TRAIL/TRAIL Receptor System and Susceptibility to Multiple Sclerosis

The TNF-related apoptosis inducing ligand (TRAIL)/TRAIL receptor system participates in crucial steps in immune cell activation or differentiation. It is able to inhibit proliferation and activation of T cells and to induce apoptosis of neurons and oligodendrocytes, and seems to be implicated in autoimmune diseases. Thus, TRAIL and TRAIL receptor genes are potential candidates for involvement in susceptibility to multiple sclerosis (MS). To test whether single-nucleotide polymorphisms (SNPs) in the human genes encoding TRAIL, TRAILR-1, TRAILR-2, TRAILR-3 and TRAILR-4 are associated with MS susceptibility, we performed a candidate gene case-control study in the Spanish population. 59 SNPs in the TRAIL and TRAIL receptor genes were analysed in 628 MS patients and 660 controls, and validated in an additional cohort of 295 MS patients and 233 controls. Despite none of the SNPs withstood the highly conservative Bonferroni correction, three SNPs showing uncorrected p values<0.05 were successfully replicated: rs4894559 in TRAIL gene, p = 9.8×10−4, OR = 1.34; rs4872077, in TRAILR-1 gene, p = 0.005, OR = 1.72; and rs1001793 in TRAILR-2 gene, p = 0.012, OR = 0.84. The combination of the alleles G/T/A in these SNPs appears to be associated with a reduced risk of developing MS (p = 2.12×10−5, OR = 0.59). These results suggest that genes of the TRAIL/TRAIL receptor system exerts a genetic influence on MS

Global methylation correlates with clinical status in multiple sclerosis patients in the first year of IFNbeta treatment.

The alteration of DNA methylation patterns are a key component of disease onset and/or progression. Our objective was to evaluate the differences in Long Interspersed Nuclear Element-1 (LINE-1) methylation levels, as a surrogate marker of global DNA methylation, between multiple sclerosis (MS) patients and healthy controls. In addition, we assessed the association of LINE-1 methylation with clinical disease activity in patients treated with IFNbeta (IFNβ). We found that individuals with high levels of LINE-1 methylation showed 6-fold increased risk of suffering MS. Additionally, treated MS patients who bear high LINE-1 methylation levels had an 11-fold increased risk of clinical activity. Moreover, a negative correlation between treatment duration and percentage of LINE-1 methylation, that was statistically significant exclusively in the group of patients without clinical activity, was observed. Our data suggest that in MS patients, a slight global DNA hypermethylation occurs that may be related to the pathophysiology of the disease. In addition, global DNA methylation levels could play a role as a biomarker for the differential clinical response to IFNβ

TRAIL and TRAIL receptors splice variants during long-term interferon β treatment of patients with multiple sclerosis: evaluation as biomarkers for therapeutic response.

We aimed to assess the effects of interferon β (IFNβ) treatment on the expression of the splice variants of the Tumour necrosis factor-Related Apoptosis Inducing Ligand (TRAIL) and its receptors in different cell subpopulations (CD14+, CD4+ and CD8+) from patients with multiple sclerosis (MS), and to determine whether this expression discriminated responders from non-responders to IFNβ therapy. We examined mRNA expression of the TRAIL and TRAIL receptors variants in patients with MS, at baseline and after one year of IFNβ therapy, according to responsiveness to this drug. Long-term therapy with IFNβ increased the expression of TRAIL-α in T cell subsets exclusively from responders and decreased the expression of the isoform 2 of TRAILR-2 in monocytes from responders as well as non-responders. Lower expression of TRAIL-α, and higher expression of TRAIL-β in monocytes and T cells, was found before the onset of IFNβ therapy in patients who will subsequently become responders. Baseline expression of TRAILR-1 was also significantly higher in monocytes and CD4+ T cells from responders. The present study shows that long-term IFNβ treatment has a direct influence on TRAIL-α and TRAILR-2 isoform 2 expression. Besides, receiver operating characteristic analysis revealed that the baseline expression of TRAIL-α in monocytes and T cells, and that of TRAILR-1 in monocytes and CD4+ T cells, showed a predictive value of the clinical response to IFNβ therapy, pointing to a role of TRAIL system in the mechanism of action of IFNβ in MS that will need further investigation

Skin Phototype Could Be a Risk Factor for Multiple Sclerosis

Environmental and genetic factors are assumed to be necessary for the development of multiple sclerosis (MS), however its interactions are still unclear. For this reason here, we have not only analyzed the impact on increased risk of MS of the best known factors (HLA-DRB1*15:01 allele, sun exposure, vitamin D levels, smoking habit), but we have included another factor (skin phototype) that has not been analyzed in depth until now. This study included 149 MS patients and 147 controls. A multivariate logistic regression (LR) model was carried out to determine the impact of each of the factors on the increased risk of MS. Receiver Operating Characteristics (ROC) analysis was performed to evaluate predictive value of the models. Our multifactorial LR model of susceptibility showed that females with light brown skin (LBS), smokers and who had HLA-DRB1*15:01 allele had a higher MS risk (LBS: OR = 5.90, IC95% = 2.39&ndash;15.45; smoker: OR = 4.52, IC95% = 2.69&ndash;7.72; presence of HLA-DRB1*15:01: OR = 2.39, IC95% = 1.30&ndash;4.50; female: OR = 1.88, IC95% = 1.08&ndash;3.30). This model had an acceptable discriminant value with an Area Under a Curve AUC of 0.76 (0.69&ndash;0.82). Our study indicates that MS risk is determined by complex interactions between sex, environmental factors, and genotype where the milieu could provide the enabling proinflammatory environment that drives an autoimmune attack against myelin by self-reactive lymphocytes

Predictive factors and early biomarkers of response in multiple sclerosis patients treated with natalizumab.

There are an increasing number of treatments available for multiple sclerosis (MS). The early identification of optimal responders to individual treatments is important to achieve individualized therapy. With this aim, we performed a multicenter retrospective longitudinal study including 186 MS patients treated with natalizumab who were followed for 2 years. We analyzed the following variables at recruitment: sex, current age, age at disease onset, disease duration, EDSS, number of T2 and Gd + lesions, IgG and IgM oligoclonal bands, HLA class II (DR, DRB, DQA, DQB, and DRB1*15:01), IgG and IgM antibody titers against human herpesvirus 6 (HHV-6) and the antibody response to Epstein-Barr virus (EBV) through the measurement of the anti-EBNA-1 and anti-VCA IgG titers, in relation to clinical response (no relapses or disability progression), and to NEDA-3 (no evidence of disease activity in terms of clinical response and no changes in MRI scans either) after 2-years follow-up. Baseline EDSS score, baseline EBNA-1 IgG titers and percentage change of HHV6 IgG titers between baseline and 6 month visits were significantly different in clinical responders and in NEDA-3 status (all of them remained significant in the multivariate analysis). We identified three variables for the early identification of natalizumab optimal responders in a rapid and cost-effective approach

The autoimmune disease-associated KIF5A, CD226 and SH2B3 gene variants confer susceptibility for multiple sclerosis

Genome-wide association studies (GWAS) have revealed that different diseases share susceptibility variants. Twelve single-nucleotide polymorphisms (SNPs) previously associated with different immune-mediated diseases in GWAS were genotyped in a Caucasian Spanish population of 2864 multiple sclerosis (MS) patients and 2930 controls. Three SNPs were found to be associated with MS: rs1678542 in KIF5A (P0.001, odds ratio (OR)1.13, 95% confidence interval (CI)1.05-1.23); rs3184504 in SH2B3 (P0.00001, OR1.19, 95% CI1.10-1.27) and rs763361 in CD226 (P0.00007, OR1.16, 95%CI1.08-1.25). These variants have previously been associated with rheumatoid arthritis and type 1 diabetes. The SH2B3 polymorphism has additionally been associated with systemic lupus erythematosus. Our results, in addition to validating some of these loci as risk factors for MS, are consistent with shared genetic mechanisms underlying different immune-mediated diseases. These data may help to shape the contribution of each pathway to different disorders. © 2010 Macmillan Publishers Limited All rights reserved.Peer Reviewe

Replication study of 10 genes showing evidence for association with multiple sclerosis: Validation of TMEM39A, IL12B and CLBL genes

Background and objectives: Ten genes previously showing different evidence of association with multiple sclerosis have been selected to validate. Methods: Eleven polymorphisms were genotyped with the iPLEX™ Sequenom in a well-powered collection of Spanish origin including 2863 multiple sclerosis cases and 2930 controls. Results: Replication extended to the following polymorphisms: PKN2 (rs305217), GTF2B (rs7538427), EPHA4 (rs1517440), YTHDF3 (rs12115114), ANKFN1 (rs17758761) and PTPRM (rs4798571), which did not reach the threshold of significance in a follow-up of the first genome-wide association study (GWAS) conducted in multiple sclerosis; TMEM39A (rs1132200), which appeared as a newly identified susceptibility gene in the same study; a gene previously reaching GWAS significance in Italy, CBLB (rs9657904); IL12B (rs6887695, rs10045431), a susceptibility gene shared by diverse autoimmune diseases and, finally, another gene showing inconclusive association with multiple sclerosis, CNR1 (rs1049353). Conclusions: Pooled analysis corroborated the effect on MS predisposition of three genes: TMEM39A [rs1132200: p M-H=0.001; OR M-H (95% CI)= 0.84 (0.75-0.93)], IL12B [rs6887695: p M-H=0.03; OR M-H (95% CI)= 1.09 (1.01-1.17)] and CBLB [rs9657904: p M-H=0.01; OR M-H (95% CI)= 0.89 (0.81-0.97)]. © The Author(s) 2012.Peer Reviewe

TRAILR-1 expression levels among Responders and Non Responders to IFN beta therapy, in different PBMC subsets.

<p>Expression level is represented as relative expression compared to the reference gene GAPDH, using the ΔΔCt method. TRAILR-1 expression levels between responder and non responder patients to IFN beta therapy in each of the assessed cell subsets were compared by a Mann Whitney test.</p

Molecular dynamics simulations of Glu228Ala SNP in TRAILR-1.

<p>A and C corresponds to the superimposed structures of the 50s and 90s loops respectively in the initial (green) and final (orange) model of the <b>wild type</b> of TRAILR-1 (Glutamatic acid at position 228). B and D corresponds to the superimposed structures of the loops in the initial (green) and final (brown) model of the <b>mutant type</b> of TRAILR-1 (Alanine at position 228).</p