Locomotory invasion of human cervical epithelium and avian fibroblasts by HeLa cells in vitro

1982 ◽  
Vol 57 (1) ◽  
pp. 293-314 ◽  
Author(s):  
E.M. Stephenson
Keyword(s):  
Epithelial Cells ◽  
Hela Cells ◽  
Time Lapse ◽  
Tumour Cells ◽  
Contact Inhibition ◽  
Type I ◽  
Original Direction ◽  
Epithelial Sheet ◽  
Invasion Index

The locomotory invasive ability of HeLa cells was tested against: (a) embryonic chick heart fibroblasts (CHF); and (b) normal epithelial cells from human cervix (HCE) in explant confrontations. Data for analyses were obtained from replicate cultures fixed 24 h after junction and from 24-h time-lapse films. The mean invasion index for HeLa versus CHF did not indicate significant obstruction but analyses of hourly radial advance and orientation frequencies showed that obstruction eventually developed as postjunctional incubation time increased. Early contacts between HeLa and CHF demonstrated non-reciprocity of type I contact inhibition of locomotion by the tumour cells, which continued moving in their original direction to underlap contact-inhibited fibroblasts and eventually to occupy spaces vacated by them. When CHF population density increased and free space diminished, HeLa cells displayed directional and probably substrate-dependent contact inhibition. The high invasion index of HeLa versus HCE was largely due to occupation of previous HCE territory by tumour cells and only occasionally to actual infiltration of the epithelial sheet. After contact with HeLa, ruffling substrate-adherent marginal epithelial cells displayed contractile, type I contact inhibition of locomotion. After orientation changes, they gradually retreated. Against HCE, HeLa cells exhibited non-reciprocity of type I contact inhibition and continued radially forward, following the retreating epithelial margin. They did not move onto exposed upper surfaces of epithelial cells and did not underlap marginal cells firmly adherent to the substratum. Invasion of the epithelial sheet was seen only when initial access beneath a cell with a non-adherent margin was available. The contact relationships of isolated invading HeLa cells with their epithelial neighbours suggested successive non-reciprocal contact inhibition reactions.

Non-reciprocal contact inhibition of locomotion of chick embryonic choroid fibroblasts by pigmented retina epithelial cells

1978 ◽  
Vol 33 (1) ◽  
pp. 103-120
Author(s):  
E.K. Parkinson ◽  
J.G. Edwards
Keyword(s):  
Epithelial Cells ◽  
Light And Electron Microscopy ◽  
Leading Edge ◽  
Time Lapse ◽  
Contact Inhibition ◽  
Cultured Fibroblasts ◽  
Lateral Contact ◽  
Fibroblastic Cells

Using light and electron microscopy, we have confirmed an earlier observation that chick embryonic pigmented retina epithelial cells (PRE cells) seeded in vitro on cultured sheets of choroid fibroblasts, are able to spread. Spreading is as rapid (and shows the same dependence on lateral contact between PRE cells) as on a serum-coated culture substrate. After 1 h most cells are spreading on the upper surface of the choroid sheet, but after 4 h, some PRE cells can be found sandwiched between overlapping choroid cells, and thus have invaded the sheet. Choroid fibroblasts underlie PRE in vivo, but the ability of PRE cells to spread on cultured fibroblasts is not specific for choroid, since PRE cells spread also on BKH21 hamster kidney fibroblasts, and on fibroblasts from chick embryonic heart. As reported by others for various fibroblastic cells, choroid cells seeded on to choroid sheets or on to cultured PRE are unable to spread. A possible explanation is that spreading of adherent cells is contact-inhibited by the cells in the sheet, just as their leading edges are paralysed on contact, and thus locomotion is inhibited, when fibroblasts collide on a plane substratum. If spreading of seeded cells and cell locomotion are inhibited by the same mechanism, PRE cells should contact-inhibit choroid fibroblasts with which they collide, but not themselves be so inhibited. Using time-lapse cinemicrography, we have found this to be the case. We first established that in homotypic collisions, choroid fibroblasts do show contact inhibition of locomotion, despite the criss-cross (not well monolayered) appearance of confluent cultures. In heterotypic collisions between choroid and PRE we found the predicted nonreciprocal behaviour: the choroid leading edge is paralysed on collision, and the cell subsequently retracts, whereas the active PRE margin appears to be completely unaffected. Speed measurements from a series of such collisions show that the speed of choroid cells is markedly reduced on collision with PRE, whereas the slight slowing of PRE is not statistically significant. We have observed similar behaviour in heterotypic collisions between various epithelial and fibroblastic cells, and so it seems possible that non-reciprocity may prove general for this interaction. If so, it has important implications for the role of contact inhibition of locomotion in phenomena such as morphogenesis, wound healing and the invasiveness of carcinoma cells. On the one hand, non-reciprocal contact-inhibition of locomotion may permit the spreading of epithelia over mesenchymal cells, thus generating or restoring an epithelial bounding membrane. On the other hand, in the absence of other interactions, it would fail to inhibit the invasion of mesenchymal territory by aberrant epithelial cells, or presumably by epithelial free edges.

Disparate cytokine regulation of ICAM-1 in rat alveolar epithelial cells and pulmonary endothelial cells in vitro

1995 ◽  
Vol 269 (1) ◽  
pp. L127-L135 ◽  
Author(s):  
W. W. Barton ◽  
S. Wilcoxen ◽  
P. J. Christensen ◽  
R. Paine
Keyword(s):  
Endothelial Cells ◽  
Epithelial Cells ◽  
Inflammatory Cytokines ◽  
Alveolar Epithelial Cells ◽  
Normal Lung ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Epithelial

Intercellular adhesion molecule-1 (ICAM-1) is expressed at high levels on type I alveolar epithelial cells in the normal lung and is induced in vitro as type II cells spread in primary culture. In contrast, in most nonhematopoetic cells ICAM-1 expression is induced in response to inflammatory cytokines. We have formed the hypothesis that the signals that control ICAM-1 expression in alveolar epithelial cells are fundamentally different from those controlling expression in most other cells. To test this hypothesis, we have investigated the influence of inflammatory cytokines on ICAM-1 expression in isolated type II cells that have spread in culture and compared this response to that of rat pulmonary artery endothelial cells (RPAEC). ICAM-1 protein, determined both by a cell-based enzyme-linked immunosorbent assay and by Western blot analysis, and mRNA were minimally expressed in unstimulated RPAEC but were significantly induced in a time- and dose-dependent manner by treatment with tumor necrosis factor-alpha, interleukin-1 beta, or interferon-gamma. In contrast, these cytokines did not influence the constitutive high level ICAM-1 protein expression in alveolar epithelial cells and only minimally affected steady-state mRNA levels. ICAM-1 mRNA half-life, measured in the presence of actinomycin D, was relatively long at 7 h in alveolar epithelial cells and 4 h in RPAEC. The striking lack of response of ICAM-1 expression by alveolar epithelial cells to inflammatory cytokines is in contrast to virtually all other epithelial cells studied to date and supports the hypothesis that ICAM-1 expression by these cells is a function of cellular differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Antiviral immunity is impaired in COPD patients with frequent exacerbations

2019 ◽  
Vol 317 (6) ◽  
pp. L893-L903 ◽  
Author(s):  
Aran Singanayagam ◽  
Su-Ling Loo ◽  
Maria Calderazzo ◽  
Lydia J. Finney ◽  
Maria-Belen Trujillo Torralbo ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Treatment Options ◽  
Stable State ◽  
Innate Immune ◽  
Chronic Obstructive ◽  
Type I ◽  
Obstructive Pulmonary Disease ◽  
Immune Mediators ◽  
Copd Patients

Patients with frequent exacerbations represent a chronic obstructive pulmonary disease (COPD) subgroup requiring better treatment options. The aim of this study was to determine the innate immune mechanisms that underlie susceptibility to frequent exacerbations in COPD. We measured sputum expression of immune mediators and bacterial loads in samples from patients with COPD at stable state and during virus-associated exacerbations. In vitro immune responses to rhinovirus infection in differentiated primary bronchial epithelial cells (BECs) sampled from patients with COPD were additionally evaluated. Patients were stratified as frequent exacerbators (≥2 exacerbations in the preceding year) or infrequent exacerbators (<2 exacerbations in the preceding year) with comparisons made between these groups. Frequent exacerbators had reduced sputum cell mRNA expression of the antiviral immune mediators type I and III interferons and reduced interferon-stimulated gene (ISG) expression when clinically stable and during virus-associated exacerbation. A role for epithelial cell-intrinsic innate immune dysregulation was identified: induction of interferons and ISGs during in vitro rhinovirus (RV) infection was also impaired in differentiated BECs from frequent exacerbators. Frequent exacerbators additionally had increased sputum bacterial loads at 2 wk following virus-associated exacerbation onset. These data implicate deficient airway innate immunity involving epithelial cells in the increased propensity to exacerbations observed in some patients with COPD. Therapeutic approaches to boost innate antimicrobial immunity in the lung could be a viable strategy for prevention and treatment of frequent exacerbations.

scholarly journals Fur Represses Adhesion to, Invasion of, and Intracellular Bacterial Community Formation within Bladder Epithelial Cells and Motility in Uropathogenic Escherichia coli

2016 ◽  
Vol 84 (11) ◽  
pp. 3220-3231 ◽  
Author(s):  
Kumiko Kurabayashi ◽  
Tomohiro Agata ◽  
Hirofumi Asano ◽  
Haruyoshi Tomita ◽  
Hidetada Hirakawa
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Antimicrobial Agents ◽  
Host Cells ◽  
Type I ◽  
Wild Type ◽  
Content Type ◽  
Type I Fimbriae ◽  
Tract Infections

Uropathogenic Escherichia coli (UPEC) is a major pathogen that causes urinary tract infections (UTIs). This bacterium adheres to and invades the host cells in the bladder, where it forms biofilm-like polymicrobial structures termed intracellular bacterial communities (IBCs) that protect UPEC from antimicrobial agents and the host immune systems. Using genetic screening, we found that deletion of the fur gene, which encodes an iron-binding transcriptional repressor for iron uptake systems, elevated the expression of type I fimbriae and motility when UPEC was grown under iron-rich conditions, and it led to an increased number of UPEC cells adhering to and internalized in bladder epithelial cells. Consequently, the IBC colonies that the fur mutant formed in host cells were denser and larger than those formed by the wild-type parent strain. Fur is inactivated under iron-restricted conditions. When iron was depleted from the bacterial cultures, wild-type UPEC adhesion, invasion, and motility increased, similar to the case with the fur mutant. The purified Fur protein bound to regions upstream of fimA and flhD , which encode type I fimbriae and an activator of flagellar expression that contributes to motility, respectively. These results suggest that Fur is a repressor of fimA and flhD and that its repression is abolished under iron-depleted conditions. Based on our in vitro experiments, we conclude that UPEC adhesion, invasion, IBC formation, and motility are suppressed by Fur under iron-rich conditions but derepressed under iron-restricted conditions, such as in patients with UTIs.

scholarly journals Identification and molecular characterization of E-MAP-115, a novel microtubule-associated protein predominantly expressed in epithelial cells.

1993 ◽  
Vol 123 (2) ◽  
pp. 357-371 ◽  
Author(s):  
D Masson ◽  
T E Kreis
Keyword(s):  
Epithelial Cells ◽  
Molecular Characterization ◽  
Hela Cells ◽  
Binding Proteins ◽  
Cdna Expression Library ◽  
Expression Library ◽  
Microtubule Binding ◽  
Terminal Domain

A novel microtubule-associated protein (MAP) of M(r) 115,000 has been identified by screening of a HeLa cell cDNA expression library with an anti-serum raised against microtubule-binding proteins from HeLa cells. Monoclonal and affinity-purified polyclonal antibodies were generated for the further characterization of this MAP. It is different from the microtubule-binding proteins of similar molecular weights, characterized so far, by its nucleotide-insensitive binding to microtubules and different sedimentation behavior. Since it is predominantly expressed in cells of epithelial origin (Caco-2, HeLa, MDCK), and rare (human skin, A72) or not detectable (Vero) in fibroblastic cells, we name it E-MAP-115 (epithelial MAP of 115 kD). In HeLa cells, E-MAP-115 is preferentially associated with subdomains or subsets of perinuclear microtubules. In Caco-2 cells, labeling for E-MAP-115 increases when they polarize and form blisters. The molecular characterization of E-MAP-115 reveals that it is a novel protein with no significant homologies to other known proteins. The secondary structure predicted from its sequence indicates two domains connected by a putative hinge region rich in proline and alanine (PAPA region). E-MAP-115 has two highly charged regions with predicted alpha-helical structure, one basic with a pI of 10.9 in the NH2-terminal domain and one neutral with a pI of 7.6 immediately following the PAPA region in the acidic COOH-terminal half of the molecule. A novel microtubule-binding site has been localized to the basic alpha-helical region in the NH2-terminal domain using in vitro microtubule-binding assays and expression of mutant polypeptides in vivo. Overexpression of this domain of E-MAP-115 by transfection of fibroblasts lacking significant levels of this protein with its cDNA renders microtubules stable to nocodazole. We conclude that E-MAP-115 is a microtubule-stabilizing protein that may play an important role during reorganization of microtubules during polarization and differentiation of epithelial cells.

Injury of rat pulmonary alveolar epithelial cells by H2O2: dependence on phenotype and catalase

1991 ◽  
Vol 260 (4) ◽  
pp. L318-L325 ◽  
Author(s):  
R. H. Simon ◽  
J. A. Edwards ◽  
M. M. Reza ◽  
R. G. Kunkel
Keyword(s):  
Epithelial Cells ◽  
Catalase Activity ◽  
Lung Diseases ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Epithelial

In a variety of inflammatory lung diseases, type I alveolar epithelial cells are more likely to be injured than are type II cells. Because oxidants have been implicated as a cause of injury in various inflammatory lung diseases, we evaluated the effects of differentiation on alveolar epithelial cell susceptibility to H2O2-induced injury. With the use of isolated rat type II cells in culture, we found that the cytotoxic effect of H2O2 increased between days 2 and 7, when type II cells are known to lose their distinctive type II properties and assume a more type I-like appearance. We previously reported that type II cells utilized both intracellular catalase and glutathione-dependent reactions to protect against H2O2. We therefore examined whether alterations in either of these protective mechanisms were responsible for the differentiation-dependent changes in sensitivity to H2O2. We found that catalase activity within alveolar epithelial cells decreased between 2 and 7 days in culture, whereas no changes were detected in glutathione-dependent systems. We then used a histochemical technique that detects catalase activity and found that type II cells within rat lungs possessed numerous catalase-containing peroxisomes, whereas very few were detected in type I cells. These findings demonstrate that as type II cells assume a type I-like phenotype, they become more susceptible to H2O2-induced injury. This increased susceptibility is associated with reductions in intracellular catalase activity, both in vitro and in vivo.

scholarly journals OCTN2-Mediated Acetyl-l-Carnitine Transport in Human Pulmonary Epithelial Cells In Vitro

Pharmaceutics ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 396 ◽  
Author(s):  
Johanna J. Salomon ◽  
Julia C. Gausterer ◽  
Mohammed Ali Selo ◽  
Ken-ichi Hosoya ◽  
Hanno Huwer ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
A549 Cells ◽  
Alveolar Epithelium ◽  
Alveolar Type ◽  
Suitable Model ◽  
Type I ◽  
Uptake Inhibition ◽  
Carnitine Transport ◽  
Carnitine Uptake

The carnitine transporter OCTN2 is associated with asthma and other inflammatory diseases. The aims of this work were (i) to determine carnitine uptake into freshly isolated human alveolar type I (ATI)-like epithelial cells in primary culture, (ii) to compare the kinetics of carnitine uptake between respiratory epithelial in vitro cell models, and (iii) to establish whether any cell line was a suitable model for studies of carnitine transport at the air-blood barrier. Levels of time-dependent [3H]-acetyl-l-carnitine uptake were similar in ATI-like, NCl-H441, and Calu-3 epithelial cells, whereas uptake into A549 cells was ~5 times higher. Uptake inhibition was more pronounced by OCTN2 modulators, such as l-Carnitine and verapamil, in ATI-like primary epithelial cells compared to NCl-H441 and Calu-3 epithelial cells. Our findings suggest that OCTN2 is involved in the cellular uptake of acetyl-l-carnitine at the alveolar epithelium and that none of the tested cell lines are optimal surrogates for primary cells.

scholarly journals Relationship between neuronal migration and cell-substratum adhesion: laminin and merosin promote olfactory neuronal migration but are anti-adhesive.

1991 ◽  
Vol 115 (3) ◽  
pp. 779-794 ◽  
Author(s):  
A L Calof ◽  
A D Lander
Keyword(s):  
Neuronal Migration ◽  
Type I Collagen ◽  
Neuronal Cells ◽  
Time Lapse ◽  
Type I ◽  
Type Iv ◽  
The Central Nervous System ◽  
Adhesive Effect ◽  
Fibronectin Type

Regulation by the extracellular matrix (ECM) of migration, motility, and adhesion of olfactory neurons and their precursors was studied in vitro. Neuronal cells of the embryonic olfactory epithelium (OE), which undergo extensive migration in the central nervous system during normal development, were shown to be highly migratory in culture as well. Migration of OE neuronal cells was strongly dependent on substratum-bound ECM molecules, being specifically stimulated and guided by laminin (or the laminin-related molecule merosin) in preference to fibronectin, type I collagen, or type IV collagen. Motility of OE neuronal cells, examined by time-lapse video microscopy, was high on laminin-containing substrata, but negligible on fibronectin substrata. Quantitative assays of adhesion of OE neuronal cells to substrata treated with different ECM molecules demonstrated no correlation, either positive or negative, between the migratory preferences of cells and the strength of cell-substratum adhesion. Moreover, measurements of cell adhesion to substrata containing combinations of ECM proteins revealed that laminin and merosin are anti-adhesive for OE neuronal cells, i.e., cause these cells to adhere poorly to substrata that would otherwise be strongly adhesive. The evidence suggests that the anti-adhesive effect of laminin is not the result of interactions between laminin and other ECM molecules, but rather an effect of laminin on cells, which alters the way in which cells adhere. Consistent with this view, laminin was found to interfere strongly with the formation of focal contacts by OE neuronal cells.

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