Proximal Tubule Albumin Transport in Disease States.

项目摘要 而蛋白尿，尤其是蛋白尿的临床相关性一直很好。 记录不同贡献的量化机制贡献或作用 蛋白尿的成分仍然是一个相当令人兴奋的领域。特别是，这个角色 近端小管在白蛋白重吸收和回收中的作用现在被认为是一个重要的 生理和病理条件下尿蛋白尿屏障的决定因素。 因此，本申请建议仔细分析和量化 已知近曲小管受体Cubilin/megalin与胎儿新生儿免疫球蛋白受体 (FcRN)用于白蛋白。为了实现这一点，我们将量化Cubilin和FcRN的相互作用 白蛋白利用生化溶液结合分析的逐步和协同组合， 人近端小管细胞和肾小管上皮细胞的细胞培养摄取、转运和受体敲除研究 慕尼黑Wistar Fromter大鼠肾表面小球和双光子的活体肾脏研究 动态成像。生化、结构、功能和机械观察将是 相互关联，以促进我们目前对这一临床重要现象的理解。我们的 总体假设是，通过了解白蛋白如何与白蛋白相互作用并受到影响 通过这两个受体，我们将了解近端小管细胞如何发挥作用。 尝试和保持生理状态的基础、交互和可诱导的角色 并尽量减少蛋白尿。我们的最终目标是最终开发出一种临床方法 这将使蛋白尿的起源可以量化为近端小管或 肾小球原发性缺陷或两者兼而有之。这将允许更具体地 待确定的治疗靶点和制剂。为了直接评估这一假设，我们有 开发了必要的技术、方法以及细胞和动物模型来解剖， 量化和了解近端小管白蛋白代谢过程。

Project Summary While the clinical relevance of proteinuria, and especially albuminuria, has been well documented the quantitative mechanistic contribution or role of different contributing components to albuminuria remains an area of considerable excitement . In particular, the role of proximal tubules in albumin reabsorption and reclamation is now known to be an important determinant of the urinary barrier to albuminuria under physiologic and pathologic conditions. Therefore, the present application proposes to dissect apart and quantify the contributions of the known proximal tubule receptors cubilin/megalin and the fetal neonatal immunoglobulin receptor (FcRn) for albumin. To accomplish this we will quantify the interactions of cubilin and FcRn with albumin utilizing a stepwise and synergistic combination of biochemical solution binding assays, cell culture uptake, trafficking and receptor knock out studies in human proximal tubule cells and in vivo kidney studies using Munich Wistar Fromter rats with surface Glomeruli and 2-photon dynamic imaging. Biochemical, structural, functional and mechanistic observations will be interrelated to advance our present understanding of this clinically important phenomenon. Our Overall Hypothesis is that by understanding how albumin interacts with and is affected by these two receptors we will then understand how proximal tubule cells play fundamental, interactive and inducible roles to try and maintain the physiological state and minimize albuminuria. Our ultimate goal is to eventually develop a clinical approach that will allow quantification of the origin of albuminuria as either a proximal tubule or glomerular primary defect or a combination of both. This will allow for more specific therapeutic targets and agents to be identified. To directly evaluate this hypothesis we have developed the necessary techniques, approaches and cell and animal models to dissect, quantify and understand the process of proximal tubule metabolism of albumin.