Molecular pathogenesis of calcineurin inhibitor-induced hypertension

钙调神经磷酸酶抑制剂诱发高血压的分子发病机制

基本信息

批准号：
8549218
负责人：
David H Ellison
金额：
$ 35.68万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-21 至 2016-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8549218
关键词：
Active Sites Binding Blood Pressure Calcineurin Calcineurin inhibitor Calcium Calmodulin Cells Chloride Ion Chlorides Chronic Kidney Failure Clinical Complex Cyclosporine Distal Distal convoluted renal tubule structure Electrolytes Equilibrium Excretory function Exhibits Exposure to Functional disorder Future Genetic Goals Graft Survival Hereditary Disease Human Hypertension Immunophilins Immunosuppression Immunosuppressive Agents In Vitro Incidence Kidney Kidney Failure Knock-out Knockout Mice Mediating Medicine Metabolic acidosis Modeling Molecular Mus Nature Nephrons Organ Organ Transplantation Pathogenesis Pathway interactions Patients Pharmaceutical Preparations Phosphoric Monoester Hydrolases Phosphotransferases Potassium Protein Serine/Threonine Phosphatase Protein phosphatase Proteins Pseudohypoaldosteronism Publishing Regulation Renal tubule structure SLC12A3 gene Shunt Device Signal Pathway Signaling Molecule Sodium Chloride Solid Syndrome System Tacrolimus Tacrolimus Binding Protein 1A Testing Therapeutic Thiazide Diuretics Toxic effect Transplant Recipients Tubular formation drug development hyperkalemia improved in vivo inhibitor/antagonist inorganic phosphate novel phosphatase inhibitor pressure protein phosphatase inhibitor-1 research study urinary

项目摘要

DESCRIPTION (provided by applicant): This project will examine how calcineurin inhibitors, such as tacrolimus and cyclosporine, cause hypertension with potassium retention. In preliminary published studies, we showed that tacrolimus activates the thiazide-sensitive Na- Cl cotransporter (NCC) in the kidney. This effect was found to be essential for the resulting hypertension and potassium retention. Here we will examine the mechanisms involved. Calcineurin is a protein phosphatase and we will test whether it removes phosphates from NCC directly, to inhibit its actions, or whether the pathway involves calcineurin acting on intermediar proteins. We will determine whether other protein phosphatases, including protein phosphatases 1A, 2A, and 4 remove phosphates from NCC. Protein phosphatase inhibitor 1 (PPP1r1a) is a canonical target of calcineurin and is highly expressed along the distal nephron. In preliminary experiments by our collaborator, genetic deletion of this inhibitor was found to reduce the abundance of phosphorylated NCC in vivo. Therefore, we will test whether calcineurin regulates NCC activity via PPP1r1a. PPP1r1a is known to inhibit the actions of protein phosphatase 1A, which can act on the kinase SPAK. SPAK is the canonical NCC activating protein. Thus, we will test the over arching hypothesis that calcineurin inhibitors activate PPP1r1a in the distal nephron, leading to inhibition of PP1A, SPAK activation, and enhanced NCC activity. This model will be tested both in vitro, using a novel cell system that we developed recently, and in vivo, by knocking out key components of the signaling pathway. The proposal has substantial clinical implications, both in terms of patient treatment today, and in terms of drug development for tomorrow.

描述（由申请人提供）：该项目将检查钙调神经蛋白抑制剂（例如他克莫司和环孢菌素）如何通过钾保留量导致高血压。在初步发表的研究中，我们表明他克莫司在肾脏中激活了对噻嗪类敏感的Na- cl共转运蛋白（NCC）。发现这种作用对于由此产生的高血压和钾保留至关重要。在这里，我们将检查涉及的机制。钙调蛋白是一种蛋白质磷酸酶，我们将测试它是否直接去除NCC，抑制其作用，或者该途径是否涉及作用于Intermediar蛋白上的钙调蛋白。我们将确定其他蛋白质磷酸酶（包括蛋白质磷酸酶1a，2a和4）是否从NCC中去除磷酸盐。蛋白质磷酸酶抑制剂1（PPP1R1A）是钙调蛋白的典型靶标，沿远端肾单位高度表达。在我们的合作者的初步实验中，发现该抑制剂的遗传缺失可减少体内磷酸化的NCC的丰度。因此，我们将测试钙调蛋白是否通过PPP1R1A调节NCC活性。已知PPP1R1A可以抑制蛋白质磷酸酶1a的作用，该蛋白质磷酸酶1a的作用可以作用于激酶SPAK。 SPAK是典型的NCC激活蛋白。因此，我们将测试过度的弓形假设，即钙调神经蛋白抑制剂在远端肾单位中激活PPP1R1A，从而抑制PP1A，SPAK激活和增强的NCC活性。该模型将在体外，使用我们最近开发的新细胞系统和体内进行测试，通过淘汰信号通路的关键组件。该提案在当今的患者治疗方面和明天的药物开发方面都具有重大的临床意义。