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Caputo M, Ivanova D, Chasserot-Golaz S, Doussau F, Haeberlé AM, Royer C, Ozkan S, Ecard J, Vitale N, Cousin MA, Tóth P, Gasman S, Ory S. Phospholipid Scramblase 1 Controls Efficient Neurotransmission and Synaptic Vesicle Retrieval at Cerebellar Synapses. J Neurosci 2024; 44:e0042242024. [PMID: 38839301 PMCID: PMC11223464 DOI: 10.1523/jneurosci.0042-24.2024] [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: 01/08/2024] [Revised: 04/23/2024] [Accepted: 04/28/2024] [Indexed: 06/07/2024] Open
Abstract
Phospholipids (PLs) are asymmetrically distributed at the plasma membrane. This asymmetric lipid distribution is transiently altered during calcium-regulated exocytosis, but the impact of this transient remodeling on presynaptic function is currently unknown. As phospholipid scramblase 1 (PLSCR1) randomizes PL distribution between the two leaflets of the plasma membrane in response to calcium activation, we set out to determine its role in neurotransmission. We report here that PLSCR1 is expressed in cerebellar granule cells (GrCs) and that PLSCR1-dependent phosphatidylserine egress occurred at synapses in response to neuron stimulation. Synaptic transmission is impaired at GrC Plscr1 -/- synapses, and both PS egress and synaptic vesicle (SV) endocytosis are inhibited in Plscr1 -/- cultured neurons from male and female mice, demonstrating that PLSCR1 controls PL asymmetry remodeling and SV retrieval following neurotransmitter release. Altogether, our data reveal a novel key role for PLSCR1 in SV recycling and provide the first evidence that PL scrambling at the plasma membrane is a prerequisite for optimal presynaptic performance.
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Affiliation(s)
- Margherita Caputo
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg F-67000, France
| | - Daniela Ivanova
- Centre for Discovery Brain Sciences, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Muir Maxwell Epilepsy Centre, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Sylvette Chasserot-Golaz
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg F-67000, France
| | - Frédéric Doussau
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg F-67000, France
| | - Anne-Marie Haeberlé
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg F-67000, France
| | - Cathy Royer
- Plateforme Imagerie In Vitro, Centre National de la Recherche Scientifique UPS3256, Strasbourg F-67000, France
| | - Sebahat Ozkan
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg F-67000, France
| | - Jason Ecard
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg F-67000, France
| | - Nicolas Vitale
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg F-67000, France
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Muir Maxwell Epilepsy Centre, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Simons Initiative for the Developing Brain, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Petra Tóth
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg F-67000, France
| | - Stéphane Gasman
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg F-67000, France
| | - Stéphane Ory
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg F-67000, France
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2
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Min JH, Sarlus H, Harris RA. Glycyl-l-histidyl-l-lysine prevents copper- and zinc-induced protein aggregation and central nervous system cell death in vitro. Metallomics 2024; 16:mfae019. [PMID: 38599632 PMCID: PMC11135135 DOI: 10.1093/mtomcs/mfae019] [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: 10/09/2023] [Accepted: 04/09/2024] [Indexed: 04/12/2024]
Abstract
Common features of neurodegenerative diseases are oxidative and inflammatory imbalances as well as the misfolding of proteins. An excess of free metal ions can be pathological and contribute to cell death, but only copper and zinc strongly promote protein aggregation. Herein we demonstrate that the endogenous copper-binding tripeptide glycyl-l-histidyl-l-lysine (GHK) has the ability to bind to and reduce copper redox activity and to prevent copper- and zinc-induced cell death in vitro. In addition, GHK prevents copper- and zinc-induced bovine serum albumin aggregation and reverses aggregation through resolubilizing the protein. We further demonstrate the enhanced toxicity of copper during inflammation and the ability of GHK to attenuate this toxicity. Finally, we investigated the effects of copper on enhancing paraquat toxicity and report a protective effect of GHK. We therefore conclude that GHK has potential as a cytoprotective compound with regard to copper and zinc toxicity, with positive effects on protein solubility and aggregation that warrant further investigation in the treatment of neurodegenerative diseases.
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Affiliation(s)
- Jin-Hong Min
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, S-171 76 Stockholm, Sweden
| | - Heela Sarlus
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, S-171 76 Stockholm, Sweden
| | - Robert A Harris
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, S-171 76 Stockholm, Sweden
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3
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Zhu F, Miao Y, Cheng M, Ye X, Chen A, Zheng G, Tian X. The CACNA1A Mutant Disrupts Lysosome Calcium Homeostasis in Cerebellar Neurons and the Resulting Endo-Lysosomal Fusion Defect Can be Improved by Calcium Modulation. Neurochem Res 2021; 47:249-263. [PMID: 34476720 DOI: 10.1007/s11064-021-03438-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 11/24/2022]
Abstract
Mutations in P/Q type voltage gated calcium channel (VGCC) lead severe human neurological diseases such as episodic ataxia 2, familial hemiplegic migraine 1, absence epilepsy, progressive ataxia and spinocerebellar ataxia 6. The pathogenesis of these diseases remains unclear. Mice with spontaneous mutation in the Cacna1a gene encoding the pore-forming subunit of P/Q type VGCC also exhibit ataxia, epilepsy and neurodegeneration. Based on the previous work showing that the P/Q type VGCC in neurons regulates lysosomal fusion through its calcium channel activity on lysosomes, we utilized CACNA1A mutant mice to further investigate the mechanism by which P/Q-type VGCCs regulate lysosomal function and neuronal homeostasis. We found CACNA1A mutant neurons have reduced lysosomal calcium storage without changing the resting calcium concentration in cytoplasm and the acidification of lysosomes. Immunohistochemistry and transmission electron microscopy reveal axonal degeneration due to lysosome dysfunction in the CACNA1A mutant cerebella. The calcium modulating drug thapsigargin, by depleting the ER calcium store, which locally increases the calcium concentration can alleviate the defective lysosomal fusion in mutant neurons. We propose a model that in cerebellar neurons, P/Q-type VGCC maintains the integrity of the nervous system by regulating lysosomal calcium homeostasis to affect lysosomal fusion, which in turn regulates multiple important cellular processes such as autophagy and endocytosis. This study helps us to better understand the pathogenesis of P/Q-type VGCC related neurodegenerative diseases and provides a feasible direction for future pharmacological treatment.
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Affiliation(s)
- Feng Zhu
- Key Laboratory of Neuropsychiatric Drug Research of Zhejiang Province, Institute of Materia Medica, Hangzhou Medical College (Zhejiang Academy of Medical Sciences), Hangzhou, 310013, China.,Department of Pharmacy, Hangzhou Medical College, Hangzhou, 310013, China
| | - Yunping Miao
- Key Laboratory of Neuropsychiatric Drug Research of Zhejiang Province, Institute of Materia Medica, Hangzhou Medical College (Zhejiang Academy of Medical Sciences), Hangzhou, 310013, China.,Department of Pharmacy, Hangzhou Medical College, Hangzhou, 310013, China
| | - Min Cheng
- Key Laboratory of Neuropsychiatric Drug Research of Zhejiang Province, Institute of Materia Medica, Hangzhou Medical College (Zhejiang Academy of Medical Sciences), Hangzhou, 310013, China.,Department of Pharmacy, Hangzhou Medical College, Hangzhou, 310013, China
| | - Xiaodi Ye
- Key Laboratory of Neuropsychiatric Drug Research of Zhejiang Province, Institute of Materia Medica, Hangzhou Medical College (Zhejiang Academy of Medical Sciences), Hangzhou, 310013, China.,Department of Pharmacy, Hangzhou Medical College, Hangzhou, 310013, China
| | - Aiying Chen
- Key Laboratory of Neuropsychiatric Drug Research of Zhejiang Province, Institute of Materia Medica, Hangzhou Medical College (Zhejiang Academy of Medical Sciences), Hangzhou, 310013, China.,Department of Pharmacy, Hangzhou Medical College, Hangzhou, 310013, China
| | - Gaoli Zheng
- National Zhejiang Center for Safety Evaluation of New Drugs, Hangzhou Medical College (Zhejiang Academy of Medical Sciences), Hangzhou, 310013, China
| | - Xuejun Tian
- Key Laboratory of Neuropsychiatric Drug Research of Zhejiang Province, Institute of Materia Medica, Hangzhou Medical College (Zhejiang Academy of Medical Sciences), Hangzhou, 310013, China. .,Department of Pharmacy, Hangzhou Medical College, Hangzhou, 310013, China. .,Life Sciences Institute and Innovation Center for Cell Biology, Zhejiang University, Hangzhou, 310058, China.
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4
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Ehinger R, Kuret A, Matt L, Frank N, Wild K, Kabagema-Bilan C, Bischof H, Malli R, Ruth P, Bausch AE, Lukowski R. Slack K + channels attenuate NMDA-induced excitotoxic brain damage and neuronal cell death. FASEB J 2021; 35:e21568. [PMID: 33817875 DOI: 10.1096/fj.202002308rr] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 03/14/2021] [Accepted: 03/17/2021] [Indexed: 12/13/2022]
Abstract
The neuronal Na+ -activated K+ channel Slack (aka Slo2.2, KNa 1.1, or Kcnt1) has been implicated in setting and maintaining the resting membrane potential and defining excitability and firing patterns, as well as in the generation of the slow afterhyperpolarization following bursts of action potentials. Slack activity increases significantly under conditions of high intracellular Na+ levels, suggesting this channel may exert important pathophysiological functions. To address these putative roles, we studied whether Slack K+ channels contribute to pathological changes and excitotoxic cell death caused by glutamatergic overstimulation of Ca2+ - and Na+ -permeable N-methyl-D-aspartic acid receptors (NMDAR). Slack-deficient (Slack KO) and wild-type (WT) mice were subjected to intrastriatal microinjections of the NMDAR agonist NMDA. NMDA-induced brain lesions were significantly increased in Slack KO vs WT mice, suggesting that the lack of Slack renders neurons particularly susceptible to excitotoxicity. Accordingly, excessive neuronal cell death was seen in Slack-deficient primary cerebellar granule cell (CGC) cultures exposed to glutamate and NMDA. Differences in neuronal survival between WT and Slack KO CGCs were largely abolished by the NMDAR antagonist MK-801, but not by NBQX, a potent and highly selective competitive antagonist of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type ionotropic glutamate receptors. Interestingly, NMDAR-evoked Ca2+ signals did not differ with regard to Slack genotype in CGCs. However, real-time monitoring of K+ following NMDAR activation revealed a significant contribution of this channel to the intracellular drop in K+ . Finally, TrkB and TrkC neurotrophin receptor transcript levels were elevated in NMDA-exposed Slack-proficient CGCs, suggesting a mechanism by which this K+ channel contributes to the activation of the extracellular-signal-regulated kinase (Erk) pathway and thereby to neuroprotection. Combined, our findings suggest that Slack-dependent K+ signals oppose the NMDAR-mediated excitotoxic neuronal injury by promoting pro-survival signaling via the BDNF/TrkB and Erk axis.
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Affiliation(s)
- Rebekka Ehinger
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Anna Kuret
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Lucas Matt
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Nadine Frank
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Katharina Wild
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Clement Kabagema-Bilan
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Helmut Bischof
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Roland Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Peter Ruth
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Anne E Bausch
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Robert Lukowski
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
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5
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Benito-Cuesta I, Ordóñez-Gutiérrez L, Wandosell F. AMPK activation does not enhance autophagy in neurons in contrast to MTORC1 inhibition: different impact on β-amyloid clearance. Autophagy 2021; 17:656-671. [PMID: 32075509 PMCID: PMC8032230 DOI: 10.1080/15548627.2020.1728095] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/08/2020] [Accepted: 02/06/2020] [Indexed: 01/04/2023] Open
Abstract
The physiological AKT-MTORC1 and AMPK signaling pathways are considered key nodes in the regulation of anabolism-catabolism, and particularly of macroautophagy/autophagy. Indeed, it is reported that these are altered processes in neurodegenerative proteinopathies such as Alzheimer disease (AD), mainly characterized by deposits of β-amyloid (Aβ) and hyperphosphorylated MAPT. These accumulations disrupt the optimal neuronal proteostasis, and hence, the recovery/enhancement of autophagy has been proposed as a therapeutic approach against these proteinopathies. The purpose of the present study was to characterize the modulation of autophagy by MTORC1 and AMPK signaling pathways in the highly specialized neurons, as well as their repercussions on Aβ production. Using a double transgenic mice model of AD, we demonstrated that MTORC1 inhibition, either in vivo or ex vivo (primary neuronal cultures), was able to reduce amyloid secretion through moderate autophagy induction in neurons. The pharmacological prevention of autophagy in neurons augmented the Aβ secretion and reversed the effect of rapamycin, confirming the anti-amyloidogenic effects of autophagy in neurons. Inhibition of AMPK with compound C generated the expected decrease in autophagy induction, though surprisingly did not increase the Aβ secretion. In contrast, increased activity of AMPK with metformin, AICAR, 2DG, or by gene overexpression did not enhance autophagy but had different effects on Aβ secretion: whereas metformin and 2DG diminished the secreted Aβ levels, AICAR and PRKAA1/AMPK gene overexpression increased them. We conclude that AMPK has a significantly different role in primary neurons than in other reported cells, lacking a direct effect on autophagy-dependent amyloidosis.Abbreviations: 2DG: 2-deoxy-D-glucose; Aβ: β-amyloid; ACACA: acetyl-CoA carboxylase alpha; ACTB: actin beta; AD: Alzheimer disease; AICAR: 5-aminoimidazole-4-carboxamide-1-β-riboside; AKT: AKT kinases group (AKT1 [AKT serine/threonine kinase 1], AKT2 and AKT3); AMPK: adenosine 5'-monophosphate (AMP)-activated protein kinase; APP: amyloid beta precursor protein; APP/PSEN1: B6.Cg-Tg (APPSwe, PSEN1dE9) 85Dbo/J; ATG: autophagy related; ATP: adenosine triphosphate; BafA1: bafilomycin A1; CA: constitutively active; CGN: cerebellar granule neuron; CoC/compound C: dorsommorphin dihydrochloride; ELISA: enzyme-linked immunosorbent assay; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GFP: green fluorescent protein; Gmax: GlutaMAX™; IN1: PIK3C3/VPS34-IN1; KI: kinase-inactive; MAP1LC3B/LC3: microtubule associated protein 1 light chain 3; MAPT/TAU: microtubule associated protein tau; Metf: metformin; MRT: MRT68921; MTORC1: mechanistic target of rapamycin kinase complex 1; NBR1: NBR1 autophagy cargo receptor; PRKAA: 5'-AMP-activated protein kinase catalytic subunit alpha; PtdIns3K: phosphatidylinositol 3-kinase; Rapa: rapamycin; RPS6KB1/S6K: ribosomal protein S6 (RPS6) kinase polypeptide 1; SCR: scramble; SQSTM1/p62: sequestosome 1; ULK1/2: unc-51 like autophagy activating kinase 1/2; WT: wild type.
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Affiliation(s)
- Irene Benito-Cuesta
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| | - Lara Ordóñez-Gutiérrez
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| | - Francisco Wandosell
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
- Alzheimer's Disease and Other Degenerative Dementias, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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6
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Kim MH, Park SR, Choi BH. Comparative Analysis of the Expression of Chondroitin Sulfate Subtypes and Their Inhibitory Effect on Axonal Growth in the Embryonic, Adult, and Injured Rat Brains. Tissue Eng Regen Med 2020; 18:165-178. [PMID: 32939673 DOI: 10.1007/s13770-020-00295-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 08/01/2020] [Accepted: 08/16/2020] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND Chondroitin sulfate glycosaminoglycans (CS-GAGs) are the primary inhibitory GAGs for neuronal growth after central nervous system (CNS) injury. However, the inhibitory or permissive activity of CS-GAG subtypes is controversial and depends on the physiological needs of CNS tissues. In this study, we investigated the characteristics and effects of CS-GAGs on axonal growth, which was isolated from the brain cortices of normal rat embryo at E18, normal adult rat brain and injured adult rat brain. METHODS Isolated CS-GAGs from embryo, normal adult, and injured adult rat brains were used for analyzing their effect on attachment and axonal growth using modified spot assay with dorsal root ganglion (DRG) explants and cerebellar granule neurons (CGNs). CS-GAGs were separated using high performance liquid chromatography (HPLC), and the subtypes of CS-GAGs were analyzed. RESULTS CS-GAGs of all three groups inhibited CGN attachment and axonal growth of DRGs. However, CS-GAGs of normal adult rat brain exhibited higher inhibitory activity than those of the other groups in both assays. When subtypes of CS-GAGs were analyzed using HPLC, CS-A (4S) was the most abundant in all three groups and found in largest amount in normal adult rat brain. In contrast, unsulfated CS (CS0) and CS-C (6S) were more abundant by 3-4-folds in E18 group than in the two adult groups. CONCLUSION When compared with the normal adult rat brain, injured rat brain showed relatively similar patterns to that of embryonic rat brain at E18 in the expression of CS subtypes and their inhibitory effect on axonal growth. This phenomenon could be due to differential expression of CS-GAGs subtypes causing decrease in the amount of CS-A and mature-type CS proteoglycan core proteins.
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Affiliation(s)
- Moon Hang Kim
- Biomedical Research Institute, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - So Ra Park
- Department of Physiology, Inha University College of Medicine, 100 Inha-ro, Michuhol-gu, Incheon, 22212, Republic of Korea
| | - Byung Hyune Choi
- Department of Biomedical Sciences, Inha University College of Medicine, 100 Inha-ro, Michuhol-gu, Incheon, 22212, Republic of Korea.
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7
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Zhan X, Asmara H, Cheng N, Sahu G, Sanchez E, Zhang FX, Zamponi GW, Rho JM, Turner RW. FMRP(1-297)-tat restores ion channel and synaptic function in a model of Fragile X syndrome. Nat Commun 2020; 11:2755. [PMID: 32488011 PMCID: PMC7265297 DOI: 10.1038/s41467-020-16250-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 04/22/2020] [Indexed: 01/21/2023] Open
Abstract
Fragile X Syndrome results from a loss of Fragile X Mental Retardation Protein (FMRP). We now show that FMRP is a member of a Cav3-Kv4 ion channel complex that is known to regulate A-type potassium current in cerebellar granule cells to produce mossy fiber LTP. Mossy fiber LTP is absent in Fmr1 knockout (KO) mice but is restored by FMRP(1-297)-tat peptide. This peptide further rapidly permeates the blood-brain barrier to enter cells across the cerebellar-cortical axis that restores the balance of protein translation for at least 24 h and transiently reduces elevated levels of activity of adult Fmr1 KO mice in the Open Field Test. These data reveal that FMRP(1-297)-tat can improve function from the levels of protein translation to synaptic efficacy and behaviour in a model of Fragile X syndrome, identifying a potential therapeutic strategy for this genetic disorder.
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Affiliation(s)
- Xiaoqin Zhan
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Hadhimulya Asmara
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Ning Cheng
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Giriraj Sahu
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Eduardo Sanchez
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Fang-Xiong Zhang
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Gerald W Zamponi
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Jong M Rho
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Ray W Turner
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.
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8
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Jiwani T, Kim JJ, Rosenblum ND. Suppressor of fused controls cerebellum granule cell proliferation by suppressing Fgf8 and spatially regulating Gli proteins. Development 2020; 147:dev.170274. [PMID: 31932349 DOI: 10.1242/dev.170274] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 12/19/2019] [Indexed: 01/07/2023]
Abstract
Cerebellar granule cell (GC) development relies on precise regulation of sonic hedgehog (Shh)-Gli signalling activity, failure of which is associated with motor disorders and medulloblastoma. Mutations in the pathway regulator suppressor of fused (Sufu), which modulates Gli activators and repressors, are linked to cerebellar dysfunction and tumourigenesis. The mechanism by which Sufu calibrates Shh signalling in GCs is unknown. Math1-Cre-mediated deletion of Sufu in mouse GC progenitors (GCPs) demonstrated that Sufu restricts GCP proliferation and promotes cell cycle exit, by promoting expression of Gli3R and suppressing Gli2 levels. Sufu is also required to promote a high threshold of pathway activity in GCPs. Remarkably, central cerebellar lobules are more deleteriously impacted by Sufu deletion, but are less sensitive to downstream genetic manipulations to reduce Gli2 expression or overexpress a Gli3R mimic, compared with anterior lobules. Transcriptome sequencing uncovered new Sufu targets, especially Fgf8, which is upregulated in Sufu-mutant GCPs. We demonstrate that Fgf8 is necessary and sufficient to drive Sufu-mutant GCP proliferation. This study reveals new insights into the spatial and temporal regulation of cerebellar Shh-Gli signalling, while uncovering new targets, such as Fgf8.
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Affiliation(s)
- Tayyaba Jiwani
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Jinny J Kim
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Norman D Rosenblum
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada .,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Department of Paediatrics, University of Toronto, Toronto, Ontario M5G 1X8, Canada
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9
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Fu Y, Dong J, Wang J, You M, Wei L, Fu H, Wang Y, Chen J. Developmental Exposure to Di-(2-ethylhexyl) Phthalate Induces Cerebellar Granule Cell Apoptosis via the PI3K/AKT Signaling Pathway. Exp Neurobiol 2018; 27:472-488. [PMID: 30636900 PMCID: PMC6318557 DOI: 10.5607/en.2018.27.6.472] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 12/11/2018] [Accepted: 12/12/2018] [Indexed: 12/26/2022] Open
Abstract
Di-(2-ethylhexyl) phthalate (DEHP) is an ubiquitous environmental contaminant because of its extensive use in plastics and its persistence. As an environmental endocrine disruptor, it is suspected to interfere with neurodevelopment in people. However, evidence of the effects of maternal DEHP exposure on cerebellar development in offspring is scarce. The objective of this study was to investigate maternal exposure to DEHP and its effect on apoptosis of cerebellar granule cells (CGCs) and related mechanisms. Pregnant Wistar rats were administrated DEHP (0, 30, 300 and 750 mg/kg/d) by gavage from gestational day (GD) 0 to postnatal day (PN) 21. Primary CGCs were also exposed to mono-(2-ethylhexyl) phthalate (MEHP), the main metabolite of DEHP, for 24 h with concentrations of 0, 25, 100 and 250 µM. The CGCs of male offspring from 300 and 750 mg/kg/d DEHP exposure groups showed significantly increased apoptosis. In addition, the PI3K/AKT signaling pathway was inhibited in the male offspring of the 300 and 750 mg/kg/d DEHP exposure groups. However, effects on female pups were not obvious. Apoptosis was also elevated and the PI3K/AKT signaling pathway was inhibited after primary CGCs were exposed to MEHP. Furthermore, apoptosis was reduced after treatment with the PI3K/AKT signaling pathway activator, insulin-like growth factor (IGF) 1, and increased after treatment with LY294002, an inhibitor of the PI3K/AKT signaling pathway. These results suggested that maternal DEHP exposure induced apoptosis in the CGCs of male pups via the PI3K/AKT signaling pathway, and the apoptosis could be rescued by IGF1 and aggravated by LY294002.
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Affiliation(s)
- Yuanyuan Fu
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China
| | - Jing Dong
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China
| | - Jianan Wang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China
| | - Mingdan You
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China
| | - Lingling Wei
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China
| | - Hui Fu
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China
| | - Yuan Wang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China
| | - Jie Chen
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China
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10
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Gilmore-Hall S, Kuo J, Ward JM, Zahra R, Morrison RS, Perkins G, La Spada AR. CCP1 promotes mitochondrial fusion and motility to prevent Purkinje cell neuron loss in pcd mice. J Cell Biol 2018; 218:206-219. [PMID: 30337352 PMCID: PMC6314562 DOI: 10.1083/jcb.201709028] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 08/03/2018] [Accepted: 10/01/2018] [Indexed: 12/22/2022] Open
Abstract
A perplexing question in neurodegeneration is why different neurons degenerate. The Purkinje cell degeneration (pcd) mouse displays a dramatic phenotype of degeneration of cerebellar Purkinje cells. Loss of CCP1/Nna1 deglutamylation of tubulin accounts for pcd neurodegeneration, but the mechanism is unknown. In this study, we modulated the dosage of fission and fusion genes in a Drosophila melanogaster loss-of-function model and found that mitochondrial fragmentation and disease phenotypes were rescued by reduced Drp1. We observed mitochondrial fragmentation in CCP1 null cells and in neurons from pcd mice, and we documented reduced mitochondrial fusion in cells lacking CCP1. We examined the effect of tubulin hyperglutamylation on microtubule-mediated mitochondrial motility in pcd neurons and noted markedly reduced retrograde axonal transport. Mitochondrial stress promoted Parkin-dependent turnover of CCP1, and CCP1 and Parkin physically interacted. Our results indicate that CCP1 regulates mitochondrial motility through deglutamylation of tubulin and that loss of CCP1-mediated mitochondrial fusion accounts for the exquisite vulnerability of Purkinje neurons in pcd mice.
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Affiliation(s)
| | - Jennifer Kuo
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Jacqueline M Ward
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Rabaab Zahra
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | | | - Guy Perkins
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA
| | - Albert R La Spada
- Department of Pediatrics, University of California, San Diego, La Jolla, CA .,Department of Neurosciences, University of California, San Diego, La Jolla, CA.,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA.,Division of Biological Sciences, University of California, San Diego, La Jolla, CA.,Department of Neurology, Duke University School of Medicine, Durham, NC.,Department of Neurobiology, Duke University School of Medicine, Durham, NC.,Department of Cell Biology, Duke University School of Medicine, Durham, NC.,Duke Center for Neurodegeneration and Neurotherapeutics, Duke University School of Medicine, Durham, NC
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11
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Sharma A, Kaur G. Tinospora cordifolia as a potential neuroregenerative candidate against glutamate induced excitotoxicity: an in vitro perspective. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2018; 18:268. [PMID: 30285727 PMCID: PMC6167833 DOI: 10.1186/s12906-018-2330-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 09/20/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND Glutamate, the major excitatory neurotransmitter of CNS acts as a neurotoxin at higher concentrations. Prolonged activation of glutamate receptors results in progressive neuronal damage by aggravating calcium influx, inducing mitochondrial damage and oxidative stress. Excitotoxic cell death is associated with the pathogenesis of various neurodegenerative disorders such as trauma, brain injury and neurodegenerative diseases. The current study was designed to investigate the neuroprotective and neuroregenerative potential of Tinospora cordifolia against glutamate-induced excitotoxicity using primary cerebellar neuronal cultures as a model system. METHODS Monosodium salt of glutamate was used to induce neurotoxic injury in primary cerebellar neurons. Four extracts including Hexane extract, Chloroform extract, Ethyl acetate, and Butanol extract were obtained from fractionation of previously reported aqueous ethanolic extract of T. cordifolia and tested for neuroprotective activity. Out of the four fractions, Butanol extract of T. cordifolia (B-TCE) exhibited neuroprotective potential by preventing degeneration of neurons induced by glutamate. Expression of different neuronal, apoptotic, inflammatory, cell cycle regulatory and plasticity markers was studied by immunostaining and Western blotting. Neurite outgrowth and migration were also studied using primary explant cultures, wound scratch and gelatin zymogram assay. RESULTS At molecular level, B-TCE pretreatment of glutamate-treated cultures normalized the stress-induced downregulation in the expression of neuronal markers (MAP-2, GAP-43, NF200) and anti-apoptotic marker (Bcl-xL). Further, cells exposed to glutamate showed enhanced expression of inflammatory (NF-κB, AP-1) and senescence markers (HSP70, Mortalin) as well as the extent of mitochondrial damage. However, B-TCE pretreatment prevented this increase and inhibited glutamate-induced onset of inflammation, stress and mitochondrial membrane damage. Furthermore, B-TCE was observed to promote regeneration, migration and plasticity of cerebellar neurons, which was otherwise significantly inhibited by glutamate treatment. CONCLUSION These results suggest that B-TCE may have neuroprotective and neuroregenerative potential against catastrophic consequences of glutamate-mediated excitotoxicity and could be a potential therapeutic candidate for neurodegenerative diseases.
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Affiliation(s)
- Anuradha Sharma
- Department of Biotechnology, Medical Biotechnology lab, Guru Nanak Dev University, Amritsar, Punjab 143005 India
| | - Gurcharan Kaur
- Department of Biotechnology, Medical Biotechnology lab, Guru Nanak Dev University, Amritsar, Punjab 143005 India
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12
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Berntsen HF, Bjørklund CG, Strandabø R, Haug TM, Moldes-Anaya A, Fuentes-Lazaro J, Verhaegen S, Paulsen RE, Tasker RA, Ropstad E. PFOS-induced excitotoxicity is dependent on Ca2+ influx via NMDA receptors in rat cerebellar granule neurons. Toxicol Appl Pharmacol 2018; 357:19-32. [DOI: 10.1016/j.taap.2018.08.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/10/2018] [Accepted: 08/20/2018] [Indexed: 12/31/2022]
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13
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Dihydroceramide Desaturase 1 Inhibitors Reduce Amyloid-β Levels in Primary Neurons from an Alzheimer's Disease Transgenic Model. Pharm Res 2018; 35:49. [PMID: 29411122 DOI: 10.1007/s11095-017-2312-2] [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: 07/10/2017] [Accepted: 11/16/2017] [Indexed: 02/07/2023]
Abstract
PURPOSE The induction of autophagy has recently been explored as a promising therapeutic strategy to combat Alzheimer's disease. Among many other factors, there is evidence that ceramides/dihydroceramides act as mediators of autophagy, although the exact mechanisms underlying such effects are poorly understood. Here, we describe how two dihydroceramide desaturase inhibitors (XM461 and XM462) trigger autophagy and reduce amyloid secretion by neurons. METHODS Neurons isolated from wild-type and APP/PS1 transgenic mice were exposed to the two dihydroceramide desaturase inhibitors to assess their effect on these cell's protein and lipid profiles. RESULTS Both dihydroceramide desaturase inhibitors increased the autophagic vesicles in wild-type neurons, reflected as an increase in LC3-II, and this was correlated with the accumulation of dihydroceramides and dihydrosphingomyelins. Exposing APP/PS1 transgenic neurons to these inhibitors also produced a 50% reduction in amyloid secretion and/or production. The lipidomic defects triggered by these dihydroceramide desaturase inhibitors were correlated with a loss of S6K activity, witnessed by the changes in S6 phosphorylation, which strongly suggested a reduction of mTORC1 activity. CONCLUSIONS The data obtained strongly suggest that dihydroceramide desaturase 1 activity may modulate autophagy and mTORC1 activity in neurons, inhibiting amyloid secretion and S6K activity. As such, it is tantalizing to propose that dihydroceramide desaturase 1 may be an important therapeutic target to combat amyloidosis.
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14
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Marangoni N, Kowal K, Deliu Z, Hensley K, Feinstein DL. Neuroprotective and neurotrophic effects of Lanthionine Ketimine Ester. Neurosci Lett 2017; 664:28-33. [PMID: 29128626 DOI: 10.1016/j.neulet.2017.11.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/06/2017] [Accepted: 11/08/2017] [Indexed: 11/17/2022]
Abstract
Lanthionine ketimine ethyl ester (LKE) is a synthetic derivative of the naturally occurring amino acid lanthionine ketimine. We previously showed that LKE reduced clinical signs in a mouse model of multiple sclerosis (MS) associated with reductions in axonal damage; however, whether LKE has direct beneficial actions on mammalian neuronal cells was not examined. In the current study, we tested the effects of LKE in SH-SY5Y human neuronal cells and in primary mouse cerebellar granule neurons. In both cell types, LKE dose-dependently reduced the cell death that occurred spontaneously followed a change in media. LKE also reduced cell death due to glutamate excitoxicity, accompanied by a reduction in production of reactive oxygen species. LKE induced neuritogenesis in both undifferentiated SH-SY5Y cells and in primary neuron, increasing process numbers and lengths. These results demonstrate that direct neuroprotective and neurotrophic effects of LKE likely contribute to its beneficial actions in vivo.
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Affiliation(s)
- Natalia Marangoni
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, United States
| | - Kathy Kowal
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, United States
| | - Zane Deliu
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, United States
| | - Kenneth Hensley
- Department of Biochemistry, Molecular and Cell Science, Arkansas College of Osteopathic Medicine, Fort Smith, AK 72916, United States
| | - Douglas L Feinstein
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, United States; Department of Veterans Affairs, Jesse Brown VA Medical Center, Chicago, IL 60612, United States.
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15
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Laaper M, Haque T, Slack RS, Jahani-Asl A. Modeling Neuronal Death and Degeneration in Mouse Primary Cerebellar Granule Neurons. J Vis Exp 2017. [PMID: 29155785 DOI: 10.3791/55871] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Cerebellar granule neurons (CGNs) are a commonly used neuronal model, forming an abundant homogeneous population in the cerebellum. In light of their post-natal development, abundance, and accessibility, CGNs are an ideal model to study neuronal processes, including neuronal development, neuronal migration, and physiological neuronal activity stimulation. In addition, CGN cultures provide an excellent model for studying different modes of cell death including excitotoxicity and apoptosis. Within a week in culture, CGNs express N-methyl-D-aspartate (NMDA) receptors, a specific ionotropic glutamate receptor with many critical functions in neuronal health and disease. The addition of low concentrations of NMDA in conjunction with membrane depolarization to rodent primary CGN cultures has been used to model physiological neuronal activity stimulation while the addition of high concentrations of NMDA can be employed to model excitotoxic neuronal injury. Here, a method of isolation and culturing of CGNs from 6 day old pups as well as genetic manipulation of CGNs by adenoviruses and lentiviruses are described. We also present optimized protocols on how to stimulate NMDA-induced excitotoxicity, low-potassium-induced apoptosis, oxidative stress and DNA damage following transduction of these neurons.
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Affiliation(s)
- Matthew Laaper
- Lady Davis Institute for Medical Research, Jewish General Hospital; Integrated Program in Neuroscience, McGill University
| | - Takrima Haque
- Lady Davis Institute for Medical Research, Jewish General Hospital
| | - Ruth S Slack
- Department of Cellular and Molecular Medicine, University of Ottawa
| | - Arezu Jahani-Asl
- Lady Davis Institute for Medical Research, Jewish General Hospital; Integrated Program in Neuroscience, McGill University; Department of Oncology, Faculty of Medicine, McGill University;
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16
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Lopachev AV, Lopacheva OM, Osipova EA, Vladychenskaya EA, Smolyaninova LV, Fedorova TN, Koroleva OV, Akkuratov EE. Ouabain-induced changes in MAP kinase phosphorylation in primary culture of rat cerebellar cells. Cell Biochem Funct 2017; 34:367-77. [PMID: 27338714 DOI: 10.1002/cbf.3199] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 05/21/2016] [Accepted: 05/23/2016] [Indexed: 02/06/2023]
Abstract
Cardiotonic steroid (CTS) ouabain is a well-established inhibitor of Na,K-ATPase capable of inducing signalling processes including changes in the activity of the mitogen activated protein kinases (MAPK) in various cell types. With increasing evidence of endogenous CTS in the blood and cerebrospinal fluid, it is of particular interest to study ouabain-induced signalling in neurons, especially the activation of MAPK, because they are the key kinases activated in response to extracellular signals and regulating cell survival, proliferation and apoptosis. In this study we investigated the effect of ouabain on the level of phosphorylation of three MAPK (ERK1/2, JNK and p38) and on cell survival in the primary culture of rat cerebellar cells. Using Western blotting we described the time course and concentration dependence of phosphorylation for ERK1/2, JNK and p38 in response to ouabain. We discovered that ouabain at a concentration of 1 μM does not cause cell death in cultured neurons while it changes the phosphorylation level of the three MAPK: ERK1/2 is phosphorylated transiently, p38 shows sustained phosphorylation, and JNK is dephosphorylated after a long-term incubation. We showed that ERK1/2 phosphorylation increase does not depend on ouabain-induced calcium increase and p38 activation. Changes in p38 phosphorylation, which is independent from ERK1/2 activation, are calcium dependent. Changes in JNK phosphorylation are calcium dependent and also depend on ERK1/2 and p38 activation. Ten-micromolar ouabain leads to cell death, and we conclude that different effects of 1-μM and 10-μM ouabain depend on different ERK1/2 and p38 phosphorylation profiles. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Alexander V Lopachev
- Research Center of Neurology, Moscow, Russia.,Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Olga M Lopacheva
- Research Center of Neurology, Moscow, Russia.,Lomonosov Moscow State University, International Biotechnological Center, Moscow, Russia
| | - Ekaterina A Osipova
- Lomonosov Moscow State University, International Biotechnological Center, Moscow, Russia.,Lomonosov Moscow State University, Faculty of Chemistry, Department of Chemical Enzymology, Moscow, Russia
| | | | - Larisa V Smolyaninova
- Lomonosov Moscow State University, International Biotechnological Center, Moscow, Russia.,Lomonosov Moscow State University, Faculty of Biology, Department of Biochemistry, Moscow, Russia
| | | | - Olga V Koroleva
- Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Evgeny E Akkuratov
- St. Petersburg State University, Institute of Translational Biomedicine, St. Petersburg, Russia
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17
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Lopachev AV, Lopacheva OM, Abaimov DA, Koroleva OV, Vladychenskaya EA, Erukhimovich AA, Fedorova TN. Neuroprotective Effect of Carnosine on Primary Culture of Rat Cerebellar Cells under Oxidative Stress. BIOCHEMISTRY (MOSCOW) 2017; 81:511-20. [PMID: 27297901 DOI: 10.1134/s0006297916050084] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Dipeptide carnosine (β-alanyl-L-histidine) is a natural antioxidant, but its protective effect under oxidative stress induced by neurotoxins is studied insufficiently. In this work, we show the neuroprotective effect of carnosine in primary cultures of rat cerebellar cells under oxidative stress induced by 1 mM 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH), which directly generates free radicals both in the medium and in the cells, and 20 nM rotenone, which increases the amount of intracellular reactive oxygen species (ROS). In both models, adding 2 mM carnosine to the incubation medium decreased cell death calculated using fluorescence microscopy and enhanced cell viability estimated by the MTT assay. The antioxidant effect of carnosine inside cultured cells was demonstrated using the fluorescence probe dichlorofluorescein. Carnosine reduced by half the increase in the number of ROS in neurons induced by 20 nM rotenone. Using iron-induced chemiluminescence, we showed that preincubation of primary neuronal cultures with 2 mM carnosine prevents the decrease in endogenous antioxidant potential of cells induced by 1 mM AAPH and 20 nM rotenone. Using liquid chromatography-mass spectrometry, we showed that a 10-min incubation of neuronal cultures with 2 mM carnosine leads to a 14.5-fold increase in carnosine content in cell lysates. Thus, carnosine is able to penetrate neurons and exerts an antioxidant effect. Western blot analysis revealed the presence of the peptide transporter PEPT2 in rat cerebellar cells, which suggests the possibility of carnosine transport into the cells. At the same time, Western blot analysis showed no carnosine-induced changes in the level of apoptosis regulating proteins of the Bcl-2 family and in the phosphorylation of MAP kinases, which suggests that carnosine could have minimal or no side effects on proliferation and apoptosis control systems in normal cells.
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Affiliation(s)
- A V Lopachev
- Research Center of Neurology, Moscow, 125367, Russia.
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18
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Montelli S, Suman M, Corain L, Cozzi B, Peruffo A. Sexually Diergic Trophic Effects of Estradiol Exposure on Developing Bovine Cerebellar Granule Cells. Neuroendocrinology 2017; 104:51-71. [PMID: 26882349 DOI: 10.1159/000444528] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 02/06/2016] [Indexed: 11/19/2022]
Abstract
In the mammalian brain, the differentiation of neural cells and the developmental organization of the underlying circuitry are influenced by steroid hormones. The estrogen 17-β estradiol (E2) is one of the most potent regulators of neural growth during prenatal life, synthetized locally from steroid precursors including prenatal testicular testosterone. Estradiol promotes brain differentiation counting sexually dimorphic neural circuits by binding to the estrogen receptors, ER-α and ER-β. The cerebellum has been described as a site of estrogen action and a potentially sexually dimorphic area. The goal of this study was to analyze the capacity of E2 to affect the growth of male and female fetal bovine cerebellar granule. We performed primary cultures of fetal cerebellar granules, and verified the mRNA expression of the ER-α and ER-β in both sexes. Moreover, the distribution of ERs in the male and female cerebellar granules of the second fetal stage was characterized by immunohistochemistry. We measured morphological parameters in presence (or absence) of estradiol administration, focusing on the variations of the dendritic branching pattern of granule neurons. By using the nonparametric combination and permutation testing approach, we proposed a sophisticated multivariate statistical analysis to demonstrate that E2 induces multifarious and dimorphic changes in the granule cells. E2 exerts trophic effects in both female and male granules and this effect is stronger in female. Male granules treated with E2 became similar to female control granule. Bos taurus species has a long gestation and a large brain that offers an interesting alternative in comparative neuroscience.
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Affiliation(s)
- Stefano Montelli
- Department of Comparative Biomedicine and Food Science of the University of Padova, Legnaro, taly
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19
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Soodi M, Dashti A, Hajimehdipoor H, Akbari S, Ataei N. Melissa officinalis Acidic Fraction Protects Cultured Cerebellar Granule Neurons Against Beta Amyloid-Induced Apoptosis and Oxidative Stress. CELL JOURNAL 2016; 18:556-564. [PMID: 28042540 PMCID: PMC5086334 DOI: 10.22074/cellj.2016.4722] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 04/25/2016] [Indexed: 12/18/2022]
Abstract
Objective Extracellular deposition of the beta-amyloid (Aβ) peptide, which is the main finding in the pathophysiology of Alzheimer’s disease (AD), leads to oxidative damage and apoptosis in neurons. Melissa officinalis (M. officinalis) is a medicinal plant from the Lamiaceae
family that has neuroprotective activity. In the present study we have investigated the protective effect of the acidic fraction of M. officinalis on Aβ-induced oxidative stress and apoptosis
in cultured cerebellar granule neurons (CGN). Additionally, we investigated a possible role of
the nicotinic receptor.
Materials and Methods This study was an in vitro experimental study performed on
mice cultured CGNs. CGNs were pre-incubated with different concentrations of the acidic
fraction of M. officinalis for 24 hours, followed by incubation with Aβ for an additional 48
hours. CGNs were also pre-incubated with the acidic fraction of M. officinalis and mecamylamin, followed by incubation with Aβ. We used the 3-(4,5-dimethylthiazol-2-yl)-2,5-
diphenyltetrazolium bromide (MTT) assay to measure cell viability. Acetylcholinesterase
(AChE) activity, reactive oxygen species (ROS) production, lipidperoxidation, and caspase-3 activity were measured after incubation. Hochst/annexin Vfluorescein isothiocyanate (FITC)/propidium iodide (PI) staining was performed to detect apoptotic cells.
Results The acidic fraction could protect CGNs from Aβ-induced cytotoxicity. Mecamylamine did not abolish the protective effect of the acidic fraction. AChE activity, ROS
production, lipid peroxidation, and caspase-3 activity increased after Aβ incubation. Preincubation with the acidic fraction of M. officinalis ameliorated these factors and decreased
the number of apoptotic cells.
Conclusion Our results indicated that the protective effect of the acidic fraction of M.
officinalis was not mediated through nicotinic receptors. This fraction could protect CGNs
through antioxidant and anti-apoptotic activities.
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Affiliation(s)
- Maliheh Soodi
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Abolfazl Dashti
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Homa Hajimehdipoor
- Department of Traditional Pharmacy, School of Traditional Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shole Akbari
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Nasim Ataei
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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20
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Amani N, Soodi M, Daraei B, Dashti A. Chlorpyrifos Toxicity in Mouse Cultured Cerebellar Granule Neurons at Different Stages of Development: Additive Effect on Glutamate-Induced Excitotoxicity. CELL JOURNAL 2016; 18:464-72. [PMID: 27602329 PMCID: PMC5011335 DOI: 10.22074/cellj.2016.4575] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Accepted: 01/06/2016] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Chlorpyrifos (CPF) is a neurotoxic organophosphorus (OP) insecticide. Its mechanism of action includes oxidative stress, excitotoxicity, and inhibition of the acetylcholinesterase enzyme (AChE). The aim of the present study is to investigate CPF toxicity in mature and immature cerebellar granule neurons (CGNs), as well as its effect on glutamate induced excitotoxicity. MATERIALS AND METHODS This study was an in vitro experimental study performed on mice cultured CGNs. Immature and mature neurons were exposed to different concentrations of CPF (1-1000 µM) and glutamate (10-600 µM) for 48 hours after which we used the MTT assay to measure cytotoxicity. Immature neurons had exposure to CPF for 5 days in order to evaluate the cytotoxic effect on developing neurons. Mature neurons received sub-lethal concentrations of CPF (10, 100 µM) combined with different concentrations of glutamate. AChE activity and reactive oxygen species (ROS) generation were assessed after treatments. RESULTS Immature CGNs had increased sensitivity to CPF toxicity compared to mature neurons. We observed significantly greater ROS production in immature compared to mature neurons, however AChE activity was more inhibited in mature neurons. Although CPF toxicity was not well correlated with AChE inhibition, it correlated well with ROS production. Glutamate toxicity was potentiated by sub-lethal concentration of CPF, however glutamate induced ROS production was not affected. The results suggested that CPF potentiated glutamate toxicity by mechanisms other than oxidative stress. CONCLUSION CPF toxicity differed in mature and immature neurons. Potentiated glutamate toxicity by CPF implied that CPF exposure might be a risk factor for neurodegenerative disease.
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Affiliation(s)
- Nahid Amani
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Maliheh Soodi
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Bahram Daraei
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Abolfazl Dashti
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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21
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Smeets CJLM, Zmorzyńska J, Melo MN, Stargardt A, Dooley C, Bakalkin G, McLaughlin J, Sinke RJ, Marrink SJ, Reits E, Verbeek DS. Altered secondary structure of Dynorphin A associates with loss of opioid signalling and NMDA-mediated excitotoxicity in SCA23. Hum Mol Genet 2016; 25:2728-2737. [PMID: 27260403 DOI: 10.1093/hmg/ddw130] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 03/31/2016] [Accepted: 04/24/2016] [Indexed: 11/13/2022] Open
Abstract
Spinocerebellar ataxia type 23 (SCA23) is caused by missense mutations in prodynorphin, encoding the precursor protein for the opioid neuropeptides α-neoendorphin, Dynorphin (Dyn) A and Dyn B, leading to neurotoxic elevated mutant Dyn A levels. Dyn A acts on opioid receptors to reduce pain in the spinal cord, but its cerebellar function remains largely unknown. Increased concentration of or prolonged exposure to Dyn A is neurotoxic and these deleterious effects are very likely caused by an N-methyl-d-aspartate-mediated non-opioid mechanism as Dyn A peptides were shown to bind NMDA receptors and potentiate their glutamate-evoked currents. In the present study, we investigated the cellular mechanisms underlying SCA23-mutant Dyn A neurotoxicity. We show that SCA23 mutations in the Dyn A-coding region disrupted peptide secondary structure leading to a loss of the N-terminal α-helix associated with decreased κ-opioid receptor affinity. Additionally, the altered secondary structure led to increased peptide stability of R6W and R9C Dyn A, as these peptides showed marked degradation resistance, which coincided with decreased peptide solubility. Notably, L5S Dyn A displayed increased degradation and no aggregation. R6W and wt Dyn A peptides were most toxic to primary cerebellar neurons. For R6W Dyn A, this is likely because of a switch from opioid to NMDA- receptor signalling, while for wt Dyn A, this switch was not observed. We propose that the pathology of SCA23 results from converging mechanisms of loss of opioid-mediated neuroprotection and NMDA-mediated excitotoxicity.
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Affiliation(s)
- Cleo J L M Smeets
- Department of Genetics, University of Groningen, University Medical Centre GroningenGroningen, the Netherlands
| | - Justyna Zmorzyńska
- Department of Genetics, University of Groningen, University Medical Centre GroningenGroningen, the Netherlands
| | - Manuel N Melo
- Groningen Biomolecular Sciences and Biotechnology Institute, Centre for Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Anita Stargardt
- Department of Cell Biology and Histology, Academic Medical Centre, Amsterdam, The Netherlands
| | - Colette Dooley
- Torrey Pines Institute for Molecular Studies, Port St Lucie, FL, USA
| | - Georgy Bakalkin
- Division of Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Jay McLaughlin
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
| | - Richard J Sinke
- Department of Genetics, University of Groningen, University Medical Centre GroningenGroningen, the Netherlands
| | - Siewert-Jan Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute, Centre for Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Eric Reits
- Department of Cell Biology and Histology, Academic Medical Centre, Amsterdam, The Netherlands
| | - Dineke S Verbeek
- Department of Genetics, University of Groningen, University Medical Centre GroningenGroningen, the Netherlands
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Soodi M, Saeidnia S, Sharifzadeh M, Hajimehdipoor H, Dashti A, Sepand MR, Moradi S. Satureja bachtiarica ameliorate beta-amyloid induced memory impairment, oxidative stress and cholinergic deficit in animal model of Alzheimer's disease. Metab Brain Dis 2016; 31:395-404. [PMID: 26638718 DOI: 10.1007/s11011-015-9773-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 11/30/2015] [Indexed: 10/22/2022]
Abstract
Extracellular deposition of Beta-amyloid peptide (Aβ) is the main finding in the pathophysiology of Alzheimer's disease (AD), which damages cholinergic neurons through oxidative stress and reduces the cholinergic neurotransmission. Satureja bachtiarica is a medicinal plant from the Lamiaceae family which was widely used in Iranian traditional medicine. The aim of the present study was to investigate possible protective effects of S. bachtiarica methanolic extract on Aβ induced spatial memory impairment in Morris Water Maze (MWM), oxidative stress and cholinergic neuron degeneration. Pre- aggregated Aβ was injected into the hippocampus of each rat bilaterally (10 μg/rat) and MWM task was performed 14 days later to evaluate learning and memory function. Methanolic extract of S.bachtiarica (10, 50 and 100 mg/Kg) was injected intraperitoneally for 19 consecutive days, after Aβ injection. After the probe test the brain tissue were collected and lipid peroxidation, Acetylcholinesterase (AChE) activity and Cholin Acetyl Transferees (ChAT) immunorectivity were measured in the hippocampus. Intrahipocampal injection of Aβ impaired learning and memory in MWM in training days and probe trail. Methanolic extract of S. bachtiarica (50 and 100 mg/Kg) could attenuate Aβ-induced memory deficit. ChAT immunostaining revealed that cholinergic neurons were loss in Aβ- injected group and S. bachtiarica (100 mg/Kg) could ameliorate Aβ- induced ChAT reduction in the hippocampus. Also S. bachtiarica could ameliorate Aβ-induced lipid peroxidation and AChE activity increase in the hippocampus. In conclusion our study represent that S.bachtiarica methanolic extract can improve Aβ-induced memory impairment and cholinergic loss then we recommended this extract as a candidate for further investigation in treatment of AD.
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Affiliation(s)
- Maliheh Soodi
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Jalal-Al Ahmad street, Tehran, Iran.
| | - Soodabeh Saeidnia
- Medicinal Plants Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sharifzadeh
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Homa Hajimehdipoor
- Department of Traditional Pharmacy, School of Traditional Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abolfazl Dashti
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Jalal-Al Ahmad street, Tehran, Iran
| | - Mohammad Reza Sepand
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Shahla Moradi
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Jalal-Al Ahmad street, Tehran, Iran
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Dashti A, Soodi M, Amani N. Cr (VI) induced oxidative stress and toxicity in cultured cerebellar granule neurons at different stages of development and protective effect of Rosmarinic acid. ENVIRONMENTAL TOXICOLOGY 2016; 31:269-77. [PMID: 25213303 DOI: 10.1002/tox.22041] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Revised: 08/14/2014] [Accepted: 08/15/2014] [Indexed: 06/03/2023]
Abstract
Chromium (Cr) is a widespread metal ion in the workplace, industrial effluent, and water. The toxicity of chromium (VI) on various organs including the liver, kidneys, and lung were studied, but little is known about neurotoxicity. In this study, neurotoxic effects of Cr (VI) have been investigated by cultured cerebellar granule neurons (CGNs). Immature and mature neurons were exposed to different concentrations of potassium dichromate for 24 h and cytotoxicity was measured by MTT assay. In addition, immature neurons were exposed for 5 days as regards cytotoxic effect in development stages. The reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and the protective effect of Rosmarinic acid on mature and immature neurons exposed to potassium dichromate, were measured. Furthermore, lipid peroxidation, glutathione peroxidase (GPx), and acetylcholinesterase activity in mature neurons were assessed following exposure to potassium dichromate. The results indicate that toxicity of Cr (VI) dependent on maturation steps. Cr (VI) was less toxic for immature neurons. Also, Cr (VI) induced MMP reduction and ROS production in both immature and mature neurons. In Cr (VI) treated neurons, increased lipid peroxidation and GPx activity but not acetylcholinesterase activity was observed. Interestingly, Rosmarinic acid, as a natural antioxidant, could protect mature but not immature neurons against Cr (VI) induced toxicity. Our findings revealed vulnerability of mature neurons to Cr (VI) induced toxicity and oxidative stress.
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Affiliation(s)
- Abolfazl Dashti
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Maliheh Soodi
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Nahid Amani
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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Elkahloun AG, Hafko R, Saavedra JM. An integrative genome-wide transcriptome reveals that candesartan is neuroprotective and a candidate therapeutic for Alzheimer's disease. ALZHEIMERS RESEARCH & THERAPY 2016; 8:5. [PMID: 26822027 PMCID: PMC4731966 DOI: 10.1186/s13195-015-0167-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 12/08/2015] [Indexed: 12/21/2022]
Abstract
BACKGROUND Alzheimer's disease is the most frequent age-related dementia, and is currently without treatment. To identify possible targets for early therapeutic intervention we focused on glutamate excitotoxicity, a major early pathogenic factor, and the effects of candesartan, an angiotensin receptor blocker of neuroprotective efficacy in cell cultures and rodent models of Alzheimer's disease. The overall goal of the study was to determine whether gene analysis of drug effects in a primary neuronal culture correlate with alterations in gene expression in Alzheimer's disease, thus providing further preclinical evidence of beneficial therapeutic effects. METHODS Primary neuronal cultures were treated with candesartan at neuroprotective concentrations followed by excitotoxic glutamate amounts. We performed genome-wide expression profile analysis and data evaluation by ingenuity pathway analysis and gene set enrichment analysis, compared with alterations in gene expression from two independent published datasets identified by microarray analysis of postmortem hippocampus from Alzheimer's disease patients. Preferential expression in cerebrovascular endothelial cells or neurons was analyzed by comparison to published gene expression in these cells isolated from human cortex by laser capture microdissection. RESULTS Candesartan prevented glutamate upregulation or downregulation of several hundred genes in our cultures. Ingenuity pathway analysis and gene set enrichment analysis revealed that inflammation, cardiovascular disease and diabetes signal transduction pathways and amyloid β metabolism were major components of the neuronal response to glutamate excitotoxicity. Further analysis showed associations of glutamate-induced changes in the expression of several hundred genes, normalized by candesartan, with similar alterations observed in hippocampus from Alzheimer's disease patients. Gene analysis of neurons and cerebrovascular endothelial cells obtained by laser capture microdissection revealed that genes up- and downregulated by glutamate were preferentially expressed in endothelial cells and neurons, respectively. CONCLUSIONS Our data may be interpreted as evidence of direct candesartan neuroprotection beyond its effects on blood pressure, revealing common and novel disease mechanisms that may underlie the in vitro gene alterations reported here and glutamate-induced cell injury in Alzheimer's disease. Our observations provide novel evidence for candesartan neuroprotection through early molecular mechanisms of injury in Alzheimer's disease, supporting testing this compound in controlled clinical studies in the early stages of the illness.
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Affiliation(s)
- Abdel G Elkahloun
- Comparative genomics and Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Roman Hafko
- Section on Pharmacology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Juan M Saavedra
- Section on Pharmacology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892, USA. .,Department of Pharmacology and Physiology, Georgetown University Medical Center, SE402 Med/Dent, 3900 Reservoir Road, Washington, DC, 20057, USA.
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25
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Jebelli J, Piers T, Pocock J. Selective Depletion of Microglia from Cerebellar Granule Cell Cultures Using L-leucine Methyl Ester. J Vis Exp 2015:e52983. [PMID: 26275019 DOI: 10.3791/52983] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Microglia, the resident immunocompetent cells of the CNS, play multifaceted roles in modulating and controlling neuronal function, as well as mediating innate immunity. Primary rodent cell culture models have greatly advanced our understanding of neuronal-glial interactions, but only recently have methods to specifically eliminate microglia from mixed cultures been utilized. One such technique - described here - is the use of L-leucine methyl ester, a lysomotropic agent that is internalized by macrophages and microglia, wherein it causes lysosomal disruption and subsequent apoptosis(13,14). Experiments using L-leucine methyl ester have the power to identify the contribution of microglia to the surrounding cellular environment under diverse culture conditions. Using a protocol optimized in our laboratory, we describe how to eliminate microglia from P5 rodent cerebellar granule cell culture. This approach allows one to assess the relative impact of microglia on experimental data, as well as determine whether microglia are playing a neuroprotective or neurotoxic role in culture models of neurological conditions, such as stroke, Alzheimer's or Parkinson's disease.
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Affiliation(s)
| | - Thomas Piers
- Therapeutic Innovation Group, School of Life and Medical Sciences, University College London
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26
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Cunningham D, DeBarber AE, Bir N, Binkley L, Merkens LS, Steiner RD, Herman GE. Analysis of hedgehog signaling in cerebellar granule cell precursors in a conditional Nsdhl allele demonstrates an essential role for cholesterol in postnatal CNS development. Hum Mol Genet 2015; 24:2808-25. [PMID: 25652406 DOI: 10.1093/hmg/ddv042] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 02/02/2015] [Indexed: 12/21/2022] Open
Abstract
NSDHL is a 3β-hydroxysterol dehydrogenase that is involved in the removal of two C-4 methyl groups in one of the later steps of cholesterol biosynthesis. Mutations in the gene encoding the enzyme are responsible for the X-linked, male lethal mouse mutations bare patches and striated, as well as most cases of human CHILD syndrome. Rare, hypomorphic NSDHL mutations are also associated with X-linked intellectual disability in males with CK syndrome. Since hemizygous male mice with Nsdhl mutations die by midgestation, we generated a conditional targeted Nsdhl mutation (Nsdhl(tm1.1Hrm)) to investigate the essential role of cholesterol in the early postnatal CNS. Ablation of Nsdhl in radial glia using GFAP-cre resulted in live-born, normal appearing affected male pups. However, the pups develop overt ataxia by postnatal day 8-10 and die shortly thereafter. Histological abnormalities include progressive loss of cortical and hippocampal neurons, as well as deficits in the proliferation and migration of cerebellar granule precursors and subsequent massive apoptosis of the cerebellar cortex. We replicated the granule cell precursor proliferation defect in vitro and demonstrate that it results from defective signaling by SHH. Furthermore, this defect is almost completely rescued by supplementation of the culture media with exogenous cholesterol, while methylsterol accumulation above the enzymatic block appears to be associated with increased cell death. These data support the absolute requirement for cholesterol synthesis in situ once the blood-brain-barrier forms and cholesterol transport to the fetus is abolished. They further emphasize the complex ramifications of cholesterogenic enzyme deficiency on cellular metabolism.
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Affiliation(s)
- David Cunningham
- Center for Molecular and Human Genetics, The Research Institute at Nationwide Children's Hospital and Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | | | - Natalie Bir
- Center for Molecular and Human Genetics, The Research Institute at Nationwide Children's Hospital and Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Laura Binkley
- Center for Molecular and Human Genetics, The Research Institute at Nationwide Children's Hospital and Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | | | - Robert D Steiner
- Department of Pediatrics, Department of Molecular and Medical Genetics and Institute on Development and Disability, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, OR, USA and Marshfield Clinic Research Foundation and the Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Marshfield and Madison, WI, USA
| | - Gail E Herman
- Center for Molecular and Human Genetics, The Research Institute at Nationwide Children's Hospital and Department of Pediatrics, The Ohio State University, Columbus, OH, USA,
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Wang J, Pang T, Hafko R, Benicky J, Sanchez-Lemus E, Saavedra JM. Telmisartan ameliorates glutamate-induced neurotoxicity: roles of AT(1) receptor blockade and PPARγ activation. Neuropharmacology 2013; 79:249-61. [PMID: 24316465 DOI: 10.1016/j.neuropharm.2013.11.022] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 11/22/2013] [Accepted: 11/26/2013] [Indexed: 01/22/2023]
Abstract
Sartans (Angiotensin II AT(1) Receptor Blockers, ARBs) are powerful neuroprotective agents in vivo and protect against IL-1β neurotoxicity in vitro. The purpose of this research was to determine the extent of sartan neuroprotection against glutamate excitotoxicity, a common cause of neuronal injury and apoptosis. The results show that sartans are neuroprotective, significantly reducing glutamate-induced neuronal injury and apoptosis in cultured rat primary cerebellar granule cells (CGCs). Telmisartan was the most potent sartan studied, with an order of potency telmisartan > candesartan > losartan > valsartan. Mechanisms involved reduction of pro-apoptotic caspase-3 activation, protection of the survival PI3K/Akt/GSK-3β pathway and prevention of glutamate-induced ERK1/2 activation. NMDA receptor stimulation was essential for glutamate-induced cell injury and apoptosis. Participation of AT(1A) receptor was supported by glutamate-induced upregulation of AT(1A) gene expression and AT(1) receptor binding. Conversely, AT(1B) or AT(2) receptors played no role. Glutamate-induced neuronal injury and the neuroprotective effect of telmisartan were decreased, but not abolished, in CGCs obtained from AT(1A) knock-out mice. This indicates that although AT(1) receptors are necessary for glutamate to exert its full neurotoxic potential, part of the neuroprotective effect of telmisartan is independent of AT(1) receptor blockade. PPARγ activation was also involved in the neuroprotective effects of telmisartan, as telmisartan enhanced PPARγ nuclear translocation and the PPARγ antagonist GW9662 partially reversed the neuroprotective effects of telmisartan. The present results substantiate the therapeutic use of sartans, in particular telmisartan, in neurodegenerative diseases and traumatic brain disorders where glutamate neurotoxicity plays a significant role.
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Affiliation(s)
- Juan Wang
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, 20892, USA.
| | - Tao Pang
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, 20892, USA; New Drug Screening Center, China Pharmaceutical University, Nanjing 210009, PR China
| | - Roman Hafko
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, 20892, USA
| | - Julius Benicky
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, 20892, USA.
| | - Enrique Sanchez-Lemus
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, 20892, USA.
| | - Juan M Saavedra
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, 20892, USA; Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20057, USA.
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Ramírez-Franco J, Alonso B, Bartolomé-Martín D, Sánchez-Prieto J, Torres M. Studying synaptic efficiency by post-hoc immunolabelling. BMC Neurosci 2013; 14:127. [PMID: 24138605 PMCID: PMC3854067 DOI: 10.1186/1471-2202-14-127] [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: 04/16/2013] [Accepted: 10/10/2013] [Indexed: 11/10/2022] Open
Abstract
Background In terms of vesicular recycling, synaptic efficiency is a key determinant of the fidelity of synaptic transmission. The ability of a presynaptic terminal to reuse its vesicular content is thought to be a signature of synaptic maturity and this process depends on the activity of several proteins that govern exo/endocytosis. Upon stimulation, individual terminals in networks of cultured cerebellar granule neurons exhibit heterogeneous exocytic responses, which reflect the distinct states of maturity and plasticity intrinsic to individual synaptic terminals. This dynamic scenario serves as the substrate for processes such as scaling, plasticity and synaptic weight redistribution. Presynaptic strength has been associated with the activity of several types of proteins, including the scaffolding proteins that form the active zone cytomatrix and the proteins involved in presynaptic exocytosis. Methods We have combined fluorescence imaging techniques using the styryl dye FM1-43 in primary cultures of cerebellar granule cells with subsequent post-hoc immunocytochemistry in order to study synaptic efficiency in terms of vesicular release. We describe a protocol to easily quantify these results with minimal user intervention. Results In this study we describe a technique that specifically correlates presynaptic activity with the levels of presynaptic markers. This method involves the use of the styryl dye FM1-43 to estimate the release capacity of a synaptic terminal, and the subsequent post-hoc immunolabelling of thousands of individual nerve terminals. We observed a strong correlation between the release capacity of the nerve terminal and the levels of the RIM1α but not the Munc13-1 protein in the active zone. Conclusions Our findings support those of previous studies and point out to RIM1α as a crucial factor in determining synaptic efficiency. These results also demonstrate that this technique is a useful tool to analyse the molecular differences underlying the heterogeneous responses exhibited by neuronal networks.
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Affiliation(s)
| | | | | | - José Sánchez-Prieto
- Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid 28040, Spain.
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Kysenius K, Muggalla P, Mätlik K, Arumäe U, Huttunen HJ. PCSK9 regulates neuronal apoptosis by adjusting ApoER2 levels and signaling. Cell Mol Life Sci 2012; 69:1903-16. [PMID: 22481440 PMCID: PMC11114498 DOI: 10.1007/s00018-012-0977-6] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 03/05/2012] [Accepted: 03/22/2012] [Indexed: 12/30/2022]
Abstract
The secreted protease proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to low-density lipid (LDL) receptor family members LDLR, very low density lipoprotein receptor (VLDLR) and apolipoprotein receptor 2 (ApoER2), and promotes their degradation in intracellular acidic compartments. In the liver, LDLR is a major controller of blood LDL levels, whereas VLDLR and ApoER2 in the brain mediate Reelin signaling, a critical pathway for proper development of the nervous system. Expression level of PCSK9 in the brain is highest in the cerebellum during perinatal development, but is also increased in the adult brain after ischemia. The mechanism of PCSK9 function and its involvement in neuronal apoptosis is poorly understood. We show here that RNAi-mediated knockdown of PCSK9 significantly reduced the death of potassium-deprived cerebellar granule neurons (CGN), as shown by reduced levels of nuclear phosphorylated c-Jun and activated caspase-3, as well as condensed apoptotic nuclei. ApoER2 protein levels were increased in PCSK9 RNAi cells. Knockdown of ApoER2 but not of VLDLR was sufficient to reverse the protection provided by PCSK9 RNAi, suggesting that proapoptotic signaling of PCSK9 is mediated by altered ApoER2 function. Pharmacological inhibition of signaling pathways associated with lipoprotein receptors suggested that PCSK9 regulates neuronal apoptosis independently of NMDA receptor function but in concert with ERK and JNK signaling pathways. PCSK9 RNAi also reduced staurosporine-induced CGN apoptosis and axonal degeneration in the nerve growth factor-deprived dorsal root ganglion neurons. We conclude that PCSK9 potentiates neuronal apoptosis via modulation of ApoER2 levels and related anti-apoptotic signaling pathways.
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Affiliation(s)
- Kai Kysenius
- Neuroscience Center, University of Helsinki, Viikinkaari 4, P.O. Box 56, 00014 Helsinki, Finland
| | - Pranuthi Muggalla
- Neuroscience Center, University of Helsinki, Viikinkaari 4, P.O. Box 56, 00014 Helsinki, Finland
| | - Kert Mätlik
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Urmas Arumäe
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Henri J. Huttunen
- Neuroscience Center, University of Helsinki, Viikinkaari 4, P.O. Box 56, 00014 Helsinki, Finland
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30
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GSK3β inhibition is involved in the neuroprotective effects of cyclin-dependent kinase inhibitors in neurons. Pharmacol Res 2012; 65:66-73. [DOI: 10.1016/j.phrs.2011.08.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 08/11/2011] [Accepted: 08/12/2011] [Indexed: 11/17/2022]
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