Cytokeratin expression, fibrillar organization, and subtle function in liver cells

1995 ◽  
Vol 73 (9-10) ◽  
pp. 619-625 ◽  
Author(s):  
Normand Marceau ◽  
Anne Loranger
Keyword(s):  
Epithelial Cells ◽  
Cell Types ◽  
Vital Role ◽  
Hepatic Tissue ◽  
Tight Coupling ◽  
Nonparenchymal Cells ◽  
Experimental Approaches ◽  
And Function ◽  
Parenchymal Cells ◽  
Different Cell Types

Cytokeratins (CKs) constitute a diverse group of intermediate filament (IF) proteins, expressed as pairs in keratinized and nonkeratinizing epithelial cells. Much is known now about the expression, assembly, and function of CKs in keratinized epithelial cells, the main features being the tight coupling between CK pair switch and cell terminal differentiation (protection barrier) and the vital role of CK IFs in cell mechanical integrity. However, the picture about nonkeratinizing epithelia, like the hepatic tissue, remains quite unclear. The liver forms a multicellular system, where parenchymal cells (i.e., hepatocytes) exert diverse metabolic function(s) and nonparenchymal epithelial cells (e.g., biliary epithelial cells) usually serve structural (or accessory) purposes. In terms of differential CK gene expression, the data accumulated so far demonstrated that parenchymal cells can contain as few as one single CK pair, whereas nonparenchymal cells contain more than two CKs, one of them being a representative of those found in epidermis. Moreover, the distribution of the CK IF networks present in the different cell types varies a lot and can often be linked to the cell specialization. However, the function(s) played by these IF proteins in this multicellular tissue remains a major issue. The use of new experimental approaches, largely based on gene transfer technology, indicates that it is quite subtle.Key words: cytokeratins, liver, expression, organization, function(s).

scholarly journals Fractionation of Hepatic Nonparenchymal Cells

2002 ◽  
Vol 2 ◽  
pp. 1347-1350 ◽  
Author(s):  
John Graham
Keyword(s):  
Endothelial Cells ◽  
Stellate Cells ◽  
Cell Types ◽  
Low Density ◽  
Nonparenchymal Cells ◽  
Mammalian Liver ◽  
Hepatic Nonparenchymal Cells ◽  
Density Barrier ◽  
Parenchymal Cells ◽  
Different Cell Types

The majority of parenchymal cells from mammalian liver cells can be removed by very low speed centrifugation (50 g) but a simple low-density barrier (1.096 g/ml) is required to remove the remaining parenchymal cells from the 50-g supernatant which contains all of the lower density nonparenchymal cells. Continuous gradients of Nycodenz®can provide satisfactory resolution of Kupffer, stellate, and endothelial cells on an analytical basis but the separation of different cell types is not sufficient preparatively. Flotation through a low-density iodixanol barrier can, however, provide a satisfactory enrichment of the least dense nonparenchymal cell – the stellate cells.

Cultured epithelial cells derived from human foetal pancreas as a model for the study of cystic fibrosis: further analyses on the origins and nature of the cell types

1988 ◽  
Vol 90 (1) ◽  
pp. 73-77
Author(s):  
A. Harris ◽  
L. Coleman
Keyword(s):  
Cystic Fibrosis ◽  
Tissue Culture ◽  
Epithelial Cells ◽  
Culture System ◽  
Cultured Cells ◽  
Cell Types ◽  
Cultured Epithelial Cells ◽  
Different Cell Types ◽  
Foetal Pancreas

The establishment of a tissue-culture system for epithelial cells derived from human foetal pancreas has recently been reported. Further analyses have now been made on these cells in vitro, together with parallel investigation of the distribution of different cell types within the intact foetal pancreas. Results support the view that the cultured cells are ductal in origin and nature. Pancreatic epithelial cell cultures have also been established from foetuses with cystic fibrosis.

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.

scholarly journals A systems perspective of heterocellular signaling

2018 ◽  
Vol 62 (4) ◽  
pp. 607-617 ◽  
Author(s):  
Alan Wells ◽  
H. Steven Wiley
Keyword(s):  
Cell Types ◽  
Regulatory Processes ◽  
Technical Developments ◽  
Building Models ◽  
Realistic Description ◽  
Multiple Cell ◽  
Solid Foundation ◽  
And Function ◽  
Multicellular Organisms ◽  
Different Cell Types

Signal exchange between different cell types is essential for development and function of multicellular organisms, and its dysregulation is causal in many diseases. Unfortunately, most cell-signaling work has employed single cell types grown under conditions unrelated to their native context. Recent technical developments have started to provide the tools needed to follow signaling between multiple cell types, but gaps in the information they provide have limited their usefulness in building realistic models of heterocellular signaling. Currently, only targeted assays have the necessary sensitivity, selectivity, and spatial resolution to usefully probe heterocellular signaling processes, but these are best used to test specific, mechanistic models. Decades of systems biology research with monocultures has provided a solid foundation for building models of heterocellular signaling, but current models lack a realistic description of regulated proteolysis and the feedback processes triggered within and between cells. Identification and understanding of key regulatory processes in the extracellular environment and of recursive signaling patterns between cells will be essential to building predictive models of heterocellular systems.

scholarly journals Microglia and monocytes in inflammatory CNS disease: integrating phenotype and function

2021 ◽  
Author(s):  
Alanna G. Spiteri ◽  
Claire L. Wishart ◽  
Roger Pamphlett ◽  
Giuseppe Locatelli ◽  
Nicholas J. C. King
Keyword(s):  
Viral Encephalitis ◽  
Neurological Diseases ◽  
Cell Types ◽  
Cell Type ◽  
Neuroinflammatory Disease ◽  
Experimental Systems ◽  
Immune Mediated ◽  
Experimental Approaches ◽  
And Function ◽  
Disease Specific

AbstractIn neurological diseases, the actions of microglia, the resident myeloid cells of the CNS parenchyma, may diverge from, or intersect with, those of recruited monocytes to drive immune-mediated pathology. However, defining the precise roles of each cell type has historically been impeded by the lack of discriminating markers and experimental systems capable of accurately identifying them. Our ability to distinguish microglia from monocytes in neuroinflammation has advanced with single-cell technologies, new markers and drugs that identify and deplete them, respectively. Nevertheless, the focus of individual studies on particular cell types, diseases or experimental approaches has limited our ability to connect phenotype and function more widely and across diverse CNS pathologies. Here, we critically review, tabulate and integrate the disease-specific functions and immune profiles of microglia and monocytes to provide a comprehensive atlas of myeloid responses in viral encephalitis, demyelination, neurodegeneration and ischemic injury. In emphasizing the differential roles of microglia and monocytes in the severe neuroinflammatory disease of viral encephalitis, we connect inflammatory pathways common to equally incapacitating diseases with less severe inflammation. We examine these findings in the context of human studies and highlight the benefits and inherent limitations of animal models that may impede or facilitate clinical translation. This enables us to highlight common and contrasting, non-redundant and often opposing roles of microglia and monocytes in disease that could be targeted therapeutically.

scholarly journals A flagellate-to-amoeboid switch in the closest living relatives of animals

2020 ◽  
Author(s):  
Thibaut Brunet ◽  
Marvin Albert ◽  
William Roman ◽  
Danielle C. Spitzer ◽  
Nicole King
Keyword(s):  
Epithelial Cells ◽  
Common Ancestor ◽  
Cell Types ◽  
Cell Phenotype ◽  
Last Common Ancestor ◽  
Animal Evolution ◽  
Amoeboid Motility ◽  
History Of ◽  
Different Cell Types ◽  
Amoeboid Cells

The evolution of different cell types was a key process of early animal evolution1–3. Two fundamental cell types, epithelial cells and amoeboid cells, are broadly distributed across the animal tree of life4,5 but their origin and early evolution are unclear. Epithelial cells are polarized, have a fixed shape and often bear an apical cilium and microvilli. These features are shared with choanoflagellates – the closest living relatives of animals – and are thought to have been inherited from their last common ancestor with animals1,6,7. The deformable amoeboid cells of animals, on the other hand, seem strikingly different from choanoflagellates and instead evoke more distantly related eukaryotes, such as diverse amoebae – but it has been unclear whether that similarity reflects common ancestry or convergence8. Here, we show that choanoflagellates subjected to spatial confinement differentiate into an amoeboid phenotype by retracting their flagella and microvilli, generating blebs, and activating myosin-based motility. Choanoflagellate cell crawling is polarized by geometrical features of the substrate and allows escape from confined microenvironments. The confinement-induced amoeboid switch is conserved across diverse choanoflagellate species and greatly expands the known phenotypic repertoire of choanoflagellates. The broad phylogenetic distribution of the amoeboid cell phenotype across animals9–14 and choanoflagellates, as well as the conserved role of myosin, suggests that myosin-mediated amoeboid motility was present in the life history of their last common ancestor. Thus, the duality between animal epithelial and crawling cells might have evolved from a temporal phenotypic switch between flagellate and amoeboid forms in their single-celled ancestors3,15,16.

scholarly journals Multiocular organoids from human induced pluripotent stem cells displayed retinal, corneal, and retinal pigment epithelium lineages

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Helena Isla-Magrané ◽  
Anna Veiga ◽  
José García-Arumí ◽  
Anna Duarri
Keyword(s):  
Stem Cells ◽  
Retinal Pigment Epithelium ◽  
Epithelial Cells ◽  
Pluripotent Stem Cells ◽  
Eye Development ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Cell Types ◽  
Induced Pluripotent ◽  
Different Cell Types

Abstract Background Recently, great efforts have been made to design protocols for obtaining ocular cells from human stem cells to model diseases or for regenerative purposes. Current protocols generally focus on isolating retinal cells, retinal pigment epithelium (RPE), or corneal cells and fail to recapitulate the complexity of the tissue during eye development. Here, the generation of more advanced in vitro multiocular organoids from human induced pluripotent stem cells (hiPSCs) is demonstrated. Methods A 2-step method was established to first obtain self-organized multizone ocular progenitor cells (mzOPCs) from 2D hiPSC cultures within three weeks. Then, after the cells were manually isolated and grown in suspension, 3D multiocular organoids were generated to model important cellular features of developing eyes. Results In the 2D culture, self-formed mzOPCs spanned the neuroectoderm, surface ectoderm, neural crest, and RPE, mimicking early stages of eye development. After lifting, mzOPCs developed into different 3D multiocular organoids composed of multiple cell lineages including RPE, retina, and cornea, and interactions between the different cell types and regions of the eye system were observed. Within these organoids, the retinal regions exhibited correct layering and contained all major retinal cell subtypes as well as retinal morphological cues, whereas the corneal regions closely resembled the transparent ocular-surface epithelium and contained of corneal, limbal, and conjunctival epithelial cells. The arrangement of RPE cells also formed organoids composed of polarized pigmented epithelial cells at the surface that were completely filled with collagen matrix. Conclusions This approach clearly demonstrated the advantages of the combined 2D-3D construction tissue model as it provided a more ocular native-like cellular environment than that of previous models. In this complex preparations, multiocular organoids may be used to model the crosstalk between different cell types in eye development and disease. Graphical abstract

scholarly journals Comprehensive Transcriptomic Analysis Identifies Novel Antiviral Factors Against Influenza A Virus Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Ao Zhou ◽  
Xia Dong ◽  
Mengyun Liu ◽  
Bin Tang
Keyword(s):  
Epithelial Cells ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Broad Spectrum ◽  
Influenza A ◽  
Cell Types ◽  
Immune Defense ◽  
Host Responses ◽  
Different Cell Types ◽  
Host Genes

Influenza A virus (IAV) has a higher genetic variation, leading to the poor efficiency of traditional vaccine and antiviral strategies targeting viral proteins. Therefore, developing broad-spectrum antiviral treatments is particularly important. Host responses to IAV infection provide a promising approach to identify antiviral factors involved in virus infection as potential molecular drug targets. In this study, in order to better illustrate the molecular mechanism of host responses to IAV and develop broad-spectrum antiviral drugs, we systematically analyzed mRNA expression profiles of host genes in a variety of human cells, including transformed and primary epithelial cells infected with different subtypes of IAV by mining 35 microarray datasets from the GEO database. The transcriptomic results showed that IAV infection resulted in the difference in expression of amounts of host genes in all cell types, especially those genes participating in immune defense and antiviral response. In addition, following the criteria of P<0.05 and |logFC|≥1.5, we found that some difference expression genes were overlapped in different cell types under IAV infection via integrative gene network analysis. IFI6, IFIT2, ISG15, HERC5, RSAD2, GBP1, IFIT3, IFITM1, LAMP3, USP18, and CXCL10 might act as key antiviral factors in alveolar basal epithelial cells against IAV infection, while BATF2, CXCL10, IFI44L, IL6, and OAS2 played important roles in airway epithelial cells in response to different subtypes of IAV infection. Additionally, we also revealed that some overlaps (BATF2, IFI44L, IFI44, HERC5, CXCL10, OAS2, IFIT3, USP18, OAS1, IFIT2) were commonly upregulated in human primary epithelial cells infected with high or low pathogenicity IAV. Moreover, there were similar defense responses activated by IAV infection, including the interferon-regulated signaling pathway in different phagocyte types, although the differentially expressed genes in different phagocyte types showed a great difference. Taken together, our findings will help better understand the fundamental patterns of molecular responses induced by highly or lowly pathogenic IAV, and the overlapped genes upregulated by IAV in different cell types may act as early detection markers or broad-spectrum antiviral targets.

scholarly journals Neonatal Fc receptor (FcRn) – not only transporter of maternal IgG

2018 ◽  
Vol 72 ◽  
pp. 701-727
Author(s):  
Joanna E. Mikulska
Keyword(s):  
Mhc Class I ◽  
Current Knowledge ◽  
Cell Types ◽  
Fc Receptor ◽  
Class I ◽  
Neonatal Fc Receptor ◽  
The Status ◽  
And Function ◽  
Different Cell Types ◽  
Maternal Igg

The neonatal Fc receptor, (FcRn) is a transmembrane, heterodimeric glycoprotein with a structure similar to MHC class I molecules. In contrast to MHC class I antigens, FcRn does not bind to peptides (antigens) but interacts with the Fc fragment of IgG and albumin. The FcRn-IgG interaction as well as the FcRn-albumin interaction occur at acidic pH (optimally at pH 5.0-6.5) but not in physiological environment. These two ligands bind to distinct binding sites on the receptor molecule and by different mechanisms. Now, it is known that the expression of FcRn is not restricted to sites involved in the transport of maternal IgG, and this receptor is not responsible only for transfer the passive immunity from mother to the offspring. But FcRn has a much broader range of expression and function, throughout life and in many different cell types and tissues of humans and animals. This review summarizes the status of our knowledge on the expression, interaction with ligands and functions of the neonatal Fc receptor. This article shows also the possibilities of utilizing a current knowledge on FcRn for therapeutic purposes.

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