A polo-like kinase inhibitor identified by computational repositioning attenuates pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a fatal fibrotic lung disease with few effective therapeutic options. Recently, drug repositioning, which involves identifying novel therapeutic potentials for existing drugs, has been popularized as a new approach for the development of novel therapeutic reagents. However, this approach has not yet been fully utilized in the field of pulmonary fibrosis. METHODS: The present study identified novel therapeutic options for pulmonary fibrosis using a systematic computational approach for drug repositioning based on integration of public gene expression signatures of drug and diseases (in silico screening approach). RESULTS: Among the top compounds predicted to be therapeutic for IPF by the in silico approach, we selected BI2536, a polo-like kinase (PLK) 1/2 inhibitor, as a candidate for treating pulmonary fibrosis using an in silico analysis. However, BI2536 accelerated mortality and weight loss rate in an experimental mouse model of pulmonary fibrosis. Because immunofluorescence staining revealed that PLK1 expression was dominant in myofibroblasts while PLK2 expression was dominant in lung epithelial cells, we next focused on the anti-fibrotic effect of the selective PLK1 inhibitor GSK461364. Consequently, GSK461364 attenuated pulmonary fibrosis with acceptable mortality and weight loss in mice. CONCLUSIONS: These findings suggest that targeting PLK1 may be a novel therapeutic approach for pulmonary fibrosis by inhibiting lung fibroblast proliferation without affecting lung epithelial cells. In addition, while in silico screening is useful, it is essential to fully determine the biological activities of candidates by wet-lab validation studies.

[PARADOXICAL RESPONSE DURING TREATMENT OF PULMONARY TUBERCULOSIS].

BACKGROUND: Paradoxical response (PR) is defined as a clinical or radiological worsening in patients receiving adequate anti-tuberculosis treatment, with the exclusion of documented relapse or of other disease presentations. Although most patients with PR show spontaneous improvement, some cases presenting with diffuse alveolar damage have also been reported. METHODS: Retrospective clinical and laboratory data were collected on 89 patients of pulmonary tuberculosis who were treated at our hospital between April 2013 and January 2019. RESULTS: PR occurred in 21 patients (24%), and the median onset time after anti-tuberculosis treatment was 22 days. The time to onset of PR was shorter in diffuse pulmonary infiltrates group than in local pulmonary infiltrates group or in pleural effusion group. Low serum albumin, elevated lactate dehydrogenase (LDH), high Creactive protein (CRP) and chest radiographic appearance exceeding one-lung area were associated with PR incidence. There was no difference in sputum smear grading and pulmonary cavitation. Six out of the ten patients died, developing PR with diffuse pulmonary infiltrates. CONCLUSION: Low albumin and chest radiographic appearance exceeding one-lung area were risk factors for developing PR. Diffuse pulmonary infiltrates in early phase of anti-tuberculosis treatment was related with Inhospital mortality.

Two Cases of Mycobacterium shinjukuense Pulmonary Disease With a Long-Term Response to Treatment With Clarithromycin, Rifampicin, and Ethambutol.

Mycobacterium shinjukuense is a nontuberculous mycobacterium, and standard treatment for the infection has not been established. We report two cases of M. shinjukuense pulmonary disease in which two patients were treated with clarithromycin (CAM), rifampicin (RFP), and ethambutol (EB). Based on computed tomography (CT) findings, the patients experienced improvement with treatment. Reports of multiple cases of M. shinjukuense pulmonary disease treated with clarithromycin, rifampicin, and ethambutol are valuable, and they suggest that this regimen may be a new treatment option.

A Case of Autoimmune Pulmonary Alveolar Proteinosis With Predominantly Peripheral Opacities Diagnosed by Transbronchial Lung Biopsy.

Although pulmonary alveolar proteinosis (PAP) showed various shadows, its shadows are usually distributed predominantly in the central lung area. We report a case of autoimmune PAP with localized subpleural ground-glass shadows in the bilateral upper lobes, which was diagnosed based on transbronchial lung biopsy (TBLB) specimen findings and anti-granulocyte macrophage colony PAP stimulating factor antibody positivity. PAP should be listed as a differential diagnosis for subpleural shadows. If subpleural shadows are observed, TBLB should be performed aggressively, and anti-granulocyte macrophage colony-stimulating factor (anti-GM-CSF) antibodies should be submitted.

A case of successful treatment with eltrombopag for severe immune-related thrombocytopenia induced by atezolizumab:Case report.

Immune checkpoint inhibitors (ICIs) have shown impressive anti-tumor effects against multiple types of malignancies. Among the wide variety of immune-related adverse events (irAEs), immune-related thrombocytopenia (ITP) is relatively rare but often clinically significant and life-threatening. However, the appropriate treatment for severe ITP has not been determined. We herein report an 82-year-old male patient with non-small-cell lung cancer who developed severe ITP three weeks after starting the third course of atezolizumab. The initial combination therapy with high-dose prednisolone, intravenous immunoglobulin and platelet transfusion was ineffective. However, additional treatment with eltrombopag, a thrombopoietin receptor agonist, resulted in remarkable improvement in the thrombocytopenia. J. Med. Invest. 70 : 516-520, August, 2023.

A novel BRD4 degrader, ARV-825, attenuates lung fibrosis through senolysis and antifibrotic effect.

BACKGROUND: Recent studies suggest that cellular senescence is related to the pathogenesis of idiopathic pulmonary fibrosis. However, cellular senescence has yet to be targeted therapeutically in clinical practice. ARV825, a recently developed BRD4 degrader, has been reported as a novel senolytic drug. Conversely, it has also been reported that BRD4 regulates the pro-fibrotic gene expression of fibroblasts. Therefore, this study focuses on the senolytic and anti-fibrotic effects of ARV825 and evaluated these effects on lung fibrosis. METHODS: Lung fibroblasts were induced to senescence through serial passage. The expression of senescence markers and pro-fibrotic markers were determined through quantitative PCR or immunoblot analysis. Lung fibrosis was induced in mice through intratracheal administration of bleomycin. Mice treated with ARV825 underwent histological analysis of lung fibrosis using the Ashcroft score. Total lung collagen was quantified through a hydroxyproline assay. Respiratory mechanics analysis was performed using the flexiVent system. RESULTS: For senescent cells, ARV825 induced the expression of an apoptosis marker while reducing the expression of BRD4 and senescence markers. On the other hand, for early passage pre-senescent cells, ARV825 reduced the expression of collagen type 1 and α-smooth muscle actin. In an experimental mouse model of lung fibrosis, ARV825 attenuated lung fibrosis and improved lung function. Immunohistochemical staining revealed a significant decrease in the number of senescent alveolar type 2 cells in lung tissue due to ARV825 treatment. CONCLUSIONS: These results suggest that ARV825 may impact the progressive and irreversible course of fibrotic lung diseases.

The lymphocyte-specific protein tyrosine kinase-specific inhibitor A-770041 attenuates lung fibrosis via the suppression of TGF-ß production in regulatory T-cells.

BACKGROUND: Lymphocyte-specific protein tyrosine kinase (Lck) is a member of the Src family of tyrosine kinases. The significance of Lck inhibition in lung fibrosis has not yet been fully elucidated, even though lung fibrosis is commonly preceded by inflammation caused by infiltration of T-cells expressing Lck. In this study, we examined the effect of Lck inhibition in an experimental mouse model of lung fibrosis. We also evaluated the effect of Lck inhibition on the expression of TGF-ß1, an inhibitory cytokine regulating the immune function, in regulatory T-cells (Tregs). METHODS: Lung fibrosis was induced in mice by intratracheal administration of bleomycin. A-770041, a Lck-specific inhibitor, was administrated daily by gavage. Tregs were isolated from the lung using a CD4+CD25+ Regulatory T-cell Isolation Kit. The expression of Tgfb on Tregs was examined by flow cytometry and quantitative polymerase chain reaction. The concentration of TGF-ß in bronchoalveolar lavage fluid (BALF) and cell culture supernatant from Tregs was quantified by an enzyme-linked immunosorbent assay. RESULTS: A-770041 inhibited the phosphorylation of Lck in murine lymphocytes to the same degree as nintedanib. A-770041 attenuated lung fibrosis in bleomycin-treated mice and reduced the concentration of TGF-ß in BALF. A flow-cytometry analysis showed that A-770041 reduced the number of Tregs producing TGF-ß1 in the lung. In isolated Tregs, Lck inhibition by A-770041 decreased the Tgfb mRNA level as well as the concentration of TGF-ß in the supernatant. CONCLUSIONS: These results suggest that Lck inhibition attenuated lung fibrosis by suppressing TGF-ß production in Tregs and support the role of Tregs in the pathogenesis of lung fibrosis.

Lenvatinib-induced Interstitial Pneumonia in a Patient with Hepatocellular Carcinoma.

Lenvatinib is a multi-targeted tyrosine kinase inhibitor available for the treatment of unresectable hepatocellular carcinoma (HCC). We herein report an 84-year-old-man with interstitial pneumonia caused by lenvatinib. Four months after the start of lenvatinib administration for HCC, chest computed tomography revealed bilateral ground-glass opacity. However, he continued to take lenvatinib for four more months until he complained of dyspnea on exertion. This is a case of lenvatinib-induced interstitial pneumonia that progressed relatively slowly with a long asymptomatic period despite the appearance of pneumonia on image findings.

A Long-term Survival Case of Pulmonary Tumor Thrombotic Microangiopathy due to Gastric Cancer Confirmed by the Early Diagnosis based on a Transbronchial Lung Biopsy.

Pulmonary tumor thrombotic microangiopathy (PTTM) is an acute, progressive, and fatal disease. PTTM manifests as subacute respiratory failure with pulmonary hypertension, progressive right-sided heart failure, and sudden death. An antemortem diagnosis of PTTM is very difficult to obtain, and many patients die within several weeks. We herein report a case of PTTM diagnosed based on a transbronchial lung biopsy. In this case, we finally diagnosed PTTM due to gastric cancer because of its histological identity. The patient was administered chemotherapy, including angiogenesis inhibitors, against gastric cancer at an early age and survived for a long time.

Distinct improvement of pulmonary function, ground-glass opacity, hypoxia and physical findings in an idiopathic pulmonary fibrosis patient after pirfenidone treatment : a case report with a review of the literature.

Background : Pirfenidone (PFD), an anti-fibrosis drug for idiopathic pulmonary fibrosis (IPF), suppresses disease progression and delays decline of forced vital capacity. However, this drug rarely makes marked improvement of pulmonary function, chest high-resolution computed tomography (HRCT) findings and hypoxia. Case presentation : A 59 year-old-man, who was a former smoker and had a history of alcoholic liver cirrhosis, developed exertional dyspnea and was referred to our hospital. HRCT showed honeycomb changes with surrounding ground-glass opacity (GGO) in a predominantly basal and subpleural distribution. He was diagnosed with IPF and the treatment with PFD was started. At 16 months after the start of treatment, the predicted forced vital capacity value markedly improved from 82.9% to 98.6%. His resting-state partial pressure of arterial oxygen while breathing room air increased from a minimum of 54.7 mmHg (at 2 months treatment) to 72.5 mmHg. The GGO observed at diagnosis disappeared in HRCT. But after 32 months of treatment, his general condition got worse gradually, and he died from chronic progression of IPF after 48 months of treatment. Conclusion : Our case suggests that a complication of chronic liver disease and the existence of GGO may be characteristics of super-responder to PFD treatment for IPF patients. J. Med. Invest. 67 : 358-361, August, 2020.