Genetic characterization of the multipotent dedifferentiated state of pigmented epithelial cells in vitro

Development ◽  
1993 ◽  
Vol 118 (4) ◽  
pp. 1025-1030
Author(s):  
K. Agata ◽  
H. Kobayashi ◽  
Y. Itoh ◽  
M. Mochii ◽  
K. Sawada ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Genetic Characterization ◽  
Pigment Cells ◽  
Intermediate Cell ◽  
Lens Cells ◽  
Myc Gene ◽  
Retinal Pigmented Epithelial Cells ◽  
Testicular Hyaluronidase

Retinal pigmented epithelial cells (PECs) of chicken embryos extensively and almost synchronously transdifferentiate into lens cells in medium containing phenylthiourea and testicular hyaluronidase, passing through the bipotent dedifferentiated state. We have isolated genes that are expressed specifically by either pigment or lens cells and analyzed their expression in the transdifferentiation process. The expression of some proto-oncogenes was also studied. In the dedifferentiation process, expression of the c-myc gene was enhanced and the transcription of PEC-specific genes (MMP115, pP344) was completely repressed. However, transcription of lens-specific genes (alpha-, beta- and delta-crystallins genes) remained silent in dedifferentiated pigment cells. Activation of len- or PEC-specific genes occurred only in conditions permissive for lens or PEC differentiation, respectively. These results indicated that lens transdifferentiation from PECs proceeds through a multipotent (or at least bipotent) intermediate cell state in which the c-myc gene is activated, but neither PEC- nor lens-specific genes are expressed.

scholarly journals Characterization of an in vitro Model of Calcification in Retinal Pigmented Epithelial Cells

2003 ◽  
Vol 10 (1) ◽  
pp. 48-56 ◽  
Author(s):  
Hideki Sugitani ◽  
Hiroshi Wachi ◽  
Hayato Murata ◽  
Fumiaki Sato ◽  
Robert P. Mecham ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Retinal Pigmented Epithelial Cells

scholarly journals Functional and Genomic Characterization of Ligilactobacillus salivarius TUCO-L2 Isolated From Lama glama Milk: A Promising Immunobiotic Strain to Combat Infections

2020 ◽  
Vol 11 ◽  
Author(s):  
Sandra Quilodrán-Vega ◽  
Leonardo Albarracin ◽  
Flavia Mansilla ◽  
Lorena Arce ◽  
Binghui Zhou ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Functional Characterization ◽  
Comparative Genomic ◽  
Cytokines And Chemokines ◽  
Isolation And Characterization ◽  
Intestinal Pathogens ◽  
Lama Glama

Potential probiotic or immunobiotic effects of lactic acid bacteria (LAB) isolated from the milk of the South American camelid llama (Lama glama) have not been reported in published studies. The aim of the present work was to isolate beneficial LAB from llama milk that can be used as potential probiotics active against bacterial pathogens. LAB strains were isolated from llama milk samples. In vitro functional characterization of the strains was performed by evaluating the resistance against gastrointestinal conditions and inhibition of the pathogen growth. Additionally, the adhesive and immunomodulatory properties of the strains were assessed. The functional studies were complemented with a comparative genomic evaluation and in vivo studies in mice. Ligilactobacillus salivarius TUCO-L2 showed enhanced probiotic/immunobiotic potential compared to that of other tested strains. The TUCO-L2 strain was resistant to pH and high bile salt concentrations and demonstrated antimicrobial activity against Gram-negative intestinal pathogens and adhesion to mucins and epithelial cells. L. salivarius TUCO-L2 modulated the innate immune response triggered by Toll-like receptor (TLR)-4 activation in intestinal epithelial cells. This effect involved differential regulation of the expression of inflammatory cytokines and chemokines mediated by the modulation of the negative regulators of the TLR signaling pathway. Moreover, the TUCO-L2 strain enhanced the resistance of mice to Salmonella infection. This is the first report on the isolation and characterization of a potential probiotic/immunobiotic strain from llama milk. The in vitro, in vivo, and in silico investigation performed in this study reveals several research directions that are needed to characterize the TUCO-L2 strain in detail to position this strain as a probiotic or immunobiotic that can be used against infections in humans or animals, including llama.

Genetic characterization of Moniliophthora perniciosa from Ecuador and in vitro sensitivity to compost tea

2019 ◽  
Vol 154 (4) ◽  
pp. 943-959
Author(s):  
María Gabriela Maridueña-Zavala ◽  
Andrea Freire-Peñaherrera ◽  
Rodrigo Fernando Espinoza-Lozano ◽  
Mirian Villavicencio-Vasquez ◽  
Maria Jimenez-Feijoo ◽  
...  
Keyword(s):  
Genetic Characterization ◽  
Compost Tea ◽  
Moniliophthora Perniciosa ◽  
In Vitro Sensitivity

scholarly journals Near infrared light exposure is associated with increased mitochondrial membrane potential in retinal pigmented epithelial cells

2020 ◽  
Vol 19 (10) ◽  
pp. 1455-1459
Author(s):  
Catherine Rono ◽  
Tiffany R Oliver
Keyword(s):  
Membrane Potential ◽  
Epithelial Cells ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Near Infrared ◽  
Light Exposure ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Retinal Pigmented Epithelial Cells

The goal of this study was to characterize the effect of near-infrared light exposure on mitochondrial membrane potential, in vitro.

Acetylcholine induces Ca2+ signaling in chicken retinal pigmented epithelial cells during dedifferentiation

2009 ◽  
Vol 296 (5) ◽  
pp. C1195-C1206 ◽  
Author(s):  
Mariko Sekiguchi-Tonosaki ◽  
Masakatsu Obata ◽  
Akira Haruki ◽  
Toshiyuki Himi ◽  
Jun Kosaka
Keyword(s):  
Epithelial Cells ◽  
Channel Blocker ◽  
Cellular Responses ◽  
Retinal Cell ◽  
Signal Transduction Pathways ◽  
Lens Cells ◽  
Intracellular Ca ◽  
Retinal Pigmented Epithelial Cells ◽  
Cellular Phenotypes ◽  
Dedifferentiation Process

Retinal pigmented epithelial cells exchange their cellular phenotypes into lens cells and neurons, via depigmented and non-epithelial-shaped dedifferentiated intermediates. Because these dedifferentiated cells can either revert to pigmented epithelial cells or transdifferentiate into lens cells and/or neurons, they are recognized as candidates for lens and retinal cell regeneration. The purpose of the present study was to elucidate the signal transduction pathways between chicken retinal pigmented epithelial cells and their dedifferentiated intermediates. We monitored intracellular Ca2+ concentrations using Fluo-4-based Ca2+ optical imaging and focused on cellular responses to the neurotransmitter acetylcholine. Muscarinic Ca2+ mobilization was observed both in retinal pigmented epithelial cells and in dedifferentiated cells, and was inhibited by atropine. The muscarine-dependent acetylcholine response depended on Ca2+ release from intracellular Ca2+ stores, which was completely blocked by thapsigargin. In contrast, the nicotine-dependent acetylcholine response that led to Ca2+ influx through L-type Ca2+ channels was inhibited by α-bungarotoxin and attenuated by nifedipine, and it was detected only in the dedifferentiated intermediates. Application of ( S)-(-)-BayK8644 elevated intracellular Ca2+ both in retinal pigmented epithelial cells and in dedifferentiated intermediates; however, the nicotinic response was not observed in pigmented epithelial cells. Another L-type Ca2+ channel blocker, diltiazem, also blocked the nicotine-dependent acetylcholine response in dedifferentiated cells and maintained the epithelial-like morphology of retinal pigmented epithelial cells. Our results indicate that an alternative acetylcholine signaling pathway is used during the dedifferentiation process of retinal pigmented epithelial cells.

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.

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