Multiple sclerosis-linked and interferon-beta-regulated gene expression in plasmacytoid dendritic cells

Abstract

The cause of multiple sclerosis (MS) is not known and the mechanism of interferon-beta, a disease-modifying treatment, is not well-understood. We studied gene expression in plasmacytoid dendritic cells (pDCs), antigen-presenting cells implicated in MS pathogenesis. PDCs were separated from healthy donors and MS patients at two time points: before and after initiation of treatment with interferon-beta. Expression of selected MS-linked and interferon-beta-regulated genes was validated with single assays. We have identified 60 genes which were abnormally expressed in MS patients and were corrected after treatment. These genes could be studied as potential MS biomarkers and possible therapeutic targets in MS.

Copyright © 2012 Elsevier B.V. All rights reserved.

Figures

Figure 1. Pharmacogenomic analysis of plasmacytoid dendritic cells (pDCs)

pDCs from 8 healthy donors and 9 MS patients before and after IFN-beta treatment (Before Rx and After Rx) were separated and gene expression analysis was examined by microarrays. The numbers of differentially expressed/regulated genes between subject groups (based on the criteria of p 1.5) are shown.

Figure 2. Expression pattern of “disease-linked and IFN-beta-regulated” genes

The 64 “disease-linked and IFN-beta-regulated” genes were separated into several groups based on change in their expression pattern in the 8 healthy donors (HD), 9 MS patients before treatment (V1), and the same 9 MS patients after treatment with IFN-beta (V2). Thirty-seven genes were up-regulated in untreated MS patients and down-regulated (corrected) by IFN-beta treatment (A). Twenty-seven genes were down-regulated in untreated MS patients and up-regulated (corrected) by IFN-beta treatment (B). Four genes were up-regulated in untreated MS patients and further up-regulated by IFN-beta treatment (C). The Y-axis is the normalized intensity values and each line represents the average normalized expression of a single gene.

Figure 3. Validation of Microarrays Gene Expression results by RT-qPCR

Expression of THBS1 and HSPA1A relative to HPRT1 (house-keeping gene) was measured by RT-qPCR in healthy donors (HD) (n=8) and MS patients before (V1) and after IFN-beta treatment (V2) (n=8). The primers and RT-qPCR conditions are described in the method section. Fold difference in gene expression was calculated using the formula 2−ΔCt.