Respiratory Research最新文献

Background: The gut-lung axis, pivotal for respiratory health, is inadequately explored in pulmonary and critical care medicine (PCCM) inpatients.

Methods: Examining PCCM inpatients from three medical university-affiliated hospitals, we conducted 16S ribosomal RNA sequencing on stool samples (inpatients, n = 374; healthy controls, n = 105). We conducted statistical analyses to examine the gut microbiota composition in PCCM inpatients, comparing it to that of healthy controls. Additionally, we explored the associations between gut microbiota composition and various clinical factors, including age, white blood cell count, neutrophil count, platelet count, albumin level, hemoglobin level, length of hospital stay, and medical costs.

Results: PCCM inpatients exhibited lower gut microbiota diversity than healthy controls. Principal Coordinates Analysis revealed marked overall microbiota structure differences. Four enterotypes, including the exclusive Enterococcaceae enterotype in inpatients, were identified. Although no distinctions were found at the phylum level, 15 bacterial families exhibited varying abundances. Specifically, the inpatient population from PCCM showed a significantly higher abundance of Enterococcaceae, Lactobacillaceae, Erysipelatoclostridiaceae, Clostridiaceae, and Tannerellaceae. Using random forest analyses, we calculated the areas under the receiver operating characteristic curves (AUCs) to be 0.75 (95% CIs 0.69-0.80) for distinguishing healthy individuals from inpatients. The four most abundant genera retained in the classifier were Blautia, Subdoligranulum, Enterococcus, and Klebsiella.

Conclusions: Evidence of gut microbiota dysbiosis in PCCM inpatients underscores the gut-lung axis's significance, promising further avenues in respiratory health research.

Background: Previous research has revealed the potential impact of circadian rhythms on pulmonary diseases; however, the connection between circadian rhythm-associated Thyrotroph Embryonic Factor (TEF) and Pulmonary Arterial Hypertension (PAH) remains unclear. We aim to assess the genetic causal relationship between TEF and PAH by utilizing two sets of genetic instrumental variables (IV) and publicly available Pulmonary Arterial Hypertension Genome-Wide Association Studies (GWAS).

Methods: Total of 23 independent TEF genetic IVs from recent MR reports and PAH GWAS including 162,962 European individuals were used to perform this two-sample MR study. Gain- and loss-of-function experiments were used to demonstrate the role of TEF in PAH.

Results: Our analysis revealed that as TEF levels increased genetically, there was a corresponding increase in the risk of PAH, as evidenced by IVW (OR = 1.233, 95% CI: 1.054-1.441; P = 0.00871) and weighted median (OR = 1.292, 95% CI for OR: 1.064-1.568; P = 0.00964) methods. Additionally, the up-regulation of TEF expression was associated with a significantly higher likelihood of abnormal circadian rhythm (IVW: P = 0.0024733, β = 0.05239). However, we did not observe a significant positive correlation between circadian rhythm and PAH (IVW: P = 0.3454942, β = 1.4980398). In addition, our in vitro experiments demonstrated that TEF is significantly overexpressed in pulmonary artery smooth muscle cells (PASMCs). And overexpression of TEF promotes PASMC viability and migratory capacity, as well as upregulates the levels of inflammatory cytokines.

Conclusion: Our analysis suggests a causal relationship between genetically increased TEF levels and an elevated risk of both PAH and abnormal circadian rhythm. Consequently, higher TEF levels may represent a risk factor for individuals with PAH.

Background: Increasing functional residual capacity (FRC) or tidal volume (V_T) reduces airway resistance and attenuates the response to bronchoconstrictor stimuli in animals and humans. What is unknown is which one of the above mechanisms is more effective in modulating airway caliber and whether their combination yields additive or synergistic effects. To address this question, we investigated the effects of increased FRC and increased V_T in attenuating the bronchoconstriction induced by inhaled methacholine (MCh) in healthy humans.

Methods: Nineteen healthy volunteers were challenged with a single-dose of MCh and forced oscillation was used to measure inspiratory resistance at 5 and 19 Hz (R₅ and R₁₉), their difference (R_5-19), and reactance at 5 Hz (X₅) during spontaneous breathing and during imposed breathing patterns with increased FRC, or V_T, or both. Importantly, in our experimental design we held the product of V_T and breathing frequency (BF), i.e, minute ventilation (V_E) fixed so as to better isolate the effects of changes in V_T alone.

Results: Tripling V_T from baseline FRC significantly attenuated the effects of MCh on R₅, R₁₉, R_5-19 and X₅. Doubling V_T while halving BF had insignificant effects. Increasing FRC by either one or two V_T significantly attenuated the effects of MCh on R_5, R₁₉, R_5-19 and X₅. Increasing both V_T and FRC had additive effects on R₅, R₁₉, R_5-19 and X₅, but the effect of increasing FRC was more consistent than increasing V_T thus suggesting larger bronchodilation. When compared at iso-volume, there were no differences among breathing patterns with the exception of when V_T was three times larger than during spontaneous breathing.

Conclusions: These data show that increasing FRC and V_T can attenuate induced bronchoconstriction in healthy humans by additive effects that are mainly related to an increase of mean operational lung volume. We suggest that static stretching as with increasing FRC is more effective than tidal stretching at constant V_E, possibly through a combination of effects on airway geometry and airway smooth muscle dynamics.

Background: In recent years, the incorporation of LAMAs into asthma therapy has been expected to enhance symptom control. However, a significant number of patients with asthma continue to experience poorly managed symptoms. There have been limited investigations on LAMA-induced airway alterations in asthma treatment employing IOS. In this study, we administered a LAMA to patients with poorly controlled asthma, evaluated clinical responses and respiratory function, and investigated airway changes facilitated by LAMA treatments using the IOS.

Methods: Of a total of 1282 consecutive patients with asthma, 118 exhibited uncontrolled symptoms. Among them, 42 switched their treatment to high-dose fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) (ICS/LABA/LAMA). The patients were then assessed using AHQ-33 or LCQ and ACT. Spirometry parameters (such as FEV₁ or MMEF) and IOS parameters (such as R20 or AX) were measured and compared before and after exacerbations and the addition of LAMA.

Results: Of the 42 patients, 17 who switched to FF/UMEC/VI caused by dyspnea exhibited decreased pulmonary function between period 1 and baseline, followed by an increase in pulmonary function between baseline and period 2. Significant differences were observed in IOS parameters such as R20, R5-R20, Fres, or AX between period 1 and baseline as well as between baseline and period 2. Among the patients who switched to inhaler due to cough, 25 were classified as responders (n = 17) and nonresponders (n = 8) based on treatment outcomes. Among nonresponders, there were no significant differences in spirometry parameters such as FEV₁ or PEF and IOS parameters such as R20 or AX between period 1 and baseline. However, among responders, significant differences were observed in all IOS parameters, though not in most spirometry parameters, between period 1 and baseline. Furthermore, significant differences were noted between baseline and period 2 in terms of FEV₁, %MMEF, %PEF, and all IOS parameters.

Conclusion: ICS/LABA/LAMA demonstrates superiority over ICS/LABA in improving symptoms and lung function, which is primarily attributed to the addition of LAMA. Additionally, IOS revealed the effectiveness of LAMA across all airway segments, particularly in the periphery. Hence, LAMA can be effective against various asthma phenotypes characterized by airway inflammation, even in real-world cases.

Background: Although recent studies provide mechanistic understanding to the pathogenesis of radiation induced lung injury (RILI), rare therapeutics show definitive promise for treating this disease. Type II alveolar epithelial cells (AECII) injury in various manner results in an inflammation response to initiate RILI.

Results: Here, we reported that radiation (IR) up-regulated the TNKS1BP1, causing progressive accumulation of the cellular senescence by up-regulating EEF2 in AECII and lung tissue of RILI mice. Senescent AECII induced Senescence-Associated Secretory Phenotype (SASP), consequently activating fibroblasts and macrophages to promote RILI development. In response to IR, elevated TNKS1BP1 interacted with and decreased CNOT4 to suppress EEF2 degradation. Ectopic expression of EEF2 accelerated AECII senescence. Using a model system of TNKS1BP1 knockout (KO) mice, we demonstrated that TNKS1BP1 KO prevents IR-induced lung tissue senescence and RILI.

Conclusions: Notably, this study suggested that a regulatory mechanism of the TNKS1BP1/CNOT4/EEF2 axis in AECII senescence may be a potential strategy for RILI.

Background: Acute lung injury (ALI) following pneumonia involves uncontrolled inflammation and tissue injury, leading to high mortality. We previously confirmed the significantly increased cargo content and extracellular vesicle (EV) production in thrombin-preconditioned human mesenchymal stromal cells (thMSCs) compared to those in naïve and other preconditioning methods. This study aimed to investigate the therapeutic efficacy of EVs derived from thMSCs in protecting against inflammation and tissue injury in an Escherichia coli (E. coli)-induced ALI mouse model.

Methods: In vitro, RAW 264.7 cells were stimulated with 0.1 µg/mL liposaccharides (LPS) for 1 h, then were treated with either PBS (LPS Ctrl) or 5 × 10⁷ particles of thMSC-EVs (LPS + thMSC-EVs) for 24 h. Cells and media were harvested for flow cytometry and ELISA. In vivo, ICR mice were anesthetized, intubated, administered 2 × 10⁷ CFU/100 µl of E. coli. 50 min after, mice were then either administered 50 µL saline (ECS) or 1 × 10⁹ particles/50 µL of thMSC-EVs (EME). Three days later, the therapeutic efficacy of thMSC-EVs was assessed using extracted lung tissue, bronchoalveolar lavage fluid (BALF), and in vivo computed tomography scans. One-way analysis of variance with post-hoc TUKEY test was used to compare the experimental groups statistically.

Results: In vitro, IL-1β, CCL-2, and MMP-9 levels were significantly lower in the LPS + thMSC-EVs group than in the LPS Ctrl group. The percentages of M1 macrophages in the normal control, LPS Ctrl, and LPS + thMSC-EV groups were 12.5, 98.4, and 65.9%, respectively. In vivo, the EME group exhibited significantly lower histological scores for alveolar congestion, hemorrhage, wall thickening, and leukocyte infiltration than the ECS group. The wet-dry ratio for the lungs was significantly lower in the EME group than in the ECS group. The BALF levels of CCL2, TNF-a, and IL-6 were significantly lower in the EME group than in the ECS group. In vivo CT analysis revealed a significantly lower percentage of damaged lungs in the EME group than in the ECS group.

Conclusion: Intratracheal thMSC-EVs administration significantly reduced E. coli-induced inflammation and lung tissue damage. Overall, these results suggest therapeutically enhanced thMSC-EVs as a novel promising therapeutic option for ARDS/ALI.

Chronic obstructive pulmonary disease(COPD) is a gradually worsening and fatal heterogeneous lung disease characterized by airflow limitation and increasingly decline in lung function. Currently, it is one of the leading causes of death worldwide. The consistent feature of COPD is airway inflammation. Several inflammatory factors are known to be involved in COPD pathogenesis; however, anti-inflammatory therapy is not the first-line treatment for COPD. Although bronchodilators, corticosteroids and roflumilast could improve airflow and control symptoms, they could not reverse the disease. The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) signaling pathway plays an important novel role in the immune system and has been confirmed to be a key mediator of inflammation during infection, cellular stress, and tissue damage. Recent studies have emphasized that abnormal activation of cGAS-STING contributes to COPD, providing a direction for new treatments that we urgently need to develop. Here, we focused on the cGAS-STING pathway, providing insight into its molecular mechanism and summarizing the current knowledge on the role of the cGAS-STING pathway in COPD. Moreover, we explored antagonists of cGAS and STING to identify potential therapeutic strategies for COPD that target the cGAS-STING pathway.

Background: Japanese guidelines recommend triple inhaled corticosteroid (ICS)/long-acting muscarinic antagonist (LAMA)/long-acting β₂-agonist (LABA) therapy in patients with chronic obstructive pulmonary disease (COPD) and no concurrent asthma diagnosis who experience frequent exacerbations and have blood eosinophil (EOS) count ≥ 300 cells/mm³, and in patients with COPD and asthma with continuing/worsening symptoms despite receiving dual ICS/LABA therapy. These post-hoc analyses of the KRONOS study in patients with COPD and without an asthma diagnosis, examine the effects of fixed-dose triple therapy with budesonide/glycopyrronium/formoterol fumarate dihydrate (BGF) versus dual therapies on lung function and exacerbations based on blood EOS count - focusing on blood EOS count 100 to < 300 cells/mm³ - as a function of exacerbation history and COPD severity.

Methods: In KRONOS, patients were randomized to receive treatments that included BGF 320/14.4/10 µg, glycopyrronium/formoterol fumarate dihydrate (GFF) 14.4/10 µg, or budesonide/formoterol fumarate dihydrate (BFF) 320/10 µg via metered dose inhaler (two inhalations twice-daily for 24 weeks). These post-hoc analyses assessed changes from baseline in morning pre-dose trough forced expiratory volume in 1 s (FEV₁) over 12-24 weeks and moderate or severe COPD exacerbations rates over 24 weeks. The KRONOS study was not prospectively powered for these subgroup analyses.

Results: Among patients with blood EOS count 100 to < 300 cells/mm³, least squares mean treatment differences for lung function improvement favored BGF over BFF in patients without an exacerbation history in the past year and in patients with moderate and severe COPD, with observed differences ranging from 62 ml to 73 ml across populations. In this same blood EOS population, moderate or severe exacerbation rates were reduced for BGF relative to GFF by 56% in patients without an exacerbation history in the past year, by 47% in patients with moderate COPD, and by 50% in patients with severe COPD.

Conclusions: These post-hoc analyses of patients with moderate-to-very severe COPD from the KRONOS study seem to indicate clinicians may want to consider a step-up to triple therapy in patients with persistent/worsening symptoms with blood EOS count > 100 cells/mm³, even if disease severity is moderate and there is no recent history of exacerbations.

Trial registration: ClinicalTrials.gov registry number NCT02497001 (registration date, 13 July 2015).

Background: Lianhuaqingwen (LHQW) has been used in the treatment of chronic bronchitis, but the precise mechanism through which LHQW exhibits its anti-inflammatory effects in this context is not yet fully understood. The aim of this study was to investigate the active ingredients and signaling pathways responsible for LHQW's effectiveness in managing chronic bronchitis.

Methods: The research leveraged the TCMSP database to determine the active compounds and drug targets of LHQW. In parallel, the GeneCards, DrugBank, and PharmGkb databases were used to uncover targets pertinent to chronic bronchitis. To discern the potential mechanisms by which LHQW's active ingredients might treat chronic bronchitis, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed. Network pharmacology facilitated the construction of a drug-active ingredient-disease target network, aiding in forecasting the core targets for chronic bronchitis treatment by LHQW. Subsequently, molecular docking techniques alongside in vitro experiments were applied to confirm the interactions between the active ingredients and the primary targets.

Results: A total of 157 active ingredients, 225 potential drug targets, and 594 bronchitis-related targets were derived from various databases. Following this, 76 potential gene targets were pinpointed by integrating drug and related targets. GO and KEGG enrichment analyses were employed to identify key pathways involved in LHQW's mechanism for treating chronic bronchitis. By constructing a protein-protein interaction (PPI) network for the 76 potential gene targets, four core targets (TNF, IL6, IFNG, and STAT3) were identified as primarily involved in responses to lipopolysaccharide, the TNF pathway, and the JAK-STAT pathway. Molecular docking results revealed a favorable affinity between multiple active ingredients of LHQW and the four core targets, suggesting that the therapeutic effects are mediated through the inhibition of inflammatory responses and signaling pathways. Interestingly, quercetin, an active ingredient of LHQW, was observed to bind to all four core targets simultaneously. Furthermore, cell experiment and western blot analysis indicated that both LHQW and quercetin exhibit anti-inflammatory effects by targeting the four core proteins and the JAK-STAT pathways.

Conclusion: This research emphasizes the diverse active ingredients, targets, channels, and pathways of LHQW in the treatment of chronic bronchitis, providing important perspectives for the creation of novel therapeutic drugs and clinical uses.

Shortening of airway smooth muscle and bronchoconstriction are pathognomonic for asthma. Airway shortening occurs through calcium-dependent activation of myosin light chain kinase, and RhoA-dependent calcium sensitization, which inhibits myosin light chain phosphatase. The mechanism through which pro-contractile stimuli activate calcium sensitization is poorly understood. Our review of the literature suggests that pro-contractile G protein coupled receptors likely signal through G_12/13 to activate RhoA and mediate calcium sensitization. This hypothesis is consistent with the effects of pro-contractile agonists on RhoA and Rho kinase activation, actin polymerization and myosin light chain phosphorylation. Recognizing the likely role of G_12/13 signaling in the pathophysiology of asthma rationalizes the effects of pro-contractile stimuli on airway hyperresponsiveness, immune activation and airway remodeling, and suggests new approaches for asthma treatment.