Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.8 (cholinesterase)
 12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously shown that the P19 line of embryonal carcinoma cells develops into neurons, astroglia, and fibroblasts after aggregation and exposure to retinoic acid. The neurons were initially identified by their morphology and by the presence of neurofilaments within their cytoplasm. We have more fully documented the neuronal nature of these cells by showing that their cell surfaces display tetanus toxin receptors, a neuronal cell marker, and that choline acetyl-transferase and acetyl cholinesterase activities appear coordinately in neuron-containing cultures. Several days before the appearance of neurons, there is a marked decrease in the amount of an embryonal carcinoma surface antigen, and at the same time there is a substantial decrease in the volumes of individual cells. Various retinoids were able to induce the development of neurons in cultures of aggregated P19 cells, but it did not appear that polyamine metabolism was involved in the effect. We have isolated a mutant clone which does not differentiate in the presence of any of the drugs which are normally effective in inducing differentiation of P19 cells. This mutant and others may help to elucidate the chain of events triggered by retinoic acid and other differentiation-inducing drugs.
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PMID:Retinoic acid-induced neural differentiation of embryonal carcinoma cells. 665 66

P19 is a mouse-derived embryonal carcinoma cell-line capable of differentiation toward ectodermal, mesodermal and endodermal lineages. Following treatment with retinoic acid these cells differentiate into neurons, astrocytes and fibroblast-like cells. We induced P19 differentiation under conditions which lead to a homogeneous neuronal culture (> 95% neurons). Under these conditions, most cells (approximately 85%) express high levels of the cholinergic markers acetyl cholinesterase and choline acetyltransferase while approximately 10% of cells express the GABAergic marker glutamic acid decarboxylase. While the proportion of the GABAergic neurons is constant at different culture conditions, the cholinergic phenotype is suppressed at high cell densities. The cholinergic nature of P19 neurons is also evident in their ability to form contacts with a muscle cell-line--C2. At day 10 of differentiation cells are capable of depolarization-dependent acetylcholine release. The release is Ca2+ dependent, and drops to baseline levels at 0.5 mM Ca2+. The cells also respond to sub-nM levels of alpha-latrotoxin by acetylcholine release. All major proteins implicated in synapse functionality are expressed prior to day 10 at both at RNA and protein levels. However, the expression pattern of each gene is unique. The genes include cytoskeletal proteins, synaptic vesicle proteins and terminal specific proteins. We suggest that this cell-line can serve as an in-vitro model system for the study of neuronal phenotype acquisition. Under our conditions, the P19 cells can also provide a system in which to study the differentiation of functional cholinergic neurons.
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PMID:Cholinergic properties of neurons differentiated from an embryonal carcinoma cell-line (P19). 878 67

The P19 embryonal carcinoma cells differentiate into neurons, astrocytes, and fibroblast-like cells following induction with retinoic acid. The cells mature into functional neurons, as determined by their ability to release neurotransmitters in a Ca(2+)- and depolarization-dependent manner. P19 neurons in culture represent a mixed population in terms of their neurotransmitter phenotype. The cholinergic phenotype of these neurons is modulated by culture density. Cholinergic markers, such as the vesicular acetylcholine transporter, acetyl cholinesterase, and choline acetyltransferase, are expressed in about 85% of the cells in sparse cultures and are largely suppressed at high cell densities. In contrast, glutamate release is enhanced in dense P19 neuronal cultures. The factor mediating the density effect is concentrated exclusively on the cell membrane of P19 neurons and not on the nonneuronal cells, which also differentiate from P19 embryonal carcinoma cells. This membrane-associated component retains its functionality, even after membrane fixation. The downregulation of the cholinergic properties in dense cultures is paralleled by a downregulation of the alpha subunit of the ciliary neurotrophic factor (CNTF) receptor. Thus, it is suggested that the membrane-associated factor, which mediates the density effect, downregulates the cholinergic phenotype by inhibiting the responsiveness of these neurons to CNTF. We further suggest that the P19 cell line can serve as a model system for the study of neurotransmitter phenotype acquisition and plasticity throughout neuronal differentiation.
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PMID:Culture density regulates both the cholinergic phenotype and the expression of the CNTF receptor in P19 neurons. 918 41