The Properties of Cytokines in Multiple Sclerosis: Pros and Cons

The Microbiota-Gut-Brain Axis and Neurological Disorders: A Comprehensive Review

Microbes have inhabited the earth for hundreds of millions of years longer than humans. The microbiota-gut-brain axis (MGBA) represents a bidirectional communication pathway. These communications occur between the central nervous system (CNS), the enteric nervous system (ENS), and the emotional and cognitive centres of the brain. The field of research on the gut-brain axis has grown significantly during the past two decades. Signalling occurs between the gut microbiota and the brain through the neural, endocrine, immune, and humoral pathways. A substantial body of evidence indicates that the MGBA plays a pivotal role in various neurological diseases. These include Alzheimer's disease (AD), autism spectrum disorder (ASD), Rett syndrome, attention deficit hyperactivity disorder (ADHD), non-Alzheimer's neurodegeneration and dementias, fronto-temporal lobe dementia (FTLD), Wilson-Konovalov disease (WD), multisystem atrophy (MSA), Huntington's chorea (HC), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), temporal lobe epilepsy (TLE), depression, and schizophrenia (SCZ). Furthermore, the bidirectional correlation between therapeutics and the gut-brain axis will be discussed. Conversely, the mood of delivery, exercise, psychotropic agents, stress, and neurologic drugs can influence the MGBA. By understanding the MGBA, it may be possible to facilitate research into microbial-based interventions and therapeutic strategies for neurological diseases.

circRNAs as Epigenetic Regulators of Integrity in Blood-Brain Barrier Architecture: Mechanisms and Therapeutic Strategies in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory neurodegenerative disease leading to progressive demyelination and neuronal loss, with extensive neurological symptoms. As one of the most widespread neurodegenerative disorders, with an age onset of about 30 years, it turns out to be a socio-health and economic issue, thus necessitating therapeutic interventions currently unavailable. Loss of integrity in the blood-brain barrier (BBB) is one of the distinct MS hallmarks. Brain homeostasis is ensured by an endothelial cell-based monolayer at the interface between the central nervous system (CNS) and systemic bloodstream, acting as a selective barrier. MS results in enhanced barrier permeability, mainly due to the breakdown of tight (TJs) and adherens junctions (AJs) between endothelial cells. Specifically, proinflammatory mediator release causes failure in cytoplasmic exposure of junctions, resulting in compromised BBB integrity that enables blood cells to cross the barrier, establishing iron deposition and neuronal impairment. Cells with a compromised cytoskeletal protein network, fiber reorganization, and discontinuous junction structure can occur, resulting in BBB dysfunction. Recent investigations on spatial transcriptomics have proven circularRNAs (circRNAs) to be powerful multi-functional molecules able to epigenetically regulate transcription and structurally support proteins. In the present review, we provide an overview of the recent role ascribed to circRNAs in maintaining BBB integrity/permeability via cytoskeletal stability. Increased knowledge of the mechanisms responsible for impairment and circRNA's role in driving BBB damage and dysfunction might be helpful for the recognition of novel therapeutic targets to overcome BBB damage and unrestrained neurodegeneration.

Can Vitamin D Supplementation Improve Inflammation in Relapsing-Remitting Multiple Sclerosis Patients?

(1) Background: Studies indicate that vitamin D (VitD) may reduce inflammation in multiple sclerosis (MS). The aim of the study was to assess the effect of supplementation with different doses of VitD on inflammation in relapsing-remitting MS (RRMS) patients. (2) Methods: The effect of 6-month supplementation with different doses of oral VitD (2000 IU/day) in a high-dose group (HD, n = 23) and a low-dose group (15,960 IU/month) (LD, n = 29) on selected markers of inflammation was assessed in 52 RRMS patients. (3) Results: Females constituted the majority of participants (63.46%). The median age [years] was 39.5 [34.5-49.8] and 47 [40.0-55.0] in the HD and LD groups, respectively. Significant differences were observed in age (p = 0.028), body weight (p = 0.014) and height (p = 0.001) between the study groups. Considering the BMI, statistically significant differences were not found (p = 0.496). The median 25(OH)D concentration [ng/mL] increased from 23.023 [15.578-25.76] in the HD group and 28.318 [20.644-32.232] in the LD group to 29.819 [24.937-38.064] and 30.837 [25.382-36.789], respectively (p < 0.01), and the increase was significantly higher in the HD group (p = 0.01). Hypovitaminosis D was found in most patients (71.2%) initially, and serum VitD levels were still <30.0 ng/mL in 46.2% of the participants at the follow-up. A significant increase in the levels of IL-4, IL-6, IL-17A, IL-22, IL-23 and TNF -α [pg/mL] and a decrease in IL-10 levels were reported during the study (p < 0.01). A significant positive correlation was observed between 25(OH)D serum levels and sCD40L (R = 0.33; p < 0.05) and TNF-α (R = 0.28; p < 0.05), and a significant negative correlation was reported between 25(OH)D and IL-23 (R = -0.32; p < 0.01) at the beginning of the study. (4) Conclusions: In RRMS patients, the doses of VitD were probably too low to induce beneficial effects on inflammation. Further studies are warranted to determine the effect of VitD supplementation on inflammatory markers in MS patients.

Cytokine Profiling in Cerebrospinal Fluid of Patients with Newly Diagnosed Relapsing-Remitting Multiple Sclerosis (RRMS): Associations between Inflammatory Biomarkers and Disease Activity

Cytokines regulate immune responses and are crucial to MS pathogenesis. This study evaluated pro-inflammatory and anti-inflammatory cytokine concentrations in the CSF of de novo diagnosed RRMS patients compared to healthy controls. We assessed cytokine levels in the CSF of 118 de novo diagnosed RRMS patients and 112 controls, analyzing relationships with time from symptom onset to diagnosis, MRI lesions, and serum vitamin D levels. Elevated levels of IL-2, IL-4, IL-6, IL-13, FGF-basic, and GM-CSF, and lower levels of IL-1β, IL-1RA, IL-5, IL-7, IL-9, IL-10, IL-12p70, IL-15, G-CSF, PDGF-bb, and VEGF were observed in RRMS patients compared to controls. IL-2, IL-4, IL-12p70, PDGF, G-CSF, GM-CSF, and FGF-basic levels increased over time, while IL-10 decreased. IL-1β, IL-1RA, IL-6, TNF-α, and PDGF-bb levels negatively correlated with serum vitamin D. TNF-α levels positively correlated with post-contrast-enhancing brain lesions. IL-15 levels negatively correlated with T2 and Gd(+) lesions in C-spine MRI, while TNF-α, PDGF-bb, and FGF-basic correlated positively with T2 lesions in C-spine MRI. IL-6 levels positively correlated with post-contrast-enhancing lesions in Th-spine MRI. Distinct cytokine profiles in the CSF of de novo diagnosed MS patients provide insights into MS pathogenesis and guide immunomodulatory therapy strategies.

GV-971 attenuates the progression of neuromyelitis optica in murine models and reverses alterations in gut microbiota and associated peripheral abnormalities

AIMS

Growing evidence suggests that an imbalanced gut microbiota composition plays a crucial role in the development of neuromyelitis optica spectrum disorders (NMOSD), an inflammatory demyelinating disease primarily affecting the optic nerves and central nervous system (CNS). In light of this, we explored the potential therapeutic benefits of GV-971 in NMOSD. GV-971 is a drug used for treating mild-to-moderate Alzheimer's disease, which targets the gut-brain axis and reduces neuroinflammation.

METHODS

To evaluate GV-971's effects, we employed the experimental autoimmune encephalomyelitis (EAE) mouse model to establish NMOSD animal models. This was achieved by injecting NMO-IgG into aged mice (11 months old) or using NMO-IgG along with complement injection and microbubble-enhanced low-frequency ultrasound (MELFUS) techniques in young mice (7 weeks old). We assessed the impact of GV-971 on incidence rate, clinical scores, body weight, and survival, with methylprednisolone serving as a positive control. In NMOSD models of young mice, we analyzed spinal cord samples through H&E staining, immunohistochemistry, and Luxol Fast Blue staining. Fecal samples collected at different time points underwent 16S rRNA gene sequencing, while plasma samples were analyzed using cytokine array and untargeted metabolomics analysis.

RESULTS

Our findings indicated that GV-971 significantly reduced the incidence of NMOSD, alleviated symptoms, and prolonged survival in NMOSD mouse models. The NMOSD model exhibited substantial neuroinflammation and injury, accompanied by imbalances in gut microbiota, peripheral inflammation, and metabolic disorders, suggesting a potentially vicious cycle that accelerates disease pathogenesis. Notably, GV-971 effectively reduces neuroinflammation and injury, and restores gut microbiota composition, as well as ameliorates peripheral inflammation and metabolic disorders.

CONCLUSIONS

GV-971 attenuates the progression of NMOSD in murine models and reduces neuroinflammation and injury, likely through its effects on remodeling gut microbiota and peripheral inflammation and metabolic disorders.

The level of cytokines in tears as a novel indicator of demyelinating diseases

INTRODUCTION

A novel research objective is to identify new molecules in more readily accessible biological fluids that could be used in the diagnosis of multiple sclerosis (MS) and other demyelinating disorders.

AIM

To compare the level of selected cytokines in tears between patients with MS or other demyelinating disorder and healthy controls.

MATERIAL AND METHODS

84 patients with diagnosed MS during remission or with other demyelinating disease of the CNS and 70 healthy controls were enrolled in the study. Tears were collected without any stimulation and stored till the day of assessment. The concentration of selected cytokines was measured by the Bio-Plex Pro Human cytokine screening panel 27 cytokines assay according to the manufacturer's instructions. Statistical analysis was performed with Statistica 13.

RESULTS

IL-1b level was significantly lower in the study group compared to the control group [3,6 vs 8.71, p < 0.001]. The same pattern was observed for IL-6 [3,1 vs 5.26, p = 0.027] and IL-10 [1,7 vs 10.92, p < 0.001] (Table 1). In the study group, IL-1RA (p = 0.015), IL-5 (p = 0.04), IL-9 (p = 0.014), and IL-15 (p = 0.037) showed significant correlations with age. In the total sample, IL-1Ra (p = 0.016) and IFN-g (p = 0.041) were significantly correlated with age, while in the control group, IL-8 (p = 0.09), MIP-1a (p = 0.009), and RANTES (p = 0.031) showed significant correlations.

CONCLUSIONS

Our results show that MS and other demyelination diseases lead to decrease in the overall level of cytokines in tears. Further research is needed to determine the role of tear fluid in the assessment of demyelinating disorders like MS.

Selected cannabis cultivars modulate glial activation: in vitro and in vivo studies

INTRODUCTION

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system characterized by neuroinflammation, demyelination and axonal loss. Cannabis, an immunomodulating agent, is known for its ability to treat MS effectively. However, due to variations in the profile of secondary metabolites, especially cannabinoids, among cannabis cultivars, the effectiveness of cannabis treatment can vary, with significant variability in the effects on different biological parameters. For screening available cultivars, cellular in vitro as well as pre-clinical in vivo assays, are required to evaluate the effectiveness of the wide range of chemical variability that exists in cannabis cultivars. This study evaluated comparatively three chemically diverse cannabis cultivars, CN2, CN4 and CN6, containing different ratios of phytocannabinoids, for their neuroinflammatory activity in MS model.

MATERIALS AND METHODS

In vitro experiments were performed with lipopolysaccharide (LPS)-activated BV-2 microglia and primary glial cells to evaluate the effect of different cannabis cultivars on nitric oxide (NO) and inflammatory cytokines, as well as inducible nitric oxide synthase (iNOS) protein expression. An in vivo experiment using the experimental autoimmune encephalomyelitis (EAE) MS model was conducted using Myelin oligodendrocyte glycoprotein (MOG) as the activating peptide. The cannabis extracts of the cultivars CN2, CN4, CN6 or vehicle, were intraperitoneally injected with clinical scores given based on observed symptoms over the course of study. At the end of the experiment, the mice were sacrificed, and splenocyte cytokine secretion was measured using ELISA. Lumbar sections from the spinal cord of treated MS mice were evaluated for microglia, astrocytes and CD4+ cells.

RESULTS

Extracts of the CN2 cultivar contained tetrahydrocannabinolic acid (THCA) and tetrahydrocannabinol (THC) without cannabidiol (CBD), and a number of monoterpenes. CN4 contained cannabidiolic acid (CBDA) and tetrahydrocannabidiolic acid (THCA), with significant amounts of THC: CBD in a 1:1 ratio, as well as sesquiterpenes and some monoterpenes; and CN6 contained primarily CBDA and THCA, as well as THC and CBD in a 2:1 ratio, with some sesquiterpenes and no monoterpenes. All extracts were not cytotoxic in glial cells up to 50 µg/ml. Dose dependent inhibition of LPS-induced BV2 as well as primary microglial NO secretion confirmed the anti-inflammatory and anti-oxidative activity of the three cannabis cultivars. CN2 but not CN4 reduced both astrocytosis and microglial activation in lumbar sections of EAE mice. In contrast, CN4 but not CN2 significantly decreased the secretion of TNFα and Interferon γ (IFNγ) in primary splenocytes extracted from EAE mice.

CONCLUSIONS

While both cannabis cultivars, CN2 and CN4, significantly reduced the severity of the clinical signs throughout the course of the study, they modulated different inflammatory mediators and pathways, probably due to differences in their phytocannabinoid composition. This demonstrates the differential potential of cannabis cultivars differing in chemotype to regulate neuroinflammation and their potential to treat MS.

Blood-brain barrier biomarkers

The blood-brain barrier (BBB) is a dynamic interface that regulates the exchange of molecules and cells between the brain parenchyma and the peripheral blood. The BBB is mainly composed of endothelial cells, astrocytes and pericytes. The integrity of this structure is essential for maintaining brain and spinal cord homeostasis and protection from injury or disease. However, in various neurological disorders, such as traumatic brain injury, Alzheimer's disease, and multiple sclerosis, the BBB can become compromised thus allowing passage of molecules and cells in and out of the central nervous system parenchyma. These agents, however, can serve as biomarkers of BBB permeability and neuronal damage, and provide valuable information for diagnosis, prognosis and treatment. Herein, we provide an overview of the BBB and changes due to aging, and summarize current knowledge on biomarkers of BBB disruption and neurodegeneration, including permeability, cellular, molecular and imaging biomarkers. We also discuss the challenges and opportunities for developing a biomarker toolkit that can reliably assess the BBB in physiologic and pathophysiologic states.

CSF1R antagonism results in increased supraspinal infiltration in EAE

BACKGROUND

Colony stimulating factor 1 receptor (CSF1R) signaling is crucial for the maintenance and function of various myeloid subsets. CSF1R antagonism was previously shown to mitigate clinical severity in experimental autoimmune encephalomyelitis (EAE). The associated mechanisms are still not well delineated.

METHODS

To assess the effect of CSF1R signaling, we employed the CSF1R antagonist PLX5622 formulated in chow (PLX5622 diet, PD) and its control chow (control diet, CD). We examined the effect of PD in steady state and EAE by analyzing cells isolated from peripheral immune organs and from the CNS via flow cytometry. We determined CNS infiltration sites and assessed the extent of demyelination using immunohistochemistry of cerebella and spinal cords. Transcripts of genes associated with neuroinflammation were also analyzed in these tissues.

RESULTS

In addition to microglial depletion, PD treatment reduced dendritic cells and macrophages in peripheral immune organs, both during steady state and during EAE. Furthermore, CSF1R antagonism modulated numbers and relative frequencies of T effector cells both in the periphery and in the CNS during the early stages of the disease. Classical neurological symptoms were milder in PD compared to CD mice. Interestingly, a subset of PD mice developed atypical EAE symptoms. Unlike previous studies, we observed that the CNS of PD mice was infiltrated by increased numbers of peripheral immune cells compared to that of CD mice. Immunohistochemical analysis showed that CNS infiltrates in PD mice were mainly localized in the cerebellum while in CD mice infiltrates were primarily localized in the spinal cords during the onset of neurological deficits. Accordingly, during the same timepoint, cerebella of PD but not of CD mice had extensive demyelinating lesions, while spinal cords of CD but not of PD mice were heavily demyelinated.

CONCLUSIONS

Our findings suggest that CSF1R activity modulates the cellular composition of immune cells both in the periphery and within the CNS, and affects lesion localization during the early EAE stages.

Association of OX40L gene polymorphism with multiple sclerosis in Iranians

Introduction

The exact etiology of multiple sclerosis is unknown but recent studies indicated a link between tumor necrosis factor superfamily member 4 and the disease. Polymorphisms located in the regulatory region of the gene may affect its phenotype. Hence, we aimed to investigate the association of promoter polymorphisms of the gene with multiple sclerosis and also to estimate the frequency of haplotypes in the patients and healthy subjects.

Methods

Two hundred age- and sex-matched subjects including 100 patients and 100 healthy subjects were investigated in the study. Genotype and allele distributions of rs3850641, rs1234313, and rs10912580 polymorphisms in the promoter region of the gene were investigated by polymerase chain reaction-restriction fragment length polymorphism. In addition, haplotype frequencies estimation and linkage disequilibrium analysis were performed by SNPStats web tool.

Results

The distribution of AA, AG and GG genotypes of rs3850641 was significantly different between the patient and healthy groups (P = 0.009). In addition, frequencies of A and G alleles of rs3850641 were different between the groups (P < 0.001). Also the distribution of rs3850641 genotypes was different between the women of the both groups (P = 0.007). Our analysis revealed that rs3850641 AG (Odds ratio = 0.393, 95 % confidence interval = 0.170-0.907, P = 0.029) and GG (Odds ratio = 0.373, 95 % confidence interval = 0.168-0.830, P = 0.016) genotypes were associated with decreased risk of the disease. However, rs1234313 genotype and allele distributions were not different between the groups. The distribution of rs10912580polymorphism. AA, AG, and GG genotypes was significantly different between the groups (P = 0.007). rs10912580 AG genotype was associated with low risk of the disease (Odds ratio = 0.252, 95 % confidence interval = 0.102-0.623, P = 0.003). The distribution of haplotypes was statistically different between the patient and healthy groups (P < 0.001). A-G-A was the most frequent haplotype among the patients and the estimated frequency was higher than that of the control group (0.5527 versus 0.3739).

Conclusion

The distribution of rs3850641 and rs10912580 genotypes was different between the patients and healthy subjects. Moreover, rs3850641 AG and GG genotypes and also rs10912580 AG genotype were associated with low risk of the disease in Iranians. Further studies with large groups are recommended to show whether genotype variation in the patients could alter the response to treatment or not.

Relation between microRNA-155 and inflammatory mediators in multiple sclerosis

Multiple sclerosis (MS) is a complex autoimmune condition affecting the central nervous system characterized by axonal damage, demyelination, and chronic inflammation. Multiple molecular and cellular components mediate neuroinflammation in MS. In human macrophages and microglia, miRNA-155 is an essential proinflammatory noncoding RNA that regulates phenotypic and functional polarization properties. This study was conducted to detect the plasma level of miRNA-155 in RRMS and assess its relationship with inflammatory and anti-inflammatory mediators. The study included 60 MS patients and 30 healthy controls. Real-time quantitative polymerase chain reaction was utilized to detect miRNA-155, iNOS, and SMAD2, whereas ELISA was used to determine TNF-α, IFN-ɣ, TGF-β, and IL-10 levels. There was no significant difference in miRNA-155, SMAD2, and iNOS expression in MS patients compared to control subjects. In addition, there was a statistically significant increase in TNF-α, INF-ɣ, and TGF-β levels. IL-10 levels did not differ significantly between MS patients and healthy controls. There was a positive correlation between miRNA-155 and TNF-α (p < 0.000, r = 0.922), INF-ɣ (p < 0.000, r = 0.81), and iNOS (p < 0.000, r = 0.916) and inverse correlation between miRNA-155 and IL-10 (p < 0.000, r = -0.928), TGF-β (p < 0.000, r = -0.904) and SMAD2 (p < 0.000, r = -0.848). We conclude that expression of miRNA-155 in MS may modulate macrophage/microglia polarization by increasing the secretion of TNF-α, IFN-ɣ & iNOS and decreasing anti-inflammatory mediators IL10 and TGF-β.

Prebiotic inulin controls Th17 cells mediated central nervous system autoimmunity through modulating the gut microbiota and short chain fatty acids

Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory demyelination occurring in the central nervous system (CNS). Inulin is a common prebiotic that can improve metabolic disorders by modulating the gut microbiota. However, its capacity to affect CNS autoimmunity is poorly recognized. Experimental autoimmune encephalomyelitis (EAE) is a classical mouse model of MS. Herein, we found that oral administration of inulin ameliorated the severity EAE in mice, accompanied by reductions in inflammatory cell infiltration and demyelination in the CNS. These reductions were associated with decreased proportion and numbers of Th17 cells in brain and spleen. Consistent with the findings, the serum concentrations of IL-17, IL-6, and TNF-α were reduced in inulin treated EAE mice. Moreover, the proliferation of auto-reactive lymphocytes, against MOG35-55 antigen, was attenuated ex vivo. Mechanistically, inulin treatment altered the composition of gut microbiota. It increased Lactobacillus and Dubosiella whereas decreased g_Prevotellaceae_NK3B31_group at the genus level, alongside with elevated concentration of butyric acid in fecal content and serum. In vitro, butyrate, but not inulin, could inhibit the activation of MOG35-55 stimulated lymphocytes. Furthermore, fecal microbiota transplantation assay confirmed that fecal contents of inulin-treated normal mice had an ameliorative effect on EAE mice. In contrast, antibiotic cocktail (ABX) treatment diminished the therapeutic effect of inulin in EAE mice as well as the reduction of Th17 cells, while supplementation with Lactobacillus reuteri restored the amelioration effect. These results confirmed that the attenuation of inulin on Th17 cells and inflammatory demyelination in EAE mice was dependent on its modulation on gut microbiota and metabolites. Our findings provide a potential therapeutic regimen for prebiotic inulin supplementation in patients with multiple sclerosis.

Potential of Nano-Engineered Stem Cells in the Treatment of Multiple Sclerosis: A Comprehensive Review

Multiple sclerosis (MS) is a chronic and degrading autoimmune disorder mainly targeting the central nervous system, leading to progressive neurodegeneration, demyelination, and axonal damage. Current treatment options for MS are limited in efficacy, generally linked to adverse side effects, and do not offer a cure. Stem cell therapies have emerged as a promising therapeutic strategy for MS, potentially promoting remyelination, exerting immunomodulatory effects and protecting against neurodegeneration. Therefore, this review article focussed on the potential of nano-engineering in stem cells as a therapeutic approach for MS, focusing on the synergistic effects of combining stem cell biology with nanotechnology to stimulate the proliferation of oligodendrocytes (OLs) from neural stem cells and OL precursor cells, by manipulating neural signalling pathways-PDGF, BMP, Wnt, Notch and their essential genes such as Sox, bHLH, Nkx. Here we discuss the pathophysiology of MS, the use of various types of stem cells in MS treatment and their mechanisms of action. In the context of nanotechnology, we present an overview of its applications in the medical and research field and discuss different methods and materials used to nano-engineer stem cells, including surface modification, biomaterials and scaffolds, and nanoparticle-based delivery systems. We further elaborate on nano-engineered stem cell techniques, such as nano script, nano-exosome hybrid, nano-topography and their potentials in MS. The article also highlights enhanced homing, engraftment, and survival of nano-engineered stem cells, targeted and controlled release of therapeutic agents, and immunomodulatory and tissue repair effects with their challenges and limitations. This visual illustration depicts the process of utilizing nano-engineering in stem cells and exosomes for the purpose of delivering more accurate and improved treatments for Multiple Sclerosis (MS). This approach targets specifically the creation of oligodendrocytes, the breakdown of which is the primary pathological factor in MS.

The Comparison of the Selected Parameters of Brain Injury and Interleukins in the CSF in Patients Diagnosed De Novo with RRMS Compared to the Control Group

BACKGROUND

Multiple sclerosis (MS) is a chronic autoimmune disorder affecting the central nervous system (CNS). Due to the different phenotypes of the disease and non-specific symptoms of MS, there is a great need for a validated panel of biomarkers to facilitate the diagnosis, predict disease progression, and evaluate treatment outcomes.

METHODS

We determined the levels of the parameters of brain injury (NF-H, GPAF, S100B, and UCHL1) and the selected cytokines in the cerebrospinal fluid (CSF) in 101 patients diagnosed de novo with RRMS and 75 healthy controls. All determinations were made using the Bio-Plex method.

RESULTS

We found higher levels of NF-H and GFAP in the relapsing-remitting multiple sclerosis (RRMS) group compared to the controls. The concentrations of both molecules were significantly increased in patients with Gd+ lesions on brain MRI. The level of S100B did not differ significantly between the groups. UCHL1 concentrations were higher in the control group. We found some correlations between the selected cytokines, the levels of the parameters of brain injury, and the time from the first symptoms to the diagnosis of MS.

CONCLUSIONS

The role of the above molecules in MS is promising. However, further research is warranted to define their precise functions.

The fluctuations of expression profiles of critical genes in the miRNA maturation process and pro-and anti-inflammatory cytokines in the pathogenesis and progression of multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a central nervous system disease known for immune-mediated demyelination, inflammatory, and neurodegeneration symptoms. Discovering molecular biomarkers to classify RRMS and SPMS patients, monitor the disease activity, and response to particular treatments is one area that has received notable attraction. MicroRNA (miRNA), a single-stranded non-coding RNA molecule, is a significant regulator of gene expression recruited in pathogenic mechanisms in diverse diseases, especially cancer and MS. Also, the relapsing-remitting features of MS exhibit that both inflammatory and anti-inflammatory cytokines are effective in the progression of the disease over time.

METHODS AND RESULTS

It was assessed the expression patterns of the genes (Drosha, Pasha (DGCR8), and Dicer ) encoding the critical enzymes in the processing steps of miRNA maturation and major pro-inflammatory and anti-inflammatory cytokines (IFN-α, IFN-β, and IL-6) in blood cells of 40 MS patients (two groups of 10 men and women in both clinical courses of RR and SPMS patients) in comparison with 20 healthy control group (10 males and 10 females). The highest transcription activity of Drosha was observed for RRMS patients (4.2 and 3.6-fold, respectively), and the expression ratio was down regulated in male and female patients with SPMS (3.9- and 3.1-fold, respectively). Considering the studied cytokines, the increase in expression ratio of IL-6 in SPMS patients and the decrease in transcript abundance of INF-α, and INF-β cytokines are consistent with the progression of the disease.

CONCLUSIONS

Our findings showed that the high and low transcriptional levels of the considered genes seem to be effective in the pathogenesis and progression of MS.

A comparison of serum inflammatory parameters in progressive forms of multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is a chronic, inflammatory demyelinating disease of the central nervous system. Primary progressive MS (PPMS) is diagnosed in approximately 10-15 % of MS patients. Disease-modifying therapies (DMT) are less effective in modifying the course of progressive types of MS. It seems that inflammatory processes differ in the MS subtypes.

OBJECTIVES

The objective of this study was to assess differences in the inflammatory parameters between PPMS and other courses of MS.

MATERIALS AND METHODS

A total of 84 subjects were included in the study. The study group was divided according to the course of MS into the following categories: PPMS (n = 24); SPMS-secondary progressive multiple sclerosis (n = 14); RRMS-relapsing-remitting multiple sclerosis (n = 46). PPMS patients were further divided into treated with ocrelizumab and treatment-naive groups. The concentrations of serum inflammatory parameters were evaluated.

RESULTS

PPMS and SPMS significantly differed in the serum levels of sCD30, gp130, sIL-6R alpha, osteopontin, pentraxin-3 and sTNF-R1. The serum concentrations of IFN-alpha2, IL-10, IL-20, IL-29 and osteopontin significantly differed between PPMS and RRMS. The serum levels of BAFF, IL-19, IL-20, pentraxin-3, s-TNF-R1 and s-TNF-R2 significantly differed between PPMS treated with ocrelizumab and treatment-naive.

CONCLUSION

Although inflammatory processes take part in the pathogenesis of all types of MS, they differ between MS courses. Serum inflammatory parameters seem to be promising biomarkers in helping to differentiate courses of MS, and in assessing reactions to DMT treatment. Further investigations on their usage are required.

Therapeutic Plasma Exchange and Multiple Sclerosis Dysregulations: Focus on the Removal of Pathogenic Circulatory Factors and Altering Nerve Growth Factor and Sphingosine-1-Phosphate Plasma Levels

Multiple sclerosis (MS) is predominantly an immune-mediated disease of the central nervous system (CNS) of unknown etiology with a possible genetic predisposition and effect of certain environmental factors. It is generally accepted that the disease begins with an autoimmune inflammatory reaction targeting oligodendrocytes followed by a rapid depletion of their regenerative capacity with subsequent permanent neurodegenerative changes and disability. Recent research highlights the central role of B lymphocytes and the corresponding IgG and IgM autoantibodies in newly forming MS lesions. Thus, their removal along with the modulation of certain bioactive molecules to improve neuroprotection using therapeutic plasma exchange (TPE) becomes of utmost importance. Recently, it has been proposed to determine the levels and precise effects of both beneficial and harmful components in the serum of MS patients undergoing TPE to serve as markers for appropriate TPE protocols. In this review we discuss some relevant examples, focusing on the removal of pathogenic circulating factors and altering the plasma levels of nerve growth factor and sphingosine-1-phosphate by TPE. Altered plasma levels of the reviewed molecular compounds in response to TPE reflect a successful reduction of the pro-inflammatory burden at the expense of an increase in anti-inflammatory potential in the circulatory and CNS compartments.

Early miR-320b and miR-25-3p miRNA levels correlate with multiple sclerosis severity at 10 years: a cohort study

BACKGROUND

Multiple sclerosis (MS) is a chronic demyelinating autoimmune disorder which may cause long-term disability. MicroRNA (miRNA) are stable, non-coding molecules that have been identified in our Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women's Hospital (CLIMB)-cohort, as well as other international cohorts, as potential disease biomarkers in MS. However, few studies have evaluated the association of miRNA expression early in the MS disease course with long-term outcomes. Therefore, we aimed to evaluate the potential role of three candidate serum miRNAs previously correlated with MS disability in patients with MS, miR-320b, miR-25-3p and miRNA 486-5p, as early biomarkers of MS disability at 10-year follow-up.

MAIN BODY

We included 144 patients with serum obtained within three years of MS onset. miRNA expression was measured by RNA extraction followed by RT-PCR. Demographic, clinical, brain MRI and other biomarkers were collected. The primary outcome was the association between early miRNA expression and retaining benign MS, defined as EDSS ≤ 2 at 10-year follow-up. Among the 144 patients, 104 were benign and 40 were not benign at 10-year follow-up. 89 (62%) were women, with mean age at onset 37.7 (SD: 9.6) years. Patients who retained benign MS had lower values of miR-25-3p (p = 0.047) and higher miR-320b (p = 0.025) values. Development of SPMS was associated with higher miR-320b (p = 0.002) levels. Brain parenchymal fraction at year 10 was negatively correlated with miR-25-3p (p = 0.0004) and positively correlated with miR-320b (p = 0.006). No association was found between miR-486-5p and any outcome, and 10-year T2-lesion volume was not associated with any miRNA.

CONCLUSIONS

Our results show that miR-320b and miR-25-3p expression are early biomarkers associated with MS severity and brain atrophy. This study provides class III evidence of that miR-320b and miR-25-3p are associated with long-term MS disability which may be a potential tool to risk-stratify patients with MS for early treatment decisions.

The Role of BDNF in Multiple Sclerosis Neuroinflammation

Multiple sclerosis (MS) is a chronic, inflammatory, and degenerative disease of the central nervous system (CNS). Inflammation is observed in all stages of MS, both within and around the lesions, and can have beneficial and detrimental effects on MS pathogenesis. A possible mechanism for the neuroprotective effect in MS involves the release of brain-derived neurotrophic factor (BDNF) by immune cells in peripheral blood and inflammatory lesions, as well as by microglia and astrocytes within the CNS. BDNF is a neurotrophic factor that plays a key role in neuroplasticity and neuronal survival. This review aims to analyze the current understanding of the role that inflammation plays in MS, including the factors that contribute to both beneficial and detrimental effects. Additionally, it explores the potential role of BDNF in MS, as it may modulate neuroinflammation and provide neuroprotection. By obtaining a deeper understanding of the intricate relationship between inflammation and BDNF, new therapeutic strategies for MS may be developed.

Association between autoimmune diseases of the nervous system and schizophrenia: A systematic review and meta-analysis of cohort studies

INTRODUCTION

Numerous studies have found an association between autoimmune diseases of the nervous system (ADNS) and schizophrenia (SCZ), but the findings remain controversial. We conducted the first meta-analysis to summarize the current evidence from cohort studies that evaluated the association between ADNS and SCZ.

METHODS

PubMed, Web of Science, and Embase were comprehensively searched until May 30, 2022 for articles on the association between ADNS and SCZ. Every included study was reported effect size with 95% CIs for the association between ADNS and SCZ. Meta-regression and subgroup analysis were used to assess the heterogeneity.

RESULTS

A total of 8 cohort studies with 12 cohorts were included in the meta-analysis. We observed a significant association between ADNS and SCZ (RR = 1.42; 95%CI, 1.18-1.72). Subgroup analysis showed that the risk of SCZ was significantly increased when ADNS were used as exposure factors (RR = 1.48; 95%CI, 1.15-1.89), whereas with SCZ did not observe an increased risk of subsequent ADNS (RR = 1.33; 95%CI, 0.92-1.92); multiple sclerosis (MS) was positively associated with SCZ (RR = 1.36; 95%CI, 1.12-1.66), but no significant association was found between Guillain-Barre syndrome (GBS) and SCZ (RR = 1.90; 95%CI, 0.87-4.17). Meanwhile, we found location was the source of heterogeneity.

LIMITATIONS

High heterogeneity was observed (I² = 92.0%), and only English literature was included in the meta-analysis.

CONCLUSIONS

We found a positive association between ADNS and SCZ, and the association was different across the different types of ADNS. The results of the study are helpful for clinicians to carry out targeted preventive measures for ADNS and SCZ.

Immune Regulatory Functions of Macrophages and Microglia in Central Nervous System Diseases

Macrophages can be characterized as a very multifunctional cell type with a spectrum of phenotypes and functions being observed spatially and temporally in various disease states. Ample studies have now demonstrated a possible causal link between macrophage activation and the development of autoimmune disorders. How these cells may be contributing to the adaptive immune response and potentially perpetuating the progression of neurodegenerative diseases and neural injuries is not fully understood. Within this review, we hope to illustrate the role that macrophages and microglia play as initiators of adaptive immune response in various CNS diseases by offering evidence of: (1) the types of immune responses and the processes of antigen presentation in each disease, (2) receptors involved in macrophage/microglial phagocytosis of disease-related cell debris or molecules, and, finally, (3) the implications of macrophages/microglia on the pathogenesis of the diseases.

CDX-modified chitosan nanoparticles remarkably reduce therapeutic dose of fingolimod in the EAE model of mice

Fingolimod (Fin), an FDA-approved drug, is used to control relapsing-remitting multiple sclerosis (MS). This therapeutic agent faces crucial drawbacks like poor bioavailability rate, risk of cardiotoxicity, potent immunosuppressive effects, and high cost. Here, we aimed to assess the therapeutic efficacy of nano-formulated Fin in a mouse model of experimental autoimmune encephalomyelitis (EAE). Results showed the suitability of the present protocol in the synthesis of Fin-loaded CDX-modified chitosan (CS) nanoparticles (NPs) (Fin@CSCDX) with suitable physicochemical features. Confocal microscopy confirmed the appropriate accumulation of synthesized NPs within the brain parenchyma. Compared to the control EAE mice, INF-γ levels were significantly reduced in the group that received Fin@CSCDX (p < 0.05). Along with these data, Fin@CSCDX reduced the expression of TBX21, GATA3, FOXP3, and Rorc associated with the auto-reactivation of T cells (p < 0.05). Histological examination indicated a low-rate lymphocyte infiltration into the spinal cord parenchyma after the administration of Fin@CSCDX. Of note, HPLC data revealed that the concentration of nano-formulated Fin was about 15-fold less than Fin therapeutic doses (TD) with similar reparative effects. Neurological scores were similar in both groups that received nano-formulated fingolimod 1/15th of free Fin therapeutic amounts. Fluorescence imaging indicated that macrophages and especially microglia can efficiently uptake Fin@CSCDX NPs, leading to the regulation of pro-inflammatory responses. Taken together, current results indicated that CDX-modified CS NPs provide a suitable platform not only for the efficient reduction of Fin TD but also these NPs can target the brain immune cells during neurodegenerative disorders.

The expression profile of HAR1A and HAR1B in the peripheral blood cells of multiple sclerosis patients

BACKGROUND

Multiple sclerosis (MS) is a progressive neurodegenerative disease of the central nervous system (CNS) with varying degrees of axonal and neuronal damage. The onset and progression of the disease are influenced by several environmental and genetic variables. Long non-coding RNAs (lncRNAs) have a crucial role in the pathophysiology of MS. Our study aimed to assess the levels of HAR1A and HAR1B lncRNA expression in the blood samples of MS patients and investigate the relationship between these lncRNAs and disease activity.

METHODS AND RESULTS

The blood samples of 100 MS patients, including 82 relapsing-remitting (RR), 8 primary progressive (PP), and 10 secondary progressive (SP) MS cases, and 100 healthy controls were collected. Quantitative real-time PCR was used for the evaluation of gene expression. ROC curve analysis was performed to evaluate the diagnostic potential of lncRNA levels. A significant decrease was detected in HAR1A expressions (P < 0.0001), and a moderate increase was also shown in HAR1B of SPMS patients (P value = 0.0189). HAR1A showed different expression levels in patients over forty (P value = 0.034). The expression levels of HAR1A and HAR1B were positively correlated in MS patients (r = 0.2003, P value = 0.0457). In addition, ROC curve results suggested that HAR1A can be introduced as a novel biomarker for MS diagnosis (AUC = 0.776).

CONCLUSION

The low serum level of HAR1A may be a potential molecular biomarker for MS diagnosis; however, no discernible difference was detected in the expression level of HAR1B in the blood samples of MS patients.

Recent Progress in Multiple Sclerosis Treatment Using Immune Cells as Targets

Multiple sclerosis (MS) is an autoimmune-mediated demyelinating disease of the central nervous system. The main pathological features are inflammatory reaction, demyelination, axonal disintegration, reactive gliosis, etc. The etiology and pathogenesis of the disease have not been clarified. The initial studies believed that T cell-mediated cellular immunity is the key to the pathogenesis of MS. In recent years, more and more evidence has shown that B cells and their mediated humoral immune and innate immune cells (such as microglia, dendritic cells, macrophages, etc.) also play an important role in the pathogenesis of MS. This article mainly reviews the research progress of MS by targeting different immune cells and analyzes the action pathways of drugs. The types and mechanisms of immune cells related to the pathogenesis are introduced in detail, and the mechanisms of drugs targeting different immune cells are discussed in depth. This article aims to clarify the pathogenesis and immunotherapy pathway of MS, hoping to find new targets and strategies for the development of therapeutic drugs for MS.

The comparative analysis of selected interleukins and proinflammatory factors in CSF among de novo diagnosed patients with RRMS

OBJECTIVES

Cytokines play a key role in neuroinflammation, which is present in every subset of multiple sclerosis (MS). The aim of the study was to assess levels of selected interleukins and proinflammatory factors in cerebrospinal fluid (CSF) among patients diagnosed with relapsing-remitting multiple sclerosis (RRMS).

METHODS

One hundred eighteen patients diagnosed de novo with RRMS were enrolled in the study. We analysed the relationships between selected cytokines' levels depending on the age at diagnosis, time from the first symptoms to diagnosis and presence of MRI lesions.

RESULTS

Among the study group the levels of IL-5 and IL-13 increased with the age at the diagnosis of MS. The concentration of IL-10 was lower in group of patients over the age of 35. The levels of IFN-γ, TNF-α, IL-5, IL-10 and IL-15 increased with the longer time from the first symptoms to diagnosis. Positive correlations were found between the levels of IL-2 and IL-12, IL-17, IL-4, IL-1RA as well as IL-1 and IL-4, IL-17. The concentration of IL-5 correlated positively with IL-4, IL-9 and IL-13. The level of IL-10 increased with IL-6 and IL-9 concentrations. A negative correlation was found for IL-10 and IL-4. In turn, between IL-13 and both IL-5 and IL-9, the relationship was positive. The level of IL-2 was significantly higher among patients without gadolinium-enhanced (Gd(+)) MRI lesions.

CONCLUSIONS

The results of the study provide new insight into the role of selected molecules in the development of inflammation in MS. It might be crucial in planning the most adequate immunomodulatory therapy.

Contribution of Intravital Neuroimaging to Study Animal Models of Multiple Sclerosis

Multiple sclerosis (MS) is a complex and long-lasting neurodegenerative disease of the central nervous system (CNS), characterized by the loss of myelin within the white matter and cortical fibers, axonopathy, and inflammatory responses leading to consequent sensory-motor and cognitive deficits of patients. While complete resolution of the disease is not yet a reality, partial tissue repair has been observed in patients which offers hope for therapeutic strategies. To address the molecular and cellular events of the pathomechanisms, a variety of animal models have been developed to investigate distinct aspects of MS disease. Recent advances of multiscale intravital imaging facilitated the direct in vivo analysis of MS in the animal models with perspective of clinical transfer to patients. This review gives an overview of MS animal models, focusing on the current imaging modalities at the microscopic and macroscopic levels and emphasizing the importance of multimodal approaches to improve our understanding of the disease and minimize the use of animals.

The Dectin-1 Receptor Signaling Pathway Mediates the Remyelination Effect of Lentinan through Suppression of Neuroinflammation and Conversion of Microglia

Demyelinating diseases such as multiple sclerosis (MS) are chronic inflammatory autoimmune diseases and involve demyelination and axonal degeneration. Microglia rapidly respond to changes in the environment by altering morphotype and function during the progressive disease stage. Although substantial progress has been made in the drug development for MS, treatment of the progressive forms of the disease remains unsatisfactory. There is great interest in identifying novel agents for treating MS. Lentinus edodes is a traditional food, which can improve physiological function. Lentinan (LNT), a type of polysaccharide extracted from mushroom Lentinus edodes, is an anti-inflammatory and immunomodulatory agent. Here, we studied the remyelination effects of LNT and its therapeutic target in regulating the functions of neuroinflammation. We found that LNT enhanced remyelination and rescued motor deficiency by regulating dectin-1 receptor to inhibit neuroinflammation and microglial cell transformation. LNT promoted the conversion of microglial cells from the M1 status induced by LPS to the M2 status, enhanced the anti-inflammatory markers IL-10 and BDNF, inhibited inflammatory markers TNF-α and IL-1β, and downregulated the microglia activation and oligodendrocyte and astrocyte proliferation by modulating dectin-1. If we injected the dectin-1-specific inhibitor laminarin (Lam), the remyelination effects induced by LNT were completely abolished. Thus, these results suggest that LNT is a novel and potential therapeutic agent that can rescue MS neuroimmune imbalance and remyelination through a dectin-1 receptor-dependent mechanism.

Evidence of increased sequestration of pro-resolving lipid mediators within brain esterified lipid pools of multiple sclerosis patients

BACKGROUND

Unresolved inflammation in multiple sclerosis (MS) is associated with progressive demyelination and symptom worsening. In the brain, both inflammation and resolution pathways are mediated by free lipid mediators (i.e., oxylipins) that can be derived from the enzymatic hydrolysis of esterified oxylipins . It is not known whether disturbances in the turnover of free lipid mediators from esterified pools exist in postmortem brain of MS patients. We hypothesized that resolution pathways are impaired in MS patients because of disturbances in the turnover of free pro-resolving lipid mediators from esterified lipids. The objective was to characterize free and esterified oxylipins in postmortem prefrontal cortex of MS and unaffected control participants.

METHODS

Oxylipins in free, neutral lipid and phospholipid pools were extracted from prefrontal cortex of 10 MS participants and 5 unaffected controls, separated by solid phase extraction columns, and quantified by ultra-high-pressure liquid chromatography-tandem mass spectrometry. Significant differences between the control and MS groups were determined by an unpaired t-test with Benjamini and Hochberg False Discovery Rate correction (10%) applied to oxylipins within each lipid pool.

RESULTS

The concentration of 7 esterified pro-resolving fatty acid epoxides within neutral lipids were significantly higher by 126%-285% in postmortem prefrontal cortex of MS compared to control participants. The concentration of esterified linoleic acid-derived 9(10)-epoxy-octadecenoic acid, a pro-inflammatory epoxide, was higher by 206% in MS compared to controls. No significant changes were observed in free or phospholipid-bound oxylipins.

CONCLUSION

In MS, several pro-resolving lipid mediators are trapped within prefrontal cortex neutral lipids, potentially limiting their supply and availability in the free bioactive form. This may explain why inflammation resolution is impaired in MS patients.

Sex bias in lymphocytes: Implications for autoimmune diseases

Autoimmune diseases are characterized by a significant sex dimorphism, with women showing increased susceptibility to disease. This is, at least in part, due to sex-dependent differences in the immune system that are influenced by the complex interplay between sex hormones and sex chromosomes, with contribution from sociological factors, diet and gut microbiota. Sex differences are evident in the number and function of lymphocyte populations. Women mount a stronger pro-inflammatory response than males, with increased lymphocyte proliferation, activation and pro-inflammatory cytokine production, whereas men display expanded regulatory cell subsets. Ageing alters the immune landscape of men and women in differing ways, resulting in changes in autoimmune disease susceptibility. Here we review the current literature on sex differences in lymphocyte function, the factors that influence this, and the implications for autoimmune disease. We propose that improved understanding of sex bias in lymphocyte function can provide sex-specific tailoring of treatment strategies for better management of autoimmune diseases.

Anti-Caspr-conjugated gold nanoparticles emergence as a novel approach in the treatment of EAE animal model

Multiple sclerosis (MS) is a chronic autoimmune disorder of central nervous system which is increasing worldwide. Although immunosuppressive agents are used for the treatment of MS disease, nevertheless the lack of non-toxic and efficient therapeutic method is perceptible. Hence, this study aims to evaluate the effect of Contactin-associated protein (Caspr) antibody-, poly ethylene glycol (PEG)- and exosome combined gold nanoparticles (GNPs) in comparison to Glatiramer acetate as a selective treatment of MS disease in the experimental autoimmune encephalomyelitis (EAE) mouse model. EAE was induced in female C57BL/6 mice and 25-day treatment with anti-Caspr-, PEG- and exosome combined GNPs was evaluated. Histopathological examination of spinal cord, regulatory T cells as well as inflammatory pathway including IFN-ɣ and IL-17 and mir-326 were investigated. The results showed the severity of MS symptoms was significantly decreased in all treated groups. Histological examination of the spinal cord indicated the reduced demyelination and immune cell infiltration. Besides, regulatory T cells were significantly increased following all treatments. Remarkably, the cytokine levels of IFN-ɣ and IL-17 as well as mir-326 is altered in treated groups. Taken together, the obtained findings demonstrate that the administration of anti-Caspr-, PEG- and exosome combined GNPs can be considered a potential treatment in MS disease.

Role of Demyelination in the Persistence of Neurological and Mental Impairments after COVID-19

Long-term neurological and mental complications of COVID-19, the so-called post-COVID syndrome or long COVID, affect the quality of life. The most persistent manifestations of long COVID include fatigue, anosmia/hyposmia, insomnia, depression/anxiety, and memory/attention deficits. The physiological basis of neurological and psychiatric disorders is still poorly understood. This review summarizes the current knowledge of neurological sequelae in post-COVID patients and discusses brain demyelination as a possible mechanism of these complications with a focus on neuroimaging findings. Numerous reviews, experimental and theoretical studies consider brain demyelination as one of the mechanisms of the central neural system impairment. Several factors might cause demyelination, such as inflammation, direct effect of the virus on oligodendrocytes, and cerebrovascular disorders, inducing myelin damage. There is a contradiction between the solid fundamental basis underlying demyelination as the mechanism of the neurological injuries and relatively little published clinical evidence related to demyelination in COVID-19 patients. The reason for this probably lies in the fact that most clinical studies used conventional MRI techniques, which can detect only large, clearly visible demyelinating lesions. A very limited number of studies use specific methods for myelin quantification detected changes in the white matter tracts 3 and 10 months after the acute phase of COVID-19. Future research applying quantitative MRI assessment of myelin in combination with neurological and psychological studies will help in understanding the mechanisms of post-COVID complications associated with demyelination.

Interleukin-17 Family Cytokines in Metabolic Disorders and Cancer

Interleukin-17 (IL-17) family cytokines are potent drivers of inflammatory responses. Although IL-17 was originally identified as a cytokine that induces protective effects against bacterial and fungal infections, IL-17 can also promote chronic inflammation in a number of autoimmune diseases. Research in the last decade has also elucidated critical roles of IL-17 during cancer development and treatment. Intriguingly, IL-17 seems to play a role in the risk of cancers that are associated with metabolic disorders. In this review, we summarize our current knowledge on the biochemical basis of IL-17 signaling, IL-17′s involvement in cancers and metabolic disorders, and postulate how IL-17 family cytokines may serve as a bridge between these two types of diseases.

The Role of Cytotoxic T-Lymphocyte Antigen 4 in the Pathogenesis of Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune neurodegenerative disorder of the central nervous system that presents heterogeneous clinical manifestations and course. It has been shown that different immune checkpoints, including Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4), can be involved in the pathogenesis of MS. CTLA-4 is a critical regulator of T-cell homeostasis and self-tolerance and represents a key inhibitor of autoimmunity. In this scopingreview, we resume the current preclinical and clinical studies investigating the role of CTLA-4 in MS with different approaches. While some of these studies assessed the expression levels of CTLA-4 on T cells by comparing MS patients with healthy controls, others focused on the evaluation of the effects of common MS therapies on CTLA-4 modulation or on the study of the CTLA-4 blockade or deficiency in experimental autoimmune encephalomyelitis models. Moreover, other studies in this field aimed to discover if the CTLA-4 gene might be involved in the predisposition to MS, whereas others evaluated the effects of treatment with CTLA4-Ig in MS. Although these results are of great interest, they are often conflicting. Therefore, further studies are needed to reveal the exact mechanisms underlying the action of a crucial immune checkpoint such as CTLA-4 in MS to identify novel immunotherapeutic strategies for MS patients.

Efficacy of Vafidemstat in Experimental Autoimmune Encephalomyelitis Highlights the KDM1A/RCOR1/HDAC Epigenetic Axis in Multiple Sclerosis

Lysine specific demethylase 1 (LSD1; also known as KDM1A), is an epigenetic modulator that modifies the histone methylation status. KDM1A forms a part of protein complexes that regulate the expression of genes involved in the onset and progression of diseases such as cancer, central nervous system (CNS) disorders, viral infections, and others. Vafidemstat (ORY-2001) is a clinical stage inhibitor of KDM1A in development for the treatment of neurodegenerative and psychiatric diseases. However, the role of ORY-2001 targeting KDM1A in neuroinflammation remains to be explored. Here, we investigated the effect of ORY-2001 on immune-mediated and virus-induced encephalomyelitis, two experimental models of multiple sclerosis and neuronal damage. Oral administration of ORY-2001 ameliorated clinical signs, reduced lymphocyte egress and infiltration of immune cells into the spinal cord, and prevented demyelination. Interestingly, ORY-2001 was more effective and/or faster acting than a sphingosine 1-phosphate receptor antagonist in the effector phase of the disease and reduced the inflammatory gene expression signature characteristic ofEAE in the CNS of mice more potently. In addition, ORY-2001 induced gene expression changes concordant with a potential neuroprotective function in the brain and spinal cord and reduced neuronal glutamate excitotoxicity-derived damage in explants. These results pointed to ORY-2001 as a promising CNS epigenetic drug able to target neuroinflammatory and neurodegenerative diseases and provided preclinical support for the subsequent design of early-stage clinical trials.

Symptom Interconnectivity in Multiple Sclerosis: A Narrative Review of Potential Underlying Biological Disease Processes

Introduction

Fatigue, cognitive impairment, depression, and pain are highly prevalent symptoms in multiple sclerosis (MS). These often co-occur and may be explained by a common etiology. By reviewing existing literature, we aimed to identify potential underlying biological processes implicated in the interconnectivity between these symptoms.

Methods

A literature search was conducted to identify articles reporting research into the biological mechanisms responsible for the manifestation of fatigue, cognitive impairment, depression, and pain in MS. PubMed was used to search for articles published from July 2011 to July 2021. We reviewed and assessed findings from the literature to identify biological processes common to the symptoms of interest.

Results

Of 693 articles identified from the search, 252 were selected following screening of titles and abstracts and assessing reference lists of review articles. Four biological processes linked with two or more of the symptoms of interest were frequently identified from the literature: (1) direct neuroanatomical changes to brain regions linked with symptoms of interest (e.g., thalamic injury associated with cognitive impairment, fatigue, and depression), (2) pro-inflammatory cytokines associated with so-called ‘sickness behavior,’ including manifestation of fatigue, transient cognitive impairment, depression, and pain, (3) dysregulation of monoaminergic pathways leading to depressive symptoms and fatigue, and (4) hyperactivity of the hypothalamic–pituitary-adrenal (HPA) axis as a result of pro-inflammatory cytokines promoting the release of brain noradrenaline, serotonin, and tryptophan, which is associated with symptoms of depression and cognitive impairment.

Conclusion

The co-occurrence of fatigue, cognitive impairment, depression, and pain in MS appears to be associated with a common set of etiological factors, namely neuroanatomical changes, pro-inflammatory cytokines, dysregulation of monoaminergic pathways, and a hyperactive HPA axis. This association of symptoms and biological processes has important implications for disease management strategies and, eventually, could help find a common therapeutic pathway that will impact both inflammation and neuroprotection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-022-00368-2.

Transcriptomic Analysis of Fumarate Compounds Identifies Unique Effects of Isosorbide Di-(Methyl Fumarate) on NRF2, NF-kappaB and IRF1 Pathway Genes

Dimethyl fumarate (DMF) has emerged as a first-line therapy for relapsing-remitting multiple sclerosis (RRMS). This treatment, however, has been limited by adverse effects, which has prompted development of novel derivatives with improved tolerability. We compared the effects of fumarates on gene expression in astrocytes. Our analysis included diroximel fumarate (DRF) and its metabolite monomethyl fumarate (MMF), along with a novel compound isosorbide di-(methyl fumarate) (IDMF). Treatment with IDMF resulted in the largest number of differentially expressed genes. The effects of DRF and MMF were consistent with NRF2 activation and NF-κB inhibition, respectively. IDMF responses, however, were concordant with both NRF2 activation and NF-κB inhibition, and we confirmed IDMF-mediated NF-κB inhibition using a reporter assay. IDMF also down-regulated IRF1 expression and IDMF-decreased gene promoters were enriched with IRF1 recognition sequences. Genes altered by each fumarate overlapped significantly with those near loci from MS genetic association studies, but IDMF had the strongest overall effect on MS-associated genes. These results show that next-generation fumarates, such as DRF and IDMF, have effects differing from those of the MMF metabolite. Our findings support a model in which IDMF attenuates oxidative stress via NRF2 activation, with suppression of NF-κB and IRF1 contributing to mitigation of inflammation and pyroptosis.

Construction of miRNA-regulated drug-pathway network to screen drug repurposing candidates for multiple sclerosis

ABSTRACT

Given the high disability rate of multiple sclerosis (MS), there is a need for safer and more effective therapeutic agents. Existing literature highlights the prominent roles of miRNA in MS pathophysiology. Nevertheless, there are few studies that have explored the usefulness of existing drugs in treating MS through potential miRNA-modulating abilities.The current investigation identifies genes that may exacerbate the risk of MS due to their respective miRNA associations. These findings were then used to determine potential drug candidates through the construction of miRNA-regulated drug-pathway network through genes. We uncovered a total of 48 MS risk pathways, 133 MS risk miRNAs, and 186 drugs that can affect these pathways. Potential MS risk miRNAs that are also regulated by therapeutic candidates were hsa05215 and hsa05152. We analyzed the properties of the miRNA-regulated drug-pathway network through genes and uncovered a number of novel MS agents by assessing their respective Z-values.A total of 20 likely drug candidates were identified, including human immunoglobulin, aspirin, alemtuzumab, minocycline, abciximab, alefacept, palivizumab, bevacizumab, efalizumab, tositumomab, minocycline, etanercept, catumaxomab, and sarilumab. Each of these agents were then explored with regards to their likely mechanism of action in treating MS.The current investigation provides a fresh perspective on MS biological mechanisms as well as likely treatment strategies.

Herpesvirus Infections in KIR2DL2-Positive Multiple Sclerosis Patients: Mechanisms Triggering Autoimmunity

In multiple sclerosis (MS), there is a possible relationship with viral infection, evidenced by clinical evidence of an implication of infectious events with disease onset and/or relapse. The aim of this research is to study how human herpesvirus (HHVs) infections might dysregulate the innate immune system and impact autoimmune responses in MS. We analyzed 100 MS relapsing remitting patients, in the remission phase, 100 healthy controls and 100 subjects with other inflammatory neurological diseases (OIND) (neuro-lupus) for their immune response to HHV infection. We evaluated NK cell response, levels of HHVs DNA, IgG and pro- and anti-inflammatory cytokines. The results demonstrated that the presence of KIR2DL2 expression on NK cells increased the susceptibility of MS patients to HHV infections. We showed an increased susceptibility mainly to EBV and HHV-6 infections in MS patients carrying the KIR2DL2 receptor and HLA-C1 ligand. The highest HHV-6 viral load was observed in MS patients, with an increased percentage of subjects positive for IgG against HHV-6 in KIR2DL2-positive MS and OIND subjects compared to controls. MS and OIND patients showed the highest levels of IL-8, IL-12p70, IL-10 and TNF-alpha in comparison with control subjects. Interestingly, MS and OIND patients showed similar levels of IL-8, while MS patients presented higher IL-12p70, TNF-alpha and IL-10 levels in comparison with OIND patients. We can hypothesize that HHVs’ reactivation, by inducing immune activation via also molecular mimicry, may have the ability to induce autoimmunity and cause tissue damage and consequent MS lesion development.

Phytochemicals as inhibitors of tumor necrosis factor alpha and neuroinflammatory responses in neurodegenerative diseases

Inflammatory processes and proinflammatory cytokines have a key role in the cellular processes of neurodegenerative diseases and are linked to the pathogenesis of functional and mental health disorders. Tumor necrosis factor alpha has been reported to play a major role in the central nervous system in Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis and many other neurodegenerative diseases. Therefore, a potent proinflammatory/proapoptotic tumor necrosis factor alpha could be a strong candidate for targeted therapy. Plant derivatives have now become promising candidates as therapeutic agents because of their antioxidant and chemical characteristics, and anti-inflammatory features. Recently, phytochemicals including flavonoids, terpenoids, alkaloids, and lignans have generated interest as tumor necrosis factor alpha inhibitor candidates for a number of diseases involving inflammation within the nervous system. In this review, we discuss how phytochemicals as tumor necrosis factor alpha inhibitors are a therapeutic strategy targeting neurodegeneration.

Role of IL-33/ST2 Axis in Chronic Inflammatory Neurological Disorderss

Interleukin-33 (IL-33) is a member of IL-1 family of cytokines, produced constitutively by fibroblasts, endothelial cells, and epithelial cells. IL-33 can be released passively from cells during tissue damage and cell necrosis, suggesting that it may act as an alarmin. Function of IL-33 is mediated by its interaction with ST2 molecule that is expressed on many immune cells: Th2 lymphocytes, NK, NKT and mast cells, monocytes, dendritic cells and granulocytes. IL-33/ST2 pathway plays, often dual, roles in different physiological and inflammatory processes, mediating both, pathological immune responses and tissue repair. Expression of IL-33 in the central nervous system (CNS) is significantly enhanced during various pathological processes, indicating its important role in the pathogenesis of neurological inflammatory and degenerative diseases. In this review the biological features, expression of IL-33 and its ligand ST2 in CNS, and the role of IL- 33/ST2 pathway in development of Alzheimer’s disease and multiple sclerosis are discussed.

Timing of treatment with an endogenous opioid alters immune response and spinal cord pathology in female mice with experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is a progressive disease of the central nervous system (CNS) that primarily affects women during the second or third decade of life. The mechanism is hypothesized to involve unregulated peripheral inflammation resulting in blood-brain barrier damage, and eventual axonal damage and demyelination. Based on this understanding, the animal model of MS, experimental autoimmune encephalomyelitis (EAE), often is utilized to study lymphocyte activation. Therapeutic paradigms of exogenous opioid growth factor (OGF) or low-dose naltrexone (LDN) treatment can modulate EAE, but little is reported regarding OGF or LDN effects on peripheral inflammation, microglia activation, and/or macrophage proliferation. Moreover, little is known about differential responses to LDN or OGF relative to the duration and timing of treatment. Utilizing a female mouse model of EAE, two treatment regimens were established to investigate differences between prophylactic treatment and traditional therapy initiated at the time of disease presentation. Prophylactic OGF or LDN treatment delayed the onset of behavior, suppressed neutrophil replication, and curtailed lymphocyte proliferation which ultimately improved behavioral outcome. Traditional therapy with OGF or LDN reversed behavioral deficits, restored OGF and IL-17 serum levels, and inhibited microglial activation within 8 days. Reduced serum OGF levels in untreated EAE mice correlated with increased microglia activation within lumbar spinal cords. Both treatment regimens of OGF or LDN reduced activated microglia, whereas only prophylactic treatment prevented CNS macrophage aggregation. These data demonstrate that the timing of LDN or OGF treatment initiation alters outcomes and can prevent or reverse behavioral deficits, cytokine activation, and spinal cord pathology.

Construction of a lncRNA-miRNA-mRNA network to determine the key regulators of the Th1/Th2 imbalance in multiple sclerosis

Aim: The exact epigenetic mechanisms that determine the balance of T helper (Th)1 and Th2 cells and autoimmune responses in multiple sclerosis (MS) remain unclear. We aim to clarify these. Methods: A combination of bioinformatics analysis and molecular evaluations was utilized to identify master hub genes. Results: A competitive endogenous RNA network containing six long noncoding RNAs (lncRNAs), 21 miRNAs and 86 mRNAs was provided through enrichment analysis and a protein-protein interaction network. NEAT1 and MALAT1 were found as differentially expressed lncRNAs using Gene Expression Omnibus (GSE21942). Quantitative real-time PCR results demonstrate dysregulation in the RUNX3 (a regulator of Th1/Th2 balance), GATA3 and TBX21, as well as miR-544a and miR-210-3p (which directly target RUNX3). ELISA also confirmed an imbalance in IFN-γ (Th1)/IL-4 (Th2) in MS patients. Conclusion: Our findings introduce novel biomarkers leading to Th1/Th2 imbalance in MS.

Th17-Related Cytokines as Potential Discriminatory Markers between Neuromyelitis Optica (Devic's Disease) and Multiple Sclerosis-A Review

Multiple sclerosis (MS) and Devic’s disease (NMO; neuromyelitis optica) are autoimmune, inflammatory diseases of the central nervous system (CNS), the etiology of which remains unclear. It is a serious limitation in the treatment of these diseases. The resemblance of the clinical pictures of these two conditions generates a partial possibility of introducing similar treatment, but on the other hand, a high risk of misdiagnosis. Therefore, a better understanding and comparative characterization of the immunopathogenic mechanisms of each of these diseases are essential to improve their discriminatory diagnosis and more effective treatment. In this review, special attention is given to Th17 cells and Th17-related cytokines in the context of their potential usefulness as discriminatory markers for MS and NMO. The discussed results emphasize the role of Th17 immune response in both MS and NMO pathogenesis, which, however, cannot be considered without taking into account the broader perspective of immune response mechanisms.

Anti-inflammatory Therapy by Cholinergic and Purinergic Modulation in Multiple Sclerosis Associated with SARS-CoV-2 Infection

The virus "acute respiratory syndrome coronavirus 2" (SARS-CoV-2) is the etiologic agent of coronavirus disease 2019 (COVID-19), initially responsible for an outbreak of pneumonia in Wuhan, China, which, due to the high level of contagion and dissemination, has become a pandemic. The clinical picture varies from mild to critical cases; however, all of these signs already show neurological problems, from sensory loss to neurological diseases. Thus, patients with multiple sclerosis (MS) infected with the new coronavirus are more likely to develop severe conditions; in addition to worsening the disease, this is due to the high level of pro-inflammatory cytokines, which is closely associated with increased mortality both in COVID-19 and MS. This increase is uncontrolled and exaggerated, characterizing the cytokine storm, so a possible therapy for this neuronal inflammation is the modulation of the cholinergic anti-inflammatory pathway, since acetylcholine (ACh) acts to reduce pro-inflammatory cytokines and acts directly on the brain for being released by cholinergic neurons, as well as acting on other cells such as immune and blood cells. In addition, due to tissue damage, there is an exacerbated release of adenosine triphosphate (ATP), potentiating the inflammatory process and activating purinergic receptors which act directly on neuroinflammation and positively modulate the inflammatory cycle. Associated with this, in neurological pathologies, there is greater expression of P2X7 in the cells of the microglia, which positively activates the immune inflammatory response. Thus, the administration of blockers of this receptor can act in conjunction with the action of ACh in the anticholinergic inflammatory pathway. Finally, there will be a reduction in the cytokine storm and triggered hyperinflammation, as well as the level of mortality in patients with multiple sclerosis infected with SARS-CoV-2 and the development of possible neurological damage.

Immunomodulation with IL-17 and TNF-α in spondyloarthritis: focus on the eye and the central nervous system

Tumor necrosis factor alpha (TNF-α) and interleukin-17 (IL-17) are two pro-inflammatory cytokines involved in the pathophysiology of spondyloarthritis (SpA). Therapies targeting TNF-α or IL-17 are used as a second line among SpA patients failing non-steroidal anti-inflammatory drugs. The choice of such treatment has to take into account the patient’s comorbidities. Neurologic diseases are common and their association with SpA deserves to be studied. Therefore, the role of TNF-α and IL-17 cytokines is worth investigating in these neuropsychiatric diseases. This review aimed to explore the role of TNF-α and IL-17 in the pathogenesis of uveitis, multiple sclerosis, neuromyelitis optica, Alzheimer’s disease, Parkinson’s disease and depression. This update is critical to guide the therapeutic management of these co-morbidities in SpA patients.