Respiratory Research最新文献

Chronic obstructive pulmonary disease (COPD) is an irreversible and progressive chronic inflammatory lung disease which affects millions of people worldwide. Activated fibroblasts are observed to accumulate in lung of COPD patients and promote COPD progression through aberrant extracellular matrix (ECM) deposition. In this study, we identified that miR-1307-5p expression was significantly increased in lung fibroblasts derived from COPD patients. Mechanistically, we found that upregulation of miR-1307-5p promoted TGF-β induced lung fibroblast activation and transdifferentiation. We also identified FBXL16 as a direct target for miR-1307-5p mediated myofibroblast activation in COPD. Knockdown of FBXL16 by siRNA prominently increased the expression of myofibroblast markers in MRC-5 fibroblasts after TGF-β administration. Ectopic expression of FBXL16 in MRC-5 counteracted miR-1307-5p agomir-induced fibroblast transdifferentiation. Furthermore, We found that miR-1307-5p promoted pulmonary fibroblast transdifferentiation through FBXL16 regulated HIF1α degradation. In general, our findings indicate that miR-1307-5p is important for COPD pathogenesis, and may serve as a potential target for COPD treatment.

Background: Respiratory distress syndrome (RDS) and transient tachypnoea (TTN) are the two commonest neonatal respiratory disorders. The optimal continuous positive airway pressure (CPAP) to treat them is unknown. We aim to clarify the effect of different CPAP levels on lung aeration and gas exchange in patients with RDS and TTN.

Methods: Prospective, observational, pragmatic, physiological cohort study. CPAP was sequentially increased from 4 to 6 and 8 cmH₂O and backwards, with interposed wash-out periods. Lung aeration was assessed with a validated neonatal lung ultrasound score. Gas exchange was non-invasively evaluated with transcutaneous monitoring. Ultrasound score and PtcO₂/FiO₂ ratio were the co-primary outcomes. PtcCO₂ and other oxygenation metrics were the secondary outcomes.

Results: 30 neonates with RDS and 30 with TTN were studied. Each CPAP increment significantly (overall always p < 0.001) improved both lung aeration and oxygenation, but the increase from 6 to 8 cmH₂O achieved a small absolute benefit. In RDS patients, the absolute improvements were small and the diagnosis of TTN was significantly associated with greater improvement of lung aeration (β= -1.4 (95%CI: -2.4; -0.3), p = 0.01) and oxygenation (β = 39.6 (95%CI: 4.1; 75.1), p = 0.029). Aeration improved in 16 (53.3%) and 27 (90%) patients in the RDS and TTN groups, respectively (p = 0.034). Lung aeration showed significant hysteresis in TTN patients. Secondary outcomes gave similar results.

Conclusions: Increasing CPAP from 4 to 8 cmH₂O improves ultrasound-assessed lung aeration and oxygenation in RDS and TTN. The absolute improvements are small when CPAP is beyond 6 cmH₂O or for RDS patients.

Background: Dual bronchodilator therapy, consisting of a long-acting beta-agonist (LABA) and a long-acting muscarinic antagonist (LAMA), has proven effective for patients with chronic obstructive pulmonary disease (COPD). However, it remains uncertain whether there are efficacy differences between current and former smokers with COPD. This study aims to explore the effectiveness of LABA/LAMA therapies in both these groups.

Methods: The TOReTO trial assessed lung function, symptoms, health status, the occurrence of exacerbations, clinically significant exacerbations, and the use of LABA/LAMA therapies. These therapies include Tio/Olo, umeclidinium/vilanterol (Umec/Vi), and umeclidinium/vilanterol (Umec/Vi) are used in patients with COPD. The study examined the differences in outcomes between current and former smokers. To balance the baseline characteristics, propensity score matching (PSM) was employed.

Results: Data from 967 patients were collected. After PSM, the time to the first acute exacerbation in current smokers was analyzed separately for the three treatment groups and was significantly different between them (p = 0.0457). Among, there are differences in the occurrence of acute exacerbation between treatment and smoking status in Umec/Vi (p = 0.0114). There is no significant difference in the treatment of former smokers among the three different groups of LABA/LAMA fixed-dose combinations (p = 0.3079). COPD-related symptoms remained stable throughout the treatment period. There were no significant differences in symptom scores, including CAT and mMRC, among the three groups at the end of the study.

Conclusions: The three fixed-dose combinations of LABA/LAMA showed no difference in reducing exacerbations in former smokers but did show differences in current smokers. This trend has clinical significance, and future research will be conducted to control influencing variables to validate this point. However, due to the non-randomized study design, these findings should be interpreted with caution.

Background: Comprehensive summaries on real-world outcomes in pulmonary arterial hypertension (PAH)-a rare, incurable condition, are lacking. We conducted a systematic literature review to describe current survival, morbidity, and quality of life (QoL) outcomes in adult and pediatric PAH patients. We searched Medline and Embase electronic databases, clinicaltrials.gov, and encepp.eu entries, and grey literature to identify outcome estimates for right-heart catheterization-confirmed PAH patients from population-based observational studies (search date: 25 Nov 2021). Data were synthesized using a narrative approach and post-hoc subgroup meta-analyses were conducted to explore adult survival by region, disease severity, representativeness, and study period. The search yielded 7473 records. Following screening and full text review, 22 unique studies with 31 individual reports of outcomes were included. Studies were mostly national registries (n = 21), European (n = 13) and covering adults (n = 17); only six had systematic countrywide coverage of centers. Survival was the most frequently reported outcome (n = 22). Global adult 1-, 3-, and 5-year survival ranged from 85 to 99% (n = 15), 65 to 95% (n = 14), and 50 to 86% (n = 9), respectively. Subgroup meta-analysis showed that 1-, 3-, and 5-year survival in Europe was 90% (95% CI 86-94%; n = 8), 78% (95% CI 68-86%; n = 8), and 61% (95% CI 49-72%; n = 6), respectively; 1-year survival in North America was 88% (95% CI 83-93%; n = 3) and 3-year survival in Asia was 85% (95% CI 82-88%; n = 3). No difference in survival between regions was observed. Subgroup analysis suggested higher survival in patients with better baseline functional class; however, interpretation should be cautioned due to large subgroup heterogeneity and potential missingness of data.

Short conclusion: This review describes current disease outcomes based on well-defined and representative PAH populations. There is an overall lack of follow-up data for morbidity and QoL outcomes; survival estimates for pediatric patients are scarce and may not be generalizable to the current treatment era, although publications from large pediatric registries became available after our search date. This study demonstrated a remaining unmet need world-wide to improve long-term prognosis in PAH in the current era.

Background: Community-acquired pneumonia (CAP) is associated with high morbidity and hospitalization rate. In infectious diseases, host genetics plays a critical role in susceptibility and immune response, and the immune pathways involved are highly dependent on the microorganism and its route of infection. Here we aimed to identify genetic risk loci for CAP using a case-control genome-wide association study (GWAS).

Methods: We performed a GWAS on 3,765 Spanish individuals, including 257 adult patients hospitalized with CAP and 3,508 population controls. Pneumococcal CAP was documented in 30% of patients; the remaining 70% were selected among patients with unidentified microbiological etiology. We tested 7,6 million imputed genotypes using logistic regressions. UK Biobank GWAS of bacterial pneumonia were used for results validation. Subsequently, we prioritized genes and likely causal variants based on Bayesian fine mapping and functional evidence. Imputation and association of classical HLA alleles and amino acids were also conducted.

Results: Six independent sentinel variants reached the genome-wide significance (p < 5 × 10^-8), three on chromosome 6p21.32, and one for each of the chromosomes 4q28.2, 11p12, and 20q11.22. Only one variant at 6p21.32 was validated in independent GWAS of bacterial and pneumococcal pneumonia. Our analyses prioritized C4orf33 on 4q28.2, TAPBP on 6p21.32, and ZNF341 on 20q11.22. Interestingly, genetic defects of TAPBP and ZNF341 are previously known inborn errors of immunity predisposing to bacterial pneumonia, including pneumococcus and Haemophilus influenzae. Associations were all non-significant for the classical HLA alleles.

Conclusions: We completed a GWAS of CAP and identified four novel risk loci involved in CAP susceptibility.

Background: Identification of exposures in patients with interstitial lung diseases (ILDs) is essential for diagnosis and management and can be facilitated through the use of exposure questionnaires. However, for most ILDs, a patient-focused questionnaire is lacking. Cognitive interviewing is a methodology used to evaluate sources of understanding and misunderstanding in a questionnaire and to provide evidence of content validity. We developed and refined a new exposure questionnaire for patients with fibrotic ILDs by using cognitive interviewing to establish its understandability and content validity.

Methods: An exposure assessment questionnaire was developed by a multidisciplinary team. Cognitive interviews with 24 patients with fibrosing ILDs were conducted by trained interviewers over the phone or Zoom using a semi-structured interview guide. The questionnaire was amended based on the interviewers' interpretation of sources of misunderstanding. The revised questionnaire was tested in a second round of cognitive interviews with a different group of 24 patients.

Results: Among the 48 patients who completed interviews, mean age was 61 years, 58.3% were male and 75.0% were white. Based on the first round of cognitive interviews, the multidisciplinary team modified the questions, organization, and instructions of the questionnaire to facilitate recall, adjust for exposures that were frequently misunderstood or required clarification, and focus on clinically relevant exposures. The revised questionnaire performed well in the second round of interviews.

Conclusion: An exposure questionnaire, developed with input from patients, can be used to assess clinically relevant exposures in adults with fibrosing ILDs. This is the first questionnaire for all types of fibrosing ILD to have undergone content validation.

Background: The transformation of airway smooth muscle cells (ASMCs) from a quiescent phenotype to a hypersecretory and hypercontractile phenotype is a defining feature of asthmatic airway remodeling. Fisetin, a flavonoid compound, possesses anti-inflammatory characteristics in asthma; yet, its impact on airway remodeling and ASMCs phenotype transition has not been investigated.

Objectives: This research seeked to assess the impact of fisetin on ovalbumin (OVA) induced asthmatic airway remodeling and ASMCs phenotype transition, and clarify the mechanisms through network pharmacology predictions as well as in vivo and in vitro validation.

Methods: First, a fisetin-asthma-ASMCs network was constructed to identify potential targets. Subsequently, cellular and animal studies were carried out to examine the inhibitory effects of fisetin on airway remodeling in asthmatic mice, and to detemine how fisetin impacts the phenotypic transition of ASMCs.

Results: Network analysis indicated that fisetin might affect asthma via mediating the phosphatidylinositol 3-kinase (PI3K)/ protein kinase B (AKT) pathway. Intraperitoneal administration of fisetin in vivo reduced airway inflammation and remodeling, as shown by reduced inflammatory cells, decreased T helper type 2 (Th2) cytokine release, diminished collagen accumulation, mitigated airway smooth muscle thickening, and decreased expression of osteopontin (OPN), collagen-I and α-smooth muscle actin (α-SMA). Moreover, fisetin suppressed the PI3K/AKT pathway in asthmatic lung tissue. According to the in vitro data, fisetin downregulated the expression of the synthetic phenotypic proteins OPN and collagen-I, contractile protein α-SMA, and inhibited cellular migration, potentially through the PI3K/AKT pathway.

Conclusion: These results suggest that fisetin inhibits airway remodeling in asthma by regulating ASMCs phenotypic shift, emphasizing that fisetin is a promising candidate for the treatment of airway smooth muscle remodeling.

Background: The first 24 h of infection represent a critical time window in interactions between pathogens and host tissue. However, it is not possible to study such early events in human lung during natural infection due to lack of clinical access to tissue this early in infection. We, therefore, applied RNA sequencing to ex vivo cultured human lung tissue explants (HLTE) from patients with emphysema to study global changes in small noncoding RNA, mRNA, and long noncoding RNA (lncRNA, lincRNA) populations during the first 24 h of infection with influenza A virus (IAV), Mycobacterium bovis Bacille Calmette-Guerin (BCG), and Pseudomonas aeruginosa.

Results: Pseudomonas aeruginosa caused the strongest expression changes and was the only pathogen that notably affected expression of microRNA and PIWI-associated RNA. The major classes of long RNAs (> 100 nt) were represented similarly among the RNAs that were differentially expressed upon infection with the three pathogens (mRNA 77-82%; lncRNA 15-17%; pseudogenes 4-5%), but lnc-DDX60-1, RP11-202G18.1, and lnc-THOC3-2 were part of an RNA signature (additionally containing SNX10 and SLC8A1) specifically associated with IAV infection. IAV infection induced brisk interferon responses, CCL8 being the most strongly upregulated mRNA. Single-cell RNA sequencing identified airway epithelial cells and macrophages as the predominant IAV host cells, but inflammatory responses were also detected in cell types expressing few or no IAV transcripts. Combined analysis of bulk and single-cell RNAseq data identified a set of 6 mRNAs (IFI6, IFI44L, IRF7, ISG15, MX1, MX2) as the core transcriptomic response to IAV infection. The two bacterial pathogens induced qualitatively very similar changes in mRNA expression and predicted signaling pathways, but the magnitude of change was greater in P. aeruginosa infection. Upregulation of GJB2, VNN1, DUSP4, SerpinB7, and IL10, and downregulation of PKMYT1, S100A4, GGTA1P, and SLC22A31 were most strongly associated with bacterial infection.

Conclusions: Human lung tissue mounted substantially different transcriptomic responses to infection by IAV than by BCG and P. aeruginosa, whereas responses to these two divergent bacterial pathogens were surprisingly similar. This HLTE model should prove useful for RNA-directed pathogenesis research and tissue biomarker discovery during the early phase of infections, both at the tissue and single-cell level.

Background: Chronic airway disease (CAD) is characterized by chronic airway inflammation and colonization of the lungs by pro-inflammatory pathogens. However, while various other bacterial species are present in the lower airways, it is not fully understood how they influence inflammation. We aimed to identify novel anti-inflammatory species present in lower airway samples of patients with CAD.

Methods: Paired sputum microbiome and inflammatory marker data of adults with CAD across three separate cohorts (Australian asthma and bronchiectasis, Scottish bronchiectasis) was analyzed using Linear discriminant analysis Effect Size (LEfSE) and Spearman correlation analysis to identify species associated with a low inflammatory profile in patients.

Results: We identified the genus Aggregatibacter as more abundant in patients with lower levels of airway inflammatory markers in two CAD cohorts (Australian asthma and bronchiectasis). In addition, the relative abundance of Aggregatibacter was inversely correlated with sputum IL-8 (Australian bronchiectasis) and IL-1β levels (Australian asthma and bronchiectasis). Subsequent in vitro testing, using a physiologically relevant three-dimensional lung epithelial cell model, revealed that Aggregatibacter spp. (i.e. A. actinomycetemcomitans, A. aphrophilus) and their cell-free supernatant exerted anti-inflammatory activity without influencing host cell viability.

Conclusions: These findings suggest that Aggregatibacter spp. might act to reduce airway inflammation in CAD patients.