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Manukjan N, Majcher D, Leenders P, Caiment F, van Herwijnen M, Smeets HJ, Suidgeest E, van der Weerd L, Vanmierlo T, Jansen JFA, Backes WH, van Oostenbrugge RJ, Staals J, Fulton D, Ahmed Z, Blankesteijn WM, Foulquier S. Hypoxic oligodendrocyte precursor cell-derived VEGFA is associated with blood-brain barrier impairment. Acta Neuropathol Commun 2023; 11:128. [PMID: 37550790 PMCID: PMC10405482 DOI: 10.1186/s40478-023-01627-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/23/2023] [Indexed: 08/09/2023] Open
Abstract
Cerebral small vessel disease is characterised by decreased cerebral blood flow and blood-brain barrier impairments which play a key role in the development of white matter lesions. We hypothesised that cerebral hypoperfusion causes local hypoxia, affecting oligodendrocyte precursor cell-endothelial cell signalling leading to blood-brain barrier dysfunction as an early mechanism for the development of white matter lesions. Bilateral carotid artery stenosis was used as a mouse model for cerebral hypoperfusion. Pimonidazole, a hypoxic cell marker, was injected prior to humane sacrifice at day 7. Myelin content, vascular density, blood-brain barrier leakages, and hypoxic cell density were quantified. Primary mouse oligodendrocyte precursor cells were exposed to hypoxia and RNA sequencing was performed. Vegfa gene expression and protein secretion was examined in an oligodendrocyte precursor cell line exposed to hypoxia. Additionally, human blood plasma VEGFA levels were measured and correlated to blood-brain barrier permeability in normal-appearing white matter and white matter lesions of cerebral small vessel disease patients and controls. Cerebral blood flow was reduced in the stenosis mice, with an increase in hypoxic cell number and blood-brain barrier leakages in the cortical areas but no changes in myelin content or vascular density. Vegfa upregulation was identified in hypoxic oligodendrocyte precursor cells, which was mediated via Hif1α and Epas1. In humans, VEGFA plasma levels were increased in patients versus controls. VEGFA plasma levels were associated with increased blood-brain barrier permeability in normal appearing white matter of patients. Cerebral hypoperfusion mediates hypoxia induced VEGFA expression in oligodendrocyte precursor cells through Hif1α/Epas1 signalling. VEGFA could in turn increase BBB permeability. In humans, increased VEGFA plasma levels in cerebral small vessel disease patients were associated with increased blood-brain barrier permeability in the normal appearing white matter. Our results support a role of VEGFA expression in cerebral hypoperfusion as seen in cerebral small vessel disease.
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Affiliation(s)
- Narek Manukjan
- Department of Pharmacology and Toxicology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- CARIM - School for Cardiovascular Diseases, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - Daria Majcher
- Department of Pharmacology and Toxicology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - Peter Leenders
- Department of Pharmacology and Toxicology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - Florian Caiment
- Department of Toxicogenomics, GROW–School for Oncology and Developmental Biology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - Marcel van Herwijnen
- Department of Toxicogenomics, GROW–School for Oncology and Developmental Biology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - Hubert J. Smeets
- Department of Toxicogenomics, GROW–School for Oncology and Developmental Biology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- MHeNs—School for Mental Health and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - Ernst Suidgeest
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, P.O. Box 9500, 2300 RA Leiden, the Netherlands
| | - Louise van der Weerd
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, P.O. Box 9500, 2300 RA Leiden, the Netherlands
- Department of Human Genetics, Leiden University Medical Center, P.O. Box 9500, 2300 RA Leiden, The Netherlands
| | - Tim Vanmierlo
- MHeNs—School for Mental Health and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- Department of Neuroscience, Biomedical Research Institute, Hasselt University, 3500 Hasselt, Belgium
- Department of Psychiatry and Neuropsychology, European Graduate School of Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - Jacobus F. A. Jansen
- MHeNs—School for Mental Health and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
| | - Walter H. Backes
- CARIM - School for Cardiovascular Diseases, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- MHeNs—School for Mental Health and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
| | - Robert J. van Oostenbrugge
- CARIM - School for Cardiovascular Diseases, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- MHeNs—School for Mental Health and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- Department of Neurology, Maastricht University Medical Center+, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
| | - Julie Staals
- CARIM - School for Cardiovascular Diseases, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- Department of Neurology, Maastricht University Medical Center+, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
| | - Daniel Fulton
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - Zubair Ahmed
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
- Centre for Trauma Sciences Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - W. Matthijs Blankesteijn
- Department of Pharmacology and Toxicology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- CARIM - School for Cardiovascular Diseases, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - Sébastien Foulquier
- Department of Pharmacology and Toxicology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- CARIM - School for Cardiovascular Diseases, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- MHeNs—School for Mental Health and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
- Department of Neurology, Maastricht University Medical Center+, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
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Zhao RY, Wei PJ, Sun X, Zhang DH, He QY, Liu J, Chang JL, Yang Y, Guo ZN. Role of lipocalin 2 in stroke. Neurobiol Dis 2023; 179:106044. [PMID: 36804285 DOI: 10.1016/j.nbd.2023.106044] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 01/22/2023] [Accepted: 02/12/2023] [Indexed: 02/18/2023] Open
Abstract
Stroke is the second leading cause of death worldwide; however, the treatment choices available to neurologists are limited in clinical practice. Lipocalin 2 (LCN2) is a secreted protein, belonging to the lipocalin superfamily, with multiple biological functions in mediating innate immune response, inflammatory response, iron-homeostasis, cell migration and differentiation, energy metabolism, and other processes in the body. LCN2 is expressed at low levels in the brain under normal physiological conditions, but its expression is significantly up-regulated in multiple acute stimulations and chronic pathologies. An up-regulation of LCN2 has been found in the blood/cerebrospinal fluid of patients with ischemic/hemorrhagic stroke, and could serve as a potential biomarker for the prediction of the severity of acute stroke. LCN2 activates reactive astrocytes and microglia, promotes neutrophil infiltration, amplifies post-stroke inflammation, promotes blood-brain barrier disruption, white matter injury, and neuronal death. Moreover, LCN2 is involved in brain injury induced by thrombin and erythrocyte lysates, as well as microvascular thrombosis after hemorrhage. In this paper, we review the role of LCN2 in the pathological processes of ischemic stroke; intracerebral hemorrhage; subarachnoid hemorrhage; and stroke-related brain diseases, such as vascular dementia and post-stroke depression, and their underlying mechanisms. We hope that this review will help elucidate the value of LCN2 as a therapeutic target in stroke.
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Affiliation(s)
- Ruo-Yu Zhao
- Stroke Center, Department of Neurology, the First Hospital of Jilin University, Chang Chun, China
| | - Peng-Ju Wei
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Xin Sun
- Stroke Center, Department of Neurology, the First Hospital of Jilin University, Chang Chun, China
| | - Dian-Hui Zhang
- Stroke Center, Department of Neurology, the First Hospital of Jilin University, Chang Chun, China
| | - Qian-Yan He
- Stroke Center, Department of Neurology, the First Hospital of Jilin University, Chang Chun, China
| | - Jie Liu
- Stroke Center, Department of Neurology, the First Hospital of Jilin University, Chang Chun, China
| | - Jun-Lei Chang
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Yi Yang
- Stroke Center, Department of Neurology, the First Hospital of Jilin University, Chang Chun, China; Neuroscience Research Center, the First Hospital of Jilin University, Chang Chun, China; Jilin Provincial Key Laboratory of Cerebrovascular Disease, Changchun, China.
| | - Zhen-Ni Guo
- Stroke Center, Department of Neurology, the First Hospital of Jilin University, Chang Chun, China; Neuroscience Research Center, the First Hospital of Jilin University, Chang Chun, China; Jilin Provincial Key Laboratory of Cerebrovascular Disease, Changchun, China.
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White Matter Injury: An Emerging Potential Target for Treatment after Subarachnoid Hemorrhage. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2023; 2023:3842493. [PMID: 36798684 PMCID: PMC9928519 DOI: 10.1155/2023/3842493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 12/20/2022] [Accepted: 01/04/2023] [Indexed: 02/10/2023]
Abstract
Subarachnoid hemorrhage (SAH) refers to vascular brain injury mainly from a ruptured aneurysm, which has a high lifetime risk and imposes a substantial burden on patients, families, and society. Previous studies on SAH mainly focused on neurons in gray matter (GM). However, according to literature reports in recent years, in-depth research on the mechanism of white matter (WM) is of great significance to injury and recovery after SAH. In terms of functional recovery after SAH, all kinds of cells in the central nervous system (CNS) should be protected. In other words, it is necessary to protect not only GM but also WM, not only neurons but also glial cells and axons, and not only for the lesion itself but also for the prevention and treatment of remote damage. Clarifying the mechanism of white matter injury (WMI) and repair after SAH is of great importance. Therefore, this present review systematically summarizes the current research on WMI after SAH, which might provide therapeutic targets for treatment after SAH.
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Hong X, Jian Y, Ding S, Zhou J, Zheng X, Zhang H, Zhou B, Zhuang C, Wan J, Tong X. Kir4.1 channel activation in NG2 glia contributes to remyelination in ischemic stroke. EBioMedicine 2022; 87:104406. [PMID: 36527899 PMCID: PMC9791134 DOI: 10.1016/j.ebiom.2022.104406] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 11/23/2022] [Accepted: 11/23/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Stroke is one of the most common neurological diseases in the world and is clinically manifested by transient or permanent brain dysfunction. It has a high mortality and disability rate, which severely affects people's health and diminishes the quality of life. However, there is no efficient treatment that can be considered curative and there are other less well-known theories of pathogenesis. Therefore, it is imperative to gain a full understanding of the pathophysiology of ischemia and to seek new therapeutic strategies. METHODS We first examined Kir4.1 channel and myelin based protein (MBP) expression in brain tissues from acute ischemic patients by Western blotting. We then established a transient ischemic mouse model (tMCAO) to conduct molecular, cell biological, transmission electron microscopy and pharmacokinetic studies, as well as in Kir4.1 cKO mice. Finally, neuroimaging and behavioral analyses were used to examine whether activation of Kir4.1 channel by luteolin could contribute to neuronal functional recovery in ischemic stroke. FINDINGS In acute ischemic stroke patients, we first demonstrated that Kir4.1 ion channels were greatly impaired and a severe demyelination of axons occurred in ischemic infarction area of cerebral cortex in these patients. Further evidence showed that the deficits of Kir4.1 channels in NG2 glia led to the myelin loss of axons in a transient ischemic mouse model (tMCAO). Treating ischemic mice with a natural botanical extract, luteolin augmented Kir4.1 channel currents in NG2 glia and consequently promoted remyelination of axons, alleviated the infarction area and ultimately improved motor function in a series of behavioral tests. INTERPRETATION Targeting Kir4.1 ion channels expressed in NG2 glial cells by luteolin treatment highlights an effective therapeutic strategy for a prompt brain functional recovery in ischemic stroke. FUNDING This work was supported by grants from the Ministry of Science and Technology China Brain Initiative (2022ZD0204702, to X.T.), the National Natural Science Foundation of China (82271466, 82171279, 31970904 and 31571063), the Program for Professor of Special Appointment (Eastern Scholar for Dr. X.T.) at Shanghai Institutions for Higher Learning (1510000084), Shanghai Pujiang Talent Award (15PJ1404600), Shanghai Municipal Science and Technology Major Project (2018SHZDZX05) and Shanghai Science and Technology Project (17411954000).
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Affiliation(s)
- Xiaoqi Hong
- Songjiang Institute and Songjiang Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yujin Jian
- Songjiang Institute and Songjiang Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shenghao Ding
- Department of Neurosurgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jianpo Zhou
- Department of Neurosurgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaoli Zheng
- Songjiang Institute and Songjiang Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Huimin Zhang
- Songjiang Institute and Songjiang Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Butian Zhou
- Songjiang Institute and Songjiang Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Canbin Zhuang
- Department of Neurosurgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jieqing Wan
- Department of Neurosurgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Corresponding author.
| | - Xiaoping Tong
- Songjiang Institute and Songjiang Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai, China,Corresponding author.
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Wang Z, Zhang Y, Feng W, Pang Y, Chen S, Ding S, Chen Y, Sheng C, Marshall C, Shi J, Xiao M. Miconazole Promotes Cooperative Ability of a Mouse Model of Alzheimer Disease. Int J Neuropsychopharmacol 2022; 25:951-967. [PMID: 36112386 PMCID: PMC9670758 DOI: 10.1093/ijnp/pyac061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 08/10/2022] [Accepted: 09/08/2022] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Cooperative defect is 1 of the earliest manifestations of disease patients with Alzheimer disease (AD) exhibit, but the underlying mechanism remains unclear. METHODS We evaluated the cooperative function of APP/PS1 transgenic AD model mice at ages 2, 5, and 8 months by using a cooperative drinking task. We examined neuropathologic changes in the medial prefrontal cortex (mPFC). Another experiment was designed to observe whether miconazole, which has a repairing effect on myelin sheath, could promote the cooperative ability of APP/PS1 mice in the early AD-like stage. We also investigated the protective effects of miconazole on cultured mouse cortical oligodendrocytes exposed to human amyloid β peptide (Aβ1-42). RESULTS We observed an age-dependent impairment of cooperative water drinking behavior in APP/PS1 mice. The AD mice with cooperative dysfunction showed decreases in myelin sheath thickness, oligodendrocyte nuclear heterochromatin percentage, and myelin basic protein expression levels in the mPFC. The cooperative ability was significantly improved in APP/PS1 mice treated with miconazole. Miconazole treatment increased oligodendrocyte maturation and myelin sheath thickness without reducing Aβ plaque deposition, reactive gliosis, and inflammatory factor levels in the mPFC. Miconazole also protected cultured oligodendrocytes from the toxicity of Aβ1-42. CONCLUSIONS These results demonstrate that mPFC hypomyelination is involved in the cooperative deficits of APP/PS1 mice. Improving myelination through miconazole therapy may offer a potential therapeutic approach for early intervention in AD.
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Affiliation(s)
| | | | - Weixi Feng
- Jiangsu Province Key Laboratory of Neurodegeneration, Center for Global Health, Nanjing Medical University, Nanjing, China,Brain Institute, the Affiliated Nanjing Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Yingting Pang
- Jiangsu Province Key Laboratory of Neurodegeneration, Center for Global Health, Nanjing Medical University, Nanjing, China,Brain Institute, the Affiliated Nanjing Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Sijia Chen
- Jiangsu Province Key Laboratory of Neurodegeneration, Center for Global Health, Nanjing Medical University, Nanjing, China,Brain Institute, the Affiliated Nanjing Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Shixin Ding
- Jiangsu Province Key Laboratory of Neurodegeneration, Center for Global Health, Nanjing Medical University, Nanjing, China,Brain Institute, the Affiliated Nanjing Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Yan Chen
- Jiangsu Province Key Laboratory of Neurodegeneration, Center for Global Health, Nanjing Medical University, Nanjing, China,Brain Institute, the Affiliated Nanjing Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Chengyu Sheng
- Jiangsu Province Key Laboratory of Neurodegeneration, Center for Global Health, Nanjing Medical University, Nanjing, China
| | - Charles Marshall
- Department of Rehabilitation Sciences, University of Kentucky Center of Excellence in Rural Health, Hazard, USA
| | - Jingping Shi
- Brain Institute, the Affiliated Nanjing Brain Hospital of Nanjing Medical University, Nanjing, China,Department of Neurology, the Affiliated Nanjing Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Ming Xiao
- Correspondence: Ming Xiao, MD, PhD, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, No. 101 Longmian Ave, Nanjing 211166, China ()
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Yu W, Li Y, Hu J, Wu J, Huang Y. A Study on the Pathogenesis of Vascular Cognitive Impairment and Dementia: The Chronic Cerebral Hypoperfusion Hypothesis. J Clin Med 2022; 11:jcm11164742. [PMID: 36012981 PMCID: PMC9409771 DOI: 10.3390/jcm11164742] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/27/2022] [Accepted: 08/02/2022] [Indexed: 11/16/2022] Open
Abstract
The pathogenic mechanisms underlying vascular cognitive impairment and dementia (VCID) remain controversial due to the heterogeneity of vascular causes and complexity of disease neuropathology. However, one common feature shared among all these vascular causes is cerebral blood flow (CBF) dysregulation, and chronic cerebral hypoperfusion (CCH) is the universal consequence of CBF dysregulation, which subsequently results in an insufficient blood supply to the brain, ultimately contributing to VCID. The purpose of this comprehensive review is to emphasize the important contributions of CCH to VCID and illustrate the current findings about the mechanisms involved in CCH-induced VCID pathological changes. Specifically, evidence is mainly provided to support the molecular mechanisms, including Aβ accumulation, inflammation, oxidative stress, blood-brain barrier (BBB) disruption, trophic uncoupling and white matter lesions (WMLs). Notably, there are close interactions among these multiple mechanisms, and further research is necessary to elucidate the hitherto unsolved questions regarding these interactions. An enhanced understanding of the pathological features in preclinical models could provide a theoretical basis, ultimately achieving the shift from treatment to prevention.
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Affiliation(s)
- Weiwei Yu
- Department of Neurology, Peking University Shenzhen Hospital, 1120 Lianhua Road, Futian District, Shenzhen 518036, China
| | - Yao Li
- Department of Neurology, Peking University Shenzhen Hospital, 1120 Lianhua Road, Futian District, Shenzhen 518036, China
| | - Jun Hu
- Department of Neurology, Peking University Shenzhen Hospital, 1120 Lianhua Road, Futian District, Shenzhen 518036, China
| | - Jun Wu
- Department of Neurology, Peking University Shenzhen Hospital, 1120 Lianhua Road, Futian District, Shenzhen 518036, China
- Correspondence: (J.W.); (Y.H.); Tel.: +86-0755-8392-2833 (J.W.); +86-010-83572857 (Y.H.)
| | - Yining Huang
- Department of Neurology, Peking University First Hospital, 8 Xishiku Street Xicheng District, Beijing 100034, China
- Correspondence: (J.W.); (Y.H.); Tel.: +86-0755-8392-2833 (J.W.); +86-010-83572857 (Y.H.)
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Akay LA, Effenberger AH, Tsai LH. Cell of all trades: oligodendrocyte precursor cells in synaptic, vascular, and immune function. Genes Dev 2021; 35:180-198. [PMID: 33526585 PMCID: PMC7849363 DOI: 10.1101/gad.344218.120] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Oligodendrocyte precursor cells (OPCs) are not merely a transitory progenitor cell type, but rather a distinct and heterogeneous population of glia with various functions in the developing and adult central nervous system. In this review, we discuss the fate and function of OPCs in the brain beyond their contribution to myelination. OPCs are electrically sensitive, form synapses with neurons, support blood-brain barrier integrity, and mediate neuroinflammation. We explore how sex and age may influence OPC activity, and we review how OPC dysfunction may play a primary role in numerous neurological and neuropsychiatric diseases. Finally, we highlight areas of future research.
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Affiliation(s)
- Leyla Anne Akay
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Audrey H Effenberger
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Li-Huei Tsai
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Ru X, Gao L, Zhou J, Li Q, Zuo S, Chen Y, Liu Z, Feng H. Secondary White Matter Injury and Therapeutic Targets After Subarachnoid Hemorrhage. Front Neurol 2021; 12:659740. [PMID: 34335439 PMCID: PMC8319471 DOI: 10.3389/fneur.2021.659740] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 06/11/2021] [Indexed: 01/19/2023] Open
Abstract
Aneurysmal subarachnoid hemorrhage (SAH) is one of the special stroke subtypes with high mortality and mobility. Although the mortality of SAH has decreased by 50% over the past two decades due to advances in neurosurgery and management of neurocritical care, more than 70% of survivors suffer from varying degrees of neurological deficits and cognitive impairments, leaving a heavy burden on individuals, families, and the society. Recent studies have shown that white matter is vulnerable to SAH, and white matter injuries may be one of the causes of long-term neurological deficits caused by SAH. Attention has recently focused on the pivotal role of white matter injury in the pathophysiological processes after SAH, mainly related to mechanical damage caused by increased intracerebral pressure and the metabolic damage induced by blood degradation and hypoxia. In the present review, we sought to summarize the pathophysiology processes and mechanisms of white matter injury after SAH, with a view to providing new strategies for the prevention and treatment of long-term cognitive dysfunction after SAH.
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Affiliation(s)
- Xufang Ru
- State Key Laboratory of Trauma, Burn and Combined Injury, Department of Neurosurgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Ling Gao
- Department of General Practice, Audio-Visual Education Center, Third Military Medical University (Army Medical University), Chongqing, China
| | - Jiru Zhou
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qiang Li
- State Key Laboratory of Trauma, Burn and Combined Injury, Department of Neurosurgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Shilun Zuo
- Department of Neurology, Xinqiao Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Yujie Chen
- State Key Laboratory of Trauma, Burn and Combined Injury, Department of Neurosurgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Zhi Liu
- State Key Laboratory of Trauma, Burn and Combined Injury, Department of Neurosurgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Hua Feng
- State Key Laboratory of Trauma, Burn and Combined Injury, Department of Neurosurgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
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9
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Metz I, Gavrilova RH, Weigand SD, Frischer JM, Popescu BF, Guo Y, Gloth M, Tobin WO, Zalewski NL, Lassmann H, Tillema JM, Erickson BJ, Parisi JE, Becker S, König FB, Brück W, Lucchinetti CF. Magnetic Resonance Imaging Correlates of Multiple Sclerosis Immunopathological Patterns. Ann Neurol 2021; 90:440-454. [PMID: 34231919 DOI: 10.1002/ana.26163] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 07/06/2021] [Accepted: 07/06/2021] [Indexed: 01/02/2023]
Abstract
OBJECTIVE Histology reveals that early active multiple sclerosis lesions can be classified into 3 main interindividually heterogeneous but intraindividually stable immunopathological patterns of active demyelination (patterns I-III). In patterns I and II, a T-cell- and macrophage-associated demyelination is suggested, with pattern II only showing signs of a humoral immune response. Pattern III is characterized by inflammatory lesions with an oligodendrocyte degeneration. Patterns suggest pathogenic heterogeneity, and we postulated that they have distinct magnetic resonance imaging (MRI) correlates that may serve as biomarkers. METHODS We evaluated in an international collaborative retrospective cohort study the MRI lesion characteristics of 789 conventional prebiopsy and follow-up MRIs in relation to their histopathologically classified immunopathological patterns (n = 161 subjects) and lesion edge features (n = 112). RESULTS A strong association of a ringlike enhancement and a hypointense T2-weighted (T2w) rim with patterns I and II, but not pattern III, was observed. Only a fraction of pattern III patients showed a ringlike enhancement, and this was always atypical. Ringlike enhancement and T2w rims colocalized, and ringlike enhancement showed a strong association with macrophage rims as shown by histology. A strong concordance of MRI lesion characteristics, meaning that different lesions showed the same features, was found when comparing biopsied and nonbiopsied lesions at a given time point, indicating lesion homogeneity within individual patients. INTERPRETATION We provide robust evidence that MRI characteristics reflect specific morphological features of multiple sclerosis immunopatterns and that ringlike enhancement and T2w hypointense rims might serve as a valuable noninvasive biomarker to differentiate pathological patterns of demyelination. ANN NEUROL 2021.
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Affiliation(s)
- Imke Metz
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Ralitza H Gavrilova
- Department of Neurology, Mayo Clinic, Rochester, MN.,Department of Clinical Genomics, Mayo Clinic, Rochester, MN
| | | | - Josa M Frischer
- Department of Neurosurgery, Medical University Vienna, Vienna, Austria
| | - Bogdan F Popescu
- Department of Anatomy, Physiology, and Pharmacology, and Cameco MS Neuroscience Research Center, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Yong Guo
- Department of Neurology, Mayo Clinic, Rochester, MN
| | - Mareike Gloth
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - William Oliver Tobin
- Department of Neurology, Mayo Clinic, Rochester, MN.,Center for MS and Autoimmune Neurology, Mayo Clinic, Rochester, MN
| | - Nicholas L Zalewski
- Department of Neurology, Mayo Clinic, Rochester, MN.,Department of Neurology, Mayo Clinic, Scottsdale, AZ
| | - Hans Lassmann
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | | | | | - Joseph E Parisi
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN
| | - Stephanie Becker
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany.,Department of Palliative Medicine, University Medical Center Göttingen, Göttingen, Germany
| | - Fatima B König
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany.,Institute of Pathology, Hospital Kassel, Kassel, Germany
| | - Wolfgang Brück
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
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10
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Barhwal KK, Biswal S, Chandra Nag T, Chaurasia OP, Hota SK. Class switching of carbonic anhydrase isoforms mediates remyelination in CA3 hippocampal neurons during chronic hypoxia. Free Radic Biol Med 2020; 161:102-114. [PMID: 33035636 DOI: 10.1016/j.freeradbiomed.2020.09.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/19/2020] [Accepted: 09/29/2020] [Indexed: 12/17/2022]
Abstract
Chronic exposure to hypoxia results in cerebral white matter hyperintensities, increased P300 latency, delayed response and impairment in working memory. Despite burgeoning evidence on role of myelination in nerve conduction, the effect of chronic hypoxia on myelination of hippocampal neurons has been less studied. The present study provides novel evidence on alterations in myelination of hippocampal CA3 neurons following chronic hypoxic exposure. Sprague Dawley rats exposed to global hypobaric hypoxia simulating altitude of 25,000 ft showed progressive demyelination in CA3 hippocampal neurons on 14 days followed by remyelination on 21 and 28 days. The demyelination of CA3 neurons was associated with increased apoptosis of both oligodendrocyte precursor cells (OPCs) and mature oligodendrocytes (OLs), peroxidation of myelin lipids, and nitration induced reduced expression of Carbonic Anhydrase II (CAII). Prolonged hypoxic exposure of 21 and 28 days on the other hand resulted in peroxisome proliferator-activated receptor alpha (PPARα) induced upregulation of Carbonic Anhydrase IV (CAIV) expression in mature oligodendrocytes through iNOS mediated mechanisms along with reduction in lipid peroxidation and remyelination. Inhibition of carbonic anhydrase activity on the other hand prevented remyelination of CA3 neurons. Based on these findings we propose a novel iNOS mediated mechanism for regulation of myelination in hypoxic hippocampal neurons through class switching of carbonic anhydrases.
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Affiliation(s)
- Kalpana Kumari Barhwal
- Department of Physiology, All India Institute of Medical Sciences, Bhubaneswar, Odisha, 751019, India.
| | - Suryanarayan Biswal
- Centre for Brain Development and Repair, Institute of Stem Cell Biology and Regenerative Medicine, Bangalore, 560065, India; Defence Institute of High Altitude Research, DRDO, C/o 56 APO, Leh-Ladakh, Jammu & Kashmir, 901205, India
| | - Tapas Chandra Nag
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Om Prakash Chaurasia
- Defence Institute of High Altitude Research, DRDO, C/o 56 APO, Leh-Ladakh, Jammu & Kashmir, 901205, India
| | - Sunil Kumar Hota
- O/o Director General (Life Sciences), DRDO Head Quarters, Rajaji Marg, New Delhi, 110011, India
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11
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Belov Kirdajova D, Kriska J, Tureckova J, Anderova M. Ischemia-Triggered Glutamate Excitotoxicity From the Perspective of Glial Cells. Front Cell Neurosci 2020; 14:51. [PMID: 32265656 PMCID: PMC7098326 DOI: 10.3389/fncel.2020.00051] [Citation(s) in RCA: 171] [Impact Index Per Article: 42.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/21/2020] [Indexed: 12/21/2022] Open
Abstract
A plethora of neurological disorders shares a final common deadly pathway known as excitotoxicity. Among these disorders, ischemic injury is a prominent cause of death and disability worldwide. Brain ischemia stems from cardiac arrest or stroke, both responsible for insufficient blood supply to the brain parenchyma. Glucose and oxygen deficiency disrupts oxidative phosphorylation, which results in energy depletion and ionic imbalance, followed by cell membrane depolarization, calcium (Ca2+) overload, and extracellular accumulation of excitatory amino acid glutamate. If tight physiological regulation fails to clear the surplus of this neurotransmitter, subsequent prolonged activation of glutamate receptors forms a vicious circle between elevated concentrations of intracellular Ca2+ ions and aberrant glutamate release, aggravating the effect of this ischemic pathway. The activation of downstream Ca2+-dependent enzymes has a catastrophic impact on nervous tissue leading to cell death, accompanied by the formation of free radicals, edema, and inflammation. After decades of “neuron-centric” approaches, recent research has also finally shed some light on the role of glial cells in neurological diseases. It is becoming more and more evident that neurons and glia depend on each other. Neuronal cells, astrocytes, microglia, NG2 glia, and oligodendrocytes all have their roles in what is known as glutamate excitotoxicity. However, who is the main contributor to the ischemic pathway, and who is the unsuspecting victim? In this review article, we summarize the so-far-revealed roles of cells in the central nervous system, with particular attention to glial cells in ischemia-induced glutamate excitotoxicity, its origins, and consequences.
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Affiliation(s)
- Denisa Belov Kirdajova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia.,Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Jan Kriska
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia.,Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Jana Tureckova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Miroslava Anderova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia.,Second Faculty of Medicine, Charles University, Prague, Czechia
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12
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Warnock A, Toomey LM, Wright AJ, Fisher K, Won Y, Anyaegbu C, Fitzgerald M. Damage Mechanisms to Oligodendrocytes and White Matter in Central Nervous System Injury: The Australian Context. J Neurotrauma 2020; 37:739-769. [DOI: 10.1089/neu.2019.6890] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Andrew Warnock
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - Lillian M. Toomey
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, Nedlands, Western Australia, Australia
| | - Alexander J. Wright
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - Katherine Fisher
- School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Yerim Won
- School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Chidozie Anyaegbu
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - Melinda Fitzgerald
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, Nedlands, Western Australia, Australia
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13
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Masjosthusmann S, Siebert C, Hübenthal U, Bendt F, Baumann J, Fritsche E. Arsenite interrupts neurodevelopmental processes of human and rat neural progenitor cells: The role of reactive oxygen species and species-specific antioxidative defense. CHEMOSPHERE 2019; 235:447-456. [PMID: 31272005 DOI: 10.1016/j.chemosphere.2019.06.123] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 06/15/2019] [Accepted: 06/16/2019] [Indexed: 05/10/2023]
Abstract
Arsenic exposure disturbs brain development in humans. Although developmental neurotoxicity (DNT) of arsenic has been studied in vivo and in vitro, its mode-of-action (MoA) is not completely understood. Here, we characterize the adverse neurodevelopmental effects of sodium arsenite on developing human and rat neural progenitor cells (hNPC, rNPC). Moreover, we analyze the involvement of reactive oxygen species (ROS) and the role of the glutathione (GSH)-dependent antioxidative defense for arsenite-induced DNT in a species-specific manner. We determined IC50 values for sodium arsenite-dependent (0.1-10 μM) inhibition of hNPC and rNPC migration (6.0 μM; >10 μM), neuronal (2.7 μM; 4.4 μM) and oligodendrocyte (1.1 μM; 2.0 μM) differentiation. ROS involvement was studied by quantifying the expression of ROS-regulated genes, measuring glutathione (GSH) levels, inhibiting GSH synthesis and co-exposing cells to the antioxidant N-acetylcysteine. Arsenite reduces NPC migration, neurogenesis and oligodendrogenesis of differentiating hNPC and rNPC at sub-cytotoxic concentrations. Species-specific arsenite cytotoxicity and induction of antioxidative gene expression is inversely related to GSH levels with rNPC possessing >3-fold the amount of GSH than hNPC. Inhibition of GSH synthesis increased the sensitivity towards arsenite in rNPC > hNPC. N-acetylcysteine antagonized arsenite-mediated induction of HMOX1 expression as well as reduction of neuronal and oligodendrocyte differentiation in hNPC suggesting involvement of oxidative stress in arsenite DNT. hNPC are more sensitive towards arsenite-induced neurodevelopmental toxicity than rNPC, probably due to their lower antioxidative defense capacities. This species-specific MoA data might be useful for adverse outcome pathway generation and future integrated risk assessment strategies concerning DNT.
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Affiliation(s)
- Stefan Masjosthusmann
- IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Duesseldorf, Germany
| | - Clara Siebert
- IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Duesseldorf, Germany
| | - Ulrike Hübenthal
- IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Duesseldorf, Germany
| | - Farina Bendt
- IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Duesseldorf, Germany
| | - Jenny Baumann
- IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Duesseldorf, Germany
| | - Ellen Fritsche
- IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Duesseldorf, Germany; Heinrich-Heine University, Universitätsstr. 1, 40225, Düsseldorf, Germany.
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14
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Naidu PSR, Gavriel N, Gray CGG, Bartlett CA, Toomey LM, Kretzmann JA, Patalwala D, McGonigle T, Denham E, Hee C, Ho D, Taylor NL, Norret M, Smith NM, Dunlop SA, Iyer KS, Fitzgerald M. Elucidating the Inability of Functionalized Nanoparticles to Cross the Blood-Brain Barrier and Target Specific Cells in Vivo. ACS APPLIED MATERIALS & INTERFACES 2019; 11:22085-22095. [PMID: 31150197 DOI: 10.1021/acsami.9b01356] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The adsorption of serum proteins on the surface of nanoparticles (NPs) delivered into a biological environment has been known to alter NP surface properties and consequently their targeting efficiency. In this paper, we use random copolymer (p(HEMA- ran-GMA))-based NPs synthesized using 2-hydroxyethyl methacrylate (HEMA) and glycidyl methacrylate (GMA). We show that serum proteins bind to the NP and that functionalization with antibodies and peptides designed to facilitate NP passage across the blood-brain barrier (BBB) to bind specific cell types is ineffective. In particular, we use systematic in vitro and in vivo analyses to demonstrate that p(HEMA- ran-GMA) NPs functionalized with HIV-1 trans-activating transcriptor peptide (known to cross the BBB) and α neural/glial antigen 2 (NG2) (known for targeting oligodendrocyte precursor cells (OPCs)), individually and in combination, do not specifically target OPCs and are unable to cross the BBB, likely due to the serum protein binding to the NPs.
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Affiliation(s)
| | | | | | | | | | | | | | - Terence McGonigle
- Curtin Health Innovation Research Institute , Curtin University , Bentley 6102 , Australia
| | - Eleanor Denham
- Curtin Health Innovation Research Institute , Curtin University , Bentley 6102 , Australia
| | | | | | | | | | | | | | | | - Melinda Fitzgerald
- Curtin Health Innovation Research Institute , Curtin University , Bentley 6102 , Australia
- Perron Institute for Neurological and Translational Science, Ralph and Patricia Sarich Neuroscience Research Institute Building , Verdun Street , Nedlands 6009 , Western Australia , Australia
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15
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Xu M, Wang MM, Gao Y, Keep RF, Shi Y. The effect of age-related risk factors and comorbidities on white matter injury and repair after ischemic stroke. Neurobiol Dis 2018; 126:13-22. [PMID: 30017454 DOI: 10.1016/j.nbd.2018.07.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 06/17/2018] [Accepted: 07/10/2018] [Indexed: 02/06/2023] Open
Abstract
White matter injury is a crucial component of human stroke, but it has often been neglected in preclinical studies. Most human stroke is associated with one or more comorbidities, including aging, hypertension, diabetes and metabolic syndrome including hyperlipidemia. The purpose of this review is to examine how age and hypertension impact stroke-induced white matter injury as well as white matter repair in both human stroke and preclinical models. It is essential that comorbidities be examined in preclinical trials as they may impact translatability to the clinic. In addition, understanding how comorbidities impact white matter injury and repair may provide new therapeutic opportunities for patients with those conditions.
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Affiliation(s)
- Mingyue Xu
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology, Institute of Brain Sciences and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | - Michael M Wang
- Departments of Neurology and Physiology, University of Michigan, Ann Arbor, MI 48109, USA; VA Ann Arbor Healthcare System, Ann Arbor, MI 48105, USA
| | - Yanqin Gao
- State Key Laboratory of Medical Neurobiology, Institute of Brain Sciences and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Yejie Shi
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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16
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Dutta R, Trapp BD. Much, if not all, of the cortical damage in MS can be attributed to the microglial cell - No. Mult Scler 2018; 24:897-899. [PMID: 29754529 DOI: 10.1177/1352458517743094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Ranjan Dutta
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Bruce D Trapp
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
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17
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Brown CA, Jiang Y, Smith CD, Gold BT. Age and Alzheimer's pathology disrupt default mode network functioning via alterations in white matter microstructure but not hyperintensities. Cortex 2018; 104:58-74. [PMID: 29758374 DOI: 10.1016/j.cortex.2018.04.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 02/07/2018] [Accepted: 04/06/2018] [Indexed: 02/06/2023]
Abstract
The default mode network (DMN) comprises defined brain regions contributing to internally-directed thought processes. Reductions in task-induced deactivation in the DMN have been associated with increasing age and poorer executive task performance, but factors underlying these functional changes remain unclear. We investigated contributions of white matter (WM) microstructure, WM hyperintensities (WMH) and Alzheimer's pathology to age-related alterations in DMN function. Thirty-five cognitively normal older adults and 29 younger adults underwent working memory task fMRI and diffusion tensor imaging. In the older adults, we measured cerebrospinal fluid tau and Aβ42 (markers of AD pathology), and WMH on FLAIR imaging (marker of cerebrovascular disease). We identified a set of regions showing DMN deactivation and a set of inter-connecting WM tracts (DMN-WM) common to both age groups. There were negative associations between DMN deactivation and task performance in older adults, consistent with previous studies. Decreased DMN deactivation was associated with AD pathology and WM microstructure but not with WMH volume. Mediation analyses showed that WM microstructure mediated declines in DMN deactivation associated with both aging and AD pathology. Together these results suggest that AD pathology may exert a "second-hit" on WM microstructure, over-and-above the effects of age, both contributing to diminished DMN deactivation in older adults.
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Affiliation(s)
| | - Yang Jiang
- Department of Behavioral Science, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY, USA
| | - Charles D Smith
- Department of Neurology, University of Kentucky, Lexington, KY, USA; Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY, USA
| | - Brian T Gold
- Department of Neuroscience, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY, USA.
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18
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Yanqin Y, Jing T, Wei C, Nan L. Grifolin Attenuates White Matter Lesion in Oxygen/Glucose Deprivation. Transl Neurosci 2017; 8:102-110. [PMID: 29071135 PMCID: PMC5650725 DOI: 10.1515/tnsci-2017-0016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 07/27/2017] [Indexed: 01/01/2023] Open
Abstract
The present study evaluates the effect of grifolin (GFL) in oxygen/glucose deprivation (OGD) induced white matter lesion. Injury induced with OGD was found to be significant at the 9th h of OGD induction and the effect of GFL on the proliferation of oligodendrocyte precursor cells (OPCs) was assessed by CCK-8 and Hoechst 33258 assay at GFL 1, 5, 25, 50 and 100 μm concentrations. Whereas immunocytochemistry was performed for the assessment of survival and apoptosis of OPCs, western blot assay and RT-PCR were performed after 8th day of OGD injury for the estimation of expressions of myelin basic protein (MBP) and inhibitor of DNA binding 2 (Id2) in OPCs respectively. Results of the study suggests that treatment with GFL significantly enhances the survival rate and decreases the apoptosis of OPCs in OGD induced injury model. Immunocytochemical staining of Oligodendrocyte transcription factor (Olig2) and Bromodeoxyuridine (Brdu) shows that GFL treatment improves the proliferation of OPCs than OGD group. Moreover data of western blot assay suggested that treatment with GFL significantly enhances the expressions of MBP and Olig2 than OGD. It was observed that expressions of Id2 decreases and Olig2 enhances in GFL treated group than OGD group. Data of our study concludes that GFL enhances the differentiation and proliferation of OPCs in OGD-induced injury by altering the expressions of Id2 and Olig2.
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Affiliation(s)
- Ying Yanqin
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China, 430030, China
| | - Tang Jing
- Department of Pediatrics, Jinzhou Maternal and Children Healthy Care Hospital, Jinzhou, China, 434020
| | - Chen Wei
- Department of Pediatrics, Jinzhou Maternal and Children Healthy Care Hospital, Jinzhou, China, 434020
| | - Li Nan
- Department of intensive care unit, The first hospital of Jilin University, Changchun, China, 130021
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19
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Cai W, Yang T, Liu H, Han L, Zhang K, Hu X, Zhang X, Yin KJ, Gao Y, Bennett MVL, Leak RK, Chen J. Peroxisome proliferator-activated receptor γ (PPARγ): A master gatekeeper in CNS injury and repair. Prog Neurobiol 2017; 163-164:27-58. [PMID: 29032144 DOI: 10.1016/j.pneurobio.2017.10.002] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 10/06/2017] [Accepted: 10/08/2017] [Indexed: 01/06/2023]
Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) is a widely expressed ligand-modulated transcription factor that governs the expression of genes involved in inflammation, redox equilibrium, trophic factor production, insulin sensitivity, and the metabolism of lipids and glucose. Synthetic PPARγ agonists (e.g. thiazolidinediones) are used to treat Type II diabetes and have the potential to limit the risk of developing brain injuries such as stroke by mitigating the influence of comorbidities. If brain injury develops, PPARγ serves as a master gatekeeper of cytoprotective stress responses, improving the chances of cellular survival and recovery of homeostatic equilibrium. In the acute injury phase, PPARγ directly restricts tissue damage by inhibiting the NFκB pathway to mitigate inflammation and stimulating the Nrf2/ARE axis to neutralize oxidative stress. During the chronic phase of acute brain injuries, PPARγ activation in injured cells culminates in the repair of gray and white matter, preservation of the blood-brain barrier, reconstruction of the neurovascular unit, resolution of inflammation, and long-term functional recovery. Thus, PPARγ lies at the apex of cell fate decisions and exerts profound effects on the chronic progression of acute injury conditions. Here, we review the therapeutic potential of PPARγ in stroke and brain trauma and highlight the novel role of PPARγ in long-term tissue repair. We describe its structure and function and identify the genes that it targets. PPARγ regulation of inflammation, metabolism, cell fate (proliferation/differentiation/maturation/survival), and many other processes also has relevance to other neurological diseases. Therefore, PPARγ is an attractive target for therapies against a number of progressive neurological disorders.
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Affiliation(s)
- Wei Cai
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Tuo Yang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Huan Liu
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Lijuan Han
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Kai Zhang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Xiaoming Hu
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology and Institutes of Brain Science, Fudan University, Shanghai 200032, China; Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh PA, USA
| | - Xuejing Zhang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Ke-Jie Yin
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Yanqin Gao
- State Key Laboratory of Medical Neurobiology and Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Michael V L Bennett
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rehana K Leak
- Division of Pharmaceutical Sciences, School of Pharmacy, Duquesne University, Pittsburgh, PA 15282, USA.
| | - Jun Chen
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology and Institutes of Brain Science, Fudan University, Shanghai 200032, China; Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh PA, USA.
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20
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Understanding a role for hypoxia in lesion formation and location in the deep and periventricular white matter in small vessel disease and multiple sclerosis. Clin Sci (Lond) 2017; 131:2503-2524. [PMID: 29026001 DOI: 10.1042/cs20170981] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Revised: 08/01/2017] [Accepted: 08/15/2017] [Indexed: 12/28/2022]
Abstract
The deep and periventricular white matter is preferentially affected in several neurological disorders, including cerebral small vessel disease (SVD) and multiple sclerosis (MS), suggesting that common pathogenic mechanisms may be involved in this injury. Here we consider the potential pathogenic role of tissue hypoxia in lesion development, arising partly from the vascular anatomy of the affected white matter. Specifically, these regions are supplied by a sparse vasculature fed by long, narrow end arteries/arterioles that are vulnerable to oxygen desaturation if perfusion is reduced (as in SVD, MS and diabetes) or if the surrounding tissue is hypoxic (as in MS, at least). The oxygen crisis is exacerbated by a local preponderance of veins, as these can become highly desaturated 'sinks' for oxygen that deplete it from surrounding tissues. Additional haemodynamic deficiencies, including sluggish flow and impaired vasomotor reactivity and vessel compliance, further exacerbate oxygen insufficiency. The cells most vulnerable to hypoxic damage, including oligodendrocytes, die first, resulting in demyelination. Indeed, in preclinical models, demyelination is prevented if adequate oxygenation is maintained by raising inspired oxygen concentrations. In agreement with this interpretation, there is a predilection of lesions for the anterior and occipital horns of the lateral ventricles, namely regions located at arterial watersheds, or border zones, known to be especially susceptible to hypoperfusion and hypoxia. Finally, mitochondrial dysfunction due to genetic causes, as occurs in leucodystrophies or due to free radical damage, as occurs in MS, will compound any energy insufficiency resulting from hypoxia. Viewing lesion formation from the standpoint of tissue oxygenation not only reveals that lesion distribution is partly predictable, but may also inform new therapeutic strategies.
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Chronic cerebral hypoperfusion: a key mechanism leading to vascular cognitive impairment and dementia. Closing the translational gap between rodent models and human vascular cognitive impairment and dementia. Clin Sci (Lond) 2017; 131:2451-2468. [PMID: 28963120 DOI: 10.1042/cs20160727] [Citation(s) in RCA: 225] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/28/2017] [Accepted: 09/04/2017] [Indexed: 12/15/2022]
Abstract
Increasing evidence suggests that vascular risk factors contribute to neurodegeneration, cognitive impairment and dementia. While there is considerable overlap between features of vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD), it appears that cerebral hypoperfusion is the common underlying pathophysiological mechanism which is a major contributor to cognitive decline and degenerative processes leading to dementia. Sustained cerebral hypoperfusion is suggested to be the cause of white matter attenuation, a key feature common to both AD and dementia associated with cerebral small vessel disease (SVD). White matter changes increase the risk for stroke, dementia and disability. A major gap has been the lack of mechanistic insights into the evolution and progress of VCID. However, this gap is closing with the recent refinement of rodent models which replicate chronic cerebral hypoperfusion. In this review, we discuss the relevance and advantages of these models in elucidating the pathogenesis of VCID and explore the interplay between hypoperfusion and the deposition of amyloid β (Aβ) protein, as it relates to AD. We use examples of our recent investigations to illustrate the utility of the model in preclinical testing of candidate drugs and lifestyle factors. We propose that the use of such models is necessary for tackling the urgently needed translational gap from preclinical models to clinical treatments.
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Oxygen impairs oligodendroglial development via oxidative stress and reduced expression of HIF-1α. Sci Rep 2017; 7:43000. [PMID: 28230075 PMCID: PMC5322337 DOI: 10.1038/srep43000] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 01/18/2017] [Indexed: 12/20/2022] Open
Abstract
The premature increase of oxygen tension may contribute to oligodendroglial precursor cell (OPC) damage in preterm infants. Fetal OPCs are exposed to low oxygen tissue tensions not matched when cells are cultured in room air. Maturation (A2B5, O4, O1, MBP, CNP, arborization), oxidative stress (nitrotyrosine Western blot, NRF2 and SOD2 expression), apoptosis (TUNEL), proliferation (Ki67), and expression of transcription factors regulated by Hypoxia-Inducible-Factor-1-alpha (Hif-1α) expressed in OPCs (Olig1, Olig2, Sox9, Sox10) were assessed in rat OPCs and OLN93 cells cultured at 5% O2 and 21% O2. Influences of Hif-1α were investigated by Hif-1α luciferase reporter assays and Hif-1α-knockdown experiments. At 21% O2, cell proliferation was decreased and process arborization of OPCs was reduced. Expression of MBP, CNP, Olig1, Sox9 and Sox10 was lower at 21% O2, while Nrf2, SOD2, nitrotyrosine were increased. Apoptosis was unchanged. Luciferease reporter assay in OLN93 cells indicated increased Hif-1α activity at 5% O2. In OLN93 cells at 5% O2, Hif-1α knockdown decreased the expression of MBP and CNP, similar to that observed at 21% O2. These data indicate that culturing OPCs at 21% O2 negatively affects development and maturation. Both enhanced oxidative stress and reduced expression of Hif-1α-regulated genes contribute to these hyperoxia-induced changes.
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Common and heritable components of white matter microstructure predict cognitive function at 1 and 2 y. Proc Natl Acad Sci U S A 2016; 114:148-153. [PMID: 27994134 DOI: 10.1073/pnas.1604658114] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Previous studies indicate that the microstructure of individual white matter (WM) tracts is related to cognitive function. More recent studies indicate that the microstructure of individual tracts is highly correlated and that a property common across WM is related to overall cognitive function in adults. However, little is known about whether these common WM properties exist in early childhood development or how they are related to cognitive development. In this study, we used diffusion tensor imaging (DTI) to investigate common underlying factors in 12 fiber tracts, their relationship with cognitive function, and their heritability in a longitudinal sample of healthy children at birth (n = 535), 1 y (n = 322), and 2 y (n = 244) of age. Our data show that, in neonates, there is a highly significant correlation between major WM tracts that decreases from birth to 2 y of age. Over the same period, the factor structure increases in complexity, from one factor at birth to three factors at age 2 y, which explain 50% of variance. The identified common factors of DTI metrics in each age group are significantly correlated with general cognitive scores and predict cognitive ability in later childhood. These factors are moderately heritable. These findings illustrate the anatomical differentiation of WM fiber from birth to 2 y of age that correlate with cognitive development. Our results also suggest that the common factor approach is an informative way to study WM development and its relationship with cognition and is a useful approach for future imaging genetic studies.
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Lim JL, van der Pol SMA, Baron W, McCord JM, de Vries HE, van Horssen J. Protandim Protects Oligodendrocytes against an Oxidative Insult. Antioxidants (Basel) 2016; 5:antiox5030030. [PMID: 27618111 PMCID: PMC5039579 DOI: 10.3390/antiox5030030] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/02/2016] [Indexed: 01/23/2023] Open
Abstract
Oligodendrocyte damage and loss are key features of multiple sclerosis (MS) pathology. Oligodendrocytes appear to be particularly vulnerable to reactive oxygen species (ROS) and cytokines, such as tumor necrosis factor-α (TNF), which induce cell death and prevent the differentiation of oligodendrocyte progenitor cells (OPCs). Here, we investigated the efficacy of sulforaphane (SFN), monomethyl fumarate (MMF) and Protandim to induce Nrf2-regulated antioxidant enzyme expression, and protect oligodendrocytes against ROS-induced cell death and ROS-and TNF-mediated inhibition of OPC differentiation. OLN-93 cells and primary rat oligodendrocytes were treated with SFN, MMF or Protandim resulting in significant induction of Nrf2-driven (antioxidant) proteins heme oygenase-1, nicotinamide adenine dinucleotide phosphate (NADPH): quinone oxidoreductase-1 and p62/SQSTM1, as analysed by Western blotting. After incubation with the compounds, oligodendrocytes were exposed to hydrogen peroxide. Protandim most potently promoted oligodendrocyte cell survival as measured by live/death viability assay. Moreover, OPCs were treated with Protandim or vehicle control prior to exposing them to TNF or hydrogen peroxide for five days, which inhibited OPC differentiation. Protandim significantly promoted OPC differentiation under influence of ROS, but not TNF. Protandim, a combination of five herbal ingredients, potently induces antioxidants in oligodendrocytes and is able to protect oligodendrocytes against oxidative stress by preventing ROS-induced cell death and promoting OPC differentiation.
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Affiliation(s)
- Jamie L Lim
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Neuroscience Campus Amsterdam, 1081 HZ Amsterdam, the Netherlands.
| | - Susanne M A van der Pol
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Neuroscience Campus Amsterdam, 1081 HZ Amsterdam, the Netherlands.
| | - Wia Baron
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands.
| | - Joe M McCord
- Department of Medicine, Division of Pulmonary Science and Critical Care Medicine, University of Colorado at Denver, Aurora, CO 80045, USA.
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Neuroscience Campus Amsterdam, 1081 HZ Amsterdam, the Netherlands.
| | - Jack van Horssen
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Neuroscience Campus Amsterdam, 1081 HZ Amsterdam, the Netherlands.
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Wang Y, Liu G, Hong D, Chen F, Ji X, Cao G. White matter injury in ischemic stroke. Prog Neurobiol 2016; 141:45-60. [PMID: 27090751 PMCID: PMC5677601 DOI: 10.1016/j.pneurobio.2016.04.005] [Citation(s) in RCA: 183] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 04/01/2016] [Accepted: 04/10/2016] [Indexed: 02/06/2023]
Abstract
Stroke is one of the major causes of disability and mortality worldwide. It is well known that ischemic stroke can cause gray matter injury. However, stroke also elicits profound white matter injury, a risk factor for higher stroke incidence and poor neurological outcomes. The majority of damage caused by stroke is located in subcortical regions and, remarkably, white matter occupies nearly half of the average infarct volume. Indeed, white matter is exquisitely vulnerable to ischemia and is often injured more severely than gray matter. Clinical symptoms related to white matter injury include cognitive dysfunction, emotional disorders, sensorimotor impairments, as well as urinary incontinence and pain, all of which are closely associated with destruction and remodeling of white matter connectivity. White matter injury can be noninvasively detected by MRI, which provides a three-dimensional assessment of its morphology, metabolism, and function. There is an urgent need for novel white matter therapies, as currently available strategies are limited to preclinical animal studies. Optimal protection against ischemic stroke will need to encompass the fortification of both gray and white matter. In this review, we discuss white matter injury after ischemic stroke, focusing on clinical features and tools, such as imaging, manifestation, and potential treatments. We also briefly discuss the pathophysiology of WMI and future research directions.
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Affiliation(s)
- Yuan Wang
- Department of Neurology, Xuanwu Hospital, Capital University of Medicine, Beijing 100053, China
| | - Gang Liu
- Department of Neurology, Xuanwu Hospital, Capital University of Medicine, Beijing 100053, China
| | - Dandan Hong
- Department of Bioengineering, University of Pittsburgh School of Engineering, United States
| | - Fenghua Chen
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, United States
| | - Xunming Ji
- Department of Neurosurgery, Xuanwu Hospital, Capital University of Medicine, Beijing 100053, China.
| | - Guodong Cao
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, United States; Geriatric Research Education and Clinical Centers, VA Pittsburgh Healthcare System, Pittsburgh, PA 15240, United States.
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Yoon H, Kleven A, Paulsen A, Kleppe L, Wu J, Ying Z, Gomez-Pinilla F, Scarisbrick IA. Interplay between exercise and dietary fat modulates myelinogenesis in the central nervous system. Biochim Biophys Acta Mol Basis Dis 2016; 1862:545-555. [PMID: 26826016 DOI: 10.1016/j.bbadis.2016.01.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 12/15/2015] [Accepted: 01/14/2016] [Indexed: 12/14/2022]
Abstract
Here we show that the interplay between exercise training and dietary fat regulates myelinogenesis in the adult central nervous system. Mice consuming high fat with coordinate voluntary running wheel exercise for 7weeks showed increases in the abundance of the major myelin membrane proteins, proteolipid (PLP) and myelin basic protein (MBP), in the lumbosacral spinal cord. Expression of MBP and PLP RNA, as well that for Myrf1, a transcription factor driving oligodendrocyte differentiation were also differentially increased under each condition. Furthermore, expression of IGF-1 and its receptor IGF-1R, known to promote myelinogenesis, were also increased in the spinal cord in response to high dietary fat or exercise training. Parallel increases in AKT signaling, a pro-myelination signaling intermediate activated by IGF-1, were also observed in the spinal cord of mice consuming high fat alone or in combination with exercise. Despite the pro-myelinogenic effects of high dietary fat in the context of exercise, high fat consumption in the setting of a sedentary lifestyle reduced OPCs and mature oligodendroglia. Whereas 7weeks of exercise training alone did not alter OPC or oligodendrocyte numbers, it did reverse reductions seen with high fat. Evidence is presented suggesting that the interplay between exercise and high dietary fat increase SIRT1, PGC-1α and antioxidant enzymes which may permit oligodendroglia to take advantage of diet and exercise-related increases in mitochondrial activity to yield increases in myelination despite higher levels of reactive oxygen species.
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Affiliation(s)
- Hyesook Yoon
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA; Rehabilitation Medicine Research Center, Mayo Clinic, Rochester, MN 55905, USA
| | - Andrew Kleven
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA
| | - Alex Paulsen
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA
| | - Laurel Kleppe
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA
| | - Jianmin Wu
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA; Rehabilitation Medicine Research Center, Mayo Clinic, Rochester, MN 55905, USA
| | - Zhe Ying
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, CA 90095, USA
| | | | - Isobel A Scarisbrick
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA; Rehabilitation Medicine Research Center, Mayo Clinic, Rochester, MN 55905, USA.
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Liu J, Tian D, Murugan M, Eyo UB, Dreyfus CF, Wang W, Wu LJ. Microglial Hv1 proton channel promotes cuprizone-induced demyelination through oxidative damage. J Neurochem 2015; 135:347-56. [PMID: 26173779 DOI: 10.1111/jnc.13242] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 06/14/2015] [Accepted: 07/06/2015] [Indexed: 12/21/2022]
Abstract
NADPH oxidase (NOX)-dependent reactive oxygen species (ROS) production in inflammatory cells including microglia plays an important role in demyelination and free radical-mediated tissue injury in multiple sclerosis (MS). However, the mechanism underlying microglial ROS production and demyelination remains largely unknown. The voltage-gated proton channel, Hv1, is selectively expressed in microglia and is required for NOX-dependent ROS generation in the brain. In the present study, we sought to determine the role of microglial Hv1 proton channels in a mouse model of cuprizone-induced demyelination, a model for MS. Following cuprizone exposure, wild-type mice presented obvious demyelination, decreased myelin basic protein expression, loss of mature oligodendrocytes, and impaired motor coordination in comparison to mice on a normal chow diet. However, mice lacking Hv1 (Hv1(-/-) ) are partially protected from demyelination and motor deficits compared with those in wild-type mice. These rescued phenotypes in Hv1(-/-) mice in cuprizone-induced demyelination is accompanied by reduced ROS production, ameliorated microglial activation, increased oligodendrocyte progenitor cell (NG2) proliferation, and increased number of mature oligodendrocytes. These results demonstrate that the Hv1 proton channel is required for cuprizone-induced microglial oxidative damage and subsequent demyelination. Our study suggests that the microglial Hv1 proton channel is a unique target for controlling NOX-dependent ROS production in the pathogenesis of MS.
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Affiliation(s)
- Junli Liu
- Cancer center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Cell Biology and Neuroscience, School of Arts and Sciences, Rutgers University, Piscataway, New Jersey, USA
| | - Daishi Tian
- Department of Cell Biology and Neuroscience, School of Arts and Sciences, Rutgers University, Piscataway, New Jersey, USA.,Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Madhuvika Murugan
- Department of Cell Biology and Neuroscience, School of Arts and Sciences, Rutgers University, Piscataway, New Jersey, USA
| | - Ukpong B Eyo
- Department of Cell Biology and Neuroscience, School of Arts and Sciences, Rutgers University, Piscataway, New Jersey, USA
| | - Cheryl F Dreyfus
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Wei Wang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Long-Jun Wu
- Cancer center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Cell Biology and Neuroscience, School of Arts and Sciences, Rutgers University, Piscataway, New Jersey, USA
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28
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Shi H, Hu X, Leak RK, Shi Y, An C, Suenaga J, Chen J, Gao Y. Demyelination as a rational therapeutic target for ischemic or traumatic brain injury. Exp Neurol 2015; 272:17-25. [PMID: 25819104 DOI: 10.1016/j.expneurol.2015.03.017] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 03/15/2015] [Accepted: 03/18/2015] [Indexed: 12/11/2022]
Abstract
Previous research on stroke and traumatic brain injury (TBI) heavily emphasized pathological alterations in neuronal cells within gray matter. However, recent studies have highlighted the equal importance of white matter integrity in long-term recovery from these conditions. Demyelination is a major component of white matter injury and is characterized by loss of the myelin sheath and oligodendrocyte cell death. Demyelination contributes significantly to long-term sensorimotor and cognitive deficits because the adult brain only has limited capacity for oligodendrocyte regeneration and axonal remyelination. In the current review, we will provide an overview of the major causes of demyelination and oligodendrocyte cell death following acute brain injuries, and discuss the crosstalk between myelin, axons, microglia, and astrocytes during the process of demyelination. Recent discoveries of molecules that regulate the processes of remyelination may provide novel therapeutic targets to restore white matter integrity and improve long-term neurological recovery in stroke or TBI patients.
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Affiliation(s)
- Hong Shi
- The State Key Laboratory of Medical Neurobiology, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China; Department of Anesthesiology of Shanghai Pulmonary Hospital, Tongji University, Shanghai 200433, China
| | - Xiaoming Hu
- The State Key Laboratory of Medical Neurobiology, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China; Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA
| | - Rehana K Leak
- Division of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA 15282, USA
| | - Yejie Shi
- The State Key Laboratory of Medical Neurobiology, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China; Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA
| | - Chengrui An
- The State Key Laboratory of Medical Neurobiology, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | - Jun Suenaga
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Jun Chen
- The State Key Laboratory of Medical Neurobiology, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China; Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA.
| | - Yanqin Gao
- The State Key Laboratory of Medical Neurobiology, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China; Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
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29
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Kim JY, Lee EY, Sohn HJ, Kim SW, Kim CH, Ahn HY, Kim DW, Cho SS, Seo JH. Differential expression of αB-crystallin causes maturation-dependent susceptibility of oligodendrocytes to oxidative stress. BMB Rep 2014; 46:501-6. [PMID: 24148771 PMCID: PMC4133838 DOI: 10.5483/bmbrep.2013.46.10.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Oligodendrocyte precursor cells (OPCs) are most susceptible to oxidative stress in the brain. However, the cause of differences in susceptibility to oxidative stress between OPCs and mature oligodendrocytes (mOLs) remains unclear. Recently, we identified in vivo that αB-crystallin (aBC) is expressed in mOLs but not in OPCs. Therefore, we examined in the present study whether aBC expression could affect cell survival under oxidative stress induced by hydrogen peroxide using primary cultures of OPCs and mOLs from neonatal rat brains. Expression of aBC was greater in mOLs than in OPCs, and the survival rate of mOLs was significantly higher than that of OPCs under oxidative stress. Suppression of aBC by siRNA transfection resulted in a decrease in the survival rate of mOLs under oxidative stress. These data suggest that higher susceptibility of OPCs than mOLs to oxidative stress is due, at least in part, to low levels of aBC expression. [BMB Reports 2013; 46(10): 501-506]
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Affiliation(s)
- Ji Young Kim
- Departments of Anatomy, Chungbuk National University School of Medicine, Cheongju 361-763, Korea
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30
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Lim JL, Wilhelmus MMM, de Vries HE, Drukarch B, Hoozemans JJM, van Horssen J. Antioxidative defense mechanisms controlled by Nrf2: state-of-the-art and clinical perspectives in neurodegenerative diseases. Arch Toxicol 2014; 88:1773-86. [DOI: 10.1007/s00204-014-1338-z] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 08/12/2014] [Indexed: 12/21/2022]
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31
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Plemel JR, Keough MB, Duncan GJ, Sparling JS, Yong VW, Stys PK, Tetzlaff W. Remyelination after spinal cord injury: Is it a target for repair? Prog Neurobiol 2014; 117:54-72. [DOI: 10.1016/j.pneurobio.2014.02.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 02/15/2014] [Accepted: 02/20/2014] [Indexed: 12/12/2022]
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32
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Stein LR, Imai SI. Specific ablation of Nampt in adult neural stem cells recapitulates their functional defects during aging. EMBO J 2014; 33:1321-40. [PMID: 24811750 DOI: 10.1002/embj.201386917] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Neural stem/progenitor cell (NSPC) proliferation and self-renewal, as well as insult-induced differentiation, decrease markedly with age. The molecular mechanisms responsible for these declines remain unclear. Here, we show that levels of NAD(+) and nicotinamide phosphoribosyltransferase (Nampt), the rate-limiting enzyme in mammalian NAD(+) biosynthesis, decrease with age in the hippocampus. Ablation of Nampt in adult NSPCs reduced their pool and proliferation in vivo. The decrease in the NSPC pool during aging can be rescued by enhancing hippocampal NAD(+) levels. Nampt is the main source of NSPC NAD(+) levels and required for G1/S progression of the NSPC cell cycle. Nampt is also critical in oligodendrocytic lineage fate decisions through a mechanism mediated redundantly by Sirt1 and Sirt2. Ablation of Nampt in the adult NSPCs in vivo reduced NSPC-mediated oligodendrogenesis upon insult. These phenotypes recapitulate defects in NSPCs during aging, giving rise to the possibility that Nampt-mediated NAD(+) biosynthesis is a mediator of age-associated functional declines in NSPCs.
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Affiliation(s)
- Liana R Stein
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Shin-ichiro Imai
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
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33
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Wu X, Qu X, Zhang Q, Dong F, Yu H, Yan C, Qi D, Wang M, Liu X, Yao R. Quercetin promotes proliferation and differentiation of oligodendrocyte precursor cells after oxygen/glucose deprivation-induced injury. Cell Mol Neurobiol 2014; 34:463-71. [PMID: 24519463 DOI: 10.1007/s10571-014-0030-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 01/08/2014] [Indexed: 11/24/2022]
Abstract
The aim of this study was to investigate quercetin's (Qu) ability to promote proliferation and differentiation of oligodendrocyte precursor cells (OPCs) under oxygen/glucose deprivation (OGD)-induced injury in vitro. The results showed that after OGD, OPCs survival rate was significantly increased by Qu as measured by Cell Counting Kit-8. Furthermore, Qu treatment reduced apoptosis of OPCs surveyed by Hoechst 33258 nuclear staining. Qu at 9 and 27 μM promoted the proliferation of OPCs the most by Brdu and Olig2 immunocytochemical staining after OGD 3 days. Also, Qu treatment for 8 days after OGD, the differentiation of OPCs to oligodendrocyte was detected by immunofluorescence staining showing that O4, Olig2, and myelin basic protein (MBP) positive cells were significantly increased compared to control group. Additionally, the protein levels of Olig2 and MBP of OPCs were quantified using western blot and mRNA levels of Olig2 and Inhibitor of DNA binding 2 (Id2) were measured by RT-PCR. Western blot showed a significant increase in Olig2 and MBP expression levels compared with controls after OGD and Qu treatment with a linear does-response curve from 3 to 81 μM. After treatment with Qu compared to its control group, Olig2 mRNA level was significantly up-regulated, whereas Id2 mRNA level was down-regulated. In conclusion, Qu at 3-27 μM can promote the proliferation and differentiation of OPCs after OGD injury and may regulate the activity of Olig2 and Id2.
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Affiliation(s)
- Xiuxiang Wu
- Department of Neurobiology, Xuzhou Medical College, Xuzhou, 221002, Jiangsu, People's Republic of China
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34
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McQueen J, Reimer MM, Holland PR, Manso Y, McLaughlin M, Fowler JH, Horsburgh K. Restoration of oligodendrocyte pools in a mouse model of chronic cerebral hypoperfusion. PLoS One 2014; 9:e87227. [PMID: 24498301 PMCID: PMC3911923 DOI: 10.1371/journal.pone.0087227] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 12/25/2013] [Indexed: 12/05/2022] Open
Abstract
Chronic cerebral hypoperfusion, a sustained modest reduction in cerebral blood flow, is associated with damage to myelinated axons and cognitive decline with ageing. Oligodendrocytes (the myelin producing cells) and their precursor cells (OPCs) may be vulnerable to the effects of hypoperfusion and in some forms of injury OPCs have the potential to respond and repair damage by increased proliferation and differentiation. Using a mouse model of cerebral hypoperfusion we have characterised the acute and long term responses of oligodendrocytes and OPCs to hypoperfusion in the corpus callosum. Following 3 days of hypoperfusion, numbers of OPCs and mature oligodendrocytes were significantly decreased compared to controls. However following 1 month of hypoperfusion, the OPC pool was restored and increased numbers of oligodendrocytes were observed. Assessment of proliferation using PCNA showed no significant differences between groups at either time point but showed reduced numbers of proliferating oligodendroglia at 3 days consistent with the loss of OPCs. Cumulative BrdU labelling experiments revealed higher numbers of proliferating cells in hypoperfused animals compared to controls and showed a proportion of these newly generated cells had differentiated into oligodendrocytes in a subset of animals. Expression of GPR17, a receptor important for the regulation of OPC differentiation following injury, was decreased following short term hypoperfusion. Despite changes to oligodendrocyte numbers there were no changes to the myelin sheath as revealed by ultrastructural assessment and fluoromyelin however axon-glial integrity was disrupted after both 3 days and 1 month hypoperfusion. Taken together, our results demonstrate the initial vulnerability of oligodendroglial pools to modest reductions in blood flow and highlight the regenerative capacity of these cells.
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Affiliation(s)
- Jamie McQueen
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Michell M. Reimer
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Philip R. Holland
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Yasmina Manso
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
| | - Mark McLaughlin
- School of Veterinary Medicine, Division of Veterinary Biosciences, University of Glasgow, Glasgow, United Kingdom
| | - Jill H. Fowler
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
| | - Karen Horsburgh
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
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Hypoxia and oxygenation induce a metabolic switch between pentose phosphate pathway and glycolysis in glioma stem-like cells. Acta Neuropathol 2013; 126:763-80. [PMID: 24005892 DOI: 10.1007/s00401-013-1173-y] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 08/14/2013] [Accepted: 08/25/2013] [Indexed: 12/12/2022]
Abstract
Fluctuations in oxygen tension during tissue remodeling impose a major metabolic challenge in human tumors. Stem-like tumor cells in glioblastoma, the most common malignant brain tumor, possess extraordinary metabolic flexibility, enabling them to initiate growth even under non-permissive conditions. We identified a reciprocal metabolic switch between the pentose phosphate pathway (PPP) and glycolysis in glioblastoma stem-like (GS) cells. Expression of PPP enzymes is upregulated by acute oxygenation but downregulated by hypoxia, whereas glycolysis enzymes, particularly those of the preparatory phase, are regulated inversely. Glucose flux through the PPP is reduced under hypoxia in favor of flux through glycolysis. PPP enzyme expression is elevated in human glioblastomas compared to normal brain, especially in highly proliferative tumor regions, whereas expression of parallel preparatory phase glycolysis enzymes is reduced in glioblastomas, except for strong upregulation in severely hypoxic regions. Hypoxia stimulates GS cell migration but reduces proliferation, whereas oxygenation has opposite effects, linking the metabolic switch to the "go or grow" potential of the cells. Our findings extend Warburg's observation that tumor cells predominantly utilize glycolysis for energy production, by suggesting that PPP activity is elevated in rapidly proliferating tumor cells but suppressed by acute severe hypoxic stress, favoring glycolysis and migration to protect cells against hypoxic cell damage.
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Evidence for therapeutic intervention in the prevention of cerebral palsy: hope from animal model research. Semin Pediatr Neurol 2013; 20:75-83. [PMID: 23948682 DOI: 10.1016/j.spen.2013.06.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Knowledge translation, as defined by the Canadian Institute of Health Research, is defined as the exchange, synthesis, and ethically sound application of knowledge--within a complex system of interactions among researchers and users--to accelerate the capture of the benefits of research through improved health, more effective services and products, and a strengthened healthcare system. The requirement for this to occur lies in the ability to continue to determine mechanistic actions at the molecular level, to understand how they fit at the in vitro and in vivo levels, and for disease states, to determine their safety, efficacy, and long-term potential at the preclinical animal model level. In this regard, particularly as it relates to long-term disabilities such as cerebral palsy that begin in utero, but only express their full effect in adulthood, animal models must be used to understand and rapidly evaluate mechanisms of injury and therapeutic interventions. In this review, we hope to provide the reader with a background of animal data upon which therapeutic interventions for the prevention and treatment of cerebral palsy, benefit this community, and increasingly do so in the future.
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The evidence for hypoperfusion as a factor in multiple sclerosis lesion development. Mult Scler Int 2013; 2013:598093. [PMID: 23691321 PMCID: PMC3649777 DOI: 10.1155/2013/598093] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 02/08/2013] [Accepted: 03/19/2013] [Indexed: 01/19/2023] Open
Abstract
The evidence that hypoxia is a precipitating factor in causing early MS lesions includes increased protein levels of hypoxia-inducible factor-1α; presence of the D-110 hypoxia-inducible protein; increased expression of hypoxia-inducible genes in lesions as well as in adjacent normal-appearing white matter (NAWM); loss of myelin-associated glycoprotein in myelin of early MS lesions; a 50% reduction of blood flow through NAWM with areas of lowest blood flow having the greatest probability of lesion development. Why MS-like lesions develop following hypoxemic insults in some individuals but not in others is likely dependent upon the presence of immune predisposing factors that are governed genetically. Hypoperfusion may be due to decreased arterial supply, restricted venous return, or a combination of these. There are clinical trials ongoing or planned to treat chronic cerebrospinal venous insufficiency (CCSVI) through angioplasty. I suggest that it is important that clinical trials addressing vascular issues in MS should examine how the vascular intervention affects white matter perfusion and determine whether the extent of perfusion recovery and maintenance of this recovery is related to functional recovery and maintenance of functional recovery. Consideration should also be given to the possibility of arterial problems playing a role in hypoperfusion in some MS patients.
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Juurlink BHJ. Dietary Nrf2 activators inhibit atherogenic processes. Atherosclerosis 2012; 225:29-33. [PMID: 22986182 DOI: 10.1016/j.atherosclerosis.2012.08.032] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 08/23/2012] [Accepted: 08/25/2012] [Indexed: 12/21/2022]
Abstract
Dietary Nrf2 activators increase expression of phase 2 protein genes in cells undergoing oxidative stress resulting in a lowering of oxidative stress. Oxidative stress promotes atherogenic processes through oxidizing low density lipoproteins and promotion of inflammation through activation of nuclear factor kappa B and activation of mitogen-activated protein kinases. Nrf2 activators by decreasing oxidative stress decrease the probability of developing atherosclerotic lesions.
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Affiliation(s)
- Bernhard H J Juurlink
- College of Medicine, University of Saskatchewan, SK, Canada; College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.
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Backos DS, Franklin CC, Reigan P. The role of glutathione in brain tumor drug resistance. Biochem Pharmacol 2011; 83:1005-12. [PMID: 22138445 DOI: 10.1016/j.bcp.2011.11.016] [Citation(s) in RCA: 132] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 11/18/2011] [Accepted: 11/18/2011] [Indexed: 12/24/2022]
Abstract
Chemotherapy is central to the current treatment modality for primary human brain tumors, but despite high-dose and intensive treatment regimens there has been little improvement in patient outcome. The development of tumor chemoresistance has been proposed as a major contributor to this lack of response. While there have been some improvements in our understanding of the molecular mechanisms underlying brain tumor drug resistance over the past decade, the contribution of glutathione (GSH) and the GSH-related enzymes to drug resistance in brain tumors have been largely overlooked. GSH constitutes a major antioxidant defense system in the brain and together with the GSH-related enzymes plays an important role in protecting cells against free radical damage and dictating tumor cell response to adjuvant cancer therapies, including irradiation and chemotherapy. Glutamate cysteine ligase (GCL), glutathione synthetase (GS), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferases (GST), and GSH complex export transporters (GS-X pumps) are major components of the GSH-dependent enzyme system that function in a dynamic cascade to maintain redox homeostasis. In many tumors, the GSH system is often dysregulated, resulting in a more drug resistant phenotype. This is commonly associated with GST-mediated GSH conjugation of various anticancer agents leading to the formation of less toxic GSH-drug complexes, which can be readily exported from the cell. Advances in our understanding of the mechanisms of drug resistance and patient selection based on biomarker profiles will be crucial to adapt therapeutic strategies and improve outcomes for patients with primary malignant brain tumors.
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Affiliation(s)
- Donald S Backos
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, 80045, United States
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Wang XQ, Yao RQ, Liu X, Huang JJ, Qi DS, Yang LH. Quercetin protects oligodendrocyte precursor cells from oxygen/glucose deprivation injury in vitro via the activation of the PI3K/Akt signaling pathway. Brain Res Bull 2011; 86:277-84. [PMID: 21803128 DOI: 10.1016/j.brainresbull.2011.07.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 07/14/2011] [Accepted: 07/15/2011] [Indexed: 02/05/2023]
Abstract
The aim of this study was to investigate the protection of quercetin (QUE) on oligodendrocyte precursor cells (OPCs) from oxygen/glucose deprivation (OGD)-induced injury in vitro and explore whether the PI3K/Akt signaling pathway contributed to the protection provided by quercetin. The OGD condition was induced by including 2mM sodium dithionite (Na(2)S(2)O(4)) in glucose-free DMEM medium. The concentration of QUE in this study ranged from 3μM to 81μM. OPCs were identified by immunocytochemical staining. Cell viability was analyzed using the water soluble tetrazolium salt-8 (WST-8) and lactate dehydrogenase assay (LDH). The morphological changes of the nucleus were measured using Hoechst 33258 nuclear staining, and the ratio of apoptotic cells was determined by FITC annexin V- and propidium iodide (PI) flow cytometry assay kit. In addition, the levels of pro-apoptotic proteins such as cleaved-caspase-3 and Bax and the anti-apoptotic proteins p-Akt and Bcl-2 were quantified using western blotting. The results showed that the OPC cell survival rate was significantly increased by incubation in conditioned medium supplemented with QUE as measured by the WST-8 assay, while the LDH release rate was significantly decreased as analyzed by the LDH assay. Furthermore, apoptosis assay showed that the apoptosis ratio of OPCs was also dramatically reduced by QUE. Western blotting showed that the expression levels of Bax and cleaved-caspase-3 proteins were down-regulated, while Bcl-2 and p-Akt were up-regulated. Further study showed that the increase in p-Akt by QUE was reduced by the PI3K inhibitor LY294002. These results indicated that QUE effectively protected OPCs from OGD-induced injury and that the mechanism might be related to the activation of the PI3K/Akt signaling pathway.
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Affiliation(s)
- X-Q Wang
- Department of Neurobiology, Xuzhou Medical College, Xuzhou, Jiangsu Province, People's Republic of China
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41
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Correa F, Gauberti M, Parcq J, Macrez R, Hommet Y, Obiang P, Hernangómez M, Montagne A, Liot G, Guaza C, Maubert E, Ali C, Vivien D, Docagne F. Tissue plasminogen activator prevents white matter damage following stroke. ACTA ACUST UNITED AC 2011; 208:1229-42. [PMID: 21576385 PMCID: PMC3173251 DOI: 10.1084/jem.20101880] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Tissue plasminogen activator (tPA) is the only available treatment for acute stroke. In addition to its vascular fibrinolytic action, tPA exerts various effects within the brain, ranging from synaptic plasticity to control of cell fate. To date, the influence of tPA in the ischemic brain has only been investigated on neuronal, microglial, and endothelial fate. We addressed the mechanism of action of tPA on oligodendrocyte (OL) survival and on the extent of white matter lesions in stroke. We also investigated the impact of aging on these processes. We observed that, in parallel to reduced levels of tPA in OLs, white matter gets more susceptible to ischemia in old mice. Interestingly, tPA protects murine and human OLs from apoptosis through an unexpected cytokine-like effect by the virtue of its epidermal growth factor-like domain. When injected into aged animals, tPA, although toxic to the gray matter, rescues white matter from ischemia independently of its proteolytic activity. These studies reveal a novel mechanism of action of tPA and unveil OL as a target cell for cytokine effects of tPA in brain diseases. They show overall that tPA protects white matter from stroke-induced lesions, an effect which may contribute to the global benefit of tPA-based stroke treatment.
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Affiliation(s)
- Fernando Correa
- Institut National de la Santé et de la Recherche Médicale (INSERM), INSERM-U919, Caen Cedex, F-14074 France
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The Cerebral Palsy Demonstration Project: a multidimensional research approach to cerebral palsy. Semin Pediatr Neurol 2011; 18:31-9. [PMID: 21575839 DOI: 10.1016/j.spen.2011.02.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cerebral palsy is the most common cause of physical impairment in pediatrics. As a heterogeneous disorder in all its disparate aspects it defies a simplistic research approach that seeks to further our understanding of its mechanisms, outcomes and treatments. Within NeuroDevNet, with its focus on abnormal brain development, cerebral palsy was selected as one of the three neurodevelopmental disabilities to be the focus of a dedicated demonstration project. The Cerebral Palsy Demonstration Project will feature a multi-dimensional approach utilizing epidemiologic, imaging, genetics, animal models and stem cell modalities that will at all times emphasize clinical relevance, translation into practice, and potential synergies between investigators now segregated by both academic disciplines and geographic distance. The objective is to create a national platform of varied complementary and inter-digitated efforts. The specific research plan to enable this will be outlined in detail.
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Todorich B, Olopade JO, Surguladze N, Zhang X, Neely E, Connor JR. The mechanism of vanadium-mediated developmental hypomyelination is related to destruction of oligodendrocyte progenitors through a relationship with ferritin and iron. Neurotox Res 2010; 19:361-73. [PMID: 20237879 DOI: 10.1007/s12640-010-9167-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Revised: 12/28/2009] [Accepted: 02/24/2010] [Indexed: 11/28/2022]
Abstract
The second post-natal week in rat is the period of the most intense oligodendrocyte development and myelination. This period coincides with peak iron import by oligodendrocytes. During that time oligodendrocyte progenitors (OPCs) are sensitive to agents that may disturb normal iron homeostasis and assimilation of iron into these cells. One mechanism by which iron homeostasis can be disrupted is by environmental exposure to other metals. Vanadium is a transition metal, and exposure to vanadium during early brain development produces hypomyelination with variety of related neuro-behavioral phenotypes. In the current study, we investigated mechanisms of hypomyelination induced by vanadium exposure in developing rat brain. We demonstrate that both in vivo and in vitro, OPCs are more sensitive to vanadium exposure than astrocytes or mature oligodendrocytes. Vanadium exposure in OPCs resulted in increased ROS generation and increased annexinV labeling suggestive of apoptosis. Because ferritin is a major iron delivery protein for oligodendrocytes, we exposed the cells to recombinant ferritin and iron both of which exacerbated vanadium cytotoxicity, while the iron chelator desferroxamine (DFO) prevented cytotoxic/apoptotic effects of vanadium. To illustrate relationship between ferritin and vanadium, we demonstrate that vanadium exacerbated DNA nicking produced by iron-rich spleen ferritin, but not iron-poor apoferritin, resulting in a single and double strand breaks in a DNA relaxation assay. We propose that developmental exposure to vanadium interferes with normal iron assimilation into oligodendrocytes resulting in oxidative stress and apoptosis. Therefore, depletion of OPCs due to vanadium exposure in early post-natal period may be an important mechanism of vanadium-induced hypomyelination.
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Affiliation(s)
- Bozho Todorich
- Department of Neurosurgery, Pennsylvania State University College of Medicine, M.S. Hershey Medical Center, 500 University Drive, Hershey, PA 17033-0850, USA
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Abstract
Aging is associated with significant white matter deterioration and this deterioration is assumed to be at least partly a consequence of myelin degeneration. The present study investigated specific predictions of the myelodegeneration hypothesis using diffusion tensor tractography. This technique has several advantages over other methods of assessing white matter architecture, including the possibility of isolating individual white matter tracts and measuring effects along the whole extent of each tract. The study yielded three main findings. First, age-related white matter deficits increased gradually from posterior to anterior segments within specific fiber tracts traversing frontal and parietal, but not temporal cortex. This pattern inverts the sequence of myelination during childhood and early development observed in previous studies and lends support to a "last-in-first-out" theory of the white matter health across the lifespan. Second, both the effects of aging on white matter and their impact on cognitive performance were stronger for radial diffusivity (RD) than for axial diffusivity (AD). Given that RD has previously been shown to be more sensitive to myelin integrity than AD, this second finding is also consistent with the myelodegeneration hypothesis. Finally, the effects of aging on select white matter tracts were associated with age difference in specific cognitive functions. Specifically, FA in anterior tracts was shown to be primarily associated with executive tasks and FA in posterior tracts mainly associated with visual memory tasks. Furthermore, these correlations were mirrored in RD, but not AD, suggesting that RD is more sensitive to age-related changes in cognition. Taken together, the results help to clarify how age-related white matter decline impairs cognitive performance.
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Abstract
In making a selection of cellular tools and animal models for generating screening assays in the search for new drugs, one needs to take into consideration the practicality of their use in the drug discovery process. Conducting high-throughput primary screens using libraries of small molecules, close to 1 million members in size, requires the generation of large numbers of cells which are easily acquired, reliably enriched, and reproducibly responsive to standard positive controls. These cells need to be similar in form and function to their counterparts in human disease. In vitro assays that can be mechanized by using robots can therefore save time and costs. In selecting in vivo models, consideration must be given to the species and strain of animal chosen, the appropriateness of the model to human disease, the extent of animal husbandry required during the in-life pharmacological assessment, the technical aspects of generating the model and harvesting the tissues for analyses, the cost of research tools in terms of time and money (demyelinating and remyelinating agents, amount of compound to be generated), and the length of time required for drug testing in the model. A consideration of the translational aspects of the in vivo model compared to those used in the clinic is also important. These themes will be developed with examples for drug discovery in the field of CNS demyelination and repair, specifically as it pertains to multiple sclerosis.
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Neurotoxicological effects of 3-nitropropionic acid on the neonatal rat. Neurotoxicology 2008; 29:1023-9. [DOI: 10.1016/j.neuro.2008.07.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Revised: 07/01/2008] [Accepted: 07/14/2008] [Indexed: 11/21/2022]
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McTigue DM, Tripathi RB. The life, death, and replacement of oligodendrocytes in the adult CNS. J Neurochem 2008; 107:1-19. [PMID: 18643793 DOI: 10.1111/j.1471-4159.2008.05570.x] [Citation(s) in RCA: 329] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Oligodendrocytes (OLs) are mature glial cells that myelinate axons in the brain and spinal cord. As such, they are integral to functional and efficient neuronal signaling. The embryonic lineage and postnatal development of OLs have been well-studied and many features of the process have been described, including the origin, migration, proliferation, and differentiation of precursor cells. Less clear is the extent to which OLs and damaged/dysfunctional myelin are replaced following injury to the adult CNS. OLs and their precursors are very vulnerable to conditions common to CNS injury and disease sites, such as inflammation, oxidative stress, and elevated glutamate levels leading to excitotoxicity. Thus, these cells become dysfunctional or die in multiple pathologies, including Alzheimer's disease, spinal cord injury, Parkinson's disease, ischemia, and hypoxia. However, studies of certain conditions to date have detected spontaneous OL replacement. This review will summarize current information on adult OL progenitors, mechanisms that contribute to OL death, the consequences of their loss and the pathological conditions in which spontaneous oligodendrogenesis from endogenous precursors has been observed in the adult CNS.
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Affiliation(s)
- Dana M McTigue
- Department of Neuroscience and Center for Brain and Spinal Cord Repair, The Ohio State University, Columbus, Ohio, USA.
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Hertz L. Bioenergetics of cerebral ischemia: a cellular perspective. Neuropharmacology 2008; 55:289-309. [PMID: 18639906 DOI: 10.1016/j.neuropharm.2008.05.023] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 05/14/2008] [Accepted: 05/14/2008] [Indexed: 12/27/2022]
Abstract
In cerebral ischemia survival of neurons, astrocytes, oligodendrocytes and endothelial cells is threatened during energy deprivation and/or following re-supply of oxygen and glucose. After a brief summary of characteristics of different cells types, emphasizing the dependence of all on oxidative metabolism, the bioenergetics of focal and global ischemia is discussed, distinguishing between events during energy deprivation and subsequent recovery attempt after re-circulation. Gray and white matter ischemia are described separately, and distinctions are made between mature and immature brains. Next comes a description of bioenergetics in individual cell types in culture during oxygen/glucose deprivation or exposure to metabolic inhibitors and following re-establishment of normal aerated conditions. Due to their expression of NMDA and non-NMDA receptors neurons and oligodendrocytes are exquisitely sensitive to excitotoxicity by glutamate, which reaches high extracellular concentrations in ischemic brain for several reasons, including failing astrocytic uptake. Excitotoxicity kills brain cells by energetic exhaustion (due to Na(+) extrusion after channel-mediated entry) combined with mitochondrial Ca(2+)-mediated injury and formation of reactive oxygen species. Many (but not all) astrocytes survive energy deprivation for extended periods, but after return to aerated conditions they are vulnerable to mitochondrial damage by cytoplasmic/mitochondrial Ca(2+) overload and to NAD(+) deficiency. Ca(2+) overload is established by reversal of Na(+)/Ca(2+) exchangers following Na(+) accumulation during Na(+)-K(+)-Cl(-) cotransporter stimulation or pH regulation, compensating for excessive acid production. NAD(+) deficiency inhibits glycolysis and eventually oxidative metabolism, secondary to poly(ADP-ribose)polymerase (PARP) activity following DNA damage. Hyperglycemia can be beneficial for neurons but increases astrocytic death due to enhanced acidosis.
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Affiliation(s)
- Leif Hertz
- College of Basic Medical Sciences, China Medical University, Shenyang, PR China.
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Sakakibara SI, Nakadate K, Ookawara S, Ueda S. Non-cell autonomous impairment of oligodendrocyte differentiation precedes CNS degeneration in the Zitter rat: implications of macrophage/microglial activation in the pathogenesis. BMC Neurosci 2008; 9:35. [PMID: 18394170 PMCID: PMC2323389 DOI: 10.1186/1471-2202-9-35] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 04/05/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The zitter (zi/zi) rat, a loss-of-function mutant of the glycosylated transmembrane protein attractin (atrn), exhibits widespread age-dependent spongiform degeneration, hypomyelination, and abnormal metabolism of reactive oxygen species (ROS) in the brain. To date, the mechanisms underlying these phenotypes have remained unclear. RESULTS Here, we show differentiation defects in zi/zi oligodendrocytes, accompanied by aberrant extension of cell-processes and hypomyelination. Axonal bundles were relatively preserved during postnatal development. With increasing in age, the injured oligodendrocytes in zi/zi rats become pathological, as evidenced by the accumulation of iron in their cell bodies. Immunohistochemical analysis revealed that atrn expression was absent from an oligodendrocyte lineage, including A2B5-positive progenitors and CNPase-positive differentiated cells. The number and distribution of Olig2-positive oligodendrocyte progenitors was unchanged in the zi/zi brain. Furthermore, an in vitro differentiation assay of cultured oligodendrocyte progenitors prepared from zi/zi brains revealed their normal competence for proliferation and differentiation into mature oligodendrocytes. Interestingly, we demonstrated the accelerated recruitment of ED1-positive macrophages/microglia to the developing zi/zi brain parenchyma prior to the onset of hypomyelination. Semiquantitative RT-PCR analysis revealed a significant up-regulation of CD26 and IL1-beta in the zi/zi brain during this early postnatal stage. CONCLUSION We demonstrated that the onset of the impairment of oligodendrocyte differentiation occurs in a non-cell autonomous manner in zi/zi rats. Hypomyelination of oligodendrocytes was not due to a failure of the intrinsic program of oligodendrocytes, but rather, was caused by extrinsic factors that interrupt oligodendrocyte development. It is likely that macrophage/microglial activation in the zi/zi CNS leads to disturbances in oligodendrocyte differentiation via deleterious extrinsic factors, such as the cytokine IL1-beta or ROS. Atrn might be involved in the activation of brain macrophages/microglia by suppressing excessive migration of monocytes into the CNS, or by accelerating the transformation of brain monocytes into resting microglia. Understanding the pathogenesis of the zi/zi rat may provide novel insights into the developmental interaction betweens macrophages/microglia and cells of an oligodendrocyte lineage.
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Affiliation(s)
- Shin-ichi Sakakibara
- Department of Histology and Neurobiology, Dokkyo Medical University School of Medicine, Tochigi, Japan.
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Goldbaum O, Vollmer G, Richter-Landsberg C. Proteasome inhibition by MG-132 induces apoptotic cell death and mitochondrial dysfunction in cultured rat brain oligodendrocytes but not in astrocytes. Glia 2006; 53:891-901. [PMID: 16609961 DOI: 10.1002/glia.20348] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Proteasomal dysfunction has been implicated in neurodegenerative disorders and during aging processes. In frontotemporal dementias, corticobasal degeneration, and progressive supranuclear palsy, oligodendrocytes are specifically damaged. Application of proteasomal inhibitors to cultured oligodendrocytes is associated with apoptotic cell death. The present study was undertaken to investigate the death pathway activated in oligodendrocytes by proteasomal inhibition. Our data show that the proteasomal inhibitor MG-132 causes oxidative stress, as indicated by the upregulation of the small heat shock protein heme oxygenase-1 (HO-1) and the appearance of oxidized proteins. Activation of the mitochondrial pathway was involved in the apoptotic process. Mitochondrial membrane potential was disturbed, and cytochrome c was released from the mitochondria. Concomitantly, death-related caspases 3 and 9 were activated and poly(ADP-ribose)-polymerase cleavage occurred. MG-132-induced cell death, DNA-fragmentation, and caspase activation could be prevented by the broad caspase inhibitor zVAD-fmk. In contrast to oligodendrocytes, cultured astrocytes showed resistance to the treatment with proteasomal inhibitors and did not reveal cytotoxic responses. This was also observed in astrocytes differentiated in the presence of dibutyryl cyclic AMP. Hence, individual cells respond differently to proteasomal inhibition and the therapeutic use of proteasomal inhibitors, e.g. for the treatment of cancer or inflammatory diseases, needs to be carefully evaluated.
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Affiliation(s)
- Olaf Goldbaum
- Department of Biology, Molecular Neurobiology, University of Oldenburg, Oldenburg, Germany
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