Characterization of 5-hydroxytryptamine release from isolated rabbit and rat trachea: the role of neuroendocrine epithelial cells and mast cells

Author(s):  
Anke Freitag ◽  
Ignaz Wessler ◽  
Kurt Rack�
2007 ◽  
Vol 204 (2) ◽  
pp. 253-258 ◽  
Author(s):  
Zoulfia Allakhverdi ◽  
Michael R. Comeau ◽  
Heidi K. Jessup ◽  
Bo-Rin Park Yoon ◽  
Avery Brewer ◽  
...  

Compelling evidence suggests that the epithelial cell–derived cytokine thymic stromal lymphopoietin (TSLP) may initiate asthma or atopic dermatitis through a dendritic cell–mediated T helper (Th)2 response. Here, we describe how TSLP might initiate and aggravate allergic inflammation in the absence of T lymphocytes and immunoglobulin E antibodies via the innate immune system. We show that TSLP, synergistically with interleukin 1 and tumor necrosis factor, stimulates the production of high levels of Th2 cytokines by human mast cells (MCs). We next report that TSLP is released by primary epithelial cells in response to certain microbial products, physical injury, or inflammatory cytokines. Direct epithelial cell–mediated, TSLP-dependent activation of MCs may play a central role in “intrinsic” forms of atopic diseases and explain the aggravating role of infection and scratching in these diseases.


2001 ◽  
Vol 69 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Ioannis Gryllos ◽  
Jonathan G. Shaw ◽  
Rosalina Gavı́n ◽  
Susana Merino ◽  
Juan M. Tomás

ABSTRACT The adherence mechanism of Aeromonas caviae Sch3N to HEp-2 cells was initially investigated through four mini-Tn5 mutants that showed a 10-fold decrease in adherence. These mutants lost motility, flagella, and their lipopolysaccharide (LPS) O antigen (O-Ag). Three genes,flmB-neuA-flmD, were found to be interrupted by the transposon insertions; additionally, two other genes, one lying upstream (flmA) and one downstream (neuB), were found to be clustered in the same operon. While the flmAand flmB genes were present in all mesophilicAeromonas spp. (A. hydrophila, A. caviae, A. veronii bv. veronii, andA. veronii bv. sobria) tested, this was not the case for the neuA-flmD-neuB genes. Construction and characterization of flmB insertion mutants in five other mesophilic Aeromonas strains revealed the loss of motility, flagella, and adherence but did not alter the LPS composition of these strains. Taking the above findings into consideration, we conclude (i) that flagella and possibly the LPS O-Ag are involved in the adherence of the mesophilic Aeromonas to human epithelial cells; (ii)flmA and flmB are genes widely distributed in the mesophilic Aeromonas and are involved in flagella assembly, and thus adherence; and (iii) in A. caviae Sch3N the flmA and flmB genes are found in a putative operon together with neuA, flmD, andneuB and are involved in LPS O-Ag biosynthesis and probably have a role in flagellum assembly.


1997 ◽  
Vol 338 (3) ◽  
pp. 259-268 ◽  
Author(s):  
Guy F Joos ◽  
Romain A Lefebvre ◽  
Gillian R Bullock ◽  
Romain A Pauwels
Keyword(s):  

2021 ◽  
Author(s):  
Victoria G Castiglioni ◽  
Joao J Ramalho ◽  
Jason R Kroll ◽  
Riccardo Stucchi ◽  
Hanna van Beuzekom ◽  
...  

The apical domain of epithelial cells can acquire a diverse array of morphologies and functions, which is critical for the function of epithelial tissues. The Crumbs proteins are evolutionary conserved transmembrane proteins with essential roles in promoting apical domain formation in epithelial cells. The short intracellular tail of Crumbs proteins interacts with a variety of proteins, including the scaffolding protein Pals1 (protein associated with LIN7, Stardust in Drosophila). Pals1 in turn binds to a second scaffolding protein termed PATJ (Pals1-associated tight junction protein), to form the core Crumbs/ Pals1/PATJ Crumbs complex. While essential roles in epithelial organization have been shown for Crumbs proteins in Drosophila and mammalian systems, the three Caenorhabditis elegans crumbs genes are dispensable for epithelial polarization and animal development. Moreover, the presence and functioning of orthologs of Pals1 and PATJ has not been investigated. Here, we identify MAGU-2 and MPZ-1 as the C. elegans orthologs of Pals1 and PATJ, respectively. We show that MAGU-2 interacts with all three Crumbs proteins as well as MPZ-1, and localizes to the apical membrane domain in a Crumbs-dependent fashion. Similar to crumbs mutants, a magu-2 null mutant shows no developmental or epithelial polarity defects. Finally, we show that overexpression of the Crumbs proteins EAT-20 or CRB-3 in the C. elegans intestine can lead to apical membrane expansion. Our results shed light into the composition of the C. elegans Crumbs complex and indicate that the role of Crumbs proteins in promoting apical domain identity is conserved.


Author(s):  
W.T. Gunning ◽  
M.R. Marino ◽  
M.S. Babcock ◽  
G.D. Stoner

The role of calcium in modulating cellular replication and differentiation has been described for various cell types. In the present study, the effects of Ca++ on the growth and differentiation of cultured rat esophageal epithelial cells was investigated.Epithelial cells were isolated from esophagi taken from 8 week-old male CDF rats by the enzymatic dissociation method of Kaighn. The cells were cultured in PFMR-4 medium supplemented with 0.25 mg/ml dialyzed fetal bovine serum, 5 ng/ml epidermal growth factor, 10-6 M hydrocortisone 10-6 M phosphoethanolamine, 10-6 M ethanolamine, 5 pg/ml insulin, 5 ng/ml transferrin, 10 ng/ml cholera toxin and 50 ng/ml garamycin at 36.5°C in a humidified atmosphere of 3% CO2 in air. At weekly intervals, the cells were subcultured with a solution containing 1% polyvinylpyrrolidone, 0.01% EGTA, and 0.05% trypsin. After various passages, the replication rate of the cells in PFMR-4 medium containing from 10-6 M to 10-3 M Ca++ was determined using a clonal growth assay.


Author(s):  
L. T. Germinario

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.


Author(s):  
D.S. Friend ◽  
N. Ghildyal ◽  
M.F. Gurish ◽  
K.F. Austen ◽  
R.L. Stevens

Trichinella spiralis induces a profound mastocytosis and eosinophilia in the small intestine of the infected mouse. Mouse mast cells (MC) store in their granules various combinations of at least five chymotryptic chymases [designated mouse MC protease (mMCP) 1 to 5], two tryptic proteases designated mMCP-6 and mMCP-7 and an exopeptidase, carboxypeptidase A (mMC-CPA). Using antipeptide, protease -specific antibodies to these MC granule proteases, immunohistochemistry was done to determine the distribution, number and protease phenotype of the MCs in the small intestine and spleen 10 to >60 days after Trichinella infection of BALB/c and C3H mice. TEM was performed to evaluate the granule morphology of the MCs between intestinal epithelial cells and in the lamina propria (mucosal MCs) and in the submucosa, muscle and serosa of the intestine (submucosal MCs).As noted in the table below, the number of submucosal MCs remained constant throughout the study. In contrast, on day 14, the number of MCs in the mucosa increased ~25 fold. Increased numbers of MCs were observed between epithelial cells in the mucosal crypts, in the lamina propria and to a lesser extent, between epithelial cells of the intestinal villi.


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