Function and Regulation of TSPAN2 in Vascular Disease

TSPAN2在血管疾病中的功能和调控

基本信息

批准号：
10083017
负责人：
Xiaochun Long
金额：
$ 52.22万
依托单位：
AUGUSTA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-01-08 至 2023-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10083017
关键词：
Adult Allografting Apolipoprotein E Arteriovenous fistula Atherosclerosis Attenuated Blood Vessels CD44 gene CRISPR/Cas technology Cell Differentiation process Cell membrane Cell surface Data Dependence Development Disease Docking Electrophoretic Mobility Shift Assay Endocytosis Epigenetic Process Exhibits Failure Gene Expression Genes Genetic Transcription Goals High Fat Diet Homeostasis Human Impairment In Vitro Injury Integrin Binding Integrin alpha3beta1 Integrins Knockout Mice Knowledge Laminin Lead Lesion Link Luciferases Maintenance Medial Mediator of activation protein Membrane Modeling Molecular Mus Mutant Strains Mice Operative Surgical Procedures Pathologic Pathology Pathway interactions Phenotype Proliferating Proteins RNA Receptor Protein-Tyrosine Kinases Regulation Role Sampling Serum Response Factor Signal Transduction Smooth Muscle Myocytes Stimulus Testing Therapeutic Translating Triad Acrylic Resin Vascular Diseases Vascular Smooth Muscle blood pressure regulation cell motility effective therapy genome editing genome wide association study improved in vitro Assay in vivo loss of function member mouse model myocardin neointima formation novel programs protein activation protein degradation response restenosis vascular abnormality vascular smooth muscle cell proliferation

项目摘要

PROJECT SUMMARY Differentiated vascular smooth muscle cells (VSMCs) are genetically programmed to proliferate and migrate at low rate while carrying out contractility for adult vessel homeostasis. VSMCs are not terminally differentiated and can undergo phenotypic switching to a dedifferentiated synthetic mode in response to various pathophysiological stimuli, contributing to diverse vascular diseases such as atherosclerosis and restenosis. Due to cell surface accessibility, cell membrane regulators required for VSMC differentiation may hold attractive therapeutic potential. However, there is a paucity of information on key transmembrane regulators governing VSMC differentiation. TSPANs possess a unique signaling platform, termed as tetraspanin-enriched microdomains (TEMs) organized in cis with TSPANs and other transmembrane partners including receptor tyrosine kinases and integrin(s). TSPANs serve as membrane “docking” molecules, exerting critical roles in diverse signal cascades. Recent genome wide association studies have specifically linked TSPAN2 to atherosclerosis and blood pressure control. Inspired by these findings, we interrogated data from multiple RNA screenings and consistently found that TSPAN2 is the sole TSPANs member significantly decreased during VSMC phenotypic modulation and in diseased vessels. TSPAN2 is enriched in VSMCs and exhibits serum response factor (SRF) /Myocardin (MYOCD)-dependent expression in vitro. New functional data shows that depletion of TSPAN2 in VSMCs attenuates contractile gene expression, while promoting VSMC proliferation and migration; forced expression of TSPAN2 blocks neointima formation in a balloon injury model. TSPAN2 interacts with and promotes degradation of CD44 protein, a prominent pathological mediator in vascular disease. In addition, TSPAN2 interacts with the laminin-binding integrin α3β1, and β1 integrins are essential to the maintenance of the VSMC contractile phenotype. These preliminary findings support a novel hypothesis that TSPAN2 stabilizes the VSMC contractile phenotype and suppresses vascular pathology via two distinct pathways: by promoting degradation of CD44 protein which inactivates the synthetic VSMC phenotype and interaction with integrin α3β1 which facilitates the contractile phenotype. Three specific aims are proposed to test this hypothesis. Aim 1 will determine functions of TSPAN2 in arteriovenous fistula and atherosclerosis mouse models. Aim 2 will elucidate the mechanisms through which TSPAN2 stabilizes the VSMC contractile phenotype involving inactivation of the synthetic VSMC phenotype by promoting CD44 protein degradation and activation of the contractile phenotype by interacting with integrin α3β1. Aim 3 will elucidate the molecular basis for the impaired TSPAN2 gene expression under pathological vascular conditions via perturbation of SRF/MYOCD pathway. Successful completion of this proposal will reveal previously unknown molecular mechanisms governing VSMC phenotypic plasticity involving the actions of key transmembrane regulators, which will potentially lead to more effective therapies for vascular diseases.

项目概要分化的血管平滑肌细胞 (VSMC) 经过基因编程，可在以下时间增殖和迁移：在进行成体血管稳态收缩时，VSMC 没有终末分化。并且可以响应各种不同的反应而进行表型转换至去分化的合成模式病理生理刺激，导致多种血管疾病，如动脉粥样硬化和再狭窄。由于细胞表面可及性，VSMC 分化所需的细胞膜调节因子可能会存在然而，关于关键跨膜调节因子的信息却很少。控制 VSMC 分化的 TSPAN 拥有独特的信号平台，称为富含四跨膜蛋白的信号平台。微结构域 (TEM) 与 TSPAN 和其他跨膜伙伴（包括受体）顺式组织酪氨酸激酶和整合素 TSPAN 作为膜“对接”分子，在细胞膜中发挥关键作用。最近的全基因组关联研究已明确将 TSPAN2 与多种信号级联联系起来。受这些发现的启发，我们询问了来自多个 RNA 的数据。筛选并一致发现 TSPAN2 是唯一的 TSPAN 成员，在 VSMC 表型调节和病变血管中的 TSPAN2 在 VSMC 中富集并表现出血清。新的功能数据表明，反应因子（SRF）/心肌素（MYOCD）依赖性体外表达。 VSMC 中 TSPAN2 的缺失会减弱收缩基因表达，同时促进 VSMC 增殖 TSPAN2 的强制表达可阻止球囊损伤模型中的新内膜形成。与 CD44 蛋白相互作用并促进其降解，CD44 蛋白是血管中重要的病理介质此外，TSPAN2 与层粘连蛋白结合整合素 α3β1 相互作用，而 β1 整合素对于疾病至关重要。这些初步发现支持了一个新的假设。 TSPAN2 通过两种不同的方式稳定 VSMC 收缩表型并抑制血管病理途径：通过促进 CD44 蛋白的降解，使合成的 VSMC 表型失活，与整合素 α3β1 的相互作用促进收缩表型。目标 1 将确定 TSPAN2 在动静脉瘘和动脉粥样硬化中的功能。目标 2 将阐明 TSPAN2 稳定 VSMC 收缩的机制。表型涉及通过促进 CD44 蛋白降解和合成 VSMC 表型失活通过与整合素 α3β1 相互作用激活收缩表型将阐明该分子。在病理血管条件下通过扰动 TSPAN2 基因表达受损的基础 SRF/MYOCD 途径的成功完成将揭示以前未知的分子。涉及关键跨膜调节因子作用的 VSMC 表型可塑性调控机制，这将有可能带来更有效的血管疾病治疗方法。