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Da Silva DE, Richards CM, McRae SA, Riar I, Yang S(S, Zurfluh NE, Gibon J, Klegeris A. Extracellular mixed histones are neurotoxic and modulate select neuroimmune responses of glial cells. PLoS One 2024; 19:e0298748. [PMID: 38630734 PMCID: PMC11023449 DOI: 10.1371/journal.pone.0298748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 01/29/2024] [Indexed: 04/19/2024] Open
Abstract
Although histone proteins are widely known for their intranuclear functions where they organize DNA, all five histone types can also be released into the extracellular space from damaged cells. Extracellular histones can interact with pattern recognition receptors of peripheral immune cells, including toll-like receptor 4 (TLR4), causing pro-inflammatory activation, which indicates they may act as damage-associated molecular patterns (DAMPs) in peripheral tissues. Very limited information is available about functions of extracellular histones in the central nervous system (CNS). To address this knowledge gap, we applied mixed histones (MH) to cultured cells modeling neurons, microglia, and astrocytes. Microglia are the professional CNS immunocytes, while astrocytes are the main support cells for neurons. Both these cell types are critical for neuroimmune responses and their dysregulated activity contributes to neurodegenerative diseases. We measured effects of extracellular MH on cell viability and select neuroimmune functions of microglia and astrocytes. MH were toxic to cultured primary murine neurons and also reduced viability of NSC-34 murine and SH-SY5Y human neuron-like cells in TLR4-dependent manner. MH did not affect the viability of resting or immune-stimulated BV-2 murine microglia or U118 MG human astrocytic cells. When applied to BV-2 cells, MH enhanced secretion of the potential neurotoxin glutamate, but did not modulate the release of nitric oxide (NO), tumor necrosis factor-α (TNF), C-X-C motif chemokine ligand 10 (CXCL10), or the overall cytotoxicity of lipopolysaccharide (LPS)- and/or interferon (IFN)-γ-stimulated BV-2 microglial cells towards NSC-34 neuron-like cells. We demonstrated, for the first time, that MH downregulated phagocytic activity of LPS-stimulated BV-2 microglia. However, MH also exhibited protective effect by ameliorating the cytotoxicity of LPS-stimulated U118 MG astrocytic cells towards SH-SY5Y neuron-like cells. Our data demonstrate extracellular MH could both damage neurons and alter neuroimmune functions of glial cells. These actions of MH could be targeted for treatment of neurodegenerative diseases.
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Affiliation(s)
- Dylan E. Da Silva
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Christy M. Richards
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Seamus A. McRae
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Ishvin Riar
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Sijie (Shirley) Yang
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Noah E. Zurfluh
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Julien Gibon
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
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2
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Ren J, Zhu F, Sang D, Cong M, Jiang S. The Protective Effect and Mechanism of Mild Hypothermia on Lung Injury after Cardiopulmonary Resuscitation in Pigs. Crit Rev Immunol 2024; 44:51-58. [PMID: 38618728 DOI: 10.1615/critrevimmunol.2024052420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
To explore the protective effect and mechanism of mild hypothermia on lung tissue damage after cardiopulmonary resuscitation in pigs. In this experiment, we electrically stimulated 16 pigs (30 ± 2 kg) for 10 min to cause ventricular fibrillation. The successfully resuscitated animals were randomly divided into two groups, a mild hypothermia group and a control group. We took arterial blood 0.5, 1, 3, and 6 h after ROSC recovery in the two groups of animals for blood gas analysis. We observed the structural changes of lung tissue under an electron microscope and calculate the wet weight/dry weight (W/D) ratio. We quantitatively analyzed the expression differences of representative inflammatory factors [interleukin-6 (IL-6) and tumor necrosis factor-alpha TNF-α)] through the ELISA test. We detected the expression levels of Bax, Bcl-2, and Caspase-3 proteins in lung tissues by Western blot. After 3 h and 6 h of spontaneous circulation was restored, compared with the control group, PaO2/FiO2 decreased significantly (P < 0.05). In addition, the pathological changes, lung W/D and lung MDA of the mild hypothermia group were better than those of the control group. The levels of IL-6 and TNF-α in the lung tissue of the mild hypothermia group were significantly lower than those of the control group (P < 0.05). The content of Caspase-3 and Bax in the mild hypothermia group was significantly lower than that of the control group. Our experiments have shown that mild hypothermia can reduce lung tissue damage after cardiopulmonary resuscitation.
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Affiliation(s)
- Jinlin Ren
- Department of Emergency, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250000, Shandong, China
| | - Fangfang Zhu
- General Practice, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250000, Shandong, China
| | - Dongdong Sang
- Department of Emergency, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250000, Shandong, China
| | - Mulin Cong
- Department of Emergency, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250000, Shandong, China
| | - Shujuan Jiang
- Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University
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Yang SS, Simtchouk S, Gibon J, Klegeris A. Regulation of the phagocytic activity of astrocytes by neuroimmune mediators endogenous to the central nervous system. PLoS One 2023; 18:e0289169. [PMID: 37498903 PMCID: PMC10374099 DOI: 10.1371/journal.pone.0289169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 07/11/2023] [Indexed: 07/29/2023] Open
Abstract
The phagocytic activity of glial cells is essential for maintaining normal brain activity, and its dysfunction may contribute to the central nervous system (CNS) pathologies, including neurodegenerative diseases. Phagocytic activity is one of the well-established neuroimmune functions of microglia. Although emerging evidence indicates that astrocytes can also function as CNS phagocytes in humans and rodents, limited information is available about the molecular mechanism regulating this function. To address this knowledge gap, we studied modulation of the phagocytic activity of human U118 MG astrocytic cells and murine primary astrocytes by four CNS inflammatory mediators and bacterial endotoxin lipopolysaccharide (LPS). LPS and cytochrome c (CytC) upregulated, while interferon (IFN)-γ downregulated, phagocytosis of latex beads by human astrocytic cells and phagocytosis of synaptosomes by murine primary astrocytes. Interleukin (IL)-1β and tumor necrosis factor (TNF)-α had no effect on the phagocytic activity of human astrocytic cells but upregulated this function in murine astrocytes. Varying effects of combinations of the above inflammatory mediators were observed in these two cell types. LPS- and CytC-induced phagocytic activity of human astrocytic cells was partially mediated by activation of toll-like receptor 4 (TLR4). By monitoring other functions of astrocytes, we concluded there were no correlations between the effects of the mediators studied on astrocyte phagocytic activity and their secretion of cytokines, cytotoxins, or glutamate. Our study identified four candidate CNS regulators of astrocyte phagocytic activity. Future investigation of molecular mechanisms behind this regulation could identify novel therapeutic targets allowing modulation of this astrocyte-mediated clearance mechanism in CNS pathologies.
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Affiliation(s)
- Sijie Shirley Yang
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Svetlana Simtchouk
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Julien Gibon
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
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Kim B, Kim R, Kim HJ, Kim Y, Park SJ, Lee EH, Kim J, Kim J, Choi JW, Park JH, Park KD. Optimization and evaluation of pyridinyl vinyl sulfones as Nrf2 activator for the antioxidant and anti-inflammatory effects. Eur J Med Chem 2023; 256:115433. [PMID: 37187090 DOI: 10.1016/j.ejmech.2023.115433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/21/2023] [Accepted: 04/28/2023] [Indexed: 05/17/2023]
Abstract
Many studies have reported that chalcone-based compounds exhibit biological activities such as anticancer, antioxidant, anti-inflammatory and neuroprotective effects. Among the published chalcone derivatives, (E)-1-(3-methoxypyridin-2-yl)-3-(2-(trifluoromethyl)phenyl)prop-2-en-1-one (VEDA-1209), which is currently undergoing preclinical study, was selected as a starting compound for the development of new nuclear factor erythroid 2-related factor 2 (Nrf2) activators. Based on our previous knowledge, we attempted to redesign and synthesize VEDA-1209 derivatives by introducing the pyridine ring and sulfone moiety to ameliorate its Nrf2 efficacy and drug-like properties. Among the synthesized compounds, (E)-3-chloro-2-(2-((3-methoxypyridin-2-yl)sulfonyl)vinyl) pyridine (10e) was found to have approximately 16-folds higher Nrf2 activating effects than VEDA-1209 (10e: EC50 = 37.9 nM vs VEDA-1209: EC50 = 625 nM) in functional cell-based assay. In addition, 10e effectively improved drug-like properties such as CYP inhibition probability and metabolic stability. Finally, 10e demonstrated excellent antioxidant and anti-inflammatory effects in BV-2 microglial cells and significantly restored spatial memory deficits in lipopolysaccharide (LPS)-induced neuroinflammatory mouse models.
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Affiliation(s)
- Byungeun Kim
- Center for Brain Disorders, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Division of Bio-Medical Science & Technology, University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Rium Kim
- Center for Brain Disorders, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Division of Bio-Medical Science & Technology, University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Hyeon Jeong Kim
- Center for Brain Disorders, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Yoowon Kim
- Center for Brain Disorders, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Sun Jun Park
- Center for Brain Disorders, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Cureverse Co., Ltd., KIST, 1st Floor, H2 Building, Seoul, 02792, Republic of Korea
| | - Elijah Hwejin Lee
- Center for Brain Disorders, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Division of Bio-Medical Science & Technology, University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Jushin Kim
- Center for Brain Disorders, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Jaehwan Kim
- Center for Brain Disorders, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Division of Bio-Medical Science & Technology, University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Ji Won Choi
- Center for Brain Disorders, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Cureverse Co., Ltd., KIST, 1st Floor, H2 Building, Seoul, 02792, Republic of Korea.
| | - Jong-Hyun Park
- Center for Brain Disorders, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Division of Bio-Medical Science & Technology, University of Science and Technology, Daejeon, 34113, Republic of Korea.
| | - Ki Duk Park
- Center for Brain Disorders, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Division of Bio-Medical Science & Technology, University of Science and Technology, Daejeon, 34113, Republic of Korea.
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Microglia secrete distinct sets of neurotoxins in a stimulus-dependent manner. Brain Res 2023; 1807:148315. [PMID: 36878343 DOI: 10.1016/j.brainres.2023.148315] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/07/2023] [Accepted: 03/02/2023] [Indexed: 03/07/2023]
Abstract
Microglia are the resident immune cells of the brain which regulate both the innate and adaptive neuroimmune responses in health and disease. In response to specific endogenous and exogenous stimuli, microglia transition to one of their reactive states characterized by altered morphology and function, including their secretory profile. A component of the microglial secretome is cytotoxic molecules capable of causing damage and death to nearby host cells, thus contributing to the pathogenesis of neurodegenerative disorders. Indirect evidence from secretome studies and measurements of mRNA expression using diverse microglial cell types suggest different stimuli may induce microglia to secrete distinct subsets of cytotoxins. We demonstrate the accuracy of this hypothesis directly by challenging murine BV-2 microglia-like cells with eight different immune stimuli and assessing secretion of four potentially cytotoxic molecules, including nitric oxide (NO), tumor necrosis factor α (TNF), C-X-C motif chemokine ligand 10 (CXCL10), and glutamate. Lipopolysaccharide (LPS) and a combination of interferon (IFN)-γ plus LPS induced secretion of all toxins studied. IFN-β, IFN-γ, polyinosinic:polycytidylic acid (poly I:C), and zymosan A upregulated secretion of subsets of these four cytotoxins. LPS and IFN-γ, alone or in combination, as well as IFN-β induced toxicity of BV-2 cells towards murine NSC-34 neuronal cells, while ATP, N-formylmethionine-leucyl-phenylalanine (fMLP), and phorbol 12-myristate 13-acetate (PMA) did not affect any parameters studied. Our observations contribute to a growing body of knowledge on the regulation of the microglial secretome, which may inform future development of novel therapeutics for neurodegenerative diseases, where dysregulated microglia are key contributors to pathogenesis.
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Guo Y, Sun CK, Tang L, Tan MS. Microglia PTK2B/Pyk2 in the Pathogenesis of Alzheimer's Disease. Curr Alzheimer Res 2023; 20:692-704. [PMID: 38321895 DOI: 10.2174/0115672050299004240129051655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 01/16/2024] [Accepted: 01/22/2024] [Indexed: 02/08/2024]
Abstract
Alzheimer's disease (AD) is a highly hereditary disease with complex genetic susceptibility factors. Extensive genome-wide association studies have established a distinct susceptibility link between the protein tyrosine kinase 2β (PTK2B) gene and late-onset Alzheimer's disease (LOAD), but the specific pathogenic mechanisms remain incompletely understood. PTK2B is known to be expressed in neurons, and recent research has revealed its more important significance in microglia. Elucidating the role of PTK2B high expression in microglia in AD's progression is crucial for uncovering novel pathogenic mechanisms of the disease. Our review of existing studies suggests a close relationship between PTK2B/proline-rich tyrosine kinase 2 (Pyk2) and tau pathology, and this process might be β-amyloid (Aβ) dependence. Pyk2 is hypothesized as a pivotal target linking Aβ and tau pathologies. Concurrently, Aβ-activated Pyk2 participates in the regulation of microglial activation and its proinflammatory functions. Consequently, it is reasonable to presume that Pyk2 in microglia contributes to amyloid-induced tau pathology in AD via a neuroinflammatory pathway. Furthermore, many things remain unclear, such as identifying the specific pathways that lead to the release of downstream inflammatory factors due to Pyk2 phosphorylation and whether all types of inflammatory factors can activate neuronal kinase pathways. Additionally, further in vivo experiments are essential to validate this hypothesized pathway. Considering PTK2B/Pyk2's potential role in AD pathogenesis, targeting this pathway may offer innovative and promising therapeutic approaches for AD.
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Affiliation(s)
- Yun Guo
- School of Clinical Medicine, Weifang Medical University, Weifang, China
| | - Cheng-Kun Sun
- Department of Neurology, Qingdao Municipal Hospital, Dalian Medical University, Qingdao, China
| | - Lian Tang
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Meng-Shan Tan
- School of Clinical Medicine, Weifang Medical University, Weifang, China
- Department of Neurology, Qingdao Municipal Hospital, Dalian Medical University, Qingdao, China
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
- Department of Neurology, Qingdao Municipal Hospital, University of Health and Rehabilitation Sciences, Qingdao, China
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7
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Zhang Y, Chu JMT, Wong GTC. Cerebral Glutamate Regulation and Receptor Changes in Perioperative Neuroinflammation and Cognitive Dysfunction. Biomolecules 2022; 12:biom12040597. [PMID: 35454185 PMCID: PMC9029551 DOI: 10.3390/biom12040597] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/11/2022] [Accepted: 04/15/2022] [Indexed: 12/23/2022] Open
Abstract
Glutamate is the major excitatory neurotransmitter in the central nervous system and is intricately linked to learning and memory. Its activity depends on the expression of AMPA and NMDA receptors and excitatory amino transporters on neurons and glial cells. Glutamate transporters prevent the excess accumulation of glutamate in synapses, which can lead to aberrant synaptic signaling, excitotoxicity, or cell death. Neuroinflammation can occur acutely after surgical trauma and contributes to the development of perioperative neurocognitive disorders, which are characterized by impairment in multiple cognitive domains. In this review, we aim to examine how glutamate handling and glutamatergic function are affected by neuroinflammation and their contribution to cognitive impairment. We will first summarize the current data regarding glutamate in neurotransmission, its receptors, and their regulation and trafficking. We will then examine the impact of inflammation on glutamate handling and neurotransmission, focusing on changes in glial cells and the effect of cytokines. Finally, we will discuss these changes in the context of perioperative neuroinflammation and the implications they have for perioperative neurocognitive disorders.
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8
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Munawara U, Catanzaro M, Xu W, Tan C, Hirokawa K, Bosco N, Dumoulin D, Khalil A, Larbi A, Lévesque S, Ramassamy C, Barron AE, Cunnane S, Beauregard PB, Bellenger JP, Rodrigues S, Desroches M, Witkowski JM, Laurent B, Frost EH, Fulop T. Hyperactivation of monocytes and macrophages in MCI patients contributes to the progression of Alzheimer's disease. IMMUNITY & AGEING 2021; 18:29. [PMID: 34154615 PMCID: PMC8215492 DOI: 10.1186/s12979-021-00236-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/09/2021] [Indexed: 02/07/2023]
Abstract
Background Alzheimer’s disease (AD) is the most common neurodegenerative disease ultimately manifesting as clinical dementia. Despite considerable effort and ample experimental data, the role of neuroinflammation related to systemic inflammation is still unsettled. While the implication of microglia is well recognized, the exact contribution of peripheral monocytes/macrophages is still largely unknown, especially concerning their role in the various stages of AD. Objectives AD develops over decades and its clinical manifestation is preceded by subjective memory complaints (SMC) and mild cognitive impairment (MCI); thus, the question arises how the peripheral innate immune response changes with the progression of the disease. Therefore, to further investigate the roles of monocytes/macrophages in the progression of AD we assessed their phenotypes and functions in patients at SMC, MCI and AD stages and compared them with cognitively healthy controls. We also conceptualised an idealised mathematical model to explain the functionality of monocytes/macrophages along the progression of the disease. Results We show that there are distinct phenotypic and functional changes in monocyte and macrophage populations as the disease progresses. Higher free radical production upon stimulation could already be observed for the monocytes of SMC patients. The most striking results show that activation of peripheral monocytes (hyperactivation) is the strongest in the MCI group, at the prodromal stage of the disease. Monocytes exhibit significantly increased chemotaxis, free radical production, and cytokine production in response to TLR2 and TLR4 stimulation. Conclusion Our data suggest that the peripheral innate immune system is activated during the progression from SMC through MCI to AD, with the highest levels of activation being in MCI subjects and the lowest in AD patients. Some of these parameters may be used as biomarkers, but more holistic immune studies are needed to find the best period of the disease for clinical intervention. Supplementary Information The online version contains supplementary material available at 10.1186/s12979-021-00236-x.
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Affiliation(s)
- Usma Munawara
- Research Center on Aging, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, Quebec, J1H 5N4, Canada
| | - Michael Catanzaro
- Research Center on Aging, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, Quebec, J1H 5N4, Canada.,Department of Drug Sciences, University of Pavia, Pavia, Italy
| | - Weili Xu
- Singapore Immunology Network (SIgN), Agency for Science Technology and Research (A*STAR), Immunos Building, Biopolis, Singapore, Singapore
| | - Crystal Tan
- Singapore Immunology Network (SIgN), Agency for Science Technology and Research (A*STAR), Immunos Building, Biopolis, Singapore, Singapore
| | - Katsuiku Hirokawa
- Department of Diagnostic Pathology, Institute of Health and Life Science, Tokyo Med. Dent. University, Tokyo and Nitobe Memorial Nakanosogo Hospital, Tokyo, Japan
| | - Nabil Bosco
- Nestlé Research, Nestlé Institute of Health Sciences, Department of Cell Biology, Cellular Metabolism, EPFL Innovation Park, CH-1015, Lausanne, Switzerland
| | - David Dumoulin
- Department of Biology, Faculty of Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Abdelouahed Khalil
- Research Center on Aging, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, Quebec, J1H 5N4, Canada
| | - Anis Larbi
- Research Center on Aging, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, Quebec, J1H 5N4, Canada.,Singapore Immunology Network (SIgN), Agency for Science Technology and Research (A*STAR), Immunos Building, Biopolis, Singapore, Singapore
| | - Simon Lévesque
- Department of Microbiology and Infectiology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Charles Ramassamy
- INRS-Centre Armand-Frappier Santé-biotechnologie, Montréal, Québec, Canada
| | - Annelise E Barron
- Department of Bioengineering, Stanford School of Medicine, Stanford, California, USA
| | - Stephen Cunnane
- Research Center on Aging, Endocrinology Division, Department of Medicine, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Pascale B Beauregard
- Department of Biology, Faculty of Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Jean-Pierre Bellenger
- Department of Chemistry, Faculty of Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Serafim Rodrigues
- Ikerbasque, The Basque Foundation for Science, Bilbao, Spain. .,Basque Center for Applied Mathematics, Mathematical, Computational and Experimental Neuroscience research group, Alameda de Mazarredo 14, 48009, Bilbao, Bizkaia, Basque-Country, Spain.
| | - Mathieu Desroches
- MathNeuro Team, Inria Sophia Antipolis Méditerranée, Valbonne, France.,Université Côte d'Azur, Nice, France
| | - Jacek M Witkowski
- Department of Pathophysiology, Medical University of Gdansk, Gdansk, Poland
| | - Benoit Laurent
- Research Center on Aging, Department of Biochemistry, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Eric H Frost
- Department of Microbiology and Infectiology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Tamas Fulop
- Research Center on Aging, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, Quebec, J1H 5N4, Canada.
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Chung MK, Ro JY. Peripheral glutamate receptor and transient receptor potential channel mechanisms of craniofacial muscle pain. Mol Pain 2021; 16:1744806920914204. [PMID: 32189565 PMCID: PMC7153498 DOI: 10.1177/1744806920914204] [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] [Indexed: 11/20/2022] Open
Abstract
Temporomandibular joint disorder is a common chronic craniofacial pain condition,
often involving persistent, widespread craniofacial muscle pain. Although the
etiology of chronic muscle pain is not well known, sufficient clinical and
preclinical information supports a contribution of trigeminal nociceptors to
craniofacial muscle pain processing under various experimental and pathological
conditions. Here, we review cellular and molecular mechanisms underlying
sensitization of muscle nociceptive afferents. In particular, we summarize
findings on pronociceptive roles of peripheral glutamate in humans, and we
discuss mechanistic contributions of glutamate receptors, including
N-methyl-D-aspartate receptors and metabotropic glutamate receptors, which have
considerably increased our understanding of peripheral mechanisms of
craniofacial muscle pain. Several members of the transient receptor potential
(TRP) family, such as transient receptor potential vanilloid 1 (TRPV1) and
transient receptor potential ankyrin 1, also play essential roles in the
development of spontaneous pain and mechanical hypersensitivity in craniofacial
muscles. Furthermore, glutamate receptors and TRP channels functionally and
bi-directionally interact to modulate trigeminal nociceptors. Activation of
glutamate receptors invokes protein kinase C, which leads to the phosphorylation
of TRPV1. Sensitization of TRPV1 by inflammatory mediators and glutamate
receptors in combination with endogenous ligands contributes to masseter
hyperalgesia. The distinct intracellular signaling pathways through which both
receptor systems engage and specific molecular regions of TRPV1 are offered as
novel targets for the development of mechanism-based treatment strategies for
myogenous craniofacial pain conditions.
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Affiliation(s)
- Man-Kyo Chung
- Department of Neural and Pain Sciences, School of Dentistry, Program in Neuroscience, Center to Advance Chronic Pain Research, The University of Maryland, Baltimore, MD, USA
| | - Jin Y Ro
- Department of Neural and Pain Sciences, School of Dentistry, Program in Neuroscience, Center to Advance Chronic Pain Research, The University of Maryland, Baltimore, MD, USA
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Kadry H, Noorani B, Cucullo L. A blood-brain barrier overview on structure, function, impairment, and biomarkers of integrity. Fluids Barriers CNS 2020; 17:69. [PMID: 33208141 PMCID: PMC7672931 DOI: 10.1186/s12987-020-00230-3] [Citation(s) in RCA: 587] [Impact Index Per Article: 146.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/07/2020] [Indexed: 02/07/2023] Open
Abstract
The blood–brain barrier is playing a critical role in controlling the influx and efflux of biological substances essential for the brain’s metabolic activity as well as neuronal function. Thus, the functional and structural integrity of the BBB is pivotal to maintain the homeostasis of the brain microenvironment. The different cells and structures contributing to developing this barrier are summarized along with the different functions that BBB plays at the brain–blood interface. We also explained the role of shear stress in maintaining BBB integrity. Furthermore, we elaborated on the clinical aspects that correlate between BBB disruption and different neurological and pathological conditions. Finally, we discussed several biomarkers that can help to assess the BBB permeability and integrity in-vitro or in-vivo and briefly explain their advantages and disadvantages.
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Affiliation(s)
- Hossam Kadry
- Department of Pharmaceutical Sciences, Jerry H. Hodge School of Pharmacy, Texas Tech University Health Sciences Center, 1300 S. Coulter Street, Amarillo, TX, 79106, USA
| | - Behnam Noorani
- Department of Pharmaceutical Sciences, Jerry H. Hodge School of Pharmacy, Texas Tech University Health Sciences Center, 1300 S. Coulter Street, Amarillo, TX, 79106, USA
| | - Luca Cucullo
- Dept. of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Office 415, Rochester, MI, 48309, USA.
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Simpson DSA, Oliver PL. ROS Generation in Microglia: Understanding Oxidative Stress and Inflammation in Neurodegenerative Disease. Antioxidants (Basel) 2020; 9:E743. [PMID: 32823544 PMCID: PMC7463655 DOI: 10.3390/antiox9080743] [Citation(s) in RCA: 404] [Impact Index Per Article: 101.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/06/2020] [Accepted: 08/08/2020] [Indexed: 12/14/2022] Open
Abstract
Neurodegenerative disorders, such as Alzheimer's disease, are a global public health burden with poorly understood aetiology. Neuroinflammation and oxidative stress (OS) are undoubtedly hallmarks of neurodegeneration, contributing to disease progression. Protein aggregation and neuronal damage result in the activation of disease-associated microglia (DAM) via damage-associated molecular patterns (DAMPs). DAM facilitate persistent inflammation and reactive oxygen species (ROS) generation. However, the molecular mechanisms linking DAM activation and OS have not been well-defined; thus targeting these cells for clinical benefit has not been possible. In microglia, ROS are generated primarily by NADPH oxidase 2 (NOX2) and activation of NOX2 in DAM is associated with DAMP signalling, inflammation and amyloid plaque deposition, especially in the cerebrovasculature. Additionally, ROS originating from both NOX and the mitochondria may act as second messengers to propagate immune activation; thus intracellular ROS signalling may underlie excessive inflammation and OS. Targeting key kinases in the inflammatory response could cease inflammation and promote tissue repair. Expression of antioxidant proteins in microglia, such as NADPH dehydrogenase 1 (NQO1), is promoted by transcription factor Nrf2, which functions to control inflammation and limit OS. Lipid droplet accumulating microglia (LDAM) may also represent a double-edged sword in neurodegenerative disease by sequestering peroxidised lipids in non-pathological ageing but becoming dysregulated and pro-inflammatory in disease. We suggest that future studies should focus on targeted manipulation of NOX in the microglia to understand the molecular mechanisms driving inflammatory-related NOX activation. Finally, we discuss recent evidence that therapeutic target identification should be unbiased and founded on relevant pathophysiological assays to facilitate the discovery of translatable antioxidant and anti-inflammatory therapeutics.
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Affiliation(s)
- Dominic S. A. Simpson
- Mammalian Genetics Unit, MRC Harwell Institute, Harwell, Oxfordshire OX11 0RD, UK;
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Peter L. Oliver
- Mammalian Genetics Unit, MRC Harwell Institute, Harwell, Oxfordshire OX11 0RD, UK;
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, UK
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Zhang X, Wang D, Zhang B, Zhu J, Zhou Z, Cui L. Regulation of microglia by glutamate and its signal pathway in neurodegenerative diseases. Drug Discov Today 2020; 25:1074-1085. [PMID: 32320851 DOI: 10.1016/j.drudis.2020.04.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 03/10/2020] [Accepted: 04/03/2020] [Indexed: 02/06/2023]
Abstract
Microglia are an essential component of the central nervous system (CNS) and are involved in the primary response to microorganisms, neuroinflammation, homeostasis, and tissue regeneration, as well as contributing to the pathogenesis of neurodegenerative diseases. Research has shown that microglial diversity, multifunctionality, and their relationship with glutamate are crucial to determining their roles in these diseases. In this review, we focus on recent progress in determining microglial characteristics and the role of glutamate and its receptors in microglia regulation, which could be a novel therapeutic strategy for neurodegenerative diseases.
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Affiliation(s)
- Xinyue Zhang
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China; Department of Neurobiology, Care Sciences & Society, Division of Neurogeriatrics, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden.
| | - Dan Wang
- Department of Ophthalmology, the First Hospital of Jilin University, Changchun, China.
| | - Bo Zhang
- Department of Neurobiology, Care Sciences & Society, Division of Neurogeriatrics, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden; Department of Neurosurgery, The First Hospital of Jilin University, Changchun, China.
| | - Jie Zhu
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China; Department of Neurobiology, Care Sciences & Society, Division of Neurogeriatrics, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden.
| | - Zhulin Zhou
- Department of Neurobiology, Care Sciences & Society, Division of Neurogeriatrics, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden.
| | - Li Cui
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China.
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Ding S, Li M, Gong H, Zhu Q, Shi G, Zhu A. Sensitive and Selective Measurement of Hydroxyl Radicals at Subcellular Level with Tungsten Nanoelectrodes. Anal Chem 2020; 92:2543-2549. [PMID: 31927939 DOI: 10.1021/acs.analchem.9b04139] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Hydroxyl radical (•OH) is an essential reactive oxygen species involved in critical cell functions. However, the mechanisms controlling its subcellular localization and intracellular level during health and disease remain poorly understood. This is due to the challenge of detecting •OH that are highly reactive and consequently short-lived (in vivo half-life of ∼10-9 s). Herein, we present tungsten nanoelectrodes functionalized with stable 1-hexanethiol (HAT) for selective and sensitive detection of •OH at the subcellular level via the destruction of the self-assembled monolayer of HAT on the nanoelectrode tip. Taking advantage of the ultrasmall nanotip and the super mechanical toughness, the tungsten nanoelectrode could easily penetrate a single living cell without inducing any observable damage. Controlled by a high precision micromanipulator, the •OH level in RAW 264.7 murine macrophages under amyloid β (Aβ) induced oxidative stress were first investigated by the nanoelectrodes at the subcellular level. Moreover, the results revealed the cordycepin-mediated cytoprotection of macrophages through modulation of PI3K/Akt pathway activity and introduction of heme oxygenase-1 (HO-1). We believe that the developed nanoelectrochemical method has shown great capacities for the study of potential drugs for therapeutic intervention of Alzheimer's disease.
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Affiliation(s)
- Shushu Ding
- School of Pharmacy , Nantong University , 19 Qixiu Road , Nantong 226019 , People's Republic of China
| | - Meina Li
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration , East China Normal University , 500 Dongchuan Road , Shanghai 200241 , People's Republic of China
| | - Haoyang Gong
- School of Pharmacy , Nantong University , 19 Qixiu Road , Nantong 226019 , People's Republic of China
| | - Qing Zhu
- School of Pharmacy , Nantong University , 19 Qixiu Road , Nantong 226019 , People's Republic of China
| | - Guoyue Shi
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration , East China Normal University , 500 Dongchuan Road , Shanghai 200241 , People's Republic of China
| | - Anwei Zhu
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration , East China Normal University , 500 Dongchuan Road , Shanghai 200241 , People's Republic of China
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14
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Chen W, Ding S, Wu J, Shi G, Zhu A. In situ detection of hydroxyl radicals in mitochondrial oxidative stress with a nanopipette electrode. Chem Commun (Camb) 2020; 56:13225-13228. [DOI: 10.1039/d0cc05889k] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A nanopipette sensor was designed for the in situ detection of ˙OH around mitochondria with high selectivity and sensitivity.
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Affiliation(s)
- Wenting Chen
- School of Chemistry and Molecular Engineering
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration
- East China Normal University
- Shanghai 200241
- People's Republic of China
| | - Shushu Ding
- School of Chemistry and Molecular Engineering
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration
- East China Normal University
- Shanghai 200241
- People's Republic of China
| | - Jiaren Wu
- School of Chemistry and Molecular Engineering
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration
- East China Normal University
- Shanghai 200241
- People's Republic of China
| | - Guoyue Shi
- School of Chemistry and Molecular Engineering
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration
- East China Normal University
- Shanghai 200241
- People's Republic of China
| | - Anwei Zhu
- School of Chemistry and Molecular Engineering
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration
- East China Normal University
- Shanghai 200241
- People's Republic of China
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Ullah R, Khan M, Shah SA, Saeed K, Kim MO. Natural Antioxidant Anthocyanins-A Hidden Therapeutic Candidate in Metabolic Disorders with Major Focus in Neurodegeneration. Nutrients 2019; 11:E1195. [PMID: 31141884 PMCID: PMC6628002 DOI: 10.3390/nu11061195] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 05/23/2019] [Accepted: 05/24/2019] [Indexed: 12/15/2022] Open
Abstract
All over the world, metabolic syndrome constitutes severe health problems. Multiple factors have been reported in the pathogenesis of metabolic syndrome. Metabolic disorders result in reactive oxygen species (ROS) induced oxidative stress, playing a vital role in the development and pathogenesis of major health issues, including neurological disorders Alzheimer's disease (AD) Parkinson's disease (PD). Considerable increasing evidence indicates the substantial contribution of ROS-induced oxidative stress in neurodegenerative diseases. An imbalanced metabolism results in a defective antioxidant defense system, free radicals causing inflammation, cellular apoptosis, and tissue damage. Due to the annual increase in financial and social burdens, in addition to the adverse effects associated with available synthetic agents, treatment diversion from synthetic to natural approaches has occurred. Antioxidants are now being considered as convincing therapeutic agents against various neurodegenerative disorders. Therefore, medicinal herbs and fruits currently receive substantially more attention as commercial sources of antioxidants. In this review, we argue that ROS-targeted therapeutic interventions with naturally occurring antioxidant flavonoid, anthocyanin, and anthocyanin-loaded nanoparticles might be the ultimate treatment against devastating illnesses. Furthermore, we elucidate the hidden potential of the neuroprotective role of anthocyanins and anthocyanin-loaded nanoparticles in AD and PD neuropathies, which lack sufficient attention compared with other polyphenols, despite their strong antioxidant potential. Moreover, we address the need for future research studies of native anthocyanins and nano-based-anthocyanins, which will be helpful in developing anthocyanin treatments as therapeutic mitochondrial antioxidant drug-like regimens to delay or prevent the progression of neurodegenerative diseases, such as AD and PD.
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Affiliation(s)
- Rahat Ullah
- Division of Applied Life Science (BK 21), College of Natural Sciences, Gyeongsang National University, Jinju 52828, Korea.
| | - Mehtab Khan
- Division of Applied Life Science (BK 21), College of Natural Sciences, Gyeongsang National University, Jinju 52828, Korea.
| | - Shahid Ali Shah
- Division of Applied Life Science (BK 21), College of Natural Sciences, Gyeongsang National University, Jinju 52828, Korea.
- Department of Chemistry, Sarhad University of Science & Information Technology (SUIT), Peshawar Khyber Pakhtunkhwa 25000, Pakistan.
| | - Kamran Saeed
- Division of Applied Life Science (BK 21), College of Natural Sciences, Gyeongsang National University, Jinju 52828, Korea.
| | - Myeong Ok Kim
- Division of Applied Life Science (BK 21), College of Natural Sciences, Gyeongsang National University, Jinju 52828, Korea.
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Swanson A, Wolf T, Sitzmann A, Willette AA. Neuroinflammation in Alzheimer's disease: Pleiotropic roles for cytokines and neuronal pentraxins. Behav Brain Res 2018; 347:49-56. [PMID: 29462653 PMCID: PMC5988985 DOI: 10.1016/j.bbr.2018.02.015] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 01/30/2018] [Accepted: 02/13/2018] [Indexed: 12/14/2022]
Abstract
Neuroinflammation is a potential factor speculated to underlie Alzheimer's disease (AD) etiopathogenesis and progression. The overwhelming focus in this area of research to date has been on the chronic upregulation of pro-inflammatory cytokines to understand how neuroinflammatory mechanisms contribute to neurodegeneration. Yet, it is important to understand the pleiotropic roles of these cytokines in modulating neuroinflammation in which they cannot be labeled as a strictly "good" or "bad" biomarker phenotype. As such, biomarkers with more precise functions are needed to better understand how neuroinflammation impacts the brain in AD. Neuronal pentraxins are a concentration- dependent group of pro- or anti- inflammatory cytokines. There is contradictory evidence of these pentraxins as being both neuroprotective and potentially detrimental in AD. Potential neuroprotective examples include their ability to predict AD-related outcomes such as cognition, memory function and synaptic refinement. This review will briefly outline the basis of AD and subsequently summarize findings for neuropathological mechanisms of neuroinflammation, roles for traditional pro-and anti-inflammatory cytokines, and data found thus far on the neuronal pentraxins.
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Affiliation(s)
- Ashley Swanson
- Department of Food Science and Human Nutrition, Iowa State University, 2312 Food Sciences Building, 536 Farm House Lane, Ames, IA 50011, United States.
| | - Tovah Wolf
- Department of Food Science and Human Nutrition, Iowa State University, 2312 Food Sciences Building, 536 Farm House Lane, Ames, IA 50011, United States.
| | - Alli Sitzmann
- Department of Psychology, Iowa State University, W112 Lagomarcino Hall, 901 Stange Road, Ames, IA 50011, United States.
| | - Auriel A Willette
- Department of Food Science and Human Nutrition, Iowa State University, 2312 Food Sciences Building, 536 Farm House Lane, Ames, IA 50011, United States; Department of Psychology, Iowa State University, W112 Lagomarcino Hall, 901 Stange Road, Ames, IA 50011, United States; Department of Biomedical Sciences, Iowa State University, 2008 Veterinary Medicine, Ames, IA 50011, United States; Department of Neurology, University of Iowa, 2007 Roy Carver Pavilion, 200 Hawkins Drive, Iowa City, IA 52242, United States.
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Abstract
Although the cause of Alzheimer’s disease (AD) remains unknown, a number of new findings suggest that the immune system may play a critical role in the early stages of the disease. Genome-wide association studies have identified a wide array of risk-associated genes for AD, many of which are associated with abnormal functioning of immune cells. Microglia are the brain’s immune cells. They play an important role in maintaining the brain’s extracellular environment, including clearance of aggregated proteins such as amyloid-β (Aβ). Recent studies suggest that microglia play a more active role in the brain than initially considered. Specifically, microglia provide trophic support to neurons and also regulate synapses. Microglial regulation of neuronal activity may have important consequences for AD. In this article we review the function of microglia in AD and examine the possible relationship between microglial dysfunction and network abnormalities, which occur very early in disease pathogenesis.
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Affiliation(s)
- Katherine A. Southam
- Correspondence to: Dr. Katherine Southam, Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, TAS 7000 Australia. Tel.: +61 3 6226 4834; Fax: +61 3 6226 7704; E-mail:
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Mechanisms Underlying Interferon-γ-Induced Priming of Microglial Reactive Oxygen Species Production. PLoS One 2016; 11:e0162497. [PMID: 27598576 PMCID: PMC5012572 DOI: 10.1371/journal.pone.0162497] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/23/2016] [Indexed: 01/01/2023] Open
Abstract
Microglial priming and enhanced reactivity to secondary insults cause substantial neuronal damage and are hallmarks of brain aging, traumatic brain injury and neurodegenerative diseases. It is, thus, of particular interest to identify mechanisms involved in microglial priming. Here, we demonstrate that priming of microglia with interferon-γ (IFN γ) substantially enhanced production of reactive oxygen species (ROS) following stimulation of microglia with ATP. Priming of microglial ROS production was substantially reduced by inhibition of p38 MAPK activity with SB203580, by increases in intracellular glutathione levels with N-Acetyl-L-cysteine, by blockade of NADPH oxidase subunit NOX2 activity with gp91ds-tat or by inhibition of nitric oxide production with L-NAME. Together, our data indicate that priming of microglial ROS production involves reduction of intracellular glutathione levels, upregulation of NADPH oxidase subunit NOX2 and increases in nitric oxide production, and suggest that these simultaneously occurring processes result in enhanced production of neurotoxic peroxynitrite. Furthermore, IFNγ-induced priming of microglial ROS production was reduced upon blockade of Kir2.1 inward rectifier K+ channels with ML133. Inhibitory effects of ML133 on microglial priming were mediated via regulation of intracellular glutathione levels and nitric oxide production. These data suggest that microglial Kir2.1 channels may represent novel therapeutic targets to inhibit excessive ROS production by primed microglia in brain pathology.
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20
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Worker A, Blain C, Jarosz J, Chaudhuri KR, Barker GJ, Williams SCR, Brown RG, Leigh PN, Dell’Acqua F, Simmons A. Diffusion tensor imaging of Parkinson's disease, multiple system atrophy and progressive supranuclear palsy: a tract-based spatial statistics study. PLoS One 2014; 9:e112638. [PMID: 25405990 PMCID: PMC4236070 DOI: 10.1371/journal.pone.0112638] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 10/09/2014] [Indexed: 11/19/2022] Open
Abstract
Although often clinically indistinguishable in the early stages, Parkinson's disease (PD), Multiple System Atrophy (MSA) and Progressive Supranuclear Palsy (PSP) have distinct neuropathological changes. The aim of the current study was to identify white matter tract neurodegeneration characteristic of each of the three syndromes. Tract-based spatial statistics (TBSS) was used to perform a whole-brain automated analysis of diffusion tensor imaging (DTI) data to compare differences in fractional anisotropy (FA) and mean diffusivity (MD) between the three clinical groups and healthy control subjects. Further analyses were conducted to assess the relationship between these putative indices of white matter microstructure and clinical measures of disease severity and symptoms. In PSP, relative to controls, changes in DTI indices consistent with white matter tract degeneration were identified in the corpus callosum, corona radiata, corticospinal tract, superior longitudinal fasciculus, anterior thalamic radiation, superior cerebellar peduncle, medial lemniscus, retrolenticular and anterior limb of the internal capsule, cerebral peduncle and external capsule bilaterally, as well as the left posterior limb of the internal capsule and the right posterior thalamic radiation. MSA patients also displayed differences in the body of the corpus callosum corticospinal tract, cerebellar peduncle, medial lemniscus, anterior and superior corona radiata, posterior limb of the internal capsule external capsule and cerebral peduncle bilaterally, as well as the left anterior limb of the internal capsule and the left anterior thalamic radiation. No significant white matter abnormalities were observed in the PD group. Across groups, MD correlated positively with disease severity in all major white matter tracts. These results show widespread changes in white matter tracts in both PSP and MSA patients, even at a mid-point in the disease process, which are not found in patients with PD.
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Affiliation(s)
- Amanda Worker
- Institute of Psychiatry, King’s College London, London, United Kingdom
- National Institute for Health Research Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London, London, United Kingdom
- National Institute for Health Research Biomedical Research Unit for Dementia at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London, London, United Kingdom
| | - Camilla Blain
- Institute of Psychiatry, King’s College London, London, United Kingdom
- King’s College Hospital, London, United Kingdom
| | | | - K. Ray Chaudhuri
- Institute of Psychiatry, King’s College London, London, United Kingdom
- National Institute for Health Research Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London, London, United Kingdom
- National Institute for Health Research Biomedical Research Unit for Dementia at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London, London, United Kingdom
- King’s College Hospital, London, United Kingdom
| | - Gareth J. Barker
- Institute of Psychiatry, King’s College London, London, United Kingdom
| | - Steve C. R. Williams
- Institute of Psychiatry, King’s College London, London, United Kingdom
- National Institute for Health Research Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London, London, United Kingdom
| | - Richard G. Brown
- Institute of Psychiatry, King’s College London, London, United Kingdom
- National Institute for Health Research Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London, London, United Kingdom
- National Institute for Health Research Biomedical Research Unit for Dementia at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London, London, United Kingdom
| | - P. Nigel Leigh
- Trafford Centre for Biomedical Research, Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton, United Kingdom
| | - Flavio Dell’Acqua
- Institute of Psychiatry, King’s College London, London, United Kingdom
- National Institute for Health Research Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London, London, United Kingdom
- National Institute for Health Research Biomedical Research Unit for Dementia at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London, London, United Kingdom
| | - Andrew Simmons
- Institute of Psychiatry, King’s College London, London, United Kingdom
- National Institute for Health Research Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London, London, United Kingdom
- National Institute for Health Research Biomedical Research Unit for Dementia at South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London, London, United Kingdom
- * E-mail:
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Expression of vesicular glutamate transporters VGLUT1 and VGLUT2 in the rat dental pulp and trigeminal ganglion following inflammation. PLoS One 2014; 9:e109723. [PMID: 25290694 PMCID: PMC4188624 DOI: 10.1371/journal.pone.0109723] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 09/04/2014] [Indexed: 01/07/2023] Open
Abstract
Background There is increasing evidence that peripheral glutamate signaling mechanism is involved in the nociceptive transmission during pathological conditions. However, little is known about the glutamate signaling mechanism and related specific type of vesicular glutamate transporter (VGLUT) in the dental pulp following inflammation. To address this issue, we investigated expression and protein levels of VGLUT1 and VGLUT2 in the dental pulp and trigeminal ganglion (TG) following complete Freund’s adjuvant (CFA) application to the rat dental pulp by light microscopic immunohistochemistry and Western blot analysis. Results The density of VGLUT2− immunopositive (+) axons in the dental pulp and the number of VGLUT2+ soma in the TG increased significantly in the CFA-treated group, compared to control group. The protein levels of VGLUT2 in the dental pulp and TG were also significantly higher in the CFA-treated group than control group by Western blot analysis. The density of VGLUT1+ axons in the dental pulp and soma in the TG remained unchanged in the CFA-treated group. Conclusions These findings suggest that glutamate signaling that is mediated by VGLUT2 in the pulpal axons may be enhanced in the inflamed dental pulp, which may contribute to pulpal axon sensitization leading to hyperalgesia following inflammation.
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Tracking neuroinflammation in Alzheimer's disease: the role of positron emission tomography imaging. J Neuroinflammation 2014; 11:120. [PMID: 25005532 PMCID: PMC4099095 DOI: 10.1186/1742-2094-11-120] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 06/20/2014] [Indexed: 12/02/2022] Open
Abstract
Alzheimer’s disease (AD) has been reconceptualized as a dynamic pathophysiological process, where the accumulation of amyloid-beta (Aβ) is thought to trigger a cascade of neurodegenerative events resulting in cognitive impairment and, eventually, dementia. In addition to Aβ pathology, various lines of research have implicated neuroinflammation as an important participant in AD pathophysiology. Currently, neuroinflammation can be measured in vivo using positron emission tomography (PET) with ligands targeting diverse biological processes such as microglial activation, reactive astrocytes and phospholipase A2 activity. In terms of therapeutic strategies, despite a strong rationale and epidemiological studies suggesting that the use of non-steroidal anti-inflammatory drugs (NSAIDs) may reduce the prevalence of AD, clinical trials conducted to date have proven inconclusive. In this respect, it has been hypothesized that NSAIDs may only prove protective if administered early on in the disease course, prior to the accumulation of significant AD pathology. In order to test various hypotheses pertaining to the exact role of neuroinflammation in AD, studies in asymptomatic carriers of mutations deterministic for early-onset familial AD may prove of use. In this respect, PET ligands for neuroinflammation may act as surrogate markers of disease progression, allowing for the development of more integrative models of AD, as well as for the measuring of target engagement in the context of clinical trials using NSAIDs. In this review, we address the biological basis of neuroinflammatory changes in AD, underscore therapeutic strategies using anti-inflammatory compounds, and shed light on the possibility of tracking neuroinflammation in vivo using PET imaging ligands.
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Jeong JH, Jeong HR, Jo YN, Kim HJ, Shin JH, Heo HJ. Ameliorating effects of aged garlic extracts against Aβ-induced neurotoxicity and cognitive impairment. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 13:268. [PMID: 24134394 PMCID: PMC4015812 DOI: 10.1186/1472-6882-13-268] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 10/08/2013] [Indexed: 12/18/2022]
Abstract
Background In vitro antioxidant activities and neuron-like PC12 cell protective effects of solvent fractions from aged garlic extracts were investigated to evaluate their anti-amnesic functions. Ethyl acetate fractions of aged garlic had higher total phenolics than other fractions. Methods Antioxidant activities of ethyl acetate fractions from aged garlic were examined using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) and malondialdehyde (MDA) inhibitory effect using mouse whole brain homogenates. Levels of cellular oxidative stress as reactive oxygen species (ROS) accumulation were measured using 2',7'-dichlorofluorescein diacetate (DCF-DA). PC12 cell viability was investigated by 3-[4,5-dimethythiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and lactate dehydtrogenase (LDH) assay. The learning and memory impairment in institute of cancer research (ICR) mice was induced by neurotoxic amyloid beta protein (Aβ) to investigate in vivo anti-amnesic effects of aged garlic extracts by using Y-maze and passive avoidance tests. Results We discovered that ethyl acetate fractions showed the highest ABTS radical scavenging activity and MDA inhibitory effect. Intracellular ROS accumulation resulting from Aβ treatment in PC12 cells was significantly reduced when ethyl acetate fractions were presented in the medium compare to PC12 cells which was only treated with Aβ only. Ethyl acetate fractions from aged garlic extracts showed protection against Aβ-induced neurotoxicity. Pre-administration with aged garlic extracts attenuated Aβ-induced learning and memory deficits in both in vivo tests. Conclusions Our findings suggest that aged garlic extracts with antioxidant activities may improve cognitive impairment against Aβ-induced neuronal deficit, and possess a wide range of beneficial activities for neurodegenerative disorders, notably Alzheimer's disease (AD).
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Abstract
The identification of microglia-associated, neurological disease-causing mutations in patients, combined with studies in mouse models has highlighted microglia, the brain’s intrinsic myeloid cells, as key modulators of pathogenesis and disease progression in neurodegenerative diseases. In Alzheimer’s disease (AD) in particular, the activation and accumulation of microglial cells around b-Amyloid (Ab) plaques has long been described and is believed to result in chronic neuroinflammation—a term that, despite being commonly used, lacks a precise definition. This seemingly directed response of microglia to amyloid deposits conflicts with the fact that the increasing buildup of Ab plaques is not inhibited by these cells during disease progression. While recent evidence suggests that microglia lose their intrinsic beneficial function during the course of AD and may even acquire a ‘‘toxic’’ phenotype over time, Ab may also simply not be an appropriate trigger to induce phagocytosis and degradation by microglia in vivo. As recent experimental evidence has indicated the importance of the microglia in AD pathogenesis, future efforts aimed at tackling this disease via utilization or modulation of microglia or factors therefrom appear to be an exciting and challenging research front.
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Immune privilege as an intrinsic CNS property: astrocytes protect the CNS against T-cell-mediated neuroinflammation. Mediators Inflamm 2013; 2013:320519. [PMID: 24023412 PMCID: PMC3760105 DOI: 10.1155/2013/320519] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 07/09/2013] [Indexed: 12/26/2022] Open
Abstract
Astrocytes have many functions in the central nervous system (CNS). They support differentiation and homeostasis of neurons and influence synaptic activity. They are responsible for formation of the blood-brain barrier (BBB) and make up the glia limitans. Here, we review their contribution to neuroimmune interactions and in particular to those induced by the invasion of activated T cells. We discuss the mechanisms by which astrocytes regulate pro- and anti-inflammatory aspects of T-cell responses within the CNS. Depending on the microenvironment, they may become potent antigen-presenting cells for T cells and they may contribute to inflammatory processes. They are also able to abrogate or reprogram T-cell responses by inducing apoptosis or secreting inhibitory mediators. We consider apparently contradictory functions of astrocytes in health and disease, particularly in their interaction with lymphocytes, which may either aggravate or suppress neuroinflammation.
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Pluta R. Is the ischemic blood–brain barrier insufficiency responsible for full-blown Alzheimer's disease? Neurol Res 2013; 28:665-71. [PMID: 16945220 DOI: 10.1179/016164106x130399] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The goal of this paper is to provide scientists with a comprehensive review of the state-of-the-art influence the ischemic blood-brain barrier (BBB) has on the final development of Alzheimer's disease and to provide detailed food-for-thought which will hopefully stimulate more researchers in this area of neuroscience. Understanding new and fundamental concepts about the behavior of the BBB during long-term reperfusion after ischemia with a variety of new neuropathogenic factors can hopefully provide some interesting clues related to the pathologic processes issues that have been receiving considerable attention in the human clinic. We present the recent data to understand the role of the BBB in maturation of both diseases and try to differentiate between primary and secondary pathologic mechanisms. In conclusion, the neuropathogenesis of Alzheimer's disease involves an initial ischemic neuronal alterations leading to enhanced neuronal vulnerability to beta-amyloid peptide and the ischemic breakdown of the BBB with leakage of serum borne beta-amyloid peptide into brain parenchyma, activation of beta-amyloid peptide-dependent toxicity culminating in the formation of amyloid plaques and finally end in full-blown Alzheimer's disease. In summary, probably we have combined mechanism(s) of ischemia processes, ischemic and chronic BBB dysfunction and beta-amyloid peptide-dependent injury in pathology of neurodegeneration that is observed in Alzheimer's disease. We speculate that Alzheimer's disease may be caused by silent and sublethal ischemic episodes that attack and slowly steal the minds of its victims. Finally, our review proposes the ischemic BBB-dependent mechanism(s) that probably are responsible for full-blown Alzheimer's disease.
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Affiliation(s)
- Ryszard Pluta
- Department of Neurodegenerative Disorders, Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.
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Ridolfi E, Barone C, Scarpini E, Galimberti D. The role of the innate immune system in Alzheimer's disease and frontotemporal lobar degeneration: an eye on microglia. Clin Dev Immunol 2013; 2013:939786. [PMID: 23970926 PMCID: PMC3732611 DOI: 10.1155/2013/939786] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 07/04/2013] [Indexed: 01/12/2023]
Abstract
In the last few years, genetic and biomolecular mechanisms at the basis of Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD) have been unraveled. A key role is played by microglia, which represent the immune effector cells in the central nervous system (CNS). They are extremely sensitive to the environmental changes in the brain and are activated in response to several pathologic events within the CNS, including altered neuronal function, infection, injury, and inflammation. While short-term microglial activity has generally a neuroprotective role, chronic activation has been implicated in the pathogenesis of neurodegenerative disorders, including AD and FTLD. In this framework, the purpose of this review is to give an overview of clinical features, genetics, and novel discoveries on biomolecular pathogenic mechanisms at the basis of these two neurodegenerative diseases and to outline current evidence regarding the role played by activated microglia in their pathogenesis.
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Affiliation(s)
- Elisa Ridolfi
- Neurology Unit, Department of Pathophysiology and Transplantation, University of Milan, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Via F. Sforza 35, 20122 Milan, Italy.
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28
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Protective Effects of Hydroxysafflor Yellow A on β-Amyloid-Induced Neurotoxicity in PC12 Cells. Neurochem Res 2013; 38:951-60. [DOI: 10.1007/s11064-013-1002-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 01/28/2013] [Accepted: 02/08/2013] [Indexed: 10/27/2022]
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Danysz W, Parsons CG. Alzheimer's disease, β-amyloid, glutamate, NMDA receptors and memantine--searching for the connections. Br J Pharmacol 2013; 167:324-52. [PMID: 22646481 DOI: 10.1111/j.1476-5381.2012.02057.x] [Citation(s) in RCA: 335] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
β-amyloid (Aβ) is widely accepted to be one of the major pathomechanisms underlying Alzheimer's disease (AD), although there is presently lively debate regarding the relative roles of particular species/forms of this peptide. Most recent evidence indicates that soluble oligomers rather than plaques are the major cause of synaptic dysfunction and ultimately neurodegeneration. Soluble oligomeric Aβ has been shown to interact with several proteins, for example glutamatergic receptors of the NMDA type and proteins responsible for maintaining glutamate homeostasis such as uptake and release. As NMDA receptors are critically involved in neuronal plasticity including learning and memory, we felt that it would be valuable to provide an up to date review of the evidence connecting Aβ to these receptors and related neuronal plasticity. Strong support for the clinical relevance of such interactions is provided by the NMDA receptor antagonist memantine. This substance is the only NMDA receptor antagonist used clinically in the treatment of AD and therefore offers an excellent tool to facilitate translational extrapolations from in vitro studies through in vivo animal experiments to its ultimate clinical utility.
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Affiliation(s)
- Wojciech Danysz
- Merz Pharmaceuticals GmbH, Eckenheimer Landstraße, Frankfurt am Main, Germany
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30
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Abstract
Wider use of pharmacological models would facilitate the development of new drugs for Alzheimer's disease (AD), The two main models currently used are based on the cholinergic and glutamatergic hypotheses of AD, Although they lead to some of the attention and memory impairment observed in AD, they do not fully reproduce the AD pattern. The few studies that used a combination modeling approach, ie, the simultaneous administration of several drugs with the aim of impairing several neurotransmitters or different aspects of a single system, have reported no or marginal cumulative effect. On the basis of current understanding of glutamate and acetylcholine involvement in AD pathophysiology, we suggest that models using selective muscarinic-1 (M(1)) receptor blockers would better mimic the status of the cholinergic system in AD, This kind of model might be suitable for the assessment of drugs that do not act directly on the cholinergic system.
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Affiliation(s)
- C Gilles
- CNS Aging Research, FORENAP - Institute for Research in Neuroscience and Neuropsychiatry, Rouffach, France
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31
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Inhibition of β-amyloid peptide-induced neurotoxicity by kaempferol 3-O-(6″-acetyl)-β-glucopyranoside from butterbur (Petasites japonicus) leaves in B103 cells. Food Sci Biotechnol 2012. [DOI: 10.1007/s10068-012-0109-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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32
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Santos RX, Correia SC, Zhu X, Lee HG, Petersen RB, Nunomura A, Smith MA, Perry G, Moreira PI. Nuclear and mitochondrial DNA oxidation in Alzheimer's disease. Free Radic Res 2012; 46:565-76. [DOI: 10.3109/10715762.2011.648188] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Anand R, Kaushal A, Wani WY, Gill KD. Road to Alzheimer's disease: the pathomechanism underlying. Pathobiology 2011; 79:55-71. [PMID: 22205086 DOI: 10.1159/000332218] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 08/23/2011] [Indexed: 12/22/2022] Open
Abstract
Alzheimer's disease (AD), the most common cause of dementia, results from the interplay of various deregulated mechanisms triggering a complex pathophysiology. The neurons suffer from and slowly succumb to multiple irreversible damages, resulting in cell death and thus memory deficits that characterize AD. In spite of our vast knowledge, it is still unclear as to when the disease process starts and how long the perturbations continue before the disease manifests. Recent studies provide sufficient evidence to prove amyloid β (Aβ) as the primary cause initiating secondary events, but Aβ is also known to be produced under normal conditions and to possess physiological roles, hence, the questions that remain are: What are the factors that lead to abnormal Aβ production? When does Aβ turn into a pathological molecule? What is the chain of events that follows Aβ? The answers are still under debate, and further insight may help us in creating better diagnostic and therapeutic options in AD. The present article attempts to review the current literature regarding AD pathophysiology and proposes a pathophysiologic cascade in AD.
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Affiliation(s)
- R Anand
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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34
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Freeman LR, Keller JN. Oxidative stress and cerebral endothelial cells: regulation of the blood-brain-barrier and antioxidant based interventions. Biochim Biophys Acta Mol Basis Dis 2011; 1822:822-9. [PMID: 22206999 DOI: 10.1016/j.bbadis.2011.12.009] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 12/14/2011] [Indexed: 12/21/2022]
Abstract
While numerous lines of evidence point to increased levels of oxidative stress playing a causal role in a number of neurodegenerative conditions, our current understanding of the specific role of oxidative stress in the genesis and/or propagation of neurodegenerative diseases remains poorly defined. Even more challenging to the "oxidative stress theory of neurodegeneration" is the fact that many antioxidant-based clinical trials and therapeutic interventions have been largely disappointing in their therapeutic benefit. Together, these factors have led researchers to begin to focus on understanding the contribution of highly localized structures, and defined anatomical features, within the brain as the sites responsible for oxidative stress-induced neurodegeneration. This review focuses on the potential for oxidative stress within the cerebrovascular architecture serving as a modulator of neurodegeneration in a variety of pathological settings. In particular, this review highlights important implications for vascular-derived oxidative stress in the initiating and promoting pathophysiology in the brain, identifying new roles for cerebrovascular oxidative stress in a variety of brain disorders. This article is part of a Special Issue entitled: Antioxidants and Antioxidant Treatment in Disease.
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Affiliation(s)
- Linnea R Freeman
- Pennington Biomedical Research Center, BAton Rouge, LA 70808, USA
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35
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Amyloid-β-induced reactive oxygen species production and priming are differentially regulated by ion channels in microglia. J Cell Physiol 2011; 226:3295-302. [DOI: 10.1002/jcp.22675] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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36
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Lee M, Suk K, Kang Y, McGeer E, McGeer PL. Neurotoxic factors released by stimulated human monocytes and THP-1 cells. Brain Res 2011; 1400:99-111. [PMID: 21640980 DOI: 10.1016/j.brainres.2011.05.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 05/10/2011] [Accepted: 05/11/2011] [Indexed: 11/25/2022]
Abstract
Activated monocytes/macrophages are known to release toxic materials. Identification of these materials is important for developing more effective treatments for inflammatory disorders where self attack occurs. We stimulated human monocytes and THP-1 cells with LPS/IFNγ and measured the toxic effects of their conditioned media against differentiated human NT-2 cells. Their cytotoxicity, as measured by LDH release, was reduced by half when their conditioned media was passed through a 3kDa cutoff filter, indicating an equal division between high and low molecular weight materials. When the high molecular weight components tumor necrosis factor-α (TNFα), interleukin-1β (IL-1β), and IL-6 were removed from the conditioned medium by specific antibodies, the toxicity was reduced by 37-38%. When prostaglandin production was blocked by treatment with the COX inhibitors acetylsalicylic acid and ibuprofen, toxicity was reduced by 15-16%. When oxygen free radical production was blocked by the NADPH inhibitor diphenylene iodonium (DPI) the toxicity was reduced by 17-18%. Treatment with the nitric oxide scavenger carboxy-phenyl-tetramethylimidazolineoxyl-oxide, or the NOS inhibitor N(G)-monomethylene-l-arginine, attenuated the toxicity by about 20%. Removal of released glutamate by glutamate decarboxylase also attenuated the toxicity by 12-13%. In combination, these treatments reduced the toxicity by approximately 50% accounting for the low molecular weight component toxicity. About 10% of the overall toxicity, which was associated with the high molecular weight component, was not identified. Optimal antiinflammatory therapy may require combined suppression of these identified toxin-generating pathways as well as relatively minor pathways yet to be identified.
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Affiliation(s)
- Moonhee Lee
- Kinsmen Laboratory of Neurological Research, Vancouver, BC, Canada
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37
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Neuronal cell protection and acetylcholinesterase inhibitory effect of the phenolics in chestnut inner skin. Food Sci Biotechnol 2011. [DOI: 10.1007/s10068-011-0044-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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38
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Kim YN, Ku KH, Kang SK, Choi JH. Effect of Enzyme-Treated Radish Leaves on Lipid Metabolism in Rats Fed a High-Fat Diet. Prev Nutr Food Sci 2011. [DOI: 10.3746/jfn.2011.16.1.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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39
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Hong SY, Park IS, Jun MR. Suppression of β-Secretase (BACE1) Activity and β-Amyloid Protein-Induced Neurotoxicity by Solvent Fractions from Petasites japonicus Leaves. Prev Nutr Food Sci 2011. [DOI: 10.3746/jfn.2011.16.1.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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40
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Salemi J, Obregon DF, Cobb A, Reed S, Sadic E, Jin J, Fernandez F, Tan J, Giunta B. Flipping the switches: CD40 and CD45 modulation of microglial activation states in HIV associated dementia (HAD). Mol Neurodegener 2011; 6:3. [PMID: 21223591 PMCID: PMC3030526 DOI: 10.1186/1750-1326-6-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Accepted: 01/11/2011] [Indexed: 12/21/2022] Open
Abstract
Microglial dysfunction is associated with the pathogenesis and progression of a number of neurodegenerative disorders including HIV associated dementia (HAD). HIV promotion of an M1 antigen presenting cell (APC) - like microglial phenotype, through the promotion of CD40 activity, may impair endogenous mechanisms important for amyloid- beta (Aβ) protein clearance. Further, a chronic pro-inflammatory cycle is established in this manner. CD45 is a protein tyrosine phosphatase receptor which negatively regulates CD40L-CD40-induced microglial M1 activation; an effect leading to the promotion of an M2 phenotype better suited to phagocytose and clear Aβ. Moreover, this CD45 mediated activation state appears to dampen harmful cytokine production. As such, this property of microglial CD45 as a regulatory "off switch" for a CD40-promoted M1, APC-type microglia activation phenotype may represent a critical therapeutic target for the prevention and treatment of neurodegeneration, as well as microglial dysfunction, found in patients with HAD.
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Affiliation(s)
- Jon Salemi
- Department of Psychiatry and Neurosciences, Neuroimmunology Laboratory, University of South Florida, College of Medicine, Tampa, FL 33613, USA.
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41
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Rammouz G, Lecanu L, Papadopoulos V. Oxidative Stress-Mediated Brain Dehydroepiandrosterone (DHEA) Formation in Alzheimer's Disease Diagnosis. Front Endocrinol (Lausanne) 2011; 2:69. [PMID: 22654823 PMCID: PMC3356139 DOI: 10.3389/fendo.2011.00069] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 10/19/2011] [Indexed: 02/06/2023] Open
Abstract
Neurosteroids are steroids made by brain cells independently of peripheral steroidogenic sources. The biosynthesis of most neurosteroids is mediated by proteins and enzymes similar to those identified in the steroidogenic pathway of adrenal and gonadal cells. Dehydroepiandrosterone (DHEA) is a major neurosteroid identified in the brain. Over the years we have reported that, unlike other neurosteroids, DHEA biosynthesis in rat, bovine, and human brain is mediated by an oxidative stress-mediated mechanism, independent of the cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1) enzyme activity found in the periphery. This alternative pathway is induced by pro-oxidant agents, such as Fe(2+) and β-amyloid peptide. Neurosteroids are involved in many aspects of brain function, and as such, are involved in various neuropathologies, including Alzheimer's disease (AD). AD is a progressive, yet irreversible neurodegenerative disease for which there are limited means for ante-mortem diagnosis. Using brain tissue specimens from control and AD patients, we provided evidence that DHEA is formed in the AD brain by the oxidative stress-mediated metabolism of an unidentified precursor, thus depleting levels of the precursor in the blood stream. We tested for the presence of this DHEA precursor in human serum using a Fe(2+)-based reaction and determined the amounts of DHEA formed. Fe(2+) treatment of the serum resulted in a dramatic increase in DHEA levels in control patients, whereas only a moderate or no increase was observed in AD patients. The DHEA variation after oxidation correlated with the patients' cognitive and mental status. In this review, we present the cumulative evidence for oxidative stress as a natural regulator of DHEA formation and the use of this concept to develop a blood-based diagnostic tool for neurodegenerative diseases linked to oxidative stress, such as AD.
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Affiliation(s)
- Georges Rammouz
- Department of Medicine, The Research Institute of the McGill University Health Centre, McGill UniversityMontreal, QC, Canada
| | - Laurent Lecanu
- Department of Medicine, The Research Institute of the McGill University Health Centre, McGill UniversityMontreal, QC, Canada
| | - Vassilios Papadopoulos
- Department of Medicine, The Research Institute of the McGill University Health Centre, McGill UniversityMontreal, QC, Canada
- Department of Biochemistry, McGill UniversityMontreal, QC, Canada
- Department of Pharmacology and Therapeutics, McGill UniversityMontreal, QC, Canada
- *Correspondence: Vassilios Papadopoulos, The Research Institute of the McGill University Health Center, Montreal General Hospital, 1650 Cedar Avenue, C10-148, Montreal, QC, Canada H3G 1A4. e-mail:
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42
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Schwab C, Klegeris A, McGeer PL. Inflammation in transgenic mouse models of neurodegenerative disorders. Biochim Biophys Acta Mol Basis Dis 2009; 1802:889-902. [PMID: 19883753 DOI: 10.1016/j.bbadis.2009.10.013] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 10/09/2009] [Accepted: 10/23/2009] [Indexed: 12/31/2022]
Abstract
Much evidence is available that inflammation contributes to the development of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and Huntington's disease. Our review investigates how well current mouse models reflect this aspect of the pathogenesis. Transgenic models of AD have been available for several years and are the most extensively studied. Modulation of cytokine levels, activation of microglia and, to a lesser extent, activation of the complement system have been reported. Mouse models of PD and HD so far show less evidence for the involvement of inflammation. An increasing number of transgenic mouse strains is being created to model human neurodegenerative diseases. A perfect model should reflect all aspects of a disease. It is important to evaluate continuously the models for their match with the human disease and reevaluate them in light of new findings in human patients. Although none of the transgenic mouse models recapitulates all aspects of the human disorder they represent, all models have provided valuable information on basic molecular pathways. In particular, the mouse models of Alzheimer disease have also led to the development of new therapeutic strategies such as vaccination and modulation of microglial activity.
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Affiliation(s)
- Claudia Schwab
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC V6T1Z3, Canada.
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43
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Hooper C, Pinteaux-Jones F, Fry VAH, Sevastou IG, Baker D, Heales SJ, Pocock JM. Differential effects of albumin on microglia and macrophages; implications for neurodegeneration following blood-brain barrier damage. J Neurochem 2009; 109:694-705. [DOI: 10.1111/j.1471-4159.2009.05953.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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44
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Sholl-Franco A, da Silva AGLS, Adão-Novaes J. Interleukin-4 as a neuromodulatory cytokine: roles and signaling in the nervous system. Ann N Y Acad Sci 2009; 1153:65-75. [PMID: 19236329 DOI: 10.1111/j.1749-6632.2008.03962.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Although interleukin (IL)-4 is described as a prototypical anti-inflammatory cytokine, in recent years its role as a neuromodulatory cytokine has been extensively discussed. This review highlights the pivotal contributions of IL-4 during the development and normal physiology of neural cells as well as IL-4 connections with the pathophysiology of degenerative or inflammatory processes observed in the central and peripheral nervous system.
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Affiliation(s)
- Alfred Sholl-Franco
- Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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45
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Su B, Wang X, Nunomura A, Moreira PI, Lee HG, Perry G, Smith MA, Zhu X. Oxidative stress signaling in Alzheimer's disease. Curr Alzheimer Res 2009; 5:525-32. [PMID: 19075578 DOI: 10.2174/156720508786898451] [Citation(s) in RCA: 199] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Multiple lines of evidence demonstrate that oxidative stress is an early event in Alzheimer's disease (AD), occurring prior to cytopathology, and therefore may play a key pathogenic role in AD. Oxidative stress not only temporally precedes the pathological lesions of the disease but also activates cell signaling pathways, which, in turn, contribute to lesion formation and, at the same time, provoke cellular responses such as compensatory upregulation of antioxidant enzymes found in vulnerable neurons in AD. In this review, we provide an overview of the evidence of oxidative stress and compensatory responses that occur in AD, particularly focused on potential sources of oxidative stress and the roles and mechanism of activation of stress-activated protein kinase pathways.
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Affiliation(s)
- B Su
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio 44106, USA
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46
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Colton CA, Wilcock DM, Wink DA, Davis J, Van Nostrand WE, Vitek MP. The effects of NOS2 gene deletion on mice expressing mutated human AbetaPP. J Alzheimers Dis 2008; 15:571-87. [PMID: 19096157 PMCID: PMC2667339 DOI: 10.3233/jad-2008-15405] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Nitric oxide synthase 2 (NOS2) and its gene product, inducible NOS (iNOS) play an important role in neuroinflammation by generating nitric oxide (NO), a critical signaling and redox factor in the brain. Although NO is associated with tissue damage, it can also promote cell survival. We hypothesize that during long-term exposure to amyloid-beta (Abeta) in Alzheimer's disease (AD), NO levels fall in the brain to a threshold at which the protective effects of NO cannot be sustained, promoting Abeta mediated damage. Two new mouse models of AD have been developed that utilize this concept of NO's action. These mice express human amyloid-beta protein precursor (AbetaPP) mutations that generate Abeta peptides on a mouse NOS2 knockout background. The APP/NOS2(-/-) bigenic mice progress from Abeta production and amyloid deposition to hyperphosphorylated normal mouse tau at AD-associated epitopes, aggregation and redistribution of tau to somatodendritic regions of neurons and significant neuronal loss including loss of interneurons. This AD-like pathology is accompanied by robust behavioral changes. As APP/NOS2(-/-) bigenic mice more fully model the human AD disease pathology, they may serve as a tool to better understand disease progression in AD and the role of NO in altering chronic neurological disease processes.
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Affiliation(s)
- Carol A Colton
- Division of Neurology, Duke University Medical Center, Durham, NC 27710, USA.
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47
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Szczepanik AM, Rampe D, Ringheim GE. Amyloid-β peptide fragments p3 and p4 induce pro-inflammatory cytokine and chemokine production in vitro and in vivo. J Neurochem 2008. [DOI: 10.1046/j.1471-4159.2001.00240.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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48
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Ishizawa K, Komori T, Arai N, Mizutani T, Hirose T. Glial cytoplasmic inclusions and tissue injury in multiple system atrophy: A quantitative study in white matter (olivopontocerebellar system) and gray matter (nigrostriatal system). Neuropathology 2008; 28:249-57. [DOI: 10.1111/j.1440-1789.2007.00855.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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49
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Macrophage-induced neurotoxicity is mediated by glutamate and attenuated by glutaminase inhibitors and gap junction inhibitors. Life Sci 2008; 82:1111-6. [PMID: 18452953 DOI: 10.1016/j.lfs.2008.03.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 03/11/2008] [Accepted: 03/19/2008] [Indexed: 11/22/2022]
Abstract
We have shown previously, that the most neurotoxic factor from activated microglia is glutamate that is produced by glutaminase utilizing extracellular glutamine as a substrate. Drugs that inhibit glutaminase or gap junction through which the glutamate is released were effective in reducing neurotoxic activity of microglia. In this study, to elucidate whether or not a similar mechanism is operating in macrophages infiltrating into the central nervous system during inflammatory, demyelinating, and ischemic brain diseases, we examined the neurotoxicity induced by macrophages, in comparison with microglia in vitro. LPS- or TNF-alpha-stimulated macrophage-conditioned media induced robust neurotoxicity, which was completely inhibited by the NMDA receptor antagonist MK801. Both the glutaminase inhibitor 6-diazo-5-oxo-l-norleucine (DON), and the gap junction inhibitor carbenoxolone (CBX), effectively suppressed glutamate production and subsequent neurotoxicity by activated macrophages. These results revealed that macrophages produce glutamate via glutaminase from extracelluar glutamine, and release it through gap junctions. This study demonstrated that a similar machinery is operating in macrophages as well, and DON and CBX that prevent microglia-mediated neurotoxicity should be effective for preventing macrophage-mediated neurotoxicity. Thus, these drugs may be effective therapeutic reagents for inflammatory, demyelinating, and ischemic brain diseases.
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Moretti R, Torre P, Vilotti C, Manganaro D, Zanet L, Antonello RM. Memantine: Reality and Potentiality. Drug Target Insights 2008. [DOI: 10.4137/dti.s622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Rita Moretti
- Department of Medicine and Neurology, University of Trieste, Trieste, Italy
| | - Paola Torre
- Department of Medicine and Neurology, University of Trieste, Trieste, Italy
| | - Cristina Vilotti
- Department of Medicine and Neurology, University of Trieste, Trieste, Italy
| | - Davide Manganaro
- Department of Medicine and Neurology, University of Trieste, Trieste, Italy
| | - Luca Zanet
- Department of Medicine and Neurology, University of Trieste, Trieste, Italy
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