Contributions
Abstract: P1115
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - 25 Biomarkers
Background and aims: Multiple Sclerosis (MS) is an autoimmune disease thought to be caused by the interaction of genetic predisposition and the environment. Erythrocytes may contribute to MS pathology through impaired antioxidant capacity and altered haemorheological features. Recent studies discovered an abundance of erythrocyte microRNAs (miRNA) that may be deregulated in disease. MiRNAs control gene expression at the post-transcriptional level and are gaining increasing interest as biomarkers. The aim of this study was to compare the erythrocyte miRNA profiles of relapsing-remitting MS (RRMS) patients to healthy controls (HC).
Methods: Erythrocytes were purified from whole blood by density-gradient centrifugation and RNA was extracted. Samples were sequenced by paired-end 100 bp sequencing on HiSeq4000. Sequenced erythrocyte miRNA profiles (10 RRMS, 9 HC) were analysed by DESeq2. P values were adjusted for false discovery rate. Differentially expressed miRNAs were confirmed with an orthogonal assay and in a replication cohort (20 RRMS, 17 HC) by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) using miR-152-3p as endogenous control. MiRNA targets were predicted by miRSystem. Following logarithmic transformation, differential expression was determined by unpaired two-tailed t-tests. Predictive indices were determined using area under the curve.
Results: High throughput sequencing identified 236 erythrocyte miRNAs, 12 of which were deregulated in RRMS (adj. p< 0.05). RT-qPCR confirmed down-regulation of miR-30b-5p (0.61 fold; p< 0.05) and miR-3200-3p (0.57 fold; p< 0.05) in RRMS. Only minor fold-changes were evident across deregulated miRNAs. However, several down-regulated miRNAs shared targets including SCN3A. No correlations between confirmed miRNAs and disease outcome measures were identified. Relative expression of miR-3200-3p was able to predict RRMS with 76.5% accuracy, 80% sensitivity and 76.5% specificity and relative expression of miR-30b-5p with 72.1% accuracy, 85% sensitivity and 64.7% specificity.
Conclusions: This is the first study to report differences in erythrocyte miRNAs in RRMS. Deregulation of miR-3200-3p has also been observed in Alzheimer disease, possibly indicating shared pathological mechanisms. While the role of miRNAs in mature erythrocytes remains to be elucidated, deregulated miRNAs may be exploited as biomarkers and their potential contribution to MS pathology should be further investigated.
Disclosure: The study was funded by an MS Research Australia Grant.
Professor J Lechner-Scott's institution receives non-directed funding, as well as honoraria for presentations and membership on advisory boards from Sanofi Aventis, Biogen Idec, Bayer Health Care, Merck Serono, Teva, Roche, and Novartis Australia.
K Groen: nothing to disclose.
V Maltby: nothing to disclose.
L Tajouri: nothing to disclose.
R Lea: nothing to disclose.
L Fink: nothing to disclose.
K Sanders: nothing to disclose.
R Scott: nothing to disclose.
Abstract: P1115
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - 25 Biomarkers
Background and aims: Multiple Sclerosis (MS) is an autoimmune disease thought to be caused by the interaction of genetic predisposition and the environment. Erythrocytes may contribute to MS pathology through impaired antioxidant capacity and altered haemorheological features. Recent studies discovered an abundance of erythrocyte microRNAs (miRNA) that may be deregulated in disease. MiRNAs control gene expression at the post-transcriptional level and are gaining increasing interest as biomarkers. The aim of this study was to compare the erythrocyte miRNA profiles of relapsing-remitting MS (RRMS) patients to healthy controls (HC).
Methods: Erythrocytes were purified from whole blood by density-gradient centrifugation and RNA was extracted. Samples were sequenced by paired-end 100 bp sequencing on HiSeq4000. Sequenced erythrocyte miRNA profiles (10 RRMS, 9 HC) were analysed by DESeq2. P values were adjusted for false discovery rate. Differentially expressed miRNAs were confirmed with an orthogonal assay and in a replication cohort (20 RRMS, 17 HC) by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) using miR-152-3p as endogenous control. MiRNA targets were predicted by miRSystem. Following logarithmic transformation, differential expression was determined by unpaired two-tailed t-tests. Predictive indices were determined using area under the curve.
Results: High throughput sequencing identified 236 erythrocyte miRNAs, 12 of which were deregulated in RRMS (adj. p< 0.05). RT-qPCR confirmed down-regulation of miR-30b-5p (0.61 fold; p< 0.05) and miR-3200-3p (0.57 fold; p< 0.05) in RRMS. Only minor fold-changes were evident across deregulated miRNAs. However, several down-regulated miRNAs shared targets including SCN3A. No correlations between confirmed miRNAs and disease outcome measures were identified. Relative expression of miR-3200-3p was able to predict RRMS with 76.5% accuracy, 80% sensitivity and 76.5% specificity and relative expression of miR-30b-5p with 72.1% accuracy, 85% sensitivity and 64.7% specificity.
Conclusions: This is the first study to report differences in erythrocyte miRNAs in RRMS. Deregulation of miR-3200-3p has also been observed in Alzheimer disease, possibly indicating shared pathological mechanisms. While the role of miRNAs in mature erythrocytes remains to be elucidated, deregulated miRNAs may be exploited as biomarkers and their potential contribution to MS pathology should be further investigated.
Disclosure: The study was funded by an MS Research Australia Grant.
Professor J Lechner-Scott's institution receives non-directed funding, as well as honoraria for presentations and membership on advisory boards from Sanofi Aventis, Biogen Idec, Bayer Health Care, Merck Serono, Teva, Roche, and Novartis Australia.
K Groen: nothing to disclose.
V Maltby: nothing to disclose.
L Tajouri: nothing to disclose.
R Lea: nothing to disclose.
L Fink: nothing to disclose.
K Sanders: nothing to disclose.
R Scott: nothing to disclose.