Airway Responsiveness Research Articles

In utero exposures to mint-flavored JUUL aerosol impair lung development and aggravate house dust mite-induced asthma in adult offspring mice

There are few reports concerning electronic nicotine delivery system (ENDS) use during pregnancy and no studies on asthma in prenatally JUUL-exposed offspring. Here, we tested the hypothesis that in utero JUUL exposure causes unfavorable birth outcomes and lasting pulmonary health effects in adult offspring. BALB/c dams were exposed to either air or mint-flavored JUUL aerosol, 1-hr/d, 20 consecutive days during gestation. Offspring were sacrificed on post-natal day (PND) 0 or at 11-week of age, following house dust mite (HDM) challenge. Gene expression was assessed in the uterine/placental tissue of the dams and lung responses were assessed in offspring at PND0 and at 11 weeks of age. JUUL-exposed offspring exhibited decreased body weights and lengths at PND0. These birth outcomes were accompanied by dysregulation of 54 genes associated with hypoxia and oxidative stress in the uterine/placental tissues of JUUL-exposed dams, as well as 24 genes in the lungs of the offspring related to Wnt signaling, plus 9 genes related to epigenetics, and 7 genes related to inflammation. At 11 weeks of age, JUUL + HDM exposed mice exhibited pulmonary inflammation when compared to their respective air + HDM controls. Additionally, the JUUL + HDM exposure dysregulated several genes associated with allergies and asthma. Further, the JUUL + HDM females showed decreased methylation of the promoter region of the Il10ra gene. Taken together, our mouse model shows that inhalation of JUUL aerosols during pregnancy affects the intrauterine environment, impairs lung development, and heightens the effects of allergic airway responses later in life.

To study the effect of yoga asana and pranayama on pulmonary function test in chronic obstructive pulmonary disease (copd) patients

Background: Pranayama is an integral part of yoga training. Pranayama is a regulated breathing practice that improves airway responsiveness. Yoga asana and pranayama have been shown to reduce resting respiratory rate and enhance vital capacity, maximum voluntary ventilation, breath-holding time, maximal inspiratory pressure, and expiratory pressure. Aim: This study aims to study the effect of yoga, asana, and pranayama on pulmonary function disease (chronic obstructive pulmonary disease [COPD]) patients. Materials and Methods: This was a prospective observational study which was conducted in the Department of Physiology in association with the Department of Respiratory Medicine Santosh Medical College and Hospital, Ghaziabad, Uttar Pradesh, with a sample size of 55 participants on stable patients diagnosed (COPD) with aged between 40 and 65 years of either sex. Written informed consent and approval from the institutional ethics committee were taken before starting the study. The paired t-test was used to compare the mean and standard deviation of the quantitative variables. When the P < 0.05, the results are statistically significant. To conduct statistical analysis, SPSS 20.0 was used. Results: We observed a statistically significant increase in forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FVC/FEV1 ratio, and peak expiratory flow rate after 8 and 12 weeks of yoga training compared to the first visit (0 week) baseline before yoga training. Conclusion: The results of our study showed that the regular practice of yoga, asana, and pranayama for 45 min a day minimum of 3 days a week for 12 weeks showed improvement in pulmonary function tests of COPD patients. It was also concluded that yoga and asana along with pharmacological treatment for COPD patients showed improved breathing patterns and pulmonary function parameters. It was observed that yoga, asana, and pranayama had improved physical condition by reducing weight and body mass index which enhances pulmonary function.

Muscarinic Receptor Antagonism and Allergen Induced Airway Responses in Allergic Asthma: A Scoping Review

The purpose of this scoping review was to identify existing clinical and basic science knowledge surrounding the effect of muscarinic receptor antagonism on allergen-induced airway responses to inform future clinical research in this area. Multiple advanced searches were performed using the National Library of Medicine PubMed search engine. Each search began with two terms; for example, "atropine and asthma" or "tiotropium and airway inflammation". Results were then further refined to include terms such as "allergen" or "ovalbumin (OVA)". Abstracts of refined searches were reviewed for relevance to allergic asthma and allergen-induced airway responses including the early and late asthmatic responses, airway inflammation and tissue remodelling. There was no restriction regarding publication date. Reference lists of selected papers were also reviewed for relevant publications. Nine human clinical trial publications and fourteen animal model publications were identified. In humans, single dose atropine (n=4), ipratropium (n=4) or oxitropium (n=1) administered pre-challenge produced equivocal effects on allergen-induced early asthmatic responses as reported but favored inhibition in eight of nine studies after re-analyses. Animal model investigations (n=14) showed mostly favorable results, especially with respect to airway inflammation and tissue remodelling, although two studies were negative, and one study showed a worsening in allergen induced airway inflammation following muscarinic receptor antagonism. Existing human and animal model data suggest muscarinic receptor antagonism may be beneficial in preventing allergen induced airway responses in those with allergic asthma. Additional human research utilizing current standardized methodologies is required.

Usefulness of simultaneous impulse oscillometry and spirometry with airway response to bronchodilator in the diagnosis of asthmatic cough

Objective: Some of the most common causes of chronic cough include cough variant asthma (CVA), bronchial asthma (BA), and asthma–COPD overlap (ACO). Although there is some overlap in the etiology of these diseases, it is clinically important to attempt an early differential diagnosis due to treatment strategies and prognoses. Methods: Spirometry and impulse oscillometry (IOS) before and after bronchodilator inhalation were analyzed for clinically diagnosed CVA (cCVA, n = 203), BA (cBA, n = 222), and ACO (cACO, n = 61). Results: A significant difference in ΔFEV1 was observed between cBA and cCVA (ΔFEV1 improvement of 122.5 mL/5.4% and 65.7 mL/2.2%, respectively), but no difference was observed in ΔPEF, ΔV50, or ΔV25. Except for R20 (resistance at 20 Hz), significant differences between the three groups were observed in IOS. In IOS, cCVA and cBA showed comparable peripheral airway response to bronchodilator which was thought to be commensurate with changes in V50 and V25. cACO improved ΔFEV1 improvement of 81.0 mL/6.2% and was distinguished by a downward respiratory system reactance (Xrs) waveform with a limited bronchodilator response. FEV1/FVC, %FEV1, and %V25 had relatively strong correlations with the three IOS parameters, X5 (reactance at 5 Hz), resonant frequency (Fres), and low-frequency reactance area (ALX), in the correlation between IOS and spirometers. Conclusion: Changes in IOS parameters were more sensitive in this study than changes in FEV1 or the flow-volume curve. Considering the benefits and relevance of the two different tests, simultaneous IOS and spirometry testing were useful in the diagnosis of asthmatic cough.

Effect of intravenous versus intratracheal lidocaine on airway and hemodynamic responses during extubation after thyroid surgery. A prospective cohort study

IntroductionCoughing during extubation after thyroid surgery can increase venous pressure and release the vessel ligation which leads to active bleeding, and form hematoma which can be a life threatening due to airway obstruction. Lidocaine before extubation may reduce cough and hemodynamic instability. The aim of this study was to compare effect of intra-tracheal and intravenous lidocaine on airway and hemodynamic responses during extubation. MethodA hospital based prospective cohort study was conducted on 74 patients who underwent thyroid surgery. A Systematic random sampling technique was employed. Data recording was made after Anesthetists gave 1.5 mg/kg 2% lidocaine either intravenous (control group) or intra-tracheal (exposed group) before extubation. The episode and grade of coughs were recorded. Heart rate and blood pressure were also recorded at the time of lidocaine administration, and at 1,2,3,4 and 5 minutes post extubation. Independent two sample t-test and chi-square were computed. P-value < 0.05 considered as statistically significant. ResultThe two groups were comparable with respect to socio -demographic and clinical characteristics. The incidence of coughing after intravenous and intratracheal lidocaine was 11% and 15%, p-value, 0.425, respectively. The sedation score after extubation also was comparable between the two groups. Even though the difference between the two groups was statistically insignificant, the mean heart rates and blood pressure after lidocaine in intravenous and intratracheal lidocaine groups were higher at 1 min post extubation and then decline to baseline mean heart rate at 5 munities post extubation. ConclusionIntravenous and intratracheal lidocaine have comparable effects on airway and hemodynamic response during extubation after thyroid surgery. The sedation score after lidocaine was also similar among the two groups. Therefore lidocaine can be used either intra tracheal or intravenously before extubation.

In mice of both sexes, repeated contractions of smooth muscle in vivo greatly enhance the response of peripheral airways to methacholine

BALB/c mice from both sexes underwent one of two nebulized methacholine challenges that were preceded by a period of 20 min either with or without tone induced by repeated contractions of the airway smooth muscle. Impedance was monitored throughout and the constant phase model was used to dissociate the impact of tone on conducting airways (RN – Newtonian resistance) versus the lung periphery (G and H – tissue resistance and elastance). The effect of tone on smooth muscle contractility was also tested on excised tracheas. While tone markedly potentiated the methacholine-induced gains in H and G in both sexes, the gain in RN was only potentiated in males. The contractility of female and male tracheas was also potentiated by tone. Inversely, the methacholine-induced gain in hysteresivity (G/H) was mitigated by tone in both sexes. Therefore, the tone-induced muscle hypercontractility impacts predominantly the lung periphery in vivo, but also promotes further airway narrowing in males while protecting against narrowing heterogeneity in both sexes.

Increased Expression of LASI lncRNA Regulates the Cigarette Smoke and COPD Associated Airway Inflammation and Mucous Cell Hyperplasia.

Research ImpactCigarette smoke (CS) exposure is strongly associated with chronic obstructive pulmonary disease (COPD). In respiratory airways, CS exposure disrupts airway barrier functions, mucous/phlegm production, and basic immune responses of airway epithelial cells. Based on our recent identification of a specific immunomodulatory long noncoding RNA (lncRNA), we investigated its role in CS-induced responses in bronchial airways of cynomolgus macaque model of CS-induced COPD and in former smokers with and without COPD. The lncRNA was significantly upregulated in CS-induced macaque airways and in COPD airways that exhibited higher mucus expression and goblet cell hyperplasia. Experimental models of cells derived from COPD subjects recapitulated the augmented inflammation and mucus expression following the smoke challenge. Blocking of lncRNA expression in cell culture setting suppressed the smoke-induced and COPD-associated dysregulated mucoinflammatory response suggesting that this airway specific immunomodulatory lncRNA may represent a novel target to mitigate the smoke-mediated inflammation and mucus hyperexpression.RationaleIn conducting airways, CS disrupts airway epithelial functions, mucociliary clearances, and innate immune responses that are primarily orchestrated by human bronchial epithelial cells (HBECs). Mucus hypersecretion and dysregulated immune response are the hallmarks of chronic bronchitis (CB) that is often exacerbated by CS. Notably, we recently identified a long noncoding RNA (lncRNA) antisense to ICAM-1 (LASI) that mediates airway epithelial responses.ObjectiveTo investigate the role of LASI lncRNA in CS-induced airway inflammation and mucin hyperexpression in an animal model of COPD, and in HBECs and lung tissues from former smokers with and without COPD. To interrogate LASI lncRNA role in CS-mediated airway mucoinflammatory responses by targeted gene editing.MethodsSmall airway tissue sections from cynomolgus macaques exposed to long-term mainstream CS, and those from former smokers with and without COPD were analyzed. The structured-illumination imaging, RNA fluorescence in-situ hybridization (FISH), and qRT-PCR were used to characterize lncRNA expression and the expression of inflammatory factors and airway mucins in a cell culture model of CS extract (CSE) exposure using HBECs from COPD (CHBEs) in comparison with cells from normal control (NHBEs) subjects. The protein levels of mucin MUC5AC, and inflammatory factors ICAM-1, and IL-6 were determined using specific ELISAs. RNA silencing was used to block LASI lncRNA expression and lentivirus encoding LASI lncRNA was used to achieve LASI overexpression (LASI-OE).ResultsCompared to controls, LASI lncRNA was upregulated in CS-exposed macaques and in COPD smoker airways, correlating with mucus hyperexpression and mucus cell hyperplasia in severe COPD airways. At baseline, the unstimulated CHBEs showed increased LASI lncRNA expression with higher expression of secretory mucin MUC5AC, and inflammatory factors, ICAM-1, and IL-6 compared to NHBEs. CSE exposure of CHBEs resulted in augmented inflammation and mucus expression compared to controls. While RNA silencing-mediated LASI knockdown suppressed the mucoinflammatory response, cells overexpressing LASI lncRNA showed elevated mRNA levels of inflammatory factors.ConclusionsAltogether, LASI lncRNA may represent a novel target to control the smoke-mediated dysregulation in airway responses and COPD exacerbations.

Acute Accidental Exposure to Chlorine Gas: Clinical Presentation, Pulmonary Functions and Outcomes

To study the clinical presentation, pulmonary functions and outcomes in subjects who were accidentally exposed to chlorine gas. Prospective observational study of 64 patients who sustained acute accidental exposure to chlorine gas during a leak in the chlorination system of the public bathing pool of a temple. The major presenting symptoms and signs included acute dyspnoea (100%), chest discomfort (100%), cough (97%), eye irritation (88%), giddiness (72%), vomiting (46%), and heaviness in the head (44%); tachycardia (100%), tachypnoea (96%) and polyphonic wheezing (28%). All patients were managed in the emergency room with humidified oxygen inhalation and beta-2 agonist nebulisation and 52 were discharged within six hours. Twelve patients were severely affected and required hospitalisation; three of them were admitted into the intensive care unit. Three patients developed pulmonary oedema six to eight hours following admission. Pulmonary function testing (n = 12) at presentation revealed obstructive defect in eight and mixed obstructive-cum-restrictive defect in four patients. The mean duration of hospital stay was 5.1 +/- 2.1 days. None of the patients died. Reactive airway dysfunction syndrome (RADS) was observed in three of the 12 hospitalised patients, who complained of manifested persistent cough that lasted for three months period following discharge. Serial pulmonary functions recovered to normal range by the end of the six months in all patients and remained so at one-year follow-up. Acute exposure to chlorine gas is an uncommon, but important public health hazard and can cause RADS, acute lung injury and pulmonary function abnormalities, which are reversible on prompt and appropriate management.

Effectiveness of intravenous lidocaine and fentanyl on attenuation of hemodynamic response to extubation for ear, nose and throat surgeries at JLNMCH, Bhagalpur, Bihar

Background: Tracheal extubation, the purposeful removal of the endotracheal tube from the trachea, can be associated with detrimental hemodynamic and airway responses. Lidocaine and fentanyl are known to suppress hemodynamic response to extubation during Ear, nose, and throat surgeries. Smooth tracheal extubation is important after Ear, nose, and throat surgeries.Objective: To compare the effect of intravenous lidocaine and fentanyl on attenuation of hemodynamic response to extubation for Ear, nose, and throat (ENT) surgeries at JLNMCH, Bhagalpur, Bihar. Methods: This prospective cohort study recruits 74 American Society of Anesthesiologist (ASA) class I and II, age between 18 and 60 patients who underwent Ear, Nose and Throat surgeries. Unpaired T test was used to compare the mean of heart rate and mean arterial blood pressure between groups. Mann Whitney U Test was used for distribution free data. Association of categorical independent variables between two groups were analyzed using Chi Square or fisher exact test. P-values &lt; 0.05 were considered as statistically significant with a power of 80%. Results: The demographic and clinical characteristics were comparable between groups.

N-Acetylcysteine decreases lung inflammation and fibrosis by modulating ROS and Nrf2 in mice model exposed to particulate matter.

Air pollutants can induce and incite airway diseases such as asthma. N-acetylcysteine (NAC) affects signaling pathways involved in apoptosis, angiogenesis, cell growth and arrest, redox-regulated gene expression, and the inflammatory response. However, it is not known how NAC change redox-regulated gene expression in asthma mouse model exposed to particulate matter (PM). To investigate the effects of NAC (100 mg/kg) on redox-regulated gene expression and lung fibrosis in a mouse model of asthma exposed to PM. A mice model of asthma induced by ovalbumin (OVA) or OVA plus titanium dioxide (OVA + TiO2) was established using wild-type BALB/c female mice, and the levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and mucin 5AC (Muc5ac) proteins following NAC treatment were examined by Western blotting and immunostaining. In addition, the protein levels of Reactive oxygen species (ROS) were checked. Airway hyperresponsiveness and inflammation, goblet cell hyperplasia, and lung fibrosis were higher in OVA, OVA + TiO2 mice than in control mice. NAC diminished OVA + TiO2-induced airway hyperresponsiveness and inflammation, goblet cell hyperplasia, and lung fibrosis. Levels of ROS, Nrf2 and Muc5ac protein were higher in lung tissue from OVA + TiO2 mice than that from control mice and were decreased by treatment with NAC. NAC reduce airway inflammation and responsiveness, goblet cell hyperplasia, and lung fibrosis by modulating ROS and Nrf2.

Macrophage-intrinsic DUOX1 contributes to type 2 inflammation and mucus metaplasia during allergic airway disease.

The NADPH oxidase DUOX1 contributes to epithelial production of alarmins, including interleukin (IL)-33, in response to injurious triggers such as airborne protease allergens, and mediates development of mucus metaplasia and airway remodeling in chronic allergic airways diseases. DUOX1 is also expressed in non-epithelial lung cell types, including macrophages that play an important role in airway remodeling during chronic lung disease. We therefore conditionally deleted DUOX1 in either lung epithelial or monocyte/macrophage lineages to address its cell-specific actions in innate airway responses to acute airway challenge with house dust mite (HDM) allergen, and in chronic HDM-driven allergic airway inflammation. As expected, acute responses to airway challenge with HDM, as well as type 2 inflammation and related features of airway remodeling during chronic HDM-induced allergic inflammation, were largely driven by DUOX1 with the respiratory epithelium. However, in the context of chronic HDM-driven inflammation, DUOX1 deletion in macrophages also significantly impaired type 2 cytokine production and indices of mucus metaplasia. Further studies revealed a contribution of macrophage-intrinsic DUOX1 in macrophage recruitment upon chronic HDM challenge, as well as features of macrophage activation that impact on type 2 inflammation and remodeling.

Circadian molecular clock disruption in chronic pulmonary diseases.

The circadian clock is the biochemical oscillator with a near 24-h period that is responsible for generating the circadian rhythms in peripheral organs including the lung. Mounting evidence suggests that circadian clock disruption during chronic lung diseases plays an essential role in augmented oxidative stress, inflammatory response, metabolic imbalances, hypoxia/hyperoxia, mucus secretion, dysregulated autophagy, and alters pulmonary function. Here, we review circadian clock disruption and discuss candidate clock genes that are altered at the transcriptional or translational level in chronic pulmonary diseases. This review aims to provide the current knowledge and understanding of the circadian molecular clock disruption in chronic pulmonary diseases which will further advance the development of novel clock-based therapeutics in the future.

Daily Inhaled Corticosteroids Treatment Abolishes Airway Hyperresponsiveness to Mannitol in Defence and Police Recruits.

BackgroundAirway hyperresponsiveness (AHR) is a key pathophysiological feature of asthma and causes exercise-induced bronchoconstriction (EIB). Indirect bronchial provocation tests (BPTs) (e.g., exercise, mannitol) aid to diagnose asthma and identify EIB. Daily inhaled corticosteroids (ICS) can abolish AHR caused by indirect stimuli. Where strenuous physical exertion is integral to an occupation, identification of those at risk of EIB is important and documentation of inhibition of AHR with ICS is required before recruitment.Methods/ObjectivesA retrospective analysis was performed on 155 potential recruits with AHR to mannitol who underwent follow-up assessment after daily ICS treatment to determine the proportion that can abolish AHR using ICS and to determine any predictors of the persistence of AHR.ResultsAirway hyperresponsiveness was abolished in the majority (84%, n = 130) over the treatment period (mean ± SD 143 ± 72days), and it was defined as the provoking dose of mannitol to cause a 15% fall in FEV1 (cumulative inhaled dose of mannitol to cause 15% fall in FEV1, PD15) improved from (GeoMean) 183 to 521 mg. Compared with recruits in whom AHR was abolished with daily ICS (i.e., no 15% fall in FEV1 to the maximum cumulative dose of mannitol of 635 mg), in those where AHR remained (16%, n = 25), baseline AHR was more severe (PD15: 85 mg vs. 213 mg, P < 0.001), baseline FEV1% was lower (89 vs. 96%; 95%CI:2–12, P=0.004), and they had a longer follow-up duration (180 vs. 136 days; 13–74, P = 0.006). Baseline FEV1% (adjusted odds ratio 0.85; 95%CI:0.77–0.93), FEV1/FVC (0.78; 0.67–0.90), FEF25−75% (1.15; 1.06–1.25), and airway reactivity to mannitol (%Fall/cumulative dose of mannitol multiplied by 100) (1.07; 1.03–1.11) predicted AHR remaining after daily ICS.ConclusionAirway hyperresponsiveness to mannitol can be abolished after 20 weeks of daily treatment with ICS. Inhibition of AHR is likely due to attenuation of airway inflammation in response to ICS treatment. Increased airway reactivity and lower spirometry variables predicted the persistence of AHR. Thus, those with a slower response to daily ICS on AHR can potentially be identified at the commencement of monitoring ICS using inhaled mannitol.

Distinct Immunological Profiles Help in the Maintenance of Salivary Secretory IgA Production in Mild Symptoms COVID-19 Patients.

BackgroundRelevant aspects regarding the SARS-CoV-2 pathogenesis and the systemic immune response to this infection have been reported. However, the mucosal immune response of the upper airways two months after SARS-CoV-2 infection in patients with mild/moderate symptoms is still not completely described. Therefore, we investigated the immune/inflammatory responses of the mucosa of the upper airways of mild/moderate symptom COVID-19 patients two months after the SARS-CoV-2 infection in comparison to a control group composed of non-COVID-19 healthy individuals.MethodsA cohort of 80 volunteers (age 37.2 ± 8.2), including non-COVID-19 healthy individuals (n=24) and COVID-19 patients (n=56) who presented mild/moderate symptoms during a COVID-19 outbreak in Brazil in November and December of 2020. Saliva samples were obtained two months after the COVID-19 diagnosis to assess the levels of SIgA by ELISA and the cytokines by multiplex analysis.ResultsSalivary levels of SIgA were detected in 39 volunteers into the COVID-19 group and, unexpectedly, in 14 volunteers in the control group. Based on this observation, we distributed the volunteers of the control group into without SIgA or with SIgA sub-groups, and COVID-19 group into without SIgA or with SIgA sub-groups. Individuals with SIgA showed higher levels of IL-10, IL-17A, IFN-γ, IL-12p70, IL-13, and IFN-α than those without SIgA. In intergroup analysis, the COVID-19 groups showed higher salivary levels of IL-10, IL-13, IL-17A, and IFN-α than the control group. No statistical differences were verified in the salivary levels of IL-6 and IFN-β. Lower IL-12p70/IL-10 and IFN-γ/IL-10 ratios were found in the control group without SIgA than the control group with SIgA and the COVID-19 group with SIgA.ConclusionWe were able to present, for the first time, that associations between distinct immunological profiles can help the mucosal immunity to maintain the salivary levels of SIgA in COVID-19 patients two months after the SARS-CoV-2 infection.

Exogenous leptin enhances markers of airway fibrosis in a mouse model of chronic allergic airways disease

BackgroundAsthma patients with comorbid obesity exhibit increased disease severity, in part, due to airway remodeling, which is also observed in mouse models of asthma and obesity. A mediator of remodeling that is increased in obesity is leptin. We hypothesized that in a mouse model of allergic airways disease, mice receiving exogenous leptin would display increased airway inflammation and fibrosis.MethodsFive-week-old male and female C57BL/6J mice were challenged with intranasal house dust mite (HDM) allergen or saline 5 days per week for 6 weeks (n = 6–9 per sex, per group). Following each HDM exposure, mice received subcutaneous recombinant human leptin or saline. At 48 h after the final HDM challenge, lung mechanics were evaluated and the mice were sacrificed. Bronchoalveolar lavage was performed and differential cell counts were determined. Lung tissue was stained with Masson’s trichrome, periodic acid-Schiff, and hematoxylin and eosin stains. Mouse lung fibroblasts were cultured, and whole lung mRNA was isolated.ResultsLeptin did not affect mouse body weight, but HDM+leptin increased baseline blood glucose. In mixed-sex groups, leptin increased mouse lung fibroblast invasiveness and increased lung Col1a1 mRNA expression. Total lung resistance and tissue damping were increased with HDM+leptin treatment, but not leptin or HDM alone. Female mice exhibited enhanced airway responsiveness to methacholine with HDM+leptin treatment, while leptin alone decreased total respiratory system resistance in male mice.ConclusionsIn HDM-induced allergic airways disease, administration of exogenous leptin to mice enhanced lung resistance and increased markers of fibrosis, with differing effects between males and females.

Head rotation improves airway obstruction, especially in patients with less severe obstructive sleep apnea without oropharyngeal collapse.

Head rotation is thought to have an effect on obstructive sleep apnea (OSA) severity. However, keeping the head rotated fully during sleep is difficult to maintain, and the effect of head rotation is not the same in all OSA patients. Thus, this study aimed to identify whether less head rotation has an effect on airway patency and determine the responder characteristics to the head rotation maneuver (HRM). We recruited 221 patients who underwent overnight polysomnography and drug-induced sleep endoscopy (DISE) in a tertiary hospital from June 2019 to July 2020. Airway patency and the site of airway collapse were determined in the supine position with the head at 0, 30, and 60 degrees of rotation (HRM0°, HRM30°, and HRM60°, respectively) during DISE. The site of collapse was determined using the VOTE classification system: the velum (palate), oropharyngeal lateral walls, tongue base, and epiglottis. Each structure was labeled as 0, 1, or 2 (patent, partially obstructed, and completely obstructed, respectively). Airway response to the HRM30° and 60° and the clinical characteristics associated with airway opening were analyzed. The study population had a median age of 52 (25-61) years, a body mass index of 26.7(24.6-29.4) kg/m2, and the apnea-hypopnea index (AHI) of 28.2(13.7-71.9) events/h. HRM influenced airway patency positively not only with HRM60° (p<0.001) but also following limited rotation (HRM30°, p<0.001). Patients with tongue base (40.0% with HRM 60°) and epiglottic (52.6% with HRM 60°) collapse responded particularly well to HRM. Multivariate analysis revealed that lower AHI (p<0.001) and an absence of oropharyngeal lateral walls collapse (p = 0.011) were significant predictors of responders to HRM. Head rotation improved airway obstruction in OSA patients, even with a small degree of rotation, and should be further explored as a potential form of therapy in appropriately selected patients.

Intranasal bovine β-defensin-5 enhances antituberculosis immunity in a mouse model by a novel protein-based respiratory mucosal vaccine

ABSTRACT Respiratory mucosal immunization is an effective immunization strategy against tuberculosis (TB), and effective mucosal vaccines require adjuvants that can promote protective immunity without deleterious inflammation. Mucosal BCG (Bacille Calmette-Guerin) is effective, but it causes a severe inflammatory response in the lung. A novel less cytotoxic mucosal vaccine AH-PB containing Mycobacterium tuberculosis (Mtb) cell surface antigens Ag85A and HspX (AH), as well as polyinosinic-polycytidylic acid (Poly IC) and bovine neutrophil β-defensin-5 (B5) adjuvants were prepared, with the overarching goal of protecting against TB. Then, the immunogenicity and protective efficacy of these vaccines via the intranasal route were evaluated in a mouse model. Results showed that intranasal AH-PB promoted tissue-resident memory T cells (TRMs) development in the lung, induced antigen-specific antibody response in airway, provided protection against Mycobacterium bovis (M. bovis), conferred better protection than parenteral BCG in the later stage of infection, and boosted the protective immunity generated by BCG in mice. Moreover, both B5 and Poly IC were indispensable for the protection generated by AH-PB. Furthermore, intranasal immunization with AH-B5 fusion vaccines also provided similar protection against M. bovis compared to AH-PB. Collectively, B5-based TB vaccine via the intranasal route is a promising immunization strategy against bovine TB, and this kind of immunization strategy may be applied to human TB vaccine development. These findings highlight the potential importance of B5 as a mucosal adjuvant used in TB vaccines or other respiratory disease vaccines.

Early-life infection of the airways with Streptococcus pneumoniae exacerbates HDM-induced asthma in a murine model

Respiratory tract infection early in life plays a significant role in the pathogenesis of asthma. In the present study we examine, using a murine surrogate, the effects of early life respiratory infection with Streptococcus pneumoniae (SP) on adult asthma induced by sensitisation and exposure to house dust mite (HDM) allergen. Mice (one week old) were infected with SP, then 3 weeks later sensitised to HDM emulsified with Al (OH)3 intraperitoneally and challenged intranasally with same allergen for up to a further 5 weeks to establish the asthma surrogate. Outcome measures were quantified using the FlexiVent apparatus, histology and immunohistology, ELISA and flow cytometry. The murine surrogates of asthma infected with SP early in life exhibited significantly more severe disease compared with the controls of mice without SP infection, as shown by airways responsiveness, inflammatory cellular infiltration of the airways, expression of markers of airways remodelling, serum concentrations of HDM-specific IgE and the concentrations of Th2-type cytokines and the numbers of activated Th2 and ILC2 cells in the lung tissues. These data are compatible with the hypothesis that early-life infection of the airways with SP exacerbates, at least in some individuals, subsequent HDM-induced allergic airways inflammation and associated asthma in adulthood in this murine surrogate.

The Val34Met, Thr164Ile and Ser220Cys Polymorphisms of the β2-Adrenergic Receptor and Their Consequences on the Receptor Conformational Features: A Molecular Dynamics Simulation Study.

The gene encoding the β2-adrenergic receptor (β2-AR) is polymorphic, which results in possible differences in a primary structure of this protein. It has been shown that certain types of polymorphisms are correlated with some clinical features of asthma, including airways reactivity, whereas the influence of other is not yet understood. Among polymorphisms affecting amino acids at positions 16, 27, 34, 164 and 220, the latter three are present in the crystal structure of β2-AR, which facilitates studying them by means of molecular dynamics simulations. The current study was focused on investigating to what extent the three polymorphisms of β2-AR (i.e., Val34Met, Thr164Ile and Ser220Cys) affect the interaction of β2-AR with its natural molecular environment which includes: lipid bilayer (in the case of all three polymorphs) and Gs protein (which participates in β2-AR-mediated signaling; in the case of Ser220Cys). We have designed and carried out a series of molecular dynamics simulations at different level of resolution (i.e., either coarse-grained or atomistic simulations), accompanied by thermodynamic integration protocol, in order to identify potential polymorphism-induced alterations in structural, conformational or energetic features of β2-AR. The results indicate the lack of significant differences in the case of energies involved in the β2-AR-lipid bilayer interactions. Some differences have been observed when considering the polymorphism-induced alterations in β2-AR-Gs protein binding, but their magnitude is also negligible in relation to the absolute free energy difference correlated with the β2-AR-Gs affinity. The Val34Met and Thr164Ile polymorphisms are weakly correlated with alteration of the conformational features of the receptor around polymorphic sites. On the contrary, it has been concluded that the Ser220Cys polymorphism is correlated with several structural alterations located in the intracellular region of β2-AR, which can induce G-protein binding and, subsequently, the polymorphism-correlated therapeutic responses. More precisely, these alterations involve vicinity of intracellular loops and, in part, are the direct consequence of disturbed interactions of Ser/Cys220 sidechain within 5th transmembrane domain. Structurally, the dynamic structure exhibited by the β2-ARSer220 polymorph is closer to the Gs-compatible structure of β2-AR.

Berberine Alleviates Gastroesophageal Reflux-Induced Airway Hyperresponsiveness in a Transient Receptor Potential A1-Dependent Manner.

Background To investigate the beneficial effect of berberine on gastroesophageal reflux-induced airway hyperresponsiveness (GERAHR) and explore the underlying mechanism. Methods Coword cluster analysis and strategic coordinates were used to identify hotspots for GERAHR research, and an online tool (STRING, https://string-db.org/) was used to predict the potential relationships between proteins. Guinea pigs with chemically induced GERAHR received PBS or different berberine-based treatments to evaluate the therapeutic effect of berberine and characterize the underlying mechanism. Airway responsiveness was assessed using a plethysmography system, and protein expression was evaluated by western blotting, immunohistochemical staining, and quantitative PCR analysis. Results Bioinformatics analyses revealed that TRP channels are hotspots of GERAHR research, and TRPA1 is related to the proinflammatory neuropeptide substance P (SP). Berberine, especially at the middle dose tested (MB, 150 mg/kg), significantly improved lung function, suppressed inflammatory cell infiltration, and protected inflammation-driven tissue damage in the lung, trachea, esophagus, and nerve tissues in GERAHR guinea pigs. MB reduced the expression of TRPA1, SP, and tumor necrosis factor-alpha (TNF-α) in evaluated organs and tissues. Meanwhile, the MB-mediated protective effects were attenuated by simultaneous TRPA1 activation. Conclusions Mechanistically, berberine was found to suppress GERAHR-induced upregulation of TRPA1, SP, and TNF-α in many tissues. Our study has highlighted the potential therapeutic value of berberine for the treatment of GERAHR.