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Assis-de-Lemos G, Moura-do-Nascimento R, Amaral-do-Nascimento M, Miceli AC, Vieira TCRG. Interactions between Cytokines and the Pathogenesis of Prion Diseases: Insights and Implications. Brain Sci 2024; 14:413. [PMID: 38790392 PMCID: PMC11117815 DOI: 10.3390/brainsci14050413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/16/2024] [Accepted: 04/21/2024] [Indexed: 05/26/2024] Open
Abstract
Transmissible Spongiform Encephalopathies (TSEs), including prion diseases such as Bovine Spongiform Encephalopathy (Mad Cow Disease) and variant Creutzfeldt-Jakob Disease, pose unique challenges to the scientific and medical communities due to their infectious nature, neurodegenerative effects, and the absence of a cure. Central to the progression of TSEs is the conversion of the normal cellular prion protein (PrPC) into its infectious scrapie form (PrPSc), leading to neurodegeneration through a complex interplay involving the immune system. This review elucidates the current understanding of the immune response in prion diseases, emphasizing the dual role of the immune system in both propagating and mitigating the disease through mechanisms such as glial activation, cytokine release, and blood-brain barrier dynamics. We highlight the differential cytokine profiles associated with various prion strains and stages of disease, pointing towards the potential for cytokines as biomarkers and therapeutic targets. Immunomodulatory strategies are discussed as promising avenues for mitigating neuroinflammation and delaying disease progression. This comprehensive examination of the immune response in TSEs not only advances our understanding of these enigmatic diseases but also sheds light on broader neuroinflammatory processes, offering hope for future therapeutic interventions.
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Affiliation(s)
| | | | | | | | - Tuane C. R. G. Vieira
- Institute of Medical Biochemistry Leopoldo de Meis and National Institute of Science and Technology for Structural Biology and Bioimaging, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (G.A.-d.-L.); (R.M.-d.-N.); (M.A.-d.-N.); (A.C.M.)
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2
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Spiers JG, Cortina Chen HJ, Barry TL, Bourgognon JM, Steinert JR. Redox stress and metal dys-homeostasis appear as hallmarks of early prion disease pathogenesis in mice. Free Radic Biol Med 2022; 192:182-190. [PMID: 36170956 DOI: 10.1016/j.freeradbiomed.2022.09.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/19/2022] [Accepted: 09/21/2022] [Indexed: 11/16/2022]
Abstract
Neurodegenerative diseases are associated with a multitude of dysfunctional cellular pathways. One major contributory factor is a redox stress challenge during the development of several protein misfolding conditions including Alzheimer's (AD), Parkinson's disease (PD), and less common conditions such as Creutzfeldt Jakob disease (CJD). CJD is caused by misfolding of the neuronal prion protein and is characterised by a neurotoxic unfolded protein response involving chronic endoplasmic reticulum stress, reduced protein translation and spongiosis leading subsequently to synaptic and neuronal loss. Here we have characterised prion disease in mice to assess redox stress components including nitrergic and oxidative markers associated with neuroinflammatory activation. Aberrant regulation of the homeostasis of several redox metals contributes to the overall cellular redox stress and we have identified altered levels of iron, copper, zinc, and manganese in the hippocampus of prion diseased mice. Our data show that early in disease, there is evidence for oxidative stress in conjunction with reduced antioxidant superoxide dismutase mRNA and protein expression. Moreover, expression of divalent metal transporter proteins was reduced for Atp7b, Atox1, Slc11a2, Slc39a14 at 6-7 weeks but increased for Slc39a14 and Mt1 at 10 weeks of disease. Our data present evidence for a strong pro-oxidant environment and altered redox metal homeostasis in early disease pathology which both may be contributory factors to aggravating this protein misfolding disease.
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Affiliation(s)
- Jereme G Spiers
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, 3083, Australia.
| | - Hsiao-Jou Cortina Chen
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Tiffany L Barry
- School of Geography, Geology and the Environment, University of Leicester, University Road, Leicester, LE1 7RH, UK
| | - Julie-Myrtille Bourgognon
- School of Infection and Immunity, Sir Graeme Davies Building, 120 University Place, Glasgow, G12 8TA, UK
| | - Joern R Steinert
- Division of Physiology, Pharmacology and Neuroscience, University of Nottingham, School of Life Sciences, Nottingham, NG7 2NR, UK.
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Sušjan-Leite P, Ramuta TŽ, Boršić E, Orehek S, Hafner-Bratkovič I. Supramolecular organizing centers at the interface of inflammation and neurodegeneration. Front Immunol 2022; 13:940969. [PMID: 35979366 PMCID: PMC9377691 DOI: 10.3389/fimmu.2022.940969] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 07/05/2022] [Indexed: 11/17/2022] Open
Abstract
The pathogenesis of neurodegenerative diseases involves the accumulation of misfolded protein aggregates. These deposits are both directly toxic to neurons, invoking loss of cell connectivity and cell death, and recognized by innate sensors that upon activation release neurotoxic cytokines, chemokines, and various reactive species. This neuroinflammation is propagated through signaling cascades where activated sensors/receptors, adaptors, and effectors associate into multiprotein complexes known as supramolecular organizing centers (SMOCs). This review provides a comprehensive overview of the SMOCs, involved in neuroinflammation and neurotoxicity, such as myddosomes, inflammasomes, and necrosomes, their assembly, and evidence for their involvement in common neurodegenerative diseases. We discuss the multifaceted role of neuroinflammation in the progression of neurodegeneration. Recent progress in the understanding of particular SMOC participation in common neurodegenerative diseases such as Alzheimer's disease offers novel therapeutic strategies for currently absent disease-modifying treatments.
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Affiliation(s)
- Petra Sušjan-Leite
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Taja Železnik Ramuta
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Elvira Boršić
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Sara Orehek
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Iva Hafner-Bratkovič
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
- EN-FIST Centre of Excellence, Ljubljana, Slovenia
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4
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The Therapeutic Prospects of Targeting IL-1R1 for the Modulation of Neuroinflammation in Central Nervous System Disorders. Int J Mol Sci 2022; 23:ijms23031731. [PMID: 35163653 PMCID: PMC8915186 DOI: 10.3390/ijms23031731] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/24/2022] [Accepted: 01/30/2022] [Indexed: 11/16/2022] Open
Abstract
The interleukin-1 receptor type 1 (IL-1R1) holds pivotal roles in the immune system, as it is positioned at the “epicenter” of the inflammatory signaling networks. Increased levels of the cytokine IL-1 are a recognized feature of the immune response in the central nervous system (CNS) during injury and disease, i.e., neuroinflammation. Despite IL-1/IL-1R1 signaling within the CNS having been the subject of several studies, the roles of IL-1R1 in the CNS cellular milieu still cause controversy. Without much doubt, however, the persistent activation of the IL-1/IL-1R1 signaling pathway is intimately linked with the pathogenesis of a plethora of CNS disease states, ranging from Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS), all the way to schizophrenia and prion diseases. Importantly, a growing body of evidence is showing that blocking IL-1R1 signaling via pharmacological or genetic means in different experimental models of said CNS diseases leads to reduced neuroinflammation and delayed disease progression. The aim of this paper is to review the recent progress in the study of the biological roles of IL-1R1, as well as to highlight key aspects that render IL-1R1 a promising target for the development of novel disease-modifying treatments for multiple CNS indications.
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Adhikari UK, Sakiz E, Habiba U, Mikhael M, Senesi M, David MA, Guillemin GJ, Ooi L, Karl T, Collins S, Tayebi M. Treatment of microglia with Anti-PrP monoclonal antibodies induces neuronal apoptosis in vitro. Heliyon 2021; 7:e08644. [PMID: 35005289 PMCID: PMC8715334 DOI: 10.1016/j.heliyon.2021.e08644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/23/2021] [Accepted: 12/16/2021] [Indexed: 11/04/2022] Open
Abstract
Previous reports highlighted the neurotoxic effects caused by some motif-specific anti-PrPC antibodies in vivo and in vitro. In the current study, we investigated the detailed alterations of the proteome with liquid chromatography–mass spectrometry following direct application of anti-PrPC antibodies on mouse neuroblastoma cells (N2a) and mouse primary neuronal (MPN) cells or by cross-linking microglial PrPC with anti-PrPC antibodies prior to co-culture with the N2a/MPN cells. Here, we identified 4 (3 upregulated and 1 downregulated) and 17 (11 upregulated and 6 downregulated) neuronal apoptosis-related proteins following treatment of the N2a and N11 cell lines respectively when compared with untreated cells. In contrast, we identified 1 (upregulated) and 4 (2 upregulated and 2 downregulated) neuronal apoptosis-related proteins following treatment of MPN cells and N11 when compared with untreated cells. Furthermore, we also identified 3 (2 upregulated and 1 downregulated) and 2 (1 upregulated and 1 downregulated) neuronal apoptosis-related related proteins following treatment of MPN cells and N11 when compared to treatment with an anti-PrP antibody that lacks binding specificity for mouse PrP. The apoptotic effect of the anti-PrP antibodies was confirmed with flow cytometry following labelling of Annexin V-FITC. The toxic effects of the anti-PrP antibodies was more intense when antibody-treated N11 were co-cultured with the N2a and the identified apoptosis proteome was shown to be part of the PrPC-interactome. Our observations provide a new insight into the prominent role played by microglia in causing neurotoxic effects following treatment with anti-PrPC antibodies and might be relevant to explain the antibody mediated toxicity observed in other related neurodegenerative diseases such as Alzheimer. Antibody cross-linking neuronal PrPC induces apoptosis. Antibody cross-linking microglial PrPC induces neuronal apoptosis. Different apoptotic pathways were triggered by specific anti-PrP antibody treatments.
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Guo S, Wang R, Hu J, Sun L, Zhao X, Zhao Y, Han D, Hu S. Photobiomodulation Promotes Hippocampal CA1 NSC Differentiation Toward Neurons and Facilitates Cognitive Function Recovery Involving NLRP3 Inflammasome Mitigation Following Global Cerebral Ischemia. Front Cell Neurosci 2021; 15:731855. [PMID: 34489645 PMCID: PMC8417562 DOI: 10.3389/fncel.2021.731855] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 07/27/2021] [Indexed: 12/12/2022] Open
Abstract
Our recent study revealed that photobiomodulation (PBM) inhibits delayed neuronal death by preserving mitochondrial dynamics and function following global cerebral ischemia (GCI). In the current study, we clarified whether PBM exerts effective roles in endogenous neurogenesis and long-lasting neurological recovery after GCI. Adult male rats were treated with 808 nm PBM at 20 mW/cm2 irradiance for 2 min on cerebral cortex surface (irradiance ∼7.0 mW/cm2, fluence ∼0.8 J/cm2 on the hippocampus) beginning 3 days after GCI for five consecutive days. Cognitive function was evaluated using the Morris water maze. Neural stem cell (NSC) proliferation, immature neurons, and mature neurons were examined using bromodeoxyuridine (BrdU)-, doublecortin (DCX)-, and NeuN-staining, respectively. Protein expression, such as NLRP3, cleaved IL1β, GFAP, and Iba1 was detected using immunofluorescence staining, and ultrastructure of astrocyte and microglia was observed by transmission electron microscopy. The results revealed that PBM exerted a markedly neuroprotective role and improved spatial learning and memory ability at 58 days of ischemia/reperfusion (I/R) but not at 7 days of reperfusion. Mechanistic studies revealed that PBM suppressed reactive astrocytes and maintained astrocyte regeneration at 7 days of reperfusion, as well as elevated neurogenesis at 58 days of reperfusion, as evidenced by a significant decrease in the fluorescence intensity of GFAP (astrocyte marker) but unchanged the number of BrdU-GFAP colabeled cells at the early timepoint, and a robust elevation in the number of DCX-NeuN colabeled cells at the later timepoint in the PBM-treated group compared to the GCI group. Notably, PBM treatment protected the ultrastructure of astrocyte and microglia cells at 58 days but not 7 days of reperfusion in the hippocampal CA1 region. Furthermore, PBM treatment significantly attenuated the GCI-induced immunofluorescence intensity of NLRP3 (an inflammasome component), cleaved IL1β (reflecting inflammasome activation) and Iba1, as well as the colocalization of NLRP3/GFAP or cleaved IL-1β/GFAP, especially in animals subjected to I/R at 58 days. Taken together, PBM treatment performed postischemia exerted a long-lasting protective effect on astrocytes and promoted endogenous neurogenesis in the hippocampal CA1 region, which might contribute to neurological recovery after GCI.
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Affiliation(s)
- Sihan Guo
- School of Life Sciences, Jiangsu Provincial Institute of Health Emergency, Xuzhou Medical University, Xuzhou, China
| | - Ruimin Wang
- Neurobiology Institute, School of Public Health, North China University of Science and Technology, Tangshan, China
| | - Jiewei Hu
- Neurobiology Institute, School of Public Health, North China University of Science and Technology, Tangshan, China
| | - Liping Sun
- School of Life Sciences, Jiangsu Provincial Institute of Health Emergency, Xuzhou Medical University, Xuzhou, China
| | - Xinru Zhao
- School of Life Sciences, Jiangsu Provincial Institute of Health Emergency, Xuzhou Medical University, Xuzhou, China
| | - Yufeng Zhao
- School of Life Sciences, Jiangsu Provincial Institute of Health Emergency, Xuzhou Medical University, Xuzhou, China
| | - Dong Han
- School of Life Sciences, Jiangsu Provincial Institute of Health Emergency, Xuzhou Medical University, Xuzhou, China
| | - Shuqun Hu
- School of Life Sciences, Jiangsu Provincial Institute of Health Emergency, Xuzhou Medical University, Xuzhou, China
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7
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Neuroinflammation in Prion Disease. Int J Mol Sci 2021; 22:ijms22042196. [PMID: 33672129 PMCID: PMC7926464 DOI: 10.3390/ijms22042196] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 02/20/2021] [Accepted: 02/20/2021] [Indexed: 12/24/2022] Open
Abstract
Neuroinflammation, typically manifest as microglial activation and astrogliosis accompanied by transcriptomic alterations, represents a common hallmark of various neurodegenerative conditions including prion diseases. Microglia play an overall neuroprotective role in prion disease, whereas reactive astrocytes with aberrant phenotypes propagate prions and contribute to prion-induced neurodegeneration. The existence of heterogeneous subpopulations and dual functions of microglia and astrocytes in prion disease make them potential targets for therapeutic intervention. A variety of neuroinflammation-related molecules are involved in prion pathogenesis. Therapeutics targeting neuroinflammation represents a novel approach to combat prion disease. Deciphering neuroinflammation in prion disease will deepen our understanding of pathogenesis of other neurodegenerative disorders.
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8
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Neuroimmune Response Mediated by Cytokines in Natural Scrapie after Chronic Dexamethasone Treatment. Biomolecules 2021; 11:biom11020204. [PMID: 33540568 PMCID: PMC7912810 DOI: 10.3390/biom11020204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 01/27/2021] [Indexed: 01/15/2023] Open
Abstract
The actual role of prion protein-induced glial activation and subsequent cytokine secretion during prion diseases is still incompletely understood. The overall aim of this study is to assess the effect of an anti-inflammatory treatment with dexamethasone on different cytokines released by neuroglial cells that are potentially related to neuroinflammation in natural scrapie. This study emphasizes the complex interactions existent among several pleiotropic neuromodulator peptides and provides a global approach to clarify neuroinflammatory processes in prion diseases. Additionally, an impairment of communication between microglial and astroglial populations mediated by cytokines, mainly IL-1, is suggested. The main novelty of this study is that it is the first one assessing in situ neuroinflammatory activity in relation to chronic anti-inflammatory therapy, gaining relevance because it is based on a natural model. The cytokine profile data would suggest the activation of some neurotoxicity-associated route. Consequently, targeting such a pathway might be a new approach to modify the damaging effects of neuroinflammation.
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Rashidi M, Wicks IP, Vince JE. Inflammasomes and Cell Death: Common Pathways in Microparticle Diseases. Trends Mol Med 2020; 26:1003-1020. [DOI: 10.1016/j.molmed.2020.06.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/02/2020] [Accepted: 06/04/2020] [Indexed: 12/11/2022]
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Microglia in Prion Diseases: Angels or Demons? Int J Mol Sci 2020; 21:ijms21207765. [PMID: 33092220 PMCID: PMC7589037 DOI: 10.3390/ijms21207765] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/16/2020] [Accepted: 10/16/2020] [Indexed: 02/08/2023] Open
Abstract
Prion diseases are rare transmissible neurodegenerative disorders caused by the accumulation of a misfolded isoform (PrPSc) of the cellular prion protein (PrPC) in the central nervous system (CNS). Neuropathological hallmarks of prion diseases are neuronal loss, astrogliosis, and enhanced microglial proliferation and activation. As immune cells of the CNS, microglia participate both in the maintenance of the normal brain physiology and in driving the neuroinflammatory response to acute or chronic (e.g., neurodegenerative disorders) insults. Microglia involvement in prion diseases, however, is far from being clearly understood. During this review, we summarize and discuss controversial findings, both in patient and animal models, suggesting a neuroprotective role of microglia in prion disease pathogenesis and progression, or—conversely—a microglia-mediated exacerbation of neurotoxicity in later stages of disease. We also will consider the active participation of PrPC in microglial functions, by discussing previous reports, but also by presenting unpublished results that support a role for PrPC in cytokine secretion by activated primary microglia.
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Chen J, Chen C, Hu C, Liu L, Xia Y, Wang L, Yang W, Wu HY, Zhou W, Xiao K, Shi Q, Wu Y, Chen ZB, Dong XP. IP10, KC and M-CSF Are Remarkably Increased in the Brains from the Various Strains of Experimental Mice Infected with Different Scrapie Agents. Virol Sin 2020; 35:614-625. [PMID: 32314275 PMCID: PMC7736440 DOI: 10.1007/s12250-020-00216-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 11/27/2019] [Indexed: 12/21/2022] Open
Abstract
Activation of inflammatory cells and upregulations of a number of cytokines in the central nervous system (CNS) of patients with prion diseases are frequently observed. To evaluate the potential changes of some brain cytokines that were rarely addressed during prion infection, the levels of 17 different cytokines in the brain homogenates of mice infected with different scrapie mouse-adapted agents were firstly screened with Luminex assay. Significant upregulations of interferon gamma-induced protein 10 (IP10), keratinocyte chemoattractant (KC) and macrophage colony stimulating factor (M-CSF) were frequently detected in the brain lysates of many strains of scrapie infected mice. The upregulations of those three cytokines in the brains of scrapie infected mice were further validated by the individual specific ELISA and immunohistochemical assay. Increased specific mRNAs of IP10, M-CSF and KC in the brains of scrapie infected mice were also detected by the individual specific qRT-PCRs and IP10-specific digital PCR. Dynamic analyses of the brain samples collected at different time points post infection revealed the time-dependent increases of those three cytokines, particularly IP10 during the incubation period of scrapie infection. In addition, we also found that the levels of IP10 in cerebral spinal fluid (CSF) of 45 sporadic Creutzfeldt-Jakob disease (sCJD) patients were slightly but significantly higher than those of the cases who were excluded the diagnosis of prion diseases. These data give us a better understanding of inflammatory reaction during prion infection and progression of prion disease.
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Affiliation(s)
- Jia Chen
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, 163000, China
- State Key Laboratory of Infectious Disease Prevention and Control, NHC Key Laboratory of Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100000, China
| | - Cao Chen
- State Key Laboratory of Infectious Disease Prevention and Control, NHC Key Laboratory of Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100000, China.
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310000, China.
- Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, 430000, China.
| | - Chao Hu
- State Key Laboratory of Infectious Disease Prevention and Control, NHC Key Laboratory of Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100000, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310000, China
| | - Lian Liu
- State Key Laboratory of Infectious Disease Prevention and Control, NHC Key Laboratory of Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100000, China
- College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, 163000, China
| | - Ying Xia
- State Key Laboratory of Infectious Disease Prevention and Control, NHC Key Laboratory of Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100000, China
- College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, 163000, China
| | - Lin Wang
- State Key Laboratory of Infectious Disease Prevention and Control, NHC Key Laboratory of Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100000, China
- College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, 163000, China
| | - Wei Yang
- State Key Laboratory of Infectious Disease Prevention and Control, NHC Key Laboratory of Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100000, China
- College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, 163000, China
| | - Hai-Yan Wu
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, 163000, China
| | - Wei Zhou
- State Key Laboratory of Infectious Disease Prevention and Control, NHC Key Laboratory of Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100000, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310000, China
| | - Kang Xiao
- State Key Laboratory of Infectious Disease Prevention and Control, NHC Key Laboratory of Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100000, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310000, China
| | - Qi Shi
- State Key Laboratory of Infectious Disease Prevention and Control, NHC Key Laboratory of Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100000, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310000, China
| | - Yuezhang Wu
- State Key Laboratory of Infectious Disease Prevention and Control, NHC Key Laboratory of Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100000, China
| | - Zhi-Bao Chen
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, 163000, China.
| | - Xiao-Ping Dong
- State Key Laboratory of Infectious Disease Prevention and Control, NHC Key Laboratory of Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100000, China.
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310000, China.
- Center for Global Public Health, Chinese Center for Disease Control and Prevention, Beijing, 100000, China.
- Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, 430000, China.
- China Academy of Chinese Medical Sciences, Beijing, 100000, China.
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12
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Guijarro IM, Garcés M, Marín B, Otero A, Barrio T, Badiola JJ, Monzón M. Neuroimmune Response in Natural Preclinical Scrapie after Dexamethasone Treatment. Int J Mol Sci 2020; 21:ijms21165779. [PMID: 32806582 PMCID: PMC7460817 DOI: 10.3390/ijms21165779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/04/2020] [Accepted: 08/10/2020] [Indexed: 12/18/2022] Open
Abstract
A recently published report on chronic dexamethasone treatment for natural scrapie supported the hypothesis of the potential failure of astroglia in the advanced stage of disease. Herein, we aimed to extend the aforementioned study on the effect of this anti-inflammatory therapy to the initial phase of scrapie, with the aim of elucidating the natural neuroinflammatory process occurring in this neurodegenerative disorder. The administration of this glucocorticoid resulted in an outstanding reduction in vacuolation and aberrant protein deposition (nearly null), and an increase in glial activation. Furthermore, evident suppression of IL-1R and IL-6 and the exacerbation of IL-1α, IL-2R, IL-10R and IFNγR were also demonstrated. Consequently, the early stage of the disease is characterized by an intact neuroglial response similar to that of healthy individuals attempting to re-establish homeostasis. A complex network of neuroinflammatory markers is involved from the very early stages of this prion disease, which probably becomes impaired in the more advanced stages. The in vivo animal model used herein provides essential observations on the pathogenesis of natural scrapie, as well as the possibility of establishing neuroglia as potential target cells for anti-inflammatory therapy.
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MicroRNA Alterations in a Tg501 Mouse Model of Prion Disease. Biomolecules 2020; 10:biom10060908. [PMID: 32549330 PMCID: PMC7355645 DOI: 10.3390/biom10060908] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/31/2020] [Accepted: 06/12/2020] [Indexed: 12/11/2022] Open
Abstract
MicroRNAs (miRNAs) may contribute to the development and pathology of many neurodegenerative diseases, including prion diseases. They are also promising biomarker candidates due to their stability in body fluids. We investigated miRNA alterations in a Tg501 mouse model of prion diseases that expresses a transgene encoding the goat prion protein (PRNP). Tg501 mice intracranially inoculated with mouse-adapted goat scrapie were compared with age-matched, mock inoculated controls in preclinical and clinical stages. Small RNA sequencing from the cervical spinal cord indicated that miR-223-3p, miR-151-3p, and miR-144-5p were dysregulated in scrapie-inoculated animals before the onset of symptoms. In clinical-stage animals, 23 significant miRNA alterations were found. These miRNAs were predicted to modify the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways including prion disease, extracellular matrix interactions, glutaminergic synapse, axon guidance, and transforming growth factor-beta signaling. MicroRNAs miR-146a-5p (up in cervical spinal cord) and miR-342-3p (down in cervical spinal cord, cerebellum and plasma), both indicated in neurodegenerative diseases earlier, were verified by quantitative real-time polymerase chain reaction (qRT-PCR). Minimal changes observed before the disease onset suggests that most miRNA alterations observed here are driven by advanced prion-associated pathology, possibly limiting their use as diagnostic markers. However, the results encourage further mechanistic studies on miRNA-regulated pathways involved in these neurodegenerative conditions.
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Tanaka M, Yamasaki T, Hasebe R, Suzuki A, Horiuchi M. Enhanced phosphorylation of PERK in primary cultured neurons as an autonomous neuronal response to prion infection. PLoS One 2020; 15:e0234147. [PMID: 32479530 PMCID: PMC7263615 DOI: 10.1371/journal.pone.0234147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 05/19/2020] [Indexed: 01/29/2023] Open
Abstract
Conversion of cellular prion protein (PrPC) into the pathogenic isoform of prion protein (PrPSc) in neurons is one of the key pathophysiological events in prion diseases. However, the molecular mechanism of neurodegeneration in prion diseases has yet to be fully elucidated because of a lack of suitable experimental models for analyzing neuron-autonomous responses to prion infection. In the present study, we used neuron-enriched primary cultures of cortical and thalamic mouse neurons to analyze autonomous neuronal responses to prion infection. PrPSc levels in neurons increased over the time after prion infection; however, no obvious neuronal losses or neurite alterations were observed. Interestingly, a finer analysis of individual neurons co-stained with PrPSc and phosphorylated protein kinase RNA-activated-like endoplasmic reticulum (ER) kinase (p-PERK), the early cellular response of the PERK-eukaryotic initiation factor 2 (eIF2α) pathway, demonstrated a positive correlation between the number of PrPSc granular stains and p-PERK granular stains, in cortical neurons at 21 dpi. Although the phosphorylation of PERK was enhanced in prion-infected cortical neurons, there was no sign of subsequent translational repression of synaptic protein synthesis or activations of downstream unfolded protein response (UPR) in the PERK-eIF2α pathway. These results suggest that PrPSc production in neurons induces ER stress in a neuron-autonomous manner; however, it does not fully activate UPR in prion-infected neurons. Our findings provide insights into the autonomous neuronal responses to prion propagation and the involvement of neuron-non-autonomous factor(s) in the mechanisms of neurodegeneration in prion diseases.
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Affiliation(s)
- Misaki Tanaka
- Laboratory of Veterinary Hygiene, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Takeshi Yamasaki
- Laboratory of Veterinary Hygiene, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Rie Hasebe
- Laboratory of Veterinary Hygiene, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Akio Suzuki
- Laboratory of Veterinary Hygiene, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Motohiro Horiuchi
- Laboratory of Veterinary Hygiene, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
- Global Station for Zoonosis Control, Global Institute for Collaborative Research and Education, Hokkaido University, Sapporo, Japan
- * E-mail:
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15
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Voet S, Srinivasan S, Lamkanfi M, van Loo G. Inflammasomes in neuroinflammatory and neurodegenerative diseases. EMBO Mol Med 2020; 11:emmm.201810248. [PMID: 31015277 PMCID: PMC6554670 DOI: 10.15252/emmm.201810248] [Citation(s) in RCA: 436] [Impact Index Per Article: 109.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Neuroinflammation and neurodegeneration often result from the aberrant deposition of aggregated host proteins, including amyloid‐β, α‐synuclein, and prions, that can activate inflammasomes. Inflammasomes function as intracellular sensors of both microbial pathogens and foreign as well as host‐derived danger signals. Upon activation, they induce an innate immune response by secreting the inflammatory cytokines interleukin (IL)‐1β and IL‐18, and additionally by inducing pyroptosis, a lytic cell death mode that releases additional inflammatory mediators. Microglia are the prominent innate immune cells in the brain for inflammasome activation. However, additional CNS‐resident cell types including astrocytes and neurons, as well as infiltrating myeloid cells from the periphery, express and activate inflammasomes. In this review, we will discuss current understanding of the role of inflammasomes in common degenerative diseases of the brain and highlight inflammasome‐targeted strategies that may potentially treat these diseases.
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Affiliation(s)
- Sofie Voet
- VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Sahana Srinivasan
- VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Mohamed Lamkanfi
- Department of Internal Medicine, Ghent University, Ghent, Belgium .,Janssen Immunosciences, World without Disease Accelerator, Pharmaceutical Companies of Johnson & Johnson, Beerse, Belgium
| | - Geert van Loo
- VIB Center for Inflammation Research, Ghent, Belgium .,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
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16
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Region-specific glial homeostatic signature in prion diseases is replaced by a uniform neuroinflammation signature, common for brain regions and prion strains with different cell tropism. Neurobiol Dis 2020; 137:104783. [PMID: 32001329 DOI: 10.1016/j.nbd.2020.104783] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/21/2020] [Accepted: 01/25/2020] [Indexed: 02/08/2023] Open
Abstract
Chronic neuroinflammation is recognized as a major neuropathological hallmark in a broad spectrum of neurodegenerative diseases including Alzheimer's, Parkinson's, Frontal Temporal Dementia, Amyotrophic Lateral Sclerosis, and prion diseases. Both microglia and astrocytes exhibit region-specific homeostatic transcriptional identities, which under chronic neurodegeneration, transform into reactive phenotypes in a region- and disease-specific manner. Little is known about region-specific identity of glia in prion diseases. The current study was designed to determine whether the region-specific homeostatic signature of glia changes with the progression of prion diseases, and whether these changes occur in a region-dependent or universal manner. Also of interest was whether different prion strains give rise to different reactive phenotypes. To answer these questions, we analyzed gene expression in the thalamus, cortex, hypothalamus and hippocampus of mice infected with 22L and ME7 prion strains using a Nanostring Neuroinflammation panel at the subclinical, early clinical and advanced stages of the disease. We found that at the preclinical stage of the disease, the region-specific homeostatic identities were preserved. However, with the appearance of clinical signs, the region-specific signatures were partially lost and replaced with a neuroinflammation signature. While the same sets of genes were activated by both prion strains, the timing of neuroinflammation and the degree of activation in different brain regions was strain-specific. Changes in astrocyte function scored at the top of the activated pathways. Moreover, clustering analysis suggested that the astrocyte function pathway responded to prion infection prior to the Activated Microglia or Neuron and Neurotransmission pathways. The current work established neuroinflammation gene expression signature associated with prion diseases. Our results illustrate that with the disease progression, the region-specific homeostatic transcriptome signatures are replaced by the region-independent neuroinflammation signature, which is common for prion strains with different cell tropism. The prion-associated neuroinflammation signature identified in the current study overlapped only partially with the microglia degenerative phenotype and the disease-associated microglia phenotype reported for animal models of other neurodegenerative diseases.
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17
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Makarava N, Chang JCY, Kushwaha R, Baskakov IV. Region-Specific Response of Astrocytes to Prion Infection. Front Neurosci 2019; 13:1048. [PMID: 31649496 PMCID: PMC6794343 DOI: 10.3389/fnins.2019.01048] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/18/2019] [Indexed: 12/31/2022] Open
Abstract
Chronic neuroinflammation involves reactive microgliosis and astrogliosis, and is regarded as a common pathological hallmark of neurodegenerative diseases including Alzheimer’s, Parkinson’s, ALS and prion diseases. Reactive astrogliosis, routinely observed immunohistochemically as an increase in glial fibrillary acidic protein (GFAP) signal, is a well-documented feature of chronic neuroinflammation associated with neurodegenerative diseases. Recent studies on single-cell transcriptional profiling of a mouse brain revealed that, under normal conditions, several distinct subtypes of astrocytes with regionally specialized distribution exist. However, it remains unclear whether astrocytic response to pro-inflammatory pathological conditions is uniform across whole brain or is region-specific. The current study compares the response of microglia and astrocytes to prions in mice infected with 22L mouse-adapted prion strain. While the intensity of reactive microgliosis correlated well with the extent of PrPSc deposition, reactive astrogliosis displayed a different, region-specific pattern. In particular, the thalamus and stratum oriens of hippocampus, which are both affected by 22L prions, displayed strikingly different response of astrocytes to PrPSc. Astrocytes in stratum oriens of hippocampus responded to accumulation of PrPSc with visible hypertrophy and increased GFAP, while in the thalamus, despite stronger PrPSc signal, the increase of GFAP was milder than in hippocampus, and the change in astrocyte morphology was less pronounced. The current study suggests that astrocyte response to prion infection is heterogeneous and, in part, defined by brain region. Moreover, the current work emphasizes the needs for elucidating region-specific changes in functional states of astrocytes and exploring the impact of these changes to chronic neurodegeneration.
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Affiliation(s)
- Natallia Makarava
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Jennifer Chen-Yu Chang
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Rajesh Kushwaha
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Ilia V Baskakov
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
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18
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Abstract
Mammalian prion diseases are a group of neurodegenerative conditions caused by infection of the central nervous system with proteinaceous agents called prions, including sporadic, variant, and iatrogenic Creutzfeldt-Jakob disease; kuru; inherited prion disease; sheep scrapie; bovine spongiform encephalopathy; and chronic wasting disease. Prions are composed of misfolded and multimeric forms of the normal cellular prion protein (PrP). Prion diseases require host expression of the prion protein gene (PRNP) and a range of other cellular functions to support their propagation and toxicity. Inherited forms of prion disease are caused by mutation of PRNP, whereas acquired and sporadically occurring mammalian prion diseases are controlled by powerful genetic risk and modifying factors. Whereas some PrP amino acid variants cause the disease, others confer protection, dramatically altered incubation times, or changes in the clinical phenotype. Multiple mechanisms, including interference with homotypic protein interactions and the selection of the permissible prion strains in a host, play a role. Several non-PRNP factors have now been uncovered that provide insights into pathways of disease susceptibility or neurotoxicity.
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Affiliation(s)
- Simon Mead
- Medical Research Council Prion Unit at UCL, Institute of Prion Diseases, University College London, London W1W 7FF, United Kingdom;
| | - Sarah Lloyd
- Medical Research Council Prion Unit at UCL, Institute of Prion Diseases, University College London, London W1W 7FF, United Kingdom;
| | - John Collinge
- Medical Research Council Prion Unit at UCL, Institute of Prion Diseases, University College London, London W1W 7FF, United Kingdom;
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19
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Bouybayoune I, Comerio L, Pasetto L, Bertani I, Bonetto V, Chiesa R. Cyclophillin A deficiency accelerates RML-induced prion disease. Neurobiol Dis 2019; 130:104498. [PMID: 31181281 DOI: 10.1016/j.nbd.2019.104498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/14/2019] [Accepted: 06/05/2019] [Indexed: 01/17/2023] Open
Abstract
Prion diseases typically involve brain deposition of abnormally folded prion protein, which is associated with activated glia and increased cytokine production. Cyclophilin A (CypA) is a ubiquitous protein with peptidyl prolyl cis-trans isomerase activity, which regulates protein folding, and can be secreted by cells in response to inflammatory stimuli. On the basis of in vitro studies, CypA was proposed to mediate glial activation during prion infection. To investigate the role of CypA in vivo, we inoculated CypA+/+, CypA+/- and CypA-/- mice with the RML prion strain, and recorded the time to onset of neurological signs and to terminal disease, and the astrocyte and microglia response at presymptomatic and symptomatic stages. Time to onset of disease and survival were significantly shorter in CypA-deficient mice than CypA-expressing controls. CypA-deficient mice had significantly greater microglial activation in the presymptomatic stage, and analysis of anti- and pro-inflammatory microglial markers indicated a shift towards a pro-inflammatory phenotype. There was no difference in astrocyte activation. This suggests that CypA contributes to dampening the pro-inflammatory microglial response during the early stage of RML-induced prion disease.
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Affiliation(s)
- Ihssane Bouybayoune
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Liliana Comerio
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Laura Pasetto
- Department of Biochemistry and Molecular Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Ilaria Bertani
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Valentina Bonetto
- Department of Biochemistry and Molecular Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Roberto Chiesa
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy.
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20
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Yang XL, Wang X, Shao L, Jiang GT, Min JW, Mei XY, He XH, Liu WH, Huang WX, Peng BW. TRPV1 mediates astrocyte activation and interleukin-1β release induced by hypoxic ischemia (HI). J Neuroinflammation 2019; 16:114. [PMID: 31142341 PMCID: PMC6540554 DOI: 10.1186/s12974-019-1487-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/25/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Hypoxic-ischemic encephalopathy (HIE) is a serious birth complication with high incidence in both advanced and developing countries. Children surviving from HIE often have severe long-term sequela including cerebral palsy, epilepsy, and cognitive disabilities. The severity of HIE in infants is tightly associated with increased IL-1β expression and astrocyte activation which was regulated by transient receptor potential vanilloid 1 (TRPV1), a non-selective cation channel in the TRP family. METHODS Neonatal hypoxic ischemia (HI) and oxygen-glucose deprivation (OGD) were used to simulate HIE in vivo and in vitro. Primarily cultured astrocytes were used for investigating the expression of glial fibrillary acidic protein (GFAP), IL-1β, Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), and activation of the nucleotide-binding, oligomerization domain (NOD)-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome by using Western blot, q-PCR, and immunofluorescence. Brain atrophy, infarct size, and neurobehavioral disorders were evaluated by Nissl staining, 2,3,5-triphenyltetrazolium chloride monohydrate (TTC) staining and neurobehavioral tests (geotaxis reflex, cliff aversion reaction, and grip test) individually. RESULTS Astrocytes were overactivated after neonatal HI and OGD challenge. The number of activated astrocytes, the expression level of IL-1β, brain atrophy, and shrinking infarct size were all downregulated in TRPV1 KO mice. TRPV1 deficiency in astrocytes attenuated the expression of GFAP and IL-1β by reducing phosphorylation of JAK2 and STAT3. Meanwhile, IL-1β release was significantly reduced in TRPV1 deficiency astrocytes by inhibiting activation of NLRP3 inflammasome. Additionally, neonatal HI-induced neurobehavioral disorders were significantly improved in the TRPV1 KO mice. CONCLUSIONS TRPV1 promotes activation of astrocytes and release of astrocyte-derived IL-1β mainly via JAK2-STAT3 signaling and activation of the NLRP3 inflammasome. Our findings provide mechanistic insights into TRPV1-mediated brain damage and neurobehavioral disorders caused by neonatal HI and potentially identify astrocytic TRPV1 as a novel therapeutic target for treating HIE in the subacute stages (24 h).
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Affiliation(s)
- Xing-Liang Yang
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Donghu Rd185#, Wuhan, 430071, Hubei, China
| | - Xin Wang
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Donghu Rd185#, Wuhan, 430071, Hubei, China
| | - Lin Shao
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Donghu Rd185#, Wuhan, 430071, Hubei, China
| | - Guang-Tong Jiang
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Donghu Rd185#, Wuhan, 430071, Hubei, China
| | - Jia-Wei Min
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Donghu Rd185#, Wuhan, 430071, Hubei, China
| | - Xi-Yu Mei
- No.1 Middle School affiliated to Central China Normal University, Wuhan, China
| | - Xiao-Hua He
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Wan-Hong Liu
- Department of Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Wen-Xian Huang
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Donghu Rd185#, Wuhan, 430071, Hubei, China. .,Department of Pathology, Renmin Hospital of Wuhan University, Jiefang Rd238#, Wuhan, 430071, Hubei, China.
| | - Bi-Wen Peng
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Donghu Rd185#, Wuhan, 430071, Hubei, China.
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21
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Bertuzzi M, Hayes GE, Bignell EM. Microbial uptake by the respiratory epithelium: outcomes for host and pathogen. FEMS Microbiol Rev 2019; 43:145-161. [PMID: 30657899 PMCID: PMC6435450 DOI: 10.1093/femsre/fuy045] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 01/17/2019] [Indexed: 12/21/2022] Open
Abstract
Intracellular occupancy of the respiratory epithelium is a useful pathogenic strategy facilitating microbial replication and evasion of professional phagocytes or circulating antimicrobial drugs. A less appreciated but growing body of evidence indicates that the airway epithelium also plays a crucial role in host defence against inhaled pathogens, by promoting ingestion and quelling of microorganisms, processes that become subverted to favour pathogen activities and promote respiratory disease. To achieve a deeper understanding of beneficial and deleterious activities of respiratory epithelia during antimicrobial defence, we have comprehensively surveyed all current knowledge on airway epithelial uptake of bacterial and fungal pathogens. We find that microbial uptake by airway epithelial cells (AECs) is a common feature of respiratory host-microbe interactions whose stepwise execution, and impacts upon the host, vary by pathogen. Amidst the diversity of underlying mechanisms and disease outcomes, we identify four key infection scenarios and use best-characterised host-pathogen interactions as prototypical examples of each. The emergent view is one in which effi-ciency of AEC-mediated pathogen clearance correlates directly with severity of disease outcome, therefore highlighting an important unmet need to broaden our understanding of the antimicrobial properties of respiratory epithelia and associated drivers of pathogen entry and intracellular fate.
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Affiliation(s)
- Margherita Bertuzzi
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
- Lydia Becker Institute of Immunology and Inflammation, Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre
| | - Gemma E Hayes
- Northern Devon Healthcare NHS Trust, North Devon District Hospital, Raleigh Park, Barnstaple EX31 4JB, UK
| | - Elaine M Bignell
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
- Lydia Becker Institute of Immunology and Inflammation, Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre
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22
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Neuroinflammation, Microglia, and Cell-Association during Prion Disease. Viruses 2019; 11:v11010065. [PMID: 30650564 PMCID: PMC6356204 DOI: 10.3390/v11010065] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 01/09/2019] [Accepted: 01/10/2019] [Indexed: 02/06/2023] Open
Abstract
Prion disorders are transmissible diseases caused by a proteinaceous infectious agent that can infect the lymphatic and nervous systems. The clinical features of prion diseases can vary, but common hallmarks in the central nervous system (CNS) are deposition of abnormally folded protease-resistant prion protein (PrPres or PrPSc), astrogliosis, microgliosis, and neurodegeneration. Numerous proinflammatory effectors expressed by astrocytes and microglia are increased in the brain during prion infection, with many of them potentially damaging to neurons when chronically upregulated. Microglia are important first responders to foreign agents and damaged cells in the CNS, but these immune-like cells also serve many essential functions in the healthy CNS. Our current understanding is that microglia are beneficial during prion infection and critical to host defense against prion disease. Studies indicate that reduction of the microglial population accelerates disease and increases PrPSc burden in the CNS. Thus, microglia are unlikely to be a foci of prion propagation in the brain. In contrast, neurons and astrocytes are known to be involved in prion replication and spread. Moreover, certain astrocytes, such as A1 reactive astrocytes, have proven neurotoxic in other neurodegenerative diseases, and thus might also influence the progression of prion-associated neurodegeneration.
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23
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Alibhai JD, Diack AB, Manson JC. Unravelling the glial response in the pathogenesis of Alzheimer's disease. FASEB J 2018; 32:5766-5777. [PMID: 30376380 DOI: 10.1096/fj.201801360r] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease is a progressive, incurable neurodegenerative disease targeting specific neuronal populations within the brain while neighboring neurons appear unaffected. The focus for defining mechanisms has therefore been on the pathogenesis in affected neuronal populations and developing intervention strategies to prevent their cell death. However, there is growing recognition of the importance of glial cells in the development of pathology. Determining exactly how glial cells are involved in the disease process and the susceptibility of the aging brain provides unprecedented challenges. The present review examines recent studies attempting to unravel the glial response during the course of disease and how this action may dictate the outcome of neurodegeneration. The importance of regional heterogeneity of glial cells within the CNS during healthy aging and disease is examined to understand how the glial cells may contribute to neuronal susceptibility or resilience during the neurodegenerative process.-Alibhai, J. D., Diack, A. B., Manson, J. C. Unravelling the glial response in the pathogenesis of Alzheimer's disease.
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Affiliation(s)
- James D Alibhai
- National Creutzfeldt-Jakob Disease (CJD) Research and Surveillance Unit, University of Edinburgh, Edinburgh, United Kingdom.,UK Dementia Research Institute, University of Edinburgh, Edinburgh, United Kingdom; and
| | - Abigail B Diack
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, United Kingdom
| | - Jean C Manson
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
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24
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25
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Alibhai J, Diack A, Manson J. Disease-associated protein seeding suggests a dissociation between misfolded protein accumulation and neurodegeneration in prion disease. Prion 2017; 11:381-387. [PMID: 29023184 PMCID: PMC5786362 DOI: 10.1080/19336896.2017.1378289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Chronic neurodegenerative diseases, such as prion diseases or Alzheimer's disease, are associated with progressive accumulation of host proteins which misfold and aggregate. Neurodegeneration is restricted to specific neuronal populations which show clear accumulation of misfolded proteins, whilst neighbouring neurons remain unaffected. Such data raise interesting questions about the vulnerability of specific neuronal populations to neurodegeneration and much research has concentrated only on the mechanisms of neurodegeneration in afflicted neuronal populations. An alternative, undervalued and almost completely unstudied question however is how and why neuronal populations are resilient to neurodegeneration. One potential answer is unaffected regions do not accumulate misfolded proteins, thus mechanisms of neurodegeneration do not become activated. In this perspectives, we discuss novel data from our laboratories which demonstrate that misfolded proteins do accumulate in regions of the brain which do not show evidence of neurodegeneration and further evidence that microglial responses may define the severity of neurodegeneration.
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Affiliation(s)
- James Alibhai
- The National CJD Research and Surveillance Unit, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Abigail Diack
- Neurobiology Division, The Roslin Institute, University of Edinburgh, Easter Bush, UK
| | - Jean Manson
- Neurobiology Division, The Roslin Institute, University of Edinburgh, Easter Bush, UK,Correspondence to: Jean Manson; The Roslin Institute, University of Edinburgh, Easter Bush, UK, EH25 9RG;
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26
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Inhibition of IL-1β Signaling Normalizes NMDA-Dependent Neurotransmission and Reduces Seizure Susceptibility in a Mouse Model of Creutzfeldt-Jakob Disease. J Neurosci 2017; 37:10278-10289. [PMID: 28924012 DOI: 10.1523/jneurosci.1301-17.2017] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/31/2017] [Accepted: 08/23/2017] [Indexed: 11/21/2022] Open
Abstract
Creutzfeldt-Jakob disease (CJD) is a neurodegenerative disorder caused by prion protein (PrP) misfolding, clinically recognized by cognitive and motor deficits, electroencephalographic abnormalities, and seizures. Its neurophysiological bases are not known. To assess the potential involvement of NMDA receptor (NMDAR) dysfunction, we analyzed NMDA-dependent synaptic plasticity in hippocampal slices from Tg(CJD) mice, which model a genetic form of CJD. Because PrP depletion may result in functional upregulation of NMDARs, we also analyzed PrP knock-out (KO) mice. Long-term potentiation (LTP) at the Schaffer collateral-commissural synapses in the CA1 area of ∼100-d-old Tg(CJD) mice was comparable to that of wild-type (WT) controls, but there was an inversion of metaplasticity, with increased GluN2B phosphorylation, which is indicative of enhanced NMDAR activation. Similar but less marked changes were seen in PrP KO mice. At ∼300 d of age, the magnitude of LTP increased in Tg(CJD) mice but decreased in PrP KO mice, indicating divergent changes in hippocampal synaptic responsiveness. Tg(CJD) but not PrP KO mice were intrinsically more susceptible than WT controls to focal hippocampal seizures induced by kainic acid. IL-1β-positive astrocytes increased in the Tg(CJD) hippocampus, and blocking IL-1 receptor signaling restored normal synaptic responses and reduced seizure susceptibility. These results indicate that alterations in NMDA-dependent glutamatergic transmission in Tg(CJD) mice do not depend solely on PrP functional loss. Moreover, astrocytic IL-1β plays a role in the enhanced synaptic responsiveness and seizure susceptibility, suggesting that targeting IL-1β signaling may offer a novel symptomatic treatment for CJD.SIGNIFICANCE STATEMENT Dementia and myoclonic jerks develop in individuals with Creutzfeldt-Jakob disease (CJD), an incurable brain disorder caused by alterations in prion protein structure. These individuals are prone to seizures and have high brain levels of the inflammatory cytokine IL-1β. Here we show that blocking IL-1β receptors with anakinra, the human recombinant form of the endogenous IL-1 receptor antagonist used to treat rheumatoid arthritis, normalizes hippocampal neurotransmission and reduces seizure susceptibility in a CJD mouse model. These results link neuroinflammation to defective neurotransmission and the enhanced susceptibility to seizures in CJD and raise the possibility that targeting IL-1β with clinically available drugs may be beneficial for symptomatic treatment of the disease.
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Abstract
Prion diseases are a group of progressive and fatal neurodegenerative disorders characterized by deposition of scrapie prion protein (PrPSc) in the CNS. This deposition is accompanied by neuronal loss, spongiform change, astrogliosis, and conspicuous microglial activation. Here, we argue that microglia play an overall neuroprotective role in prion pathogenesis. Several microglia-related molecules, such as Toll-like receptors (TLRs), the complement system, cytokines, chemokines, inflammatory regulators, and phagocytosis mediators, are involved in prion pathogenesis. However, the molecular mechanisms underlying the microglial response to prion infection are largely unknown. Consequently, we lack a comprehensive understanding of the regulatory network of microglial activation. On the positive side, recent findings suggest that therapeutic strategies modulating microglial activation and function may have merit in prion disease. Moreover, studies on the role of microglia in prion disease could deepen our understanding of neuroinflammation in a broad range of neurodegenerative disorders.
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Obst J, Simon E, Mancuso R, Gomez-Nicola D. The Role of Microglia in Prion Diseases: A Paradigm of Functional Diversity. Front Aging Neurosci 2017; 9:207. [PMID: 28690540 PMCID: PMC5481309 DOI: 10.3389/fnagi.2017.00207] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 06/09/2017] [Indexed: 12/26/2022] Open
Abstract
Inflammation is a major component of neurodegenerative diseases. Microglia are the innate immune cells in the central nervous system (CNS). In the healthy brain, microglia contribute to tissue homeostasis and regulation of synaptic plasticity. Under disease conditions, they play a key role in the development and maintenance of the neuroinflammatory response, by showing enhanced proliferation and activation. Prion diseases are progressive chronic neurodegenerative disorders associated with the accumulation of the scrapie prion protein PrPSc, a misfolded conformer of the cellular prion protein PrPC. This review article provides the current knowledge on the role of microglia in the pathogenesis of prion disease. A large body of evidence shows that microglia can trigger neurotoxic pathways contributing to progressive degeneration. Yet, microglia are also crucial for controlling inflammatory, repair and regenerative processes. This dual role of microglia is regulated by multiple pathways and evidences the ability of these cells to polarize into distinct phenotypes with characteristic functions. The awareness that the neuroinflammatory response is inextricably involved in producing tissue damage as well as repair in neurodegenerative disorders, opens new perspectives for the modulation of the immune system. A better understanding of this complex process will be essential for developing effective therapies for neurodegenerative diseases, in order to improve the quality of life of patients and mitigating the personal, economic and social consequences derived from these diseases.
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Affiliation(s)
- Juliane Obst
- Biological Sciences, University of Southampton, Southampton General HospitalSouthampton, United Kingdom
| | - Emilie Simon
- Biological Sciences, University of Southampton, Southampton General HospitalSouthampton, United Kingdom
| | - Renzo Mancuso
- Biological Sciences, University of Southampton, Southampton General HospitalSouthampton, United Kingdom
| | - Diego Gomez-Nicola
- Biological Sciences, University of Southampton, Southampton General HospitalSouthampton, United Kingdom
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Newaz K, Sriram K, Bera D. Identification of Major Signaling Pathways in Prion Disease Progression Using Network Analysis. PLoS One 2015; 10:e0144389. [PMID: 26646948 PMCID: PMC4672924 DOI: 10.1371/journal.pone.0144389] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/17/2015] [Indexed: 12/27/2022] Open
Abstract
Prion diseases are transmissible neurodegenerative diseases that arise due to conformational change of normal, cellular prion protein (PrPC) to protease-resistant isofrom (rPrPSc). Deposition of misfolded PrpSc proteins leads to an alteration of many signaling pathways that includes immunological and apoptotic pathways. As a result, this culminates in the dysfunction and death of neuronal cells. Earlier works on transcriptomic studies have revealed some affected pathways, but it is not clear which is (are) the prime network pathway(s) that change during the disease progression and how these pathways are involved in crosstalks with each other from the time of incubation to clinical death. We perform network analysis on large-scale transcriptomic data of differentially expressed genes obtained from whole brain in six different mouse strain-prion strain combination models to determine the pathways involved in prion diseases, and to understand the role of crosstalks in disease propagation. We employ a notion of differential network centrality measures on protein interaction networks to identify the potential biological pathways involved. We also propose a crosstalk ranking method based on dynamic protein interaction networks to identify the core network elements involved in crosstalk with different pathways. We identify 148 DEGs (differentially expressed genes) potentially related to the prion disease progression. Functional association of the identified genes implicates a strong involvement of immunological pathways. We extract a bow-tie structure that is potentially dysregulated in prion disease. We also propose an ODE model for the bow-tie network. Predictions related to diseased condition suggests the downregulation of the core signaling elements (PI3Ks and AKTs) of the bow-tie network. In this work, we show using transcriptomic data that the neuronal dysfunction in prion disease is strongly related to the immunological pathways. We conclude that these immunological pathways occupy influential positions in the PFNs (protein functional networks) that are related to prion disease. Importantly, this functional network involvement is prevalent in all the five different mouse strain-prion strain combinations that we studied. We also conclude that the dysregulation of the core elements of the bow-tie structure, which belongs to PI3K-Akt signaling pathway, leads to dysregulation of the downstream components corresponding to other biological pathways.
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Affiliation(s)
- Khalique Newaz
- Department of Computer Science, IIIT Delhi, New Delhi, India
| | - K. Sriram
- Center for Computational Biology, IIIT Delhi, New Delhi, India
| | - Debajyoti Bera
- Department of Computer Science, IIIT Delhi, New Delhi, India
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Tian A, Ma H, Zhang R, Tan W, Wang X, Wu B, Wang J, Wan C. Interleukin17A Promotes Postoperative Cognitive Dysfunction by Triggering β-Amyloid Accumulation via the Transforming Growth Factor-β (TGFβ)/Smad Signaling Pathway. PLoS One 2015; 10:e0141596. [PMID: 26509545 PMCID: PMC4624903 DOI: 10.1371/journal.pone.0141596] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Accepted: 10/09/2015] [Indexed: 02/05/2023] Open
Abstract
Although postoperative cognitive dysfunction (POCD) is relatively common in elderly patients who have undergone major surgery, the mechanisms underlying this postoperative complication are unclear. Previously, we have investigated the role of cytokine-mediated hippocampal inflammation in the development of POCD in a rat model. Here, we sought to determine in mice the role of cytokine interleukin17A (IL17A) in POCD and to characterize the associated signaling pathways. Old mice underwent hepatectomy surgery in the presence or absence of IL17A monoclonal antibody, and cognitive function, hippocampal neuroinflammation, and pathologic markers of Alzheimer’s disease (AD) were assessed. We found that the level of IL17A in the hippocampus was increased in hepatectomy mice and that cognitive impairment after surgery was associated with the appearance of certain pathological hallmarks of AD: activation of astrocytes, β-amyloid1-42 (Aβ1–42) production, upregulation of transforming growth factor-β (TGFβ), and increased phosphorylation of signaling mother against decapentaplegic peptide 3 (Smad3) protein in the hippocampus. Surgery-induced changes in cognitive dysfunction and changes in Aβ1–42 and TGFβ/Smad signaling were prevented by the administration of IL17A monoclonal antibody. In addition, IL17A-stimulated TGFβ/Smad activation and Aβ1–42 expression were reversed by IL17A receptor small interfering RNA and a TGFβ receptor inhibitor in cultured astrocytes. Our findings suggest that surgery can provoke IL17A-related hippocampal damage, as characterized by activation of astrocytes and TGFβ/Smad pathway dependent Aβ1–42 accumulation in old subjects. These changes likely contribute to the cognitive decline seen in POCD.
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Affiliation(s)
- Ayong Tian
- Department of Anesthesiology, the first Affiliated Hospital of China Medical University, Nanjing North Street 155, Shenyang, Liaoning, China
| | - Hong Ma
- Department of Anesthesiology, the first Affiliated Hospital of China Medical University, Nanjing North Street 155, Shenyang, Liaoning, China
- * E-mail:
| | - Rongwei Zhang
- Department of Gerontology and Geriatrics, the first Affiliated Hospital of China Medical University, Nanjing North Street 155, Shenyang, Liaoning, China
| | - Wenfei Tan
- Department of Anesthesiology, the first Affiliated Hospital of China Medical University, Nanjing North Street 155, Shenyang, Liaoning, China
| | - Xiaolong Wang
- Department of Anesthesiology, the first Affiliated Hospital of China Medical University, Nanjing North Street 155, Shenyang, Liaoning, China
| | - Binyang Wu
- Department of Anesthesiology, the first Affiliated Hospital of China Medical University, Nanjing North Street 155, Shenyang, Liaoning, China
| | - Jun Wang
- Department of Neurology, the first Affiliated Hospital of China Medical University, Nanjing North Street 155, Shenyang, Liaoning, China
| | - Chengfu Wan
- Department of Pain Medicine, the first Affiliated Hospital of China Medical University, Nanjing North Street 155, Shenyang, Liaoning, China
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Soto C, Satani N. The intricate mechanisms of neurodegeneration in prion diseases. Trends Mol Med 2015; 17:14-24. [PMID: 20889378 DOI: 10.1016/j.molmed.2010.09.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 08/27/2010] [Accepted: 09/01/2010] [Indexed: 12/20/2022]
Abstract
Prion diseases are a group of infectious neurodegenerative diseases with an entirely novel mechanism of transmission, involving a protein-only infectious agent that propagates the disease by transmitting protein conformational changes. The disease results from extensive and progressive brain degeneration. The molecular mechanisms involved in neurodegeneration are not entirely known but involve multiple processes operating simultaneously and synergistically in the brain, including spongiform degeneration, synaptic alterations, brain inflammation, neuronal death and the accumulation of protein aggregates. Here, we review the pathways implicated in prion-induced brain damage and put the pieces together into a possible model of neurodegeneration in prion disorders. A more comprehensive understanding of the molecular basis of brain degeneration is essential to develop a much needed therapy for these devastating diseases.
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Affiliation(s)
- Claudio Soto
- Mitchell Center for Alzheimer's disease and related Brain disorders, Department of Neurology, University of Texas Houston Medical School, 6431 Fannin St, Houston, TX 77030, USA
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Nuvolone M, Sorce S, Schwarz P, Aguzzi A. Prion pathogenesis in the absence of NLRP3/ASC inflammasomes. PLoS One 2015; 10:e0117208. [PMID: 25671600 PMCID: PMC4324825 DOI: 10.1371/journal.pone.0117208] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 12/19/2014] [Indexed: 12/31/2022] Open
Abstract
The accumulation of the scrapie prion protein PrPSc, a misfolded conformer of the cellular prion protein PrPC, is a crucial feature of prion diseases. In the central nervous system, this process is accompanied by conspicuous microglia activation. The NLRP3 inflammasome is a multi-molecular complex which can sense heterogeneous pathogen-associated molecular patterns and culminates in the activation of caspase 1 and release of IL 1β. The NLRP3 inflammasome was reported to be essential for IL 1β release after in vitro exposure to the amyloidogenic peptide PrP106-126 and to recombinant PrP fibrils. We therefore studied the role of the NLRP3 inflammasome in a mouse model of prion infection. Upon intracerebral inoculation with scrapie prions (strain RML), mice lacking NLRP3 (Nlrp3-/-) or the inflammasome adaptor protein ASC (Pycard-/-) succumbed to scrapie with attack rates and incubation times similar to wild-type mice, and developed the classic histologic and biochemical features of prion diseases. Genetic ablation of NLRP3 or ASC did not significantly impact on brain levels of IL 1β at the terminal stage of disease. Our results exclude a significant role for NLRP3 and ASC in prion pathogenesis and invalidate their claimed potential as therapeutic target against prion diseases.
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Affiliation(s)
- Mario Nuvolone
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
- * E-mail: (AA); (MN)
| | - Silvia Sorce
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
| | - Petra Schwarz
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
| | - Adriano Aguzzi
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
- * E-mail: (AA); (MN)
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Prion infection of mouse brain reveals multiple new upregulated genes involved in neuroinflammation or signal transduction. J Virol 2014; 89:2388-404. [PMID: 25505076 DOI: 10.1128/jvi.02952-14] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
UNLABELLED Gliosis is often a preclinical pathological finding in neurodegenerative diseases, including prion diseases, but the mechanisms facilitating gliosis and neuronal damage in these diseases are not understood. To expand our knowledge of the neuroinflammatory response in prion diseases, we assessed the expression of key genes and proteins involved in the inflammatory response and signal transduction in mouse brain at various times after scrapie infection. In brains of scrapie-infected mice at pre- and postclinical stages, we identified 15 previously unreported differentially expressed genes related to inflammation or activation of the STAT signal transduction pathway. Levels for the majority of differentially expressed genes increased with time postinfection. In quantitative immunoblotting experiments of STAT proteins, STAT1α, phosphorylated-STAT1α (pSTAT1α), and pSTAT3 were increased between 94 and 131 days postinfection (p.i.) in brains of mice infected with strain 22L. Furthermore, a select group of STAT-associated genes was increased preclinically during scrapie infection, suggesting early activation of the STAT signal transduction pathway. Comparison of inflammatory markers between mice infected with scrapie strains 22L and RML indicated that the inflammatory responses and gene expression profiles in the brains were strikingly similar, even though these scrapie strains infect different brain regions. The endogenous interleukin-1 receptor antagonist (IL-1Ra), an inflammatory marker, was newly identified as increasing preclinically in our model and therefore might influence scrapie pathogenesis in vivo. However, in IL-1Ra-deficient or overexpressor transgenic mice inoculated with scrapie, neither loss nor overexpression of IL-1Ra demonstrated any observable effect on gliosis, protease-resistant prion protein (PrPres) formation, disease tempo, pathology, or expression of the inflammatory genes analyzed. IMPORTANCE Prion infection leads to PrPres deposition, gliosis, and neuroinflammation in the central nervous system before signs of clinical illness. Using a scrapie mouse model of prion disease to assess various time points postinoculation, we identified 15 unreported genes that were increased in the brains of scrapie-infected mice and were associated with inflammation and/or JAK-STAT activation. Comparison of mice infected with two scrapie strains (22L and RML), which have dissimilar neuropathologies, indicated that the inflammatory responses and gene expression profiles in the brains were similar. Genes that increased prior to clinical signs might be involved in controlling scrapie infection or in facilitating damage to host tissues. We tested the possible role of the endogenous IL-1Ra, which was increased at 70 days p.i. In scrapie-infected mice deficient in or overexpressing IL-1Ra, there was no observable effect on gliosis, PrPres formation, disease tempo, pathology, or expression of inflammatory genes analyzed.
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Llorens F, López-González I, Thüne K, Carmona M, Zafar S, Andréoletti O, Zerr I, Ferrer I. Subtype and regional-specific neuroinflammation in sporadic creutzfeldt-jakob disease. Front Aging Neurosci 2014; 6:198. [PMID: 25136317 PMCID: PMC4120692 DOI: 10.3389/fnagi.2014.00198] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Accepted: 07/19/2014] [Indexed: 11/13/2022] Open
Abstract
The present study identifies deregulated cytokines and mediators of the immune response in the frontal cortex and cerebellum of sporadic Creutzfeldt-Jakob disease (sCJD) MM1 and VV2 subtypes compared to age-matched controls. Deregulated genes include pro- and anti-inflammatory cytokines, toll-like receptors, colony stimulating factors, cathepsins, members of the complement system, and members of the integrin and CTL/CTLD family with particular regional and sCJD subtype patterns. Analysis of cytokines and mediators at protein level shows expression of selected molecules and receptors in neurons, in astrocytes, and/or in microglia, thus suggesting interactions between neurons and glial cells, mainly microglia, in the neuroinflammatory response in sCJD. Similar inflammatory responses have been shown in the tg340 sCJD MM1 mice, revealing a progressive deregulation of inflammatory mediators with disease progression. Yet, inflammatory molecules involved are subjected to species differences in humans and mice. Moreover, inflammatory-related cell signaling pathways NFκB/IKK and JAK/STAT are activated in sCJD and sCJD MM1 mice. Together, the present observations show a self-sustained complex inflammatory and inflammatory-related responses occurring already at early clinical stages in animal model and dramatically progressing at advanced stages of sCJD. Considering this scenario, measures tailored to modulate (activate or inhibit) specific molecules could be therapeutic options in CJD.
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Affiliation(s)
- Franc Llorens
- Department of Neurology, Clinical Dementia Center and DZNE, University Medical School, Georg-August University , Göttingen , Germany ; Institute of Neuropathology, IDIBELL-University Hospital Bellvitge, University of Barcelona, Hospitalet de Llobregat , Barcelona , Spain
| | - Irene López-González
- Institute of Neuropathology, IDIBELL-University Hospital Bellvitge, University of Barcelona, Hospitalet de Llobregat , Barcelona , Spain
| | - Katrin Thüne
- Department of Neurology, Clinical Dementia Center and DZNE, University Medical School, Georg-August University , Göttingen , Germany
| | - Margarita Carmona
- Institute of Neuropathology, IDIBELL-University Hospital Bellvitge, University of Barcelona, Hospitalet de Llobregat , Barcelona , Spain ; Network Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Institute Carlos III, Ministry of Health , Madrid , Spain
| | - Saima Zafar
- Department of Neurology, Clinical Dementia Center and DZNE, University Medical School, Georg-August University , Göttingen , Germany
| | - Olivier Andréoletti
- Ecole Nationale Vétérinaire de Toulouse, Institut National de la Recherche Agronomique , Toulouse , France
| | - Inga Zerr
- Department of Neurology, Clinical Dementia Center and DZNE, University Medical School, Georg-August University , Göttingen , Germany
| | - Isidre Ferrer
- Institute of Neuropathology, IDIBELL-University Hospital Bellvitge, University of Barcelona, Hospitalet de Llobregat , Barcelona , Spain ; Network Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Institute Carlos III, Ministry of Health , Madrid , Spain
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Asuni AA, Gray B, Bailey J, Skipp P, Perry VH, O'Connor V. Analysis of the hippocampal proteome in ME7 prion disease reveals a predominant astrocytic signature and highlights the brain-restricted production of clusterin in chronic neurodegeneration. J Biol Chem 2013; 289:4532-45. [PMID: 24366862 PMCID: PMC3924314 DOI: 10.1074/jbc.m113.502690] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Prion diseases are characterized by accumulation of misfolded protein, gliosis, synaptic dysfunction, and ultimately neuronal loss. This sequence, mirroring key features of Alzheimer disease, is modeled well in ME7 prion disease. We used iTRAQTM/mass spectrometry to compare the hippocampal proteome in control and late-stage ME7 animals. The observed changes associated with reactive glia highlighted some specific proteins that dominate the proteome in late-stage disease. Four of the up-regulated proteins (GFAP, high affinity glutamate transporter (EAAT-2), apo-J (Clusterin), and peroxiredoxin-6) are selectively expressed in astrocytes, but astrocyte proliferation does not contribute to their up-regulation. The known functional role of these proteins suggests this response acts against protein misfolding, excitotoxicity, and neurotoxic reactive oxygen species. A recent convergence of genome-wide association studies and the peripheral measurement of circulating levels of acute phase proteins have focused attention on Clusterin as a modifier of late-stage Alzheimer disease and a biomarker for advanced neurodegeneration. Since ME7 animals allow independent measurement of acute phase proteins in the brain and circulation, we extended our investigation to address whether changes in the brain proteome are detectable in blood. We found no difference in the circulating levels of Clusterin in late-stage prion disease when animals will show behavioral decline, accumulation of misfolded protein, and dramatic synaptic and neuronal loss. This does not preclude an important role of Clusterin in late-stage disease, but it cautions against the assumption that brain levels provide a surrogate peripheral measure for the progression of brain degeneration.
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Abstract
Individuals infected with prions succumb to brain damage, and prion infections continue to be inexorably lethal. However, many crucial steps in prion pathogenesis occur in lymphatic organs and precede invasion of the central nervous system. In the past two decades, a great deal has been learnt concerning the cellular and molecular mechanisms of prion lymphoinvasion. These properties are diagnostically useful and have, for example, facilitated preclinical diagnosis of variant Creutzfeldt-Jakob disease in the tonsils. Moreover, the early colonization of lymphoid organs can be exploited for post-exposure prophylaxis of prion infections. As stromal cells of lymphoid organs are crucial for peripheral prion infection, the dedifferentiation of these cells offers a powerful means of hindering prion spread in infected individuals. In this Review, we discuss the current knowledge of the immunobiology of prions with an emphasis on how basic discoveries might enable translational strategies.
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Absence of CD14 delays progression of prion diseases accompanied by increased microglial activation. J Virol 2013; 87:13433-45. [PMID: 24089559 DOI: 10.1128/jvi.02072-13] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Prion diseases are fatal neurodegenerative disorders characterized by accumulation of PrP(Sc), vacuolation of neurons and neuropil, astrocytosis, and microglial activation. Upregulation of gene expressions of innate immunity-related factors, including complement factors and CD14, is observed in the brains of mice infected with prions even in the early stage of infections. When CD14 knockout (CD14(-/-)) mice were infected intracerebrally with the Chandler and Obihiro prion strains, the mice survived longer than wild-type (WT) mice, suggesting that CD14 influences the progression of the prion disease. Immunofluorescence staining that can distinguish normal prion protein from the disease-specific form of prion protein (PrP(Sc)) revealed that deposition of PrP(Sc) was delayed in CD14(-/-) mice compared with WT mice by the middle stage of the infection. Immunohistochemical staining with Iba1, a marker for activated microglia, showed an increased microglial activation in prion-infected CD14(-/-) mice compared to WT mice. Interestingly, accompanied by the increased microglial activation, anti-inflammatory cytokines interleukin-10 (IL-10) and transforming growth factor β (TGF-β) appeared to be expressed earlier in prion-infected CD14(-/-) mice. In contrast, IL-1β expression appeared to be reduced in the CD14(-/-) mice in the early stage of infection. Double immunofluorescence staining demonstrated that CD11b- and Iba1-positive microglia mainly produced the anti-inflammatory cytokines, suggesting anti-inflammatory status of microglia in the CD14(-/-) mice in the early stage of infection. These results imply that CD14 plays a role in the disease progression by suppressing anti-inflammatory responses in the brain in the early stage of infection.
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Sod1 deficiency reduces incubation time in mouse models of prion disease. PLoS One 2013; 8:e54454. [PMID: 23349894 PMCID: PMC3551847 DOI: 10.1371/journal.pone.0054454] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 12/11/2012] [Indexed: 11/19/2022] Open
Abstract
Prion infections, causing neurodegenerative conditions such as Creutzfeldt-Jakob disease and kuru in humans, scrapie in sheep and BSE in cattle are characterised by prolonged and variable incubation periods that are faithfully reproduced in mouse models. Incubation time is partly determined by genetic factors including polymorphisms in the prion protein gene. Quantitative trait loci studies in mice and human genome-wide association studies have confirmed that multiple genes are involved. Candidate gene approaches have also been used and identified App, Il1-r1 and Sod1 as affecting incubation times. In this study we looked for an association between App, Il1-r1 and Sod1 representative SNPs and prion disease incubation time in the Northport heterogeneous stock of mice inoculated with the Chandler/RML prion strain. No association was seen with App, however, significant associations were seen with Il1-r1 (P = 0.02) and Sod1 (P<0.0001) suggesting that polymorphisms at these loci contribute to the natural variation observed in incubation time. Furthermore, following challenge with Chandler/RML, ME7 and MRC2 prion strains, Sod1 deficient mice showed highly significant reductions in incubation time of 20, 13 and 24%, respectively. No differences were detected in Sod1 expression or activity. Our data confirm the protective role of endogenous Sod1 in prion disease.
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Prion propagation and toxicity occur in vitro with two-phase kinetics specific to strain and neuronal type. J Virol 2012; 87:2535-48. [PMID: 23255799 DOI: 10.1128/jvi.03082-12] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Prion diseases, or transmissible spongiform encephalopathies (TSEs), are fatal neurodegenerative disorders that occur in humans and animals. The neuropathological hallmarks of TSEs are spongiosis, glial proliferation, and neuronal loss. The only known specific molecular marker of TSEs is the abnormal isoform (PrP(Sc)) of the host-encoded prion protein (PrP(C)), which accumulates in the brain of infected subjects and forms infectious prion particles. Although this transmissible agent lacks a specific nucleic acid component, several prion strains have been isolated. Prion strains are characterized by differences in disease outcome, PrP(Sc) distribution patterns, and brain lesion profiles at the terminal stage of the disease. The molecular factors and cellular mechanisms involved in strain-specific neuronal tropism and toxicity remain largely unknown. Currently, no cellular model exists to facilitate in vitro studies of these processes. A few cultured cell lines that maintain persistent scrapie infections have been developed, but only two of them have shown the cytotoxic effects associated with prion propagation. In this study, we have developed primary neuronal cultures to assess in vitro neuronal tropism and toxicity of different prion strains (scrapie strains 139A, ME7, and 22L). We have tested primary neuronal cultures enriched in cerebellar granular, striatal, or cortical neurons. Our results showed that (i) a strain-specific neuronal tropism operated in vitro; (ii) the cytotoxic effect varied among strains and neuronal cell types; (iii) prion propagation and toxicity occurred in two kinetic phases, a replicative phase followed by a toxic phase; and (iv) neurotoxicity peaked when abnormal PrP accumulation reached a plateau.
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Bradford BM, Mabbott NA. Prion disease and the innate immune system. Viruses 2012; 4:3389-419. [PMID: 23342365 PMCID: PMC3528271 DOI: 10.3390/v4123389] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Revised: 11/14/2012] [Accepted: 11/22/2012] [Indexed: 02/06/2023] Open
Abstract
Prion diseases or transmissible spongiform encephalopathies are a unique category of infectious protein-misfolding neurodegenerative disorders. Hypothesized to be caused by misfolding of the cellular prion protein these disorders possess an infectious quality that thrives in immune-competent hosts. While much has been discovered about the routing and critical components involved in the peripheral pathogenesis of these agents there are still many aspects to be discovered. Research into this area has been extensive as it represents a major target for therapeutic intervention within this group of diseases. The main focus of pathological damage in these diseases occurs within the central nervous system. Cells of the innate immune system have been proven to be critical players in the initial pathogenesis of prion disease, and may have a role in the pathological progression of disease. Understanding how prions interact with the host innate immune system may provide us with natural pathways and mechanisms to combat these diseases prior to their neuroinvasive stage. We present here a review of the current knowledge regarding the role of the innate immune system in prion pathogenesis.
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Affiliation(s)
- Barry M Bradford
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK.
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Matsumoto T, Samuel MD, Bollinger T, Pybus M, Coltman DW. Association mapping of genetic risk factors for chronic wasting disease in wild deer. Evol Appl 2012; 6:340-52. [PMID: 23467626 PMCID: PMC3586622 DOI: 10.1111/eva.12003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 07/11/2012] [Indexed: 01/06/2023] Open
Abstract
Chronic wasting disease (CWD) is a fatal transmissible spongiform encephalopathy affecting North American cervids. We assessed the feasibility of association mapping CWD genetic risk factors in wild white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) using a panel of bovine microsatellite markers from three homologous deer linkage groups predicted to contain candidate genes. These markers had a low cross-species amplification rate (27.9%) and showed weak linkage disequilibrium (<1 cM). Markers near the prion protein and the neurofibromin 1 (NF1) genes were suggestively associated with CWD status in white-tailed deer (P = 0.006) and mule deer (P = 0.02), respectively. This is the first time an association between the NF1 region and CWD has been reported.
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Affiliation(s)
- Tomomi Matsumoto
- Department of Biological Sciences, University of Alberta Edmonton, AB, Canada
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Hafner-Bratkovič I, Benčina M, Fitzgerald KA, Golenbock D, Jerala R. NLRP3 inflammasome activation in macrophage cell lines by prion protein fibrils as the source of IL-1β and neuronal toxicity. Cell Mol Life Sci 2012; 69:4215-28. [PMID: 22926439 DOI: 10.1007/s00018-012-1140-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 08/01/2012] [Accepted: 08/13/2012] [Indexed: 12/12/2022]
Abstract
Prion diseases are fatal transmissible neurodegenerative diseases, characterized by aggregation of the pathological form of prion protein, spongiform degeneration, and neuronal loss, and activation of astrocytes and microglia. Microglia can clear prion plaques, but on the other hand cause neuronal death via release of neurotoxic species. Elevated expression of the proinflammatory cytokine IL-1β has been observed in brains affected by several prion diseases, and IL-1R-deficiency significantly prolonged the onset of the neurodegeneration in mice. We show that microglial cells stimulated by prion protein (PrP) fibrils induced neuronal toxicity. Microglia and macrophages release IL-1β upon stimulation by PrP fibrils, which depends on the NLRP3 inflammasome. Activation of NLRP3 inflammasome by PrP fibrils requires depletion of intracellular K(+), and requires phagocytosis of PrP fibrils and consecutive lysosome destabilization. Among the well-defined molecular forms of PrP, the strongest NLRP3 activation was observed by fibrils, followed by aggregates, while neither native monomeric nor oligomeric PrP were able to activate the NLRP3 inflammasome. Our results together with previous studies on IL-1R-deficient mice suggest the IL-1 signaling pathway as the perspective target for the therapy of prion disease.
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Affiliation(s)
- Iva Hafner-Bratkovič
- Department of Biotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
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Early cytokine elevation, PrPres deposition, and gliosis in mouse scrapie: no effect on disease by deletion of cytokine genes IL-12p40 and IL-12p35. J Virol 2012; 86:10377-83. [PMID: 22787236 DOI: 10.1128/jvi.01340-12] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Neurodegenerative diseases are typically associated with an activation of glia and an increased level of cytokines. In our previous studies of prion disease, the cytokine response in the brains of clinically sick scrapie-infected mice was restricted to a small group of cytokines, of which IL-12p40, CCL2, and CXCL10 were present at the highest levels. The goal of our current research was to determine the relationship between cytokine responses, gliosis, and neuropathology during prion disease. Here, in time course studies of C57BL/10 mice intracerebrally inoculated with 22L scrapie, abnormal protease-resistant prion protein (PrPres), astrogliosis, and microgliosis were first detected at 40 days after intracerebral scrapie inoculation. In cytokine studies, IL-12p40 was first elevated by 60 days; CCL3, IL-1β, and CXCL1 were elevated by 80 days; and CCL2 and CCL5 were elevated by 115 days. IL-12p40 showed the most extensive increase throughout disease and was 30-fold above control levels at the terminal stage. Because of the early onset and dramatic elevation of IL-12p40 during scrapie, we investigated whether IL-12p40 contributed to the development of prion disease neuropathogenesis by using three different scrapie strains (22L, RML, 79A) to infect knockout mice in which the gene encoding IL-12p40 was deleted. We also studied knockout mice lacking IL-12p35, which combines with IL-12p40 to form active IL-12 heterodimers. In all instances, knockout mice did not differ from control mice in survival time, clinical tempo, or levels of spongiosis, gliosis, or PrPres in the brain. Thus, neither IL-12p40 nor IL-12p35 molecules were required for prion disease-associated neurodegeneration or neuroinflammation.
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Iwamaru Y, Takenouchi T, Murayama Y, Okada H, Imamura M, Shimizu Y, Hashimoto M, Mohri S, Yokoyama T, Kitani H. Anti-prion activity of Brilliant Blue G. PLoS One 2012; 7:e37896. [PMID: 22693582 PMCID: PMC3365075 DOI: 10.1371/journal.pone.0037896] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 04/30/2012] [Indexed: 12/11/2022] Open
Abstract
Background Prion diseases are fatal neurodegenerative disorders with no effective therapy currently available. Accumulating evidence has implicated over-activation of P2X7 ionotropic purinergic receptor (P2X7R) in the progression of neuronal loss in several neurodegenerative diseases. This has led to the speculation that simultaneous blockade of this receptor and prion replication can be an effective therapeutic strategy for prion diseases. We have focused on Brilliant Blue G (BBG), a well-known P2X7R antagonist, possessing a chemical structure expected to confer anti-prion activity and examined its inhibitory effect on the accumulation of pathogenic isoforms of prion protein (PrPres) in a cellular and a mouse model of prion disease in order to determine its therapeutic potential. Principal Findings BBG prevented PrPres accumulation in infected MG20 microglial and N2a neural cells at 50% inhibitory concentrations of 14.6 and 3.2 µM, respectively. Administration of BBG in vivo also reduced PrPres accumulation in the brains of mice with prion disease. However, it did not appear to alleviate the disease progression compared to the vehicle-treated controls, implying a complex role of P2X7R on the neuronal degeneration in prion diseases. Significance These results provide novel insights into the pathophysiology of prion diseases and have important implications for the treatment.
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Affiliation(s)
- Yoshifumi Iwamaru
- Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| | - Takato Takenouchi
- Animal Immune and Cell Biology Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Yuichi Murayama
- Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| | - Hiroyuki Okada
- Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| | - Morikazu Imamura
- Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| | - Yoshihisa Shimizu
- Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| | - Makoto Hashimoto
- Division of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, Japan
| | - Shirou Mohri
- Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| | - Takashi Yokoyama
- Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| | - Hiroshi Kitani
- Animal Immune and Cell Biology Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
- * E-mail:
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Lively S, Schlichter LC. Age-related comparisons of evolution of the inflammatory response after intracerebral hemorrhage in rats. Transl Stroke Res 2012; 3:132-46. [PMID: 22707991 PMCID: PMC3372776 DOI: 10.1007/s12975-012-0151-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 02/28/2012] [Accepted: 03/01/2012] [Indexed: 12/14/2022]
Abstract
In the hours to days after intracerebral hemorrhage (ICH), there is an inflammatory response within the brain characterized by the infiltration of peripheral neutrophils and macrophages and the activation of brain-resident microglia and astrocytes. Despite the strong correlation of aging and ICH incidence, and increasing information about cellular responses, little is known about the temporal- and age-related molecular responses of the brain after ICH. Here, we monitored a panel of 27 genes at 6 h and 1, 3, and 7 days after ICH was induced by injecting collagenase into the striatum of young adult and aged rats. Several molecules (CR3, TLR2, TLR4, IL-1β, TNFα, iNOS, IL-6) were selected to reflect the classical activation of innate immune cells (macrophages, microglia) and the potential to exacerbate inflammation and damage brain cells. Most of the others are associated with the resolution of innate inflammation, alternative pathways of macrophage/microglial activation, and the repair phase after acute injury (TGFβ, IL-1ra, IL-1r2, IL-4, IL-13, IL-4Rα, IL-13Rα1, IL-13Rα2, MRC1, ARG1, CD163, CCL22). In young animals, the up-regulation of 26 in 27 genes (not IL-4) was detected within the first week. Differences in timing or levels between young and aged animals were detected for 18 of 27 genes examined (TLR2, GFAP, IL-1β, IL-1ra, IL-1r2, iNOS, IL-6, TGFβ, MMP9, MMP12, IL-13, IL-4Rα, IL-13Rα1, IL-13Rα2, MRC1, ARG1, CD163, CCL22), with a generally less pronounced or delayed inflammatory response in the aged animals. Importantly, within this complex response to experimental ICH, the induction of pro-inflammatory, potentially harmful mediators often coincided with resolving and beneficial molecules.
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Cognitive decline following major surgery is associated with gliosis, β-amyloid accumulation, and τ phosphorylation in old mice. Crit Care Med 2010; 38:2190-8. [PMID: 20711073 DOI: 10.1097/ccm.0b013e3181f17bcb] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Elderly patients undergoing major surgery often develop cognitive dysfunction and the mechanism of this postoperative complication remains elusive. We sought to determine whether postoperative cognitive dysfunction in old mice is associated with the pathogenesis of Alzheimer's disease. DESIGN Prospective, randomized study. SETTING University teaching hospital-based research laboratory. SUBJECTS One-hundred and twenty C57BL/6 14-mo-old male mice (weighing 30-40 g). INTERVENTIONS Mice received intraperitoneal injections of either vehicle or Celastrol (a potent anti-inflammatory compound) for 3 days before undergoing sham surgery or partial hepatectomy, on the surgery day, and for a further 4 days after surgery. Cognitive function, hippocampal neuroinflammation, and pathologic markers of Alzheimer's disease were assessed 1 day after surgery day 1, 3, or 7. MEASUREMENTS AND MAIN RESULTS Cognitive impairment following surgery was associated with the appearance of certain pathologic hallmarks of Alzheimer's disease: microgliosis, astrogliosis, enhanced transcriptional and translational activity of β-amyloid precursor protein, β-amyloid production, and τ protein hyperphosphorylation in the hippocampus. Surgery-induced changes in cognitive dysfunction were prevented by the administration of Celastrol as were changes in β-amyloid and τ processing. CONCLUSIONS These data suggest that surgery can provoke astrogliosis, β-amyloid accumulation, and τ phosphorylation in old subjects, which is likely to be associated with the cognitive decline seen in postoperative cognitive dysfunction.
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Ammari M, Gamez C, Lecomte A, Sakly M, Abdelmelek H, De Seze R. GFAP expression in the rat brain following sub-chronic exposure to a 900 MHz electromagnetic field signal. Int J Radiat Biol 2010; 86:367-75. [PMID: 20397841 DOI: 10.3109/09553000903567946] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE The rapid development and expansion of mobile communications contributes to the general debate on the effects of electromagnetic fields emitted by mobile phones on the nervous system. This study aims at measuring the glial fibrillary acidic protein (GFAP) expression in 48 rat brains to evaluate reactive astrocytosis, three and 10 days after long-term head-only sub-chronic exposure to a 900 MHz electromagnetic field (EMF) signal, in male rats. METHODS Sprague-Dawley rats were exposed for 45 min/day at a brain-averaged specific absorption rate (SAR) = 1.5 W/kg or 15 min/day at a SAR = 6 W/kg for five days per week during an eight-week period. GFAP expression was measured by the immunocytochemistry method in the following rat brain areas: Prefrontal cortex, cerebellar cortex, dentate gyrus of the hippocampus, lateral globus pallidus of the striatum, and the caudate putamen. RESULTS Compared to the sham-treated rats, those exposed to the sub-chronic GSM (Global System for mobile communications) signal at 1.5 or 6 W/kg showed an increase in GFAP levels in the different brain areas, three and ten days after treatment. CONCLUSION Our results show that sub-chronic exposures to a 900 MHz EMF signal for two months could adversely affect rat brain (sign of a potential gliosis).
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Affiliation(s)
- Mohamed Ammari
- National Institute of Industrial Environment and Risk (INERIS), Parc technologique ALATA, Verneuil-en-Halatte, France.
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Loss of cerebellar granule neurons is associated with punctate but not with large focal deposits of prion protein in Creutzfeldt-Jakob disease. J Neuropathol Exp Neurol 2009; 68:892-901. [PMID: 19606064 DOI: 10.1097/nen.0b013e3181af7f23] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Whether aggregates of prion protein (PrP) reflect neurotoxicity or are neuroprotective in prion diseases is unclear. To address this question, we performed a clinicopathologic study of cerebellar granular neurons in 100 patients affected with sporadic Creutzfeldt-Jakob disease (CJD). There was significant loss of these neurons in the subset of cases with Val/Val genotype at PRNP Codon 129 and Molecular Isotype 2 of abnormal PrP (sporadic CJD-VV2) (n=32) compared with both the other CJD subtypes and to controls. Pathological PrP deposits of the punctate-type (synaptic-type) in this subgroup correlated with neuronal loss and proliferation of astrocytes and microglia. By contrast, the numbers of large deposits (5- to 50-microm-diameter) and numbers of amyloid plaques did not correlate with neuronal loss. These findings are consistent with the view that large aggregates may protect neurons by sequestering neurotoxic PrP oligomers, whereas punctate deposits may indicate the location of neuronal death processes in CJD.
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Analysis of protein levels of 24 cytokines in scrapie agent-infected brain and glial cell cultures from mice differing in prion protein expression levels. J Virol 2009; 83:11244-53. [PMID: 19710140 DOI: 10.1128/jvi.01413-09] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Activation of microglia and astroglia is seen in many neurodegenerative diseases including prion diseases. Activated glial cells produce cytokines as a protective response against certain pathogens and as part of the host inflammatory response to brain damage. In addition, cytokines might also exacerbate tissue damage initiated by other processes. In the present work using multiplex assays to analyze protein levels of 24 cytokines in scrapie agent-infected C57BL/10 mouse brains, we observed elevation of CCL2, CCL5, CXCL1, CXCL10, granulocyte-macrophage colony-stimulating factor (GM-CSF), gamma interferon (IFN-gamma), interleukin 1alpha (IL-1alpha), IL-1beta, IL-6, and IL-12p40. Scrapie agent-infected wild-type mice and transgenic mice expressing anchorless prion protein (PrP) had similar cytokine responses in spite of extensive differences in neuropathology. Therefore, these responses may be primarily a reaction to brain damage induced by prion infection rather than specific inducers of a particular type of pathology. To study the roles of astroglia and microglia in these cytokine responses, primary glial cultures were exposed to scrapie agent-infected brain homogenates. Microglia produced only IL-12p40 and CXCL10, whereas astroglia produced these cytokines plus CCL2, CCL3, CCL5, CXCL1, G-CSF, IL-1beta, IL-6, IL-12p70, and IL-13. Glial cytokine responses from wild-type mice and transgenic mice expressing anchorless PrP differed only slightly, but glia from PrP-null mice produced only IL-12p40, indicating that PrP expression was required for scrapie agent induction of other cytokines detected. The difference in cytokine response between microglia and astroglia correlated with 20-fold-higher levels of PrP expression in astroglia versus microglia, suggesting that high-level PrP expression on astroglia might be important for induction of certain cytokines.
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Abstract
Prions are infectious proteins that cause fatal neurodegenerative diseases. Because astrocytic gliosis marked by the deposition of fibrils composed of GFAP is a prominent feature of prion disease, we asked whether GFAP might be used as a surrogate marker for prions. To interrogate this posit, we inoculated prions into transgenic (Tg) mice expressing luciferase (luc) under the GFAP gene (Gfap) promoter, denoted Tg(Gfap-luc) mice. Weekly noninvasive, bioluminescence imaging (BLI) detected an increase in light emitted from the brains of Tg(Gfap-luc) mice at approximately 55 d after inoculation and approximately 62 d before neurologic deficits appeared. To determine whether BLI could be used as a proxy bioassay for prion infectivity, we performed endpoint titrations of prions in Tg(Gfap-luc) mice. BLI bioassays were as or more sensitive than those determined by the onset of neurological dysfunction, and were completed in approximately half the time. Our studies argue that BLI is likely to be a suitable surrogate for measuring prion infectivity, and might be useful in the study of Tg mouse models for other neurodegenerative illnesses.
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