Experimental autoimmune encephalomyelitis (EAE) as a model for multiple sclerosis (MS)

Role of copper in central nervous system physiology and pathology

Copper is a transition metal and an essential element for the organism, as alterations in its homeostasis leading to metal accumulation or deficiency have pathological effects in several organs, including the central nervous system. Central copper dysregulations have been evidenced in two genetic disorders characterized by mutations in the copper-ATPases ATP7A and ATP7B, Menkes disease and Wilson's disease, respectively, and also in multifactorial neurological disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis. This review summarizes current knowledge about the role of copper in central nervous system physiology and pathology, reports about unbalances in copper levels and/or distribution under disease, describes relevant animal models for human disorders where copper metabolism genes are dysregulated, and discusses relevant therapeutic approaches modulating copper availability. Overall, alterations in copper metabolism may contribute to the etiology of central nervous system disorders and represent relevant therapeutic targets to restore tissue homeostasis.

Vortioxetine ameliorates experimental autoimmune encephalomyelitis model of multiple sclerosis in mice via activation of PI3K/Akt/CREB/BDNF cascade and modulation of serotonergic pathway signaling

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-HT1A) 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.

Extracellular Purine Metabolism-Potential Target in Multiple Sclerosis

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 A2A 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 P2Y12 receptors and the major extracellular ADP producing enzyme nucleoside triphosphate diphosphohydrolase 2 (NTPDase2) as novel potential targets in MS.

LPA3 agonist-producing Bacillus velezensis ADS024 is efficacious in multiple neuroinflammatory disease models

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.

Transplantation of human umbilical cord mesenchymal stem cells optimized with IFN-γ is a potential procedure for modification of motor impairment in multiple sclerosis cases: a preclinical systematic review and meta-analysis study

Stem cells transplantation (SCT) is known as a newfound strategy for multiple sclerosis (MS) treatment. Human umbilical cord mesenchymal stem cells (hUCMSCs) contain various regenerative features. Experimental autoimmune encephalomyelitis (EAE) is a laboratory model of MS. This meta-analysis study was conducted to assess the overall therapeutic effects of hUCMSCs on reduction of clinical score (CS) and restoration of active movement in EAE-induced animals. For comprehensive searching (in various English and Persian databases until May 1, 2024), the main keywords of "Experimental Autoimmune Encephalomyelitis", "Multiple Sclerosis", "Human", "Umbilical Cord", "Mesenchymal", and "Stem Cell" were hired. Collected data were transferred to the citation manager software (EndNote x8) and duplicate papers were merged. Primary and secondary screenings were applied (according to the inclusion and exclusion criteria) and eligible studies were prepared for data collection. CS of two phases of peak and recovery of EAE were extracted as the difference in means and various analyses including heterogeneity, publication bias, funnel plot, and sensitivity index were reported. Meta-analysis was applied by CMA software (v.2), P<0.05 was considered a significant level, and the confidence interval (CI) was determined 95% (95% CI). Six eligible high-quality (approved by ARRIVE checklist) papers were gathered. The difference in means of peak and recovery phases were -0.775 (-1.325 to -0.225; P=0.006; I2=90.417%) and -1.230 (-1.759 to -0.700; P<0.001; I2=93.402%), respectively. The overall therapeutic effects of SCT of hUCMSCs on the EAE cases was -1.011 (95% CI=-1.392 to -0.629; P=0.001). hUCMSCs transplantation through the intravenous route to the animal MS model (EAE) seems a considerably effective procedure for the alleviation of motor defects in both phases of peak and recovery.

Discovery and Optimization of a Series of Vinyl Sulfoximine-Based Analogues as Potent Nrf2 Activators for the Treatment of Multiple Sclerosis

Multiple sclerosis (MS) is an immune-mediated neurodegenerative disease of the central nervous system (CNS), which leads to demyelination, axonal loss, and neurodegeneration. Increased oxidative stress and neurodegeneration have been implicated in all stages of MS, making neuroprotective therapeutics a promising strategy for its treatment. We previously have reported vinyl sulfones with antioxidative and anti-inflammatory properties that activate nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that induces the expression of cytoprotective genes against oxidative stress. In this study, we synthesized vinyl sulfoximine derivatives by modifying the core structure and determined therapeutic potential as Nrf2 activators. Among them, 10v effectively activated Nrf2 (EC50 = 83.5 nM) and exhibited favorable drug-like properties. 10v successfully induced expression of Nrf2-dependent antioxidant enzymes and suppressed lipopolysaccharide (LPS)-induced inflammatory responses in BV-2 microglial cells. We also confirmed that 10v effectively reversed disease progression and attenuated demyelination in an experimental autoimmune encephalitis (EAE) mouse model of MS.

Novel model of multiple sclerosis induced by EBV-like virus generates a unique B cell population

Epstein-Barr virus (EBV) is deemed a necessary, yet insufficient factor in the development of multiple sclerosis (MS). In this study, myelin basic protein-specific transgenic T cell receptor mice were infected with murid gammaherpesvirus 68 virus (MHV68), an EBV-like virus that infects mice, resulting in the onset neurological deficits at a significantly higher frequency than influenza or mock-infected mice. MHV68 infected mice exhibited signs including optic neuritis and ataxia which are frequently observed in MS patients but not in experimental autoimmune encephalomyelitis mice. MHV68-infected mice exhibited increased focal immune cell infiltration in the central nervous system. Single cell RNA sequencing identified the emergence of a population of B cells that express genes associated with antigen presentation and costimulation, indicating that gammaherpesvirus infection drives a distinct, pro-inflammatory transcriptional program in B cells that may promote autoreactive T cell responses in MS.

Niacin produces an inconsistent treatment response in the EAE model of multiple sclerosis

Niacin was found in the lysolecithin model of multiple sclerosis (MS) to promote the phagocytic clearance of debris and enhance remyelination. Lysolecithin lesions have prominent microglia/macrophages but lack lymphocytes that populate plaques of MS or its experimental autoimmune encephalomyelitis (EAE) model. Thus, the current study assessed the efficacy of niacin in EAE. We found that niacin inconsistently affects EAE clinical score, and largely does not ameliorate neuropathology. In culture, niacin enhances phagocytosis by macrophages, but does not reduce T cell proliferation. We suggest that studies of niacin for potential remyelination in MS should include a therapeutic that targets adaptive immunity.

The Effect of Tissue Inhibitor of Metalloproteinases on Scar Formation after Spinal Cord Injury

Spinal cord injury (SCI) often results in permanent loss of motor and sensory function. After SCI, the blood-spinal cord barrier (BSCB) is disrupted, causing the infiltration of neutrophils and macrophages, which secrete several kinds of cytokines, as well as matrix metalloproteinases (MMPs). MMPs are proteases capable of degrading various extracellular matrix (ECM) proteins, as well as many non-matrix substrates. The tissue inhibitor of MMPs (TIMP)-1 is significantly upregulated post-SCI and operates via MMP-dependent and MMP-independent pathways. Through the MMP-dependent pathway, TIMP-1 directly reduces inflammation and destruction of the ECM by binding and blocking the catalytic domains of MMPs. Thus, TIMP-1 helps preserve the BSCB and reduces immune cell infiltration. The MMP-independent pathway involves TIMP-1's cytokine-like functions, in which it binds specific TIMP surface receptors. Through receptor binding, TIMP-1 can stimulate the proliferation of several types of cells, including keratinocytes, aortic smooth muscle cells, skin epithelial cells, corneal epithelial cells, and astrocytes. TIMP-1 induces astrocyte proliferation, modulates microglia activation, and increases myelination and neurite extension in the central nervous system (CNS). In addition, TIMP-1 also regulates apoptosis and promotes cell survival through direct signaling. This review provides a comprehensive assessment of TIMP-1, specifically regarding its contribution to inflammation, ECM remodeling, and scar formation after SCI.

Systematic review of photobiomodulation for multiple sclerosis

Background

Multiple sclerosis (MS) is an inflammatory chronic autoimmune and neurodegenerative disorder of the brain and spinal cord, resulting in loss of motor, sensorial, and cognitive function. Among the non-pharmacological interventions for several brain conditions, photobiomodulation (PBM) has gained attention in medical society for its neuroprotective effects. We systematically reviewed the effects of PBM on MS.

Methods

We conducted a systematic search on the bibliographic databases (PubMed and ScienceDirect) with the keywords based on MeSH terms: PBM, low-level laser therapy, multiple sclerosis, autoimmune encephalomyelitis, demyelination, and progressive multiple sclerosis. Data search was limited from 2012 to July 2024. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The initial systematic search identified 126 articles. Of these, 68 articles were removed by duplicity and 50 by screening. Thus, 8 studies satisfied the inclusion criteria.

Results

The reviewed studies showed that PBM modulates brain markers linked to inflammation, oxidative stress, and apoptosis. Improvements in motor, sensorial, and cognitive functions in MS patients were also observed after PBM therapy. No study reported adverse effects of PBM.

Conclusion

These findings suggest the potential of PBM as a promising non-pharmacological intervention for the management of MS, although further research is needed to standardize PBM protocols and assess its long-term effects.

Potential Application of Plant-Derived Compounds in Multiple Sclerosis Management

Multiple sclerosis (MS) is a chronic autoimmune disorder characterized by inflammation, demyelination, and neurodegeneration, resulting in significant disability and reduced quality of life. Current therapeutic strategies primarily target immune dysregulation, but limitations in efficacy and tolerability highlight the need for alternative treatments. Plant-derived compounds, including alkaloids, phenylpropanoids, and terpenoids, have demonstrated anti-inflammatory effects in both preclinical and clinical studies. By modulating immune responses and promoting neuroregeneration, these compounds offer potential as novel adjunctive therapies for MS. This review provides insights into the molecular and cellular basis of MS pathogenesis, emphasizing the role of inflammation in disease progression. It critically evaluates emerging evidence supporting the use of plant-derived compounds to attenuate inflammation and MS symptomology. In addition, we provide a comprehensive source of information detailing the known mechanisms of action and assessing the clinical potential of plant-derived compounds in the context of MS pathogenesis, with a focus on their anti-inflammatory and neuroprotective properties.

S100A4 promotes experimental autoimmune encephalomyelitis by impacting microglial inflammation through TLR4/NF-κB signaling pathway

Multiple sclerosis (MS) is a neurodegenerating autoimmune disease with no clinical cure currently. The calcium-binding protein S100A4 has been demonstrated to exert regulatory roles in inflammatory disorders including MS. However, the precise mechanisms by which S100A4 regulates neuroinflammation in MS remains unknown. To investigate the regulatory effect of S100A4 on microglial inflammation and its impact on neuroinflammation, the mouse-derived microglia cell line BV2 cells were infected with lentivirus to knockout S100A4 for in vitro studies. Wild-type (WT) and S100A4-/- mice were induced to develop experimental autoimmune encephalomyelitis (EAE), an animal model of MS, for in vivo investigation. Results indicated that the frequencies of microglia in the spinal cord and brain and the expression of S100A4 in these tissues varied kinetically along with the progression of the disease in mice with EAE. S100A4-/- mice presented ameliorated clinical scores of EAE and exhibited less severe EAE signs, including inflammatory cell infiltration in the spinal cord and brain and demyelination of the spinal cord. Moreover, these mice demonstrated overall reduced levels of inflammatory cytokines in the spinal cord and brain. Compromised systematic inflammatory responses including circulating cytokines and frequencies of immune cells in the spleen were also observed in these mice. In addition, both exogenous and endogenous S100A4 could promote the microglial inflammation, affect the polarization of microglia and enhance inflamed microglia-mediated apoptosis of neuronal cells through TLR4/NF-κB signaling pathway. Thus, S100A4 may participate in the regulation of neuroinflammation at least partly through regulating the inflammation of microglia.

Glial Cells as Key Regulators in Neuroinflammatory Mechanisms Associated with Multiple Sclerosis

Even though several highly effective treatments have been developed for multiple sclerosis (MS), the underlying pathological mechanisms and drivers of the disease have not been fully elucidated. In recent years, there has been a growing interest in studying neuroinflammation in the context of glial cell involvement as there is increasing evidence of their central role in disease progression. Although glial cell communication and proper function underlies brain homeostasis and maintenance, their multiple effects in an MS brain remain complex and controversial. In this review, we aim to provide an overview of the contribution of glial cells, oligodendrocytes, astrocytes, and microglia in the pathology of MS during both the activation and orchestration of inflammatory mechanisms, as well as of their synergistic effects during the repair and restoration of function. Additionally, we discuss how the understanding of glial cell involvement in MS may provide new therapeutic targets either to limit disease progression or to facilitate repair.

The role of integrins in brain health and neurodegenerative diseases

Integrins are heterodimeric membrane proteins expressed on the surface of most cells. They mediate adhesion and signaling processes relevant for a wealth of physiological processes, including nervous system development and function. Interestingly, integrins are also recognized therapeutic targets for inflammatory diseases, such as multiple sclerosis. Here, we discuss the role of integrins in brain development and function, as well as in neurodegenerative diseases affecting the brain (Alzheimer's disease, multiple sclerosis, stroke). Furthermore, we discuss therapeutic targeting of these adhesion receptors in inflammatory diseases of the brain.

Identifying and reducing risks of neurological complications associated with vaccination

Vaccines protect against many infectious diseases, including some that can directly or indirectly cause nervous system damage. Serious neurological consequences of immunization are typically extremely rare, although they have the potential to jeopardize vaccination programmes, as demonstrated most recently during the COVID-19 pandemic. Neurologists have an important role in identifying safety signals at population and individual patient levels, as well as providing advice on the benefit-risk profile of vaccination in cohorts of patients with diverse neurological conditions. This article reviews the links between vaccination and neurological disease and considers how emerging signals can be evaluated and their mechanistic basis identified. We review examples of neurotropic infections with live attenuated vaccines, as well as neuroimmunological and neurovascular sequelae of other types of vaccines. We emphasize that such risks are typically dwarfed by neurological complications associated with natural infection and discuss how the risks can be further mitigated. The COVID-19 pandemic has highlighted the need to rapidly identify and minimize neurological risks of vaccination, and we review the structures that need to be developed to protect public health against these risks in the future.

A Systematic Online Living Evidence Summary of experimental Alzheimer's disease research

BACKGROUND

Despite extensive investment, the development of effective treatments for Alzheimer's disease (AD) has been largely unsuccessful. To improve translation, it is crucial to ensure the quality and reproducibility of foundational evidence generated from laboratory models. Systematic reviews play a key role in providing an unbiased overview of the evidence, assessing rigour and reporting, and identifying factors that influence reproducibility. However, the sheer pace of evidence generation is prohibitive to evidence synthesis and assessment.

NEW METHOD

To address these challenges, we have developed AD-SOLES, an integrated workflow of automated tools that collect, curate, and visualise the totality of evidence from in vivo experiments.

RESULTS

AD-SOLES is a publicly accessible interactive dashboard aiming to surface and expose data from in vivo experiments. It summarises the latest evidence, tracks reporting quality and transparency, and allows research users to easily locate evidence relevant to their specific research question.

COMPARISON WITH EXISTING METHODS

Using automated screening methodologies within AD-SOLES, systematic reviews can begin at an accelerated starting point compared to traditional approaches. Furthermore, through text-mining approaches within the full-text of publications, users can identify research of interest using specific models, outcomes, or interventions without relying on details in the title and/or abstract.

CONCLUSIONS

By automating the collection, curation, and visualisation of evidence from in vivo experiments, AD-SOLES addresses the challenges posed by the rapid pace of evidence generation. AD-SOLES aims to offer guidance for research improvement, reduce research waste, highlight knowledge gaps, and support informed decision making for researchers, funders, patients, and the public.

Rigid crosslinking of the CD3 complex leads to superior T cell stimulation

Functionally bivalent non-covalent Fab dimers (Bi-Fabs) specific for the TCR/CD3 complex promote CD3 signaling on T cells. While comparing functional responses to stimulation with Bi-Fab, F(ab')2 or mAb specific for the same CD3 epitope, we observed fratricide requiring anti-CD3 bridging of adjacent T cells. Surprisingly, anti-CD3 Bi-Fab ranked first in fratricide potency, followed by anti-CD3 F(ab')2 and anti-CD3 mAb. Low resolution structural studies revealed anti-CD3 Bi-Fabs and F(ab')2 adopt similar global shapes with CD3-binding sites oriented outward. However, under molecular dynamic simulations, anti-CD3 Bi-Fabs crosslinked CD3 more rigidly than F(ab')2. Furthermore, molecular modelling of Bi-Fab and F(ab')2 binding to CD3 predicted crosslinking of T cell antigen receptors located in opposing plasma membrane domains, a feature fitting with T cell fratricide observed. Thus, increasing rigidity of Fab-CD3 crosslinking between opposing effector-target pairs may result in stronger T cell effector function. These findings could guide improving clinical performance of bi-specific anti-CD3 drugs.

The fetal programming effect of maternal immune activation (MIA) on the offspring's immune system

The first 1000 days of life is a critical period of development in which adverse circumstances can have long-term consequences for the child's health. Maternal immune activation is associated with increased risk of neurodevelopmental disorders in the child. Aberrant immune responses have been reported in individuals with neurodevelopmental disorders. Moreover, lasting effects of maternal immune activation on the offspring's immune system have been reported. Taken together, this indicates that the effect of maternal immune activation is not limited to the central nervous system. Here, we explore the impact of maternal immune activation on the immune system of the offspring. We first describe the development of the immune system and provide an overview of reported alterations in the cytokine profiles, immune cell profiles, immune cell function, and immune induction in pre-clinical models. Additionally, we highlight recent research on the impact of maternal COVID-19 exposure on the neonatal immune system and the potential health consequences for the child. Our review shows that maternal immune activation alters the offspring's immune system under certain conditions, but the reported effects are conflicting and inconsistent. In general, epigenetic modifications are considered the mechanism for fetal programming. The available data was insufficient to identify specific pathways that may contribute to immune programming. As a consequence of the COVID-19 pandemic, more research now focuses on the possible health effects of maternal immune activation on the offspring. Future research addressing the offspring's immune response to maternal immune activation can elucidate specific pathways that contribute to fetal immune programming and the long-term health effects for the offspring.

Endothelial Cell-Derived Soluble CD200 Determines the Ability of Immune Cells to Cross the Blood-Brain Barrier

The infiltration of immune cells into the central nervous system mediates the development of autoimmune neuroinflammatory diseases. We previously showed that the loss of either Fabp5 or calnexin causes resistance to the induction of experimental autoimmune encephalomyelitis (EAE) in mice, an animal model of multiple sclerosis (MS). Here we show that brain endothelial cells lacking either Fabp5 or calnexin have an increased abundance of cell surface CD200 and soluble CD200 (sCD200) as well as decreased T-cell adhesion. In a tissue culture model of the blood-brain barrier, antagonizing the interaction of CD200 and sCD200 with T-cell CD200 receptor (CD200R1) via anti-CD200 blocking antibodies or the RNAi-mediated inhibition of CD200 production by endothelial cells increased T-cell adhesion and transmigration across monolayers of endothelial cells. Our findings demonstrate that sCD200 produced by brain endothelial cells regulates immune cell trafficking through the blood-brain barrier and is primarily responsible for preventing activated T-cells from entering the brain.

Deferoxamine preconditioning of canine stem cell derived extracellular vesicles alleviates inflammation in an EAE mouse model through STAT3 regulation

Extracellular vesicles (EVs) from mesenchymal stem cells (MSCs), specifically those preconditioned with deferoxamine (DFO) in canine adipose tissue-derived MSCs (cAT-MSCs), were explored for treating autoimmune diseases. This study assessed the effects of DFO-preconditioned EVs (EVDFO) in an experimental autoimmune encephalomyelitis (EAE) mouse model. cAT-MSCs were treated with DFO for 48 h, after which EVs were isolated. EAE mice received intranasal EV or EVDFO treatments and were euthanized following histopathologic analysis; RNA and protein expression levels were measured. Histologically, EV and EVDFO groups showed a significant reduction in inflammatory cell infiltration and demyelination. Immunofluorescence revealed increased CD206 and Foxp3 expression, indicating elevated M2 macrophages and regulatory T (Treg) cells, particularly in the EVDFO group. Treg cells also notably increased in the spleen of EVDFO -treated mice. STAT3 and pSTAT3 proteins were upregulated in the EAE groups compared to the naïve group. However, following EV treatment, STAT3 expression decreased compared to the EAE group, whereas pSTAT3 expression was similar in both the EV and EAE groups. In conclusion, EVDFO treatment resulted in reduced STAT3 expression, suggesting its role in T cell regulation and the potential of EVDFO in modulating the STAT3 pathway for reducing inflammation more effectively than non-preconditioned EVs.

Microbiota-Derived Extracellular Vesicle as Emerging Actors in Host Interactions

The human microbiota is an intricate micro-ecosystem comprising a diverse range of dynamic microbial populations mainly consisting of bacteria, whose interactions with hosts strongly affect several physiological and pathological processes. The gut microbiota is being increasingly recognized as a critical player in maintaining homeostasis, contributing to the main functions of the intestine and distal organs such as the brain. However, gut dysbiosis, characterized by composition and function alterations of microbiota with intestinal barrier dysfunction has been linked to the development and progression of several pathologies, including intestinal inflammatory diseases, systemic autoimmune diseases, such as rheumatic arthritis, and neurodegenerative diseases, such as Alzheimer's disease. Moreover, oral microbiota research has gained significant interest in recent years due to its potential impact on overall health. Emerging evidence on the role of microbiota-host interactions in health and disease has triggered a marked interest on the functional role of bacterial extracellular vesicles (BEVs) as mediators of inter-kingdom communication. Accumulating evidence reveals that BEVs mediate host interactions by transporting and delivering into host cells effector molecules that modulate host signaling pathways and cell processes, influencing health and disease. This review discusses the critical role of BEVs from the gut, lung, skin and oral cavity in the epithelium, immune system, and CNS interactions.

Contribution of microglia/macrophage to the pathogenesis of TMEV infection in the central nervous system

The infection of the central nervous system (CNS) with neurotropic viruses induces neuroinflammation and an immune response, which is associated with the development of neuroinflammatory and neurodegenerative diseases, including multiple sclerosis (MS). The activation of both innate and adaptive immune responses, involving microglia, macrophages, and T and B cells, while required for efficient viral control within the CNS, is also associated with neuropathology. Under pathological events, such as CNS viral infection, microglia/macrophage undergo a reactive response, leading to the infiltration of immune cells from the periphery into the brain, disrupting CNS homeostasis and contributing to the pathogenesis of disease. The Theiler's murine encephalomyelitis virus (TMEV)-induced demyelination disease (TMEV-IDD), which serves as a mouse model of MS. This murine model made significant contributions to our understanding of the pathophysiology of MS following subsequent to infection. Microglia/macrophages could be activated into two different states, classic activated state (M1 state) and alternative activated state (M2 state) during TMEV infection. M1 possesses the capacity to initiate inflammatory response and secretes pro-inflammatory cytokines, and M2-liked microglia/macrophages are anti-inflammatory characterized by the secretion of anti-inflammatory cytokines. This review aims to discuss the roles of microglia/macrophages M1/M2-liked polarization during TMEV infection, and explore the potential therapeutic effect of balancing M1/M2-liked polarization of microglia/macrophages on MS.

How does Nogo-A signalling influence mitochondrial function during multiple sclerosis pathogenesis?

Multiple sclerosis (MS) is a severe neurological disorder that involves inflammation in the brain, spinal cord and optic nerve with key disabling neuropathological outcomes being axonal damage and demyelination. When degeneration of the axo-glial union occurs, a consequence of inflammatory damage to central nervous system (CNS) myelin, dystrophy and death can lead to large membranous structures from dead oligodendrocytes and degenerative myelin deposited in the extracellular milieu. For the first time, this review covers mitochondrial mechanisms that may be operative during MS-related neurodegenerative changes directly activated during accumulating extracellular deposits of myelin associated inhibitory factors (MAIFs), that include the potent inhibitor of neurite outgrowth, Nogo-A. Axonal damage may occur when Nogo-A binds to and signals through its cognate receptor, NgR1, a multimeric complex, to initially stall axonal transport and limit the delivery of important growth-dependent cargo and subcellular organelles such as mitochondria for metabolic efficiency at sites of axo-glial disintegration as a consequence of inflammation. Metabolic efficiency in axons fails during active demyelination and progressive neurodegeneration, preceded by stalled transport of functional mitochondria to fuel axo-glial integrity.

Cavβ3 Contributes to the Maintenance of the Blood-Brain Barrier and Alleviates Symptoms of Experimental Autoimmune Encephalomyelitis

BACKGROUND

Tight control of cytoplasmic Ca2+ concentration in endothelial cells is essential for the regulation of endothelial barrier function. Here, we investigated the role of Cavβ3, a subunit of voltage-gated Ca2+ (Cav) channels, in modulating Ca2+ signaling in brain microvascular endothelial cells (BMECs) and how this contributes to the integrity of the blood-brain barrier.

METHODS

We investigated the function of Cavβ3 in BMECs by Ca2+ imaging and Western blot, examined the endothelial barrier function in vitro and the integrity of the blood-brain barrier in vivo, and evaluated disease course after induction of experimental autoimmune encephalomyelitis in mice using Cavβ3-/- (Cavβ3-deficient) mice as controls.

RESULTS

We identified Cavβ3 protein in BMECs, but electrophysiological recordings did not reveal significant Cav channel activity. In vivo, blood-brain barrier integrity was reduced in the absence of Cavβ3. After induction of experimental autoimmune encephalomyelitis, Cavβ3-/- mice showed earlier disease onset with exacerbated clinical disability and increased T-cell infiltration. In vitro, the transendothelial resistance of Cavβ3-/- BMEC monolayers was lower than that of wild-type BMEC monolayers, and the organization of the junctional protein ZO-1 (zona occludens-1) was impaired. Thrombin stimulates inositol 1,4,5-trisphosphate-dependent Ca2+ release, which facilitates cell contraction and enhances endothelial barrier permeability via Ca2+-dependent phosphorylation of MLC (myosin light chain). These effects were more pronounced in Cavβ3-/- than in wild-type BMECs, whereas the differences were abolished in the presence of the MLCK (MLC kinase) inhibitor ML-7. Expression of Cacnb3 cDNA in Cavβ3-/- BMECs restored the wild-type phenotype. Coimmunoprecipitation and mass spectrometry demonstrated the association of Cavβ3 with inositol 1,4,5-trisphosphate receptor proteins.

CONCLUSIONS

Independent of its function as a subunit of Cav channels, Cavβ3 interacts with the inositol 1,4,5-trisphosphate receptor and is involved in the tight control of cytoplasmic Ca2+ concentration and Ca2+-dependent MLC phosphorylation in BMECs, and this role of Cavβ3 in BMECs contributes to blood-brain barrier integrity and attenuates the severity of experimental autoimmune encephalomyelitis disease.

Therapy with regulatory T-cell infusion in autoimmune diseases and organ transplantation: A review of the strengths and limitations

In the last decade, cell therapies have revolutionized the treatment of some diseases, earning the definition of being the "third pillar" of therapeutics. In particular, the infusion of regulatory T cells (Tregs) is explored for the prevention and control of autoimmune reactions and acute/chronic allograft rejection. Such an approach represents a promising new treatment for autoimmune diseases to recover an immunotolerance against autoantigens, and to prevent an immune response to alloantigens. The efficacy of the in vitro expanded polyclonal and antigen-specific Treg infusion in the treatment of a large number of autoimmune diseases has been extensively demonstrated in mouse models. Similarly, experimental work documented the efficacy of Treg infusions to prevent acute and chronic allograft rejections. The Treg therapy has shown encouraging results in the control of type 1 diabetes (T1D) as well as Crohn's disease, systemic lupus erythematosus, autoimmune hepatitis and delaying graft rejection in clinical trials. However, the best method for Treg expansion and the advantages and pitfalls with the different types of Tregs are not fully understood in terms of how these therapeutic treatments can be applied in the clinical setting. This review provides an up-to-date overview of Treg infusion-based treatments in autoimmune diseases and allograft transplantation, the current technical challenges, and the highlights and disadvantages of this therapeutic approaches."

Formyl peptide receptor 2 regulates dendritic cell metabolism and Th17 cell differentiation during neuroinflammation

Formyl peptide receptor 2 (FPR2) is a receptor for formylated peptides and specific pro-resolving mediators, and is involved in various inflammatory processes. Here, we aimed to elucidate the role of FPR2 in dendritic cell (DC) function and autoimmunity-related central nervous system (CNS) inflammation by using the experimental autoimmune encephalomyelitis (EAE) model. EAE induction was accompanied by increased Fpr2 mRNA expression in the spinal cord. FPR2-deficient (Fpr2 KO) mice displayed delayed onset of EAE compared to wild-type (WT) mice, associated with reduced frequencies of Th17 cells in the inflamed spinal cord at the early stage of the disease. However, FPR2 deficiency did not affect EAE severity after the disease reached its peak. FPR2 deficiency in mature DCs resulted in decreased expression of Th17 polarizing cytokines IL6, IL23p19, IL1β, and thereby diminished the DC-mediated activation of Th17 cell differentiation. LPS-activated FPR2-deficient DCs showed upregulated Nos2 expression and nitric oxide (NO) production, as well as reduced oxygen consumption rate and impaired mitochondrial function, including decreased mitochondrial superoxide levels, lower mitochondrial membrane potential and diminished expression of genes related to the tricarboxylic acid cycle and genes related to the electron transport chain, as compared to WT DCs. Treatment with a NO inhibitor reversed the reduced Th17 cell differentiation in the presence of FPR2-deficient DCs. Together, by regulating DC metabolism, FPR2 enhances the production of DC-derived Th17-polarizing cytokines and hence Th17 cell differentiation in the context of neuroinflammation.

Impaired olfactory performance and anxiety-like behavior in a rat model of multiple sclerosis are associated with enhanced adenosine signaling in the olfactory bulb via A1R, A2BR, and A3R

The present study shows that animals with experimental autoimmune encephalomyelitis (EAE) exhibit olfactory dysfunction and impaired general cognitive abilities, as well as anxiety-like behavior. Olfactory dysfunction occurs on average at 2 dpi, well before the onset of the first motor signs of EAE (8-10 dpi). After the initial olfactory dysfunction, the EAE animals show a fluctuation in olfactory performance that resembles the relapsing-remitting course of human MS. The study also shows severe neuroinflammation in the olfactory bulb (OB), with numerous infiltrated CD4+ T cells and peripheral macrophages in the superficial OB layers, marked microgliosis, and massive induction of TNF-α, IL-1β, and IL-6. Reduced tyrosine hydroxylase activity in the glomerular layer, pronounced granule cell atrophy, and reduced numbers of type B neuroblasts in the rostral migratory stream also indicate altered plasticity of the neuronal network in the OB. Considering the exceptionally high purinome expression in the OB, the possible involvement of purinergic signaling was also investigated. The study shows that macrophages infiltrating the OB overexpress A3R, while highly reactive microglia overexpress the adenosine-producing enzyme eN/CD73 as well as A2BR, A3R, and P2X4R. Given the simultaneous induction of complement component C3, the results suggest that the microglial cells develop a functional phenotype of phagocytizing microglia. The study also demonstrates transcriptional and translational upregulation of A1R in mitral and tufted cells, which likely influence resting network activity in OB and likely contribute to olfactory dysfunction in EAE. Overall, our study shows that olfactory dysfunction and altered social and cognitive behavior in EAE are associated with increased adenosine signaling via A1R, A2BR, and A3R.

A preclinical mice model of multiple sclerosis based on the toxin-induced double-site demyelination of callosal and cerebellar fibers

BACKGROUND

Multiple sclerosis (MS) is an irreversible progressive CNS pathology characterized by the loss of myelin (i.e. demyelination). The lack of myelin is followed by a progressive neurodegeneration triggering symptoms as diverse as fatigue, motor, locomotor and sensory impairments and/or bladder, cardiac and respiratory dysfunction. Even though there are more than fourteen approved treatments for reducing MS progression, there are still no cure for the disease. Thus, MS research is a very active field and therefore we count with different experimental animal models for studying mechanisms of demyelination and myelin repair, however, we still lack a preclinical MS model assembling demyelination mechanisms with relevant clinical-like signs.

RESULTS

Here, by inducing the simultaneous demyelination of both callosal and cerebellar white matter fibers by the double-site injection of lysolecithin (LPC), we were able to reproduce CNS demyelination, astrocyte recruitment and increases levels of proinflammatory cytokines levels along with motor, locomotor and urinary impairment, as well as cardiac and respiratory dysfunction, in the same animal model. Single site LPC-injections either in corpus callosum or cerebellum only, fails in to reproduce such a complete range of MS-like signs.

CONCLUSION

We here report that the double-site LPC injections treatment evoke a complex MS-like mice model. We hope that this experimental approach will help to deepen our knowledge about the mechanisms of demyelinated diseases such as MS.

Leonurine: a comprehensive review of pharmacokinetics, pharmacodynamics, and toxicology

Leonurine is an alkaloid unique to the Leonurus genus, which has many biological activities, such as uterine contraction, anti-inflammation, anti-oxidation, regulation of cell apoptosis, anti-tumor, angiogenesis, anti-platelet aggregation, and inhibition of vasoconstriction. This paper summarizes the extraction methods, synthetic pathways, biosynthetic mechanisms, pharmacokinetic properties, pharmacological effects in various diseases, toxicology, and clinical trials of leonurine. To facilitate a successful transition into clinical application, intensified efforts are required in several key areas: structural modifications of leonurine to optimize its properties, comprehensive pharmacokinetic assessments to understand its behavior within the body, thorough mechanistic studies to elucidate how it works at the molecular level, rigorous safety evaluations and toxicological investigations to ensure patient wellbeing, and meticulously conducted clinical trials to validate its efficacy and safety profile.

Exploring the impact of m6A modification on immune diseases: mechanisms and therapeutic implication

N6-methyladenosine (m6A) is a chemical modification of RNA and has become a widely discussed topic among scientific researchers in recent years. It is distributed in various organisms, including eukaryotes and bacteria. It has been found that m6A is composed of writers, erasers and readers and is involved in biological functions such as splicing, transport and translation of RNA. The balance of the human immune microenvironment is important for human health abnormalities. Increasing studies have found that m6A affects the development of immune diseases such as inflammatory enteritis and systemic lupus erythematosus (SLE) by participating in the homeostatic regulation of the immune microenvironment in vivo. In this manuscript, we introduce the composition, biological function, regulation of m6A in the immune microenvironment and its progression in various immune diseases, providing new targets and directions for the treatment of immune diseases in clinical practice.

Identifying Diagnostic Markers and Constructing Predictive Models for Oxidative Stress in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic disease characterized by inflammation and neurodegeneration of the central nervous system. Despite the significant role of oxidative stress in the pathogenesis of MS, its precise molecular mechanisms remain unclear. This study utilized microarray datasets from the GEO database to analyze differentially expressed oxidative-stress-related genes (DE-OSRGs), identifying 101 DE-OSRGs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicate that these genes are primarily involved in oxidative stress and immune responses. Through protein-protein interaction (PPI) network, LASSO regression, and logistic regression analyses, four genes (MMP9, NFKBIA, NFKB1, and SRC) were identified as being closely related to MS. A diagnostic prediction model based on logistic regression demonstrated good predictive power, as shown by the nomogram curve index and DAC results. An immune-cell infiltration analysis using CIBERSORT revealed significant correlations between these genes and immune cell subpopulations. Abnormal oxidative stress and upregulated expression of key genes were observed in the blood and brain tissues of EAE mice. A molecular docking analysis suggested strong binding potentials between the proteins of these genes and several drug molecules, including isoquercitrin, decitabine, benztropine, and curcumin. In conclusion, this study identifies and validates potential diagnostic biomarkers for MS, establishes an effective prediction model, and provides new insights for the early diagnosis and personalized treatment of MS.

Chemokine CX3CL1 (Fractalkine) Signaling and Diabetic Encephalopathy

Diabetes mellitus (DM) is the most common metabolic disease in humans, and its prevalence is increasing worldwide in parallel with the obesity pandemic. A lack of insulin or insulin resistance, and consequently hyperglycemia, leads to many systemic disorders, among which diabetic encephalopathy (DE) is a long-term complication of the central nervous system (CNS), characterized by cognitive impairment and motor dysfunctions. The role of oxidative stress and neuroinflammation in the pathomechanism of DE has been proven. Fractalkine (CX3CL1) has unique properties as an adhesion molecule and chemoattractant, and by acting on its only receptor, CX3CR1, it regulates the activity of microglia in physiological states and neuroinflammation. Depending on the clinical context, CX3CL1-CX3CR1 signaling may have neuroprotective effects by inhibiting the inflammatory process in microglia or, conversely, maintaining/intensifying inflammation and neurotoxicity. This review discusses the evidence supporting that the CX3CL1-CX3CR1 pair is neuroprotective and other evidence that it is neurotoxic. Therefore, interrupting the vicious cycle within neuron-microglia interactions by promoting neuroprotective effects or inhibiting the neurotoxic effects of the CX3CL1-CX3CR1 signaling axis may be a therapeutic goal in DE by limiting the inflammatory response. However, the optimal approach to prevent DE is simply tight glycemic control, because the elimination of dysglycemic states in the CNS abolishes the fundamental mechanisms that induce this vicious cycle.

Functional Role of DDR1 in Oligodendrocyte Signaling Mechanism in Association with Myelination and Remyelination Process in the Central Nerve System

ABSTRACT

Multiple sclerosis (MS) is a complicated, inflammatory disease that causes demyelination of the central nervous system (CNS), resulting in a variety of neurological abnormalities. Over the past several decades, different animal models have been used to replicate the clinical symptoms and neuropathology of MS. The experimental model of experimental autoimmune/allergic encephalomyelitis (EAE) and viral and toxin-induced model was widely used to investigate the clinical implications of MS. Discoidin domain receptor 1 (DDR1) signaling in oligodendrocytes (OL) brings a new dimension to our understanding of MS pathophysiology. DDR1 is effectively involved in the OL during neurodevelopment and remyelination. It has been linked to many cellular processes, including migration, invasion, proliferation, differentiation, and adhesion. However, the exact functional involvement of DDR1 in developing OL and myelinogenesis in the CNS remains undefined. In this review, we critically evaluate the current literature on DDR1 signaling in OL and its proliferation, migration, differentiation, and myelination mechanism in OL in association with the progression of MS. It increases our knowledge of DDR1 in OL as a novel target molecule for oligodendrocyte-associated diseases in the CNS, including MS.

Targeting ferroptosis in neuroimmune and neurodegenerative disorders for the development of novel therapeutics

Neuroimmune and neurodegenerative ailments impose a substantial societal burden. Neuroimmune disorders involve the intricate regulatory interactions between the immune system and the central nervous system. Prominent examples of neuroimmune disorders encompass multiple sclerosis and neuromyelitis optica. Neurodegenerative diseases result from neuronal degeneration or demyelination in the brain or spinal cord, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. The precise underlying pathogenesis of these conditions remains incompletely understood. Ferroptosis, a programmed form of cell death characterised by lipid peroxidation and iron overload, plays a pivotal role in neuroimmune and neurodegenerative diseases. In this review, we provide a detailed overview of ferroptosis, its mechanisms, pathways, and regulation during the progression of neuroimmune and neurodegenerative diseases. Furthermore, we summarise the impact of ferroptosis on neuroimmune-related cells (T cells, B cells, neutrophils, and macrophages) and neural cells (glial cells and neurons). Finally, we explore the potential therapeutic implications of ferroptosis inhibitors in diverse neuroimmune and neurodegenerative diseases.

The protective role of interaction between vitamin D, sex hormones and calcium in multiple sclerosis

Multiple sclerosis (MS) is a neurological disorder that causes disability and paralysis, especially among young adults. Although interactions of several factors, such as viral infections, autoimmunity, genetic and environmental factors, performance a role in the beginning and progression of the disease, the exact cause of MS is unknown to date. Different immune cells such as Th1 and Th17 play an impressive role in the immunopathogenesis of MS, while, regulatory cells such as Th2 and Treg diminish the severity of the illness. Sex hormones have a vital role in many autoimmune disorders, including multiple sclerosis. Testosterone, estrogen and progesterone have various roles in the progress of MS, which higher prevalence of disease in women and more severe in men reveals the importance of sex hormones' role in this disease. Vitamin D after chemical changes in the body, as an active hormone called calcitriol, plays an important role in regulating immune responses and improves MS by modulating the immune system. The optimum level of calcium in the body with vitamin D modulates immune responses and calcium as an essential ion in the body plays a key role in the treatment of autoimmune diseases. The interaction between vitamin D and sex hormones has protective and therapeutic effects against MS and functional synergy between estrogen and calcitriol occurs in disease recovery. Moreover, vitamin D and calcium interact with each other to regulate the immune system and shift them to anti-inflammatory responses.

Cellular Therapy in Experimental Autoimmune Encephalomyelitis as an Adjuvant Treatment to Translate for Multiple Sclerosis

This study aims to evaluate and compare cellular therapy with human Wharton's jelly (WJ) mesenchymal stem cells (MSCs) and neural precursors (NPs) in experimental autoimmune encephalomyelitis (EAE), a preclinical model of Multiple Sclerosis. MSCs were isolated from WJ by an explant technique, differentiated to NPs, and characterized by cytometry and immunocytochemistry analysis after ethical approval. Forty-eight rats were EAE-induced by myelin basic protein and Freund's complete adjuvant. Forty-eight hours later, the animals received intraperitoneal injections of 250 ng/dose of Bordetella pertussis toxin. Fourteen days later, the animals were divided into the following groups: a. non-induced, induced: b. Sham, c. WJ-MSCs, d. NPs, and e. WJ-MSCs plus NPs. 1 × 105. Moreover, the cells were placed in a 10 µL solution and injected via a stereotaxic intracerebral ventricular injection. After ten days, the histopathological analysis for H&E, Luxol, interleukins, and CD4/CD8 was carried out. Statistical analyses demonstrated a higher frequency of clinical manifestation in the Sham group (15.66%) than in the other groups; less demyelination was seen in the treated groups than the Sham group (WJ-MSCs, p = 0.016; NPs, p = 0.010; WJ-MSCs + NPs, p = 0.000), and a lower cellular death rate was seen in the treated groups compared with the Sham group. A CD4/CD8 ratio of <1 showed no association with microglial activation (p = 0.366), astrocytes (p = 0.247), and cell death (p = 0.577) in WJ-MSCs. WJ-MSCs and NPs were immunomodulatory and neuroprotective in cellular therapy, which would be translated as an adjunct in demyelinating diseases.

Dabrafenib mitigates the neuroinflammation caused by ferroptosis in experimental autoimmune encephalomyelitis by up regulating Axl receptor

Multiple sclerosis is an autoimmune disease that causes inflammatory damage to the central nervous system. At present, the pathogenesis of the disease is unknown. There is a lack of few effective therapy medications available. Therefore, it is necessary to further explore the pathogenesis of this illness and develop potential therapeutic drugs. Dabrafenib is potential therapeutic medicine for nervous system disease. In this study, we preliminarily studied the possible mechanism of dabrafenib in the treatment of multiple sclerosis from the perspective of ferroptosis. First, we observed that dabrafenib significantly improved symptoms of gait abnormalities, limb weakness or paralysis, and down-regulated levels of spinal cord inflammation in an experimental autoimmune encephalitis (EAE) model. Meanwhile, we also observed that dabrafenib could inhibit the proteins of ferroptosis in spinal cord tissue of EAE mice by Western blot. The results of immunohistochemical analysis showed that the effect of dabrafenib on ferroptosis mainly occurred in microglia. Second, dabrafenib was demonstrated to be able to inhibit the S phase of the cell cycle, reduce ROS levels, and reinstate mitochondrial activity in the LPS-induced BV2 inflammatory cell model. Futhermore, we found that dabrafenib inhibits P-JAK2 and P-STAT3 activation by acting Axl receptor, which in turn prevents neurogenic inflammation in microglia. The co-stimulated BV2 cell model with LPS and Erastin also verified these findings. Ultimately, the Axl knockout mice used to construct the EAE model allowed for the confirmation that dabrafenib prevented ferroptosis in microglia by up-regulating Axl receptor, which reduced the inflammatory demyelination associated with EAE. In summary, our research demonstrates the advantages of dabrafenib in multiple sclerosis treatment, which can prevent ferroptosis in microglia in multiple sclerosis through up-regulating Axl receptor, thus halting the progression of multiple sclerosis.

The emerging role of T helper 9 (Th9) cells in immunopathophysiology: A comprehensive review of their effects and responsiveness in various disease states

Th9 cells, a subset of T-helper cells producing interleukin-9 (IL-9), play a vital role in the adaptive immune response and have diverse effects in different diseases. Regulated by transcription factors like PU.1 and IRF4, and cytokines such as IL-4 and TGF-β, Th9 cells drive tissue inflammation. This review focuses on their emerging role in immunopathophysiology. Th9 cells exhibit immune-mediated cancer cell destruction, showing promise in glioma and cervical cancer treatment. However, their role in breast and lung cancer is intricate, requiring a deeper understanding of pro- and anti-tumor aspects. Th9 cells, along with IL-9, foster T cell and immune cell proliferation, contributing to autoimmune disorders. They are implicated in psoriasis, atopic dermatitis, and infections. In allergic reactions and asthma, Th9 cells fuel pro-inflammatory responses. Targeting Foxo1 may regulate innate and adaptive immune responses, alleviating disease symptoms. This comprehensive review outlines Th9 cells' evolving immunopathophysiological role, emphasizing the necessity for further research to grasp their effects and potential therapeutic applications across diseases.

Characterization of spinal cord tissue-derived extracellular vesicles in neuroinflammation

Extracellular vesicles (EVs) are released by all cells, can cross the blood-brain barrier, and have been shown to play an important role in cellular communication, substance shuttling, and immune modulation. In recent years EVs have shifted into focus in multiple sclerosis (MS) research as potential plasma biomarkers and therapeutic vehicles. Yet little is known about the disease-associated changes in EVs in the central nervous system (CNS). To address this gap, we characterized the physical and proteomic changes of mouse spinal cord-derived EVs before and at 16 and 25 days after the induction of experimental autoimmune encephalomyelitis (EAE), a neuroinflammatory model of MS. Using various bioinformatic tools, we found changes in inflammatory, glial, and synaptic proteins and pathways, as well as a shift in the predicted contribution of immune and glial cell types over time. These results show that EVs provide snapshots of crucial disease processes such as CNS-compartmentalized inflammation, re/de-myelination, and synaptic pathology, and might also mediate these processes. Additionally, inflammatory plasma EV biomarkers previously identified in people with MS were also altered in EAE spinal cord EVs, suggesting commonalities of EV-related pathological processes during EAE and MS and overlap of EV proteomic changes between CNS and circulating EVs.

Myelin oligodendrocyte glycoprotein reactive Th17 cells drive Janus Kinase 1 dependent transcriptional reprogramming in astrocytes and alter cell surface cytokine receptor profiles during experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is an autoimmune demyelinating disease affecting the central nervous system (CNS). T helper (Th) 17 cells are involved in the pathogenesis of MS and its animal model of experimental autoimmune encephalomyelitis (EAE) by infiltrating the CNS and producing effector molecules that engage resident glial cells. Among these glial cells, astrocytes have a central role in coordinating inflammatory processes by responding to cytokines and chemokines released by Th17 cells. In this study, we examined the impact of pathogenic Th17 cells on astrocytes in vitro and in vivo. We identified that Th17 cells reprogram astrocytes by driving transcriptomic changes partly through a Janus Kinase (JAK)1-dependent mechanism, which included increased chemokines, interferon-inducible genes, and cytokine receptors. In vivo, we observed a region-specific heterogeneity in the expression of cell surface cytokine receptors on astrocytes, including those for IFN-γ, IL-1, TNF-α, IL-17, TGFβ, and IL-10. Additionally, these receptors were dynamically regulated during EAE induced by adoptive transfer of myelin-reactive Th17 cells. This study overall provides evidence of Th17 cell reprogramming of astrocytes, which may drive changes in the astrocytic responsiveness to cytokines during autoimmune neuroinflammation.

Oxytocin and Vasopressin Gene Expression in the Brain as Potential Biomarkers for Cannabidiol Therapeutic Efficacy

Over the last several years, there has been increased interest in cannabidiol (CBD) to treat various ailments such as pain, anxiety, insomnia, and inflammation. The potential for CBD as an anti-inflammatory therapy has come, in part, from its demonstrated ability to suppress neuroinflammation in autoimmune diseases, such as the mouse model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). The increased use of CBD strongly suggests that more research is necessary to elucidate its safety and efficacy and determine the mechanisms by which it acts. Thus, we conducted two separate studies. In the first, RNA sequencing (RNA-Seq) analysis of brains of female mice undergoing EAE in the presence and absence of CBD was conducted to identify potential genes that mediated its neuroprotective effects when efficacious. In the second, we assessed some of the same genes in male and female mice treated with CBD in the absence of an immune stimulus. Together, these data showed that CBD modestly increased oxytocin (Oxt) and arginine vasopressin (vasopressin, Avp) gene expression in the brains of mice, regardless of whether there was active inflammation. Overall, these data suggest that Oxt and Avp might act as biomarkers for CBD exposure.

Probing the basis of disease heterogeneity in multiple sclerosis using genetically diverse mice

Multiple sclerosis (MS) is a complex disease with significant heterogeneity in disease course and progression. Genetic studies have identified numerous loci associated with MS risk, but the genetic basis of disease progression remains elusive. To address this, we leveraged the Collaborative Cross (CC), a genetically diverse mouse strain panel, and experimental autoimmune encephalomyelitis (EAE). The thirty-two CC strains studied captured a wide spectrum of EAE severity, trajectory, and presentation, including severe-progressive, monophasic, relapsing remitting, and axial rotary (AR)-EAE, accompanied by distinct immunopathology. Sex differences in EAE severity were observed in six strains. Quantitative trait locus analysis revealed distinct genetic linkage patterns for different EAE phenotypes, including EAE severity and incidence of AR-EAE. Machine learning-based approaches prioritized candidate genes for loci underlying EAE severity ( Abcc4 and Gpc6 ) and AR-EAE ( Yap1 and Dync2h1 ). This work expands the EAE phenotypic repertoire and identifies novel loci controlling unique EAE phenotypes, supporting the hypothesis that heterogeneity in MS disease course is driven by genetic variation.

Summary

The genetic basis of disease heterogeneity in multiple sclerosis (MS) remains elusive. We leveraged the Collaborative Cross to expand the phenotypic repertoire of the experimental autoimmune encephalomyelitis (EAE) model of MS and identify loci controlling EAE severity, trajectory, and presentation.

MicroRNAs targeting TGF-β signaling exacerbate central nervous system autoimmunity by disrupting regulatory T cell development and function

Transforming growth factor beta (TGF-β) signaling is essential for a balanced immune response by mediating the development and function of regulatory T cells (Tregs) and suppressing autoreactive T cells. Disruption of this balance can result in autoimmune diseases, including multiple sclerosis (MS). MicroRNAs (miRNAs) targeting TGF-β signaling have been shown to be upregulated in naïve CD4 T cells in MS patients, resulting in a limited in vitro generation of human Tregs. Utilizing the murine model experimental autoimmune encephalomyelitis, we show that perinatal administration of miRNAs, which target the TGF-β signaling pathway, enhanced susceptibility to central nervous system (CNS) autoimmunity. Neonatal mice administered with these miRNAs further exhibited reduced Treg frequencies with a loss in T cell receptor repertoire diversity following the induction of experimental autoimmune encephalomyelitis in adulthood. Exacerbated CNS autoimmunity as a result of miRNA overexpression in CD4 T cells was accompanied by enhanced Th1 and Th17 cell frequencies. These findings demonstrate that increased levels of TGF-β-associated miRNAs impede the development of a diverse Treg population, leading to enhanced effector cell activity, and contributing to an increased susceptibility to CNS autoimmunity. Thus, TGF-β-targeting miRNAs could be a risk factor for MS, and recovering optimal TGF-β signaling may restore immune homeostasis in MS patients.

Therapeutic role of interferon-γ in experimental autoimmune encephalomyelitis is mediated through a tolerogenic subset of splenic CD11b+ myeloid cells

Cumulative evidence has established that Interferon (IFN)-γ has both pathogenic and protective roles in Multiple Sclerosis and the animal model, Experimental Autoimmune Encephalomyelitis (EAE). However, the underlying mechanisms to the beneficial effects of IFN-γ are not well understood. In this study, we found that IFN-γ exerts therapeutic effects on chronic, relapsing-remitting, and chronic progressive EAE models. The frequency of regulatory T (Treg) cells in spinal cords from chronic EAE mice treated with IFN-γ was significantly increased with no effect on Th1 and Th17 cells. Consistently, depletion of FOXP3-expressing cells blocked the protective effects of IFN-γ, indicating that the therapeutic effect of IFN-γ depends on the presence of Treg cells. However, IFN-γ did not trigger direct in vitro differentiation of Treg cells. In vivo administration of blocking antibodies against either interleukin (IL)-10, transforming growth factor (TGF)-β or program death (PD)-1, revealed that the protective effects of IFN-γ in EAE were also dependent on TGF-β and PD-1, but not on IL-10, suggesting that IFN-γ might have an indirect role on Treg cells acting through antigen-presenting cells. Indeed, IFN-γ treatment increased the frequency of a subset of splenic CD11b+ myeloid cells expressing TGF-β-Latency Associated Peptide (LAP) and program death ligand 1 (PD-L1) in a signal transducer and activator of transcription (STAT)-1-dependent manner. Furthermore, splenic CD11b+ cells from EAE mice preconditioned in vitro with IFN-γ and myelin oligodendrocyte glycoprotein (MOG) peptide exhibited a tolerogenic phenotype with the capability to induce conversion of naïve CD4+ T cells mediated by secretion of TGF-β. Remarkably, adoptive transfer of splenic CD11b+ cells from IFN-γ-treated EAE mice into untreated recipient mice ameliorated clinical symptoms of EAE and limited central nervous system infiltration of mononuclear cells and effector helper T cells. These results reveal a novel cellular and molecular mechanism whereby IFN-γ promotes beneficial effects in EAE by endowing splenic CD11b+ myeloid cells with tolerogenic and therapeutic activities.

Brain-targeted drug delivery - nanovesicles directed to specific brain cells by brain-targeting ligands

Neurodegenerative diseases are characterized by extensive loss of function or death of brain cells, hampering the life quality of patients. Brain-targeted drug delivery is challenging, with a low success rate this far. Therefore, the application of targeting ligands in drug vehicles, such as lipid-based and polymeric nanoparticles, holds the promise to overcome the blood-brain barrier (BBB) and direct therapies to the brain, in addition to protect their cargo from degradation and metabolization. In this review, we discuss the barriers to brain delivery and the different types of brain-targeting ligands currently in use in brain-targeted nanoparticles, such as peptides, proteins, aptamers, small molecules, and antibodies. Moreover, we present a detailed review of the different targeting ligands used to direct nanoparticles to specific brain cells, like neurons (C4-3 aptamer, neurotensin, Tet-1, RVG, and IKRG peptides), astrocytes (Aquaporin-4, D4, and Bradykinin B2 antibodies), oligodendrocytes (NG-2 antibody and the biotinylated DNA aptamer conjugated to a streptavidin core Myaptavin-3064), microglia (CD11b antibody), neural stem cells (QTRFLLH, VPTQSSG, and NFL-TBS.40-63 peptides), and to endothelial cells of the BBB (transferrin and insulin proteins, and choline). Reports demonstrated enhanced brain-targeted delivery with improved transport to the specific cell type targeted with the conjugation of these ligands to nanoparticles. Hence, this strategy allows the implementation of high-precision medicine, with reduced side effects or unwanted therapy clearance from the body. Nevertheless, the accumulation of some of these nanoparticles in peripheral organs has been reported indicating that there are still factors to be improved to achieve higher levels of brain targeting. This review is a collection of studies exploring targeting ligands for the delivery of nanoparticles to the brain and we highlight the advantages and limitations of this type of approach in precision therapies.

Multi-parametric MRI can detect enhanced myelination in the Gli1 -/- mouse brain

This study investigated the potential of combining multiple MR parameters to enhance the characterization of myelin in the mouse brain. We collected ex vivo multi-parametric MR data at 7 Tesla from control and Gli1 -/- mice; the latter exhibit enhanced myelination at postnatal day 10 (P10) in the corpus callosum and cortex. The MR data included relaxivity, magnetization transfer, and diffusion measurements, each targeting distinct myelin properties. This analysis was followed by and compared to myelin basic protein (MBP) staining of the same samples. Although a majority of the MR parameters included in this study showed significant differences in the corpus callosum between the control and Gli1 -/- mice, only T 2 , T 1 /T 2, and radial diffusivity (RD) demonstrated a significant correlation with MBP values. Based on data from the corpus callosum, partial least square regression suggested that combining T 2 , T 1 /T 2 , and inhomogeneous magnetization transfer ratio could explain approximately 80% of the variance in the MBP values. Myelin predictions based on these three parameters yielded stronger correlations with the MBP values in the P10 mouse brain corpus callosum than any single MR parameter. In the motor cortex, combining T 2 , T 1 /T 2, and radial kurtosis could explain over 90% of the variance in the MBP values at P10. This study demonstrates the utility of multi-parametric MRI in improving the detection of myelin changes in the mouse brain.

A diet-dependent host metabolite shapes the gut microbiota to protect from autoimmunity

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 (Th17) cell activation in vitro . Finally, we isolated a L. murinus strain that protected from EAE, which was phenocopied by the Lactobacillus metabolite indole lactic acid. 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.

Stem cell therapies: a new era in the treatment of multiple sclerosis

Multiple Sclerosis (MS) is an immune-mediated condition that persistently harms the central nervous system. While existing treatments can slow its course, a cure remains elusive. Stem cell therapy has gained attention as a promising approach, offering new perspectives with its regenerative and immunomodulatory properties. This article reviews the application of stem cells in MS, encompassing various stem cell types, therapeutic potential mechanisms, preclinical explorations, clinical research advancements, safety profiles of clinical applications, as well as limitations and challenges, aiming to provide new insights into the treatment research for MS.

A serine-conjugated butyrate prodrug with high oral bioavailability suppresses autoimmune arthritis and neuroinflammation in mice

Butyrate-a metabolite produced by commensal bacteria-has been extensively studied for its immunomodulatory effects on immune cells, including regulatory T cells, macrophages and dendritic cells. However, the development of butyrate as a drug has been hindered by butyrate's poor oral bioavailability, owing to its rapid metabolism in the gut, its low potency (hence, necessitating high dosing), and its foul smell and taste. Here we report that the oral bioavailability of butyrate can be increased by esterifying it to serine, an amino acid transporter that aids the escape of the resulting odourless and tasteless prodrug (O-butyryl-L-serine, which we named SerBut) from the gut, enhancing its systemic uptake. In mice with collagen-antibody-induced arthritis (a model of rheumatoid arthritis) and with experimental autoimmune encephalomyelitis (a model of multiple sclerosis), we show that SerBut substantially ameliorated disease severity, modulated key immune cell populations systemically and in disease-associated tissues, and reduced inflammatory responses without compromising the global immune response to vaccination. SerBut may become a promising therapeutic for autoimmune and inflammatory diseases.

Protein Tyrosine Amination: Detection, Imaging, and Chemoproteomic Profiling with Synthetic Probes

Protein tyrosine nitration (PTN) by oxidative and nitrative stress is a well-known post-translational modification that plays a role in the initiation and progression of various diseases. Despite being recognized as a stable modification for decades, recent studies have suggested the existence of a reduction in PTN, leading to the formation of 3-aminotyrosine (3AT) and potential denitration processes. However, the vital functions of 3AT-containing proteins are still unclear due to the lack of selective probes that directly target the protein tyrosine amination. Here, we report a novel approach to label and enrich 3AT-containing proteins with synthetic salicylaldehyde (SAL)-based probes: SALc-FL with a fluorophore and SALc-Yn with an alkyne tag. These probes exhibit high selectivity and efficiency in labeling and can be used in cell lysates and live cells. More importantly, SALc-Yn offers versatility when integrated into multiple platforms by enabling proteome-wide quantitative profiling of cell nitration dynamics. Using SALc-Yn, 355 proteins were labeled, enriched, and identified to carry the 3AT modification in oxidatively stressed RAW264.7 cells. These findings provide compelling evidence supporting the involvement of 3AT as a critical intermediate in nitrated protein turnover. Moreover, our probes serve as powerful tools to investigate protein nitration and denitration processes, and the identification of 3AT-containing proteins contributes to our understanding of PTN dynamics and its implications in cellular redox biology.