circPPM1F/NF-κB调控网络介导的巨噬细胞M1型极化在儿童1型糖尿病发生发展中的作用和机制研究

Macrophage polarization plays a key role in the pathogenesis and treatment of children type 1 diabetes mellitus (T1DM)，however，the regulation mechanisms of macrophage polarization in T1DM remain unclear. Recently, a kind of burgeoning noncoding RNAs, circular RNAs (circRNAs) are participated in multiple physiological and pathological diseases by mediating genes translation or acting as ceRNA. Here, in children T1DM PBMCs samples, we screened a number of abnormal circRNA expression by RNA-seq，and firstly found that circPPM1F was upregulated, and positively regulated the M1 macrophage polarization through activing NF-κB signal pathway. Based on our previous work, we hold the following hypothesis: In the nucleus, circPPM1F may competitively interact with RNA-binding protein（HuR） to suppress PPM1F (protein phosphatase) protein synthesis, leading to activate NF-κB signal pathway; In the cytoplasm, circPPM1F may act as a sponge to bind to miRNA, which enhances the key molecules of NF-κB signal pathway expression, leading to activate NF-κB signal pathway and promote the M1 macrophages polarization. In this study, we will use bioinformatics and biological technologies like RIP and RNA pull-down assay, to study the molecular mechanism that circPPM1F/ NF-κB regulates macrophage polarization in vitro. Meanwhile, we plan to establish T1DM mice model to explore the function of circPPM1F in vivo. Expected results could help us to open up new ideas and find new targets for the pathogenesis, diagnosis and treatment of children T1DM.

巨噬细胞极化在儿童1型糖尿病（T1DM）发病中扮演重要角色，但其调控机理尚不清。近来研究揭示环状RNA（circRNA）可通过调控基因翻译和ceRNA等方式参与到机体的生理病理活动中。在儿童T1DM患者PBMCs中,通过RNA高通量测序，我们首次发现异常高表达的circPPM1F可以激活NF-κB通路来促进巨噬细胞M1极化。我们推测其可能的机理为：在胞核内circPPM1F通过竞争性结合RNA结合蛋白来抑制蛋白磷酸酶PPM1F的翻译，从而缓解PPM1F对NF-κB通路的阻遏作用；在胞质中circPPM1F以ceRNA方式吸附miRNA，释放miRNA调控NF-κB通路关键分子的功能，促进巨噬细胞M1极化。本课题将结合生物信息学、RIP和小鼠T1DM模型等手段，研究circPPM1F调控巨噬细胞极化的分子机理及其体内功能。预期结果将为儿童T1DM的发病机制和诊断治疗开拓新思路及发现新靶点。

1型糖尿病（Type 1 diabetes mellitus，T1DM）是一种慢性的自身免疫性疾病，发病人群主要是儿童青少年，一般会累及肾脏、眼睛及心脏等多处器官损伤，近年来儿童青少年T1DM的发病率呈逐年上升趋势。在T1DM的疾病进程中，巨噬细胞是最早浸润胰岛的免疫细胞之一，其中M1型巨噬细胞可通过分泌促炎因子，增强炎症反应、促进T1DM的发生，而与免疫调节和修复相关的M2型巨噬细胞则控制炎症，减轻自身免疫反应，调节T1DM的发生发展过程。近年来研究揭示环状RNA(circular RNA，circRNA)不仅参与调节基因表达、海绵吸附miRNA、结合RNA结合蛋白、翻译蛋白质等生理过程，而且参与多种癌症和免疫性疾病的病理进展。虽然如此，但circRNA在调节巨噬细胞活化和儿童T1DM发生发展中的作用机理尚不清楚。.本研究通过对临床样本获取分离和利用高通量测序等手段建立了儿童T1DM 病人的miRNA和circRNA图谱。随后结合生物信息学分析、RIP、巨噬细胞与胰岛细胞共培养系统和小鼠T1DM模型等实验手段，阐明了儿童T1DM中异常高表达的circRNA参与T1DM发病过程的作用机理：发现circPPM1F可分别通过结合RNA结合蛋白HuR和海绵吸附miR-7-5p两种方式来调控巨噬细胞M1型激活及胰岛损伤,进而参与T1DM的发病过程；而hsa_circ_0060450通过海绵吸附miR-199a来负向调控Type I IFN诱导的巨噬细胞炎症释放进而参与T1DM的发病过程。相关研究成果发表于Theranostics和Frontiers in Immunology等期刊上。以上研究成果将为了解儿童青少年T1DM的发病机理﹑发现新的临床诊治药物靶点奠定基础。现目前已发表标注有本课题基金资助的文章共9篇，并已授权相关发明专利3项。