scholarly journals Role for Mucin-5AC in Upper and Lower Airway Pathogenesis in Mice

2021 ◽  
pp. 019262332110044
Author(s):  
Hye-Youn Cho ◽  
Soojung Park ◽  
Laura Miller ◽  
Huei-Chen Lee ◽  
Robert Langenbach ◽  
...  

Mucin-5AC (MUC5AC) is a major secreted mucin in pathogenic airways. To determine its role in mucus-related airway disorders, Muc5ac-deficient ( Muc5ac−/−) and wild-type ( Muc5ac+/+) mice were compared in bleomycin-induced pulmonary fibrosis, respiratory syncytial virus (RSV) disease, and ozone toxicity. Significantly greater inflammation and fibrosis by bleomycin were developed in Muc5ac−/− lungs compared to Muc5ac+/+ lungs. More severe mucous cell metaplasia in fibrotic Muc5ac−/− lungs coincided with bronchial Muc2, Muc4, and Muc5b overexpression. Airway RSV replication was higher in Muc5ac−/− than in Muc5ac+/+ during early infection. RSV-caused pulmonary epithelial death, bronchial smooth muscle thickening, and syncytia formation were more severe in Muc5ac−/− compared to Muc5ac+/+. Nasal septal damage and subepithelial mucoserous gland enrichment by RSV were greater in Muc5ac−/− than in Muc5ac+/+. Ozone exposure developed more severe nasal airway injury accompanying submucosal gland hyperplasia and pulmonary proliferation in Muc5ac−/− than in Muc5ac+/+. Ozone caused periodic acid-Schiff-positive secretion only in Muc5ac−/− nasal airways. Lung E-cadherin level was relatively lower in Muc5ac−/− than in Muc5ac+/+ basally and after bleomycin, RSV, and ozone exposure. Results indicate that MUC5AC is an essential mucosal component in acute phase airway injury protection. Subepithelial gland hyperplasia and adaptive increase of other epithelial mucins may compensate airway defense in Muc5ac−/− mice.

2011 ◽  
Vol 300 (2) ◽  
pp. L242-L254 ◽  
Author(s):  
Stephan A. Carey ◽  
Carol A. Ballinger ◽  
Charles G. Plopper ◽  
Ruth J. McDonald ◽  
Alfred A. Bartolucci ◽  
...  

Children chronically exposed to high levels of ozone (O3), the principal oxidant pollutant in photochemical smog, are more vulnerable to respiratory illness and infections. The specific factors underlying this differential susceptibility are unknown but may be related to air pollutant-induced nasal alterations during postnatal development that impair the normal physiological functions (e.g., filtration and mucociliary clearance) serving to protect the more distal airways from inhaled xenobiotics. In adult animal models, chronic ozone exposure is associated with adaptations leading to a decrease in airway injury. The purpose of our study was to determine whether cyclic ozone exposure induces persistent morphological and biochemical effects on the developing nasal airways of infant monkeys early in life. Infant (180-day-old) rhesus macaques were exposed to 5 consecutive days of O3 [0.5 parts per million (ppm), 8 h/day; “1-cycle”] or filtered air (FA) or 11 biweekly cycles of O3 (FA days 1– 9; 0.5 ppm, 8 h/day on days 10– 14; “11-cycle”). The left nasal passage was processed for light microscopy and morphometric analysis. Mucosal samples from the right nasal passage were processed for GSH, GSSG, ascorbate (AH2), and uric acid (UA) concentration. Eleven-cycle O3 induced persistent rhinitis, squamous metaplasia, and epithelial hyperplasia in the anterior nasal airways of infant monkeys, resulting in a 39% increase in the numeric density of epithelial cells. Eleven-cycle O3 also induced a 65% increase in GSH concentrations at this site. The persistence of epithelial hyperplasia was positively correlated with changes in GSH. These results indicate that early life ozone exposure causes persistent nasal epithelial alterations in infant monkeys and provide a potential mechanism for the increased susceptibility to respiratory illness exhibited by children in polluted environments.


Author(s):  
Ishita Choudhary ◽  
Thao Vo ◽  
Kshitiz Paudel ◽  
Sonika Patial ◽  
Yogesh Saini

Ozone is known to cause lung injury and resident cells of the respiratory tract, i.e., epithelial cells and macrophages, respond to inhaled ozone in a variety of ways that affect their survival, morphology, and functioning. However, a complete understanding of the sex-associated and the cell type-specific gene expression changes in response to ozone exposure is still limited. Through transcriptomics, we aimed to analyze gene expression alterations and associated enrichment of biological pathways enrichment in three distinct cell type-enriched compartments of ozone-exposed murine lungs. We sub-chronically exposed adult males and females to 0.8ppm ozone or filtered air. RNA-Seq was performed on airway epithelium-enriched airways, parenchyma, and purified airspace macrophages. Differential gene expression and biological pathway analyses were performed and supported by cellular and immunohistochemical analyses. While a majority of differentially expressed genes (DEGs) in ozone-exposed versus air-exposed groups were common between both sexes, sex-specific DEGs were also identified in all the three tissue compartments. As compared to ozone-exposed males, ozone-exposed females had significant alterations in gene expression in three compartments. Pathways relevant to cell division and DNA repair were enriched in the ozone-exposed airways indicating ozone-induced airway injury and repair which was further supported by immunohistochemical analyses. In addition to cell division and DNA repair pathways, inflammatory pathways were also enriched within the parenchyma supporting contribution by both epithelial and immune cells. Finally, immune response and cytokine-cytokine receptor interactions were enriched in macrophages, indicating ozone-induced macrophage activation. Lastly, our analyses also revealed ozone-induced upregulation of mucoinflammation- and mucous cell metaplasia-associated pathways.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Nurhan Güler ◽  
Nil Çomunoğlu ◽  
Fatih Cabbar

The aim of this study was to investigate whether there is any association between inflammation and the expression of markers of cell cycle entry (Ki-67 and MCM-2) in dental follicle (DF) of asymptomatic impacted teeth and odontogenic cysts. The study consisted of 70 DFs and 20 odontogenic cysts (radicular cyst (RC), dentigerous cyst (DC) and keratocytic odontogenic tumor (KCOT) located at posterior mandibular region. Histological findings of inflammation for all specimen and mucous cell prosoplasia, squamous metaplasia, glandular epithelium for all DFs were stained with hematoxyline and eosin, periodic acid schiff, alcian blue, and mucin. Epithelial cell proliferation was determined by using immunohistochemical labeling for Ki-67 and MCM-2. The histologic examinations showed 16% mucous cell prosoplasia, 54% squamous metaplasia, 20% glandular epithelium, 37% inflammation. Inflammation was detected in all RCs and %62 in DF, %43 in DC and KCOT. Positive correlation was found between the inflammation of DF and odontogenic cysts (P<0.01). The mean Ki-67 and MCM-2 expressions were found9,64±5,99and6,34±3,81in DF,11,85±9,01and13,6±9,94in odontogenic cysts, respectively. While the mean Ki-67 expressions were statistically significant in DF and KCOT (P<0.01), MCM-2 were significant in RC and KCOT (P<0.01). MCM-2 expresion in RCs were statistically significant than KCOT (P<0.01). The results of this study indicated that the higher MCM-2 expressions in RC than the KCOT might be related to the inflammation and this protein might be more sensitive to inflammation.


2004 ◽  
Vol 287 (2) ◽  
pp. L286-L295 ◽  
Author(s):  
Shawnessy D. Larson ◽  
Charles G. Plopper ◽  
Greg Baker ◽  
Brian K. Tarkington ◽  
Kendra C. Decile ◽  
...  

Mucous cell hypersecretion and increased neuropeptide production play a role in the exacerbation of symptoms associated with asthma. The source of these neuropeptides have been confined to the contributions of small afferent nerves or possibly neuroendocrine cells. We tested the hypothesis that repeated exposure to allergen would alter the sources and abundance of neuropeptides in airways. Right middle lobes from rats (8 wk old) exposed to 2.5% ovalbumin (OVA) for five episodes (30 min each) or filtered air were inflation fixed with paraformaldehyde. The lobes were dissected to expose the airway tree, permeabilized with DMSO, and incubated in antibody to rat calcitonin gene-related peptide (CGRP), followed with a fluorochrome-labeled second antibody. CGRP-positive structures were imaged via confocal microscopy. Airways were later embedded in plastic and sectioned for cell identification. In animals challenged with OVA, CGRP-positive cells, not neuroendocrine or neuronal in origin (confirmed by a lack of protein gene product 9.5 signal), were recorded along the axial path. In section, this fluorescent signal was localized to granules within epithelial cells. Alcian blue/periodic acid-Schiff staining of these same sections positively identify these cells as mucous cells. Mucous cells of animals not challenged with OVA were not positive for CGRP. We conclude that episodic allergen exposure results in the accumulation of CGRP within mucous cells, creating a new source for the release of this neuropeptide within the airway.


Author(s):  
J. R. Ruby

Parotid glands were obtained from five adult (four male and one female) armadillos (Dasypus novemcinctus) which were perfusion-fixed. The glands were located in a position similar to that of most mammals. They extended interiorly to the anterior portion of the submandibular gland.In the light microscope, it was noted that the acini were relatively small and stained strongly positive with the periodic acid-Schiff (PAS) and alcian blue techniques, confirming the earlier results of Shackleford (1). Based on these qualities and other structural criteria, these cells have been classified as seromucous (2). The duct system was well developed. There were numerous intercalated ducts and intralobular striated ducts. The striated duct cells contained large amounts of PAS-positive substance.Thin sections revealed that the acinar cells were pyramidal in shape and contained a basally placed, slightly flattened nucleus (Fig. 1). The rough endoplasmic reticulum was also at the base of the cell.


1983 ◽  
Vol 49 (03) ◽  
pp. 182-186
Author(s):  
G T E Zonneveld ◽  
E F van Leeuwen ◽  
A Sturk ◽  
J W ten Cate

SummaryQuantitative glycoprotein (GP) analysis of whole platelets or platelet membranes was performed by SDS-polyacrylamide gelelectrophoresis (SDS-PAGE) and periodic acid Schiff staining in the families of two unrelated Glanzmann’s thrombasthenia (GT) patients. Each family consisted of two symptom free parents, a symptom free daughter and a GT daughter. All symptom free members had a normal bleeding time, clot retraction and platelet aggregation response to adenosine 5’-diphosphate (ADP), collagen and adrenalin. Platelet Zw* antigen was normally expressed in these subjects. GT patiens, classified as a type I and II subject, showed reduced amounts of GP lib and of GP nia. Analysis of isolated membranes in the non-reduced state, however, showed that the amount of GP Ilia was also reduced in three of the four parents, whereas one parent (of the GT type I patient) and the two unaffected daughters had normal amounts of GP Ilia. Quantitative SDS-PAGE may therefore provide a method for the detection of asymptomatic carriers in GT type I and II.


2020 ◽  
Vol 138 ◽  
pp. 237-246 ◽  
Author(s):  
J Řehulka ◽  
A Kubátová ◽  
V Hubka

In this study, spontaneous swim bladder mycosis was documented in a farmed fingerling rainbow trout from a raceway culture system. At necropsy, the gross lesions included a thickened swim bladder wall, and the posterior portion of the swim bladder was enlarged due to massive hyperplasia of muscle. A microscopic wet mount examination of the swim bladder contents revealed abundant septate hyphae, and histopathological examination showed periodic acid-Schiff-positive mycelia in the lumen and wall of the swim bladder. Histopathological examination of the thickened posterior swim bladder revealed muscle hyperplasia with expansion by inflammatory cells. The causative agent was identified as Phoma herbarum through morphological analysis and DNA sequencing. The disease was reproduced in rainbow trout fingerlings using intraperitoneal injection of a spore suspension. Necropsy in dead and moribund fish revealed extensive congestion and haemorrhages in the serosa of visceral organs and in liver and abdominal serosanguinous fluid. Histopathological examination showed severe hepatic congestion, sinusoidal dilatation, Kupffer cell reactivity, leukostasis and degenerative changes. Fungi were disseminated to the liver, pyloric caeca, kidney, spleen and heart. Although infections caused by Phoma spp. have been repeatedly reported in fish, species identification has been hampered by extensive taxonomic changes. The results of this study confirmed the pathogenicity of P. herbarum in salmonids by using a reliably identified strain during experimental fish infection and provides new knowledge regarding the course of infection.


2017 ◽  
Vol 26 (2) ◽  
pp. 183-187
Author(s):  
George P. Christophi ◽  
Yeshika Sharma ◽  
Quader Farhan ◽  
Umang Jain ◽  
Ted Walker ◽  
...  

Background: Non-Langerhans histiocytosis is a group of inflammatory lymphoproliferative disorders originating from non-clonal expansion of hematopoietic stem cells into cytokine-secreting dendritic cells or macrophages. Erdheim-Chester Disease (ECD) is a rare type of non-Langerhans cell histiocytosis characterized by tissue inflammation and injury caused by macrophage infiltration and histologic findings of foamy histiocytes. Often ECD involves the skeleton, retroperitoneum and the orbits. This is the first report documenting ECD manifesting as segmental colitis and causing cytokine-release syndrome.Case presentation: A 68-year old woman presented with persistent fever without infectious etiology and hematochezia. Endoscopy showed segmental colitis and pathology revealed infiltration of large foamy histiocytes CD3-/CD20-/CD68+/CD163+/S100- consistent with ECD. The patient was empirically treated with steroids but continued to have fever and developed progressive distributive shock.Conclusion: This case report describes the differential diagnosis of infectious and immune-mediated inflammatory and rheumatologic segmental colitis. Non-Langerhans histiocytosis and ECD are rare causes of gastrointestinal inflammation. Prompt diagnosis is imperative for the appropriate treatment to prevent hemodynamic compromise due to distributive shock or gastrointestinal bleeding. Importantly, gastrointestinal ECD might exhibit poor response to steroid treatment and other potential treatments including chemotherapy, and biologic treatments targeting IL-1 and TNF-alpha signaling should be considered.Abbreviations: AFB: acid-fast bacilli; ECD: Erdheim-Chester Disease; IBD: inflammatory bowel disease; PASD: periodic acid-Schiff with diastase; TB: tuberculosis


2008 ◽  
Vol 295 (2) ◽  
pp. H691-H698 ◽  
Author(s):  
Alex Y. Tan ◽  
Shengmei Zhou ◽  
Byung Chun Jung ◽  
Masahiro Ogawa ◽  
Lan S. Chen ◽  
...  

The purpose of the present study was to determine whether thoracic veins may act as ectopic pacemakers and whether nodelike cells and rich sympathetic innervation are present at the ectopic sites. We used a 1,792-electrode mapping system with 1-mm resolution to map ectopic atrial arrhythmias in eight normal dogs during in vivo right and left stellate ganglia (SG) stimulation before and after sinus node crushing. SG stimulation triggered significant elevations of transcardiac norepinephrine levels, sinus tachycardia in all dogs, and atrial tachycardia in two of eight dogs. Sinus node crushing resulted in a slow junctional rhythm (51 ± 6 beats/min). Subsequent SG stimulation induced 20 episodes of ectopic beats in seven dogs and seven episodes of pulmonary vein tachycardia in three dogs (cycle length 273 ± 35 ms, duration 16 ± 4 s). The ectopic beats arose from the pulmonary vein ( n = 11), right atrium ( n = 5), left atrium ( n = 2), and the vein of Marshall ( n = 2). There was no difference in arrhythmogenic effects of left vs. right SG stimulation (13/29 vs. 16/29 episodes, P = nonsignificant). There was a greater density of periodic acid Schiff-positive cells ( P < 0.05) and sympathetic nerves ( P < 0.05) at the ectopic sites compared with other nonectopic atrial sites. We conclude that, in the absence of a sinus node, thoracic veins may function as subsidiary pacemakers under heightened sympathetic tone, becoming the dominant sites of initiation of focal atrial arrhythmias that arise from sites with abundant sympathetic nerves and periodic acid Schiff-positive cells.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hamed Nosrati ◽  
Manijeh Hamzepoor ◽  
Maryam Sohrabi ◽  
Massoud Saidijam ◽  
Mohammad Javad Assari ◽  
...  

Abstract Background Silver nanoparticles (AgNPs) can accumulate in various organs after oral exposure. The main objective of the current study is to evaluate the renal toxicity induced by AgNPs after repeated oral exposure and to determine the relevant molecular mechanisms. Methods In this study, 40 male Wistar rats were treated with solutions containing 30, 125, 300, and 700 mg/kg of AgNPs. After 28 days of exposure, histopathological changes were assessed using hematoxylin-eosin (H&E), Masson’s trichrome, and periodic acid-Schiff (PAS) staining. Apoptosis was quantified by TUNEL and immunohistochemistry of caspase-3, and the level of expression of the mRNAs of growth factors was determined using RT-PCR. Results Histopathologic examination revealed degenerative changes in the glomeruli, loss of tubular architecture, loss of brush border, and interrupted tubular basal laminae. These changes were more noticeable in groups treated with 30 and 125 mg/kg. The collagen intensity increased in the group treated with 30 mg/kg in both the cortex and the medulla. Apoptosis was much more evident in middle-dose groups (i.e., 125 and 300 mg/kg). The results of RT-PCR indicated that Bcl-2 and Bax mRNAs upregulated in the treated groups (p < 0.05). Moreover, the data related to EGF, TNF-α, and TGF-β1 revealed that AgNPs induced significant changes in gene expression in the groups treated with 30 and 700 mg/kg compared to the control group. Conclusion Our observations showed that AgNPs played a critical role in in vivo renal toxicity.


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