scholarly journals Oxytocin Receptor Down-Regulation Is Not Necessary for Reducing Oxytocin-Induced Prostaglandin F2α Accumulation by Interferon-τ in a Bovine Endometrial Epithelial Cell Line

Endocrinology ◽  
2009 ◽  
Vol 150 (2) ◽  
pp. 897-905 ◽  
Author(s):  
Narayanan Krishnaswamy ◽  
Ghislain Danyod ◽  
Pierre Chapdelaine ◽  
Michel A. Fortier

Interferon-τ (IFNτ) is the embryonic signal responsible for pregnancy recognition in ruminants. The primary action of IFNτ is believed to be mediated through inhibition of prostaglandin F2α (PGF2α) released from the endometrial epithelial cells in response to oxytocin (OT). Our working hypothesis was that the antiluteolytic effect of IFNτ also involved modulation of PG production downstream of OT receptor (OTR) and/or cyclooxygenase 2 (COX2). There is currently no OT-sensitive endometrial cell line to study the molecular mechanisms underlying our hypotheses. Therefore, we established an immortalized bovine endometrial epithelial cell line (bEEL) exhibiting OT response. These cells were cytokeratin positive, expressed steroid receptors, and exhibited preferential accumulation of PGF2α over PGE2. The bEEL cells were highly sensitive to OT, showing time- and concentration-dependent increase in COX2 transcript and protein and PGF2α accumulation. Interestingly, IFNτ (20 ng/ml) significantly reduced OT-induced PGF2α accumulation, but surprisingly, the effect was not mediated through down-regulation of either OTR or COX2. Rather, IFNτ up-regulated COX2 in a time- and concentration-dependent manner while decreasing OT-induced PG accumulation. This suggests that COX2 is not a primary target for the antiluteolytic effect of IFNτ. Because IFNτ reduced OT-stimulated PGF2α accumulation within 3 h, the mechanism likely involves a direct interference at the level of the OT signaling or transcription in addition to the down-regulation of OTR observed in vivo. In summary, bEEL cells offer a unique in vitro model for investigating the cellular and molecular mechanisms underlying OT and IFNτ response in relation with luteolysis and recognition of pregnancy in the bovine. Interferon-τ acts as a competitive partial agonist, stimulating basal but inhibiting oxytocin- and phorbol myristate acetate-stimulated prostaglandin F2α production in immortalized bovine endometrial epithelial cells.

2001 ◽  
Vol 280 (5) ◽  
pp. G910-G921 ◽  
Author(s):  
Frederic Hollande ◽  
Emmanuelle M. Blanc ◽  
Jean Pierre Bali ◽  
Robert H. Whitehead ◽  
Andre Pelegrin ◽  
...  

The regulation of intercellular adhesion by hepatocyte growth factor (HGF) was examined on a novel nontumorigenic gastric epithelial cell line (IMGE-5) derived from H-2Kb-tsA58 transgenic mice. IMGE-5 cells constitutively expressed cytokeratin 18 and HGF receptors. Under permissive conditions (33°C + interferon-γ), IMGE-5 cells proliferated rapidly but did not display membrane expression of adherens and tight junction proteins. Under nonpermissive conditions, their proliferation was decreased and they displayed a strong, localized membrane expression of E-cadherin/β-catenin and occludin/ZO-1. HGF treatment largely prevented the targeting of ZO-1 to the tight junction and induced a significant decrease of the transepithelial resistance measured across a confluent IMGE-5 cell monolayer. HGF rapidly increased the tyrosine phosphorylation of ZO-1 and decreased its association with occludin in a phosphatidylinositol 3-kinase (PI 3-kinase)-dependent manner. PI 3-kinase was also involved in HGF-induced migration of IMGE-5 cells. Our results demonstrate that 1) HGF prevents the appearance of ZO-1 in the membrane during epithelial cell differentiation; 2) HGF causes partial relocalization of ZO-1 to the cytoplasm and nucleus and concomitantly stimulates cell dissociation and migration; and 3) IMGE-5 cells offer a useful model for the study of gastric epithelial cell differentiation.


Author(s):  
Rino P. Donato ◽  
Adaweyah El-Merhibi ◽  
Batjargal Gundsambuu ◽  
Kai Yan Mak ◽  
Emma R. Formosa ◽  
...  

1986 ◽  
Vol 86 (1) ◽  
pp. 95-107
Author(s):  
M. Paye ◽  
C.M. Lapiere

PER cells, a transformed pulmonary epithelial cell line that adhered to a large extent to a fibronectin substratum, were found to be attachment-deficient to collagen I. Although fibronectin can bind to collagen I monomers and polymers, the addition of exogenous fibronectin in the attachment medium induced the adhesion of these cells to collagen I polymers but not to monomers. By adding the transglutaminase of blood coagulation, FXIII, in the presence of fibronectin, the attachment of PER cells to collagen I monomers could be recovered while the minimal concentration of fibronectin needed to promote their adhesion to polymers was lowered. These studies indicate that FXIII enhances the fibronectin-mediated attachment of PER cells to collagen I.


1989 ◽  
Vol 94 (2) ◽  
pp. 327-332
Author(s):  
E.J. Hughson ◽  
D.F. Cutler ◽  
C.R. Hopkins

The immunoglobulin kappa light chain is constitutively secreted in non-polarised cells. It is therefore unlikely to display any of the signals thought to be required for the selective delivery of proteins to the apical or basolateral borders of polarised epithelial cells. We have transfected the gene for the kappa light chain into a polarised epithelial cell line (Caco-2) and shown that it is secreted predominantly from the basolateral surface. Metabolically labelled endogenous secretory products show the same polarity and we conclude, therefore, that in Caco-2 cells there is a major intracellular trafficking route to the basolateral border that requires no sorting signal.


1996 ◽  
Vol 313 (1) ◽  
pp. 35-38 ◽  
Author(s):  
Geneviève VALLETTE ◽  
Anne JARRY ◽  
Jean-Eric BRANKA ◽  
Christian L. LABOISSE

We evaluated the effects of two NO donors, sodium nitroprusside (SNP) and 3-morpholino-sydnonimine (SIN-1), characterized by alternative redox states, i.e. nitrosonium ion (NO+) and nitric oxide (NO•) respectively, on intracellular interleukin-1 (IL-1) production, by a human colonic epithelial cell line (HT29-Cl.16E). SNP was able to induce intracellular IL-1α production up to 10 h incubation, in a dose-dependent manner. Several experiments provide evidence that the NO+ redox form, and not the free radical NO•, is implicated in the IL-1α production: (i) SIN-1, devoid of any NO+ character, led to a very weak IL-1 production as compared with SNP; (ii) the reductive action of a thiol such as cysteine on NO+ led to a dose-dependent increase in NO• concentration, measured as NO2-/NO3- accumulation, and to a large decrease in IL-1 production. Dibutyryl cGMP had no effect on IL-1 production, this finding supporting the concept that a cGMP-independent pathway is involved in the intracellular signalling of NO+. Together these results point out that NO, depending on its redox form, is able to modulate IL-1 production in cultured colonic epithelial cells.


Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 867
Author(s):  
Olga Povolyaeva ◽  
Yaroslava Chalenko ◽  
Egor Kalinin ◽  
Olga Kolbasova ◽  
Elena Pivova ◽  
...  

L. monocytogenes is a widespread facultative intracellular pathogen. The range of natural hosts that supporting L. monocytogenes persistence in the environment has not been fully established yet. In this study, we were interested in the potential of L. monocytogenes to infect cells of bats, which are being increasingly recognized as a reservoir for microorganisms that are pathogenic to humans and domestic animals. A stable epithelial cell line was developed from the kidneys of Pipistrellus nathusii, a small bat widely distributed across Europe. The wild-type L. monocytogenes strain EGDe infected this cell line with an invasion efficiency of 0.0078 ± 0.0009%. Once it entered bat cells, L. monocytogenes doubled within about 70 min. When L. monocytogenes lacked either of the major invasion factors, InlA and InlB, invasion efficiency decreased by a factor of 10 and 25 respectively (p < 0.000001). The obtained results suggest that bat epithelial cells are susceptible to L. monocytogenes infection and that L. monocytogenes invasion of bat cells depends on the major invasion factors InlA and InlB. These results constitute the first report on in vitro studies of L. monocytogenes infection in bats.


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