MECHANISM/S OF ALCOHOL-INDUCED LIVER GRAFT FAILURE

肝移植已成为一种越来越被接受的治疗方法 不可逆性肝病患者的治疗。不幸的是， 然而，许多儿童和成人在等待捐赠器官时死亡。一 肝移植的关键问题是脂肪肝导致的 在用作捐赠器官时会失败。因为源 肝移植的主要是脑死亡的受害者， 涉及酒精，酒精，脂肪肝， 移植后的移植物衰竭迫切需要了解，如果 可用器官的捐赠者库将扩大。因此， 该项目旨在确定和澄清 脂肪肝失败，并制定预防移植失败的策略 移植后。我们处于独特的位置来执行这一点 由于我们的实验室在啮齿类动物方面拥有丰富的经验， 肝移植对于这些研究，我们计划建立在最近的 在NIAAA支持的第一个周期中获得的令人兴奋的发现： 也就是说，酒精处理过的大鼠的脂肪肝产生SOD/过氧化氢酶- 移植后早期的不敏感自由基 并且白色细胞粘附也发生得非常早， 酒精处理大鼠肝脏中的程度。对于这些研究，我们将使用 我们新的临床相关的移植失败的啮齿动物模型， 脂肪肝移植是我们研制的。我们的第一个目标是 测试SOD/过氧化氢酶不敏感自由基来源于 从脂类中。对照组和乙醇处理组大鼠将被移植，脂质 氢过氧化物将被测量，自由基将被捕获 术后使用自旋捕获技术， 电子顺磁共振波谱。我们预计将检测到脂质过氧化氢， 随后被GSH单酯减少。第二贴壁白色细胞 术后将被隔离，特定呼叫类型负责 将确定自由基的产生。以氧为中心的自由基 可以产生脂质自由基的物质将使用自旋阱来鉴定 DMPO接下来，我们将测试早期氧化剂对大脑皮层的损伤 内皮细胞和枯否细胞的活化导致 粘附分子（例如，ICAM-I和选择素）， 白色细胞粘附。具体来说，我们将确定手术后 粘附分子表达的时间进程。下一个是 我们将确定白色细胞是否粘附于内皮，枯否细胞， 和/或Ito细胞。灌注的肝脏将 用于评价术后内皮损伤的时间进程 以及用透明质酸和碳摄取激活枯否细胞， 分别第三个目标将是评估假设， 自由基的产生和/或白色细胞粘附是导致 暴露于酒精的大鼠移植失败。因此，我们将开发 减少白色细胞粘附的策略（例如，抗ICAM-1，唾液酸 刘易斯[X]）和减少自由基（例如，GSH单酯），并评估 它们对脂肪移植物长期存活的影响。获得的信息 这些研究将使我们能够开发基于特定机制的 防止脂肪肝衰竭的程序。这些信息将 最终增加可用肝移植物的数量，减少对 再次移植手术，减少术后并发症。

Liver transplantation has become an increasingly accepted therapy worldwide for patients with irreversible liver disease. Tragically, however, many children and adults die while waiting for a donor organ. One critical problem in liver transplantation is that fatty livers resulting from alcohol consumption fail when used a donor organs. Because the source of liver grafts is largely brain-dead victims of accidents heavily involving alcohol, the relationship between alcohol, fatty liver, and graft failure following transplantation urgently needs to be understood if the donor pool of usable organs is to be expanded. Therefore, the goals of this project are to identify and clarify mechanisms involved in the failure of fatty livers and to develop strategies to prevent graft failure following transplantation. We are uniquely positioned to perform this research since our laboratories have extensive experience with rodent liver transplantation. For these studies, we plan to build on recent exciting findings obtained during the first cycle of NIAAA support: namely, that fatty livers from alcohol-treated rat produce SOD/catalase- insensitive free radicals in the early minutes following transplantation and that white cell adhesion also occurs very early and to a much greater extent in livers from alcohol-treated rats. For these studies we will use our new clinically relevant rodent model of graft failure following transplantation of fatty liver developed by us. Our first goal will be to test the hypothesis that SOD/catalase-insensitive free radicals are derive from lipids. Control and ethanol-treated rats will be transplanted, lipid hydroperoxides will be measured and free radicals will be trapped postoperatively using the spin-trapping technique and quantitated using EPR spectroscopy. We expect that lipid hydroperoxides will be detected and subsequently diminished by GSH monoesters. Second adhering white cells will be isolated postoperatively and specific call types responsible for free radical production will be identified. Oxygen-centered free radicals, which could produce lipid radicals will be identified using the spin trap DMPO. Next, we will test the hypothesis that early oxidant damage to the endothelium and activation of Kupffer cells leads to expression of adhesion molecules (e.g., ICAM-I and selectins) which are responsible for white cell adhesion. Specifically, we will determine the post-operative time course of adhesion molecule expression immunohistochemically. Next, we will determine if white cells adhere to endothelium, Kupffer cells, and/or Ito cells by video and electron microscopy. The perfused liver will be used to evaluate the time course of postoperative damage to endothelium and activation of Kupffer cells with hyaluronic acid and carbon uptake, respectively. The third goal will be to evaluate the hypothesis that free radical production and/or white cell adhesion is causally responsible for failure of grafts from alcohol-exposed rats. Accordingly, we will develop strategies to decrease white cell sticking (e.g., anti-ICAM-1, Sialyl Lewis[X]) and to reduce free radicals (e.g., GSH monoester) and evaluate their effects on long-term survival of fatty grafts. Information gained from these studies will allow us to develop specific mechanism-based procedures to prevent failure of fatty livers. This information will ultimately increase the pool of usable liver grafts, decrease the need for retransplantation surgery and minimize postoperative complications.