Applied Reasearch Group, Affymetrix Inc, Santa Clara, California, United States of America.
PLoS One. 2012;7(2):e31241. doi: 10.1371/journal.pone.0031241. Epub 2012 Feb 16.
Inflammatory Bowel Disease--comprised of Crohn's Disease and Ulcerative Colitis (UC)--is a complex, multi-factorial inflammatory disorder of the gastrointestinal tract. In this study we have explored the utility of naturally occurring circulating miRNAs as potential blood-based biomarkers for non-invasive prediction of UC incidences. Whole genome maps of circulating miRNAs in micro-vesicles, Peripheral Blood Mononuclear Cells and platelets have been constructed from a cohort of 20 UC patients and 20 normal individuals. Through Significance Analysis of Microarrays, a signature of 31 differentially expressed platelet-derived miRNAs has been identified and biomarker performance estimated through a non-probabilistic binary linear classification using Support Vector Machines. Through this approach, classifier measurements reveal a predictive score of 92.8% accuracy, 96.2% specificity and 89.5% sensitivity in distinguishing UC patients from normal individuals. Additionally, the platelet-derived biomarker signature can be validated at 88% accuracy through qPCR assays, and a majority of the miRNAs in this panel can be demonstrated to sub-stratify into 4 highly correlated intensity based clusters. Analysis of predicted targets of these biomarkers reveal an enrichment of pathways associated with cytoskeleton assembly, transport, membrane permeability and regulation of transcription factors engaged in a variety of regulatory cascades that are consistent with a cell-mediated immune response model of intestinal inflammation. Interestingly, comparison of the miRNA biomarker panel and genetic loci implicated in IBD through genome-wide association studies identifies a physical linkage between hsa-miR-941 and a UC susceptibility loci located on Chr 20. Taken together, analysis of these expression maps outlines a promising catalog of novel platelet-derived miRNA biomarkers of clinical utility and provides insight into the potential biological function of these candidates in disease pathogenesis.
炎症性肠病（IBD）包括克罗恩病和溃疡性结肠炎（UC），是一种复杂的、多因素的胃肠道炎症性疾病。在这项研究中，我们探讨了天然存在的循环 microRNA 作为潜在的非侵入性预测 UC 发生率的血液生物标志物的应用。我们从 20 名 UC 患者和 20 名正常个体中构建了 microvesicles、外周血单核细胞和血小板中循环 microRNA 的全基因组图谱。通过显著性分析微阵列，鉴定出 31 个差异表达的血小板衍生 microRNA 的特征，并通过支持向量机的非概率二元线性分类估计了生物标志物的性能。通过这种方法，分类器测量结果显示，区分 UC 患者和正常个体的预测评分准确率为 92.8%，特异性为 96.2%，敏感性为 89.5%。此外，通过 qPCR 检测可以验证血小板衍生生物标志物特征的准确性为 88%，并且该面板中的大多数 microRNA 可以证明可以分为 4 个高度相关的基于强度的聚类。对这些生物标志物的预测靶点的分析表明，与细胞骨架组装、运输、膜通透性以及参与各种调节级联的转录因子的调节相关的途径富集，这与肠道炎症的细胞介导免疫反应模型一致。有趣的是，比较 miRNA 生物标志物面板和全基因组关联研究中涉及 IBD 的遗传基因座，发现 hsa-miR-941 与位于 Chr 20 上的 UC 易感性基因座之间存在物理联系。综上所述，这些表达图谱的分析概述了一种有前途的新型血小板衍生 microRNA 生物标志物的临床应用目录，并为这些候选物在疾病发病机制中的潜在生物学功能提供了深入了解。
