SGLT2 Mediates Glucose-Induced Angiotensinogen Synthesis in Proximal Tubule Cells

SGLT2 介导近端小管细胞中葡萄糖诱导的血管紧张素原合成

• 批准号: 8983617
• 负责人: Michael Winthers Cypress
• 金额: $ 4.31万
• 依托单位: TULANE UNIVERSITY OF LOUISIANA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-04 至 2017-01-03
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8983617
• 关键词: Address; Angiotensin II; Angiotensinogen; Antioxidants; Attenuated; Blood Glucose; Blood Pressure; Cell Culture Techniques; Cell Line; Cell membrane; Cells; Chronic; Development; Diabetes Mellitus; Diabetic Nephropathy; Experimental Designs; Generations; Glucose; Hyperglycemia; Hypertension; Injury; Insulin-Dependent Diabetes Mellitus; Kidney; Kidney Failure; Knockout Mice; Laboratories; Measures; Mediating; Messenger RNA; Mitochondria; Molecular; Mus; NADPH Oxidase; Non-Insulin-Dependent Diabetes Mellitus; Oxidative Stress; Oxygen Consumption; Pathway interactions; Patients; Pharmacologic Substance; Plasma; Prevention; Process; Production; Proteins; Proximal Kidney Tubules; Reactive Oxygen Species; Receptor Activation; Receptor, Angiotensin, Type 1; Regulation; Renin-Angiotensin System; Reporting; Research; Respiration; Role; Sodium; Source; Staging; Testing; Tubular formation; United States; Up-Regulation; Urine; extracellular; glucose metabolism; human CYBA protein; improved; inhibitor/antagonist; insight; prevent; public health relevance; receptor; response; symporter; tempol; treatment strategy

 DESCRIPTION (provided by applicant): The intra-renal renin-angiotensin system (RAS) has been implicated in the development of hypertension and the progression of kidney injury that results from diabetes mellitus. RAS blockade is an effective strategy in preventing diabetic nephropathy and hypertension during diabetes. The production of angiotensinogen (AGT) is upregulated in the renal proximal tubular cells under high glucose conditions. This process is partially mediated by the formation of reactive oxygen species (ROS) as a result of glucose metabolism and mitochondrial respiration. AGT forms angiotensin II (Ang II) which causes oxidative stress by activating the Ang II Type 1 Receptor (AT1R). AT1R activation is also a major source of ROS generation in proximal tubular cells. The overall aim of this proposal is to elucidate the mechanisms underlying the up-regulation of AGT in the proximal tubule during diabetes and chronic hyperglycemia. The sodium-glucose cotransporter 2 (SGLT2) is the primary mechanism responsible for reabsorbing filtered glucose in the kidney. It is not known if SGLT2- mediated glucose reabsorption is responsible for the increased intratubular AGT expression reported during diabetes. Therefore, our overall hypothesis is that the increase in AGT expression in proximal tubular cells under high glucose conditions is mediated by increased glucose entry via SGLT2 which synergizes with the effects of AT1R activation. This will provide insight into the molecular mechanisms that occur in the kidney in the early stages of diabetes. To test this hypothesis, we will establish an increase in ROS accumulation and AGT expression in proximal tubular cells cultured in high glucose conditions and that this upregulation is dependent on glucose entry via SGLT2. We will demonstrate that glucose entry and mitochondrial respiration are increased by Ang II through AT1R activation. In addition, we will show that AT1R activation synergizes with the effects of high glucose to augment AGT expression. The experimental design will utilize immortalized proximal tubular cell lines derived from the wild type and AT1R knockout mice. Canagliflozin, a highly selective pharmaceutical blocker of SGLT2, will be used to demonstrate the role of SGLT2 on the production of AGT during high glucose conditions and address the overall hypothesis.

 描述（由适用提供）：在高血压的发展和肾脏损伤的发展中，已实施了肾脏内肾素 - 血管紧张素系统（RAS）。 RAS桶是预防糖尿病期间糖尿病性肾病和高血压的有效策略。在高葡萄糖条件下，在肾近端肾小管细胞中更新了血管紧张素原（AGT）的产生。由于葡萄糖代谢和线粒体呼吸的结果，该过程是由活性氧（ROS）形成的部分介导的。 AGT形成血管紧张素II（ANG II），该ANG II型1受体（AT1R）通过激活ANG II型引起氧化应激。 AT1R激活也是近端管状细胞中ROS产生的主要来源。该提案的总体目的是阐明糖尿病和慢性高血糖期间AGT上调的机制。葡萄糖共转运蛋白2（SGLT2）是负责肾脏中过滤葡萄糖的主要机制。尚不清楚SGLT2-介导的葡萄糖重吸收是否导致糖尿病期间报道的细胞内AGT表达增加。因此，我们的总体假设是，在高葡萄糖条件下，近端管状细胞中AGT表达的增加是通过通过SGLT2进入葡萄糖进入的，该葡萄糖通过SGLT2进入，该SGLT2与AT1R激活的影响合成。这将提供有关糖尿病早期肾脏中发生的分子机制的见解。为了检验这一假设，我们将在高葡萄糖条件下培养的近端结节细胞中ROS的积累和AGT表达增加，并且该上调取决于通过SGLT2进入葡萄糖。我们将证明，ANG II通过AT1R激活增加了葡萄糖进入和线粒体呼吸。此外，我们将表明AT1R激活与高葡萄糖增强AGT表达的影响合成。实验设计将利用源自野生型和AT1R敲除小鼠的永生近端结节细胞系。 Canagliflozin是SGLT2的高度选择性药物阻滞剂，将用于证明SGLT2在高葡萄糖条件下AGT生产的作用并解决总体假设。