Molecular Pathogenesis of Chronic Kidney Disease-Dependent Vascular Calcification

慢性肾病依赖性血管钙化的分子发病机制

基本信息

批准号：
8642176
负责人：
Makoto Miyazaki
金额：
$ 43.05万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-04-01 至 2018-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8642176
关键词：
Accounting Adenoviruses Affect Aorta ApoE knockout mouse Apolipoprotein E Atherosclerosis Attenuated Basic Science Blood Vessels Calcified Cardiovascular Diseases Cardiovascular system Cause of Death Cell Culture Techniques Cells Cessation of life Chronic Chronic Kidney Failure Clinical Sciences Cyclic AMP-Dependent Protein Kinases Cyclic AMP-Responsive DNA-Binding Protein Data Development Endoplasmic Reticulum Eukaryotic Initiation Factor-2 Event Exhibits Forskolin GRP78 gene Goals Human Inflammation Inflammatory Inorganic Phosphate Transporter Knockout Mice Lipids Medial Mediating Metabolism Minerals Modeling Molecular Morbidity - disease rate Mus Mutation Nephrectomy Osteoblasts Osteoclasts Osteogenesis Pathogenesis Pathway interactions Patients Phosphorylation Phosphotransferases Population Procedures Process Protein Family Proteins Recovery Regulation Research Project Grants Research Proposals Resistance Role Saturated Fatty Acids Scheme Series Serine Signal Pathway Smooth Muscle Myocytes Sodium Staging Stearates Stearic Acids Subfamily lentivirinae Techniques Testing Transgenic Mice Translations Vascular calcification activating transcription factor 4 base calcification cytokine endoplasmic reticulum stress gain of function in vitro Model in vivo Model inhibitor/antagonist inorganic phosphate lipid biosynthesis loss of function member mineralization mortality mouse model mutant novel osteoblast differentiation overexpression public health relevance response small hairpin RNA transcription factor uptake

项目摘要

DESCRIPTION (provided by applicant): The long term objective of this research proposal is to determine the molecular mechanisms of vascular calcification in order to identify novel target(s) for the treatment of chronic kidney disease (CKD)-dependent vascular calcification. Vascular calcification is closely associated with cardiovascular morbidity and mortality in patients with CKD. In fact, more than half of all deaths in CKD subjects can be attributed to cardiovascular diseases. We hypothesized that a central event in the pathogenesis of CKD-dependent vascular calcification is increased expression of phosphorylated activating transcription factor 4 (ATF4). ATF4 is a member of the cAMP-responsive element-binding protein (CREB) family of basic zipper-containing transcription factors that regulates osteogenesis and also mediates unfolded protein response (UPR) in the endoplasmic reticulum (ER). Our hypothesis is based on the following evidence derived from a series of preliminary results from our lab: 1) total and phosphorylated ATF4 protein levels were induced by a number of positive regulatory factors for vascular calcification, such as inorganic phosphate, inflammatory cytokines (TNFa) and saturated fatty acids through the activation of the PERK-elF2a axis of the UPR in vascular smooth muscle cells (VSMCs); 2) adenovirus-mediated overexpression of ATF4 induced mineralization of VSMCs; 3) ATF4 knockdown, on the other hand, attenuated vascular calcification; 4) serine-phosphorylation of ATF4 (p-ATF4) was induced by PKA activation by forskolin, which is known to promote vascular calcification; 5) PKA and ERK inhibitors inhibited the phosphorylation of ATF4, resulting in the reduction of vascular calcification; 6) Total ATF4 and p-ATF4 proteins were increased in the aortas of murine models of atherosclerotic calcification such as ApoE knockout mice with 5/6 nephrectomy (5/6 nx), and medial calcification such as DBA2/J mice with 5/6 nx and klotho knockout mice; 7) ATF4 targets (CHOP and GADD34) increased in these models and 8) ATF4 regulates the expression of Pit-1, a major phosphate transporter in VSMCs. To determine the pivotal role of ATF4 in the pathogenesis of vascular calcification, we propose three specific aims. Specific Aim 1: Determine whether global ATF4 deficiency and overexpression modulate CKD-dependent medial and atherosclerotic calcification. Specific Aim 2: Determine whether VSMC-specific activation and inhibition of ATF4 influence CKD-dependent medial and atherosclerotic calcification. Specific Aim 3: Elucidate molecular mechanisms by which ATF4 regulates osteoblastic differentiation and mineralization of VSMCs.

描述（由申请人提供）：本研究计划的长期目标是确定血管钙化的分子机制，以确定治疗慢性肾病（CKD）依赖性血管钙化的新靶点。血管钙化与 CKD 患者的心血管发病率和死亡率密切相关。事实上，超过一半的 CKD 患者死亡可归因于心血管疾病。我们假设 CKD 依赖性血管钙化发病机制中的一个核心事件是磷酸化激活转录因子 4 (ATF4) 表达的增加。 ATF4 是 cAMP 反应元件结合蛋白 (CREB) 家族的成员，该家族是含碱性拉链的转录因子，可调节成骨并介导内质网 (ER) 中的未折叠蛋白反应 (UPR)。我们的假设基于以下来自我们实验室的一系列初步结果的证据：1) 总 ATF4 蛋白和磷酸化 ATF4 蛋白水平是由许多血管钙化的正调节因子诱导的，例如无机磷酸盐、炎症细胞因子 (TNFa)和饱和脂肪酸，通过激活血管平滑肌细胞 (VSMC) 中 UPR 的 PERK-elF2a 轴； 2) 腺病毒介导的ATF4过表达诱导VSMC矿化； 3) 另一方面，ATF4 敲低可减弱血管钙化； 4) ATF4 (p-ATF4) 的丝氨酸磷酸化是由毛喉素 (forskolin) 激活 PKA 诱导的，已知毛喉素可促进血管钙化； 5）PKA和ERK抑制剂抑制ATF4的磷酸化，导致血管钙化减少； 6) 动脉粥样硬化钙化小鼠模型（例如 5/6 肾切除术 (5/6 nx) 的 ApoE 敲除小鼠）和内侧钙化小鼠（例如 5/6 肾切除术的 DBA2/J 小鼠）的主动脉中 ATF4 和 p-ATF4 总蛋白增加nx 和 klotho 基因敲除小鼠； 7) ATF4 靶标（CHOP 和 GADD34）在这些模型中增加，8) ATF4 调节 Pit-1（VSMC 中的主要磷酸盐转运蛋白）的表达。为了确定 ATF4 在血管钙化发病机制中的关键作用，我们提出了三个具体目标。具体目标 1：确定整体 ATF4 缺乏和过度表达是否调节 CKD 依赖性中层和动脉粥样硬化钙化。具体目标 2：确定 ATF4 的 VSMC 特异性激活和抑制是否影响 CKD 依赖性中层和动脉粥样硬化钙化。具体目标 3：阐明 ATF4 调节成骨细胞分化和 VSMC 矿化的分子机制。