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是炎症的负性调节因子。它通过识别3‘非翻译区(UTRs)中的茎环(SL)结构来限制炎症mRNAs(IL6、IL1b、Regnase-1等)的稳定性，从而限制免疫反应。在这个项目中，我们的目标是开发一种通过操纵Regnase-1的可用性来抑制炎症的治疗策略。我们通过调节Regnase-1与其SL结构之间的结合作用来实现这一点，这是通过同时使用两个靶向SL结构右臂的反义磷酸二氢吗啉寡核苷酸(MOS)来实现的。MOS对Regnase-1的自我调节成功地增强了巨噬细胞中Regnase-1的表达，从而降低了Regnase-1靶向的炎症转录产物的表达。此外，我们观察到，在急性呼吸窘迫综合征、博莱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，组织靶向递送Regnase-1靶向-mos减轻了炎症和免疫细胞对疾病部位的渗透。最后，我们发现多发性硬化症患者Regnase-1的表达与疾病的严重程度呈负相关，而针对人Regnase-1 SL结构的MO治疗成功地钝化了其在内毒素刺激下的促炎基因的表达。总体而言，我们的发现强调了MO介导的Regnase-1表达的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.