scholarly journals Clozapine Regulates Microglia and Is Effective in Chronic Experimental Autoimmune Encephalomyelitis

2021 ◽  
Vol 12 ◽  
Author(s):  
Ulaş Ceylan ◽  
Steffen Haupeltshofer ◽  
Laura Kämper ◽  
Justus Dann ◽  
Björn Ambrosius ◽  
...  

ObjectiveProgressive multiple sclerosis is characterized by chronic inflammation with microglial activation, oxidative stress, accumulation of iron and continuous neurodegeneration with inadequate effectiveness of medications used so far. We now investigated effects of iron on microglia and used the previously identified neuroprotective antipsychotic clozapine in vitro and in chronic experimental autoimmune encephalomyelitis (EAE).MethodsMicroglia were treated with iron and clozapine followed by analysis of cell death and response to oxidative stress, cytokine release and neuronal phagocytosis. Clozapine was investigated in chronic EAE regarding optimal dosing and therapeutic effectiveness in different treatment paradigms. Animals were scored clinically by blinded raters. Spinal cords were analyzed histologically for inflammation, demyelination, microglial activation and iron accumulation and for transcription changes of regulators of iron metabolism and inflammation. Effects on immune cells were analyzed using flow cytometry.ResultsIron impaired microglial function in vitro regarding phagocytosis and markers of inflammation; this was regulated by clozapine, reflected in reduced release of IL-6 and normalization of neuronal phagocytosis. In chronic EAE, clozapine dose-dependently attenuated clinical signs and still had an effect if applied in a therapeutic setting. Early mild sedative effects habituated over time. Histologically, demyelination was reduced by clozapine and positive effects on inflammation strongly correlated with reduced iron deposition. This was accompanied by reduced expression of DMT-1, an iron transport protein.ConclusionsClozapine regulates microglial function and attenuates chronic EAE, even in a therapeutic treatment paradigm. This well-defined generic medication might therefore be considered as promising add-on therapeutic for further development in progressive 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 31 (Supplement_2) ◽  
Author(s):  
Maiara Carolina Perussolo ◽  
Bassam Felipe Mogharbel ◽  
Lucia de Noronha ◽  
Katherine Athayde Teixeira de Carvalho

Abstract Background Multiple sclerosis (MS) is an autoimmune disease of the central nervous system, characterized as an inflammatory demyelinating disease. It presents a diversity of neurologic signs and symptoms as well the incapacities. Since the need for advances in MS treatment, many studies are for new therapeutic technologies, mainly through using preclinical models as experimental autoimmune encephalomyelitis (EAE). This study aimed to observe and analyze the development in Lewis rats-induced model of EAE. Methods It was used 23 females of Rattus norvegicus, from 6 to 8 weeks, weighing around 170 g. Of 23 rats, 19 underwent EAE induction distributed in six groups to establish the evolution of clinical signs. B. pertussis toxin (PTX) doses were 200, 250, 300, 350–400 ng, and four animals as the control group. The animals had weight and scores analyzed daily, starting seven and ending 24 days after induction. Then, all animals were euthanized, and the brain and spinal cord were collected for histopathological analyses. Results The results showed that the dose of 250 ng of PTX induced de higher score and weight reduction. All groups who received the PTX demonstrated histopathological findings. Those characterized as leukocyte infiltration, activation of microglia and astrocytes, and demyelinated plaques in the brain. In the spinal cord, the loosening of the myelinated fibers was observed by increasing the axonal space in all tested doses of PTX. Conclusions EAE was not dose-dependent. Histopathological findings do not proportionally related to clinical signs, as in human patients with MS.


2021 ◽  
Author(s):  
Bárbara Fernandes Pinto ◽  
Lorena Natasha Brito Ribeiro ◽  
Gisela Bevilacqua Rolfsen Ferreira da Silva ◽  
Camila Simões Freitas ◽  
Lucas Kraemer ◽  
...  

Rationale: The FDA approved Dimethyl Fumarate (DMF) as an oral drug for Multiple Sclerosis treatment based on its immunomodulatory activities. However, it also caused severe adverse effects mainly related to the gastrointestinal system. Objective: Investigated the potential effects of solid lipid nanoparticles (SLN) containing DMF, administered by inhalation on the clinical signs, central nervous system (CNS) inflammatory response, and lung function changes in mice with experimental autoimmune encephalomyelitis (EAE). Materials and Methods: EAE was induced using MOG35-55 peptide in female C57BL/6J mice and were treated via inhalation with DMF-encapsulated SLN (CTRL/SLN/DMF and EAE/SLN/DMF), empty SLN (CTRL/SLN and EAE/SLN), or saline solution (CTRL/saline and EAE/saline), every 72 hours during 21 days. Results: After 21 days post-induction, EAE mice treated with DMF-loaded SLN, when compared to EAE/saline and EAE/SLN, showed decreased clinical score and weight loss, reduction in brain and spinal cord injury and inflammation, also related to the increased influx of Foxp3+ cells into the spinal cord and lung tissues. Moreover, our data revealed that EAE mice showed signs of respiratory disease, marked by increased vascular permeability, leukocyte influx, production of TNF-α and IL-17, perivascular and peribronchial inflammation, with pulmonary mechanical dysfunction associated with loss of respiratory volumes and elasticity, which DMF-encapsulated reverted in SLN nebulization. Conclusion: Our study suggests that inhalation of DMF-encapsulated SLN is an effective therapeutic protocol that reduces not only the CNS inflammatory process and disability progression, characteristic of EAE disease, but also protects mice from lung inflammation and pulmonary dysfunction.


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.


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