Mesenchymal Stromal Cells, Autophagy, and the Host Response to Systemic Bacterial Infection

间充质基质细胞、自噬和宿主对全身细菌感染的反应

基本信息

批准号：
10557214
负责人：
Mark A PERRELLA
金额：
$ 34.28万
依托单位：
BRIGHAM AND WOMEN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-04-01 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10557214
关键词：
Autophagocytosis Bacterial Infections Bone Marrow Carbon Monoxide Cell Communication Cell Survival Cell Therapy Cell physiology Cells Cellular biology Cessation of life Clinical Complex Complication Conditioned Culture Media Cultured Cells Data Death Rate Diagnosis Disease Dose Environment Event Experimental Models Exposure to Functional disorder Gases Genes Genetic Polymorphism Harvest Homing Immune Immune response Impairment Infection Inflammation Inflammatory Inflammatory Response Injury Invaded Investigation Link Lung Mediating Mediator Medical Microbe Mitochondria Modeling Morbidity - disease rate Mus Organ Organ Preservation Organelles Organism Outcome Oxidative Stress Pathway interactions Persons Phagocytosis Population Predisposition Process Protein Deficiency Proteins Regulation Resolution Role Sepsis Testing Therapeutic Therapeutic Uses Wild Type Mouse Work cecal ligation puncture cell injury cell motility conditioning early phase clinical trial extracellular vesicles functional improvement genome wide association study hemodynamics human disease immunoregulation improved improved outcome in vivo insight mesenchymal stromal cell mortality novel strategies organ injury paracrine pharmacologic polymicrobial sepsis preconditioning response sepsis induced ARDS systemic inflammatory response

项目摘要

PROJECT ABSTRACT: Sepsis is a disease process that causes significant morbidity and mortality by inciting a systemic inflammatory response. The invading organism(s) activate immune cells of the host, in an effort to eradicate the infection. However, this pro-inflammatory response often persists, leading to organ dysfunction and subsequent death. Mesenchymal stromal cells (MSCs), and the autophagy process, are key mediators of the response to sepsis. Autophagy represents a pathway for the turnover of damaged proteins and organelles (such as mitochondria), which can promote survival under various disease conditions. Genes critical for the regulation of autophagy include Beclin 1. MSCs are a population of cells, originally isolated from the bone marrow, that are a promising platform for cell-based therapy. We have shown that MSCs improve survival in murine sepsis by decreasing organ injury, improving bacterial clearance, interacting with immune cells and promoting resolution of inflammation. Low-dose CO exposure induces autophagy in vivo, however the impact of CO conditioning on the autophagy response in MSCs, and its effect on MSC function during sepsis, requires investigation. We hypothesize that autophagy is a key mediator in regulating the ability of CO (ex vivo) to enhance MSC function in experimental models of sepsis, both by cell-to-cell and paracrine actions of MSCs. To test our hypothesis, we propose three aims. In Aim 1, we will decipher the importance of the autophagy pathway, for enhanced MSC function during sepsis, after CO pre-conditioning of MSCs ex vivo. MSCs will be harvested from Beclin1+/– and wild-type (WT) mice, or Beclin1 will be silenced (shBeclin1) in WT MSCs, and then administered to WT mice after cecal ligation and puncture (CLP), an experimental model of sepsis. We will determine whether the enhanced function of CO pre-conditioning is lost in autophagy protein deficient MSCs. We will also study the effect of CO on WT and autophagy protein deficient MSCs to promote bacterial clearance, resolution of inflammation, preservation of organ function, and survival. In Aim 2 we will determine the role of extracellular vesicles (EVs) in the paracrine actions of MSCs pre-conditioned with CO, and investigate the importance of autophagy in this response. EVs will be isolated from MSCs derived from WT and Beclin1+/– mice, or from shBeclin1 MSCs, and given to WT mice after the onset of sepsis. In Aim 3, we will determine whether ex vivo pre-conditioning of MSCs with CO improves the outcome of autophagy protein deficient mice during sepsis. WT MSCs pre-conditioned with CO, will be administered to Beclin1+/– mice, and mice in which autophagy is pharmacologically inhibited, after CLP-induced sepsis. In addition, we will assess EVs derived from MSCs exposed to CO, on sepsis outcome in autophagy protein deficient mice. If successful, this application will elucidate mechanisms by which MSCs improve the host response to sepsis. Elucidating the importance of autophagy in MSCs, and the enhancement of MSC function by CO will also advance our understanding of MSC biology and optimize their potential therapeutic use.

项目摘要：败血症是一种疾病过程，可通过煽动引起明显的发病率和死亡率系统性炎症反应。入侵的生物会激活宿主的免疫细胞，以努力消除感染。但是，这种促炎的反应通常会持续存在，导致器官功能障碍和随后的死亡。间充质基质细胞（MSC）和自噬过程是对败血症的反应。自噬代表了受损蛋白质和细胞器的营业额的途径（例如线粒体），可以在各种疾病条件下促进生存。基因对自噬的调节包括Beclin1。MSC是一个细胞群，最初是从骨骼中分离出来的骨髓，这是一个基于细胞疗法的有前途的平台。我们已经表明，MSC在通过减少器官损伤，改善细菌清除率，与免疫细胞相互作用和促进炎症的分辨率。低剂量CO暴露会在体内诱导自噬，但是 MSC中自噬响应的CO调节，其对败血症期间MSC功能的影响需要调查。我们假设自噬是确定CO（Ex Vivo）能力的关键调解人通过MSC的细胞到细胞和旁分泌作用，在败血症实验模型中增强了MSC功能。到检验我们的假设，我们提出了三个目标。在AIM 1中，我们将破译自噬的重要性在败血症过程中，在败血症期间的MSC功能增强的途径，在co前体内进行了前体内。 MSC将是从Beclin1 +/-和Wild-Type（WT）小鼠或Beclin1收获，将在WT MSC中保持沉默（SHBECLIN1），并且然后在盲肠结扎和穿刺后（CLP）（败血症的实验模型）对WT小鼠施用。我们将确定在自噬蛋白缺陷MSC中，CO预先调节的增强功能是否丢失。我们还将研究CO对WT和自噬蛋白缺乏MSC的影响以促进细菌清除，炎症的解决，器官功能保存和生存。在AIM 2中，我们将确定细胞外蔬菜（EV）在用CO预先调节的MSC的旁分泌作用中的作用，研究自噬在此反应中的重要性。电动汽车将从源自WT的MSC中隔离， beclin1 +/-小鼠或shbeclin1 MSC，并在败血症发作后送给WT小鼠。在AIM 3中，我们将确定MSC与CO的离体预处理是否可以改善自噬蛋白的结果败血症中的小鼠不足。用CO预先调节的WT MSC将用于Beclin1 +/-小鼠，并且 CLP诱导的败血症后，自噬抑制了自噬的小鼠。此外，我们将评估自噬蛋白缺乏小鼠的败血症结果，源自接触CO的MSC的电动汽车。如果成功，该应用将阐明MSC改善宿主对败血症的反应的机制。阐明自噬在MSC中的重要性，以及CO的MSC功能增强也将推动我们的了解MSC生物学并优化其潜在的治疗用途。