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）：该研究建议的长期目标是确定血管钙化的分子机制，以确定用于治疗慢性肾脏病（CKD）依赖性血管钙化的新靶标。血管钙化与CKD患者的心血管发病率和死亡率密切相关。实际上，CKD受试者的所有死亡中有一半以上可以归因于心血管疾病。我们假设CKD依赖性血管钙化发病机理中的一个中心事件是增加磷酸化激活转录因子4的表达（ATF4）。 ATF4是含基本含拉链的转录因子的cAMP响应元件结合蛋白（CREB）的成员，可调节成骨的转录因子，并介导内质网（ER）中的蛋白质反应（UPR）。我们的假设基于以下证据，这些证据来自我们实验室的一系列初步结果：1）多种阳性调节因子的血管钙化诱导的总和磷酸化的ATF4蛋白水平是诱导的，例如无机磷酸盐，炎性细胞因子（TNFA）和通过平滑的脂肪酸的平滑液含量液化液含量的液化液和饱和脂肪酸的液体效率。（VSMC）; 2）腺病毒介导的ATF4诱导的VSMC矿化过表达； 3）另一方面，ATF4敲低会减弱血管钙化； 4）Forskolin诱导ATF4（P-ATF4）的丝氨酸磷酸化（P-ATF4），据已知会促进血管钙化； 5）PKA和ERK抑制剂抑制了ATF4的磷酸化，导致血管钙化的减少； 6）在动脉粥样硬化钙化的鼠模型的主动脉中，总ATF4和P-ATF4蛋白增加了，例如，具有5/6肾切除术（5/6 nx）的APOE敲除小鼠，以及内侧钙化，例如DBA2/J小鼠，具有5/6 nx和Klotho敲除小鼠； 7）在这些模型中，ATF4靶标（CHOP和GADD34）增加，8）ATF4调节VSMC中主要磷酸转运蛋白的PIT-1的表达。为了确定ATF4在血管钙化发病机理中的关键作用，我们提出了三个特定目标。具体目标1：确定全局ATF4缺乏和过表达是否调节CKD依赖性内侧和动脉粥样硬化钙化。具体目标2：确定VSMC特异性激活和对ATF4的抑制是否影响CKD依赖性内侧和动脉粥样硬化钙化。特定目标3：阐明ATF4调节成骨细胞分化和VSMC矿化的分子机制。