miR-29b and autophagy regulate alveolar macrophage function post-BMT

miR-29b 和自噬调节 BMT 后肺泡巨噬细胞功能

• 批准号: 9189677
• 负责人: Bethany B. Moore
• 金额: $ 42.64万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-15 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9189677
• 关键词: Abbreviations; Acute; Allogenic; Alveolar Macrophages; Arachidonate 5-Lipoxygenase; Arachidonic Acids; Autologous; Autophagocytosis; Bacteria; Bacterial Infections; Bone Marrow Transplantation; Cells; Complement Factor B; Cyclooxygenase Inhibitors; DNA Modification Methylases; DNA biosynthesis; Data; Defect; Dinoprostone; Disease; Epithelial Cells; Genes; Genetic; Hematopoietic; Hematopoietic Stem Cell Transplantation; Hematopoietic System; Host Defense; Human; Immune; Impairment; In Vitro; Incidence; Infection; Leukotrienes; Lung; Malignant - descriptor; Malignant Neoplasms; Mediating; Metabolism; Mus; Mutation; Natural Immunity; Pathway interactions; Patients; Phagocytes; Phagocytosis; Pharmacology; Predisposition; Production; Prostaglandin Inhibition; Prostaglandin-Endoperoxide Synthase; Prostaglandins; Pseudomonas aeruginosa; Regimen; Role; Safety; Shunt Device; Signal Transduction; Streptococcus pneumoniae; Structure; Testing; Therapeutic; Transforming Growth Factor beta; Transforming Growth Factors; Transplantation; Treatment Efficacy; Up-Regulation; Work; conditioning; cyclooxygenase 2; cytokine; fighting; improved; in vivo; innate immune function; insight; killings; macrophage; man; mouse model; neutrophil; novel therapeutics; overexpression; pathogen; public health relevance; receptor; reconstitution; scavenger receptor; targeted treatment

 DESCRIPTION (provided by applicant): Hematopoietic stem cell transplantation (HSCT) is used to treat a variety of genetic defects and malignancies, but its usefulness is limited by pulmonary infections. Infectious complications can occur both in allogeneic and autologous transplant settings and susceptibility to infection remains elevated despite hematopoietic reconstitution. To better understand innate immune deficiencies that characterize HSCT, we developed a murine model of bacterial infection post-syngeneic (syn) bone marrow transplant (BMT). We have previously shown that these mice are more susceptible to infection with Pseudomonas aeruginosa even after the hematopoietic system is reconstituted. We identified the upregulation of cyclooxygenase-2 (COX-2) and the overproduction of PGE2 as major contributing factors to the impaired innate immune function in these mice. We identified that alveolar macrophages (AMs) and neutrophils (PMNs) had defects in innate immune functions such as phagocytosis, bacterial killing and cytokine secretion. In addition, the profile of scavenger receptors on AMs were altered post-BMT, with loss of macrophage receptor with collagenous structure (MARCO), a critical receptor for recognition of P. aeurignosa. We determined that PGE2 signaled via elevated E prostanoid 2 (EP2) receptors on these AMs to inhibit their functions. Importantly, our murine studies have shown that pharmacologic or genetic inhibition of COX-2 post-BMT restores lung innate immunity and AM function against P. aeruginosa. These results are exciting because they suggest inhibition of PGE2 signaling can be a therapeutic to improve host defense post-transplant. However, there are systemic problems with a therapeutic strategy that globally blocks all prostaglandin synthesis. Thus, one aspect of this proposal will be to test a newly developed EP2 antagonist (PF-044148948) which we have obtained from Pfizer. We believe this will be a much more specific and effective therapeutic to block the inhibitory PGE2 signaling. The application also seeks to provide insight into the following unanswered questions. 1) Why is COX-2 elevated post-BMT leading to overproduction of PGE2? 2) Do these same innate immune defects characterize allogeneic (allo) BMT? 3) Do these defects post-BMT make mice more susceptible to Gram positive infections (like Streptococcus pneumoniae) as well as Gram negative ones? 4) Can we determine whether impairment of autophagy is one mechanism for impaired killing post-BMT? 5) Are the defects we have noted in our murine model also present in human HSCT patients? Our overall hypothesis is: BMT conditioning induces transforming growth factor (TGF) ß secretion from lung epithelial cells. This augments miR-29b expression to block synthesis of DNA methyltransferases (DNMTs) causing hypomethylation of COX-2 leading to PGE2 overexpression in AMs. Furthermore, PGE2-EP2 induced alterations in autophagy impair host defense against P. aeruginosa and S. pneumoniae post-BMT and we speculate that host defense post-BMT can be improved via treatment with a COX inhibitor, an EP2 antagonist or via induction of autophagy. These hypotheses will be explored in the following specific aims. Aim 1) To determine if syn BMT and allo BMT mice are more susceptible to P. aeruginosa and S. pneumoniae infection and if susceptibility is related to PGE2 signaling via EP2 in mice and man Aim 2: To determine whether TGFß-induced miR-29b causes COX-2 hypomethylation to increase PGE2 production post-BMT Aim 3: Aim 3: To determine if autophagy is impaired in syn and allo BMT AMs, to determine whether this is related to PGE2- EP2 signaling and the importance of autophagy to host defense post-BMT

 描述（由适用提供）：造血干细胞移植（HSCT）用于治疗多种遗传缺陷和恶性肿瘤，但其有用性受肺部感染的限制。在同种异体和自体移植环境中可能发生传染性并发​​症，并且对感染的敏感性仍然升高了绝望的造血重建。为了更好地理解表征HSCT的免疫缺陷，我们开发了一种鼠类感染的鼠模型（SYNGENEIIC（SYN）骨髓移植（BMT）。我们以前已经表明，即使在重构造血系统之后，这些小鼠也更容易受到铜绿假单胞菌的感染。我们确定了环氧酶-2（COX-2）的上调，并且PGE2过量生产是这些小鼠先天免疫功能受损的主要因素。我们确定肺泡巨噬细胞（AMS）和中性粒细胞（PMN）在先天免疫功能（例如吞噬作用，细菌杀死和细胞因子分泌）中存在缺陷。另外，在BMT后，清道夫受体在AMS上的特征会改变，巨噬细胞受体损失具有胶原结构（MARCO），这是一种识别Aeurignosa的关键受体。我们确定PGE2通过这些AM上的E升高前列腺素2（EP2）受体签名以抑制其功能。重要的是，我们的鼠研究表明，COX-2 BMT后BMT的药理学或遗传抑制可恢复肺先天免疫和对铜绿假单胞菌的AM功能。这些结果令人兴奋，因为它们表明抑制PGE2信号传导可能是改善移植后宿主防御的治疗方法。但是，治疗策略存在全身问题，该策略在全球范围内阻止了所有前列腺素的合成。这是该提案的一个方面是测试我们从辉瑞公司获得的新开发的EP2拮抗剂（PF-044148948）。我们认为，这将是一种更具体和有效的疗法，可以阻止抑制性PGE2信号传导。该应用程序还旨在洞悉以下未解决的问题。 1）为什么COX-2升高BMT会导致PGE2的生产过多？ 2）这些先天免疫抗污染物是否表征了同种异体（Allo）BMT？ 3）BMT后这些缺陷是否会使小鼠更容易受到革兰氏阳性感染（例如肺炎链球菌）和革兰氏阴性阴性？ 4）我们能否确定自噬损伤是否是杀死BMT后杀死的一种机制？ 5）我们在人类HSCT患者中还存在我们在鼠模型中注意到的缺陷吗？我们的总体假设是：BMT调节诱导肺上皮细胞的转化生长因子（TGF）ß分泌。这增加了miR-29b表达以阻断DNA甲基转移酶（DNMTS）的合成，从而导致COX-2的低甲基化导致AMS中的PGE2过表达。此外，PGE2-EP2诱导自噬损害宿主防御对铜绿假单胞菌和BMT肺炎链球菌的防御变化，我们推测可以通过使用COX抑制剂，EP2拮抗剂或通过诱导自噬来改善宿主防御后BMT。这些假设将在以下特定目标中探讨。目的1）确定Syn BMT和Allo BMT小鼠是否更容易受到铜绿假单胞菌和肺炎链球菌感染的影响，以及是否与PGE2通过EP2通过EP2发出的易感性与小鼠的目标2：tgfß诱导的miR-29b诱导的miR-29b是否会导致Cox-2-29B对PGE2的生产率是否增加了IS AUT IS IS 3：AIM IS IS IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM IM是否增加，AIM IM IM IM IM是否会增加。 Allo BMT AMS，确定这是否与PGE2- EP2信号传导以及自噬对托管BMT后托管防御的重要性有关