scholarly journals Differential expression of lectin-binding sites defines mouse intestinal M-cells.

1993 ◽  
Vol 41 (11) ◽  
pp. 1679-1687 ◽  
Author(s):  
M A Clark ◽  
M A Jepson ◽  
N L Simmons ◽  
T A Booth ◽  
B H Hirst

We investigated the binding of four lectins to the follicle-associated epithelium (FAE) overlying fixed mouse small intestinal Peyer's patches to identify M-cell-specific surface markers. Wheat germ agglutinin and peanut agglutinin displayed heterogeneous staining patterns, binding most avidly to the intestine goblet cells. In contrast, the lectins Ulex europaeus 1 (UEA 1) and Psophocarpus tetragonolobus (winged bean; WBA) were almost exclusively M-cell specific. When confocal laser scanning images of tissues stained with fluorescein isothiocyanate (FITC)-conjugated UEA1 or WBA were compared with the appearance of the same tissues under the scanning electron microscope (SEM), UEA1 strongly stained 97.2% (106/109) of M-cells, 0.6% (3/516) enterocytes, and 0% (0/28) goblet cells, whereas WBA stained 100% (83/83) M-cells, 1.7% (6/361) enterocytes, and 5.3% (1/19) goblet cells. The M-cell specificity of the lectin binding was further demonstrated by localization of horseradish peroxidase (HRP)-conjugated lectins under the transmission electron microscope (TEM). This is the first demonstration of carbohydrates in the glycocalyx of M-cells that are not expressed elsewhere on the FAE surface. These carbohydrates not only provide a means to identify mouse M-cells by LM but may also contribute to the occurrence of specific interactions between microorganisms and the M-cell apical membrane.

2000 ◽  
Vol 68 (3) ◽  
pp. 1696-1699 ◽  
Author(s):  
Michael K. Zenni ◽  
Peter C. Giardina ◽  
Hillery A. Harvey ◽  
Jianqiang Shao ◽  
Margaret R. Ketterer ◽  
...  

ABSTRACT Gonococcal entry into primary human urethral epithelial cells (HUEC) can occur by macropinocytosis. Scanning and transmission electron microscopy revealed lamellipodia surrounding gonococci, and confocal laser scanning microscopy analysis showed organisms colocalized with M r 70,000 fluorescein isothiocyanate-labeled dextran within the cells. Phosphoinositide 3-kinase inhibitors and an actin polymerization inhibitor prevented macropinocytic entry of gonococci into HUEC.


2002 ◽  
Vol 50 (6) ◽  
pp. 829-838 ◽  
Author(s):  
Ina Leverkoehne ◽  
Achim D. Gruber

The putative anion channel mCLCA3 (alias gob-5) is the third murine member of the recently discovered family of calcium-activated chloride channels (CLCA family). Preliminary data suggest that mCLCA3 may play a significant role in diseases with secretory dysfunctions, including asthma and cystic fibrosis. In this study, the mCLCA3 protein was characterized biochemically and its cellular and subcellular distribution pattern was established in normal murine tissues. Polyclonal rabbit antibodies were generated and affinity-immunopurified using synthetic oligopeptides corresponding to the extracellular amino terminus of the mCLCA3 polypeptide. After in vitro translation and glycosylation, protein-ase K protection assay, and heterologous expression in COS-7 or HEK 293 cells, SDS-PAGE and immunoblotting revealed a protein structure similar to that of previously characterized CLCA proteins. A systematic light, confocal laser scanning, and transmission electron microscopic immunolocalization study, including virtually all murine tissues, identified the mCLCA3 protein exclusively associated with mucin granule membranes of gastrointestinal, respiratory, and uterine goblet cells and other mucin-producing cells. The results suggest that mCLCA3 may be involved in the synthesis, condensation, or secretion of mucins.


2004 ◽  
Vol 10 (5) ◽  
pp. 513-527 ◽  
Author(s):  
Wanderley de Souza ◽  
Adriana Lanfredi-Rangel ◽  
Loraine Campanati

Giardia lambliais a flagellated protozoan of great medical and biological importance. It is the causative agent of giardiasis, one of the most prevalent diarrheal disease both in developed and third-world countries. Morphological studies have shown thatG. lambliadoes not present structures such as peroxisomes, mitochondria, and a well-elaborated Golgi complex. In this review, special emphasis is given to the contribution made by various microscopic techniques to a better knowledge of the biology of the protozoan. The application of video microscopy, immunofluorescence confocal laser scanning microscopy, and several techniques associated with transmission electron microscopy (thin section, enzyme cytochemistry, freeze-fracture, deep-etching, fracture-flip) to the study of the cell surface, peripheral vesicles, endoplasmic reticulum–Golgi complex system, and of the encystation vesicles found in trophozoites and during the process of trophozoite-cyst transformation are discussed.


1993 ◽  
Vol 67 (3) ◽  
pp. 179-188 ◽  
Author(s):  
T. Fujino ◽  
B. Fried

AbstractMouse (C3H) mucosal glycoconjugates were examined in normal small intestines and intestines infected with Echinostoma caproni, or E. trivolvis using six different fluorescein-conjugated lectins: Triticum, vulgaris agglutinin (WGA), Ulex europaeus agglutinin I (UEA-I), Ricinus communis agglutinin I (RCA-I). Glycine max soybean agglutinin (SBA), Dolichos biflorus agglutinin (DBA), and Arachis hypogaeu peanut agglutinin (PNA). The expression of lectin-binding sites and the intensity of the binding of lectins in the mouse small intestines were changed by infection with the echinostomes. Specific differences in the reaction to glycoproteins were clearly observed between the mouse intestines infected with E. caproni and those infected with E. trivolvis. In E. caproni infection, binding of most of the lectins to the villi was remarkably reduced in accord with the villous atrophy and loss of goblet cells. In contrast, in E. trivolvis infection, the binding of WGA, RCA-I and DBA was reduced in the microvillar surfaces, but binding of UEA-I and SBA were unchanged compared to the control intestines. The lectin binding to goblet cells in E. trivolvis-infected mice mostly increased. These observations may reflect the marked increase in goblet cells and the less severe damage in the villi of E. trivolvis infection compared to E. caproni infection. Most of the glycoconjugates were slightly reduced in the hyperplastic crypts except for N-acetyl glucosamine. It is possible that glucose metabolism in the host intestines infected with E. trivolvis was activated. resulting in an increase in the rate of mucin synthesis as well as qualitative changes in mucus, thereby mediating the expulsion of the worms.


2019 ◽  
Vol 20 (24) ◽  
pp. 6238 ◽  
Author(s):  
Anna L. Gill ◽  
Monica Z. Wang ◽  
Beth Levine ◽  
Alan Premasiri ◽  
Fernando G. Vieira

A repeat expansion mutation in the C9orf72 gene is the most common known genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). In this study, using multiple cell-based assay systems, we reveal both increased dipeptide repeat protein (DRP) toxicity in primary neurons and in differentiated neuronal cell lines. Using flow cytometry and confocal laser scanning microscopy of cells treated with fluorescein isothiocyanate (FITC)-labeled DRPs, we confirm that poly-glycine-arginine (GR) and poly-proline-arginine (PR) DRPs entered cells more readily than poly-glycine-proline (GP) and poly-proline-alanine (PA) DRPs. Our findings suggest that the toxicity of C9-DRPs may be influenced by properties associated with differentiated and aging motor neurons. Further, our findings provide sensitive cell-based assay systems to test phenotypic rescue ability of potential interventions.


1994 ◽  
Vol 267 (6) ◽  
pp. G1108-G1121 ◽  
Author(s):  
P. J. Giannasca ◽  
K. T. Giannasca ◽  
P. Falk ◽  
J. I. Gordon ◽  
M. R. Neutra

We have used a panel of lectins and antibodies to describe the composition of complex carbohydrates associated with M cells in various regions of the intestinal tract of adult BALB/c mice. The fucose-specific lectin Ulex europaeus agglutinin type I (UEA I) is a marker of M cells in the small intestine and recognized M cells at an early stage of differentiation. Subpopulations of M cells in a single follicle-associated epithelium (FAE) could be distinguished by different fucose-specific probes. Certain lectins revealed that M cells have basal processes that extend into the underlying lymphoid tissue. Colonic and rectal M cells display glycosylation patterns distinct from M cells of Peyer's patches and are characterized by terminal galactose. UEA I selectively adhered to Peyer's patch M cells in mucosal explants and in ligated intestinal loops in vivo. The lectin was taken up into endocytic vesicles and transported to the intra-epithelial pocket and other domains of the basolateral membrane. Thus M cell-specific glycoconjugates could serve as "receptors" for targeting of lectin-antigen conjugates to the mucosal immune system.


2016 ◽  
Vol 186 ◽  
pp. 45-59 ◽  
Author(s):  
Radhika Poojari ◽  
Rohit Srivastava ◽  
Dulal Panda

Polymeric nanoassemblies represent an attractive strategy for efficient cellular internalization of microtubule targeted anticancer drugs. Using dynamic light scattering, zeta potential, transmission electron microscopy and scanning electron microscopy, the physical properties and surface morphology of microtubule-binding PEGylated PLGA assembled nanospheres (100–200 nm) were analyzed. The present approach leads to strong internalization as observed by confocal laser scanning microscopy and transmission electron microscopy in hepatocarcinoma cells. The effect of these nanoassemblies on microtubules and mitosis were explored using immunofluorescence microscopy. The effects of these nanoassemblies on cancer cell proliferation and cell death revealed their antitumor enhancing effects. Perturbation of the microtubule assembly, mitosis and nuclear modulations potentiated the antineoplastic effects delivered via nanospheres in hepatocarcinoma cells. The extensive biomolecular and physical characterizations of the synthesized nanoassemblies will help to design potent therapeutic materials and the present approach can be applied to deliver microtubule-targeted drugs for liver cancer therapy.


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