The Cytoskeletal System in Preservation Injury

描述（由申请人提供）：肾移植是终末期肾衰竭患者唯一可行的治疗方法。然而，严重的器官短缺使美国数千人在等待名单上受苦和死亡。如果这些移植物能够得到适当的保存，扩大供体库以包括高风险供体可能会解决这种短缺。然而，器官获取后遭受的器官保存损伤尚未得到很好的了解，过去20年来在该领域几乎没有取得重大进展。因此，本提案的目的是确定涉及细胞骨架系统的肾脏保存损伤的新分子机制，并利用这些知识指导未来的治疗方法。初步数据显示，细胞骨架蛋白ezrin在肾脏冷藏过程中失效，并且增加ezrin的表达显著保护肾小管上皮细胞免受保存损伤。相反，ezrin敲低则相反，这表明因果关系。该提案将通过使用分子和遗传方法来改变ezrin功能，在细胞和肾脏冷藏损伤模型中测试ezrin诱导的细胞保护的可能机制。这些研究将确定ezrin在其适当的配置下，是否在冷缺血和再灌注期间保护细胞膜结构并保持细胞线粒体功能。将使用肾上皮细胞模型，其中细胞表达不同量的野生型和突变型埃兹蛋白。还将使用来自表达突变ezrin基因的转基因ezrin敲入小鼠的分离的肾小管和全肾的保存损伤的高阶模型。在这些研究的最后，我们将收集到有用的分子信息如何ezrin参与冷藏肾保存损伤，如果这种参与是临床相关的。这些见解，加上以前确定的机制，可能会建议可能的治疗目标，以改善肾脏保护，这将允许收获不太强大的肾脏从高风险的捐助者，以帮助缓解捐助者短缺。 公共卫生相关性：肾移植是终末期肾衰竭患者的治疗选择，但没有足够的可用供体肾。这种扩大供体库的需求增加了了解如何更好地保存移植器官的需求，这反过来又需要更全面地了解器官保存损伤的机制。这一提议与人类健康有关，因为它将弥补我们在了解肾脏从捐赠者体内取出后如何受损的基本分子机制方面的一些关键知识空白。这将揭示新的治疗靶点，以集中治疗并帮助缓解供体短缺。

DESCRIPTION (provided by applicant): Kidney transplantation is the only viable treatment for patients with end stage renal failure. However, the severe organ shortage leaves thousands in the US to suffer and die on waiting lists. Expanding the donor pool to include high risk donors may solve this shortage if those grafts could be preserved properly. However, organ preservation injury that is suffered after organ harvest is not well understood and little major advancement have been made in this area in the last 20 years. Therefore, the objective of this proposal is to identify novel molecular mechanisms of renal preservation injury involving the cytoskeleton system and to use this knowledge to direct future therapeutic approaches. Preliminary data show that the cytoskeleton protein ezrin fails during renal cold storage and that augmenting expression of ezrin significantly protects renal tubule epithelial cells from preservation injury. Conversely, ezrin knock-down does the opposite, which suggests causation. This proposal will test likely mechanisms of ezrin-induced cytoprotection in cell and kidney cold storage injury models by using molecular and genetic approaches to alter ezrin functionality. These studies will determine if ezrin, in its proper configuration, protects cell membrane structure and preserves cell mitochondrial function during cold ischemia and reperfusion. Renal epithelial cell models will be used where the cells express different amounts of wild type and mutant ezrin protein. Higher order models of preservation injury using isolated renal tubules and whole kidneys derived from transgenic ezrin knock-in mice expressing mutant ezrin genes will also be used. At the end of these studies, we will have gathered useful molecular information of how ezrin is involved in cold storage renal preservation injury and if this involvement is clinically relevant. These insights, together with previously identified mechanisms, may suggest likely therapeutic targets to improve renal preservation, which will allow harvesting of less robust kidneys from high risk donors to help alleviate the donor shortage. PUBLIC HEALTH RELEVANCE: Kidney transplantation is the treatment of choice for patients in end stage renal failure but there are not enough usable donor kidneys available. This need to expand the donor pool has increased the need to understand how to better preserve organs for transplantation, which in turn requires a more complete understanding of the mechanisms of organ preservation injury. This proposal is relevant to human health because it will bridge some of the key knowledge gaps in our understanding of the basic molecular mechanisms of how kidneys are injured after they are removed from the donor. This will reveal novel therapeutic targets to focus treatments and help alleviate the donor shortage.