Regulation of short-lived myeloid cells by the novel long non-coding RNA Morrbid

新型长非编码 RNA Morrbid 对短命骨髓细胞的调节

基本信息

批准号：
9287305
负责人：
Jorge Henao-Mejia
金额：
$ 40.25万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-05-01 至 2022-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9287305
关键词：
ATAC-seq Ablation Alleles Allergic Allergic inflammation Apoptosis Apoptotic Asthma Atherosclerosis BCL2L11 gene Bioinformatics Biological Assay Blood Circulation Cell Survival Cell physiology Cells Chromatin Complex Cues Data Defect Development Disease Environment Frequencies Gene Expression Gene Targeting Genes Genetic Genetic Transcription High-Throughput Nucleotide Sequencing Human Human body Immune Immune response Infection Inflammation Inflammatory Inflammatory Response Injury Intervention Laboratories Leukocytes Longevity Lung Malignant Neoplasms Mediating Modeling Molecular Mouse Strains Mus Myeloid Cells Obesity Organism Pathology Pathway interactions Patients Play Process RNA purification Regulation Repression Resolution Role Sepsis Signal Transduction System Testing Therapeutic Time Tissues Translating Untranslated RNA cell type chromatin modification cytokine eosinophil experimental study extracellular histone modification human disease humanized mouse immunopathology in vivo monocyte mouse model neutrophil new therapeutic target novel novel therapeutic intervention novel therapeutics pathogen prevent progenitor promoter response

项目摘要

PROJECT SUMMARY Neutrophils, eosinophils and “inflammatory” monocytes collectively account for ~70% of blood leukocytes and are among the shortest-lived cells in the body. Precise regulation of the lifespan of these myeloid cells is critical to maintain effective host responses to pathogens while minimizing the deleterious consequences of prolonged inflammation. However, how the lifespan of these cells is strictly controlled remains largely unknown. This proposal is focused on a novel long non-coding RNA (lncRNA) we recently discovered that acts as a molecular `timer' to control the duration of the lifespan of these inflammatory cells. In my recently established laboratory, we used high-throughput sequencing and a novel bioinformatic workflow to identify Morrbid, a previously uncharacterized lncRNA that is potently and specifically induced by pro-survival cytokines in neutrophils, eosinophils and “inflammatory” monocytes. Our preliminary data shows that ablation of Morrbid in mice leads to a dramatic reduction in the frequency of these cells at steady state as a result of significant defects in their survival capacity. We found that Morrbid controls cell survival by repressing the transcription of its neighboring pro-apoptotic gene, Bcl2l11 (Bim), in an allelic-specific manner. In addition, we show that Morrbid is conserved in humans, highly expressed in human short-lived myeloid cells and alterations in its levels of expression are associated with hypereosinophilic (HE) pathologies. Thus, defining the molecular mechanisms by which Morrbid controls short-lived myeloid cell lifespan and the role of this novel lncRNA during inflammatory responses will likely reveal new therapeutic targets. As lncRNAs are known to target chromatin modifying complexes to neighboring genes to regulate their expression and Morrbid is potently induced by pro- survival cytokines, our central hypothesis is that Morrbid integrates pro-survival extracellular signals with chromatin modification pathways to control Bcl2l11 expression and thus short-lived myeloid cell survival. Aim 1 of this project will define the molecular mechanism by which Morrbid represses Bcl2l11 expression in response to pro-survival cytokines. In aim 2, we will establish the role of Morrbid in controlling the magnitude of inflammatory responses. For this purpose, we will first use mouse strains with different levels of Morrbid to determine how this lncRNA controls the onset and resolution of eosinophil-mediated lung allergic inflammation. We will then translate these studies to humans as our preliminary data shows that patients with hypereosinophic (HE) pathologies have drastically elevated levels of MORRBID. We will use ex vivo eosinophil culture systems and a humanized mouse model to establish whether MORRBID controls human eosinophil survival. Moreover, using eosinophils from HE patients we will define whether increased MORRBID levels contribute to the development of hypereosinophilia. Collectively, these studies will delineate a novel mechanism by which a lncRNA determines the lifespan of short-lived myeloid cells in response to extracellular cues in mouse and humans. Ultimately, we hope to harness the power of these regulatory mechanisms for therapeutic benefit.

项目概要中性粒细胞、嗜酸性粒细胞和“炎症”单核细胞总共占血液白细胞的 70% 是体内寿命最短的细胞之一，对这些骨髓细胞的寿命进行精确调节。对于维持宿主对病原体的有效反应至关重要，同时最大限度地减少病原体的有害后果然而，如何严格控制这些细胞的寿命在很大程度上仍然存在。未知该提案重点关注我们最近发现的一种新型长非编码 RNA (lncRNA)。我最近建立了一个分子“计时器”来控制这些炎症细胞的寿命。在实验室中，我们使用高通量测序和新颖的生物信息学工作流程来识别 Morrbid，一种以前未表征的lncRNA，它是由促生存细胞因子有效且特异性诱导的我们的初步数据显示，中性粒细胞、嗜酸性粒细胞和“炎症”单核细胞的消融。小鼠导致这些细胞在稳定状态下的频率急剧减少，这是由于显着的结果我们发现 Morrbid 通过抑制细胞的转录来控制细胞的存活。此外，我们还发现其邻近的促凋亡基因 Bcl2l11 (Bim) 以等位基因特异性的方式。 Morrbid 在人类中是保守的，在人类短命骨髓细胞中高度表达，并且其改变表达水平与嗜酸性粒细胞增多（HE）病理学相关，因此，定义了分子水平。 Morrbid 控制短命骨髓细胞寿命的机制以及这种新型 lncRNA 在炎症反应可能会揭示新的治疗靶点，因为已知 lncRNA 会靶向染色质。修饰邻近基因的复合物以调节其表达，并且 Morrbid 是由 pro- 有效诱导的生存细胞因子，我们的中心假设是 Morrbid 整合了促生存的细胞外信号通过染色质修饰途径来控制 Bcl2l11 表达，从而缩短骨髓细胞的寿命该项目的目标 1 将确定 Morrbid 抑制 Bcl2l11 的分子机制。在目标 2 中，我们将确定 Morrbid 在控制促生存细胞因子中的作用。为此，我们将首先使用具有不同水平的小鼠品系。 Morrbid 确定该 lncRNA 如何控制嗜酸性粒细胞介导的肺部过敏的发生和消退然后，我们将把这些研究应用到人类身上，因为我们的初步数据显示，患有炎症的患者。嗜酸性粒细胞增多 (HE) 病变的 MORRBID 水平显着升高，我们将使用离体嗜酸性粒细胞。培养系统和人源化小鼠模型以确定 MORRBID 是否控制人类嗜酸性粒细胞此外，使用 HE 患者的嗜酸性粒细胞，我们将确定 MORRBID 水平是否增加。总的来说，这些研究将描述一种新的机制。小鼠中，lncRNA 决定了短命骨髓细胞响应细胞外信号的寿命最终，我们希望利用这些调节机制的力量来获得治疗益处。