Respiratory Research

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.

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 [≥]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.

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.

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

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.

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.

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.

Rationale: Preclinical familial pulmonary fibrosis (FPF) represents an early stage of fibrotic lung disease, yet the compartment- and cell-specific molecular programs preceding fibrosis remain poorly understood. Objective: To define spatially organized molecular signatures associated with preclinical FPF and identify tissue-informed circulating biomarkers linked to early fibrotic remodeling. Methods: We performed integrated multi-omic profiling of histologically preserved and remodeled lung regions from subjects with preclinical FPF, Idiopathic Pulmonary Fibrosis (IPF), and controls using spatial transcriptomics, single-nucleus RNA sequencing (snRNAseq), and blood proteomics. Differential expression and pathway enrichment analyses were performed across spatial compartments and epithelial cell states. Results: Histologically preserved lung regions in preclinical FPF demonstrated transcriptional abnormalities including stress-response, ciliary, and extracellular matrix-associated programs despite minimal architectural distortion. Spatial analyses identified alterations in alveolar niche molecular programs accompanied by increasing profibrotic signaling across preserved and tissue remodeled lung compartments. Compared with advanced IPF, preclinical FPF retained epithelial repair and surfactant-associated signatures. Integration with snRNAseq demonstrated enrichment of alveolar and airway epithelial cell dysregulated states associated with transitional phenotypes previously implicated in IPF. Compartment- and epithelial-associated transcriptional signatures identified in lung tissue were partially represented in the peripheral blood. Conclusion: Preclinical FPF is characterized by compartment- and cell-specific molecular programs that precede established fibrosis. We identified distinct alveolar, airway, and vascular molecular signatures and epithelial remodeling states represented in the peripheral blood. These findings provide an initial framework for molecular classification of early stages of pulmonary fibrosis and support future studies evaluating minimally invasive approaches for disease stratification and precision therapeutics.

BackgroundWildland firefighters experience repeated occupational exposure to wildfire smoke at high particulate matter (PM) concentrations, leading to elevated cardiovascular disease risk and hypertension prevalence. However, the pathophysiological processes linking cumulative smoke inhalation to vascular damage and blood pressure elevation remain poorly characterized. To evaluate these effects under controlled exposure conditions, we used a preclinical exposure model calibrated to match the cumulative PM burden deposited in wildland firefighter airways over 7-14 years of service. Male apolipoprotein E knockout (Apoe-/-) mice underwent whole-body inhalation of Douglas fir smoke or filtered air for 2 hours/day, 5 days/week, for 8 or 16 weeks at target PM concentrations of 40 mg/m3. ResultsProlonged smoke exposure induced sustained elevation of circulating tumor necrosis factor-alpha (TNF-), interleukin-1 beta (IL-1{beta}), and interleukin-6 (IL-6), coupled with diffused nuclear factor kappa B (NF-{kappa}B) activation throughout the aortic wall. Smoke inhalation disrupted endothelial adherens junctions, upregulated intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), and promoted monocyte recruitment to aortic tissues, concurrent with enhanced monocyte chemoattractant protein-1 (MCP-1) expression. Oxidative stress was evidenced by increased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit 2 (NOX2) expression, elevated superoxide levels, and endothelial nitric oxide synthase (eNOS) uncoupling in the aorta, leading to lipid peroxidation and accompanied by intimal apoptosis. These inflammatory and oxidative perturbations occurred alongside a pro-fibrotic phenotypic shift characterized by transforming growth factor beta 1 (TGF-{beta}1) upregulation, myofibroblast differentiation, and progressive collagen accumulation in medial and adventitial compartments of the aortic wall. Functionally, smoke exposure progressively impaired aortic cyclic distensibility through combined wall thickening and circumferential tissue stiffening, while severely attenuating endothelium-dependent and nitric oxide (NO)-mediated vasodilation. These functional and structural shifts culminated in elevated systolic and diastolic blood pressures. While endothelial dysfunction reached maximal impairment by 8 weeks, aortic stiffening continued to worsen through 16 weeks of exposure, demonstrating differential temporal progression of vascular damage. ConclusionsThese findings demonstrate that occupationally relevant wildfire smoke exposure produces convergent inflammatory, oxidative, and profibrotic vascular remodeling with progressive loss of arterial compliance and impaired endothelium-dependent vasodilation, underscoring potential vascular targets for cardiovascular health surveillance and risk mitigation in wildland firefighters.

Background: The chromosome 1q31 Th2 pathway-associated interval has been linked to asthma, but its phenotype specificity and cross-ancestry architecture remain unclear. Methods: We analyzed African (AFR) and European (EU) ancestry datasets, including 9,965 asthma cases and 37,391 controls of AFR, and 6,074 cases and 116,255 controls of EU ancestry. Imputed dosage-based association analyses were performed for asthma, steroid-dependent asthma (SDA), and non-steroid-dependent asthma, followed by QC-filtered SDA remapping, leave-one-batch-out analysis, cross-ancestry comparison, and functional enrichment. Results: Strong regional association was observed only for SDA. After quality-control (QC) filtering, the SDA signal remained significant in both ancestries, with 2,280 genome-wide significant variants in AFR and 859 in EU. Cross-ancestry comparison identified 3,129 significant variants: 10 shared, 2,270 AFR-specific, and 849 EU-specific. Shared variants showed concordant effects, whereas 237 variants showed nominal heterogeneity. AFR-specific signals included PTPRC variants with larger effects in AFR. Functional enrichment suggested different biological emphases within the same interval: immune and contractile airway-wall biology in AFR, and additional neuroaxonal components in EU. Conclusions: The 1q31 interval is strongly associated with SDA in both AFR and EU populations, and its fine-scale architecture differs by ancestry. These findings highlight population-specific effects within a shared SDA susceptibility interval, with potential implications for population-informed precision medicine in steroid responsiveness and asthma management.

Introduction Recent respiratory illness, especially influenza, may trigger acute cardiac events via elevated inflammatory mediators. During the 2018 influenza season in Bangladesh, this study examined whether recent acute clinical respiratory illness (CRI) or laboratory-confirmed influenza was associated with elevated hs-CRP and IL-6, linked to acute cardiac events. Methods A total of 139 participants aged [&ge;]40 were recruited from a Dhaka cardiac hospital: 70 with acute myocardial infarction (AMI), 30 with other acute cardiac events, and 39 healthy individuals. CRI was defined as fever with cough and/or respiratory symptoms within seven days. Respiratory swabs were tested for influenza, and blood was analyzed for hs-CRP and IL-6. Results Median hs-CRP and IL-6 were higher in participants with CRI or influenza but not significantly. Cardiac patients had elevated hs-CRP (9.98 mg/L in other cardiac; 4.86 mg/L in AMI vs. 1.73 mg/L in healthy) and IL-6 (0.1 pg/mL in other cardiac; 0.145 pg/mL in AMI vs. 0.08 pg/mL in healthy) (p<0.001). CRI was not significantly associated with elevated hs-CRP or IL-6, though influenza in healthy participants was linked to higher IL-6. Cardiac patients had a higher risk of hs-CRP [&ge;]3 mg/L and elevated IL-6. Conclusion Cardiac patients showed significantly increased inflammatory markers, but CRI was not clearly linked to inflammation. Further research should assess biomarker utility for early cardiac risk.

Background. Tobacco smoke exposure, quantified by serum cotinine, is associated with cardiovascular, metabolic, and sleep-related health risks. The relationship between biomarker-verified tobacco smoke exposure and objectively measured, free-living wrist-worn ambient light patterns has not been examined in a nationally representative U.S. adult sample. Methods. We analyzed NHANES 2011-2014 cross-sectional data from 6,937 adults aged >20 years with valid serum cotinine and wrist-worn Physical Activity Monitor (PAM) ambient light data. Seven light outcomes were modeled using survey-weighted linear regression with log2(cotinine+1) as the continuous exposure across four covariate adjustment levels. Benjamini-Hochberg false discovery rate (FDR) correction was applied across the 7 outcomes within each model. Results. In Model 2 (adjusted for age, sex, race/ethnicity, education, poverty-income ratio, BMI, and survey cycle; N = 6,350), higher serum cotinine was associated with significantly higher nighttime light (beta = +0.024, 95% CI: 0.010, 0.038; p-FDR = 0.014) and lower evening light (beta = -0.031, 95% CI: -0.055, -0.008; p-FDR = 0.042). In exploratory behavioral models without alcohol (Model 3a; N = 5,766), both nighttime and evening associations remained FDR-significant. After additional adjustment for alcohol, which substantially reduced the sample due to 37.6% missingness (Model 3b; N = 3,866), the nighttime association attenuated below the FDR threshold, while the evening association remained FDR-significant. Categorical analyses showed progressively higher nighttime light across cotinine groups, and a hypothesis-generating sex interaction was identified (p-interaction = 0.001). Conclusions. Higher serum cotinine concentrations were associated with higher nighttime and lower evening ambient light after sociodemographic adjustment. Attenuation after behavioral adjustment and the cross-sectional design preclude causal inference. Longitudinal studies with formal mediation analyses are needed to clarify the temporal ordering and mechanisms linking tobacco smoke exposure, smoking-related behaviors, and personal light-dark cycle patterns.

Collagens are key components of the extracellular matrix (ECM) that play a crucial role in maintaining structure, strength, and function of the lungs. Fibrillar collagens are crosslinked by enzymes such as lysyl oxidases and transglutaminases and organized into networks by proteoglycans and glycoproteins. Collagens are the main load-bearing components and along with elastin may impart a non-linear strain hardening behavior to the lung. In disease, collagen crosslinking and organization can be disrupted, possibly due to abnormal levels of enzymes or ECM components. Few studies have examined collagen crosslinking and organization in healthy and diseased human lungs. In this study, alterations in collagen crosslinking and organization were investigated in human lung control, fibrotic and chronic obstructive pulmonary disease (COPD) tissue sections. Ultra-performance liquid chromatography and second harmonic generation microscopy measured pyridinoline crosslinks and the distribution of mature and immature collagens within the decellularized scaffolds, respectively. Fibrotic scaffolds had higher total collagen but less crosslinking per mole of collagen compared with COPD donors. Image analysis by second harmonic generation microscopy showed mature collagens populated airway or blood vessel walls in all three groups and in the parenchyma of fibrotic scaffolds. Immature collagens, on the other hand, were mainly localized to parenchymal regions in control and COPD scaffolds, with fewer immature collagens in fibrotic parenchyma. Additionally, quantification of the mature to immature collagen ratio in defined regions of control and diseased scaffolds showed increased organized collagen in fibrotic tissue. Our study shows that collagen crosslinking and organization are disrupted in fibrotic and COPD lungs and these changes may be compartment specific and can contribute to aberrant mechanical properties of diseased lungs. Our findings highlight that along with total collagen content, collagen crosslinking and organization are equally important while investigating collagen-mediated pathological changes in lung tissue. These changes may have implications for developing ECM-based therapeutics for patients with lung diseases.

Background. The intrapulmonary pharmacokinetics of antimicrobial agents used to treat nontuberculous mycobacterial (NTM) pulmonary disease remain poorly characterized, limiting the optimization of dosing regimens. This study characterized the plasma and intrapulmonary pharmacokinetics of azithromycin, ethambutol, rifampicin, clofazimine, and amikacin, as well as their penetration into pulmonary lesion sites. Methods. We prospectively enrolled patients undergoing guideline-based treatment for NTM pulmonary disease who were indicated for surgical resection at a single center in Japan. Drug concentrations were measured in the plasma and lung samples, and analyzed using a population pharmacokinetic model. The lung lesion site, cavity, or nodule/bronchiectatic were evaluated as covariates of the plasma-to-lung partition ratios. Results. Twenty-four patients were enrolled in the study. Antimicrobial agents other than rifampicin and amikacin accumulate in the lungs at concentrations > 40-fold higher than those in the plasma. Notably, the intrapulmonary half-life of ethambutol, which has not been well-characterized to date, is estimated to be approximately 2 months, indicating prolonged retention within the lungs. Evaluation of drug penetration into cavities and nodular/bronchiectatic lesions showed no clearly reduced concentration compared to that of normal lung tissue. However, in the single case where the caseum was obtained, azithromycin, ethambutol, and rifampicin levels exhibited clearly lower concentrations. Conclusions. Ethambutol shows a prolonged intrapulmonary half-life, suggesting sustained lung exposure even with intermittent dosing. The absence of clearly reduced drug penetration into lesion sites suggests that lesion phenotype alone may have limited value in guiding drug selection.

Manufacturers are adopting propellants for use in pressurized metered-dose inhalers (pMDIs) that have lower global warming potentials (GWPs) than the propellants traditionally used in pMDIs. Hydrofluoroalkane (HFA)-134a has been used as the propellant in the pMDI used to deliver the fixed-dose triple combination of budesonide, glycopyrrolate and formoterol fumarate (BGF); following successful clinical evaluation, the BGF pMDI is now being transitioned to the next generation propellant hydrofluoroolefin (HFO)-1234ze(E), which has near-zero GWP. We describe formulation development efforts that led to selection of HFO-1234ze(E) over another propellant, HFA-152a, for reformulation. Propellant-specific studies evaluated active pharmaceutical ingredient (API) stability and aerodynamic particle size distribution (aPSD). Those analyses have been complemented by in silico regional lung deposition modeling conducted after the clinical evaluation of the reformulated BGF pMDI. HFO-1234ze(E) supported favorable stability and aPSD characteristics for BGF pMDI reformulation, compared with HFA-152a, and modeling predicted regional deposition consistent with therapeutic intent. Given that each pMDI is a unique combination of APIs, device, propellant, and excipients, propellant substitution requires product-specific evidence and regulatory approval, and typically takes several years. Targeted analyses, such as those described here, helped to identify the most suitable candidate propellant for successful substitution in the BGF pMDI. HighlightsO_LIFormulation development efforts that led to evaluation of a budesonide-glycopyrrolate-formoterol fumarate pressurized metered-dose inhaler (BGF pMDI) reformulated with the next generation propellant HFO-1234ze(E) in a clinical trial program are described; the suitability of another propellant, HFA-152a, was also assessed C_LIO_LIOver 6 months under accelerated storage conditions (40{degrees}C/75% relative humidity [RH]), the HFA-152a formulation approached and, in one replicate, fell below the 90% of formulation label claim threshold of evaluation, whereas the original HFA-134a product and the HFO-1234ze(E) formulation remained above that threshold C_LIO_LIOver 6 months under accelerated storage conditions (40{degrees}C/75% RH) and 18 months under long-term stability storage conditions (25{degrees}C/60% RH), the fine particle mass and fine particle fraction for all active pharmaceutical ingredients (APIs) showed that the HFO-1234ze(E) formulation tracked more closely than the HFA-152a formulation to the original HFA-134a product C_LIO_LILater in silico modeling, conducted after clinical testing, predicted a trend for greater deposition of APIs in early airway generations with HFA-152a, whereas HFO-1234ze(E) was predicted to more closely match HFA-134a, indicating a greater likelihood of achieving equivalence to the original HFA-134a product with HFO-1234ze(E) than with HFA-152a C_LIO_LIBased on these analyses and other formulation development efforts, HFO-1234ze(E) was identified as the most suitable propellant for reformulation of the BGF pMDI; for HFA-152a, analyses raised concerns about storage stability, and differences in aerosol characteristics that can impact API deposition in the lungs and, in turn, efficacy C_LI

BackgroundBoth rare and common variants in the SRY-Box Transcription Factor 17 (SOX17) locus are associated with pulmonary arterial hypertension (PAH). SOX17 dysregulation leads to pulmonary artery endothelial cell (PAEC) dysfunction and the obstructive remodelling that characterises PAH. HypothesisImpaired SOX17 expression contributes to the pathogenesis of PAH. Restoring the function of SOX17 or its downstream targets using compounds that mimic its transcriptomic signature will rescue PAEC dysfunction and prevent PAH development. Methods and ResultsWe defined thousands of genes with direct SOX17 genomic binding sites and identified important potential binding partners, including ETS-transcription factors such as ERG by ChIP-seq in PAECs. Through the integration of three PAEC RNA-seq datasets involving overexpression and silencing of SOX17, we defined a robust SOX17 transcriptomic signature. In PAH patients, circulating plasma protein levels of 10 SOX17 signature genes were associated with the SOX17 common risk variants. This included EFNB2 and UNC5B; knockdown of these genes altered the viability and apoptosis of PAECs in response to TNF treatment. The drug-transcriptome database Connectivity Map (CMap) was used to predict novel potential therapeutic compounds to correct the SOX17 transcriptomic signature. Five compounds were selected for in vitro testing and were able to partially reinstate SOX17 target gene expression in PAECs. One compound, BX-912, was selected for in vivo testing as it corrected the levels of multiple target genes, including suppressing Runt-related transcription factor-1 (RUNX1). BX-912 blocked the development of pulmonary hypertension in mice lacking the SOX17 enhancer associated with human disease. ConclusionWe have demonstrated the therapeutic potential of targeting SOX17 in PAH through correction of its gene targets, identifying BX-912 as a lead compound with in vivo efficacy.

Biological sex has systemic effects on gene expression, cell behavior, and disease etiology. Despite these widespread effects, sex as a biological variable is understudied, particularly in chronic lung diseases. In idiopathic pulmonary fibrosis (IPF), 70% of patients are male, and male patients have overall worse survival post-diagnosis. While behavioral differences between sexes might account for some of the epidemiological differences, the contribution of underlying biology is not known. In this study, we performed regional proteomic analysis via laser-captured microdissection-coupled mass spectrometry and analyzed the data for sex-biased protein expression. We discovered that even in control lung, sex differences existed in both airway and alveolar regions. Sex differences became more pronounced in diseased regions, with sex-biased expression of diverse proteins including those involved in extracellular vesicle secretion, cellular metabolism, and extracellular matrix remodeling. These data suggest that baseline sex differences in lung proteome may contribute to sex-specific susceptibility, progression, and clinical outcomes in IPF, underscoring the need for future mechanistic and clinical studies to account for sex as a biological variable.