An Autopsy Case of COVID-19 with New Diffuse Pulmonary Ossification

We present the case of a 61-year-old man who developed Coronavirus disease 2019 (COVID-19) and died during treatment for relapsing polychondritis. The patient was intubated and treated with steroid pulse therapy, remdecivir, antibacterial agents, baricitinib, and tocilizumab. However, his respiratory condition worsened, and he died 108 days after disease onset. An autopsy revealed diffuse alveolar damage in the fibrotic phase in all lung lobes, diffuse pulmonary ossification, and cytomegalovirus-infected cells in the middle lobe of the right lung. We herein discuss the clinical features and pathological findings of COVID-19 in immunosuppressed patients.

Correlation of 4-meter gait speed with clinical indicators of chronic obstructive pulmonary disease

BACKGROUND

Measuring daily physical activity and exercise capacity is recommended in the routine care of patients with chronic obstructive pulmonary disease (COPD). The 4-m gait speed (4mGS) is simple and effective in stratifying patients according to exercise performance, dyspnea, health status, and prognosis. We assessed the reliability of the 4mGS as a clinical marker by examining its association with established clinical indicators among hospitalized patients with COPD.

METHODS

This retrospective study included 78 patients hospitalized with COPD (mean age: 76.3 ± 0.9 years; males, n = 69) between January 2016 and June 2018 who were assessed using the 4mGS and divided into slow (<0.8 m/s) and normal (≥0.8 m/s) 4mGS groups. Clinical characteristics were compared, including death during the observation period, time to first exacerbation, and long-term oxygen therapy requirement.

RESULTS

There were strong relationships between 4mGS performance, the 6-min walk test (R = 0.70; p < 0.0001), and the modified Medical Research Council dyspnea scale (R = 0.68; p < 0.0001) among the 78 patients. The slow 4mGS group had a higher frequency of death during the observation period (p = 0.0095) and a greater requirement for long-term oxygen therapy (p = 0.0063). The 4mGS correlated with inspiratory capacity (IC) and IC/total lung capacity ratios, which are respiratory failure indicators.

CONCLUSIONS

The 4mGS is a simple and easy method of assessing the physical condition as well as estimating the prognosis of patients with COPD, and may serve as a useful marker in home medical treatment or clinical settings.

The Evaluation of the Sputum Antigen Kit in the Diagnosis of Pneumococcal Pneumonia

Objective A previously developed sputum antigen detection kit for Streptococcus pneumoniae enabled the early diagnosis of pneumococcal pneumonia using sputum samples. We conducted a prospective study to compare the sensitivity of the sputum and urinary antigen kits. Methods Pneumonia patients who were treated from April 2014 to September 2015 were recruited for the present study. Patients with pneumococcal pneumonia who could not participate in the prospective arm of the study were analyzed in the retrospective arm. Results Nine of the 69 participants in the prospective study had pneumococcal pneumonia. The sputum antigen kit results correlated well with the sputum culture results. The sensitivity of the sputum antigen kit was 88.9% (8/9), which was higher than that of the urinary antigen kit (5/9; 55.6%). When patients from the retrospective arm of the study were included, the sensitivity of the sputum culture was 93.5% (29/31), which was significantly higher than that of the urinary antigen kit (19/31; 60.6%). False positives were obtained using the sputum antigen kit in four cases. Three of the four false positives were suspected to have resulted from the administration of antibiotics prior to the use of the kit; the remaining case likely occurred due to a false reaction to S. milleri-induced pyothorax. Conclusion Collectively, our findings suggest that the sputum antigen kit has a higher sensitivity for detecting S. pneumoniae than the urinary antigen kit. However, the prior administration of antibiotics can render the sputum culture results negative or lead to a false-positive result.

Prognostic value of serial serum KL-6 measurements in patients with idiopathic pulmonary fibrosis

BACKGROUND

The prognostic significance of serial measurements of serum KL-6 levels in patients with idiopathic pulmonary fibrosis (IPF) is unclear; hence, it was assessed in this study.

METHODS

Medical records of 66 patients with IPF, who were not treated with pirfenidone prior to enrollment, were retrospectively reviewed for information on clinical progress, forced vital capacity (FVC), survival, and serum KL-6 levels. We assessed initial serum levels of KL-6, serial changes in serum KL-6 levels, yearly decline in FVC (ΔFVC), and the rate of decline (%ΔFVC).

RESULTS

Patients with increased serum KL-6 levels during follow-up had a significantly steeper decline in ΔFVC than those with no KL-6 increase (-201 vs. -50.7ml/year; p=0.0001). Patients with both initial serum KL-6 ≥1000U/ml and serial increases in serum KL-6 had the steepest decline, while those with both initial serum KL-6 <1000ml and no serial increases in KL-6 had the least decline in ΔFVC and %ΔFVC. Relative to the non-increased KL-6 group, survival in the increased KL-6 group tended to be poorer (p=0.0530). Patients with both initial serum KL-6 values <1000U/ml and no serial increase in KL-6 had more favorable prognoses than those with serial increases in KL-6 or initial serum KL-6 values ≥1000U/ml (p<0.0044). Prognosis was significantly poorer in patients with serial KL-6 changes >51.8U/ml/year than in those with serial KL-6 changes <51.8U/ml/year (p=0.0009).

CONCLUSION

Thus, serial serum KL-6 measurements can be useful for assessing prognosis in patients with IPF.

Heterogeneous clinical features in patients with pulmonary fibrosis showing histology of pleuroparenchymal fibroelastosis

BACKGROUND

The histological pattern of pleuroparenchymal fibroelastosis (PPFE) is well defined, but its clinical features remain unclear.

METHODS

We retrospectively examined the predominantly involved lung-fields (based on abnormal opacities on computed tomography [CT] images), and the initial value and annual decline of respiratory function in patients with pulmonary fibrosis presenting with histologically confirmed PPFE.

RESULTS

Thirteen female and nine male subjects were included. Eleven interpreters independently analyzed 231 CT image series. One-third of the CT series (78/231) was interpreted as demonstrating equal involvement of the upper and lower lung fields, i.e., six out of 21 patients had equal involvement of the upper and lower lung fields, based on a majority decision of the interpreters. The residual volume/total lung capacity (RV/TLC) was increased and correlated inversely with forced vital capacity (FVC) at the initial measurement. FVC followed two patterns of decline over time: a gradual decline over a follow-up period of more than 6 years (-55mL/year, R(2)=0.799), and a relatively rapid decline over a shorter period (-364mL/year, R(2)=0.855) as determined by mixed-effect linear regression.

CONCLUSIONS

The predominantly involved sites seen on CT images of PPFE were not limited to the upper lobes. In some cases, upper lung fields were predominantly involved, but in other cases, both upper and lower lung fields were equally involved. Two patterns of FVC decline exists: a rapid decline over a short period and a slow decline over a longer period, suggesting that the disease follows a heterogeneous clinical course.

Histological evolution of pleuroparenchymal fibroelastosis

AIMS

To investigate the histological evolution in the development of pleuroparenchymal fibroelastosis (PPFE).

METHODS AND RESULTS

We examined four patients who had undergone surgical lung biopsy twice, or who had undergone surgical lung biopsy and had been autopsied, and in whom the histological diagnosis of the first biopsy was not PPFE, but the diagnosis of the second biopsy or of the autopsy was PPFE. The histological patterns of the first biopsy were cellular and fibrotic interstitial pneumonia, cellular interstitial pneumonia (CIP) with organizing pneumonia, CIP with granulomas and acute lung injury in cases 1, 2, 3, and 4, respectively. Septal elastosis was already present in the non-specific interstitial pneumonia-like histology of case 1, but a few additional years were necessary to reach consolidated subpleural fibroelastosis. In case 3, subpleural fibroelastosis was already present in the first biopsy, but only to a small extent. Twelve years later, it was replaced by a long band of fibroelastosis. The septal inflammation and fibrosis and airspace organization observed in the first biopsies were replaced by less cellular subpleural fibroelastosis within 3-12 years.

CONCLUSIONS

Interstitial inflammation or acute lung injury may be an initial step in the development of PPFE.

Randomized Phase III Trial of Erlotinib Versus Docetaxel As Second- or Third-Line Therapy in Patients With Advanced Non–Small-Cell Lung Cancer: Docetaxel and Erlotinib Lung Cancer Trial (DELTA)

Purpose

To investigate the efficacy of erlotinib versus docetaxel in previously treated patients with advanced non–small-cell lung cancer (NSCLC) in an epidermal growth factor receptor (EGFR) –unselected patient population.

Patients and Methods

The primary end point was progression-free survival (PFS). Secondary end points included overall survival (OS), response rate, safety, and analyses on EGFR wild-type tumors. Patients with stage IIIB or IV NSCLC, previous treatment with one or two chemotherapy regimens, evaluable or measurable disease, and performance status of 0 to 2 were eligible.

Results

From August 2009 to July 2012, 150 and 151 patients were randomly assigned to erlotinib (150 mg daily) and docetaxel (60 mg/m2 every 3 weeks), respectively. EGFR wild-type NSCLC was present in 109 and 90 patients in the erlotinib and docetaxel groups, respectively. Median PFS for erlotinib versus docetaxel was 2.0 v 3.2 months (hazard ratio [HR], 1.22; 95% CI, 0.97 to 1.55; P = .09), and median OS was 14.8 v 12.2 months (HR, 0.91; 95% CI, 0.68 to 1.22; P = .53), respectively. In a subset analysis of EGFR wild-type tumors, PFS for erlotinib versus docetaxel was 1.3 v 2.9 months (HR, 1.45; 95% CI, 1.09 to 1.94; P = .01), and OS was 9.0 v 10.1 months (HR, 0.98; 95% CI, 0.69 to 1.39; P = .91), respectively.

Conclusion

Erlotinib failed to show an improvement in PFS or OS compared with docetaxel in an EGFR-unselected patient population.

Variations in the structure and transcription of the mitochondrial atp and cox genes in wild Solanum species that induce male sterility in eggplant (S. melongena)

In order to determine the molecular basis of cytoplasmic male sterility (CMS) in alloplasmic lines of eggplant, the genomic structures and transcription patterns of mitochondrial ATP synthase subunit (atp) and cytochrome oxidase subunit (cox) genes were studied for wild and cultivated eggplants. Alloplasmic eggplant lines with cytoplasms of wild Solanum species showing either anther indehiscent type of CMS or non-pollen production type of CMS were studied with the cultivated eggplant Solanum melongena, used as a control. Southern hybridization of the mitochondrial genes indicated the difference between the two types of CMS and showed complete identity within each type. The cytoplasmic patterns of all wild species differed from that of the cultivated eggplant. Thus, the cytoplasm of the six wild eggplants and the one cultivated eggplant was classified into three groups. Male sterile plants of both types of CMS showed novel transcription patterns of atp1, whereas a different transcription pattern of cox2 was observed only in the anther indehiscent type. Based on these differences, we determined the DNA sequences of about a 4 kbp segment in the atp1 region. Although the coding and 3' flanking regions were almost identical among the cytoplasms, the 5' flanking region was completely different and novel open reading frames (orfs) were found for each of the CMS types and the cultivated eggplant. The cytoplasm of Solanum kurzii inducing the anther indehiscent type CMS had orf312, and those of Solanum aethiopicum and Solanum grandifolium of non-pollen production type CMS had orf218. The correspondence between the transcription patterns of these orfs and phenotypic expression of male sterility strongly suggests that these orfs are causal genes for each type of CMS.

Randomized phase III trial of erlotinib (E) versus docetaxel (D) as second- or third-line therapy in patients with advanced non-small cell lung cancer (NSCLC) who have wild-type or mutant epidermal growth factor receptor (EGFR): Docetaxel and Erlotinib Lung Cancer Trial (DELTA)

8006

Background: E and D are standard cares for previously treated patients with advanced NSCLC. Although E shows significant clinical benefits over best supportive care in the EGFR wild type tumors, it remains unknown whether E or D is more active against the disease. Methods: This is an open-label, multi-center phase III study, sponsored by the Japanese National Hospital Organization. Patients were randomized to E (150 mg, daily), or D (60 mg/m2, q3w) by the minimization method according to gender, performance status, histology, and institution. The primary endpoint was progression free survival (PFS), and secondary endpoints included overall survival (OS), response rate, safety, and analyses on EGFR wild type tumors. Eligible patients were those with pathologically proven NSCLC with stage IIIB or IV (AJCC version 6) previously treated with one or two chemotherapy regimens including at least one platinum agent, evaluable or measurable disease, and ECOG PS 0-2. Target sample size was calculated to be 280 based on the assumption that E was superior to D in PFS (3.5 months [m] v 2.5 m, α =0.05 [two sided], β =0.80). Results: From August 2009 to July 2012, 301 patients were accrued from 41 institutions. In the ITT population, 150 and 151 patients were randomly assigned to E and D, respectively, including respective 109 (73%, E) and 89 (59%, D) with EGFR wild type tumors. Median PFS and OS for E v D were 2.0 m (95% CI: 1.3-2.8) v 3.2 m (2.8-4.0, log-rank p=0.092; HR=1.22, 95% CI: 0.97-1.55), and 14.8 m (9.0-19.4) v 12.2 m (9.0-15.5, p=0.527; HR=0.91, 95% CI: 0.68-1.22), respectively. In the EGFR wild type tumors, PFS and OS for E v D were 1.3 m v 2.9 m (p=0.013; HR =1.44, 95% CI: 1.08-1.92), and 9.0 m v 9.2 m (p=0.914; HR =0.98, 95% CI: 0.69-1.39), respectively. Main grade 3/4 toxicities were rash (13.3% [E] v 0.7% [D]) and leukopenia (5.4% [E] v 62.9% [D]). Conclusions: E failed to show better PFS over D. While PFS was significantly longer in D than E in EGFR wild type tumors, the difference did not translate into OS in this pragmatic trial. Clinical trial information: 000002314.

Combined unclassifiable interstitial pneumonia and emphysema: a report of two cases

We herein report two cases of combined pulmonary fibrosis and emphysema (CPFE), whose histological patterns of lung pathology could not be categorized into any subset of idiopathic interstitial pneumonias(IIPs). Case 1 was a 62-year-old man, who presented with dyspnea on exertion and cough. Case 2 was a 51-year-old man with a dry cough. The CT findings of both cases fit the definition of CPFE. Surgical lung biopsies of both patients revealed alveolar septal widening due to collagen deposition, with emphysema and respiratory bronchiolitis mainly in the subpleural parenchyma. These cases suggest that the fibrosis of CPFE includes smoking-related interstitial fibrosis other than the known histological patterns of IIPs.

The role of high mobility group box1 in pulmonary fibrosis

High mobility group box1 protein (HMGB1) was originally discovered as a nuclear binding protein, and is known to play an important role in acute lung injury. However, the role of HMGB1 in pulmonary fibrosis has not been addressed. Therefore, we measured the HMGB1 levels in serum and bronchoalveolar lavage fluids (BALF) from patients with idiopathic pulmonary fibrosis (IPF), nonspecific interstitial pneumonia, interstitial pneumonia associated with collagen vascular diseases, and hypersensitivity pneumonitis (HP) by enzyme-linked immunosorbent assay. We also assessed the HMGB1 expression in bleomycin-induced pulmonary fibrosis in mice, and examined the effect of anti-HMGB1 antibody and ethyl pyluvate, which inhibits the HMGB1 secretion from alveolar macrophages. In addition, we examined the effect of HMGB1 on fibroblast proliferation, apoptosis, and collagen synthesis in vitro. Serum HMGB1 levels were not significantly increased in interstitial lung diseases compared with control subjects. BALF HMGB1 levels were significantly increased in IPF and HP compared with control subjects. HMGB1 protein was predominantly detected in inflammatory cells and hyperplasic epithelial cells in IPF. In bleomycin-induced pulmonary fibrosis in mice, HMGB1 protein was predominantly up-regulated in bronchiolar epithelial cells at early phase and in alveolar epithelial and inflammatory cells in fibrotic lesions at later phase. Intraperitoneal injection of anti-HMGB1 antibody or ethyl pyluvate significantly attenuated lung inflammation and fibrosis in this model. HMGB1 significantly induced proliferation, but not apoptosis or collagen synthesis on cultured fibroblasts. HMGB1 may be a promising target against pulmonary fibrosis as well as acute lung injury.

Gene transfer of soluble transforming growth factor type II receptor by in vivo electroporation attenuates lung injury and fibrosis

BACKGROUND

Transforming growth factor-beta1 (TGF-beta1) has the potential to induce acute inflammation and apoptosis in lung epithelial cells and plays a central role in subsequent fibrosis.

AIMS

To examine a new anti-TGF-beta1 therapy against lung injury and fibrosis, which comprises the transfection of soluble TGF type II receptor (sTGFRII) gene into skeletal muscles by in vivo electroporation.

METHODS

Soluble TGFRII was detectable between 1 and 14 days in the serum and significantly increased between 3 and 10 days after gene transfer into muscles. Based on these findings, the sTGFRII gene was injected at 3 days before or 4 days after the bleomycin instillation in order to examine the significance of TGF-beta1 on the early inflammatory phase (day 0 to day 7) or the fibrotic phase (day 7 to day 14) in this model.

RESULTS

Transfection of sTGFRII gene at 3 days before or 4 days after bleomycin instillation significantly attenuated apoptosis, injury, and fibrosis at 7 or 14 days, respectively. This method does not require the use of viral vector or neutralising antibody, and it is therefore possible to avoid problems regarding the pathogenicity of the viral vector or immunocomplex.

CONCLUSIONS

This novel anti-TGF-beta1 strategy may have clinical application in the treatment of lung injury and fibrosis.

Apoptosis signaling pathways in lung diseases

Evidence that apoptosis plays an important role in the pathophysiology of lung diseases has been accumulated. Apoptosis signaling is classically composed of two principle pathways. One is a direct pathway from death receptor ligation to caspase cascade activation and cell death. Death receptor ligation triggers recruitment of the precursor form of caspase-8 to a death-inducing complex, through the adaptor protein FADD, which leads to caspase-8 activation. The other pathway triggered by stimuli such as drugs, radiation, infectious agents and reactive oxygen species is initiated in mitochondria. After cytochrome c is released into the cytosol from the mitochondria, it binds to Apaf1 and ATP, which then activate caspase-9. Recently, endoplasmic reticulum has also been shown to be the organelle to execute apoptosis. Further understanding of molecular mechanisms of apoptosis and its regulation by novel drugs may lead to the development of effective strategies against lung diseases. We overview the signaling pathways of apoptosis and discuss the involvement of apoptosis in the pathophysiology of various lung diseases.

The p53-Mdm2 association in epithelial cells in idiopathic pulmonary fibrosis and non-specific interstitial pneumonia

BACKGROUND

Wild-type p53 is increased during cellular responses to various stresses. Mdm2, which is induced by p53, regulates p53 protein concentrations through the ubiquitin-proteasome pathway.

AIM

To investigate whether the Mdm2 mediated ubiquitination of p53 is associated with epithelial cell apoptosis in idiopathic pulmonary fibrosis (IPF).

METHODS

Immunohistochemistry and western blot analysis were carried out on lung samples obtained by lung biopsy from patients with IPF and non-specific interstitial pneumonia (NSIP).

RESULTS

The expression of p53, phosphorylated p53, Mdm2, p21, and Bax was upregulated in epithelial cells from patients with IPF and NSIP compared with normal lung parenchyma. Except for p21, there was a significant increase in the expression of these factors in IPF compared with NSIP. In addition, the number of apoptotic cells and the number of p53 and Bax positive cells was increased compared with controls. p53 conjugated with Mdm2 was decreased in IPF compared with NSIP and controls. Ubiquitinated p53 was increased in both IPF and NSIP compared with controls.

CONCLUSIONS

Signalling molecules associated with p53 mediated apoptosis may participate in epithelial cell apoptosis, and the attenuation of p53-Mdm2 conjugation and of p53 degradation may be involved in the epithelial cell apoptosis seen in IPF. Augmented epithelial apoptosis in IPF may lead to the poor prognosis compared with NSIP.

Anti-Vascular Endothelial Growth Factor Gene Therapy Attenuates Lung Injury and Fibrosis in Mice

Vascular endothelial growth factor (VEGF) is an angiogenesis factor with proinflammatory roles. Flt-1 is one of the specific receptors for VEGF, and soluble flt-1 (sflt-1) binds to VEGF and competitively inhibits it from binding to the receptors. We examined the role of VEGF in the pathophysiology of bleomycin-induced pneumopathy in mice, using a new therapeutic strategy that comprises transfection of the sflt-1 gene into skeletal muscles as a biofactory for anti-VEGF therapy. The serum levels of sflt-1 were significantly increased at 3-14 days after the gene transfer. Transfection of the sflt-1 gene at 3 days before or 7 days after the intratracheal instillation of bleomycin decreased the number of inflammatory cells, the protein concentration in the bronchoalveolar lavage fluid and with von Willebrand factor expression at 14 days. Transfection of the sflt-1 gene also attenuated pulmonary fibrosis and apoptosis at 14 days. Since the inflammatory cell infiltration begins at 3 days and is followed by interstitial fibrosis, it is likely that VEGF has important roles as a proinflammatory, a permeability-inducing, and an angiogenesis factor not only in the early inflammatory phase but also in the late fibrotic phase. Furthermore, this method may be beneficial for treating lung injury and fibrosis from the viewpoint of clinical application, since it does not require the use of a viral vector or neutralizing Ab.

The perforin mediated apoptotic pathway in lung injury and fibrosis

AIMS

The perforin mediated pathway is the major pathway of cytotoxicity induced by activated T cells and natural killer cells, and may be involved in the development of pulmonary fibrosis.

METHODS

Perforin and granzyme B expression were examined in idiopathic pulmonary fibrosis by means of immunohistochemistry, and perforin knockout mice were used to examine whether or not perforin mediated cytotoxicity participates in the pathophysiology of bleomycin induced pneumopathy.

RESULTS

Perforin and granzyme B expression were upregulated in infiltrating lymphocytes in lung tissue from patients with idiopathic pulmonary fibrosis compared with normal lung parenchyma. Perforin and granzyme B expression were upregulated predominantly in infiltrating mononuclear cells after bleomycin instillation in wild-type mice. Although the development of bleomycin induced pneumopathy was not completely prevented, the pathological grade of inflammation and fibrosis, and the number of apoptotic cells in lung tissue, were significantly decreased in perforin knockout mice compared with wild-type mice.

CONCLUSIONS

These results suggest that perforin mediated apoptosis may be associated with the pathophysiology of lung injury and fibrosis.

[A case of rapidly deteriorated pulmonary aspergillosis with various clinical manifestations]

A 62-year-old man with chronic hepatitis was admitted to the hospital because of severe asthma, fever, and a chest radiograph abnormality. He had previously been treated unsuccessfully with several antibiotics in another hospital. The chest radiographs and CT films showed multiple infiltrations along the bronchi and in the peripheral regions of both lungs. Aspergillus fumigatus was detected in a sputum culture and the non-specific serum IgE was elevated. Allergic broncho-pulmonary aspergillosis (ABPA) was suspected and then steroids were administered. Although the asthma symptoms improved after the steroid therapy, lung infiltration deteriorated rapidly, affecting both lungs, and cavitations appeared. We concluded that invasive aspergillosis had developed from ABPA. Itraconazole and amphotericin B were administered, resulting in gradual improvements in the bilateral infiltration seen in the chest radiographs. The patient underwent open lung biopsy to rule out systemic vasculitis. The histological diagnosis was organizing pneumonia without vasculitis and without aspergillus or other organisms. The pathological findings resulted from the intensive anti-fungal therapy. There is a possibility that the temporal steroid therapy may have affected the conversion of ABPA to invasive aspergillosis.

Anti-monocyte chemoattractant protein-1 gene therapy attenuates pulmonary fibrosis in mice

Monocyte chemoattractant protein-1 (MCP-1) is a proinflammatory chemokine and may play an important role in the development of pulmonary fibrosis. We examined a new therapeutic strategy that comprises the transfection of the mutant MCP-1 gene into skeletal muscles as a biofactory for anti-MCP-1 therapy against bleomycin-induced pulmonary fibrosis in mice. Overexpression of the mutant MCP-1 gene at 10–14 days after intratracheal instillation of bleomycin resulted in decreased DNA damage, apoptosis, and pulmonary fibrosis at 14 days. However, overexpression of the mutant MCP-1 at 0–4 days after bleomycin instillation did not result in decreased pathological grade, DNA damage, or apoptosis at 7 and 14 days. Because, in this model, inflammatory cell infiltration begins at 3 days and is followed by interstitial fibrosis, it is likely that MCP-1 has an important role to play in the development of fibrogenesis but not in the development of early lung inflammation. This method does not require the use of viral vector or neutralizing antibody, and, as such, it is possible to avoid problems regarding the pathogenicity of the viral vector or immunocomplex. This new strategy may be a beneficial method of treating pulmonary fibrosis from the viewpoint of clinical application.

Induction of CDK inhibitor p21 gene as a new therapeutic strategy against pulmonary fibrosis

Alveolar epithelial cells are known to be present at the primary site of lung damage in pulmonary fibrosis. Apoptosis has been implicated as being involved in epithelial cell damage and pulmonary fibrosis. Because the cyclin-dependent kinase inhibitor p21 induces G1 arrest and DNA repair and because it also prevents apoptosis in some cells, we hypothesized that p21 gene transfer may attenuate bleomycin-induced pulmonary fibrosis in mice, the pathogenesis of which likely involves epithelial cell apoptosis. Human p21 protein was expressed in mouse alveolar epithelial cells at 1-7 days in vitro and was detected predominantly in lung epithelial cells at 1-7 days in vivo after adenoviral transfer of the human p21 gene. Inflammatory cell infiltration and fibrosis had already begun at 7 days in this model. Adenoviral transfer of the human p21 gene at 7 days after intratracheal instillation of bleomycin led to a decrease in the number of apoptotic cells, lung inflammation, and fibrosis at 14 days. Therefore, the forced expression of p21 exerted both anti-apoptotic and anti-fibrotic effects, which would facilitate the ultimate goal of treatment for pulmonary fibrosis.

Oxidative stress in lung epithelial cells from patients with idiopathic interstitial pneumonias

Lung epithelial cells are a primary target for reactive oxygen species (ROS). ROS can cause oxidative deoxyribonucleic acid modification, such as 8-hydroxy-deoxyguanosine (8-OHdG). A human homologue of the MutT protein (hMTH1) prevents this modification. Mitochondria are the most important cellular source of ROS and may be susceptible to oxidative damage. The purpose of this study is to investigate oxidative stress and mitochondrial damage in lung epithelial cells from idiopathic interstitial pneumonias (IIPs). The authors analysed 8-OHdG, hMTH1, and mitochondrial proteins on lung specimens from 13 patients with IlPs consisted of eight patients with usual interstitial pneumonia and five patients with nonspecific interstitial pneumonia using Western blot analysis and immunohistochemistry. Immunoreactivity for 8-OHdG and hMTH1 was significantly increased in the lung epithelial cells from patients with IIPs compared with controls. The expression of hMTH1 was localised in the nuclear and cytoplasmic, but not the mitochondrial, fraction of lung homogenates. Immunoreactivity for mitochondrial protein and cytochrome c oxidase complex subunit IV was increased in the lung epithelial cells from patients with IIPs compared with controls. The current study concludes that oxidative stress may participate in epithelial cell damage in idiopathic interstitial pneumonia, and that increased mitochondrial mass may associate with increased reactive oxygen species production in idiopathic interstitial pneumonia.

Mitochondria-mediated apoptosis of lung epithelial cells in idiopathic interstitial pneumonias

We previously demonstrated that the up-regulation of p53, Fas, and DNA damage are present in lung epithelial cells from patients with idiopathic interstitial pneumonias (IIP). Fas ligation induces apoptosis of lung epithelial cells predominantly through the direct activation of the caspase cascade via caspase-8 activation, whereas the up-regulation of p53 and other cellular stresses can induce mitochondria-mediated apoptosis. In this study, we investigated the incidence of mitochondria-mediated apoptosis of epithelial cells in IIP. We performed TUNEL staining to detect apoptotic cells and western blot analysis and immunohistochemistry to assess the expression and activation of caspases and the cytochrome c release from mitochondria in lung tissues from eight patients with usual interstitial pneumonia, five patients with nonspecific interstitial pneumonia, and eight patients with normal lung parenchyma. The expressions of pro- and cleaved caspase-8, 9, 3, and cytochrome c release from the mitochondria were all significantly increased in the lung tissues of IIP compared with normal lung parenchyma. The positive signals for caspases in epithelial cells were increased in IIP compared with normal lung parenchyma by immunohistochemistry. The results of TUNEL and electron microscopy suggested that apoptotic cells were predominantly epithelial cells. TUNEL-positive cells in % of epithelial cells were significantly increased in IIP compared with normal lung parenchyma, and significantly correlated with cytochrome c release from the mitochondria and with the expression of cleaved caspase-3 in epithelial cells. We conclude that mitochondria-mediated apoptosis may be involved in the pathophysiology of IIP.

Resistance to Fas-mediated apoptosis in human lung fibroblast

The current authors have demonstrated previously that epithelial cell apoptosis, induced by the Fas-Fas ligand pathway, might be involved in fibrosing lung diseases. Whereas lung epithelial cells are sensitive to the Fas-mediated apoptosis, lung fibroblasts may be resistant to Fas-mediated apoptosis and replace damaged epithelial cells. The WI-38 lung fibroblast cell line and primary lung fibroblasts were used to examine the resistant to Fas-mediated apoptosis and the association of anti-apoptotic proteins with this resistance. The administration of agonistic anti-Fas antibody (CH-11) or cycloheximide alone did not induce apoptosis, whereas the co-administration of CH-11 with cycloheximide induced apoptosis in WI-38 cells, in which caspase-8 and -3, but not -9, were activated, and X chromosome-linked inhibitor of apoptosis (ILP) and FLICE-like inhibitor protein (FLIP(L)), but not bcl-xL and bcl-2, were remarkably down regulated. Primary lung fibroblasts were also resistant to Fas-mediated apoptosis, and ILP and FLIP appeared to be involved in this resistance. Furthermore, the results of immunohistochemistry demonstrated that fibroblasts expressed ILP and FLIP(L) proteins in lung tissues from patients with idiopathic pulmonary fibrosis. These results suggest that anti-apoptotic proteins such as X chromosome-linked inhibitor of apoptosis and FLICE-like inhibitor protein may play an important role in preventing Fas-mediated apoptosis in lung fibroblasts, and participate in the development of pulmonary fibrosis.

TGF-beta 1 as an enhancer of Fas-mediated apoptosis of lung epithelial cells

Transforming growth factor-beta 1 (TGF-beta 1) has important roles in lung fibrosis and the potential to induce apoptosis in several types of cells. We previously demonstrated that apoptosis of lung epithelial cells induced by Fas ligation may be involved in the development of pulmonary fibrosis. In this study, we show that TGF-beta1 induces apoptosis of primary cultured bronchiolar epithelial cells via caspase-3 activation and down-regulation of cyclin-dependent kinase inhibitor p21. Concentrations of TGF-beta 1 that were not sufficient to induce apoptosis alone could enhance agonistic anti-Fas Ab or rFas ligand-mediated apoptosis of cultured bronchiolar epithelial cells. Soluble Fas ligand in the bronchoalveolar lavage fluid (BALF) from patients with idiopathic pulmonary fibrosis (IPF) also induced apoptosis of cultured bronchiolar epithelial cells that was significantly attenuated by anti-TGF-beta Ab. Otherwise, BALF from patients with hypersensitivity pneumonitis (HP) could not induce apoptosis on bronchiolar epithelial cells, despite its comparable amounts of soluble Fas ligand. The concentrations of TGF-beta 1 in BALF from patients with IPF were significantly higher compared with those in BALF from patients with HP or controls. Furthermore, coincubation with the low concentration of TGF-beta 1 and HP BALF created proapoptotic effects comparable with the IPF BALF. In vivo, the administration of TGF-beta 1 could enhance Fas-mediated epithelial cell apoptosis and lung injury via caspase-3 activation in mice. Our results demonstrate a novel role of TGF-beta 1 in the pathophysiology of pulmonary fibrosis as an enhancer of Fas-mediated apoptosis of lung epithelial cells.

Increased circulating levels of soluble Fas ligand are correlated with disease activity in patients with fibrosing lung diseases

OBJECTIVE

The Fas-Fas ligand (FasL) pathway is one of the important apoptosis-signalling molecule systems. We previously determined that this pathway may be involved in the pathogenesis of fibrosing lung diseases. In the present study, we evaluated the clinical significance of the levels of soluble forms of Fas (sFas) and FasL (sFasL) in serum from patients with fibrosing lung diseases.

METHODOLOGY

We measured sFas, sFasL, KL-6 (a measure of alveolar type II cell damage), surfactant protein D (SP-D), and surfactant protein A (SP-A) levels in serum from 35 patients with idiopathic pulmonary fibrosis (IPF), 17 patients with interstitial pneumonia associated with collagen vascular diseases (CVD-IP), and 13 normal healthy controls using enzyme-linked immunosorbent assays (ELISA).

RESULTS

The serum levels of sFasL were significantly increased in patients with active IPF and CVD-IP, compared with those with inactive disease and controls. There was no significant difference in sFasL levels between patients with inactive disease and controls. Serum sFasL levels were significantly correlated with lactate dehydrogenase and KL-6 levels in IPF. The decrease in sFasL levels following corticosteroid therapy was not correlated with the clinical course of IPF. There was no significant difference in serum sFas levels between IPF or CVD-IP patients and controls.

CONCLUSIONS

Although further studies need to be performed on a large number of patients with histologically proven IPF or CVD-IP, it would seem that serum sFasL levels may reflect the activity of IPF and CVD-IP.

Upregulation of Fas-signalling molecules in lung epithelial cells from patients with idiopathic pulmonary fibrosis

The caspase cascade is an executioner of apoptosis, mediated by Fas. Fas-associating protein with death domain (FADD) interacts with Fas and initiates apoptosis through activating caspase-8. It has previously been demonstrated that the Fas-Fas ligand pathway may be involved in the pathophysiology of idiopathic pulmonary fibrosis (IPF). The aim of this study was to investigate Fas-signalling molecules in epithelial cells in IPF. The immunohistochemistry for FADD and caspase-1 and -3 and terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick endlabelling (TUNEL) methods were performed in lung tissues from 10 patients with IPF obtained by thoracoscopic biopsy and in seven normal lung parenchyma specimens. The induction of caspases expression and activation by Fas-ligation on lung epithelial cell line A549 was also investigated. The immunoreactivity grade for FADD and caspase-1 and -3, and positive signals for TUNEL were significantly increased in epithelial cells of IPF compared with controls. Fas-ligation induced upregulation of caspase-1 and -3 expression in the nucleus and cytoplasm in A549 cells. Procaspase-1, -3, and -8 were activated in apoptotic cells, but not in viable cells. Although direct measurement of the caspase activity in lung epithelial cells of idiopathic pulmonary fibrosis could not be made, these results suggest that the Fas-signalling pathway is upregulated in lung epithelial cells of idiopathic pulmonary fibrosis.

Attenuation of bleomycin-induced pneumopathy in mice by a caspase inhibitor

Caspases have been implicated in the effector process of apoptosis in several systems including the Fas-Fas ligand pathway. We previously demonstrated that excessive apoptosis of lung epithelial cells and the Fas-Fas ligand pathway were essential in the pathogenesis of bleomycin-induced pneumopathy in mice. Therefore, the purpose of this study was to investigate whether a caspase inhibitor could prevent the development of this model. The expression of caspase-1 and caspase-3 was upregulated on lung epithelial cells, alveolar macrophages, and infiltrating inflammatory cells in this model. We demonstrated that a broad-spectrum caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone, decreased the caspase-1- and caspase-3-like activity, the number of apoptotic cells, the pathological grade of lung inflammation and fibrosis, and the hydroxyproline content in lung tissues in this model. We conclude that caspase inhibitors could be a new therapeutic approach against lung injury and pulmonary fibrosis.

Inhibition of N-linked glycosylation causes apoptosis in hamster BHK21 cells

The tsBN7 cell line is one of the temperature-sensitive mutants for cell proliferation derived from hamster BHK21 cell line. It has a mutation in the DAD1 gene and enters apoptosis at the restrictive temperature of 39 degrees C. The defect of Dad1p causes a loss of N-linked glycosylation; therefore, it was thought that an inhibition of N-linked glycosylation induced apoptosis.However, tunicamycin, a potent inhibitor of N-linked glycosylation, had not caused apoptosis in wild-type BHK21 cells. In order to clarify this discrepancy, wild-type BHK21 cells treated with tunicamycin and tsBN7 cells incubated at 39.5 degrees C were examined by the annexin V staining and TUNEL methods. Both methods showed that tunicamycin induces apoptosis in wild-type BHK21 cells, similar to the defect of Dad1p. Thus, we concluded that loss of N-linked glycosylation causes apoptosis.

A subunit of the mammalian oligosaccharyltransferase, DAD1, interacts with Mcl-1, one of the bcl-2 protein family

DAD1 is a mammalian homologue of Saccharomyces cerevisiae Ost2p, a subunit of the oligosaccharyltransferase complex. Loss of its function induces apoptosis in hamster BHK21 cells. By means of a two-hybrid method involving DAD1 as bait, the C-terminal region of Mcl-1, one of the bcl-2 family, was isolated. Consistently, DAD1 binds well to Mcl-1 in COS cells when overexpressed. On deletion analysis, the C-terminal domain of Mcl-1 containing BH(2) (bcl-2 homologous domain) was found to be essential for the interaction with DAD1. On the other hand, the C-terminal half of DAD1 was concluded to be essential for the interaction with Mcl-1. Surprisingly, a DeltaC-DAD1 mutant lacking only 4 amino acid residues from the C-terminus did not complement the tsBN7 mutation, while it interacted well with Mcl-1. In contrast, DeltaN-DAD1 lacking 20 amino acid residues from the N-terminus still exhibited the ability to complement the tsBN7 mutation. Thus, the C-terminus of DAD1 was suggested to play an important role in N-linked glycosylation and to complement the tsBN7 mutation. Mcl-1 may be required for the inhibition of apoptotic cell death caused by a loss of DAD1.

Analysis of Fas and Fas ligand expression and function in lung cancer cell lines

The aim of this study was to investigate the expression of Fas and Fas ligand (FasL) and to determine the significance of these molecules in lung cancer cell lines. Immunoblotting, RT-PCR and flow cytometric analyses were carried out to measure the expression of Fas and FasL and to examine their interactions and effects on cell growth and apoptosis. Fas and FasL were co-expressed in most of the cell lines but to varying degrees. Apoptosis induced by the agonistic anti-Fas antibody was significantly correlated with Fas expression (P=0.0075), whereas cisplatin-induced apoptosis was not. Upregulation of Fas and FasL expression by the administration of cisplatin was found in 7 of 11 (64%) and 9 of 11 (82%) cell lines, respectively. However, cisplatin-induced apoptosis was not suppressed by antagonistic anti-FasL antibody. Thus, our data indicated that Fas and FasL were co-expressed in lung cancer cell lines, and that Fas ligation induced by agonistic anti-Fas antibody is functional and induced apoptosis that was dependent on the levels of Fas expression. In contrast, Fas-FasL interactions appeared to be non-functional. Furthermore, our results suggest that cisplatin-induced apoptosis in lung cancer cells was independent of the Fas-FasL interaction.

Induction of interleukin-8 secretion and apoptosis in bronchiolar epithelial cells by Fas ligation

Epithelial cell injury is the common manifestation of lung injury. Contributing to such injury of epithelial cells is apoptosis. Although apoptosis is part of the normal process of epithelial renewal, in excess it is pathologic. We previously demonstrated the excessive apoptosis of lung epithelial cells and the upregulation of Fas and Fas ligand (FasL) in fibrosing lung diseases. We also showed that inhalation of anti-Fas antibody induced lung injury and fibrosis in mice. Interleukin (IL)-8 is one of the most important cytokines in the pathophysiology of acute lung injury and pulmonary fibrosis. In this study we investigated whether Fas ligation induces IL-8 secretion in addition to apoptosis in bronchiolar epithelial cells in vitro. Bronchiolar epithelial cells underwent apoptosis and also secreted IL-8 in response to tumor necrosis factor (TNF)-alpha or Fas ligation. New gene expression and protein synthesis were not necessary for Fas ligation- and TNF-alpha- mediated apoptosis, but were necessary for IL-8 secretion. We further found that Fas ligation induced activation of nuclear factor-kappa B. We conclude that the Fas/FasL pathway not only mediates apoptosis but also plays a proinflammatory role, and that stimulation of the Fas/FasL pathway in bronchiolar epithelial cells leads to IL-8 production, which may amplify the inflammatory cascade in lung injury and pulmonary fibrosis.

[Spontaneous recovery from cytomegalovirus pneumonia]

A 30-year-old woman with systemic lupus erythematosus was admitted to our hospital because of a slight fever and diffuse interstitial shadows on a chest X-ray film. She had taken prednisolone (60 mg per day) at another hospital for six weeks. At the time of admission to our hospital, she had been treated with antituberculosis drugs (streptomycin, isoniazid, and rifampicin) for two weeks because of suspected miliary tuberculosis. Chest radiography on admission revealed diffuse nodular and micronodular shadows in the middle and lower lung fields on both sides. Examination of transbronchial lung biopsy specimens revealed intranuclear viral inclusion bodies in infected alveolar epithelial cells, which suggested the diagnosis of cytomegalovirus infection. The elevation of serum IgM antibody to cytomegalovirus and positive results of in situ hybridization for cytomegalovirus DNA supported this diagnosis. The symptoms and radiographic abnormalities resolved completely without ganciclovir. Although we cannot exclude the possibility that the antituberculosis drugs caused the resolution of the cytomegalovirus pneumonia, it appears most probable that the cytomegalovirus pneumonia resolved spontaneously.

[Pulmonary arterio-venous fistula treated by embolization with steel coils]

A 63-year-old man was referred to our hospital for evaluation and treatment of severe dyspnea on exertion which had persisted for a few years. He presented with cyanosis and markedly clubbed fingers, and laboratory data disclosed hypoxemia, polycythemia, and liver dysfunction. A chest X-ray film showed increased vascular markings in both lower lung fields. Arterial blood gas analysis showed severe hypoxemia, with a PaO2 of 46 Torr and a PaCO2 of 31 Torr while the patient was breathing room air. The PaO2 increased only slightly with inhalation of 100% oxygen, which suggested the presence of a large R-L shunt. The hepatopulmonary syndrome was diagnosed. Angiography of the pulmonary artery revealed a large pulmonary arterio-venous fistula with markedly dilated arteries in both lower lobes. Transarterial embolization was done three times with a total of 62 metal coils. There were no complications. Embolization reduced the shunt from 56% to 31%, increased the PaO2, and relieved the dyspnea. Pulmonary artery embolization can be useful in treating pulmonary arterio-venous fistulas associated with the hepatopulmonary syndrome.

Percutaneous stenting for malignant biliary stenosis

Percutaneous stenting for malignant biliary stenosis is quite beneficial to patients with unresectable or recurrent disease, tremendously improving the quality of their lives. Percutaneous transhepatic biliary drainage (PTBD) was attempted in 92 patients with obstructive jaundice during the period between January 1986 and July 1989. Implantation of an endoprosthesis was performed in 14 cases (15.2%) and succeeded in 12 (85.7%). When a guide wire could not be passed distally across the stricture site, percutaneous transhepatic cholangioscopy (PTCS) through the dilated PTBD fistula was carried out to enable its passage. PTCS is also valuable in the preoperative diagnosis of obstructive jaundice. The patients who are not candidates for surgery are suitable for this procedure. A Miller double-mushroom stent is used as the endoprosthesis in the majority of cases. One patient with recurrent hepatoma has lived at home with this stent for greater than 3 years due to repeated transarterial embolization and chemotherapy and does not need to wash or change the stent.

Surface hydrophobicity of spores of Bacillus spp

The surface hydrophobicity of 12 strains of Bacillus spp. was examined in a hexadecane-aqueous partition system. Mature and germinated spores of Bacillus megaterium QM B1551 transferred to the hexadecane layer, while vegetative and sporulating cells did not. Wild-type spores were more hydrophobic than spores of an exosporium-deficient mutant of B. megaterium QM B1551, although the mutant spores were shown to be hydrophobic to some extent by using increased volumes of hexadecane. This result suggests that the exosporium is more hydrophobic than the spore coat and that the surface hydrophobicity of spores depends mainly on components of the exosporium. The surface hydrophobicity of spores of nine other species of Bacillus was also examined, and spores having an exosporium were more hydrophobic than those lacking an exosporium. Thus measurement of the hydrophobicity of spores by the hexadecane partition method may provide a simple and rapid preliminary means of determining the presence or absence of an exosporium.