Paraboschi Elvezia Maria, Cardamone Giulia, Rimoldi Valeria, Gemmati Donato, Spreafico Marta, Duga Stefano, Soldà Giulia, Asselta Rosanna
Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Via Viotti 3/5, Milan 20133, Italy.
Department of Biomedical Sciences, Humanitas University, Via Manzoni 113, Rozzano, Milan 20089, Italy.
Int J Mol Sci. 2015 Sep 30;16(10):23463-81. doi: 10.3390/ijms161023463.
Abnormalities in RNA metabolism and alternative splicing (AS) are emerging as important players in complex disease phenotypes. In particular, accumulating evidence suggests the existence of pathogenic links between multiple sclerosis (MS) and altered AS, including functional studies showing that an imbalance in alternatively-spliced isoforms may contribute to disease etiology. Here, we tested whether the altered expression of AS-related genes represents a MS-specific signature. A comprehensive comparative analysis of gene expression profiles of publicly-available microarray datasets (190 MS cases, 182 controls), followed by gene-ontology enrichment analysis, highlighted a significant enrichment for differentially-expressed genes involved in RNA metabolism/AS. In detail, a total of 17 genes were found to be differentially expressed in MS in multiple datasets, with CELF1 being dysregulated in five out of seven studies. We confirmed CELF1 downregulation in MS (p=0.0015) by real-time RT-PCRs on RNA extracted from blood cells of 30 cases and 30 controls. As a proof of concept, we experimentally verified the unbalance in alternatively-spliced isoforms in MS of the NFAT5 gene, a putative CELF1 target. In conclusion, for the first time we provide evidence of a consistent dysregulation of splicing-related genes in MS and we discuss its possible implications in modulating specific AS events in MS susceptibility genes.
RNA代谢和可变剪接（AS）异常正逐渐成为复杂疾病表型中的重要因素。特别是，越来越多的证据表明多发性硬化症（MS）与AS改变之间存在致病联系，包括功能研究表明可变剪接异构体的失衡可能导致疾病病因。在此，我们测试了AS相关基因表达的改变是否代表MS特异性特征。对公开可用的微阵列数据集（190例MS病例，182例对照）的基因表达谱进行全面比较分析，随后进行基因本体富集分析，结果突出显示参与RNA代谢/AS的差异表达基因显著富集。具体而言，在多个数据集中共发现17个基因在MS中差异表达，其中CELF1在七项研究中的五项中表达失调。我们通过对30例病例和30例对照血细胞提取的RNA进行实时RT-PCR，证实了MS中CELF1的下调（p = 0.0015）。作为概念验证，我们通过实验验证了MS中NFAT5基因可变剪接异构体的失衡，NFAT5基因是一个假定的CELF1靶点。总之，我们首次提供了MS中剪接相关基因一致失调的证据，并讨论了其在调节MS易感基因中特定AS事件方面的可能意义。
