Hideki Yasui

Surface-retained tPA is essential for effective fibrinolysis on vascular endothelial cells

In a previous study, we demonstrated unique secretory dynamics of tissue plasminogen activator (tPA) in which tPA was retained on the cell surface in a heavy chain-dependent manner after exocytosis from secretory granules in vascular endothelial cells. Here, we examined how retained tPA expresses its enzymatic activity. Retained tPA effectively increased the lysine binding site-dependent binding of plasminogen on the cell surface and pericellular area; this was abolished by inhibition of enzymatic activity of either tPA or plasmin, which suggests that de novo generation of carboxyl-terminal lysine as a consequence of degradation of surface/pericellular proteins by plasmin is essential. Retained tPA initiated zonal clot lysis of a fibrin network that had been formed on vascular endothelial cells, which was preceded by the binding of plasminogen to the lysis front. Our results provide evidence that secreted and retained tPA is essential for maintaining both high fibrinolytic activity and effective clot lysis on the vascular endothelial cell surface.

Early coagulation events induce acute lung injury in a rat model of blunt traumatic brain injury.

Acute lung injury (ALI) and systemic coagulopathy are serious complications of traumatic brain injury (TBI) that frequently lead to poor clinical outcomes. Although the release of tissue factor (TF), a potent initiator of the extrinsic pathway of coagulation, from the injured brain is thought to play a key role in coagulopathy after TBI, its function in ALI following TBI remains unclear. In this study, we investigated whether the systemic appearance of TF correlated with the ensuing coagulopathy that follows TBI in ALI using an anesthetized rat blunt trauma TBI model. Blood and lung samples were obtained after TBI. Compared with controls, pulmonary edema and increased pulmonary permeability were observed as early as 5 min after TBI without evidence of norepinephrine involvement. Systemic TF increased at 5 min and then diminished 60 min after TBI. Lung injury and alveolar hemorrhaging were also observed as early as 5 min after TBI. A biphasic elevation of TF was observed in the lungs after TBI, and TF-positive microparticles (MPs) were detected in the alveolar spaces. Fibrin(ogen) deposition was also observed in the lungs within 60 min after TBI. Additionally, preadministration of a direct thrombin inhibitor, Refludan, attenuated lung injuries, thus implicating thrombin as a direct participant in ALI after TBI. The results from this study demonstrated that enhanced systemic TF may be an initiator of coagulation activation that contributes to ALI after TBI.

TM5275 prolongs secreted tissue plasminogen activator retention and enhances fibrinolysis on vascular endothelial cells

INTRODUCTION Elevated plasminogen activator inhibitor-1 (PAI-1) reduces fibrinolytic potential in plasma, contributing to thrombotic disease. Thus, inhibiting PAI-1 activity is clinically desirable. We recently demonstrated that tissue plasminogen activator (tPA) remains on the surface of vascular endothelial cells (VECs) after secretion in a heavy-chain dependent manner, which is essential for high fibrinolytic activity on the surface of VECs, and that PAI-1 dissociates retained tPA from the cell surface as a result of high-molecular weight complex formation. Based on the model whereby amounts of tPA and its equilibrium with PAI-1 dynamically change after exocytosis, we examined how TM5275, a newly synthesized small molecule PAI-1 inhibitor, modulated tPA retention and VEC surface-derived fibrinolytic activity using microscopic techniques. MATERIALS AND METHODS The effects of TM5275 on the kinetics of the secretion and retention of green fluorescent protein (GFP)-tagged tPA (tPA-GFP) on VECs were analyzed using total internal reflection fluorescence microscopy. The effects of TM5275 on the generation of plasmin activity were evaluated by both plasminogen accumulation and fibrin clot lysis on tPA-GFP-expressing VECs using confocal laser scanning microscopy. RESULTS TM5275 at concentrations of 20 and 100 μM significantly prolonged the retention of tPA-GFP on VECs by inhibiting tPA-GFP-PAI-1 high-molecular-weight complex formation. TM5275 enhanced the time-dependent accumulation of plasminogen as well as the dissolution of fibrin clots on and around the tPA-GFP-expressing cells. CONCLUSIONS The profibrinolytic effects of TM5275 were clearly demonstrated by the prolongation of tPA retention and enhancement of plasmin generation on the VEC surface as a result of PAI-1 inhibition.

Effect of Switching from Salmeterol Fluticasone to Formoterol Budesonide Combinations in Patients with Uncontrolled Asthma

BACKGROUND Combination therapy with an inhaled corticosteroid (ICS) and a long-acting β(2)-agonist (LABA) in a single inhaler is the mainstay of asthma management and salmeterol/fluticasone combination (SFC) and fixed-dose formoterol/budesonide combination (FBC) are currently available in Japan; however, there is nothing to choose between the two. The purpose of this study was to clarify the effect of switching from SFC to FBC in patients with asthma not adequately controlled under the former treatment regimen. METHODS This was a prospective, multicenter, open-label, uncontrolled longitudinal study in 87 adult patients with an Asthma Control Questionnaire, 5-item version (ACQ5) score of greater than 0.75 under treatment with SFC 50/250μg one inhalation twice daily (bid). SFC was switched to FBC 4.5/160μg two inhalations bid. Study outcomes included ACQ5 score, peak expiratory flow (PEF), FEV(1), and fractional exhaled nitric oxide (FeNO) at the end of treatment period. RESULTS Eighty-three patients completed the study. ACQ5 scores improved and exceeded the clinically meaningful difference after 12 weeks of treatment and well-controlled asthma (ACQ5 score ≤0.75) was attained in 37 (44.6%) patients. Minimum and maximum PEF and FEV(1) values improved significantly, but not FeNO values, after switching from SFC to FBC. CONCLUSIONS Switching ICS/LABA combination therapy is a useful option in the management of asthma that is not optimally controlled.

Effects of indacaterol versus tiotropium on respiratory mechanics assessed by the forced oscillation technique in patients with chronic obstructive pulmonary disease.

The forced oscillation technique (FOT) can measure respiratory mechanics and has attracted attention in chronic obstructive pulmonary disease (COPD). We aimed to evaluate the effects of only indacaterol and tiotropium monotherapies on airflow limitation and respiratory impedance. Pulmonary function tests, COPD assessment test (CAT), and multifrequency FOT with MostGraph-01 were performed at the beginning and after 8 weeks of treatment with indacaterol or tiotropium. The resistance index, resistance at 5 Hz (R5), resistance at 20 Hz (R20), reactance index, reactance at 5 Hz (X5), resonant frequency (Fres), and low-frequency reactance area (ALX) were determined at whole-breath, inspiratory, and expiratory phases. Eighty-two patients (mean age: 73 years; mean forced expiratory volume in 1 second (FEV1): 61.6%±19.0% predicted) were randomized to indacaterol or tiotropium treatment. Both bronchodilators improved airflow limitation, with mean trough improvements in FEV1 of 165 mL and 80 mL in the indacaterol and tiotropium groups, respectively. The CAT score decreased in the indacaterol group (P<0.001; 11.2±6.6 to 7.5±5.6). Compared with tiotropium, indacaterol significantly improved FEV1, percent predicted FEV1, and CAT score (P=0.042, P=0.008, and P=0.027, respectively). For respiratory impedance, indacaterol and tiotropium changed R5, X5, Fres, and ALX at whole-breath, inspiratory, and expiratory phases. In the indacaterol group, the changes in R5, R5–R20, X5, Fres, and ALX were significantly correlated with the changes in FEV1. The use of the FOT may enable the evaluation of the effects of bronchodilators in addition to FEV1-indicated therapeutic effects in COPD.

A severe case of acute exogenous lipoid pneumonia treated with systemic corticosteroid

Acute exogenous lipoid pneumonia is a rare disorder in adults. A treatment of choice for lipoid pneumonia has not been established, and systemic corticosteroid use remains controversial. We report the case of a 32-year-old man with schizophrenia who presented with kerosene-induced acute exogenous lipoid pneumonia that was treated with a systemic corticosteroid. In this case, supportive therapy did not improve the patients condition, so systemic corticosteroid therapy was commenced four days after he ingested the kerosene. After corticosteroid commencement, the patients symptoms and hypoxia improved within a few days. Although some radiological characteristics of this disorder have been reported previously, the process of radiological improvement of exogenous lipoid pneumonia is not well known. In this case, computed tomography findings changed dramatically after corticosteroid therapy was initiated. Extensive bilateral consolidations that were observed on admission improved. Although pneumatoceles developed two weeks after corticosteroid commencement, they were nearly gone after two months of the treatment. While corticosteroid therapy is not suitable for all cases, it should be considered for severe or refractory cases.

A case of spontaneous regression of pulmonary mucosa-associated lymphoid tissue (MALT) type lymphoma with Sjögren's syndrome treated with methotrexate for rheumatoid arthritis

A 72-year-old man who had suffered from rheumatoid arthritis (RA) and Sjögrens syndrome (Sjs) since he was 66 years of age had been treated with methotrexate (MTX) for six years. He presented with a cough, sputum and dyspnea on exertion, and computed tomography findings showed multiple ground-glass opacities in both of his lungs. A biopsy of the lungs revealed low-grade mucosa-associated lymphoid tissue (MALT) type B-cell non-Hodgkins lymphoma. Spontaneous complete remission of the lymphoma was achieved six months after withdrawing immune suppression with MTX. To our knowledge, no previous cases of spontaneous regression of pulmonary MALT-type lymphoma with Sjs treated with MTX for RA have been reported. Patients on MTX who are being treated for RA should be carefully monitored, especially when they have been diagnosed with coexistent Sjs.

An Acquired Epidermal Growth Factor Receptor T790M Mutation after the Addition of Bevacizumab to Preceding Erlotinib Monotherapy in a Lung Cancer Patient with Leptomeningeal Metastases

A 53-year-old man with advanced lung adenocarcinoma harboring epidermal growth factor receptor (EGFR) exon 19 deletion received erlotinib. After 12 months of disease control with erlotinib monotherapy, leptomeningeal metastases (LM) occurred. A cerebrospinal fluid examination demonstrated a pre-existing EGFR exon 19 deletion. Bevacizumab was combined with erlotinib, and the LM improved. After six months of combination therapy, however, the LM was exacerbated. A re-examination of the cerebrospinal fluid revealed a T790M mutation and exon 19 deletion. Osimertinib was administered, and the LM improved. The combination of bevacizumab and erlotinib was effective for erlotinib-resistant LM and resulted in the expression of a newly acquired T790M mutation, which enabled successful treatment with osimertinib.

Macrophage mannose receptor, CD206, predict prognosis in patients with pulmonary tuberculosis

Tuberculosis (TB) remains a leading cause of fatal infectious disease. Accumulations of macrophages are found in infected sites; thus, we hypothesized that a marker of activated macrophages may be related to prognosis of pulmonary TB (PTB). This study investigated serum soluble macrophage mannose receptor, sCD206, in PTB and examined its clinical significance. First, the concentration of sCD206 was measured in the sera of 96 patients with PTB (Tenryu cohort), and in pleural effusions from 29 patients with TB pleurisy. These were verified in another independent cohort (Shizuoka cohort). We found increased concentrations of sCD206 in sera, but not in pleural effusions of PTB patients. Notably, PTB patients with poor prognosis showed significantly higher levels of serum sCD206. At a cut-off value of 1,600 ng/mL in the Tenryu cohort, sCD206 predicted prognosis of PTB with area under the curve 0.847, sensitivity 77.3%, and specificity 86.5%. These results were validated in the Shizuoka cohort. Pathological analyses showed concordance of enhanced CD206 expression in lung and pleural tissues with caseating granuloma in TB. Serum sCD206 increased in PTB and was associated with prognosis. sCD206 is a potential biomarker for PTB.

Distinct profile and prognostic impact of body composition changes in idiopathic pulmonary fibrosis and idiopathic pleuroparenchymal fibroelastosis

Change in body composition with skeletal muscle wasting, a major component of pulmonary cachexia, is associated with mortality in chronic obstructive pulmonary disease and cancer. However, its relevance in interstitial lung diseases (ILDs) remains unclear. We hypothesized changes in body composition would be associated with mortality in ILDs. We measured the cross-sectional-area (ESMCSA) and muscle attenuation (ESMMA) of erector-spinae muscles, as determined by CT-imaging, in patients with idiopathic pulmonary fibrosis (IPF; n = 131) and idiopathic pleuroparenchymal fibroelastosis (iPPFE; n = 43) and controls. Subsequently, implications with prognosis were evaluated. The ESMCSA of ILD patients, but not ESMMA, was significantly smaller than that in controls. Lower ESMCSA with decreased BMI were recorded in iPPFE patients versus IPF patients, whilst IPF patients had decreased ESMCSA without BMI decline. Lower ESMCSA in IPF patients were associated with poorer prognoses. Conversely, decreased ESMMA were associated with worse survival in iPPFE patients. Multivariate analyses showed that ESMCSA in IPF and ESMMA in iPPFE were independent risk factors for mortality. Distinct changes in body composition had prognostic significance among patients with IPF and iPPFE. Lower ESMCSA and ESMMA were independently associated with poor prognosis in IPF and iPPFE, respectively. These results suggest values to measure body composition changes in managing patients with IPF and iPPFE.