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Giri RK. Molecular signatures in prion disease: altered death receptor pathways in a mouse model. J Transl Med 2024; 22:503. [PMID: 38802941 PMCID: PMC11129387 DOI: 10.1186/s12967-024-05121-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 03/20/2024] [Indexed: 05/29/2024] Open
Abstract
BACKGROUND Prion diseases are transmissible and fatal neurodegenerative diseases characterized by accumulation of misfolded prion protein isoform (PrPSc), astrocytosis, microgliosis, spongiosis, and neurodegeneration. Elevated levels of cell membrane associated PrPSc protein and inflammatory cytokines hint towards the activation of death receptor (DR) pathway/s in prion diseases. Activation of DRs regulate, either cell survival or apoptosis, autophagy and necroptosis based on the adaptors they interact. Very little is known about the DR pathways activation in prion disease. DR3 and DR5 that are expressed in normal mouse brain were never studied in prion disease, so also their ligands and any DR adaptors. This research gap is notable and investigated in the present study. METHODS C57BL/6J mice were infected with Rocky Mountain Laboratory scrapie mouse prion strain. The progression of prion disease was examined by observing morphological and behavioural abnormalities. The levels of PrP isoforms and GFAP were measured as the marker of PrPSc accumulation and astrocytosis respectively using antibody-based techniques that detect proteins on blot and brain section. The levels of DRs, their glycosylation and ectodomain shedding, and associated factors warrant their examination at protein level, hence western blot analysis was employed in this study. RESULTS Prion-infected mice developed motor deficits and neuropathology like PrPSc accumulation and astrocytosis similar to other prion diseases. Results from this research show higher expression of all DR ligands, TNFR1, Fas and p75NTR but decreased levels DR3 and DR5. The levels of DR adaptor proteins like TRADD and TRAF2 (primarily regulate pro-survival pathways) are reduced. FADD, which primarily regulate cell death, its level remains unchanged. RIPK1, which regulate pro-survival, apoptosis and necroptosis, its expression and proteolysis (inhibits necroptosis but activates apoptosis) are increased. CONCLUSIONS The findings from the present study provide evidence towards the involvement of DR3, DR5, DR6, TL1A, TRAIL, TRADD, TRAF2, FADD and RIPK1 for the first time in prion diseases. The knowledge obtained from this research discuss the possible impacts of these 16 differentially expressed DR factors on our understanding towards the multifaceted neuropathology of prion diseases and towards future explorations into potential targeted therapeutic interventions for prion disease specific neuropathology.
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Affiliation(s)
- Ranjit Kumar Giri
- Molecular and Cellular Neuroscience Division, National Brain Research Centre, Manesar, Gurgaon, Haryana, 122052, India.
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Chen X, Tang SJ. Neural Circuitry Polarization in the Spinal Dorsal Horn (SDH): A Novel Form of Dysregulated Circuitry Plasticity during Pain Pathogenesis. Cells 2024; 13:398. [PMID: 38474361 PMCID: PMC10930392 DOI: 10.3390/cells13050398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 03/14/2024] Open
Abstract
Pathological pain emerges from nociceptive system dysfunction, resulting in heightened pain circuit activity. Various forms of circuitry plasticity, such as central sensitization, synaptic plasticity, homeostatic plasticity, and excitation/inhibition balance, contribute to the malfunction of neural circuits during pain pathogenesis. Recently, a new form of plasticity in the spinal dorsal horn (SDH), named neural circuit polarization (NCP), was discovered in pain models induced by HIV-1 gp120 and chronic morphine administration. NCP manifests as an increase in excitatory postsynaptic currents (EPSCs) in excitatory neurons and a decrease in EPSCs in inhibitory neurons, presumably facilitating hyperactivation of pain circuits. The expression of NCP is associated with astrogliosis. Ablation of reactive astrocytes or suppression of astrogliosis blocks NCP and, concomitantly, the development of gp120- or morphine-induced pain. In this review, we aim to compare and integrate NCP with other forms of plasticity in pain circuits to improve the understanding of the pathogenic contribution of NCP and its cooperation with other forms of circuitry plasticity during the development of pathological pain.
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Affiliation(s)
| | - Shao-Jun Tang
- Stony Brook University Pain and Anesthesia Research Center (SPARC), Department of Anesthesiology, Stony Brook University, Stony Brook, NY 11794, USA;
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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: 19] [Impact Index Per Article: 9.5] [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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Pogue AI, Lukiw WJ. microRNA-146a-5p, Neurotropic Viral Infection and Prion Disease (PrD). Int J Mol Sci 2021; 22:ijms22179198. [PMID: 34502105 PMCID: PMC8431499 DOI: 10.3390/ijms22179198] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/09/2021] [Accepted: 08/16/2021] [Indexed: 12/15/2022] Open
Abstract
The human brain and central nervous system (CNS) harbor a select sub-group of potentially pathogenic microRNAs (miRNAs), including a well-characterized NF-kB-sensitive Homo sapiens microRNA hsa-miRNA-146a-5p (miRNA-146a). miRNA-146a is significantly over-expressed in progressive and often lethal viral- and prion-mediated and related neurological syndromes associated with progressive inflammatory neurodegeneration. These include ~18 different viral-induced encephalopathies for which data are available, at least ~10 known prion diseases (PrD) of animals and humans, Alzheimer’s disease (AD) and other sporadic and progressive age-related neurological disorders. Despite the apparent lack of nucleic acids in prions, both DNA- and RNA-containing viruses along with prions significantly induce miRNA-146a in the infected host, but whether this represents part of the host’s adaptive immunity, innate-immune response or a mechanism to enable the invading prion or virus a successful infection is not well understood. Current findings suggest an early and highly interactive role for miRNA-146a: (i) as a major small noncoding RNA (sncRNA) regulator of innate-immune responses and inflammatory signaling in cells of the human brain and CNS; (ii) as a critical component of the complement system and immune-related neurological dysfunction; (iii) as an inducible sncRNA of the brain and CNS that lies at a critical intersection of several important neurobiological adaptive immune response processes with highly interactive associations involving complement factor H (CFH), Toll-like receptor pathways, the innate-immunity, cytokine production, apoptosis and neural cell decline; and (iv) as a potential biomarker for viral infection, TSE and AD and other neurological diseases in both animals and humans. In this report, we review the recent data supporting the idea that miRNA-146a may represent a novel and unique sncRNA-based biomarker for inflammatory neurodegeneration in multiple species. This paper further reviews the current state of knowledge regarding the nature and mechanism of miRNA-146a in viral and prion infection of the human brain and CNS with reference to AD wherever possible.
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Affiliation(s)
| | - Walter J. Lukiw
- LSU Neuroscience Center, Louisiana State University Health Science Center, New Orleans, LA 70112, USA
- Department of Ophthalmology, Louisiana State University Health Science Center, New Orleans, LA 70112, USA
- Department of Neurology, Louisiana State University Health Science Center, New Orleans, LA 70112, USA
- Correspondence:
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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: 20] [Impact Index Per Article: 6.7] [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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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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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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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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Assessment of Glial Activation Response in the Progress of Natural Scrapie after Chronic Dexamethasone Treatment. Int J Mol Sci 2020; 21:ijms21093231. [PMID: 32370224 PMCID: PMC7247567 DOI: 10.3390/ijms21093231] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 04/24/2020] [Accepted: 04/30/2020] [Indexed: 02/07/2023] Open
Abstract
Neuroinflammation has been correlated with the progress of neurodegeneration in many neuropathologies. Although glial cells have traditionally been considered to be protective, the concept of them as neurotoxic cells has recently emerged. Thus, a major unsolved question is the exact role of astroglia and microglia in neurodegenerative disorders. On the other hand, it is well known that glucocorticoids are the first choice to regulate inflammation and, consequently, neuroglial inflammatory activity. The objective of this study was to determine how chronic dexamethasone treatment influences the host immune response and to characterize the beneficial or detrimental role of glial cells. To date, this has not been examined using a natural neurodegenerative model of scrapie. With this aim, immunohistochemical expression of glial markers, prion protein accumulation, histopathological lesions and clinical evolution were compared with those in a control group. The results demonstrated how the complex interaction between glial populations failed to compensate for brain damage in natural conditions, emphasizing the need for using natural models. Additionally, the data showed that modulation of neuroinflammation by anti-inflammatory drugs might become a research focus as a potential therapeutic target for prion diseases, similar to that considered previously for other neurodegenerative disorders classified as prion-like diseases.
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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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Sun C, Zhu L, Ma R, Ren J, Wang J, Gao S, Yang D, Ning K, Ling B, Lu B, Chen X, Xu J. Astrocytic miR-324-5p is essential for synaptic formation by suppressing the secretion of CCL5 from astrocytes. Cell Death Dis 2019; 10:141. [PMID: 30760705 PMCID: PMC6374376 DOI: 10.1038/s41419-019-1329-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 12/01/2018] [Accepted: 01/04/2019] [Indexed: 12/18/2022]
Abstract
There is accumulating evidence that astrocytes play an important role in synaptic formation, plasticity, and pruning. Dicer and the fine-tuning of microRNA (miRNA) network are important for maintaining the normal functions of central nervous system and dysregulation of miRNAs is implicated in neurological disorders. However, little is known about the role of Dicer and miRNAs of astrocytes in the homeostasis of synapse as well as its plasticity. By selectively deleting Dicer in postnatal astrocytes, Dicer-deficient mice exhibited reactive astrogliosis and deficits in dendritic spine formation. Astrocyte-conditioned medium (ACM) collected from Dicer-null astrocytes caused synapse degeneration in cultured primary neurons. The expression of chemokine ligand 5 (CCL5) elevated in Dicer-deleted astrocytes which led to the significant augmentation of secreted CCL5 in ACM. In neurons treated with Dicer KO-ACM, CCL5 supplementation inhibited MAPK/CREB signaling pathway and exacerbated the synaptic formation deficiency, while CCL5 knockdown partially rescued the synapse degeneration. Moreover, we validated CCL5 as miR-324-5p targeted gene. ACM collected from miR-324-5p antagomir-transfected astrocytes mimicked the effect of CCL5 treatment on inhibiting synapse formation and MAPK/CREB signaling in Dicer KO-ACM-cocultured neurons. Furthermore, decreased miR-324-5p expression and elevated CCL5 expression were observed in the brain of aging mice. Our work reveals the non-cell-autonomous roles of astroglial miRNAs in regulation of astrocytic secretory milieu and neuronal synaptogenesis, implicating the loss or misregulation of astroglial miRNA network may contribute to neuroinflammation, neurodegeneration, and aging.
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Affiliation(s)
- Chenxi Sun
- East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Liang Zhu
- East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Rongjie Ma
- East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Jie Ren
- East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Jian Wang
- East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Shane Gao
- East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Danjing Yang
- East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Ke Ning
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, University of Sheffield, Sheffield, UK
| | - Bin Ling
- The Second People's Hospital of Yunnan Province, Kunming, China.
| | - Bing Lu
- East Hospital, Tongji University School of Medicine, Shanghai, China.
| | - Xu Chen
- Eighth People's Hospital Affiliated to Jiangsu University, Shanghai, China.
| | - Jun Xu
- East Hospital, Tongji University School of Medicine, Shanghai, China.
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Bang WS, Kim KT, Seo YJ, Cho DC, Sung JK, Kim CH. Curcumin Increase the Expression of Neural Stem/Progenitor Cells and Improves Functional Recovery after Spinal Cord Injury. J Korean Neurosurg Soc 2017; 61:10-18. [PMID: 29354231 PMCID: PMC5769840 DOI: 10.3340/jkns.2017.0203.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/12/2017] [Accepted: 05/31/2017] [Indexed: 12/03/2022] Open
Abstract
Objective To investigates the effect of curcumin on proliferation of spinal cord neural stem/progenitor cells (SC-NSPCs) and functional outcome in a rat spinal cord injury (SCI) model. Methods Sixty adult male Sprague-Dawley rats were randomly and blindly allocated into three groups (sham control group; curcumin treated group after SCI; vehicle treated group after SCI). Functional recovery was evaluated by the Basso, Beattie, and Bresnahan (BBB) scale during 6 weeks after SCI. The expression of SC-NSPC proliferation and astrogliosis were analyzed by nestin/Bromodeoxyuridine (BrdU) and Glial fibrillary acidic protein (GFAP) staining. The injured spinal cord was then examined histologically, including quantification of cavitation. Results The BBB score of the SCI-curcumin group was better than that of SCI-vehicle group up to 14 days (p<0.05). The co-immunoreactivity of nestin/BrdU in the SCI-curcumin group was much higher than that of the SCI-vehicle group 1 week after surgery (p<0.05). The GFAP immunoreactivity of the SCI-curcumin group was remarkably lower than that of the SCI-vehicle group 4 weeks after surgery (p<0.05). The lesion cavity was significantly reduced in the curcumin group as compared to the control group (p<0.05). Conclusion These results indicate that curcumin could increase the expression of SC-NSPCs, and reduce the activity of reactive astrogliosis and lesion cavity. Consequently curcumin could improve the functional recovery after SCI via SC-NSPC properties.
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Affiliation(s)
- Woo-Seok Bang
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea
| | - Kyoung-Tae Kim
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea
| | - Ye Jin Seo
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea
| | - Dae-Chul Cho
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea
| | - Joo-Kyung Sung
- Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea
| | - Chi Heon Kim
- Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea
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Shan Z, Hirai Y, Nakayama M, Hayashi R, Yamasaki T, Hasebe R, Song CH, Horiuchi M. Therapeutic effect of autologous compact bone-derived mesenchymal stem cell transplantation on prion disease. J Gen Virol 2017; 98:2615-2627. [PMID: 28874230 DOI: 10.1099/jgv.0.000907] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Prion diseases are fatal neurodegenerative disorders of humans and animals and no effective treatments are currently available. Allogenic transplantation of immortalized human mesenchymal stem cells (MSCs) can prolong the survival of mice infected with prions. However, autologous transplantation is an appropriate model for evaluating the effects of MSCs on prion diseases. Therefore, we isolated and purified MSCs from the femur and tibia of mice as compact bone-derived MSCs (CB-MSCs). Flow cytometric analysis showed that CB-MSCs were negative for myeloid stem cell-derived cell markers CD11b and CD45, but positive for molecules such as Sca-1, CD105 and CD90.2, which are reported to be expressed on MSCs. The ability of CB-MSCs to migrate to brain extracts from prion-infected mice was confirmed by an in vitro migration assay. Intra-hippocampus transplantation of CB-MSCs at 120 days post-inoculation marginally but significantly prolonged the survival of mice infected with the Chandler prion strain. The transplantation of CB-MSCs did not influence the accumulation of disease-specific prion protein. However, the CB-MSC transplantation enhanced microglial activation, which appeared to be polarized to the M2-type activation state. These results suggest that autologous MSC transplantation is a possible treatment for prion diseases, while the modification of microglial activation may be a therapeutic target for neurodegenerative diseases.
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Affiliation(s)
- Zhifu Shan
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Yuji Hirai
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Momoko Nakayama
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Ryo Hayashi
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Takeshi Yamasaki
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Rie Hasebe
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Chang-Hyun Song
- Department of Anatomy and Histology, College of Oriental Medicine, Daegue Haany University, Gyeongsan, 712-715, Republic of Korea
| | - Motohiro Horiuchi
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
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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: 27] [Impact Index Per Article: 3.9] [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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Hou L, Zhou X, Zhang C, Wang K, Liu X, Che Y, Sun F, Li H, Wang Q, Zhang D, Hong JS. NADPH oxidase-derived H 2O 2 mediates the regulatory effects of microglia on astrogliosis in experimental models of Parkinson's disease. Redox Biol 2017; 12:162-170. [PMID: 28237879 PMCID: PMC5328707 DOI: 10.1016/j.redox.2017.02.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 02/12/2017] [Accepted: 02/21/2017] [Indexed: 12/17/2022] Open
Abstract
Astrogliosis has long been recognized in Parkinson's disease (PD), the most common neurodegenerative movement disorder. However, the mechanisms of how astroglia become activated remain unclear. Reciprocal interactions between microglia and astroglia play a pivotal role in regulating the activities of astroglia. The purpose of this study is to investigate the mechanism by which microglia regulate astrogliosis by using lipopolysaccharide (LPS) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse PD models. We found that the activation of microglia preceded astroglia in the substantia nigra of mice treated with either LPS or MPTP. Furthermore, suppression of microglial activation by pharmacological inhibition or genetic deletion of NADPH oxidase (NOX2) in mice attenuated astrogliosis. The important role of NOX2 in microglial regulation of astrogliosis was further mirrored in a mixed-glia culture system. Mechanistically, H2O2, a product of microglial NOX2 activation, serves as a direct signal to regulate astrogliosis. Astrogliosis was induced by H2O2 through a process in which extracellularly generated H2O2 diffused into the cytoplasm and subsequently stimulated activation of transcription factors, STAT1 and STAT3. STAT1/3 activation regulated the immunological functions of H2O2-induced astrogliosis since AG490, an inhibitor of STAT1/3, attenuated the gene expressions of both proinflammatory and neurotrophic factors in H2O2-treated astrocyte. Our findings indicate that microglial NOX2-generated H2O2 is able to regulate the immunological functions of astroglia via a STAT1/3-dependent manner, providing additional evidence for the immune pathogenesis and therapeutic studies of PD. Microglia are capable of regulating the immunological functions of astrogliosis in Parkinson's disease. NADPH oxidase-derived H2O2 is recognized as a paracrine signal for microglial regulation of astrogliosis. Transcription factors STAT1 and STAT3 play pivotal roles in H2O2-induced astroglial activation.
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Affiliation(s)
- Liyan Hou
- Department of Occupational and Environmental Health, School of Public Health, Dalian Medical University, No. 9 W. Lvshun South Road, Dalian 116044, China
| | - Xueying Zhou
- Department of Occupational and Environmental Health, School of Public Health, Dalian Medical University, No. 9 W. Lvshun South Road, Dalian 116044, China
| | - Cong Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, Dalian Medical University, No. 9 W. Lvshun South Road, Dalian 116044, China
| | - Ke Wang
- Department of Nutrition, Second Hospital, Dalian Medical University, Dalian 116023, China
| | - Xiaofang Liu
- Department of Nutrition and Food Hygiene, School of Public Health, Dalian Medical University, No. 9 W. Lvshun South Road, Dalian 116044, China
| | - Yuning Che
- Department of Occupational and Environmental Health, School of Public Health, Dalian Medical University, No. 9 W. Lvshun South Road, Dalian 116044, China
| | - Fuqiang Sun
- Department of Occupational and Environmental Health, School of Public Health, Dalian Medical University, No. 9 W. Lvshun South Road, Dalian 116044, China
| | - Huihua Li
- Department of Nutrition and Food Hygiene, School of Public Health, Dalian Medical University, No. 9 W. Lvshun South Road, Dalian 116044, China
| | - Qingshan Wang
- Department of Occupational and Environmental Health, School of Public Health, Dalian Medical University, No. 9 W. Lvshun South Road, Dalian 116044, China.
| | - Dan Zhang
- State Key Laboratory of Natural Products and Functions, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Jau-Shyong Hong
- Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
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Monzón M. Approaches to therapy against prion diseases focused on the individual defence system. AIMS MOLECULAR SCIENCE 2017. [DOI: 10.3934/molsci.2017.3.241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Astrocyte physiopathology: At the crossroads of intercellular networking, inflammation and cell death. Prog Neurobiol 2015; 130:86-120. [PMID: 25930681 DOI: 10.1016/j.pneurobio.2015.04.003] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 04/15/2015] [Accepted: 04/20/2015] [Indexed: 12/11/2022]
Abstract
Recent breakthroughs in neuroscience have led to the awareness that we should revise our traditional mode of thinking and studying the CNS, i.e. by isolating the privileged network of "intelligent" synaptic contacts. We may instead need to contemplate all the variegate communications occurring between the different neural cell types, and centrally involving the astrocytes. Basically, it appears that a single astrocyte should be considered as a core that receives and integrates information from thousands of synapses, other glial cells and the blood vessels. In turn, it generates complex outputs that control the neural circuitry and coordinate it with the local microcirculation. Astrocytes thus emerge as the possible fulcrum of the functional homeostasis of the healthy CNS. Yet, evidence indicates that the bridging properties of the astrocytes can change in parallel with, or as a result of, the morphological, biochemical and functional alterations these cells undergo upon injury or disease. As a consequence, they have the potential to transform from supportive friends and interactive partners for neurons into noxious foes. In this review, we summarize the currently available knowledge on the contribution of astrocytes to the functioning of the CNS and what goes wrong in various pathological conditions, with a particular focus on Amyotrophic Lateral Sclerosis, Alzheimer's Disease and ischemia. The observations described convincingly demonstrate that the development and progression of several neurological disorders involve the de-regulation of a finely tuned interplay between multiple cell populations. Thus, it seems that a better understanding of the mechanisms governing the integrated communication and detrimental responses of the astrocytes as well as their impact towards the homeostasis and performance of the CNS is fundamental to open novel therapeutic perspectives.
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Herrmann US, Sonati T, Falsig J, Reimann RR, Dametto P, O’Connor T, Li B, Lau A, Hornemann S, Sorce S, Wagner U, Sanoudou D, Aguzzi A. Prion infections and anti-PrP antibodies trigger converging neurotoxic pathways. PLoS Pathog 2015; 11:e1004662. [PMID: 25710374 PMCID: PMC4339193 DOI: 10.1371/journal.ppat.1004662] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 01/06/2015] [Indexed: 02/08/2023] Open
Abstract
Prions induce lethal neurodegeneration and consist of PrPSc, an aggregated conformer of the cellular prion protein PrPC. Antibody-derived ligands to the globular domain of PrPC (collectively termed GDL) are also neurotoxic. Here we show that GDL and prion infections activate the same pathways. Firstly, both GDL and prion infection of cerebellar organotypic cultured slices (COCS) induced the production of reactive oxygen species (ROS). Accordingly, ROS scavenging, which counteracts GDL toxicity in vitro and in vivo, prolonged the lifespan of prion-infected mice and protected prion-infected COCS from neurodegeneration. Instead, neither glutamate receptor antagonists nor inhibitors of endoplasmic reticulum calcium channels abolished neurotoxicity in either model. Secondly, antibodies against the flexible tail (FT) of PrPC reduced neurotoxicity in both GDL-exposed and prion-infected COCS, suggesting that the FT executes toxicity in both paradigms. Thirdly, the PERK pathway of the unfolded protein response was activated in both models. Finally, 80% of transcriptionally downregulated genes overlapped between prion-infected and GDL-treated COCS. We conclude that GDL mimic the interaction of PrPSc with PrPC, thereby triggering the downstream events characteristic of prion infection. Prion diseases are a group of infectious, invariably fatal neurodegenerative diseases. Progress in developing therapeutics is slow, partly because animal models of prion diseases require stringent biosafety and are very slow. We recently found that treatment of cerebellar slices with antibodies targeting the globular domain (GD ligands) of the prion protein (PrP) is neurotoxic. Here we compared this model to prion infection, and describe striking similarities. Both models involved the production of reactive oxygen species, and antioxidants could reverse the toxicity in cerebellar slices and even prolong the survival time of prion-infected mice. Antibodies targeting the flexible tail of PrP that prevent toxicity of GD ligands reduced the toxicity induced by prions. Endoplasmic reticulum stress, which is involved in prion toxicity, is also found in GD-ligand induced neurotoxicity. Finally, changes of gene expression were similar in both models. We conclude that prion infection and GD ligands use converging neurotoxic pathways. Because GD ligands induce toxicity within days rather than months and do not pose biosafety hazards, they may represent a powerful tool for furthering our understanding of prion pathogenesis and also for the discovery of antiprion drugs.
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Affiliation(s)
- Uli S. Herrmann
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
| | - Tiziana Sonati
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
| | - Jeppe Falsig
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
| | - Regina R. Reimann
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
| | - Paolo Dametto
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
| | - Tracy O’Connor
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
| | - Bei Li
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
| | - Agnes Lau
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
| | - Simone Hornemann
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
| | - Silvia Sorce
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
| | - Uli Wagner
- Institute of Surgical Pathology, University Hospital of Zurich, Zurich, Switzerland
| | - Despina Sanoudou
- Department of Pharmacology, Medical School, University of Athens, Athens, Greece
| | - Adriano Aguzzi
- Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
- * E-mail:
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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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Abstract
Research models show a strong interrelationship between sleep quality and immune function. The proinflammatory cytokines, interleukin-1, interleukin-6, and tumor necrosis factor α are classified as official sleep-regulatory substances. However, sleep-promoting properties are also possessed by several other immune and proinflammatory cellular classes. This article reviews the current physiologic evidence for the prominent somnogenic and sleep-regulatory properties inherent to these immune substances. Clinical examples of this relationship are discussed from the perspective of infectious and primarily immune-related conditions associated with significant sleep disruption and from the perspective of immune dysregulation associated with several primary sleep disorders.
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Affiliation(s)
- Charlene E Gamaldo
- Neurology, Pulmonary and Critical Care Medicine, Johns Hopkins Sleep Disorders Center, 600 North Wolfe Street, Meyer 6-119, Baltimore, MD 21287, USA.
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Xie WL, Shi Q, Zhang J, Zhang BY, Gong HS, Guo Y, Wang SB, Xu Y, Wang K, Chen C, Liu Y, Dong XP. Abnormal activation of microglia accompanied with disrupted CX3CR1/CX3CL1 pathway in the brains of the hamsters infected with scrapie agent 263K. J Mol Neurosci 2013; 51:919-32. [PMID: 23526370 DOI: 10.1007/s12031-013-0002-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Accepted: 03/11/2013] [Indexed: 10/27/2022]
Abstract
Microglial cells are resident mononuclear phagocytes of the central nervous system (CNS). Active proliferation of microglia in the brain has been identified in neurodegenerative disorders, including some kinds of prion disease. However, the detailed regional distribution between microglia and PrP(Sc) deposition has not been presented, and investigation of fractalkine signaling which is involved in the regulation of activation of microglia in prion disease is not well documented. In this study, the disease phenomenon of microglial accumulation in the CNS was thoroughly analyzed using a scrapie-infected experimental model. Western blots of microglia-specific markers Iba1 and CD68, immunohistochemical and immunofluorescent assays demonstrated obviously activation of microglia in almost whole brain regions in the infected animals. Under the dynamic analysis on hallmarks of activation of microglia, a time-dependent increase of Iba1 and CD68 was detected, accompanied by accumulation of PrP(Sc) and progression of neurodegenerative symptoms. With serial brain sections and double staining of Iba1 and PrP(Sc), we observed that the microglia distributed around PrP(Sc) deposits in 263K-infected hamsters' brains, proposing PrP(Sc) phagocytosis. Flow cytometry assays with the single-cell suspensions prepared from the cortical region of the infected brains verified an activation of microglial population. ELISA assays of the cytokines in brain homogenates revealed significant upregulations of interleukin (IL)-1β, IL-6 and TNF-α when infected. Evaluation of fractalkine signaling in the infected hamsters' brains showed progressively downregulation of CX3CL1 during the incubation. Prion peptide PrP106-126 also disrupted fractalkine and evoked microglial activation in rat primary neuron-glia mixed cultures. Our data here demonstrate an activated status of microglia in CNS tissues of infectious prion disease, possibly through fractalkine signaling deficiency.
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Affiliation(s)
- Wu-Ling Xie
- School of Medicine, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China
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Karimi-Abdolrezaee S, Billakanti R. Reactive astrogliosis after spinal cord injury-beneficial and detrimental effects. Mol Neurobiol 2012; 46:251-64. [PMID: 22684804 DOI: 10.1007/s12035-012-8287-4] [Citation(s) in RCA: 258] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 05/29/2012] [Indexed: 11/29/2022]
Abstract
Reactive astrogliosis is a pathologic hallmark of spinal cord injury (SCI). It is characterised by profound morphological, molecular, and functional changes in astrocytes that occur within hours of SCI and evolves as time elapses after injury. Astrogliosis is a defense mechanism to minimize and repair the initial damage but eventually leads to some detrimental effects. Reactive astrocytes secrete a plethora of both growth promoting and inhibitory factors after SCI. However, the production of inhibitory components surpasses the growth stimulating factors, thus, causing inhibitory effects. In severe cases of injury, astrogliosis results in the formation of irreversible glial scarring that acts as regeneration barrier due to the expression of inhibitory components such as chondroitin sulfate proteoglycans. Scar formation was therefore recognized from a negative perspective for many years. Accumulating evidence from pharmacological and genetic studies now signifies the importance of astrogliosis and its timing for spinal cord repair. These studies have advanced our knowledge regarding signaling pathways and molecular mediators, which trigger and modulate reactive astrocytes and scar formation. In this review, we discuss the recent advances in this field. We also review therapeutic strategies that have been developed to target astrocytes reactivity and glial scaring in the environment of SCI. Astrocytes play pivotal roles in governing SCI mechanisms, and it is therefore crucial to understand how their activities can be targeted efficiently to harness their potential for repair and regeneration after SCI.
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Affiliation(s)
- Soheila Karimi-Abdolrezaee
- Regenerative Medicine Program, Departments of Physiology and Biochemistry and Medical Genetics, the Spinal Cord Research Center, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
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Yang Y, Jalal FY, Thompson JF, Walker EJ, Candelario-Jalil E, Li L, Reichard RR, Ben C, Sang QX, Cunningham LA, Rosenberg GA. Tissue inhibitor of metalloproteinases-3 mediates the death of immature oligodendrocytes via TNF-α/TACE in focal cerebral ischemia in mice. J Neuroinflammation 2011; 8:108. [PMID: 21871134 PMCID: PMC3180275 DOI: 10.1186/1742-2094-8-108] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 08/29/2011] [Indexed: 11/10/2022] Open
Abstract
Background and Purpose Oligodendrocyte (OL) death is important in focal cerebral ischemia. TIMP-3 promotes apoptosis in ischemic neurons by inhibiting proteolysis of TNF-α superfamily of death receptors. Since OLs undergo apoptosis during ischemia, we hypothesized that TIMP-3 contributes to OL death. Methods Middle cerebral artery occlusion (MCAO) was induced in Timp-3 knockout (KO) and wild type (WT) mice with 24 or 72 h of reperfusion. Cell death in white matter was investigated by stereology and TUNEL. Mature or immature OLs were identified using antibodies against glutathione S-transferase-π (GST-π) and galactocerebroside (GalC), respectively. Expression and level of proteins were examined using immunohistochemistry and immunoblotting. Protein activities were determined using a FRET peptide. Results Loss of OL-like cells was detected at 72 h only in WT ischemic white matter where TUNEL showed greater cell death. TIMP-3 expression was increased in WT reactive astrocytes. GST-π was reduced in ischemic white matter of WT mice compared with WT shams with no difference between KO and WT at 72 h. GalC level was significantly increased in both KO and WT ischemic white matter at 72 h. However, the increase in GalC in KO mice was significantly higher than WT; most TUNEL-positive cells in ischemic white matter expressed GalC, suggesting TIMP-3 deficiency protects the immature OLs from apoptosis. There were significantly higher levels of cleaved caspase-3 at 72 h in WT white matter than in KO. Greater expression of MMP-3 and -9 was seen in reactive astrocytes and/or microglia/macrophages in WT at 72 h. We found more microglia/macrophages in WT than in KO, which were the predominant source of increased TNF-α detected in the ischemic white matter. TACE activity was significantly increased in ischemic WT white matter, which was expressed in active microglia/macrophages and OLs. Conclusions Our results suggested that focal ischemia leads to proliferation of immature OLs in white matter and that TIMP-3 contributes to a caspase-3-dependent immature OL death via TNF-α-mediated neuroinflammation. Future studies will be needed to delineate the role of MMP-3 and MMP-9 that were increased in the Timp-3 wild type.
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Affiliation(s)
- Yi Yang
- Department of Neurology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
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Singh N, Singh A, Das D, Mohan ML. Redox control of prion and disease pathogenesis. Antioxid Redox Signal 2010; 12:1271-94. [PMID: 19803746 PMCID: PMC2864664 DOI: 10.1089/ars.2009.2628] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 09/22/2009] [Accepted: 10/03/2009] [Indexed: 11/12/2022]
Abstract
Imbalance of brain metal homeostasis and associated oxidative stress by redox-active metals like iron and copper is an important trigger of neurotoxicity in several neurodegenerative conditions, including prion disorders. Whereas some reports attribute this to end-stage disease, others provide evidence for specific mechanisms leading to brain metal dyshomeostasis during disease progression. In prion disorders, imbalance of brain-iron homeostasis is observed before end-stage disease and worsens with disease progression, implicating iron-induced oxidative stress in disease pathogenesis. This is an unexpected observation, because the underlying cause of brain pathology in all prion disorders is PrP-scrapie (PrP(Sc)), a beta-sheet-rich conformation of a normal glycoprotein, the prion protein (PrP(C)). Whether brain-iron dyshomeostasis occurs because of gain of toxic function by PrP(Sc) or loss of normal function of PrP(C) remains unclear. In this review, we summarize available evidence suggesting the involvement of oxidative stress in prion-disease pathogenesis. Subsequently, we review the biology of PrP(C) to highlight its possible role in maintaining brain metal homeostasis during health and the contribution of PrP(Sc) in inducing brain metal imbalance with disease progression. Finally, we discuss possible therapeutic avenues directed at restoring brain metal homeostasis and alleviating metal-induced oxidative stress in prion disorders.
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Affiliation(s)
- Neena Singh
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Involvement of peptidylarginine deiminase-mediated post-translational citrullination in pathogenesis of sporadic Creutzfeldt-Jakob disease. Acta Neuropathol 2010; 119:199-210. [PMID: 20013286 DOI: 10.1007/s00401-009-0625-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 11/27/2009] [Accepted: 12/05/2009] [Indexed: 02/02/2023]
Abstract
Peptidylarginine deiminases (PADs)-mediated post-translational citrullination processes play key roles in protein functions and structural stability through the conversion of arginine to citrulline in the presence of excessive calcium concentrations. In brain, PAD2 is abundantly expressed and can be involved in citrullination in disease. Recently, we have reported pathological characterization of PAD2 and citrullinated proteins in scrapie-infected mice, but the implication of protein citrullination in the pathophysiology in human prion disease is not clear. In the present study, we explored the molecular and biological involvement of PAD2 and the pathogenesis of citrullinated proteins in frontal cortex of patients with sporadic Creutzfeldt-Jakob disease (sCJD). We found increased expression of PAD2 in reactive astrocytes that also contained increased levels of citrullinated proteins. In addition, PAD activity was significantly elevated in patients with sCJD compared to controls. From two-dimensional gel electrophoresis and MALDI-TOF mass analysis, we found various citrullinated candidates, including cytoskeletal and energy metabolism-associated proteins such as vimentin, glial fibrillary acidic protein, enolase, and phosphoglycerate kinase. Based on these findings, our investigations suggest that PAD2 activation and aberrant citrullinated proteins could play a role in pathogenesis and have value as a marker for the postmortem classification of neurodegenerative diseases.
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Appel SA, Chapman J, Kahana E, Rosenmann H, Prohovnik I, Pras E, Reznik-Wolf H, Cohen OS. Rapidly progressive Creutzfeldt-Jakob disease in patients with Familial Mediterranean Fever. Eur J Neurol 2010; 17:861-5. [PMID: 20113338 DOI: 10.1111/j.1468-1331.2010.02948.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The largest cluster of familial Creutzfeldt-Jakob disease (fCJD) exists in Jews of Libyan origin. Familial Mediterranean fever (FMF) is an inflammatory disease also common in this population. OBJECTIVES We hypothesized that FMF, as a pro-inflammatory condition, may affect the course of CJD. METHODS Three hundred and seventy-two consecutive patients diagnosed clinically and genetically as CJD were included in the study. Two hundred and thirty-six had fCJD, and 136 had sporadic disease (sCJD). Review of the patient's records revealed three patients with FMF-CJD co-morbidity. In addition, 50 DNA samples of patients with CJD were genotyped as homozygote, heterozygote, and non-carriers of the FMF mutation. The demographic and clinical variables of the groups were compared. RESULTS The three patients with FMF had an earlier age of onset and significantly shorter disease duration than the patients without FMF. Heterozygote carriers did not differ in disease onset and duration from patients without FMF. CONCLUSIONS The shorter disease duration of CJD patients with FMF may indicate the importance of pro-inflammatory factors in the disease.
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Affiliation(s)
- S A Appel
- Department of Neurology, The Sagol Neuroscience Center at the Chaim Sheba Medical Center affiliated to the Sackler Faculty of Medicine, Tel-Aviv University, Tel-Hashomer, Israel
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Astrocytes in the damaged brain: molecular and cellular insights into their reactive response and healing potential. Biochem Pharmacol 2009; 79:77-89. [PMID: 19765548 DOI: 10.1016/j.bcp.2009.09.014] [Citation(s) in RCA: 238] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 09/08/2009] [Accepted: 09/10/2009] [Indexed: 12/29/2022]
Abstract
Long considered merely a trophic and mechanical support to neurons, astrocytes have progressively taken the center stage as their ability to react to acute and chronic neurodegenerative situations became increasingly clear. Reactive astrogliosis starts when trigger molecules produced at the injury site drive astrocytes to leave their quiescent state and become activated. Distinctive morphological and biochemical features characterize this process (cell hypertrophy, upregulation of intermediate filaments, and increased cell proliferation). Moreover, reactive astrocytes migrate towards the injured area to constitute the glial scar, and release factors mediating the tissue inflammatory response and remodeling after lesion. A novel view of astrogliosis derives from the finding that subsets of reactive astrocytes can recapitulate stem cell/progenitor features after damage, fostering the concept of astroglia as a promising target for reparative therapies. But which biochemical/signaling pathways modulate astrogliosis with respect to both the time after injury and the type of damage? Are reactive astrocytes overall beneficial or detrimental for neuroprotection and tissue regeneration? This debate has been animating this research field for several years now, and an integrated view on the results obtained and the possible future perspectives is needed. With this Commentary article we have attempted to answer the above-mentioned questions by reviewing the current knowledge on the molecular mechanisms controlling and sustaining the reaction of astroglia to injury and its stem cell-like properties. Moreover, the cellular/molecular mechanisms supporting the detrimental or beneficial features of astrogliosis have been scrutinized to gain insights on possible pharmacological approaches to enhance astrocyte neuroprotective activities.
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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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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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Scalabrino G. The multi-faceted basis of vitamin B12 (cobalamin) neurotrophism in adult central nervous system: Lessons learned from its deficiency. Prog Neurobiol 2009; 88:203-20. [DOI: 10.1016/j.pneurobio.2009.04.004] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Revised: 03/03/2009] [Accepted: 04/16/2009] [Indexed: 10/20/2022]
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Mutant Prion Protein Expression Causes Motor and Memory Deficits and Abnormal Sleep Patterns in a Transgenic Mouse Model. Neuron 2008; 60:598-609. [DOI: 10.1016/j.neuron.2008.09.008] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Revised: 07/22/2008] [Accepted: 09/04/2008] [Indexed: 11/18/2022]
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Scalabrino G, Veber D, Mutti E. Experimental and clinical evidence of the role of cytokines and growth factors in the pathogenesis of acquired cobalamin-deficient leukoneuropathy. ACTA ACUST UNITED AC 2008; 59:42-54. [DOI: 10.1016/j.brainresrev.2008.05.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 04/30/2008] [Accepted: 05/01/2008] [Indexed: 01/08/2023]
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LaCasse RA, Striebel JF, Favara C, Kercher L, Chesebro B. Role of Erk1/2 activation in prion disease pathogenesis: absence of CCR1 leads to increased Erk1/2 activation and accelerated disease progression. J Neuroimmunol 2008; 196:16-26. [PMID: 18396336 DOI: 10.1016/j.jneuroim.2008.02.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 01/16/2008] [Accepted: 02/11/2008] [Indexed: 12/14/2022]
Abstract
Prion diseases are neurodegenerative infections with gliosis and vacuolation. The mechanisms of degeneration remain unclear, but chemokines may be important. In current experiments CCR1 knock-out (KO) mice succumbed more rapidly to scrapie infection than WT controls. Infected KO mice had upregulation of CCL3, a CCR1 ligand, and CCR5, a receptor with specificity for CCL3. Both infected KO and WT mice had upregulation of CCR5-mediated signaling involving activation of Erk1/2 in astrocytes; however, activation was earlier in KO mice suggesting a role in pathogenesis. In both mouse strains activation of the Erk1/2 pathway may lead to astrocyte dysfunction resulting in neurodegeneration.
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Affiliation(s)
- Rachel A LaCasse
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South 4th Street, Hamilton, MT 59840, United States
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Tian DS, Dong Q, Pan DJ, He Y, Yu ZY, Xie MJ, Wang W. Attenuation of astrogliosis by suppressing of microglial proliferation with the cell cycle inhibitor olomoucine in rat spinal cord injury model. Brain Res 2007; 1154:206-14. [PMID: 17482149 DOI: 10.1016/j.brainres.2007.04.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2007] [Revised: 04/02/2007] [Accepted: 04/02/2007] [Indexed: 11/29/2022]
Abstract
Microglial activation/proliferation and reactive astrogliosis are commonly observed and have been considered to be closely relevant pathological processes during spinal cord injury (SCI). However, the molecular mechanisms underlying this microglial-astroglial interaction are still poorly understood. We showed recently that the continuous injection of the cell cycle inhibitor olomoucine not only markedly suppressed microglial proliferation and associated release of pro-inflammatory cytokines, but also attenuated astroglial scar formation and the lesion cavity and mitigated the functional deficits in rat SCI animal model. In this study, we asked whether microglial activation/proliferation plays an initial role and also necessary in maintaining astrogliosis in SCI model. Our results showed that traumatic induced microglial activation/proliferation precedes astrogliosis, and the up-regulated GFAP expression at both mRNA and protein levels was temporally posterior to the microglial activation. Furthermore, when the cell cycle inhibitor olomoucine was administered only once 1 h post-SCI that should selectively suppress microglial proliferation, the subsequent SCI induced increase in GFAP expression at 1, 2 and 4 weeks was significantly attenuated, suggesting that microglial activation/proliferation played an important role for the later onset astrogliosis after SCI. Consistent with the results that microglial proliferation always precedes astroglial proliferation and there is at present no evidence of other astroglial precursors, which as always does not mean that they will not be uncovered by further searching, and in view of the fact that microglial-derived pro-inflammatory cytokines promote astrogliosis as we reported recently, these findings together suggest that by release of cytokines and other soluble products, the early onset microglial activation/proliferation can significantly influence the subsequent development of reactive astrogliosis and glial scar formation in SCI animal model.
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Affiliation(s)
- Dai-shi Tian
- Department of Neurology, Affiliated Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, PR China
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Röhl C, Lucius R, Sievers J. The effect of activated microglia on astrogliosis parameters in astrocyte cultures. Brain Res 2006; 1129:43-52. [PMID: 17169340 DOI: 10.1016/j.brainres.2006.10.057] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 09/13/2006] [Accepted: 10/27/2006] [Indexed: 10/23/2022]
Abstract
In the diseased central nervous system, astrogliosis is accompanied by microglial activation. Depending on the context of their activation, reactive astrocytes are involved in neuronal survival and regeneration in an either protective or impedimental way. Major reactive changes of astrocytes in vivo are the upregulation of the intermediate filaments GFAP (glial fibrillary acidic protein) and vimentin with accompanying cellular hypertrophy and/or hyperplasia. To examine the involvement of activated microglia in the onset and maintenance of astrogliosis, we used an in vitro model of purified cultures of astrocytes and assessed as parameters for astrogliosis GFAP, vimentin, astroglial hypertrophy and cell growth after treatment with medium conditioned by LPS (lipopolysaccarides)-stimulated microglia. Furthermore, IL-6 as a typically upregulated cytokine in proinflammatory processes in the brain was determined in treated astrocytes. GFAP, the classical marker for astrogliosis, was downregulated on its protein and in parallel with vimentin on its mRNA level. The expression of actin, another cytoskeleton protein used as control, remained unchanged. Ultrastructural studies of astroglial intermediate filaments supported these findings. No hypertrophy was found. Nevertheless, LPS-activated microglia stimulated astrocytes as demonstrated by an increased cell number and an enhanced mRNA expression of IL-6. Resting microglia did not change any of the determined parameters. Our results suggest that the role of activated microglia in astrogliotic processes following injury of the brain has to be reevaluated, as microglia in their activated state might support the onset of astrogliosis on the one hand, but might delay or reduce subsequent glial scar formation on the other hand.
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Affiliation(s)
- Claudia Röhl
- Department of Anatomy, University of Kiel, Olshausenstr. 40, D-24098 Kiel, Germany.
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38
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Schneider B, Pietri M, Mouillet-Richard S, Ermonval M, Mutel V, Launay JM, Kellermann O. Control of Bioamine Metabolism by 5-HT2Band α1DAutoreceptors through Reactive Oxygen Species and Tumor Necrosis Factor-α Signaling in Neuronal Cells. Ann N Y Acad Sci 2006; 1091:123-41. [PMID: 17341609 DOI: 10.1196/annals.1378.061] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Homeostasis of the central nervous system relies on the proper integration of cell-signaling pathways recruited by a variety of neuronal and non-neuronal factors, with the aim of tightly controlling neurotransmitter metabolism, storage, and transport. We took advantage of the 1C11 neuroectodermal cell line, endowed with the capacity to selectively differentiate into serotonergic (1C11(5-HT)) or noradrenergic (1C11(NE)) neurons, to identify functional targets of serotonin (5-hydroxytryptamine [5-HT]) and norepinephrine (NE) autoreceptors possibly involved in the control of neuronal functions. We demonstrate that 5-HT(2B) and adreno alpha(1D) receptors are coupled to reactive oxygen species (ROS) production through NADPH oxidase activation in 1C11(5-HT) and 1C11(NE) neuronal cells, respectively. In the signaling cascade linking 5-HT(2B) receptors to NADPH oxidase, phospholipase A2-mediated arachidonic acid production is required for ROS synthesis. ROS, in turn, act as second message signals and control the activation of TACE (TNF-alpha converting enzyme), a member of a disintegrin and metalloproteinase family. 5-HT(2B) and alpha(1D) receptor stimulation triggers TACE-dependent TNF-alpha shedding in the surrounding milieu of 1C11(5-HT) and 1C11(NE) cells. In these cells, shed TNF-alpha triggers degradation of 5-HT and NE into 5-HIAA and MHPG, respectively. Finally, we observe that 5-HT(2B) and alpha(1D) receptor couplings to the NADPH oxidase-TACE cascade are strictly restricted to 1C11-derived progenies that have implemented a complete neuronal phenotype. Altogether, our data indicate that couplings of 5-HT(2B) and alpha(1D) autoreceptors to ROS and TNF-alpha signaling control neurotransmitter metabolism in 1C11-derived neuronal cells. Eventually, we might explain the origin of oxidative stress and high level of TNF-alpha in neurodegenerative diseases as a consequence of deviation of normal signaling pathways coupled to neurotransmitters.
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Affiliation(s)
- Benoit Schneider
- Institut André Lwoff-Institut Pasteur, CNRS FRE 2937, Laboratoire Différenciation Cellulaire et Prions, 7 rue Guy Môquet, 94801 Villejuif Cedex, France.
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39
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Veber D, Mutti E, Galmozzi E, Cedrola S, Galbiati S, Morabito A, Tredici G, La Porta CA, Scalabrino G. Increased levels of the CD40:CD40 ligand dyad in the cerebrospinal fluid of rats with vitamin B12(cobalamin)-deficient central neuropathy. J Neuroimmunol 2006; 176:24-33. [PMID: 16716410 DOI: 10.1016/j.jneuroim.2006.04.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2005] [Revised: 03/31/2006] [Accepted: 04/03/2006] [Indexed: 01/30/2023]
Abstract
The levels of the soluble (s) CD40:sCD40 ligand (L) dyad, which belongs to the tumor necrosis factor (TNF)-alpha:TNF-alpha-receptor superfamily, are significantly increased in the cerebrospinal fluid (CSF), but not the serum of cobalamin (Cbl)-deficient (Cbl-D) rats. They were normalized or significantly reduced after treatment with Cbl, transforming growth factor-beta1 or S-adenosyl-L-methionine, and the normal myelin ultrastructure of the spinal cord was concomitantly restored. The concomitance of the two beneficial effects of these treatments strongly suggests that the increases in CSF sCD40:sCD40L levels may participate in the pathogenesis of purely myelinolytic Cbl-D central neuropathy in the rat. In keeping with this, an anti-CD40 treatment prevented myelin lesions.
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Affiliation(s)
- Daniela Veber
- Institute of General Pathology and Center of Excellence on Neurodegenerative Diseases, University of Milan, via Mangiagalli 31, 20133 Milano, Italy
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40
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Scalabrino G, Peracchi M. New insights into the pathophysiology of cobalamin deficiency. Trends Mol Med 2006; 12:247-54. [PMID: 16690356 DOI: 10.1016/j.molmed.2006.04.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 04/07/2006] [Accepted: 04/24/2006] [Indexed: 11/29/2022]
Abstract
Cobalamin-deficient (Cbl-D) central neuropathy in the rat is associated with a locally increased expression of neurotoxic tumour necrosis factor-alpha (TNF-alpha) and a locally decreased expression of neurotrophic epidermal growth factor (EGF). These recent findings suggest that cobalamin oppositely regulates the expression of TNF-alpha and EGF, and raise the possibility that these effects might be independent of its coenzyme function. Furthermore, adult Cbl-D patients have high levels of TNF-alpha and low levels of EGF in the serum and cerebrospinal fluid. Serum levels of TNF-alpha and EGF of cobalamin-treated patients normalize concomitantly with haematological disease remission. These observations suggest that cobalamin deficiency induces an imbalance in TNF-alpha and EGF levels in biological fluids that might have a role in the pathogenesis of the damage caused by pernicious anaemia.
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Affiliation(s)
- Giuseppe Scalabrino
- Institute of General Pathology and Centre of Excellence on Neurodegenerative Diseases, University of Milan, Via Mangiagalli 31, I-20133 Milano, Italy.
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Guentchev M, Groschup MH, Kordek R, Liberski PP, Budka H. Severe, early and selective loss of a subpopulation of GABAergic inhibitory neurons in experimental transmissible spongiform encephalopathies. Brain Pathol 2006; 8:615-23. [PMID: 9804371 PMCID: PMC8098355 DOI: 10.1111/j.1750-3639.1998.tb00188.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Little is known about the pathogenetic basis of characteristic symptoms in transmissible spongiform encephalopathies (TSEs) such as myoclonus and characteristic EEG hyperactivity. We investigated the GABAergic system and its subpopulations in mice inoculated with experimental scrapie (ME7, RML, 22A strains) and Creutzfeldt-Jakob disease (CJD; Fujisaki strain), to study damage to inhibitory neurons. Since recent studies have shown electrophysiological changes in prion protein (PrP) knockout mice, we also studied mice lacking or overexpressing the PrP gene. Antibodies against glutamic acid decarboxylase (GAD), parvalbumin (PV), calbindin (CB), and calretinin (CR) were used to stain GABAergic neurons, and isolectin-B4 to stain perineuronal nets around PV+ neurons. In scrapie infected mice, cortical PV+ neurons were severely reduced while CB+ and CR+ neurons were well preserved. In CJD inoculated mice, loss of PV+ neurons was severe and occurred very early after inoculation. PrP-/- and tg20 mice showed normal appearance of PV, CB, CR, GAD+ neurons and their neuropil, and of isolectin-B4+ perineuronal nets. The early, severe and selective loss of cortical PV+ neurons in experimental scrapie and CJD suggest selective loss of PV+ GABAergic neurons as important event during disease development, possibly as one basis of excitatory symptoms in TSEs.
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Affiliation(s)
- M Guentchev
- Austrian Reference Center for Human Prion Diseases and Institute of Neurology, University of Vienna
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Brazier MW, Lewis V, Ciccotosto GD, Klug GM, Lawson VA, Cappai R, Ironside JW, Masters CL, Hill AF, White AR, Collins S. Correlative studies support lipid peroxidation is linked to PrPres propagation as an early primary pathogenic event in prion disease. Brain Res Bull 2006; 68:346-54. [PMID: 16377442 DOI: 10.1016/j.brainresbull.2005.09.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2005] [Accepted: 09/20/2005] [Indexed: 11/29/2022]
Abstract
To assess whether heightened oxidative stress plays an early and primary pathogenic role in transmissible spongiform encephalopathies (TSE), we undertook detailed correlative studies using a mouse-adapted model of human disease. The spatio-temporal evolution of the abnormal, protease-resistant isoform of the prion protein (PrP(res)) and neuropathological changes were correlated with the occurrence and type of oxidative stress. Heightened oxidative stress was demonstrated, but restricted to elevated levels of free aldehydic breakdown products of lipid peroxidation, affecting all brain regions to varying extents. The increase in lipid peroxidation was highest over the mid-incubation period, with the onset showing close temporal and general topographical concordance with the first detection of PrP(res) with both pre-empting the typical neuropathological changes of spongiform change, gliosis and neuronal loss. Further, prion propagation over the disease course was assessed using murine bioassay. This revealed that the initial rapid increase in infectivity titres was contemporaneous with the abrupt onset and maximisation of lipid peroxidation. The present results are an important extension to previous studies, showing that heightened oxidative stress in the form of lipid peroxidation is likely to constitute an early primary pathogenic event in TSE, associated temporally with the integral disease processes of prion propagation and PrP(res) formation, and consistent with causal links between these events and subsequent typical neuropathological changes.
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Affiliation(s)
- Marcus W Brazier
- Department of Pathology, The University of Melbourne, Vic. 3010, Australia
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43
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Pietri M, Schneider B, Mouillet-Richard S, Ermonval M, Mutel V, Launay JM, Kellermann O. Reactive oxygen species‐dependent TNF‐α converting enzyme activation through stimulation of 5‐HT2Band α1Dautoreceptors in neuronal cells. FASEB J 2005; 19:1078-87. [PMID: 15985531 DOI: 10.1096/fj.04-3631com] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A major determinant of neuronal homeostasis is the proper integration of cell signaling pathways recruited by a variety of neuronal and non-neuronal factors. By taking advantage of a neuroectodermal cell line (1C11) endowed with the capacity to differentiate into serotonergic (1C115-HT) or noradrenergic (1C11NE) neurons, we identified serotonin (5-hydroxytryptamine, 5-HT)- and norepinephrine (NE)-dependent signaling cascades possibly involved in neuronal functions. First, we establish that 5-HT2B receptors and 1D adrenoceptors are functionally coupled to reactive oxygen species (ROS) synthesis through NADPH oxidase activation in 1C115-HT and 1C11NE cells. This observation constitutes the prime evidence that bioaminergic autoreceptors take part in the control of the cellular redox equilibrium in a neuronal context. Second, our data identify TACE (TNF- Converting Enzyme), a member of a disintegrin and metalloproteinase (ADAM) family, as a downstream target of the 5-HT2B and 1D receptor-NADPH oxidase signaling pathways. Upon 5-HT2B or 1D receptor stimulation, ROS fully govern TNF- shedding in the surrounding milieu of 1C115-HT or 1C11NE cells. Third, 5-HT2B and 1Dreceptor couplings to the NADPH oxidase-TACE cascade are strictly restricted to 1C11-derived progenies that have implemented a complete serotonergic or noradrenergic phenotype. Overall, these observations suggest that 5-HT2B and 1D autoreceptors may play a role in the maintenance of neuron- and neurotransmitter-associated functions. Eventually, our study may have implications regarding the origin of oxidative stress as well as up-regulated expression of proinflammatory cytokines in neurodegenerative disorders, which may relate to the deviation of normal signaling pathways.
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Affiliation(s)
- Mathéa Pietri
- Institut André Lwoff-Institut Pasteur, CNRS UPR 1983, Laboratoire de Différenciation Cellulaire et Prions, Villejuif Cedex, France
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Magri G, Clerici M, Dall'Ara P, Biasin M, Caramelli M, Casalone C, Giannino ML, Longhi R, Piacentini L, Della Bella S, Gazzuola P, Martino PA, Della Bella S, Pollera C, Puricelli M, Servida F, Crescio I, Boasso A, Ponti W, Poli G. Decrease in pathology and progression of scrapie after immunisation with synthetic prion protein peptides in hamsters. Vaccine 2005; 23:2862-8. [PMID: 15780734 DOI: 10.1016/j.vaccine.2004.11.067] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Revised: 10/12/2004] [Accepted: 11/25/2004] [Indexed: 01/06/2023]
Abstract
Effective therapy for prion diseases is currently unavailable. Recently, vaccination was shown to be effective in mouse models of a particular neurodegenerative conditions: Alzheimer's disease (AD). Here, we report that vaccination with synthetic oligopeptides homologous to the hamster (Mesocricetus auratus) prion protein augments survival time in animals infected intraperitoneally with 263K scrapie agent. For each hamster included in the study, prion-specific serum antibodies as well as deposition of pathological prion protein (PrP(res)), glial fibrillary acidic protein (GFAP), and mRNA expression for cytokines (TNF alpha, IL-1beta, IL-10) in brain tissues were evaluated. In immunized animals, increased survival after challenge was associated with a reduction of cerebral lesion, PrP deposition and GFAP expression; in these animals, anti-prion protein peptide antibody levels were increased, and the expression of pro-inflammatory cytokines (TNF alpha and IL-1beta) was reduced. Vaccination could be an effective therapeutic approach to postpone disease onset.
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Affiliation(s)
- Giuliana Magri
- Laboratory of Immunology, DSP LITA Vialba, Universita' degli Studi di Milano, Via G.B. Grassi 74, 20157 Milano, Italy
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Scalabrino G. Cobalamin (vitamin B12) in subacute combined degeneration and beyond: traditional interpretations and novel theories. Exp Neurol 2005; 192:463-79. [PMID: 15755562 DOI: 10.1016/j.expneurol.2004.12.020] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Revised: 12/14/2004] [Accepted: 12/16/2004] [Indexed: 11/19/2022]
Abstract
Subacute combined degeneration (SCD) is a neuropathy due to cobalamin (Cbl) (vitamin B(12)) deficiency acquired in adult age. Hitherto, the theories advanced to explain the pathogenesis of SCD have postulated a causal relationship between SCD lesions and the impairment of either or both of two Cbl-dependent reactions. We have identified a new experimental model, the totally gastrectomized rat, to reproduce the key morphological features of the disease [spongy vacuolation, intramyelinic and interstitial edema of the white matter of the central nervous system (CNS), and astrogliosis], and found new mechanisms responsible for the pathogenesis of SCD: the neuropathological lesions in TGX rats are not only due to mere vitamin withdrawal but also to the overproduction of the myelinolytic tumor necrosis factor (TNF)-alpha and the reduced synthesis of the two neurotrophic agents, epidermal growth factor (EGF) and interleukin-6. This deregulation of the balance between TNF-alpha and EGF synthesis induced by Cbl deficiency has been verified in the sera of patients with pernicious anemia (but not in those with iron-deficient anemia), and in the cerebrospinal fluid (CSF) of SCD patients. These new functions are not linked to the coenzyme functions of the vitamin, but it is still unknown whether they involve genetic or epigenetic mechanisms. Low Cbl levels have also been repeatedly observed in the sera and/or CSF of patients with Alzheimer's disease or multiple sclerosis, but whether Cbl deficit plays a role in the pathogenesis of these diseases is still unclear.
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Affiliation(s)
- Giuseppe Scalabrino
- Institute of General Pathology and Center of Excellence on Neurodegenerative Diseases, University of Milan, Via Mangiagalli 31, I-20133 Milan, Italy.
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Thackray AM, McKenzie AN, Klein MA, Lauder A, Bujdoso R. Accelerated prion disease in the absence of interleukin-10. J Virol 2004; 78:13697-707. [PMID: 15564479 PMCID: PMC533935 DOI: 10.1128/jvi.78.24.13697-13707.2004] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The identity of pro- and anti-inflammatory cytokines in the neuropathogenesis of prion diseases remains undefined. Here we have investigated the role of anti-inflammatory cytokines on the progression of prion disease through the use of mice that lack interleukin-4 (IL-4), IL-10, IL-13, or both IL-4 and IL-13. Collectively our data show that among these anti-inflammatory cytokines, IL-10 plays a prominent role in the regulation of prion disease. Mice deficient in IL-10 are highly susceptible to the development of prion disease and show a markedly shortened incubation time. In addition, we have correlated cytokine gene expression in prion-inoculated IL-10(-/-) mice to wild-type-inoculated animals. Our experiments show that in the absence of IL-10 there is an early expression of tumor necrosis factor alpha (TNF-alpha). In wild-type prion-inoculated mice, the expression of TNF-alpha mRNA occurs at a later time point that correlates with the extended incubation time for terminal disease development in these animals compared to those that lack IL-10. Elevated levels of IL-13 mRNA are found at early time points in the central nervous system of prion-inoculated IL-10(-/-) mice. At terminal disease, the brains of wild-type mice inoculated with RML or ME7 are characterized by elevated levels of mRNA for the proinflammatory cytokines TNF-alpha and IL-1beta, together with the anti-inflammatory cytokines IL-10, IL-13, and transforming growth factor beta. Our data are consistent with a role for proinflammatory cytokines in the initiation of pathology during prion disease and an attempt by anti-inflammatory cytokines to regulate the ensuing, invariably fatal pathology.
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Affiliation(s)
- Alana M Thackray
- Centre for Veterinary Science, Department of Clinical Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 OES, United Kingdom
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Khan HA. Detection and semi-quantitative determination of low abundance GFAP mRNA in mouse brain by capillary electrophoresis coupled with laser-induced fluorescence. BRAIN RESEARCH. BRAIN RESEARCH PROTOCOLS 2004; 14:13-7. [PMID: 15519947 DOI: 10.1016/j.brainresprot.2004.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/05/2004] [Indexed: 02/08/2023]
Abstract
The sensitivity of capillary electrophoresis coupled with laser-induced fluorescence (CE-LIF) was compared with conventional agarose gel electrophoresis-ethidium bromide-UV method (AE-EUV) for detection and semi-quantitative determination of GFAP mRNA in mouse brain. GFAP expression was induced by the neurotoxin MPTP in C57BL mice. Serially diluted RNA samples (0.0003, 0.003, 0.03, 0.3, and 3 microg total RNA) were subjected to RT-PCR and analyzed by both procedures. The integrated pixel density (AE-EUV) and peak area (CE-LIF) were directly proportional to the amount of RNA. However, the observed high sensitivity of CE-LIF suggests its potential application for detection and semi-quantitative determination of low-abundance mRNA transcripts.
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Affiliation(s)
- Haseeb Ahmad Khan
- Department of Biochemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
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Brown AR, Webb J, Rebus S, Williams A, Fazakerley JK. Identification of up-regulated genes by array analysis in scrapie-infected mouse brains. Neuropathol Appl Neurobiol 2004; 30:555-67. [PMID: 15488032 DOI: 10.1111/j.1365-2990.2004.00565.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The major neuropathological features of the transmissible spongiform encephalopathies (TSEs) are well documented, however, the underlying molecular events are poorly defined. We have applied cDNA expression arrays and quantitative RT-PCR to the study of gene expression in the brain, and more specifically in the hippocampus, of the well-characterized ME7/CV mouse model of scrapie. The number of genes showing consistent, scrapie-associated changes in expression was limited, and was primarily restricted to glial-associated genes. Increased expression of genes encoding glial fibrillary acidic protein, vimentin, complement component 1q (alpha and beta polypeptides), cathepsin D, clusterin and cystatin C was evident in the hippocampus from 170 days after inoculation (dpi), with expression increasing thereafter to terminal disease (225-235 dpi). Elevation of gene expression preceded clinical disease by approximately 30 days, and coincided with a 20-day period in the ME7/CV model during which 50% of the CA1 hippocampal neurones are lost. Increased expression of cystatin C, an inhibitor of lysosomal cysteine proteases, is a novel finding in the context of TSE neuropathology and was confirmed by Western analysis and immunocytochemistry.
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Affiliation(s)
- A R Brown
- Centre for Infectious Diseases, University of Edinburgh, Edinburgh, UK
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Brown AR, Webb J, Rebus S, Walker R, Williams A, Fazakerley JK. Inducible cytokine gene expression in the brain in the ME7/CV mouse model of scrapie is highly restricted, is at a strikingly low level relative to the degree of gliosis and occurs only late in disease. J Gen Virol 2003; 84:2605-2611. [PMID: 12917482 DOI: 10.1099/vir.0.19137-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The temporal course of cerebral cytokine gene expression was investigated in the ME7/CV murine scrapie model to determine any association with neuropathological events. Analysis by RNase protection assay (RPA) demonstrated no transcripts for ILs 2, 3, 4, 5, 6, 7, 10, 12p40 and 13, granulocyte macrophage colony-stimulating factor, IFN-gamma or lymphotoxin-alpha at any time during the course of this disease. Transcripts for transforming growth factor-beta 1 were constitutively expressed in both control and scrapie-infected brain and were elevated at terminal disease. RPA and quantitative real-time RT-PCR detected low levels of transcripts for IL-1 alpha, IL-1 beta and TNF alpha in scrapie-infected brain but only IL-1 beta was elevated consistently in all mice studied. Although glial cell activation within the hippocampus was evident from 100 days post-infection (p.i.), elevated IL-1 beta transcripts (and immunoreactivity) were evident from 180 days p.i., around the time of hippocampal pyramidal neuron loss, and increased steadily thereafter to reach a 3.5-fold increase at terminal disease. Even at their maximum, levels of these transcripts were disproportionately low relative to the degree of glial cell activation. It is concluded that cytokine gene expression in the ME7 scrapie-infected mouse brain, relative to the degree of reactive gliosis, is highly restricted, temporally late and disproportionately low.
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Affiliation(s)
- Alan R Brown
- Centre for Infectious Diseases, University of Edinburgh, Summerhall, Edinburgh EH9 1QH, UK
| | - Jeanette Webb
- Centre for Infectious Diseases, University of Edinburgh, Summerhall, Edinburgh EH9 1QH, UK
| | - Selma Rebus
- Institute of Comparative Medicine, Department of Veterinary Pathology, University of Glasgow, Glasgow, UK
| | - Robert Walker
- Centre for Infectious Diseases, University of Edinburgh, Summerhall, Edinburgh EH9 1QH, UK
| | - Alun Williams
- Institute of Comparative Medicine, Department of Veterinary Pathology, University of Glasgow, Glasgow, UK
| | - John K Fazakerley
- Centre for Infectious Diseases, University of Edinburgh, Summerhall, Edinburgh EH9 1QH, UK
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Waliś A, Bratosiewicz J, Sikorska B, Brown P, Gajdusek DC, Liberski PP. Ultrastructural changes in the optic nerves of rodents with experimental Creutzfeldt-Jakob Disease (CJD), Gerstmann-Sträussler-Scheinker disease (GSS) or scrapie. J Comp Pathol 2003; 129:213-25. [PMID: 12921728 DOI: 10.1016/s0021-9975(03)00037-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This report describes the ultrastructural changes in the optic nerves of (1) hamsters infected with the Echigo-1 strain of Creutzfeldt-Jakob disease (CJD), (2) hamsters infected with the 263K or 22C-H strain of scrapie, and (3) mice infected with the Fujisaki strain of Gerstmann-Sträussler-Scheinker disease (GSS). Vacuolation of myelinated fibres was present in the myelin sheaths, with splitting of myelin lamellae. These vacuoles contained typical secondary vacuoles and curled membrane fragments. Myelinated fibre vacuolation was also accompanied by an exuberant cellular reaction consisting of macrophages containing numerous mitochondria, abundant rough endoplasmic reticulum, and secondary lysosomes filled with digested myelin debris and other electron-dense material. Within macrophages, myelin fragments undergoing active digestion, lyre-like bodies and paracrystalline inclusions were frequently noted. Astrocytes and their processes were prominent; glial filaments and many mitochondria were readily detected. Proliferation of inner mesaxons was observed. Cross-sectional profiles of innumerable myelinated fibres contained membranous organelles continuous with the inner lamellae of the oligodendroglial cells. The proliferations of inner mesaxons formed whorls and loops, and intrusion of the membranous tongue of the inner mesaxon into the axoplasm was occasionally observed; dystrophic neurites were relatively numerous. In mice infected with the Fujisaki strain of GSS, fibres had undergone demyelination with stripping of the myelin lamellae, while others showed vesicular myelin degeneration.
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Affiliation(s)
- A Waliś
- Department of Molecular Pathology and Neuropathology, Medical University of Lodz, Poland
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