Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The capacities of retinal and pigmented cells to regenerate histotypic in-vitro-retinae (IVR) in rotary culture were investigated by dividing the eye cups of 6-day-old chicken embryos into a central and a peripheral part; they were cut along the ora serrata, and the retinal and the pigmented constituents of both parts were isolated. The 4 dissociated cell populations were cultured separately and in all double combinations. Two different types of IVR's were generated; one developed from central or peripheral retinal cells, the other required the addition of pigmented cells from the ciliary margin of the eye. The shape of these IVR's was examined using scanning electron microscopy, and they were also characterized histologically. The acetylcholinesterase pattern marked the inner half of the retina; F11-antibody and a peanut agglutinin marker revealed both plexiform layers and a radial fiber system. In both types, organized histotypical areas consisted of complete sets of retinal layers. In the type containing pigmented cells from the eye periphery, the sequence of layers was identical with that of an in-situ-retina ("laminar IVR"). In IVR's derived from retinal cells only, the sequence of layers was reversed ("rosetted IVR").
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PMID:Embryonic chicken retinal cells can regenerate all cell layers in vitro, but ciliary pigmented cells induce their correct polarity. 258 75

During chicken neurogenesis, the sequential expression of butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) between final cell proliferation and differentiation is functionally not understood. Recently, cholinesterases have been shown to regulate neurite growth in vitro. Here, we investigated the effects of inhibition of BChE on laminar histogenesis in retinospheroids that arise from dissociated embryonic chicken retinal cells in rotation culture. In the presence of the BChE inhibitor iso-OMPA (tetraisopropyl pyrophosphoramide), the number of spheroids/dish is increased, and their diameter is decreased by about 20%, corresponding to about 50% volume size. As a corollary, the course of histotypical differentiation is dramatically accelerated. Thus as a consequence of BChE inhibition both, organization of nuclear cell layers and of plexiform-like (neuropile) areas, as detected by an antibody to the fiber fasciculation protein F11, is temporally advanced by at least two days. Moreover, AChE is almost fully diminished in these areas. The results further demonstrate novel roles of cholinesterases during laminar histogenesis of coherent neural networks in vitro.
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PMID:Butyrylcholinesterase regulates laminar retinogenesis of the chick embryo in vitro. 795 7

Butyrylcholinesterase (BChE) is a glial cell marker with unknown function. For neuroepithelial cells, BChE has been shown to regulate cell division and expression of the postmitotic marker acetylcholinesterase (AChE), while similar studies are lacking for glial cells. By transducing an antisense-5'BChE cDNA expression vector via calcium phosphate precipitation, we have analyzed the effect of BChE inhibition on proliferation and differentiation of rat oligodendroglia-derived OLN-93 cells. OLN-93 cells were chosen because they are highly proliferative, while expressing markers of differentiated oligodendrocytes (Richter-Landsberg and Heinrich, 1996). First, we established that OLN-93 cells do express BChE protein, albeit chiefly in an inactive state, and that BChE was decreased by antisense-5'BChE transfection. Cell proliferation was also strongly diminished, protein kinase C (PKCalpha) was upregulated, and expression of cytoskeletal and cell surface proteins was altered. In particular, immunoreactivities of the intermediate filament proteins vimentin and the cell adhesion protein F11 were detected, indicating that BChE-inhibited OLN-93 cells have shifted toward an astrocytic phenotype. These data support a role of the glia marker BChE in CNS glial cell proliferation and differentiation, achieved via a nonenzymatic mechanism. The possible biomedical impact of BChE protein, e.g., on CNS nerve regeneration, is briefly discussed.
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PMID:Regulation of the rat oligodendroglia cell line OLN-93 by antisense transfection of butyrylcholinesterase. 1094 Nov 46

We investigated the developmental role of alpha(1-6)-linked fucose, applying Aleuria aurantia lectin to a specific retinal regeneration system. Thereby, dissociated retinal cells of chicken embryos reaggregate, proliferate, and differentiate in vitro into histotypical spheres, so-called retinospheroids. Under the influence of A. aurantia lectin, processes of proliferation, differentiation and histogenesis of retinospheroids were disturbed. Extending these in vitro studies, we here show that A. aurantia lectin treatment decreases cells of the inner half retina and their processes into inner plexiform layer areas, as revealed by quantitative enzyme histochemistry for butyryl- and acetylcholinesterase, and immunohistochemistry using antibodies to acetylcholinesterase, Pax-6, calbindin-D, and F11. Concomitantly, the number of rod and red/green photoreceptors dramatically increases, using the antibodies rho4D2 and CERN901 (both specific for rods) and CERN906 (specific for red/green cones). These findings show that glycoproteins exhibiting fucose in alpha(1-6)-linkage are involved in processes determining retinal cell fate, strongly shifting the relative ratio of cells of the inner towards cells of the outer retina.
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PMID:Inhibition of alpha(1-6)-linked fucose decreases inner retinal cells and increases photoreceptors in chicken retinal reaggregates. 1187 47

Methamidophos resistance and acetylcholinesterase (AChE) insensitivity to methamidophos, dichlorvos, and carbofuran were determined in the field populations of Plutella xylostella (L.) (Lepidoptera: Yponomeutidae) and its parasitoid Cotesia plutellae Kurdjumov (Hymenoptera: Braconidae) collected from the corresponding hosts between October 1998 and December 2003 in Fuzhou and Minhou, Fijian, China. Resistance levels to methamidophos and AChE insensitivity to the three insecticides in the two species of insects were high during autumn and spring and low during summer. Resistance to methamidophos was 15.3- and 12.6-fold higher in resistant F0 parents of P. xylostella and C. plutellae than in their susceptible F11 progeny, respectively. The bimolecular rate constant (k(i)) values of AChE to methamidophos, dichlorvos, and carbofuran were 4.6-, 6.3-, and 7.7-fold higher in F11 progeny of P. xylostella, and 3.7-, 4.5-, and 3.7-fold higher in F11 progeny of C. plutellae than those in their F0 parents, respectively. Compared with susceptible F11 progeny, the resistance ratios for methamidophos were 4.2-29.8 and 3.8-13.1 in 21 field populations of P. xylostella and C. plutellae, respectively. The k(i) values of AChE to methamidophos, dichlorvos, and carbofuran were 2.0-21.6-, 3.6-9.5-, and 2.6-9.2-fold higher in F11 progeny of P. xylostella, and 1.8-7.6-, 1.9-4.6-, and 2.2-7.6-fold higher in F11 progeny of C. plutellae than those in 21 field populations, respectively. Significant correlative variations of methamidophos resistance as well as significant correlative variations of k(i) values of AChE to insecticides between the two species of insects also were found in space and time. The k(i) values of AChE to insecticides in C. plutellae were far higher than those in P. xylostella. There were no obvious differences in the Km and Vmax of AChE between F0 parents and F11 progeny of P. xylostella and C. plutellae, respectively. But carboxylesterase activity was 1.6-fold higher in F0 parents of C. plutellae than in F11 progeny, and glutathione S-transferase activity was 1.5-fold higher in F0 parents of P. xylostella than in F11 progeny. The results suggested that the AChE insensitivity to insecticides might play the most important role in methamidophos resistance in the two species of insects. From these results, a spatial and temporal correlative evolution of methamidophos resistance and insensitive AChE was found to exist between P. xylostella and C. plutellae.
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PMID:Seasonal changes of methamidophos susceptibility and biochemical properties in Plutella xylostella (Lepidoptera: Yponomeutidae) and its parasitoid Cotesia plutellae (Hymenoptera: Braconidae). 1556 61