Response of single, pairs, and clusters of epithelial cells to substratum topography

1995 ◽  
Vol 73 (7-8) ◽  
pp. 473-489 ◽  
Author(s):  
C. Oakley ◽  
D. M. Brunette
Keyword(s):  
Epithelial Cells ◽  
Actin Filaments ◽  
Cell Shape ◽  
Single Cells ◽  
Cell Spreading ◽  
Contact Guidance ◽  
Adjacent Cell ◽  
Cell Contact ◽  
Topographic Effects ◽  
Control Surfaces

Cells cultured on grooved substrata change their shape, orientation, and direction of locomotion in response to substratum topography, a phenomenon called contact or topographic guidance. Porcine epithelial cells (E-cells) spread on micromachined grooved or smooth control surfaces were examined by epifluorescence and confocal microscopy to determine area, cell shape, and orientation in conjunction with distributions and orientations of actin filaments and microtubules. Single cells, cells within a pair or cluster, and pairs or clusters considered as a unit were compared. As expected, cell contact increased cell spreading, but surprisingly, increased cell contact influenced cell shape on smooth and grooved surfaces and increased alignment of cells spread on grooves. Both actin filaments and microtubules aligned initially and most consistently along the walls and ridge–groove edges. Single E-cells displayed the least variability of aligned cytoskeletal patterns. E-cells within clusters displayed the most variability as local topographic effects on the cytoskeleton could be overridden by adjacent cell contact. Overall, contact guidance of E-cells was neither synonymous with nor contingent upon an elliptical morphology oriented to the topography. E-cells also differed from fibroblasts in their response to cell contact and in their lack of a relationship between cell polarity and locomotion.Key words: microtubules, actin, topographic guidance, micromachined substrata.

scholarly journals Differential control of cytokeratins and vimentin synthesis by cell-cell contact and cell spreading in cultured epithelial cells.

1984 ◽  
Vol 99 (4) ◽  
pp. 1424-1433 ◽  
Author(s):  
A Ben-Ze'ev
Keyword(s):  
Epithelial Cells ◽  
Blot Hybridization ◽  
Cell Spreading ◽  
Suspension Cultures ◽  
In Vitro Translation ◽  
Serum Starvation ◽  
Translation System ◽  
Cell Contact ◽  
Low Levels ◽  
Cell Cell

The expression of cytokeratins and vimentin was investigated in Madin-Darby bovine epithelial cells (MDBK) in culture under conditions of varied cell spreading and cell-cell contact. When extensive cell-cell contact was achieved by seeding cells at high density in monolayer, or in suspension culture in which multicellular aggregates formed, the cells synthesized high levels of cytokeratins and low levels of vimentin. In contrast, in sparse monolayer and suspension cultures where cell-cell contact was minimal, the cells synthesized very low levels of cytokeratins. The level of vimentin synthesis was high in sparse monolayer culture and was low in both sparse and dense suspension cultures. The ratio of cytokeratin to vimentin synthesis was not affected during the cell cycle, or when cell growth was inhibited by ara C and in serum-starvation-stimulation experiments. The variations in the synthesis of cytokeratins and vimentin under the various culture conditions were also reflected at the level of mRNA activity in a cell-free in vitro translation system and as determined by RNA blot hybridization with cDNA to vimentin and cytokeratins. The results suggest that control of cytokeratin synthesis involves cell-cell contact, characteristic of epithelia in vivo, while vimentin synthesis responds to alterations in cell spreading.

scholarly journals Requirement of basement membrane for the suppression of programmed cell death in mammary epithelium

1996 ◽  
Vol 109 (3) ◽  
pp. 631-642 ◽  
Author(s):  
S. Pullan ◽  
J. Wilson ◽  
A. Metcalfe ◽  
G.M. Edwards ◽  
N. Goberdhan ◽  
...  
Keyword(s):  
Cell Death ◽  
Mammary Gland ◽  
Epithelial Cells ◽  
Basement Membrane ◽  
Single Cells ◽  
Control Point ◽  
Collagen I ◽  
Cell Phenotype ◽  
Cell Contact ◽  
Isolated Cells

Apoptosis is an active mechanism of cell death required for normal tissue homeostasis. Cells require survival signals to avoid the engagement of apoptosis. In the mammary gland, secretory epithelial cells are removed by apoptosis during involution. This cell loss coincides with matrix metalloproteinase activation and basement membrane degradation. In this paper we describe studies that confer a new role for basement membrane in the regulation of cell phenotype. We demonstrate that the first passage epithelial cells isolated from pregnant mouse mammary gland die by apoptosis in culture, but that cell death is suppressed by basement membrane. The correct type of extracellular matrix was required, since only a basement membrane, not plastic or a collagen I matrix, lowered the rate of apoptosis. Attachment to a matrix per se was not sufficient for survival, since apoptotic cells were observed when still attached to a collagen I substratum. Experiments with individually isolated cells confirmed the requirement of basement membrane for survival, and demonstrated that survival is enhanced by cell-cell contact. A function-blocking anti-beta1 integrin antibody doubled the rate of apoptosis in single cells cultured with basement membrane, indicating that integrin-mediated signals contributed to survival. We examined the cell death-associated genes bcl-2 and bax in mammary epithelia, and found that although the expression of Bcl-2 did not correlate with cell survival, increased levels of Bax were associated with apoptosis. We propose that basement membrane provides a survival stimulus for epithelial cells in vivo, and that loss of interaction with this type of matrix acts as a control point for cell deletions that occur at specific times during development, such as in mammary gland involution.

scholarly journals Effect of cell shape change on the function and differentiation of rabbit mammary cells in culture

1983 ◽  
Vol 96 (5) ◽  
pp. 1425-1434 ◽  
Author(s):  
M Haeuptle ◽  
YLM Suard ◽  
E Bogenmann ◽  
H Reggio ◽  
L Racine ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Shape ◽  
Cell Layer ◽  
Single Cells ◽  
Milk Proteins ◽  
Collagen Matrix ◽  
Secretory Cells ◽  
Mammary Cells ◽  
Collagen Gels ◽  
Cell Type

We examined the role of cell shape, cytodifferentiation, and tissue topography on the induction and maintenance of functional differentiation in rabbit mammary cells grown as primary cultures on two-dimensional collagen surfaces or in three-dimensional collagen matrices. Mammary glands from mid-pregnant rabbits were dissociated into single cells, and epithelial cells were enriched by isopycnic centrifugation. Small spheroids of epithelial cells (approximately 50 cells) that formed on a rotary shaker were plated on or embedded in collagen gels. The cells were cultured for 1 d in serum-containing medium and then for up to 25 d in chemically defined medium. In some experiments, epithelial monolayers on gels were mechanically freed from the dishes on day 2 or 5. These gels retracted and formed floating collagen gels. On attached collagen gels, flat monolayers of a single cell type developed within a few days. The cells synthesized DNA until the achievement of confluence but did not accumulate milk proteins. No morphological changes were induced by prolactin (PRL). On floating gels, two cell types appeared in the absence of cell proliferation. The cells in direct contact with the medium became cuboidal and developed intracellular organelles typical of secretory cells. PRL-induced lipogenesis, resulting in large fat droplets filling the apical cytoplasm and accumulation of casein and α-lactalbumin in vesicles surrounding the fat droplets. We detected tranferrin in the presence or absence of PRL intracellularly in small vesicles but also in the collagen matrix in contact with the cell layer. The second cell type, rich in microfilaments and reminiscent of the myoepithelial cells, was situated between the secretory cell layer and the collagen matrix. In embedding gels, the cells formed hollow ductlike structures, which grew continuously in size. Secretory cells formed typical lumina distended by secretory products. We found few microfilament-rich cells in contact with the collagen gels. Storage and secretion of fat, caseins and alpha-lactalbumin required the presence of PRL, whereas the accumulation and vectorial discharge of transferrin was prolactin independent. There was no differentiation gradient between the tip and the cent of the outgrowth, since DNA synthesis and milk protein storage were random along the tubular structures. These results indicate that establishment of functional polarity and induction of cytodifferentiation are influenced by the nature of the interaction of the cells with the collagen structure. The morphological differentiation in turn plays an important role in the synthesis, storage, and secretion of fat and milk proteins.

Modulated polarization microscopy displays the dynamics of cytoskeletal structures in living, motile cells

1995 ◽  
Vol 53 ◽  
pp. 902-903
Author(s):  
J. R. Kuhn ◽  
M. Poenie
Keyword(s):  
Mitotic Spindle ◽  
Actin Filaments ◽  
Cell Shape ◽  
Dynamic Structure ◽  
Living Cells ◽  
Cytoskeletal Proteins ◽  
Polarization Microscopy ◽  
Video Enhancement ◽  
Ultrastructural Studies ◽  
Motile Cells

Cell shape and movement are controlled by elements of the cytoskeleton including actin filaments an microtubules. Unfortunately, it is difficult to visualize the cytoskeleton in living cells and hence follow it dynamics. Immunofluorescence and ultrastructural studies of fixed cells while providing clear images of the cytoskeleton, give only a static picture of this dynamic structure. Microinjection of fluorescently Is beled cytoskeletal proteins has proved useful as a way to follow some cytoskeletal events, but long terry studies are generally limited by the bleaching of fluorophores and presence of unassembled monomers.Polarization microscopy has the potential for visualizing the cytoskeleton. Although at present, it ha mainly been used for visualizing the mitotic spindle. Polarization microscopy is attractive in that it pro vides a way to selectively image structures such as cytoskeletal filaments that are birefringent. By combing ing standard polarization microscopy with video enhancement techniques it has been possible to image single filaments. In this case, however, filament intensity depends on the orientation of the polarizer and analyzer with respect to the specimen.

Comparison of Ocular Surface Cytological Appearance in Glaucoma Patient Treated with Timolol Maleat 0,5% Latanoprost 0,005% and Timolol-Latanoprost Fixed Combination Preservative Free Eye Drop

2019 ◽  
Vol 44 (2) ◽  
pp. 82
Author(s):  
Maretha Amrayni ◽  
Elsa Gustianty ◽  
Susi Heryati ◽  
Andika Prahasta ◽  
Maula Rifada ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Density ◽  
Goblet Cell ◽  
Ocular Surface ◽  
Fixed Combination ◽  
Cell Contact ◽  
Corneal Epithelial ◽  
Preservative Free ◽  
Goblet Cell Density ◽  
Epithelial Metaplasia

Introduction : The longterm use of topical antiglaucoma might cause ocular surface instability due to active substance or preservative used. Impression cytology examination may reveal superficial epithelial cells on conjunctiva and cornea, including goblet cells. Goblet cell density decrease is the most important parameter on evaluation of ocular surface disorder. Objective : This study was to understand ocular surface remodeling due to active substance of topical antiglaucoma with impression cytology examination among the patient prior and 3 months after therapy. Methods : This was a randomized controlled trial study with single blind masking. A total of 45 eyes from 31 patients were used as subject and distributed onto three groups treatment, which were timolol maleat 0.5%, latanoprost 0.005%, and latanoprost-timolol maleat fixed combination. All topical antiglaucoma in this study were preservative free. Result : There were differences between 3 groups in goblet cells density after 3 months therapy (p=0,030). Goblet cell density in timolol group was lower than latanoprost (p=0,041) and fixed combination (p=0,045). There was no significantly difference between 3 groups in conjunctival epithelial metaplasia degree (p=0,706) and cell to cell contact degree in corneal epithelial cells (p=0.66) after 3 months therapy. Conjunctival epithelial metaplasia degree were increased among group of timolol (p=0,008) and fixed combination (p=0,046). Conclusion : Timolol maleat 0,5% caused lower goblet cell density after 3 months therapy compare with latanoprost and fixed combination. There was no significantly difference in conjunctival epithelial metaplasia and cell to cell contact degree in corneal epithelial cells among these glaucoma treatment groups.

scholarly journals Single cell transcriptome atlas of mouse mammary epithelial cells across development

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Bhupinder Pal ◽  
Yunshun Chen ◽  
Michael J. G. Milevskiy ◽  
François Vaillant ◽  
Lexie Prokopuk ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Single Cell ◽  
Developmental Stages ◽  
Mammary Epithelial Cells ◽  
Expression Profiles ◽  
Single Cells ◽  
Chromatin Accessibility ◽  
Mammary Epithelial ◽  
Cell Transcriptome ◽  
Single Cell Transcriptome

Abstract Background Heterogeneity within the mouse mammary epithelium and potential lineage relationships have been recently explored by single-cell RNA profiling. To further understand how cellular diversity changes during mammary ontogeny, we profiled single cells from nine different developmental stages spanning late embryogenesis, early postnatal, prepuberty, adult, mid-pregnancy, late-pregnancy, and post-involution, as well as the transcriptomes of micro-dissected terminal end buds (TEBs) and subtending ducts during puberty. Methods The single cell transcriptomes of 132,599 mammary epithelial cells from 9 different developmental stages were determined on the 10x Genomics Chromium platform, and integrative analyses were performed to compare specific time points. Results The mammary rudiment at E18.5 closely aligned with the basal lineage, while prepubertal epithelial cells exhibited lineage segregation but to a less differentiated state than their adult counterparts. Comparison of micro-dissected TEBs versus ducts showed that luminal cells within TEBs harbored intermediate expression profiles. Ductal basal cells exhibited increased chromatin accessibility of luminal genes compared to their TEB counterparts suggesting that lineage-specific chromatin is established within the subtending ducts during puberty. An integrative analysis of five stages spanning the pregnancy cycle revealed distinct stage-specific profiles and the presence of cycling basal, mixed-lineage, and 'late' alveolar intermediates in pregnancy. Moreover, a number of intermediates were uncovered along the basal-luminal progenitor cell axis, suggesting a continuum of alveolar-restricted progenitor states. Conclusions This extended single cell transcriptome atlas of mouse mammary epithelial cells provides the most complete coverage for mammary epithelial cells during morphogenesis to date. Together with chromatin accessibility analysis of TEB structures, it represents a valuable framework for understanding developmental decisions within the mouse mammary gland.

scholarly journals Cbl-transforming Variants Trigger a Cascade of Molecular Alterations That Lead to Epithelial Mesenchymal Conversion

2000 ◽  
Vol 11 (10) ◽  
pp. 3397-3410 ◽  
Author(s):  
Tanya M. Fournier ◽  
Louie Lamorte ◽  
Christiane R. Maroun ◽  
Mark Lupher ◽  
Hamid Band ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epithelial Cells ◽  
Hepatocyte Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Morphological Changes ◽  
Cell Spreading ◽  
Mesenchymal Transition ◽  
Amino Terminal ◽  
Src Homology ◽  
Hepatocyte Growth

Dispersal of epithelial cells is an important aspect of tumorigenesis, and invasion. Factors such as hepatocyte growth factor induce the breakdown of cell junctions and promote cell spreading and the dispersal of colonies of epithelial cells, providing a model system to investigate the biochemical signals that regulate these events. Multiple signaling proteins are phosphorylated in epithelial cells during hepatocyte growth factor–induced cell dispersal, including c-Cbl, a protooncogene docking protein with ubiquitin ligase activity. We have examined the role of c-Cbl and a transforming variant (70z-Cbl) in epithelial cell dispersal. We show that the expression of 70z-Cbl in Madin-Darby canine kidney epithelial cells resulted in the breakdown of cell–cell contacts and alterations in cell morphology characteristic of epithelial–mesenchymal transition. Structure–function studies revealed that the amino-terminal portion of c-Cbl, which corresponds to the Cbl phosphotyrosine-binding/Src homology domain 2 , is sufficient to promote the morphological changes in cell shape. Moreover, a point mutation at Gly-306 abrogates the ability of the Cbl Src homology domain 2 to induce these morphological changes. Our results identify a role for Cbl in the regulation of epithelial–mesenchymal transition, including loss of adherens junctions, cell spreading, and the initiation of cell dispersal.

scholarly journals Screening Platform for Cell Contact Guidance Based on Inorganic Biomaterial Micro/nanotopographical Gradients

2017 ◽  
Vol 9 (37) ◽  
pp. 31433-31445 ◽  
Author(s):  
Qihui Zhou ◽  
Olga Castañeda Ocampo ◽  
Carlos F. Guimarães ◽  
Philipp T. Kühn ◽  
Theo G. van Kooten ◽  
...  
Keyword(s):  
Contact Guidance ◽  
Cell Contact ◽  
Screening Platform

scholarly journals Bacterial Secretions of Nonpathogenic Escherichia coli Elicit Inflammatory Pathways: a Closer Investigation of Interkingdom Signaling

mBio ◽  
2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Amin Zargar ◽  
David N. Quan ◽  
Karen K. Carter ◽  
Min Guo ◽  
Herman O. Sintim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Negative Feedback ◽  
Cell Contact ◽  
Bacterial Cells ◽  
Content Type ◽  
Phenotypic Differences ◽  
E Coli ◽  
Autoinducer 2 ◽  
Human Epithelial Cells

ABSTRACTThere have been many studies on the relationship between nonpathogenic bacteria and human epithelial cells; however, the bidirectional effects of the secretomes (secreted substances in which there is no direct bacterium-cell contact) have yet to be fully investigated. In this study, we use a transwell model to explore the transcriptomic effects of bacterial secretions from two different nonpathogenicEscherichia colistrains on the human colonic cell line HCT-8 using next-generation transcriptome sequencing (RNA-Seq).E. coliBL21 and W3110, while genetically very similar (99.1% homology), exhibit key phenotypic differences, including differences in their production of macromolecular structures (e.g., flagella and lipopolysaccharide) and in their secretion of metabolic byproducts (e.g., acetate) and signaling molecules (e.g., quorum-sensing autoinducer 2 [AI-2]). After analysis of differential epithelial responses to the respective secretomes, this study shows for the first time that a nonpathogenic bacterial secretome activates the NF-κB-mediated cytokine-cytokine receptor pathways while also upregulating negative-feedback components, including the NOD-like signaling pathway. Because of AI-2's relevance as a bacterium-bacterium signaling molecule and the differences in its secretion rates between these strains, we investigated its role in HCT-8 cells. We found that the expression of the inflammatory cytokine interleukin 8 (IL-8) responded to AI-2 with a pattern of rapid upregulation before subsequent downregulation after 24 h. Collectively, these data demonstrate that secreted products from nonpathogenic bacteria stimulate the transcription of immune-related biological pathways, followed by the upregulation of negative-feedback elements that may serve to temper the inflammatory response.IMPORTANCEThe symbiotic relationship between the microbiome and the host is important in the maintenance of human health. There is a growing need to further understand the nature of these relationships to aid in the development of homeostatic probiotics and also in the design of novel antimicrobial therapeutics. To our knowledge, this is the first global-transcriptome study of bacteria cocultured with human epithelial cells in a model to determine the transcriptional effects of epithelial cells in which epithelial and bacterial cells are allowed to “communicate” with each other only through diffusible small molecules and proteins. By beginning to demarcate the direct and indirect effects of bacteria on the gastrointestinal (GI) tract, two-way interkingdom communication can potentially be mediated between host and microbe.

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