scholarly journals Acid exposure impairs mucus secretion and disrupts mucus transport in neonatal piglet airways

2019 ◽  
Author(s):  
Yan Shin J. Liao ◽  
Shin Ping Kuan ◽  
Maria V. Guevara ◽  
Emily N. Collins ◽  
Kalina R. Atanasova ◽  
...  
Keyword(s):  
Chloride Transport ◽  
Ex Vivo ◽  
Lavage Fluid ◽  
Mucus Secretion ◽  
Submucosal Gland ◽  
Cholinergic Stimulation ◽  
Diminazene Aceturate ◽  
Gland Duct ◽  
Airway Acidification

ABSTRACTTenacious mucus produced by tracheal and bronchial submucosal glands is a defining feature of cystic fibrosis (CF). Although airway acidification occurs early in CF, whether transient acidification is sufficient to initiate mucus abnormalities is unknown. We studied mucus secretion and mucus transport in piglets forty-eight hours following an intra-airway acid challenge. Acid-challenged piglet airways were distinguished by increased mucin 5B (MUC5B) in the submucosal gland but decreased lung lavage fluid MUC5B, following in vivo cholinergic stimulation, suggesting a failure in submucosal gland secretion. Concomitantly, intrapulmonary airways were obstructed with glycoprotein rich material under both basal and methacholine-stimulated conditions. To mimic a CF-like environment, we also studied mucus secretion and transport under diminished bicarbonate and chloride transport conditions ex vivo. Cholinergic stimulation in acid-challenged piglet airways induced extensive mucus films, greater mucus strand formation, increased dilation of submucosal gland duct openings and decreased mucociliary transport. Finally, to elucidate potential mediators of acid-induced mucus defects, we investigated diminazene aceturate, a small molecule that inhibits the acid-sensing ion channel (ASIC). Diminazene aceturate restored surface MUC5B in acid-challenged piglet airways under basal conditions, mitigated acid-induced airway obstruction, and magnified the number of dilated submucosal gland duct openings. These findings suggest that even transient airway acidification early in life might have profound impacts on mucus secretion and transport properties. Further they highlight diminazene aceturate as an agent that might be beneficial in alleviating certain mucus defects in CF airway disease.One sentence summaryEarly life airway acidification has profound impacts on mucus secretion and transport.

scholarly journals Acid exposure disrupts mucus secretion and impairs mucociliary transport in neonatal piglet airways

2020 ◽  
Vol 318 (5) ◽  
pp. L873-L887 ◽  
Author(s):  
Yan Shin J. Liao ◽  
Shin Ping Kuan ◽  
Maria V. Guevara ◽  
Emily N. Collins ◽  
Kalina R. Atanasova ◽  
...  
Keyword(s):  
Airway Obstruction ◽  
Chloride Transport ◽  
Ex Vivo ◽  
Mucus Secretion ◽  
Mucociliary Transport ◽  
Cholinergic Stimulation ◽  
Diminazene Aceturate ◽  
Airway Pathology ◽  
Submucosal Glands ◽  
Airway Acidification

Tenacious mucus produced by tracheal and bronchial submucosal glands is a defining feature of several airway diseases, including cystic fibrosis (CF). Airway acidification as a driving force of CF airway pathology has been controversial. Here we tested the hypothesis that transient airway acidification produces pathologic mucus and impairs mucociliary transport. We studied pigs challenged with intra-airway acid. Acid had a minimal effect on mucus properties under basal conditions. However, cholinergic stimulation in acid-challenged pigs revealed retention of mucin 5B (MUC5B) in the submucosal glands, decreased concentrations of MUC5B in the lung lavage fluid, and airway obstruction. To more closely mimic a CF-like environment, we also examined mucus secretion and transport following cholinergic stimulation under diminished bicarbonate and chloride transport conditions ex vivo. Under these conditions, airways from acid-challenged pigs displayed extensive mucus films and decreased mucociliary transport. Pretreatment with diminazene aceturate, a small molecule with ability to inhibit acid detection through blockade of the acid-sensing ion channel (ASIC) at the doses provided, did not prevent acid-induced pathologic mucus or transport defects but did mitigate airway obstruction. These findings suggest that transient airway acidification early in life has significant impacts on mucus secretion and transport properties. Furthermore, they highlight diminazene aceturate as an agent that might be beneficial in alleviating airway obstruction.

scholarly journals Healthy versus inflamed lung environments differentially effect MSCs

2021 ◽  
pp. 2004149
Author(s):  
Sara Rolandsson Enes ◽  
Thomas H. Hampton ◽  
Jayita Barua ◽  
David H. McKenna ◽  
Claudia C. dos Santos ◽  
...  
Keyword(s):  
Gene Expression ◽  
Healthy Volunteers ◽  
Cell Injury ◽  
Ex Vivo ◽  
Lavage Fluid ◽  
Cell Therapies ◽  
Inflammatory Microenvironment ◽  
Self Recognition ◽  
Clinical Investigations

BackgroundDespite increased interest in MSC-based cell therapies for the acute respiratory distress syndrome (ARDS), clinical investigations have not yet been successful and understanding of the potential in vivo mechanisms of MSC actions in ARDS remain limited. ARDS is driven by an acute severe innate immune dysregulation, often characterised by inflammation, coagulation, and cell injury. How this inflammatory microenvironment influences MSC functions remains to be determined.AimTo comparatively assess how the inflammatory environment present in ARDS lungs versus the lung environment present in healthy volunteers alters MSC behaviors.MethodsClinical grade human bone marrow-derived MSCs (hMSCs) were exposed to bronchoalveolar lavage fluid (BALF) samples obtained from ARDS patients or from healthy volunteers. Following exposure, hMSCs and their conditioned media were evaluated for a broad panel of relevant properties including viability, levels of expression of inflammatory cytokines, gene expression, cell surface HLA expression, and activation of coagulation and complement pathways.ResultsPro-inflammatory, pro-coagulant, and major histocompatibility complex (self recognition) related gene expression was markedly up-regulated in hMSCs exposed ex vivo to BALF obtained from healthy volunteers. In contrast, these changes were less apparent and often opposite in hMSCs exposed to ARDS BALF samples.ConclusionThese data provide new insights into how hMSCs behave in healthy versus inflamed lung environments strongly suggesting that the inflamed environment in ARDS induces hMSC responses potentially benefical for cell survival and actions. This further highlights the need to understand how different disease environments affect hMSC functions.

Effect of anion transport inhibition on mucus secretion by airway submucosal glands

1997 ◽  
Vol 272 (2) ◽  
pp. L372-L377 ◽  
Author(s):  
S. K. Inglis ◽  
M. R. Corboz ◽  
A. E. Taylor ◽  
S. T. Ballard
Keyword(s):  
Cystic Fibrosis ◽  
Anion Transport ◽  
Mucus Secretion ◽  
Disulfonic Acid ◽  
Pathological Changes ◽  
Submucosal Gland ◽  
Anion Secretion ◽  
Submucosal Glands ◽  
Gland Duct

To model the airway glandular defect in cystic fibrosis (CF), the effect of anion secretion blockers on submucosal gland mucus secretion was investigated. Porcine distal bronchi were isolated, pretreated with a Cl- secretion blocker (bumetanide) and/or a combination of blockers to inhibit HCO3- secretion (dimethylamiloride, acetazolamide, and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid), and then treated with acetylcholine (ACh), a glandular liquid and mucus secretagogue. Bronchi were then fixed, sectioned, and stained for mucins. Each gland duct was ranked for mucin content from zero (no mucin) to five (duct completely occluded with mucin). Untreated bronchi, bronchi treated only with ACh, and ACh-treated bronchi that received either bumetanide or the HCO3- secretion blockers all exhibited low gland duct mucin content (1.18 +/- 0.34, 0.59 +/- 0.07, 0.65 +/- 0.03, and 0.83 +/- 0.11, respectively). However, pretreatment with both Cl- and HCO3- secretion blockers before ACh addition resulted in substantial and significant ductal mucus accumulation (3.57 +/- 0.22). In situ videomicroscopy studies of intact airways confirmed these results. Thus inhibition of the anion (and presumably liquid) secretion response to ACh leads to mucus obstruction of submucosal gland ducts that resembles the early pathological changes observed in CF.

Muscarinic stimulation of submucosal glands in swine trachea

1988 ◽  
Vol 64 (1) ◽  
pp. 200-209 ◽  
Author(s):  
C. M. Yang ◽  
J. M. Farley ◽  
T. M. Dwyer
Keyword(s):  
Acetylcholine Receptors ◽  
Relative Proportion ◽  
Muscarinic Acetylcholine Receptors ◽  
Mucus Secretion ◽  
Submucosal Gland ◽  
Isolated Cells ◽  
Gland Cells ◽  
Submucosal Glands ◽  
Tracheal Explants

The properties of muscarinic acetylcholine receptors (mAChR) on tracheal explants and isolated submucosal gland cells were determined using [3H]quinuclidinyl benzilate ([3H]QNB) and N-[3H]methylscopolamine ([3H]NMS) as ligands. Analysis of competitive displacement of ([3H]NMS binding by pirenzepine demonstrated the presence of M1- (27 +/- 2%) and M2G- (73 +/- 2%) receptors on isolated tracheal submucosal gland cells (TSGC's) in control. Daily administration of diisopropylfluorophosphate (DFP) inhibited cholinesterase activity by greater than 95%. After 7 days of DFP treatment, [3H]QNB binding to intact TSGC's decreased from 14.2 +/- 0.6 to 6.3 +/- 0.8 fmol/10(6) cells; similarly, [3H]NMS binding fell from 8.1 +/- 1.9 to 2.0 +/- 0.8 fmol/10(6) cells. The loss of mAChR's was predominantly of the M2G subtype with the relative proportion dropping to 33%. In addition, 90% of the receptors assumed the high-affinity state for carbachol displacement of [3H]NMS. Mucus secretion was quantitated by measuring the release of 3H-labeled mucus macromolecules from explants of tracheal submucosal glands and isolated cells. Acetylcholine (ACh), 2 X 10(-5) M, stimulated mucus secretion by 2.5 and 2.3 times the basal rate, respectively. Elimination of acetylcholinesterase (AChe) by DFP increased the ACh sensitivity by 18- and 5-fold. Tracheal explants or TSGC's obtained 2 h after an in vivo DFP treatment showed a 6- and 3-fold ACh stimulation. This ACh sensitivity decreased during the continued daily dosing with DFP such that only a 1.3- and 1.1-fold ACh stimulation was apparent after 7 days of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Multimodality Approach to Characterizing the Distinctive Hallmarks of Lung Fibrosis: A Mouse Model with Bleomycin and Indocyanine Green

2021 ◽  
Author(s):  
Andrea Grandi ◽  
Erica Ferrini ◽  
Roberta Ciccimarra ◽  
Martina Mambrini ◽  
Laura Mecozzi ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Time Course ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Lavage Fluid ◽  
Pharmacological Therapy ◽  
Micro Ct ◽  
Oropharyngeal Aspiration ◽  
Multimodality Approach

Abstract Background.Idiopathic Pulmonary Fibrosis is a progressive disease with short life expectancy and no disease-modifying pharmacological therapy. The continuous refinement of animal models and the integration of in-vivo imaging techniques is fundamental for the selection of new antifibrotic drugs.Indocyanine Green (ICG), a fluorescent dye, was administered by oropharyngeal aspiration (OA) to mice with Bleomycin (BLM) to map the lung exposure.Methods.Female mice C57bl/6 were treated via OA with BLM+ICG or ICG. Animals were imaged at 7, 14 and 21 days either with the fluorescent system or Micro-CT. At each time point subsets of mice were sampled for ex-vivo assessment. Histological assessment of fibrosis by Ashcroft score, airspace enlargements and mean linear intercept (MLI) were evaluated at 7, 14 and 21 days. Leukocytes and cytokines were measured in bronchoalveolar lavage fluid. Results.Fluorescence imaging revealed a persistent lung signal in both groups until 21 days. In BLM+ICG group, Micro-CT detected a marked increase in hypo- and non-aerated tissues throughout the study. At later time points hyper-inflated tissue was detected. Histology revealed high Ashcroft score throughout the time-course with a prominent increase in airspace size and MLI at day 21. ICG mice had healthy lungs.Conclusions.We showed that ICG can be used as a tracer to map the distribution of BLM in lungs. However, BLM+ICG produced unexpected severe lung changes different from pure BLM model, such as emphysema-like features which progressively worsened. The multimodalities approach warranted characterization of the distinctive features of this new pulmonary fibrosis model and provided fundamentals for in-vivo translation.

scholarly journals Thymic Stromal Lymphopoietin Enhances Th2/Th22 and Reduces IL-17A in Protease-Allergen-Induced Airways Inflammation

ISRN Allergy ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Dieudonnée Togbe ◽  
Louis Fauconnier ◽  
Fahima Madouri ◽  
Tiffany Marchiol ◽  
Pauline Chenuet ◽  
...  
Keyword(s):  
T Cells ◽  
Lung Inflammation ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Allergic Inflammation ◽  
Lavage Fluid ◽  
Thymic Stromal Lymphopoietin ◽  
Antigen Uptake ◽  
Eosinophil Recruitment

Background. Thymic stromal lymphopoietin (TSLP) is induced in allergic skin and lung inflammation in man and mice. Methods. Allergic lung inflammation induced by two proteases allergens HDM and papain and a classical allergen ovalbumin was evaluated in vivo in mice deficient for TSLPR. Eosinophil recruitment, Th2 and Th17 cytokine and chemokine levels were determined in bronchoalveolar lavage fluid, lung homogenates and lung mononuclear cells ex vivo. Results. Here we report that mice challenged with house dust mite extract or papain in the absence of TSLPR have a drastic reduction of allergic inflammation with diminished eosinophil recruitment in BAL and lung and reduced mucus overproduction. TSLPR deficient DCs displayed diminished OVA antigen uptake and reduced capacity to activate antigen specific T cells. TSLPR deficient mice had diminished proinflammatory IL-1β, IL-13, and IL-33 chemokines production, while IL-17A, IL-12p40 and IL-10 were increased. Together with impaired Th2 cytokines, IL-17A expressing TCRβ+ T cells were increased, while IL-22 expressing CD4+ T cells were diminished in the lung. Conclusion. Therefore, TSLPR signaling is required for the development of both Th2 and Th22 responses and may restrain IL-17A. TSLP may mediate its effects in part by increasing allergen uptake and processing by DCs resulting in an exacerbated asthma.

scholarly journals Sequential expression of IGF-IB followed by active TGF-β1 induces synergistic pulmonary fibroproliferation in vivo

2012 ◽  
Vol 303 (9) ◽  
pp. L788-L798 ◽  
Author(s):  
Graciela Andonegui ◽  
Ai Ni ◽  
Caroline Léger ◽  
Margaret M. Kelly ◽  
Josée F. Wong ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Ex Vivo ◽  
Smooth Muscle Actin ◽  
Wild Type Mouse ◽  
Inflammatory Cells ◽  
Lung Parenchyma ◽  
Lavage Fluid ◽  
Igf I ◽  
Tgf Β1

Pulmonary fibrosis, the end stage of a variety of fibroproliferative lung diseases, is usually induced after repetitive or chronic lung injury or inflammation. The mechanisms of fibroproliferation are poorly understood. Insulin-like growth factor-I (IGF-I) is significantly elevated in patients with pulmonary fibrosis and fibroproliferative acute respiratory distress syndrome. However, we showed that IGF-I overexpression alone in wild-type mouse lungs does not cause fibroproliferation. We therefore questioned whether IGF-I, acting together with active TGF-β1, a known profibrotic cytokine, enhances pulmonary fibroproliferation caused by active TGF-β1. A unique sequential adenoviral transgene mouse model was used expressing AdEmpty/AdTGF-β1 or AdhIGF-IB/AdTGF-β1 transgenes. IGF-IB plus active TGF-β1 transgene expression synergistically increased collagen deposition in the lung parenchyma compared with active TGF-β1 expression alone. The enhanced fibrosis was accompanied by an increased recruitment of macrophages and lymphocytes into the bronchoalveolar lavage fluid (BALF) and inflammatory cells in the lungs. α-Smooth muscle actin expression, a marker of myofibroblast proliferation and differentiation, was also increased. Finally, fibroblasts exposed ex vivo to BALF isolated from AdhIGF-IB/AdTGF-β1-transduced mice showed synergistic collagen induction compared with BALF from AdEmpty/AdTGF-β1-transduced mice. This study provides the first direct evidence that IGF-I is able to synergistically enhance pulmonary fibroproliferation in cooperation with TGF-β1.

scholarly journals Differential effects of the cystic fibrosis lung inflammatory environment on mesenchymal stromal cells

2020 ◽  
Vol 319 (6) ◽  
pp. L908-L925
Author(s):  
Soraia C. Abreu ◽  
Thomas H. Hampton ◽  
Evan Hoffman ◽  
Jacob Dearborn ◽  
Alix Ashare ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cystic Fibrosis ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Ex Vivo ◽  
Lavage Fluid ◽  
Cell Therapies ◽  
Acute Exacerbations ◽  
Aspergillus Sp

Growing evidence demonstrates that human mesenchymal stromal cells (MSCs) modify their in vivo anti-inflammatory actions depending on the specific inflammatory environment encountered. Understanding this better is crucial to refine MSC-based cell therapies for lung and other diseases. Using acute exacerbations of cystic fibrosis (CF) lung disease as a model, the effects of ex vivo MSC exposure to clinical bronchoalveolar lavage fluid (BALF) samples, as a surrogate for the in vivo clinical lung environment, on MSC viability, gene expression, secreted cytokines, and mitochondrial function were compared with effects of BALF collected from healthy volunteers. CF BALF samples that cultured positive for Aspergillus sp. (Asp) induced rapid MSC death, usually within several hours of exposure. Further analyses suggested the fungal toxin gliotoxin as a potential mediator contributing to CF BALF-induced MSC death. RNA sequencing analyses of MSCs exposed to either Asp+ or Asp− CF BALF samples identified a number of differentially expressed transcripts, including those involved in interferon signaling, antimicrobial gene expression, and cell death. Toxicity did not correlate with bacterial lung infections. These results suggest that the potential use of MSC-based cell therapies for CF or other lung diseases may not be warranted in the presence of Aspergillus.

scholarly journals Male sex hormones promote vagally mediated reflex airway responsiveness to cholinergic stimulation

2007 ◽  
Vol 292 (4) ◽  
pp. L908-L914 ◽  
Author(s):  
Jeffrey W. Card ◽  
James W. Voltz ◽  
Catherine D. Ferguson ◽  
Michelle A. Carey ◽  
Laura M. DeGraff ◽  
...  
Keyword(s):  
Sex Hormones ◽  
Ex Vivo ◽  
Airway Responsiveness ◽  
Male Mice ◽  
Cholinergic Stimulation ◽  
Intact Female ◽  
Reflex Mechanism ◽  
Female Mice ◽  
Male Sex

A sex disparity in airway responsiveness to cholinergic stimulation has been observed in laboratory mice in that males are considerably more responsive than females, but the basis for this difference is unclear. In this report, we demonstrate that male sex hormones promote murine airway responsiveness to cholinergic stimulation via vagus nerve-mediated reflex mechanisms. In tissue bath preparations, no sex-based differences were observed in the contractile responses of isolated tracheal and bronchial ring segments to carbachol, indicating that the mechanism(s) responsible for the in vivo sex difference is (are) absent ex vivo. Bilateral cervical vagotomy was found to abolish in vivo airway responsiveness to methacholine in male mice, whereas it did not alter the responses of females, suggesting a regulatory role for male sex hormones in promoting reflex airway constriction. To test this possibility, we next studied mice with altered circulating male sex hormone levels. Castrated male mice displayed airway responsiveness equivalent to that observed in intact females, whereas administration of exogenous testosterone to castrated males restored responsiveness, albeit not to the level observed in intact males. Administration of exogenous testosterone to intact female mice similarly enhanced responsiveness. Importantly, the promotive effects of exogenous testosterone in castrated male and intact female mice were absent when bilateral vagotomy was performed. Together, these data indicate that male sex hormones promote cholinergic airway responsiveness via a vagally mediated reflex mechanism that may be important in the regulation of airway tone in the normal and diseased lung.

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