Autophagy and VSMC migration

自噬和 VSMC 迁移

基本信息

批准号：
9251904
负责人：
Zhonglin Xie
金额：
$ 67.56万
依托单位：
GEORGIA STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-04-01 至 2020-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9251904
关键词：
Acetylation Adenoviruses Amino Acids Angioplasty Animal Model Aorta Apolipoprotein E Arginine Atherosclerosis Autophagocytosis Basic Science Biological Assay Biomedical Research Blood Vessels Bypass Cardiac Myocytes Carotid Artery Injuries Cell Cycle Cultured Cells Data Development Diabetes Mellitus Diabetic Angiopathies Diet Event Exhibits Extracellular Matrix Fluorescence Foundations Gene Silencing Genetic Suppression Goals High Fat Diet Hyperplasia Hypertension In Vitro Injury Ligation Light Lysine MAP1 Microtubule-Associated Protein Mediating Microtubule Stabilization Microtubules Molecular Mus Muscle Cells Muscle function Operative Surgical Procedures Pathway interactions Pharmacology Platelet-Derived Growth Factor Prevention Process Protein Biosynthesis Proteins Role Skeletal Muscle Small Interfering RNA Smooth Muscle Smooth Muscle Myocytes Stents Testing Therapeutic Intervention Transcriptional Activation Transgenic Mice Vascular Diseases Vascular Proliferation Vascular Smooth Muscle Vascular remodeling Wound Healing alpha Tubulin base directional cell graft failure histone acetyltransferase in vivo insight loss of function migration novel oxidized lipid prevent public health relevance response restenosis tool vascular smooth muscle cell migration

项目摘要

DESCRIPTION (provided by applicant): In response to pro-atherosclerotic factors such as oxidized lipids, or to therapeutic interventions such as angioplasty, stents, or bypass surgery, vascular smooth muscle cells (VSMC) migrate to the intima, resulting in intimal hyperplasia, restenosis, graft failure, or atherosclerosis. Understanding the mechanisms involved in VSMC migration has been a major focus of biomedical research. Our exciting preliminary data show that in response to or wire-mediated carotid artery injury, increased expression of autophagy-related (Atg) proteins is associated with increased VSMC migration and intimal hyperplasia. Pharmacological and genetic suppression of autophagy inhibits VSMC migration. Mechanistically, suppression of vascular autophagy leads to the accumulation of amino acid synthesis protein 5 (GCN5), a ubiquitous histone acetyltransferase (HAT) that promotes transcriptional activation. Furthermore, we found that GCN5 accumulation is associated with increased α-tubulin acetylation, microtubule stabilization, and inhibition of VSMC migration. The central hypothesis is that autophagy-dependent degradation of GCN5 promotes VSMC migration via inhibition of α-tubulin acetylation. This hypothesis will be tested using gain-/lossof-function strategies in both animal models and cultured cells. Aim 1 will determine the role of autophagy in regulating VSMC migration in response to vascular injury in vivo by characterizing the spatial and temporal dynamics of vascular autophagy, VSMC migration, and neointimal hyperplasia using smMHC/eGFP transgenic mice, determining whether autophagy deficiency inhibits VSMC migration and neointimal formation in response to carotid ligation and/or vascular injury using Beclin1 heterozygous mice (beclin1+/-), and examining whether enhanced VSMC autophagy promotes VSMC migration and exacerbates neointimal hyperplasia and atherosclerosis in response to vascular injury in Atg7 SMC-specific transgenic mice (Atg-TG). In addition, the role of autophagy in regulating VSMC migration will be determined using gain- and loss-of-function approaches in cultured aortic rings and VSMCs. Aim 2 is to delineate the mechanism by which autophagy promotes VSMC migration. By test the hypothesis that autophagy promotes VSMC migration by enhancing GCN5 degradation and reducing α-tubulin acetylation. The proposed study will characterize the molecular mechanism by which autophagy degrades GCN5 in VSMCs, examine whether GCN5 acetylates α-tubulin and stabilizes microtubules, and determine whether autophagy suppression inhibits VSMC migration by increasing GCN5-mediated acetylation of α-tubulin in beclin+/- mice of wire-mediated carotid artery injury, carotid ligation, and atherosclerosis, and Apoe-/-/beclin1+/- mice fed with a high-ft diet.

描述（由申请人提供）：响应促动脉粥样硬化因子（例如氧化脂质）或治疗干预（例如血管成形术、支架或搭桥手术），血管平滑肌细胞（VSMC）迁移至内膜，导致内膜增生，我们令人兴奋的初步数据表明，了解 VSMC 迁移的机制一直是研究的重点。对于或线介导的颈动脉损伤，自噬相关 (Atg) 蛋白的表达增加与 VSMC 迁移增加和内膜增生相关，自噬的药理和基因抑制会抑制 VSMC 迁移。氨基酸合成蛋白 5 (GCN5)，一种普遍存在的组蛋白乙酰转移酶 (HAT)，可促进转录激活。 GCN5 积累与 α-微管蛋白乙酰化增加、微管稳定和 VSMC 迁移抑制相关。核心假设是 GCN5 的自噬依赖性降解通过抑制 α-微管蛋白乙酰化促进 VSMC 迁移。动物模型和培养细胞中的功能丧失策略将通过以下方式确定自噬在调节 VSMC 迁移以响应体内血管损伤中的作用。使用 smMHC/eGFP 转基因小鼠表征血管自噬、VSMC 迁移和新内膜增生的空间和时间动态，使用 Beclin1 杂合子小鼠 (beclin1+/ -)，并检查增强的 VSMC 自噬是否促进 VSMC 迁移并恶化新内膜增生和Atg7 SMC 特异性转基因小鼠 (Atg-TG) 中血管损伤引起的动脉粥样硬化此外，将使用培养的主动脉环和 VSMC 的功能获得和丧失方法来确定自噬在调节 VSMC 迁移中的作用。目标 2 是通过检验自噬通过增强 GCN5 降解和减少 VSMC 迁移来促进 VSMC 迁移的假设，从而阐明自噬促进 VSMC 迁移的机制。拟议的研究将表征自噬降解 VSMC 中 GCN5 的分子机制，检查 GCN5 是否乙酰化 α-微管蛋白并稳定微管，并确定自噬抑制是否通过增加 GCN5 介导的 α-微管蛋白乙酰化来抑制 VSMC 迁移。在 beclin+/- 小鼠中进行线介导的颈动脉损伤、颈动脉结扎和动脉粥样硬化，以及用高ft饮食喂养的Apoe-/-/beclin1+/-小鼠。