Rictor-targeting exosomal microRNA-16 ameliorates lung fibrosis by inhibiting the mTORC2-SPARC axis.

Idiopathic pulmonary fibrosis (IPF), a progressive disorder of unknown etiology, is characterized by pathological lung fibroblast activation and proliferation resulting in abnormal deposition of extracellular matrix proteins within the lung parenchyma. The pathophysiological roles of exosomal microRNAs in pulmonary fibrosis remain unclear; therefore, we aimed to identify and characterize fibrosis-responsive exosomal microRNAs. We used microRNA array analysis and profiled the expression of exosome-derived miRNA in sera of C57BL/6 mice exhibiting bleomycin-induced pulmonary fibrosis. The effect of microRNAs potentially involved in fibrosis was then evaluated in vivo and in vitro. The expression of exosomal microRNA-16 was increased by up to 8.0-fold on day 14 in bleomycin-treated mice, compared to vehicle-treated mice. MicroRNA-16 mimic administration on day 14 after bleomycin challenge ameliorated pulmonary fibrosis and suppressed lung and serum expression of secreted protein acidic and rich in cysteine (SPARC). Pretreatment of human lung fibroblasts with the microRNA-16 mimic decreased the expression of rapamycin-insensitive companion of mTOR (Rictor) and TGF-ß1-induced expression of SPARC. This is the first study reporting the anti-fibrotic properties of microRNA-16 and demonstrating that these effects occur via the mTORC2 pathway. These findings support that microRNA-16 may be a promising therapeutic target for IPF.

Resolution of bleomycin-induced murine pulmonary fibrosis via a splenic lymphocyte subpopulation.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive disease with high mortality, and the pathogenesis of the disease is still incompletely understood. Although lymphocytes, especially CD4+CD25+FoxP3+ regulatory T cells (Tregs), have been implicated in the development of IPF, contradictory results have been reported regarding the contribution of Tregs to fibrosis both in animals and humans. The aim of this study was to investigate whether a specific T cell subset has therapeutic potential in inhibiting bleomycin (BLM)-induced murine pulmonary fibrosis. METHODS: C57BL/6 mice received BLM (100 mg/kg body weight) with osmotic pumps (day 0), and pulmonary fibrosis was induced. Then, splenocytes or Tregs were adoptively transferred via the tail vein. The lungs were removed and subjected to histological and biochemical examinations to study the effects of these cells on pulmonary fibrosis, and blood samples were collected by cardiac punctures to measure relevant cytokines by enzyme-linked immunosorbent assay. Tregs isolated from an interleukin (IL)-10 knock-out mice were used to assess the effect of this mediator. To determine the roles of the spleen in this model, spleen vessels were carefully cauterized and the spleen was removed either on day 0 or 14 after BLM challenge. RESULTS: Splenocytes significantly ameliorated BLM-induced pulmonary fibrosis when they were administered on day 14. This effect was abrogated by depleting Tregs with an anti-CD25 monoclonal antibody. Adoptive transfer of Tregs on day 14 after a BLM challenge significantly attenuated pulmonary fibrosis, and this was accompanied by decreased production of fibroblast growth factor (FGF) 9-positive cells bearing the morphology of alveolar epithelial cells. In addition, BLM-induced plasma IL-10 expression reverted to basal levels after adoptive transfer of Tregs. Moreover, BLM-induced fibrocyte chemoattractant chemokine (CC motif) ligand-2 production was significantly ameliorated by Treg adoptive transfer in lung homogenates, accompanied by reduced accumulation of bone-marrow derived fibrocytes. Genetic ablation of IL-10 abrogated the ameliorating effect of Tregs on pulmonary fibrosis. Finally, splenectomy on day 0 after a BLM challenge significantly ameliorated lung fibrosis, whereas splenectomy on day 14 had no effect. CONCLUSIONS: These findings warrant further investigations to develop a cell-based therapy using Tregs for treating IPF.

XPLN is modulated by HDAC inhibitors and negatively regulates SPARC expression by targeting mTORC2 in human lung fibroblasts.

Pathogenesis of idiopathic pulmonary fibrosis (IPF) remains unclear. Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein that participates in the assembly and turnover of the extracellular matrix, whose expression is regulated by transforming growth factor (TGF)-ß1 through activation of mammalian target of rapamycin complex 2 (mTORC2). Exchange factor found in platelets, leukemic, and neuronal tissues (XPLN) is an endogenous inhibitor of mTORC2. However, whether XPLN modulates SPARC expression remains unknown. Herein, we investigated the regulatory mechanisms of XPLN in human lung fibroblasts. Effect of XPLN on mTORC2 activity was evaluated by silencing XPLN in human foetal lung fibroblasts (HFL-1 cells), using small interfering RNA. SPARC expression was quantified by quantitative real-time RT-PCR and western blotting. Fibroblasts were treated with TGF-ß1, histone deacetylase (HDAC) inhibitors, entinostat, or vorinostat, to assess their effects on XPLN expression. Moreover, the effect of mTORC1 inhibition on SPARC and XPLN was examined. XPLN depletion stimulated SPARC expression and Akt phosphorylation on Ser473. TGF-ß1 treatment down-regulated XPLN via Smad 2/3. XPLN mRNA expression was up-regulated upon treatment with HDAC inhibitors in a concentration-dependent manner, and TGF-ß1-induced SPARC expression was reversed by entinostat treatment. mTORC1 inhibition by rapamycin and Raptor depletion stimulated SPARC expression. In conclusion, this is the first study describing the involvement of XPLN in the regulation of SPARC. These findings may help uncover the regulatory mechanisms of the mTORC2-SPARC axis. The up-regulation of XPLN by HDAC inhibitors may be a novel therapeutic approach in patients with IPF.

Pirfenidone exerts a suppressive effect on CCL18 expression in U937-derived macrophages partly by inhibiting STAT6 phosphorylation.

CONTEXT: CC chemokine ligand 18 (CCL18) is suggested to play a role in the development of pulmonary fibrosis. Macrophages are thought to be the main source of CCL18, and the effect of pirfenidone, an anti-fibrotic agent for idiopathic pulmonary fibrosis, on the expression of CCL18 in macrophages warrants investigation. OBJECTIVE: The purpose of this study was to investigate the effect of pirfenidone on the expression of CCL18 in macrophages. MATERIALS AND METHODS: U937 cells were differentiated into macrophages by phorbol myristate acetate and then stimulated with recombinant IL-4 to induce the production of CCL18. The cells were treated with pirfenidone, and the mRNA and protein levels for CCL18 were measured by a reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The effects of pirfenidone on the IL-4 receptor (IL-4R) expression and STAT6 activation were investigated and on the JAK kinase activity were measured using the Z'-LYTE™ kinase assay. RESULTS: Pirfenidone significantly suppressed the expression of CCL18 when the cells were treated with concentrations of 50-250 µg/mL. Pirfenidone did not affect the expression of the IL-4R components. The selective STAT6 inhibitor AS1517499 suppressed CCL18 expression. Both AS1517499 and pirfenidone suppressed STAT6 phosphorylation (p < .05), although the effect of pirfenidone was less marked than that of AS1517499. The Z'-LYTE™ kinase assay showed a reduction in the activities of JAK1, JAK3 and TYK2 by pirfenidone. CONCLUSION: Pirfenidone suppresses CCL18 expression in macrophages and this effect is thought to be attributed partly to the inhibition of STAT6 phosphorylation.

Nintedanib modulates surfactant protein-D expression in A549 human lung epithelial cells via the c-Jun N-terminal kinase-activator protein-1 pathway.

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with a high mortality rate. Signalling pathways activated by several tyrosine kinase receptors are known to be involved in lung fibrosis, and this knowledge has led to the development of the triple tyrosine kinase inhibitor nintedanib, an inhibitor of vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and fibroblast growth factor receptor (FGFR), for the treatment of IPF. Pulmonary surfactant protein D (SP-D), an important biomarker of IPF, reportedly attenuates bleomycin-induced pulmonary fibrosis in mice. In this study, we investigated whether nintedanib modulates SP-D expression in human lung epithelial (A549) cells using quantitative real-time reverse transcriptase polymerase chain reaction and western blotting. To investigate the mechanisms underlying the effects of nintedanib, we evaluated the phosphorylation of c-Jun N-terminal kinase (JNK) and its downstream target c-Jun. The effect of the JNK inhibitor SP600125 on c-Jun phosphorylation was also tested. Activation of activator protein-1 (AP-1) was examined using an enzyme-linked immunosorbent assay-based test, and cell proliferation assays were performed to estimate the effect of nintedanib on cell proliferation. Furthermore, we treated mice with nintedanib to examine its in vivo effect on SP-D levels in lungs. These experiments showed that nintedanib up-regulated SP-D messenger RNA expression in a dose-dependent manner at concentrations up to 5 µM, with significant SP-D induction observed at concentrations of 3 µM and 5 µM, in comparison with that observed in vehicle controls. Nintedanib stimulated a rapid increase in phosphorylated JNK in A549 cells within 30 min of treatment and stimulated c-Jun phosphorylation, which was inhibited by the JNK inhibitor SP600125. Additionally, nintedanib was found to activate AP-1. A549 cell proliferation was not affected by nintedanib at any of the tested concentrations. Moreover, blocking FGFR, PDGFR, and VEGFR function did not affect nintedanib-induced SP-D expression, suggesting that nintedanib mediates its effects through a mechanism that is distinct from its known role as a tyrosine kinase inhibitor. Nintedanib is also reported to inhibit Src kinase although pre-treatment of cells with a Src kinase inhibitor had no effect on nintedanib-induced SP-D expression. Increased expression of SFTPD mRNA and SP-D protein in the lungs of nintedanib-treated mice was also observed. In this work, we demonstrated that nintedanib up-regulated SP-D expression in A549 cells via the JNK-AP-1 pathway and did not affect cell proliferation. This is the first report describing SP-D induction by nintedanib.

Diagnostic Values For Club Cell Secretory Protein (CC16) in Serum of Patients of Combined Pulmonary Fibrosis and Emphysema.

Combined pulmonary fibrosis and emphysema (CPFE) is an under-recognized syndrome for which the diagnostic use of serum biomarkers is an attractive possibility. We hypothesized that CC16 and/or TGF-ß1 or combinations with other biomarkers are useful for diagnosing CPFE. Patients with respiratory symptoms and a smoking history, with or without chronic obstructive pulmonary disease, were divided into the following three groups according to findings of high-resolution computed tomography of the chest: controls without either emphysema or fibrosis, patients with emphysema alone, and patients compatible with the diagnosis of CPFE. Serum concentrations of CC16, TGF-ß1, SP-D, and KL-6 were measured in patients whose condition was stable for at least 3 months. To investigate changes in biomarkers of lung fibrosis in patients with a life-long smoking history, additional measurements were performed on the patients with idiopathic pulmonary fibrosis (IPF) of smoking history. The mean age of the first three groups was 68.0 years, whereas that of the IPF group was 71.8 years, and the groups contained 36, 115, 27, and 10 individuals, respectively. The serum concentration of CC16 in the four groups was 5.67 ± 0.42, 5.66 ± 0.35, 9.38 ± 1.04 and 22.15 ± 4.64 ng/ml, respectively, indicating that those patients with lung fibrosis had a significantly higher concentration. The combined use of CC16, SP-D, and KL-6 provided supportive diagnosis in conjunction with radiological imaging in diagnosis of CPFE. We conclude that a combination of biomarkers including CC16 could provide useful information to screen and predict the possible diagnosis of CPFE.

Pirfenidone inhibits fibrocyte accumulation in the lungs in bleomycin-induced murine pulmonary fibrosis.

BACKGROUND: Bone marrow-derived fibrocytes reportedly play important roles in the pathogenesis of idiopathic pulmonary fibrosis. Pirfenidone is an anti-fibrotic agent; however, its effects on fibrocytes have not been investigated. The aim of this study was to investigate whether pirfenidone inhibits fibrocyte pool size in the lungs of bleomycin-treated mice. METHODS: Bleomycin (100 mg/kg) was infused with osmotic pumps into C57BL/6 mice, and pirfenidone (300 mg/kg/day) was orally administered daily for 2 wk. The lungs were removed, and single-cell suspensions were subjected to fluorescence-activated cell sorter (FACS) analysis to detect fibrocytes, which were defined as CD45 and collagen-I double-positive cells. Immunohistochemistry was performed on the lung specimens to quantify fibrocytes. Chemokines in the lung digests were measured with enzyme-linked immunosorbent assay. The effect of pirfenidone on alveolar macrophages was evaluated with bronchoalveolar lavage (BAL). In a therapeutic setting, pirfenidone administration was initiated 10 days after bleomycin treatment. For chemotaxis assay, lung fibrocytes were isolated with immunomagnetic selection (CD45-positive mesenchymal cells) after culture and allowed to migrate toward chemokines in the presence or absence of pirfenidone. Moreover, the effect of pirfenidone on the expression of chemokine receptors on fibrocytes was evaluated. RESULTS: Pirfenidone significantly ameliorated bleomycin-induced pulmonary fibrosis as assessed with quantitative histology and collagen measurement. Fibrocyte pool size in bleomycin-treated mice lungs was attenuated from 26.5% to 13.7% by pirfenidone on FACS analysis. This outcome was also observed in a therapeutic setting. Immunohistochemistry revealed that fibrocytes were significantly decreased by pirfenidone administration compared with those in bleomycin-treated mice (P = 0.0097). Increased chemokine (CC motif) ligand-2 (CCL2) and CCL12 production in bleomycin-treated mouse lungs was significantly attenuated by pirfenidone (P = 0.0003 and P < 0.0001, respectively). Pirfenidone also attenuated macrophage counts stimulated by bleomycin in BAL fluid. Fibrocyte migration toward CCL2 and chemokine (CC motif) receptor-2 expression on fibrocytes was significantly inhibited by pirfenidone in vitro. CONCLUSIONS: Pirfenidone attenuated the fibrocyte pool size in bleomycin-treated mouse lungs via attenuation of CCL2 and CCL12 production in vivo, and fibrocyte migration was inhibited by pirfenidone in vitro. Fibrocyte inhibition is considered a mechanism of anti-fibrotic action of pirfenidone.

Association of group component genetic variations in COPD and COPD exacerbation in a Japanese population.

BACKGROUND AND OBJECTIVE: Vitamin D supplementation can decrease the vulnerability to pulmonary infections. Therefore, it is speculated that the genes related to vitamin D metabolism are associated with an exacerbation-prone phenotype in chronic obstructive pulmonary disease (COPD). Because genetic variations of group component (GC) affect immunological capacity and serum vitamin D concentration, they could also affect the susceptibility to COPD exacerbation and the disease progression. We investigated the association between GC genetic variations and COPD and its exacerbation frequency in a Japanese population. METHODS: We performed genotype analysis of 361 COPD patients and 219 controls to identify two coding single nucleotide polymorphisms of GC, rs4588 and rs7041. We examined whether these polymorphisms were associated with the frequency of COPD exacerbation and analysed the correlation between the genotypes, COPD, emphysema severity and COPD progression, namely, the annual decline in airflow obstruction and diffusing capacity. RESULTS: Subjects with a C allele at rs4588 exhibited a higher frequency of exacerbations (P = 0.0048), greater susceptibility to chronic obstructive pulmonary disease (P = 0.0003), and emphysema (P = 0.0029), and a tendency for rapid decline of airflow obstruction (P = 0.0927). CONCLUSIONS: GC variations may affect exacerbation susceptibility, possibly leading to COPD worsening and its progression.

Double-blind controlled trial of lecithinized superoxide dismutase in patients with idiopathic interstitial pneumonia - short term evaluation of safety and tolerability.

BACKGROUND: Idiopathic interstitial pneumonias such as idiopathic pulmonary fibrosis or fibrotic nonspecific interstitial pneumonia are irreversible progressive pulmonary diseases that often have fatal outcomes. Although the etiology of idiopathic interstitial pneumonias is not yet fully understood, anti-fibrotic and anti-inflammatory agents have shown limited therapeutic effectiveness. Reactive oxygen species and their cytotoxic effects on the lung epithelial cells have been reported to participate in the pathophysiology of the disease. Because superoxide dismutase catalyzes the detoxification of reactive oxygen species, we developed lecithinized superoxide dismutase for the treatment of patients with idiopathic interstitial pneumonias. METHODS: A multicenter, randomized, placebo-controlled trial was conducted as a pilot study to investigate the safety and effectiveness of 40 or 80 mg lecithinized superoxide dismutase in patients with progressive idiopathic interstitial pneumonias who presented with either idiopathic pulmonary fibrosis or corticosteroid-resistant fibrotic nonspecific interstitial pneumonia and showed arterial oxygen tension compatible with stage III or IV on the Japanese severity grading scale for idiopathic interstitial pneumonias. Before and following infusion of lecithinized superoxide dismutase for 28 days, the primary endpoint of forced vital capacity and the secondary endpoints of lactate dehydrogenase, surfactant protein-A, surfactant protein-D and Krebs von den Lungen-6 levels were measured in the serum. RESULTS: The primary endpoint of forced vital capacity did not improve significantly in the lecithinized superoxide dismutase groups in comparison with the placebo group. The secondary endpoints of lactate dehydrogenase and surfactant protein-A levels were significantly attenuated by 28 days in the higher-dose (80 mg) group. However, these changes returned to the baseline levels by 56 days after the cessation of lecithinized superoxide dismutase. Adverse events and mortality in the drug-treated groups did not differ from those in the placebo group. CONCLUSIONS: Treatment with lecithinized superoxide dismutase is safe and improves the levels of serum markers such as lactate dehydrogenase and surfactant protein-A in patients with advanced idiopathic interstitial pneumonias with severe respiratory dysfunction. Considering the results of the current study, further investigations into the effects and treatment potential of long-term administration of lecithinized superoxide dismutase may be warranted. TRIAL REGISTRATION: University hospital Medical Information Network (UMIN) clinical trials registry no. 000000752.

Improvement in idiopathic interstitial pneumonia by adding macitentan to a patient unresponsive to nintedanib.

A 69-year-old woman was diagnosed with idiopathic interstitial pneumonia (IIP). The patient underwent a combination therapy of steroid therapy and intravenous cyclophosphamide, long-term oxygen therapy, and the initiation of Nintedanib. However, there was no improvement in IIP, and as a result, the activities of daily living also declined. As one of the various examinations conducted, the results of the right heart catheterization diagnosed the patient with mild pulmonary hypertension, and Macitentan therapy was initiated. The subsequent clinical course appeared to show an improvement in Idiopathic Interstitial Pneumonia (IIP) by adding Macitentan therapy to Nintedanib therapy.

Exploring effective biomarkers and potential immune related gene in small cell lung cancer.

Small cell lung cancer (SCLC) is well known as a highly malignant neuroendocrine tumor. Immunotherapy combined with chemotherapy has become a standard treatment for extensive SCLC. However, since most patients quickly develop resistance and relapse, finding new therapeutic targets for SCLC is important. We obtained four microarray datasets from the Gene Expression Omnibus database and screened differentially expressed genes by two methods: batch correction and "RobustRankAggregation". After the establishment of a protein-protein interaction network through Cytoscape, seven hub genes (AURKB, BIRC5, TOP2A, TYMS, PCNA, UBE2C, and AURKA) with high expression in SCLC samples were obtained by eight CytoHubba algorithms. The Least Absolute Shrinkage and Selection Operator regression and the Wilcoxon test were used to analyze the differences in the immune cells' infiltration between normal and SCLC samples. The contents of seven kinds of immune cells were considered to differ significantly between SCLC samples and normal samples. A negative association was found between BIRC5 and monocytes in the correlation analysis between immune cells and the seven hub genes. The subsequent in vitro validation of experimental results showed that downregulating the expression of BIRC5 by siRNA can promote apoptotic activity of SCLC cells and inhibit their vitality, migration, and invasion. The use of BIRC5 inhibitor inhibited the vitality of SCLC cells and increased their apoptotic activity. BIRC5 may be a novel therapeutic target option for SCLC.

A Case of Immune Aplastic Anemia during Combined Treatment with Atezolizumab and Chemotherapy for Non-Small Cell Lung Cancer.

Immune check point inhibitors (ICIs) have durable antitumor effects. However, autoimmune toxicities, termed immune-related adverse events, occur in some patients. We report a case of severe immune aplastic anemia (AA) in a patient with non-small cell lung cancer who was receiving atezolizumab with bevacizumab/carboplatin/paclitaxel. Although the cancer has not recurred, his bone marrow is depleted and he did not respond to immunosuppressive therapy. He has survived for 1.5 years with blood transfusions and infection control. Immune AA associated with ICIs is rare, and a treatment has not yet been established. This case report provides information on the management and treatment response of patients with AA caused by ICIs. Further studies should investigate the mechanism and pathogenesis of immune AA caused by ICIs.

Osimertinib plus local treatment for brain metastases versus osimertinib alone in patients with EGFR-Mutant Non-Small Cell Lung Cancer.

OBJECTIVES: Osimertinib is a standard treatment for patients with EGFR-mutant non-small cell lung cancer (NSCLC) and is highly effective for brain metastases (BMs). However, it is unclear whether local treatment (LT) for BMs prior to osimertinib administration improves survival in EGFR-mutant NSCLC. We aimed to reveal the survival benefit of upfront local treatment (LT) for BMs in patients treated with osimertinib. MATERIALS AND METHODS: This multicenter retrospective study included consecutive patients with EGFR mutation (19del or L858R)-positive NSCLC who had BMs before osimertinib initiation between August 2018 and October 2021. We compared overall survival (OS) and central nervous system progression-free survival (CNS-PFS) between patients who received upfront LT for BMs (the upfront LT group), and patients who received osimertinib only (the osimertinib-alone group). Inverse-probability treatment weighting (IPTW) analysis was performed to adjust for potential confounding factors. RESULTS: Of the 121 patients analyzed, 57 and 64 patients had 19del and L858R, respectively. Forty-five and 76 patients were included in the upfront LT group and the osimertinib-alone groups, respectively. IPTW-adjusted Kaplan-Meier curves showed that the OS of the upfront LT group was significantly longer than that of the osimertinib-alone group (median, 95 % confidence intervals [95 %CI]: Not reached [NR], NR-NR vs. 31.2, 21.7-33.2; p = 0.021). The hazard ratio (HR) for OS and CNS-PFS was 0.37 (95 %CI, 0.16-0.87) and 0.36 (95 %CI, 0.15-0.87), respectively. CONCLUSIONS: The OS and CNS-PFS of patients who received upfront LT for BMs followed by osimertinib were significantly longer than those of patients who received osimertinib alone. Upfront LT for BMs may be beneficial in patients with EGFR-mutant NSCLC treated with osimertinib.

Clinicopathological Characteristics of Everolimus-Associated Interstitial Lung Disease: A Single-Center Consecutive Analysis.

BACKGROUND: Everolimus, a mammalian target of rapamycin inhibitor used as an antineoplastic drug, is associated with a remarkably high incidence of interstitial lung disease (ILD). The clinical and pathological characteristics of ILD caused by everolimus have not been thoroughly investigated; therefore, we aimed to elucidate the features of everolimus-associated ILD. METHODS: We retrospectively reviewed the medical records of patients who received everolimus for cancer treatment at our hospital. Patient backgrounds were compared between the ILD and non-ILD groups. Chest computed tomography (CT), changes in biomarkers, and lung histopathological features were analyzed for ILD cases. RESULTS: Sixty-six patients were reviewed, and ILD developed in 19. There were no differences in patient demographics between the ILD and non-ILD groups. The severity of ILD was grade 1 (G1) in 9 and grade 2 (G2) in 10 cases. Chest CT showed organizing pneumonia (OP) or a hypersensitive pneumonia pattern. The levels of lactate dehydrogenase, C-reactive protein, Krebs von den lungen-6, and surfactant protein-D (SP-D) at the onset of ILD were significantly higher than those at baseline. Analysis of G1 and G2 ILD subgroups showed a higher SP-D levels in the G2 subgroup. Five patients underwent lung biopsies; all specimens demonstrated alveolitis with lymphocytic infiltration and granulomatous lesions, and some had OP findings. CONCLUSIONS: Everolimus-associated ILD is mild and has a favorable prognosis. Patients with symptomatic ILD were more likely to have higher SP-D levels than those with asymptomatic ILD. Granulomatous lesions are an important pathological feature of everolimus-associated ILD.

Increased CTGF expression in alveolar epithelial cells by cyclic mechanical stretch: Its mechanism and the therapeutic effect of pirfenidone.

The mechanisms of fibrosis onset and development remain to be elucidated. However, it has been reported that mechanical stretch promotes fibrosis in various organs and cells, and may be involved in the pathogenesis of pulmonary fibrosis. We demonstrated that ventilator-induced lung hyperextension stimulation in mice increased the expression of connective tissue growth factor (CTGF), a profibrotic cytokine, in lung tissue. Increased CTGF expression induced by cyclic mechanical stretch (CMS) was also observed in vitro using A549 human alveolar epithelial cells. Pathway analysis revealed that the induction of CTGF expression by CMS involved MEK phosphorylation. Furthermore, early growth response 1 (Egr-1) was identified as a transcription factor associated with CTGF expression. Finally, the antifibrotic drug pirfenidone significantly reduced CTGF expression, MEK phosphorylation, and Egr-1 levels induced by CMS. Thus, our results demonstrated that profibrotic cytokine CTGF induced by CMS may be a therapeutic target of pirfenidone.

Pulmonary sarcoidosis complicated by rheumatoid arthritis in a patient presenting with progressive fibrosing interstitial lung disease and treated with nintedanib: a case report and literature review.

Sarcoidosis is a multisystem disease with an unknown etiology and is characterized by the formation of noncaseating granulomas in the affected organs. We present the case of a 69-year-old male Japanese patient with bilateral hilar lymphadenopathy on chest radiographs for more than 10 years, left without further investigation. The patient reported no clinical symptoms. Chest computed tomography revealed ground-glass opacities and reticular shadows in both lungs, along with bilateral hilar and mediastinal lymphadenopathy. Lymphocytosis was observed in bronchoalveolar lavage fluid. Pathological examination of transbronchial lung biopsy revealed noncaseating, epithelioid granulomas congruous with sarcoidosis, together with other findings. There were no abnormalities on electrocardiogram, echocardiogram, and ophthalmic examination.For progressive dyspnea on exertion, systemic corticosteroid therapy with oral prednisolone (25 mg/day) was initiated in 2017 and gradually tapered. Despite this intervention, the decline in forced vital capacity (FVC) was accelerated. Three years later, the patient noticed swelling in his right wrist. Further investigation revealed elevated anti-cyclic citrullinated peptide antibodies and absence of noncaseating epithelioid granuloma on surgical biopsy, leading to the diagnosis of rheumatoid arthritis (RA). Thereafter, the anti-fibrotic agent nintedanib was initiated, because interstitial lung disease (ILD) was considered to have converted into a progressive fibrosing phenotype (PF-ILD) with overlapping RA-associated lung involvement. With treatment, the progression of decline in FVC was slowed, although home oxygen therapy was introduced.

Exploratory phase 2 study of the novel oral multi-kinase inhibitor TAS-115 in patients with idiopathic pulmonary fibrosis.

BACKGROUND: TAS-115, a novel oral multi-kinase inhibitor, showed antifibrotic effects in in vitro and in vivo animal models of idiopathic pulmonary fibrosis (IPF). METHODS: In this exploratory phase 2 study, IPF patients with a percent predicted forced vital capacity (%FVC) decline ≥5% acquired within the previous 6 months were enrolled. Patients were divided into three pre-treatment cohorts, namely, treatment-naïve, pirfenidone, or nintedanib. TAS-115 was administered orally at 200 mg/day with a 5-day on and 2-day off regimen. After 13 weeks of treatment, patients entered a 13-week extension treatment period where the efficacy was evaluated. The primary endpoint was the difference in slope of %FVC decline at Week 13 from baseline. Safety was also evaluated. RESULTS: Between June 2018 and July 2019, 46 patients were enrolled, and 30 (65.2%) patients completed the 13-week treatment. Of these, 22 (47.8%) proceeded to extension treatment. For the primary endpoint, TAS-115 treatment lowered the slope of the %FVC decline of 0.0750%/day (95% confidence interval: 0.0341-0.1158%/day) at Week 13. Efficacy was also demonstrated at Week 26. Treatment-related adverse events were reported in 40 (88.9%) patients, but most were manageable by dose reduction, dose interruption, or symptomatic treatment. CONCLUSIONS: TAS-115 treatment was effective, assessed using intra-patient change in slope of %FVC decline as a surrogate endpoint in patients with IPF pre-treated with pirfenidone or nintedanib and treatment-naïve patients. TAS-115 showed acceptable tolerability and a manageable safety profile. TRIAL REGISTRATION: Japic-Clinical Trials Information, JapicCTI-183898 (first registered: March 15, 2018).

α1,6-Fucosyltransferase (Fut8) is implicated in vulnerability to elastase-induced emphysema in mice and a possible non-invasive predictive marker for disease progression and exacerbations in chronic obstructive pulmonary disease (COPD).

Fut8 (α1,6-Fucosyltransferase) heterozygous knock-out (Fut8(+/-)) mice had an increased influx of inflammatory cells into the lungs, and this was associated with an up-regulation of matrix metalloproteinases, MMP-2 and MMP-9, after treatment with porcine pancreatic elastase (PPE), exhibiting an emphysema-prone phenotype as compared with wild type mice (Fut8(+/+)). The present data as well as our previous data on cigarette-smoke-induced emphysema [8] led us to hypothesize that reduced Fut8 levels leads to COPD with increased inflammatory response in humans and is associated with disease progression. To test this hypothesis, symptomatic current or ex-smokers with stable COPD or at risk outpatients were recruited. We investigated the association between serum Fut8 activity and disease severity, including the extent of emphysema (percentage of low-attenuation area; LAA%), airflow limitation, and the annual rate of decline in forced expiratory volume in 1 s (FEV(1)). Association with the exacerbation of COPD was also evaluated over a 3-year period. Serum Fut8 and MMP-9 activity were measured. Fut8 activity significantly increased with age among the at risk patients. In the case of COPD patients, however, the association was not clearly observed. A faster annual decline of FEV(1) was significantly associated with lower Fut8 activity. Patients with lower Fut8 activity experienced exacerbations more frequently. These data suggest that reduced Fut8 activity is associated with the progression of COPD and serum Fut8 activity is a non-invasive predictive biomarker candidate for progression and exacerbation of COPD.

Reduction in serum high mobility group box-1 level by polymyxin B-immobilized fiber column in patients with idiopathic pulmonary fibrosis with acute exacerbation.

BACKGROUND/AIM: Recent reports suggest that polymyxin B (PMX)-immobilized fiber may have beneficial effects in idiopathic pulmonary fibrosis (IPF) with acute exacerbation (AE). High mobility group box-1 (HMGB-1) is an important pro-inflammatory mediator that contributes to acute lung inflammation. This study was aimed to investigate whether PMX treatment affects serum HMGB-1 levels and oxygenation in IPF patients with AE. MATERIALS AND METHODS: Twenty IPF patients with AE were treated by PMX. PMX treatment was carried out once daily for 2 successive days. Serum HMGB-1 levels were measured before and after PMX treatment. We also monitored arterial oxygen tension (PaO(2))/inspiratory oxygen fraction (FiO(2)) (P/F) ratio. PMX fiber columns were analyzed to examine whether HMGB-1 was absorbed by PMX. RESULTS: PMX treatment significantly improved both the serum HMGB-1 level and P/F ratio. HMGB-1 was detected in washing medium from the PMX column. CONCLUSION: PMX treatment may reduce serum HMGB-1 and improve oxygenation in patients with IPF with AE.

A Possible, Non-Invasive Method of Measuring Dynamic Lung Compliance in Patients with Interstitial Lung Disease Using Photoplethysmography.

BACKGROUND: Measuring lung compliance is useful for evaluating progression of interstitial lung disease (ILD), because reduced lung compliance due to fibrosis progression is the main cause of decreased vital capacity. However, because insertion of a balloon into the esophagus is invasive, lung compliance is rarely measured. A recently developed method uses fingertip photoplethysmography to estimate intrathoracic pressure. This method non-invasively measures lung dynamic compliance (Cdyn) by simultaneously measuring tidal volume. We evaluated the efficacy of this method in assessing ILD. METHODS: This single-center, cross-sectional, observational study evaluated the efficacy of this method in patients with ILD and healthy controls. The primary outcome was estimated Cdyn (eCdyn), as determined with this method. We also evaluated baseline characteristics that are potential confounding factors for eCdyn. RESULTS: Median eCdyn was significantly lower in the ILD group (n = 14) than in the control group (n = 49) (0.122 vs. 0.183; P = 0.011). In univariate regression analysis, eCdyn was significantly correlated with height, weight, forced vital capacity, forced expiratory volume in 1 second, diffusing capacity for carbon monoxide, and usual interstitial pneumonia. In multivariate regression analysis, weight (ß = 0.49, P = 0.011) and usual interstitial pneumonia (ß = 0.52, P = 0.007) were significantly correlated with eCdyn. CONCLUSIONS: Using photoplethysmography, we noted a significant reduction in Cdyn in patients with ILD. This novel non-invasive method is a promising tool for evaluating fibrosis progression in ILD.