth factors, including platelet-derived growth factor and insulin-like growth factor I, in vitro. TAE226 strongly suppressed the production of type I collagen by lung fibroblasts. Furthermore, treatment of fibroblasts with TAE226 reduced the expression of α-smooth muscle actin induced by transforming growth factor β, indicating the inhibition of differentiation of fibroblasts to myofibroblasts. Administration of TAE226 ameliorated the pulmonary fibrosis induced by bleomycin in mice even when used late in the treatment. The number of proliferating mesenchymal cells was reduced in the lungs of TAE226-treated mice. These data suggest that FAK signal plays a significant role in the progression of pulmonary fibrosis and that it can become a promising target for therapeutic approaches to pulmonary fibrosis.

Thymidine Phosphorylase Regulates the Expression of CXCL10 in Rheumatoid Arthritis Fibroblast‐like Synoviocytes

Thymidine phosphorylase (TP) in rheumatoid arthritis (RA) fibroblast‐like synoviocytes (FLS) is induced by tumor necrosis factor α (TNFα) and other cytokines that have been reported to be major inflammation mediators in RA. We previously demonstrated that TP plays an important role in angiogenesis and tumor growth, invasion, and metastasis. The aim of this study was to investigate whether the role of TP in the pathogenesis of RA is similar to its role in tumors.

Clinical features and outcome of acute exacerbation of interstitial pneumonia associated with connective tissue disease.

Acute exacerbation (AE) of interstitial lung disease is reported to be developed in not only idiopathic pulmonary fibrosis but also connective tissue disease-associated interstitial pneumonia (CTD-IP). As the significance of AE of CTD-IP has not been so widely recognized, its clinical feature is not fully elucidated. In the present study, we investigated the incidence, clinical features and outcome of AE of CTD-IP. We retrospectively reviewed admitted cases in our department with medical record from 2011 to 2015. Among 155 patients with CTD-IP, 10 (6.5%) cases developed AE (6 rheumatoid arthritis, 2 polymyositis/dermatomyositis, 1 systemic lupus erythematosus, 1 Sjögren syndrome), and one died of AE within 30 days. Median survival time after the onset of AE was 169 days in all 10 patients. The treatment with immunosuppressant just before AE onset might improve the prognosis of AE. The median survival time after the onset of AE was significantly longer in patients showing good response to corticosteroid compared with those with poor response to corticosteroid (805 days and 45 days, respectively) (p <0.05), suggesting that there are some cases in CTD-IP, showing the good response to corticosteroid even when AE was complicated. J. Med. Invest. 63: 294-299, August, 2016.

A case of interstitial pneumonia associated with anti‐PL‐7 antibody in a patient with rheumatoid arthritis

A 65-year-old female had been treated rheumatoid arthritis (RA), interstitial pneumonia (IP) and nephrotic syndrome with prednisolone and cyclosporine. She was emergently admitted to our hospital due to the worsening exertional dyspnea and severe hypoxemia. Chest computed tomography (CT) showed new diffuse ground-glass opacities (GGOs) with slight consolidations along with bronchovascular bundle were observed in addition to pre-existing reticular shadows in both lungs with lower lobe-predominance. An acute exacerbation (AE) of pre-existing IP triggered by an infection was suspected, and the treatment with antibiotics and corticosteroid pulse therapy improved her general condition and chest radiological findings. Because some auto-antibodies associated with acute/subacute onset IP have recently become available in clinic, we examined those including anti-aminoacyl tRNA synthetase (ARS) antibodies, and found that she was positive for anti-PL-7 antibody. We diagnosed her anti-synthetase syndrome (ASS) without symptom of myositis, and her IP was considered to be ASS-related. The careful consideration is necessary to precisely diagnose and treat the patients with RA-associated interstitial lung diseases as the several etiologies may be overlapped in the same patient. J. Med. Invest. 65:147-150, February, 2018.