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Previously, we reported that both S-nitrosoglutathione (GSNO), a carrier of cellular nitric oxide, and N6022, an injectable form of GSNO reductase (GSNOR) inhibitor that increases endogenous GSNO levels, alleviate experimental autoimmune encephalomyelitis (EAE) in mice by suppressing Th1 and Th17 immune responses. Building on these findings, we explored the role of GSNOR in EAE pathogenesis and evaluated the efficacy of an orally active GSNOR inhibitor (N91115) in treating the EAE disease. EAE mice exhibited heightened expression/activity of GSNOR in the spinal cord, and the knockout of the GSNOR gene resulted in much milder clinical manifestations of EAE, with lower degrees of demyelination and axonal loss, reduced microglial and astrocyte activations, as well as suppressed Th1 and Th17 cell responses, alongside bolstered Treg immune responses. Next, we evaluated the efficacy of N91115 against EAE immunopathology. Consistent with our findings in GSNOR deficient EAE mice, daily N91115 administration reduced clinical EAE severity, with less spinal cord demyelination and axonal loss compared to untreated EAE mice. Furthermore, N91115 treated EAE mice showed diminished Th1 and Th17 immune responses and enhanced Treg responses. This observation underscores the potential of increased GSNOR expression and activity as a risk factor exacerbating EAE immunopathology, while simultaneously highlighting its potential as a target for modifying the disease. Furthermore, the balanced immune regulation provided by orally active N91115 (IL-6/IL-17a vs. IL-10) presents a promising alternative to immunosuppressive drugs, reducing the risk of opportunistic infections., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Multiple Sclerosis (MS) is a chronic degenerative disease of the central nervous system (CNS) characterized by inflammation, demyelination, and progressive neurodegeneration. These processes, combined with the failure of reparative remyelination initiated by oligodendrocyte precursor cells (OPCs), lead to irreversible neurological impairment. The cytokine tumor necrosis factor (TNF) has been implicated in CNS repair via activation of its cognate receptor TNFR2 in glia. Here, we demonstrate the important role of TNFR2 in regulating OPC function in vivo during demyelinating disease, and that TNFR2 expressed in OPCs modulates OPC-microglia interactions. In Pdgfrα CreERT :Tnfrsf1b fl/fl :Eyfp mice with selective TNFR2 ablation in OPCs, we observed an earlier onset and disease peak in experimental autoimmune encephalomyelitis (EAE). This was associated with accelerated immune cell infiltration and increased microglia activation in the spinal cord. Similarly, Pdgfrα CreERT :Tnfrsf1b fl/fl :Eyfp mice showed rapid and increased microglia reactivity compared to control mice in the corpus callosum after cuprizone-induced demyelination, followed by chronic reduction in the number of mature myelinating oligodendrocytes (OLs). With EAE and cuprizone models combined, we uncovered that TNFR2 does not have a cell autonomous role in OPC differentiation, but may be important for survival of newly formed mature OLs. Finally, using an in vitro approach, we demonstrated that factors released by Tnfrsf1b ablated OPCs drove microglia to develop an exacerbated "foamy" phenotype when incubated with myelin-rich spinal cord homogenate, aberrantly increasing lysosomal lipid accumulation. Together, our data indicate that TNFR2 signaling in OPCs is protective by dampening their immune-inflammatory activation and by suppressing neurotoxic microglia reactivity. This suggests that boosting TNFR2 activation or its downstream cascades could be an effective strategy to restore OPC reparative capacity in neuroimmune and demyelinating disease., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

HPGD encodes 15-Hydroxyprostaglandin dehydrogenase catalyzing the decomposition of prostaglandin E2 and has not been reported in multiple sclerosis (MS). We previously found that Nr4a1 regulated microglia polarization and inhibited the progression of experimental autoimmune encephalomyelitis (EAE). Bioinformatics analysis suggested that HPGD might be regulated by Nr4a1. Therefore, this study aimed to explore the role of HPGD in microglia polarization and determine whether HPGD mediates the inhibition of EAE by Nr4a1. C57BL/6 mice were treated with MOG 35-55 peptide to induce EAE. BV-2 cells were treated with LPS/IL-4 to induce M1/M2 polarization. We then analyzed the pathological changes of spinal cord tissue, detected the expression levels of M1/M2 genes in tissues and cells, and explored the effect of HPGD on PPARγ activation to clarify the role of HPGD in EAE. The interaction between HPGD and Nr4a1 was verified by ChIP and pull-down assay. HPGD was downregulated in the spinal cord of EAE mice and HPGD overexpression alleviated the progression of EAE. Experiments in vitro and in vivo revealed that HPGD inhibited M1 polarization, promoted M2 polarization and increased PPARγ-DNA complex level. Nr4a1 could bind to the promoter of HPGD and its overexpression increased HPGD level. HPGD overexpression (or knockdown) reversed the effect of Nr4a1 knockdown (or overexpression) on M1/2 polarization. HPGD is regulated by Nr4a1 and inhibits the progression of EAE through shifting the M1/M2 polarization and promoting the activation of PPARγ signaling pathway. This study provides potential targets and basis for the development of MS therapeutic drugs., Competing Interests: Declarations. Ethics Approval: All animal experiments were performed with the approval of the Life Sciences Ethical Review Committee of Zhengzhou University. Competing Interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Fas has been shown to positively regulate the differentiation of T helper 17 (Th17) cells in mouse models of experimental autoimmune encephalomyelitis (EAE). Fas protein expression is regulated by ubiquitination but has not been further studied. In this study, we investigated the role of the Fas ubiquitin ligase in Th17 cell differentiation and highlighted its potential as a therapeutic target for EAE. The E3 ubiquitin ligase CBL of Fas was predicted using the online prediction software ubibrowser. Overexpression of CBL significantly reduced Fas protein levels but did not affect mRNA levels. The decrease in Fas protein mediated by CBL overexpression was rescued by the proteasome inhibitor MG132. Co-IP analysis revealed that CBL interacted with Fas. Further results suggested that CBL regulated Fas expression through ubiquitination, thereby affecting Th17 cell differentiation. Cbl-b, a homologue of CBL, significantly promoted the degradation of Fas protein and increased its ubiquitination modification. Furthermore, CBL and Cbl-b could synergistically regulate Fas to influence Th17 cell differentiation. The same conclusion was also reached in animal models. Luxol Fast Blue staining showed that myelinated fibres in the spinal cord were significantly increased after CBL/Cbl-b overexpression in EAE. Finally, flow cytometry and immunofluorescence staining showed that overexpression of CBL or Cbl-b decreased the proportion of Th17 cells in the spinal cord of EAE mice, ultimately reducing neuronal damage. Taken together, these data demonstrate that CBL and Cbl-b can synergistically regulate Fas to inhibit Th17 cell differentiation, thereby alleviating spinal cord nerve injury in the EAE model., (© 2024 The Scandinavian Foundation for Immunology.)

Cerium oxide nanoparticles are a unique antioxidant mimicking the activity of natural antioxidant enzymes. Previous research showed its' promising effect mitigating free radical damage in neurodegenerative disorders. However, there is still unmet therapeutic needs due to poor BBB penetration, a high accumulation in liver, kidney and spleen. This study aimed to synthesize and optimize nanoceria stabilized by natural bioactive polymers suitable for intranasal administration to manage multiple sclerosis. Among the different employed biopolymers, pectin-stabilized nanoceria exhibited the ideal properties with small particles size 87.20 ± 3.43 nm, high zeta potential -56.37 ± 2.39 mV and high free radical scavenging activity 85.27 ± 0.07 %. Then coating was achieved for the first time by two biopolymers: lactoferrin and chitosan producing a double coated cationic nanoceria. Biological assessment involved using experimental autoimmune encephalomyelitis animal model treated in a dose of 1 mg/kg nanoceria for 15 days. Motor function testing in rats revealed 6- and 17-folds increase in latency time in rotating rod and hanging wire tests, respectively. Biochemical analysis revealed significant reduction in lipid peroxidation along with about 1-fold upgrading of the intrinsic antioxidant system. Moreover, histologic examination disclosed decreased degeneration of the brain and spinal cord of treated rats and much decreased liver toxicity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Microglia and astrocytes are the main components of the central nervous system (CNS). Upon activation, microglia is able to phagocyte cell debris, pathogens, and toxins; astrocytes support neuronal functions, blood-brain barrier (BBB) homeostasis, and neurotransmitter uptake and metabolism. Furthermore, both cell types can produce cytokines and chemokines. Aging impacts microglia and astrocytes by promoting the production of pro-inflammatory cytokines, impairing microglial phagocytosis and motility and astrocyte glutamate uptake. During neurodegenerative and neuroinflammatory diseases, the aging process may be accelerated contributing to the alteration of CNS glial cells functions. Multiple sclerosis (MS) is an autoimmune, demyelinating disease in which immunosenescence can promote the conversion from relapsing-remitting form to progressive disease. The murine model of experimental autoimmune encephalomyelitis (EAE) allows to investigate MS pathogenesis. Furthermore, EAE can be developed as acute or progressive, mimicking different forms of human MS. Microglia and astrocytes report morphological and functional changes during neuroinflammation that can be investigated in different ways. We here present a protocol for the study of glial cell activation in the spinal cord tissue of EAE mice., (© 2025. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) mediated by CD4 + T helper (Th) cells, and characterized by immune cell infiltration, demyelination and neurodegeneration, with no definitive cure available. Thus, it is pivotal and imperative to acquire more profound comprehension of the underlying mechanisms implicated in MS. Dysregulated immune responses are widely believed to play a primary role in the pathogenesis of MS. Recently, a plethora of studies have demonstrated the involvement of T follicular helper (Tfh) cells and tertiary lymphoid-like structures (TLSs) in the pathogenesis and progression of MS. Cathepsin C (CatC) is a cysteine exopeptidase which is crucial for the activation of immune-cell-associated serine proteinases in many inflammatory diseases in peripheral system, such as rheumatoid arthritis and septicemia. We have previously demonstrated that CatC is involved in neuroinflammation and exacerbates demyelination in both cuprizone-induced and experimental autoimmune encephalomyelitis (EAE) mouse models. However, the underlying immunopathological mechanism remains elusive. In the present study, we established a recombinant myelin oligodendrocyte glycoprotein 35-55 peptide-induced EAE model using conditional CatC overexpression mice to investigate the effects of CatC on the alteration of CD4 + Th subsets, including Th1, Th2, Th17, Tfh and T regulatory cells. Our findings demonstrated that CatC particularly enhanced the population of Tfh cell in the brain, resulting in the earlier onset and more severe chronic syndrome of EAE. Furthermore, CatC promoted the formation of TLSs in the brain, leading to persistent neuroinflammation and exacerbating the severity of EAE in the chronic phase. Conversely, treatment with AZD7986, a specific inhibitor of CatC, effectively attenuated the syndrome of EAE and its effects caused by CatC both in vivo and in vitro. These findings provide a novel insight into the critical role of CatC in innate and adaptive immunity in EAE, and specific inhibitor of CatC, AZD7986, may contribute to potential therapeutic strategies for MS., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

In clinical practice, we found cerebrospinal fluid magnesium concentration significantly lower in neuromyelitis optica spectrum disorder (NMOSD) patients compared to controls with non-autoimmune encephalitis neurological diseases. To investigate the effects and potential mechanisms of long-term magnesium supplementation on neuroinflammation, demyelination, and blood-brain barrier (BBB) integrity in NMOSD, we used two models: (1) NMOSD mouse model, which was induced by intraperitoneal injection of purified NMO-IgG to experimental autoimmune encephalomyelitis (EAE) mice, and (2) cultured human cerebral microvascular endothelial cells/D3 (hCMEC/D3). In the NMOSD mouse model, Magnesium L-threonate (MgT) pretreatment alleviated NMO-IgG-induced effects, including AQP4 loss, leukocyte infiltration, astrocyte and microglia activation, demyelination, decreased tight junction (TJ) protein expression, and neurological deficits. In vitro, MgT pretreatment ameliorated NMO-IgG induced damage to TJ protein expression in a (transient receptor potential melastatin 7) TRPM7-dependent manner. Magnesium supplementation shows potential protective effects against NMOSD, suggesting it may be a novel therapeutic approach for this condition. The beneficial effects appear to be mediated through preservation of blood-brain barrier integrity and reduction of neuroinflammation and demyelination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Delivering protein drugs to the central nervous system (CNS) is challenging due to the blood-brain and blood-spinal cord barrier. Here we show that neutrophils, which naturally migrate through these barriers to inflamed CNS sites and release neutrophil extracellular traps (NETs), can be leveraged for therapeutic delivery. Tannic acid nanoparticles tethered with anti-Ly6G antibody and interferon-β (aLy6G-IFNβ@TLP) are constructed for targeted neutrophil delivery. These nanoparticles protect interferon-β from reactive oxygen species and preferentially accumulate in neutrophils over other immune cells. Upon encountering inflammation, neutrophils release the nanoparticles during NET formation. In the female mouse model of experimental autoimmune encephalomyelitis, intravenous administration of aLy6G-IFNβ@TLP reduce disease progression and restore motor function. Although this study focuses on IFNβ and autoimmune encephalomyelitis, the concept of hitchhiking neutrophils for CNS delivery and employing NET formation for inflamed site-specific nanoparticle release can be further applied for delivery of other protein drugs in the treatment of neurodegenerative diseases., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Evidence that myelin repair is crucial for functional recovery in multiple sclerosis (MS) led to the identification of bexarotene (BXT). This clinically promising remyelinating agent activates multiple nuclear hormone receptor subtypes implicated in myelin repair. However, BXT produces unacceptable hyperlipidemia. In contrast, IRX4204 selectively activates the retinoid X receptor (RXR). Given compelling links between RXR activation and increased myelin repair, we employed IRX4204 to investigate the impact of RXR agonism alone on functional recovery in mice subjected to experimental autoimmune encephalomyelitis (EAE). Since gait deficits are common in MS, we used machine learning to obtain highly sensitive and reliable measurements of sagittal hindleg joint movements for mice walking on a treadmill. IRX4204 not only blocked the progressive loss of knee and ankle movements but also reversed joint movement impairments in EAE mice. Our biochemical, transcriptional and histological measurements in spinal cord suggest these gait improvements reflect increased axon survival and remyelination and reduced inflammation. Using microglia, astrocytes and oligodendrocyte progenitor cells, we present additional data suggesting that IRX4204 may act on multiple glial subtypes to orchestrate myelin repair. These results inform the discovery of restorative neural therapeutics for MS by demonstrating that selective RXR agonism is sufficient for effective myelin repair. Moreover, our findings support the therapeutic potential of IRX4204 to promote functional recovery in MS., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: Drs. Vuligonda and Sanders are equity holders, officers, and members of the Board of Directors of Io Therapeutics, Inc., which is developing IRX4204 for commercialization as a treatment for multiple sclerosis and other neurodegenerative diseases., (© 2024. The Author(s).)

Introduction: Over the past few decades, there has been a sudden rise in the incidence of Multiple Sclerosis (MS) in Western countries. However, current treatments often show limited efficacy in certain patients and are associated with adverse effects, which highlights the need for safer and more effective therapeutic approaches. Environmental factors, particularly dietary habits, have been observed to play a substantial role in the development of MS. In this study, we are the first to investigate the potential protective effect of the phytohormone abscisic acid (ABA) in MS. ABA, which is abundant in fruits such as figs, apricots and bilberries, is known to cross the blood-brain barrier and has demonstrated neuroprotective effects in conditions like depression and Alzheimer's disease., Methods: In this study, we investigated whether ABA supplementation enhances remyelination in both ex vivo and in vivo mouse models., Results: Our results indicated that ABA enhanced remyelination and that this enhanced remyelination is associated with increased lipid droplet load, reduced levels of degraded myelin, and a higher abundance of F4/80+ cells in the demyelinated brain of mice treated with ABA. In in vitro models, we further demonstrated that ABA treatment elevates lipid droplet formation by enhancing the phagocytic capacity of macrophages. Additionally, in a mouse model of microglial activation, we showed that ABA-treated mice maintain a less inflammatory microglial phenotype., Conclusion: Our findings highlight a crucial role for macrophages and microglia in enabling ABA to enhance the remyelination process. Furthermore, ABA's ability to improve remyelination together with its ability to reduce microglial activation, make ABA a promising candidate for modulating macrophage phenotype and reducing neuroinflammation in MS., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Van Gaever, Mingneau, Vanherle, Driege, Haegman, Van Wonterghem, Xie, Vandenbroucke, Hendriks, Beyaert and Staal.)

The crosstalk between microglia inflamed in multiple sclerosis (MIMS) and astrocytes inflamed in MS (AIMS) is a crucial factor in the formation of the central inflammatory microenvironment and neurotoxicity. Astragalus polysaccharides (APS), an important bioactive component extracted from the dried root of Astragalus, was previously found by our team to attenuate the formation of pro-inflammatory microglia and neurological dysfunction in the experimental autoimmune encephalomyelitis (EAE) mice, a classic model of MS. To investigate the effect of APS on the MIMS-AIMS crosstalk and its underlying mechanism, in this study, a mouse model of EAE and a co-culture model of microglia-astrocytes in vitro were established. It was discovered that APS can alleviate the neurological dysfunction of EAE mice and effectively inhibit the formation of MIMS and AIMS both in vivo and in vitro. Furthermore, it was found that APS can suppress the inflammatory factors of MIMS-AIMS crosstalk in EAE mice and the resulting neurotoxicity in vivo and in vitro. The Sema4D-PlexinB2 signaling is essential for MIMS-AIMS crosstalk and promotes CNS inflammation. We demonstrated that APS can inhibit this signaling in vivo and in vitro. Treatment of recombinant Sema4D protein on cultured astrocytes in vitro significantly increases pro-inflammatory and neurotoxic factors, while APS significantly inhibits them. Conversely, after knockdown of Sema4D expression in microglia, APS no longer improves the neurotoxicity from MIMS-AIMS crosstalk. Overall, these results indicate that APS may modulate MIMS-AIMS crosstalk via the Sema4D-PlexinB2 signaling. This study provides a scientific basis for APS as a potential treatment candidate for demyelinating diseases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Multiple sclerosis (MS) is one of the most common neurodegenerative diseases, causing demyelination and inflammation in the central nervous system. The pathology of MS has been extensively studied using the experimental autoimmune encephalomyelitis (EAE) mouse model. However, the molecular mechanisms are still largely unclear and require further investigation. In this study, we carried out quantitative proteomic analysis of the brain and spinal cord tissues in mice induced with EAE using a data-independent acquisition strategy and identified 744 differentially regulated proteins in the brain and 741 in the spinal cord. The changed proteins were highly related with phagocytosis, lysosomal enzymes, inflammasome activation, complements, and synaptic loss processes. Moreover, gene set enrichment analysis revealed the elevation of the SUMOylation process in EAE with the increase of SUMOylation-related enzymes and modification targets. Furthermore, to test the possibility of treating MS by targeting SUMOylation, we explored the application of a selective SUMO E1 inhibitor, TAK-981. Intriguingly, TAK-981 suppressed the global SUMOylation level in the brain and significantly alleviated the symptoms of EAE in mice. Our findings contribute to a better understanding of MS pathology, reveal the important role of SUMOylation in disease progression, and demonstrate the potential of the SUMO E1 inhibitor as a novel treatment for MS.

Demyelinating diseases such as multiple sclerosis (MS) cause myelin degradation and oligodendrocyte death, resulting in the release of toxic iron and iron-induced oxidative stress. Astrocytes have a large capacity for iron transport and storage, however the role of astrocytic iron homeostasis in demyelinating disorders is not completely understood. Here we investigate whether astrocytic iron metabolism modulates neuroinflammation, oligodendrocyte survival, and oxidative stress following demyelination. To this aim, we conditionally knock out ferritin in astrocytes and induce experimental autoimmune encephalomyelitis (EAE), an autoimmune-mediated model of demyelination. Ferritin ablation in astrocytes reduced the severity of disease in both the acute and chronic phases. The day of onset, peak disease severity, and cumulative clinical score were all significantly reduced in ferritin KO animals. This corresponded to better performance on the rotarod and increased mobility in ferritin KO mice. Furthermore, the spinal cord of ferritin KO mice display decreased numbers of reactive astrocytes, activated microglia, and infiltrating lymphocytes. Correspondingly, the size of demyelinated lesions, iron accumulation, and oxidative stress were attenuated in the CNS of ferritin KO subjects, particularly in white matter regions of the spinal cord. Thus, deleting ferritin in astrocytes reduced neuroinflammation, oxidative stress, and myelin deterioration in EAE animals. Collectively, these findings suggest that iron storage in astrocytes is a potential therapeutic target to lessen CNS inflammation and myelin loss in autoimmune demyelinating diseases., (© 2024 Wiley Periodicals LLC.)

Incomplete Freund's adjuvant (IFA) has long been used to trigger autoimmune diseases in animal models, such as experimental autoimmune encephalitis and collagen-induced arthritis. However, the molecular mechanisms that control CD4 T cell effector functions and lead to the development of autoimmune diseases are not well understood. A self-antigen and heat-killed Mycobacterium tuberculosis emulsified in IFA augmented the activation of CD4 T cells, leading to the differentiation of pathogenic CD4 T cells in the draining lymph nodes. In contrast, IFA emulsification did not elicit Foxp3 + regulatory T cell expansion. We found that pathogenic Th1 cells expressed miR-147-3p, which targets multiple genes to affect T cell function. Finally, miR-147-3p expressed in CXCR6 + SLAMF6 - Th1 cells was required for the onset of neurological symptoms through the control of CXCR3 expression. Our findings demonstrate that miR-147-3p expressed in pathogenic CD4 T cells regulates the migratory potential in peripheral tissues and impacts the development of autoimmune diseases., Competing Interests: Declaration of competing interest The authors declare no competing financial interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Oligodendrocytes (OLs) are differentiated from oligodendrocyte precursor cells (OPCs) in the central nervous system (CNS). Demyelination is a common feature of many neurological diseases such as multiple sclerosis (MS) and leukodystrophies. Although spontaneous remyelination can happen after myelin injury, nevertheless, it is often insufficient and may lead to aggravated neurodegeneration and neurological disabilities. Our previous study has discovered that MEK/ERK pathway negatively regulates OPC-to-OL differentiation and remyelination in mouse models. To facilitate possible clinical evaluation, here we investigate several MEK inhibitors which have been approved by FDA for cancer therapies in both mouse and human OPC-to-OL differentiation systems. Trametinib, the first FDA approved MEK inhibitor, displays the best effect in stimulating OL generation in vitro among the four MEK inhibitors examined. Trametinib also significantly enhances remyelination in both MOG-induced EAE model and LPC-induced focal demyelination model. More exciting, trametinib facilitates the generation of MBP + OLs from human embryonic stem cells (ESCs)-derived OPCs. Mechanism study indicates that trametinib promotes OL generation by reducing E2F1 nuclear translocation and subsequent transcriptional activity. In summary, our studies indicate a similar inhibitory role of MEK/ERK in human and mouse OL generation. Targeting the MEK/ERK pathway might help to develop new therapies or repurpose existing drugs for demyelinating diseases., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Shanghai Institute of Materia Medica, Chinese Academy of Sciences and Chinese Pharmacological Society.)

Treatment of multiple sclerosis (MS) remains a major challenge. The aim of this study was to evaluate the therapeutic potential of mesenchymal stem cells (MSCs) engineered with secreted Klotho (SKL) in an experimental autoimmune encephalomyelitis (EAE) mouse model of MS. EAE was induced in mice. MSCs or MSCs engineered with SKL (SKL-MSCs) were administered to EAE mice at the onset of disease. Hematoxylin-eosin and luxol fast blue staining were performed to evaluate histopathological changes. Expression of pro-inflammatory (TNF-α, IFN-γ, and IL-17) and anti-inflammatory (IL-10) cytokines was determined in the spinal cord using real-time PCR. Spinal cords were then processed for immunohistochemistry of the aforementioned cytokines. The frequencies of Th1, Th17, and regulatory T (Treg) cells were evaluated by flow cytometry of the spleen. The results showed that SKL-MSCs decreased clinical scores and reduced demyelination and inflammatory infiltration in the spinal cord more significantly than MSCs. Compared to MSCs, SKL-MSCs also exhibited a more profound capability of decreasing expression of TNF-α, IFN-γ, and IL-17 and increasing expression of IL-10 in the spinal cord with an enhanced homing to the inflamed tissue. Moreover, SKL-MSCs decreased the frequencies of Th1 and Th17 cells and increased the frequency of Treg cells in the spleen more potently than MSCs. Taken together, these findings demonstrate that SKL overexpression enhances the therapeutic potential of MSCs, as evidenced by significantly improved disease severity, decreased inflammation and tissue damage in the spinal cord, and a promoted shift in the Th17/Treg balance towards the anti-inflammatory Treg side in the EAE mice., Competing Interests: Declarations. Ethics Approval: All experimental procedures of this study were conducted according to the international guidelines for care and use of laboratory animals and approved (Ethic code number: IR.MODARES.REC.1398.076) by the ethical committee of Tarbiat Modares University. Competing Interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Multiple sclerosis (MS) is an inflammatory demyelination neurodegenerative disease of the central nervous system (CNS). Ferroptosis has been implicated in a range of brain disorders, and iron-loaded microglia are frequently found in affected brain regions. However, the molecular mechanisms linking ferroptosis with MS have not been well-defined. The present study seeks to bridge this gap and investigate the impact of matrine (MAT), a herbal medicine with immunomodulatory capacities, on the regulation of oxidative stress and ferroptosis in the CNS of mice with experimental autoimmune encephalomyelitis (EAE), an animal model of MS. CNS of EAE mice contained elevated levels of ferroptosis-related molecules, e.g., MDA, LPCAT3 and PTGS2, but decreased expression of antioxidant molecules, including GSH and SOD, GPX4 and SLC7A11. This pathogenic process was reversed by MAT treatment, together with significant reduction of disease severity and CNS inflammatory demyelination. Furthermore, the expression of PTGS2 and LOX was largely increased in microglia of EAE mice, accompanied with increased production of IL-6 and TNF-α, indicating a proinflammatory phenotype of microglia that undergo oxidative stress/ferroptosis, and their expression was significantly reduced after MAT treatment. Together, our results indicate that ferroptosis/inflammation plays an important role in the pathogenesis of CNS autoimmunity, and inhibiting ferroptosis-induced microglial activation/inflammation could be a novel mechanism underlying the therapeutic effects of MAT on CNS inflammatory demyelination in EAE., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:LinZhu reports financial support was provided by National Natural Science Foundation of China. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Diet can protect from autoimmune disease; however, whether diet acts via the host and/or microbiome remains unclear. Here, we use a ketogenic diet (KD) as a model to dissect these complex interactions. A KD rescued the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis in a microbiota-dependent fashion. Dietary supplementation with a single KD-dependent host metabolite (β-hydroxybutyrate [βHB]) rescued EAE, whereas transgenic mice unable to produce βHB in the intestine developed more severe disease. Transplantation of the βHB-shaped gut microbiota was protective. Lactobacillus sequence variants were associated with decreased T helper 17 cell activation in vitro. Finally, we isolated an L. murinus strain that protected from EAE, which was phenocopied by a Lactobacillus metabolite enriched by βHB supplementation, indole lactate. Thus, diet alters the immunomodulatory potential of the gut microbiota by shifting host metabolism, emphasizing the utility of taking a more integrative approach to study diet-host-microbiome interactions., Competing Interests: Declaration of interests P.J.T. is on the scientific advisory boards for Pendulum, Seed, and SNIPRbiome; there is no direct overlap between the current study and these consulting duties. P.A.C. has served as an external consultant for Pfizer, Inc., Abbott Laboratories, Janssen Research & Development, and Selah Therapeutics. J.C.N. is scientific co-founder and stockholder for BHB Therapeutics (which provided the ketone ester) and Selah Therapeutics., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Inappropriate CD4 + T helper (T H ) cell differentiation leads to progression of inflammatory and autoimmune diseases, yet the regulatory mechanisms governing stability and activity of transcription factors controlling T H cell differentiation remain elusive. Here, we describe how pseudokinase serine threonine kinase 40 (STK40) facilitates T H 1/T H 17 differentiation under pathological conditions. STK40 in T cells is dispensable for immune homeostasis in resting mice. However, mice with T cell-specific deletion of STK40 exhibit attenuated symptoms of experimental autoimmune encephalomyelitis and colitis, accompanied by diminished T H 1 and T H 17 cell differentiation. Mechanistically, STK40 facilitates K48-linked polyubiquitination and proteasomal degradation of FOXO1/4 through promoting their interaction with E3 ligase COP1. Inhibition of FOXO4 or FOXO1, respectively, restores differentiation potential of STK40-deficient T H 1/T H 17 cells. Together, our data suggest a crucial role of STK40 in T H 1 and T H 17 cell differentiation, thereby enabling better understanding of the molecular regulatory network of CD4 + T cell differentiation and providing effective targets for the treatment of autoimmune diseases.

Aldehyde dehydrogenase-2 deficiency (ALDH2∗2) found in 36 % of Han Chinese, affects approximately 8 % of the world population. ALDH2 is a mitochondrial key enzyme in detoxifying reactive aldehydes to less reactive forms. Studies demonstrate a potential link between ALDH2∗2 mutation and neurodegenerative diseases. Multiple sclerosis (MS) is an incurable and disabling neurodegenerative autoimmune disease that induces motor, and cognitive impairment, and hypersensitivity, including chronic pain. Accumulating evidence suggests that reactive aldehydes, such as 4-hydroxynonenal (4-HNE), contribute to MS pathogenesis. Here, using knock-in mice carrying the inactivating point mutation in ALDH2, identical to the mutation found in Han Chinese, we showed that the impairment in ALDH2 activity heightens motor disabilities, and hypernociception induced by experimental autoimmune encephalomyelitis (EAE). The deleterious clinical signs are followed by glial cell activation in the spinal cord and increased 4-HNE levels in the spinal cord and serum. Importantly, the pharmacological ALDH2 activation by Alda-1 ameliorates EAE-induced hypernociception and motor impairment in both wild-type and ALDH2∗2KI mice. Reduced hypernociception was associated with less early growth response protein 1 (EGR1), neuronal and glial activation, and reactive aldehyde accumulation in the spinal cord and serum. Taken together, our data suggest that the mitochondrial enzyme ALDH2 plays a role in regulating clinical, cellular, and molecular responses associated with EAE. This indicates that ALDH2 could serve as a molecular target for MS control, with ALDH2 activators, like Alda-1 as potential neuroprotective candidates. Furthermore, ALDH2∗2 carriers may be at increased risk of developing more accentuated MS symptoms., Competing Interests: Declaration of competing interest Vanessa Olzon Zambelli is named inventor of patents related to Alda-1., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Interleukin-37 (IL-37) has anti-inflammatory properties in innate and adaptive immunity. Patients with multiple sclerosis (MS), an autoimmune inflammatory demyelinating disease of the central nervous system (CNS), have increased serum levels of IL-37. However, it is unknown whether IL-37 has an inhibitory effect on ongoing autoimmune neuroinflammation, thus offering a potential MS therapy., Aim: Here, we examined the effect of IL-37 in an experimental autoimmune encephalomyelitis (EAE) model after disease onset to determine if it was protective., Findings: IL-37-treated mice developed a less severe disease than control mice, with reduced demyelination as determined by increased expression of myelin basic protein. IL-37 suppressed inflammation by decreasing infiltration of CD4 + T cells into the CNS and increasing the frequency of regulatory T cells, while IL-10 expression by CD4 + T cells decreased over time in the CNS., Conclusion: Our findings confirm the immunomodulatory role of IL-37 in CNS inflammation during ongoing disease, thus indicating the potential of IL-37 as an inhibitory reagent for MS therapy., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Multiple sclerosis (MS) is an autoimmune disease mediated by T helper cells, which is characterized by neuroinflammation, axonal or neuronal loss, demyelination, and astrocytic gliosis. Histone deacetylase inhibitors (HDACis) are noted for their roles in easing inflammatory conditions and suppressing the immune response. Panobinostat, an HDACi, is now being used in treating multiple myeloma. Nevertheless, the effect of panobinostat on autoimmune diseases remains largely unclear. Thus, our research endeavored to determine if the administration of panobinostat could prevent experimental autoimmune encephalomyelitis (EAE) in mice, one of the most commonly used animal models of MS, and further explored the underlying mechanisms. The EAE mice were generated and then administered continuously with panobinostat at a dosage of 30 mg/kg for 16 days. The results indicated that panobinostat markedly alleviated the clinical symptoms of EAE mice, inhibiting demyelination and loss of oligodendrocytes in the central nervous system (CNS). Moreover, panobinostat decreased inflammation and the activation of microglia and astrocytes in the spinal cords of EAE mice. Mechanistically, treatment with panobinosat significantly suppressed M1 microglial polarization by blocking the activation of toll-like receptor 2 (TLR2)/myeloid differentiation factor 88 (MyD88)/interferon regulatory factor 5 (IRF5) pathway. Additionally, panobinostat inhibited mitochondrial dysfunction and reduced oxidative stress in the spinal cords of EAE mice. In conclusion, our findings reveal that panobinostat significantly ameliorates experimental autoimmune encephalomyelitis in mice by inhibiting oxidative stress-linked neuroinflammation and mitochondrial dysfunction.

Multiple sclerosis (MS) is a chronic condition characterized by immune cell infiltration and cytokine overproduction that led to myelin sheath inflammatory assaults, thus causing axonal destruction. The former consequently provokes motor impairment and psychological disorders. Markedly, depression is one of the most prevalent lifelong comorbidities that negatively impacts the quality of life in MS patients. Vortioxetine (VTX), a multi-modal molecule prescribed to manage depression and anxiety disorder, additionally, it displays a promising neuroprotective properties against neurodegenerative diseases such as Alzheimer's and Parkinson's. To this end, the present study investigated the potential therapeutic efficacy of VTX against experimental autoimmune encephalomyelitis (EAE) model of MS in mice. Notably, treatment with VTX significantly ameliorated EAE-induced motor disability, as evident by enhanced performance in open field, rotarod and grip strength tests, alongside a reduction in immobility time during the forced swimming test, indicating a mitigation of the depressive-like behavior; outcomes that were corroborated with histological examinations and biochemical analyses. Mechanistically, VTX enhanced serotonin levels by inhibiting both serotonin transporter (SERT) and indoleamine 2,3-dioxygenase (IDO) enzyme, thereby promoting the activation of serotonin 1A (5-HT 1A ) receptor. The latter triggered the stimulation of phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) cascade that entailed activation/phosphorylation of cAMP response element-binding protein (CREB). This activation increased brain derived neurotrophic factor (BDNF) and myelin basic protein (MBP) contents that mitigated demyelination in the corpus callosum. Furthermore, VTX suppressed phospho serine 536 nuclear factor kappa B (pS536 NF-κB p65) activity and reduced tumor necrosis factor-alpha (TNF-α) production. The results underscore VTX's beneficial effects on disease severity in EAE model of MS in mice by amending both inflammatory and neurodegenerative components of MS progression., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Immune cell metabolism governs the outcome of immune responses and contributes to the development of autoimmunity by controlling lymphocyte pathogenic potential. In this study, we evaluated the metabolic profile of myelin-specific murine encephalitogenic T cells, to identify novel therapeutic targets for autoimmune neuroinflammation., Methods: We performed metabolomics analysis on actively-proliferating encephalitogenic T cells to study their overall metabolic profile in comparison to resting T cells. Metabolomics, phosphoproteomics, in vitro functional assays, and in vivo studies in experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS), were then implemented to evaluate the effect of metabolic targeting on autoreactive T cell pathogenicity. Finally, we confirmed the translational potential of our targeting approach in human pro-inflammatory T helper cell subsets and in T cells from MS patients., Results: We found that autoreactive encephalitogenic T cells display an altered coenzyme A (CoA) synthesis pathway, compared to resting T cells. CoA fueling with the CoA precursor pantethine (PTTH) affected essential immune-related processes of myelin-specific T cells, such as cell proliferation, cytokine production, and cell adhesion, both in vitro and in vivo. Accordingly, pre-clinical treatment with PTTH before disease onset inhibited the development of EAE by limiting T cell pro-inflammatory potential in vivo. Importantly, PTTH also significantly ameliorated the disease course when administered after disease onset in a therapeutic setting. Finally, PTTH reduced pro-inflammatory cytokine production by human T helper 1 (Th1) and Th17 cells and by T cells from MS patients, confirming its translational potential., Conclusion: Our data demonstrate that CoA fueling with PTTH in pro-inflammatory and autoreactive T cells may represent a novel therapeutic approach for the treatment of autoimmune neuroinflammation., (© 2024. The Author(s).)

Blood-brain barrier (BBB) breakdown, an early hallmark of multiple sclerosis (MS), remains crucial for MS progression. Our previous works have confirmed that Astragalus polysaccharides (APS) can significantly ameliorate demyelination and disease progression in experimental autoimmune encephalomyelitis (EAE) mice. However, it remains unclear whether APS protects BBB and the potential mechanism. In this study, we found that APS effectively reduced BBB leakage in EAE mice, which was accompanied by a decreased level of endothelial-to-mesenchymal transition (EndoMT) in the central nervous system (CNS). We further induced EndoMT in the mouse brain endothelial cells (bEnd.3) by interleukin-1β (IL-1β) in vitro. The results showed that APS treatment could inhibit IL-1β-induced EndoMT and endothelial cell dysfunction. In addition, the transcription factor ETS1 is a central regulator of EndoMT related to the compromise of BBB. We tested the regulation of APS on ETS1 and identified the expression of ETS1 was upregulated in both EAE mice and bEnd.3 cells by APS. ETS1 knockdown facilitated EndoMT and endothelial cell dysfunction, which completely abolished the regulatory effect of APS. Collectively, APS treatment could protect BBB integrity by inhibiting EndoMT, which might be associated with upregulating ETS1 expression. Our findings indicated that APS has potential value in the prevention of MS., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Masson SAS.)

Background: Multiple Sclerosis (MS) is an autoimmune neurodegenerative disease, whose primary hallmark is the occurrence of inflammatory lesions in white and grey matter structures. Increasing evidence in MS patients and respective murine models reported an impaired ionic homeostasis driven by inflammatory-demyelination, thereby profoundly affecting signal propagation. However, the impact of a focal inflammatory lesion on single-cell and network functionality has hitherto not been fully elucidated., Objectives: In this study, we sought to determine the consequences of a localized cortical inflammatory lesion on the excitability and firing pattern of thalamic neurons in the auditory system. Moreover, we tested the neuroprotective effect of Retigabine (RTG), a specific K v 7 channel opener, on disease outcome., Methods: To resemble the human disease, we focally administered pro-inflammatory cytokines, TNF-α and IFN-γ, in the primary auditory cortex (A1) of MOG 35-55 immunized mice. Thereafter, we investigated the impact of the induced inflammatory milieu on afferent thalamocortical (TC) neurons, by performing ex vivo recordings. Moreover, we explored the effect of K v 7 channel modulation with RTG on auditory information processing, using in vivo electrophysiological approaches., Results: Our results revealed that a cortical inflammatory lesion profoundly affected the excitability and firing pattern of neighboring TC neurons. Noteworthy, RTG restored control-like values and TC tonotopic mapping., Conclusion: Our results suggest that RTG treatment might robustly mitigate inflammation-induced altered excitability and preserve ascending information processing., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

The role that astrocytes play in central nervous system (CNS) myelination is poorly understood. We investigated the contribution of astrocyte-derived factors to myelination and revealed a substantial overlap in the secretomes of human and rat astrocytes. Using in vitro myelinating co-cultures of primary retinal ganglion cells and cortical oligodendrocyte precursor cells, we discovered that factors secreted by resting astrocytes, but not reactive astrocytes, facilitated myelination. Soluble brevican emerged as a new enhancer of developmental myelination in vivo, CNS and its absence was linked to remyelination deficits following an immune-mediated damage in an EAE mouse model. The observed reduction of brevican expression in reactive astrocytes and human MS lesions suggested a potential link to the compromised remyelination characteristic of neurodegenerative diseases. Our findings suggested brevican's role in myelination may be mediated through interactions with binding partners such as contactin-1 and tenascin-R. Proteomic analysis of resting versus reactive astrocytes highlighted a shift in protein expression profiles, pinpointing candidates that either facilitate or impede CNS repair, suggesting that depending on their reactivity state, astrocytes play a dual role during myelination., (© 2024 The Author(s). GLIA published by Wiley Periodicals LLC.)

Experimental autoimmune encephalomyelitis (EAE) is widely used animal model of multiple sclerosis (MS). The disease is characterized by demyelination and neurodegeneration triggered by infiltrated autoimmune cells and their interaction with astrocytes and microglia. While neuroinflammation is most common in the spinal cord and brainstem, it is less prevalent in the cerebellum, where it predisposes to rapid disease progression. Because the induction and progression of EAE are tightly regulated by adenosinergic signaling, in the present study we compared the adenosine-producing and -degrading enzymes, ecto-5'-nucleotidase (eN/CD73) and adenosine deaminase (ADA), as well as the expression levels of adenosine receptors A 1 R and A 2A R subtypes in nearby areas around the fourth cerebral ventricle-the pontine tegmentum, the choroid plexus (CP), and the cerebellum. Significant differences in histopathological findings were observed between pontine tegmentum and cerebellum on the same horizontal section level. Reactive astrogliosis and massive infiltration of CD4 + cells and macrophages in CP and pontine tegmentum resulted in local demyelination. In cerebellum, there was no evidence of infiltrates, microgliosis and neuroinflammation at the same sectional level. In addition, Bergman glia showed no signs of reactive gliosis. As for adenosinergic signaling, significant upregulation of eN/CD73 was observed in all areas studied, but in association with different adenosine receptor subtypes. In CP and pons, overexpression of eN/CD73 was coupled with induction of A 2A R, whereas in cerebellum, a modest increase in eN/CD73 in resident Bergman glia was accompanied by a strong induction of A 1 R in the same type of astrocytes. Thus, the presence of specialized astroglia and intrinsic differences in adenosinergic signaling may play a critical role in the differential regional susceptibility to EAE inflammation., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Pyroptosis, a form of inflammatory programmed cell death, plays a pivotal role in the pathogenesis of various diseases. This process is primarily mediated by the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3). Gastrodenol (Bismuth tripotassium dicitrate, GAS) is a mineral compound which is used to treat duodenal and gastric ulcers associated with Helicobacter pylori. In this study, GAS was found to exhibit protective effects against classical pyroptosis in macrophages. Specifically, GAS effectively inhibits the activation of the NLRP3 inflammasome, Gasdermin D (GSDMD)-mediated pyroptosis, and the secretion of pro-inflammatory cytokines. Mechanistically, GAS inhibited NLRP3 oligomerization and reduced the oligomerization of adaptor protein apoptosis-associated speck like protein containing a caspase activation and recruitment domain (ASC) by directly binding to NLRP3. The interaction between GAS and NLRP3 is primarily mediated through hydrogen bonding and hydrophobic forces. Hydrogen bonds are formed with PHE-727, LEU-723, and ASP-700. Remarkably, GAS treatment attenuated pyroptosis-mediated inflammatory diseases, including experimental autoimmune encephalomyelitis (EAE), lipopolysaccharide (LPS)-induced septic, and monosodium urate (MSU)-induced peritonitis in mice. To conclude, this is the first report that discovered clinical old medicine GAS as a potent inhibitor of pyroptosis and propose a novel therapeutic strategy for the prevention and treatment of NLRP3-GSDMD mediated diseases., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The deubiquitinating enzyme CYLD negatively regulates NF-κB signaling by removing activating ubiquitin chains from several members of the NF-κB pathway. Thereby, CYLD is critical for the maintenance and differentiation of various immune cells. Despite the importance of the NF-κB pathway in microglia regulation, the role of CYLD in microglia has not been investigated so far. In this study, we investigated whether CYLD in microglia can protect against neuroinflammation using a newly generated conditional mouse strain (Rosa26-Cyld-tdTomato) that allows cell type-specific CYLD overexpression. Here, we show that overexpression of CYLD in microglia did not alter microglia numbers or microglia morphology in different brain regions. Additionally, CYLD overexpression did not modify the microglial response to LPS-induced neuroinflammation or the disease severity in experimental autoimmune encephalomyelitis (EAE). Finally, also immune cell infiltration into the CNS during EAE and under steady state conditions remained unaffected by microglial CYLD overexpression. Our findings suggest that CYLD overexpression does not alter microglial function, and thus does not represent a viable therapeutic strategy in neuroinflammatory conditions. This study highlights the complexity of ubiquitin-mediated signaling in neuroinflammation and the need for cell-type-specific investigations. The Rosa26-Cyld-tdTomato mouse model offers a valuable tool for studying CYLD's role across various tissues and cell types. KEY MESSAGES: Novel mouse strain for cell type-specific overexpression of the deubiquitinating enzyme CYLD. CYLD overexpression in microglia did not alter microglia numbers or morphology in the steady state. CYLD overexpression in microglia did not protect mice from LPS-induced neuroinflammation or EAE. CYLD overexpression in microglia did not influence their gene expression during neuroinflammation., (© 2024. The Author(s).)

Ceramide C16 is a sphingolipid detected at high levels in several neurodegenerative disorders, including multiple sclerosis (MS). It can be generated de novo or from the hydrolysis of other sphingolipids, such as sphingomyelin or through the recycling of sphingosine, in what is known as the salvage pathway. While the myelin damage occurring in MS suggests the importance of the hydrolytic and salvage pathways, the growing interest on the importance of diet in demyelinating disorders, prompted us to investigate the involvement of de novo ceramide C16 synthesis on disease severity. A diet rich in saturated fats such as palmitic acid, as found in many highly processed foods, provides substrates for the ceramide C16 synthetic enzymes ceramide synthase 6 (CERS6) and 5 (CERS5), which are expressed in the central nervous system. Using the experimental autoimmune encephalomyelitis (EAE) model of inflammatory demyelination, we show here that mice with CamK2a+ neuronal specific deletion of both CerS6 and CerS5 show a milder course of EAE than wild type mice, even when fed a diet enriched in palmitic acid. At a cellular level, neurons lacking both CerS6 and CerS5 are protected from the mitochondrial dysfunction arising from exposure to oxidative stress and palmitic acid in the medium. These data underscore the importance of a healthy diet avoiding processed foods for demyelinating disorders and identifies endogenous neuronal synthesis of ceramide C16 as an important determinant of disease severity., (© 2024 The Author(s). GLIA published by Wiley Periodicals LLC.)

CD4+ T cells are considered the main orchestrators of autoimmune diseases. Their disruptive effect on CD4+ T cell differentiation and the imbalance between T helper cell populations can be most accurately determined using experimental autoimmune encephalomyelitis (EAE) as an animal model of multiple sclerosis (MS). One epigenetic factor known to promote autoimmune inflammation is miRNA-155 (miR-155), which is significantly upregulated in inflammatory T cells. The aim of the present study was to profile the transcriptome of immunized mice and determine their gene expression levels based on mRNA and miRNA sequencing. No statistically significant differences in miRNA profile were observed; however, substantial changes in gene expression between miRNA-155 knockout (KO) mice and WT were noted. In miR-155 KO mice, mRNA expression in CD4+ T cells changed in response to immunization with the myeloid antigen MOG 35-55 . After restimulation with MOG 35-55 , increased Ffar1 (free fatty acid receptor 1) and Scg2 (secretogranin-2) expression were noted in the CD4+ T cells of miR-155-deficient mice; this is an example of an alternative response to antigen stimulation.

Demyelination and axonal degeneration are fundamental pathological characteristics of multiple sclerosis (MS), an inflammatory disease of the central nervous system (CNS). Although the molecular mechanisms driving these processes are not fully understood, hepatocyte growth factor (HGF) has emerged as a potential regulator of neuroinflammation and tissue protection in MS. Elevated HGF levels have been reported in MS patients receiving immunomodulatory therapy, indicating its relevance in disease modulation. This study investigated HGF's neuroprotective effects using transgenic mice that overexpressed HGF. The experimental autoimmune encephalomyelitis (EAE) model, which mimics MS pathology, was employed to assess demyelination and axonal damage in the CNS. HGF transgenic mice showed delayed EAE progression, with reduced CNS inflammation, decreased demyelination, and limited axonal degeneration. Scanning electron microscopy confirmed the preservation of myelin and axonal integrity in these mice. In addition, we explored HGF's effects using a cuprizone-induced demyelination model, which operates independently of the immune system. HGF transgenic mice exhibited significant protection against demyelination in this model as well. We also investigated the expression of key HGF receptors, particularly c-Met and KAI-1. While c-Met, which is associated with increased inflammation, was upregulated in EAE, its expression was significantly reduced in HGF transgenic mice, correlating with decreased neuroinflammation. Conversely, KAI-1, which has been linked to axonal protection and stability, showed enhanced expression in HGF transgenic mice, suggesting a protective mechanism against axonal degeneration. These findings underscore HGF's potential in preserving CNS structure and function, suggesting it may be a promising therapeutic target for MS, offering new hope for mitigating disease progression and enhancing neuroprotection.

Under neuroinflammatory conditions, astrocytes acquire a reactive phenotype that drives acute inflammatory injury as well as chronic neurodegeneration. We hypothesized that astrocytic Delta-like 4 (DLL4) may interact with its receptor NOTCH1 on neighboring astrocytes to regulate astrocyte reactivity via downstream juxtacrine signaling pathways. Here we investigated the role of astrocytic DLL4 on neurovascular unit homeostasis under neuroinflammatory conditions. We probed for downstream effectors of the DLL4-NOTCH1 axis and targeted these for therapy in two models of CNS inflammatory disease. We first demonstrated that astrocytic DLL4 is upregulated during neuroinflammation, both in mice and humans, driving astrocyte reactivity and subsequent blood-brain barrier permeability and inflammatory infiltration. We then showed that the DLL4-mediated NOTCH1 signaling in astrocytes directly drives IL-6 levels, induces STAT3 phosphorylation promoting upregulation of astrocyte reactivity markers, pro-permeability factor secretion and consequent blood-brain barrier destabilization. Finally we revealed that blocking DLL4 with antibodies improves experimental autoimmune encephalomyelitis symptoms in mice, identifying a potential novel therapeutic strategy for CNS autoimmune demyelinating disease. As a general conclusion, this study demonstrates that DLL4-NOTCH1 signaling is not only a key pathway in vascular development and angiogenesis, but also in the control of astrocyte reactivity during neuroinflammation., (© 2024. The Author(s).)

Several studies have proposed a potential role for oxidative stress in the development of multiple sclerosis (MS). For this reason, it seems tentative to think that treatment with antioxidant substances could be useful in the treatment of this disease. In this narrative review, we provide a summary of the current findings on antioxidant treatments, both in experimental models of MS, especially in experimental autoimmune encephalomyelitis (EAE) and in the cuprizone-induced demyelination model, and clinical trials in patients diagnosed with MS. Practically all the antioxidants tested in experimental models of MS have shown improvement in clinical parameters, in delaying the evolution of the disease, and in improving histological and biochemical parameters, including decreased levels of markers of inflammation and oxidative stress in the central nervous system and other tissues. Only a few clinical trials have been carried out to investigate the potential efficacy of antioxidant substances in patients with MS, most of them in the short term and involving a short series of patients, so the results of these should be considered inconclusive. In this regard, it would be desirable to design long-term, randomized, multicenter clinical trials with a long series of patients, assessing several antioxidants that have demonstrated efficacy in experimental models of MS.

Background: The IL-7 receptor alpha (IL-7Rα) binds both IL-7 and thymic stromal lymphopoietin (TSLP). IL-7Rα is essential for the development and survival of naive CD4 + T cells and their differentiation to effector/memory CD4 + T cells. Mice lacking IL-7Rα have severe lymphopenia and are resistant to experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis. However, it has been reported that IL-7Rα on peripheral CD4 + T cells is disposable for their maintenance and EAE pathogenesis, which does not align with the body of knowledge on the role of IL-7Rα in the biology of CD4 + T cells. Given that a definitive study on this important topic is lacking, we revisited it using a novel approach, an inducible knockout of the IL-7Rα gene in CD4 + T cells., Methods: We generated Il7ra fl/fl /CD4CreER T2 double transgenic mouse line (henceforth CD4 ΔIl7ra ), susceptible to tamoxifen-induced knockout of the IL-7Rα gene in CD4 + T cells. CD4 ΔIl7ra mice were immunized with MOG 35 - 55 for EAE induction and monitored for disease development. The expression of IL-7Rα, CD4 + T cell numbers, and MOG 35 - 55 -specific CD4 + T cell response was evaluated in the central nervous system (CNS) and lymphoid tissues by flow cytometry. Additionally, splenocytes of CD4 ΔIl7ra mice were stimulated with MOG 35 - 55 to assess their proliferative response and cytokine production by T helper cells., Results: Loss of IL-7Rα from the surface of CD4 + T cells in CD4 ΔIl7ra mice was virtually complete several days after tamoxifen treatment. The loss of IL-7Rα in CD4 + T cells led to a gradual and substantial decrease in their numbers in both non-immunized and immunized CD4 ΔIl7ra mice, followed by slow repopulation up to the initial numbers. CD4 ΔIl7ra mice did not develop EAE. We found a decrease in the total numbers of TNF-, IFN-γ-, IL-17 A-, and GM-CSF-producing CD4 + T cells and regulatory T cells in the spleens and CNS of immunized CD4 ΔIl7ra mice. Tracking MOG 35 - 55 -specific CD4 + T cells revealed a significant reduction in their numbers in CD4 ΔIl7ra mice and decreased proliferation and cytokine production in response to MOG 35 - 55 ., Conclusion: Our study demonstrates that IL-7Rα on peripheral CD4 + T cells is essential for their maintenance, immune response, and EAE pathogenesis., (© 2024. The Author(s).)

Kinins are vasoactive peptides that are involved in various cellular mechanisms, including the inflammatory response. Kinins, released in vessel walls, exacerbate inflammation by modulating the production and release of pro-inflammatory factors via two types of G protein-related receptors-B1 and B2 receptors. B1 R is overexpressed during the inflammation that accompanies numerous neurological disorders, including multiple sclerosis (MS), in which loss of BBB integrity is an early pathomechanism of the disease. In this work, we apply pharmacological inhibition of the kinin B1 receptor with DALBK to investigate its effect on blood-brain barrier (BBB) permeability during the course of EAE, an animal model of MS. Functional, ultrastructural and molecular analyses were performed. The expression of selected BBB-associated proteins such as occludin and claudin-5 was assessed, as well as the astrocytic marker GFAP. We show that administration of a specific antagonist attenuates neurological symptoms in EAE rats and recovers the downregulation of TJ proteins and BBB leakage observed during the course of the disease, as well as significantly reducing the disease-specific activation of astroglia. The results show that B1 R-mediated signaling is involved in inducing molecular changes at the level of cerebral microvessels, leading to increased permeability of the BBB following neuroinflammation in EAE.

Obesity has been implicated in the rise of autoimmunity in women. We report that obesity induces a serum protein signature that is associated with T helper 1 (Th1), interleukin (IL)-17, and multiple sclerosis (MS) signaling pathways selectively in human females. Females, but not male mice, subjected to diet-induced overweightness/obesity (DIO) exhibited upregulated Th1/IL-17 inflammation in the central nervous system during experimental autoimmune encephalomyelitis, a model of MS. This was associated with worsened disability and a heightened expansion of myelin-specific Th1 cells in the peripheral lymphoid organs. Moreover, at steady state, DIO increased serum levels of interferon (IFN)-α and potentiated STAT1 expression and IFN-γ production by naive CD4 + T cells uniquely in female mice. This T cell phenotype was driven by increased adiposity and was prevented by the removal of ovaries or knockdown of the type I IFN receptor in T cells. Our findings offer a mechanistic explanation of how obesity enhances autoimmunity., Competing Interests: Declaration of interests J.J.A. is currently an employee of Bristol Myers Squibb. R.C.A. is on the advisory board for Progentec Diagnostics Inc., (Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Ependymal cells form a specialized brain-cerebrospinal fluid (CSF) interface and regulate local CSF microcirculation. It is becoming increasingly recognized that ependymal cells assume a reactive state in response to aging and disease, including conditions involving hypoxia, hydrocephalus, neurodegeneration, and neuroinflammation. Yet what transcriptional signatures govern these reactive states and whether this reactivity shares any similarities with classical descriptions of glial reactivity (i.e., in astrocytes) remain largely unexplored. Using single-cell transcriptomics, we interrogated this phenomenon by directly comparing the reactive ependymal cell transcriptome to the reactive astrocyte transcriptome using a well-established model of autoimmune-mediated neuroinflammation (MOG 35-55 EAE). In doing so, we unveiled core glial reactivity-associated genes that defined the reactive ependymal cell and astrocyte response to MOG 35-55 EAE. Interestingly, known reactive astrocyte genes from other CNS injury/disease contexts were also up-regulated by MOG 35-55 EAE ependymal cells, suggesting that this state may be conserved in response to a variety of pathologies. We were also able to recapitulate features of the reactive ependymal cell state acutely using a classic neuroinflammatory cocktail (IFNγ/LPS) both in vitro and in vivo. Taken together, by comparing reactive ependymal cells and astrocytes, we identified a conserved signature underlying glial reactivity that was present in several neuroinflammatory contexts. Future work will explore the mechanisms driving ependymal reactivity and assess downstream functional consequences., (© 2024 The Authors. Journal of Neurochemistry published by John Wiley & Sons Ltd on behalf of International Society for Neurochemistry.)

The purinergic signaling system comprises a complex network of extracellular purines and purine-metabolizing ectoenzymes, nucleotide and nucleoside receptors, ATP release channels, and nucleoside transporters. Because of its immunomodulatory function, this system is critically involved in the pathogenesis of multiple sclerosis (MS) and its best-characterized animal model, experimental autoimmune encephalomyelitis (EAE). MS is a chronic neuroinflammatory demyelinating and neurodegenerative disease with autoimmune etiology and great heterogeneity, mostly affecting young adults and leading to permanent disability. In MS/EAE, alterations were detected in almost all components of the purinergic signaling system in both peripheral immune cells and central nervous system (CNS) glial cells, which play an important role in the pathogenesis of the disease. A decrease in extracellular ATP levels and an increase in its downstream metabolites, particularly adenosine and inosine, were frequently observed at MS, indicating a shift in metabolism toward an anti-inflammatory environment. Accordingly, upregulation of the major ectonucleotidase tandem CD39/CD73 was detected in the blood cells and CNS of relapsing-remitting MS patients. Based on the postulated role of A 2A receptors in the transition from acute to chronic neuroinflammation, the association of variants of the adenosine deaminase gene with the severity of MS, and the beneficial effects of inosine treatment in EAE, the adenosinergic system emerged as a promising target in neuroinflammation. More recently, several publications have identified ADP-dependent P2Y 12 receptors and the major extracellular ADP producing enzyme nucleoside triphosphate diphosphohydrolase 2 (NTPDase2) as novel potential targets in MS., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Neuroinflammation is a common component of neurological disorders. In the gut-brain-immune axis, bacteria and their metabolites are now thought to play a role in the modulation of the nervous and immune systems which may impact neuroinflammation. In this respect, commensal bacteria of humans have recently been shown to produce metabolites that mimic endogenous G-protein coupled receptor (GPCR) ligands. To date, it has not been established whether plant commensal bacteria, which may be ingested by animals including humans, can impact the gut-brain-immune axis via GPCR agonism. We screened an isopropanol (IPA) extract of the plant commensal Bacillus velezensis ADS024, a non-engrafting live biotherapeutic product (LBP) with anti-inflammatory properties isolated from human feces, against a panel of 168 GPCRs and identified strong agonism of the lysophosphatidic acid (LPA) receptor LPA3. The ADS024 IPA extracted material (ADS024-IPA) did not agonize LPA2, and only very weakly agonized LPA1. The agonism of LPA3 was inhibited by the reversible LPA1/3 antagonist Ki16425. ADS024-IPA signaled downstream of LPA3 through G-protein-induced calcium release, recruitment of β-arrestin, and recruitment of the neurodegeneration-associated proteins 14-3-3γ, ε and ζ but did not recruit the β isoform. Since LPA3 agonism was previously indirectly implicated in the reduction of pathology in models of Parkinson's disease (PD) and multiple sclerosis (MS) by use of the nonselective antagonist Ki16425, and since we identified an LPA3-specific agonist within ADS024, we sought to examine whether LPA3 might indeed be part of a broad underlying mechanism to control neuroinflammation. We tested oral treatment of ADS024 in multiple models of neuroinflammatory diseases using three models of PD, two models of MS, and a model each of amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and chemo-induced peripheral neuropathy (CIPN). ADS024 treatment improved model-specific functional effects including improvements in motor movement, breathing and swallowing, and allodynia suggesting that ADS024 treatment impacted a universal underlying neuroinflammatory mechanism regardless of the initiating cause of disease. We used the MOG-EAE mouse model to examine early events after disease initiation and found that ADS024 attenuated the increase in circulating lymphocytes and changes in neutrophil subtypes, and ADS024 attenuated the early loss of cell-surface LPA3 receptor expression on circulating white blood cells. ADS024 efficacy was partially inhibited by Ki16425 in vivo suggesting LPA3 may be part of its mechanism. Altogether, these data suggest that ADS024 and its LPA3 agonism activity should be investigated further as a possible treatment for diseases with a neuroinflammatory component., Competing Interests: Declaration of Competing Interest During these studies, S.A, L.C., and B.D. were employees and/or consultants of Adiso Therapeutics and C.H. and P.R. were consultants for Adiso Therapeutics. C.H. and P.R. own stock and S.A., L.C., B.D. and M.O’D were granted options in Adiso Therapeutics. S.A., L.C., M.O’D., C.H., and P.R. are inventors on ADS024 patents and/or patent applications. M.O’D. was an employee of APC Microbiome Ireland and was supported by a grant from Adiso Therapeutics. K.P. is the owner of Pentagrit. H.E. is an employee of BioInvenu Corp., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Newly formed leaky vessels and blood-brain barrier (BBB) damage are present in demyelinating acute and chronic lesions in multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). However, the endothelial cell subtypes and signaling pathways contributing to these leaky neovessels are unclear. Here, using single-cell transcriptional profiling and in vivo validation studies, we show that venous endothelial cells express neoangiogenesis gene signatures and show increased proliferation resulting in enlarged veins and higher venous coverage in acute and chronic EAE lesions in female adult mice. These changes correlate with the upregulation of vascular endothelial growth factor A (VEGF-A) signaling. We also confirmed increased expression of neoangiogenic markers in acute and chronic human MS lesions. Treatment with a VEGF-A blocking antibody diminishes the neoangiogenic transcriptomic signatures and vascular proliferation in female adult mice with EAE, but it does not restore BBB function or ameliorate EAE pathology. Our data demonstrate that venous endothelial cells contribute to neoangiogenesis in demyelinating neuroinflammatory conditions., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Cortical pathology involving inflammatory and neurodegenerative mechanisms is a hallmark of multiple sclerosis and a correlate of disease progression and cognitive decline. Astrocytes play a pivotal role in multiple sclerosis initiation and progression but astrocyte-neuronal network alterations contributing to gray matter pathology remain undefined. Here we unveil deregulation of astrocytic calcium signaling and astrocyte-to-neuron communication as key pathophysiological mechanisms of cortical dysfunction in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis. Using two-photon imaging ex vivo and fiber photometry in freely behaving mice, we found that acute EAE was associated with the emergence of spontaneously hyperactive cortical astrocytes exhibiting dysfunctional responses to cannabinoid, glutamate and purinoreceptor agonists. Abnormal astrocyte signaling by G i and G q protein coupled receptors was observed in the inflamed cortex. This was mirrored by treatments with pro-inflammatory factors both in vitro and ex vivo, suggesting cell-autonomous effects of the cortical neuroinflammatory environment. Finally, deregulated astrocyte calcium activity was associated with an enhancement of glutamatergic gliotransmission and a shift of astrocyte-mediated short-term and long-term plasticity mechanisms towards synaptic potentiation. Overall, our data identify astrocyte-neuronal network dysfunctions as key pathological features of gray matter inflammation in multiple sclerosis and potentially additional neuroimmunological disorders., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

To investigate the spinal cord neuron apoptosis and neuroprotective mechanism of nerve growth factorganismsor (NGF) gene mediated by recombinant adenovirus (Ad-NGF) via peripheral transfection in mice with experimental autoimmune encephalomyelitis (EAE). Forty healthy female C57BL/6 mice were randomly divided into a control group, adenovirus (AdV) group, EAE group, and Ad-NGF transfection group; the control group received no treatment; the AdV group received adenovirus injection via the tail vein; the EAE and Ad-NGF transfection groups were induced with experimental autoimmune encephalomyelitis (EAE) using myelin oligodendrocyte glycoprotein 35-55 (MOG35-55), Ad-NGF transfection group received Ad-NGF injection via the tail vein, and daily neurological impairment scores were obtained. AQThe TUNEL method was employed to observe spinal neuron apoptosis in each group of mice; protein immunoblotting (western blot) and RT-PCR were used to measure NGF levels in the spinal cord tissues of each group, and western blotting was used to assess levels of cleaved caspase-3, Bax, and Bcl-2. ELISA and RT-PCR were employed to detect protein and mRNA levels of neuron-specific enolase (NSE) in spinal cord tissues, respectively. The control group and AdV mice did not develop symptoms. Compared to the EAE group, in the Ad-NGF transfection group, neurological function scores, TUNEL-positive cell counts, the ratio of NeuN + TUNEL to NeuN, levels of Bax and cleaved caspase-3 apoptotic proteins were significantly reduced, while Bcl-2 protein expression was increased. Expression levels of NGF, NGF-mRNA, NSE, and NSE-mRNA in spinal cord tissues were significantly elevated (P < 0.01). Immunofluorescence labeling revealed a significant punctate aggregation of apoptotic cells in spinal neurons of the EAE group, while the aggregation phenomenon was less pronounced in the Ad-NGF transfection group. Ad-NGF transfected by the periphery has a protective effect on spinal cord neurons in EAE mice by up-regulation NGF level, down-regulating apoptotic protein Caspase-3 in spinal cord neurons, inhibiting spinal cord neuron apoptosis and promoting NSE expression., (© 2024. The Author(s).)

Previously, we described the mechanisms of development of autoimmune encephalomyelitis (EAE) in 3-month-old C57BL/6, Th, and 2D2 mice. The faster and more profound spontaneous development of EAE with the achievement of deeper pathology occurs in hybrid 2D2/Th mice. Here, the cellular and immunological analysis of EAE development in 2D2/Th mice was carried out. In Th, 2D2, and 2D2/Th mice, the development of EAE is associated with a change in the differentiation profile of hemopoietic bone marrow stem cells, which, in 2D2/Th, differs significantly from 2D2 and Th mice. Hybrid 2D2/Th mice demonstrate a significant difference in these changes in all strains of mice, leading to the production of antibodies with catalytic activities, known as abzymes, against self-antigens: myelin oligodendrocyte glycoprotein (MOG), DNA, myelin basic protein (MBP), and five histones (H1-H4) hydrolyze these antigens. There is also the proliferation of B and T lymphocytes in different organs (blood, bone marrow, thymus, spleen, lymph nodes). The patterns of changes in the concentration of antibodies and the relative activity of abzymes during the spontaneous development of EAE in the hydrolysis of these immunogens are significantly or radically different for the three lines of mice: Th, 2D2, and 2D2/Th. Several factors may play an essential role in the acceleration of EAE in 2D2/Th mice. The treatment of mice with MOG accelerates the development of EAE pathology. In the initial period of EAE development, the concentration of anti-MOG antibodies in 2D2/Th is significantly higher than in Th (29.1-fold) and 2D2 (11.7-fold). As shown earlier, antibodies with DNase activity penetrate cellular and nuclear membranes and activate cell apoptosis, stimulating autoimmune processes. In the initial period of EAE development, the concentration of anti-DNA antibodies in 2D2/Th hybrids is higher than in Th (4.6-fold) and 2D2 (25.7-fold); only 2D2/Th mice exhibited a very strong 10.6-fold increase in the DNase activity of IgGs during the development of EAE. Free histones in the blood are cytotoxic and stimulate the development of autoimmune diseases. Only in 2D2/Th mice, during different periods of EAE development, was a sharp increase in the anti-antibody activity in the hydrolysis of some histones observed.

Reactive astrocytes play critical roles in the occurrence of various neurological diseases such as multiple sclerosis. Activation of astrocytes is often accompanied by a glycolysis-dominant metabolic switch. However, the role and molecular mechanism of metabolic reprogramming in activation of astrocytes have not been clarified. Here, we found that PKM2, a rate-limiting enzyme of glycolysis, displayed nuclear translocation in astrocytes of EAE (experimental autoimmune encephalomyelitis) mice, an animal model of multiple sclerosis. Prevention of PKM2 nuclear import by DASA-58 significantly reduced the activation of mice primary astrocytes, which was observed by decreased proliferation, glycolysis and secretion of inflammatory cytokines. Most importantly, we identified the ubiquitination-mediated regulation of PKM2 nuclear import by ubiquitin ligase TRIM21. TRIM21 interacted with PKM2, promoted its nuclear translocation and stimulated its nuclear activity to phosphorylate STAT3, NF-κB and interact with c-myc. Further single-cell RNA sequencing and immunofluorescence staining demonstrated that TRIM21 expression was upregulated in astrocytes of EAE. TRIM21 overexpressing in mice primary astrocytes enhanced PKM2-dependent glycolysis and proliferation, which could be reversed by DASA-58. Moreover, intracerebroventricular injection of a lentiviral vector to knockdown TRIM21 in astrocytes or intraperitoneal injection of TEPP-46, which inhibit the nuclear translocation of PKM2, effectively decreased disease severity, CNS inflammation and demyelination in EAE. Collectively, our study provides novel insights into the pathological function of nuclear glycolytic enzyme PKM2 and ubiquitination-mediated regulatory mechanism that are involved in astrocyte activation. Targeting this axis may be a potential therapeutic strategy for the treatment of astrocyte-involved neurological disease., Competing Interests: LY, CH, XC, JZ, ZF, YX, WH, TC, XZ, YY, YZ, YY No competing interests declared, (© 2024, Yang, Hu, Chen et al.)

Multiple sclerosis (MS) is a chronic autoimmune disease with an unknown etiology. The purpose of this research was to assess miR-223, miR-146a, and miR-193a in acute and chronic phases of experimental autoimmune encephalomyelitis (EAE) mice to consider the possible role of these genes in the pathogenesis of MS. EAE induction was given by myelin oligodendrocyte glycoprotein peptide on female C57BL/6 mice. Clinical scores and other criteria were followed daily until day 21 for the acute group and day 77 for the chronic group. At the end of the course, inflammation and demyelination of the central nervous system (CNS) were assessed by histological analysis. MicroRNA expression levels were assessed by real-time PCR. EAE development attenuated in the chronic group, and histological analysis showed less infiltration and demyelination in the chronic group compared to the acute group. The upper expression of miR-223 is demonstrated in the acute phase of EAE. Moreover, the expression levels of miR-146a and miR-193a decreased in the chronic phase of EAE. MiR-223 showed a highly coordinated elevation in the acute phase both in vivo and in vitro. MiR-146a shares a pathway with miR-223 through effecting IL-6 expression. Further studies are needed to reveal their impact on EAE and possible applications as drug targets and biomarkers.

Galactosyl-ceramidase (GALC) is a ubiquitous lysosomal enzyme crucial for the correct myelination of the mammalian nervous system during early postnatal development. However, the physiological consequence of GALC deficiency in the adult brain remains unknown. In this study, we found that mice with conditional ablation of GALC activity in post-myelinating oligodendrocytes were lethally sensitized when challenged with chronic experimental allergic encephalomyelitis (EAE), in contrast with the non-lethal dysmyelination observed in Galc-ablated mice without the EAE challenge. Mechanistically, we found strong inflammatory demyelination without remyelination and an impaired fusion of lysosomes and autophagosomes with accumulation of myelin debris after a transcription factor EB-dependent increase in the lysosomal autophagosome flux. These results indicate that the physiological impact of GALC deficiency is highly influenced by the cell context (oligodendroglial vs. global expression), the presence of inflammation, and the developmental time when it happens (pre-myelination vs. post-myelination). We conclude that Galc expression in adult oligodendrocytes is crucial for the maintenance of adult central myelin and to decrease vulnerability to additional demyelinating insults., Competing Interests: Declaration of interests The authors declare absence of any conflict of interest in the preparation, execution, and decision to publish of this study. All data are available upon request., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

In mice with acute and chronic models of experimental autoimmune encephalomyelitis (EAE), a quantitative study of the dynamics of CSF-1 and IL-34 protein levels in the spinal cord and blood plasma was conducted by ELISA and the specificity of CSF-1 expression in spinal cord cells was examined by immunohistological methods. A significant increase in the level of CSF-1 in the spinal cord was detected and populations of motoneurons with intense CSF-1 immunoreactivity were identified in mice with acute and chronic EAE. The obtained results suggest a possible role of CSF-1 in the pathogenesis and progression of EAE/multiple sclerosis., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)