Airway Epithelial Cells in Various Models of Bronchial Allergic Inflammation in Guinea Pigs

1992 ◽  
Vol 5 (3) ◽  
pp. 165-172
Author(s):  
J.P. Tarayre ◽  
M. Aliaga ◽  
M. Barbara ◽  
N. Malfetes ◽  
S. Vieu

The number of airway epithelial cells (AEC) in bronchus lumen after various types of anaphylactic shock of similar intensity was determined in guinea pigs. Aerosol-induced anaphylactic shocks were studied after four types of active sensitization: sensitization by IM injection of 30 mg/kg ovalbumin mixed with Freund's complete adjuvant; sensitization by IM injection of 30 mg/kg ovalbumin; sensitization by IP injection of 1 μg ovalbumin and 50 mg A1 (OH)3 by animal; sensitization by 2 exposures to 1%-ovalbumin aerosol at a 7-day interval. One, 3,6,24 and 48 h after the anaphylactic reaction the number of AEC in bronchoalveolar lavage fluid (BALF) was counted in comparison to guinea pigs sensitized but exposed to 0.9% NaCl aerosol. The number of AEC was significantly increased only 24–48 h after the shock in animals sensitized with ovalbumin in Freund's complete adjuvant. In animals passively sensitized by antiserum obtained with sensitization by ovalbumin in Freund's complete adjuvant and challenged by IV or aerosol administration of antigen, non rise in the number of AEC was obtained 24–48 h after the shock. The higher amount of AEC 24–48 h after the anaphylactic reaction in animals actively sensitized by ovalbumin in Freund's complete adjuvant could be related to the higher increase in the number of neutrophils and of mononuclears obtained in the BALF at these times in comparison to other types of active sensitization. The rise in the number of AEC only after the active reaction seems to show the part played by T-lymphocytes in the induction of this effect. The increase in the number of eosinophils in BALF and the appearance of the hyperreactivity cannot be related to the rise in the AEC in bronchus lumen.

2002 ◽  
Vol 92 (1) ◽  
pp. 155-161 ◽  
Author(s):  
Hiroyuki Mochizuki ◽  
Yasushi Ohki ◽  
Hirokazu Arakawa ◽  
Masahiko Kato ◽  
Kenichi Tokuyama ◽  
...  

We evaluated the mechanism of the anti-asthmatic effect of inhaled indomethacin (Indo) by using an animal model (guinea pigs) of airway inflammation. After being exposed to either ozone or room air at identical flow rates (5 l/min) for 2 h, guinea pigs were anesthetized, tracheostomized, and lung resistance (Rl) was subsequently measured. Guinea pigs inhaled either saline or Indo (1.5 mg/ml) for 1 min before undergoing an ultrasonically nebulized distilled water (UNDW) inhalation test. Rl increased significantly after 10 min of UNDW inhalation in the room air and ozone groups but more so in the ozone group. This increase in Rl was significantly suppressed by pretreatment with Indo. In the morphometric assessment of airway mucosa, a significant swelling of the epithelial cells after UNDW inhalation was observed in both the room air and ozone groups but especially so in the ozone group. This increase was also suppressed with Indo pretreatment. These results suggest that the increase in Rl and the swelling of airway epithelial cells induced by inhaled UNDW in ozone-exposed guinea pigs was suppressed by pretreatment of inhaled Indo and that this suppression may be one of the reasons for the anti-asthmatic effect of inhaled Indo.


2021 ◽  
Author(s):  
Shakti Sagar ◽  
Md. Imam Faizan ◽  
Nisha Chaudhary ◽  
Atish Gheware ◽  
Khushboo Sharma ◽  
...  

Mesenchymal stem cell (MSC) transplantation alleviates metabolic defects in diseased recipient cells by intercellular mitochondrial transport (IMT). However, the effect of host metabolic conditions on MSCs in general, and IMT in particular, has largely remained unexplored. This study has identified a molecular pathway that primarily governs the metabolic function and IMT of MSCs. We found underlying mitochondrial dysfunction, impaired mitophagy, and reduced IMT in MSCs derived from high-fat diet (HFD)-induced obese mice (MSC-Ob). Mechanistically, MSC-Ob failed to sequester their damaged mitochondria into LC3-dependent autophagosomes due to decrease in mitochondrial cardiolipin content, which we propose as a putative mitophagy receptor for LC3 in MSCs. Functionally, MSC-Ob exhibited diminished potential to rescue metabolic deficits and cell death in stress-induced epithelial cells. In a small molecule screen, we found pyrroloquinoline quinone (PQQ) as a regulator of mitophagy and IMT. Long-term culture of MSC-Ob with PQQ (MSC-ObPQQ) restored cardiolipin content and sequestration of mitochondria to autophagosomes with concomitant activation of mitophagy. Upon co-culture, MSC-ObPQQ rescued cell death in stress-induced epithelial cells by enhancing IMT. The beneficial effect of PQQ was also evident in MSCs derived from human subjects in an in vitro model. In two independent mice models, the transplantation of MSC-ObPQQ restored IMT to airway epithelial cells, improved their mitochondrial metabolism and attenuated features of allergic airway inflammation (AAI). However, unmodulated MSC-Ob failed to do so. In summary, we uncover the molecular mechanism leading to the therapeutic decline of obese-derived MSCs and highlight the importance of pharmacological modulation of these cells for therapeutic intervention.


2006 ◽  
Vol 291 (3) ◽  
pp. L502-L511 ◽  
Author(s):  
Robert J. Homer ◽  
Zhou Zhu ◽  
Lauren Cohn ◽  
Chun Gun Lee ◽  
Wendy I. White ◽  
...  

The mammalian chitinase family includes members both with and without enzymatic activity against chitin, a product of fungal cell walls, exoskeletons of crustaceans and insects, and the microfilarial sheaths of parasitic nematodes. Two members of that family, Ym1 and acidic mammalian chitinase (AMCase), are strongly upregulated in pulmonary T helper (Th) 2 inflammation but not in Th1 inflammation. The sites of expression of these products are incompletely known. We show here that, in two different models of Th2 inflammation, Ym1 and AMCase are mutually exclusively expressed in proximal vs. distal airway epithelium, respectively, whereas both are expressed in alveolar macrophages. This regional difference along the airway corresponds to the previously noted distinction between mucus positive proximal cells and mucus negative distal cells under the same conditions. Among distal cells, AMCase colocalizes with epithelial cells expressing the Clara cell marker Clara cell secretory protein. These AMCase-expressing cells retain expression of FOXA2, a transcription factor whose downregulation in association with IL-13 signaling has previously been associated with production of mucus in proximal airway epithelial cells. These results provide evidence that secretory cells of proximal and distal airways undergo fundamentally different gene expression programs in response to allergic inflammation. Furthermore, AMCase provides the first positive molecular marker of distal Clara cell secretory protein-expressing cells under these conditions.


2012 ◽  
Vol 446 (3) ◽  
pp. 383-394 ◽  
Author(s):  
Kyubo Kim ◽  
Youlia M. Petrova ◽  
Brenton L. Scott ◽  
Rupesh Nigam ◽  
Anurag Agrawal ◽  
...  

Airway mucin secretion and MC (mast cell) degranulation must be tightly controlled for homoeostasis of the lungs and immune system respectively. We found the exocytic protein Munc18b to be highly expressed in mouse airway epithelial cells and MCs, and localized to the apical pole of airway secretory cells. To address its functions, we created a mouse with a severely hypomorphic Munc18b allele such that protein expression in heterozygotes was reduced by ~50%. Homozygous mutant mice were not viable, but heterozygotes showed a ~50% reduction in stimulated release of mucin from epithelial cells and granule contents from MCs. The defect in MCs affected only regulated secretion and not constitutive or transporter-mediated secretion. The severity of passive cutaneous anaphylaxis was also reduced by ~50%, showing that reduction of Munc18b expression results in an attenuation of physiological responses dependent on MC degranulation. The Munc18b promoter is controlled by INR (initiator), Sp1 (specificity protein 1), Ets, CRE (cAMP-response element), GRE (glucocorticoid-response element), GATA and E-box elements in airway epithelial cells; however, protein levels did not change during mucous metaplasia induced by allergic inflammation. Taken together, the results of the present study identify Munc18b as an essential gene that is a limiting component of the exocytic machinery of epithelial cells and MCs.


2015 ◽  
Vol 46 (5) ◽  
pp. 1350-1360 ◽  
Author(s):  
Irene K. Oglesby ◽  
Sebastian F. Vencken ◽  
Raman Agrawal ◽  
Kevin Gaughan ◽  
Kevin Molloy ◽  
...  

Interleukin (IL)-8 levels are higher than normal in cystic fibrosis (CF) airways, causing neutrophil infiltration and non-resolving inflammation. Overexpression of microRNAs that target IL-8 expression in airway epithelial cells may represent a therapeutic strategy for cystic fibrosis.IL-8 protein and mRNA were measured in cystic fibrosis and non-cystic fibrosis bronchoalveolar lavage fluid and bronchial brushings (n=20 per group). miRNAs decreased in the cystic fibrosis lung and predicted to target IL-8 mRNA were quantified in βENaC-transgenic, cystic fibrosis transmembrane conductance regulator (Cftr)-/- and wild-type mice, primary cystic fibrosis and non-cystic fibrosis bronchial epithelial cells and a range of cystic fibrosis versus non-cystic fibrosis airway epithelial cell lines or cells stimulated with lipopolysaccharide, Pseudomonas-conditioned medium or cystic fibrosis bronchoalveolar lavage fluid. The effect of miRNA overexpression on IL-8 protein production was measured.miR-17 regulates IL-8 and its expression was decreased in adult cystic fibrosis bronchial brushings, βENaC-transgenic mice and bronchial epithelial cells chronically stimulated with Pseudomonas-conditioned medium. Overexpression of miR-17 inhibited basal and agonist-induced IL-8 protein production in F508del-CFTR homozygous CFTE29o− tracheal, CFBE41o− and/or IB3 bronchial epithelial cells.These results implicate defective CFTR, inflammation, neutrophilia and mucus overproduction in regulation of miR-17. Modulating miR-17 expression in cystic fibrosis bronchial epithelial cells may be a novel anti-inflammatory strategy for cystic fibrosis and other chronic inflammatory airway diseases.


Pneumologie ◽  
2015 ◽  
Vol 69 (07) ◽  
Author(s):  
S Ulrich ◽  
S Weinreich ◽  
R Haller ◽  
S Menke ◽  
R Olmer ◽  
...  

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