scholarly journals Investigating the mechanism by which the atypical antipsychotic clozapine reduces disease in experimental autoimmune encephalomyelitis

2021 ◽  
Author(s):  
◽  
Pirooz Zareie

<p>Multiple sclerosis (MS) is an inflammatory disease of the central nervous system characterized by damage to the myelin sheaths that surround nerve axons. Inflammatory damage to the myelin sheath leads to severe physical disability in patients. Whereas approved disease modifying treatments are available for relapsing-remitting forms of MS, there are no approved treatments for the progressive stages, leaving approximately 50% of MS sufferers without treatment. Therefore, there is an urgent need for development of effective alternatives.  Atypical antipsychotic agents used for treating schizophrenia have recently been recognized for their immune-modifying properties and our laboratory has shown previously that treating mice with risperidone or clozapine reduces the severity of disease in experimental autoimmune encephalomyelitis (EAE), an animal model for MS. Although atypical antipsychotic agents like clozapine have been used in the clinic for almost 60 years, there is very little experimental data that describes the mechanism by which atypical antipsychotic agents like clozapine are able to modify the immune response. This thesis aimed to describe the immunological mechanisms by which clozapine is able to reduce EAE disease and to determine the underlying cellular signalling alterations that occur during treatment to facilitate immune modifying properties.  In vitro experiments showed that clozapine can impair induction of Th1 and Th17 cells while promoting the differentiation of iTreg and increasing Foxp3 expression. However, although clozapine effectively delayed disease onset and reduced the severity of EAE, the therapeutic effect of clozapine was not associated with impaired capacity to induce antigen specific Th1 or Th17 responses in the periphery. Moreover, Treg function was dispensable for disease protection by clozapine. Instead, disease protection by clozapine was associated with a suppressed state of activation in CNS resident microglia and infiltrating monocytes assessed by flow cytometric measurement of activation associated receptor expression. In vitro experiments using primary macrophage cell culture revealed that clozapine can alter the activation of activated macrophages towards a less inflammatory state directly. Interestingly, the altered state of activation in primary macrophages was not associated with detectable changes in cell signalling pathways known to mediate activation.  This thesis demonstrated that clozapine treatment protects from EAE by a multi-faceted immunological mechanism that likely involves modifying multiple pathways and cell types during EAE and may be of therapeutic benefit to MS patients in the progressive stages of disease. Finally, this thesis also has relevance to psychiatry as it demonstrates that clozapine has potential to alter cellular immune responses.</p>

2021 ◽  
Author(s):  
◽  
Pirooz Zareie

<p>Multiple sclerosis (MS) is an inflammatory disease of the central nervous system characterized by damage to the myelin sheaths that surround nerve axons. Inflammatory damage to the myelin sheath leads to severe physical disability in patients. Whereas approved disease modifying treatments are available for relapsing-remitting forms of MS, there are no approved treatments for the progressive stages, leaving approximately 50% of MS sufferers without treatment. Therefore, there is an urgent need for development of effective alternatives.  Atypical antipsychotic agents used for treating schizophrenia have recently been recognized for their immune-modifying properties and our laboratory has shown previously that treating mice with risperidone or clozapine reduces the severity of disease in experimental autoimmune encephalomyelitis (EAE), an animal model for MS. Although atypical antipsychotic agents like clozapine have been used in the clinic for almost 60 years, there is very little experimental data that describes the mechanism by which atypical antipsychotic agents like clozapine are able to modify the immune response. This thesis aimed to describe the immunological mechanisms by which clozapine is able to reduce EAE disease and to determine the underlying cellular signalling alterations that occur during treatment to facilitate immune modifying properties.  In vitro experiments showed that clozapine can impair induction of Th1 and Th17 cells while promoting the differentiation of iTreg and increasing Foxp3 expression. However, although clozapine effectively delayed disease onset and reduced the severity of EAE, the therapeutic effect of clozapine was not associated with impaired capacity to induce antigen specific Th1 or Th17 responses in the periphery. Moreover, Treg function was dispensable for disease protection by clozapine. Instead, disease protection by clozapine was associated with a suppressed state of activation in CNS resident microglia and infiltrating monocytes assessed by flow cytometric measurement of activation associated receptor expression. In vitro experiments using primary macrophage cell culture revealed that clozapine can alter the activation of activated macrophages towards a less inflammatory state directly. Interestingly, the altered state of activation in primary macrophages was not associated with detectable changes in cell signalling pathways known to mediate activation.  This thesis demonstrated that clozapine treatment protects from EAE by a multi-faceted immunological mechanism that likely involves modifying multiple pathways and cell types during EAE and may be of therapeutic benefit to MS patients in the progressive stages of disease. Finally, this thesis also has relevance to psychiatry as it demonstrates that clozapine has potential to alter cellular immune responses.</p>


2017 ◽  
Vol 3 (1) ◽  
pp. 205521731769872 ◽  
Author(s):  
Laura K Green ◽  
Pirooz Zareie ◽  
Nikki Templeton ◽  
Robert A Keyzers ◽  
Bronwen Connor ◽  
...  

Background Atypical antipsychotic agents (AAP) alleviate the symptoms of severe mental health disorders, such as schizophrenia, by antagonizing dopamine and serotonin receptors. Recently, AAP have also been shown to exhibit immunomodulatory properties in the central nervous system (CNS). Objective Building on research which demonstrated the ability of the AAP risperidone and clozapine to modify the disease course of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), we aimed to more fully investigate the potential of clozapine as a possible treatment for MS. Results We report that orally administered clozapine significantly reduced the disease severity of EAE in a dose-dependent manner and was effective when administered prophylactically and therapeutically. In comparison to risperidone, quetiapine, and olanzapine, clozapine was the best at reducing disease severity. While clozapine-treated mice had only modest changes to peripheral leukocytes and cytokine responses, these animals had significantly fewer CNS-infiltrating CD4 T cells and myeloid cells. Furthermore, the CNS myeloid cells displayed a less activated phenotype in mice treated with clozapine. Finally, we found that co-administration of clozapine with glatiramer acetate enhanced disease protection compared to either treatment alone. Conclusion These studies indicate that clozapine is an effective immunomodulatory agent with the potential to treat immune-mediated diseases such as MS.


2021 ◽  
Author(s):  
Xiaomei Liu ◽  
Feng Zhou ◽  
Weixiao Wang ◽  
Guofang Chen ◽  
Qingxiu Zhang ◽  
...  

Abstract Background Interleukin 9 (IL-9), produced mainly by T helper 9 (Th9) cells, has been recognized as an important regulator in multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Astrocytes respond to IL-9 and reactive astrocytes always associate with blood-brain barrier damage, immune cells infiltration and spinal injury in MS and EAE. Several long non-coding RNAs (lncRNAs) with aberrant expression have been identified in the pathogenesis of MS. Here, we examined the effects of lncRNA Gm13568 (a co-upregulated lncRNA both in EAE mice and in mouse primary astrocytes activated by IL-9) on the activation of astrocytes and the process of EAE. Methods In vitro, shRNA-recombinant lentivirus with Glial fibrillary acidic protein (GFAP) promoter were performed to determine the relative gene expression and proinflammatory cytokines production in IL-9 treated-astrocytes using Western blot, real-time PCR and Cytometric bead array, respectively. RIP and ChIP assays were analyzed for the mechanism of lncRNA Gm13568 regulating gene expression. Immunofluorescence assays was performed to measure the protein expression in astrocytes. In vivo, H&E staining and LFB staining were applied to detect the inflammatory cells infiltrations and the medullary sheath damage in spinal cords of EAE mice infected by the recombinant lentivirus. Results were analyzed by one-way ANOVA or student’s t-test, as appropriate. Results Knockdown of the endogenous lncRNA Gm13568 remarkably inhibits the Notch1 expression, astrocytosis and the phosphorylation of signal transducer and activator of transcription 3 (p-STAT3) as well as the production of inflammatory cytokines and chemokines (IL-6, TNF-α, IP-10) in IL-9 activated astrocytes. In which, Gm13568 associates with CBP/P300 is enriched in the promoter of Notch1 genes. More importantly, inhibiting Gm13568 with lentiviral vector in astrocytes ameliorates significantly inflammation and demyelination in EAE mice, therefore delaying the EAE process. Conclusions These findings uncover that Gm13568 regulates the production of inflammatory cytokines in active astrocytes and affects the pathogenesis of EAE through the Notch1/STAT3 pathway. LncRNA Gm13568 may be a promising target for treating MS and demyelinating diseases.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Wen-Tsan Weng ◽  
Ping-Chang Kuo ◽  
Dennis A. Brown ◽  
Barbara A. Scofield ◽  
Destin Furnas ◽  
...  

Abstract Background Multiple sclerosis (MS) is a progressive autoimmune disease characterized by the accumulation of pathogenic inflammatory immune cells in the central nervous system (CNS) that subsequently causes focal inflammation, demyelination, axonal injury, and neuronal damage. Experimental autoimmune encephalomyelitis (EAE) is a well-established murine model that mimics the key features of MS. Presently, the dietary consumption of foods rich in phenols has been reported to offer numerous health benefits, including anti-inflammatory activity. One such compound, 4-ethylguaiacol (4-EG), found in various foods, is known to attenuate inflammatory immune responses. However, whether 4-EG exerts anti-inflammatory effects on modulating the CNS inflammatory immune responses remains unknown. Thus, in this study, we assessed the therapeutic effect of 4-EG in EAE using both chronic and relapsing-remitting animal models and investigated the immunomodulatory effects of 4-EG on neuroinflammation and Th1/Th17 differentiation in EAE. Methods Chronic C57BL/6 EAE and relapsing-remitting SJL/J EAE were induced followed by 4-EG treatment. The effects of 4-EG on disease progression, peripheral Th1/Th17 differentiation, CNS Th1/Th17 infiltration, microglia (MG) activation, and blood-brain barrier (BBB) disruption in EAE were evaluated. In addition, the expression of MMP9, MMP3, HO-1, and Nrf2 was assessed in the CNS of C57BL/6 EAE mice. Results Our results showed that 4-EG not only ameliorated disease severity in C57BL/6 chronic EAE but also mitigated disease progression in SJL/J relapsing-remitting EAE. Further investigations of the cellular and molecular mechanisms revealed that 4-EG suppressed MG activation, mitigated BBB disruption, repressed MMP3/MMP9 production, and inhibited Th1 and Th17 infiltration in the CNS of EAE. Furthermore, 4-EG suppressed Th1 and Th17 differentiation in the periphery of EAE and in vitro Th1 and Th17 cultures. Finally, we found 4-EG induced HO-1 expression in the CNS of EAE in vivo as well as in MG, BV2 cells, and macrophages in vitro. Conclusions Our work demonstrates that 4-EG confers protection against autoimmune disease EAE through modulating neuroinflammation and inhibiting Th1 and Th17 differentiation, suggesting 4-EG, a natural compound, could be potentially developed as a therapeutic agent for the treatment of MS/EAE.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Xuebin Qu ◽  
Jingjing Han ◽  
Ying Zhang ◽  
Xingqi Wang ◽  
Hongbin Fan ◽  
...  

Abstract Background Toll-like receptor 4 (TLR4) is well known for activating the innate immune system; however, it is also highly expressed in adaptive immune cells, such as CD4+ T-helper 17 (Th17) cells, which play a key role in multiple sclerosis (MS) pathology. However, the function and governing mechanism of TLR4 in Th17 remain unclear. Methods The changes of TLR4 in CD4+ T cells from MS patients and experimental autoimmune encephalomyelitis (EAE) mice were tested. TLR4-deficient (TLR4−/−) naïve T cells were induced in vitro and transferred into Rag1−/− mice to measure Th17 differentiation and EAE pathology. DNA sequence analyses combining with deletion fragments and mutation analyses, chromatin immunoprecipitation (ChIP), and electrophoretic mobility shift assay (EMSA) were used to explore the mechanism of TLR4 signaling pathway in regulating Th17 differentiation. Results The levels of TLR4 were increased in CD4+ Th17 cells both from MS patients and EAE mice, as well as during Th17 differentiation in vitro. TLR4−/− CD4+ naïve T cells inhibited their differentiation into Th17, and transfer of TLR4−/− CD4+ naïve T cells into Rag1−/− mice was defective in promoting EAE, characterized by less demyelination and Th17 infiltration in the spinal cord. TLR4 signal enhanced Th17 differentiation by activating RelA, downregulating the expression of miR-30a, a negative regulator of Th17 differentiation. Inhibition of RelA activity increased miR-30a level, but decreased Th17 differentiation rate. Furthermore, RelA directly regulated the expression of miR-30a via specific binding to a conserved element of miR-30a gene. Conclusions TLR4−/− CD4+ naïve T cells are inadequate in differentiating to Th17 cells both in vitro and in vivo. TLR4-RelA-miR-30a signal pathway regulates Th17 differentiation via direct binding of RelA to the regulatory element of miR-30a gene. Our results indicate modulating TLR4-RelA-miR-30a signal in Th17 may be a therapeutic target for Th17-mediated neurodegeneration in neuroinflammatory diseases.


2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Pei-Yuan Zhao ◽  
Jing Ji ◽  
Xi-Hong Liu ◽  
Hui Zhao ◽  
Bin Xue ◽  
...  

Multiple sclerosis (MS) is a common inflammatory demyelinating disorder of the central nervous system. Bu-shen-yi-sui capsule (BSYSC) could significantly reduce the relapse rate, prevent the progression of MS, and enhance remyelination following neurological injury in experimental autoimmune encephalomyelitis (EAE), an established model of MS; however, the mechanism underlying the effect of BSYSC on remyelination has not been well elucidated. This study showed that exosomes carrying biological information are involved in the pathological process of MS and that modified exosomes can promote remyelination by modulating related proteins and microRNAs (miRs). Here, the mechanism by which BSYSC promoted remyelination via exosome-mediated molecular signals was investigated in EAE mice and oligodendrocyte progenitor cells (OPCs) in vitro. The results showed that BSYSC treatment significantly improved the body weight and clinical scores of EAE mice, alleviated inflammatory infiltration and nerve fiber injury, protected the ultrastructural integrity of the myelin sheath, and significantly increased the expression of myelin basic protein (MBP) in EAE mice. In an in vitro OPC study, BSYSC-containing serum, especially 20% BSYSC, promoted the proliferation and migration of OPCs and induced OPCs to differentiate into mature oligodendrocytes that expressed MBP. Furthermore, BSYSC treatment regulated the expression of neuropilin- (NRP-) 1 and GTX, downregulated the expression of miR-16, let-7, miR-15, miR-98, miR-486, and miR-182, and upregulated the level of miR-146 in serum exosomes of EAE mice. In conclusion, these results suggested that BSYSC has a neuroprotective effect and facilitates remyelination and that the mechanism underlying the effect of BSYSC on remyelination probably involves regulation of the NRP-1 and GTX proteins and miRs in serum exosomes, which drive promyelination.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Kuo-Kuei Huang ◽  
Meng-Nan Lin ◽  
Yi-Ling Hsu ◽  
I-Huang Lu ◽  
I-Hong Pan ◽  
...  

Alpinia oxyphylla is a traditional Chinese medicine widely used for treating diarrhea, ulceration, and enuresis. Moreover, A. oxyphylla is effective for cognitive function improvement and nerve regeneration. Multiple sclerosis (MS) is a chronic neuronal inflammatory autoimmune disease that commonly affects young adults in high-latitude regions. The aim of this study was to evaluate the beneficial effects of A. oxyphylla in an experimental autoimmune encephalomyelitis (EAE) mouse model, which is an extensively used model for human MS. The ethanolic extract of A. oxyphylla fruit (AO-1) was orally administered to EAE mice. Our results showed AO-1 significantly reduced EAE symptoms. Histopathological analysis showed AO-1 reduced demyelination, inflammation, gliosis, and axonal swelling in the spinal cord. Furthermore, immunohistochemistry and quantitative polymerase chain reaction (qPCR) studies revealed that the infiltration of CD4+, CD8+ T cells, and CD11b+ monocytes into the spinal cord decreased in the AO-1-treated group. Mechanistically, the Th1 transcription factor T-bet, Th17 transcription factor retinoic acid receptor–related orphan receptor γ (RORγt), and inflammatory cytokines interferon (IFN)-γ and interleukin (IL)-17 were reduced in the spinal cords of mice treated with AO-1. The expression levels of T-bet and RORγt were also lowered in the spleens of those mice. Further in vitro study showed AO-1 inhibited production of IFN-γ, IL-2, and tumor necrosis factor-α from MOG35-55-peptide-stimulated splenocytes. One component isolated from AO-1, yakuchinone A, inhibited IL-17 production in vitro and reduced EAE symptoms in the mice. Collectively, our results indicate that AO-1 ameliorated the severity of EAE in mice and may involve the regulation of Th1/Th17 response. A. oxyphylla warrants further investigation, particularly regarding its clinical benefits for MS.


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