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；然而，小型移植物仍然是一个主要问题，因为许多移植物在用作供体器官时失败。因此，需要了解移植物尺寸和移植物失败之间的关系。该项目的目标是阐明小型移植物失败的机制，并制定预防策略。我们将在大鼠中使用减少移植物重量/标准肝脏重量（GW/SLW）的缩小尺寸肝移植来检验小尺寸移植物中自由基增加导致移植失败的独特假设。我们目标 1 的目标是研究移植物体积、收获期间的操作和冷藏对部分肝移植物存活的影响。移植后体内观察存活时间、转氨酶释放和肝功能。移植后，还将通过移植物的分离灌注来评估肝功能。将测定 ATP/ADP/AMP 含量和摄氧量以评估线粒体功能。将建立生存和非生存条件，验证其作为机制研究的有用模型。接下来，我们将检验小尺寸移植物中产生自由基导致损伤的假设。移植物体积、冷藏和收获期间的操作对部分移植物移植后自由基产生、4-羟基壬烯醛和 GSH 的影响将在目标 2 中确定。我们预计自由基产生将在小范围内更大程度地增加。适合大小的肝移植以及冷藏和操作将进一步增强这种效果。此外，我们将使用荧光探针和活体多光子显微镜来识别自由基的细胞来源。在目标 3 中，将在目标 1 中确定的非存活条件下评估抗氧化疗法（多酚、Carolina Rinse 溶液和超氧化物歧化酶基因传递）对小型移植物存活的影响，以及对转氨酶的影响，将比较肝功能和自由基产生。我们期望抗氧化疗法将防止自由基产生并减少小尺寸移植物的移植失败，并确定最有效的疗法。最后，目标 4 将评估抗氧化疗法对肝再生的影响。将评估 5-溴-2'-脱氧尿苷和再生调节因子（细胞因子、转录因子、生长因子和能量供应）的掺入。总而言之，我们期望这些研究将提供明确的证据，支持自由基在小型移植物的原发性移植失败中的作用。这项工作将开发基于机制的策略，以增加临床上部分肝脏移植的使用并改善其结果。