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Chali F, Milior G, Marty S, Morin-Brureau M, Le Duigou C, Savary E, Blugeon C, Jourdren L, Miles R. Lipid markers and related transcripts during excitotoxic neurodegeneration in kainate-treated mice. Eur J Neurosci 2019; 50:1759-1778. [PMID: 30767299 DOI: 10.1111/ejn.14375] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/30/2019] [Accepted: 01/31/2019] [Indexed: 12/16/2022]
Abstract
Lipid homeostasis is dysregulated in some neurodegenerative diseases and after brain injuries due to excess glutamate or lack of oxygen. However the kinetics and cell specificity of dysregulation in different groups of lipids during excitotoxic neuronal death are not clear. Here we examined the changes during excitotoxic neuronal death induced by injecting kainic acid (KA) into the CA1 region of mouse hippocampus. We compared neuronal loss and glial cell proliferation with changes in lipid-related transcripts and markers for different lipid groups, over 12 days after KA-treatment. As neurons showed initial signs of damage, transcripts and proteins linked to fatty acid oxidation were up-regulated. Cholesterol biosynthesis induced by transcripts controlled by the transcription factor Srebp2 seems to be responsible for a transient increase in neuronal free cholesterol at 1 to 2 days. In microglia, but not in neurons, Perilipin-2 associated lipid droplets were induced and properties of Nile red emissions suggest lipid contents change over time. After microglial expression of phagocytotic markers at 2 days, some neutral lipid deposits co-localized with lysosome markers of microglia and were detected within putative phagocytotic cups. These data delineate distinct lipid signals in neurons and glial cells during excitotoxic processes from initial neuronal damage to engagement of the lysosome-phagosome system.
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Affiliation(s)
- Farah Chali
- Inserm U1127, CNRS UMR7225, Sorbonne Université, UPMC Université Paris 6 UMR S1127, Institut du Cerveau et de la Moelle Epinière, CHU Pitié-Salpêtrière, Paris, France
| | - Giampaolo Milior
- Inserm U1127, CNRS UMR7225, Sorbonne Université, UPMC Université Paris 6 UMR S1127, Institut du Cerveau et de la Moelle Epinière, CHU Pitié-Salpêtrière, Paris, France
| | - Serge Marty
- Inserm U1127, CNRS UMR7225, Sorbonne Université, UPMC Université Paris 6 UMR S1127, Institut du Cerveau et de la Moelle Epinière, CHU Pitié-Salpêtrière, Paris, France
| | - Mélanie Morin-Brureau
- Inserm U1127, CNRS UMR7225, Sorbonne Université, UPMC Université Paris 6 UMR S1127, Institut du Cerveau et de la Moelle Epinière, CHU Pitié-Salpêtrière, Paris, France
| | - Caroline Le Duigou
- Inserm U1127, CNRS UMR7225, Sorbonne Université, UPMC Université Paris 6 UMR S1127, Institut du Cerveau et de la Moelle Epinière, CHU Pitié-Salpêtrière, Paris, France
| | - Etienne Savary
- Inserm U1127, CNRS UMR7225, Sorbonne Université, UPMC Université Paris 6 UMR S1127, Institut du Cerveau et de la Moelle Epinière, CHU Pitié-Salpêtrière, Paris, France
| | - Corinne Blugeon
- Institut de Biologie de l'École normale supérieure (IBENS), École Normale Supérieure, CNRS, INSERM PSL Université Paris, Paris, France
| | - Laurent Jourdren
- Institut de Biologie de l'École normale supérieure (IBENS), École Normale Supérieure, CNRS, INSERM PSL Université Paris, Paris, France
| | - Richard Miles
- Inserm U1127, CNRS UMR7225, Sorbonne Université, UPMC Université Paris 6 UMR S1127, Institut du Cerveau et de la Moelle Epinière, CHU Pitié-Salpêtrière, Paris, France
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Jiang J, Yu Y, Kinjo ER, Du Y, Nguyen HP, Dingledine R. Suppressing pro-inflammatory prostaglandin signaling attenuates excitotoxicity-associated neuronal inflammation and injury. Neuropharmacology 2019; 149:149-160. [PMID: 30763657 DOI: 10.1016/j.neuropharm.2019.02.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/29/2019] [Accepted: 02/09/2019] [Indexed: 02/06/2023]
Abstract
Glutamate receptor-mediated excitotoxicity is a common pathogenic process in many neurological conditions including epilepsy. Prolonged seizures induce elevations in extracellular glutamate that contribute to excitotoxic damage, which in turn can trigger chronic neuroinflammatory reactions, leading to secondary damage to the brain. Blocking key inflammatory pathways could prevent such secondary brain injury following the initial excitotoxic insults. Prostaglandin E2 (PGE2) has emerged as an important mediator of neuroinflammation-associated injury, in large part via activating its EP2 receptor subtype. Herein, we investigated the effects of EP2 receptor inhibition on excitotoxicity-associated neuronal inflammation and injury in vivo. Utilizing a bioavailable and brain-permeant compound, TG6-10-1, we found that pharmacological inhibition of EP2 receptor after a one-hour episode of kainate-induced status epilepticus (SE) in mice reduced seizure-promoted functional deficits, cytokine induction, reactive gliosis, blood-brain barrier impairment, and hippocampal damage. Our preclinical findings endorse the feasibility of blocking PGE2/EP2 signaling as an adjunctive strategy to treat prolonged seizures. The promising benefits from EP2 receptor inhibition should also be relevant to other neurological conditions in which excitotoxicity-associated secondary damage to the brain represents a pathogenic event.
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Affiliation(s)
- Jianxiong Jiang
- Department of Pharmaceutical Sciences and Drug Discovery Center, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA; Division of Pharmaceutical Sciences, College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, OH, USA.
| | - Ying Yu
- Department of Pharmaceutical Sciences and Drug Discovery Center, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Erika Reime Kinjo
- Division of Pharmaceutical Sciences, College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, OH, USA
| | - Yifeng Du
- Division of Pharmaceutical Sciences, College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, OH, USA
| | - Hoang Phuong Nguyen
- Department of Pharmaceutical Sciences and Drug Discovery Center, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Ray Dingledine
- Department of Pharmacology and Chemical Biology, School of Medicine, Emory University, Atlanta, GA, USA
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Lerner R, Post JM, Ellis SR, Vos DRN, Heeren RMA, Lutz B, Bindila L. Simultaneous lipidomic and transcriptomic profiling in mouse brain punches of acute epileptic seizure model compared to controls. J Lipid Res 2017; 59:283-297. [PMID: 29208697 DOI: 10.1194/jlr.m080093] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 11/28/2017] [Indexed: 01/07/2023] Open
Abstract
In this study, we report the development of a dual extraction protocol for RNA and lipids, including phospholipids, endocannabinoids, and arachidonic acid, at high spatial resolution, e.g., brain punches obtained from whole frozen brains corresponding to four brain subregions: dorsal hippocampus, ventral hippocampus, basolateral amygdala, and hypothalamus. This extraction method combined with LC/multiple reaction monitoring for lipid quantifi-cation and quantitative PCR for RNA investigation allows lipidomic and transcriptomic profiling from submilligram amounts of tissue, thus benefiting the time and animal costs for analysis and the data reliability due to prevention of biological variability between animal batches and/or tissue heterogeneity, as compared with profiling in distinct animal batches. Moreover, the method allows a higher extraction efficiency and integrity preservation for RNA, while allowing concurrently quantitative analysis of low and high abundant lipids. The method was applied for brain punches obtained 1 h after kainic acid-induced epileptic seizures in mice (n = 10) compared with controls (n = 10), and enabled the provision of valuable new insights into the subregional lipid and RNA changes with epilepsy, highlighting its potential as a new viable tool in quantitative neurobiology.
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Affiliation(s)
- Raissa Lerner
- University Medical Center of Johannes Gutenberg University Mainz, Institute of Physiological Chemistry, 55128 Mainz, Germany; and
| | - Julia M Post
- University Medical Center of Johannes Gutenberg University Mainz, Institute of Physiological Chemistry, 55128 Mainz, Germany; and
| | - Shane R Ellis
- Maastricht MultiModal Molecular Imaging Institute (M4I), Maastricht University, 6229 ER Maastricht, The Netherlands
| | - D R Naomi Vos
- Maastricht MultiModal Molecular Imaging Institute (M4I), Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Ron M A Heeren
- Maastricht MultiModal Molecular Imaging Institute (M4I), Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Beat Lutz
- University Medical Center of Johannes Gutenberg University Mainz, Institute of Physiological Chemistry, 55128 Mainz, Germany; and
| | - Laura Bindila
- University Medical Center of Johannes Gutenberg University Mainz, Institute of Physiological Chemistry, 55128 Mainz, Germany; and
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The GABA excitatory/inhibitory developmental sequence: a personal journey. Neuroscience 2014; 279:187-219. [PMID: 25168736 DOI: 10.1016/j.neuroscience.2014.08.001] [Citation(s) in RCA: 194] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/17/2014] [Accepted: 08/01/2014] [Indexed: 12/11/2022]
Abstract
The developing brain is talkative but its language is not that of the adult. Most if not all voltage and transmitter-gated ionic currents follow a developmental sequence and network-driven patterns differ in immature and adult brains. This is best illustrated in studies engaged almost three decades ago in which we observed elevated intracellular chloride (Cl(-))i levels and excitatory GABA early during development and a perinatal excitatory/inhibitory shift. This sequence is observed in a wide range of brain structures and animal species suggesting that it has been conserved throughout evolution. It is mediated primarily by a developmentally regulated expression of the NKCC1 and KCC2 chloride importer and exporter respectively. The GABAergic depolarization acts in synergy with N-methyl-d-aspartate (NMDA) receptor-mediated and voltage-gated calcium currents to enhance intracellular calcium exerting trophic effects on neuritic growth, migration and synapse formation. These sequences can be deviated in utero by genetic or environmental insults leading to a persistence of immature features in the adult brain. This "neuroarcheology" concept paves the way to novel therapeutic perspectives based on the use of drugs that block immature but not adult currents. This is illustrated notably with the return to immature high levels of chloride and excitatory actions of GABA observed in many pathological conditions. This is due to the fact that in the immature brain a down regulation of KCC2 and an up regulation of NKCC1 are seen. Here, I present a personal history of how an unexpected observation led to novel concepts in developmental neurobiology and putative treatments of autism and other developmental disorders. Being a personal account, this review is neither exhaustive nor provides an update of this topic with all the studies that have contributed to this evolution. We all rely on previous inventors to allow science to advance. Here, I present a personal summary of this topic primarily to illustrate why we often fail to comprehend the implications of our own observations. They remind us - and policy deciders - why Science cannot be programed, requiring time, and risky investigations that raise interesting questions before being translated from bench to bed. Discoveries are always on sideways, never on highways.
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Bellavance MA, Gosselin D, Yong VW, Stys PK, Rivest S. Patrolling monocytes play a critical role in CX3CR1-mediated neuroprotection during excitotoxicity. Brain Struct Funct 2014; 220:1759-76. [PMID: 24706067 DOI: 10.1007/s00429-014-0759-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 03/16/2014] [Indexed: 12/17/2022]
Abstract
Excitotoxicity underlies neuronal death in many neuropathological disorders, such as Alzheimer's disease and multiple sclerosis. In murine models of these diseases, disruption of CX3CR1 signaling has thus far generated data either in favor or against a neuroprotective role of this crucial regulator of microglia and monocyte functions. In this study, we investigated the recruitment of circulating PU.1-expressing cells following sterile excitotoxicity and delineated the CX3CR1-dependent neuroprotective functions of circulating monocytes versus that of microglia in this context. WT, Cx3cr1-deficient and chimeric mice were subjected to a sterile excitotoxic insult via an intrastriatal injection of kainic acid (KA), a conformational analog of glutamate. Following KA administration, circulating monocytes physiologically engrafted the brain and selectively accumulated in the vicinity of excitotoxic lesions where they gave rise to activated macrophages depicting strong Iba1 and CD68 immunoreactivity 7 days post-injury. Monocyte-derived macrophages completely vanished upon recovery and did thus not permanently seed the brain. Furthermore, Cx3cr1 deletion significantly exacerbated neuronal death, behavioral deficits and activation of microglia cells following sterile excitotoxicity. Cx3cr1 disruption also markedly altered the blood levels of patrolling monocytes 24 h after KA administration. The specific elimination of patrolling monocytes using Nr4a1(-/-) chimeric mice conditioned with chemotherapy provided direct evidence that these circulating monocytes are essential for neuroprotection. Taken together, these data support a beneficial role of CX3CR1 signaling during excitotoxicity and highlight a novel and pivotal role of patrolling monocytes in neuroprotection. These findings open new research and therapeutic avenues for neuropathological disorders implicating excitotoxicity.
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Affiliation(s)
- Marc-André Bellavance
- Neuroscience Laboratory, Department of Molecular Medicine, Faculty of Medicine, CHU de Québec Research Center, Laval University, 2705 Laurier Blvd., Quebec, G1V 4G2, Canada,
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