Relapsing-remitting multiple sclerosis patients exhibit differential natural killer functional subpopulations.

BACKGROUND: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) and has been known as T-cell mediated. However, the contribution of multiple cell types, notably natural killer (NK) cells, has also been reported. AIM: To quantify circulating total NK cells and its subpopulations, CD56 dim and bright, and to characterize the functional phenotype and IFN-γ and TNF-α production in relapsing-remitting patients treated with IFN-ß and in apparently healthy controls. RESULTS: CD56bright NK cells were found to be the least represented subpopulation. In relapse patients, the frequencies of IFN-γ-producing NK cells and their subpopulations were significantly decreased. In remission patients, CD56dim NK cells expressed high levels of HLA-DR and CD54. CONCLUSION: These results suggest that remission RRMS patients, although in an inactive stage of MS, present circulating NK cells with an activation phenotype, supporting the idea that NK cells may be relevant mediators in the MS pathophysiology.

In Silico Analysis Highlights Potential Predictive Indicators Associated with Secondary Progressive Multiple Sclerosis.

Multiple sclerosis (MS) is a complex inflammatory disease affecting the central nervous system. Most commonly, it begins with recurrent symptoms followed by partial or complete recovery, known as relapsing-remitting MS (RRMS). Over time, many RRMS patients progress to secondary progressive MS (SPMS), marked by gradual symptom deterioration. The factors triggering this transition remain unknown, lacking predictive biomarkers. This study aims to identify blood biomarkers specific to SPMS. We analyzed six datasets of SPMS and RRMS patients' blood and brain tissues, and compared the differential expressed genes (DEGs) obtained to highlight DEGs reflecting alterations occurring in both brain and blood tissues and the potential biological processes involved. We observed a total of 38 DEGs up-regulated in both blood and brain tissues, and their interaction network was evaluated through network analysis. Among the aforementioned DEGs, 21 may be directly involved with SPMS transition. Further, we highlighted three biological processes, including the calcineurin-NFAT pathway, related to this transition. The investigated DEGs may serve as a promising means to monitor the transition from RRMS to SPMS, which is still elusive. Given that they can also be sourced from blood samples, this approach could offer a relatively rapid and convenient method for monitoring MS and facilitating expedited assessments.

Serum glial fibrillary acidic protein in natalizumab-treated relapsing-remitting multiple sclerosis: An alternative to neurofilament light.

BACKGROUND: There is a need in Relapsing-Remitting Multiple Sclerosis (RRMS) treatment for biomarkers that monitor neuroinflammation, neurodegeneration, treatment response, and disease progression despite treatment. OBJECTIVE: To assess the value of serum glial fibrillary acidic protein (sGFAP) as a biomarker for clinical disease progression and brain volume measurements in natalizumab-treated RRMS patients. METHODS: sGFAP and neurofilament light (sNfL) were measured in an observational cohort of natalizumab-treated RRMS patients at baseline, +3, +12, and +24 months and at the last sample follow-up (median 5.17 years). sGFAP was compared between significant clinical progressors and non-progressors and related to magnetic resonance imaging (MRI)-derived volumes of the whole brain, ventricle, thalamus, and lesion. The relationship between sGFAP and sNfL was assessed. RESULTS: A total of 88 patients were included, and 47.7% progressed. sGFAP levels at baseline were higher in patients with gadolinium enhancement (1.3-fold difference, p = 0.04) and decreased in 3 months of treatment (adj. p < 0.001). No association was found between longitudinal sGFAP levels and progressor status. sGFAP at baseline and 12 months was significantly associated with normalized ventricular (positively), thalamic (negatively), and lesion volumes (positively). Baseline and 12-month sGFAP predicted annualized ventricle volume change rate after 1 year of treatment. sGFAP correlated with sNfL at baseline (p < 0.001) and last sample follow-up (p < 0.001) but stabilized earlier. DISCUSSION: sGFAP levels related to MRI markers of neuroinflammation and neurodegeneration.

Early derangement of axonal mitochondria occurs in a mouse model of progressive but not relapsing-remitting multiple sclerosis.

INTRODUCTION: Derangement of axonal mitochondrial bioenergetics occurs during progressive multiple sclerosis (PMS). However, whether this is a delayed epiphenomenon or an early causative event of disease progression waits to be understood. Answering this question might further our knowledge of mechanisms underlying neurobiology of PMS and related therapy. METHODS: MOG35-55-immunized NOD and PLP139-151-immunized SJL female mice were adopted as models of progressive or relapsing-remitting experimental autoimmune encephalomyelitis (EAE), respectively. Multiple parameters of mitochondrial homeostasis were analyzed in the mouse spinal cord during the early asymptomatic stage, also evaluating the effects of scavenging mitochondrial reactive oxygen species with Mito-TEMPO. RESULTS: Almost identical lumbar spinal cord immune infiltrates consisting of Th1 cells and neutrophils without B and Th17 lymphocytes occurred early upon immunization in both mouse strains. Still, only NOD mice showed axon-restricted dysregulation of mitochondrial homeostasis, with reduced mtDNA contents and increased cristae area. Increased expression of mitochondrial respiratory complex subunits Nd2, Cox1, Atp5d, Sdha also exclusively occurred in lumbar spinal cord of NOD and not SJL mice. Accordingly, in this region genes regulating mitochondrial morphology (Opa1, Mfn1, Mfn2 and Atp5j2) and mitochondriogenesis (Pgc1α, Foxo, Hif-1α and Nrf2) were induced early upon immunization. A reduced extent of mitochondrial derangement occurred in the thoracic spinal cord. Notably, the mitochondrial radical scavenger Mito-TEMPO reduced H2O2 content and prevented both mtDNA depletion and cristae remodeling, having no effects on dysregulation of mitochondrial transcriptome. DISCUSSION: We provide here the first evidence that axonal-restricted derangement of mitochondrial homeostasis already occurs during the asymptomatic state exclusively in a mouse model of PMS. Data further our understanding of mechanisms related to EAE progression, and point to very early axonal mitochondrial dysfunction as central to the neuropathogenesis of MS evolution.

[Gut microbiota in patients with relapsing-remitting multiple sclerosis]. / Mikrobiota kishechnika u patsientov s remittiruyushchim rasseyannym sklerozom.

Microorganisms in human life play a huge role: in particular, those that coexist with the host organism, inhabiting the skin, upper respiratory tract, external genitalia and especially the digestive tract. The intestinal microbiota, including bacteriome, mycobiome and virome, not only takes part in the digestion process, but also provides the synthesis of a number of vitamins. The intestinal microbiome also serves as the basis for a system of extensive bidirectional neuroendocrine pathways that connect microbiota with various regions of the central nervous system, the hypothalamic-pituitary-adrenal system, and the peripheral parts of the autonomic nervous system. This system of connections has got the name of gut-brain axis and has attracted close attention of scientists over the past two decades, since a targeted impact on the intestinal flora is potentially capable of changing the nature of nervous system regulatory influences on the whole body. It is especially important to study patterns of functioning of the gut-brain axis in patients with the nervous system pathology, namely neurodegenerative and demyelinating diseases. Methods for their treatment continue to improve, and perhaps the correction of the gut microbiotic composition will serve as an additional therapeutic approach. The review article describes current views on the role of the intestinal microbiota, provides the latest data on the composition of bacteriome, mycobiome, and virome in patients with relapsing-remitting multiple sclerosis.

Blood-based untargeted metabolomics in relapsing-remitting multiple sclerosis revealed the testable therapeutic target.

Metabolic aberrations impact the pathogenesis of multiple sclerosis (MS) and possibly can provide clues for new treatment strategies. Using untargeted metabolomics, we measured serum metabolites from 35 patients with relapsing-remitting multiple sclerosis (RRMS) and 14 healthy age-matched controls. Of 632 known metabolites detected, 60 were significantly altered in RRMS. Bioinformatics analysis identified an altered metabotype in patients with RRMS, represented by four changed metabolic pathways of glycerophospholipid, citrate cycle, sphingolipid, and pyruvate metabolism. Interestingly, the common upstream metabolic pathway feeding these four pathways is the glycolysis pathway. Real-time bioenergetic analysis of the patient-derived peripheral blood mononuclear cells showed enhanced glycolysis, supporting the altered metabolic state of immune cells. Experimental autoimmune encephalomyelitis mice treated with the glycolytic inhibitor 2-deoxy-D-glucose ameliorated the disease progression and inhibited the disease pathology significantly by promoting the antiinflammatory phenotype of monocytes/macrophage in the central nervous system. Our study provided a proof of principle for how a blood-based metabolomic approach using patient samples could lead to the identification of a therapeutic target for developing potential therapy.

Genome-wide DNA methylation profiling identifies epigenetic changes in CD4+ and CD14+ cells of multiple sclerosis patients.

Multiple sclerosis (MS) is a chronic autoimmune and degenerative disease of the central nervous system, which develops in genetically predisposed individuals upon exposure to environmental influences. Environmental triggers of MS, such as viral infections or smoking, were demonstrated to affect DNA methylation, and thus to involve this important epigenetic mechanism in the development of pathological process. To identify MS-associated DNA methylation hallmarks, we performed genome-wide DNA methylation profiling of two cell populations (CD4+ T-lymphocytes and CD14+ monocytes), collected from the same treatment-naive relapsing-remitting MS patients and healthy subjects, using Illumina 450 K methylation arrays. We revealed significant changes in DNA methylation for both cell populations in MS. In CD4+ cells of MS patients the majority of differentially methylated positions (DMPs) were shown to be hypomethylated, while in CD14+ cells - hypermethylated. Differential methylation of HLA-DRB1 gene in CD4+ and CD14+ cells was associated with carriage of DRB1*15 allele independently from the disease status. Besides, about 20% of identified DMPs were shared between two cell populations and had the same direction of methylation changes; they may be involved in basic epigenetic processes occuring in MS. These findings suggest that the epigenetic mechanism of DNA methylation in immune cells contributes to MS; further studies are now required to validate these results and understand their functional significance.

The Modulatory Effects of DMF on Microglia in Aged Mice Are Sex-Specific.

There is a striking sex-related difference in the prevalence of many neurodegenerative diseases, highlighting the need to consider whether treatments may exert sex-specific effects. A change in microglial activation state is a common feature of several neurodegenerative diseases and is considered to be a key factor in driving the inflammation that characterizes these conditions. Among the changes that have been described is a switch in microglial metabolism towards glycolysis which is associated with production of inflammatory mediators and reduced function. Marked sex-related differences in microglial number, phenotype and function have been described in late embryonic and early postnatal life in rodents and some reports suggest that sexual dimorphism extends into adulthood and age and, in models of Alzheimer's disease, the changes are more profound in microglia from female, compared with male, mice. Dimethyl fumarate (DMF) is a fumaric acid ester used in the treatment of psoriasis and relapsing remitting multiple sclerosis and, while its mechanism of action is unclear, it possesses anti-inflammatory and anti-oxidant properties and also impacts on cell metabolism. Here we treated 16-18-month-old female and male mice with DMF for 1 month and assessed its effect on microglia. The evidence indicates that it exerted sex-specific effects on microglial morphology and metabolism, reducing glycolysis only in microglia from female mice. The data suggest that this may result from its ability to inactivate glyceraldehyde-3-phosphate dehydrogenase (GAPDH).

Neurocognitive performance in relapsing-remitting multiple sclerosis patients is associated with metabolic abnormalities of the thalamus but not the hippocampus- GABA-edited 1H MRS study.

OBJECTIVES: Multiple sclerosis (MS) is an inflammatory demyelinating disease that may cause physical disabling as well as cognitive dysfunction. The presented study investigated how the neuropsychological status depends on the thalamus and hippocampus's metabolic processes, using γ-aminobutyric acid-edited magnetic resonance spectroscopy (GABA-edited 1H MRS) in patients with early MS, and how the results differ from healthy volunteers. METHODS: We recruited 36 relapsing-remitting (RRMS) MS patients and 22 controls (CON). In addition to common 1H MRS metabolites, such as N-acetyl-aspartate (tNAA), myoinositol (mIns), total choline and creatine (tCr, tCho), we also evaluated GABA and glutamate/glutamine (Glx). Metabolite ratios were correlated with the results of Single-Digit Modality Test (SDMT) and Expanded Disability Status Score (EDSS). RESULTS: In the thalamus, GABA ratios (GABA/tCr, GABA/tNAA) were significantly lower in RRMS patients than in CON. Both tCho- and mIns-ratios correlated with lower scores of SDMT but not with EDSS. Metabolic ratios in the hippocampus did not differ between RRMS and CON and did not correlate with any of performed tests. DISCUSSION: This study is the first to provide GABA-edited 1H MRS evidence for MS-related metabolic changes of the thalamus and hippocampus. The findings underline the importance of evaluating subcortical grey matter in MS patients to improve understanding of the clinical manifestations of MS and as a potential future target for treatment.

Downregulation of miR-125a-5p and miR-218-5p in Peripheral Blood Mononuclear Cells of Patients with Relapsing-Remitting Multiple Sclerosis.

Multiple sclerosis (MS) is a chronic neuroinflammatory disease of the brain and spinal cord. Evidences have demonstrated that microRNAs (miRNAs) are involved in the pathological process of MS that may confer a valuable diagnostic biomarker for disease diagnosis, prognosis, and treatment. Hence, we assessed the expression pattern of miR-125a-5p and miR-218-5p in the peripheral blood mononuclear cells (PBMCs) of subjects with relapsing-remitting multiple sclerosis (RRMS). We recruited 50 RRMS patients and 50 age- and sex-matched healthy control subjects. PBMCs were isolated from the peripheral blood samples, RNA content was extracted, cDNA was synthesized, and finally expression level of miRNAs was determined using quantitative real-time PCR. Our data indicate significant downregulation of both miR-125a-5p and miR-218-5p in RRMS patients compared to healthy controls (P< .0001). The levels of both miRNAs were significantly downregulated in an age-dependent manner compared with consistent healthy control groups (30-40 years old P< .0001). Expression level of miR-218-5p was significantly changed in only female patients (Female group P< .0001; Male group P= .12). Receiver operating characteristic (ROC) curve data indicated that the expression levels of both miRNAs were able to discriminate RRMS patients from healthy subjects (P< .05). Moreover, bioinformatic enrichment analysis revealed that the target genes of these miRNAs had cardinal roles in the regulation of key biological pathways involved in the clinical course and pathogenesis of MS. Collectively, our results suggested that miR-125a-5p and miR-218-5p play a role in RRMS pathogenesis and have an age- and sex-dependent expression pattern in these patients.

C1q inhibits differentiation of oligodendrocyte progenitor cells via Wnt/ß-catenin signaling activation in a cuprizone-induced mouse model of multiple sclerosis.

Multiple sclerosis (MS) is a chronic central nervous system demyelinating disease of autoimmune originate. Complement C1q, a complex glycoprotein, mediates a variety of immunoregulatory functions considered important in the prevention of autoimmunity. Although we found that the increased serum C1q level was highly associated with the Fazekas scores and T2 lesion volume of MS patients, the effect and mechanism of C1q on demyelination remains unclear. Cluster analysis and protein array results showed that serum Wnt receptors Frizzled-6 and LRP-6 levels in MS patients were both increased, we proposed that C1q may be involved in demyelination via Wnt signaling. The increased C1q protein levels in the serum and brain tissue were confirmed in a cuprizone (CPZ)-induced demyelination mice model. Moreover, CPZ treatment induced significant increase of LRP-6 and Frizzled-6 protein in mice corpus callosum. LRP-6 extra-cellular domain (LRP-6-ECD) level in the serum and cerebrospinal fluid (CSF) of CPZ mice also significantly increased. Knockdown of the subunit C1s of C1 not only substantially attenuated demyelination, promoted M2 microglia polarization and improved neurological function, but inhibited ß-catenin expression and its nuclear translocation in oligodendrocyte progenitor cells (OPCs). In vitro, C1s silence reversed the increased level of LRP-6-ECD in the medium and ß-catenin expression in OPCs induced by C1q treatment. Meanwhile, inhibition of C1s also markedly lowered the number of EDU positive OPCs, but enhanced the number of CNPase positive oligodendrocyte and the protein of MBP. The present study indicated that C1q was involved in demyelination in response to CPZ in mice by preventing OPC from differentiating into mature oligodendrocyte via Wnt/ß-catenin signaling activation.

Identification and Clinical Validation of Key Extracellular Proteins as the Potential Biomarkers in Relapsing-Remitting Multiple Sclerosis.

Background: Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS) mediated by autoimmunity. No objective clinical indicators are available for the diagnosis and prognosis of MS. Extracellular proteins are most glycosylated and likely to enter into the body fluid to serve as potential biomarkers. Our work will contribute to the in-depth study of the functions of extracellular proteins and the discovery of disease biomarkers. Methods: MS expression profiling data of the human brain was downloaded from the Gene Expression Omnibus (GEO). Extracellular protein-differentially expressed genes (EP-DEGs) were screened by protein annotation databases. GO and KEGG were used to analyze the function and pathway of EP-DEGs. STRING, Cytoscape, MCODE and Cytohubba were used to construct a protein-protein interaction (PPI) network and screen key EP-DEGs. Key EP-DEGs levels were detected in the CSF of MS patients. ROC curve and survival analysis were used to evaluate the diagnostic and prognostic ability of key EP-DEGs. Results: We screened 133 EP-DEGs from DEGs. EP-DEGs were enriched in the collagen-containing extracellular matrix, signaling receptor activator activity, immune-related pathways, and PI3K-Akt signaling pathway. The PPI network of EP-DEGs had 85 nodes and 185 edges. We identified 4 key extracellular proteins IL17A, IL2, CD44, IGF1, and 16 extracellular proteins that interacted with IL17A. We clinically verified that IL17A levels decreased, but Del-1 and resolvinD1 levels increased. The diagnostic accuracy of Del-1 (AUC: 0.947) was superior to that of IgG (AUC: 0.740) with a sensitivity of 82.4% and a specificity of 100%. High Del-1 levels were significantly associated with better relapse-free and progression-free survival. Conclusion: IL17A, IL2, CD44, and IGF1 may be key extracellular proteins in the pathogenesis of MS. IL17A, Del-1, and resolvinD1 may co-regulate the development of MS and Del-1 is a potential biomarker of MS. We used bioinformatics methods to explore the biomarkers of MS and validated the results in clinical samples. The study provides a theoretical and experimental basis for revealing the pathogenesis of MS and improving the diagnosis and prognosis of MS.

Dimethyl fumarate treatment restrains the antioxidative capacity of T cells to control autoimmunity.

Dimethyl fumarate, an approved treatment for relapsing-remitting multiple sclerosis, exerts pleiotropic effects on immune cells as well as CNS resident cells. Here, we show that dimethyl fumarate exerts a profound alteration of the metabolic profile of human CD4+ as well as CD8+ T cells and restricts their antioxidative capacities by decreasing intracellular levels of the reactive oxygen species scavenger glutathione. This causes an increase in mitochondrial reactive oxygen species levels accompanied by an enhanced mitochondrial stress response, ultimately leading to impaired mitochondrial function. Enhanced mitochondrial reactive oxygen species levels not only result in enhanced T-cell apoptosis in vitro as well as in dimethyl fumarate-treated patients, but are key for the well-known immunomodulatory effects of dimethyl fumarate both in vitro and in an animal model of multiple sclerosis, i.e. experimental autoimmune encephalomyelitis. Indeed, dimethyl fumarate immune-modulatory effects on T cells were completely abrogated by pharmacological interference of mitochondrial reactive oxygen species production. These data shed new light on dimethyl fumarate as bona fide immune-metabolic drug that targets the intracellular stress response in activated T cells, thereby restricting mitochondrial function and energetic capacity, providing novel insight into the role of oxidative stress in modulating cellular immune responses and T cell-mediated autoimmunity.

Methylprednisolone stimulated gene expression (GILZ, MCL-1) and basal cortisol levels in multiple sclerosis patients in relapse are associated with clinical response.

Glucocorticoids (GCs) are the main treatment of relapse in multiple sclerosis (MS). Decreased sensitivity to GCs in MS patients has been associated with lack of the suppressive effect of GCs on inflammatory molecules as well as increased resistance to apoptosis. We investigated GC-sensitivity by measuring the effect of intravenous methylprednisolone (IVMP) treatment on transactivation of anti-inflammatory and apoptotic genes (GILZ, MCL-1 and NOXA respectively), in accordance to clinical outcome. Thirty nine MS patients were studied: 15 with clinically isolated syndrome (CIS), 12 with relapsing remitting (RRMS) and 12 with secondary progressive (SPMS) under relapse. Patients underwent treatment with IVMP for 5 days. Blood was drawn before IVMP treatment on day 1 and 1 h after IVMP treatment on days 1 and 5. GIlZ, MCL-1 and NOXA were determined by qPCR. The Expanded Disability Status was evaluated and patients were divided according to their clinical response to IVMP. GILZ and MCL-1 gene expression were significantly higher following first IVMP treatment in responders, compared to non-responders. Furthermore, serum basal cortisol and 1,25-OH Vitamin D levels were significantly higher in clinical-responders as compared to non-clinical responders. Our findings suggest that the differential GILZ and MCL-1 gene expression between clinical-responders and non-clinical responders may implicate the importance of GILZ and MCL-1 as possible markers for predicting glucocorticoid sensitivity and response to GC-therapy in MS patients following first IVMP injection.

Changes in DNA methylation in APOE and ACKR3 genes in multiple sclerosis patients and the relationship with their heavy metal blood levels.

Multiple sclerosis (MS) is a chronic inflammatory disease with demyelinated lesions in the central nervous system caused by genetic and environmental factors. DNA methylation as an epigenetic change influenced by environmental factors, including heavy metals has been implemented in MS disease. We investigated the correlation of DNA methylation changes in APOE and ACKR3 genes in MS patients and the possible association with blood concentration of arsenic (As), cadmium (Cd) and lead (Pb) as major heavy metal pollutants. This study included 69 relapsing-remitting multiple sclerosis (RR-MS) patients and 69 age/gender-matched healthy subjects. The HRM real-time PCR method was used to investigate the changes in DNA methylation and heavy metal concentrations were measured by electrothermal atomic absorption spectrometry. Our results showed that the methylation pattern in the ACKR3 gene of the patient group was more hypomethylated, while in the case of the APOE gene, this pattern was more towards hypermethylation compared to healthy subjects. Moreover, the blood levels of As and Cd metals, but not Pb, were significantly higher in the patient group compare to the control group (p ≤ 0.05). The data indicate that the increase in expression of ACKR3 gene by hypomethylation and the decrease in expression of APOE gene via hypermethylation are possibly involved in the onset and progression of inflammatory processes in MS patients. The level of As can also lead to hypomethylation by disrupting the methylation patterns of the ACKR3 gene, resulting in increased expression in MS patients. Finally, we have shown that epigenetic changes can be an important factor in increasing and decreasing the expression of genes involved in the onset and/or progression of inflammatory processes in MS. Furthermore, exposure to heavy metals, especially As, by changing the natural patterns of DNA methylation can be effective in this disease.

Combined Training Improves the Expression Profile of Inflammation-associated Antimicrobial Peptides, MicroRNAs, and TLR-4 in Patients with Multiple Sclerosis.

Some antimicrobial peptides (AMPs), microRNAs (miRs), and Toll-like receptor 4 (TLR-4) are involved in autoimmune diseases, which may be affected by exercise training. The purpose of this study was to investigate the effect of an eight-week combined exercise training (aerobic and resistance) on the expression of inflammatory factors, including, human beta-defensin-2 (hBD-2), cathelicidin (LL-37), TLR-4, miR-23b, miR-155, and miR-326 in women with relapsing and remitting multiple sclerosis (RRMS), which has not been investigated yet. Twenty-three women (20-40 years) with RRMS were randomized into the combined training (CT) and control (CON) groups. The CT group subjects completed eight weeks of supervised CT using a treadmill and stationary bicycle for aerobic exercise and weight machines for resistance exercise. The expression levels of hBD-2, LL-37, TLR-4, miR-23b, miR-155, and miR-326 were measured by real-time polymerase chain reaction (RT-PCR) at the baseline and end of the study. Although the expression of hBD-2 and miR-23b decreased in both CT and CON groups, the reduction was lower in the CT group than in the CON group (p=0.001). The expression of LL-37 in the CT group remained unchanged, but that of the CON group increased; thus, the between-group difference was significant. Although the TLR-4, miR-155, and miR-326 expression increased in both groups compared to the baseline, the increase in the CT group was lower than the CON group. Our results showed that the combined training might improve inflammatory symptoms by affecting the expression of some AMPs, miRs, and TLR-4 in patients with relapsing and remitting multiple sclerosis.

Skin sodium is increased in male patients with multiple sclerosis and related animal models.

Novel MRI techniques allow a noninvasive quantification of tissue sodium and reveal the skin as a prominent compartment of sodium storage in health and disease. Since multiple sclerosis (MS) immunopathology is initiated in the periphery and increased sodium concentrations induce proinflammatory immune cells, the skin represents a promising compartment linking high sodium concentrations and MS immunopathology. We used a 7-T sodium MRI (23Na-MRI) and inductively coupled plasma mass spectrometry to investigate the skin sodium content in two mouse models of MS. We additionally performed 3-T 23Na-MRI of calf skin and muscles in 29 male relapsing-remitting MS (RRMS) patients and 29 matched healthy controls. Demographic and clinical information was collected from interviews, and disease activity was assessed by expanded disability status scale scoring. 23Na-MRI and chemical analysis demonstrated a significantly increased sodium content in the skin during experimental autoimmune encephalomyelitis independent of active immunization. In male patients with RRMS, 23Na-MRI demonstrated a higher sodium signal in the area of the skin compared to age- and biological sex-matched healthy controls with higher sodium, predicting future disease activity in cranial MRI. In both studies, the sodium enrichment was specific to the skin, as we found no alterations of sodium signals in the muscle or other tissues. Our data add to the recently identified importance of the skin as a storage compartment of sodium and may further represent an important organ for future investigations on salt as a proinflammatory agent driving autoimmune neuroinflammation such as that in MS.

RNA Sequencing of CD4+ T Cells in Relapsing-Remitting Multiple Sclerosis Patients at Relapse: Deciphering the Involvement of Novel genes and Pathways.

CD4+ T cells are known as a noteworthy potential modulator of inflammation in multiple sclerosis (MS). In the current study, we investigated the transcriptome profile of CD4+ T cells in patients with relapsing-remitting MS (RRMS) at the relapse phase. We performed RNA sequencing of CD4+ T cells isolated from four relapsing-remitting MS (RRMS) patients at the relapse phase and four age- and sex-matched healthy controls. The edgeR statistical method was employed to determine differentially expressed genes (DEGs). Gene set enrichment analysis was subsequently performed. Applying a physical interaction network, genes with higher degrees were selected as hub genes. A total of 1278 and 1034 genes were defined at significantly higher or lower levels, respectively, in CD4+ T cells of RRMS patients at the relapse phase as compared with healthy controls. The top up- and downregulated genes were JAML and KDM3A. The detected DEGs were remarkable on chromosomes 1 and 2, respectively. The DEGs were mainly enriched in the pathways "regulation of transcription, DNA-templated," "regulation of B cell receptor signaling pathway," "protein phosphorylation," "epidermal growth factor receptor signaling pathway," and "positive regulation of neurogenesis." Moreover, 16 KEGG pathways mostly associated with the immune system and viral infections were enriched. In the constructed physical interaction networks, UBA52 and TP53 were shown to be the most highly ranked hub genes among upregulated and downregulated genes, respectively. By applying global transcriptome profiling of CD4+ T cells, we deciphered the involvement of several novel genes and pathways in MS pathogenesis. The present results must be confirmed by in vivo and in vitro studies.

In vivo evidence of differential frontal cortex metabolic abnormalities in progressive and relapsing-remitting multiple sclerosis.

The pathophysiology of progressive multiple sclerosis remains elusive, significantly limiting available disease-modifying therapies. Proton MRS (1 H-MRS) enables in vivo measurement of small molecules implicated in multiple sclerosis, but its application to key metabolites glutamate, γ-aminobutyric acid (GABA), and glutathione has been sparse. We employed, at 7 T, a previously validated 1 H-MRS protocol to measure glutamate, GABA, and glutathione, as well as glutamine, N-acetyl aspartate, choline, and myoinositol, in the frontal cortex of individuals with relapsing-remitting (N = 26) or progressive (N = 21) multiple sclerosis or healthy control adults (N = 25) in a cross-sectional analysis. Only individuals with progressive multiple sclerosis demonstrated reduced glutamate (F2,65 = 3.424, p = 0.04; 12.40 ± 0.62 mM versus control 13.17 ± 0.95 mM, p = 0.03) but not glutamine (F2,65 = 0.352, p = 0.7; 4.71 ± 0.35 mM versus control 4.84 ± 0.42 mM), reduced GABA (F2,65 = 3.89, p = 0.03; 1.29 ± 0.23 mM versus control 1.47 ± 0.25 mM, p = 0.05), and possibly reduced glutathione (F2,65 = 0.352, p = 0.056; 2.23 ± 0.46 mM versus control 2.51 ± 0.48 mM, p < 0.1). As a group, multiple sclerosis patients demonstrated significant negative correlations between disease duration and glutamate or GABA (ρ = -0.4, p = 0.02) but not glutamine or glutathione. Alone, only relapsing-remitting multiple sclerosis patients exhibited a significant negative correlation between disease duration and GABA (ρ = -0.5, p = 0.03). Taken together, these results indicate that frontal cortex metabolism is differentially disturbed in progressive and relapsing-remitting multiple sclerosis.

An In-vivo 1H-MRS short-echo time technique at 7T: Quantification of metabolites in chronic multiple sclerosis and neuromyelitis optica brain lesions and normal appearing brain tissue.

Magnetic Resonance Spectroscopy (MRS) allows for the non-invasive quantification of neurochemicals and has the potential to differentiate between the pathologically distinct diseases, multiple sclerosis (MS) and AQP4Ab-positive neuromyelitis optica spectrum disorder (AQP4Ab-NMOSD). In this study we characterised the metabolite profiles of brain lesions in 11 MS and 4 AQP4Ab-NMOSD patients using an optimised MRS methodology at ultra-high field strength (7T) incorporating correction for T2 water relaxation differences between lesioned and normal tissue. MS metabolite results were in keeping with the existing literature: total N-acetylaspartate (NAA) was lower in lesions compared to normal appearing brain white matter (NAWM) with reciprocal findings for myo-Inositol. An unexpected subtlety revealed by our technique was that total NAA differences were likely driven by NAA-glutamate (NAAG), a ubiquitous CNS molecule with functions quite distinct from NAA though commonly quantified together with NAA in MRS studies as total NAA. Surprisingly, AQP4Ab-NMOSD showed no significant differences for total NAA, NAA, NAAG or myo-Inositol between lesion and NAWM sites, nor were there any differences between MS and AQP4Ab-NMOSD for a priori hypotheses. Post-hoc testing revealed a significant correlation between NAWM Ins:NAA and disability (as measured by EDSS) for disease groups combined, driven by the AP4Ab-NMOSD group. Utilising an optimised MRS methodology, our study highlights some under-explored subtleties in MRS profiles, such as the absence of myo-Inositol concentration differences in AQP4Ab-NMOSD brain lesions versus NAWM and the potential influence of NAAG differences between lesions and normal appearing white matter in MS.