Mouse Model Of Multiple Sclerosis Research Articles

Remibrutinib Inhibits Neuroinflammation Driven by B Cells and Myeloid Cells in Preclinical Models of Multiple Sclerosis (P2-3.013)

<h3>Objective:</h3> To assess the mechanism of action and efficacy of remibrutinib in experimental autoimmune encephalomyelitis (EAE) mouse models of multiple sclerosis (MS). <h3>Background:</h3> Bruton’s tyrosine kinase (BTK) is a key node in B-cell receptor and fragment crystallizable receptor signaling. BTK inhibitors (BTKis) are an emerging oral option for patients with MS. Remibrutinib (LOU064) is a potent and highly selective covalent BTKi with promising preclinical and clinical profiles for the treatment of MS. <h3>Design/Methods:</h3> Two C57BL/6 mouse EAE models (induced by immunization with human or rat myelin oligodendrocyte glycoprotein [HuMOG and RatMOG EAE, respectively]) were used. Target engagement was assessed in tissue and clinical disease activity was determined. Serum antibody levels, biomarkers, and central nervous system tissue transcriptome were analyzed. <h3>Results:</h3> Remibrutinib inhibited B-cell–dependent HuMOG EAE at daily oral doses of 3 and 30 mg/kg and strongly reduced neurological symptoms. The ex vivo MOG-specific T-cell recall response was inhibited, but the polyclonal T-cell response was not, indicating selective B-cell inhibition. Remibrutinib did not decrease total immunoglobulin G antibody levels. Remibrutinib demonstrated strong BTK occupancy in the peripheral immune organs and brain at the efficacious dose of 30 mg/kg. Remibrutinib also inhibited RatMOG EAE, indicating that myeloid cell and microglia inhibition contributes to its efficacy in MS; this is supported by anti-inflammatory effects detected via single-cell RNA sequencing of the mouse brain and spinal cord. Remibrutinib also significantly reduced neurofilament light chain levels in serum. <h3>Conclusions:</h3> Remibrutinib exhibited dose-dependent efficacy in B-cell–driven EAE models. Potential for efficacy and anti-inflammatory effects on myeloid cells and microglia was observed. Remibrutinib may represent a novel treatment option for patients with MS. <b>Disclosure:</b> Bernd C. Kieseier, MD has nothing to disclose. Mr. Cenni has received personal compensation for serving as an employee of Novartis. Dr. Nuesslein-Hildesheim has received personal compensation for serving as an employee of Novartis Pharma AG. Dr. Nuesslein-Hildesheim has stock in Novartis Pharma AG. Dr. Ferrero has received personal compensation for serving as an employee of Novartis. Catherine Huck has received personal compensation for serving as an employee of Novartis. Mr. Eichlisberger has nothing to disclose. Dr. Ziehn has received personal compensation for serving as an employee of Novartis AG.

Modulating CNS neuroinflammation in animal models of intracerebral hemorrhage by nasal anti-CD3 (S4.010)

<h3>Objective:</h3> Investigate the therapeutic benefit of nasal anti-CD3 treatment in animal model of ICH. <h3>Background:</h3> Intracerebral hemorrhage (ICH) is the most devastating type of stroke, with a disproportionately high mortality approaching 40%. Current investigations in ICH treatment have focused on limiting hematoma expansion which unfortunately, have not led to an effective treatment. Neuroinflammation play a critical role in secondary injury post-ICH. Exposure of brain parenchyma to blood products initiates a complex inflammatory cascade start with activation of resident microglia. Resulting cytokine release recruits circulating monocytes and lymphocytes, further enhancing inflammation, and contributing to secondary injury. The cellular and molecular mechanisms leading to neurological deficits following ICH are poorly understood, and there is no effective therapy to modulate the mitigate CNS injury and promote recovery. The mucosal immune system is a unique tolerogenic organ that provides a physiological approach for the induction of regulatory T cells (Tregs). We found that nasal anti-CD3 monoclonal antibody induces IL-10-secreting Tregs that migrate to the brain and suppresses microglial inflammation in a mouse model of multiple sclerosis. The therapeutic potential of the Tregs/IL-10 axis in ICH is largely unexplored. <h3>Design/Methods:</h3> We employed the collagenases model of ICH in mice and administered nasal anti-CD3 treatment within 24 hours of ICH which was continued up to 1-month post-bleed. We performed Flow cytometry, histopathology and behavioral analyses to characterize the cells and assess the effects of treatment on the behavioral outcomes at 1-month post-ICH. <h3>Results:</h3> Nasal anti-CD3 increased FoxP3+ Tregs and IL10 producing FoxP3+ Tregs in the brain. It also reduced microglial activation and lesion volume in the ipsilateral hemisphere post-ICH. Treatment improved behavioral outcomes, including motor, spatial learning, and hippocampal-dependent working memory functions at 1-month post-ICH. <h3>Conclusions:</h3> Our findings suggest that the nasal anti-CD3 may represent a novel therapeutic approach for treating ICH and potentially other types of acute brain injury. <b>Disclosure:</b> Dr. Izzy has received publishing royalties from a publication relating to health care. Taha Yahya has nothing to disclose. Dr. Cao has nothing to disclose. Dr. Waed has nothing to disclose. Dr. Moreira has nothing to disclose. Dr. Rezende has nothing to disclose. Dr. Weiner has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Genentech. Dr. Weiner has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Medday Pharmaceuticals. Dr. Weiner has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for vTv Therapeutics. Dr. Weiner has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Tiziana Life Sciences. Dr. Weiner has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for vTv Therapeutics. Dr. Weiner has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Medday Pharmaceuticals. Dr. Weiner has received personal compensation in the range of $10,000-$49,999 for serving as an officer or member of the Board of Directors for vTv Therapeutics. Dr. Weiner has received stock or an ownership interest from vTv Therapeutics. The institution of Dr. Weiner has received research support from National Institute of Health. The institution of Dr. Weiner has received research support from National MS Society. The institution of Dr. Weiner has received research support from Genzyme Corp. The institution of Dr. Weiner has received research support from Genentech, Inc. . The institution of Dr. Weiner has received research support from Verily Life Sciences LLC. The institution of Dr. Weiner has received research support from EMD Serono, Inc..

Very-long-chain fatty acids induce glial-derived sphingosine-1-phosphate synthesis, secretion, and neuroinflammation

VLCFAs (very-long-chain fatty acids) are the most abundant fatty acids in myelin. Hence, during demyelination or aging, glia are exposed to higher levels of VLCFA than normal. We report that glia convert these VLCFA into sphingosine-1-phosphate (S1P) via a glial-specific S1P pathway. Excess S1P causes neuroinflammation, NF-κB activation, and macrophage infiltration into the CNS. Suppressing the function of S1P in fly glia or neurons, or administration of Fingolimod, an S1P receptor antagonist, strongly attenuates the phenotypes caused by excess VLCFAs. In contrast, elevating the VLCFA levels in glia and immune cells exacerbates these phenotypes. Elevated VLCFA and S1P are also toxic in vertebrates based on a mouse model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE). Indeed, reducing VLCFA with bezafibrate ameliorates the phenotypes. Moreover, simultaneous use of bezafibrate and fingolimod synergizes to improve EAE, suggesting that lowering VLCFA and S1P is a treatment avenue for MS.

MHC class I and MHC class II reporter mice enable analysis of immune oligodendroglia in mouse models of multiple sclerosis.

Oligodendrocytes and their progenitors upregulate MHC pathways in response to inflammation, but the frequency of this phenotypic change is unknown and the features of these immune oligodendroglia are poorly defined. We generated MHC class I and II transgenic reporter mice to define their dynamics in response to inflammatory demyelination, providing a means to monitor MHC activation in diverse cell types in living mice and define their roles in aging, injury, and disease.

Obesity increases blood-brain barrier permeability and aggravates the mouse model of multiple sclerosis.

Obesity-induced insulin resistance (OIR) has been associated with an increased prevalence of neurodegenerative disorders such as multiple sclerosis. Obesity results in increased blood-brain barrier (BBB) permeability, specifically in the hypothalamic regions associated with the control of caloric intake. In obesity, the chronic state of low-grade inflammation has been implicated in several chronic autoimmune inflammatory disorders. However, the mechanisms that connect the inflammatory profile of obesity with the severity of experimental autoimmune encephalomyelitis (EAE) are poorly defined. In this study, we show that obese mice are more susceptible to EAE, presenting a worse clinical score with more severe pathological changes in the spinal cord when compared with control mice. Analysis of immune infiltrates at the peak of the disease shows that high-fat diet (HFD)- and control (chow)-fed groups do not present any difference in innate or adaptive immune cell compartments, indicating the increased severity occurs prior to disease onset. In the setting of worsening EAE in HFD-fed mice, we observed spinal cord lesions in myelinated regions and (blood brain barrier) BBB disruption. We also found higher levels of pro-inflammatory monocytes, macrophages, and IFN-γ+CD4+ T cells in the HFD-fed group compared to chow-fed animals. Altogether, our results indicate that OIR promotes BBB disruption, allowing the infiltration of monocytes/macrophages and activation of resident microglia, ultimately promoting CNS inflammation and exacerbation of EAE.

Magnetic resonance imaging approaches for studying mouse models of multiple sclerosis: A mini review.

Given that multiple sclerosis (MS) is a complex disease with an unclear etiology, a single animal model is unlikely to accurately represent all aspects of pathology and clinical features of the human condition. However, the availability of three major types of murine models of MS, that is, experimental autoimmune encephalomyelitis (EAE), viral models, and toxic models, enables studies of several relevant features of this debilitating disease. Researchers have recently begun to combine magnetic resonance imaging (MRI) technologies with other experimental strategies to acquire complementary information, for example, anatomical and functional, and study the effect of experimental manipulations longitudinally in a noninvasive way. This review summarizes the latest MRI studies investigating critical aspects of MS, such as atrophy, demyelination, neuroaxonal damage, and neuroinflammation, in mouse models of MS. Advanced techniques will be briefly discussed, providing references to specialized literature for the readers. Thus, this review aims to describe different imaging protocols used to study critical aspects of MS in a research laboratory, discussing the main related findings in the most significant murine models of the disease.

Role of the adipocyte immune brain axis in Parkinson's disease: friend or foe?

Role of the adipocyte immune brain axis in Parkinson's disease: friend or foe?

IL-10-providing B cells govern pro-inflammatory activity of macrophages and microglia in CNS autoimmunity

B cells contribute to chronic inflammatory conditions as source of antibody-secreting plasma cells and as antigen-presenting cells activating T cells, making anti-CD20-mediated B cell depletion a widely used therapeutic option. B cells or B cell subsets may, however, exert regulatory effects, while to date, the immunological and/or clinical impact of these observations remained unclear. We found that in multiple sclerosis (MS) patients, B cells contain regulatory features and that their removal enhanced activity of monocytes. Using a co-culture system, we identified B cell-provided interleukin (IL)-10 as key factor in controlling pro-inflammatory activity of peripheral myeloid cells as well as microglia. Depleting B cells via anti-CD20 in a mouse model of MS unleashed the activity of myeloid cells and microglia and accelerated disease severity; in contrast, adoptive transfer of IL-10-providing B cells restored in vivo control of central nervous system (CNS) macrophages and microglia and reversed clinical exacerbation. These findings suggest that B cells exert meaningful regulatory properties, which should be considered when designing novel B cell-directed agents.

MicroRNA-155 Plays Selective Cell-Intrinsic Roles in Brain-Infiltrating Immune Cell Populations during Neuroinflammation.

The proinflammatory microRNA-155 (miR-155) is highly expressed in the serum and CNS lesions of patients with multiple sclerosis (MS). Global knockout (KO) of miR-155 in mice confers resistance to a mouse model of MS, experimental autoimmune encephalomyelitis (EAE), by reducing the encephalogenic potential of CNS-infiltrating Th17 T cells. However, cell-intrinsic roles for miR-155 during EAE have not been formally determined. In this study, we use single-cell RNA sequencing and cell-specific conditional miR-155 KOs to determine the importance of miR-155 expression in distinct immune cell populations. Time-course single-cell sequencing revealed reductions in T cells, macrophages, and dendritic cells (DCs) in global miR-155 KO mice compared with wild-type controls at day 21 after EAE induction. Deletion of miR-155 in T cells, driven by CD4 Cre, significantly reduced disease severity similar to global miR-155 KOs. CD11c Cre-mediated deletion of miR-155 in DCs also resulted in a modest yet significant reduction in the development of EAE, with both T cell- and DC-specific KOs showing a reduction in Th17 T cell infiltration into the CNS. Although miR-155 is highly expressed in infiltrating macrophages during EAE, deletion of miR-155 using LysM Cre did not impact disease severity. Taken together, these data show that although miR-155 is highly expressed in most infiltrating immune cells, miR-155 has distinct roles and requirements depending on the cell type, and we have demonstrated this using the gold standard conditional KO approach. This provides insights into which functionally relevant cell types should be targeted by the next generation of miRNA therapeutics.

Therapeutic Potential of Phytocannabinoid Cannabigerol for Multiple Sclerosis: Modulation of Microglial Activation In Vitro and In Vivo.

Multiple sclerosis (MS) is a widespread chronic neuroinflammatory and neurodegenerative disease. Microglia play a crucial role in the pathogenesis of MS via the release of cytokines and reactive oxygen species, e.g., nitric oxide. Research involving the role of phytocannabinoids in neuroinflammation is currently receiving much attention. Cannabigerol is a main phytocannabinoid, which has attracted significant pharmacological interest due to its non-psychotropic nature. In this research, we studied the effects of cannabigerol on microglial inflammation in vitro, followed by an in vivo study. Cannabigerol attenuated the microglial production of nitric oxide in BV2 microglia and primary glial cells; concomitant treatment of the cells with cannabigerol and telmisartan (a neuroprotective angiotensin receptor blocker) decreased nitric oxide production additively. Inducible nitric oxide synthase (iNOS) expression was also reduced by cannabigerol. Moreover, tumor necrosis factor-α (TNF-α), a major cytokine involved in MS, was significantly reduced by cannabigerol in both cell cultures. Next, we studied the effects of cannabigerol in vivo using a mice model of MS, experimental autoimmune encephalomyelitis (EAE). The clinical scores of EAE mice were attenuated upon cannabigerol treatment; additionally, lumbar sections of EAE mice showed enhanced neuronal loss (relative to control mice), which was restored by cannabigerol treatment. Altogether, the set of experiments presented in this work indicates that cannabigerol possesses an appealing therapeutic potential for the treatment of MS.

The activity of the aryl hydrocarbon receptor in T cells tunes the gut microenvironment to sustain autoimmunity and neuroinflammation.

Multiple sclerosis (MS) is a T cell-driven autoimmune disease that attacks the myelin of the central nervous system (CNS) and currently has no cure. MS etiology is linked to both the gut flora and external environmental factors but this connection is not well understood. One immune system regulator responsive to nonpathogenic external stimuli is the aryl hydrocarbon receptor (AHR). The AHR, which binds diverse molecules present in the environment in barrier tissues, is a therapeutic target for MS. However, AHR's precise function in T lymphocytes, the orchestrators of MS, has not been described. Here, we show that in a mouse model of MS, T cell-specific Ahr knockout leads to recovery driven by a decrease in T cell fitness. At the mechanistic level, we demonstrate that the absence of AHR changes the gut microenvironment composition to generate metabolites that impact T cell viability, such as bile salts and short chain fatty acids. Our study demonstrates a newly emerging role for AHR in mediating the interdependence between T lymphocytes and the microbiota, while simultaneously identifying new potential molecular targets for the treatment of MS and other autoimmune diseases.

Effects of perinatal exposure to bisphenol A or S in EAE model of multiple sclerosis

Epidemiological studies support the idea that multiple sclerosis (MS) is a multifactorial disease, overlapping genetic, epigenetic, and environmental factors. A better definition of environmental risks is critical to understand both etiology and the sex-related differences of MS. Exposure to endocrine-disrupting compounds (EDCs) fully represents one of these risks. EDCs are natural or synthetic exogenous substances (or mixtures) that alter the functions of the endocrine system. Among synthetic EDCs, exposure to bisphenol A (BPA) has been implicated in the etiology of MS, but to date, controversial data has emerged. Furthermore, nothing is known about bisphenol S (BPS), one of the most widely used substitutes for BPA. As exposure to bisphenols will not disappear soon, it is necessary to clarify their role also in this pathological condition defining their role in disease onset and course in both sexes. In this study, we examined, in both sexes, the effects of perinatal exposure to BPA and BPS in one of the most widely used mouse models of MS, experimental autoimmune encephalomyelitis (EAE). Exposure to bisphenols seemed to be particularly deleterious in males. In fact, both BPA- and BPS-treated males showed anticipation of the disease onset and an increased motoneuron loss in the spinal cord. Overall, BPA-treated males also displayed an exacerbation of EAE course and an increase in inflammation markers in the spinal cord. Analyzing the consequences of bisphenol exposure on EAE will help to better understand the role of both xenoestrogens and endogenous estrogens on the sexually dimorphic characteristics of MS.

Icariin ameliorates behavioral deficits and neuropathology in a mouse model of multiple sclerosis

Multiple sclerosis (MS) is a systemic inflammatory illness of the central nervous system that involves demyelinating lesions in the myelin-rich white matter and pathology in the grey matter. Despite significant advancements in drug research for MS, the disease's complex pathophysiology makes it difficult to treat the progressive forms of the disease. In this study, we identified a natural flavonoid compound icariin (ICA) as a potent effective agent for MS in ameliorating the deterioration of symptoms including the neurological deficit score and the body weight in a murine experimental autoimmune encephalomyelitis (EAE) model. These improvements were associated with decreased demyelination in the corpus callosum and neuron loss in the hippocampus and cortex confirmed by immunohistochemistry analysis. Meanwhile, it was observed that the activation of microglia in cerebral cortex and hippocampus were inhibited followed by the neuroinflammatory cytokines downregulation such as IL-1β, IL-6 and TNF-α after ICA treatment, which was probably attributable to the suppression of microglial NLRP3 inflammasome activation. Additionally, molecular docking also revealed the binding force of ICA to NLRP3 inflammasome protein complexes in vitro. Taken together, our findings have demonstrated that ICA, as pleiotropic agent, prevents EAE-induced MS by improving demyelination and neuron loss, which interferes with the neuroinflammation via microglial NLRP3 inflammasome activation.

The presence of cerebellar B cell aggregates is associated with a specific chemokine profile in the cerebrospinal fluid in a mouse model of multiple sclerosis

BackgroundThe presence of meningeal ectopic lymphoid structures (ELS) in a subgroup of patients diagnosed with secondary progressive multiple sclerosis (SPMS) corresponds to a pronounced cortical inflammation and an aggravated disease course. In MP4-induced experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS), B cell aggregates develop in the central nervous system (CNS) in the chronic stage of the disease. Therefore, the model is suitable for studying key molecules of ELS development and maintenance. Here, we investigated whether there is a specific cytokine and chemokine signature in paired cerebrospinal fluid (CSF) and serum samples associated with the presence of cerebellar B cell and T cell pathology and B cell aggregates of MP4-immunized mice.MethodsPaired CSF and serum samples were collected from the cisterna magna and periphery of MP4-immunized mice at the chronic stage of disease. A control group with mice immunized only with the adjuvant (vehicle) was included in the study. A selected panel of 34 cytokines and chemokines were measured by MAGPIX® for both cohorts. For the assessment of B cell and T cell infiltration, immunohistochemical staining was performed and analyzed using light microscopy. To detect specific chemokine receptors additional staining was conducted.ResultsWhile we detected several upregulated cytokines and chemokines in the CSF of MP4-immunized mice independent of the extent of B cell and T cell pathology compared to vehicle-immunized mice, C-C motif chemokine ligand (CCL)-1 was associated with high B cell and T cell infiltration. Furthermore, the level of certain chemokines, including CCL1, CCL5, CCL7, CCL12, CCL22 and C-X-C motif chemokine ligand (CXCL)-13, was significantly increased (p < 0.05) in MP4-immunized mice showing a high number of B cell aggregates. While C-C motif chemokine receptor (CCR)5 had a ubiquitous expression independent of the extent of B cell and T cell pathology, C-X-C motif chemokine receptor (CXCR)-5 and CXCR6 expression was specifically associated with high B cell and T cell pathology.ConclusionOur data suggest that multiple cytokines and chemokines are involved in the pathophysiology of MP4-induced EAE. Furthermore, the presence of B cell aggregates was associated with a specific chemokine profile in the CSF, which might be useful for predicting the presence of these aggregates without the necessity to histologically screen the CNS tissue.

Nanoparticulate MgH2 ameliorates anxiety/depression-like behaviors in a mouse model of multiple sclerosis by regulating microglial polarization and oxidative stress

Multiple sclerosis (MS) is an autoimmune demyelinating disease of the central nervous system (CNS). Anxiety and depression are the most common psychiatric comorbidities of MS, which seriously affect patients’ quality of life, treatment compliance, and prognosis. However, current treatments for anxiety and depression in MS show low therapeutic efficacy and significant side effects. In the present study, we explored the therapeutic effects of a novel low-toxic anti-inflammatory drug, nanoparticulate magnesium hydride (MgH2), on mood disorders of MS. We observed that anxiety/depression-like behaviors in experimental autoimmune encephalomyelitis (EAE) mice were alleviated by MgH2 treatment. In addition, disease severity and inflammatory demyelination were also diminished. Furthermore, we confirmed the suppressive effect of MgH2 on depression in the acute restraint stress model. Mechanistically, MgH2 may play a therapeutic role by promoting microglial M2 polarization, inhibiting microglial M1 polarization, and reducing oxidative stress and mitochondrial damage. Therefore, nanoparticulate MgH2 may be a promising therapeutic drug for psychiatric comorbidities of MS.

Therapeutic Effects of Benzoylacetonitrile on Microglia Activation in Multiple Sclerosis

Background:&#x0D; Multiple Sclerosis (MS) is an autoimmune disease of the central nervous system (CNS). Pathogenic T cells, such as Th1 and Th17, infiltrate the CNS, resulting in neuroinflammation, demyelination and axonal damage. Th1 activates microglia (MG) in the CNS and Th17 acts as a chemokine to recruit immune cells into the CNS. MG is a resident immune cell in the CNS and its activation is associated with destruction of myelin and secretion of inflammatory cytokines such as IL-12, IL-23 and IL-1β. IL-12 and IL-23 are important for Th1 and Th17 differentiation and reactivation, respectively. IL-1β is a key mediator of the inflammatory response. Benzoylacetonitrile (BTN) has been shown to reduce disease severity in mouse model of MS and reduce Th1 and Th17 differentiation in vitro. However, the effects of BTN on MG are unknown, and this study was aimed to investigate the effects of BTN on MG activation in vitro. We hypothesize that BTN can suppress MG activation and decrease the production of inflammatory cytokines.&#x0D; Methods:&#x0D; Primary MG were pretreated with BTN at concentration of 200μM or 300μM for 2 hours or with DMSO (vehicle), followed by lipopolysaccharide (LPS) 100ng/ml stimulation for 1.5 or 3 hours. RNA was isolated from MG and mRNA expression levels of IL-12, IL-23, IL-1β were measured using Q-PCR.&#x0D; Results:&#x0D; Our results showed that BTN suppressed MG activation and reduced inflammatory cytokine production. The mRNA expression levels of IL-12, IL-23, and IL-1β in LPS and BTN-treated MG were significantly lower than LPS-treated MG.Conclusion: This study demonstrated that BTN was able to suppress MG expression of inflammatory cytokines in vitro, suggesting that BTN exhibits immunomodulatory effects on MG activation in vitro. BTN has a potential to attenuate neuroinflammation in MS through the reduction of inflammatory cytokines.&#x0D; Conclusion:&#x0D; This study demonstrated that BTN was able to suppress MG expression of inflammatory cytokines in vitro, suggesting that BTN exhibits immunomodulatory effects on MG activation in vitro. BTN has a potential to attenuate neuroinflammation in MS through the reduction of inflammatory cytokines.

Posttranscriptional Regulation of Gene Expression Participates in the Myelin Restoration in Mouse Models of Multiple Sclerosis: Antisense Modulation of HuR and HuD ELAV RNA Binding Protein

Neuropathic pain is the most difficult-to-treat pain syndrome in multiple sclerosis. Evidence relates neuropathic pain to demyelination, which often originates from unresolved neuroinflammation or altered immune response. Posttranscriptional regulation of gene expression might play a fundamental role in the regulation of these processes. The ELAV RNA-binding proteins HuR and HuD are involved in the promotion of inflammatory phenomena and in neuronal development and maintenance, respectively. Thus, the aim of this study was to investigate the role of HuR and HuD in demyelination-associated neuropathic pain in the mouse experimental autoimmune encephalomyelitis (EAE) model. HuR resulted overexpressed in the spinal cord of MOG35-55–EAE and PLP139-151–EAE mice and was detected in CD11b + cells. Conversely, HuD was largely downregulated in the MOG–EAE spinal cord, along with GAP43 and neurofilament H, while in PLP-EAE mice, HuD and neuronal markers remained unaltered. Intranasal antisense oligonucleotide (ASO) delivery to knockdown HuR, increased myelin basic protein expression, and Luxol Fast Blue staining in both EAE models, an indication of increased myelin content. These effects temporally coincided with attenuation of pain hypersensitivity. Anti-HuR ASO increased the expression of HuD in GAP43-expressing cells and promoted a HuD-mediated neuroprotective activity in MOG–EAE mice, while in PLP–EAE mice, HuR silencing dampened pro-inflammatory responses mediated by spinal microglia activation. In conclusion, anti-HuR ASO showed myelin protection at analgesic doses with multitarget mechanisms, and it deserves further consideration as an innovative agent to counteract demyelination in neuropathic pain states.Graphical

Imaging CD19+ B Cells in an Experimental Autoimmune Encephalomyelitis Mouse Model using Positron Emission Tomography.

Multiple sclerosis (MS) is the most common demyelinating central nervous system (CNS) disease affecting young adults, often resulting in neurological deficits and disability as the disease progresses. B lymphocytes play a complex and critical role in MS pathology and are the target of several therapeutics in clinical trials. Currently, there is no way to accurately select patients for specific anti-B cell therapies or to non-invasively quantify the effects of these treatments on B cell load in the CNS and peripheral organs. Positron emission tomography (PET) imaging has enormous potential to provide highly specific, quantitative information regarding the in vivo spatiotemporal distribution and burden of B cells in living subjects. This paper reports methods to synthesize and employ a PET tracer specific for human CD19+ B cells in a well-established B cell-driven mouse model of MS, experimental autoimmune encephalomyelitis (EAE), which is induced with human recombinant myelin oligodendrocyte glycoprotein 1-125. Described here are optimized techniques to detect and quantify CD19+ B cells in the brain and spinal cord using in vivo PET imaging. Additionally, this paper reports streamlined methods for ex vivo gamma counting of disease-relevant organs, including bone marrow, spinal cord, and spleen, together with high-resolution autoradiography of CD19 tracer binding in CNS tissues.

Therapeutic effect of combination vitamin D3 and siponimod on remyelination and modulate microglia activation in cuprizone mouse model of multiple sclerosis.

Stimulation of remyelination is critical for the treatment of multiple sclerosis (MS) to alleviate symptoms and protect the myelin sheath from further damage. The current study aimed to investigate the possible therapeutic effects of combining vitamin D3 (Vit D3) and siponimod (Sipo) on enhancing remyelination and modulating microglia phenotypes in the cuprizone (CPZ) demyelination mouse model. The study was divided into two stages; demyelination (first 5 weeks) and remyelination (last 4 weeks). In the first 5 weeks, 85 mice were randomly divided into two groups, control (n = 20, standard rodent chow) and CPZ (n = 65, 0.3% CPZ mixed with chow for 6 weeks, followed by 3 weeks of standard rodent chow). At week 5, the CPZ group was re-divided into four groups (n = 14) for remyelination stages; untreated CPZ (0.2 ml of CMC orally), CPZ+Vit D3 (800 IU/kg Vit D3 orally), CPZ+Sipo (1.5 mg/kg Sipo orally), and CPZ+Vit D3 (800 IU/kg Vit D3) + Sipo (1.5 mg/kg Sipo orally). Various behavioral tasks were performed to evaluate motor performance. Luxol Fast Blue (LFB) staining, the expression level of myelin basic protein (MBP), and M1/M2 microglia phenotype genes were assessed in the corpus callosum (CC). The results showed that the combination of Vit D3 and Sipo improved behavioral deficits, significantly promoted remyelination, and modulated expression levels of microglia phenotype genes in the CC at early and late remyelination stages. These results demonstrate for the first time that a combination of Vit D3 and Sipo can improve the remyelination process in the cuprizone (CPZ) mouse model by attenuating the M1 microglia phenotype. This may help to improve the treatment of MS patients.

Valproic acid effects on human adipose-derived stem cell differentiation into oligodendrocytes and improved remyelination in a mouse model of Multiple Sclerosis.

Valproic acid (VPA), a neuroprotective agent and inhibitor of GSK3-β, along with human Adipose-Derived Stem Cells (hADSCs) have been proposed to be potential therapeutic agents for neurodegenerative disorders. In the present study, we have assessed the effects of VPA alone or in combination with hADSCs on oligodendrocyte differentiation, remyelination, and functional recovery in a mouse model of Multiple Sclerosis (MS). These MS-model mice were randomly divided into cuprizone, sham, VPA, hADSC, and VPA/hADSC groups, with 10 mice considered a control group (healthy mice). The hanging wire test was used to measure motor behavior. To estimate the level of myelination, we performed toluidine blue staining and immunofluorescent staining for OLIG2 and MOG-positive cells. Real-time PCR was used to evaluate the expression of β-catenin, human and mouse Mbp, Mog, and Olig2 genes. Remyelination and motor function improved in mice receiving VPA, hADSCs, and especially VPA/hADSCs compared to the Cup and Sham groups (P < 0.01). Additionally, the number of MOG and OLIG2 positive cells significantly increased in the VPA/hADSCs group compared to the Cup and Sham groups (P < 0.01). The expression of β-catenin, myelin and the other oligodendrocyte-specific genes was significantly higher in the VPA recipient groups. Valproic acid can enhance the differentiation of stem cells into oligodendrocytes, making it a potential candidate for MS treatment.