1
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Sussman J, Argov Z, Wirguin Y, Apolski S, Milic-Rasic V, Soreq H. Further developments with antisense treatment for myasthenia gravis. Ann N Y Acad Sci 2013; 1275:13-6. [PMID: 23278572 DOI: 10.1111/j.1749-6632.2012.06825.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We present further developments in the study of the antisense oligonucleotide EN101. Ongoing in vitro and in vivo studies demonstrate that EN101 is a TLR9-specific ligand that can suppress pro-inflammatory functions and shift nuclear factor kappa B (NF-κB) from the pro-inflammatory canonical pathway to the anti-inflammatory alternative pathway, which results in decreases acetylcholinesterase (AChE) activity. Preliminary results of a double-blinded phase II cross-over study compared 10, 20, and 40 mg EN101 administered to patients with myasthenia gravis. Patients were randomly assigned to one of three treatment groups in weeks 1, 3, and 5 and received their pretreatment dose of pyridostigmine in weeks 2 and 4. Thus far, all doses show a decrease in QMG scores, with a greater response to higher doses.
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Affiliation(s)
- Jon Sussman
- Greater Manchester Neuroscience Centre, Manchester UK.
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2
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Dori A, Soreq H. Neuromuscular therapeutics by RNA-targeted suppression of ACHE gene expression. Ann N Y Acad Sci 2007; 1082:77-90. [PMID: 17145929 DOI: 10.1196/annals.1348.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
RNA-targeted therapeutics offers inherent advantages over small molecule drugs wherever one out of several splice variant enzymes should be inhibited. Here, we report the use of Monarsen, a 20-mer acetylcholinesterase-targeted antisense agent with three 3'-2'o-methyl-protected nucleotides, for selectively attenuating the stress-induced accumulation of the normally rare, soluble "readthrough" acetylcholinesterase variant AChE-R. Acetylcholine hydrolysis by AChE-R may cause muscle fatigue and moreover, limit the cholinergic anti-inflammatory blockade, yielding inflammation-associated pathology. Specific AChE-R targeting by Monarsen was achieved in cultured cells, experimental animals, and patient volunteers. In rats with experimental autoimmune myasthenia gravis, oral delivery of Monarsen improved muscle action potential in a lower dose regimen (nanomolar versus micromolar), rapid and prolonged manner (up to 72 h versus 2-4 h) as compared with the currently used small molecule anticholinesterases. In central nervous system neurons of both rats and cynomolgus monkeys, systematic Monarsen treatment further suppressed the levels of the proinflammatory cytokines interleukin-1 (IL-1) and IL-6. Toxicology testing and ongoing clinical trials support the notion that Monarsen treatment would offer considerable advantages over conventional cholinesterase inhibitors with respect to dosing, specificity, side effects profile, and duration of efficacy, while raising some open questions regarding its detailed mechanism of action.
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Affiliation(s)
- Amir Dori
- Department of Neurology, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel 84105
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3
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Boneva N, Hamra-Amitay Y, Wirguin I, Brenner T. Stimulated-single fiber electromyography monitoring of anti-sense induced changes in experimental autoimmune myasthenia gravis. Neurosci Res 2006; 55:40-4. [PMID: 16504322 DOI: 10.1016/j.neures.2006.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Revised: 12/28/2005] [Accepted: 01/19/2006] [Indexed: 11/26/2022]
Abstract
The neuromuscular weakness associated with myasthenia gravis (MG) can be transiently relieved by pharmacological inhibitors of acetylcholinesterase (AChE). Here, we expand the anticholinesterase repertoire to include 2'-O-methyl-protected antisense oligonucleotides targeted to AChE mRNA (EN101). Using stimulated-single fiber electromyography, we show that EN101 treatment of rats with experimental autoimmune myasthenia gravis (EAMG), improved the mean consecutive difference (MCD) and blocking for 24h. This treatment was more efficient than pyridostigmine and was accompanied by marked improvement in stamina and clinical profile.
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MESH Headings
- Acetylcholinesterase/genetics
- Animals
- Electric Stimulation/methods
- Electromyography
- Exercise Test/methods
- Female
- Monitoring, Physiologic
- Muscles/drug effects
- Muscles/physiopathology
- Muscles/radiation effects
- Myasthenia Gravis, Autoimmune, Experimental/chemically induced
- Myasthenia Gravis, Autoimmune, Experimental/drug therapy
- Myasthenia Gravis, Autoimmune, Experimental/physiopathology
- Neuromuscular Junction/drug effects
- Neuromuscular Junction/physiopathology
- Neuromuscular Junction/radiation effects
- Oligodeoxyribonucleotides
- Oligonucleotides, Antisense/therapeutic use
- RNA, Messenger/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred Lew
- Receptors, Cholinergic/immunology
- Time Factors
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Affiliation(s)
- Neli Boneva
- Laboratory of Neuroimmunology, Department of Neurology, and the Agnes Ginges Center for Human Neurogenetics, Hadassah University Hospital and Hebrew University Medical School, Jerusalem
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4
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Thullbery MD, Cox HD, Schule T, Thompson CM, George KM. Differential localization of acetylcholinesterase in neuronal and non-neuronal cells. J Cell Biochem 2005; 96:599-610. [PMID: 16052514 PMCID: PMC1853316 DOI: 10.1002/jcb.20530] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Acetylcholinesterase (AChE) expression is regulated in cell types at the transcriptional and translational levels. In this study, we characterized and compared AChE catalytic activity, mRNA, protein expression, and protein localization in a variety of neuronal (SH-SY5Y neuroblastoma and primary cerebellar granule neurons (CGN)) and non-neuronal (LLC-MK2, HeLa, THP-1, and primary astrocytes) cell types. All cell lines expressed AChE catalytic activity; however the levels of AChE-specific activity were higher in neuronal cells than in the non-neuronal cell types. CGN expressed significantly more AChE activity than SH-SY5Y cells. All cell lines analyzed expressed AChE protein at equivalent levels, as well as mRNA splice variants. Localization of AChE was characterized by immunofluorescence and confocal microscopy. SH-SY5Y, CGN, and nerve-growth factor-differentiated PC-12 cells exhibited a pattern of AChE localization characterized as diffuse in the cytoplasm and punctate staining along neurites and on the plasma membrane. The localization in HeLa, LLC-MK2, fibroblasts, and undifferentiated PC-12 cells was significantly different than in neuronal cells-AChE was intensely localized in the perinuclear region, without staining near or on the plasma membrane. Based on the evidence presented here, we hypothesize that the presence of AChE protein doesn't correlate with catalytic activity, and the diffuse cytoplasmic and plasma membrane localization of AChE is a property of neuronal cell types.
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Affiliation(s)
- Matthew D. Thullbery
- Center for Environmental Health Sciences, The University of Montana, Missoula, Montana
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, Montana
| | - Holly D. Cox
- Center for Structural and Functional Neuroscience, The University of Montana, Missoula, Montana
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, Montana
| | - Travis Schule
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, Montana
| | - Charles M. Thompson
- Center for Environmental Health Sciences, The University of Montana, Missoula, Montana
- Center for Structural and Functional Neuroscience, The University of Montana, Missoula, Montana
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, Montana
| | - Kathleen M. George
- Center for Environmental Health Sciences, The University of Montana, Missoula, Montana
- Center for Structural and Functional Neuroscience, The University of Montana, Missoula, Montana
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, Montana
- *Correspondence to: Kathleen M. George, PhD, Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT 59812. E-mail:
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5
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Cruz R, Chávez-Gutiérrez L, Joseph-Bravo P, Charli JL. 3,3',5'-triiodo-L-thyronine reduces efficiency of mRNA knockdown by antisense oligodeoxynucleotides: a study with pyroglutamyl aminopeptidase II in adenohypophysis. Oligonucleotides 2005; 14:176-90. [PMID: 15625913 DOI: 10.1089/oli.2004.14.176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The impact of hormones on the efficacy of antisense oligodeoxynucleotides (ASOs) is a poorly analyzed subject. We designed, based on the identification of potentially favorable local elements of mRNA secondary structure, eight phosphorothioate ASOs to knock down the expression of an ectopeptidase, pyroglutamyl aminopeptidase II (PPII), in primary cultures of adenohypophysis. Two of the PPII ASOs were very efficient, sequence-specific, and target-specific. Because the expression of PPII is upregulated by 3,3',5'-triiodo-L-thyronine (T3), we studied the impact of varying the protocol of PPII induction on the knockdown efficacy. Hormone removal at transfection increased markedly the ability of (1) PPII ASOs to reduce PPII mRNA levels or PPII activity in adenohypophyseal cells or in C6 rat glioma cells and (2) a thyrotropin-releasing hormone (TRH) receptor-1 (TRH-R1) ASO to reduce TRH-R1 mRNA levels in adenohypophyseal cells. There was no effect of hormone removal on transfection efficacy and no correlation between target mRNA levels and ASO efficacy. These data demonstrated that ASO efficacy could depend on T3 levels; this might be due to regulation of a step generally critical for ASO efficiency.
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MESH Headings
- Aminopeptidases/genetics
- Animals
- Cells, Cultured
- Down-Regulation
- Female
- Oligonucleotides, Antisense/antagonists & inhibitors
- Oligonucleotides, Antisense/genetics
- Pituitary Gland, Anterior/drug effects
- Pituitary Gland, Anterior/enzymology
- Pyrrolidonecarboxylic Acid/analogs & derivatives
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptors, Thyrotropin-Releasing Hormone/genetics
- Receptors, Thyrotropin-Releasing Hormone/metabolism
- Triiodothyronine, Reverse/pharmacology
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Affiliation(s)
- Raymundo Cruz
- Departamento de Genetica del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mor., México
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6
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Tang LL, Wang R, Tang XC. Effects of huperzine A on secretion of nerve growth factor in cultured rat cortical astrocytes and neurite outgrowth in rat PC12 cells. Acta Pharmacol Sin 2005; 26:673-8. [PMID: 15916732 DOI: 10.1111/j.1745-7254.2005.00130.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
AIM To study the effects of huperzine A (HupA) on neuritogenic activity and the expression of nerve growth factor (NGF). METHODS After being treated with 10 micromol/L HupA, neurite outgrowth of PC12 cells was observed and counted under phase-contrast microscopy. Mitogenic activity was assayed by [3H]thymidine incorporation. Cell cytotoxicity was evaluated by lactate dehydrogenase (LDH) release. AChE activity, mRNA and protein expression were measured by the Ellman method, RT-PCR, and Western blot, respectively. NGF mRNA and protein levels were determined by RT-PCR and ELISA assays. RESULTS Treatment of PC12 cells with 10 micromol/L HupA for 48 h markedly increased the number of neurite-bearing cells, but caused no significant alteration in cell viability or other signs of cytotoxicity. In addition to inhibiting AChE activity, 10 micromol/L HupA also increased the mRNA and protein levels of this enzyme. In addition, following 2 h exposure of the astrocytes to 10 micromol/L HupA, there was a significant up-regulation of mRNA for NGF and P75 low-affinity NGF receptor. The protein level of NGF was also increased after 24 h treatment with HupA. CONCLUSION Our findings demonstrate for the first time that HupA has a direct or indirect neurotrophic activity, which might be beneficial in treatment of neurodegenerative disorders such as Alzheimer disease.
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Affiliation(s)
- Li-li Tang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, China
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7
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Fischer S, Arad A, Margalit R. Lipsome-formulated enzymes for organophosphate scavenging: Butyrylcholinesterase and Demeton-S. Arch Biochem Biophys 2005; 434:108-15. [PMID: 15629114 DOI: 10.1016/j.abb.2004.10.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2004] [Revised: 10/27/2004] [Indexed: 11/17/2022]
Abstract
Butyrylcholinesterase-encapsulating bioadhesive liposomes are investigated as prophylactic scavengers of organophosphates for local administration to skin, eyes, airways, and lungs-gates through which organophosphates penetrate living systems. The systems were optimized with respect to: encapsulation efficiency; type of bioadhesive ligand bound to liposomes (collagen or hyaluronan); ligand density at the liposomal surface; retention of encapsulated-enzyme activity; protection of encapsulated enzyme from proteolysis; and scavenging the model organophosphate Demeton-S (DS). Monolayers of PC-12 cells were selected for feasibility testing based on: high affinity binding of the bioadhesive liposomes-DeltaG0 release upon binding ranged from -9 to -12 kcal/mol ligand; ability to mimic an organophosphate attack upon intact cells and measuring its impact on intracellular acetylcholinesterase. Under attack, unprotected cells lost 80-90% of intracellular enzyme activity. The loss was reduced to 20-30% for protected cells (pre-treated with the formulations), at the expense of liposomal Butyrylcholinesterase. These results support our prophylactic approach.
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Affiliation(s)
- Sharon Fischer
- Department of Biochemistry, Tel Aviv University, Tel Aviv 69978, Israel
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8
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Brenner T, Hamra-Amitay Y, Evron T, Boneva N, Seidman S, Soreq H. The role of readthrough acetylcholinesterase in the pathophysiology of myasthenia gravis. FASEB J 2003; 17:214-22. [PMID: 12554700 DOI: 10.1096/fj.02-0609com] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Alternative splicing induces, under abnormal cholinergic neurotransmission, overproduction of the rare "readthrough" acetylcholinesterase variant AChE-R. We explored the pathophysiological relevance of this phenomenon in patients with myasthenia gravis (MG) and rats with experimental autoimmune MG (EAMG), neuromuscular junction diseases with depleted acetylcholine receptors. In MG and EAMG, we detected serum AChE-R accumulation. In EAMG, we alleviated electromyographic abnormalities by nanomolar doses of EN101, an antisense oligonucleotide that selectively lowers AChE-R in blood and muscle yet leaves unaffected the synaptic variant AChE-S. Whereas animals treated with placebo or conventional anticholinesterases continued to deteriorate, a 4 wk daily oral administration of EN101 improved survival, neuromuscular strength and clinical status in moribund EAMG rats. The efficacy of targeting only one AChE splicing variant highlights potential advantages of mRNA-targeted therapeutics for chronic cholinergic malfunctioning.
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MESH Headings
- Acetylcholinesterase/genetics
- Acetylcholinesterase/metabolism
- Animals
- Electromyography
- Gene Expression
- Humans
- Mice
- Mice, Inbred Strains
- Mice, Transgenic
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/physiopathology
- Myasthenia Gravis/blood
- Myasthenia Gravis/drug therapy
- Myasthenia Gravis/physiopathology
- Oligodeoxyribonucleotides
- Oligonucleotides, Antisense/pharmacology
- RNA, Messenger/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred Lew
- Receptors, Cholinergic/blood
- Receptors, Cholinergic/genetics
- Receptors, Cholinergic/metabolism
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Affiliation(s)
- Talma Brenner
- Department of Neurology, Hadassah University Hospital and Hebrew University Hadassah Medical School, Jerusalem, Israel 91120
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9
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Abstract
Runx1/AML1, a chromosome 21q22 hematopoietic regulator, is frequently translocated in leukemia. Its protein product, a relatively weak transcriptional activator, becomes an effective transcriptional enhancer or repressor, when co-operating with transcriptional co-activators or co-repressors. Runx1/AML1 association with its partners is disrupted in leukemia. For example, Runx1/AML1 mutations and translocations (e.g. t(8;21), t(12;21) and t(3;21)) impair binding of Runx1/AML1-CBFbeta complexes to Runt motifs in myelopoietically active promoters, preventing normal hematopoiesis. However, Runx1/AML1-associated translocations are not leukemogenic in animal models, suggesting the involvement of yet unidentified regulatory proteins. New candidates are cholinesterases, inhibition of which increases leukemic risk in a manner potentially associated with Runx1/AML1.
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Affiliation(s)
- Chava Perry
- Department of Biological Chemistry, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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10
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Grisaru D, Deutsch V, Shapira M, Pick M, Sternfeld M, Melamed-Book N, Kaufer D, Galyam N, Gait MJ, Owen D, Lessing JB, Eldor A, Soreq H. ARP, A Peptide Derived from the Stress-Associated Acetylcholinesterase Variant, Has Hematopoietic Growth Promoting Activities. Mol Med 2001. [DOI: 10.1007/bf03401943] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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11
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Galyam N, Grisaru D, Grifman M, Melamed-Book N, Eckstein F, Seidman S, Eldor A, Soreq H. Complex host cell responses to antisense suppression of ACHE gene expression. ANTISENSE & NUCLEIC ACID DRUG DEVELOPMENT 2001; 11:51-7. [PMID: 11258621 DOI: 10.1089/108729001750072128] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
3'-End-capped, 20-mer antisense oligodeoxynucleotides (AS-ODN) protected with 2'-O-methyl (Me) or phosphorothioate (PS) substitutions were targeted to acetylcholinesterase (AChE) mRNA and studied in PC12 cells. Me-modified AS-ODN suppressed AChE activity up to 50% at concentrations of 0.02-100 nM. PS-ODN was effective at 1-100 nM. Both AS-ODN displayed progressively decreased efficacy above 10 nM. In situ hybridization and confocal microscopy demonstrated dose-dependent decreases, then increases, in AChE mRNA. Moreover, labeling at nuclear foci suggested facilitated transcription or stabilization of AChE mRNA or both under AS-ODN. Intracellular concentrations of biotinylated oligonucleotide equaled those of target mRNA at extracellular concentrations of 0.02 nM yet increased only 6-fold at 1 microM ODN. Above 50 nM, sequence-independent swelling of cellular, but not nuclear, volume was observed. Our findings demonstrate suppressed AChE expression using extremely low concentrations of AS-ODN and attribute reduced efficacy at higher concentrations to complex host cell feedback responses.
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Affiliation(s)
- N Galyam
- Department of Biological Chemistry, The Institute of Life Sciences, The Hebrew University of Jerusalem, Israel
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12
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Anderson RB, Key B. Role of acetylcholinesterase in the development of axon tracts within the embryonic vertebrate brain. Int J Dev Neurosci 1999; 17:787-93. [PMID: 10593614 DOI: 10.1016/s0736-5748(99)00064-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
In the developing vertebrate brain, acetylcholinesterase (AChE) expression coincides temporally with axon tract formation. Although AChE promotes neurite outgrowth in vitro, the role of this molecule in the development of axon tracts in vivo is unknown. To address this question, we examined the effects of the AChE inhibitor, BW284C51, on the formation of the early scaffold of axon tracts in the embryonic Xenopus brain. In exposed Xenopus brain preparations, axons elongate and establish a normal topography of axon tracts. However, when brains were exposed to BW284C51, the thickness of the major longitudinal axon tract, the tract of the post-optic commissure decreased in a dose-dependent manner. When BW284C51 was removed from the culture media axon tract development returned to normal within 5 h. These findings provide the first evidence for a non-classical role of AChE in the initial formation of axon tracts within the developing vertebrate brain.
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Affiliation(s)
- R B Anderson
- Department of Anatomy and Cell Biology, University of Melbourne, Parkville, Australia
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13
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Grisaru D, Lev-Lehman E, Shapira M, Chaikin E, Lessing JB, Eldor A, Eckstein F, Soreq H. Human osteogenesis involves differentiation-dependent increases in the morphogenically active 3' alternative splicing variant of acetylcholinesterase. Mol Cell Biol 1999; 19:788-95. [PMID: 9858601 PMCID: PMC83935 DOI: 10.1128/mcb.19.1.788] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The extended human acetylcholinesterase (AChE) promoter contains many binding sites for osteogenic factors, including 1,25-(OH)2 vitamin D3 and 17beta-estradiol. In differentiating osteosarcoma Saos-2 cells, both of these factors enhanced transcription of the AChE mRNA variant 3' terminated with exon 6 (E6-AChE mRNA), which encodes the catalytically and morphogenically active E6-AChE isoform. In contrast, antisense oligodeoxynucleotide suppression of E6-AChE mRNA expression increased Saos-2 proliferation in a dose- and sequence-dependent manner. The antisense mechanism of action was most likely mediated by mRNA destruction or translational arrest, as cytochemical staining revealed reduction in AChE gene expression. In vivo, we found that E6-AChE mRNA levels rose following midgestation in normally differentiating, postproliferative fetal chondrocytes but not in the osteogenically impaired chondrocytes of dwarf fetuses with thanatophoric dysplasia. Taken together, these findings suggest morphogenic involvement of E6-AChE in the proliferation-differentiation balance characteristic of human osteogenesis.
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Affiliation(s)
- D Grisaru
- Department of Biological Chemistry, Life Sciences Institute, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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14
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Grifman M, Galyam N, Seidman S, Soreq H. Functional redundancy of acetylcholinesterase and neuroligin in mammalian neuritogenesis. Proc Natl Acad Sci U S A 1998; 95:13935-40. [PMID: 9811904 PMCID: PMC24973 DOI: 10.1073/pnas.95.23.13935] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Accumulated evidence attributes noncatalytic morphogenic activitie(s) to acetylcholinesterase (AChE). Despite sequence homologies, functional overlaps between AChE and catalytically inactive AChE-like cell surface adhesion proteins have been demonstrated only for the Drosophila protein neurotactin. Furthermore, no mechanism had been proposed to enable signal transduction by AChE, an extracellular enzyme. Here, we report impaired neurite outgrowth and loss of neurexin Ialpha mRNA under antisense suppression of AChE in PC12 cells (AS-ACHE cells). Neurite growth was partially rescued by addition of recombinant AChE to the solid substrate or by transfection with various catalytically active and inactive AChE variants. Moreover, overexpression of the homologous neurexin I ligand, neuroligin-1, restored both neurite extension and expression of neurexin Ialpha. Differential PCR display revealed expression of a novel gene, nitzin, in AS-ACHE cells. Nitzin displays 42% homology to the band 4.1 protein superfamily capable of linking integral membrane proteins to the cytoskeleton. Nitzin mRNA is high throughout the developing nervous system, is partially colocalized with AChE, and increases in rescued AS-ACHE cells. Our findings demonstrate redundant neurite growth-promoting activities for AChE and neuroligin and implicate interactions of AChE-like proteins and neurexins as potential mediators of cytoarchitectural changes supporting neuritogenesis.
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Affiliation(s)
- M Grifman
- Department of Biological Chemistry, Institute of Life Sciences, Hebrew University of Jerusalem, 91904, Jerusalem, Israel
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