scholarly journals NLRP3 Inflammasome and MS/EAE

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Makoto Inoue ◽  
Mari L. Shinohara

Inflammasomes are cytosolic sensors that detect pathogens and danger signals in the innate immune system. The NLRP3 inflammasome is currently the most fully characterized inflammasome and is known to detect a wide array of microbes and endogenous damage-associated molecules. Possible involvement of the NLRP3 inflammasome (or inflammasomes) in the development of multiple sclerosis (MS) was suggested in a number of studies. Recent studies showed that the NLRP3 inflammasome exacerbates experimental autoimmune encephalomyelitis (EAE), an animal model of MS, although EAE can also develop without the NLRP3 inflammasome. In this paper, we discuss the NLRP3 inflammasome in MS and EAE development.

2021 ◽  
Author(s):  
William E. Barclay ◽  
M. Elizabeth Deerhake ◽  
Makoto Inoue ◽  
Toshiaki Nonaka ◽  
Kengo Nozaki ◽  
...  

ABSTRACTInflammasomes are a class of innate immune signaling platforms that activate in response to an array of cellular damage and pathogens. Inflammasomes promote inflammation under many circumstances to enhance immunity against pathogens and inflammatory responses through their effector cytokines, IL-1β and IL-18. Multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), are such autoimmune conditions influenced by inflammasomes. Despite work investigating inflammasomes during EAE, little remains known concerning the role of inflammasomes in the central nervous system (CNS) during the disease. Here we use multiple genetically modified mouse models to monitor activated inflammasomes in situ based on ASC oligomerization in the spinal cord. Using inflammasome reporter mice, we found heightened inflammasome activation in astrocytes after the disease peak. In contrast, microglia and CNS-infiltrated myeloid cells had few activated inflammasomes in the CNS during EAE. Astrocyte inflammasome activation was dependent on AIM2, but low IL-1β expression and no significant signs of cell death were found in astrocytes during EAE. Thus, the AIM2 inflammasome activation in astrocytes may have a distinct role from traditional inflammasome-mediated inflammation.SIGNIFICANCE STATEMENTInflammasome activation in the peripheral immune system is pathogenic in multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). However, inflammasome activity in the central nervous system (CNS) is largely unexplored. Here, we used genetically modified mice to determine inflammasome activation in the CNS during EAE. Our data indicated heightened AIM2 inflammasome activation in astrocytes after the disease peak. Unexpectedly, neither CNS-infiltrated myeloid cells nor microglia were the primary cells with activated inflammasomes in SC during EAE. Despite AIM2 inflammasome activation, astrocytes did not undergo apparent cell death and produced little of the proinflammatory cytokine, IL-1β, during EAE. This study showed that CNS inflammasome activation occurs during EAE without associating with IL-1β-mediated inflammation.


2016 ◽  
Vol 113 (41) ◽  
pp. E6145-E6152 ◽  
Author(s):  
Joel Kaye ◽  
Victor Piryatinsky ◽  
Tal Birnberg ◽  
Tal Hingaly ◽  
Emanuel Raymond ◽  
...  

Laquinimod is an oral drug currently being evaluated for the treatment of relapsing, remitting, and primary progressive multiple sclerosis and Huntington’s disease. Laquinimod exerts beneficial activities on both the peripheral immune system and the CNS with distinctive changes in CNS resident cell populations, especially astrocytes and microglia. Analysis of genome-wide expression data revealed activation of the aryl hydrocarbon receptor (AhR) pathway in laquinimod-treated mice. The AhR pathway modulates the differentiation and function of several cell populations, many of which play an important role in neuroinflammation. We therefore tested the consequences of AhR activation in myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) using AhR knockout mice. We demonstrate that the pronounced effect of laquinimod on clinical score, CNS inflammation, and demyelination in EAE was abolished in AhR−/− mice. Furthermore, using bone marrow chimeras we show that deletion of AhR in the immune system fully abrogates, whereas deletion within the CNS partially abrogates the effect of laquinimod in EAE. These data strongly support the idea that AhR is necessary for the efficacy of laquinimod in EAE and that laquinimod may represent a first-in-class drug targeting AhR for the treatment of multiple sclerosis and other neurodegenerative diseases.


2015 ◽  
Vol 37 (1) ◽  
pp. 269-275 ◽  
Author(s):  
Ramona Halmer ◽  
Laura Davies ◽  
Yang Liu ◽  
Klaus Fassbender ◽  
Silke Walter

Background: Multiple sclerosis is the most common autoimmune disease of the central nervous system in young adults and histopathologically characterized by inflammation, demyelination and gliosis. It is considered as a CD4+ T cell-mediated disease, but also a disease-promoting role of the innate immune system has been proposed, based e.g. on the observation that innate immune receptors modulate disease severity of experimental autoimmune encephalomyelitis. Recent studies of our group provided first evidence for a key role of the innate immune LPS receptor (CD14) in pathophysiology of experimental autoimmune encephalomyelitis. CD14-deficient experimental autoimmune encephalomyelitis mice showed increased clinical symptoms and enhanced infiltration of monocytes and neutrophils in brain and spinal cord. Methods: In the current study, we further investigated the causes of the disease aggravation by CD14-deficiency and examined T cell activation, also focusing on the costimulatory molecules CTLA-4 and CD28, and T cell migration capacity over the blood brain barrier by FACS analysis, in vitro adhesion and transmigration assays. Results: In the results, we observed a significantly increased migration of CD14-deficient lymphocytes across an endothelial monolayer. In contrast, we did not see any differences in expression levels of TCR/CTLA-4 or TCR/CD28 and lymphocyte adhesion to endothelial cells from CD14-deficient compared to wildtype mice. Conclusion: The results demonstrate an important role of CD14 in migration of lymphocytes, and strengthen the importance of innate immune receptors in adaptive immune disorders, such as multiple sclerosis.


2020 ◽  
Vol 6 (4) ◽  
pp. 205521732095980
Author(s):  
Antoine Philippe Fournier ◽  
Erwan Baudron ◽  
Isabelle Wagnon ◽  
Philippe Aubert ◽  
Denis Vivien ◽  
...  

Background Clinical observations support the hypothesis that stressful events increase relapse occurrence in multiple sclerosis patients, while stress-reduction strategies can modulate this effect. However, a direct cause-effect relationship between stress level and relapse cannot be firmly established from these data. Objectives The purpose of this work was to address whether modulation of stress could interfere with symptom relapse in an animal model of multiple sclerosis with relapsing-remitting course. Methods Mice bred in standard or enriched environment were subjected to repeated acute stress during the remission phase of relapsing-remitting PLP-induced experimental autoimmune encephalomyelitis. Results We report that repeated acute stress induced a twofold increase in relapse incidence in experimental autoimmune encephalomyelitis. On the other hand, environmental enrichment reduced relapse incidence and severity, and reversed the effects of repeated acute stress. Conclusion These data provide the platform for further studies on the biological processes that link stress and multiple sclerosis relapses in a suitable animal model.


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