[CQ IN THE LONG-TERM MANAGEMENT OF ADULT ASTHMATIC PATIENTS WHO ARE NOT ADEQUATELY CONTROLLED WITH INHALED CORTICOSTEROIDS MONOTHERAPY, WHICH IS MORE BENEFICIAL: ADDING A LONG ACTING BETA2 AGONIST OR A LONG ACTING MUSCARINIC ANTAGONIST?]

Long-acting beta2-agonists (LABA) are preferred add-on treatment for adult asthmatic patients whose symptoms cannot be controlled with inhaled corticosteroids (ICS) alone. However, over the last decade, long-acting muscarinic antagonists (LAMA) have gained approval for use in treating asthma, and their efficacy is anticipated. Therefore, we conducted a systematic review to investigate whether the addition of LABA or LAMA is more beneficial for the long-term management of adult asthmatic patients poorly controlled on ICS monotherapy. We extracted eight relevant randomized controlled trials (represented in 18 articles) conducted by June 2022 form the corresponding Cochrane review and additional searches through medical databases (CINAHL, Cochrane Library, EMBASE, MEDLINE, PsycINFO, and ICHUSHI (https://www.jamas.or.jp/)). While the LAMA add-on group showed a significantly better improvement in some respiratory function tests, the difference between groups did not exceed the minimum clinically important difference (MCID). On the other hand, the Asthma Quality of Life Questionnaire, a quality of life metric, was significantly higher in the LABA add-on group, but the difference also did not surpass the MCID. Because no outcomes exceeded the MCID, we could not determine whether adding LABA or LAMA on ICS is more beneficial in the long-term management of adult asthmatic patients. Given that no significant differences were found in the incidence of adverse events (including serious ones), when specific adverse events associated with one treatment occur, switching to the other treatment (from LABA to LAMA, or vice versa) can be considered as an option.

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.

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.

Iron-Regulated Reactive Oxygen Species Production and Programmed Cell Death in Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is characterized by persistent respiratory symptoms and airflow limitation. However, the pathogenesis of COPD remains unclear. Currently, it is known to involve the loss of alveolar surface area (emphysema) and airway inflammation (bronchitis), primarily due to exposure to cigarette smoke (CS). CS causes epithelial cell death, resulting in pulmonary emphysema. Moreover, CS induces iron accumulation in the mitochondria and cytosol, resulting in programmed cell death. Although apoptosis has long been investigated as the sole form of programmed cell death in COPD, accumulating evidence indicates that a regulated form of necrosis, called necroptosis, and a unique iron-dependent form of non-apoptotic cell death, called ferroptosis, is implicated in the pathogenesis of COPD. Iron metabolism plays a key role in producing reactive oxygen species (ROS), including mitochondrial ROS and lipid peroxidation end-products, and activating both necroptosis and ferroptosis. This review outlines recent studies exploring CS-mediated iron metabolism and ROS production, along with the regulation of programmed cell death in COPD. Elucidating the mechanisms of these pathways may provide novel therapeutic targets for COPD.

Genomic analysis between idiopathic pulmonary fibrosis and associated lung cancer using laser-assisted microdissection: A case report.

Lung cancer (LC) is the most fatal complication of idiopathic pulmonary fibrosis (IPF). However, the molecular pathogenesis of the development of LC from IPF is still unclear. Here, we report a case of IPF-associated LC for which we investigated the genetic alterations between IPF and LC. We extracted formalin-fixed paraffin-embedded DNA from each part of the surgical lung tissue using a laser-assisted microdissection technique. The mutations in each part were detected by next-generation sequencing (NGS) using 72 lung cancer-related mutation panels. Five mutations were found in IPF and four in LC. Almost all somatic mutations did not overlap between the IPF and LC regions. These findings suggest that IPF-associated LC may not be a result of the accumulation of somatic mutations in the regenerated epithelium of the honeycomb lung in the IPF region.

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.

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.

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.

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.

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.

Increased extracellular vesicle miRNA-466 family in the bronchoalveolar lavage fluid as a precipitating factor of ARDS.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is a life-threatening disease; however, its treatment has not yet been fully established. The progression of ARDS is considered to be mediated by altered intercellular communication between immune and structural cells in the lung. One of several factors involved in intercellular communication is the extracellular vesicle (EV). They act as carriers of functional content such as RNA molecules, proteins, and lipids and deliver cargo from donor to recipient cells. EVs have been reported to regulate the nucleotide-binding oligomerization like receptor 3 (NLRP3) inflammasome. This has been identified as the cellular machinery responsible for activating inflammatory processes, a key component responsible for the pathogenesis of ARDS. METHODS: Here, we provide comprehensive genetic analysis of microRNAs (miRNAs) in EVs, demonstrating increased expression of the miRNA-466 family in the bronchoalveolar lavage fluid of a mouse ARDS model. RESULTS: Transfection of bone marrow-derived macrophages (BMDMs) with miRNA-466 g and 466 m-5p resulted in increased interleukin-1 beta (IL-1ß) release after LPS and ATP treatment, which is an established in vitro model of NLRP3 inflammasome activation. Moreover, LPS-induced pro-IL-1ß expression was accelerated by miRNA-466 g and 466 m-5p in BMDMs. CONCLUSIONS: These findings imply that miRNA-466 family molecules are secreted via EVs into the airways in an ARDS model, and this exacerbates inflammation through the NLRP3 inflammasome. Our results suggest that the NLRP3 inflammasome pathway, regulated by extracellular vesicle miRNA, could act as a therapeutic target for ARDS.

Combined Assessment of Serum Periostin and YKL-40 May Identify Asthma-COPD Overlap.

BACKGROUND: Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) has been proposed as a different diagnosis from asthma and COPD. However, little is known about the role of serum biomarkers in ACO. OBJECTIVE: To evaluate serum periostin, a type 2 biomarker, and serum chitinase-3-like protein 1 (YKL-40), a useful biomarker for COPD, in Japanese patients with asthma, ACO, or COPD, and investigate the role of these biomarkers in identifying ACO. METHODS: Subjects included Japanese patients with asthma (n = 177), ACO (n = 115), or COPD (n = 61). Serum periostin, YKL-40, and total IgE, blood eosinophils, and fractional exhaled nitric oxide were measured and compared among the patients. RESULTS: Serum periostin was high in both asthma and ACO, but not in COPD, whereas serum YKL-40 was high in both COPD and ACO, but not in asthma. Serum periostin levels correlated weakly with eosinophil counts in asthma, ACO, and COPD. Multivariate linear regression analysis revealed that older age, lower body mass index, higher eosinophil counts, higher total IgE, and the absence of the diagnosis of COPD were significantly associated with higher periostin levels. Based on cutoff values derived by receiver operating characteristic analysis (periostin: 55.1 ng/mL; YKL-40: 61.3 ng/mL), patients were classified into high or low groups. The proportion of patients with both high serum periostin and YKL-40 levels was significantly higher in ACO than in asthma or COPD. CONCLUSIONS: Serum periostin levels were comparable between asthma and ACO, whereas YKL-40 was comparable between ACO and COPD. Combined assessment of serum periostin and YKL-40 may identify ACO.

Autophagy, selective autophagy, and necroptosis in COPD.

COPD is characterized by persistent respiratory symptoms and airflow limitation, caused by a mixture of small airway disease and pulmonary emphysema. Programmed cell death has drawn the attention of COPD researchers because emphysema is thought to result from epithelial cell death caused by smoking. Although apoptosis has long been thought to be the sole form of programmed cell death, recent studies have reported the existence of a genetically programmed and regulated form of necrosis called necroptosis. Autophagy was also previously considered a form of programmed cell death, but this has been reconsidered. However, recent studies have revealed that autophagy can regulate programmed cell death, including apoptosis and necroptosis. It is also becoming clear that autophagy can selectively degrade specific proteins, organelles, and invading bacteria by a process termed "selective autophagy" and that this process is related to the pathogenesis of human diseases. In this review, we outline the most recent studies implicating autophagy, selective autophagy, and necroptosis in COPD. Strategies targeting these pathways may yield novel therapies for COPD.