Role and Regualtion of miRNA223 in EAE

描述(由申请人提供)： 越来越多的证据表明，microRNAs(MiRs)在调节免疫细胞发育/功能中起着关键作用。最近，我们做了一个重要的观察，发现miR223不仅在患病的中枢神经系统(CNS)中增加，而且在多发性硬化症(MS)的动物模型EAE小鼠的外周免疫隔室中也增加。值得注意的是，EAE脊髓中miR223表达的增加可被抗免疫剂1，25(OH)2D3阻断。此外，MS患者血细胞中miR223水平升高。这些发现表明miR223在中枢神经系统自身免疫性炎症中起致病作用。现在我们已经获得了令人信服的证据来支持这一前提，即在造血干细胞来源的免疫细胞中全局或有条件地取消miR223导致了对EAE的显著抵抗。这些突破使miR223成为调控中枢自身免疫性炎症的一种新的miR。我们的目标是进一步评价miR223‘S在EAE发病机制中的作用，并探讨miR223’S的作用机制。我们将首先验证自身抗原诱导的miR223表达是EAE的原因而不是结果。我们将通过研究miR223诱导和脱髓鞘开始的时间序列来解决这个问题，然后研究miR223功能阻断是否会减少脱髓鞘。然后，我们将确定miR223促进EAE的细胞机制。具体地说，我们将测试假设，即miR223通过增强致病的Th17和M1巨噬细胞极化来促进轴突脱髓鞘，使用条件基因敲除和细胞特异性拯救。最后，我们将确定和功能鉴定miR223的下游介体，即在EAE中的miR223靶基因。我们使用精心设计的筛选策略确定了一系列潜在的miR223靶点。我们将集中在两个潜在的神经保护基因，单核细胞增强因子(MEF2C)，一个已知的miR223靶基因，以及内毒素反应性米色样锚基因(LRBA)，一个潜在的新靶基因。我们的工作可能会发现中枢神经系统自身免疫发展的新机制。就这项工作的临床相关性而言，确定miR223在EAE中的作用和机制可能会导致开发基于miR223的治疗多发性硬化症的疗法，这种疗法在平民和退伍军人中都有发生。

DESCRIPTION (provided by applicant): There is rapidly accumulating evidence for a pivotal role of microRNAs (miRs) in regulating immune cell development/function. Recently we made an important observation that miR223 was increased not only in the diseased central nerve system (CNS) but also in the peripheral immune compartments of EAE mice, an animal model of multiple sclerosis (MS). Notably, increased miR223 expression in EAE spinal cord was blocked by an anti-immune agent 1,25(OH)2D3. Moreover, miR223 in the MS patient's blood cells was elevated. These findings point to a pathogenic role of miR223 in CNS autoimmune inflammation. Now we have obtained compelling evidence to support this premise; namely, abrogation of miR223 either globally or conditionally in hematopoietic stem cell-derived immune cells resulted in a remarkable resistance to EAE. These breakthroughs establish miR223 as a novel miR in regulating CNS autoimmune inflammation. Our goal is to further evaluate miR223's function in pathogenesis of EAE and identify the mechanisms of the miR223's action. We will first verify that autoantigen-elicited miR223 expression is the cause rather than the result of EAE. We will address this issue by studying the temporal sequence in onset of miR223 induction and demyelination, followed by investigating if miR223 functional blockade will reduce demyelination. We will then identify the cellular mechanism by which miR223 promotes EAE. Specifically we will test the hypothesis that miR223 promotes axonal demyelination by enhancing pathogenic Th17 and M1 macrophage polarization using conditional knockout and cell-specific rescue. Finally, we will identify and functionally characterize the downstream mediators of miR223, namely the miR223 target genes, in EAE. We have identified a list of potential miR223 targets using carefully designed screening strategies. We will focus on two potentially neuroprotective genes, monocyte enhancer factor (Mef2c), a known miR223 target, and the lipopolysaccharide responsive beige-like anchor gene (Lrba), a potentially novel target. Our work will likely uncover new mechanisms by which autoimmunity develop in CNS. In terms of the clinical relevance of this work, identification of the role and mechanism of the action of miR223 in EAE could potentially lead to development of miR223-based therapy for treatment of MS, which occurs in both civilian and military-veteran populations.