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Hampl M, Jandová N, Lusková D, Nováková M, Szotkowská T, Čada Š, Procházka J, Kohoutek J, Buchtová M. Early embryogenesis in CHDFIDD mouse model reveals facial clefts and altered cranial neurogenesis. Dis Model Mech 2024; 17:dmm050261. [PMID: 38511331 PMCID: PMC11212636 DOI: 10.1242/dmm.050261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 03/12/2024] [Indexed: 03/22/2024] Open
Abstract
CDK13-related disorder, also known as congenital heart defects, dysmorphic facial features and intellectual developmental disorder (CHDFIDD) is associated with mutations in the CDK13 gene encoding transcription-regulating cyclin-dependent kinase 13 (CDK13). Here, we focused on the development of craniofacial structures and analyzed early embryonic stages in CHDFIDD mouse models, with one model comprising a hypomorphic mutation in Cdk13 and exhibiting cleft lip/palate, and another model comprising knockout of Cdk13, featuring a stronger phenotype including midfacial cleft. Cdk13 was found to be physiologically expressed at high levels in the mouse embryonic craniofacial structures, namely in the forebrain, nasal epithelium and maxillary mesenchyme. We also uncovered that Cdk13 deficiency leads to development of hypoplastic branches of the trigeminal nerve including the maxillary branch. Additionally, we detected significant changes in the expression levels of genes involved in neurogenesis (Ache, Dcx, Mef2c, Neurog1, Ntn1, Pou4f1) within the developing palatal shelves. These results, together with changes in the expression pattern of other key face-specific genes (Fgf8, Foxd1, Msx1, Meis2 and Shh) at early stages in Cdk13 mutant embryos, demonstrate a key role of CDK13 in the regulation of craniofacial morphogenesis.
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Affiliation(s)
- Marek Hampl
- Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, 60200 Brno, Czech Republic
- Department of Experimental Biology, Faculty of Science, Masaryk University, 60200 Brno, Czech Republic
| | - Nela Jandová
- Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, 60200 Brno, Czech Republic
- Department of Experimental Biology, Faculty of Science, Masaryk University, 60200 Brno, Czech Republic
| | - Denisa Lusková
- Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, 60200 Brno, Czech Republic
| | - Monika Nováková
- Department of Chemistry and Toxicology, Veterinary Research Institute, 62100 Brno, Czech Republic
| | - Tereza Szotkowská
- Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, 60200 Brno, Czech Republic
| | - Štěpán Čada
- Department of Experimental Biology, Faculty of Science, Masaryk University, 60200 Brno, Czech Republic
| | - Jan Procházka
- Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics, Czech Academy of Sciences, 14220 Prague, Czech Republic
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, 14220 Prague, Czech Republic
| | - Jiri Kohoutek
- Department of Experimental Biology, Faculty of Science, Masaryk University, 60200 Brno, Czech Republic
| | - Marcela Buchtová
- Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, 60200 Brno, Czech Republic
- Department of Experimental Biology, Faculty of Science, Masaryk University, 60200 Brno, Czech Republic
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Silencing of multiple target genes via ingestion of dsRNA and PMRi affects development and survival in Helicoverpa armigera. Sci Rep 2022; 12:10405. [PMID: 35729318 PMCID: PMC9213516 DOI: 10.1038/s41598-022-14667-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 06/10/2022] [Indexed: 11/15/2022] Open
Abstract
RNA interference (RNAi) triggered by exogenous double-stranded RNA (dsRNA) is a powerful tool to knockdown genetic targets crucial for the growth and development of agriculturally important insect pests. Helicoverpa armigera is a pest feeding on more than 30 economically important crops worldwide and a major threat. Resistance to insecticides and Bt toxins has been gradually increasing in the field. RNAi-mediated knockdown of H. armigera genes by producing dsRNAs homologous to genetic targets in bacteria and plants has a high potential for insect management to decrease agricultural loss. The acetylcholinesterase (AChE), ecdysone receptor (EcR) and v-ATPase-A (vAA) genes were selected as genetic targets. Fragments comprising a coding sequence of < 500 bp were cloned into the L4440 vector for dsRNA production in bacteria and in a TRV-VIGS vector in antisense orientation for transient expression of dsRNA in Solanum tuberosum leaves. After ingesting bacterial-expressed dsRNA, the mRNA levels of the target genes were significantly reduced, leading to mortality and abnormal development in larva of H. armigera. Furthermore, the S. tuberosum plants transformed with TRV-VIGS expressing AChE exhibited higher mortality > 68% than the control plants 17%, recorded ten days post-feeding and significant resistance in transgenic (transient) plants was observed. Moreover, larval lethality and molting defects were observed in larva fed on potato plants expressing dsRNA specific to EcR. Analysis of transcript levels by quantitative RT–PCR revealed that larval mortality was attributable to the knockdown of genetic targets by RNAi. The results demonstrated that down-regulation of H. armigera genes involved in ATP hydrolysis, transcriptional stimulation of development genes and neural conduction has aptitude as a bioinsecticide to control H. armigera population sizes and therefore decreases crop loss.
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Damián JP, Vázquez Alberdi L, Canclini L, Rosso G, Bravo SO, Martínez M, Uriarte N, Ruiz P, Calero M, Di Tomaso MV, Kun A. Central Alteration in Peripheral Neuropathy of Trembler-J Mice: Hippocampal pmp22 Expression and Behavioral Profile in Anxiety Tests. Biomolecules 2021; 11:biom11040601. [PMID: 33921657 PMCID: PMC8074002 DOI: 10.3390/biom11040601] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/15/2021] [Accepted: 04/15/2021] [Indexed: 12/14/2022] Open
Abstract
Charcot–Marie–Tooth (CMT) type 1 disease is the most common human hereditary demyelinating neuropathy. Mutations in pmp22 cause about 70% of all CMT1. Trembler-J (TrJ/+) mice are an animal model of CMT1E, having the same spontaneous pmp22 mutation that is found in humans. We compared the behavior profile of TrJ/+ and +/+ (wild-type) in open-field and elevated-plus-maze anxiety tests. In these tests, TrJ/+ showed an exclusive head shake movement, a lower frequency of rearing, but a greater frequency of grooming. In elevated-plus-maze, TrJ/+ defecate more frequently, performed fewer total entries, and have fewer entries to closed arms. These hippocampus-associated behaviors in TrJ/+ are consistent with increased anxiety levels. The expression of pmp22 and soluble PMP22 were evaluated in E17-hippocampal neurons and adult hippocampus by in situ hybridization and successive immunohistochemistry. Likewise, the expression of pmp22 was confirmed by RT-qPCR in the entire isolated hippocampi of both genotypes. Moreover, the presence of aggregated PMP22 was evidenced in unmasked granular hippocampal adult neurons and shows genotypic differences. We showed for the first time a behavior profile trait associated with anxiety and a differential expression of pmp22/PMP22 in hippocampal neurons of TrJ/+ and +/+ mice, demonstrating the involvement at the central level in an animal model of peripheral neuropathy (CMT1E).
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Affiliation(s)
- Juan Pablo Damián
- Unidad de Bioquímica, Departamento de Biociencias Veterinarias, Facultad de Veterinaria, Universidad de la República, 11600 Montevideo, Uruguay;
| | - Lucia Vázquez Alberdi
- Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay; (L.V.A.); (M.M.)
| | - Lucía Canclini
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay; (L.C.); (M.V.D.T.)
| | - Gonzalo Rosso
- Max Planck Institute for the Science of Light, Max-Planck-Zentrum für Physik und Medizin, 91058 Erlangen, Germany;
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Silvia Olivera Bravo
- Neurobiología Celular y Molecular, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay;
| | - Mariana Martínez
- Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay; (L.V.A.); (M.M.)
| | - Natalia Uriarte
- Laboratorio de Neurociencias, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay;
| | - Paul Ruiz
- Unidad de Biofísica, Departamento de Biociencias Veterinarias, Facultad de Veterinaria, Universidad de la República, 11600 Montevideo, Uruguay;
| | - Miguel Calero
- Unidad de Encefalopatías Espongiformes, UFIEC, CIBERNED, CIEN Foundation, Queen Sofia Foundation Alzheimer Center, Instituto de Salud Carlos III, 28031 Madrid, Spain;
| | - María Vittoria Di Tomaso
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay; (L.C.); (M.V.D.T.)
| | - Alejandra Kun
- Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay; (L.V.A.); (M.M.)
- Sección Bioquímica, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay
- Correspondence: ; Tel.: +598-2487-1616; Fax: +598-2487-5461
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The multiple biological roles of the cholinesterases. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 162:41-56. [PMID: 33307019 DOI: 10.1016/j.pbiomolbio.2020.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 11/30/2020] [Accepted: 12/03/2020] [Indexed: 12/14/2022]
Abstract
It is tacitly assumed that the biological role of acetylcholinesterase is termination of synaptic transmission at cholinergic synapses. However, together with its structural homolog, butyrylcholinesterase, it is widely distributed both within and outside the nervous system, and, in many cases, the role of both enzymes remains obscure. The transient appearance of the cholinesterases in embryonic tissues is especially enigmatic. The two enzymes' extra-synaptic roles, which are known as 'non-classical' roles, are the topic of this review. Strong evidence has been presented that AChE and BChE play morphogenetic roles in a variety of eukaryotic systems, and they do so either by acting as adhesion proteins, or as trophic factors. As trophic factors, one mode of action is to directly regulate morphogenesis, such as neurite outgrowth, by poorly understood mechanisms. The other mode is by regulating levels of acetylcholine, which acts as the direct trophic factor. Alternate substrates have been sought for the cholinesterases. Quite recently, it was shown that levels of the aggression hormone, ghrelin, which also controls appetite, are regulated by butyrylcholinesterase. The rapid hydrolysis of acetylcholine by acetylcholinesterase generates high local proton concentrations. The possible biophysical and biological consequences of this effect are discussed. The biological significance of the acetylcholinesterases secreted by parasitic nematodes is reviewed, and, finally, the involvement of acetylcholinesterase in apoptosis is considered.
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Catae AF, da Silva Menegasso AR, Pratavieira M, Palma MS, Malaspina O, Roat TC. MALDI-imaging analyses of honeybee brains exposed to a neonicotinoid insecticide. PEST MANAGEMENT SCIENCE 2019; 75:607-615. [PMID: 30393944 DOI: 10.1002/ps.5226] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/27/2018] [Accepted: 09/26/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Toxicological studies evaluating the possible harmful effects of pesticides on bees are important and allow the emergence of protection and pollinator conservation strategies. This study aimed to evaluate the effects of exposure to a sublethal concentration of imidacloprid (LC50/100 : 0.014651 ng imidacloprid µL-1 diet) on the distribution of certain proteins identified in the brain of Apis mellifera worker bees using a MALDI-imaging approach. This technique enables proteomic analysis of tissues in situ by monitoring the spatiotemporal dynamics of the biochemical processes occurring at a specific time in specific brain neuropils. For this purpose, foraging bees were exposed to an 8-day diet containing a sublethal concentration of imidacloprid corresponding to the LC50/100 . Bees were collected on day 8 of exposure, and their brains analyzed using protein density maps. RESULTS The results showed that exposure to imidacloprid led to a series of biochemical changes, including alterations in synapse regulation, apoptosis regulation and oxidative stress, which may adversely impair the physiology of these colony bees. CONCLUSION Worker bee contact with even tiny amounts of imidacloprid had potent effects leading to the overexpression of a series of proteins related to important cellular processes that were possibly damaged by the insecticide. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Aline F Catae
- Center of the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Anally R da Silva Menegasso
- Center of the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Marcel Pratavieira
- Center of the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Mario S Palma
- Center of the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Osmar Malaspina
- Center of the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Thaisa C Roat
- Center of the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, São Paulo State University (UNESP), Rio Claro, Brazil
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Sabbir MG, Fernyhough P. Muscarinic receptor antagonists activate ERK-CREB signaling to augment neurite outgrowth of adult sensory neurons. Neuropharmacology 2018; 143:268-281. [PMID: 30248305 DOI: 10.1016/j.neuropharm.2018.09.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 08/09/2018] [Accepted: 09/12/2018] [Indexed: 01/09/2023]
Abstract
A major cellular effector activated by G protein coupled receptors is extracellular signal-regulated kinase (ERK). The ERK signaling cascade regulates a variety of cellular processes including growth and proliferation. Both G protein and β-arrestin-mediated signaling lead to ERK activation by phosphorylation through different kinases. Recently, we have shown muscarinic acetylcholine type 1 receptor (M1R) antagonists, muscarinic toxin 7 (MT7) and pirenzepine, elevated neurite outgrowth and protected from small and large fiber neuropathy in adult sensory neurons in various animal models. Thus, we tested the novel hypothesis that muscarinic antagonists could drive neurite outgrowth through altered M1R-ERK signaling. We have used two dimensional isoelectric focusing/SDS-PAGE combined with analysis using multiple phospho-epitope specific antibodies to study ERK1/2 phosphorylation and activation of its downstream nuclear effector cyclic response element binding protein (CREB). Activated CREB is known to exhibit neuroprotective and growth promoting effects. One hour of treatment with MT7 and pirenzepine activated ERK through M1R and induced a significant increase in levels of pCREB(S133) in cultured sensory neurons. Further, pharmacological blockade or siRNA based knockdown of ERK abolished the MT7 and pirenzepine mediated neuritogenic effect. In addition, we have shown drug-induced alterations of charged protein fractions that may possess additional post-translationally modified forms of ERK and CREB. For the first time we show that long-term treatment, e.g. 1 h, with muscarinic antagonists selective or specific for M1R can activate a biased β-arrestin dependent ERK-CREB signal cascade. Our study gives novel insight into muscarinic antagonist-mediated modulation of M1R-ERK-CREB signaling which could be exploited for therapy in neuropathic diseases.
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Affiliation(s)
- Mohammad Golam Sabbir
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, R2H 2A6, Canada.
| | - Paul Fernyhough
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, R2H 2A6, Canada; Dept of Pharmacology & Therapeutics, University of Manitoba, MB, R3T 2N2, Canada.
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7
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Kim YH, Kim JH, Kim K, Lee SH. Expression of acetylcholinesterase 1 is associated with brood rearing status in the honey bee, Apis mellifera. Sci Rep 2017; 7:39864. [PMID: 28045085 PMCID: PMC5206625 DOI: 10.1038/srep39864] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 11/28/2016] [Indexed: 12/16/2022] Open
Abstract
Acetylcholinesterase 1 (AmAChE1) of the honey bee, Apis mellifera, has been suggested to have non-neuronal functions. A systematic expression profiling of AmAChE1 over a year-long cycle on a monthly basis revealed that AmAChE1 was predominantly expressed in both head and abdomen during the winter months and was moderately expressed during the rainy summer months. Interestingly, AmAChE1 expression was inhibited when bees were stimulated for brood rearing by placing overwintering beehives in strawberry greenhouses with a pollen diet, whereas it resumed when the beehives were moved back to the cold field, thereby suppressing brood rearing. In early spring, pollen diet supplementation accelerated the induction of brood-rearing activity and the inhibition of AmAChE1 expression. When active beehives were placed in a screen tent in late spring, thereby artificially suppressing brood-rearing activity, AmAChE1 was highly expressed. In contrast, AmAChE1 expression was inhibited when beehives were allowed to restore brood rearing by removing the screen, supporting the hypothesis that brood rearing status is a main factor in the regulation of AmAChE1 expression. Since brood rearing status is influenced by various stress factors, including temperature and diet shortage, our finding discreetly suggests that AmAChE1 is likely involved in the stress response or stress management.
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Affiliation(s)
- Young Ho Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea.,Department of Applied Biology, Kyungpook National University, Sangju, Korea
| | - Ju Hyeon Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea.,Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA, USA
| | - Kyungmun Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
| | - Si Hyeock Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea.,Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
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Malik HJ, Raza A, Amin I, Scheffler JA, Scheffler BE, Brown JK, Mansoor S. RNAi-mediated mortality of the whitefly through transgenic expression of double-stranded RNA homologous to acetylcholinesterase and ecdysone receptor in tobacco plants. Sci Rep 2016; 6:38469. [PMID: 27929123 PMCID: PMC5143975 DOI: 10.1038/srep38469] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 11/10/2016] [Indexed: 01/09/2023] Open
Abstract
The whitefly Bemisia tabaci (Genn.) is a pest and vector of plant viruses to crop and ornamental plants worldwide. Using RNA interference (RNAi) to down regulate whitefly genes by expressing their homologous double stranded RNAs in plants has great potential for management of whiteflies to reduce plant virus disease spread. Using a Tobacco rattle virus-derived plasmid for in planta transient expression of double stranded RNA (dsRNA) homologous to the acetylcholinesterase (AChE) and ecdysone receptor (EcR) genes of B. tabaci, resulted in significant adult whitefly mortality. Nicotiana tabacum L. plants expressing dsRNA homologous to B. tabaci AChE and EcR were constructed by fusing sequences derived from both genes. Mortality of adult whiteflies exposed to dsRNA by feeding on N. tabacum plants, compared to non-dsRNA expressing plants, recorded at 24-hr intervals post-ingestion for three days, was >90% and 10%, respectively. Analysis of gene expression by real time quantitative PCR indicated that whitefly mortality was attributable to the down-regulation of both target genes by RNAi. Results indicated that knock down of whitefly genes involved in neuronal transmission and transcriptional activation of developmental genes, has potential as a bio-pesticide to reduce whitefly population size and thereby decrease virus spread.
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Affiliation(s)
- Hassan Jamil Malik
- Molecular Virology and Gene Silencing Laboratory, Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, PO Box #577, Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Amir Raza
- Molecular Virology and Gene Silencing Laboratory, Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, PO Box #577, Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Imran Amin
- Molecular Virology and Gene Silencing Laboratory, Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, PO Box #577, Faisalabad, Pakistan
| | - Jodi A. Scheffler
- USDA-ARS, Crop Genetics Research Unit, 141 Experiment Station Rd, Stoneville, MS 38776, USA
| | - Brian E. Scheffler
- USDA-ARS, Genomics and Bioinformatics Research Unit, 141 Experiment Station Rd, Stoneville, MS 38776, USA
| | - Judith K. Brown
- School of Plant Sciences, The University of Arizona, Tucson, AZ 85721, USA
| | - Shahid Mansoor
- Molecular Virology and Gene Silencing Laboratory, Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, PO Box #577, Faisalabad, Pakistan
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Duan JJ, Lozada AF, Gou CY, Xu J, Chen Y, Berg DK. Nicotine recruits glutamate receptors to postsynaptic sites. Mol Cell Neurosci 2015; 68:340-9. [PMID: 26365992 DOI: 10.1016/j.mcn.2015.09.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/04/2015] [Accepted: 09/07/2015] [Indexed: 01/20/2023] Open
Abstract
Cholinergic neurons project throughout the nervous system and activate nicotinic receptors to modulate synaptic function in ways that shape higher order brain function. The acute effects of nicotinic signaling on long-term synaptic plasticity have been well-characterized. Less well understood is how chronic exposure to low levels of nicotine, such as those encountered by habitual smokers, can alter neural connections to promote addiction and other lasting behavioral effects. We show here that chronic exposure of hippocampal neurons in culture to low levels of nicotine recruits AMPA and NMDA receptors to the cell surface and sequesters them at postsynaptic sites. The receptors include GluA2-containing AMPA receptors, which are responsible for most of the excitatory postsynaptic current mediated by AMPA receptors on the neurons, and include NMDA receptors containing GluN1 and GluN2B subunits. Moreover, we find that the nicotine treatment also increases expression of the presynaptic component synapsin 1 and arranges it in puncta juxtaposed to the additional AMPA and NMDA receptor puncta, suggestive of increases in synaptic contacts. Consistent with increased synaptic input, we find that the nicotine treatment leads to an increase in the excitatory postsynaptic currents mediated by AMPA and NMDA receptors. Further, the increases skew the ratio of excitatory-to-inhibitory input that the cell receives, and this holds both for pyramidal neurons and inhibitory neurons in the hippocampal CA1 region. The GluN2B-containing NMDA receptor redistribution at synapses is associated with a significant increase in GluN2B phosphorylation at Tyr1472, a site known to prevent GluN2B endocytosis. These results suggest that chronic exposure to low levels of nicotine not only alters functional connections but also is likely to change excitability levels across networks. Further, it may increase the propensity for synaptic plasticity, given the increase in synaptic NMDA receptors.
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Affiliation(s)
- Jing-Jing Duan
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Neurobiology Section, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0357, United States
| | - Adrian F Lozada
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0357, United States
| | - Chen-Yu Gou
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Jing Xu
- Pain Research Center and Department of Physiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Yuan Chen
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.
| | - Darwin K Berg
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0357, United States.
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10
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Cha DJ, Lee SH. Evolutionary origin and status of two insect acetylcholinesterases and their structural conservation and differentiation. Evol Dev 2015; 17:109-19. [DOI: 10.1111/ede.12111] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Deok Jea Cha
- Department of Agricultural Biotechnology; Seoul National University; Gwanakno; Gwanakgu Seoul 151-742 Republic of Korea
| | - Si Hyeock Lee
- Department of Agricultural Biotechnology; Seoul National University; Gwanakno; Gwanakgu Seoul 151-742 Republic of Korea
- Research Institute for Agriculture and Life Science; Seoul National University; Seoul 151-742 Republic of Korea
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11
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Kim YH, Kwon DH, Ahn HM, Koh YH, Lee SH. Induction of soluble AChE expression via alternative splicing by chemical stress in Drosophila melanogaster. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 48:75-82. [PMID: 24637386 DOI: 10.1016/j.ibmb.2014.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 03/03/2014] [Accepted: 03/03/2014] [Indexed: 06/03/2023]
Abstract
Various molecular forms of acetylcholinesterase (AChE) have been characterized in insects. Post-translational modification is known to be a major mechanism for the molecular diversity of insect AChE. However, multiple forms of Drosophila melanogaster AChE (DmAChE) were recently suggested to be generated via alternative splicing (Kim and Lee, 2013). To confirm alternative splicing as the mechanism for generating the soluble form of DmAChE, we generated a transgenic fly strain carrying the cDNA of DmAChE gene (Dm_ace) that predominantly expressed a single transcript variant encoding the membrane-anchored dimer. 3' RACE (rapid amplification of cDNA ends) and western blotting were performed to compare Dm_ace transcript variants and DmAChE forms between wild-type and transgenic strains. Various Dm_ace transcripts and DmAChE molecular forms were observed in wild-type flies, whereas the transgenic fly predominantly expressed Dm_ace transcript variant encoding the membrane-anchored dimer. This supports alternative splicing as the major determinant in the generation of multiple forms of DmAChE. In addition, treatment with DDVP as a chemical stress induced the expression of the Dm_ace splice variant without the glycosylphosphatidylinositol anchor site in a dose-dependent manner and, accordingly, the soluble form of DmAChE in wild-type flies. In contrast, little soluble DmAChE was expressed in the transgenic fly upon exposure to DDVP. DDVP bioassays revealed that transgenic flies, which were unable to express a sufficient amount of soluble monomeric DmAChE, were more sensitive to DDVP compared to wild-type flies, suggesting that the soluble monomer may exert non-neuronal functions, such as chemical defense against xenobiotics.
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Affiliation(s)
- Young Ho Kim
- Research Institute for Agriculture and Life Sciences, Seoul National University, 599 Gwanakno Gwanakgu, Seoul 151-742, Republic of Korea
| | - Deok Ho Kwon
- Research Institute for Agriculture and Life Sciences, Seoul National University, 599 Gwanakno Gwanakgu, Seoul 151-742, Republic of Korea
| | - Hyo Min Ahn
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeoggi-do 431-060, Republic of Korea
| | - Young Ho Koh
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeoggi-do 431-060, Republic of Korea
| | - Si Hyeock Lee
- Research Institute for Agriculture and Life Sciences, Seoul National University, 599 Gwanakno Gwanakgu, Seoul 151-742, Republic of Korea; Department of Agricultural Biotechnology, Seoul National University, 599 Gwanakno Gwanakgu, Seoul 151-742, Republic of Korea.
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12
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Oxime-type acetylcholinesterase reactivators in pregnancy: an overview. Arch Toxicol 2013; 88:575-84. [DOI: 10.1007/s00204-013-1160-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 11/05/2013] [Indexed: 10/26/2022]
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13
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Romero AM, Renau-Piqueras J, Pilar Marin M, Timoneda J, Berciano MT, Lafarga M, Esteban-Pretel G. Chronic alcohol alters dendritic spine development in neurons in primary culture. Neurotox Res 2013; 24:532-48. [PMID: 23820986 DOI: 10.1007/s12640-013-9409-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 06/07/2013] [Accepted: 06/21/2013] [Indexed: 12/24/2022]
Abstract
Dendritic spines are specialised membrane protrusions of neuronal dendrites that receive the majority of excitatory synaptic inputs. Abnormal changes in their density, size and morphology have been associated with various neurological and psychiatric disorders, including those deriving from drug addiction. Dendritic spine formation, morphology and synaptic functions are governed by the actin cytoskeleton. Previous in vivo studies have shown that ethanol alters the number and morphology of spines, although the mechanisms underlying these alterations remain unknown. It has also been described how chronic ethanol exposure affects the levels, assembly and cellular organisation of the actin cytoskeleton in hippocampal neurons in primary culture. Therefore, we hypothesised that the ethanol-induced alterations in the number and shape of dendritic spines are due to alterations in the mechanisms regulating actin cytoskeleton integrity. The results presented herein show that chronic exposure to moderate levels of alcohol (30 mM) during the first 2 weeks of culture reduces dendritic spine density and alters the proportion of the different morphologies of these structures in hippocampal neurons, which affects the formation of mature spines. Apparently, these effects are associated with an increase in the G-actin/F-actin ratio due to a reduction of the F-actin fraction, leading to changes in the levels of the different factors regulating the organisation of this cytoskeletal component. The data presented herein indicate that these effects occur between weeks 1 and 2 of culture, an important period in dendritic spines development. These changes may be related to the dysfunction in the memory and learning processes present in children prenatally exposed to ethanol.
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Affiliation(s)
- Ana M Romero
- Sección de Biología y Patología Celular, Centro de Investigación, Hospital Universitario ''La Fe'', Avenida Campanar 21, 46009, Valencia, Spain
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14
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Zhang Y, Jiang T, Yang X, Xue Y, Wang C, Liu J, Zhang X, Chen Z, Zhao M, Li JC. Toll-like receptor -1, -2, and -6 polymorphisms and pulmonary tuberculosis susceptibility: a systematic review and meta-analysis. PLoS One 2013; 8:e63357. [PMID: 23691034 PMCID: PMC3653945 DOI: 10.1371/journal.pone.0063357] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Accepted: 04/02/2013] [Indexed: 12/18/2022] Open
Abstract
Background A large number of studies have investigated whether polymorphisms in the Toll-like receptor (TLR) genes are implicated in susceptibility to tuberculosis (TB) in different populations. However, the results are inconsistent and inconclusive. Methods A literature search was conducted using the PubMed, EMBASE, Medline (Ovid), ISI Web of Knowledge and Chinese National Knowledge Infrastructure (CNKI). A meta-analysis on the associations between the TLR1 G1805T, TLR2 T597C, T1350C, G2258A, and TLR6 C745T polymorphisms and TB risk was carried out by comparison using different genetic models. Results In total, 16 studies from 14 articles were included in this review. In meta-analysis, significant associations were observed between the TLR2 2258AA (AA vs. AG+AG, OR 5.82, 95% CI 1.30–26.16, P = 0.02) and TLR6 745TT (TT vs. CT+CC, OR 0.61, 95% CI 0.39–0.97, P = 0.04) polymorphisms and TB risk. In the subgroup analysis by ethnicity, Africans and American Hispanic subjects with the TLR1 1805T allele had an increased susceptibility, whereas Asian and European subjects with the TLR2 2258A allele had an increased susceptibility to TB. Conclusions The meta-analysis indicated that TLR2 G2258A is associated with increased TB risk, especially in Asians and Europeans. TLR1 G1805T is associated with increased TB in Africans and American Hispanics. TLR6 C745T is associated with decreased TB risk. Our systematic review and meta-analysis reported an interesting preliminary conclusion, but this must be validated by future large-scale and functional studies in different populations.
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Affiliation(s)
- Yuxiang Zhang
- Institute of Cell Biology, Zhejiang University, Hangzhou, Zhejiang, China
- Department of Pharmacology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Tingting Jiang
- Institute of Cell Biology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiuyun Yang
- Department of Respiratory Medicine, Tongde Hospital of Zhejiang, Hangzhou, Zhejiang, China
| | - Yun Xue
- Institute of Cell Biology, Zhejiang University, Hangzhou, Zhejiang, China
- Henan University of Science and Technology, Luoyang, Henan, China
| | - Chong Wang
- Institute of Cell Biology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jiyan Liu
- Institute of Cell Biology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xing Zhang
- Institute of Cell Biology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhongliang Chen
- Institute of Cell Biology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Mengyuan Zhao
- Institute of Cell Biology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ji-Cheng Li
- Institute of Cell Biology, Zhejiang University, Hangzhou, Zhejiang, China
- * E-mail:
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15
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Kim YH, Lee SH. Which acetylcholinesterase functions as the main catalytic enzyme in the Class Insecta? INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2013; 43:47-53. [PMID: 23168079 DOI: 10.1016/j.ibmb.2012.11.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 11/08/2012] [Accepted: 11/08/2012] [Indexed: 06/01/2023]
Abstract
Most insects possess two different acetylcholinesterases (AChEs) (i.e., AChE1 and AChE2; encoded by ace1 and ace2 genes, respectively). Between the two AChEs, AChE1 has been proposed as a major catalytic enzyme based on its higher expression level and frequently observed point mutations associated with insecticide resistance. To investigate the evolutionary distribution of AChE1 and AChE2, we determined which AChE had a central catalytic function in several insect species across 18 orders. The main catalytic activity in heads was determined by native polyacrylamide gel electrophoresis in conjunction with Western blotting using AChE1- and AChE2-specific antibodies. Of the 100 insect species examined, 67 species showed higher AChE1 activity; thus, AChE1 was considered as the main catalytic enzyme. In the remaining 33 species, ranging from Palaeoptera to Hymenoptera, however, AChE2 was predominantly expressed as the main catalytic enzyme. These findings challenge the common notion that AChE1 is the only main catalytic enzyme in insects with the exception of Cyclorrhapha, and further demonstrate that the specialization of AChE2 as the main enzyme or the replacement of AChE1 function with AChE2 were rather common events, having multiple independent origins during insect evolution. It was hypothesized that the generation of multiple AChE2 isoforms by alternative splicing allowed the loss of ace1 during the process of functional replacement of AChE1 with AChE2 in Cyclorrhapha. However, the presence of AChE2 as the main catalytic enzyme in higher social Hymenoptera provides a case for the functional replacement of AChE1 with AChE2 without the loss of ace1. The current study will provide valuable insights into the evolution of AChE: which AChE has been specialized as the main catalytic enzyme and to become the main target for insecticides in different insect species.
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Affiliation(s)
- Young Ho Kim
- Research Institute for Agriculture and Life Sciences, Seoul National University, 599 Gwanakno, Gwanakgu, Seoul 151-742, Republic of Korea
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16
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Sperling LE, Klaczinski J, Schütz C, Rudolph L, Layer PG. Mouse acetylcholinesterase enhances neurite outgrowth of rat R28 cells through interaction with laminin-1. PLoS One 2012; 7:e36683. [PMID: 22570738 PMCID: PMC3343015 DOI: 10.1371/journal.pone.0036683] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 04/11/2012] [Indexed: 02/02/2023] Open
Abstract
The enzyme acetylcholinesterase (AChE) terminates synaptic transmission at cholinergic synapses by hydrolyzing the neurotransmitter acetylcholine, but can also exert 'non-classical', morpho-regulatory effects on developing neurons such as stimulation of neurite outgrowth. Here, we investigated the role of AChE binding to laminin-1 on the regulation of neurite outgrowth by using cell culture, immunocytochemistry, and molecular biological approaches. To explore the role of AChE, we examined fiber growth of cells overexpressing different forms of AChE, and/or during their growth on laminin-1. A significant increase of neuritic growth as compared with controls was observed for neurons over-expressing AChE. Accordingly, addition of globular AChE to the medium increased total length of neurites. Co-transfection with PRIMA, a membrane anchor of AChE, led to an increase in fiber length similar to AChE overexpressing cells. Transfection with an AChE mutant that leads to the retention of AChE within cells had no stimulatory effect on neurite length. Noticeably, the longest neurites were produced by neurons overexpressing AChE and growing on laminin-1, suggesting that the AChE/laminin interaction is involved in regulating neurite outgrowth. Our findings demonstrate that binding of AChE to laminin-1 alters AChE activity and leads to increased neurite growth in culture. A possible mechanism of the AChE effect on neurite outgrowth is proposed due to the interaction of AChE with laminin-1.
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Affiliation(s)
- Laura E Sperling
- Entwicklungsbiologie und Neurogenetik, Fachbereich Biologie, Technische Universität Darmstadt, Darmstadt, Germany.
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17
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Lin T, Duek O, Dori A, Kofman O. Differential long term effects of early diisopropylfluorophosphate exposure in Balb/C and C57Bl/J6 mice. Int J Dev Neurosci 2011; 30:113-20. [PMID: 22197972 DOI: 10.1016/j.ijdevneu.2011.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 12/01/2011] [Accepted: 12/08/2011] [Indexed: 11/17/2022] Open
Abstract
The long-term effect of postnatal administration of a sub-toxic dose of the irreversible acetylcholinesterase inhibitor diisopropylfluorophosphate (DFP) on depression and anxiety behavior was compared in two strains of inbred mice. C57BL/6J and Balb/C mice were injected for 7 consecutive days with either 1 mg/kg DFP or saline on postnatal days 14-20. Mice were tested at age 3-4 months for initial and learned anxiety using double-exposure elevated plus maze and to a novel enclosed environment. Depression was assayed using the sweet preference model of anhedonia and the forced swim test for despair. Postnatal DFP pretreatment led to less activity and more immobility in the elevated plus maze in both mouse strains in the first session. The effect was attenuated in the second session in the C57BL/6J strain but not the Balb/C strain. DFP did not affect the sweet preference or forced swim tests, suggesting a dissociation between the long-term effects of DFP on immobility in the context of approach-avoidance conflict (elevated plus maze) versus despair (forced swim).
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Affiliation(s)
- Tamar Lin
- Department of Psychology and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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18
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Nourizadeh-Lillabadi R, Seilø Torgersen J, Vestrheim O, König M, Aleström P, Syed M. Early embryonic gene expression profiling of zebrafish prion protein (Prp2) morphants. PLoS One 2010; 5:e13573. [PMID: 21042590 PMCID: PMC2962645 DOI: 10.1371/journal.pone.0013573] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 09/26/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The Prion protein (PRNP/Prp) plays a crucial role in transmissible spongiform encephalopathies (TSEs) like Creutzfeldt-Jakob disease (CJD), scrapie and mad cow disease. Notwithstanding the importance in human and animal disease, fundamental aspects of PRNP/Prp function and transmission remains unaccounted for. METHODOLOGY/PRINCIPAL FINDINGS The zebrafish (Danio rerio) genome contains three Prp encoding genes assigned prp1, prp2 and prp3. Currently, the second paralogue is believed to be the most similar to the mammalian PRNP gene in structure and function. Functional studies of the PRNP gene ortholog was addressed by prp2 morpholino (MO) knockdown experiments. Investigation of Prp2 depleted embryos revealed high mortality and apoptosis at 24 hours post fertilization (hpf) as well as impaired brain and neuronal development. In order to elucidate the underlying mechanisms, a genome-wide transcriptome analysis was carried out in viable 24 hpf morphants. The resulting changes in gene expression profiles revealed 249 differently expressed genes linked to biological processes like cell death, neurogenesis and embryonic development. CONCLUSIONS/SIGNIFICANCE The current study contributes to the understanding of basic Prp functions and demonstrates that the zebrafish is an excellent model to address the role of Prp in vertebrates. The gene knockdown of prp2 indicates an essential biological function for the zebrafish ortholog with a morphant phenotype that suggests a neurodegenerative action and gene expression effects which are apoptosis related and effects gene networks controlling neurogenesis and embryo development.
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Affiliation(s)
| | - Jacob Seilø Torgersen
- Department of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, Oslo, Norway
| | - Olav Vestrheim
- Department of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, Oslo, Norway
| | - Melanie König
- Department of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, Oslo, Norway
| | - Peter Aleström
- Department of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, Oslo, Norway
| | - Mohasina Syed
- Department of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, Oslo, Norway
- * E-mail:
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19
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Johnson G, Swart C, Moore SW. Non-enzymatic developmental functions of acetylcholinesterase - the question of redundancy. FEBS J 2008; 275:5129-38. [DOI: 10.1111/j.1742-4658.2008.06644.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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20
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Old and new questions about cholinesterases. Chem Biol Interact 2008; 175:30-44. [DOI: 10.1016/j.cbi.2008.04.039] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Revised: 04/25/2008] [Accepted: 04/28/2008] [Indexed: 01/21/2023]
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21
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Interaction of acetylcholinesterase with the G4 domain of the laminin alpha1-chain. Biochem J 2008; 411:507-14. [PMID: 18215127 DOI: 10.1042/bj20071404] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Although the primary function of AChE (acetylcholinesterase) is the synaptic hydrolysis of acetylcholine, it appears that the protein is also able to promote various non-cholinergic activities, including cell adhesion, neurite outgrowth and amyloidosis. We have observed previously that AChE is able to bind to mouse laminin-111 in vitro by an electrostatic mechanism. We have also observed that certain mAbs (monoclonal antibodies) recognizing AChE's PAS (peripheral anionic site) inhibit both laminin binding and cell adhesion in neuroblastoma cells. Here, we investigated the interaction sites of the two molecules, using docking, synthetic peptides, ELISAs and conformational interaction site mapping. Mouse AChE was observed on docking to bind to a discontinuous, largely basic, structure, Val(2718)-Arg-Lys-Arg-Leu(2722), Tyr(2738)-Tyr(2739), Tyr(2789)-Ile-Lys-Arg-Lys(2793) and Val(2817)-Glu-Arg-Lys(2820), on the mouse laminin alpha1 G4 domain. ELISAs using synthetic peptides confirmed the involvement of the AG-73 site (2719-2729). This site overlaps extensively with laminin's heparin-binding site, and AChE was observed to compete with heparan sulfate for laminin binding. Docking showed the major component of the interaction site on AChE to be the acidic sequence Arg(90)-Glu-Leu-Ser-Glu-Asp(95) on the omega loop, and also the involvement of Pro(40)-Pro-Val(42), Arg(46) (linked to Glu(94) by a salt bridge) and the hexapeptide Asp(61)-Ala-Thr-Thr-Phe-Gln(66). Epitope analysis, using CLiPS technology, of seven adhesion-inhibiting mAbs (three anti-human AChE, one anti-Torpedo AChE and three anti-human anti-anti-idiotypic antibodies) showed their major recognition site to be the sequence Pro(40)-Pro-Met-Gly-Pro-Arg-Arg-Phe(48) (AChE human sequence). The antibodies, however, also reacted with the proline-containing sequences Pro(78)-Gly-Phe-Glu-Gly-Thr-Glu(84) and Pro(88)-Asn-Arg-Glu-Leu-Ser-Glu-Asp(95). Antibodies that recognized other features of the PAS area but not the Arg(90)-Gly-Leu-Ser-Glu-Asp(95) motif interfered neither with laminin binding nor with cell adhesion. These results define sites for the interaction of AChE and laminin and suggest that the interaction plays a role in cell adhesion. They also suggest the strong probability of functional redundancy between AChE and other molecules in early development, particularly heparan sulfate proteoglycans, which may explain the survival of the AChE-knockout mouse.
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22
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Anderson AA, Ushakov DS, Ferenczi MA, Mori R, Martin P, Saffell JL. Morphoregulation by acetylcholinesterase in fibroblasts and astrocytes. J Cell Physiol 2008; 215:82-100. [PMID: 17948252 DOI: 10.1002/jcp.21288] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Acetylcholinesterase (AChE) terminates neurotransmission at cholinergic synapses by hydrolysing acetylcholine, but also has non-enzymatic morphoregulatory effects on neurons such as stimulation of neurite outgrowth. It is widely expressed outside the nervous system, but its function in non-neuronal cells is unclear. Here we have investigated the distribution and function of AChE in fibroblasts and astrocytes. We show that these cells express high levels of AChE protein that co-migrates with recombinant AChE but contains little catalytic activity. Fibroblasts express transcripts encoding the synaptic AChE-T isoform and its membrane anchoring peptide PRiMA-I. AChE is strikingly distributed in arcs, rings and patches at the leading edge of spreading and migrating fibroblasts and astrocytes, close to the cell-substratum interface, and in neuronal growth cones. During in vivo healing of mouse skin, AChE becomes highly expressed in re-epithelialising epidermal keratinocytes 1 day after wounding. AChE appears to be functionally important for polarised cell migration, since an AChE antibody reduces substratum adhesion of fibroblasts, and slows wound healing in vitro as effectively as a beta1-integrin antibody. Moreover, elevation of AChE expression increases fibroblast wound healing independently of catalytic activity. Interestingly, AChE surface patches precisely co-localise with amyloid precursor protein and the extracellular matrix protein perlecan, but not focal adhesions or alpha-dystroglycan, and contain a high concentration of tyrosine phosphorylated proteins in spreading cells. These findings suggest that cell surface AChE, possibly in a novel signalling complex containing APP and perlecan, contributes to a generalised mechanism for polarised membrane protrusion and migration in all adherent cells.
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Affiliation(s)
- Alexandra A Anderson
- Division of Cell & Molecular Biology, Faculty of Natural Sciences, Imperial College London, South Kensington Campus, London, UK
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23
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Johnson G, Moore SW. Acetylcholinesterase readthrough peptide shares sequence similarity to the 28-53 peptide sequence of the acetylcholinesterase adhesion-mediating site and competes for ligand binding in vitro. J Mol Neurosci 2008; 31:113-26. [PMID: 17478885 DOI: 10.1385/jmn/31:02:113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Revised: 08/15/2006] [Accepted: 08/15/2006] [Indexed: 11/11/2022]
Abstract
It has been reported that unlike the more commonly expressed splice variants, the embryonic and stress-associated readthrough form of acetylcholinesterase (AChE-R) is unable to promote cell adhesion and neurite outgrowth. We investigated the possibility that the unique AChE-R C-terminal peptide (ARP) might be responsible for this difference, either by binding to AChE itself and inactivating the adhesion-mediating site or by competing with AChE for ligand binding. Synthetic peptides representing the ARP, a scrambled version of the ARP, and sequences of the previously identified adhesion-mediating site on AChE were used in in vitro binding and neuroblastoma cell-spreading assays. It was observed that the ARP was able to bind to laminin-1, identified previously as an in vitro AChE ligand and, to a lesser extent, to collagen IV and to AChE itself. ARP-AChE binding was, however, of very low affinity and was not significantly affected by peripheral site inhibitors, suggesting that inactivation of the AChE adhesion site is not the reason for AChE-R's antiadhesive character. On the other hand, the ARP competed with AChE and the adhesion site peptides for binding to laminin in vitro, and the ARP was observed to inhibit cell spreading in neuroblastoma cells grown on laminin. Monoclonal antibodies recognizing the known AChE adhesion site reacted with the ARP, suggesting structural similarities. These were borne out by an examination of sequence alignments of the ARP and the 28-53 AChE sequence. The ARP contains part of the PPxxxxRFxPPEP motif seen in AChEs and cholinesterase-domain proteins, and both it and the 37-53 sequence bear some resemblance to collagen and collagen-like proteins. It therefore appears likely that the ARP's structural similarity to the AChE adhesion-mediating site is the basis for the observed competition for ligand binding and might account for the antiadhesive characteristics of AChE-R.
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Affiliation(s)
- Glynis Johnson
- Departments of Pediatric Surgery, Medical Biochemistry, Faculty of Health Sciences, University of Stellenbosch, Tygerberg, South Africa.
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24
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Farchi N, Ofek K, Podoly E, Dong H, Xiang YY, Diamant S, Livnah O, Li J, Hochner B, Lu WY, Soreq H. Peripheral site acetylcholinesterase blockade induces RACK1-associated neuronal remodeling. NEURODEGENER DIS 2007; 4:171-84. [PMID: 17596712 DOI: 10.1159/000101842] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Peripheral anionic site (PAS) blockade of acetylcholinesterase (AChE) notably affects neuronal activity and cyto-architecture, however, the mechanism(s) involved are incompletely understood. OBJECTIVE We wished to specify the PAS extracellular effects on specific AChE mRNA splice variants, delineate the consequent cellular remodeling events, and explore the inhibitory effects on interchanging RACK1 interactions. METHODS We exposed rat hippocampal cultured neurons to BW284C51, the peripheral anionic site inhibitor of AChE, and to the non-selective AChE active site inhibitor, physostigmine for studying the neuronal remodeling of AChE mRNA expression and trafficking. RESULTS BW284C51 induced overexpression of both AChE splice variants, yet promoted neuritic translocation of the normally rare AChE-R, and retraction of AChE-S mRNA in an antisense-suppressible manner. BW284C51 further caused modest decreases in the expression of the scaffold protein RACK1 (receptor for activated protein kinase betaII), followed by drastic neurite retraction of both RACK1 and the AChE homologue neuroligin1, but not the tubulin-associated MAP2 protein. Accompanying BW284C51 effects involved decreases in the Fyn kinase and membrane insertion of the glutamate receptor NR2B variant and impaired glutamatergic activities of treated cells. Intriguingly, molecular modeling suggested that direct, non-catalytic competition with Fyn binding by the RACK1-interacting AChE-R variant may be involved. CONCLUSIONS Our findings highlight complex neuronal AChE-R/RACK1 interactions and are compatible with the hypothesis that peripheral site AChE inhibitors induce RACK1-mediated neuronal remodeling, promoting suppressed glutamatergic neurotransmission.
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MESH Headings
- Acetylcholinesterase/genetics
- Acetylcholinesterase/metabolism
- Alternative Splicing
- Animals
- Benzenaminium, 4,4'-(3-oxo-1,5-pentanediyl)bis(N,N-dimethyl-N-2-propenyl-), Dibromide/pharmacology
- Cells, Cultured
- Cholinesterase Inhibitors/pharmacology
- Cricetinae
- Cricetulus
- Embryo, Mammalian
- Excitatory Postsynaptic Potentials/drug effects
- Excitatory Postsynaptic Potentials/physiology
- Excitatory Postsynaptic Potentials/radiation effects
- Gene Expression Regulation, Enzymologic/drug effects
- Hippocampus/cytology
- Models, Molecular
- Nerve Tissue Proteins/metabolism
- Neurons/cytology
- Neurons/drug effects
- Neurons/physiology
- Patch-Clamp Techniques/methods
- Physostigmine/pharmacology
- RNA, Messenger/biosynthesis
- Rats
- Receptors for Activated C Kinase
- Receptors, Cell Surface/metabolism
- Receptors, Glutamate/drug effects
- Receptors, Glutamate/metabolism
- Reverse Transcriptase Polymerase Chain Reaction/methods
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Affiliation(s)
- Noa Farchi
- Department of Neurobiology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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Giordano C, Poiana G, Augusti-Tocco G, Biagioni S. Acetylcholinesterase modulates neurite outgrowth on fibronectin. Biochem Biophys Res Commun 2007; 356:398-404. [PMID: 17359933 DOI: 10.1016/j.bbrc.2007.02.146] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Accepted: 02/27/2007] [Indexed: 11/27/2022]
Abstract
Acetylcholinesterase (AChE) has been reported to be involved in the modulation of neurite outgrowth. To understand the role played by different domains, we transfected neuroblastoma cells with three constructs containing the invariant region of AChE, differing in the exon encoding the C-terminus and therefore in AChE cellular fate and localization. All isoforms increased neurite extension, suggesting the involvement of the invariant domain [A. De Jaco, G. Augusti-Tocco, S. Biagioni, Alternative AChE molecular forms exhibit similar ability to induce neurite outgrowth, J. Neurosci. Res. 70 (2002) 756-765]. The peripheral anionic site (PAS) is encoded by invariant exons and represents the domain involved in non-cholinergic functions of AChE. Masking of PAS with fasciculin results in a significant decrease of neurite outgrowth in all clones overexpressing AChE. A strong reduction was also observed when clones were cultured on fibronectin. Treatment of clones with fasciculin, therefore masking PAS, abolished the fibronectin-induced reduction. The inhibition of the catalytic site cannot revert the fibronectin effect. Finally, when clones were cultured on fibronectin in the presence of heparin, a ligand of fibronectin, the inhibitory effect was completely reversed. Our results indicate that PAS could directly or indirectly mediate AChE/fibronectin interactions.
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Affiliation(s)
- C Giordano
- Dipartimento Biologia Cellulare e Sviluppo, Università La Sapienza, Piazzale A. Moro 5, 00185 Roma, Italy
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Gingras M, Champigny MF, Berthod F. Differentiation of human adult skin-derived neuronal precursors into mature neurons. J Cell Physiol 2007; 210:498-506. [PMID: 17111366 DOI: 10.1002/jcp.20889] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The isolation of autologous neuronal precursors from skin-derived precursor cells extracted from adult human skin would be a very efficient source of neurons for the treatment of various neurodegenerative diseases. The purpose of this study was to demonstrate that these neuronal precursors were able to differentiate into mature neurons. We isolated neuronal precursors from breast skin and expanded them in vitro for over ten passages. We showed that 48% of these cells were proliferating after the first passage, while this growth rate decreased after the second passage. We demonstrated that 70% of these cells were nestin-positive after the third passage, while only 17% were neurofilament M-positive after 7 days of differentiation. These neuronal precursors expressed betaIII tubulin, the dendritic marker MAP2 and the presynaptic marker synaptophysin after 7 days of in vitro maturation. They also expressed the postsynaptic marker PSD95 and the late neuronal markers NeuN and neurofilament H after 21 days of differentiation, demonstrating they became terminally differentiated neurons. These markers were still expressed after 50 days of culture. The generation of autologous neurons from an accessible adult human source opens many potential therapeutic applications and has a great potential for the development of experimental studies on normal human neurons.
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Affiliation(s)
- Marie Gingras
- Laboratoire d'Organogénèse Expérimentale (LOEX), Centre Hospitalier Affilié Universitaire de Québec, Hôpital du St-Sacrement and Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, Canada
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Zimmerman G, Soreq H. Termination and beyond: acetylcholinesterase as a modulator of synaptic transmission. Cell Tissue Res 2006; 326:655-69. [PMID: 16802134 DOI: 10.1007/s00441-006-0239-8] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Accepted: 05/05/2006] [Indexed: 11/28/2022]
Abstract
Termination of synaptic transmission by neurotransmitter hydrolysis is a substantial characteristic of cholinergic synapses. This unique termination mechanism makes acetylcholinesterase (AChE), the enzyme in charge of executing acetylcholine breakdown, a key component of cholinergic signaling. AChE is now known to exist not as a single entity, but rather as a combinatorial complex of protein products. The diverse AChE molecular forms are generated by a single gene that produces over ten different transcripts by alternative splicing and alternative promoter choices. These transcripts are translated into six different protein subunits. Mature AChE proteins are found as soluble monomers, amphipatic dimers, or tetramers of these subunits and become associated to the cellular membrane by specialized anchoring molecules or members of other heteromeric structural components. A substantial increasing body of research indicates that AChE functions in the central nervous system go far beyond the termination of synaptic transmission. The non-enzymatic neuromodulatory functions of AChE affect neurite outgrowth and synaptogenesis and play a major role in memory formation and stress responses. The structural homology between AChE and cell adhesion proteins, together with the recently discovered protein partners of AChE, predict the future unraveling of the molecular pathways underlying these multileveled functions.
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Affiliation(s)
- Gabriel Zimmerman
- The Institute of Life Sciences and the Interdisciplinary Center for Neural Computation (ICNC), The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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Morley BJ. Nicotinic cholinergic intercellular communication: implications for the developing auditory system. Hear Res 2005; 206:74-88. [PMID: 16081000 DOI: 10.1016/j.heares.2005.02.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2004] [Accepted: 02/24/2005] [Indexed: 02/02/2023]
Abstract
In this paper, research on the temporal and spatial distribution of cholinergic-related molecules in the lower auditory brainstem, with an emphasis on nicotinic acetylcholine receptors (nAChRs), is reviewed. The possible functions of acetylcholine (ACh) in driving selective auditory neurons before the onset of hearing, inducing glutamate receptor gene expression, synaptogenesis, differentiation, and cell survival are discussed. Experiments conducted in other neuronal and non-neuronal systems are drawn on extensively to discuss putative functions of ACh and nAChRs. Data from other systems may provide insight into the functions of ACh and nAChRs in auditory processing. The mismatch of presynaptic and postsynaptic markers and novel endogenous agonists of nAChRs are discussed in the context of non-classical interneuronal communication. The molecular mechanism that may underlie the many functions of ACh and its agonists is the regulation of intracellular calcium through nAChRs. The possible reorganization that may take place in the auditory system by the exposure to nicotine during critical developmental periods is also briefly considered.
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Affiliation(s)
- Barbara J Morley
- Boys Town National Research Hospital, Neurochemistry Laboratory, 555 North 30th Street, Omaha, NE 68131, USA.
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Bravo SO, Henley J, Rodriguez-Ithurralde D. (35) Acetylcholinesterase effects on glutamate receptors. Chem Biol Interact 2005. [DOI: 10.1016/j.cbi.2005.10.080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Rasheed S, Mao Z, Chan JMC, Chan LS. Is Melanoma a stem cell tumor? Identification of neurogenic proteins in trans-differentiated cells. J Transl Med 2005; 3:14. [PMID: 15784142 PMCID: PMC1083422 DOI: 10.1186/1479-5876-3-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2005] [Accepted: 03/22/2005] [Indexed: 11/10/2022] Open
Abstract
Background Although several genes and proteins have been implicated in the development of melanomas, the molecular mechanisms involved in the development of these tumors are not well understood. To gain a better understanding of the relationship between the cell growth, tumorigenesis and differentiation, we have studied a highly malignant cat melanoma cell line that trans-differentiates into neuronal cells after exposure to a feline endogenous retrovirus RD114. Methods To define the repertoire of proteins responsible for the phenotypic differences between melanoma and its counterpart trans-differentiated neuronal cells we have applied proteomics technology and compared protein profiles of the two cell types and identified differentially expressed proteins by 2D-gel electrophoresis, image analyses and mass spectrometry. Results The melanoma and trans-differentiated neuronal cells could be distinguished by the presence of distinct sets of proteins in each. Although approximately 60–70% of the expressed proteins were shared between the two cell types, twelve proteins were induced de novo after infection of melanoma cells with RD114 virus in vitro. Expression of these proteins in trans-differentiated cells was significantly associated with concomitant down regulation of growth promoting proteins and up-regulation of neurogenic proteins (p = < 0.001). Based on their physiologic properties, >95% proteins expressed in trans-differentiated cells could be associated with the development, differentiation and regulation of nervous system cells. Conclusion Our results indicate that the cat melanoma cells have the ability to differentiate into distinct neuronal cell types and they express proteins that are essential for self-renewal. Since melanocytes arise from the neural crest of the embryo, we conclude that this melanoma arose from embryonic precursor stem cells. This model system provides a unique opportunity to identify domains of interactions between the expressed proteins that halt the tumorigenic potential of melanoma cells and drive them toward neurogenerative pathways involved in early neurogenesis. A better understanding of these proteins in a well-coordinated signaling network would also help in developing novel approaches for suppression of highly malignant tumors that arise from stem-like embryonic cells.
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Affiliation(s)
- Suraiya Rasheed
- Laboratory of Viral Oncology and Proteomics Research, Department of Pathology, University of Southern California, 1840 N.Soto St. Los Angeles, CA 90032-3626USA
| | | | | | - Linda S Chan
- Department of Pediatrics, Keck School of Medicine, University of Southern California, 1840 N. Soto St. Los Angeles, CA 90032-3626, USA
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Dong H, Xiang YY, Farchi N, Ju W, Wu Y, Chen L, Wang Y, Hochner B, Yang B, Soreq H, Lu WY. Excessive expression of acetylcholinesterase impairs glutamatergic synaptogenesis in hippocampal neurons. J Neurosci 2005; 24:8950-60. [PMID: 15483114 PMCID: PMC6730061 DOI: 10.1523/jneurosci.2106-04.2004] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Acetylcholinesterase (AChE) exerts noncatalytic activities on neural cell differentiation, adhesion, and neuritogenesis independently of its catalytic function. The noncatalytic functions of AChE have been attributed to its peripheral anionic site (PAS)-mediated protein-protein interactions. Structurally, AChE is highly homologous to the extracellular domain of neuroligin, a postsynaptic transmembrane molecule that interacts with presynaptic beta-neurexins, thus facilitating synaptic formation and maturation. Potential effects of AChE expression on synaptic transmission, however, remain unknown. Using electrophysiology, immunocytochemistry, and molecular biological approaches, this study investigated the role of AChE in the regulation of synaptic formation and functions. We found that AChE was highly expressed in cultured embryonic hippocampal neurons at early culture days, particularly in dendritic compartments including the growth cone. Subsequently, the expression level of AChE declined, whereas synaptic activity and synaptic proteins progressively increased. Chronic blockade of the PAS of AChE with specific inhibitors selectively impaired glutamatergic functions and excitatory synaptic structures independently of cholinergic activation, while inducing AChE overexpression. Moreover, the PAS blockade-induced glutamatergic impairments were associated with a depressed expression of beta-neurexins and an accumulation of other synaptic proteins, including neuroligins, and were mostly preventable by antisense suppression of AChE expression. Our findings demonstrate that interference with the nonenzymatic features of AChE alters AChE expression, which impairs excitatory synaptic structure and functions.
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Affiliation(s)
- Haiheng Dong
- Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada M4N 3M5
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Johnson G, Moore SW. Identification of a structural site on acetylcholinesterase that promotes neurite outgrowth and binds laminin-1 and collagen IV. Biochem Biophys Res Commun 2004; 319:448-55. [PMID: 15178427 DOI: 10.1016/j.bbrc.2004.05.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2004] [Indexed: 11/29/2022]
Abstract
The cell adhesion and neurite outgrowth-promoting function of acetylcholinesterase has been localised to the area of the peripheral anionic site. In order to precisely determine the site involved, we used synthetic peptides representing sequences of the peripheral anionic site and its surrounds, and investigated their binding to a panel of monoclonal antibodies that inhibit cell adhesion/neurite outgrowth and/or to recognise the peripheral anionic site. Binding to laminin-1 and collagen IV was also investigated. A relationship between recognition of the sequence 37-50, representing a surface loop adjacent to the peripheral anionic site, and the degree of inhibition of cell adhesion was observed; both laminin-1 and collagen IV also bound this loop with high affinity. Neurite outgrowth on coverslips coated with this peptide was similar to those coated with acetylcholinesterase itself. Adhesion-inhibiting antibodies also recognised the omega loop 69-96, as did laminin-1 and collagen IV. Laminin also bound the sequences 55-66 and 340-353, recognised by the antibodies to varying degrees, but collagen did not. All these peptides were able to promote neurite outgrowth to some degree. No binding to the amyloid-binding omega loop 275-304 by the ligands was observed, nor did the antibodies recognise this consistently. No relationship was observed between the degree of inhibition of acetylcholinesterase and inhibition of neurite outgrowth by the antibodies from which we conclude that the neurite outgrowth function is non-cholinergic. In conclusion, we have identified a specific conformational structure on acetylcholinesterase, comprising adjacent surface loops between residues 37-50 and 69-96, with additional involvement of the sequences 55-66 and 340-353, that mediates cell adhesion and neurite outgrowth.
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Affiliation(s)
- Glynis Johnson
- Department of Pediatric Surgery/Medical Biochemistry, Faculty of Health Sciences, University of Stellenbosch, P.O. Box 19063, Tygerberg 7505, South Africa.
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Johnson G, Moore SW. Functional idiotypic mimicry of an adhesion- and differentiation-promoting site on acetylcholinesterase. J Cell Biochem 2004; 91:999-1009. [PMID: 15034934 DOI: 10.1002/jcb.10785] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Acetylcholinesterase mediates cell adhesion and neurite outgrowth through a site associated with the peripheral anionic site (PAS). Monoclonal antibodies raised to this site block cell adhesion. We have raised anti-idiotypic antibodies to one of these antibodies. The anti-idiotypic antibodies recognized the immunogenic antibody and non-specific mouse IgG, but not acetylcholinesterase. Five antibodies (out of 143 clones, an incidence of 3.5%) were able to promote neurite outgrowth in human neuroblastoma cells in vitro in a similar manner to acetylcholinesterase itself, suggesting that these antibodies carry an internal image of the neuritogenic site. Two of the antibodies were significantly more effective (P < 0.01) than acetylcholinesterase in this regard. The antibodies also bound specifically to mouse laminin-1 and human collagen IV, as does acetylcholinesterase. This binding was displaced by unlabelled antibody, as well as by acetylcholinesterase itself, indicating competition with acetylcholinesterase. We have also investigated the development of anti-anti-idiotypic antibodies in mice in vivo, and have observed that four of these (out of 318 clones, an incidence of 1.26%) mimic the idiotypic antibody and abrogate adhesion in neuroblastoma cells. We have thus demonstrated functional mimicry of the neuritogenic site on acetylcholinesterase in anti-idiotypic antibodies, enhancement of this activity in one antibody, and mimicry of the idiotypic antibody site in anti-anti-idiotypic antibodies. Implications of these findings for differentiation-promoting cancer therapy are discussed.
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Affiliation(s)
- Glynis Johnson
- Departments of Pediatric Surgery and Medical Biochemistry, University of Stellenbosch, Tygerberg, South Africa.
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