Intranasal therapy with miRNA-219 reduces viral load and encephalomyelitis in the TMEV model of multiple sclerosis

Purpose: RNA sequencing of spinal cord following intranasal administration of miRNA-219 in Theiler’s murine encephalomyelitis virus (TMEV) model of multiple sclerosis Methods: RNA isolated from spinal cords was analyzed by Next-Generation RNA Sequencing (Illumina) Results: Here, we analyzed the therapeutic effects of miR-219 in a virus-induced demyelinating model. Following intranasal administration of miR-219 in TMEV-infected mice, we found significant reduction of clinical signs, virus persistence (virus genome copy numbers), neuroglia activation, proinflammatory cytokine levels, and demyelination. RNA sequencing of expressed host genes demonstrated that miR-219 potentiates transcriptional changes in cholesterol-related genes, leading to reduced levels of this lipid. Conclusions: Since virus replication relies on hijacking cholesterol biosynthesis and trafficking of host cell endogenous pools as well as remodeling intracellular membranes, i.e., the virus replication organelles or viroplasm, treatment with miR-219 may interfere with virus RNA replication through downregulation of cholesterol synthesis. Our findings show that miR-219 administration lessens pathological changes by reducing the CNS virus loads and favoring myelin repair. RNA isolated from spinal cords of TMEV-infecetd mice. Experimental groups consist of healthy mice (control) and mice with chronic demyelination treated with vehicle (TMEV+veh), scrambled miR (TMEV+miR-scr) or miR-219 (TMEV+miR-219)

研究目的：在多发性硬化的泰泽氏鼠脑脊髓炎病毒（TMEV）模型中，对鼻内给予miRNA-219后的小鼠脊髓进行RNA测序。实验方法：从脊髓中分离得到的RNA通过下一代RNA测序（Illumina平台）进行分析。研究结果：本研究分析了miR-219在病毒诱导脱髓鞘模型中的治疗作用。在TMEV感染小鼠鼻内给予miR-219后，我们观察到其临床症状、病毒持续感染水平（病毒基因组拷贝数）、神经胶质细胞激活、促炎细胞因子水平以及脱髓鞘程度均显著降低。对宿主表达基因的RNA测序结果显示，miR-219可调控胆固醇相关基因的转录变化，进而降低该脂质的水平。研究结论：由于病毒复制依赖于劫持宿主细胞内源性胆固醇的生物合成与转运过程，同时还需要重塑细胞内膜结构以形成病毒复制细胞器或病毒质，因此miR-219处理可通过下调胆固醇合成途径干扰病毒RNA的复制。本研究结果表明，鼻内给予miR-219可通过降低中枢神经系统（CNS）的病毒载量并促进髓鞘修复，从而减轻病理损伤。实验样本为TMEV感染小鼠的脊髓分离RNA，实验分组包括健康小鼠（对照组）、经赋形剂处理的慢性脱髓鞘小鼠（TMEV+veh组）、经乱序miR处理的慢性脱髓鞘小鼠（TMEV+miR-scr组）以及经miR-219处理的慢性脱髓鞘小鼠（TMEV+miR-219组）