Contributions
Abstract: P1617
Type: LB Poster
Abstract Category: Late Breaking News
Introduction: MicroRNAs are small non-coding RNAs that are involved in numerous cellular processes. They are increasingly recognized as molecules that regulate the immune response, notably in multiple sclerosis (MS). Several publications have analysed miRNAs in different biological compartments. Results are however variable across studies. This study aims to analyse in parallel the expression of miRNAs in serum, peripheral blood mononuclear cells (PBMCs) and the cerebrospinal fluid (CSF) of MS patients.
Methods: two 84-plex qPCR assays from Qiagen (specific for T/B-cell activation and inflammatory response/auto-immunity) using a pool from 10 MS patients (in relapse) and 10 healthy control subjects (HC) were performed on CSF, serum and PBMCs. In parallel, selected miRNAs were amplified by qPCR from the three compartments in individual samples. In order to further validate results on the CSF, the sample size was increased (relapsing MS: n=42; stable MS: n=15; HC: n=17). Relative amount of transcripts were expressed by normalization against either an exogenous spiked-in control miRNA (cel-miR-39) or an endogenous miRNA (miR-24), using the comparative Ct method (2-ΔΔCt).
Results: The PCR arrays identified more deregulated miRNAs in the CSF than in other compartments (17 versus only 2 in the serum and 3 in PBMCs). In the validation cohort, using both normalization strategies, we confirmed the upregulation of miR-150 in the CSF of relapsing MS patients versus HC (p< 0.005). Additionally, we identified several CSF miRNAs that were differentially expressed according to disease activity: miR-34a and miR-155 levels were increased in stable MS patients in comparison to HC (p< 0.001 and p< 0.005 respectively). On the contrary, miR-20a levels were decreased in stable MS patients (p< 0.05). No differences for these miRNAs were found in the serum or PBMCs across all subgroups.
Conclusions: Using our approach, more differentially deregulated miRNAs are found in the CSF but not in the serum or PBMCs of MS patients. miR-150 is identified as a novel candidate biomarker, increased in the CSF of relapsing MS patients. Other miRNAs are differentially expressed according to disease activity, opening up perspectives in the analysis of their targets and of the pathophysiological mechanisms involved.
This work was supported by Bayer Schering Research Grants. We thank Qiagen for graciously performing the multiplex qPCR assays.
Disclosure: V. van Pesch has received travel grants from Biogen, Bayer Schering, Genzyme, Merck, Teva and Novartis Pharma. His institution receives honoraria for consultancy and lectures from Biogen, Bayer Schering, Genzyme, Merck, Roche, Teva and Novartis Pharma as well as research grants from Novartis Pharma and Bayer Schering.
H.A. Dang has nothing to disclose.
Abstract: P1617
Type: LB Poster
Abstract Category: Late Breaking News
Introduction: MicroRNAs are small non-coding RNAs that are involved in numerous cellular processes. They are increasingly recognized as molecules that regulate the immune response, notably in multiple sclerosis (MS). Several publications have analysed miRNAs in different biological compartments. Results are however variable across studies. This study aims to analyse in parallel the expression of miRNAs in serum, peripheral blood mononuclear cells (PBMCs) and the cerebrospinal fluid (CSF) of MS patients.
Methods: two 84-plex qPCR assays from Qiagen (specific for T/B-cell activation and inflammatory response/auto-immunity) using a pool from 10 MS patients (in relapse) and 10 healthy control subjects (HC) were performed on CSF, serum and PBMCs. In parallel, selected miRNAs were amplified by qPCR from the three compartments in individual samples. In order to further validate results on the CSF, the sample size was increased (relapsing MS: n=42; stable MS: n=15; HC: n=17). Relative amount of transcripts were expressed by normalization against either an exogenous spiked-in control miRNA (cel-miR-39) or an endogenous miRNA (miR-24), using the comparative Ct method (2-ΔΔCt).
Results: The PCR arrays identified more deregulated miRNAs in the CSF than in other compartments (17 versus only 2 in the serum and 3 in PBMCs). In the validation cohort, using both normalization strategies, we confirmed the upregulation of miR-150 in the CSF of relapsing MS patients versus HC (p< 0.005). Additionally, we identified several CSF miRNAs that were differentially expressed according to disease activity: miR-34a and miR-155 levels were increased in stable MS patients in comparison to HC (p< 0.001 and p< 0.005 respectively). On the contrary, miR-20a levels were decreased in stable MS patients (p< 0.05). No differences for these miRNAs were found in the serum or PBMCs across all subgroups.
Conclusions: Using our approach, more differentially deregulated miRNAs are found in the CSF but not in the serum or PBMCs of MS patients. miR-150 is identified as a novel candidate biomarker, increased in the CSF of relapsing MS patients. Other miRNAs are differentially expressed according to disease activity, opening up perspectives in the analysis of their targets and of the pathophysiological mechanisms involved.
This work was supported by Bayer Schering Research Grants. We thank Qiagen for graciously performing the multiplex qPCR assays.
Disclosure: V. van Pesch has received travel grants from Biogen, Bayer Schering, Genzyme, Merck, Teva and Novartis Pharma. His institution receives honoraria for consultancy and lectures from Biogen, Bayer Schering, Genzyme, Merck, Roche, Teva and Novartis Pharma as well as research grants from Novartis Pharma and Bayer Schering.
H.A. Dang has nothing to disclose.