Neurofilament Proteins as Body Fluid Biomarkers of Neurodegeneration in Multiple Sclerosis

Biomarkers of axonal degeneration have the potential to improve our capacity to predict and monitor neurological outcome in multiple sclerosis (MS) patients. Neurofilament proteins, one of the major proteins expressed within neurons and axons, have been detected in cerebrospinal fluid and blood samples from MS patients and are now being actively investigated for their utility as prognostic indicators of disease progression in MS. In this paper, we summarize the current literature on neurofilament structure, assembly, and degeneration and discuss their potential utility as biomarkers for monitoring neurological decline in MS. We also discuss the need to further develop sensitive methods for assaying neurofilaments in blood to improve clinical applicability

Causes of Multiple Sclerosis: a functional genomics approach

Multiple Sclerosis (MS) is the most common disabling neurological disease affecting young adults in Western Society. To date, 55 strongly associated single nucleotide polymorphisms have been discovered. We now need to identify causal genes. While T-cells as targets for therapeutic intervention have rarely proven useful, there is strong clinical and in-vitro data identifying NK cell deficiencies in patients, and key roles for monocytes in myelin and axon destruction and autoantigen presentation. RNA extracted from magnetic bead sorted monocytes and NK cells, of healthy controls (HC) and untreated patients with relapsing remitting MS (RRMS), was labelled and hybridised to Affymetrix Human Gene 1.0 ST arrays. Expression values were standardized across chips using RMA and quantile normalization as implemented in GenePattern. Genes were ranked by expression difference significance by Mann Whitney U test and ANOVA. To date, we have analysed monocytes of 30 patients and 39 HC, and NK cells from 25 patients and 32 HC. Expression differences of those genes adjacent to MS associated risk SNPs lying between 110kb upstream and 40kb downstream of a candidate gene were considered. We have identified three genes worthy of further analysis on this basis: RGS1, HHEX and THEMIS. To test the relevance of these candidates to central nervous system (CNS) autoimmunity, we aim to mimic phenotypes associated with these expression quantitative trait loci (eQTL) in in-vitro cultures of purified NK cells and monocytes, and in-vivo in a mouse model of MS - experimental autoimmune encephalomyelitis (EAE)

Multiple Sclerosis risk variants regulate gene expression in innate and adaptive immune cells

At least 200 single-nucleotide polymorphisms (SNPs) are associated with multiple sclerosis (MS) risk. A key function that could mediate SNP-encoded MS risk is their regulatory effects on gene expression. We performed microarrays using RNA extracted from purified immune cell types from 73 untreated MS cases and 97 healthy controls and then performed Cis expression quantitative trait loci mapping studies using additive linear models. We describe MS risk expression quantitative trait loci associations for 129 distinct genes. By extending these models to include an interaction term between genotype and phenotype, we identify MS risk SNPs with opposing effects on gene expression in cases compared with controls, namely, rs2256814 MYT1 in CD4 cells (q = 0.05) and rs12087340 RF00136 in monocyte cells (q = 0.04). The rs703842 SNP was also associated with a differential effect size on the expression of the METTL21B gene in CD8 cells of MS cases relative to controls (q = 0.03). Our study provides a detailed map of MS risk loci that function by regulating gene expression in cell types relevant to MS

Common and low Frequency variants in MERTK are independently associated with multiple sclerosis susceptibility with discordant association dependent upon HLA-DRB1*15:01 status

Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. The risk of developing MS is strongly influenced by genetic predisposition, and over 100 loci have been established as associated with susceptibility. However, the biologically relevant variants underlying disease risk have not been defined for the vast majority of these loci, limiting the power of these genetic studies to define new avenues of research for the development of MS therapeutics. It is therefore crucial that candidate MS susceptibility loci are carefully investigated to identify the biological mechanism linking genetic polymorphism at a given gene to the increased chance of developing MS. MERTK has been established as an MS susceptibility gene and is part of a family of receptor tyrosine kinases known to be involved in the pathogenesis of demyelinating disease. In this study we have refined the association of MERTK with MS risk to independent signals from both common and low frequency variants. One of the associated variants was also found to be linked with increased expression of MERTK in monocytes and higher expression of MERTK was associated with either increased or decreased risk of developing MS, dependent upon HLA-DRB1*15:01 status. This discordant association potentially extended beyond MS susceptibility to alterations in disease course in established MS. This study provides clear evidence that distinct polymorphisms within MERTK are associated with MS susceptibility, one of which has the potential to alter MERTK transcription, which in turn can alter both susceptibility and disease course in MS patients

Natalizumab, Fingolimod and Dimethyl Fumarate Use and Pregnancy-Related Relapse and Disability in Women With Multiple Sclerosis

To investigate pregnancy-related disease activity in a contemporary multiple sclerosis (MS) cohort

Vaginally Administered PEGylated LIF Antagonist Blocked Embryo Implantation and Eliminated Non-Target Effects on Bone in Mice

Female-controlled contraception/HIV prevention is critical to address health issues associated with gender inequality. Therefore, a contraceptive which can be administered in tandem with a microbicide to inhibit sexually transmitted infections, is desirable. Uterine leukemia inhibitory factor (LIF) is obligatory for blastocyst implantation in mice and associated with infertility in women. We aimed to determine whether a PEGylated LIF inhibitor (PEGLA) was an effective contraceptive following vaginal delivery and to identify non-uterine targets of PEGLA in mice

Review Article Neurofilament Proteins as Body Fluid Biomarkers of Neurodegeneration in Multiple Sclerosis

Biomarkers of axonal degeneration have the potential to improve our capacity to predict and monitor neurological outcome in multiple sclerosis (MS) patients. Neurofilament proteins, one of the major proteins expressed within neurons and axons, have been detected in cerebrospinal fluid and blood samples from MS patients and are now being actively investigated for their utility as prognostic indicators of disease progression in MS. In this paper, we summarize the current literature on neurofilament structure, assembly, and degeneration and discuss their potential utility as biomarkers for monitoring neurological decline in MS. We also discuss the need to further develop sensitive methods for assaying neurofilaments in blood to improve clinical applicability

Multiple Sclerosis risk SNPs modify gene expression in immune cells

Background: Population based genome wide association studies have identified 110 single nucleotide polymorphisms (SNPs) that are associated with an increase in MS risk. These SNPs are all common, and have odds ratios of between 1.1 and 1.4. Most are found in non-protein coding regions, and their functions are largely unknown. Objectives: Importantly, recent work has shown that some non-coding SNPs can function by changing immune gene expression levels as a quantitative trait, termed expression quantitative trait loci (eQTL). We conducted studies to evaluate the effects of MS risk SNPs on gene expression in four main immune cell types. Methods: We isolated monocytes, B-cells, CD4- and CD8- T-cells from untreated relapsing MS cases (n=79) and healthy controls (n=101). To test for cis-eQTL associations, we selected all genes within +/-500kb of an MS risk SNP (2500 pairs in total). The Illumina Immunochip was used to genotype for MS risk SNPs, and gene expression was measured for each cell type by microarray. Results: We have identified MS risk eQTL associations in each immune cell type, some of which are cell type specific. We also present preliminary data showing that some MS risk SNPs could exert differential effects on gene expression in cases compared to controls. Here we report likely disease state specific eQTLs for all cell types with the top associations being: RNF26/rs9736016, B cells; MACROD1/rs694739, CD8 cells; SLC25A41/rs1077667, CD4 cells; GPR18/rs4772201, monocyte cells. Conclusions: We have shown that MS risk SNPs contribute to immune heterogeneity. It is hoped that through an understanding of the functions of individual common risk variants, it may be possible to uncover the processes and cell types that are most important for conveying the genetic risk of MS

Transcriptomics identifies blunted immunomodulatory effects of vitamin D in people with multiple sclerosis

Vitamin D deficiency is a risk factor for developing multiple sclerosis (MS). However, the immune effects of vitamin D in people with MS are not well understood. We analyzed transcriptomic datasets generated by RNA sequencing of immune cell subsets (CD4+, CD8+ T cells, B cells, monocytes) from 33 healthy controls and 33 untreated MS cases. We utilized a traditional bioinformatic pipeline and weighted gene co-expression network analysis (WGCNA) to determine genes and pathways correlated with endogenous vitamin D. In controls, CD4+ and CD8+ T cells had 1079 and 1188 genes, respectively, whose expressions were correlated with plasma 25-hydroxyvitamin D level (P + T cells of controls, vitamin D level was associated with expression levels of several genes proximal to multiple sclerosis risk loci (P = 0.01). Genes differentially associated with endogenous vitamin D by case–control status were enriched in TNF-alpha signaling via NF-κB. WGCNA suggested a blunted response to vitamin D in cases relative to controls. Collectively, our findings provide further evidence for the immune effects of vitamin D, and demonstrate a differential immune response to vitamin D in cases relative to controls, highlighting a possible mechanism contributing to MS pathophysiology.</p

Journal of economics & management strategy : JEMS

Leukemia inhibitory factor (LIF) and Ciliary Neurotrophic factor (CNTF) are members of the interleukin-6 family of cytokines, defined by use of the gp130 molecule as an obligate receptor. In the murine experimental autoimmune encephalomyelitis (EAE) model, antagonism of LIF and genetic deletion of CNTF worsen disease. The potential mechanism of action of these cytokines in EAE is complex, as gp130 is expressed by all neural cells, and could involve immuno-modulation, reduction of oligodendrocyte injury, neuronal protection, or a combination of these actions. In this study we aim to investigate whether the beneficial effects of CNTF/LIF signalling in EAE are associated with axonal protection; and whether this requires signalling through oligodendrocytes. We induced MOG(35–55) EAE in CNTF, LIF and double knockout mice. On a CNTF null background, LIF knockout was associated with increased EAE severity (EAE grade 2.1±0.14 vs 2.6±0.19; P<0.05). These mice also showed increased axonal damage relative to LIF heterozygous mice, as indicated by decreased optic nerve parallel diffusivity on MRI (1540±207 µm(2)−/s vs 1310±175 µm(2)−/s; P<0.05), and optic nerve (−12.5%) and spinal cord (−16%) axon densities; and increased serum neurofilament-H levels (2.5 fold increase). No differences in inflammatory cell numbers or peripheral auto-immune T-cell priming were evident. Oligodendrocyte-targeted gp130 knockout mice showed that disruption of CNTF/LIF signalling in these cells has no effect on acute EAE severity. These studies demonstrate that endogenous CNTF and LIF act centrally to protect axons from acute inflammatory destruction via an oligodendrocyte-independent mechanism