scholarly journals Intercellular adhesive selectivity. III. Species selectivity of embryonic liver intercellular adhesion.

1976 ◽  
Vol 71 (1) ◽  
pp. 96-106 ◽  
Author(s):  
S R Grady ◽  
E J McGuire
Keyword(s):  
Species Difference ◽  
Cell Types ◽  
Liver Cells ◽  
Evolutionary Divergence ◽  
Embryonic Liver ◽  
Embryonic Cells ◽  
Adhesive Properties ◽  
Assay Procedure ◽  
Double Label ◽  
Different Cell Types

A species difference in the intercellular adhesive selectivity of mixtures of embryonic liver cells is reported. This is first quantitative assessment of species differences in the intercellular adhesive properties of embryonic cells. A collecting aggregate assay, a new double-label assay procedure, and histological and autoradiographic procedures were used to elucidate the intercellular adhesive selectivity of developing mammalian and avian liver cells. Evidence is presented that the reported adhesive differences are not due to the different cell types composing the respective embryonic mammalian and avian livers. Finally, such heterolgous-homotypic selectivity of adhesion is not a property of all tissues, since it is shown that developing brain cells (mesencephalon) do not exhibit the avove intercellular adhesive selectivity (mammalian vs. avian). These findings provide further support for the hypothesis that generic identity as well as cell type may play an important part in determining the intercellular adhesive behavior of heterologous-homotypic mixtures of embryonic cells. A possible evolutionary divergence of morphogenetic mechanisms is discussed.

The sorting out of embryonic cells in monolayer, the differential adhesion hypothesis and the non-specificity of cell adhesion

1979 ◽  
Vol 38 (1) ◽  
pp. 249-266
Author(s):  
A. Nicol ◽  
D.R. Garrod
Keyword(s):  
Corneal Epithelium ◽  
Liver Parenchyma ◽  
Cell Types ◽  
Limb Bud ◽  
The Other ◽  
Embryonic Cells ◽  
Differential Adhesion ◽  
Discontinuous Phase ◽  
Different Cell Types ◽  
Differential Adhesion Hypothesis

It has been reported previously that sorting out of chick embryonic liver parenchyma and limb bud mesenchymal cells would take place in monolayer culture. The distribution of cell types obtained (liver formed the internal, discontinuous phase) was interpreted in terms of the differential adhesion hypothesis. It was suggested that, in monolayer, liver cells were more cohesive than limb bud cells. In this paper we set out to extend the previous observations with 2 particular questions in mind: (i) Is sorting out in monolayer a general phenomenon occurring between a wider range of cell types? (ii) Can evidence be provided for or against the interpretation of results in terms of the differential adhesion hypothesis? Sorting-out experiments were conducted on circular hydrophilic islands, on an otherwise hydrophobic substratum. Under these conditions, sorting-out in monolayer was obtained with binary combinations of 4 chick embryonic tissue types: liver parenchyma, limb bud mesenchyme, pigmented epithelium of the eye and corneal epithelium. With every combination but one, the cells of one type surrounded the cells of the other type, generating what we have called a ‘circle-within-a-circle’ configuration. With the remaining combination, liver parenchyma and corneal epithelium, only localized sorting was obtained. The ‘circle-within-a-circle’ configuration is consistent with an interpretation in terms of the differential adhesion hypothesis, according to which the distribution of cells is determined by the relative strengths of cohesions between their lateral surfaces. In direct support of this is the finding from plating the different cell types at sub-confluent density on hydrophilic substrata that limb bud is the cell tye having the weakest lateral cohesion in monolayer. Limb bud surrounded the other 3 tissues on hydrophilic island. A hierachy of lateral cohesiveness between the 4 cell types has been constructed. It is unlikely that the results can be explained in terms of specific cohesion. When plated together at subconfluent density, the 3 epithelial cell types aggregate together to form mixed monolayered islands, suggesting that they share common adhesive mechanisms.

Observations on the sorting-out of embryonic cells in monolayer culture

1975 ◽  
Vol 18 (3) ◽  
pp. 385-403
Author(s):  
M.S. Steinberg ◽  
D.R. Garrod
Keyword(s):  
Monolayer Culture ◽  
Cell Movement ◽  
Time Lapse ◽  
Cell Types ◽  
Liver Cells ◽  
Contact Inhibition ◽  
Limb Bud ◽  
Embryonic Cells ◽  
Embryo Cells ◽  
Embryonic Limb

Two problems are raised concerning the movement of cells during tissue-specific sorting-out of chick embryo cells in mixed aggregates. (i) A possible expectation from the hypothesis of ‘contact inhibition’ is that cells which are entirely surrounded by other cells in monolayer should be held stationary. Cells within solid aggregates, being totally surrounded by others, might also not be expected to move. How is it then that cell movement takes place within solid aggregates during sorting-out? (ii) Are the movements of cells within sorting aggregates ‘passive’, being driven by adhesive differentials or ‘active’, being merely guided by such differentials? In order to study these questions, sorting out experiments with chick embryonic limb bud mesenchyme and liver cells were carried out in monolayer culture, permitting direct observation of cell movements. Cell behavior was observed by time-lapse cinematography. Sorting-out of these cells in monolayer began before and continued after the cells had spread to confluency. During sorting, liver cells showed ruffing activity even when they appeared to be totally surrounded by other cells. Both cell types showed contact inhibition as judged by the criterion of monolayering, for they did not move over each other but remained attached to the substratum. Yet the cells in the confluent monolayer were not immobilized. Because of this, we suggest that the observed restraint against overlapping did not result from an inhibition of movement. Several considerations, detailed in the text, suggest that cell movement during sorting-out involve active locomotion. Previous work suggest that sorting-out configurations are determined by the relative intensities of intercellular adhesive strengths, the more cohesive of 2 cell populations tending to adopt the internal position. While limb bud cells form internal islands surrounded by liver cells in solid aggregates, the reverse was found to be the case in these monolayers. This suggests that, in the monolayer, limb bud cohesiveness is depressed relative to liver cell cohesiveness. This is consistent with the observation that the limb bud cells flattened themselves markedly against the substratum, significantly decreasing their area of mutual apposition.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Nitric Oxide Protects Murine Embryonic Liver Cells (BNL CL.2) from Cytotoxicity Induced by Glucose Deprivation

2000 ◽  
Vol 86 (3) ◽  
pp. 140-144 ◽  
Author(s):  
Hyun-Ock Pae ◽  
Hong-Gone Kim ◽  
Young-Suk Paik ◽  
Sang-Gi Paik ◽  
Young-Myeong Kim ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Glucose Deprivation ◽  
Liver Cells ◽  
Embryonic Liver

Processing and Characterization of Recombinant von Willebrand Factor Expressed in Different Cell Types Using a Vaccinia Virus Vector

1992 ◽  
Vol 67 (01) ◽  
pp. 154-160 ◽  
Author(s):  
P Meulien ◽  
M Nishino ◽  
C Mazurier ◽  
K Dott ◽  
G Piétu ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Von Willebrand Factor ◽  
Human Fibroblasts ◽  
Active Form ◽  
Cell Types ◽  
Biologically Active ◽  
L Cells ◽  
Von Willebrand ◽  
Different Cell Types ◽  
Willebrand Factor

SummaryThe cloning of the cDNA encoding von Willebrand factor (vWF) has revealed that it is synthesized as a large precursor (pre-pro-vWF) molecule and it is now clear that the prosequence or vWAgll is responsible for the intracellular multimerization of vWF. We have cloned the complete vWF cDNA and expressed it using a recombinant vaccinia virus as vector. We have characterized the structure and function of the recombinant vWF (rvWF) secreted from five different cell types: baby hamster kidney (BHK), Chinese hamster ovary (CHO), human fibroblasts (143B), mouse fibroblasts (L) and primary embryonic chicken cells. Forty-eight hours after infection, the quantity of vWF antigen found in the cell supernatant varied from 3 to 12 U/dl depending on the cell type. By SDS-agarose gel electrophoresis, the percentage of high molecular weight forms of vWF varied from 39 to 49% relative to normal plasma for BHK, CHO, 143B and chicken cells but was less than 10% for L cells. In all cell types, the two anodic subbands of each multimer were missing. The two cathodic subbands were easily detected only in BHK and L cells. By SDS-PAGE of reduced samples, pro-vWF was present in similar quantity to the fully processed vWF subunit in L cells, present in moderate amounts in BHK and CHO and in very low amounts in 143B and chicken cells. rvWF from all cells bound to collagen and to platelets in the presence of ristocetin, the latter showing a high correlation between binding efficiency and degree of multimerization. rvWF from all cells was also shown to bind to purified FVIII and in this case binding appeared to be independent of the degree of multimerization. We conclude that whereas vWF is naturally synthesized only by endothelial cells and megakaryocytes, it can be expressed in a biologically active form from various other cell types.

Role of Transcriptional Read-Through in PRE Activity in Drosophila melanogaster

Acta Naturae ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 79-86 ◽  
Author(s):  
P. V. Elizar’ev ◽  
D. V. Lomaev ◽  
D. A. Chetverina ◽  
P. G. Georgiev ◽  
M. M. Erokhin
Keyword(s):  
Dna Sequences ◽  
Cell Types ◽  
Transcription Terminator ◽  
Response Elements ◽  
Polycomb Response Elements ◽  
The Individual ◽  
Multicellular Organisms ◽  
Different Cell Types ◽  
Main Factor

Maintenance of the individual patterns of gene expression in different cell types is required for the differentiation and development of multicellular organisms. Expression of many genes is controlled by Polycomb (PcG) and Trithorax (TrxG) group proteins that act through association with chromatin. PcG/TrxG are assembled on the DNA sequences termed PREs (Polycomb Response Elements), the activity of which can be modulated and switched from repression to activation. In this study, we analyzed the influence of transcriptional read-through on PRE activity switch mediated by the yeast activator GAL4. We show that a transcription terminator inserted between the promoter and PRE doesnt prevent switching of PRE activity from repression to activation. We demonstrate that, independently of PRE orientation, high levels of transcription fail to dislodge PcG/TrxG proteins from PRE in the absence of a terminator. Thus, transcription is not the main factor required for PRE activity switch.

MAPK: A Key Player in the Development and Progression of Stroke

2020 ◽  
Vol 19 (4) ◽  
pp. 248-256
Author(s):  
Yangmin Zheng ◽  
Ziping Han ◽  
Haiping Zhao ◽  
Yumin Luo
Keyword(s):  
Ischemic Stroke ◽  
Signaling Pathway ◽  
Complex Disease ◽  
Therapeutic Targets ◽  
Cell Types ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Effective Prevention ◽  
Prevention And Treatment ◽  
Different Cell Types

Conclusion: Stroke is a complex disease caused by genetic and environmental factors, and its etiological mechanism has not been fully clarified yet, which brings great challenges to its effective prevention and treatment. MAPK signaling pathway regulates gene expression of eukaryotic cells and basic cellular processes such as cell proliferation, differentiation, migration, metabolism and apoptosis, which are considered as therapeutic targets for many diseases. Up to now, mounting evidence has shown that MAPK signaling pathway is involved in the pathogenesis and development of ischemic stroke. However, the upstream kinase and downstream kinase of MAPK signaling pathway are complex and the influencing factors are numerous, the exact role of MAPK signaling pathway in the pathogenesis of ischemic stroke has not been fully elucidated. MAPK signaling molecules in different cell types in the brain respond variously after stroke injury, therefore, the present review article is committed to summarizing the pathological process of different cell types participating in stroke, discussed the mechanism of MAPK participating in stroke. We further elucidated that MAPK signaling pathway molecules can be used as therapeutic targets for stroke, thus promoting the prevention and treatment of stroke.

scholarly journals Special Issue: “Bacteriophages and Biofilms”

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 257
Author(s):  
Zuzanna Drulis-Kawa ◽  
Barbara Maciejewska
Keyword(s):  
Cell Types ◽  
Special Issue ◽  
Different Cell Types

Biofilms are a community of surface-associated microorganisms characterized by the presence of different cell types in terms of physiology and phenotype [...]

scholarly journals In situ differentiation of iridophore crystallotypes underlies zebrafish stripe patterning

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Dvir Gur ◽  
Emily J. Bain ◽  
Kory R. Johnson ◽  
Andy J. Aman ◽  
H. Amalia Pasoili ◽  
...  
Keyword(s):  
Skin Color ◽  
Cell Types ◽  
Color Pattern ◽  
Single Type ◽  
Sequencing Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cryogenic Scanning Electron Microscopy ◽  
Different Cell Types

AbstractSkin color patterns are ubiquitous in nature, impact social behavior, predator avoidance, and protection from ultraviolet irradiation. A leading model system for vertebrate skin patterning is the zebrafish; its alternating blue stripes and yellow interstripes depend on light-reflecting cells called iridophores. It was suggested that the zebrafish’s color pattern arises from a single type of iridophore migrating differentially to stripes and interstripes. However, here we find that iridophores do not migrate between stripes and interstripes but instead differentiate and proliferate in-place, based on their micro-environment. RNA-sequencing analysis further reveals that stripe and interstripe iridophores have different transcriptomic states, while cryogenic-scanning-electron-microscopy and micro-X-ray diffraction identify different crystal-arrays architectures, indicating that stripe and interstripe iridophores are different cell types. Based on these results, we present an alternative model of skin patterning in zebrafish in which distinct iridophore crystallotypes containing specialized, physiologically responsive, organelles arise in stripe and interstripe by in-situ differentiation.

scholarly journals Extraneous E-Cadherin Engages the Deterministic Process of Somatic Reprogramming through Modulating STAT3 and Erk1/2 Activity

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 284
Author(s):  
Yu-Hao Liu ◽  
Chien-Chang Chen ◽  
Yi-Jen Hsueh ◽  
Li-Man Hung ◽  
David Hui-Kang Ma ◽  
...  
Keyword(s):  
Stochastic Process ◽  
Molecular Mechanism ◽  
Activity Ratio ◽  
Cell Types ◽  
Deterministic Process ◽  
Modes Of Action ◽  
Molecular Events ◽  
Different Cell Types ◽  
Selection Of ◽  
E Cadherin

Although several modes of reprogramming have been reported in different cell types during iPSC induction, the molecular mechanism regarding the selection of different modes of action is still mostly unknown. The present study examined the molecular events that participate in the selection of such processes at the onset of somatic reprogramming. The activity of STAT3 versus that of Erk1/2 reversibly determines the reprogramming mode entered; a lower activity ratio favors the deterministic process and vice versa. Additionally, extraneous E-cadherin facilitates the early events of somatic reprogramming, potentially by stabilizing the LIF/gp130 and EGFR/ErbB2 complexes to promote entry into the deterministic process. Our current findings demonstrated that manipulating the pSTAT3/pErk1/2 activity ratio in the surrounding milieu can drive different modes of action toward either the deterministic or the stochastic process in the context of OSKM-mediated somatic reprogramming.

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