Expression and function of microRNA in autoimmune Sjogren's Syndrome

描述（由申请人提供）：自身免疫性干燥综合征（SjS）针对大多数女性个体的外分泌腺，例如唾液腺和泪腺，导致严重的分泌功能障碍及其并发症。迄今为止，由于SjS疾病发病机制的复杂性，SjS特异性诊断和治疗尚未可用。microRNA（miRNAs）是一类重要的非编码RNA，参与多种生物学、病理学和免疫学过程。与健康对照相比，我们在原发性SjS（pSjS）患者外周血单核细胞（PBMC）或单核细胞中改变的miR-146 a和-155表达的最新发现表明，miRNA可能在SjS的自身免疫启动和进展中起关键作用。在我们的pSjS易感的C57 BL/6. NOD-Aec 1Aec 2小鼠模型的唾液腺和PBMC中的发现进一步支持了这些数据，其中从早期就观察到这些miRNAs的上调。在我们的初步体外研究中，miR-146 a在人单核细胞系（THP-1）中的过表达能够改变先天性免疫应答，例如吞噬和促炎细胞因子的产生。我们现在提出的研究旨在验证我们的假设，即miR-146 a和miR-155通过改变先天免疫应答对延长炎症过程至关重要，并且特别涉及先天免疫的pSJS特异性miRNA可以差异表达（甚至可能在疾病发作之前导致持续炎症）。在本项目的目标1中，我们将通过利用miRNA模拟物和抑制剂转染到THP-1细胞中，然后进行功能测定来研究改变的miR-146 a和/或miR-155的后果。还将在来自pSjS患者的原代培养的单核细胞中测试改变的功能。本研究旨在确定miRNAs对免疫基因的表观遗传调控是否在改变SjS的免疫过程中起关键作用。在目标2中，我们将开始通过利用miRNA微阵列方法来描绘参与pSiS的miRNA的复杂网络。在这里，我们将测试我们的假设，即特异于人类pSjS的miRNA谱是可识别的。此外，我们将继续在Aim 2中鉴定差异表达的miRNA的靶基因，并进行Aim 1中建立的功能测定，以筛选它们参与先天免疫应答。我们设想这些实验将鉴定pSjS中的新型miRNA和鉴定的miRNA在SjS的异常免疫调节中的调节功能，并且最终可能适合于生物标志物和治疗干预的开发。 公共卫生相关性：干燥综合征（SjS）影响了400万美国人，导致患者口干和干眼症。我们的研究建议，以确定SJS特异性配置文件将推进该领域的诊断和治疗，并提高生活质量，在那些受影响的疾病。

DESCRIPTION (provided by applicant): Autoimmune Sj"gren's syndrome (SjS) targets the exocrine glands, such as the salivary and lacrimal glands, of mostly female individuals, leading to severe secretory dysfunction and its complications. To date, SjS- specific diagnostics and therapeutics have not been available due to complexity of SjS disease pathogenesis. MicroRNAs (miRNAs) have been recognized as an important class of non-coding RNAs that are involved in a variety of biological, pathological, and immunological processes. Our latest findings on altered miR-146a and- 155 expression in peripheral blood mononuclear cells (PBMC) or monocytes of primary SjS (pSjS) patients in comparison with healthy controls indicate that miRNAs may play a critical role in autoimmune initiation and progression of SjS. The data were further supported by the findings in the salivary glands and PBMC of our pSjS-prone C57BL/6.NOD-Aec1Aec2 mouse model, where up-regulation of those miRNAs was observed from an early age on. Over-expression of miR-146a in human monocyte cell line (THP-1) was able to alter innate immune responses such as phagocytosis and pro-inflammatory cytokine production in our preliminary study in vitro. We now propose studies designed to test our hypotheses that miR-146a and miR-155 are vital to prolong inflammatory processes by altering innate immune response and that pSjS-specific miRNAs especially involved in innate immunity can be differentially expressed (potentially even prior to disease onset resulting in persistent inflammation). In Aim 1 of this project, we will investigate consequences of altered miR-146a and/or miR-155 by utilizing miRNA mimics and inhibitors transfected into THP-1 cells followed by functional assays. Altered functions will also be tested in primary cultured monocytes from pSjS patients. This aim is to determine if epigenetic regulation of immune genes by miRNAs are critical in altering immunological processes in SjS. In Aim 2, we will begin to profile a complex network of miRNAs involved in pSiS by utilizing a miRNA microarray approach. Here we will test our hypothesis that miRNA profiles that are specific for human pSjS are identifiable. Furthermore, we will continue to identify in Aim 2 target genes of differentially expressed miRNAs and perform functional assays established in Aim 1 to screen their involvement in innate immune responses. We envision that these experiments will identify novel miRNAs in pSjS and regulatory functions of identified miRNAs in abnormal immune regulation of SjS and may ultimately be amenable to development of biomarkers and therapeutic intervention. PUBLIC HEALTH RELEVANCE: Sj"gren's syndrome (SjS) affects 4 million Americans, resulting in dry mouth and dry eye condition in patients. Our research proposal to identify SjS-specific profiles would advance diagnostics and therapeutics in the field and improve quality of life in those affected with the disease.