Explore the vast range of titles available.

Background Patients with uncontrolled asthma despite the use of inhaled corticosteroids (ICS), may have a variety of biological pathways driving their airway inflammation. Londamocitinib (AZD4604), a selective, inhaled, Janus kinase 1 inhibitor, has been designed to target a broad inflammatory cytokine profile including those classically unresponsive to ICS. The ARTEMISIA mechanistic study aims to provide a clear understanding of the pathways impacted by londamocitinib in the lung, determine how this impact is reflected in the nose and periphery, and identify candidate biomarkers of londamocitinib-treatment response in asthma. This article reports the design and objectives of the ARTEMISIA study. Methods ARTEMISIA is a placebo-controlled, double-blind study of adults with moderate-to-severe asthma aiming to assess the effects of inhaled londamocitinib on Type 2 (T2) and non-T2 driven inflammatory pathways. Extensive parallel bio-sampling of the lung target tissue, nasal mucosa, blood and urine will be performed prior to the first dose and after 4-weeks of treatment with either londamocitinib or placebo. The main objectives of the study are to evaluate the effect of londamocitinib on gene expression in endobronchial brushings and signal transducer and activator of transcription (STAT) phosphorylation in endobronchial biopsies. Key exploratory objectives include investigating the correlation between inflammatory phenotype-specific bronchial epithelial gene signatures and other biomarkers in the lung and peripheral samples; as well as analysis of transcriptomic, proteomic, and metabolomic biomarkers in the nose, blood, and urine. Discussion ARTEMISIA commenced recruitment in 2024 and is poised to deliver a deep understanding of the mechanism of action of londamocitinib and its potential to impact on a population of asthmatics with high unmet need. The multiomic analysis of paired central and peripheral samples may reveal novel insights into the connection and translation between these compartments, deepen understanding of airways disease, and identify novel candidate biomarkers for asthma and JAK activity. In addition to sampling the airway directly, with parallel nasal and peripheral bio-sampling mirrored by the Phase 2a AJAX study (NCT06020014), the ARTEMISIA study may provide a unique link between bronchial assessed mechanisms of action and clinical outcomes. Trial registration NCT06435273 (ClinicalTrials.gov). Registered 24th May 2024.

Abstract Histone acetylation status is a key factor in the regulation of inflammatory gene transcription. We investigated the activity of histone acetylases (HAT) and deacetylases (HDAC), and the effect of glucocorticoids in alveolar macrophages (AM) and peripheral blood mononuclear cells (PBMC) from subjects with asthma. Bronchoalveolar lavage was performed in 10 patients with intermittent asthma, 8 with persistent asthma, and 10 healthy control subjects. PBMCs and granulocytes were isolated from six patients with mild and severe asthma, before and after a 7-day course of prednisolone (30 mg/day). AMs were isolated for HDAC assay or incubated with dexamethasone (1 μM). HAT activity was increased (1.43 ± 0.1 vs. 1.01 ± 0.1 standard units/10 μg, p < 0.05), and HDAC activity was reduced (3,031 ± 243 vs. 5,004 ± 164 arbitrary fluorescence units/10 μg, p < 0.001) in AMs of subjects with asthma compared with control subjects. Dexamethasone suppressed LPS-induced granulocyte macrophage-colony stimulating factor, tumor necrosis factor-α, and interleukin-8 release by 83 ± 1%, 51 ± 7% and 20 ± 9% (p < 0.001), respectively. Similar effects were seen on nuclear factor-κB inhibition, and interleukin-8 release was further reduced by the HDAC enhancer, theophylline (37 ± 6%). Prednisolone increased HDAC activity in PBMCs from subjects with mild asthma. The increased inflammatory response in asthma may be due to reduced HDAC and enhanced HAT activity. Glucocorticoids and theophylline may downregulate the inflammatory response by modulating HAT and HDAC activity, and nuclear factor-κB activation.

Abstract Recent studies suggest that a nitric oxide (NO) deficiency and elevated arginase activity may play a role in the pathogenesis of asthma. Although much attention has been directed toward measurements of exhaled NO in asthma, no studies to date have evaluated levels of plasma arginase or arginine, the substrate for NO production, in patients with asthma. This study, therefore, measured amino acid levels, arginase activity, and nitric oxide metabolites in the blood of patients with asthma, as well as NO in exhaled breath. Although levels of virtually all amino acids were reduced, patients with asthma exhibited a striking reduction in plasma arginine levels compared with normal control subjects without asthma (45 ± 22 vs. 94 ± 29 μM, p < 0.0001), and serum arginase activity was elevated (1.6 ± 0.8 vs. 0.5 ± 0.3 μmol/ml/hour, asthma vs. control, p < 0.0001). High arginase activity in patients with asthma may contribute to low circulating arginine levels, thereby limiting arginine bioavailability and creating a NO deficiency that induces hyperreactive airways. Addressing the alterations in arginine metabolism may result in new strategies for treatment of asthma.

Background We previously reported that asthmatic children with GSTM1 null genotype may be more susceptible to the acute effect of ozone on the small airways and might benefit from antioxidant supplementation. This study aims to assess the acute effect of ozone on lung function (FEF 25-75 ) in asthmatic children according to dietary intake of vitamin C and the number of putative risk alleles in three antioxidant genes: GSTM1 , GSTP1 (rs1695), and NQO1 (rs1800566). Methods 257 asthmatic children from two cohort studies conducted in Mexico City were included. Stratified linear mixed models with random intercepts and random slopes on ozone were used. Potential confounding by ethnicity was assessed. Analyses were conducted under single gene and genotype score approaches. Results The change in FEF 25-75 per interquartile range (60 ppb) of ozone in persistent asthmatic children with low vitamin C intake and GSTM1 null was −91.2 ml/s (p = 0.06). Persistent asthmatic children with 4 to 6 risk alleles and low vitamin C intake showed an average decrement in FEF 25-75 of 97.2 ml/s per 60 ppb of ozone (p = 0.03). In contrast in children with 1 to 3 risk alleles, acute effects of ozone on FEF 25-75 did not differ by vitamin C intake. Conclusions Our results provide further evidence that asthmatic children predicted to have compromised antioxidant defense by virtue of genetic susceptibility combined with deficient antioxidant intake may be at increased risk of adverse effects of ozone on pulmonary function.

Inflammatory diseases are often chronic and recurrent, and current treatments do not typically remove underlying disease drivers 1 . T cells participate in a wide range of inflammatory diseases such as psoriasis 2 , Crohn’s disease 3 , oesophagitis 4 and multiple sclerosis 5 , 6 , and clonally expanded antigen-specific T cells may contribute to disease chronicity and recurrence, in part by forming persistent pathogenic memory. Chronic rhinosinusitis and asthma are inflammatory airway diseases that often present as comorbidities 7 . Chronic rhinosinusitis affects more than 10% of the general population 8 . Among these patients, 20–25% would develop nasal polyps, which often require repeated surgical resections owing to a high incidence of recurrence 9 . Whereas abundant T cells infiltrate the nasal polyps tissue 10 , 11 , T cell subsets that drive the disease pathology and promote recurrence are not fully understood. By comparing T cell repertoires in nasal polyp tissues obtained from consecutive surgeries, here we report that persistent CD8 + T cell clones carrying effector memory-like features colonize the mucosal tissue during disease recurrence, and these cells characteristically express the tryptase Granzyme K (GZMK). We find that GZMK cleaves many complement components, including C2, C3, C4 and C5, that collectively contribute to the activation of the complement cascade. GZMK-expressing CD8 + T cells participate in organized tertiary lymphoid structures, and tissue GZMK levels predict the disease severity and comorbidities better than well-established biomarkers such as eosinophilia and tissue interleukin-5. Using a mouse asthma model, we further show that GZMK-expressing CD8 + T cells exacerbate the disease in a manner dependent on the proteolytic activity of GZMK and complements. Genetic ablation or pharmacological inhibition of GZMK after the disease onset markedly alleviates tissue pathology and restores lung function. Our work identifies a pathogenic CD8 + memory T cell subset that promotes tissue inflammation and recurrent airway diseases by the effector molecule GZMK and suggests GZMK as a potential therapeutic target. Comparing T cells in nasal polyps from repeated surgeries shows that effector memory-like persistent clones colonize the mucosal tissue during disease recurrence and promote inflammation by producing Granzyme K, a complement-activating tryptase, which is a potential therapeutic target.

Altered redox biology challenges all cells, with compensatory responses often determining a cell's fate. When 15 lipoxygenase 1 (15LO1), a lipid-peroxidizing enzyme abundant in asthmatic human airway epithelial cells (HAECs), binds phosphatidylethanolamine-binding protein 1 (PEBP1), hydroperoxy-phospholipids, which drive ferroptotic cell death, are generated. Peroxidases, including glutathione peroxidase 4 (GPX4), metabolize hydroperoxy-phospholipids to hydroxy derivatives to prevent ferroptotic death, but consume reduced glutathione (GSH). The cystine transporter SLC7A11 critically restores/maintains intracellular GSH. We hypothesized that high 15LO1, PEBP1, and GPX4 activity drives abnormal asthmatic redox biology, evidenced by lower bronchoalveolar lavage (BAL) fluid and intraepithelial cell GSH:oxidized GSH (GSSG) ratios, to enhance type 2 (T2) inflammatory responses. GSH, GSSG (enzymatic assays), 15LO1, GPX4, SLC7A11, and T2 biomarkers (Western blot and RNA-Seq) were measured in asthmatic and healthy control (HC) cells and fluids, with siRNA knockdown as appropriate. GSSG was higher and GSH:GSSG lower in asthmatic compared with HC BAL fluid, while intracellular GSH was lower in asthma. In vitro, a T2 cytokine (IL-13) induced 15LO1 generation of hydroperoxy-phospholipids, which lowered intracellular GSH and increased extracellular GSSG. Lowering GSH further by inhibiting SLC7A11 enhanced T2 inflammatory protein expression and ferroptosis. Ex vivo, redox imbalances corresponded to 15LO1 and SLC7A11 expression, T2 biomarkers, and worsened clinical outcomes. Thus, 15LO1 pathway-induced redox biology perturbations worsen T2 inflammation and asthma control, supporting 15LO1 as a therapeutic target.

Key Points Asthma and asthma-related traits are complex diseases with strong genetic and environmental components. Association and genome-wide linkage studies have identified numerous candidate genes that are associated with asthma-related traits and are involved in innate immunity, T helper 2 cell differentiation and effector functions, epithelial cell biology and lung function. The phenotypic impact of each of these genes, including the ones most often replicated in association studies, is mild, but larger effects may occur when multiple variants synergize within a permissive environmental context. Despite the achievements of asthma genetics, the identification of all the genes involved in disease, the replication of genotype–phenotype associations across populations, and the interactions of genes with environmental and developmental factors, and with one another, still represent formidable challenges. The development of novel, powerful tools for gene discovery, such as genome-wide association studies, and a closer integration with biology, should help asthma geneticists to overcome these challenges. A number of susceptibility genes for asthma and allergy have been identified in recent years. Here, Donata Vercelli discusses these genes and reviews the techniques used by geneticists to identify them. She also highlights the outstanding challenges in the field. Asthma and asthma-related traits are complex diseases with strong genetic and environmental components. Rapid progress in asthma genetics has led to the identification of several candidate genes that are associated with asthma-related traits. Typically the phenotypic impact of each of these genes, including the ones most often replicated in association studies, is mild, but larger effects may occur when multiple variants synergize within a permissive environmental context. Despite the achievements made in asthma genetics formidable challenges remain. The development of novel, powerful tools for gene discovery, and a closer integration of genetics and biology, should help to overcome these challenges.

Subepithelial fibrosis is a component of the remodeling observed in the bronchial wall of patients diagnosed with asthma. In this process, human bronchial fibroblasts (HBFs) drive the fibroblast-to-myofibroblast transition (FMT) in response to transforming growth factor-β1 (TGF-β1), which activates the canonical Smad-dependent signaling. However, the pleiotropic properties of TGF-β1 also promote the activation of non-canonical signaling pathways which can affect the FMT. In this study we investigated the effect of p38 mitogen-activated protein kinase (MAPK) inhibition by SB203580 on the FMT potential of HBFs derived from asthmatic patients using immunocytofluorescence, real-time PCR and Western blotting methods. Our results demonstrate for the first time the strong effect of p38 MAPK inhibition on the TGF-β1-induced FMT potential throughout the strong attenuation of myofibroblast-related markers: α-smooth muscle actin (α-SMA), collagen I, fibronectin and connexin 43 in HBFs. We suggest the pleiotropic mechanism of SB203580 on FMT impairment in HBF populations by the diminishing of TGF-β/Smad signaling activation and disturbances in the actin cytoskeleton architecture along with the maturation of focal adhesion sites. These observations justify future research on the role of p38 kinase in FMT efficiency and bronchial wall remodeling in asthma.

Background Patients with severe asthma may have a greater risk of dying from COVID-19 disease. Angiotensin converting enzyme-2 (ACE2) and the enzyme proteases, transmembrane protease serine 2 (TMPRSS2) and FURIN, are needed for viral attachment and invasion into host cells. Methods We examined microarray mRNA expression of ACE2, TMPRSS2 and FURIN in sputum, bronchial brushing and bronchial biopsies of the European U-BIOPRED cohort. Clinical parameters and molecular phenotypes, including asthma severity, sputum inflammatory cells, lung functions, oral corticosteroid (OCS) use, and transcriptomic-associated clusters, were examined in relation to gene expression levels. Results ACE2 levels were significantly increased in sputum of severe asthma compared to mild-moderate asthma. In multivariate analyses, sputum ACE2 levels were positively associated with OCS use and male gender. Sputum FURIN levels were significantly related to neutrophils (%) and the presence of severe asthma. In bronchial brushing samples, TMPRSS2 levels were positively associated with male gender and body mass index, whereas FURIN levels with male gender and blood neutrophils. In bronchial biopsies, TMPRSS2 levels were positively related to blood neutrophils. The neutrophilic molecular phenotype characterised by high inflammasome activation expressed significantly higher FURIN levels in sputum than the eosinophilic Type 2-high or the pauci-granulocytic oxidative phosphorylation phenotypes. Conclusion Levels of ACE2 and FURIN may differ by clinical or molecular phenotypes of asthma. Sputum FURIN expression levels were strongly associated with neutrophilic inflammation and with inflammasome activation. This might indicate the potential for a greater morbidity and mortality outcome from SARS-CoV-2 infection in neutrophilic severe asthma.

Obesity, especially truncal obesity, is a risk factor for asthma incidence, prevalence, and severity. Chitinase 3-like-1 (Chi3l1) is an evolutionarily conserved moiety that plays a critical role in antipathogen and Th2 responses. However, the mechanisms that underlie the association between asthma and obesity and the role(s) of Chi3l1 in fat accumulation have not been defined. To determine whether Chi3l1 is regulated by a high-fat diet (HFD) and simultaneously plays an important role(s) in the pathogenesis of asthma and obesity. We evaluated the regulation of Chi3l1 by an HFD and Th2 inflammation. We also used genetically modified mice to define the roles of Chi3l1 in white adipose tissue (WAT) accumulation and Th2 inflammation and blockers of sirtuin 1 (Sirt1) to define its roles in these responses. Finally, the human relevance of these findings was assessed with a case-control study involving obese and lean control subjects and those with asthma. These studies demonstrate that an HFD and aeroallergen challenge augment the expression of WAT and pulmonary Chi3l1. Chi3l1 also played a critical role in WAT accumulation and lung Th2 inflammation. In addition, Chi3l1 inhibited Sirt1 expression, and the deficient visceral fat and Th2 responses in Chi3l1 null mice were reversed by Sirt1 inhibition. Finally, serum and sputum Chi3l1 were positively associated with truncal adiposity, and serum Chi3l1 was associated with persistent asthma and low lung function in obese subjects with asthma. Chi3l1 is induced by an HFD and Th2 inflammation, and simultaneously contributes to the genesis of obesity and asthma.