Preclinical Therapy and Novel Mechanisms in Ventilator-induced Diaphragm Atrophy

呼吸机引起的膈肌萎缩的临床前治疗和新机制

基本信息

批准号：
8541548
负责人：
JOSEPH B SHRAGER
金额：
--
依托单位：
VETERANS ADMIN PALO ALTO HEALTH CARE SYS
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-07-01 至 2017-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8541548
关键词：
Animals Antioxidants Apoptosis Atrophic Autophagocytosis Bioinformatics Biological Assay Biomedical Engineering Breathing Cessation of life Chimeric Proteins Clinic Clinical Clinical Trials Critical Illness Development Devices Effectiveness Electric Stimulation Elements Engineering Event Evolution Experimental Models Fiber Functional disorder Future Genetic Goals Health Care Costs Hour Human In Vitro Industry Intensive Care Units Lead Limb structure Measures Mechanical Ventilators Mechanical ventilation Mediating Methods MicroRNAs Mitochondria Modeling Molecular Morbidity - disease rate Mus Muscle Muscle Development Muscular Atrophy Neck Oxidative Stress Pathogenesis Pathway interactions Patients Peptides Pharmaceutical Preparations Prevention Process Proteolysis Rattus Regulation Reporting Respiratory Diaphragm Rodent Role Series Small RNA Structure of phrenic nerve Superoxides Testing Therapeutic Therapy Clinical Trials Thioredoxin-2 Time Transgenic Mice Translating United States Ventilator Veterans Weaning Work base effective therapy genetic manipulation in vivo insight mortality mouse model muscle form nerve supply novel overexpression pre-clinical pre-clinical therapy preclinical study prevent public health relevance research study scale up therapeutic target ubiquitin ligase ubiquitin-protein ligase

项目摘要

DESCRIPTION (provided by applicant): It has been clearly established in both clinical and experimental models that diaphragm disuse as a result of placement upon full mechanical ventilator support leads to early and severe diaphragm atrophy and dysfunction (VIDD - Ventilator-Induced Diaphragm Dysfunction). This diaphragm dysfunction appears to be an important cause of the difficulty often encountered weaning patients from mechanical ventilation (MV); it is thus the basis for subsequent ventilator-associated complications which result in increased morbidity, mortality and health care costs among the millions of patients requiring MV yearly. Several important mechanisms underlying VIDD have been elucidated in recent years, with mitochondrial oxidative stress emerging as a central effector of the process, but preclinical therapeutic trials based upon these mechanistic insights are only now beginning. The broad goals of this work are to: 1) Carry out preclinical trials to prevent VIDD in rodents using intermittent phrenic nerve stimulation and novel mitochondrial-targeted antioxidants (MTAs). 2) To further explore a novel mechanism of VIDD involving microRNA regulation of FOXOs, and to test the therapeutic potential of microRNAs. Phrenic nerve stimulation has never been evaluated in any model of VIDD, despite the fact that VIDD clearly results from diaphragm inactivity and that the phrenic nerve is anatomically accessible to stimulation in patients. We hope to establish proof-of-concept that phrenic stimulation will prevent VIDD, allowing subsequent scale-up to a workable clinical stimulation device. Regarding MTAs, a therapeutic benefit in VIDD has been suggested by only a single, perhaps flawed, study using a small mitochondria-targeted peptide. In order to confirm the mechanism of action of MTAs in this setting and provide an alternative MTA that may be more easily advanced to the clinic, we propose to attack mitochondrial oxidative stress and thus VIDD by both endogenous and exogenous approaches. Our endogenous approach will test for prevention of VIDD by MV experiments in mice that are engineered to overexpress the mitochondria-resident antioxidant thioredoxin-2 (Trx2). Our exogenous approach will include both the exogenous delivery of a TAT-Trx2 fusion protein and the delivery of the MTA drugs, SKQ1 and MitoQ. In this series of experiments, we will use our new model of mouse MV / VIDA - a model which will also allow future exploration of VIDD using additional genetic mouse models. Lastly, we will confirm our preliminary evidence that microRNAs, particularly microRNA-320a, effect VIDA by increasing muscle proteolysis via FOXO-mediated overexpression of the E3 ubiquitin ligases atrogin and MuRF1. We will subsequently test the therapeutic potential of systemic microRNA therapy against VIDA. As a whole, these experiments will both advance our understanding of the basic mechanisms underlying VIDA/VIDD and make substantial steps towards effective clinical therapies by testing these in animals.

描述（由申请人提供）：它在临床和实验模型中都清楚地建立了，由于放置在完全机械呼吸机的支撑下，隔膜会导致早期和严重的隔膜萎缩和功能障碍（VIDD-呼吸机诱导的隔膜功能障碍）。这种隔膜功能障碍似乎是困难经常遇到机械通气（MV）的患者的重要原因。因此，它是随后与呼吸机相关并发症的基础，导致数百万年度需要MV的患者的发病率，死亡率和医疗保健费用增加。近年来，已经阐明了几种重要机制，线粒体氧化应激作为该过程的核心效应因子，但基于这些机械洞察力的临床前治疗试验才开始。这项工作的广泛目标是：1）进行临床前试验，以防止使用间歇性的神经刺激和新型的线粒体靶向抗氧化剂（MTA）来防止啮齿动物中的数量。 2）进一步探索一种涉及MicroRNA调节Foxos的新型VIDD机制，并测试microRNA的治疗潜力。尽管VIDD显然是由于diaphragmm的不活跃而导致的，并且在患者的刺激上可以从解剖学上访问Vidd，但从未在VIDD的任何模型中评估过神经刺激。我们希望建立概念概念，即伪造的刺激将阻止VIDD，从而使随后的临床刺激装置扩大规模。关于MTA，仅使用小线粒体靶向肽的单一（可能有缺陷）的研究提出了VIDD的治疗益处。为了确认MTA在这种情况下的作用机理，并提供了可能更容易前进到诊所的替代MTA，我们建议攻击线粒体氧化应激，从而通过内源性和外源性方法进行VIDD。我们的内源方法将通过MV实验测试小鼠的MV实验，这些实验旨在过表达线粒体居民抗氧化剂硫氧还蛋白-2（TRX2）。我们的外源方法将包括tat-Trx2融合蛋白的外源递送以及MTA药物，SKQ1和MITOQ的递送。在这一系列实验中，我们将使用我们的新型小鼠MV / VIDA模型 - 该模型还将允许使用其他遗传小鼠模型对VIDD进行探索。最后，我们将确认我们的初步证据表明，microRNA，尤其是microRNA-320a，通过通过FOXO介导的E3泛素连接酶Atrogin和Murf1的过表达来增加肌肉蛋白水解来影响VIDA。随后，我们将测试全身microRNA治疗对VIDA的治疗潜力。总体而言，这些实验都将提高我们对VIDA/VIDD基本机制的理解，并通过在动物中测试这些实验来实现有效的临床疗法。