免疫疾患におけるRNA分解酵素Regnase-1調節機構解明とその操作法の開発

Regnase-1是炎症的负调节因子。它通过识别3 '非翻译区（UTR）中的茎环（SL）结构来限制炎性mRNA（IL 6、IL 1b、Regnase-1等）的稳定性，从而限制免疫应答。在这个项目中，我们的目标是开发一种治疗策略，通过操纵Regnase-1的可用性来抑制炎症。我们通过调节Regnase-1与其SL结构之间的结合相互作用来实现这一点，这是通过同时使用两个靶向SL结构右臂的反义磷酰二胺吗啉代寡核苷酸（MO）来实现的。通过MO阻断Regnase-1的自我调节成功地增强了巨噬细胞中Regnase-1的表达，这反过来又降低了Regnase-1靶向的炎症转录物的表达。此外，我们观察到Regnase-1靶向-MO的组织靶向递送在急性呼吸窘迫综合征、博来霉素诱导的肺纤维化和实验性自身免疫性脑脊髓炎的小鼠模型中减弱了炎症和免疫细胞向疾病部位的浸润。最后，我们发现Regnase-1表达与多发性硬化患者的疾病严重程度呈负相关，而针对人Regnase-1 SL结构的MO治疗成功地减弱了LPS刺激后促炎基因的表达。总的来说，我们的研究结果强调MO介导的Regnase-1表达增强可以作为一种新的治疗策略来限制炎症并改善小鼠和人类的疾病结局。

Regnase-1 is a negative regulator of inflammation. It restricts immune responses by limiting the stability of inflammatory mRNAs (Il6, Il1b, Regnase-1, etc) through recognition of stem-loop (SL) structures in 3'untranslated regions (UTRs). In this project, we aimed to develop a therapeutic strategy to suppress inflammations through manipulating Regnase-1 availability. We achieved this by modulating the binding interaction between Regnase-1 and its SL structures, which was enabled by the simultaneous use of two antisense phosphorodiamidate morpholino oligonucleotides (MOs) targeting the right arms of the SL structure.Blocking Regnase-1 self-regulation by MOs successfully enhanced Regnase-1 expression in macrophages, which in turn decreased the expression of inflammatory transcripts targeted by Regnase-1. In addition, we observed that tissue-targeted delivery of Regnase-1-targeting-MOs attenuated inflammation and immune cell infiltration to disease sites in mouse models of acute respiratory distress syndrome, bleomycin-induced pulmonary fibrosis, and experimental autoimmune encephalomyelitis. At last, we found that Regnase-1 expression was inversely correlated with the disease severity of patients with multiple sclerosis, whereas MO treatment against human Regnase-1 SL structures successfully blunted their expression of pro-inflammatory genes upon LPS stimulation. Overall, our findings highlight that MO-mediated enhancement of Regnase-1 expression could serve as a novel therapeutic strategy to restrict inflammation and improve disease outcomes in mouse and human.