Cellular contacts between hindbrain and prospective ear during inductive interaction in the axolotl embryo

Development ◽  
1981 ◽  
Vol 66 (1) ◽  
pp. 27-41
Author(s):  
Pat G. Model ◽  
Lonny S. Jarrett ◽  
Robin Bonazzoli
Keyword(s):  
Structural Analysis ◽  
Gap Junctions ◽  
Surface Area ◽  
Cell Types ◽  
Cell Interaction ◽  
Ambystoma Mexicanum ◽  
Amphibian Embryo ◽  
Direct Communication ◽  
Inductive Interaction ◽  
Cell Processes

In the amphibian embryo, beginning in the late neurula and continuing through midtailbud stages, the developing medulla exerts an inductive influence on the prospective ear, effecting its determination. Fine structural analysis of the region of closest apposition between the two tissues in the axolotl (Ambystoma mexicanum) reveals that during this period, there is a significant increase in the surface area of the apposed cells through the projection of long finger-like processes that traverse the medulla-ear interspace and the appearance of many focal contacts between the two cell types. These contacts are small, varying in diameter from 10–30 nm and they exhibit the septilaminar appearance and 2–4 nm intercellular cleft characteristic of gap junctions. Once the ear has been determined, both the cell processes and the focal junctions between apposed cells virtually disappear. We suggest that the projection of processes from the surfaces of the apposed cells enhances the opportunity for cell interaction through the formation of very small gap junctions and that the junctions could provide the structural substrate for direct communication between medulla and ear during their inductive interaction.

scholarly journals Topological distribution of two connexin32 antigenic sites in intact and split rodent hepatocyte gap junctions.

1988 ◽  
Vol 107 (5) ◽  
pp. 1817-1824 ◽  
Author(s):  
D A Goodenough ◽  
D L Paul ◽  
L Jesaitis
Keyword(s):  
Amino Acids ◽  
Gap Junctions ◽  
Keyhole Limpet Hemocyanin ◽  
Cell Types ◽  
Cell Interaction ◽  
Amino Acid Sequences ◽  
Membrane Topology ◽  
Cdna Clones ◽  
Cleavage Sites ◽  
Mouse Hepatocyte

The membrane topology of connexin32, a principal polypeptide of gap junctions in diverse cell types, has been studied in rat and mouse hepatocyte gap junctions using site-specific antisera raised against synthetic oligopeptides corresponding to amino acid sequences deduced from cDNA clones. Based on published hydropathicity maps and identified protease-sensitive cleavage sites, oligopeptides were synthesized corresponding to two hydrophilic domains of connexin32, one predicted to face the cytoplasm, the other predicted to be directed extracellularly. Antisera were raised to keyhole limpet hemocyanin conjugates of the oligopeptides and used to map the distribution of their antigens using indirect immunocytochemistry on isolated gap junctions. The results directly demonstrated the cytoplasmic orientation of an antigen contained within amino acids 98-124 of the connexin32 sequence. The extracellular space in intact, isolated gap junctions is too small to permit binding of antibody molecules, necessitating the experimental separation of the junctional membranes to expose their extracellular surfaces using a urea/alkali procedure. While an antigen contained within amino acids 164-189 was visualized on the extracellular surfaces of some of the separated junctional membranes, variability in the observations and in the splitting procedure left ambiguities concerning the biological relevance of the observations after the denaturing conditions necessary to separate the junctional membranes. Using a different approach, however, the antigen could be exposed in intact liver using a hypertonic disaccharide junction-splitting procedure. The period of time of antigen exposure at the cell surface appears to peak at 30 s and disappear by 2-4 min. Taken together, these data demonstrate the extracellular orientation of an antigen contained within amino acids 164-189, which may be involved in cell-cell interaction within the gap junction.

The structure of the gills of the axolotl, Ambystoma mexicanum

1987 ◽  
Vol 45 ◽  
pp. 824-825
Author(s):  
Mohinder S. Jarial
Keyword(s):  
Leydig Cells ◽  
Secretory Granules ◽  
Light And Electron Microscopy ◽  
Cell Types ◽  
Ambystoma Mexicanum ◽  
Basal Cells ◽  
Granular Cells ◽  
Gill Filaments ◽  
Mitotic Figures ◽  
Apical Membranes

The axolotl is a strictly aquatic salamander in which the larval external gills are retained throughout life. The external gills of the adult axolotl have been studied by light and electron microscopy for ultrastructural evidence of ionic transport. The thin epidermis of the gill filaments and gill stems is composed of 3 cell types: granular cells, the basal cells and a sparce population of intervening Leydig cells. The gill epidermis is devoid of muscles, and no mitotic figures were observed in any of its cells.The granular cells cover the gill surface as a continuous layer (Fig. 1, G) and contain secretory granules of different forms, located apically (Figs.1, 2, SG). Some granules are found intimately associated with the apical membrane while others fuse with it and release their contents onto the external surface (Fig. 3). The apical membranes of the granular cells exhibit microvilli which are covered by a PAS+ fuzzy coat, termed “glycocalyx” (Fig. 2, MV).

scholarly journals Exosome Traceability and Cell Source Dependence on Composition and Cell-Cell Cross Talk

2021 ◽  
Vol 22 (10) ◽  
pp. 5346
Author(s):  
Rabab N. Hamzah ◽  
Karrer M. Alghazali ◽  
Alexandru S. Biris ◽  
Robert J. Griffin
Keyword(s):  
Donor Cell ◽  
Average Diameter ◽  
Cell Types ◽  
Cell Interaction ◽  
Target Cells ◽  
Remote Communication ◽  
Normal Cells ◽  
Growth Environment ◽  
Cell Components ◽  
The Impact

Exosomes are small vesicles with an average diameter of 100 nm that are produced by many, if not all, cell types. Exosome cargo includes lipids, proteins, and nucleic acids arranged specifically in the endosomes of donor cells. Exosomes can transfer the donor cell components to target cells and can affect cell signaling, proliferation, and differentiation. Important new information about exosomes’ remote communication with other cells is rapidly being accumulated. Recent data indicates that the results of this communication depend on the donor cell type and the environment of the host cell. In the field of cancer research, major questions remain, such as whether tumor cell exosomes are equally taken up by cancer cells and normal cells and whether exosomes secreted by normal cells are specifically taken up by other normal cells or also tumor cells. Furthermore, we do not know how exosome uptake is made selective, how we can trace exosome uptake selectivity, or what the most appropriate methods are to study exosome uptake and selectivity. This review will explain the effect of exosome source and the impact of the donor cell growth environment on tumor and normal cell interaction and communication. The review will also summarize the methods that have been used to label and trace exosomes to date.

scholarly journals Intercellular calcium signalling between chondrocytes and synovial cells in co-culture

1998 ◽  
Vol 329 (3) ◽  
pp. 681-687 ◽  
Author(s):  
Paola D'ANDREA ◽  
Alessandra CALABRESE ◽  
Micaela GRANDOLFO
Keyword(s):  
Gap Junctions ◽  
Intercellular Communication ◽  
Structural Changes ◽  
Articular Chondrocytes ◽  
Cell Metabolism ◽  
Second Messengers ◽  
Calcium Signalling ◽  
Cell Types ◽  
Synovial Cells ◽  
Cell Coupling

Intercellular communication allows the co-ordination of cell metabolism between tissues as well as sensitivity to extracellular stimuli. Paracrine stimulation and cell-to-cell coupling through gap junctions induce the formation of complex cellular networks that favour the intercellular exchange of nutrients and second messengers. Heterologous intercellular communication was studied in co-cultures of articular chondrocytes and HIG-82 synovial cells by measuring mechanically induced cytosolic changes in Ca2+ ion levels by digital fluorescence video imaging. In confluent co-cultures, mechanical stimulation induced intercellular Ca2+ waves that propagated to both cell types with similar kinetics. Intercellular wave spreading was inhibited by 18α-glycyrrhetinic acid and by treatments inhibiting the activation of purinoreceptors, suggesting that intercellular signalling between these two cell types occurs both through gap junctions and ATP-mediated paracrine stimulation. In rheumatoid arthritis the formation of the synovial pannus induces structural changes at the chondrosynovial junction, where chondrocyte and synovial cells come into close apposition: these results provide the first evidence for direct intercellular communication between these two cell types.

Mesenchymal Stem Cells and Cancer Stem Cells: An Overview of Tumor-Mesenchymal Stem Cell Interaction for therapeutic interventions

2021 ◽  
Vol 22 ◽  
Author(s):  
Soheila Montazersaheb ◽  
Ezzatollah Fathi ◽  
Ayoub Mamandi ◽  
Raheleh Farahzadi ◽  
Hamid Reza Heidari
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Tumor Microenvironment ◽  
Cancer Stem Cells ◽  
Tumor Cells ◽  
Cell Types ◽  
Cell Interaction ◽  
Therapeutic Interventions ◽  
Tumorigenic Potential ◽  
Different Types

: Tumors are made up of different types of cancer cells that contribute to tumor heterogeneity. Among these cells, cancer stem cells (CSCs) have a significant role in the onset of cancer and development. Like other stem cells, CSCs are characterized by the capacity for differentiation and self-renewal. A specific population of CSCs is constituted by mesenchymal stem cells (MSCs) that differentiate into mesoderm-specific cells. The pro-or anti-tumorigenic potential of MSCs on the proliferation and development of tumor cells has been reported as contradictory results. Also, tumor progression is specified by the corresponding tumor cells like the tumor microenvironment. The tumor microenvironment consists of a network of reciprocal cell types such as endothelial cells, immune cells, MSCs, and fibroblasts as well as growth factors, chemokines, and cytokines. In this review, recent findings related to the tumor microenvironment and associated cell populations, homing of MSCs to tumor sites, and interaction of MSCs with tumor cells will be discussed.

Abstract 16504: Low Disturbed Flow Induces Dynamic Immune Compartment Alterations in Atherogenesis as Revealed by Single Cell Rna-seq

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Lili Qu ◽  
Chuan Li ◽  
Alyssa Matz ◽  
Annabelle Rodriguez-Oquendo ◽  
Anthony Vella ◽  
...  
Keyword(s):  
Immune Cell ◽  
Paired Comparison ◽  
Cell Types ◽  
Cell Interaction ◽  
Artery Ligation ◽  
Human Artery ◽  
Disturbed Flow ◽  
Signature Genes ◽  
Sheer Stress ◽  
The Impact

Low disturbed blood flow (LDF) is a critical contributing factor to atherogenesis but its direct impact on the immune compartment was not well-depict. To fill this knowledge gap, we adopted scRNA-seq to capture sheer-stress induced immune responses during atherogenesis. A partial carotid artery ligation (PCAL) model was selected for its paired comparison of carotid arteries with normal flow (NF) or LDF. Indeed, we observed drastic changes in both endothelial and immune compartment. Macrophages were the most significantly increased population induced by LDF (from 4% to 12% of CD45+ cells) with two well-separated subsets (Mac-c8, Mac-c9). MacSpectrum analyses revealed that Mac-c8 displayed higher inflammatory states than the lipid-laden Mac-c9. Interestingly, three T subtypes displayed unique flow-induced enrichment patterns that were selectively enriched in LDF but not in the NF condition. Furthermore, we created an original algorithms to evaluate the impact of sheer-stress on membrane protein-mediated cell-cell interaction among all cell types in the atheroma. Several pairs of molecular interactions were identified, including multiple APP-ligands interaction pairs and those in BAG2 Signaling. Moreover, signature genes identified in these LDF-induced T cells displayed high correlation to the plaque severity in human artery-aorta samples. Collectively, our study provided a high-resolution and focused analyses of sheer-stress induced immune cell action during atherogenesis. This is also the first identification of unique T subsets, to our knowledge, that are enriched in arterial wall exposed to low and disturbed flow. Further characterization of these cells will provide valuable information to understand and therapeutically treat atherogenesis.

scholarly journals Regulatory network characterization in development: challenges and opportunities

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1477
Author(s):  
Guangdun Peng ◽  
Jing-Dong J. Han
Keyword(s):  
Stem Cell ◽  
Cell Fate ◽  
Regulatory Networks ◽  
Stem Cell Differentiation ◽  
Cell Types ◽  
Mammalian Development ◽  
Distinct Cell ◽  
Challenges And Opportunities ◽  
Cell Processes ◽  
Early Mammalian Development

Embryonic development and stem cell differentiation, during which coordinated cell fate specification takes place in a spatial and temporal context, serve as a paradigm for studying the orderly assembly of gene regulatory networks (GRNs) and the fundamental mechanism of GRNs in driving lineage determination. However, knowledge of reliable GRN annotation for dynamic development regulation, particularly for unveiling the complex temporal and spatial architecture of tissue stem cells, remains inadequate. With the advent of single-cell RNA sequencing technology, elucidating GRNs in development and stem cell processes poses both new challenges and unprecedented opportunities. This review takes a snapshot of some of this work and its implication in the regulative nature of early mammalian development and specification of the distinct cell types during embryogenesis.

scholarly journals Distance-dependent adhesion of vascular cells on biofunctionalized nanostructures

2017 ◽  
Vol 3 (2) ◽  
pp. 683-686
Author(s):  
Sarah Biela ◽  
Britta Striegl ◽  
Kerstin Frey ◽  
Joachim P. Spatz ◽  
Ralf Kemkemer
Keyword(s):  
Extracellular Matrix ◽  
Vascular Tissue ◽  
Cell Types ◽  
Cell Interaction ◽  
Vascular Cells ◽  
Cellular Functions ◽  
Ligand Interaction ◽  
Nanostructured Surfaces ◽  
Peptide Motifs ◽  
Cell Cell

AbstractCell-cell and cell-extracellular matrix (ECM) adhesion regulates fundamental cellular functions and is crucial for cell-material contact. Adhesion is influenced by many factors like affinity and specificity of the receptor-ligand interaction or overall ligand concentration and density. To investigate molecular details of cell-ECM and cadherins (cell-cell) interaction in vascular cells functional nanostructured surfaces were used Ligand-functionalized gold nanoparticles (AuNPs) with 6-8 nm diameter, are precisely immobilized on a surface and separated by non-adhesive regions so that individual integrins or cadherins can specifically interact with the ligands on the AuNPs. Using 40 nm and 90 nm distances between the AuNPs and functionalized either with peptide motifs of the extracellular matrix (RGD or REDV) or vascular endothelial-cadherins (VEC), the influence of distance and ligand specificity on spreading and adhesion of endothelial cells (ECs) and smooth muscle cells (SMCs) was investigated. We demonstrate that RGD-dependent adhesion of vascular cells is similar to other cell types and that the distance dependence for integrin binding to ECM-peptides is also valid for the REDV motif. VEC-ligands decrease adhesion significantly on the tested ligand distances. These results may be helpful for future improvements in vascular tissue engineering and for development of implant surfaces.

Transplantation of nuclei of various cell types from neurulae of the Mexican axolotl (Ambystoma mexicanum)

1964 ◽  
Vol 10 (2) ◽  
pp. 233-246 ◽  
Author(s):  
Robert Briggs ◽  
Jacques Signoret ◽  
R.R. Humphrey
Keyword(s):  
Cell Types ◽  
Ambystoma Mexicanum ◽  
Mexican Axolotl

scholarly journals Evidence for two physiologically distinct gap junctions expressed by the chick lens epithelial cell.

1986 ◽  
Vol 102 (1) ◽  
pp. 194-199 ◽  
Author(s):  
T M Miller ◽  
D A Goodenough
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Gap Junctions ◽  
Cell Communication ◽  
Cell Types ◽  
Lens Epithelial Cell ◽  
Dye Transfer ◽  
Fiber Cells ◽  
Junctional Permeability ◽  
Different Cell Types

Lens epithelial cells communicate with two different cell types. They communicate with other epithelial cells via gap junctions on their lateral membranes, and with fiber cells via junctions on their apices. We tested independently these two routes of cell-cell communication to determine if treatment with a 90% CO2-equilibrated medium caused a decrease in junctional permeability; the transfer of fluorescent dye was used as the assay. We found that the high-CO2 treatment blocked intraepithelial dye transfer but not fiber-to-epithelium dye transfer. The lens epithelial cell thus forms at least two physiologically distinct classes of gap junctions.

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