Klotho: Therapeutic Agent for Ischemia Reperfusion Induced Acute Kidney Injury

Klotho：缺血再灌注引起的急性肾损伤的治疗剂

• 批准号: 9307141
• 负责人: Ming-Chang Hu
• 金额: $ 36.45万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-17 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9307141
• 关键词: Acute; Acute Renal Failure with Renal Papillary Necrosis; Affect; Aging; Autophagocytosis; Benign; Biology; Blood Vessels; Blood capillaries; Catabolic Process; Cell Line; Cell physiology; Cells; Chronic Kidney Failure; Cleaved cell; Collagen; Data; Disease Progression; End stage renal failure; Endothelial Cells; Etiology; Extracellular Domain; Fibrosis; Functional Magnetic Resonance Imaging; Future; Genetic; High Resolution Computed Tomography; Histology; Human; Hyperactive behavior; Impairment; In Vitro; Injury; Ischemia; Kidney; Lead; Literature; Measurement; Membrane; Mesenchymal; Morbidity - disease rate; Mus; Outcome; Pathologic Processes; Pathway interactions; Patients; Pharmacology; Prevention; Recovery; Reperfusion Therapy; Reporter; Risk; Rodent; Testing; Therapeutic; Therapeutic Agents; Tubular formation; Up-Regulation; angiogenesis; attenuation; base; blood perfusion; capillary; driving force; effective therapy; glomerulosclerosis; improved; in vivo; kidney cell; kidney vascular structure; mortality; mutant; novel; novel strategies; pre-clinical; prevent; receptor

Project Summary/Abstract Acute kidney injury (AKI) confers high morbidity and mortality. Even though patients survive, there is a substantial risk of progression to chronic kidney disease (CKD). Unfortunately, there is no effective therapy to retard this progression. Klotho (here referred as Klotho) was shown to effectively block this transition. But, whether Klotho’s renoprotection involves prevention of vascular rarefaction and whether the suppressive effect of Klotho on renal fibrosis is associated with the clearance of collagen are largely unknown. Abnormal autophagy may lead to renal tubular and vascular damage, and renal fibrosis. Vascular rarefaction and renal fibrosis contribute to CKD. Klotho deficiency is associated with impaired angiogenesis. But, it is unclear whether Klotho can rescue peritubular capillaries in AKI. Klotho was found to upregulate autophagy, improve revascularization, and promote collagen I degradation in vitro; but, how Klotho affects autophagy and if this effect modulates vascular rarefaction and fibrosis, and prevents progression to CKD needs to be defined. The central hypothesis is that Klotho prevents AKI transition to CKD by promoting autophagy, which in turn inhibits renal fibrosis and ameliorates vascular rarefaction. There are three specific aims to test this hypothesis. Aim 1 investigates if Klotho increases autophagy flux in the kidney by (1) examining if Klotho upregulates renal autophagy flux in LC3 reporter mice; (2) defining the mechanisms of upregulation of autophagy by Klotho in vivo; (3) exploring how Klotho regulates autophagy flux in kidney cell line. Aim 2 examines if Klotho inhibits renal fibrosis via upregulation of autophagy activity by (1) examining if Klotho upregulates autophagy and inhibits renal fibrosis post-IRI; (2) defining if autophagy levels influence renal fibrosis post-AKI using mice with low or high autophagy activity; (3) investigating how autophagy reduces collagen I or promotes the degradation of collagen I in GFP-collagen I transfected cells in vitro. Aim 3 explores if Klotho ameliorates vascular rarefaction via upregulation of autophagy in endothelial cells post-AKI by (1) examining if Klotho restores peritubular capillaries with structural analysis (histology and high resolution CT), and measurement of renal blood perfusion and oxygenation (functional MRI, fMRI); (2) testing if Klotho blocks endothelial-mesenchymal transition in AKI mice with endothelial tracing markers; (3) confirming if Klotho protects endothelial damage and endothelial-mesenchymal transition in cultured endothelial cells via modulation of autophagy. Aim 1 focuses on basic biology of Klotho effect on autophagy, which builds the basis for other two independent but scientifically interconnected Aims. This renewed proposal was built based on previous 5-year studies and will provide more evidence to support the concept that Klotho upregulates autophagy to inhibit fibrosis, ameliorates rarefaction after AKI and retards AKI-to-CKD progression. Developing new approaches to enhance renal vascular recovery and inhibit fibrosis is the translational objective of the proposal. Bringing Klotho to a therapeutic platform in human AKI is in the proximal future.

项目摘要/摘要 急性肾脏损伤（AKI）承认高发病率和死亡率。即使患者幸存，也有一个 进展为慢性肾脏疾病（CKD）的很大风险。不幸的是，没有有效的疗法 阻碍了这个进展。 klotho（这里称为klotho）有效地阻止了这一过渡。但， 克洛托的命名性保护是否涉及预防血管稀疏以及抑制作用是否 肾纤维化上的klotho与胶原蛋白的清除相关。 异常自噬可能导致肾小管和血管损伤以及肾纤维化。血管稀疏 肾纤维化有助于CKD。 Klotho缺乏与血管生成受损有关。但是，是 尚不清楚Klotho是否可以在AKI中营救周围的毛细血管。发现Klotho更新自噬， 改善血运重建，并在体外促进胶原蛋白I降解；但是，克洛托如何影响自噬和 如果这种作用调节血管稀疏和纤维化，并且需要定义防止CKD的进展。 中心假设是，克洛托通过促进自噬来防止AKI过渡到CKD，这又是 抑制肾纤维化并改善血管稀疏。有三个特定的目的来检验这一假设。 AIM 1研究Klotho是否通过（1）检查Klotho是否上调肾脏是否会增加肾脏的自噬通量 LC3记者小鼠中的自噬通量； （2）定义Klotho自噬上调的机制 体内（3）探索Klotho如何调节肾细胞系中的自噬通量。 AIM 2考试如果Klotho抑制 通过（1）检查klotho是否上调自噬和 IRI后抑制肾纤维化； （2）使用与 低自噬活动或高自噬活动； （3）研究自噬如何减少胶原蛋白I或促进降解 GFP-胶原蛋白I中的胶原蛋白I的体外翻译细胞。 AIM 3探讨Klotho是否可以改善血管 通过（1）检查klotho是否还原，在AKI后内皮细胞中自噬的罕见 结构分析（组织学和高分辨率CT）和肾脏的测量 血液灌注和氧合（功能性MRI，fMRI）； （2）测试klotho是否阻塞内皮间质 具有内皮跟踪标记的AKI小鼠的过渡； （3）确认Klotho是否保护内皮损害和 通过调节自噬，内皮 - 间质转变在培养的内皮细胞中。 AIM 1专注于Klotho对自噬的影响的基本生物学，这为其他两个独立 但是科学相互联系的目的。该更新的提案是根据前5年的研究建立的， 将提供更多的证据来支持克洛托上调自噬以抑制纤维化的概念， 在AKI之后缓解稀疏，并延迟AKI至CKD的进展。开发新方法以增强 肾血管恢复和抑制纤维化是该提案的翻译目标。将克洛托带到 人类AKI的治疗平台处于近端。