CELLULAR PATHOPHYSIOLOGY OF ACUTE RENAL FAILURE

肾小管损伤是缺血性的一个显著特征 以及相关形式的急性肾功能衰竭。用于功能恢复 在组织中，必须有足够数量的小管细胞存活， 恢复足够的新陈代谢，修复结构损伤， 潜在地，进行增殖以取代丢失的细胞。这个 过去12年由这笔拨款资助的调查 提供了对这些问题的一些主要决定因素的洞察 事件，并使我们假设：a)屏障属性 从根本上允许维护的质膜 细胞活力在三磷酸腺苷耗竭和相关急性损伤中的变化 状态取决于甘氨酸的存在；b)蛋白质 去磷酸化/再磷酸化决定了程度和 甘氨酸亚致死量结构改变的可逆性- 受保护的细胞，因此，它们的能力 功能恢复。焦点粘连拆解/重组提供 这一行为的一个可接近和高度相关的实例；以及 C)甘氨酸的能量功能进行性损害- 受保护的细胞限制了它们参与ATP依赖的能力 修复功能和耐受甘氨酸撤退。这 损伤继发于线粒体的发育。 渗透率转变，以全有或全无的方式在 单个细胞，是否可以通过药物和其他方法改善 接近了。我们将测试并进一步研究这些假设 在四个具体目标中：L)优化新方法 蛋白酪氨酸磷酸化的测定以评估 单个肾小管细胞的能量状态及其在阐明中的应用 发展的进行性能量缺陷的基础 甘氨酸保护的、低氧的、孤立的小管和 在体缺血再灌注过程中肾小管的行为；2) 直接显示线粒体通透性的发育 肾小管细胞的转变，定义其与 维持线粒体膜电位，并评估 希望有新的行动来缓解能量不足；3) 进一步明确突出问题的性质和机制 整合素和粘着斑蛋白的变化 在缺氧/复氧期间，分离的小管和 体内缺血/早期再灌注及其相互关系 细胞能量状态的变化；4)测试参与 潜在调节观察到的ATP水平的主要因素。 局灶性粘连的依赖、拆解/重组 甘氨酸保护的孤立小管。

Injury to the tubule compartment is a prominent feature of ischemic and related forms of acute renal failure. For functional recovery of the tissue, sufficient numbers of tubule cells must survive, resume adequate metabolism, repair structural damage, and, potentially, undergo proliferation to replace lost cells. The investigations supported by this grant during the past 12 years have provided insight into some of the major determinants of these events and have led us to hypothesize that: a) The barrier property of the plasma membrane that most fundamentally permits maintenance of cell viability during ATP depletion and related acute injury states is dependent on the presence of glycine; b) Protein dephosphorylation/rephosphorylation determines the extent and reversibility of sublethal structural alterations in glycine- protected cells and, as a consequence, their capacity for functional recovery. Focal adhesion disassembly/reassembly provides an approachable and highly relevant instance of this behavior; and c) Progressive impairment of energetic function in glycine- protected cells limits their ability to engage in ATP-dependent repair functions and to tolerate glycine withdrawal. This impairment is secondary to development of the mitochondrial permeability transition, occurs in an all or none fashion in individual cells, and can he improved by pharmacological and other approaches. We will test and further investigate these hypotheses in four Specific Aims: l) Optimize a novel approach using measurements of protein tyrosine phosphorylation to assess the energetic state of individual tubule cells and apply it to clarify the basis for the progressive energetic defect that develops in populations of glycine-protected, hypoxic, isolated tubules and the behavior of tubules during reperfusion after ischemia in vivo; 2) Directly visualize development of the mitochondrial permeability transition in the tubule cells, define its relationship to maintenance of the mitochondrial membrane potential, and assess promising new maneuvers to alleviate the energetic deficit; 3) Further define the nature and mechanisms of the prominent alterations of integrins and focal adhesion proteins that occur during hypoxia/reoxygenation of the isolated tubules and ischemia/early reperfusion in vivo and the relationships of these changes to the cellular energetic state; 4) Test the involvement of major factors potentially mediating the observed ATP level. dependent, disassembly/reassembly of focal adhesions in the glycine-protected, isolated tubules.