1
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Bousquet D, Nader E, Connes P, Guillot N. Liver X receptor agonist upregulates LPCAT3 in human aortic endothelial cells. Front Physiol 2024; 15:1388404. [PMID: 38694208 PMCID: PMC11061552 DOI: 10.3389/fphys.2024.1388404] [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: 02/19/2024] [Accepted: 04/08/2024] [Indexed: 05/04/2024] Open
Abstract
Objective Endothelial cells (ECs) play an important role in tissue homeostasis. Recently, EC lipid metabolism has emerged as a regulator of EC function. The liver X receptors (LXRs) are involved in the transcriptional regulation of genes involved in lipid metabolism and have been identified as a potential target in cardiovascular disease. We aimed to decipher the role of LXRs in the regulation of lipid metabolism in human aortic endothelial cells. Approach and Results Lipid composition analysis of endothelial cells treated with the LXR agonist T0901317 revealed that LXR activation increased the proportion of polyunsaturated fatty acids (PUFAs) and decreased the proportion of saturated fatty acids. The LXR agonist decreased the uptake of fatty acids (FAs) by ECs. This effect was abolished by LXRα silencing. LXR activation increased the activity and the expression of lysophosphatidylcholine acyltransferase, LPCAT3, which is involved in the turnover of FAs at the sn-2 position of phospholipids. Transcriptomic analysis also revealed that LXRs increased the expression of key genes involved in the synthesis of PUFAs, including FA desaturase one and 2, FA elongase 5 and fatty acid synthase. Subsequently, the LXR agonist increased PUFA synthesis and enhanced arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid content in the EC phospholipids. Modification of the FA composition of ECs by LXRs led to a decrease of arachidonate and linoleate derived prostaglandins synthesis and release. No change on markers of inflammation induced by plasma from sickle cell patient were observed in presence of LXR agonist. Conclusion These results identify LXR as a key regulator of lipid metabolism in human aortic endothelial cells and a direct effect of LXR agonist on lysophosphatidylacyl transferase (LPCAT3).
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Affiliation(s)
- Delphine Bousquet
- University Lyon, LIBM EA7424, Vascular Biology and Red Blood Cell Team, Universite Lyon 1, Villeurbanne, France
- Labex GR-Ex, PRES Sorbonne, Paris, France
| | - Elie Nader
- University Lyon, LIBM EA7424, Vascular Biology and Red Blood Cell Team, Universite Lyon 1, Villeurbanne, France
- Labex GR-Ex, PRES Sorbonne, Paris, France
| | - Philippe Connes
- University Lyon, LIBM EA7424, Vascular Biology and Red Blood Cell Team, Universite Lyon 1, Villeurbanne, France
- Labex GR-Ex, PRES Sorbonne, Paris, France
| | - Nicolas Guillot
- University Lyon, LIBM EA7424, Vascular Biology and Red Blood Cell Team, Universite Lyon 1, Villeurbanne, France
- Labex GR-Ex, PRES Sorbonne, Paris, France
- INSA Lyon, Villeurbanne, France
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2
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Kim OY, Song J. Important roles of linoleic acid and α-linolenic acid in regulating cognitive impairment and neuropsychiatric issues in metabolic-related dementia. Life Sci 2024; 337:122356. [PMID: 38123015 DOI: 10.1016/j.lfs.2023.122356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 12/02/2023] [Accepted: 12/13/2023] [Indexed: 12/23/2023]
Abstract
Metabolic syndrome (MetS), which is characterized by insulin resistance, high blood glucose, obesity, and dyslipidemia, is known to increase the risk of dementia accompanied by memory loss and depression. The direct pathways and specific mechanisms in the central nervous system (CNS) for addressing fatty acid imbalances in MetS have not yet been fully elucidated. Among polyunsaturated acids, linoleic acid (LA, n6-PUFA) and α-linolenic acid (ALA, n3-PUFA), which are two essential fatty acids that should be provided by food sources (e.g., vegetable oils and seeds), have been reported to regulate various cellular mechanisms including apoptosis, inflammatory responses, mitochondrial biogenesis, and insulin signaling. Furthermore, inadequate intake of LA and ALA is reported to be involved in neuropathology and neuropsychiatric diseases as well as imbalanced metabolic conditions. Herein, we review the roles of LA and ALA on metabolic-related dementia focusing on insulin resistance, dyslipidemia, synaptic plasticity, cognitive function, and neuropsychiatric issues. This review suggests that LA and ALA are important fatty acids for concurrent treatment of both MetS and neurological problems.
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Affiliation(s)
- Oh Yoen Kim
- Department of Food Science and Nutrition, Dong A University, Busan, Republic of Korea; Department of Health Sciences, Graduate School of Dong-A University, Busan, Republic of Korea.
| | - Juhyun Song
- Department of Anatomy, Chonnam National University Medical School, Seoul, Republic of Korea.
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3
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Holý P, Hlaváč V, Ostašov P, Brynychová V, Koževnikovová R, Trnková M, Kopečková K, Měšťáková S, Mrhalová M, Souček P. Germline and somatic genetic variability of oxysterol-related genes in breast cancer patients with early disease of the luminal subtype. Biochimie 2022; 199:158-169. [PMID: 35525372 DOI: 10.1016/j.biochi.2022.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/12/2022] [Accepted: 04/29/2022] [Indexed: 11/25/2022]
Abstract
Oxysterols, oxidized derivatives of cholesterol, have been implicated in multiple pathologies, including cancer. In breast cancer, the link is especially strong due to interactions between oxysterols and estrogen receptor activity. Here, we provide the first dedicated study of 113 oxysterol-related genes in breast cancer patients of the luminal subtype, in terms of both their somatic and germline variability, using targeted high-throughput DNA sequencing of 100 normal-tumor pairs with very high coverage. In the full cohort, or subsets of patients stratified by therapy, we found 12 germline variants in ABCA1, ABCA8, ABCC1, GPR183, LDLR, MBTPS1, NR1I2, OSBPL2, OSBPL3, and OSBPL5 to associate with poor survival of patients and variants in ABCA8, ABCG2, and HSD3B7 (three in total) associated with better survival. However, no associations remained significant after correction for multiple tests. Analysis of somatic variants revealed significantly (after FDR correction) poorer survival in patients mutated in CYP46A1 and 9 interacting (according to STRING analysis) genes, as well as in OSBPL3 and a set of 20 genes that collectively associated with the progesterone receptor status of patients. We propose further exploration of these genes in an integrative manner together with gene expression and epigenomic data.
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Affiliation(s)
- Petr Holý
- Toxicogenomics Unit, National Institute of Public Health, Prague, Czech Republic; Third Faculty of Medicine, Charles University, Prague, Czech Republic; Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic
| | - Viktor Hlaváč
- Toxicogenomics Unit, National Institute of Public Health, Prague, Czech Republic; Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic
| | - Pavel Ostašov
- Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic
| | - Veronika Brynychová
- Toxicogenomics Unit, National Institute of Public Health, Prague, Czech Republic; Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic
| | | | | | - Kateřina Kopečková
- Department of Oncology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic
| | - Soňa Měšťáková
- Department of Surgery, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic
| | - Marcela Mrhalová
- Department of Pathology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic
| | - Pavel Souček
- Toxicogenomics Unit, National Institute of Public Health, Prague, Czech Republic; Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic.
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4
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de Freitas FA, Levy D, Reichert CO, Cunha-Neto E, Kalil J, Bydlowski SP. Effects of Oxysterols on Immune Cells and Related Diseases. Cells 2022; 11:cells11081251. [PMID: 35455931 PMCID: PMC9031443 DOI: 10.3390/cells11081251] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 04/01/2022] [Accepted: 04/05/2022] [Indexed: 12/13/2022] Open
Abstract
Oxysterols are the products of cholesterol oxidation. They have a wide range of effects on several cells, organs, and systems in the body. Oxysterols also have an influence on the physiology of the immune system, from immune cell maturation and migration to innate and humoral immune responses. In this regard, oxysterols have been involved in several diseases that have an immune component, from autoimmune and neurodegenerative diseases to inflammatory diseases, atherosclerosis, and cancer. Here, we review data on the participation of oxysterols, mainly 25-hydroxycholesterol and 7α,25-dihydroxycholesterol, in the immune system and related diseases. The effects of these oxysterols and main oxysterol receptors, LXR and EBI2, in cells of the immune system (B cells, T cells, macrophages, dendritic cells, oligodendrocytes, and astrocytes), and in immune-related diseases, such as neurodegenerative diseases, intestinal diseases, cancer, respiratory diseases, and atherosclerosis, are discussed.
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Affiliation(s)
- Fábio Alessandro de Freitas
- Lipids, Oxidation and Cell Biology Team, Laboratory of Immunology (LIM19), Heart Institute (InCor), Faculdade de Medicina, Universidade de São Paulo, Sao Paulo 05403-900, SP, Brazil; (F.A.d.F.); (D.L.); (C.O.R.)
| | - Débora Levy
- Lipids, Oxidation and Cell Biology Team, Laboratory of Immunology (LIM19), Heart Institute (InCor), Faculdade de Medicina, Universidade de São Paulo, Sao Paulo 05403-900, SP, Brazil; (F.A.d.F.); (D.L.); (C.O.R.)
| | - Cadiele Oliana Reichert
- Lipids, Oxidation and Cell Biology Team, Laboratory of Immunology (LIM19), Heart Institute (InCor), Faculdade de Medicina, Universidade de São Paulo, Sao Paulo 05403-900, SP, Brazil; (F.A.d.F.); (D.L.); (C.O.R.)
| | - Edecio Cunha-Neto
- Laboratory of Clinical Immunology and Allergy (LIM60), Heart Institute (InCor), Faculdade de Medicina, Universidade de São Paulo, Sao Paulo 05403-900, SP, Brazil;
- National Institute of Science and Technology for Investigation in Immunology-III/INCT, Sao Paulo 05403-000, SP, Brazil;
| | - Jorge Kalil
- National Institute of Science and Technology for Investigation in Immunology-III/INCT, Sao Paulo 05403-000, SP, Brazil;
- Laboratory of Immunology (LIM19), Heart Institute (InCor), Faculdade de Medicina, Universidade de São Paulo, Sao Paulo 05403-900, SP, Brazil
| | - Sérgio Paulo Bydlowski
- Lipids, Oxidation and Cell Biology Team, Laboratory of Immunology (LIM19), Heart Institute (InCor), Faculdade de Medicina, Universidade de São Paulo, Sao Paulo 05403-900, SP, Brazil; (F.A.d.F.); (D.L.); (C.O.R.)
- National Institute of Science and Technology in Regenerative Medicine (INCT-Regenera), CNPq, Rio de Janeiro 21941-902, RJ, Brazil
- Correspondence:
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5
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You JS, Lim H, Seo JY, Kang KR, Kim DK, Oh JS, Seo YS, Lee GJ, Kim JS, Kim HJ, Yu SK, Kim JS. 25-Hydroxycholesterol-Induced Oxiapoptophagy in L929 Mouse Fibroblast Cell Line. Molecules 2021; 27:199. [PMID: 35011433 PMCID: PMC8746689 DOI: 10.3390/molecules27010199] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/17/2021] [Accepted: 12/27/2021] [Indexed: 12/12/2022] Open
Abstract
25-hydroxycholesterol (25-HC) is an oxysterol synthesized from cholesterol by cholesterol-25-hydroxylase during cholesterol metabolism. The aim of this study was to verify whether 25-HC induces oxiapoptophagy in fibroblasts. 25-HC not only decreased the survival of L929 cells, but also increased the number of cells with condensed chromatin and altered morphology. Fluorescence-activated cell sorting results showed that there was a dose-dependent increase in the apoptotic populations of L929 cells upon treatment with 25-HC. 25-HC-induced apoptotic cell death was mediated by the death receptor-dependent extrinsic and mitochondria-dependent intrinsic apoptosis pathway, through the cascade activation of caspases including caspase-8, -9, and -3 in L929 cells. There was an increase in the levels of reactive oxygen species and inflammatory mediators such as inducible nitric oxide synthase, cyclooxygenase-2, nitric oxide, and prostaglandin E2 in L929 cells treated with 25-HC. Moreover, 25-HC caused an increase in the expression of beclin-1 and microtubule-associated protein 1A/1B-light chain 3, an autophagy biomarker, in L929 cells. There was a significant decrease in the phosphorylation of protein kinase B (Akt) in L929 cells treated with 25-HC. Taken together, 25-HC induced oxiapoptophagy through the modulation of Akt and p53 cellular signaling pathways in L929 cells.
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Affiliation(s)
- Jae-Seek You
- Departments of Oral and Maxillofacial Surgery, School of Dentistry, Chosun University, Gwangju 61452, Korea; (J.-S.Y.); (J.-S.O.)
| | - HyangI Lim
- Institute of Dental Science, School of Dentistry, Chosun University, Gwangju 61452, Korea; (H.L.); (J.-Y.S.); (K.-R.K.); (D.K.K.); (H.-J.K.); (S.-K.Y.)
| | - Jeong-Yeon Seo
- Institute of Dental Science, School of Dentistry, Chosun University, Gwangju 61452, Korea; (H.L.); (J.-Y.S.); (K.-R.K.); (D.K.K.); (H.-J.K.); (S.-K.Y.)
| | - Kyeong-Rok Kang
- Institute of Dental Science, School of Dentistry, Chosun University, Gwangju 61452, Korea; (H.L.); (J.-Y.S.); (K.-R.K.); (D.K.K.); (H.-J.K.); (S.-K.Y.)
| | - Do Kyung Kim
- Institute of Dental Science, School of Dentistry, Chosun University, Gwangju 61452, Korea; (H.L.); (J.-Y.S.); (K.-R.K.); (D.K.K.); (H.-J.K.); (S.-K.Y.)
| | - Ji-Su Oh
- Departments of Oral and Maxillofacial Surgery, School of Dentistry, Chosun University, Gwangju 61452, Korea; (J.-S.Y.); (J.-S.O.)
| | - Yo-Seob Seo
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Chosun University, Gwangju 61452, Korea; (Y.-S.S.); (J.-S.K.)
| | - Gyeong-Je Lee
- Department of Prosthodontics, School of Dentistry, Chosun University, Gwangju 61452, Korea;
| | - Jin-Soo Kim
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Chosun University, Gwangju 61452, Korea; (Y.-S.S.); (J.-S.K.)
| | - Heung-Joong Kim
- Institute of Dental Science, School of Dentistry, Chosun University, Gwangju 61452, Korea; (H.L.); (J.-Y.S.); (K.-R.K.); (D.K.K.); (H.-J.K.); (S.-K.Y.)
| | - Sun-Kyoung Yu
- Institute of Dental Science, School of Dentistry, Chosun University, Gwangju 61452, Korea; (H.L.); (J.-Y.S.); (K.-R.K.); (D.K.K.); (H.-J.K.); (S.-K.Y.)
| | - Jae-Sung Kim
- Institute of Dental Science, School of Dentistry, Chosun University, Gwangju 61452, Korea; (H.L.); (J.-Y.S.); (K.-R.K.); (D.K.K.); (H.-J.K.); (S.-K.Y.)
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6
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Cachón-González MB, Wang S, Cox TM. Expression of Ripk1 and DAM genes correlates with severity and progression of Krabbe disease. Hum Mol Genet 2021; 30:2082-2099. [PMID: 34172992 PMCID: PMC8561423 DOI: 10.1093/hmg/ddab159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 05/22/2021] [Accepted: 06/08/2021] [Indexed: 01/02/2023] Open
Abstract
Krabbe disease, an inherited leukodystrophy, is a sphingolipidosis caused by deficiency of β-galactocerebrosidase: it is characterized by myelin loss, and pathological activation of macrophage/microglia and astrocytes. To define driving pathogenic factors, we explored the expression repertoire of candidate neuroinflammatory genes: upregulation of receptor interacting protein kinase 1 (Ripk1) and disease-associated microglia (DAM) genes, including Cst7 and Ch25h, correlated with severity of Krabbe disease genetically modelled in the twitcher mouse. Upregulation of Ripk1 in Iba1/Mac2-positive microglia/macrophage associated with the pathognomic hypertrophic/globoid phenotype of this disease. Widespread accumulation of ubiquitinin1 in white and grey matter co-localised with p62. In Sandhoff disease, another sphingolipid disorder, neuroinflammation, accumulation of p62 and increased Ripk1 expression was observed. The upregulated DAM genes and macrophage/microglia expression of Ripk1 in the authentic model of Krabbe disease strongly resemble those reported in Alzheimer disease associating with disturbed autophagosomal/lysosomal homeostasis. Activation of this shared molecular repertoire, suggests the potential for therapeutic interdiction at a common activation step, irrespective of proximal causation. To clarify the role of Ripk1 in the pathogenesis of Krabbe disease, we first explored the contribution of its kinase function, by intercrossing twitcher and the K45A kinase-dead Ripk1 mouse and breeding to homozygosity. Genetic ablation of Ripk1 kinase activity neither altered the neuropathological features nor the survival of twitcher mice. We conclude that Ripk1 kinase-dependent inflammatory and degenerative capabilities play no instrumental role in Krabbe disease; however, putative kinase-independent functions of Ripk1 remain formally to be explored in its molecular pathogenesis.
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Affiliation(s)
- María B Cachón-González
- Department of Medicine, University of Cambridge, Level 5, PO Box 157, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Susan Wang
- Department of Medicine, University of Cambridge, Level 5, PO Box 157, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Timothy M Cox
- Department of Medicine, University of Cambridge, Level 5, PO Box 157, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
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7
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Seo YS, Cho IA, Kim TH, You JS, Oh JS, Lee GJ, Kim DK, Kim JS. Oxysterol 25-hydroxycholesterol as a metabolic pathophysiological factors of osteoarthritis induces apoptosis in primary rat chondrocytes. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2020; 24:249-257. [PMID: 32392916 PMCID: PMC7193916 DOI: 10.4196/kjpp.2020.24.3.249] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/10/2020] [Accepted: 02/26/2020] [Indexed: 11/23/2022]
Abstract
The aim of the present study was to investigate the pathophysiological etiology of osteoarthritis that is mediated by the apoptosis of chondrocytes exposed to 25-hydroxycholesterol (25-HC), an oxysterol synthesized by the expression of cholesterol-25-hydroxylase (CH25H) under inflammatory conditions. Interleukin-1β induced the apoptosis of chondrocytes in a dose- dependent manner. Furthermore, the production of 25-HC increased in the chondrocytes treated with interleukin-1β through the expression of CH25H. 25-HC decreased the viability of chondrocytes. Chondrocytes with condensed nucleus and apoptotic populations increased by 25-HC. Moreover, the activity and expression of caspase-3 were increased by the death ligand-mediated extrinsic and mitochondria-dependent intrinsic apoptotic pathways in the chondrocytes treated with 25-HC. Finally, 25-HC induced not only caspase-dependent apoptosis, but also induced proteoglycan loss in articular cartilage ex vivo cultured rat knee joints. These data indicate that 25-HC may act as a metabolic pathophysiological factor in osteoarthritis that is mediated by progressive chondrocyte death in the articular cartilage with inflammatory condition.
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Affiliation(s)
- Yo-Seob Seo
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Chosun University, Gwangju 61452, Korea
| | - In-A Cho
- Institute of Dental Science, School of Dentistry, Chosun University, Gwangju 61452, Korea
| | - Tae-Hyeon Kim
- Institute of Dental Science, School of Dentistry, Chosun University, Gwangju 61452, Korea
| | - Jae-Seek You
- Departments of Oral and Maxillofacial Surgery, School of Dentistry, Chosun University, Gwangju 61452, Korea
| | - Ji-Su Oh
- Departments of Oral and Maxillofacial Surgery, School of Dentistry, Chosun University, Gwangju 61452, Korea
| | - Gyeong-Je Lee
- Departments of Prosthodontics, School of Dentistry, Chosun University, Gwangju 61452, Korea
| | - Do Kyung Kim
- Institute of Dental Science, School of Dentistry, Chosun University, Gwangju 61452, Korea
| | - Jae-Sung Kim
- Institute of Dental Science, School of Dentistry, Chosun University, Gwangju 61452, Korea
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8
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Giatti S, Rigolio R, Diviccaro S, Falvo E, Caruso D, Garcia-Segura LM, Cavaletti G, Melcangi RC. Sex dimorphism in an animal model of multiple sclerosis: Focus on pregnenolone synthesis. J Steroid Biochem Mol Biol 2020; 199:105596. [PMID: 31958635 DOI: 10.1016/j.jsbmb.2020.105596] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 01/15/2020] [Accepted: 01/16/2020] [Indexed: 12/11/2022]
Abstract
Neuroactive steroids, molecules produced from cholesterol in steroidogenic cells (i.e., peripheral glands and nervous system) are physiological modulators and protective agents of nervous function. A possible role for neuroactive steroids in the sex-dimorphic clinical manifestation, onset and progression of Multiple Sclerosis (MS) has been recently suggested. To explore this possibility, we assessed the synthesis of the first steroidogenic product (pregnenolone; PREG) in the spinal cord of experimental autoimmune encephalomyelitis rats, a MS model. Data obtained indicate that the synthesis of PREG in the spinal cord is altered by the pathology in a sex-dimorphic way and depending on the pathological progression. Indeed, in male spinal cord the synthesis was already decreased at the acute phase of the disease (i.e., 14 days post induction - dpi) and maintained low during the chronic phase (i.e., 45 dpi), while in females this effect was observed only at the chronic phase. Substrate availability had also a role in the sex-dimorphic kinetics. Indeed, at the chronic phase, male animals showed a reduction in the levels of free cholesterol coupled to alteration of cholesterol metabolism into oxysterols; these effects were not observed in female animals. These findings suggest that the comprehension of the neurosteroidogenic processes could be relevant to better understand the sexual dimorphism of MS and to possibly design sex-oriented therapeutic strategies based on neuroactive steroids.
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Affiliation(s)
- S Giatti
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - R Rigolio
- Experimental Neurology Unit, School of Medicine and Surgery, University of Milano-Bicocca, Italy
| | - S Diviccaro
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - E Falvo
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - D Caruso
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - L M Garcia-Segura
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain; Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - G Cavaletti
- Experimental Neurology Unit, School of Medicine and Surgery, University of Milano-Bicocca, Italy
| | - R C Melcangi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy.
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9
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Jamadagni P, Patten SA. 25-hydroxycholesterol impairs neuronal and muscular development in zebrafish. Neurotoxicology 2019; 75:14-23. [PMID: 31449834 DOI: 10.1016/j.neuro.2019.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 08/16/2019] [Accepted: 08/16/2019] [Indexed: 12/12/2022]
Abstract
Oxysterols have essential effects on brain homeostasis and their levels are often altered in neurodegenerative and neuroinflammatory diseases. Several studies have demonstrated the cytotoxic effects of 25-HC on different cell lines, however, not much is known about its effects on neurons in vivo. In this study, we examined the effects of 25-HC exposure on the nervous system development in the zebrafish. We showed that survival rate of zebrafish embryos/larvae is significantly decreased at doses of 25-HC above 40 μM. 25-HC was found to affect the motility of zebrafish larvae, primary motor axon and muscle morphology. Furthermore, larvae treated with 25-HC showed a reduced neuronal network and number of HuC-positive cells in the brain. An increased cell death was also observed in both the brain and spinal cord of zebrafish treated with 25-HC. Interestingly, administration of 25-HC at later stages of development (24 and 48 h post fertilization) had no detrimental effects on motor axons. Altogether, our findings show that elevated levels of 25-HC may have important consequences on neuronal development and cell survival.
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Affiliation(s)
| | - Shunmoogum A Patten
- INRS Institut Armand-Frappier, Laval, QC, Canada; Centre d'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois (CERMO-FC), Université du Québec à Montréal (UQAM), Montréal, QC, Canada.
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10
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Magoro T, Dandekar A, Jennelle LT, Bajaj R, Lipkowitz G, Angelucci AR, Bessong PO, Hahn YS. IL-1β/TNF-α/IL-6 inflammatory cytokines promote STAT1-dependent induction of CH25H in Zika virus-infected human macrophages. J Biol Chem 2019; 294:14591-14602. [PMID: 31375561 DOI: 10.1074/jbc.ra119.007555] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 07/22/2019] [Indexed: 12/16/2022] Open
Abstract
Zika virus (ZIKV)3 is an enveloped, single-stranded, positive-sense RNA virus of the Flaviviridae family that has emerged as a public health threat because of its global transmission and link to microcephaly. Currently there is no vaccine for this virus. Conversion of cholesterol to 25-hydroxycholesterol by cholesterol 25-hydroxylase (CH25H) has been shown to have broad antiviral properties. However, the molecular basis of induction of CH25H in humans is not known. Elucidation of signaling and transcriptional events for induction of CH25H expression is critical for designing therapeutic antiviral agents. In this study, we show that CH25H is induced by ZIKV infection or Toll-like receptor stimulation. Interestingly, CH25H is induced by pro-inflammatory cytokines, including IL-1β, tumor necrosis factor α, and IL-6, and this induction depends on the STAT1 transcription factor. Additionally, we observed that cAMP-dependent transcription factor (ATF3) weakly binds to the CH25H promoter, suggesting cooperation with STAT1. However, ZIKV-induced CH25H was independent of type I interferon. These findings provide important information for understanding how the Zika virus induces innate inflammatory responses and promotes the expression of anti-viral CH25H protein.
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Affiliation(s)
- Tshifhiwa Magoro
- HIV/AIDS and Global Health Research Program, Department of Microbiology, University of Venda, Thohoyandou, Limpopo, South Africa.,Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, Virginia 22908.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia 22908
| | - Aditya Dandekar
- Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, Virginia 22908.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia 22908
| | - Lucas T Jennelle
- Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, Virginia 22908.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia 22908
| | - Rohan Bajaj
- Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, Virginia 22908.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia 22908
| | - Gabriel Lipkowitz
- Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, Virginia 22908.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia 22908
| | - Angelina R Angelucci
- Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, Virginia 22908.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia 22908
| | - Pascal O Bessong
- HIV/AIDS and Global Health Research Program, Department of Microbiology, University of Venda, Thohoyandou, Limpopo, South Africa
| | - Young S Hahn
- Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, Virginia 22908 .,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia 22908
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11
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Zhu Z, Hu Y, Zhou Y, Zhang Y, Yu L, Tao L, Guo A, Fang Q. Macrophage Migration Inhibitory Factor Promotes Chemotaxis of Astrocytes through Regulation of Cholesterol 25-Hydroxylase Following Rat Spinal Cord Injury. Neuroscience 2019; 408:349-360. [PMID: 31026565 DOI: 10.1016/j.neuroscience.2019.04.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 03/29/2019] [Accepted: 04/08/2019] [Indexed: 11/25/2022]
Abstract
Oxysterol derived from cholesterol metabolism is involved in the inflammatory activation, and consequently in development of major chronic diseases. Multiple cytokines have been found to induce the expression of cholesterol metabolism-related enzymes. Several studies have shown that the protein level of cholesterol-25-hydroxylase (CH25H) is remarkably increased in response to injury of central nervous system (CNS), but little is known about the mechanisms of cytokine-induced expression of CH25H in specific cell types, and the resultant effects. In the present study, we demonstrated that ch25h expression was significantly upregulated in the astrocytes of rat injured spinal cord, in parallel with those of MIF. Administration of MIF inhibitor 4-IPP in the lesion sites attenuated injury-induced ch25h expression. MIF facilitated ch25h expression of astrocytes through interaction with CD74 membrane receptor, which in turn promoted production of chemokines, as identified by transcriptome profiles. MIF-induced release of oxysterol 25-hydroxycholesterol (25-HC) from astrocytes affects cell migration, but inhibited cell viability in dose-dependent manner, suggesting that MIF aggravates progressive neuropathology through regulation of cholesterol metabolism following CNS injury. These results have provided a novel mechanism and a potential therapeutic strategy for injured CNS.
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Affiliation(s)
- Zhenjie Zhu
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou 215006, PR China; Department of Rehabilitation Medicine, Affiliated Hospital of Nantong University, Nantong 226001, PR China
| | - Yuming Hu
- Department of Rehabilitation Medicine, Affiliated Hospital of Nantong University, Nantong 226001, PR China
| | - Yue Zhou
- Department of Rehabilitation Medicine, Affiliated Hospital of Nantong University, Nantong 226001, PR China
| | - Yuxin Zhang
- Department of Rehabilitation Medicine, Affiliated Hospital of Nantong University, Nantong 226001, PR China
| | - Liqiang Yu
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou 215006, PR China.
| | - Lihong Tao
- Department of Neurology, The Affiliated Hospital of Yangzhou University, Yangzhou 225012, PR China
| | - Aisong Guo
- Department of Rehabilitation Medicine, Affiliated Hospital of Nantong University, Nantong 226001, PR China
| | - Qi Fang
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou 215006, PR China.
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12
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Hu X, Zhang N, Fu Y. Role of Liver X Receptor in Mastitis Therapy and Regulation of Milk Fat Synthesis. J Mammary Gland Biol Neoplasia 2019; 24:73-83. [PMID: 30066175 DOI: 10.1007/s10911-018-9403-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 07/04/2018] [Indexed: 02/03/2023] Open
Abstract
Mastitis is important disease that causes huge economic losses in the dairy industry. In recent years, antibiotic therapy has become the primary treatment for mastitis, however, due to drug residue in milk and food safety factors, we lack safe and effective drugs for treating mastitis. Therefore, new targets and drugs are urgently needed to control mastitis. LXRα, one of the main members of the nuclear receptor superfamily, is reported to play important roles in metabolism, infection and immunity. Activation of LXRα could inhibit LPS-induced mastitis. Furthermore, LXRα is reported to enhance milk fat production, thus, LXRα may serve as a new target for mastitis therapy and regulation of milk fat synthesis. This review summarizes the effects of LXRα in regulating milk fat synthesis and treatment of mastitis and highlights the potential agonists involved in both issues.
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MESH Headings
- Animals
- Anti-Inflammatory Agents/pharmacology
- Anti-Inflammatory Agents/therapeutic use
- Cattle
- Dairying
- Escherichia coli/isolation & purification
- Escherichia coli/pathogenicity
- Female
- Global Burden of Disease
- Humans
- Immunity, Innate
- Lactation/metabolism
- Lipid Metabolism
- Liver X Receptors/agonists
- Liver X Receptors/metabolism
- Mammary Glands, Animal/cytology
- Mammary Glands, Animal/metabolism
- Mammary Glands, Animal/microbiology
- Mammary Glands, Animal/pathology
- Mammary Glands, Human/cytology
- Mammary Glands, Human/immunology
- Mammary Glands, Human/microbiology
- Mammary Glands, Human/pathology
- Mastitis/drug therapy
- Mastitis/immunology
- Mastitis/microbiology
- Mastitis, Bovine/drug therapy
- Mastitis, Bovine/epidemiology
- Mastitis, Bovine/immunology
- Mastitis, Bovine/microbiology
- Membrane Microdomains/metabolism
- Milk/metabolism
- Prevalence
- Receptors, Pattern Recognition/metabolism
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Affiliation(s)
- Xiaoyu Hu
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province, 130062, People's Republic of China
| | - Naisheng Zhang
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province, 130062, People's Republic of China.
| | - Yunhe Fu
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province, 130062, People's Republic of China.
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13
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Kerr JR. Epstein-Barr Virus Induced Gene-2 Upregulation Identifies a Particular Subtype of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis. Front Pediatr 2019; 7:59. [PMID: 30918887 PMCID: PMC6424879 DOI: 10.3389/fped.2019.00059] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 02/13/2019] [Indexed: 01/04/2023] Open
Abstract
Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) is a chronic multisystem disease characterized by a variety of symptoms, and exhibits various features of an autoimmune-like disease. Subtypes are well recognized but to date are difficult to identify objectively. The disease may be triggered by infection with a variety of micro-organisms, including Epstein-Barr virus (EBV). A subset of CFS/ME patients exhibit up regulation of EBV virus induced gene 2 (EBI2) mRNA in peripheral blood mononuclear cells (PBMC), and these patients appear to have a more severe disease phenotype and lower levels of EBNA1 IgG. EBI2 is induced by EBV infection and has been found to be upregulated in a variety of autoimmune diseases. EBI2 is a critical gene in immunity and central nervous system function; it is a negative regulator of the innate immune response in monocytes. Its heterogeneous expression in CFS/ME could explain the variable occurrence of a variety of immune and neurological abnormalities which are encountered in patients with CFS/ME. The EBI2 subtype occurred in 38-55% CFS/ME patients in our studies. Further work is required to confirm the role of EBV and of EBI2 and its oxysterol ligands in CFS/ME, and to identify the most practical means to identify patients of the EBI subtype. There are two EBI2 antagonists currently in development, and these may hold promise in the treatment of CFS/ME patients of the EBI subtype.
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Affiliation(s)
- Jonathan R Kerr
- Department of Microbiology, West Suffolk Hospital Foundation Trust, Bury St Edmunds, United Kingdom
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14
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Holy P, Kloudova A, Soucek P. Importance of genetic background of oxysterol signaling in cancer. Biochimie 2018; 153:109-138. [DOI: 10.1016/j.biochi.2018.04.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 04/27/2018] [Indexed: 12/14/2022]
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15
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Rutkowska A, Sailer AW, Dev KK. EBI2 receptor regulates myelin development and inhibits LPC-induced demyelination. J Neuroinflammation 2017; 14:250. [PMID: 29246262 PMCID: PMC5732472 DOI: 10.1186/s12974-017-1025-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 12/06/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The G protein-coupled receptor EBI2 (Epstein-Barr virus-induced gene 2) is activated by 7α, 25-dihydroxycholesterol (7α25HC) and plays a role in T cell-dependant antibody response and B cell migration. Abnormal EBI2 signaling is implicated in a range of autoimmune disorders; however, its role in the CNS remains poorly understood. METHODS Here we characterize the role of EBI2 in myelination under normal and pathophysiological conditions using organotypic cerebellar slice cultures and EBI2 knock-out (KO) animals. RESULTS We find that MBP expression in brains taken from EBI2 KO mice is delayed compared to those taken from wild type (WT) mice. In agreement with these in vivo findings, we show that antagonism of EBI2 reduces MBP expression in vitro. Importantly, we demonstrate that EBI2 activation attenuates lysolecithin (LPC)-induced demyelination in mouse organotypic slice cultures. Moreover, EBI2 activation also inhibits LPC-mediated release of pro-inflammatory cytokines such as IL6 and IL1β in cerebellar slices. CONCLUSIONS These results, for the first time, display a role for EBI2 in myelin development and protection from demyelination under pathophysiological conditions and suggest that modulation of this receptor may be beneficial in neuroinflammatory and demyelinating disorders such as multiple sclerosis.
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Affiliation(s)
- Aleksandra Rutkowska
- Drug Development, School of Medicine, Trinity College, Dublin, Ireland. .,Medical University of Gdańsk, M. Skłodowskiej-Curie 3a, Gdańsk, Poland.
| | - Andreas W Sailer
- Chemical Biology & Therapeutics, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Kumlesh K Dev
- Drug Development, School of Medicine, Trinity College, Dublin, Ireland
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16
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Saeedi Saravi SS, Saeedi Saravi SS, Arefidoust A, Dehpour AR. The beneficial effects of HMG-CoA reductase inhibitors in the processes of neurodegeneration. Metab Brain Dis 2017; 32:949-965. [PMID: 28578514 DOI: 10.1007/s11011-017-0021-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 04/28/2017] [Indexed: 12/13/2022]
Abstract
Statins, cholesterol lowering drugs, have been demonstrated to exert beneficial effects in other conditions such as primary and progressing neurodegenerative diseases beyond their original role. Observation that statins ameliorate the neurodegenerative diseases such as Parkinson's disease (PD), Alzheimer's disease (AD), multiple sclerosis (MS) and cerebral ischemic stroke, the neuroprotective effects of these drugs are thought to be linked to their anti-inflammatory, anti-oxidative, and anti-excitotoxic properties. Despite the voluminous literature on the clinical advantages of 3-hydroxy-3-methylglutaryl Co-enzyme A reductase (HMGCR) inhibitors (statins) in cardiovascular system, the neuroprotective effects and the underlying mechanisms are little understood. Hence, the present review tries to provide a critical overview on the statin-induced neuroprotection, which are presumed to be associated with the ability to reduce cholesterol, Amyloid-β and apolipoprotein E (ApoE) levels, decrease reactive oxygen and nitrogen species (ROS and RNS) formation, inhibit excitotoxicity, modulate matrix metalloproteinases (MMPs), stimulate endothelial nitric oxide synthase (eNOS), and increase cerebral blood perfusion. This review is also aimed to illustrate that statins protect neurons against the neuro-inflammatory processes through balancing pro-inflammatory/anti-inflammatory cytokines. Ultimately, the beneficial role of statins in ameliorating the development of PD, AD, MS and cerebral ischemic stroke has been separately reviewed.
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Affiliation(s)
- Seyed Soheil Saeedi Saravi
- Department of Toxicology-Pharmacology, Faculty of Pharmacy, Guilan University of Medical Sciences, Rasht, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Experimental Medicine Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Sobhan Saeedi Saravi
- Department of Toxicology-Pharmacology, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
| | - Alireza Arefidoust
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Experimental Medicine Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Dehpour
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
- Experimental Medicine Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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17
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Sharma N, Baek K, Phan HTT, Shimokawa N, Takagi M. Glycosyl chains and 25-hydroxycholesterol contribute to the intracellular transport of amyloid beta (Aβ-42) in Jurkat T cells. FEBS Open Bio 2017; 7:865-876. [PMID: 28593141 PMCID: PMC5458452 DOI: 10.1002/2211-5463.12234] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 04/13/2017] [Accepted: 04/13/2017] [Indexed: 01/05/2023] Open
Abstract
Amyloid beta (Aβ) is a peptide responsible for the development of Alzheimer's disease (AD). Misfolding and accumulation of endogenous Aβ can lead to neural cell apoptosis through endoplasmic reticulum (ER) stress. Added exogenous Aβ can also result in ER stress, leading to neurotoxicity and apoptosis, which is identical to that caused by the endogenous peptide. We have speculated that the endocytic transport of Aβ causes ER stress and have previously shown that the oxysterol, in particular, 7-ketocholesterol (7-keto) induces more surface interaction between Aβ-42 and Jurkat cells than cholesterol. However, the interaction was not enough to induce intracellular transfer of the peptide. In this study, we investigated the effect of another oxysterol, 25-hydroxycholesterol (25-OH) on the membrane raft-dependent transport of Aβ-42 in Jurkat cells. Interestingly, intracellular transfer of Aβ-42 was observed in the presence of 25-OH only after the inclusion of cholera toxin B subunit (CT-B), a marker used to detect the raft domain. We speculated that 25-OH can induce intracellular movement of Aβ peptides. Furthermore, CT-B together with GM1 provided negative curvature, which resulted in the intracellular transport of Aβ-42. Notably, we used a protofibrillar species of Aβ-42 in this study. We have shown that the transport was microtubule-dependent since it could not be observed in depolymerized microtubules. These results demonstrate that oxysterols and glycosyl chains are important factors affecting intracellular transport. These compounds are also associated with aging and advanced glycation are risk factors for AD. Thus, this study should further understanding of the pathology of AD.
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Affiliation(s)
- Neha Sharma
- School of Materials Science Japan Advanced Institute of Science and Technology (JAIST) Ishikawa Japan
| | - KeangOK Baek
- School of Materials Science Japan Advanced Institute of Science and Technology (JAIST) Ishikawa Japan
| | | | - Naofumi Shimokawa
- School of Materials Science Japan Advanced Institute of Science and Technology (JAIST) Ishikawa Japan
| | - Masahiro Takagi
- School of Materials Science Japan Advanced Institute of Science and Technology (JAIST) Ishikawa Japan
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18
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Li J, Zheng X, Lou N, Zhong W, Yan D. Oxysterol binding protein-related protein 8 mediates the cytotoxicity of 25-hydroxycholesterol. J Lipid Res 2016; 57:1845-1853. [PMID: 27530118 PMCID: PMC5036365 DOI: 10.1194/jlr.m069906] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Indexed: 12/14/2022] Open
Abstract
Oxysterols are 27-carbon oxidized derivatives of cholesterol or by-products of cholesterol biosynthesis that can induce cell apoptosis in addition to a number of other bioactions. However, the mechanisms underlying this cytotoxicity are not completely understood. ORP8 is a member of the oxysterol binding protein-related protein (ORP) family, implicated in cellular lipid homeostasis, migration, and organization of the microtubule cytoskeleton. Here, we report that 25-hydroxycholesterol (OHC) induced apoptosis of the hepatoma cell lines, HepG2 and Huh7, via the endoplasmic reticulum (ER) stress response pathway, and ORP8 overexpression resulted in a similar cell response as 25-OHC, indicating a putative functional relationship between oxysterol cytotoxicity and ORP8. Further experiments demonstrated that ORP8 overexpression significantly enhanced the 25-OHC effect on ER stress and apoptosis in HepG2 cells. A truncated ORP8 construct lacking the ligand-binding domain or a closely related protein, ORP5, was devoid of this activity, evidencing for specificity of the observed effects. Importantly, ORP8 knockdown markedly dampened such responses to 25-OHC. Taken together, the present study suggests that ORP8 may mediate the cytotoxicity of 25-OHC.
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Affiliation(s)
- Jiwei Li
- Department of Biotechnology Jinan University, Guangzhou 510632, China; Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, China
| | - Xiuting Zheng
- Department of Biotechnology Jinan University, Guangzhou 510632, China; Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, China
| | - Ning Lou
- State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, China
| | - Wenbin Zhong
- Department of Biotechnology Jinan University, Guangzhou 510632, China; Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, China
| | - Daoguang Yan
- Department of Biotechnology Jinan University, Guangzhou 510632, China; Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, China.
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19
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Liver X receptors alpha and beta promote myelination and remyelination in the cerebellum. Proc Natl Acad Sci U S A 2015; 112:7587-92. [PMID: 26023184 DOI: 10.1073/pnas.1424951112] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The identification of new pathways governing myelination provides innovative avenues for remyelination. Liver X receptors (LXRs) α and β are nuclear receptors activated by oxysterols that originated from the oxidation of cholesterol. They are crucial for cholesterol homeostasis, a major lipid constituent of myelin sheaths that are formed by oligodendrocytes. However, the role of LXRs in myelin generation and maintenance is poorly understood. Here, we show that LXRs are involved in myelination and remyelination processes. LXRs and their ligands are present in oligodendrocytes. We found that mice invalidated for LXRs exhibit altered motor coordination and spatial learning, thinner myelin sheaths, and reduced myelin gene expression. Conversely, activation of LXRs by either 25-hydroxycholesterol or synthetic TO901317 stimulates myelin gene expression at the promoter, mRNA, and protein levels, directly implicating LXRα/β in the transcriptional control of myelin gene expression. Interestingly, activation of LXRs also promotes oligodendroglial cell maturation and remyelination after lysolecithin-induced demyelination of organotypic cerebellar slice cultures. Together, our findings represent a conceptual advance in the transcriptional control of myelin gene expression and strongly support a new role of LXRs as positive modulators in central (re)myelination processes.
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20
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Bandaru VVR, Haughey NJ. Quantitative detection of free 24S-hydroxycholesterol, and 27-hydroxycholesterol from human serum. BMC Neurosci 2014; 15:137. [PMID: 25539717 PMCID: PMC4304132 DOI: 10.1186/s12868-014-0137-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 12/17/2014] [Indexed: 03/25/2023] Open
Abstract
Background Cholesterol metabolism is important for the maintenance of myelin and neuronal membranes in the central nervous system. Blood concentrations of the brain specific cholesterol metabolite 24S-hydroxysterol to the peripheral metabolite 27-hydroxycholesterol may be useful surrogate markers for neurodegenerative diseases including Alzheimer’s disease, Huntington’s disease, HIV-Associated Neurocognitive Disorders, and Multiple Sclerosis. However, current methods to isolate hydroxycholesterols are labor intensive, prone to produce variable extraction efficiencies and do not discriminate between free and esterfied forms of hydroxycholesterols. Since free hydroxycholesterols are the biologically active form of these sterols, separating free from esterfied forms may provide a sensitive measure to identify disease-associated differences in brain sterol metabolism. Results We found that average human serum concentrations were 12.3 ± 4.79 ng/ml for free 24(s)-hydroxycholesterol and 17.7 ± 8.5 ng/ml for 27-hydroxycholesterol. Conclusion Serum measurements of these biologically active oxysterols may be useful surrogate measures for brain health in a variety of neurodegenerative conditions.
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Affiliation(s)
- Veera Venkata Ratnam Bandaru
- Department of Neurology, Richard T. Johnson Division of Neuroimmunology and Neurological Infections, The Johns Hopkins University School of Medicine, Carnegie 616A, 600 North Wolfe Street, Baltimore, 21287, MD, USA.
| | - Norman J Haughey
- Department of Neurology, Richard T. Johnson Division of Neuroimmunology and Neurological Infections, The Johns Hopkins University School of Medicine, Carnegie 616A, 600 North Wolfe Street, Baltimore, 21287, MD, USA. .,Department of Psychiatry, Division of Geriatric Psychiatry and Neuropsychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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21
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Zarrouk A, Vejux A, Mackrill J, O’Callaghan Y, Hammami M, O’Brien N, Lizard G. Involvement of oxysterols in age-related diseases and ageing processes. Ageing Res Rev 2014; 18:148-62. [PMID: 25305550 DOI: 10.1016/j.arr.2014.09.006] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 09/23/2014] [Accepted: 09/30/2014] [Indexed: 12/15/2022]
Abstract
Ageing is accompanied by increasing vulnerability to major pathologies (atherosclerosis, Alzheimer's disease, age-related macular degeneration, cataract, and osteoporosis) which can have similar underlying pathoetiologies. All of these diseases involve oxidative stress, inflammation and/or cell death processes, which are triggered by cholesterol oxide derivatives, also named oxysterols. These oxidized lipids result either from spontaneous and/or enzymatic oxidation of cholesterol on the steroid nucleus or on the side chain. The ability of oxysterols to induce severe dysfunctions in organelles (especially mitochondria) plays key roles in RedOx homeostasis, inflammatory status, lipid metabolism, and in the control of cell death induction, which may at least in part contribute to explain the potential participation of these molecules in ageing processes and in age related diseases. As no efficient treatments are currently available for most of these diseases, which are predicted to become more prevalent due to the increasing life expectancy and average age, a better knowledge of the biological activities of the different oxysterols is of interest, and constitutes an important step toward identification of pharmacological targets for the development of new therapeutic strategies.
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22
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Xu P, Xu H, Tang X, Xu L, Wang Y, Guo L, Yang Z, Xing Y, Wu Y, Warner M, Gustafsson JA, Fan X. Liver X receptor β is essential for the differentiation of radial glial cells to oligodendrocytes in the dorsal cortex. Mol Psychiatry 2014; 19:947-57. [PMID: 24934178 DOI: 10.1038/mp.2014.60] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 04/23/2014] [Accepted: 04/24/2014] [Indexed: 01/22/2023]
Abstract
Several psychiatric disorders are associated with aberrant white matter development, suggesting oligodendrocyte and myelin dysfunction in these diseases. There are indications that radial glial cells (RGCs) are involved in initiating myelination, and may contribute to the production of oligodendrocyte progenitor cells (OPCs) in the dorsal cortex. Liver X receptors (LXRs) are involved in maintaining normal myelin in the central nervous system (CNS), however, their function in oligodendrogenesis and myelination is not well understood. Here, we demonstrate that loss of LXRβ function leads to abnormality in locomotor activity and exploratory behavior, signs of anxiety and hypomyelination in the corpus callosum and optic nerve, providing in vivo evidence that LXRβ deletion delays both oligodendrocyte differentiation and maturation. Remarkably, along the germinal ventricular zone-subventricular zone and corpus callosum there is reduced OPC production from RGCs in LXRβ(-/-) mice. Conversely, in cultured RGC an LXR agonist led to increased differentiation into OPCs. Collectively, these results suggest that LXRβ, by driving RGCs to become OPCs in the dorsal cortex, is critical for white matter development and CNS myelination, and point to the involvement of LXRβ in psychiatric disorders.
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Affiliation(s)
- P Xu
- Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - H Xu
- Southwest Eye Hospital, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - X Tang
- Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - L Xu
- Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - Y Wang
- Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - L Guo
- Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - Z Yang
- Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - Y Xing
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, China
| | - Y Wu
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, China
| | - M Warner
- Department of Biology and Biochemistry, Center for Nuclear Receptors and Cell Signaling, University of Houston, Houston, TX, USA
| | - J-A Gustafsson
- 1] Department of Biology and Biochemistry, Center for Nuclear Receptors and Cell Signaling, University of Houston, Houston, TX, USA [2] Department of Biosciences and Nutrition, Karolinska Institute, Novum, Sweden
| | - X Fan
- Department of Histology and Embryology, Third Military Medical University, Chongqing, China
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23
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Meffre D, Grenier J, Bernard S, Courtin F, Dudev T, Shackleford G, Jafarian-Tehrani M, Massaad C. Wnt and lithium: a common destiny in the therapy of nervous system pathologies? Cell Mol Life Sci 2014; 71:1123-48. [PMID: 23749084 PMCID: PMC11113114 DOI: 10.1007/s00018-013-1378-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 04/26/2013] [Accepted: 05/16/2013] [Indexed: 02/07/2023]
Abstract
Wnt signaling is required for neurogenesis, the fate of neural progenitors, the formation of neuronal circuits during development, neuron positioning and polarization, axon and dendrite development and finally for synaptogenesis. This signaling pathway is also implicated in the generation and differentiation of glial cells. In this review, we describe the mechanisms of action of Wnt signaling pathways and their implication in the development and correct functioning of the nervous system. We also illustrate how a dysregulated Wnt pathway could lead to psychiatric, neurodegenerative and demyelinating pathologies. Lithium, used for the treatment of bipolar disease, inhibits GSK3β, a central enzyme of the Wnt/β-catenin pathway. Thus, lithium could, to some extent, mimic Wnt pathway. We highlight the possible dialogue between lithium therapy and modulation of Wnt pathway in the treatment of the diseases of the nervous system.
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Affiliation(s)
- Delphine Meffre
- UMR 8194 CNRS, University Paris Descartes, 45 rue des Saints-Pères, 75270 Paris Cedex 6, France
| | - Julien Grenier
- UMR 8194 CNRS, University Paris Descartes, 45 rue des Saints-Pères, 75270 Paris Cedex 6, France
| | - Sophie Bernard
- UMR 8194 CNRS, University Paris Descartes, 45 rue des Saints-Pères, 75270 Paris Cedex 6, France
| | - Françoise Courtin
- UMR 8194 CNRS, University Paris Descartes, 45 rue des Saints-Pères, 75270 Paris Cedex 6, France
| | - Todor Dudev
- Institute of Biomedical Sciences, Academia Sinica, 11529 Taipei, Taiwan, R.O.C
- Faculty of Chemistry and Pharmacy, University of Sofia, 1 James Bourchier Avenue, 1164 Sofia, Bulgaria
| | | | | | - Charbel Massaad
- UMR 8194 CNRS, University Paris Descartes, 45 rue des Saints-Pères, 75270 Paris Cedex 6, France
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Ren S, Ning Y. Sulfation of 25-hydroxycholesterol regulates lipid metabolism, inflammatory responses, and cell proliferation. Am J Physiol Endocrinol Metab 2014; 306:E123-30. [PMID: 24302009 PMCID: PMC3920008 DOI: 10.1152/ajpendo.00552.2013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Intracellular lipid accumulation, inflammatory responses, and subsequent apoptosis are the major pathogenic events of metabolic disorders, including atherosclerosis and nonalcoholic fatty liver diseases. Recently, a novel regulatory oxysterol, 5-cholesten-3b, 25-diol 3-sulfate (25HC3S), has been identified, and hydroxysterol sulfotransferase 2B1b (SULT2B1b) has been elucidated as the key enzyme for its biosynthesis from 25-hydroxycholesterol (25HC) via oxysterol sulfation. The product 25HC3S and the substrate 25HC have been shown to coordinately regulate lipid metabolism, inflammatory responses, and cell proliferation in vitro and in vivo. 25HC3S decreases levels of the nuclear liver oxysterol receptor (LXR) and sterol regulatory element-binding proteins (SREBPs), inhibits SREBP processing, subsequently downregulates key enzymes in lipid biosynthesis, decreases intracellular lipid levels in hepatocytes and THP-1-derived macrophages, prevents apoptosis, and promotes cell proliferation in liver tissues. Furthermore, 25HC3S increases nuclear PPARγ and cytosolic IκBα and decreases nuclear NF-κB levels and proinflammatory cytokine expression and secretion when cells are challenged with LPS and TNFα. In contrast to 25HC3S, 25HC, a known LXR ligand, increases nuclear LXR and decreases nuclear PPARs and cytosol IκBα levels. In this review, we summarize our recent findings, including the discovery of the regulatory oxysterol sulfate, its biosynthetic pathway, and its functional mechanism. We also propose that oxysterol sulfation functions as a regulatory signaling pathway.
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Affiliation(s)
- Shunlin Ren
- Departments of Medicine, McGuire Veterans Affairs Medical Center/Virginia Commonwealth University, Richmond, Virginia
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Barone E, Di Domenico F, Butterfield DA. Statins more than cholesterol lowering agents in Alzheimer disease: their pleiotropic functions as potential therapeutic targets. Biochem Pharmacol 2013; 88:605-16. [PMID: 24231510 DOI: 10.1016/j.bcp.2013.10.030] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 10/22/2013] [Accepted: 10/28/2013] [Indexed: 02/05/2023]
Abstract
Alzheimer disease (AD) is a progressive neurodegenerative disorder characterized by severe cognitive impairment, inability to perform activities of daily living and mood changes. Statins, long known to be beneficial in conditions where dyslipidemia occurs by lowering serum cholesterol levels, also have been proposed for use in neurodegenerative conditions, including AD. However, it is not clear that the purported effectiveness of statins in neurodegenerative disorders is directly related to cholesterol-lowering effects of these agents; rather, the pleiotropic functions of statins likely play critical roles. The aim of this review is to provide an overview on the new discoveries about the effects of statin therapy on the oxidative and nitrosative stress levels as well as on the modulation of the heme oxygenase/biliverdin reductase (HO/BVR) system in the brain. We propose a novel mechanism of action for atorvastatin which, through the activation of HO/BVR-A system, may contribute to the neuroprotective effects thus suggesting a potential therapeutic role in AD and potentially accounting for the observation of decreased AD incidence with persons on statin.
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Affiliation(s)
- Eugenio Barone
- Department of Chemistry, Center of Membrane Sciences, and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA
| | - Fabio Di Domenico
- Department of Biochemical Sciences, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - D Allan Butterfield
- Department of Chemistry, Center of Membrane Sciences, and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA.
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De Boussac H, Alioui A, Viennois E, Dufour J, Trousson A, Vega A, Guy L, Volle DH, Lobaccaro JMA, Baron S. Oxysterol receptors and their therapeutic applications in cancer conditions. Expert Opin Ther Targets 2013; 17:1029-38. [PMID: 23875732 DOI: 10.1517/14728222.2013.820708] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Oxysterols are implicated in various cellular processes. Among their target proteins, liver X receptors (LXRs) α and β modulate the cell cycle in a large range of cancer cell lines. Besides their role as cholesterol sensors, LXRs are also involved in the proliferation/apoptosis balance regulation in various types of cancers. AREAS COVERED This review covers oxysterols and derivatives of cholesterol as well as synthetic or natural ligands (agonist/antagonist) of LXRs. Most tumor cell lines are sensitive to LXR activation. Indeed various cancers are concerned such as prostate, breast, glioblastoma, colorectal, and ovary tumors, and leukemia. EXPERT OPINION Developing the use of LXR ligands in human health, especially in the field of cancer, represents a novel and promising strategy. Despite a wide spectrum of applications, numerous adverse effects of LXR activation need to be solved before genuine clinical trials in humans. Future directions will be based on the engineering of selective LXRs modulators (SLiMs) as already done for nuclear steroid receptors.
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Affiliation(s)
- Hugues De Boussac
- Clermont Université, Université Blaise Pascal, Génétique Reproduction et Développement, BP 10448, F-63000 Clermont-Ferrand, France
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Abstract
Whether cholesterol is implicated in the pathogenesis of Alzheimer's disease (AD) is still controversial. Several studies that explored the association between lipids and/or lipid-lowering treatment and AD indicate a harmful effect of dyslipidemia on AD risk. The findings are supported by genetic linkage and association studies that have clearly identified several genes involved in cholesterol metabolism or transport as AD susceptibility genes, including apolipoprotein E (APOE), apolipoprotein J (APOJ, CLU), ATP-binding cassette subfamily A member 7(ABCA7), and sortilin-related receptor (SORL1). Functional cell biology studies further support a critical involvement of lipid raft cholesterol in the modulation of Aβ precursor protein processing by β-secretase and γ-secretase resulting in altered Aβ production. However, conflicting evidence comes from epidemiological studies showing no or controversial association between dyslipidemia and AD risk, randomized clinical trials observing no beneficial effect of statin therapy, and cell biology studies suggesting that there is little exchange between circulating and brain cholesterol, that increased membrane cholesterol level is protective by inhibiting loss of membrane integrity through amyloid cytotoxicity, and that cellular cholesterol inhibits colocalization of β-secretase 1 and Aβ precursor protein in nonraft membrane domains, thereby increasing generation of plasmin, an Aβ-degrading enzyme. The aim of this article is to provide a comprehensive review of the findings of epidemiological, genetic, and cell biology studies aiming to elucidate the role of cholesterol in the pathogenesis of AD.
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Shackleford G, Makoukji J, Grenier J, Liere P, Meffre D, Massaad C. Differential regulation of Wnt/beta-catenin signaling by Liver X Receptors in Schwann cells and oligodendrocytes. Biochem Pharmacol 2013; 86:106-14. [DOI: 10.1016/j.bcp.2013.02.036] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 02/27/2013] [Accepted: 02/27/2013] [Indexed: 11/16/2022]
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Xu P, Li D, Tang X, Bao X, Huang J, Tang Y, Yang Y, Xu H, Fan X. LXR Agonists: New Potential Therapeutic Drug for Neurodegenerative Diseases. Mol Neurobiol 2013; 48:715-28. [DOI: 10.1007/s12035-013-8461-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 04/09/2013] [Indexed: 01/04/2023]
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Biological activities of the LXRα and β agonist, 4β-hydroxycholesterol, and of its isomer, 4α-hydroxycholesterol, on oligodendrocytes: Effects on cell growth and viability, oxidative and inflammatory status. Biochimie 2013; 95:518-30. [DOI: 10.1016/j.biochi.2012.11.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 11/15/2012] [Indexed: 12/15/2022]
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31
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On the formation and possible biological role of 25-hydroxycholesterol. Biochimie 2013; 95:455-60. [DOI: 10.1016/j.biochi.2012.06.016] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 06/14/2012] [Indexed: 11/22/2022]
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Reitz C. Dyslipidemia and dementia: current epidemiology, genetic evidence, and mechanisms behind the associations. J Alzheimers Dis 2012; 30 Suppl 2:S127-45. [PMID: 21965313 DOI: 10.3233/jad-2011-110599] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The role of cholesterol in the etiology of Alzheimer's disease (AD) is still controversial. Some studies exploring the association between lipids and/or lipid lowering treatment and AD indicate a harmful effect of dyslipidemia and a beneficial effect of statin therapy on AD risk. The findings are supported by genetic linkage and association studies that have clearly identified several genes involved in cholesterol metabolism or transport as AD susceptibility genes, including apolipoprotein E, apolipoprotein J, and the sortilin-related receptor. Functional cell biology studies support a critical involvement of lipid raft cholesterol in the modulation of amyloid-β protein precursor (AβPP) processing by β- and γ-secretase resulting in altered amyloid-β production. Contradictory evidence comes from epidemiological studies showing no or controversial association between dyslipidemia and AD risk. Additionally, cell biology studies suggest that there is little exchange between circulating and brain cholesterol, that increased membrane cholesterol is protective by inhibiting loss of membrane integrity through amyloid cytotoxicity, and that cellular cholesterol inhibits co-localization of BACE1 and AβPP in non-raft membrane domains, thereby increasing generation of plasmin, an amyloid-β-degrading enzyme. The aim of this review is to summarize the findings of epidemiological and cell biological studies to elucidate the role of cholesterol in AD etiology.
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Affiliation(s)
- Christiane Reitz
- The Gertrude H. Sergievsky Center, The Taub Institute for Research on Alzheimer's Disease and The Aging Brain New York, NY, USA.
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Zhang X, Bai Q, Kakiyama G, Xu L, Kim JK, Pandak WM, Ren S. Cholesterol metabolite, 5-cholesten-3β-25-diol-3-sulfate, promotes hepatic proliferation in mice. J Steroid Biochem Mol Biol 2012; 132:262-70. [PMID: 22732306 PMCID: PMC3463675 DOI: 10.1016/j.jsbmb.2012.06.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Revised: 06/11/2012] [Accepted: 06/13/2012] [Indexed: 11/21/2022]
Abstract
UNLABELLED Oxysterols are well known as physiological ligands of liver X receptors (LXRs). Oxysterols, 25-hydroxycholesterol (25HC) and 27-hydroxycholesterol as endogenous ligands of LXRs, suppress cell proliferation via LXRs signaling pathway. Recent reports have shown that sulfated oxysterol, 5-cholesten-3β-25-diol-3-sulfate (25HC3S) as LXRs antagonist, plays an opposite direction to oxysterols in lipid biosynthesis. The present report was to explore the effect and mechanism of 25HC3S on hepatic proliferation in vivo. Following administration, 25HC3S had a 48 h half life in the circulation and widely distributed in mouse tissues. Profiler™ PCR array and RTqPCR analysis showed that either exogenous or endogenous 25HC3S generated by overexpression of oxysterol sulfotransferase (SULT2B1b) plus administration of 25HC significantly up-regulated the proliferation gene expression of Wt1, Pcna, cMyc, cyclin A, FoxM1b, and CDC25b in a dose-dependent manner in liver while substantially down-regulating the expression of cell cycle arrest gene Chek2 and apoptotic gene Apaf1. Either exogenous or endogenous administration of 25HC3S significantly induced hepatic DNA replication as measured by immunostaining of the PCNA labeling index and was associated with reduction in expression of LXR response genes, such as ABCA1 and SREBP-1c. Synthetic LXR agonist T0901317 effectively blocked 25HC3S-induced hepatic proliferation. CONCLUSIONS 25HC3S may be a potent regulator of hepatocyte proliferation and oxysterol sulfation may represent a novel regulatory pathway in liver proliferation via inactivating LXR signaling.
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Affiliation(s)
- Xin Zhang
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
- Department of Pathology, Fudan University Shanghai Medical College, 138 Yixueyuan Road, Shanghai 200032, China
| | - Qianming Bai
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
- Department of Pathology, Fudan University Shanghai Cancer Center, 270 Dongan Road, Shanghai 200032, China
| | - Genta Kakiyama
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
| | - Leyuan Xu
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
| | - Jin Kyung Kim
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
| | - William M. Pandak
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
| | - Shunlin Ren
- Department of Medicine, Virginia Commonwealth University/Veterans Affairs McGuire Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23249, United States
- Address correspondence to: Dr. Shunlin Ren McGuire Veterans Affairs Medical Center/Virginia Commonwealth University, Research 151, 1201 Broad Rock Blvd, Richmond, VA, 23249, USA. Tel.: +1 (804) 675-5000×4973 Fax: +1 (804) 675-5359
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Exeter HJ, Folkersen L, Palmen J, Franco-Cereceda A, Cooper JA, Kalea AZ, Hooft FV, Eriksson P, Humphries SE, Talmud PJ. Functional analysis of two PLA2G2A variants associated with secretory phospholipase A2-IIA levels. PLoS One 2012; 7:e41139. [PMID: 22879865 PMCID: PMC3412631 DOI: 10.1371/journal.pone.0041139] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 06/17/2012] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Secretory phospholipase A2 group IIA (sPLA2-IIA) has been identified as a biomarker of atherosclerosis in observational and animal studies. The protein is encoded by the PLA2G2A gene and the aim of this study was to test the functionality of two PLA2G2A non-coding SNPs, rs11573156 C>G and rs3767221 T>G where the rare alleles have been previously associated with higher and lower sPLA2-IIA levels respectively. METHODOLOGY/PRINCIPAL FINDINGS Luciferase assays, electrophoretic mobility shift assays (EMSA), and RNA expression by RT-PCR were used to examine allelic differences. For rs3767221 the G allele showed ∼55% lower luciferase activity compared to the T allele (T = 62.1 (95% CI 59.1 to 65.1) G = 27.8 (95% CI 25.0 to 30.6), p = 1.22×10⁻³⁵, and stronger EMSA binding of a nuclear protein compared to the T-allele. For rs11573156 C >G there were no luciferase or EMSA allelic differences seen. In lymphocyte cell RNA, from individuals of known rs11573156 genotype, there was no allelic RNA expression difference for exons 5 and 6, but G allele carriers (n = 7) showed a trend to lower exon 1-2 expression compared to CC individuals. To take this further, in the ASAP study (n = 223), an rs11573156 proxy (r² = 0.91) showed ∼25% higher liver expression of PLA2G2A (1.67×10⁻¹⁷) associated with the G allele. However, considering exon specific expression, the association was greatly reduced for exon 2 (4.5×10⁻⁵) compared to exons 3-6 (10⁻¹⁰ to 10⁻²⁰), suggesting rs11573156 G allele-specific exon 2 skipping. CONCLUSION Both SNPs are functional and provide useful tools for Mendelian Randomisation to determine whether the relationship between sPLA2-IIA and coronary heart disease is causal.
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Affiliation(s)
- Holly J. Exeter
- Centre of Cardiovascular Genetics, Institute of Cardiovascular Sciences, University College London, London, United Kingdom
- * E-mail: (PJT); (HJE)
| | - Lasse Folkersen
- Atherosclerosis Research Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Jutta Palmen
- Centre of Cardiovascular Genetics, Institute of Cardiovascular Sciences, University College London, London, United Kingdom
| | - Anders Franco-Cereceda
- Cardiothoracic Surgery Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Jackie A. Cooper
- Centre of Cardiovascular Genetics, Institute of Cardiovascular Sciences, University College London, London, United Kingdom
| | - Anastasia Z. Kalea
- Centre of Cardiovascular Genetics, Institute of Cardiovascular Sciences, University College London, London, United Kingdom
| | - Ferdinand van’t Hooft
- Atherosclerosis Research Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Per Eriksson
- Atherosclerosis Research Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Steve E. Humphries
- Centre of Cardiovascular Genetics, Institute of Cardiovascular Sciences, University College London, London, United Kingdom
| | - Philippa J. Talmud
- Centre of Cardiovascular Genetics, Institute of Cardiovascular Sciences, University College London, London, United Kingdom
- * E-mail: (PJT); (HJE)
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Martín R, Cordova C, Nieto ML. Secreted phospholipase A2-IIA-induced a phenotype of activated microglia in BV-2 cells requires epidermal growth factor receptor transactivation and proHB-EGF shedding. J Neuroinflammation 2012; 9:154. [PMID: 22747893 PMCID: PMC3488565 DOI: 10.1186/1742-2094-9-154] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 06/04/2012] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Activation of microglia, the primary component of the innate immune response in the brain, is a hallmark of neuroinflammation in neurodegenerative disorders, including Alzheimer's disease (AD) and other pathological conditions such as stroke or CNS infection. In response to a variety of insults, microglial cells produce high levels of inflammatory cytokines that are often involved in neuronal injury, and play an important role in the recognition, engulfment, and clearance of apoptotic cells and/or invading microbes. Secreted phospholipase A2-IIA (sPLA2-IIA), an enzyme that interacts with cells involved in the systemic immune/inflammatory response, has been found up-regulated in the cerebrospinal fluid and brain of AD patients. However, despite several approaches, its functions in mediating CNS inflammation remain unknown. In the present study, the role of sPLA2-IIA was examined by investigating its direct effects on microglial cells. METHODS Primary and immortalized microglial cells were stimulated by sPLA2-IIA in order to characterize the cytokine-like actions of the phospholipase. The hallmarks of activated microglia analyzed include: mitogenic response, phagocytic capabilities and induction of inflammatory mediators. In addition, we studied several of the potential molecular mechanisms involved in those events. RESULTS The direct exposure of microglial cells to sPLA2-IIA stimulated, in a time- and dose-dependent manner, their phagocytic and proliferative capabilities. sPLA2-IIA also triggered the synthesis of the inflammatory proteins COX-2 and TNFα. In addition, EGFR phosphorylation and shedding of the membrane-anchored heparin-binding EGF-like growth factor (pro-HB-EGF) ectodomain, as well as a rapid activation/phosphorylation of the classical survival proteins ERK, P70S6K and rS6 were induced upon sPLA2-IIA treatment. We further demonstrated that the presence of an EGFR inhibitor (AG1478), a matrix metalloproteinase inhibitor (GM6001), an ADAM inhibitor (TAPI-1), and a HB-EGF neutralizing antibody abrogated the phenotype of activated microglia induced by the sPLA2-IIA. CONCLUSION These results support the hypothesis that sPLA2-IIA may act as a potent modulator of microglial functions through its ability to induce EGFR transactivation and HB-EGF release. Accordingly, pharmacological modulation of EGFR might be a useful tool for treating neuroinflammatory diseases characterized by sPLA2-IIA accumulation.
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Affiliation(s)
- Rubén Martín
- Instituto de Biología y Genetica Molecular (IBGM), CSIC-UVa, Valladolid, Spain
- ICICOR, Hospital Clínico, Valladolid, Spain
| | - Claudia Cordova
- Instituto de Biología y Genetica Molecular (IBGM), CSIC-UVa, Valladolid, Spain
| | - Maria L Nieto
- Instituto de Biología y Genetica Molecular (IBGM), CSIC-UVa, Valladolid, Spain
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Pirchl M, Ullrich C, Sperner-Unterweger B, Humpel C. Homocysteine has anti-inflammatory properties in a hypercholesterolemic rat model in vivo. Mol Cell Neurosci 2012; 49:456-63. [PMID: 22425561 PMCID: PMC3359503 DOI: 10.1016/j.mcn.2012.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 02/29/2012] [Accepted: 03/01/2012] [Indexed: 01/13/2023] Open
Abstract
Inflammation is a hallmark in many neurodegenerative diseases like Alzheimer's disease or vascular dementia. Cholesterol and homocysteine are both vascular risk factors which have been associated with dementia, inflammation and blood–brain barrier dysfunction. In previous studies we found that hypercholesterolemia but not hyperhomocysteinemia induced inflammation in rats in vivo. The aim of the present study was to investigate the effect of a combined treatment of Sprague Dawley rats with cholesterol and homocysteine for 5 months on spatial learning and memory, blood–brain barrier integrity and inflammation. Cholesterol treated rats showed severe learning deficits, while rats treated with cholesterol and homocysteine (Mix) counteracted the cholesterol-induced inflammation and partly the cortical blood–brain barrier disruptions, although cognition was still impaired. To study the potential protective effect of homocysteine, inflammation was induced in organotypic rat brain cortex slices and primary microglial cells by treatment with different inflammatory stimuli (e.g. lipopolysaccharide or tissue plasminogen activator). Tissue plasminogen activator-induced inflammation was counteracted by homocysteine. In conclusion, our data demonstrate that homocysteine significantly ameliorates cholesterol-induced inflammation and blood–brain barrier disruption but not the memory impairment, possibly involving a tissue plasminogen activator-related mechanism.
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Affiliation(s)
| | | | | | - Christian Humpel
- Corresponding author at: Dep. of Psychiatry and Psychotherapy, Anichstr. 35, A-6020 Innsbruck, Austria. Fax: + 43 512 504 23713.
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Inflammatory-induced hibernation in the fetus: priming of fetal sheep metabolism correlates with developmental brain injury. PLoS One 2011; 6:e29503. [PMID: 22242129 PMCID: PMC3248450 DOI: 10.1371/journal.pone.0029503] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 11/29/2011] [Indexed: 02/02/2023] Open
Abstract
Prenatal inflammation is considered an important factor contributing to preterm birth and neonatal mortality and morbidity. The impact of prenatal inflammation on fetal bioenergetic status and the correlation of specific metabolites to inflammatory-induced developmental brain injury are unknown. We used a global metabolomics approach to examine plasma metabolites differentially regulated by intrauterine inflammation. Preterm-equivalent sheep fetuses were randomized to i.v. bolus infusion of either saline-vehicle or LPS. Blood samples were collected at baseline 2 h, 6 h and daily up to 10 days for metabolite quantification. Animals were killed at 10 days after LPS injection, and brain injury was assessed by histopathology. We detected both acute and delayed effects of LPS on fetal metabolism, with a long-term down-regulation of fetal energy metabolism. Within the first 3 days after LPS, 121 metabolites were up-regulated or down-regulated. A transient phase (4–6 days), in which metabolite levels recovered to baseline, was followed by a second phase marked by an opposing down-regulation of energy metabolites, increased pO2 and increased markers of inflammation and ADMA. The characteristics of the metabolite response to LPS in these two phases, defined as 2 h to 2 days and at 6–9 days, respectively, were strongly correlated with white and grey matter volumes at 10 days recovery. Based on these results we propose a novel concept of inflammatory-induced hibernation of the fetus. Inflammatory priming of fetal metabolism correlated with measures of brain injury, suggesting potential for future biomarker research and the identification of therapeutic targets.
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Nelissen K, Mulder M, Smets I, Timmermans S, Smeets K, Ameloot M, Hendriks JJA. Liver X receptors regulate cholesterol homeostasis in oligodendrocytes. J Neurosci Res 2011; 90:60-71. [PMID: 21972082 DOI: 10.1002/jnr.22743] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Revised: 06/15/2011] [Accepted: 06/20/2011] [Indexed: 11/08/2022]
Abstract
Cholesterol synthesis and transport in oligodendrocytes are essential for optimal myelination and remyelination in pathological conditions such as multiple sclerosis. However, little is known about cholesterol homeostasis in the myelin-forming oligodendrocytes. Liver X receptors (LXRs) are nuclear oxysterol receptors that regulate genes involved in cholesterol homeostasis and may therefore play an important role in de- and remyelination. We investigated whether LXRs regulate cholesterol homeostasis in oligodendrocytes. mRNA expression of genes encoding LXR-α and LXR-β and their target genes (ABCA1, ABCG1, ABCG4, apoE, and LDLR) was detected in oligodendrocytes derived from both neonatal and adult rats using quantitative real-time PCR. The expression of LXR-β and several target genes was increased during oligodendrocyte differentiation. We further demonstrated that treatment of primary neonatal rat oligodendrocytes with the synthetic LXR agonist T0901317 induced the expression of several established LXR target genes, including ABCA1, ABCG1, apoE, and LDLR. Treatment of oligodendrocytes with T0901317 resulted in an enhanced cholesterol efflux in the presence of apolipoprotein A-I or high-density lipoprotein particles. These data show that LXRs are involved in regulating cholesterol homeostasis in oligodendrocytes.
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Affiliation(s)
- Katherine Nelissen
- Biomedical Research Institute, Hasselt University, and transnational University Limburg, Diepenbeek, Belgium
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Interplay between LXR and Wnt/β-catenin signaling in the negative regulation of peripheral myelin genes by oxysterols. J Neurosci 2011; 31:9620-9. [PMID: 21715627 DOI: 10.1523/jneurosci.0761-11.2011] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Oxysterols are reactive molecules generated from the oxidation of cholesterol. Their implication in cholesterol homeostasis and in the progression of neurodegenerative disorders is well known, but few data are available for their functions in the peripheral nervous system. Our aim was to study the influence of oxysterols on myelin gene expression and myelin sheath formation in peripheral nerves. We show by gas chromatography/mass spectrometry that Schwann cells and sciatic nerves contain 24(S)-hydroxycholesterol, 25-hydroxycholesterol, and 27-hydroxycholesterol and that they express their biosynthetic enzymes and receptors (liver X receptors LXRα and LXRβ). We demonstrate that oxysterols inhibit peripheral myelin gene expression [myelin protein zero (MPZ) and peripheral myelin protein-22 (PMP22)] in a Schwann cell line. This downregulation is mediated by either LXRα or LXRβ, depending on the promoter context, as suggested by siRNA strategy and chromatin immunoprecipitation assays in Schwann cells and in the sciatic nerve of LXR knock-out mice. Importantly, the knock-out of LXR in mice results in thinner myelin sheaths surrounding the axons. Oxysterols repress myelin genes via two mechanisms: by binding of LXRs to myelin gene promoters and by inhibiting the Wnt/β-catenin pathway that is crucial for the expression of myelin genes. The Wnt signaling components (Disheveled, TCF/LEF, β-catenin) are strongly repressed by oxysterols. Furthermore, the recruitment of β-catenin at the levels of the MPZ and PMP22 promoters is decreased. Our data reveal new endogenous mechanisms for the negative regulation of myelin gene expression, highlight the importance of oxysterols and LXR in peripheral nerve myelination, and open new perspectives of treating demyelinating diseases with LXR agonists.
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Mateos L, Ismail MAM, Gil-Bea FJ, Schüle R, Schöls L, Heverin M, Folkesson R, Björkhem I, Cedazo-Mínguez A. Side chain-oxidized oxysterols regulate the brain renin-angiotensin system through a liver X receptor-dependent mechanism. J Biol Chem 2011; 286:25574-85. [PMID: 21628469 PMCID: PMC3138324 DOI: 10.1074/jbc.m111.236877] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 05/26/2011] [Indexed: 12/26/2022] Open
Abstract
Disturbances in cholesterol metabolism have been associated with hypertension and neurodegenerative disorders. Because cholesterol metabolism in the brain is efficiently separated from plasma cholesterol by the blood-brain barrier (BBB), it is an unsolved paradox how high blood cholesterol can cause an effect in the brain. Here, we discuss the possibility that cholesterol metabolites permeable to the BBB might account for these effects. We show that 27-hydroxycholesterol (27-OH) and 24S-hydroxycholesterol (24S-OH) up-regulate the renin-angiotensin system (RAS) in the brain. Brains of mice on a cholesterol-enriched diet showed up-regulated angiotensin converting enzyme (ACE), angiotensinogen (AGT), and increased JAK/STAT activity. These effects were confirmed in in vitro studies with primary neurons and astrocytes exposed to 27-OH or 24S-OH, and were partially mediated by liver X receptors. In contrast, brain RAS activity was decreased in Cyp27a1-deficient mice, a model exhibiting reduced 27-OH production from cholesterol. Moreover, in humans, normocholesterolemic patients with elevated 27-OH levels, due to a CYP7B1 mutation, had markers of activated RAS in their cerebrospinal fluid. Our results demonstrate that side chain-oxidized oxysterols are modulators of brain RAS. Considering that levels of cholesterol and 27-OH correlate in the circulation and 27-OH can pass the BBB into the brain, we suggest that this cholesterol metabolite could be a link between high plasma cholesterol levels, hypertension, and neurodegeneration.
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Affiliation(s)
- Laura Mateos
- From the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet-Alzheimer's Disease Research Center, NOVUM, SE-14186 Stockholm, Sweden
| | - Muhammad-Al-Mustafa Ismail
- From the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet-Alzheimer's Disease Research Center, NOVUM, SE-14186 Stockholm, Sweden
| | - Francisco-Javier Gil-Bea
- From the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet-Alzheimer's Disease Research Center, NOVUM, SE-14186 Stockholm, Sweden
| | - Rebecca Schüle
- the Hertie Institute for Clinical Brain Research and Center of Neurology, University of Tubingen, 72076 Tubingen, Germany, and
| | - Ludger Schöls
- the Hertie Institute for Clinical Brain Research and Center of Neurology, University of Tubingen, 72076 Tubingen, Germany, and
| | - Maura Heverin
- the Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska University Hospital, 14186 Huddinge, Sweden
| | - Ronnie Folkesson
- From the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet-Alzheimer's Disease Research Center, NOVUM, SE-14186 Stockholm, Sweden
| | - Ingemar Björkhem
- the Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska University Hospital, 14186 Huddinge, Sweden
| | - Angel Cedazo-Mínguez
- From the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet-Alzheimer's Disease Research Center, NOVUM, SE-14186 Stockholm, Sweden
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Wnt/beta-catenin signaling is an essential and direct driver of myelin gene expression and myelinogenesis. J Neurosci 2011; 31:3729-42. [PMID: 21389228 DOI: 10.1523/jneurosci.4270-10.2011] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Wnt/β-catenin signaling plays a major role in the development of the nervous system and contributes to neuronal plasticity. However, its role in myelination remains unclear. Here, we identify the Wnt/β-catenin pathway as an essential driver of myelin gene expression. The selective inhibition of Wnt components by small interfering RNA or dominant-negative forms blocks the expression of myelin protein zero (MPZ) and peripheral myelin protein 22 (PMP22) in mouse Schwann cells and proteolipid protein in mouse oligodendrocytes. Moreover, the activation of Wnt signaling by recombinant Wnt1 ligand increases by threefold the transcription of myelin genes and enhances the binding of β-catenin to T-cell factor/lymphoid-enhancer factor transcription factors present in the vicinity of the MPZ and PMP22 promoters. Most important, loss-of-function analyses in zebrafish embryos show, in vivo, a key role for Wnt/β-catenin signaling in the expression of myelin genes and in myelin sheath compaction, both in the peripheral and central nervous systems. Inhibition of Wnt/β-catenin signaling resulted in hypomyelination, without affecting Schwann cell and oligodendrocyte generation or axonal integrity. The present findings attribute to Wnt/β-catenin pathway components an essential role in myelin gene expression and myelinogenesis.
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42
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Butterfield DA, Barone E, Mancuso C. Cholesterol-independent neuroprotective and neurotoxic activities of statins: perspectives for statin use in Alzheimer disease and other age-related neurodegenerative disorders. Pharmacol Res 2011; 64:180-6. [PMID: 21536132 DOI: 10.1016/j.phrs.2011.04.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 04/14/2011] [Indexed: 01/24/2023]
Abstract
Statins, long known to be beneficial in conditions where dyslipidemia occurs by lowering serum cholesterol levels, also have been proposed for use in neurodegenerative conditions, including Alzheimer disease. However, it is not clear that the purported effectiveness of statins in neurodegenerative disorders is directly related to cholesterol-lowering effects of these agents; rather, the pleiotropic functions of statins likely play critical roles. Moreover, it is becoming more apparent with additional studies that statins can have deleterious effects in preclinical studies and lack effectiveness in various recent clinical trials. This perspective paper outlines pros and cons of the use of statins in neurodegenerative disorders, with particular emphasis on Alzheimer disease.
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Affiliation(s)
- D Allan Butterfield
- Department of Chemistry, Center of Membrane Sciences, University of Kentucky, Lexington, KY 40506, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506, USA.
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Barone E, Cenini G, Di Domenico F, Martin S, Sultana R, Mancuso C, Murphy MP, Head E, Butterfield DA. Long-term high-dose atorvastatin decreases brain oxidative and nitrosative stress in a preclinical model of Alzheimer disease: a novel mechanism of action. Pharmacol Res 2011; 63:172-80. [PMID: 21193043 PMCID: PMC3034810 DOI: 10.1016/j.phrs.2010.12.007] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 12/16/2010] [Accepted: 12/16/2010] [Indexed: 01/12/2023]
Abstract
Alzheimer disease (AD) is an age-related neurodegenerative disorder characterized by progressive memory loss, inability to perform the activities of daily living and personality changes. Unfortunately, drugs effective for this disease are limited to acetylcholinesterase inhibitors that do not impact disease pathogenesis. Statins, which belong to the class of cholesterol-reducing drugs, were proposed as novel agents useful in AD therapy, but the mechanism underlying their neuroprotective effect is still unknown. In this study, we show that atorvastatin may have antioxidant effects, in aged beagles, that represent a natural higher mammalian model of AD. Atorvastatin (80 mg/day for 14.5 months) significantly reduced lipoperoxidation, protein oxidation and nitration, and increased GSH levels in parietal cortex of aged beagles. This effect was specific for brain because it was not paralleled by a concomitant reduction in all these parameters in serum. In addition, atorvastatin slightly reduced the formation of cholesterol oxidation products in cortex but increased the 7-ketocholesterol/total cholesterol ratio in serum. We also found that increased oxidative damage in the parietal cortex was associated with poorer learning (visual discrimination task). Thus, a novel pharmacological effect of atorvastatin mediated by reducing oxidative damage may be one mechanism underlying benefits of this drug in AD.
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Affiliation(s)
- Eugenio Barone
- Department of Chemistry, Center of Membrane Sciences, and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA
- Institute of Pharmacology, Catholic University School of Medicine, Largo F. Vito, 1, 00168 Roma, Italy
| | - Giovanna Cenini
- Department of Chemistry, Center of Membrane Sciences, and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA
- Department of Molecular and Biomedical Pharmacology, and Sanders-Brown Center on Aging University of Kentucky, Lexington, KY, USA
| | - Fabio Di Domenico
- Department of Chemistry, Center of Membrane Sciences, and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA
- Department of Biochemical Sciences, Sapienza University of Rome, 00185 Rome, Italy
| | - Sarah Martin
- Department of Molecular and Biomedical Pharmacology, and Sanders-Brown Center on Aging University of Kentucky, Lexington, KY, USA
| | - Rukhsana Sultana
- Department of Chemistry, Center of Membrane Sciences, and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA
| | - Cesare Mancuso
- Institute of Pharmacology, Catholic University School of Medicine, Largo F. Vito, 1, 00168 Roma, Italy
| | - Michael Paul Murphy
- Department of Molecular and Cellular Biochemistry, and Sanders-Brown Center on Aging University of Kentucky, Lexington, KY, USA
| | - Elizabeth Head
- Department of Molecular and Biomedical Pharmacology, and Sanders-Brown Center on Aging University of Kentucky, Lexington, KY, USA
| | - D. Allan Butterfield
- Department of Chemistry, Center of Membrane Sciences, and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA
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44
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Salman ED, Faye-Petersen O, Falany CN. Hydroxysteroid sulfotransferase 2B1b expression and localization in normal human brain. Horm Mol Biol Clin Investig 2011; 8:445-454. [PMID: 24683427 DOI: 10.1515/hmbci.2011.117] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Steroid sulfonation in the human brain has not been well characterized. The major sulfotransferase (SULT) isoforms that conjugate steroids in humans are SULT1E1, SULT2A1, and SULT2B1b. SULT2B1b catalyzes the sulfonation of 3β-hydroxysteroids, including neurosteroids dehydroepiandrosterone and pregnenolone, as well as cholesterol and several hydroxycholesterols. SULT2B1b mRNA and protein expression were detected in adult and fetal human brain sections, whereas neither mRNA, nor protein expression were identified for SULT1E1 or SULT2A1. Using immunohistochemical analysis, SULT2B1b expression was detected in neurons and oligodendrocytes in adult brain and in epithelial tissues in 28-week-old fetal brain. Sulfonation of cholesterol, oxysterols, and neurosteroids in the brain is apparently catalyzed by SULT2B1b since expression of neither SULT2A1 nor SULT1E1 was detected in human brain sections. SULT2B1b mRNA and protein were also detected in human U373-MG glioblastoma cells. Both mRNA and protein expression of liver X receptor (LXR)-β, but not LXR-α, were detected in U373-MG cells, and LXR-β activation resulted in a decrease in SULT2B1b protein expression. Since hydroxycholesterols are important physiological LXR activators, this suggests a role for regulation of sterol metabolism by LXR and SULT2B1b. Therefore, elucidating key enzymes in the metabolism of cholesterol and neurosteroids could help define the properties of steroid conjugation in the human brain.
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Affiliation(s)
- Emily D Salman
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ona Faye-Petersen
- Department of Anatomic and Clinical Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Charles N Falany
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL, USA
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45
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Huang JK, Jarjour AA, Nait Oumesmar B, Kerninon C, Williams A, Krezel W, Kagechika H, Bauer J, Zhao C, Baron-Van Evercooren A, Chambon P, Ffrench-Constant C, Franklin RJM. Retinoid X receptor gamma signaling accelerates CNS remyelination. Nat Neurosci 2011; 14:45-53. [PMID: 21131950 PMCID: PMC4013508 DOI: 10.1038/nn.2702] [Citation(s) in RCA: 396] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Accepted: 10/21/2010] [Indexed: 12/14/2022]
Abstract
The molecular basis of CNS myelin regeneration (remyelination) is poorly understood. We generated a comprehensive transcriptional profile of the separate stages of spontaneous remyelination that follow focal demyelination in the rat CNS and found that transcripts that encode the retinoid acid receptor RXR-γ were differentially expressed during remyelination. Cells of the oligodendrocyte lineage expressed RXR-γ in rat tissues that were undergoing remyelination and in active and remyelinated multiple sclerosis lesions. Knockdown of RXR-γ by RNA interference or RXR-specific antagonists severely inhibited oligodendrocyte differentiation in culture. In mice that lacked RXR-γ, adult oligodendrocyte precursor cells efficiently repopulated lesions after demyelination, but showed delayed differentiation into mature oligodendrocytes. Administration of the RXR agonist 9-cis-retinoic acid to demyelinated cerebellar slice cultures and to aged rats after demyelination caused an increase in remyelinated axons. Our results indicate that RXR-γ is a positive regulator of endogenous oligodendrocyte precursor cell differentiation and remyelination and might be a pharmacological target for regenerative therapy in the CNS.
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Affiliation(s)
- Jeffrey K Huang
- MRC Centre for Stem Cell Biology and Regenerative Medicine and Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Andrew A Jarjour
- MRC Centre for Regenerative Medicine and Multiple Sclerosis Society/University of Edinburgh Centre for Translational Research, Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh, UK
| | - Brahim Nait Oumesmar
- Centre de Recherche de l'Institut du Cerveau et de la Moelle Epinière, Inserm U.975; Université Pierre et Marie Curie-Paris 6 UMR-S975; Cnrs UMR 7225; and AP-HP Groupe Hospitalier Pitié-Salpêtrière, Fédération de Neurologie, Paris cedex 13, France
| | - Christophe Kerninon
- Centre de Recherche de l'Institut du Cerveau et de la Moelle Epinière, Inserm U.975; Université Pierre et Marie Curie-Paris 6 UMR-S975; Cnrs UMR 7225; and AP-HP Groupe Hospitalier Pitié-Salpêtrière, Fédération de Neurologie, Paris cedex 13, France
| | - Anna Williams
- MRC Centre for Regenerative Medicine and Multiple Sclerosis Society/University of Edinburgh Centre for Translational Research, Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh, UK
| | - Wojciech Krezel
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Department of Cell Biology and Development, Illkirch, France
| | - Hiroyuki Kagechika
- Graduate School of Biomedical Science, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Chiyoda-ku, Tokyo, Japan
| | - Julien Bauer
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - Chao Zhao
- MRC Centre for Stem Cell Biology and Regenerative Medicine and Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Anne Baron-Van Evercooren
- Centre de Recherche de l'Institut du Cerveau et de la Moelle Epinière, Inserm U.975; Université Pierre et Marie Curie-Paris 6 UMR-S975; Cnrs UMR 7225; and AP-HP Groupe Hospitalier Pitié-Salpêtrière, Fédération de Neurologie, Paris cedex 13, France
| | - Pierre Chambon
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Department of Cell Biology and Development, Illkirch, France
| | - Charles Ffrench-Constant
- MRC Centre for Regenerative Medicine and Multiple Sclerosis Society/University of Edinburgh Centre for Translational Research, Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh, UK
| | - Robin J M Franklin
- MRC Centre for Stem Cell Biology and Regenerative Medicine and Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
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46
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Ullrich C, Pirchl M, Humpel C. Hypercholesterolemia in rats impairs the cholinergic system and leads to memory deficits. Mol Cell Neurosci 2010; 45:408-17. [PMID: 20696249 PMCID: PMC2977849 DOI: 10.1016/j.mcn.2010.08.001] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 07/13/2010] [Accepted: 08/02/2010] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's disease (AD) is a chronic brain disorder characterized by cognitive impairment, cholinergic dysfunction, inflammation, tau and beta-amyloid pathology and vascular damage. Recent studies have shown, that high cholesterol levels are linked to the pathology of AD. The aim of our present work was to study the effects of hypercholesterolemia in adult rats. Five months after 5% cholesterol-enriched diet plasma cholesterol levels and total weight were significantly enhanced compared to controls. Spatial memory was studied in an 8-arm radial maze and cholesterol-treated rats showed an impaired learning and long-term memory. Hypercholesterolemia significantly reduced the number of cholinergic neurons in the basal nucleus of Meynert and decreased acetylcholine levels in the cortex. Nerve growth factor was only slightly enhanced in the cortex of cholesterol-treated animals. Levels of amyloid precursor protein, beta-amyloid(1–42), as well as tau and phospho-tau 181 were significantly enhanced in the cortex of cholesterol-fed rats. Hypercholesterolemia markedly increased several cerebral inflammatory markers and enhanced microglial CD11b-like immunoreactivity. Vascular density, stained by RECA-1 was not changed. However, cholesterol induced cortical microbleedings illustrated by intensive anti-rat IgG-positive spots in the cortex. In conclusion, our data demonstrate that hypercholesterolemia in rats caused memory impairment, cholinergic dysfunction, inflammation, enhanced cortical beta-amyloid and tau and microbleedings, all indications, which resemble an AD-like pathology.
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Affiliation(s)
- Celine Ullrich
- Laboratory of Psychiatry and Exp Alzheimers Research, Department of Psychiatry and Psychotherapy, Innsbruck Medical University, Austria
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47
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Ullrich C, Pirchl M, Humpel C. Effects of cholesterol and its 24S-OH and 25-OH oxysterols on choline acetyltransferase-positive neurons in brain slices. Pharmacology 2010; 86:15-21. [PMID: 20571288 DOI: 10.1159/000314333] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 04/25/2010] [Indexed: 01/08/2023]
Abstract
In Alzheimer's disease (AD) neurons expressing the enzyme choline acetyltransferase (ChAT) degenerate and a loss of cholinergic activity directly correlates with cognitive decline. Recent studies have suggested that cholesterol plays a role in AD. The aim of the present study was to explore if cholesterol and its oxysterols, 24S-hydroxycholesterol (24S-OH Chol) and 25-hydroxycholesterol (25-OH Chol), affect ChAT-positive neurons in organotypic brain slices of the basal nucleus of Meynert (nBM). We showed that slices expressed approximately 140 ChAT-positive neurons/slice after 2 weeks when incubated with nerve growth factor (NGF). This number markedly decreased when incubated without NGF to approximately 20 neurons/slice. Cholesterol and 24S-OH Chol delayed this decrease in ChAT-positive neurons. In contrast, 25-OH Chol induced a decline in ChAT-positive neurons in 2-week-old slices within 4 days. The effects of cholesterol and its oxysterols were exhibited in a dose- and time-dependent way. Our results show that cholesterol and 24S-OH Chol delays the decrease in ChAT-positive neurons, while 25-OH Chol rapidly decreases ChAT expression, suggesting differential mechanisms on ChAT expression in cholinergic nBM neurons.
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Affiliation(s)
- Celine Ullrich
- Laboratory of Psychiatry and Experimental Alzheimer's Research, Department of Psychiatry and Psychotherapy, Innsbruck Medical University, Innsbruck, Austria
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48
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Ong WY, Kim JH, He X, Chen P, Farooqui AA, Jenner AM. Changes in brain cholesterol metabolome after excitotoxicity. Mol Neurobiol 2010; 41:299-313. [PMID: 20140539 DOI: 10.1007/s12035-010-8099-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 01/07/2010] [Indexed: 12/15/2022]
Abstract
Excitotoxicity due to excess stimulation of glutamate receptors in neurons is accompanied by increased Ca(2+) influx, stimulation of Ca(2+)-dependent enzymes, ATP depletion, increase in lipid peroxidation products, and loss of glutathione. These changes resemble neurochemical alterations in acute neuronal injury (stroke, spinal cord injury, and traumatic brain injury) and chronic neurodegenerative diseases such as Alzheimer's disease. Intracerebroventricular injection of the potent glutamate analog kainate in rats results in increased cholesterol concentration in the hippocampus at short to medium time intervals, i.e., 3 days-1 week post-injection, as detected by gas chromatography-mass spectrometry in the lesioned hippocampus. This is accompanied by an early increase in levels of cholesterol biosynthetic precursors and increases in both enzymatically derived oxysterols such as 24-hydroxycholesterol and cholesterol oxidation products (COPs) generated by reactive oxygen species, including cholesterol epoxides and 7-ketocholesterol. In contrast to COPs, no change in concentration of the neurosteroid pregnenolone was found after KA injury. Cholesterol and COPs significantly increase exocytosis in cultured PC12 cells and neurons, and both oxysterols and COPs are able to induce cytotoxic and apoptotic injuries in different cell types, including neurons. Together, the findings suggest that increased cholesterol and COPs after KA excitotoxicity could themselves lead to disturbed neuronal ion homeostasis, increased neurotransmitter release, and propagation of excitotoxicity.
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Affiliation(s)
- Wei-Yi Ong
- Department of Anatomy, National University of Singapore, Singapore, 119260, Singapore.
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Martins IJ, Berger T, Sharman MJ, Verdile G, Fuller SJ, Martins RN. Cholesterol metabolism and transport in the pathogenesis of Alzheimer's disease. J Neurochem 2010; 111:1275-308. [PMID: 20050287 DOI: 10.1111/j.1471-4159.2009.06408.x] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder, affecting millions of people worldwide. Apart from age, the major risk factor identified so far for the sporadic form of AD is possession of the epsilon4 allele of apolipoprotein E (APOE), which is also a risk factor for coronary artery disease (CAD). Other apolipoproteins known to play an important role in CAD such as apolipoprotein B are now gaining attention for their role in AD as well. AD and CAD share other risk factors, such as altered cholesterol levels, particularly high levels of low density lipoproteins together with low levels of high density lipoproteins. Statins--drugs that have been used to lower cholesterol levels in CAD, have been shown to protect against AD, although the protective mechanism(s) involved are still under debate. Enzymatic production of the beta amyloid peptide, the peptide thought to play a major role in AD pathogenesis, is affected by membrane cholesterol levels. In addition, polymorphisms in several proteins and enzymes involved in cholesterol and lipoprotein transport and metabolism have been linked to risk of AD. Taken together, these findings provide strong evidence that changes in cholesterol metabolism are intimately involved in AD pathogenic processes. This paper reviews cholesterol metabolism and transport, as well as those aspects of cholesterol metabolism that have been linked with AD.
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Affiliation(s)
- Ian J Martins
- Centre of Excellence for Alzheimer's Disease Research and Care, Edith Cowan University, Joondalup, Australia.
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50
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Trousson A, Makoukji J, Petit PX, Bernard S, Slomianny C, Schumacher M, Massaad C. Cross-talk between oxysterols and glucocorticoids: differential regulation of secreted phopholipase A2 and impact on oligodendrocyte death. PLoS One 2009; 4:e8080. [PMID: 19956653 PMCID: PMC2779104 DOI: 10.1371/journal.pone.0008080] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Accepted: 11/05/2009] [Indexed: 11/19/2022] Open
Abstract
Background Oxysterols are oxidized forms of cholesterol. They have been shown to be implicated in cholesterol turnover, inflammation and in neurodegenerative diseases such as Alzheimer's disease and multiple sclerosis. Glial cells are targets of oxysterols: they inhibit astrocyte proliferation after brain injury, and we have previously shown that 25-hydroxycholesterol (25OH) provokes oligodendrocyte apoptosis and stimulates the expression of sPLA2 type IIA (sPLA2-IIA), which has a protective effect. Methodology/Principal Findings As glucocorticoids are well-known for their anti-inflammatory effects, our aim was to understand their direct effects on oxysterol-induced responses in oligodendrocytes (sPLA2-IIA stimulation and apoptosis). We demonstrate that the synthetic glucocorticoid dexamethasone (Dex) abolishes the stimulation of sPLA2-IIA by 25-hydroxycholesterol (25-OH). This inhibition is mediated by the glucocorticoid receptor (GR), which decreases the expression of the oxysterol receptor Pregnane X Receptor (PXR) and interferes with oxysterol signaling by recruiting a common limiting coactivator PGC1α. Consistent with the finding that sPLA2-IIA can partially protect oligodendrocytes against oxysterol-triggered apoptosis, we demonstrate here that the inhibition of sPLA2-IIA by Dex accelerates the apoptotic phenomenon, leading to a shift towards necrosis. We have shown by atomic force microscopy and electron microscopy that 25-OH and Dex alters oligodendrocyte shape and disorganizes the cytoplasm. Conclusions/Significance Our results provide a new understanding of the cross-talk between oxysterol and glucocorticoid signaling pathways and their respective roles in apoptosis and oligodendrocyte functions.
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Affiliation(s)
- Amalia Trousson
- UMR788, Inserm and University Paris-Sud 11, IFR 93, Le Kremlin-Bicêtre, France
- UPR 2228, CNRS and University Paris Descartes, IFR95, Paris, France
| | - Joelle Makoukji
- UPR 2228, CNRS and University Paris Descartes, IFR95, Paris, France
| | - Patrice X. Petit
- Cancer, Apoptosis, and Mitochondria Team, UMR8104 CNRS, Institut Cochin, Paris, France
| | - Sophie Bernard
- UPR 2228, CNRS and University Paris Descartes, IFR95, Paris, France
| | | | - Michael Schumacher
- UMR788, Inserm and University Paris-Sud 11, IFR 93, Le Kremlin-Bicêtre, France
| | - Charbel Massaad
- UMR788, Inserm and University Paris-Sud 11, IFR 93, Le Kremlin-Bicêtre, France
- UPR 2228, CNRS and University Paris Descartes, IFR95, Paris, France
- * E-mail:
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