Interdependency of NINJ2 gene expression and polymorphism with susceptibility and response to interferon beta in patients with multiple sclerosis

OBJECTIVE

Multiple sclerosis (MS) is a multifactorial inflammatory and autoimmune condition that lead to chronic neurodegeneration and central nervous system (CNS) demyelination that mainly affects young adults. The incidence and prevalence rate of MS considerably vary in ethnicities and geographic regions and affecting women more than men. Interferon-β (IFN-β) is the first-line disease management for MS, while the majority of affected members does not respond to the IFN-β. Numerous recent studies shown a significant relationship between genetic variations and responsiveness to the IFN-β. Therefore, determining the genetic differences in the drug response could help determine precise treatment strategies.

METHODS

The genotyping of the rs7298096 polymorphism (SNP) and NINJ2 gene expression were assessed in 99 responders and 106 non-responder patients with IFN-β treated RRMS.

RESULTS

The distribution of rs7298096 SNP was significantly different in the responders and non-responder patients and the NINJ2 gene expression considerably increased in the non-responder patients compare to the responders. The NINJ2 gene expression level in the AA genotype of the non-responder group was higher than to the other genotypes of both groups.

CONCLUSION

Our results showed that the NINJ2 gene expression level and rs7298096 genotype possibly affect the response to the IFN-β in patients with RRMS.

CD4+ T cell mitochondrial genotype in Multiple Sclerosis: a cross-sectional and longitudinal analysis

Multiple Sclerosis (MS) is a chronic autoimmune demyelinating disease of the central nervous system (CNS), with a largely unknown etiology, where mitochondrial dysfunction likely contributes to neuroaxonal loss and brain atrophy. Mirroring the CNS, peripheral immune cells from patients with MS, particularly CD4+ T cells, show inappropriate mitochondrial phenotypes and/or oxidative phosphorylation (OxPhos) insufficiency, with a still unknown contribution of mitochondrial DNA (mtDNA). We hypothesized that mitochondrial genotype in CD4+ T cells might influence MS disease activity and progression. Thus, we performed a retrospective cross-sectional and longitudinal study on patients with a recent diagnosis of either Clinically Isolated Syndrome (CIS) or Relapsing-Remitting MS (RRMS) at two timepoints: 6 months (VIS1) and 36 months (VIS2) after disease onset. Our primary outcomes were the differences in mtDNA extracted from CD4+ T cells between: (I) patients with CIS/RRMS (PwMS) at VIS1 and age- and sex-matched healthy controls (HC), in the cross-sectional analysis, and (II) different diagnostic evolutions in PwMS from VIS1 to VIS2, in the longitudinal analysis. We successfully performed mtDNA whole genome sequencing (mean coverage: 2055.77 reads/base pair) in 183 samples (61 triplets). Nonetheless, mitochondrial genotype was not associated with a diagnosis of CIS/RRMS, nor with longitudinal diagnostic evolution.

Response to Fingolimod in Multiple Sclerosis Patients Is Associated with a Differential Transcriptomic Regulation

Fingolimod is an immunomodulatory sphingosine-1-phosphate (S1P) analogue approved for the treatment of relapsing-remitting multiple sclerosis (RRMS). The identification of biomarkers of clinical responses to fingolimod is a major necessity in MS to identify optimal responders and avoid the risk of disease progression in non-responders. With this aim, we used RNA sequencing to study the transcriptomic changes induced by fingolimod in peripheral blood mononuclear cells of MS-treated patients and their association with clinical response. Samples were obtained from 10 RRMS patients (five responders and five non-responders) at baseline and at 12 months of fingolimod therapy. Fingolimod exerted a vast impact at the transcriptional level, identifying 7155 differentially expressed genes (DEGs) compared to baseline that affected the regulation of numerous signaling pathways. These DEGs were predominantly immune related, including genes associated with S1P metabolism, cytokines, lymphocyte trafficking, master transcription factors of lymphocyte functions and the NF-kB pathway. Responder and non-responder patients exhibited a differential transcriptomic regulation during treatment, with responders presenting a higher number of DEGs (6405) compared to non-responders (2653). The S1P, NF-kB and TCR signaling pathways were differentially modulated in responder and non-responder patients. These transcriptomic differences offer the potential of being exploited as biomarkers of a clinical response to fingolimod.

Expression analysis of vitamin D receptor-associated long noncoding RNAs in patients with relapsing-remitting multiple sclerosis

BACKGROUND

Vitamin D is a neuroactive steroid that carries out its biological functions through the vitamin D receptor (VDR). The VDR gene interacts with certain long noncoding RNAs (lncRNAs). The present study is aimed at evaluating the expression levels of the VDR gene as well as those of HOTAIR, H19, MALAT1, and P21 lncRNAs in patients with relapsing-remitting multiple sclerosis (RRMS).

METHODS

This research was conducted on 38 RRMS patients and 38 healthy individuals. The expression levels of VDR and selected lncRNAs in peripheral blood as well as those of vitamin D in the plasma were measured.

RESULTS

The results revealed a significant increase in the expression of lncRNA H19 in the RRMS group compared to the control group. The analysis of the receiver operating characteristic (ROC) curve for H19 gene expression demonstrated a diagnostic value of 0.699 (95% CI: 0.575-0.823). Positive correlations were detected between VDR and lncRNA HOTAIR (r = 0.446, p = 0.008), H19 (r = 0.351, p = 0.042), MALAT1 (r = 0.464, p = 0.006), and P21 (r = 0.512, p = 0.002) in MS patients.

CONCLUSION

The findings of this study suggest that lncRNA H19 could serve as a potential biomarker for MS diagnosis (Tab. 4, Fig. 1, Ref. 34).

Cladribine and ocrelizumab induce differential miRNA profiles in peripheral blood mononucleated cells from relapsing-remitting multiple sclerosis patients

Background and objectives

Multiple sclerosis (MS) is a chronic, progressive neurological disease characterized by early-stage neuroinflammation, neurodegeneration, and demyelination that involves a spectrum of heterogeneous clinical manifestations in terms of disease course and response to therapy. Even though several disease-modifying therapies (DMTs) are available to prevent MS-related brain damage-acting on the peripheral immune system with an indirect effect on MS lesions-individualizing therapy according to disease characteristics and prognostic factors is still an unmet need. Given that deregulated miRNAs have been proposed as diagnostic tools in neurodegenerative/neuroinflammatory diseases such as MS, we aimed to explore miRNA profiles as potential classifiers of the relapsing-remitting MS (RRMS) patients' prospects to gain a more effective DMT choice and achieve a preferential drug response.

Methods

A total of 25 adult patients with RRMS were enrolled in a cohort study, according to the latest McDonald criteria before (pre-cladribine, pre-CLA; pre-ocrelizumab, pre-OCRE, time T0) and after high-efficacy DMTs, time T1, 6 months post-CLA (n = 10, 7 F and 3 M, age 39.0 ± 7.5) or post-OCRE (n = 15, 10 F and 5 M, age 40.5 ± 10.4) treatment. A total of 15 age- and sex-matched healthy control subjects (9 F and 6 M, age 36.3 ± 3.0) were also selected. By using Agilent microarrays, we analyzed miRNA profiles from peripheral blood mononuclear cells (PBMC). miRNA-target networks were obtained by miRTargetLink, and Pearson's correlation served to estimate the association between miRNAs and outcome clinical features.

Results

First, the miRNA profiles of pre-CLA or pre-OCRE RRMS patients compared to healthy controls identified modulated miRNA patterns (40 and seven miRNAs, respectively). A direct comparison of the two pre-treatment groups at T0 and T1 revealed more pro-inflammatory patterns in the pre-CLA miRNA profiles. Moreover, both DMTs emerged as being capable of reverting some dysregulated miRNAs toward a protective phenotype. Both drug-dependent miRNA profiles and specific miRNAs, such as miR-199a-3p, miR-29b-3p, and miR-151a-3p, emerged as potentially involved in these drug-induced mechanisms. This enabled the selection of miRNAs correlated to clinical features and the related miRNA-mRNA network.

Discussion

These data support the hypothesis of specific deregulated miRNAs as putative biomarkers in RRMS patients' stratification and DMT drug response.

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.

The effect of glatiramer acetate, IFNβ-1a, fingolimod, and dimethyl fumarate on the expression of T-bet, IFN-γ, and MEG3 in PBMC of RRMS patients

OBJECTIVE

Multiple sclerosis (MS) is a progressing neurodegenerative disease marked by chronic central nervous system inflammation and degeneration.This study investigates gene expression profiles of T-box transcription factor TBX21 (T-bet), interferon-gamma (IFN-γ), and long non-coding RNA MEG3 in peripheral blood mononuclear cells (PBMCs) from treatment-naïve Relapsing-Remitting Multiple Sclerosis patients (RRMS), healthy controls, and RRMS patients on different Disease Modifying Therapies (DMTs). The aim is to understand the role of T-bet, IFN-γ, and MEG3 in MS pathogenesis and their potential as diagnostic and therapeutic targets.

RESULTS

Elevated T-bet expression is observed in treatment-naïve RRMS patients compared to healthy individuals. RRMS patients treated with Interferon beta-1alpha (IFNβ-1a) and fingolimod exhibit downregulated T-bet and MEG3 expression levels, respectively, with more pronounced effects in females. Healthy individuals show a moderate positive correlation between T-bet and MEG3 and between IFN-γ and T-bet. In RRMS patients treated with Glatiramer Acetate (GA), a strong positive correlation is observed between MEG3 and IFN-γ. Remarkably, RRMS patients treated with Dimethyl Fumarate (DMF) exhibit a significant positive correlation between T-bet and MEG3. These findings underscore the diagnostic potential of T-bet in RRMS, warranting further exploration of MEG3, T-bet, and IFN-γ interplay in RRMS patients.

Changes in the Expression of TGF-Beta Regulatory Pathway Genes Induced by Vitamin D in Patients with Relapsing-Remitting Multiple Sclerosis

Vitamin D is an environmental factor related to multiple sclerosis that plays a significant role in immune regulation. TGF-β is a superfamily of cytokines with an important dual effect on the immune system. TGF-β inhibits the Th1 response while facilitating the preservation of regulatory T cells (FOXP3+) in an immunoregulatory capacity. However, when IL-6 is present, it stimulates the Th17 response. Our aim was to analyze the regulatory effect of vitamin D on the in vivo TGF-β signaling pathway in patients with relapsing-remitting multiple sclerosis (RRMS). A total of 21 patients with vitamin D levels < 30 ng/mL were recruited and supplemented with oral vitamin D. All patients were receiving disease-modifying therapy, with the majority being on natalizumab. Expression of SMAD7, ERK1, ZMIZ1, BMP2, BMPRII, BMP4, and BMP5 was measured in CD4+ lymphocytes isolated from peripheral blood at baseline and one and six months after supplementation. SMAD7 was overexpressed at six months with respect to baseline and month one. ERK1 was overexpressed at six months with respect to month one of treatment. No significant differences in expression were observed for the remaining genes. No direct correlation was found with serum vitamin D levels. BMPRII expression changed differentially in non-natalizumab- versus natalizumab-treated patients. Changes were observed in the expression of ERK1, BMP2, and BMP5 based on disease activity measured using the Rio-Score, BMP2 in patients who had relapses, and BMP5 in those whose EDSS worsened. Our results suggest indirect regulation of vitamin D in TGF-β pathway genes in patients with RRMS.

Long non-coding RNAs BACE1-AS and BC200 in multiple sclerosis and their relation to cognitive function: A gene expression analysis

Cognitive impairment is a common and debilitating feature of multiple sclerosis (MS), and the dysregulation of synaptic plasticity is one of its direct causes. Long non-coding RNAs (lncRNAs) have been shown to play a role in synaptic plasticity, but their role in cognitive impairment in MS has not been fully explored. In this study, using quantitative real-time PCR, we examined the relative expression of two specific lncRNAs, BACE1-AS and BC200, in the serum of two cohorts of MS patients with and without cognitive impairment. Both lncRNAs were overexpressed in both cognitively impaired and non-cognitively impaired MS patients, with consistently higher levels in the cohort with cognitive impairment. We also found a strong positive correlation between the expression levels of these two lncRNAs. Notably, BACE1-AS was consistently higher in the remitting cases of both relapsing-remitting MS (RRMS) and secondary progressive MS (SPMS) groups than in the respective relapse cases of the same subtype, with the SPMS-Remitting group of cognitively impaired MS patients showing the highest expression of BACE1-AS among all MS groups. Additionally, we observed that the primary progressive MS (PPMS) group had the highest expression of BC200 in both cohorts of MS. Furthermore, we developed a model called Neuro_Lnc-2, which showed better diagnostic performance than either BACE1-AS or BC200 alone in predicting MS. Our findings suggest that these two lncRNAs may have a significant impact on the pathogenesis of the progressive types of MS and on the cognitive function of the patients. Future research is required to confirm these findings.

The familial risk and heritability of multiple sclerosis and its onset phenotypes: A case-control study

BACKGROUND

The two main phenotypes of multiple sclerosis (MS), primary progressive (PPMS) and relapsing Onset (ROMS), show clinical and demographic differences suggesting possible differential risk mechanisms. Understanding the heritable features of these phenotypes could provide aetiological insight.

OBJECTIVES

To evaluate the magnitude of familial components in PPMS and ROMS and to estimate the heritability of disease phenotypes.

METHODS

We used data from 25,186 MS patients of Nordic ancestry from the Swedish MS Registry between 1987 and 2019 with known disease phenotype (1593 PPMS and 16,718 ROMS) and 251,881 matched population-based controls and 3,364,646 relatives of cases and controls. Heritability was calculated using threshold-liability models. For familial odds ratios (ORs), logistic regression with robust sandwich estimator was utilized.

RESULTS

The OR of MS diagnosis in those with a first-degree family member with ROMS was 7.00 and 8.06 in those with PPMS. The corresponding ORs for having a second-degree family member with ROMS was 2.16 and 2.18 in PPMS. The additive genetic effect in ROMS was 0.54 and 0.22 in PPMS.

CONCLUSION

Risk of MS increases by several folds in those with a relative with MS. The likelihood of developing either disease phenotype appears independent of genetic predisposition.

[DNA Methylation Profile of CD14+ Monocytes Changes in Primary Progressive Multiple Sclerosis]

Multiple sclerosis (MS) is a chronic autoimmune inflammatory and neurodegenerative disease of the central nervous system, which is characterized by significant clinical heterogeneity. Primary progressive MS (PPMS) develops in 10-15% of patients. Unlike the most common relapsing-remitting form of MS, PPMS involves steady progress of neurodegeneration and, as a consequence, a persistent gradual increase in neurological symptoms. The peculiarities of epigenetic regulation of gene expression may be one of the reasons for the differences in the pathogenesis of the two MS forms. DNA methylation is one of the key epigenetic mechanisms, which remains almost unexplored in different cell populations of PPMS patients. The goal of this work was to identify differential methylation profiles of the CpG sites in the CD14+ monocyte DNA, which characterize PPMS. A genome-wide analysis of DNA methylation in PPMS patients and healthy individuals has identified 169 differentially methylated positions (DMPs), 90.5% of which were hypermethylated in PPMS patients. More than half of all DMPs are located in/near known genes and within CpG islands and their neighboring regions, which indicates their high functional significance. We have found six differentially methylated regions (DMRs) in the OR2L13, CAT, LCLAT1, HOXA5, RNF39, and CRTAC1 genes involved in inflammation and neurodegeneration, which indicates active epigenetic regulation of their expression.

MiRNA 106a-5p in cerebrospinal fluid as signature of early relapsing remitting multiple sclerosis: a cross sectional study

Background

Circulating microRNAs (MiRNAs) have been investigated for their role in fine-tuning the adaptive immune response to inflammatory factors and in Multiple Sclerosis (MS). They have been investigated as possible biomarkers for the diagnosis and prognosis of the disease.

Methods

A cross sectional study conducted at the MS centre of Foggia, Italy. We enrolled patients with (1) an age between 18 and 55 years, (2) a definitive diagnosis of relapsing remitting MS (RRMS) as per the revised McDonald criteria, and (3) naïve to any disease modifying therapy (DMTs), as well as (4) patients with other neurological disorders (OND). The aim of the study was to compare the levels of expression of miRNA 21-5p, miRNA 106a-5p, miRNA 146a-5p, and miRNA223-3p in cell-free cerebrospinal fluid (CSF) in RRMS patients and OND. Investigated MiRNAs were extracted, retrotranscribed, and then assessed by real-time polymerase chain reaction assay (q-PCR). A receiver-operator characteristic (ROC) curve was used to test MiRNAs as a biomarker for diagnosing MS. A linear regression analysis was done to find any association with disease characteristics at the time of diagnosis.

Results

A total cohort of 70 subjects (70% women) was analyzed. Out of them, 35 had a RRMS diagnosis. MiRNA 106a-5p (7.8 ± 3.8 vs 1.3 ± 0.9, p=0.03) had higher levels in RRMS patients when compared to OND. The ROC curve indicated that MiRNA 106a-5p could be considered as a disease biomarker with an area under the curve of 0.812 (p<.001; 95% CI 0.686-0.937). Linear regression analysis showed an association between the number of oligoclonal bands and MiRNA 106a-5p levels (B-coeff 2.6, p<.001; 95% CI 1.3-4.9).

Conclusion

We described miRNA 106a-5p as a possible signature in the CSF of RRMS patients in early phases of the disease. Further studies are needed to characterize its role in early MS as a disease biomarker.

Leukocyte Telomere Length Predicts Severe Disability in Relapsing-Remitting Multiple Sclerosis and Correlates with Mitochondrial DNA Copy Number

Multiple sclerosis (MS) is a chronic autoimmune inflammatory disease that affects the nervous system. Peripheral blood leukocyte telomere length (LTL) and mitochondrial DNA copy number (mtDNA-CN) are potential biomarkers of neurological disability and neural damage. Our objective was to assess the LTL and mtDNA-CN in relapsing-remitting MS (RRMS). We included 10 healthy controls, 75 patients with RRMS, 50 of whom had an Expanded Disability Status Scale (EDSS) from 0 to 3 (mild to moderate disability), and 25 had an EDSS of 3.5 to 7 (severe disability). We use the Real-Time Polymerase Chain Reaction (qPCR) technique to quantify absolute LTL and absolute mtDNA-CN. ANOVA test show differences between healthy control vs. severe disability RRMS and mild-moderate RRMS vs. severe disability RRMS (p = 0.0130). LTL and mtDNA-CN showed a linear correlation in mild-moderate disability RRMS (r = 0.378, p = 0.007). Furthermore, we analyzed LTL between RRMS groups with a ROC curve, and LTL can predict severe disability (AUC = 0.702, p = 0.0018, cut-off < 3.0875 Kb, sensitivity = 75%, specificity = 62%), whereas the prediction is improved with a logistic regression model including LTL plus age (AUC = 0.762, p = 0.0001, sensitivity = 79.17%, specificity = 80%). These results show that LTL is a biomarker of disability in RRMS and is correlated with mtDNA-CN in mild-moderate RRMS patients.

[A comparison of DNA methylation profiles of blood mononuclear cells in patients with multiple sclerosis in remission and relapse]

OBJECTIVE

To study the whole-genome DNA methylation profiles of peripheral blood mononuclear blood cells (PBMCs) of patients with relapsing-remitting multiple sclerosis (RRMS) in remission and relapse in order to assess the contribution of this epigenetic mechanism of gene expression regulation to the activity of the pathological process.

MATERIAL AND METHODS

Eight patients with RRMS in remission and 6 patients in relapse were included in the study. Methylation levels of DNA CpG sites in PBMCs were analyzed using Infinium HumanMethylation450 BeadChip DNA microarrays.

RESULTS

Seven differentially methylated positions (DMPs) were identified, of which 3 were hypermethylated (cg02981003, cg18486102, cg19533582) and 4 were hypomethylated (cg16814680, cg1964802, cg18584440, cg08291996) during RRMS relapse. Five DMPs are located in protein-coding genes (GPR123, FAIM2, BTNL2, ZNF8, ASAP2), one in microRNA gene (MIR548N), and one in an intergenic region. For all identified DMPs, we observed a change in DNA methylation levels of more than 20% (range 20.2-57.5%). Hierarchical clustering of DNA samples on the heatmap shows their clear aggregation into separate clusters corresponding to RRMS patients in the stages of relapse and remission.

CONCLUSION

For the first time it was shown that during relapse and remission of RRMS there are differences in the DNA methylation profile that allow discrimination between these clinical stages. These data indicate the involvement of the epigenetic mechanism of DNA methylation in the activation of the pathological process in RRMS.

Concomitant Expression of IL-6 and TGF-β Cytokines and their Receptors in Peripheral Blood of Patients with Multiple Sclerosis: The Effects of INFβ Drugs

BACKGROUND

Concomitant signals from IL-6 and TGF-β have a central role in the Th17 cells development and differentiation, and these cells are the main promoters of demyelinating inflammation in the central nervous system (CNS) resulting in multiple sclerosis (MS).

OBJECTIVES

To evaluate the simultaneous IL-6 and TGF-β gene and their receptor protein expression in patients with Relapsing-Remitting (RR)-MS.

MATERIALS AND METHODS

IL-6 and TGF-β mRNA and their receptor expression on the surface of CD4+T cells were evaluated using real-time PCR (RT-PCR) and flow cytometry, respectively.

RESULTS

The IL-6 mRNA expression in patients with RRMS was significantly higher than in the controls (p= 0.019). When patients who did not receive any other treatment were compared with the controls, the significant difference was substantial (p=0.006). The TGF-β mRNA expression in patients was lower than in the controls (p = 0.03). However, in patients receiving IFNβ, it increased compared with the other patients (p= 0.036). There was no difference in cytokine receptor expression between patients and the control group.

CONCLUSION

Our data conclude an increase and decrease in mRNA expression levels of IL-6 and TGF-β in patients with RRMS, respectively. Moreover, there were no significant differences in receptor expression of either cytokines. Based on our data the balance of TGF and IL-6 appears to have a positive impact on the disease control.

Interleukin 6 SNP rs1818879 Regulates Radiological and Inflammatory Activity in Multiple Sclerosis

(1) Background: The clinical course of multiple sclerosis (MS) is critically influenced by the expression of different pro-inflammatory and anti-inflammatory cytokines. Interleukin 6 (IL-6) represents a major inflammatory molecule previously associated with exacerbated disease activity in relapsing remitting MS (RR-MS); however, the role of single-nucleotide polymorphisms (SNPs) in the IL-6 gene has not been fully elucidated in MS. (2) Methods: We explored in a cohort of 171 RR-MS patients, at the time of diagnosis, the associations between four IL-6 SNPs (rs1818879, rs1554606, rs1800797, and rs1474347), CSF inflammation, and clinical presentation. (3) Results: Using principal component analysis and logistic regression analysis we identified an association between rs1818879, radiological activity, and a set of cytokines, including the IL-1β, IL-9, IL-10, and IL-13. No significant associations were found between other SNPs and clinical or inflammatory parameters. (4) Conclusions: The association between the rs1818879 polymorphism and subclinical neuroinflammatory activity suggests that interindividual differences in the IL-6 gene might influence the immune activation profile in MS.

Significant Association of rs77493513 Polymorphism in 3'-UTR of the NRG1 Gene with the Risk of Multiple Sclerosis Disease

Multiple sclerosis (MS) is a chronic inflammatory and autoimmune disease characterized by demyelination of the central nervous system (CNS). Neuregulin 1 (NRG1) is a signaling protein that plays an important role in a variety of biological processes, including potentiate oligodendrocyte differentiation and myelination in the CNS, immune response regulation, and inflammation. Single nucleotide polymorphism (SNP) rs77493513 is located in the untranslated region of the 3' mRNA (3'-UTR) of the NRG1 gene, which is predicted to be the binding site of several microRNAs and may play an important role in post-transcriptional regulation. Study aimed to investigate the association of SNP rs77493513 in the NRG1 gene with the risk of MS disease. In this study, genomic DNA was extracted from whole blood samples of 182 patients with relapsing-remitting multiple sclerosis (RRMS) and 198 controls. Different genotypes of rs77493513 polymorphism were determined using RFLP-PCR technique. Statistical analysis was performed using SPSS 21.0 software and by t, χ2 and logistic regression tests. Our data showed that genotypes AC (OR=3.63, CI= 1.93-6.81, p<0.001) and CC (OR=7.90, CI= 4.13-15.11, p<0.001) significantly increased the risk of MS disease and C allele is risk allele. Also, AC (OR=0.16, CI= 0.04-0.63, p= 0.009) and CC (OR=0.14, CI= 0.03-0.53, p=0.04) genotypes significantly decrease the age of onset of the disease. The results show that allele C of rs77493513 polymorphism in the NRG1 gene can be a risk factor for MS.

Impact of IL-21 Gene Polymorphisms (rs2055979) and the Levels of Serum IL-21 on the Risk of Multiple Sclerosis

Multiple sclerosis (MS) is a chronic autoimmune disorder of the central nervous system. Genetic and environmental factors have important roles in the induction, onset, and progression of MS. In this study, the IL-21 genotype (rs2055979) (G/T) in Iraqi MS patients was compared with a healthy control group to investigate the possible association of any particular genotype or allele with multiple sclerosis. This study included 70 patients with relapsing-remitting MS and 50 healthy individuals as control. Following the extraction of genomic DNA, polymerase chain reaction-restriction fragment length polymorphism, the frequencies of genotypes, and alleles were calculated and statistically analyzed. The results of the study revealed a significant reduction in the distribution of the wild homozygous genotype (GG) in MS patients, in comparison to a healthy control group (14.3% vs. 34 %; 0.0129 at P≤0.05; odds ratio [OR] 3.0909, 95% confidence interval [CI]: 1.2704-7.5203). However, MS cases and controls did not differ significantly in neither GT nor TT genotypes, 62.9% (OR 0.6402, 95% CI: 0.3064-1.3374) and 52% (OR 0.5494, 95% CI: 0.2074-1.4557), respectively. The data of allele frequencies in patients and controls showed that the G allele frequencies were 0.46 vs. 0.60 in patients and controls, respectively, while T allele frequencies were 0.54 vs. 0.40 in patients and controls, respectively. The current conclusions indicated that in the study group, the GG genotype of IL-21(rs2055979) could be related to MS.

MicroRNA-22 Level in Patients with Multiple Sclerosis and Its Relationship with Vitamin D and Vitamin D Receptor Levels

INTRODUCTION

Multiple sclerosis (MS) is known to be a multifactorial disorder. Numerous observational studies have suggested the implication of multiple genetic and environmental factors in the pathogenesis of MS. The aim of this work was to evaluate expression of the microRNA-22 (miRNA-22) level, in relation to vitamin D (VD) and VD receptor (VDR) levels in patients with MS during remission state.

METHODS

This case-control study was conducted in 50 patients with clinically definite MS and 50 age- and sex-matched healthy controls. miRNA-22 expression was assessed in both MS patients and controls using quantitative RT-PCR. The serum level of VD and VDR was assessed in both MS patients and controls using ELISA techniques.

RESULTS

The miRNA-22 level was significantly downregulated in MS patients in comparison to controls (p value <0.001). MS patients had also significantly lower VD and VDR levels in comparison to controls (p value <0.001 and <0.001, respectively). Patients with secondary progressive MS (SPMS) have a significantly higher miRNA-22 level than patients with relapsing remitting MS (RRMS) (p value = 0.042). There was a statistically significant positive correlation between the miRNA-22 level and EDSS (p value = 0.033). There was also a statistically significant positive correlation between the miRNA-22 level and VDR level (p value = 0.002).

CONCLUSION

The miRNA-22 level was significantly downregulated in MS patients, but it had a positive correlation with disability status. Patients with SPMS have a significantly higher miRNA-22 level than patients with RRMS. VD and VDR levels were significantly lower in MS patients than controls. The miRNA-22 level was positively correlated with the VDR level.

C1q inhibits differentiation of oligodendrocyte progenitor cells via Wnt/β-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 β-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 β-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/β-catenin signaling activation.

Expression of Akt1 and p-Akt1 in peripheral T cell subsets of multiple sclerosis patients

Multiple sclerosis is an autoimmune disorder induced by the infiltration of autoreactive immune cells into the central nervous system. Akt/PKB signaling pathway is crucially involved in T cell development and survival. We aimed to determine whether Akt1 expression levels of regulatory T (Treg) cells are altered in MS and are associated with disease activity. Relapsing-remitting multiple sclerosis (RR-MS, n = 17) patients and healthy individuals (n = 20) were enrolled. Peripheral blood mononuclear cells were isolated and anti-CD3, -CD4, -CD8, -CD25, -CD127 monoclonal antibodies were used to identify the T cell subsets. After stimulation with phorbol myristate acetate/ionomycin, the Akt1 and phosphorylated-Akt1 (p-Akt1) levels of T cell subsets were detected with intracellular staining using flow cytometry. Total Akt1 and p-Akt1 expression levels were found to be suppressed in CD4⁺ T cell and Treg populations of RR-MS patients. Progression indices were positively correlated with Akt1 expression levels of Tregs indicating that the Akt pathway might partake in the progression of multiple sclerosis. Flow cytometry may effectively be used for the evaluation of the Akt pathway activity. Our findings suggest that the magnitude of suppression of the Akt pathway might serve as a biomarker for the prognosis of multiple sclerosis.

Teriflunomide Inhibits JCPyV Infection and Spread in Glial Cells and Choroid Plexus Epithelial Cells

Several classes of immunomodulators are used for treating relapsing-remitting multiple sclerosis (RRMS). Most of these disease-modifying therapies, except teriflunomide, carry the risk of progressive multifocal leukoencephalopathy (PML), a severely debilitating, often fatal virus-induced demyelinating disease. Because teriflunomide has been shown to have antiviral activity against DNA viruses, we investigated whether treatment of cells with teriflunomide inhibits infection and spread of JC polyomavirus (JCPyV), the causative agent of PML. Treatment of choroid plexus epithelial cells and astrocytes with teriflunomide reduced JCPyV infection and spread. We also used droplet digital PCR to quantify JCPyV DNA associated with extracellular vesicles isolated from RRMS patients. We detected JCPyV DNA in all patients with confirmed PML diagnosis (n = 2), and in six natalizumab-treated (n = 12), two teriflunomide-treated (n = 7), and two nonimmunomodulated (n = 2) patients. Of the 21 patients, 12 (57%) had detectable JCPyV in either plasma or serum. CSF was uniformly negative for JCPyV. Isolation of extracellular vesicles did not increase the level of detection of JCPyV DNA versus bulk unprocessed biofluid. Overall, our study demonstrated an effect of teriflunomide inhibiting JCPyV infection and spread in glial and choroid plexus epithelial cells. Larger studies using patient samples are needed to correlate these in vitro findings with patient data.

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 and gut imprinted helper T cell subsets exhibit distinct functional phenotypes in central nervous system autoimmunity

Multidimensional single-cell analyses of T cells have fueled the debate about whether there is extensive plasticity or 'mixed' priming of helper T cell subsets in vivo. Here, we developed an experimental framework to probe the idea that the site of priming in the systemic immune compartment is a determinant of helper T cell-induced immunopathology in remote organs. By site-specific in vivo labeling of antigen-specific T cells in inguinal (i) or gut draining mesenteric (m) lymph nodes, we show that i-T cells and m-T cells isolated from the inflamed central nervous system (CNS) in a model of multiple sclerosis (MS) are distinct. i-T cells were Cxcr6+, and m-T cells expressed P2rx7. Notably, m-T cells infiltrated white matter, while i-T cells were also recruited to gray matter. Therefore, we propose that the definition of helper T cell subsets by their site of priming may guide an advanced understanding of helper T cell biology in health and disease.

Potential prognostic value of circulating inflamma-miR-146a-5p and miR-125a-5p in relapsing-remitting multiple sclerosis

BACKGROUND

Inflamma-miRs are a group of microRNAs involved in the regulation of innate and adaptive immune responses. Increasing evidence support the contribution of dysregulated inflamma-miRs in the pathogenesis of multiple sclerosis. The aim of this study was to evaluate the expression of selected inflamma-miRs, i.e., miR-34a-5p, -125a-5p, -146a-5p, and -155, in relapsing-remitting multiple sclerosis (RRMS) and their modulation after treatment with dimethyl fumarate (DMF).

METHODS

Circulating levels of microRNAs involved in inflammatory response (inflamma-miRs) were compared between healthy controls (CTRs, n=21) and patients with RRMS (n=24) who started treatment with DMF.

RESULTS

Plasma levels of miR-34a (p<0.001) and miR-125a-5p (p=0.034) were higher, whereas miR-146a-5p levels were lower (p=0.041) in RRMS patients compared to CTRs. Circulating miR-125a-5p (p=0.001), miR-146a-5p (p<0.001), and miR-155 (p=0.013) were reduced after 4-month treatment with DMF. Among these, baseline and 4-month follow up miR-125a-5p (p=0.028) and miR-146a-5p (p=0.042) levels were related to disability progression.

CONCLUSION

Circulating inflamma-miRs could represent candidate tools to predict MS clinical course and evaluate the effectiveness of disease-modifying treatments in RRMS.

HLA Class II Genotype Does Not Affect the Myelin Responsiveness of Multiple Sclerosis Patients

Background: When aiming to restore myelin tolerance using antigen-specific treatment approaches in MS, the wide variety of myelin-derived antigens towards which immune responses are targeted in multiple sclerosis (MS) patients needs to be taken into account. Uncertainty remains as to whether the myelin reactivity pattern of a specific MS patient can be predicted based upon the human leukocyte antigen (HLA) class II haplotype of the patient. Methods: In this study, we analyzed the reactivity towards myelin oligodendrocyte glycoprotein (MOG), myelin basic protein (MBP) and proteolipid protein (PLP) peptides using direct interferon (IFN)-γ enzyme-linked immune absorbent spot (ELISPOT). Next, the HLA class II haplotype profile was determined by next-generation sequencing. In doing so, we aimed to evaluate the possible association between the precursor frequency of myelin-reactive T cells and the HLA haplotype. Results: Reactivity towards any of the analyzed peptides could be demonstrated in 65.0% (13/20) of MS patients and in 60.0% (6/10) of healthy controls. At least one of the MS risk alleles HLA-DRB1*15:01, HLA-DQA1*01:02 and HLA-DQB1*06:02 was found in 70.0% (14/20) of patients and in 20.0% (2/10) of healthy controls. No difference in the presence of a myelin-specific response, nor in the frequency of myelin peptide-reactive precursor cells could be detected among carriers and non-carriers of these risk alleles. Conclusion: No association between HLA haplotype and myelin reactivity profile was present in our study population. This complicates the development of antigen-specific treatment approaches and implies the need for multi-epitope targeting in an HLA-unrestricted manner to fully address the wide variation in myelin responses and HLA profiles in a heterogeneous group of MS patients.

Altered PPARγ Expression Promotes Myelin-Induced Foam Cell Formation in Macrophages in Multiple Sclerosis

Macrophages play a crucial role during the pathogenesis of multiple sclerosis (MS), a neuroinflammatory autoimmune disorder of the central nervous system. Important regulators of the metabolic and inflammatory phenotype of macrophages are liver X receptors (LXRs) and peroxisome proliferator-activated receptors (PPARs). Previously, it has been reported that PPARγ expression is decreased in peripheral blood mononuclear cells of MS patients. The goal of the present study was to determine to what extent PPARγ, as well as the closely related nuclear receptors PPARα and β and LXRα and β, are differentially expressed in monocytes from MS patients and how this change in expression affects the function of monocyte-derived macrophages. We demonstrate that monocytes of relapsing-remitting MS patients display a marked decrease in PPARγ expression, while the expression of PPARα and LXRα/β is not altered. Interestingly, exposure of monocyte-derived macrophages from healthy donors to MS-associated proinflammatory cytokines mimicked this reduction in PPARγ expression. While a reduced PPARγ expression did not affect the inflammatory and phagocytic properties of myelin-loaded macrophages, it did impact myelin processing by increasing the intracellular cholesterol load of myelin-phagocytosing macrophages. Collectively, our findings indicate that an inflammation-induced reduction in PPARγ expression promotes myelin-induced foam cell formation in macrophages in MS.

TRAILR1 (rs20576) and GRIA3 (rs12557782) are not associated with interferon-β response in multiple sclerosis patients

Multiple sclerosis (MS) is an autoimmune-type inflammatory disorder in human central nervous system. Recombinant interferon beta (IFN-β) decreases the number of relapses and postpones disability progression in MS. However, up to 50% of patients treated with interferon beta continue experiencing relapses and/or worsening disability. Single nucleotide polymorphisms in different genes have been known to show significant associations with response to IFN-β in MS patients. In the present work, we examined the potential role of TRAILR1 and GRIA3 genes polymorphisms on response to IFN-β therapy in Iranian MS patients. The DNA was extracted from blood samples by standard procedures from 73 patients diagnosed with Multiple Sclerosis that were either responded to IFN-β or did not. We carried out RFLP -PCR and tetra-primer ARMS-PCR methods to study of rs20576 and rs12557782, respectively. All results were analyzed using the SPSS software. TRAILR1 rs20576 genotype frequencies in responders and non-responders were similar (χ² = 0.26, P = 0.87, Fisher^, s Exact test). Our results showed that response to IFN-β has not association with sex (p = 0.73). Also, genotypic frequencies of GRIA3 rs12557782 had no significant differences between two groups of female population (χ² = 3.75, p = 0.15). Furthermore, it had not been any statistical differences between responder and non-responder males (χ² = 0.7, p = 0.4) related to the SNP. Our results analysis revealed no significant association between the studied SNPs (TRAILR1 rs20576 and GRIA3rs 12,557,782) and response to IFN-β in Iranian MS patients.

Upregulation of MTOR, RPS6KB1, and EIF4EBP1 in the whole blood samples of Iranian patients with multiple sclerosis compared to healthy controls

Various genetic and epigenetic mechanisms have been suggested to play roles as the underlying pathophysiology of Multiple Sclerosis (MS). Changes in different parts of the mTOR signaling pathway are among the potential suggested mechanisms based on the specific roles of this pathway in CNS. MTOR, RPS6KB1, and EIFEBP1 genes are among important genes in the mTOR pathway, responsible for the proper function of acting proteins in this signaling pathway. This study aimed to investigate the relative expression levels of these genes in the blood samples of relapsing-remitting MS (RRMS) patients compared to healthy controls. In this case-control study blood samples were collected from 30 newly diagnosed RRMS patients and 30 age and sex-matched healthy controls. mRNA level of MTOR, RPS6KB1, and EIFEBP1 genes were assessed using Real-Time PCR. The expression of MTOR, RPS6KB1, and EIF4EBP1 genes was up regulated in MS patients compared to healthy controls (p < 0.001 for all mentioned genes). Considering gender differences, expression of the mentioned genes was increased among female patients (all P < 0.001). However, no statistically significant changes were observed among male patients. Based on the receiver operating characteristic, MTOR gene had the highest diagnostic value followed by EIF4EBP1 and RPS6KB1 genes in differentiating RRMS patients from controls. In conclusion, we found the simultaneous upregulation of MTOR, RPS6KB1, and EIF4EBP1 genes among RRMS patients. MTOR showed to have the highest diagnostic value compared to other 2 genes in differentiating RRMS patients. Further studies evaluating the importance of these findings from pharmacological and prognostic perspectives are necessary.

Adenosine-to-Inosine RNA Editing of Alu Double-Stranded (ds)RNAs Is Markedly Decreased in Multiple Sclerosis and Unedited Alu dsRNAs Are Potent Activators of Proinflammatory Transcriptional Responses

Sensors that detect dsRNA stimulate IFN responses as a defense against viral infection. IFN responses are also well documented in a variety of human autoimmune diseases, including relapsing-remitting multiple sclerosis (MS), in which increased IFN responses result from increased levels of double-stranded endogenous Alu RNAs. Mechanisms underlying increases in double-stranded Alu RNAs in MS are obscure. We find widespread loss of adenosine-to-inosine editing of Alu RNAs in MS. Unedited Alu RNAs are potent activators of both IFN and NF-κB responses via the dsRNA sensors, RIG-I, and TLR3. Minor editing of highly active Alu elements abrogates the ability to activate both transcriptional responses. Thus, adenosine-to-inosine editing may also represent an important defense against autoimmune diseases such as MS.

The Pharmacogenetics of Rituximab: Potential Implications for Anti-CD20 Therapies in Multiple Sclerosis

There are a broad range of disease-modifying therapies (DMTs) available in relapsing-remitting multiple sclerosis (RRMS), but limited biomarkers exist to personalise DMT choice. All DMTs, including monoclonal antibodies such as rituximab and ocrelizumab, are effective in preventing relapses and preserving neurological function in MS. However, each agent harbours its own risk of therapeutic failure or adverse events. Pharmacogenetics, the study of the effects of genetic variation on therapeutic response or adverse events, could improve the precision of DMT selection. Pharmacogenetic studies of rituximab in MS patients are lacking, but pharmacogenetic markers in other rituximab-treated autoimmune conditions have been identified. This review will outline the wider implications of pharmacogenetics and the mechanisms of anti-CD20 agents in MS. We explore the non-MS rituximab literature to characterise pharmacogenetic variants that could be of prognostic relevance in those receiving rituximab, ocrelizumab or other monoclonal antibodies for MS.

Transcriptomic and clonal characterization of T cells in the human central nervous system

T cells provide critical immune surveillance to the central nervous system (CNS), and the cerebrospinal fluid (CSF) is thought to be a main route for their entry. Further characterization of the state of T cells in the CSF in healthy individuals is important for understanding how T cells provide protective immune surveillance without damaging the delicate environment of the CNS and providing tissue-specific context for understanding immune dysfunction in neuroinflammatory disease. Here, we have profiled T cells in the CSF of healthy human donors and have identified signatures related to cytotoxic capacity and tissue adaptation that are further exemplified in clonally expanded CSF T cells. By comparing profiles of clonally expanded T cells obtained from the CSF of patients with multiple sclerosis (MS) and healthy donors, we report that clonally expanded T cells from the CSF of patients with MS have heightened expression of genes related to T cell activation and cytotoxicity.

Connection of miR-185 and miR-320a expression levels with response to interferon-beta in multiple sclerosis patients

BACKGROUND

Multiple sclerosis (MS) is an inflammatory autoimmune disease characterized by neurodegeneration in the CNS. Interferon-beta (IFN-β) is an FDA-approved drug used as the first-line treatment for relapse-remitting multiple sclerosis (RRMS). The exact mechanism of IFN-β during the treatment of RRMS still remains unknown. Recently, many studies have shifted towards the role of miRNAs in the treatment of MS patients.

METHODS

Herein, the expression level of miR-185-5p and miR-320a has been evaluated in order to candidate them as novel biomarkers for monitoring the response to IFN-β therapy. For this purpose, one-hundred whole blood samples from patients with RRMS were collected, consisting of 50 responders and 50 non-responders to IFN-β therapy. To predict the possible molecular mechanisms of IFN-β and highlight the role of these miRNAs, in silico analysis was applied to enrich the signaling pathways which may be involved based on the target genes of miR-185-5p and miR-320a.

RESULTS

It is identified that the differentially expressed miR-185-5p was statistically significant between the two treated groups with IFN-β. Furthermore, MAPK signaling pathway was suggested as the main non-canonical pathway involved in IFN-β therapy.

CONCLUSION

miR-185-5p could be considered as a novel biomarker for monitoring the response to IFN-β therapy.

Differential Transcription of SOCS5 and SOCS7 in Multiple Sclerosis Patients Treated with Interferon Beta or Glatiramer Acetate

The participation of proinflammatory cytokines in the progression of Multiple Sclerosis (MS) has been well documented. Cytokines activate the JAK-STAT pathway, in which the suppressors of cytokine signaling (SOCS) exert a negative feedback. This paper analyzes the levels of SOCS5 and SOCS7 transcripts, quantified by RT-qPCR, in MS patients, and the concentrations of proinflammatory cytokines, IFN-γ, IL17, and IL6, determined by ELISA. Samples of peripheral blood were obtained from MS patients in the relapsing–remitting phase, treated with IFN-β or glatiramer acetate (GA), and from healthy individuals. SOCS7 mRNA was significantly higher in patients treated with GA (1.36 ± 0.23) than in those treated with IFN-β (0.65 ± 0.1). Regarding gender, the level of SOCS5 and SOCS7 transcripts were similar between MS and healthy females; in MS males, the level of SOCS7 transcripts were significantly lower (0.59 ± 0.03) than in healthy males (1.008 ± 0.05). Plasmatic levels of IFN-γ were significantly higher in MS patients (60 pg/mL, range 0–160) than in healthy subjects (0 range, 0–106). The same pattern was observed in MS patients treated with IFN-β (68 pg/mL, range 0–160) compared to patients treated with GA (51 pg/mL, range 0–114), and in MS females (64 pg/mL, range 0–161) compared to healthy females (0, range 0–99). We hypothesize that the increase in SOCS7 transcription in patients treated with GA could partially explain the action mechanism of this drug, while the increase in the concentration of IFN-γ in MS patients could help elucidate the immunopathology of the disease.

Multiple Sclerosis Risk Factors and Pathogenesis

PURPOSE OF REVIEW

This article summarizes recent advances in the identification of genetic and environmental factors that affect the risk of developing multiple sclerosis (MS) and the pathogenic processes involved in acute relapses and relapse-independent disability progression.

RECENT FINDINGS

The number of single-nucleotide polymorphisms associated with increased risk of MS has increased to more than 200 variants. The evidence for the association of Epstein-Barr virus infection, vitamin D deficiency, obesity, and smoking with increased risk of MS has further accumulated, and, in cases of obesity and vitamin D deficiency, the evidence for causal association has strengthened. Interactions between genetic and environmental factors have been studied more extensively. Dietary factors and changes in the gut microbiota are emerging as possible modulators of the disease risk. Several processes important to MS pathogenesis have been newly investigated or investigated more comprehensively, including the role of B cells, innate immune cells, meningeal inflammation, cortical and gray matter demyelination, and early axonal and neuronal loss.

SUMMARY

MS is a complex disease in which the interaction between genetic and environmental factors causes a cascade of events, including activation of the adaptive and innate immune system, blood-brain barrier breakdown, central nervous system demyelination, and axonal and neuronal damage with variable degrees of repair. These events manifest as potentially reversible focal neurologic symptoms or progressive nonremitting physical and cognitive disability, or both. Advances in the understanding of the risk factors and pathogenic mechanisms of MS have resulted in improved therapeutic strategies. The results of ongoing or future studies are needed to successfully and fully translate these advances into clinical practice.

Identification of novel non-myelin biomarkers in multiple sclerosis using an improved phage-display approach

Although the etiology of multiple sclerosis is not yet understood, it is accepted that its pathogenesis involves both autoimmune and neurodegenerative processes, in which the role of autoreactive T-cells has been elucidated. Instead, the contribution of humoral response is still unclear, even if the presence of intrathecal antibodies and B-cells follicle-like structures in meninges of patients has been demonstrated. Several myelin and non-myelin antigens have been identified, but none has been validated as humoral biomarker. In particular autoantibodies against myelin proteins have been found also in healthy individuals, whereas non-myelin antigens have been implicated in neurodegenerative phase of the disease.

To provide further putative autoantigens of multiple sclerosis, we investigated the antigen specificity of immunoglobulins present both in sera and in cerebrospinal fluid of patients using phage display technology in a new improved format. A human brain cDNA phage display library was constructed and enriched for open-read-frame fragments. This library was selected against pooled and purified immunoglobulins from cerebrospinal fluid and sera of multiple sclerosis patients. The antigen library was also screened against an antibody scFv library obtained from RNA of B cells purified from the cerebrospinal fluid of two relapsing remitting patients. From all biopanning a complex of 14 antigens were identified; in particular, one of these antigens, corresponding to DDX24 protein, was present in all selections. The ability of more frequently isolated antigens to discriminate between sera from patients with multiple sclerosis or other neurological diseases was investigated. The more promising novel candidate autoantigens were DDX24 and TCERG1. Both are implicated in RNA modification and regulation which can be altered in neurodegenerative processes. Therefore, we propose that they could be a marker of a particular disease activity state.

Genetic Alterations in Patients with Two Clinical Phenotypes of Multiple Sclerosis

The etiology of multiple sclerosis (MS) is still not known, but the interaction of genetic, immunological, and environmental factors seem to be involved. This study aimed to investigate genetic alterations and the vitamin D status in patients with relapsing-remitting MS (RRMS) and secondary progressive MS (SPMS). A total of 53 patients (29 RRMS; 24 SPMS) and 25 healthy subjects were recruited to evaluate the micronucleated cell (MNC) frequency and nuclear abnormalities in the buccal mucosa, gene expression profiling in mononuclear cells, and plasmatic vitamin D concentration in the blood. Results showed a higher frequency of cells with karyorrhexis (SPMS) and lower frequencies of nuclear pyknosis (RRMS and SPMS) and karyolysis (SPMS) in patients with MS. Significant increase in the frequency of MNC was detected in the buccal mucosa of RRMS and SPMS patients. HIF1A, IL13, IL18, MYC, and TNF were differentially expressed in MS patients, and APP was overexpressed in cells of RRMS compared to SPMS patients. No relationship was observed between vitamin D level and the differentially expressed genes. In conclusion, the cytogenetic alterations in the buccal mucosa can be important indicators of genetic instability and degenerative processes in patients with MS. Furthermore, our data introduced novel biomarkers associated with the molecular pathogenesis of MS.

Down-regulation of ERMN expression in relapsing remitting multiple sclerosis

Multiple Sclerosis (MS) is a chronic inflammatory disease causing demyelination and neurodegeneration in the central nervous system (CNS). Although the exact etiology of MS is still unclear, both genetic and environmental elements are regarded as causative factors. Environmental factors can induce a cascade of events in immune system leading to neuronal death and nerve demyelination. This paper aims to compare the peripheral transcript levels of Ermin (ERMN) (a gene with putative role in cytoskeletal rearrangements during myelinogenesis) and Listerin E3 Ubiquitin Protein Ligase 1 (LTN1) (a gene with functions in regulating innate immune system) between relapsing-remitting MS (RR-MS) patients and healthy controls. The results showed a significant decrease in ERMN expression (p = 0.022); whereas, no significant difference was detected in LTN1 expression between two groups (p = 0.935). The reduction in ERMN expression in leukocytes could be the cause of demyelinating process in RR-MS patients. Current findings might also have practical importance in prognosis and targeted therapies.

RORγT is overexpressed in iNKT and γδ T cells during relapse in relapsing-remitting multiple sclerosis

The aim of the current study is to evaluate IL-17 production and RORγT, and IL-23R expression by iNKT, Th17 and γδ T cells in the peripheral blood of relapsing-remitting multiple sclerosis patients. Samples of peripheral blood from 21 relapse patients and 12 remission patients, and 15 healthy volunteers were stained with monoclonal antibodies for flow cytometry analysis. No significant differences in iNKT, γδ T and Th17 percentages were noted. The significant overexpression of RORγT was observed in all three subpopulations - therefore, iNKT, γδ T and Th cells may be an important source of IL-17 shortly prior to the relapse.

CD28 Autonomous Signaling Up-Regulates C-Myc Expression and Promotes Glycolysis Enabling Inflammatory T Cell Responses in Multiple Sclerosis

The immunopathogenesis of multiple sclerosis (MS) depend on the expansion of specific inflammatory T cell subsets, which are key effectors of tissue damage and demyelination. Emerging studies evidence that a reprogramming of T cell metabolism may occur in MS, thus the identification of stimulatory molecules and associated signaling pathways coordinating the metabolic processes that amplify T cell inflammation in MS is pivotal. Here, we characterized the involvement of the cluster of differentiation (CD)28 and associated signaling mediators in the modulation of the metabolic programs regulating pro-inflammatory T cell functions in relapsing-remitting MS (RRMS) patients. We show that CD28 up-regulates glycolysis independent of the T cell receptor (TCR) engagement by promoting the increase of c-myc and the glucose transporter, Glut1, in RRMS CD4⁺ T cells. The increase of glycolysis induced by CD28 was important for the expression of inflammatory cytokines related to T helper (Th)17 cells, as demonstrated by the strong inhibition exerted by impairing the glycolytic pathway. Finally, we identified the class 1A phosphatidylinositol 3-kinase (PI3K) as the critical signaling mediator of CD28 that regulates cell metabolism and amplify specific inflammatory T cell phenotypes in MS.

IL12B gene polymorphisms have sex-specific effects in relapsing-remitting multiple sclerosis

IL-12-family cytokines play a pivotal role in neuroinflammation and neurodegeneration in relapsing-remitting multiple sclerosis (RRMS). The aim of the study was to evaluate whether two polymorphisms in IL12B gene, rs17860508 and rs3212227, are associated with RRMS, and to define their function effect on serum level of IL-12p40 and IL-23 and degree of disability in RRMS cases. In total 156 Bulgarian patients with Expanded Disability Status Scale score ranging from 1.0 to 3.5 in remission of the disease and 379 controls were genotyped by polymerase chain reaction-based methods. The IL-12p40 and IL-23 serum levels were determined by enzyme-linked immunosorbent assay. We have found substantially higher IL-12p40 and IL-23 serum levels in cases than in controls (p < 0.01) in a sex-dependent manner. Women with RRMS had significantly higher IL-12р40 and IL-23 than men. Gender-stratified association analyses showed a significant impact of rs3212227 polymorphism on RRMS susceptibility in men. The carriers of rs3212227*CC-genotype (OR 3.390, 95% CI 1.007-11.545, p = 0.023) and haplotype rs17860508*2-allele/rs3212227*C-allele (OR 3.740; 95% CI 1.36-10.32, p = 0.007), showed higher risk of RRMS in men, in contrast to women. In women, both IL12B polymorphisms influencing the course, rather than genetic predisposition of RRMS. The rs17860508*22-genotype was associated with significantly lower disability (OR 0.208; 95% CI 0.055-0.725; p_c = 0.01) and lower IL-23 serum levels (p = 0.0345), while rs3212227*AA-genotype was associated with early onset of the disease (OR 2.368; 95% CI 1.007-5.608; p = 0.03). Our results suggest that sex-specific effects of IL12B polymorphisms, rs17860508 and rs3212227, on genetic predisposition and disease course of RRMS, is probably mediated by their gender-dependent functional effect on IL-12p40-containing cytokines.

Altered Expression of miR-326 in T Cell-derived Exosomes of Patients with Relapsing-remitting Multiple Sclerosis

 Invasion of auto-reactive CD4+ T cells especially Th17 into central nervous system (CNS) is an underlying pathogenic mechanism in multiple sclerosis (MS). CD4+ T cells release exosomes which are enriched in microRNAs, reflective of cell's physiological or pathological condition. Thus exosomes could be potent agents to provide quantitative and qualitative information about involved cells in MS. We investigated the expression of pathogenic microRNAs in T cells-derived exosomes of MS patients or healthy controls. Conventional T cells (Tconv) derived from relapsing-remitting (RR) MS patients (n=10) and healthy controls (n=10) were purified and cultured for 3 days by soluble anti-CD3/CD28. Exosomes were purified from cultured-T cells supernatants. The expression levels of exosomal miR-146a, miR-29a, miR-155, and miR-326 were quantified by real-time PCR. A statistically significant increased expression of miR-326 in Tconv-derived exosomes was observed in RRMS patients as compared with controls (7.5±1.88vs 2.51±0.9 p=0.03), On the contrary, no differences were found in the expression levels of miR-155, miR-146a, and miR-29a, in Tconv-derived exosomes of  patients as compared with controls (p>0.05). Our results point to altered expression in exosome-derived microRNAs. MiR-326 was previously shown to play a role in the immunopathogenesis of MS by inducing TH17 differentiation and maturation. Therefore, miR-326 containing exosomes might also be a potential clinical target in course of MS. Moreover, the deregulation of this miRNA in exosomes may serve as a diagnostic and prognostic biomarker.

Increased expression of mir-301a in PBMCs of patients with relapsing-remitting multiple sclerosis is associated with reduced NKRF and PIAS3 expression levels and disease activity

Most of the multiple sclerosis (MS) patients are initially diagnosed with relapsing remitting multiple sclerosis (RRMS). Th17 cells and macrophages have been shown to play critical roles in pathogenesis of MS and initiation of CNS tissue damage. MiR-301a have recently been exposed as an activator of STAT3 in Th17 cells as well as an activator of NF-κB in macrophages by targeting PIAS3 and NKRF correspondingly. However, the possible role of miR-301a in RRMS has not yet been elucidated. Herewith, for the first time, we have studied the expression of miR-301a, NKRF and PIAS3 by quantitative real-time PCR and western blotting method in peripheral blood mononuclear cells (PBMCs) of 71 RRMS patients, including two groups of patients in relapse phase (n = 44) and a group of remitting phase patients (n = 28) in comparison to healthy volunteers (n = 28). In this work, we demonstrate a significant upregulation of miR-301a in relapse phase of MS patients compared to healthy controls and remitting phase patients (P < .05). Our findings also showed a striking decrease of NKRF and PIAS3 expression in relapse phase patients, in contrast to miR-301a and, NF-κB and STAT3 downstream genes (SKA2 and RORc) (P < .05). Subsequently, using luciferase reporter system we confirmed that miR-301a directly targets the mRNA encoding PIAS3 and NKRF proteins. We also showed that miR-301a increasing expression is correlated with down-regulation of PIAS3 and NKRF expression in RRMS patients. Our findings suggest that miR-301a, PIAS3 and NKRF play crucial roles in RRMS and could be considered as promising therapeutic targets.

Expression Analysis of BDNF Gene and BDNF-AS Long Noncoding RNA in Whole Blood Samples of Multiple Sclerosis Patients: Not Always a Negative Correlation between Them

Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system (CNS), in which axonal damage is a deteriorative factor. Brain-Derived Neurotrophic Factor (BDNF) is described as a neuronal-survival gene, also capable of exerting pleiotropic effects on the immune cells. Here, we aimed to investigate expression levels of BDNF and its antisense RNA, BDNF-AS, in Iranian MS patients. Our case-control study was based on collecting 50 whole blood samples of relapsing-remitting MS patients and 50 healthy controls. Then, expression analysis of BDNF and BDNF-AS was performed by Real-time quantitative PCR. We found a strong and positive correlation between BDNF and BDNF-AS in MS patients. This is while no significant difference in BDNF and BDNF-AS expression levels was seen between MS patients and controls (p>0.05). A significant and strong positive correlation was found between the expression levels of BDNF-AS and BDNF (r=0.785, p<0.0001). Further, significant positive moderate correlations of BDNF and BDNF-AS with other lncRNAs (GSTT1-AS1 and IFNG-AS1) and genes (TNF and IFNG) were revealed (p<0.0001). Additionally, there was no correlation between the BDNF and BDNF-AS expressions and disease duration, age at onset, and Expanded Disability Status Scale of Kurtzke (EDSS) (p>0.05). BDNF and BDNF-AS expression levels revealed insignificant discrepancies in patients and controls. We found a strong and positive correlation between BDNF and BDNF-AS in MS patients, which is, based on previous studies, a quit novel finding and can be further discussed by future works to unravel its possible application in MS. We suggest evaluation of different leukocytes subsets separately along with large cohort studies comprising a higher number of individuals from different ages to unravel the effects of other possible aspects.

The FOXP3 rs3761547 Gene Polymorphism in Multiple Sclerosis as a Male-Specific Risk Factor

The FOXP3 gene encodes a transcription factor and is predominantly expressed in the CD4+CD25+ regulatory T cells which plays a pivotal role in the maintenance of immune homeostasis. The defect of FOXP3 gene may provide a critical link between autoimmunity and immune deficiency. The purpose of our study was to evaluate the association of chosen polymorphisms of FOXP3 gene (rs3761549, rs3761548, rs3761547) with different clinical multiple sclerosis (MS) data of our relapsing-remitting groups of patients and in control group. The study was performed on a group consisting of 174 relapsing-remitting MS patients, diagnosed under 40 years of life, and 174 healthy volunteers. Genotyping was performed using a real-time PCR-based method by TaqMan Assays. Significant differences in distribution of allele C rs3761547 were found in male MS patients in comparison to the male healthy group (p = 0.046, OR 1.95, CI 95%). No association between MS and the other two polymorphisms was observed in males and females of both studied groups. Our data may suggest that FOXP3 rs3761547 gene polymorphism are related notably with the increased risk of MS development in males patients. To our knowledge this is the first study which indicates gender-specific relation between rs3761547 FOXP3 gene polymorphism and multiple sclerosis.

Genome-wide DNA methylation changes in CD19+ B cells from relapsing-remitting multiple sclerosis patients

Multiple Sclerosis (MS) is an inflammatory and neurodegenerative disease of the central nervous system. The inflammatory process in MS is driven by both T and B cells and current therapies are targeted to each of these cell types. Epigenetic mechanisms may provide a valuable link between genes and environment. DNA methylation is the best studied epigenetic mechanism and is recognized as a potential contributor to MS risk. The objective of this study was to identify DNA methylation changes associated with MS in CD19+ B-cells. We performed an epigenome-wide association analysis of DNA methylation in the CD19+ B-cells from 24 patients with relapsing-remitting MS on various treatments and 24 healthy controls using Illumina 450 K arrays. A large differentially methylated region (DMR) was observed at the lymphotoxin alpha (LTA) locus. This region was hypermethylated and contains 19 differentially methylated positions (DMPs) spanning 860 bp, all of which are located within the transcriptional start site. We also observed smaller DMRs at 4 MS-associated genes: SLC44A2, LTBR, CARD11 and CXCR5. These preliminary findings suggest that B-cell specific DNA-methylation may be associated with MS risk or response to therapy, specifically at the LTA locus. Development of B-cell specific epigenetic therapies is an attractive new avenue of research in MS treatment. Further studies are now required to validate these findings and understand their functional significance.

Microarray data of transcriptome shifts in blood cell subsets during S1P receptor modulator therapy

Treatment with fingolimod, a sphingosine-1-phosphate (S1P) receptor modulator, prevents the egress of immune cell subpopulations from lymphoid tissues into the blood. We obtained peripheral blood samples from patients with relapsing multiple sclerosis before the initiation of fingolimod therapy, after one day and after 3 months. To investigate the differential expression induced by the drug, five different cell populations were isolated. We then employed 150 Human Transcriptome Arrays (HTA 2.0) interrogating >245,000 protein-coding and >40,000 non-coding transcript isoforms. After 3 months of treatment, CD4+ and CD8+ T-cells showed huge transcriptome shifts, whereas the profiles of B-cells (CD19+) were slightly altered and those of monocytes (CD14+) and natural killer cells (CD56+) remained unaffected. With >6 million probes for exons and splice junctions, our large HTA 2.0 dataset provides a deep view into alternative splicing patterns in immune cell subsets. Our data may also be useful for comparing the effects on gene expression signatures of novel S1P receptor modulators, which are currently tested in clinical trials for other autoimmune and neurodegenerative diseases.

CpG Island Methylation Patterns in Relapsing-Remitting Multiple Sclerosis

DNA methylation may predispose to multiple sclerosis (MS), as aberrant methylation in the promoter regions across the genome seems to underlie several processes of MS. We have currently determined the methylation status of eight genes in relapsing-remitting MS patients. Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) was used to determine the status of 31 CpG islands, located across eight genes, in 33 healthy individuals and 66 MS patients (33 in relapse and 33 in remission). The methylation levels in the examined sites ranged from 0 to 31%. Methylation positivity for RUNX3 and CDKN2A differed significantly between MS patients and healthy controls. Maximum methylation in RUNX3, CDKN2A, SOCS1, and NEUROG1 genes was significantly different between patients and controls. Roc curves demonstrated that the appropriate cut-offs to distinguish patients from healthy controls were 2% for RUNX3 (OR 3.316, CI 1.207-9.107, p = 0.024) and 3% for CDKN2A (OR 3.077, CI 1.281-7.39, p = 0.018). No difference in methylation was observed between patients in relapse and patients in remission, in any of the genes examined. Methylation patterns of RUNX3 and CDKN2A may be able to distinguish between MS patients and healthy controls, but not between MS patients in relapse and in remission. Graphical Abstract Methylation patterns of RUNX3 and CDKN2A may be able to discriminate healthy individuals from MS patients.

Investigating the exon 6 sequence changes of interleukin 7 receptor A (IL7RA) gene in patients with relapsing-remitting multiple sclerosis

BACKGROUND

Interleukin 7 receptor alpha (IL7RA) gene that encodes a subunit of IL7 receptor has been reported to be associated with different immunologic disease.

OBJECTIVE

Multiple Sclerosis (MS) patients have shown an aberrant blood level of soluble form of IL7R protein. The genomic changes in the sequence of this gene have been suggested to be correlated with its altered splicing specially, variants in the exon 6 of the gene have been reported to influence the maintenance or skipping of this exon and control the soluble or insoluble form of the final product. In order to evaluate this changes in the IL7RA gene and to determine a possible correlation between these changes and the MS susceptibility the whole sequence of the exon 6 and 7 and their flanking sequences were analyzed.

METHODS

In this regard, we investigate the sequence changes of the exon 6 and 7 of the IL7RA gene in 75 relapsing-remitting MS patients and compare the results with 75 healthy control using sequence analyzing.

RESULTS

The results of the sequence analysis were used in two aspects. The allelic and genotypic estimated frequencies of a reported risk variant rs6897932 in patients and controls in our population confirmed its association with the disease (P= 0.009, OR = 6.273, for TT genotype). Also, we report a possible hazardous cutoff for changes in a potential exon splicing silencer element (ESS (nt. 20-24)) and its correlation with rs6897932 to confer the risk of developing MS.

CONCLUSION

In conclusion our results confirm the association between IL7RA exon 6 sequence changes and increased susceptibility for multiple sclerosis.

Down-regulation of RORA gene expression in the blood of multiple sclerosis patients

Multiple sclerosis (MS) is an autoimmune disease characterized by recurrent episodes of demyelination and loss of oligodendrocytes. The demyelination process is caused by various subsets of CD4+ T cells with a Th1 and Th17 phenotype. The retinoid acid-related orphan receptor A (RORA) is expressed in Th17 cells and promote Th17 differentiation. In this study, we compared the expression level of RORA gene in the blood of 50 relapsing-remitting MS (RRMS) patients who were treated with IFN-β and 50 healthy controls by TaqMan Quantitative Real-Time PCR.We found that RORA expression was significantly down-regulated in MS patients compared with controls (P= 0.006). However, there was no significant correlation between RORA gene expression and Kurtzke Expanded Disability Status Scale (EDSS). Our findings suggest a possible contribution of IFN-β in the downregulation of RORA. In addition, RORA downregulation may be a potential indicator of positive response to interferon beta treatment of multiple sclerosis patients.