scholarly journals Prion Infection of Epithelial Rov Cells Is a Polarized Event

2004 ◽  
Vol 78 (13) ◽  
pp. 7148-7152 ◽  
Author(s):  
Sophie Paquet ◽  
Elifsu Sabuncu ◽  
Jean-Louis Delaunay ◽  
Hubert Laude ◽  
Didier Vilette
Keyword(s):  
Epithelial Cell ◽  
Cell Surface ◽  
Infectious Agent ◽  
Epithelial Cell Line ◽  
Target Cells ◽  
Infectious Agents ◽  
Prion Infection ◽  
Apical Side ◽  
Prion Transmission

ABSTRACT During prion infections, the cellular glycosylphosphatidylinositol-anchored glycoprotein PrP is converted into a conformational isoform. This abnormal conformer is thought to recruit and convert the normal cellular PrP into a likeness of itself and is proposed to be the infectious agent. We investigated the distribution of the PrP protein on the surface of Rov cells, an epithelial cell line highly permissive to prion multiplication, and we found that PrP is primarily expressed on the apical side. We further show that prion transmission to Rov cells is much more efficient if infectivity contacts the apical side, indicating that the apical and basolateral sides of Rov cells are not equally competent for prion infection and adding prions to the list of the conventional infectious agents (viruses and bacteria) that infect epithelial cells in a polarized manner. These data raise the possibility that apically expressed PrP may be involved in this polarized process of infection. This would add further support for a crucial role of PrP at the cell surface in prion infection of target cells.

scholarly journals Episialin (MUC1) overexpression inhibits integrin-mediated cell adhesion to extracellular matrix components.

1995 ◽  
Vol 129 (1) ◽  
pp. 255-265 ◽  
Author(s):  
J Wesseling ◽  
S W van der Valk ◽  
H L Vos ◽  
A Sonnenberg ◽  
J Hilkens
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cell ◽  
Cell Surface ◽  
Cell Line ◽  
Carcinoma Cells ◽  
Breast Epithelial Cell ◽  
Epithelial Cell Line ◽  
High Avidity ◽  
Apical Side ◽  
Extracellular Matrix Components

Episialin (MUC1) is a transmembrane molecule with a large mucin-like extracellular domain protruding high above the cell surface. The molecule is located at the apical side of most glandular epithelial cells, whereas in carcinoma cells it is often present at the entire surface and it is frequently expressed in abnormally large quantities. We have previously shown that overexpression of episialin reduces cell-cell interactions. Here we show that the integrin-mediated adhesion to extracellular matrix of transfectants of a melanoma cell line (A375), a transformed epithelial cell line (MDCK-ras-e) and a human breast epithelial cell line (HBL-100) is reduced by high levels of episialin. This reduction can be reversed by inducing high avidity of the beta 1 integrins by mAb TS2/16 (at least for beta 1-mediated adhesion). The adhesion can also be restored by redistribution of episialin on the cell surface by monoclonal antibodies into patches or caps. Similarly, capping of episialin on ZR-75-1 breast carcinoma cells, growing in suspension, caused adherence and spreading of these cells. We propose that there is a delicate balance between adhesion and anti-adhesion forces in episialin expressing cells, which can be shifted towards adhesion by strengthening the integrin-mediated adhesion, or towards anti-adhesion by increasing the level of expression of episialin.

scholarly journals PrPc Does Not Mediate Internalization of PrPSc but Is Required at an Early Stage for De Novo Prion Infection of Rov Cells

2007 ◽  
Vol 81 (19) ◽  
pp. 10786-10791 ◽  
Author(s):  
Sophie Paquet ◽  
Nathalie Daude ◽  
Marie-Pierre Courageot ◽  
Jérôme Chapuis ◽  
Hubert Laude ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
De Novo ◽  
Early Stage ◽  
Epithelial Cell Line ◽  
Target Cells ◽  
Subcellular Compartment ◽  
Prion Infection ◽  
Scrapie Agent ◽  
Heparan Sulfates ◽  
Sheep Scrapie

ABSTRACT We have studied the interactions of exogenous prions with an epithelial cell line inducibly expressing PrPc protein and permissive to infection by a sheep scrapie agent. We demonstrate that abnormal PrP (PrPSc) and prion infectivity are efficiently internalized in Rov cells, whether or not PrPc is expressed. At odds with earlier studies implicating cellular heparan sulfates in PrPSc internalization, we failed to find any involvement of such molecules in Rov cells, indicating that prions can enter target cells by several routes. We further show that PrPSc taken up in the absence of PrPc was unable to promote efficient prion multiplication once PrPc expression was restored in the cells. This observation argues that interaction of PrPSc with PrPc has to occur early, in a specific subcellular compartment(s), and is consistent with the view that the first prion multiplication events may occur at the cell surface.

Neural induction and the structure of the target cell surface

Development ◽  
1982 ◽  
Vol 70 (1) ◽  
pp. 171-187
Author(s):  
A. M. Duprat ◽  
L. Gualandris ◽  
P. Rouge
Keyword(s):  
Cell Surface ◽  
Structural Integrity ◽  
Neural Induction ◽  
Active Role ◽  
Target Cells ◽  
Similar Treatment ◽  
Structural Modifications ◽  
Pleurodeles Waltl

Lectins (SBA and PSA) were used to provoke crowding and structural modifications of the presumptive ectoderm cell surface in order to investigate the role of the membrane organization of the competent target cells in neural induction. Are specific characteristics of the cell surface essential for this phenomenon to occur? From amphibian gastrulae, it is possible to obtain neural induction in vitro by association of presumptive ectoderm (target cells) with chordamesoderm (inductor tissue): 4 h of contact is sufficient in Pleurodeles waltl for transmission of the inductive signal. Very quickly, the treatment of the normal ectoderm by lectins (SBA-FITC or PSA-FITC) provoked surface modifications. Lectin-treatment (50 µg ml1−, 30 min) of presumptive ectoderm did not result in any neural induction. Lectin-treatment (50 µg ml1−, 30 min) of presumptive ectoderm previous to its association with the natural inductor for 4 h, disturbed the phenomenon: no induction. Similar treatment followed by association with the inductor for 24 h: induction. Treatment of SBA or PSA with their respective hapten inhibitors prior to addition to ectodermal cells completely blocked the suppressive effects on induction. The structural integrity of the membrane of competent target cells is necessary for neural induction to occur. The cell membrane could thus play, directly or indirectly, an active role in the specificity of this process

The role of protein kinase C isozymes in TNF-α-induced cytotoxicity to a rat intestinal epithelial cell line

2001 ◽  
Vol 280 (4) ◽  
pp. G572-G583 ◽  
Author(s):  
Q. Chang ◽  
B. L. Tepperman
Keyword(s):  
Epithelial Cell ◽  
Caspase 3 ◽  
Cell Injury ◽  
Cell Damage ◽  
Epithelial Cell Line ◽  
Intestinal Epithelial ◽  
Kinase C ◽  
Pkc Isoforms ◽  
Tnf Α

Tumor necrosis factor (TNF)-α can induce cytotoxicity and apoptosis in a number of cell types and has been implicated in the regulation of many inflammatory processes. It has been suggested that protein kinase C (PKC) is one of the intracellular mediators of the actions of TNF-α. In the present study, the role of PKC isoforms in TNF-α-mediated cytotoxicity and apoptosis in intestinal cells was investigated using the rat epithelial cell line, IEC-18. Cells were incubated with TNF-α in the presence or absence of the transcription inhibitor actinomycin D (AMD). The extent of cell damage was enhanced when AMD was added to incubation medium, suggesting that new protein synthesis plays a role in the cytotoxic action of TNF. TNF-α also induced the translocation of PKC-α, -δ, and -ε from cytosol to the membrane fraction of the intestinal cells. Furthermore, the cytotoxic and apoptotic effects of TNF were reduced by pretreating the cells with the PKC-ε translocation inhibitor, PKC-εV1–2. In contrast, although cells incubated with the phorbol ester phorbol 12-myristate 13-acetate (PMA) also displayed an increase in cell injury, the extent of cytotoxicity and apoptosis was not enhanced by AMD. Furthermore, PMA-induced cell damage was reduced by rottlerin, a PKC-δ inhibitor. Caspase-3, an enzyme implicated in the mediation of apoptosis, was activated in cells in response to either TNF-α or PMA stimulation, and its effects on this activity were reduced by selective inhibition of PKC-ε and -δ, respectively. Furthermore, inhibition of caspase-3 activity reduced apoptosis. These data suggest that activation of selective PKC isoforms mediate the effects of TNF-α on intestinal epithelial cell injury.

Cyto-genotoxicity of amphibole asbestos fibers in cultured human lung epithelial cell line: Role of surface iron

2010 ◽  
Vol 26 (9) ◽  
pp. 575-582 ◽  
Author(s):  
Ritesh Kumar Srivastava ◽  
Mohtashim Lohani ◽  
Aditya Bhushan Pant ◽  
Qamar Rahman
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Human Lung ◽  
Epithelial Cell Line ◽  
Human Lung Epithelial Cell ◽  
Asbestos Fibers ◽  
Surface Iron ◽  
Lung Epithelial ◽  
Amphibole Asbestos

Regulation of proteolysis by cytokines in the human intestinal epithelial cell line HCT–8: role of IFNγ

Biochimie ◽  
2006 ◽  
Vol 88 (7) ◽  
pp. 759-765 ◽  
Author(s):  
Jonathan Leblond ◽  
Aurélie Hubert-Buron ◽  
Christine Bole-Feysot ◽  
Philippe Ducrotté ◽  
Pierre Déchelotte ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Intestinal Epithelial Cell ◽  
Epithelial Cell Line ◽  
Intestinal Epithelial ◽  
Human Intestinal Epithelial Cell ◽  
Intestinal Epithelial Cell Line

scholarly journals KMT2D deficiency disturbs the proliferation and cell cycle activity of dental epithelial cell line (LS8) partially via Wnt signaling

2021 ◽  
Author(s):  
Liping Pang ◽  
Hua Tian ◽  
Xuejun Gao ◽  
Weiping Wang ◽  
Xiaoyan Wang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Epithelial Cell ◽  
Wnt Signaling ◽  
Cell Line ◽  
Tooth Development ◽  
Epithelial Cell Line ◽  
Cell Proliferation Activity ◽  
Proliferation Activity

KMT2D, as one of the key histone methyltransferases responsible for histone 3 lysine 4 methylation (H3K4me), has been proved to be the main pathogenic gene of Kabuki syndrome disease. Kabuki patients with KMT2D mutation frequently present various dental abnormalities, including abnormal tooth number and crown morphology. However, the exact function of KMT2D in tooth development remains unclear. In this report, we systematically elucidate the expression pattern of KMT2D in early tooth development and outline the molecular mechanism of KMT2D in dental epithelial cell line. KMT2D and H3K4me mainly expressed in enamel organ and Kmt2d knockdown led to the reduction of cell proliferation activity and cell cycling activity in dental epithelial cell line (LS8). RNA-seq and KEGG enrichment analysis screened out several important pathways that affected by Kmt2d knockdown including Wnt signaling. Consistently, Top/Fop assay confirmed the reduction of Wnt signaling activity in Kmt2d knockdown cells. Nuclear translocation of β-catenin was significantly reduced by Kmt2d knockdown, while lithium chloride (LiCl) partially reversed this phenomenon. Moreover, LiCl partially reversed the decrease of cell proliferation activity and G1 arrest, and the downregulation of Wnt-related genes in Kmt2d knockdown cells. In summary, this study uncovered a pivotal role of histone methyltransferase KMT2D in dental epithelium proliferation and cell cycle homeostasis partially through regulating Wnt/β-catenin signaling. The findings are important for understanding the role of KMT2D and histone methylation in tooth development.

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