scholarly journals Oligodendrocyte-specific Argonaute profiling identifies microRNAs associated with experimental autoimmune encephalomyelitis

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Qin Ma ◽  
Atsuko Matsunaga ◽  
Brenda Ho ◽  
Jorge R. Oksenberg ◽  
Alessandro Didonna

Abstract Background MicroRNAs (miRNAs) belong to a class of evolutionary conserved, non-coding small RNAs with regulatory functions on gene expression. They negatively affect the expression of target genes by promoting either RNA degradation or translational inhibition. In recent years, converging studies have identified miRNAs as key regulators of oligodendrocyte (OL) functions. OLs are the cells responsible for the formation and maintenance of myelin in the central nervous system (CNS) and represent a principal target of the autoimmune injury in multiple sclerosis (MS). Methods MiRAP is a novel cell-specific miRNA affinity-purification technique which relies on genetically tagging Argonaut 2 (AGO2), an enzyme involved in miRNA processing. Here, we exploited miRAP potentiality to characterize OL-specific miRNA dynamics in the MS model experimental autoimmune encephalomyelitis (EAE). Results We show that 20 miRNAs are differentially regulated in OLs upon transition from pre-symptomatic EAE stages to disease peak. Subsequent in vitro differentiation experiments demonstrated that a sub-group of them affects the OL maturation process, mediating either protective or detrimental signals. Lastly, transcriptome profiling highlighted the endocytosis, ferroptosis, and FoxO cascades as the pathways associated with miRNAs mediating or inhibiting OL maturation. Conclusions Altogether, our work supports a dual role for miRNAs in autoimmune demyelination. In particular, the enrichment in miRNAs mediating pro-myelinating signals suggests an active involvement of these non-coding RNAs in the homeostatic response toward neuroinflammatory injury.

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.


2007 ◽  
Vol 7 ◽  
pp. 112-120 ◽  
Author(s):  
Tracey L. Papenfuss ◽  
J. Cameron Thrash ◽  
Patricia E. Danielson ◽  
Pamela E. Foye ◽  
Brian S. Hllbrush ◽  
...  

Microglia are the tissue macrophages of the CNS. Microglial activation coupled with macrophage infiltration is a common feature of many classic neurodegenerative disorders. The absence of cell-type specific markers has confounded and complicated the analysis of cell-type specific contributions toward the onset, progression, and remission of neurodegeneration. Molecular screens comparing gene expression in cultured microglia and macrophages identified Golli-myelin basic protein (MBP) as a candidate molecule enriched in peripheral macrophages.In situhybridization analysis of LPS/IFNg and experimental autoimmune encephalomyelitis (EAE)–induced CNS inflammation revealed that only a subset of CNS macrophages express Golli-MBP. Interestingly, the location and morphology of Golli-MBP+ CNS macrophages differs between these two models of CNS inflammation. These data demonstrate the difficulties of extendingin vitroobservations toin vivobiology and concretely illustrate the complex heterogeneity of macrophage activation states present in region- and stage-specific phases of CNS inflammation. Taken altogether, these are consistent with the emerging picture that the phenotype of CNS macrophages is actively defined by their molecular interactions with the CNS microenvironment.


2011 ◽  
Vol 36 (6) ◽  
pp. 1017-1026 ◽  
Author(s):  
Mir Sajad ◽  
Jamil Zargan ◽  
Jyoti Sharma ◽  
Raman Chawla ◽  
Rajesh Arora ◽  
...  

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