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JCI Insight Oct 2022Obesity-induced asthma responds poorly to all current pharmacological interventions, including steroids, suggesting that classic, eosinophilic inflammation is not a...
Obesity-induced asthma responds poorly to all current pharmacological interventions, including steroids, suggesting that classic, eosinophilic inflammation is not a mechanism. Since insulin resistance and hyperinsulinemia are common in obese individuals and associated with increased risk of asthma, we used diet-induced obese mice to study how insulin induces airway hyperreactivity. Inhaled 5-HT or methacholine induced dose-dependent bronchoconstriction that was significantly potentiated in obese mice. Cutting the vagus nerves eliminated bronchoconstriction in both obese and nonobese animals, indicating that it was mediated by a neural reflex. There was significantly greater density of airway sensory nerves in obese compared with nonobese mice. Deleting insulin receptors on sensory nerves prevented the increase in sensory nerve density and prevented airway hyperreactivity in obese mice with hyperinsulinemia. Our data demonstrate that high levels of insulin drives obesity-induced airway hyperreactivity by increasing sensory innervation of the airways. Therefore, pharmacological interventions to control metabolic syndrome and limit reflex-mediated bronchoconstriction may be a more effective approach to reduce asthma exacerbations in obese and patients with asthma.
Topics: Mice; Animals; Bronchoconstriction; Mice, Obese; Methacholine Chloride; Insulin; Receptor, Insulin; Serotonin; Asthma; Reflex; Hyperinsulinism; Obesity
PubMed: 36107629
DOI: 10.1172/jci.insight.161898 -
Life Sciences Nov 2022Recently, the European Association of Urology recommended hexane-extracted fruit of Serenoa repens (HESr) in their guidelines on management of non-neurogenic male lower...
Permixon®, hexane-extracted Serenoa repens, inhibits human prostate and bladder smooth muscle contraction and exerts growth-related functions in human prostate stromal cells.
AIMS
Recently, the European Association of Urology recommended hexane-extracted fruit of Serenoa repens (HESr) in their guidelines on management of non-neurogenic male lower urinary tracts symptoms (LUTS). Despite previously lacking recommendations, Permixon® is the most investigated HESr in clinical trials, where it proved effective for male LUTS. In contrast, underlying mechanisms were rarely addressed and are only marginally understood. We therefore investigated effects of Permixon® on human prostate and detrusor smooth muscle contraction and on growth-related functions in prostate stromal cells.
MAIN METHODS
Permixon® capsules were dissolved using n-hexane. Contractions of human prostate and detrusor tissues were induced in organ bath. Proliferation (EdU assay), growth (colony formation), apoptosis and cell death (flow cytometry), viability (CCK-8) and actin organization (phalloidin staining) were studied in cultured human prostate stromal cells (WPMY-1).
KEY FINDINGS
Permixon® inhibited α-adrenergic and thromboxane-induced contractions in prostate tissues, and methacholine-and thromboxane-induced contractions in detrusor tissues. Endothelin-1-induced contractions were not inhibited. Neurogenic contractions were inhibited in both tissues in a concentration-dependent manner. In WPMY-1 cells, Permixon® caused concentration-dependent breakdown of actin polymerization, inhibited colony formation, reduced cell viability, and proliferation, without showing cytotoxic or pro-apoptotic effects.
SIGNIFICANCE
Our results provide a novel basis that allows, for the first time, to fully explain the ubiquitous beneficial effects of HESr in clinical trials. HESr may inhibit at least neurogenic, α-adrenergic and thromboxane-induced smooth muscle contraction in the prostate and detrusor, and in parallel, prostate stromal cell growth. Together, this may explain symptom improvements by Permixon® in previous clinical trials.
Topics: Actins; Adrenergic Agents; Endothelin-1; Hexanes; Humans; Male; Methacholine Chloride; Muscle Contraction; Muscle, Smooth; Phalloidine; Plant Extracts; Prostate; Prostatic Hyperplasia; Serenoa; Sincalide; Stromal Cells; Thromboxanes; Urinary Bladder
PubMed: 36084760
DOI: 10.1016/j.lfs.2022.120931 -
The Tokai Journal of Experimental and... Sep 2022The utility of an analysis of breath sounds as a non-invasive lung function test in children and adults has been studied. Analyzing specific breath sounds during...
OBJECTIVE
The utility of an analysis of breath sounds as a non-invasive lung function test in children and adults has been studied. Analyzing specific breath sounds during methacholine inhalation challenge is useful for evaluating airway constriction in asthmatic patients.
PATIENTS AND METHODS
The study population included 57 children with atopic asthma (male: female = 38: 19; median age, 10 years [range, 5-16 years]). The breath sound spectrum was measured before a methacholine inhalation test, just after the methacholine inhalation challenge and after β agonist inhalation. The values of breath sound parameters were analyzed and the direct changes of the sound spectrum during methacholine inhalation challenge were evaluated.
RESULTS
The values of breath sound parameters, RPF and RPF, were significantly decreased after methacholine inhalation (P < 0.001, p < 0.001, respectively), indicationg bronchoconstriction, and increased after β agonist inhalation (P < 0.001, p < 0.001, respectively), indicating bronchodilation. The high-pitch area of the sound spectrum curve around 1,500 Hz was significantly increased after methacholine inhalation (P < 0.001). The values returned to the baseline level after β agonist inhalation.
CONCLUSIONS
Bronchoconstriction by methacholine inhalation induced a reversible high-pitch sound. The assessment of changes in the high-pitch area of the breath sound spectrum may be useful for the detection of airway narrowing in asthmatic patients.
Topics: Asthma; Bronchial Provocation Tests; Bronchoconstriction; Child; Female; Humans; Male; Methacholine Chloride; Respiratory Sounds
PubMed: 36073283
DOI: No ID Found -
European Journal of Sport Science Aug 2023The aim of this study was to examine lung function, bronchial hyperresponsiveness (BHR) and exercise-induced respiratory symptoms in elite athletes performing different...
The aim of this study was to examine lung function, bronchial hyperresponsiveness (BHR) and exercise-induced respiratory symptoms in elite athletes performing different sports. Norwegian national-team athletes (30 swimmers, 32 cross-country skiers, 16 speed-skaters, 11 rowers/paddlers, 17 handball players and 23 soccer players) completed a validated questionnaire, measured exhaled nitric oxide (FE), spirometry, methacholine provocation (PD) and skin prick test. Three cut-off levels defined BHR; i.e. PD ≤2 µmol, ≤4 µmol and ≤8 µmol. Mean forced vital capacity (FVC) was highest in swimmers (Mean z-score[95%CI] = 1.16 [0.80, 1.51]), and close to or higher than reference values according to the Global Lung Initiative equation, across all sports. Mean forced expiratory volume in 1 s (FEV) was higher than reference values in swimmers (0.48 [0.13, 0.84]), and ball game athletes (0.69 [0.41, 0.97]). Mean forced expiratory flow between 25 and 75% of FVC (FEF), and/or FEV/FVC were lower than reference values in all endurance groups. BHR defined by ≤2 and ≤8 µmol methacholine was observed in respectively 50%-87% of swimmers, 25%-47% of cross-country skiers, 20%-53% of speed-skaters, 18%-36% of rowers/paddlers, and 0%-17% of the ball game athletes. Exercise-induced symptoms were common in all groups, most frequent in cross-country skiers (88%), swimmers (83%) and speed-skaters (81%).Swimmers and ball game athletes had higher mean FVC and FEV when compared to the reference values predicted by the Global Lung Initiative (GLI) reference equation. Contrasting this, across all sports except ball game athletes, mean FEF and/or FEV/FVC were lower than reference values.The prevalence of bronchial hyperresponsiveness (BHR) was high among elite athletes competing in swimming, cross-country skiing, speed skating and rowing/paddling, with swimmers being most affected.The majority of the elite athletes reported exercise-induced respiratory symptoms independent of lung function or BHR.
Topics: Humans; Methacholine Chloride; Bronchial Provocation Tests; Bronchial Hyperreactivity; Athletes; Swimming; Lung
PubMed: 35975407
DOI: 10.1080/17461391.2022.2113144 -
American Journal of Physiology. Lung... Oct 2022The enzyme, nitric oxide-sensitive guanylyl cyclase (NO-GC), is activated by binding NO to its prosthetic heme group and catalyzes the formation of cGMP. The NO-GC is...
The enzyme, nitric oxide-sensitive guanylyl cyclase (NO-GC), is activated by binding NO to its prosthetic heme group and catalyzes the formation of cGMP. The NO-GC is primarily known to mediate vascular smooth muscle relaxation in the lung, and inhaled NO has been successfully used as a selective pulmonary vasodilator. In comparison, NO-GC's impact on the regulation of airway tone is less acknowledged and, most importantly, little is known about the issue that NO-GC signaling is accomplished by two isoforms: NO-GC1 and NO-GC2, implying the existence of distinct "cGMP pools." Herein, we investigated the functional role of the NO-GC isoforms in respiration by measuring lung function parameters of isoform-specific knockout (KO) mice using noninvasive and invasive techniques. Our data revealed the participation and ongoing influence of NO-GC1-derived cGMP in the regulation of airway tone by showing that respiratory resistance was enhanced in NO-GC1-KOs and increased more pronouncedly after the challenge with the bronchoconstrictor methacholine. The tissue resistance and stiffness of NO-GC1-KOs were also higher because of narrowed airways that cause tissue distortion. Contrariwise, NO-GC2-KOs displayed reduced tissue elasticity, elastic recoil, and airway reactivity to methacholine, which did not even increase in an ovalbumin model of asthma that induced hyperresponsiveness in NO-GC1-KOs. In addition, conscious NO-GC2-KOs showed a higher breathing rate with a shorter duration of inspiration and expiration time, which remained faster even in the presence of bronchoconstrictors that slow down breathing. Thus, we provide evidence of two distinct NO/cGMP pathways in airways, accomplished by either NO-GC1 or NO-GC2, adjusting differentially the airway reactivity.
Topics: Animals; Bronchoconstrictor Agents; Cyclic GMP; Guanylate Cyclase; Heme; Methacholine Chloride; Mice; Mice, Knockout; Nitric Oxide; Ovalbumin; Protein Isoforms; Soluble Guanylyl Cyclase; Vasodilator Agents
PubMed: 35972838
DOI: 10.1152/ajplung.00404.2021 -
Scientific Reports Aug 2022Asthma affects 340 million people worldwide and varies in time. Twenty years ago, in Canada, the Saguenay-Lac-Saint-Jean asthma family cohort was created to study the...
Asthma affects 340 million people worldwide and varies in time. Twenty years ago, in Canada, the Saguenay-Lac-Saint-Jean asthma family cohort was created to study the genetic and environmental components of asthma. This study is a follow-up of 125 participants of this cohort to explore the appearance, persistence, and progression of asthma over 10-20 years. Participants answered a clinical standardized questionnaire. Lung function was assessed (forced expiratory volume in 1 s, forced vital capacity, bronchial reversibility, and methacholine bronchoprovocation), skin allergy testing was performed, blood samples were obtained (immunoglobulin E, white blood cell counts) and phenotypes were compared between recruitment and follow-up. From the participants without asthma at recruitment, 12% developed a phenotype of adult-onset asthma with the presence of risk factors, such as atopy, high body mass index, and exposure to smoking. A decrease of PC values in this group was observed and a decrease in the FEV/FVC ratio in all groups. Also, 7% of individuals with asthma at recruitment developed chronic obstructive pulmonary disease, presenting risk factors at recruitment, such as moderate-to-severe bronchial hyperresponsiveness, exposure to smoking, and asthma. This study allowed a better interpretation of the evolution of asthma. Fine phenotypic characterization is the first step for meaningful genetic and epigenetic studies.
Topics: Asthma; Canada; Follow-Up Studies; Forced Expiratory Volume; Humans; Methacholine Chloride
PubMed: 35963877
DOI: 10.1038/s41598-022-17959-6 -
Nan Fang Yi Ke Da Xue Xue Bao = Journal... Jun 2022To investigate the roles of angiotensin-converting enzyme 2 (ACE2) in ozone-induced pulmonary inflammation and airway remodeling in mice.
OBJECTIVE
To investigate the roles of angiotensin-converting enzyme 2 (ACE2) in ozone-induced pulmonary inflammation and airway remodeling in mice.
METHODS
Sixteen wild-type (WT) C57BL/6J mice and 16 ACE2 knock-out (KO) mice were exposed to either filtered air or ozone (0.8 ppm) for 3 h per day for 5 consecutive days. Masson's staining and HE staining were used to observe lung pathologies. Bronchoalveolar lavage fluid (BALF) was collected and the total cell count was determined. The total proteins and cytokines in BALF were determined by BCA and ELISA method. The transcription levels of airway remodeling-related indicators in the lung tissues were detected using real-time quantitative PCR. The airway resistance of the mice was measured using a small animal ventilator with methacholine stimulation.
RESULTS
Following ozoneexposure ACE2 KO mice had significantly higher lung pathological scores than WT mice ( < 0.05). Masson staining results showed that compared with ozone-exposed WT mice, ozone-exposed ACE2 KO mice presented with significantly larger area of collagen deposition in the bronchi [(19.62±3.16)% (6.49±1.34)%, < 0.05] and alveoli [(21.63±3.78)% (4.44±0.99)%, < 0.05]. The total cell count and total protein contents in the BALF were both higher in ozone-exposed ACE2 KO mice than in WT mice, but these differences were not statistically significant ( > 0.05). The concentrations of IL-6, IL-1β, TNF-, CXCL1/KC and MCP-1 in the BALF were all higher in ozone-exposed ACE2 KO mice than in ozone-exposed WT mice, but only the difference in IL-1β was statistically significant ( < 0.05). The transcription levels of MMP-9, MMP-13, TIMP 4, COL1A1, and TGF-β in the lung tissues were all significantly higher in ozone-exposed ACE2 KO mice ( < 0.01). No significant difference was found in airway resistance between ozone-exposed ACE KO mice and WT mice after challenge with 0, 10, 25, or 100 mg/mL of methacholine.
CONCLUSION
ACE2 participates in ozone-induced lung inflammation and airway remodeling in mice.
Topics: Airway Remodeling; Angiotensin-Converting Enzyme 2; Animals; Methacholine Chloride; Mice; Mice, Inbred C57BL; Mice, Knockout; Ozone; Pneumonia
PubMed: 35790436
DOI: 10.12122/j.issn.1673-4254.2022.06.09 -
American Journal of Respiratory Cell... Oct 2022Asthma is a common respiratory disease characterized, in part, by excessive airway smooth muscle (ASM) contraction (airway hyperresponsiveness). Various GABAR...
Asthma is a common respiratory disease characterized, in part, by excessive airway smooth muscle (ASM) contraction (airway hyperresponsiveness). Various GABAR (γ-aminobutyric acid type A receptor) activators, including benzodiazepines, relax ASM. The GABAR is a ligand-operated Cl channel best known for its role in inhibitory neurotransmission in the central nervous system. Although ASM cells express GABARs, affording a seemingly logical site of action, the mechanism(s) by which GABAR ligands relax ASM remains unclear. PI320, a novel imidazobenzodiazepine designed for tissue selectivity, is a promising asthma drug candidate. Here, we show that PI320 alleviates methacholine (MCh)-induced bronchoconstriction and relaxes peripheral airways preconstricted with MCh using the forced oscillation technique and precision-cut lung slice experiments, respectively. Surprisingly, the peripheral airway relaxation demonstrated in precision-cut lung slices does not appear to be GABAR-dependent, as it is not inhibited by the GABAR antagonist picrotoxin or the benzodiazepine antagonist flumazenil. Furthermore, we demonstrate here that PI320 inhibits MCh-induced airway constriction in the absence of external Ca, suggesting that PI320-mediated relaxation is not mediated by inhibition of Ca influx in ASM. However, PI320 does inhibit MCh-induced intracellular Ca oscillations in peripheral ASM, a key mediator of contraction that is dependent on sarcoplasmic reticulum Ca mobilization. Furthermore, PI320 inhibits peripheral airway constriction induced by experimentally increasing the intracellular concentration of inositol triphosphate (IP). These novel data suggest that PI320 relaxes murine peripheral airways by inhibiting intracellular Ca mobilization in ASM, likely by inhibiting Ca release through IPRs (IP receptors).
Topics: Animals; Asthma; Calcium; Calcium Signaling; Flumazenil; Inositol; Ligands; Lung; Methacholine Chloride; Mice; Muscle Contraction; Muscle, Smooth; Picrotoxin; gamma-Aminobutyric Acid
PubMed: 35776523
DOI: 10.1165/rcmb.2022-0084OC -
Biomedicine & Pharmacotherapy =... Aug 2022Veronica persica is a flowering plant belonging to the family Scrophulariaceae. Here, we aimed to evaluate the pharmacological activity of the ethanol extract of...
Veronica persica is a flowering plant belonging to the family Scrophulariaceae. Here, we aimed to evaluate the pharmacological activity of the ethanol extract of Veronica persica (EEVP) in an airway inflammation model. We examined airway responsiveness to aerosolized methacholine, serum immunoglobulin (Ig)E levels, and total cell numbers in the lung and bronchoalveolar lavage fluid (BALF). Histological analysis of the lung tissue was performed using hematoxylin-eosin, Masson trichrome, or periodic acid-Schiff staining. Fluorescence-activated cell sorting analysis in the lung and BALF was applied to clarify the changes in immune cell types. Enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction were applied to investigate cytokine levels and gene expression related to airway inflammation. STAT-3/6 phosphorylation was examined in primary bronchial/tracheal epithelial cells using western blot analysis. EEVP significantly suppressed total IgE levels and methacholine-induced increase of Penh value in the HDM-challenged mouse model. EEVP also attenuated the severity of airway remodeling in lung tissues and decreased eosinophil and neutrophil infiltration in the lungs and BALF. EEVP significantly reduced the production of cytokines in BAL and splenocyte culture medium, and the expression of mRNAs related to airway inflammation in the lung tissue. EEVP suppressed IL-4/13-induced STAT-3/6 phosphorylation in the epithelial cells. We showed for the first time that EEVP effectively inhibits eosinophilic airway inflammation by suppressing the expression of inflammatory factors for T cell activation and polarization, and inhibits MCP-1 production of bronchial/tracheal epithelial cells by suppressing STAT-3/6 activation. EEVP may be a potential pharmacological agent to prevent inflammatory airway diseases.
Topics: Animals; Asthma; Cytokines; Ethanol; Immunoglobulin E; Inflammation; Lung; Methacholine Chloride; Mice; Pyroglyphidae; Veronica
PubMed: 35696941
DOI: 10.1016/j.biopha.2022.113264 -
Respiratory Care Aug 2022Methacholine challenge testing (MCT) is a common bronchoprovocation technique used to assess airway hyper-responsiveness. We previously demonstrated that the addition of...
BACKGROUND
Methacholine challenge testing (MCT) is a common bronchoprovocation technique used to assess airway hyper-responsiveness. We previously demonstrated that the addition of a viral filter to the nebulizer exhalation limb substantially reduced expelled particles during MCT. Our aim was to evaluate whether this modification affects the delivered dose of methacholine.
METHODS
A mechanical ventilator was connected to a lung simulator with breathing frequency 15 breaths/min, tidal volume 500 mL, inspiratory-expiratory ratio 1:1, with a sinusoidal waveform. We compared methacholine dose delivery using the Hudson Micro Mist or AeroEclipse II BAN nebulizers powered by either a dry gas source or a compressor system. A filter placed in line between the nebulizer and test lung was weighed before and after 1 min of nebulized methacholine delivery. Mean inhaled mass was measured with and without a viral filter on the exhalation limb. Dose delivery was calculated by multiplying the mean inhaled mass by the respirable fraction (particles < 5 μm) and inhalation time. Unpaired test was used to compare methacholine dose delivery with and without viral filter placement.
RESULTS
The addition of a viral filter did not significantly affect methacholine dose delivery across all devices tested. Using a 50-psi dry gas source, dose delivered with or without a viral filter did not differ with the Hudson (422.3 μg vs 282.0 μg, = .11) or the AeroEclipse nebulizer (563.0 μg vs 657.6 μg, = .59). Using the compressor, dose delivered with and without a viral filter did not differ with the Hudson (974.0 μg vs 868.0 μg, = .03) or the AeroEclipse nebulizer (818.0 μg vs 628.5 μg, = .42).
CONCLUSIONS
The addition of a viral filter to the nebulizer exhalation limb did not affect methacholine dose during bronchoprovocation testing. Routine use of a viral filter should be considered to improve pulmonary function technician safety and infection control measures during the ongoing COVID-19 pandemic.
Topics: Administration, Inhalation; Aerosols; Albuterol; Bronchodilator Agents; COVID-19; Equipment Design; Exhalation; Humans; Methacholine Chloride; Nebulizers and Vaporizers; Pandemics
PubMed: 35610032
DOI: 10.4187/respcare.09703