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Choi MR, Cho S, Kim DJ, Choi JS, Jin YB, Kim M, Chang HJ, Jeon SH, Yang YD, Lee SR. Effects of Ethanol on Expression of Coding and Noncoding RNAs in Murine Neuroblastoma Neuro2a Cells. Int J Mol Sci 2022; 23:ijms23137294. [PMID: 35806296 PMCID: PMC9267046 DOI: 10.3390/ijms23137294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/26/2022] [Accepted: 06/28/2022] [Indexed: 11/19/2022] Open
Abstract
Excessive use of alcohol can induce neurobiological and neuropathological alterations in the brain, including the hippocampus and forebrain, through changes in neurotransmitter systems, hormonal systems, and neuroimmune processes. We aimed to investigate the effects of ethanol on the expression of coding and noncoding RNAs in a brain-derived cell line exposed to ethanol. After exposing Neuro2a cells, a neuroblastoma cell line, to ethanol for 24 and 72 h, we observed cell proliferation and analyzed up- and downregulated mRNAs and long noncoding RNAs (lncRNAs) using total RNA-Seq technology. We validated the differential expression of some mRNAs and lncRNAs by RT-qPCR and analyzed the expression of Cebpd and Rnu3a through knock-down of Cebpd. Cell proliferation was significantly reduced in cells exposed to 100 mM ethanol for 72 h, with 1773 transcripts up- or downregulated by greater than three-fold in ethanol-treated cells compared to controls. Of these, 514 were identified as lncRNAs. Differentially expressed mRNAs and lncRNAs were mainly observed in cells exposed to ethanol for 72 h, in which Atm and Cnr1 decreased, but Trib3, Cebpd, and Spdef increased. On the other hand, lncRNAs Kcnq1ot1, Tug1, and Xist were changed by ethanol, and Rnu3a in particular was greatly increased by chronic ethanol treatment through inhibition of Cebpd. Our results increase the understanding of cellular and molecular mechanisms related to coding and noncoding RNAs in an in vitro model of acute and chronic exposure to ethanol.
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Affiliation(s)
- Mi Ran Choi
- Laboratory Animal Research Center, Ajou University School of Medicine, Suwon 16499, Korea;
| | - Sinyoung Cho
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon 11160, Korea; (S.C.); (S.H.J.)
| | - Dai-Jin Kim
- Department of Psychiatry, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea;
| | - Jung-Seok Choi
- Department of Psychiatry, Samsung Medical Center, Seoul 06351, Korea;
| | - Yeung-Bae Jin
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Korea;
| | - Miran Kim
- Department of Obstetrics and Gynecology, Ajou University School of Medicine, Suwon 16499, Korea; (M.K.); (H.J.C.)
| | - Hye Jin Chang
- Department of Obstetrics and Gynecology, Ajou University School of Medicine, Suwon 16499, Korea; (M.K.); (H.J.C.)
| | - Seong Ho Jeon
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon 11160, Korea; (S.C.); (S.H.J.)
| | - Young Duk Yang
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon 11160, Korea; (S.C.); (S.H.J.)
- Correspondence: (Y.D.Y.); (S.-R.L.); Tel.: +82-31-881-7170 (Y.D.Y.); +82-31-219-4499 (S.-R.L.)
| | - Sang-Rae Lee
- Laboratory Animal Research Center, Ajou University School of Medicine, Suwon 16499, Korea;
- Department of Pharmacology, Ajou University School of Medicine, Suwon 16499, Korea
- Correspondence: (Y.D.Y.); (S.-R.L.); Tel.: +82-31-881-7170 (Y.D.Y.); +82-31-219-4499 (S.-R.L.)
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Cheng J, Zhao L, Liu D, Shen R, Bai D. Potentilla anserine L. polysaccharide protects against cadmium-induced neurotoxicity. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2022; 90:103816. [PMID: 35066145 DOI: 10.1016/j.etap.2022.103816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 12/28/2021] [Accepted: 01/18/2022] [Indexed: 06/14/2023]
Abstract
Cadmium is a toxic metal that can damage the brain and other organs. This study aimed to explore the protective effects of Potentilla anserine L. polysaccharide (PAP) against CdCl2-induced neurotoxicity in N2a and SH-SY5Y cells and in the cerebral cortex of BALB/c mice. In addition, we aimed to identify the potential mechanisms underlying these protective effects. Relative to CdCl2 treatment alone, pretreatment with PAP prevented the reduction in cell viability evoked by CdCl2, decreased rates of apoptosis, promoted calcium homeostasis, decreased ROS accumulation, increased mitochondrial membrane potential, inhibited cytochrome C and AIF release, and prevented the cleavage of caspase-3 and PARP. In addition, PAP significantly decreased the CdCl2-induced phosphorylation of CaMKII, Akt, and mTOR. In conclusion, PAP represents a potential therapeutic agent for the treatment of Cd-induced neurotoxicity, functioning in part via attenuating the activation of the mitochondrial apoptosis pathway and the Ca2+-CaMKII-dependent Akt/mTOR pathway.
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Affiliation(s)
- Ju Cheng
- Institute of Genetics, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China; Institute of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China.
| | - Lixia Zhao
- School of nursing, Gansu University of Chinese Medicine, Lanzhou 730000, China; Laboratory Center for Medical Sciences, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China; Institute of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Di Liu
- Keylaboratory of Evidence Science Techniques Research and Application of Gansu Province, Gansu University of Political Science and Law, Lanzhou 730000, China; Institute of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Rong Shen
- Laboratory Center for Medical Sciences, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China; Institute of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Decheng Bai
- School of nursing, Gansu University of Chinese Medicine, Lanzhou 730000, China; Institute of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
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Prenatal exposure to oxidative phosphorylation xenobiotics and late-onset Parkinson disease. Ageing Res Rev 2018; 45:24-32. [PMID: 29689408 DOI: 10.1016/j.arr.2018.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 04/20/2018] [Accepted: 04/20/2018] [Indexed: 12/21/2022]
Abstract
Late-onset Parkinson disease is a multifactorial and multietiological disorder, age being one of the factors implicated. Genetic and/or environmental factors, such as pesticides, can also be involved. Up to 80% of dopaminergic neurons of the substantia nigra are lost before motor features of the disorder begin to appear. In humans, these neurons are only formed a few weeks after fertilization. Therefore, prenatal exposure to pesticides or industrial chemicals during crucial steps of brain development might also alter their proliferation and differentiation. Oxidative phosphorylation is one of the metabolic pathways sensitive to environmental toxicants and it is crucial for neuronal differentiation. Many inhibitors of this biochemical pathway, frequently found as persistent organic pollutants, affect dopaminergic neurogenesis, promote the degeneration of these neurons and increase the risk of suffering late-onset Parkinson disease. Here, we discuss how an early, prenatal, exposure to these oxidative phosphorylation xenobiotics might trigger a late-onset, old age, Parkinson disease.
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Su PH, Chen CC, Chang YF, Wong ZR, Chang KW, Huang BM, Yang HY. Identification and cytoprotective function of a novel nestin isoform, Nes-S, in dorsal root ganglia neurons. J Biol Chem 2013; 288:8391-8404. [PMID: 23319587 DOI: 10.1074/jbc.m112.408179] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
In this study, the first nestin isoform, Nes-S, was identified in neurons of dorsal root ganglia (DRG) of adult rats. Nes-S cannot form filaments by itself in cytoplasmic intermediate filament-free SW13 cells. Instead, it co-assembles into filaments with vimentin when transfected into vimentin(+) SW13 cells, and with peripherin and neurofilament proteins when transfected into N2a cells. In primary DRG neurons, endogenous Nes-S co-assembles with peripherin and neurofilament proteins. The expression of Nes-S first appears in DRG at postnatal day 5 and persists to adulthood. Among the adult tissues we examined, the expression of Nes-S is restricted to the sensory and motor neurons. Finally, exogenous Nes-S enhances viability when transfected into N2a cells, and knockdown of endogenous Nes-S impairs the survival of DRG neurons in primary cultures. Taken together, Nes-S is a new neuronal intermediate filament protein that exerts a cytoprotective function in mature sensory and motor neurons.
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Affiliation(s)
- Peng-Han Su
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei 10617, Taiwan
| | - Chih-Cheng Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan
| | - Ya-Fan Chang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei 10617, Taiwan
| | - Zong-Ruei Wong
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei 10617, Taiwan
| | - Kai-Wei Chang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei 10617, Taiwan
| | - Bu-Miin Huang
- Department of Cell Biology and Anatomy, National Cheng-Kung University, Tainan 701, Taiwan
| | - Hsi-Yuan Yang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei 10617, Taiwan.
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Chaballe L, Close P, Sempels M, Delstanche S, Fanielle J, Moons L, Carmeliet P, Schoenen J, Chariot A, Franzen R. Involvement of placental growth factor in Wallerian degeneration. Glia 2010; 59:379-96. [PMID: 21264946 DOI: 10.1002/glia.21108] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 10/18/2010] [Indexed: 01/13/2023]
Abstract
Wallerian degeneration (WD) is an inflammatory process of nerve degeneration, which occurs more rapidly in the peripheral nervous system compared with the central nervous system, resulting, respectively in successful and aborted axon regeneration. In the peripheral nervous system, Schwann cells (SCs) and macrophages, under the control of a network of cytokines and chemokines, represent the main cell types involved in this process. Within this network, the role of placental growth factor (PlGF) remains totally unknown. However, properties like monocyte activation/attraction, ability to increase expression of pro-inflammatory molecules, as well as neuroprotective effects, make it a candidate likely implicated in this process. Also, nothing is described about the expression and localization of this molecule in the peripheral nervous system. To address these original questions, we decided to study PlGF expression under physiological and degenerative conditions and to explore its role in WD, using a model of sciatic nerve transection in wild-type and Pgf(-/-) mice. Our data show dynamic changes of PlGF expression, from periaxonal in normal nerve to SCs 24h postinjury, in parallel with a p65/NF-κB recruitment on Pgf promoter. After injury, SC proliferation is reduced by 30% in absence of PlGF. Macrophage invasion is significantly delayed in Pgf(-/-) mice compared with wild-type mice, which results in worse functional recovery. MCP-1 and proMMP-9 exhibit a 3-fold reduction of their relative expressions in Pgf(-/-) injured nerves, as demonstrated by cytokine array. In conclusion, this work originally describes PlGF as a novel member of the cytokine network of WD.
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Affiliation(s)
- Linda Chaballe
- GIGA Neurosciences, Axonal Regeneration and Cephalic Pain unit, University of Liege, Avenue de l'Hopital, Liege, Belgium
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6
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Chen G, Bower KA, Xu M, Ding M, Shi X, Ke ZJ, Luo J. Cyanidin-3-glucoside reverses ethanol-induced inhibition of neurite outgrowth: role of glycogen synthase kinase 3 Beta. Neurotox Res 2009; 15:321-31. [PMID: 19384566 DOI: 10.1007/s12640-009-9036-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Revised: 11/10/2008] [Accepted: 12/18/2008] [Indexed: 10/20/2022]
Abstract
Ethanol is a potent teratogen for the developing central nervous system (CNS), and fetal alcohol syndrome (FAS) is the most common nonhereditary cause of mental retardation. Ethanol disrupts neuronal differentiation and maturation. It is important to identify agents that provide neuroprotection against ethanol neurotoxicity. Using an in vitro neuronal model, mouse Neuro2a (N2a) neuroblastoma cells, we demonstrated that ethanol inhibited neurite outgrowth and the expression of neurofilament (NF) proteins. Glycogen synthase kinase 3beta (GSK3beta), a multifunctional serine/threonine kinase negatively regulated neurite outgrowth of N2a cells; inhibiting GSK3beta activity by retinoic acid (RA) and lithium induced neurite outgrowth, while over-expression of a constitutively active S9A GSK3beta mutant prevented neurite outgrowth. Ethanol inhibited neurite outgrowth by activating GSK3beta through the dephosphorylation of GSK3beta at serine 9. Cyanidin-3-glucoside (C3G), a member of the anthocyanin family rich in many edible berries and other pigmented fruits, enhanced neurite outgrowth by promoting p-GSK3beta(Ser9). More importantly, C3G reversed ethanol-mediated activation of GSK3beta and inhibition of neurite outgrowth as well as the expression of NF proteins. C3G also blocked ethanol-induced intracellular accumulation of reactive oxygen species (ROS). However, the antioxidant effect of C3G appeared minimally involved in its protection. Our study provides a potential avenue for preventing or ameliorating ethanol-induced damage to the developing CNS.
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Affiliation(s)
- Gang Chen
- Department of Internal Medicine, University of Kentucky College of Medicine, 124C Combs Research Building, 800 Rose Street, Lexington, KY 40536, USA
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7
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Fitzgerald JC, Plun-Favreau H. Emerging pathways in genetic Parkinson’s disease: Autosomal-recessive genes in Parkinson’s disease - a common pathway? FEBS J 2008; 275:5758-66. [DOI: 10.1111/j.1742-4658.2008.06708.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Radio NM, Mundy WR. Developmental neurotoxicity testing in vitro: models for assessing chemical effects on neurite outgrowth. Neurotoxicology 2008; 29:361-76. [PMID: 18403021 DOI: 10.1016/j.neuro.2008.02.011] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 02/13/2008] [Accepted: 02/20/2008] [Indexed: 11/15/2022]
Abstract
In vitro models may be useful for the rapid toxicological screening of large numbers of chemicals for their potential to produce toxicity. Such screening could facilitate prioritization of resources needed for in vivo toxicity testing towards those chemicals most likely to result in adverse health effects. Cell cultures derived from nervous system tissue have proven to be powerful tools for elucidating cellular and molecular mechanisms of nervous system development and function, and have been used to understand the mechanism of action of neurotoxic chemicals. Recently, it has been suggested that in vitro models could be used to screen for chemical effects on critical cellular events of neurodevelopment, including differentiation and neurite growth. This review examines the use of neuronal cell cultures as an in vitro model of neurite outgrowth. Examples of the cell culture systems that are commonly used to examine the effects of chemicals on neurite outgrowth are provided, along with a description of the methods used to quantify this neurodevelopmental process in vitro. Issues relating to the relevance of the methods and models currently used to assess neurite outgrowth are discussed in the context of hazard identification and chemical screening. To demonstrate the utility of in vitro models of neurite outgrowth for the evaluation of large numbers of chemicals, efforts should be made to: (1) develop a set of reference chemicals that can be used as positive and negative controls for comparing neurite outgrowth between model systems, (2) focus on cell cultures of human origin, with emphasis on the emerging area of neural progenitor cells, and (3) use high-throughput methods to quantify endpoints of neurite outgrowth.
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Affiliation(s)
- Nicholas M Radio
- Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protections Agency (USEPA), B105-06 Research Triangle Park, NC 27711, USA
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9
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Kawahara K, Hashimoto M, Bar-On P, Ho GJ, Crews L, Mizuno H, Rockenstein E, Imam SZ, Masliah E. α-Synuclein Aggregates Interfere with Parkin Solubility and Distribution. J Biol Chem 2008; 283:6979-87. [DOI: 10.1074/jbc.m710418200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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10
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Morfini G, Pigino G, Opalach K, Serulle Y, Moreira JE, Sugimori M, Llinás RR, Brady ST. 1-Methyl-4-phenylpyridinium affects fast axonal transport by activation of caspase and protein kinase C. Proc Natl Acad Sci U S A 2007; 104:2442-7. [PMID: 17287338 PMCID: PMC1892945 DOI: 10.1073/pnas.0611231104] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Parkinson's disease (PD), a late-onset condition characterized by dysfunction and loss of dopaminergic neurons in the substantia nigra, has both sporadic and neurotoxic forms. Neurotoxins such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and its metabolite 1-methyl-4-phenylpyridinium (MPP+) induce PD symptoms and recapitulate major pathological hallmarks of PD in human and animal models. Both sporadic and MPP+-induced forms of PD proceed through a "dying-back" pattern of neuronal degeneration in affected neurons, characterized by early loss of synaptic terminals and axonopathy. However, axonal and synaptic-specific effects of MPP+ are poorly understood. Using isolated squid axoplasm, we show that MPP+ produces significant alterations in fast axonal transport (FAT) through activation of a caspase and a previously undescribed protein kinase C (PKCdelta) isoform. Specifically, MPP+ increased cytoplasmic dynein-dependent retrograde FAT and reduced kinesin-1-mediated anterograde FAT. Significantly, MPP+ effects were independent of both nuclear activities and ATP production. Consistent with its effects on FAT, MPP+ injection in presynaptic domains led to a dramatic reduction in the number of membranous profiles. Changes in availability of synaptic and neurotrophin-signaling components represent axonal and synaptic-specific effects of MPP+ that would produce a dying-back pathology. Our results identify a critical neuronal process affected by MPP+ and suggest that alterations in vesicle trafficking represent a primary event in PD pathogenesis. We propose that PD and other neurodegenerative diseases exhibiting dying-back neuropathology represent a previously undescribed category of neurological diseases characterized by dysfunction of vesicle transport and associated with the loss of synaptic function.
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Affiliation(s)
- G. Morfini
- *Department of Anatomy and Cell Biology, University of Illinois, Chicago, IL 60612
- Marine Biological Laboratory, Woods Hole, MA 02543
- To whom correspondence may be addressed. E-mail:
, , or
| | - G. Pigino
- *Department of Anatomy and Cell Biology, University of Illinois, Chicago, IL 60612
- Marine Biological Laboratory, Woods Hole, MA 02543
| | - K. Opalach
- Marine Biological Laboratory, Woods Hole, MA 02543
| | - Y. Serulle
- Marine Biological Laboratory, Woods Hole, MA 02543
- Department of Physiology and Neuroscience, New York University School of Medicine New York, NY 10016; and
| | - J. E. Moreira
- Marine Biological Laboratory, Woods Hole, MA 02543
- Department of Cell and Molecular Biology, Riberão Preto School of Medicine, University of São Paulo, SP 14049-900, Ribeirão Preto, Brazil
| | - M. Sugimori
- Marine Biological Laboratory, Woods Hole, MA 02543
- Department of Physiology and Neuroscience, New York University School of Medicine New York, NY 10016; and
| | - R. R. Llinás
- Marine Biological Laboratory, Woods Hole, MA 02543
- Department of Physiology and Neuroscience, New York University School of Medicine New York, NY 10016; and
- To whom correspondence may be addressed. E-mail:
, , or
| | - S. T. Brady
- *Department of Anatomy and Cell Biology, University of Illinois, Chicago, IL 60612
- Marine Biological Laboratory, Woods Hole, MA 02543
- To whom correspondence may be addressed. E-mail:
, , or
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11
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De Girolamo LA, Billett EE. Role of extracellular-regulated kinase and c-jun NH2-terminal kinase in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced neurofilament phosphorylation. J Neurosci Res 2006; 83:680-93. [PMID: 16447269 DOI: 10.1002/jnr.20765] [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] [Indexed: 11/07/2022]
Abstract
The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) causes selective degeneration of dopaminergic neurons in which the c-Jun NH2-terminal kinase (JNK) signalling cascade has been implicated. We have employed a differentiated mouse neuroblastoma N2a cell model to investigate the involvement of JNK and extracellular-regulated kinase (ERK) in MPTP-mediated toxicity and their role in neurofilament heavy chain (NF-H) phosphorylation. Acute treatment with a cytotoxic MPTP concentration (5 mM) caused rapid and sustained JNK phosphorylation and ERK dephosphorylation, accompanied by cell death. In contrast, subcytotoxic concentrations of 10 microM MPTP resulted in lower, transient JNK activation in the presence of sustained ERK activity. This resulted in an aberrant increase in a phosphorylation-dependent NF-H epitope, perikaryal accumulation of NF-H, and loss of axon-like processes, prior to cell death. Inhibition of MEK kinase, using PD98059, showed that MEK 1/2 or the downstream kinase, ERK, is required for N2a cell differentiation, NF-H phosphorylation and survival. Indeed, MPTP-induced cell death was exacerbated by the presence of PD98059. However, in the presence of MPTP, reducing JNK activity by using an upstream specific mixed-lineage kinase inhibitor (CEP-11004) significantly attenuated aberrant NF-H phosphorylation and perikaryal NF-H accumulation and maintained axon-like processes, in addition to attenuating cell death. This study reports a switch in the predominant kinase involved in NF phosphorylation in a neuronal cell model and may have implications for the formation of inclusions. Our studies provide further evidence that modulation of the JNK pathway could have a role in alleviating neuronal cell death.
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Affiliation(s)
- Luigi A De Girolamo
- Interdisciplinary Biomedical Research Centre, School of Biomedical and Natural Sciences, Nottingham Trent University, Clifton, Nottingham, United Kingdom.
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12
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Allani PK, Sum T, Bhansali SG, Mukherjee SK, Sonee M. A comparative study of the effect of oxidative stress on the cytoskeleton in human cortical neurons. Toxicol Appl Pharmacol 2004; 196:29-36. [PMID: 15050405 DOI: 10.1016/j.taap.2003.12.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2003] [Accepted: 12/11/2003] [Indexed: 10/26/2022]
Abstract
Cytoskeleton disruption is a process by which oxidative stress disrupts cellular function. This study compares and contrasts the effect of oxidative stress on the three major cytoskeleton filaments, microfilaments (MFs), microtubule (MT), and vimentin in human cortical neuronal cell line (HCN2). HCN2 cells were treated with 100 microM tertiary butylhydroperoxide (t-BuOOH), a free radical generating neurotoxin for 1, 3, or 6 h. Cell viability studies demonstrated significant cell death although the morphology studies showed that there was a substantial loss in neurites of neurons treated with t-BuOOH for 6 h. Because the cytoskeleton plays a role in neurite outgrowth, the effect of oxidative stress on the cytoskeletal was studied. In neurons subjected to oxidative stress for 30 min or 1 h, there were no major changes in microfilament distribution though there was altered distribution of microtubule and vimentin filaments as compared to controls. However, loss and disruption of all the three cytoskeletal filaments was observed at later times (3 and 6 h), which was confirmed by Western Blot analysis. Further studies were done to measure the gene expression levels of actin, tubulin, and vimentin. Results indicated that the overall loss of the cytoskeletal proteins in neurons treated with free radical generating toxin might not be a direct result of the downregulation of the cytoskeletal genes. This study shows that free radical generation in human neurons leads to the disruption of the cytoskeleton, though there may be a difference in the susceptibility to oxidative stress among the individual components of the cytoskeletal filaments.
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Affiliation(s)
- Pramod K Allani
- Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, Brookings, SD 57007, USA
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13
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Budziszewska B, Jaworska-Feil L, Tetich M, Basta-Kaim A, Kubera M, Leśkiewicz M, Lasoń W. Regulation of the human corticotropin-releasing-hormone gene promoter activity by antidepressant drugs in Neuro-2A and AtT-20 cells. Neuropsychopharmacology 2004; 29:785-94. [PMID: 14735130 DOI: 10.1038/sj.npp.1300379] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Major depression is frequently associated with hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. Clinically effective therapy with antidepressant drugs normalizes the disturbed activity of HPA axis, in part, by decreasing corticotropin-releasing hormone (CRH) synthesis, but the mechanism of this action is poorly recognized. In order to find out whether antidepressants directly affect CRH gene promoter activity, we studied their effect on undifferentiated and differentiated Neuro-2A cells, and for comparison the effect of the selected antidepressants on AtT-20 cells was also determined. The cells were stably transfected with a human CRH promoter fragment (-663 to +124 bp) linked to the chloramphenicol acetyltransferase (CAT) reporter gene. The regulation of CRH gene promoter activity is similar in Neuro-2A cells, both intact and differentiated, and in AtT-20 cell line, and cAMP/PKA-dependent pathway plays an important role in the stimulation of CRH gene. It was found that imipramine, amitryptyline, desipramine, fluoxetine, and mianserin, present in the culture medium for 5 days, in a concentration-dependent manner inhibited basal hCRH gene promoter activity in undifferentiated Neuro-2A cells, while other drugs under study (citalopram, tianeptine, moclobemide, venlafaxine, reboxetine, mirtazapine, and milnacipram) were inactive. In the differentiated cells, all examined antidepressants, except moclobemide (no effect) and tianeptine (increase), inhibited hCRH gene transcription. Moreover, in differentiated cells, the drugs acted stronger and were effective at lower concentrations. Forskolin-induced CAT activity was attenuated by imipramine and fluoxetine and to a lesser degree by amitriptyline and desipramine in differentiated cells, whereas other drugs were inactive. Moreover, imipramine and fluoxetine, but not tianeptine, showed moderate inhibitory effect on CRH gene promoter activity also in AtT-20 cell line, commonly used in CRH gene regulation studies. These results indicate that neuron-like differentiated Neuro-2A cells are a better model than pituitary and intact neuroblastoma to investigate the mechanism of psychotropic drug action. Inhibition of CRH gene promoter activity by antidepressant drugs may be a molecular mechanism by which these drugs inhibit the activity of HPA axis.
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Affiliation(s)
- Bogusława Budziszewska
- Department of Endocrinology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Smetna St, Poland.
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Opal P, Garcia JJ, Propst F, Matilla A, Orr HT, Zoghbi HY. Mapmodulin/leucine-rich acidic nuclear protein binds the light chain of microtubule-associated protein 1B and modulates neuritogenesis. J Biol Chem 2003; 278:34691-9. [PMID: 12807913 DOI: 10.1074/jbc.m302785200] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We had previously described the leucine-rich acidic nuclear protein (LANP) as a candidate mediator of toxicity in the polyglutamine disease, spinocerebellar ataxia type 1 (SCA1). This was based on the observation that LANP binds ataxin-1, the protein involved in this disease, in a glutamine repeat-dependent manner. Furthermore, LANP is expressed abundantly in purkinje cells, the primary site of ataxin-1 pathology. Here we focused our efforts on understanding the neuronal properties of LANP. In undifferentiated neuronal cells LANP is predominantly a nuclear protein, requiring a bona fide nuclear localization signal to be imported into the nucleus. LANP translocates from the nucleus to the cytoplasm during the process of neuritogenesis, interacts with the light chain of the microtubule-associated protein 1B (MAP1B), and modulates the effects of MAP1B on neurite extension. LANP thus could play a key role in neuronal development and/or neurodegeneration by its interactions with microtubule associated proteins.
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Affiliation(s)
- Puneet Opal
- Department of Neurology, Baylor College of Medicine, Houston, Texas 77030, USA.
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Sachana M, Flaskos J, Alexaki E, Glynn P, Hargreaves AJ. The toxicity of chlorpyrifos towards differentiating mouse N2a neuroblastoma cells. Toxicol In Vitro 2001; 15:369-72. [PMID: 11566565 DOI: 10.1016/s0887-2333(01)00038-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The aim of this work was to study the effects of chlorpyrifos (CPF) on the outgrowth of axons by differentiating mouse N2a neuroblastoma cells. This was achieved by morphological, Western blotting and enzymatic analyses of cells induced to differentiate in the presence and absence of CPF added either at the same time (co-differentiation) or 16 h after (post-differentiation) the induction of cell differentiation. The outgrowth of axon-like processes was impaired following 4 or 8 h exposure to CPF in both co- and post-differentiation experiments. Western blotting analysis revealed reduced levels of neurofilament heavy chain (NF-H) following 8 h of exposure but no significant effect at 4 h under both co- and post-differentiation conditions. By contrast, levels of the heat shock protein HSP-70 were raised at both time points, but only in co-differentiation experiments. Neuropathy target esterase (NTE) activity was lower than controls following 4 or 8 h of exposure under co-differentiation conditions, but not under any post-differentiation conditions. The results suggest that the inhibition of axon production and maintenance by CPF in differentiating N2a cells may involve multiple targets, which are different under co- and post-differentiation conditions.
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Affiliation(s)
- M Sachana
- Laboratory of Biochemistry and Toxicology, Faculty of Veterinary Medicine, Aristotelian University, Thessaloniki, Greece
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De Girolamo LA, Hargreaves AJ, Billett EE. Protection from MPTP-induced neurotoxicity in differentiating mouse N2a neuroblastoma cells. J Neurochem 2001; 76:650-60. [PMID: 11158235 DOI: 10.1046/j.1471-4159.2001.00066.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have shown previously that subcytotoxic concentrations of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) inhibit axon outgrowth and are associated with increased neurofilament heavy chain (NF-H) phosphorylation in differentiating mouse N2a neuroblastoma cells while higher doses (> 100 microM) cause cell death. In this work we assessed the ability of potential neuroprotective agents to alleviate both MPTP-induced cell death (cytotoxicity) and MPTP-induced NF-H phosphorylation/reduction in axon outgrowth (neurotoxicity) in N2a cells induced to differentiate by dbcAMP. The neurotoxic effects of MPTP occurred in the absence of significant alterations in energy status or mitochondrial membrane potential. The hormone oestradiol (100 microM) reduced the cytotoxic effect of MPTP, but blocked di-butyryl cyclic AMP (dbcAMP)-induced differentiation, i.e. axon outgrowth. Both the cytotoxic and neurotoxic effects of MPTP were reduced by the monoamine oxidase (MAO) inhibitors deprenyl and, to a lesser extent, clorgyline. Alleviation of both neurotoxicity and cytotoxicity was also achieved by conditioned medium derived from rat C6 glioma cells. In contrast, whilst the p38 MAP kinase inhibitor, SB202190, protected cells against MPTP-induced neurotoxicity, it could not maintain cell viability at high MPTP exposures. In each case neuroprotection involved maintenance of the differentiating phenotype linked with attenuation of NF-H hyper-phosphorylation; the latter may represent a mechanism by which neuronal cells can moderate MPTP-induced neurotoxicity. The use of a simplified neuronal cell model, which expresses subtle biochemical changes following neurotoxic insult, could therefore provide a valuable tool for the identification of potential neuroprotective agents.
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Affiliation(s)
- L A De Girolamo
- Department of Life Sciences, Faculty of Science and Mathematics, Nottingham Trent University, Clifton, Nottingham, UK
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