Contributions
Abstract: EP1470
Type: ePoster
Abstract Category: Pathology and pathogenesis of MS - 14 Genetics/Epigenetics
Background and aims: The mode of action of the MS disease modifying therapy Dimethyl fumarate (DMF) is thought to be via the nuclear factor-like 2 pathway, leading to transcription of anti-inflammatory and cytoprotective genes. We have recently described significant differences in the methylation profile of CD4+ T-cells of MS patients compared to age and gender- matched controls. In this study we explored if DMF can change the CD4+ T-cell methylation profile.
Methods: Peripheral Blood Mononuclear Cells (PBMCs) were isolated by density gradient centrifugation on lymphoprep, and CD4+ T-cells enriched using EasySep magnetic negative selection from 7 relapsing remitting MS patients before and 6 months after treatment with DMF. Change in methylation was calculated using paired Tests. Point-wise FDRs and magnitude of change was used to rank CpGs.DNA was bisulfite converted and hybridized to Illumina EPIC methylation arrays and analysed as previously described (Graves et al 2013). Data was background corrected and control-normalized aligned to the human genome using BOWTIE. Methylation levels were produced from each probe and ranged from 0 (completely unmethylated) to 1 (completely methylated). Change in methylation was calculated by subtracting the median values of group 1 to group 2 to produce scores ranging from -1 (hypomethylation) to 1 (hypermethylation).
Results: We included 3 males and 4 females with a mean age of 35 years, 3 of which were treatment naïve. Mean disease duration was 2.8 years, mean EDSS 2.1 and an annual relapse rate of 1.1 prior to treatment. In total 1347 CpGs showed a change in methylation over time (FDR< 0.05) with 97% showing an increase in methylation, while only 3% showed a decrease. 216 CpGs had a larger than 10% difference in methylation. Most methylated regions were in known genes. GSEA-KEGG of the 1347 CpGs showed pathways involved in Wnt-signalling, axon guidance, focal adhesion and MAPK enriched. In particular tumour necrosis factor (TNF) on chromosome 6 showed increased methylation associated with DMF treatment. This is in contrast to our previous study where we demonstrated that this gene was significantly hypomethylated in MS patients compared to controls.
Conclusion: This study suggests that DMF potentially alters the methylation profile of CD4+ T-cells in MS patients. We have previously shown that TNF is differentially methylated in MS patients compared to healthy individuals. This effect might to be corrected by DMF treatment.
Disclosure:
Jeannette Lechner-Scott: accepted travel compensation from Novartis, Biogen and Merck. Her institution receives the honoraria for talks and advisory board commitment from Bayer Health Care, Biogen, Genzyme Sanofi, Merck, Novartis, Teva and Roche, has been involved in clinical trials with Biogen, Novartis and Teva.
Vicki E.Maltby: Nothing to disclose.
Karen Ribbons: Nothing to disclose.
Myintzu Min: Nothing to disclose.
Rod Lea: Nothing to disclose.
Abstract: EP1470
Type: ePoster
Abstract Category: Pathology and pathogenesis of MS - 14 Genetics/Epigenetics
Background and aims: The mode of action of the MS disease modifying therapy Dimethyl fumarate (DMF) is thought to be via the nuclear factor-like 2 pathway, leading to transcription of anti-inflammatory and cytoprotective genes. We have recently described significant differences in the methylation profile of CD4+ T-cells of MS patients compared to age and gender- matched controls. In this study we explored if DMF can change the CD4+ T-cell methylation profile.
Methods: Peripheral Blood Mononuclear Cells (PBMCs) were isolated by density gradient centrifugation on lymphoprep, and CD4+ T-cells enriched using EasySep magnetic negative selection from 7 relapsing remitting MS patients before and 6 months after treatment with DMF. Change in methylation was calculated using paired Tests. Point-wise FDRs and magnitude of change was used to rank CpGs.DNA was bisulfite converted and hybridized to Illumina EPIC methylation arrays and analysed as previously described (Graves et al 2013). Data was background corrected and control-normalized aligned to the human genome using BOWTIE. Methylation levels were produced from each probe and ranged from 0 (completely unmethylated) to 1 (completely methylated). Change in methylation was calculated by subtracting the median values of group 1 to group 2 to produce scores ranging from -1 (hypomethylation) to 1 (hypermethylation).
Results: We included 3 males and 4 females with a mean age of 35 years, 3 of which were treatment naïve. Mean disease duration was 2.8 years, mean EDSS 2.1 and an annual relapse rate of 1.1 prior to treatment. In total 1347 CpGs showed a change in methylation over time (FDR< 0.05) with 97% showing an increase in methylation, while only 3% showed a decrease. 216 CpGs had a larger than 10% difference in methylation. Most methylated regions were in known genes. GSEA-KEGG of the 1347 CpGs showed pathways involved in Wnt-signalling, axon guidance, focal adhesion and MAPK enriched. In particular tumour necrosis factor (TNF) on chromosome 6 showed increased methylation associated with DMF treatment. This is in contrast to our previous study where we demonstrated that this gene was significantly hypomethylated in MS patients compared to controls.
Conclusion: This study suggests that DMF potentially alters the methylation profile of CD4+ T-cells in MS patients. We have previously shown that TNF is differentially methylated in MS patients compared to healthy individuals. This effect might to be corrected by DMF treatment.
Disclosure:
Jeannette Lechner-Scott: accepted travel compensation from Novartis, Biogen and Merck. Her institution receives the honoraria for talks and advisory board commitment from Bayer Health Care, Biogen, Genzyme Sanofi, Merck, Novartis, Teva and Roche, has been involved in clinical trials with Biogen, Novartis and Teva.
Vicki E.Maltby: Nothing to disclose.
Karen Ribbons: Nothing to disclose.
Myintzu Min: Nothing to disclose.
Rod Lea: Nothing to disclose.