Fusobacterium nucleatum putatively affects the alveoli by disrupting the alveolar epithelial cell tight junction, enlarging the alveolar space, and increasing paracellular permeability.

Fusobacterium nucleatum (Fn) is abundant in the human oral cavity and has been associated with periodontal disease, which in-turn has been linked to respiratory disease development. Tight junctions (TJs) line the airway and alveoli surfaces serving as a first line of defense against multiple pathogens. Fn has already been linked to respiratory diseases, however, how Fn affects the alveolar TJ was not fully elucidated. Here, we designed and analyzed a TJ network, grew Fn cells and inoculated it in vitro (16HBE and primary cells) and in vivo (mice lung), measured transepithelial electrical resistance, performed RT-PCR, checked for in vitro cell and mice lung permeability, and determined air space size through morphometric measurements. We found that Fn can potentially affect TJs proteins that are directly exposed to the alveolar surface. Additionally, Fn could possibly cause neutrophil accumulation and an increase in alveolar space. Moreover, Fn putatively may cause an increase in paracellular permeability in the alveoli.

A Changing Anti-Neutrophil Cytoplasmic Antibody Profile in a Patient With a Diagnosis of Eosinophilic Granulomatosis With Polyangiitis.

This report describes a hitherto unique case of eosinophilic granulomatosis with polyangiitis (EGPA), a subtype of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. The patient was an 81-year-old man whose clinical course involved notable changes in the ANCA profile, specifically a transition from positive proteinase 3 (PR3)-ANCA to myeloperoxidase (MPO)-ANCA, followed by simultaneous positivity for both. The patient's medical history included bronchial asthma, allergic rhinitis, sinusitis, and multiple comorbidities. Despite being initially PR3-ANCA-positive, subsequent admissions demonstrated MPO-ANCA positivity along with eosinophilic manifestations, highlighting the complexity of diagnosis of EGPA. Diagnostic evaluation included imaging, serological markers, and clinical symptoms, which collectively supported the classification of EGPA. Notably, this case challenges the conventional diagnostic paradigms and emphasizes the evolving nature of ANCA profiles in vasculitis. The shift in ANCA profile prompted a reevaluation of the patient's diagnosis and treatment strategy. This case underscores the importance of considering fluctuations in ANCA in patients with a diagnosis of EGPA, management decisions, and potential implications for disease progression. Further research is warranted to elucidate the mechanisms underlying changes in ANCA and their clinical significance in vasculitis.

Anti-UBE2T antibody: A novel biomarker of progressive-fibrosing interstitial lung disease.

BACKGROUND: Anti-fibrotic therapy has demonstrated efficacy against progressive-fibrosing interstitial lung disease (PF-ILD); therefore, identifying disease behavior before progression has become a priority. As autoimmunity is implicated in the pathogenesis of various ILDs, this study explored circulating biomarkers that could predict the chronic progressive behavior of ILDs. METHODS: A single-center retrospective cohort study was conducted. Circulating autoantibodies in patients with ILD were screened using microarray analysis to identify candidate biomarkers. An enzyme-linked immunosorbent assay was performed with a larger sample set for the quantification of antibodies. After 2 years of follow-up, ILDs were reclassified as PF or non-PF. The relationship between the participants' autoantibody levels measured at enrolment and final diagnosis of PF-ILD was determined. RESULTS: In total, 61 healthy participants and 66 patients with ILDs were enrolled. Anti-ubiquitin-conjugating enzyme E2T (UBE2T) antibody was detected as a candidate biomarker. Anti-UBE2T antibody levels were elevated in patients with idiopathic pulmonary fibrosis (IPF). After following up on the study participants for 2 years, anti-UBE2T levels measured at enrolment significantly correlated with the new PF-ILD diagnosis. Immunohistochemical staining of normal lung tissues revealed sparsely located UBE2T in the bronchiole epithelium and macrophages, whereas IPF lung tissues showed robust expression in the epithelial lining of honeycomb structures. CONCLUSION: To our knowledge, this is the first report to describe an anti-UBE2T antibody, a new biomarker that is significantly elevated in patients with ILD who present future disease progression.

Factors associated with surrogate families' life-sustaining treatment preferences for patients at home or in a geriatric health service facility: A cross-sectional study.

OBJECTIVE: Recently, end-of-life preference in palliative care has been gaining attention in Japan. The Ministry of Health, Labor, and Welfare established the Japanese basic policy in November 2018. Patients' decision-making is recommended; however, patients with dementia or other disorders cannot make such decisions by themselves. Thus, healthcare providers may contact surrogates and consider their backgrounds for better decision-making. Hence, the preferences of home caregivers' and geriatric health service facility (GHSF) residents' families on patient life-sustaining treatment (LST) were investigated. METHOD: This cross-sectional study involved home caregivers' and GHSF residents' families in Japan. We distributed 925 self-reported questionnaires comprising items, such as the number of people living together, care duration, comprehension of doctor's explanations, the Patient Health Questionnaire (PHQ)-9 and Short Form (SF)-8, and families' LST preference for patients. RESULTS: In all, 619 valid responses were obtained [242 men and 377 women (309 in the HOME Caregivers Group, response rate = 61.1%; 310 in the GHSF Group, response rate = 74.0%)]. LST preference was significantly associated with sex, the number of people living together, care duration, and comprehension of doctors' explanations in the HOME Caregivers Group but was not significantly associated with the GHSF Group. Furthermore, PHQ-9/SF-8 scores were not significantly associated with LST preference. SIGNIFICANCE OF RESULTS: There were many differences in opinions about LST preference between home caregivers' and GHSF residents' families. The results suggested that the burden of nursing care was greater and harder in home caregiver families, and these factors may be related to the LST preference for a patient.

Omalizumab and IgE in the Control of Severe Allergic Asthma.

Omalizumab, a human immunoglobulin (Ig)G1 antibody against IgE, is a therapeutic agent for bronchial asthma. The Global Initiative for Asthma guidelines indicate that the use of omalizumab should be considered as an option in step 5 of treatment for patients with the most severe type of bronchial asthma. In patients with atopic asthma who are at a high risk of exacerbation, and in whom symptoms are poorly controlled despite treatment with inhaled corticosteroids, omalizumab is one of the few drugs that improves symptoms, reduces the risk of exacerbation, and improves the quality of life while offering a high level of safety. On the other hand, the associated treatment costs are high, and there are no clear methods to identify responders. A recent study suggested that evaluating the therapeutic effects and monitoring the pharmacokinetics of omalizumab could improve the success of omalizumab therapy. This review outlines the relationship between IgE-targeted therapy and the serum level of IgE to enhance the current understanding of the mechanism of omalizumab therapy. It also describes the clinical significance of measuring serum free IgE levels and monitoring omalizumab therapy.

Periodontopathic Bacterium Fusobacterium nucleatum Affects Matrix Metalloproteinase-9 Expression in Human Alveolar Epithelial Cells and Mouse Lung.

BACKGROUND/AIM: Despite evidence of an association between pulmonary diseases and periodontopathic bacteria, the molecular mechanisms remain unknown. Matrix metalloproteinase-9 (MMP9) plays important roles in pneumonia, chronic obstructive pulmonary disease, and asthma; therefore, we assessed the effects of Fusobacterium nucleatum on MMP9 expression in mouse lung and A549 human alveolar epithelial cells. MATERIALS AND METHODS: Heat-killed F. nucleatum was administered to the trachea of mice or added to A549 cell cultures. MMP9 expression was determined using real-time PCR and western blotting. The involvement of mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB) in MMP9 expression was examined. RESULTS: F. nucleatum induced expression of MMP9 in mouse lung and bronchoalveolar lavage fluid. In A549 cells, F. nucleatum induced production of MMP9 protein and mRNA in a density-dependent manner; this was inhibited by inhibitors of extracellular-regulated kinase 1/2 and NF-κB, but not of p38 and Jun N-terminal protein kinase. CONCLUSION: F. nucleatum may contribute to the onset of pulmonary diseases via MMP9 expression through extracellular-regulated kinase 1/2 and NF-κB activation.

Mental Health Status before and during the COVID-19 Pandemic in Patients First Visiting a Psychosomatic Internal Medicine Clinic in Tokyo, Japan.

The coronavirus disease (COVID-19) pandemic has aggravated anxiety and depression worldwide, particularly in patients with chronic illnesses and mental disorders. Using validated questionnaires, in this paper, we examine the psychological effects of the pandemic in Japan in detail. The General Mental Health Scale (GHQ), the State-Trait Anxiety Inventory (STAI), and the Center for Epidemiologic Studies Depression Scale (CES-D) were used to assess mental health, state and trait anxiety, and depression, respectively. The survey was completed during the patients' first visits to the clinic of Psychosomatic Internal Medicine from November 2018 to April 2021. The Mann-Whitney U test was used to compare data from 226 participants before and during the COVID-19 pandemic. The GHQ total, GHQ subscales of "social dysfunction" and "anxiety and dysphoria", and state anxiety scores were significantly higher during than before the pandemic. The GHQ total, some GHQ subscales, and state anxiety scores were significantly higher among male than female participants during the pandemic. The GHQ total, some GHQ subscales, CES-D, and state anxiety scores in those aged 10-39 years were significantly higher. Thus, the COVID-19 pandemic may have caused mental health changes in many individuals based on their gender, age, and with time.

Our future: Experiencing the coronavirus disease 2019 (COVID-19) outbreak and pandemic.

Outbreaks of the novel coronavirus disease (severe acute respiratory syndrome coronavirus 2: SARS-CoV-2) (coronavirus disease 2019; COVID-19) remind us once again of the mechanisms of zoonotic outbreaks. Climate change and the expansion of agricultural lands and infrastructures due to population growth will ultimately reduce or eliminate wildlife and avian habitats and increase opportunities for wildlife and birds to come into contact with livestock and humans. Consequently, infectious pathogens are transmitted from wildlife and birds to livestock and humans, promoting zoonotic diseases. In addition, the spread of diseases has been associated with air pollution and social inequities, such as racial discrimination, gender inequality, and racial, economic, and educational disparities. The COVID-19 pandemic is a fresh reminder of the significance of excessive greenhouse gas excretion and air pollution, highlighting social inequities and distortions. This provides us with an opportunity to reflect on the appropriateness of our trajectory. Therefore, this review glances through the COVID-19 pandemic and discusses our future.

Porphyromonas gingivalis gingipains potentially affect MUC5AC gene expression and protein levels in respiratory epithelial cells.

Porphyromonas gingivalis (Pg) is a periodontopathic pathogen that may affect MUC5AC-related mucus hypersecretion along airway epithelial cells. Here, we attempted to establish whether Pg virulence factors (lipopolysaccharide, FimA fimbriae, gingipains) affect MUC5AC in immortalized and primary bronchial cells. We report that MUC5AC gene expression and protein levels are affected by Pg culture supernatant, but not by lipopolysaccharide or FimA fimbriae. Cells treated with either Pg single (Kgp or Rgp) or double (Kgp/Rgp) mutants had altered levels of MUC5AC gene expression and protein levels, and MUC5AC staining of double mutant-treated mouse lung cells showed that MUC5AC protein levels were unaffected. Taken together, we propose that Pg gingipains may be the primary virulence factor that influences both MUC5AC gene expression and protein levels.

Effective ferroptotic small-cell lung cancer cell death from SLC7A11 inhibition by sulforaphane.

Small-cell lung cancer (SCLC) is a highly aggressive cancer with poor prognosis, due to a lack of therapeutic targets. Sulforaphane (SFN) is an isothiocyanate derived from cruciferous vegetables and has shown anticancer effects against numerous types of cancer. However, its anticancer effect against SCLC remains unclear. The present study aimed to demonstrate the anticancer effects of SFN in SCLC cells by investigating cell death (ferroptosis, necroptosis and caspase inhibition). The human SCLC cell lines NCI-H69, NCI-H69AR (H69AR) and NCI-H82 and the normal bronchial epithelial cell line, 16HBE14o- were used to determine cell growth and cytotoxicity, evaluate the levels of iron and glutathione, and quantify lipid peroxidation following treatment with SFN. mRNA expression levels of cystine/glutamate antiporter xCT (SLC7A11), a key component of the cysteine/glutamate antiporter, were measured using reverse transcription-quantitative PCR, while the levels of SLC7A11 protein were measured using western blot analysis. Following the addition of SFN to the cell culture, cell growth was significantly inhibited, and cell death was shown in SCLC and multidrug-resistant H69AR cells. The ferroptotic effects of SFN were confirmed following culture with the ferroptosis inhibitor, ferrostatin-1, and deferoxamine; iron levels were elevated, which resulted in the accumulation of lipid reactive oxygen species. The mRNA and protein expression levels of SLC7A11 were significantly lower in SFN-treated cells compared with that in the control cells (P<0.0001 and P=0.0006, respectively). These results indicated that the anticancer effects of SFN may be caused by ferroptosis in the SCLC cells, which was hypothesized to be triggered from the inhibition of mRNA and protein expression levels of SLC7A11. In conclusion, the present study demonstrated that SFN-induced cell death was mediated via ferroptosis and inhibition of the mRNA and protein expression levels of SLC7A11 in SCLC cells. The anticancer effects of SFN may provide novel options for SCLC treatment.

Iron-Dependent Mitochondrial Dysfunction Contributes to the Pathogenesis of Pulmonary Fibrosis.

Although the pathogenesis of pulmonary fibrosis remains unclear, it is known to involve epithelial injury and epithelial-mesenchymal transformation (EMT) as a consequence of cigarette smoke (CS) exposure. Moreover, smoking deposits iron in the mitochondria of alveolar epithelial cells. Iron overload in mitochondria causes the Fenton reaction, leading to reactive oxygen species (ROS) production, and ROS leakage from the mitochondria induces cell injury and inflammation in the lungs. Nevertheless, the mechanisms underlying iron metabolism and pulmonary fibrosis are yet to be elucidated. In this study, we aimed to determine whether iron metabolism and mitochondrial dysfunction are involved in the pathogenesis of pulmonary fibrosis. We demonstrated that administration of the iron chelator deferoxamine (DFO) reduced CS-induced pulmonary epithelial cell death, mitochondrial ROS production, and mitochondrial DNA release. Notably, CS-induced cell death was reduced by the administration of an inhibitor targeting ferroptosis, a unique iron-dependent form of non-apoptotic cell death. Transforming growth factor-ß-induced EMT of pulmonary epithelial cells was also reduced by DFO. The preservation of mitochondrial function reduced Transforming growth factor-ß-induced EMT. Furthermore, transbronchial iron chelation ameliorated bleomycin-induced pulmonary fibrosis and leukocyte migration in a murine model. Our findings indicate that iron metabolism and mitochondrial dysfunction are involved in the pathogenesis of pulmonary fibrosis. Thus, they may be leveraged as new therapeutic targets for pulmonary fibrosis.

Circulating microRNA-15b-5p as a biomarker for asthma-COPD overlap.

BACKGROUND: It remains unclear how to characterize different subtypes of asthma and chronic obstructive pulmonary disease (COPD). We previously described serum periostin and chitinase-3-like protein 1 (YKL-40) as useful markers for asthma-COPD overlap (ACO). MicroRNAs (miRNAs) are now recognized as markers for identifying the pathophysiological features in several diseases. This study aimed to identify circulating miRNAs that could discriminate patients with ACO from patients with asthma or COPD. METHODS: This study included two independent cohorts. First, we screened 84 miRNAs for expression levels in patients with ACO (n = 6) or asthma (n = 6) using a quantitative real-time PCR array. The miRNAs showing at least a 2-fold difference in the discovery phase were analyzed in 30 patients each with asthma, COPD, or ACO in the replication phase. The diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve (AUROC). RESULTS: Nine miRNAs were identified in the discovery phase. Five of these miRNAs (miR-148a-3p, miR-15b-5p, miR-223-3p, miR-23a-3p, and miR-26b-5p) had lower levels in ACO patients and could discriminate between ACO patients and patients with either asthma or COPD. miR-15b-5p was the most accurate miRNA for the discrimination of patients with ACO (AUROC, 0.71). Moreover, the combined assessment of miR-15b-5p, serum periostin, and YKL-40 (AUROC, 0.80) improved diagnostic accuracy for ACO compared with the combined model of periostin and YKL-40 (AUROC, 0.69). CONCLUSIONS: Circulating miR-15b-5p is a potential marker for identifying patients with ACO. By elucidating the molecular pathways controlled by miRNAs, we may better understand the pathophysiology of ACO.

DsRNA induction of microRNA-155 disrupt tight junction barrier by modulating claudins.

BACKGROUND: The impaired barrier function of the airway epithelium due to RNA virus infection is closely related to the development and exacerbation of allergic airway inflammation. OBJECTIVE: In this study, we investigated the roles of microRNAs on the mechanisms of double-stranded RNA (dsRNA)-induced epithelial barrier dysfunction. METHODS: 16HBE14o- human bronchial epithelial cells were grown to confluence on Transwell inserts and exposed to poly-I:C. We studied epithelial barrier function by measuring transepithelial electrical resistance and paracellular flux of fluorescent markers and structure of tight junctions by immunofluorescence microscopy. RESULTS: Poly-I:C treated 16HBE14o- cells increased paracellular permeability. Knockdown of Toll-like receptor 3 and TRIF abrogated these effects. The expression of microRNA-155 (miR-155) was increased by poly-I:C in dose-dependent manner. Transfection of mir155 mimics into 16HBE14o- cells increased permeability and inhibited tight junction formation. Transfection of miR-155 inhibitor suppressed poly-I:C-induced barrier disruption. Poly-I:C treatment significantly decreased the expression of claudin members-claudin-1, -3, -4, -5, -9, -11, -16, -18 and -19. Transfection of miR-155 mimics showed similar changing expression pattern of claudin members with those of poly-I:C treatment. CONCLUSION: These results suggest that RNA virus infection can impair the epithelial barrier disruption mechanism by down-regulation of claudin members through the induction of miR-155.

The Diagnosis of Exogenous Lipoid Pneumonia Caused by the Silent Aspiration of Vegetable Oil Using a Lipidomic Analysis.

We herein report a case of refractory exogenous lipoid pneumonia that was successfully attributed to vegetable oil through a lipidomic analysis of bronchoalveolar lavage fluid (BALF). As a 25-year-old woman diagnosed with lipoid pneumonia experienced repeated exacerbations and improvement, we performed a BALF lipidomic analysis. The major lipid components were oleic acid, linoleic acid, and α-linolenic acid, which are constituents of vegetable oil. She stopped consuming any vegetable oil and has since experienced no instances of lipoid pneumonia relapse. A lipidomic analysis appears to be useful for identifying causative lipids, since patients with lipoid pneumonia are sometimes unaware of aspiration episodes.

Role of Nrf2 in the pathogenesis of respiratory diseases.

Nuclear factor erythroid 2-related factor (Nrf)2 is a transcription factor that integrates cellular stress signals by directing various transcriptional programs. As an evolutionarily conserved intracellular defense mechanism, Nrf2 and its endogenous inhibitor Kelch-like ECH-associated protein (Keap)1 inhibit oxidative stress in the lung, which is the internal organ that is continuously exposed to the environment. Oxidative stress is implicated in the pathogenesis of various lung diseases including asthma, acute lung injury, chronic obstructive pulmonary disease (COPD), and interstitial lung disease (ILD). Thus, Nrf2 is considered as a potential therapeutic target in lung diseases owing to its antioxidant effect. Nrf2 also plays a complex role in lung cancer, acting as a tumor suppressor and promoter; recent studies have revealed the tumor-promoting effects of Nrf2 in tumors that have undergone malignant transformation. Lung cancer-associated mutations in Keap1 disrupt Keap1-Nrf2 complex formation, resulting in the ubiquitination and degradation of Keap1, and the constitutive activation of Nrf2. In lung cancer cells, persistently high nuclear Nrf2 levels induce the expression of genes that contribute to metabolic reprogramming, and stimulate cell proliferation. In this review, we outlined the major functions of Nrf2, and discussed its importance in pulmonary diseases such as asthma, acute respiratory distress syndrome, and lung cancer. Elucidating the mechanisms through which Nrf2 modulates the initiation and progression of pulmonary diseases can lead to the development of therapeutics specifically targeting this pathway.

Molecular techniques for respiratory diseases: MicroRNA and extracellular vesicles.

miRNA are a class of evolutionarily conserved non-coding 19- to 22-nt regulatory RNA. They affect various cellular functions through modulating the transcriptional and post-transcriptional levels of their target mRNA by changing the stability of protein-coding transcripts or attenuating protein translation. miRNA were discovered in the early 1990s, and they have been the focus of new research in both basic and clinical medical sciences. Today, it has become clear that specific miRNA are linked to the pathogenesis of respiratory diseases, as well as cancer and cardiovascular disease. In addition, EV, including exosomes, which are small membrane-bound vesicles secreted by cells, were found to contain various functional miRNA that can be used for diagnostic and therapeutic purposes. As body fluids, such as blood and respiratory secretions, are major miRNA sources in the body, EV carrying extracellular miRNA are considered potentially useful for the diagnosis and assessment of pathological conditions, as well as the treatment of respiratory or other diseases. Although research in the field of lung cancer is actively progressing, studies in other respiratory fields have emerged recently as well. In this review, we provide an update in the topics of miRNA and EV focused on airway inflammatory diseases, such as asthma and COPD, and explore their potential for clinical applications on respiratory diseases.

Pathogenesis of chronic obstructive pulmonary disease (COPD) induced by cigarette smoke.

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease that is characterized by functional and structural alterations primarily caused by long-term inhalation of harmful particles. Cigarette smoke (CS) induces airway inflammation in COPD, which is known to persist even after smoking cessation. This review discusses the basic pathogenesis of COPD, with particular focus on an endogenous protective mechanism against oxidative stress via Nrf2, altered immune response of the airway inflammatory cells, exaggerated cellular senescence of the lung structural cells, and cell death with expanded inflammation. Recently, CS-induced mitochondria autophagy is reported to initiate programmed necrosis (necroptosis). Necroptosis is a new concept of cell death which is driven by a defined molecular pathway along with exaggerated inflammation. This new cell death mechanism is of importance due to its ability to produce more inflammatory substances during the process of epithelial death, contributing to persistent airway inflammation that cannot be explained by apoptosis-derived cell death. Autophagy is an auto-cell component degradation system executed by lysosomes that controls protein and organelle degradation for successful homeostasis. As well as in the process of necroptosis, autophagy is also observed during cellular senescence. Aging of the lungs results in the acquisition of senescence-associated secretory phenotypes (SASP) that are known to secrete inflammatory cytokines, chemokines, growth factors, and matrix metalloproteinases resulting in chronic low-grade inflammation. In future research, we intend to highlight the genetic and epigenetic approaches that can facilitate the understanding of disease susceptibility. The goal of precision medicine is to establish more accurate diagnosis and treatment methods based on the patient-specific pathogenic characteristics. This review provides insights into CS-induced COPD pathogenesis, which contributes to a very complex disease. Investigating the mechanism of developing COPD, along with the availability of the particular inhibitors, will lead to new therapeutic approaches in COPD treatment.