循环miR-30c调控Ⅰ型干扰素信号参与干燥综合征发病的机制研究

Primary Sjögren’s Syndrome (pSS) is a common autoimmune disease involving the exocrine glands, and its pathogenesis is unclear. Accumulating evidences suggest that type I interferon (IFN) signaling may participate in the development of pSS by affecting the activation of immune cells and damaging targeted glands. MicroRNAs may also be involved in the pathogenesis of pSS according to recent studies. Our previous study found that circulating miR-30c was decreased in pSS patients’ serum and negatively correlated with the expression of type I IFN signatures, and bioinformatics predicted miR-30c could target IFNAR2 and JAK1, the key molecules in type I IFN signaling. Therefore, we hypothesize that miR-30c may play roles in pathogenesis of pSS by regulating type I IFN signaling. This project aims ①to analyze the association between miR-30c and type I IFN signaling in peripheral blood and salivary gland of pSS patients by qRT-PCR, immunofluorescence and define its clinical significance; ②to confirm the mechanism of miR-30c affecting type I IFN signaling and cell function in three types of cells using miRNA mimics or inhibitors and dual-luciferase reporter gene assay; ③to investigate the role of miR-30c in pathogenesis of SS by the animal model and virus vectors carrying miR-30c and antimiR-30c, and to explore its effect on the activation of type I IFN signaling and glandular epithelial cell, as well as recruitment of pDC cells, which will provide a new therapeutic strategy for pSS.

原发性干燥综合征（pSS）是累及外分泌腺的自身免疫病，发病机制不清。文献报道Ⅰ型干扰素信号可通过影响免疫细胞激活、靶腺损害等参与pSS发生；microRNAs可能参与致病过程。前期发现miR-30c在pSS患者血清表达下降、且与Ⅰ型干扰素标记负相关；生物信息学预测该通路的关键分子IFNAR2、JAK1是其靶基因。故推测循环miR-30c可能通过调控Ⅰ型干扰素信号活性而影响pSS的病程。本项目拟①采用qRT-PCR、免疫荧光等方法明确pSS患者外周血和唇腺miR-30c的表达与Ⅰ型干扰素信号活性、临床指标的相关性；②通过报告基因、miRNA表达调控在PBMC、唾液腺上皮细胞和pDC中明确其对Ⅰ型干扰素信号和细胞功能的影响；③构建miR-30c高/低表达病毒载体并干预SS动物模型，阐明其是否通过影响Ⅰ型干扰素通路活性、腺上皮细胞活化、pDC招募等方面参与SS发病，为pSS的诊治提供新思路。

原发性干燥综合征（pSS）是累及外分泌腺的自身免疫病，发病机制不清。文献报道Ⅰ型干扰素信号可通过影响免疫细胞激活、靶腺损害等参与pSS发生；microRNAs可能参与致病过程。前期发现miR-30c在pSS患者血清表达下降、且与Ⅰ型干扰素标记负相关；生物信息学预测该通路关键分子IFNAR2、JAK1是其靶基因。本研究①通过qRT-PCR、免疫荧光等方法明确pSS患者外周血和唾液腺miR-30c的表达与Ⅰ型干扰素信号活性、临床指标的相关性，评估miR-30c的表达对pSS诊断及病情评估的价值，证实：与健康对照者相比，pSS患者血浆miR-30c表达显著下降，血浆miR-30c可作为生物标记用于诊断pSS，灵敏度84%，特异性76%；在ESSDAI评分较高的患者中，外周血miR-30c的低表达的比例较高；循环中miR-30c的低表达与pSS患者Ⅰ型干扰素信号活化正相关（血浆、唾液腺水平验证）；miR-30c低表达与pSS患者唾液腺损害评分正相关，提示miR-30c的低表达参与唾液腺淋巴细胞浸润的发生；②通过报告基因、miRNA表达调控在PBMC和pDC中明确其对Ⅰ型干扰素信号和细胞功能的影响，证实：JAK1为miR30c的靶基因，miR30c可通过靶向JAK1下调I型干扰素信号通路的活动，通过调控TLR9/ MyD88/IRF7信号调控pDC的活性，并影响IFN-α的分泌；循环中下调的miR-30c存在于血浆外泌体中；③构建miR-30c高表达病毒载体并干预SS动物模型，证实：miR-30c的升高改善SS唾液腺损伤的程度，减缓SS模型的发展；可负向调控I型干扰素，抑制pDC的活性及靶腺迁移，减少炎症对下颌下腺上皮细胞的损伤。本研究为pSS的早期诊断和病情判断提供了新的生物标记，同时为阐明pSS的发病机制和唾液腺损伤的机制提供了新思路，为pSS治疗提供了新靶点。