Improving Survival For Small-For-Size Liver Grafts

提高小型肝移植物的存活率

• 批准号: 6611398
• 负责人: ZHI ZHONG
• 金额: $ 10.96万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6611398
• 关键词: aldehydes; antioxidants; bromodeoxyuridine; cytokine; fluorescent dye /probe; free radicals; glutathione; growth factor; intravital microscopy; laboratory rat; liver function; liver metabolism; liver preservation; liver regeneration; liver transplantation; mitochondria; oxidative stress; superoxide dismutase; transaminases; transcription factor; transfection

DESCRIPTION (provided by applicant): Use of partial liver grafting techniques has increased rapidly in recent years; however, small-for-size grafts remain a major problem since many fail when used as donor organs. Therefore, the relationship between graft size and graft failure needs to be understood. The goals of this project are to elucidate mechanisms involved in the failure of small-for-size grafts and to develop strategies to prevent it. We will use reduced-size liver transplantation of decreasing graft weight/standard liver weight (GW/SLW) in rats to test the unique hypothesis that free radicals increase in small-for-size grafts leading to graft failure. Our goal in Aim 1 will be to investigate the effects of graft volume, manipulation during harvest, and cold storage on survival of partial liver grafts. The time course of survival, transaminase release, and liver function will be observed in vivo after transplantation. Liver function will also be evaluated in isolated-perfusion of grafts after transplantation. ATP/ADP/AMP contents and oxygen uptake will be determined to evaluate mitochondrial function. Survival and non-survival conditions will be established, validating it as a useful model for mechanistic studies. Next, we will test the hypothesis that free radicals are produced in small-for-size grafts leading to injury. Effects of graft volume, cold storage, and manipulation during harvest on free radical production, 4-hydroxynonenal, and GSH after transplantation of partial grafts will be determined in Aim 2. We expect free radical production will be increased to a greater extent in small-for-size liver grafts, and cold storage and manipulation will further enhance this effect. In addition, we will identify cellular sources of free radicals using fluorescent probes and intravital multiphoton microscopy. In Aim 3, the effects of antioxidant therapies (polyphenols, Carolina Rinse solution, and gene delivery of superoxide dismutase) on survival of small-for-size grafts will be evaluated under non-survival conditions determined in Aim 1, and effects on transaminase, liver function and free radical production will be compared. We expect that antioxidant therapies will prevent free radical production and reduce graft failure of small-for-size grafts and to identify the most effective therapy. Finally, the effects of antioxidant therapies on liver regeneration will be evaluated in Aim 4. Incorporation of 5-bromo-2'-deoxyuridine and factors regulating regeneration (cytokines, transcription factors, growth factors, and energy supply) will be evaluated. Taken together, we expect that these studies will provide unequivocal evidence supporting a role for free radicals in primary graft failure of small-for-size grafts. This work will develop mechanism-based strategies to increase the use and improve the outcome of partial livers for transplantation in the clinic.

描述（由申请人提供）： 近年来，部分肝移植技术的使用迅速增加。但是，小规模的移植物仍然是一个主要问题，因为许多人在用作供体器官时失败。因此，需要了解移植物大小与移植失败之间的关系。该项目的目标是阐明涉及小型移植物失败的机制，并制定防止其策略。我们将使用减少大小的肝移植对大鼠的移植重量/标准肝脏重量（GW/SLW）的减轻肝移植，以测试一个独特的假设，即在小尺寸移植物中自由基增加导致移植失败。我们的目标1的目标是研究移植物体积，收获过程中的操纵以及冷藏对部分肝移植物存活的影响。移植后，将在体内观察到生存期，转氨酶释放和肝功能的时间过程。肝功能还将在移植后分离的移植物中评估。 ATP/ADP/AMP含量和氧气吸收将确定评估线粒体功能。将建立生存和非生存条件，将其验证为机械研究的有用模型。接下来，我们将检验以下假设：自由基是在小小的移植物中产生的，导致损伤。收获期间移植体积，冷藏和操纵对自由基生产，4-羟基烯烯和部分移植后的GSH的影响将在AIM 2中确定。我们预计，我们预计自由基生产将在较小的较小尺寸的肝脏移植物中更大程度地增加，以及较小的肝脏移植物以及冷藏和操纵将进一步增强这种效果。此外，我们将使用荧光探针和插入式多光子显微镜来鉴定自由基的细胞来源。在AIM 3中，将在AIM 1确定的非寿命条件下评估抗氧化剂疗法（多酚，Carolina RINSE溶液和超氧化物歧化酶的基因递送）对小型尺寸移植物的存活，并且将对跨氨基酶，肝功能和自由产生的影响进行比较。我们预计抗氧化剂疗法将防止自由基生产并减少小型移植物的移植力失败，并确定最有效的疗法。最后，将在AIM 4中评估抗氧化剂对肝脏再生的影响。将评估5-溴-2'-脱氧尿苷的掺入以及调节再生的因素（细胞因子，转录因子，生长因子和能量供应）。综上所述，我们预计这些研究将提供明确的证据，以支持自由基在小尺寸移植物的一级移植失败中的作用。这项工作将制定基于机制的策略，以增加使用并改善诊所移植的部分肝脏的结果。