Function and Regulation of TSPAN2 in Vascular Disease

TSPAN2在血管疾病中的功能和调控

• 批准号: 10543854
• 负责人: Xiaochun Long
• 金额: $ 51.48万
• 依托单位: AUGUSTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-08 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10543854
• 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; Lesion; Link; Luciferases; Maintenance; Medial; Mediator; 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; Vascular Diseases; Vascular Smooth Muscle; blood pressure control; cell motility; effective therapy; genome editing; genome wide association study; improved; in vitro Assay; in vivo; loss of function; member; migration; mouse model; myocardin; neointima formation; novel; programs; protein activation; protein degradation; response; restenosis; screening; vascular abnormality; vascular smooth muscle cell proliferation

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.

项目摘要 分化的血管平滑肌细胞（VSMC）经过遗传编程，以增殖和迁移 对成年船舶体内平衡的收缩性的低率。 VSMC没有终止区分 并且可以通过反应各种 病理生理刺激，导致动脉粥样硬化和再狭窄等发散的血管疾病。 由于细胞表面可及性，VSMC分化所需的细胞膜调节剂可能会保持 有吸引力的治疗潜力。但是，关于关键跨膜调节器的信息很少 管理VSMC差异化。 TSPAN具有一个独特的信号平台，称为四翼烷蛋白富含 在带有TSPAN和其他跨膜伙伴（包括接收器）的CI中组织的微域（TEMS） 酪氨酸激酶和整联蛋白（S）。 TSPAN充当膜“对接”分子，在 各种信号级联。最近的基因组广泛的关联研究已将TSPAN2专门联系起来 动脉粥样硬化和血压控制。受这些发现的启发，我们询问了来自多个RNA的数据 放映，并一直发现TSPAN2是唯一的TSPAN成员 VSMC表型调制和患病视频中。 TSPAN2富含VSMC并展示串行 反应因子（SRF） /心肌素（MyoCD）在体外依赖性表达。新功能数据显示 VSMC中TSPAN2的耗竭减弱了收缩基因的表达，同时促进VSMC增殖 和迁移； TSPAN2的强迫表达阻塞了球囊损伤模型中的新内膜形成。 TSPAN2 与CD44蛋白的降解并促进了血管中突出的病理介质的降解 疾病。另外，TSPAN2与层粘连蛋白结合蛋白α3β1相互作用，β1整合素对 VSMC收缩表型的维护。这些初步发现支持一个新的假设 TSPAN2稳定VSMC收缩表型并通过两个不同的 途径：通过促进CD44蛋白的降解，从而使合成VSMC表型和 与整联蛋白α3β1相互作用，该α3β1有助于收缩表型。提出了三个具体目标 检验此假设。 AIM 1将确定TSPAN2在动脉瘘和动脉粥样硬化中的功能 鼠标模型。 AIM 2将阐明TSPAN2稳定VSMC收缩的机制 通过促进CD44蛋白降解和 通过与整合素α3β1相互作用，收缩表型的激活。 AIM 3将阐明分子 通过扰动在病理血管条件下TSPAN2基因表达受损的基础 SRF/MyOCD途径。该提案的成功完成将揭示以前未知的分子 控制VSMC表型可塑性的机制涉及关键跨膜调节剂的作用， 这可能会导致血管疾病更有效的疗法。