Department of Rheumatology & Clinical Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.
Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.
PLoS One. 2018 Feb 15;13(2):e0193157. doi: 10.1371/journal.pone.0193157. eCollection 2018.
Considering the important role of miRNAs in the regulation of post-transcriptional expression of target genes, we investigated circulating small non-coding RNAs (snc)RNA levels in patients with primary Sjögren's syndrome (pSS). In addition we assessed if serum sncRNA levels can be used to differentiate patients with specific disease features.
Serum RNA was isolated from 37 pSS patients as well as 21 patients with incomplete Sjögren's Syndrome (iSS) and 17 healthy controls (HC) allocated to two independent cohorts: discovery and validation. OpenArray profiling of 758 sncRNAs was performed in the discovery cohort. Selected sncRNAs were measured in the validation cohort using single-assay RT-qPCR. In addition, unsupervised hierarchical clustering was performed within the pSS group.
Ten sncRNAs were differentially expressed between the groups in the array. In the validation cohort, we confirmed the increased expression of U6-snRNA and miR-661 in the iSS group as compared to HC. We were unable to validate differential expression of any miRNAs in the pSS group. However, within this group several miRNAs correlated with laboratory parameters. Unsupervised clustering distinguished three clusters of pSS patients. Patients in one cluster showed significantly higher serum IgG, prevalence of anti-SSB autoantibodies, IFN-score, and decreased leukocyte counts compared to the two other clusters.
We were unable to identify any serum sncRNAs with differential expression in pSS patients. However, we show that circulating miRNA levels are associated with disease parameters in pSS patients and can be used to distinguish pSS patients with more severe B cell hyperactivity. As several of these miRNAs are implicated in the regulation of B cells, they may play a role in the perpetuation of the disease.
鉴于 miRNAs 在调节靶基因的转录后表达中的重要作用，我们研究了原发性干燥综合征（pSS）患者循环中的小非编码 RNA（sncRNA）水平。此外，我们评估了血清 sncRNA 水平是否可用于区分具有特定疾病特征的患者。
从 37 例 pSS 患者、21 例不典型干燥综合征（iSS）患者和 17 例健康对照者（HC）中分离血清 RNA，并将其分为两个独立的队列：发现队列和验证队列。在发现队列中进行了 758 个 sncRNA 的 OpenArray 分析。使用单测定 RT-qPCR 在验证队列中测量了选定的 sncRNA。此外，还对 pSS 组进行了无监督层次聚类分析。
在数组中，10 个 sncRNA 在组间存在差异表达。在验证队列中，与 HC 相比，我们证实 iSS 组中 U6-snRNA 和 miR-661 的表达增加。我们无法验证 pSS 组中任何 miRNA 的差异表达。然而，在该组中，一些 miRNA 与实验室参数相关。无监督聚类将 pSS 患者分为三个聚类。与另外两个聚类相比，一个聚类中的患者血清 IgG 水平显著升高，抗 SSB 自身抗体的患病率较高，IFN 评分较高，白细胞计数较低。
我们无法确定 pSS 患者中有差异表达的任何血清 sncRNA。然而，我们表明循环 miRNA 水平与 pSS 患者的疾病参数相关，并且可用于区分具有更严重 B 细胞过度活跃的 pSS 患者。由于这些 miRNA 中的几个涉及 B 细胞的调节，它们可能在疾病的持续存在中发挥作用。
