Respiratory Research

BackgroundOur group previously reported that lung cancer (LC) screening history results and subsequent timing of diagnosis are associated with significant differences in survival outcomes. As a follow-up study, we sought to develop novel personalized risk models that considered screening history for incidence cancers, interval LCs, and prevalence LCs. MethodsUsing data from the CT-arm of the NLST, four independent case-control analyses were conducted to develop parsimonious risk models. Controls (n=26,038) were those never diagnosed with LC. The four LC case groups were 270 prevalence LCs, 44 interval LCs, 206 screen-detected LCs (SDLCs) that had a baseline positive screen, and 164 SDLCs that had a baseline negative screen. For each case-control analysis, univariable analyses identified statistically significant covariates from 48 variables and then significant covariates were included into a stepwise backward selection approach to identify a model with the most informative covariates. ResultsFor prevalence LCs, the model (AUC=0.711) included age, pack-years smoked, BMI, smoking status, smoking onset age, personal history of cancer, family history of LC, alcohol consumption, and milling occupation. For interval LCs, the model (AUC=0.734) included age, smoking status, smoking onset age, cigar smoking, marital status, and asbestos occupation. For baseline positive SDLCs, the model (AUC=0.685) included age, pack-years smoked, BMI, emphysema, chemicals/plastics exposure, and milling occupation. For baseline negative SDLCs, the model (AUC=0.701) included age, pack-years smoked, BMI, smoking status, emphysema, sarcoidosis, and sandblasting occupation. ConclusionsBesides smoking and age, which are inclusion criteria for screening, these models identified other important risk factors which could be used to provide personalized LC risk assessment and screening management.

Bronchopulmonary dysplasia (BPD) in infancy is a risk factor for obstructive lung disease in adults. We hypothesized that adults born preterm and diagnosed with BPD have an altered lung architecture which is correlated to lung function impairment. Individuals from the LUNAPRE cohort (clinicaltrials.gov/ct2/show/NCT02923648) were included: preterm born (gestational week <32) with (n=24) or without (n=23) a previous diagnosis of BPD, full term born with allergic asthma (n=22) and healthy volunteers (n=24). Inspiratory and expiratory HRCT scans were performed and interpreted by two expert reviewers in a blinded manner. Structural changes were scored and quantitative density measurements were analysed automatically using a dedicated post-processing workstation. The HRCT scores were significantly higher in the BPD group compared to the other groups (p<0.001) and had highest numbers in subjects diagnosed with severe BPD. Most common HRCT changes were small peripheral opacities. Hypoattenuation during inspiration was only observed in the BPD group. Architectural distortion was observed in 6/24 BPD and 2/23 premature without BPD. HRCT scores correlated to FEV1 in a negative manner for preterm (p<0.001) and BPD (p<0.05) groups. Oxygen supplementation during the neonatal period correlated with HRCT score in a positive manner for preterm group (p<0.001). No differences in lung density were observed between the groups. Young adults previously diagnosed with BPD have structural changes on CT which correlate with airway obstruction. Severity of BPD at the diagnosis was associated with CT abnormalities in adulthood. HRCT changes in adults with BPD were correlated with spirometry findings.

Rationale: Air trapping in functional areas of the lung is common in chronic obstructive pulmonary disease (COPD). We developed a novel music-based intervention, Engagement of Music for Pulmonary Obstruction With Expiratory Restoration (EMPOWER) aimed at reducing air trapping and functional small airways disease (fSAD) in patients with COPD. Objectives: We conducted a pilot study to assess if air trapping and fSAD in COPD patients are reduced by our targeted EMPOWER music-based singing intervention. Methods: Participants completed four weeks of singing and vocalizing with a board-certified music therapist. Pre- and post-intervention assessments of standard pulmonary function tests (PFTs), and quantitative computed tomography (qCT) lung imaging documented changes in air trapping. Pre- and post-intervention change in psychological and patient-reported outcomes of hope, emotional wellbeing, agency and COPD symptom burden were also obtained. Main Results: All five adult participants with COPD who enrolled completed the study and reported strong interest in continuing with a similar program. Additionally, we observed trends toward improvement in qCT-measured fSAD, six-minute walk distance, and patient-reported symptoms on the COPD Assessment Test. Conclusion: Results of this preliminary study showed improvements in both patient-reported and imaging-indicated respiratory outcomes, suggesting that targeted singing components in music-based interventions such as the EMPOWER intervention may support physiological lung function changes in COPD patients.

Pulmonary vascular remodelling is common in patients with chronic obstructive pulmonary disease (COPD). Vascular endothelial growth factors (VEGFs) are key mediators in angiogenesis and vascular remodelling and exist in different isoforms. VEGF-A is the most potent angiogenic member binding to VEGF receptor 2 (VEGFR2). There are, however, few studies on other isoforms, as VEGF-C, and its receptor VEGFR3 in COPD and subsequent impact of cAMP therapies on VEGF isoforms. Our aim was to evaluate the VEGF isoform synthesis in primary distal lung fibroblasts from control subjects (non-smokers (n=6) and ex-smokers (n=4), and COPD subjects with GOLD stage II (n=4) or GOLD stage IV (n=6), and the expression of VEGFR2 and VEGFR3 in human lung tissue. Primary lung fibroblasts were exposed to the cAMP generating therapies formoterol, iloprost, or roflumilast, the adenylyl cyclase activator forskolin or to transforming growth factor (TGF)-b1. VEGF isoforms were evaluated with ELISA. VEGF-C release was not significantly altered by TGF-{beta}1, in contrast to the increased levels of VEGF-A, in all fibroblasts. VEGF-C was significantly decreased by iloprost, forskolin and formoterol, whereas VEGF-A was significantly increased by iloprost and forskolin, with differences in release pattern between and within fibroblasts from control and COPD subjects. Exposure to VEGF-C specifically towards VEGFR3 decreased proliferative rate in human lung fibroblasts and bronchial epithelial cells. VEGFR2 and VEGFR3 were both present in parenchymal lung tissue and VEGFR2 in pulmonary blood vessels. in both healthy and COPD, whereas there was elevated expression of VEGFR3 in bronchial epithelium. In conclusion, TGF-{beta}1 and cAMP generating compounds have significant effects on VEGF-C and VEGF-A synthesis, which appear dysregulated in lung fibroblasts from ex-smokers and patients with COPD. Increased VEGFR3 expression in the bronchial epithelium in lung tissue, and studies into their functional impact, warrants further investigations.

Background/Objectives: Influenza infection is a major trigger of pneumonia and acute exacerbations among patients with chronic obstructive pulmonary disease (COPD). However, national laboratory-confirmed evidence on influenza vaccine effectiveness (VE) in this high-risk population remains limited. This study aimed to estimate the effectiveness of seasonal influenza vaccination against influenza-associated pneumonia and COPD exacerbations among patients with COPD in Thailand.Methods: We conducted a nationwide retrospective test-negative design study using administrative healthcare data from the National Health Security Office linked with laboratory-confirmed influenza surveillance data between June 1, 2013, and May 31, 2025, covering twelve influenza seasons (2013-2024). COPD-related clinical episodes among patients aged [&ge;]40 years who presented with pneumonia or acute exacerbation of COPD and underwent RT-PCR testing for influenza were included. Multilevel Poisson regression models were used to estimate adjusted risk ratios (RRs), and VE was calculated as (1 - adjusted RR) x 100.Results: A total of 606,072 COPD-related clinical episodes were included, of which 192,224 (31.7%) were influenza-positive. The overall adjusted VE against influenza-associated pneumonia was 63.2% (95% CI: 62.5-64.0), while VE against influenza-associated COPD exacerbations was 67.0% (95% CI: 48.8-78.8). VE estimates were broadly similar across age groups and remained substantial across COPD severity strata. Although point estimates were numerically higher in severe and very severe COPD, subgroup differences should be interpreted cautiously.Conclusions: Seasonal influenza vaccination was associated with substantial protection against influenza-associated pneumonia and COPD exacerbations among patients with COPD in Thailand.

Introduction Obstructive lung diseases (OLDs) are responsible for high rates of illness and death worldwide. Inflammation, chronic airflow limitation, and bronchial remodeling occur in OLD and eventually result in the unique respiratory sounds. Despite its subjective and having low reproducibility, still traditional auscultation using a manual stethoscope is the main method used to identify the lung sounds. Nevertheless, the combination of recent advancements in digital stethoscopes and AI (Artificial Intelligence) has permitted the objective measurement of lung sounds. Nevertheless, there is a lack of standardized, region-specific databases for AI training and validation. Even though lung sound classification is an emerging aspect in research and telerehabilitation the lobar wise acoustic pattern is still novel due to lack of prevailing database to train AI models. Identifying this gap this study aims to develop an acoustic repository and analyze the data using segmental lung sounds from patients with OLDs and healthy controls through an electronic stethoscope. Methods and analysis This is a cross sectional observational study involving 120 participants (60 OLD patients and 60 healthy controls). Lobar wise acoustic signals will be captured using an electronic stethoscope in healthy and diseases population. The data will be analyzed using Audacity software for annotations and then it will be used for feature extraction and statistical analysis. The acoustic features extracted through Audacity, will include frequency, intensity, pitch, and root mean square (RMS) energy. Repeated measures ANOVA will be applied to compare mean sound intensities across lung segments while Pearson correlation will be used to assess associations with body composition parameters. The data will then be standardized for AI-based diagnostic applications. Ethics and dissemination The study is being reviewed from the Ethics Review Committee, Faculty of Medicine, University of Peradeniya (2025/EC/87) will be sought. Informed consent will be obtained in writing. The dissemination of results will take place through peer-reviewed publications and the creation of a public database containing lung sounds from the region.

Background: Chronic Obstructive Pulmonary Disease (COPD) is the third leading cause of global mortality, with persistent lung inflammation contributing to disease progression. This inflammation is partly associated with reduced levels of histone deacetylase 2 (HDAC2). Previous studies suggest that Vitamin D may modulate HDAC2 levels. This study aimed to evaluate the effect of Vitamin D supplementation on HDAC2 expression in stable COPD patients. This experimental study aimed to evaluate the effect of vitamin D supplementation on HDAC2 expression in stable COPD patients at Jemursari Islamic Hospital. Methods: Five COPD patients received a daily dose of 5000 IU of Vitamin D for three months. Serum levels of 25(OH)D3 and HDAC2 were measured before and after the intervention. Results: Vitamin D supplementation resulted in a significant increase in both 25(OH)D and HDAC2 levels. Pulmonary function parameters showed an increasing trend, however, no statistically significant differences were observed. Conclusion: Vitamin D supplementation was associated with increased HDAC2 levels, suggesting a potential anti-inflammatory effect. However, no significant improvement in pulmonary function was observed. Further studies are needed to determine its clinical impact.

Wildland firefighters experience repeated exposure to wildfire smoke, yet the pathophysiological mechanisms underlying chronic inhalation injury remain poorly understood. Although prior studies report parenchymal destruction following prolonged woodsmoke exposure, the temporal relationship between molecular, structural, and functional decline following inhalation of smoke from needles/leaves remains unclear. To address this gap, we characterized coordinated changes in lung structure, function, and underlying molecular disruptions using a dosimetry-based murine model approximating 7-14 years of firefighter service. Male apolipoprotein E-deficient mice were exposed to smoldering Douglas fir needle smoke (40 mg/m3, 2 h/day, 5 days/week) for 8 or 16 weeks. Immunofluorescence analyses revealed an early elastolytic response at 8 weeks, with increased neutrophil elastases and matrix metalloproteinases-9 and -12, accompanied by elevated surfactant protein-D, compared to air controls. These changes were resolved by 16 weeks despite progressive tissue injury. Airspace enlargement was evident at 8 weeks, progressed by 16 weeks, and included increased alveolar blunting and septal wall thickening at the later time point. Cleaved caspase-3 was elevated at 16 weeks, indicative of advanced parenchymal damage and apoptosis. Epithelial tight-junction protein ZO-1 intensity was reduced at both evaluation points, whereas the epithelial-to-mesenchymal marker N-cadherin remained undetectable in the alveolar epithelium. Functional impairment as evident by increased static compliance and upward shifts in pressure-volume curves was only significant after 16 weeks of exposure. Findings indicate that molecular and structural injury of tissue destruction preceded measurable functional decline, underscoring the need for early biomarkers to identify smoke-induced lung injury in wildland firefighters before function loss occurs.

Objective: Upper respiratory infections (URI) are the major trigger of asthma exacerbations in children with asthma and are more likely to be reported by Black and Mexican American children compared to White children in the US. We aimed to evaluate the extent to which obesity, nicotine exposure, household size, and socioeconomic status (SES) explained this excess URI risk among all children and among children with asthma. Study Design: Data collected on children aged 6-17 years from the National Health and Nutritional Examination Survey (2007-2012) were analyzed using survey weights and a mediation approach. Household SES was analyzed as a cumulative score reflecting income poverty ratio, education, and rental housing. URI was defined as cough, cold, phlegm, runny nose, or other respiratory illness (excluding hay fever and allergies) in the past 7 days. Results: Obesity and serum cotinine, a marker of nicotine exposure, explained little to none of the excess risk of URI while SES explained 36.4% (95% CI=34.1, 38.6) in Black and 28.5% (95% CI=26.7, 30.5) in Mexican American children. Living in rental housing and income poverty ratio<2, explained half (49.6%, 95% CI=46.9-52.3) and 20% (19.7%, 95% CI=18.9-20.5) of the excess URI risk among Black children, respectively. In Mexican American children, rental housing and low educational attainment each explained approximately 15-17% of the excess URI risk. Results were comparable among children with asthma. Conclusions: Markers of poverty, such as rental housing, contributed substantially to the excess risk of URI among Black and Mexican American children, including among those with asthma.

Methods: Using Global Burden of Disease (GBD) data, we analyzed prevalence, incidence, mortality, and disability-adjusted life years (DALYs) rates across global and 21 GBD regions from 1990-2023. Joinpoint regression identified temporal trends, age-period-cohort models analyzed effect contributions, Das Gupta decomposition quantified demographic and epidemiological impacts, inequality indices assessed health equity, and Bayesian models projected 2024-2038 trends. Results: In 2023, the global number of children and adolescents with asthma reached 131 million, with an age-standardized prevalence rate (ASPR) of 1,789.9 per 100,000. From 1990 to 2023, the global ASPR and age-standardized incidence rate (ASIR) of asthma in children and adolescents showed an upward trend, while the age-standardized mortality rate (ASMR) and age-standardized disability-adjusted life years (DALYs) rate (ASDR) exhibited a downward trend. Among the 0-14 age group, the disease burden was greater in males than in females, whereas in the 15-19 age group, males had a lower disease burden than females. Projections indicate that over the next 15 years, the overall disease burden will continue to decline; however, female mortality rates and DALYs rates are projected to show an upward trend. Conclusions: The increasing prevalence and incidence rates, coupled with declining mortality and DALYs rates of asthma among children and adolescents globally, underscore the necessity for targeted public health interventions. These findings provide crucial insights for early diagnosis, treatment optimization, and global health policy formulation.

E-cigarettes have attracted significant attention as a safer substitute for conventional tobacco smoking. However, they have introduced new inhalable toxicants, including benzaldehyde-propylene glycol acetal (BPGA)--a chemical adduct produced by cherry-flavoured e-cigarettes. The health risks associated with such flavour-derived acetals remain insufficiently elucidated at the cellular level. This study investigated the role of BPGA in the progression of epithelial-to-mesenchymal transition (EMT)-like changes in alveolar epithelial cells (A549 cells). A549 cells exposed to various concentrations of BPGA were analysed for cell viability, morphology, mitochondrial function, lysosomal health, and cytoskeletal integrity using viability assays and fluorescence imaging. Intracellular reactive oxygen species (ROS) production was quantified using the 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) assay. Antioxidant enzyme expression, inflammatory responses, and EMT-associated phenotypic alterations were evaluated using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunofluorescence (IF) assays. Exposure of alveolar epithelial cells to BPGA caused a concentration-dependent decrease in cell viability. BPGA exposure resulted in mitochondrial membrane depolarisation, lysosomal damage, cytoskeletal changes, and stress fibre formation, which altered cell morphology. It significantly increased intracellular ROS production. As a result, antioxidant enzyme levels were upregulated as a protective response. However, during severe oxidative stress, this response was overwhelmed. Excess ROS disrupted cellular homeostasis and initiated apoptosis, though not completely. ROS also acted as a signalling molecule, promoting the upregulation of inflammatory mediators. These changes were associated with altered EMT marker expression, suggesting that BPGA might drive EMT-like remodelling. In conclusion, BPGA, a chemical adduct from e-cigarette vapour, induces alveolar injury by promoting oxidative stress, inflammation, and EMT-related changes, which may explain a mechanism by which e-cigarette exposure could lead to lung injury and pulmonary fibrosis. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=169 SRC="FIGDIR/small/724520v1_ufig1.gif" ALT="Figure 1"> View larger version (60K): org.highwire.dtl.DTLVardef@f7739dorg.highwire.dtl.DTLVardef@1c74f11org.highwire.dtl.DTLVardef@180aeeorg.highwire.dtl.DTLVardef@75ae14_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstractC_FLOATNO C_FIG

ObjectiveChronic obstructive pulmonary disease (COPD) is a leading cause of death in the industrialized world. Although smoking, air pollution, and occupational exposures are well established risk factors, the molecular pathways linking environmental exposures and biological susceptibility to COPD remain incompletely understood. Untargeted metabolomics offers a unique opportunity to simultaneously capture internalized environmental chemicals and endogenous metabolic perturbations. However, large prospective studies integrating broad exposomic and metabolic screening prior to COPD onset are lacking. MethodsWe conducted a nested case-control study within three European population-based cohorts (Doetinchem Cohort Study, KORA, SAPALDIA) and analyzed 1473 prospectively collected plasma samples. COPD was defined by a pre-bronchodilation FEV1/FVC ratio below 0.7 at follow-up (4-16 years after blood sample collection). We applied complementary untargeted liquid- and gas chromatography high-resolution mass spectrometry (LC- and GC-HRMS), enabling extensive coverage of endogenous metabolism and exogenous environmental contaminants, including pesticides, plastic-related chemicals, and polycyclic aromatic hydrocarbons. Controls maintained normal lung function and were matched to cases on age, sex, follow-up time, and sample collection round. We performed separate conditional logistic regression models for each metabolomic feature, and used Mummichog for prediction of biological pathways involved. The false discovery rate (FDR) was controlled using the Benjamini-Hochberg procedure. Long-term measurement reliability was evaluated using intraclass correlation coefficients (ICCs) from repeat samples in the Doetinchem Cohort Study. ResultsIn total, thousands of metabolomic features were screened, including 724 annotated exogenous compounds, 13 endogenous metabolites, and 197 features that could be derived as both. Nicotine and cotinine intensity levels were statistically significantly associated with COPD incidence at an FDR of 10%, validating the analytical and epidemiologic framework. Lower levels of butyrylcarnitine were related to COPD onset in never-smokers. Beyond smoking-related markers, lower levels of butyrylcarnitine were associated with increased COPD risk among never-smokers, implicating altered mitochondrial fatty-acid metabolism as a potential early pathway independent of tobacco exposure. Although most screened environmental contaminants, including PAHs and pesticides, were not associated with COPD at stringent significance thresholds, restricting analyses to temporally stable metabolites identified the insecticide metabolite phenyl N-methylcarbamate as a predictor. ConclusionThis large-scale, prospective untargeted metabolomics study represents one of the most comprehensive assessments to date of both environmental and endogenous metabolic predictors of COPD. Our findings demonstrate the feasibility of exposome-wide molecular screening years before disease onset, identify butyrylcarnitine as a novel metabolic predictor in never-smokers, and highlight the importance of accounting for temporal variability in metabolomic epidemiology.

Background: Nitrogen dioxide (NO2) is a surrogate for traffic and industrial air pollution associated with adverse respiratory outcomes. Whether elevated NO2 and temperature jointly influence adult-onset asthma (AOA) risk is unclear, especially among subgroups with varying lifestyle and exposure profiles. We investigated further in the prospective All of Us research program. Methods: Among 596,926 U.S. participants who consented to electronic health record release, annual average NO2 concentrations from satellite data were linked to residential locations for 376,535 individuals. We used multivariable Cox regression to estimate associations between NO2, temperature, and incident AOA, adjusting for co-pollutants and potential confounders. We analyzed 4-category cross-classification variables between NO2 (high>75th percentile vs. low<=75th percentile) and maximum or average temperature (high>median vs. low<=median). We also stratified by sex, age, income, and smoking status. Additive interactions were estimated using Relative Excess Risk due to Interaction, Attributable Proportion, and Synergy Index. Results: We identified 10,413 incident AOA cases over an average 4-year follow-up. Participants with the highest categories of NO2 and temperature exposure had significantly higher risk compared to those with the lowest (HRHigh NO2 x High Max. Temp.=1.37, 95%CI:1.26-1.49; HRHigh NO2 x High Average Temp.=1.49, 95%CI:1.38-1.61). The joint association of high NO2 and high maximum temperature was more pronounced among ever-smokers (HR=1.59, 95%CI:1.40-1.81) than never-smokers (HR=1.26, 95%CI:1.13-1.41). Interaction analyses supported super-additive interactions of high NO2 and high average temperature on AOA risk, particularly among ever smokers, lower-income participants, and younger adults. Conclusion: Our findings highlight the respiratory health threat of long-term joint exposure to elevated NO2 and average temperature, particularly among vulnerable subgroups.

RationaleFibrotic lung diseases, such as idiopathic pulmonary fibrosis (IPF) and fibroproliferative remodeling in acute respiratory distress syndrome (ARDS), are characterized by increased extracellular matrix (ECM) deposition. However, measuring collagen accumulation alone does not capture differences in ECM organization or biochemical maturation that may distinguish persistent fibrosis from potentially reversible remodeling. ObjectivesTo examine collagen organization characteristics and mature (pyridinoline) collagen crosslinking amount in established end stage fibrotic lung disease (IPF) and fibroproliferation following an acutely damaged lung (non-resolving (NR) ARDS) and to investigate any relationships in these parameters and temporal tissue remodeling. MethodsHuman lung tissue samples from control subjects, patients with IPF, and NR-ARDS were analyzed. Collagen amount and fiber organization were digitally quantified using picrosirius red staining. Mature collagen crosslinking was assessed by quantification of pyridinoline crosslinks. Measurements and Main ResultsLung tissue from both IPF and NR-ARDS lungs had higher collagen content compared with controls. Collagen fiber organization differed between groups. IPF lungs exhibited collagen architectures consistent with established fibrosis, whereas NR-ARDS lungs showed altered but less stabilized collagen organization despite similarly elevated collagen levels. Mature collagen crosslinks were significantly higher in IPF lungs but not in NR-ARDS lungs compared to controls. Integrated analyses identified distinct disease-associated ECM phenotypes, indicating that higher collagen abundance in NR-ARDS, unlike IPF, is not accompanied by more mature and persistent collagen crosslinking. ConclusionsDespite shared increases in collagen content, IPF and NR-ARDS lungs differ fundamentally in collagen organization and crosslinking maturity, suggesting differences in the reversibility of these conditions.

BackgroundChronic lung allograft dysfunction (CLAD) is the major cause of late mortality after lung transplantation and includes two principal phenotypes, bronchiolitis obliterans syndrome (BOS) and restrictive allograft syndrome (RAS). RAS and other phenotypes with RAS-like opacities (RLO) on chest imaging have a poorer prognosis. Despite clear clinical and pathological differences, molecular distinctions between phenotypes remain poorly defined. We aimed to explore gene transcriptional profiles across CLAD phenotypes and relevant controls. MethodsWe performed bulk RNA sequencing on explanted lung tissue from 45 lung transplant recipients with end-stage CLAD (20 with RLO and 25 without RLO). Samples from twenty-seven control donor and lobectomy lungs and sixteen idiopathic pulmonary fibrosis (IPF) lungs served as comparators. Non-negative matrix factorization (NMF) was used to identify latent transcriptomic signatures, which were correlated with clinical, radiologic, and histopathologic features. ResultsNMF identified seven distinct gene signatures that segregated CLAD phenotypes. RLO-CLAD lungs were enriched for extracellular matrix remodeling and B-cell/plasma cell-associated signatures, overlapping partly with IPF, whereas non-RLO-CLAD showed relative enrichment of epithelial injury and surfactant-response pathways. Signatures related to epithelial homeostasis and ciliary/microtubule function were progressively reduced from control lungs to non-RLO-CLAD and were most suppressed in RLO-CLAD. ConclusionsRLO-CLAD and non-RLO-CLAD, aligning with RAS and BOS phenotypes, show distinct transcriptomic signatures. RLO-CLAD is characterized by profibrotic and humoral immune signatures with profound epithelial dysfunction, whereas non-RLO-CLAD shows relative enrichment of epithelial injury responses. These data provide molecular stratification of CLAD and support the development of phenotype-specific biomarkers and targeted therapies.

BackgroundIn patients requiring respiratory support, clinicians rely on physical exam, radiologic, laboratory, and ventilator-derived measures for the provision of sufficient support while minimizing ventilator and "work of breathing" induced lung injury. Point of care lung ultrasound (LUS) is a widely available tool in hospital and clinic environments. To date, LUS has not been used to evaluate lung strain. MethodsWe collected LUS images in four anesthetized, neuromuscularly blocked, and mechanically ventilated pigs being used for another experiment. A feature tracking tool was developed which tracked echo-bright lung structures in ten second clips obtained in triplicate of the right and left, upper and lower lung fields using tidal volumes of 4, 6, 8, 10, and 12 mL/kg. Pleural lines were manually drawn and a program for quantifying lung strain developed with assistance from Anthropic Claude Artificial Intelligence tool. Structures were identified in inspiratory and expiratory frames and tracked bidirectionally with median strain per frame used for calculations. ResultsTriplicate measures of lung ultrasound images in four pigs had a median coefficients of variation of 35% (23-47% IQR) and linear modeling of strain with tidal volumes of 4-12 mL/kg showed positive correlation with R2 value ranging from 0.89 to 0.97. Strain measurements were similar after bronchial administration of 1.5M hydrochloric acid. ConclusionsRegional lung strain quantification using LUS is a viable and potentially useful tool for respiratory support management.

Primary human bronchial epithelial cells (pHBECs) of the airways of smokers are chronically exposed to cigarette smoke, which may induce chronic obstructive pulmonary disease (COPD) ranked fourth among the most common global causes of death. Using an established protocol for differentiation of pHBECs to a pseudostratified epithelium at an air liquid interface (ALI), we analyzed functional expression of transient receptor potential vanilloid 4 (TRPV4) proteins after application of cigarette smoke extract (CSE), which upregulated seven smoke exposure regulated genes (SERGs). TRPV4 protein expression in the plasma membrane and localization next to the cilia of ciliated cells was reduced, while cell barrier function was not altered after chronic exposure to CSE for 28 days compared to untreated control cells. Accordingly, TRPV4-mediated Ca2+ influx was blocked in pHBECs after CSE exposure. Moreover, Os-9 protein, which after binding mediates protection from degradation of TRPV4 protein by polyubiquitination, was significantly less expressed in pHBECs upon CSE exposure. Most interestingly, overexpression of OS-9 in pHBECs rescued reduced TRPV4 protein levels induced by CSE. Our study identifies a novel molecular mechanism of toxicity by CSE interfering with TRPV4 and OS-9 expression in pHBECs, which may blaze the trail for new therapeutic options in COPD.

BackgroundCalcitonin gene related peptide (CGRP) hyperpolarizes pulmonary arterial smooth muscle cells (SMCs) and endothelial cells (ECs) through PKA-dependent activation of KATP channels. CGRP can diminish the severity of pulmonary fibrosis (PF), however, the effects on vascular signaling were poorly defined. We hypothesized that hyperpolarization to CGRP would be augmented in a mouse model of PF. MethodsPF was induced in male and female C57BL/6 mice by intratracheal delivery of bleomycin (3 wk), with saline used as control (sham). Pulmonary arteries (PAs; 100-150 {micro}m diameter) were cannulated and pressurized to 16 cmH2O, and endothelial tubes were studied in complementary experiments to eliminate the influence of SMCs. Membrane potential (Vm) was recorded continuously using intracellular microelectrodes. Responses were also evaluated in isolated lungs preconstricted with U46619 ([~]10 mmHg). ResultsPF led to greater indices of PH in males vs. females. Isolated lungs and PAs from male PF mice had enhanced vasodilation and hyperpolarization of Vm to CGRP, although no effect was observed in females. The greater vasodilation and hyperpolarization of SMCs to CGRP in males persisted in endothelium-disrupted PAs and during treatment with L-NAME indicating that ECs are not required for greater responsiveness to CGRP. With no effect on resting Vm, inhibition of KATP channels or PKA significantly attenuated hyperpolarization of SMCs and ECs, attenuated vasodilation to CGRP in PAs, and eliminated differences between groups in males. Direct activation of PKA, but not KATP, evoked greater Vm hyperpolarization and vasodilation in PF vs. sham PAs and lungs. Although no difference in sensory nerves was observed in fibrotic mice, perivascular nerve stimulation evoked greater vasodilation in PAs. ConclusionsIn a mouse model of PF, CGRP-dependent hyperpolarization of pulmonary arterial SMCs and ECs is augmented through increased PKA-dependent activation of KATP channels leading to increased vasodilator sensitivity.

Sarcoidosis is a multisystem disorder that primarily affects the lungs and is characterizedby granulomatous inflammation. However, much of the underlying disease mechanisms remain poorly understood. Extracellular vesicles (EVs) are small membrane-bound particles released by all cells and carry various cargos including metabolites. They are involved in intercellular communication that can be dysregulated in diseases.This study characterizes the metabolic cargo of EVs isolated from bronchoalveolar lavage fluid (BALF), using liquid chromatography-mass spectrometry (LC-MS)-based metabolomic analysis, in patients with sarcoidosis (n=37), compared to healthy controls (n=10). Additionally, the sarcoidosis signature was compared to another pulmonary disorder, anti-synthetase syndrome (ASyS, n=10). Arachidonic acid (AA) results were verified by ELISA. A total of 1202 metabolites were detected, with 111 annotated ones further analyzed. EVs from sarcoidosis patients showed distinct metabolomic profiles compared to both ASyS patients and healthy controls, with 38 annotated metabolites differentially expressed in any of the groups. In both annotated and non-annotated data, sarcoidosis patients clustered separately from ASyS patients and healthy individuals. Furthermore, sarcoidosis patients clustered in 3 subgroups, whereof one was similar to ASyS patients and one stood out as showing higher cell counts in BALF. Higher AA levels were found in sarcoidosis patient EVs by LC-MS, and AA results were verified by ELISA. Our data show that BALF EV metabolites are disease-dependent and support the notion thatsarcoidosis patients should be further subgrouped for better diagnosis and treatment.

To explore the mechanism of Hsa_circ_0000629 adsorbing miR-212-5p/ nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) through sponge in bronchial asthma. Twenty BALB/C mice were randomly divided into a normal control group and an asthma group. Pathological changes in lung tissue were observed via HE staining. Human bronchial epithelial cells (16HBE) were transfected with Hsa_circ_0000629 overexpression group (Hsa_circ_0000629-over), Hsa_circ_0000629 siRNA (Hsa_circ_0000629-si), mimic NC, miR-212-5p mimic, inhibitor NC, miR-212-5p inhibitor, and LPS+Hsa_circ_0000629 si. LPS-induced asthmatic cell models (LPS group) and untransfected 16HBE cells (NC group) served as controls. qRT-PCR was used to measure Hsa_circ_0000629, miR-212-5p and NLRP3 expression. ELISA assessed interleukin 18 (IL-18), interleukin 1{beta} (IL-1{beta}), interleukin 6 (IL-6) and tumor necrosis factor - (TNF-) levels. Cell proliferation and the apoptosis were evaluated by EDU assay and flow cytometry, respectively. Western blot analyzed Cleaved-caspase 1, 3 and 9 proteins expression. Dual-luciferase assay verified the binding sites of Hsa_circ_0000629 to miR-212-5p and NLRP3 to miR-212-5p. HE staining revealed inflammatory cell infiltration, bronchial wall thickening, smooth muscle hyperplasia, and alveolar destruction in asthmatic mice. Compared with the controls, Hsa_circ_0000629 and NLRP3 expression were significantly increased, while miR-212-5p expression was decreased in asthmatic lung tissues. In 16HBE cells, Hsa_circ_0000629-over and LPS groups showed elevated Hsa_circ_0000629 and NLRP3 expression but reduced miR-212-5p levels. Silencing Hsa_circ_0000629 in LPS-treated cells (LPS+Hsa_circ_0000629-si) reversed these effects. Overexpression of miR-212-5p counteracted Hsa_circ_0000629-induced NLRP3 upregulation, while miR-212-5p inhibition enhanced NLRP3 expression. LPS exposure increased TNF-, IL-18, IL-6, and IL-1{beta} levels, reduced cell proliferation, and promoted apoptosis. These changes were attenuated by Hsa_circ_0000629 silencing or miR-212-5p overexpression. Western blot confirmed that Hsa_circ_0000629 overexpression upregulated Cleaved-Caspase 1, 3, and 9, whereas miR-212-5p mimic or Hsa_circ_0000629-si reversed this trend. Dual-luciferase assays demonstrated targeted interactions among Hsa_circ_0000629, miR-212-5p, and NLRP3. Interference with Hsa_circ_0000629 expression can alleviate LPS induced apoptosis in 16HBE cells and inhibit the expression of inflammatory factors by targeting the miR-212-5p/NLRP pathway, which may be a new target for the treatment of asthma.