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Seferi G, Mjønes HS, Havik M, Reiersen H, Dalen KT, Nordengen K, Morland C. Distribution of lipid droplets in hippocampal neurons and microglia: impact of diabetes and exercise. Life Sci Alliance 2024; 7:e202302239. [PMID: 39117458 DOI: 10.26508/lsa.202302239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/28/2024] [Accepted: 07/29/2024] [Indexed: 08/10/2024] Open
Abstract
Neuroinflammation, aging, and neurodegenerative disorders are associated with excessive accumulation of neutral lipids in lipid droplets (LDs) in microglia. Type 2 diabetes mellitus (T2DM) may cause neuroinflammation and is a risk factor for neurodegenerative disorders. Here, we show that hippocampal pyramidal neurons contain smaller, more abundant LDs than their neighboring microglia. The density of LDs varied between pyramidal cells in adjacent subregions, with CA3 neurons containing more LDs than CA1 neurons. Within the CA3 region, a gradual increase in the LD content along the pyramidal layer from the hilus toward CA2 was observed. Interestingly, the high neuronal LD content correlated with less ramified microglial morphotypes. Using the db/db model of T2DM, we demonstrated that diabetes increased the number of LDs per microglial cell without affecting the neuronal LD density. High-intensity interval exercise induced smaller changes in the number of LDs in microglia but was not sufficient to counteract the diabetes-induced changes in LD accumulation. The changes observed in response to T2DM may contribute to the cerebral effects of T2DM and provide a mechanistic link between T2DM and neurodegenerative disorders.
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Affiliation(s)
- Gezime Seferi
- https://ror.org/01xtthb56 Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Harald S Mjønes
- https://ror.org/01xtthb56 Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Mona Havik
- https://ror.org/01xtthb56 Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Herman Reiersen
- https://ror.org/01xtthb56 Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Knut Tomas Dalen
- https://ror.org/01xtthb56 Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Kaja Nordengen
- Department of Neurology, Oslo University Hospital, Oslo, Norway
| | - Cecilie Morland
- https://ror.org/01xtthb56 Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
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Popova EY, Kawasawa YI, Leung M, Barnstable CJ. Temporal changes in mouse hippocampus transcriptome after pilocarpine-induced seizures. Front Neurosci 2024; 18:1384805. [PMID: 39040630 PMCID: PMC11260795 DOI: 10.3389/fnins.2024.1384805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Accepted: 06/07/2024] [Indexed: 07/24/2024] Open
Abstract
Introduction Status epilepticus (SE) is a seizure lasting more than 5 min that can have lethal consequences or lead to various neurological disorders, including epilepsy. Using a pilocarpine-induced SE model in mice we investigated temporal changes in the hippocampal transcriptome. Methods We performed mRNA-seq and microRNA-seq analyses at various times after drug treatment. Results At 1 h after the start of seizures, hippocampal cells upregulated transcription of immediate early genes and genes involved in the IGF-1, ERK/MAPK and RNA-PolII/transcription pathways. At 8 h, we observed changes in the expression of genes associated with oxidative stress, overall transcription downregulation, particularly for genes related to mitochondrial structure and function, initiation of a stress response through regulation of ribosome and translation/EIF2 signaling, and upregulation of an inflammatory response. During the middle of the latent period, 36 h, we identified upregulation of membrane components, cholesterol synthesis enzymes, channels, and extracellular matrix (ECM), as well as an increased inflammatory response. At the end of the latent period, 120 h, most changes in expression were in genes involved in ion transport, membrane channels, and synapses. Notably, we also elucidated the involvement of novel pathways, such as cholesterol biosynthesis pathways, iron/BMP/ferroptosis pathways, and circadian rhythms signaling in SE and epileptogenesis. Discussion These temporal changes in metabolic reactions indicate an immediate response to injury followed by recovery and regeneration. CREB was identified as the main upstream regulator. Overall, our data provide new insights into molecular functions and cellular processes involved at different stages of seizures and offer potential avenues for effective therapeutic strategies.
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Affiliation(s)
- Evgenya Y. Popova
- Department of Neural and Behavioral Sciences, Penn State University College of Medicine, Hershey, PA, United States
- Penn State Hershey Eye Center, Hershey, PA, United States
| | - Yuka Imamura Kawasawa
- Department of Pharmacology, Penn State University College of Medicine, Hershey, PA, United States
- Center for Cancer Genomics and Precision Oncology, Wake Forest Baptist Comprehensive Cancer Center, Winston Salem, NC, United States
| | - Ming Leung
- Center for Cancer Genomics and Precision Oncology, Wake Forest Baptist Comprehensive Cancer Center, Winston Salem, NC, United States
| | - Colin J. Barnstable
- Department of Neural and Behavioral Sciences, Penn State University College of Medicine, Hershey, PA, United States
- Penn State Hershey Eye Center, Hershey, PA, United States
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Clinico-biological markers for the prognosis of status epilepticus in adults. J Neurol 2022; 269:5868-5882. [PMID: 35768546 DOI: 10.1007/s00415-022-11199-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/15/2022] [Accepted: 05/16/2022] [Indexed: 10/17/2022]
Abstract
Prediction of mortality, functional outcome and recovery after status epilepticus (SE) is a challenge. Biological and clinical markers have been proposed to reflect the brain injury or to monitor critical ill patients' severity. The aim of this study was to characterize short-term and long-term prognostic factors for SE patients hospitalized in intensive care unit. Patient's outcome was assessed using the modified Rankin Scale at discharge and after 6-12 months. We first assessed the univariate prognosis significance of 51 clinical, demographic or biochemical markers. Next, we built multivariate clinico-biological models by combining most important factors. Statistical models' performances were compared to those of two previous published scales STESS and mSTESS. Eighty-one patients were enrolled. Thirty-five patients showed a steady state while 46 patients clinically worsened at discharge: 14 died, 14 had persistent disability at 6-12 months and 18 recovered. Logistic regression analysis revealed that clinical markers (SE refractoriness, SE duration, de novo SE) were significant independent predictors of worsening while lipids markers and progranulin better predicted mortality. The association of clinico-biological variables allowed to accurately predict worsening at discharge (AUC > 0.72), mortality at discharge (AUC 0.83) and recovery at long-term (AUC 0.89). Previous scales provided lower prediction for worsening (AUC 0.63, STESS; 0.53, mSTESS) and mortality (AUC 0.56, STESS; 0.62, mSTESS) (p < 0.001). We proposed new clinico-biological models with a strong discrimination power for prediction of short- and long-term outcome of hospitalized status epilepticus patients. Their implementation in electronic devices may enhance their clinical liability.
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Islimye E, Girard V, Gould AP. Functions of Stress-Induced Lipid Droplets in the Nervous System. Front Cell Dev Biol 2022; 10:863907. [PMID: 35493070 PMCID: PMC9047859 DOI: 10.3389/fcell.2022.863907] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/22/2022] [Indexed: 12/12/2022] Open
Abstract
Lipid droplets are highly dynamic intracellular organelles that store neutral lipids such as cholesteryl esters and triacylglycerols. They have recently emerged as key stress response components in many different cell types. Lipid droplets in the nervous system are mostly observed in vivo in glia, ependymal cells and microglia. They tend to become more numerous in these cell types and can also form in neurons as a consequence of ageing or stresses involving redox imbalance and lipotoxicity. Abundant lipid droplets are also a characteristic feature of several neurodegenerative diseases. In this minireview, we take a cell-type perspective on recent advances in our understanding of lipid droplet metabolism in glia, neurons and neural stem cells during health and disease. We highlight that a given lipid droplet subfunction, such as triacylglycerol lipolysis, can be physiologically beneficial or harmful to the functions of the nervous system depending upon cellular context. The mechanistic understanding of context-dependent lipid droplet functions in the nervous system is progressing apace, aided by new technologies for probing the lipid droplet proteome and lipidome with single-cell type precision.
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Baik SH, Selvaraji S, Fann DY, Poh L, Jo DG, Herr DR, Zhang SR, Kim HA, Silva MD, Lai MK, Chen CLH, Drummond GR, Lim KL, Sobey CG, Arumugam TV. Hippocampal transcriptome profiling reveals common disease pathways in chronic hypoperfusion and aging. Aging (Albany NY) 2021; 13:14651-14674. [PMID: 34074801 PMCID: PMC8221317 DOI: 10.18632/aging.203123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 05/11/2021] [Indexed: 12/13/2022]
Abstract
Vascular dementia (VaD) is a progressive cognitive impairment of vascular etiology. VaD is characterized by cerebral hypoperfusion, increased blood-brain barrier permeability and white matter lesions. An increased burden of VaD is expected in rapidly aging populations. The hippocampus is particularly susceptible to hypoperfusion, and the resulting memory impairment may play a crucial role in VaD. Here we have investigated the hippocampal gene expression profile of young and old mice subjected to cerebral hypoperfusion by bilateral common carotid artery stenosis (BCAS). Our data in sham-operated young and aged mice reveal an age-associated decline in cerebral blood flow and differential gene expression. In fact, BCAS and aging caused broadly similar effects. However, BCAS-induced changes in hippocampal gene expression differed between young and aged mice. Specifically, transcriptomic analysis indicated that in comparison to young sham mice, many pathways altered by BCAS in young mice resembled those already present in sham aged mice. Over 30 days, BCAS in aged mice had minimal effect on either cerebral blood flow or hippocampal gene expression. Immunoblot analyses confirmed these findings. Finally, relative to young sham mice the cell type-specific profile of genes in both young BCAS and old sham animals further revealed common cell-specific genes. Our data provide a genetic-based molecular framework for hypoperfusion-induced hippocampal damage and reveal common cellular signaling pathways likely to be important in the pathophysiology of VaD.
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Affiliation(s)
- Sang-Ha Baik
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Sharmelee Selvaraji
- Memory Aging and Cognition Centre, Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Integrative Sciences and Engineering Programme, NUS Graduate School, National University of Singapore
| | - David Y. Fann
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Luting Poh
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Memory Aging and Cognition Centre, Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Dong-Gyu Jo
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea
| | - Deron R. Herr
- Memory Aging and Cognition Centre, Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Shenpeng R. Zhang
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Bundoora, VIC, Australia
| | - Hyun Ah Kim
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Bundoora, VIC, Australia
| | - Michael De Silva
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Bundoora, VIC, Australia
| | - Mitchell K.P. Lai
- Memory Aging and Cognition Centre, Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Christopher Li-Hsian Chen
- Memory Aging and Cognition Centre, Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Grant R. Drummond
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Bundoora, VIC, Australia
| | - Kah-Leong Lim
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Christopher G. Sobey
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Bundoora, VIC, Australia
| | - Thiruma V. Arumugam
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Bundoora, VIC, Australia
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Hanin A, Baudin P, Demeret S, Roussel D, Lecas S, Teyssou E, Damiano M, Luis D, Lambrecq V, Frazzini V, Decavèle M, Plu I, Bonnefont-Rousselot D, Bittar R, Lamari F, Navarro V. Disturbances of brain cholesterol metabolism: A new excitotoxic process associated with status epilepticus. Neurobiol Dis 2021; 154:105346. [PMID: 33774180 DOI: 10.1016/j.nbd.2021.105346] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/05/2021] [Accepted: 03/22/2021] [Indexed: 11/26/2022] Open
Abstract
The understanding of the excitotoxic processes associated with a severe status epilepticus (SE) is of major importance. Changes of brain cholesterol homeostasis is an emerging candidate for excitotoxicity. We conducted an overall analysis of the cholesterol homeostasis both (i) in fluids and tissues from patients with SE: blood (n = 63, n = 87 controls), CSF (n = 32, n = 60 controls), and post-mortem brain tissues (n = 8, n = 8 controls) and (ii) in a mouse model of SE induced by an intrahippocampal injection of kainic acid. 24-hydroxycholesterol levels were decreased in kainic acid mouse hippocampus and in human plasma and post-mortem brain tissues of patients with SE when compared with controls. The decrease of 24-hydroxycholesterol levels was followed by increased cholesterol levels and by an increase of the cholesterol synthesis. Desmosterol levels were higher in human CSF and in mice and human hippocampus after SE. Lanosterol and dihydrolanosterol levels were higher in plasma from SE patients. Our results suggest that a CYP46A1 inhibition could occur after SE and is followed by a brain cholesterol accumulation. The excess of cholesterol is known to be excitotoxic for neuronal cells and may participate to neurological sequelae observed after SE. This study highlights a new pathophysiological pathway involved in SE excitotoxicity.
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Affiliation(s)
- Aurélie Hanin
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, INSERM U 1127, CNRS UMR 7225, Paris, France
| | - Paul Baudin
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, INSERM U 1127, CNRS UMR 7225, Paris, France
| | - Sophie Demeret
- AP-HP, Hôpital Pitié-Salpêtrière, DMU Neurosciences 6, Department of Neurology, Neuro-ICU, Paris, France
| | - Delphine Roussel
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, INSERM U 1127, CNRS UMR 7225, Paris, France
| | - Sarah Lecas
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, INSERM U 1127, CNRS UMR 7225, Paris, France
| | - Elisa Teyssou
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, INSERM U 1127, CNRS UMR 7225, Paris, France
| | - Maria Damiano
- AP-HP, Hôpital Pitié-Salpêtrière, DMU Neurosciences 6, Epileptology Unit and Clinical Neurophysiology Department, Paris, France
| | - David Luis
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, INSERM U 1127, CNRS UMR 7225, Paris, France
| | - Virginie Lambrecq
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, INSERM U 1127, CNRS UMR 7225, Paris, France; AP-HP, Hôpital Pitié-Salpêtrière, DMU Neurosciences 6, Epileptology Unit and Clinical Neurophysiology Department, Paris, France; Sorbonne Université, 75006 Paris, France
| | - Valerio Frazzini
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, INSERM U 1127, CNRS UMR 7225, Paris, France; AP-HP, Hôpital Pitié-Salpêtrière, DMU Neurosciences 6, Epileptology Unit and Clinical Neurophysiology Department, Paris, France
| | - Maxens Decavèle
- Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, 75005 Paris, France; AP-HP, Hôpital Pitié-Salpêtrière, Service de Pneumologie, Médecine Intensive et Réanimation (Département R3S), Paris, France
| | - Isabelle Plu
- Sorbonne Université, 75006 Paris, France; AP-HP, Hôpital Pitié-Salpêtrière, DMU Neurosciences 6, Department of Neuropathology, Paris, France
| | - Dominique Bonnefont-Rousselot
- AP-HP, Hôpital Pitié-Salpêtrière, Department of Metabolic Biochemistry, Paris, France; UTCBS, INSERM U 1267, UMR 8258 CNRS, Université de Paris, Paris, France
| | - Randa Bittar
- AP-HP, Hôpital Pitié-Salpêtrière, Department of Metabolic Biochemistry, Paris, France; Sorbonne Université, UMR_S 1166 ICAN, F-75013 Paris, France
| | - Foudil Lamari
- AP-HP, Hôpital Pitié-Salpêtrière, Department of Metabolic Biochemistry, Paris, France
| | - Vincent Navarro
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, INSERM U 1127, CNRS UMR 7225, Paris, France; AP-HP, Hôpital Pitié-Salpêtrière, DMU Neurosciences 6, Epileptology Unit and Clinical Neurophysiology Department, Paris, France; Sorbonne Université, 75006 Paris, France; Center of Reference for Rare Epilepsies, Pitié-Salpêtrière Hospital, Paris, France.
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Farmer BC, Walsh AE, Kluemper JC, Johnson LA. Lipid Droplets in Neurodegenerative Disorders. Front Neurosci 2020; 14:742. [PMID: 32848541 PMCID: PMC7403481 DOI: 10.3389/fnins.2020.00742] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/23/2020] [Indexed: 12/13/2022] Open
Abstract
Knowledge of lipid droplets (LDs) has evolved from simple depots of lipid storage to dynamic and functionally active organelles involved in a variety of cellular functions. Studies have now informed significant roles for LDs in cellular signaling, metabolic disease, and inflammation. While lipid droplet biology has been well explored in peripheral organs such as the liver and heart, LDs within the brain are relatively understudied. The presence and function of these dynamic organelles in the central nervous system has recently gained attention, especially in the context of neurodegeneration. In this review, we summarize the current understanding of LDs within the brain, with an emphasis on their relevance in neurodegenerative diseases.
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Affiliation(s)
- Brandon C Farmer
- Department of Physiology, University of Kentucky, Lexington, KY, United States
| | - Adeline E Walsh
- Department of Physiology, University of Kentucky, Lexington, KY, United States
| | - Jude C Kluemper
- Department of Physiology, University of Kentucky, Lexington, KY, United States
| | - Lance A Johnson
- Department of Physiology, University of Kentucky, Lexington, KY, United States.,Sanders Brown Center on Aging, University of Kentucky, Lexington, KY, United States
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