Expanding the pool of transplantable human livers by modeling perfusion dynamics

通过模拟灌注动态扩大可移植人类肝脏库

• 批准号: 8928491
• 负责人: Gautham Vivek Sridharan
• 金额: $ 5.87万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8928491
• 关键词: Accounting; Address; Adoption; Age; Age-Years; Behavior; Bile fluid; Biological Markers; Biopsy; Biopsy Specimen; Bypass; Cardiac Death; Cessation of life; Characteristics; Classification; Clinical; Complex; Computer Simulation; Data; Development; Differential Equation; Engineering; Exhibits; Fatty Liver; Fatty acid glycerol esters; Goals; Health; Hepatocyte; Human; In Vitro; Individual; Injury; Ischemia; Kinetics; Life; Light; Lipids; Liver; Liver Failure; Measurement; Metabolic; Metabolic Pathway; Metabolism; Modeling; Molecular; Operating Rooms; Organ; Outcome; Output; Pathway interactions; Patients; Perfusion; Population; Principal Component Analysis; Probability; Procedures; Reaction; Regression Analysis; Relative (related person); Reperfusion Injury; Reperfusion Therapy; Surgeon; System; Systems Biology; Testing; Time; Tissue Model; Tissues; Transplant Surgeon; Transplantation; Validation; Waiting Lists; Warm Ischemia; Weight; Work; base; body system; improved; in vivo; insight; liver biopsy; liver function; liver ischemia; metabolic abnormality assessment; metabolomics; novel; novel strategies; preconditioning; public health relevance; time use; tissue culture; tool; trend

DESCRIPTION (provided by applicant): There is a drastic shortage of transplantable livers in the US with approximately 17,000 individuals each year on the waiting list, but only 6,000 per year receiving transplants. This shortage can be significantly reduced if marginal livers with suboptimal characteristics, such as those with prolonged warm ischemia time (WIT) due to cardiac death donor (DCD), older donor age, or moderate steatosis, can also be included in the pool of transplantable livers. In this project, we propose subnormothermic machine perfusion (SNMP) as a platform to metabolically precondition and recover marginal livers prior to transplantation, thus expanding the donor pool size. In Aim 1 of this proposal, our objective is to test SNMP for the first time as a proof of concept on discarded human livers, which get donated to our lab approximately once per week. We will collect perfusate, bile, and tissue biopsy samples to analyze the liver's dynamic metabolic profile in perfusion. The tissue biopsy samples will be sent to the UC Davis Metabolomics Core to determine relative levels of ~150 intracellular metabolites from primary metabolites and ~300 lipid compounds. We will then correlate the dynamic metabolic profiles to donor characteristics using multi-way principal component analysis and multiple regression analysis. The expected outcome of this aim will be to develop a new set of cutoff metrics based on donor characteristics (age, WIT, and steatosis) to determine if a liver is transplantable after SNMP. In Aim 2, our objective is to better understand metabolic dynamics during perfusion and gain more mechanistic insight into how SNMP reverses WIT-induced injury. We will borrow computational modeling approaches from systems biology to explain trends observed with the time-course intracellular metabolomics data and determine which metabolic pathways are up or down regulated during perfusion. We will construct a stoichiometric/regulatory reaction network to describe hepatocyte metabolism, and apply structural kinetic modeling (SKM) to determine the most likely explanation of pathway flux changes to explain the metabolite data. By comparing the dynamics of a healthy liver, and one with long WIT, our expected outcome of this aim is to discover which metabolic pathways are responsible for reversing ischemic injury in perfusion. Our long term goal is to replace the current system of donor liver assessment to include an SNMP step, which will provide two key benefits: 1.) Improve the metabolic condition of suboptimal grafts, particularly those from DCDs with longer WITs and 2.) Provide the transplant surgeon in the operating room with a more robust set of quantitative biomarkers based on perfusion measurements to assess if a liver can be transplanted. The broader impact of this work is that it has the potential to save thousands of lives of those with liver failure. In addition, this study is, to our knowledge, the first to integate systems biology and metabolomics data to model the dynamics of a live human organ and should serve as an example for others trying to use time-course biopsies to model tissue metabolism in vivo.

描述（由申请人提供）：在美国，每年约有17,000名个人在等待名单上的可移植肝脏短缺，但每年只有6,000人接受移植。如果具有次优特征的边际肝脏，例如由于心脏死亡供体（DCD），年龄较大的供体年龄或中等脂肪变性，这种短缺可以大大减少，例如较长的温暖缺血时间（WIT），也可以包括在可移植肝池中。在这个项目中，我们提出亚电度机灌注（SNMP）作为代谢前提并在移植前恢复边缘肝脏的平台，从而扩大了供体池的大小。在本提案的目标1中，我们的目标是 第一次测试SNMP作为废弃的人肝脏的概念证明，该肝脏每周大约捐赠给我们的实验室。我们将收集灌注液，胆汁和组织活检样品，以分析肝脏中肝脏的动态代谢谱。组织活检样品将发送到UC Davis代谢组核心核心，以确定来自原代代谢物的〜150个细胞内代谢产物的相对水平和〜300脂脂化合物。然后，我们将使用多路主成分分析和多元回归分析将动态代谢谱与供体特征相关联。此目标的预期结果将是根据供体特征（年龄，机智和脂肪变性）开发一套新的截止指标，以确定SNMP后肝脏是否可以移植。在AIM 2中，我们的目标是更好地理解灌注过程中的代谢动力学，并对SNMP如何逆转机智诱发的损伤获得更多的机械洞察力。我们将借用系统生物学的计算建模方法来解释用时端细胞内代谢组学数据观察到的趋势，并确定在灌注过程中调节哪些代谢途径。我们将构建一个化学计量/调节反应网络来描述肝细胞代谢，并应用结构动力学建模（SKM）来确定途径通量变化的最可能解释以解释代谢物数据。通过比较健康肝脏的动力学，并具有长期机智的动力学，我们的预期结果是发现哪些代谢途径是造成灌注中缺血性损伤的原因。我们的长期目标是替换当前的供体肝脏评估系统，包括一个SNMP步骤，该步骤将提供两个关键的好处：1。）改善次优移植物的代谢状况，尤其是那些来自DCD的具有较长机智的DCD和2.）提供手术室中的移植外科医生，以更强大的定量生物标记来评估一组基于灌注量的延伸，以评估一个Liver iviver a Liver的延伸。这项工作的更广泛的影响是，它有可能挽救肝脏衰竭患者的数千次生命。此外，据我们所知，这项研究是第一个使系统生物学和代谢组学数据模拟活力的人体器官动力学的方法，并应作为其他试图使用时务活检对体内组织代谢进行建模的其他人的例子。