Regulation of vascular smooth muscle cell plasticity

血管平滑肌细胞可塑性的调节

• 批准号: 8798690
• 负责人: Kathleen Ann Martin
• 金额: $ 41万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-02-03 至 2018-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8798690
• 关键词: Accounting; Angioplasty; Atherosclerosis; Biology; Blood Vessels; Blood flow; Bypass; Cardiovascular Diseases; Cardiovascular system; Cell Cycle; Cell Differentiation process; Cellular biology; Chromatin; Complement; DNA; DNA Methylation; Data; Embryo; Epigenetic Process; Failure; Family; Future; Gene Expression; Genes; Goals; Growth; Growth Factor; Healed; Health; Hematopoietic stem cells; Hyperplasia; In Vitro; Individual; Injury; Knock-out; Knockout Mice; Lead; Mediating; Mediator of activation protein; MicroRNAs; Modeling; Molecular; Molecular Conformation; Operative Surgical Procedures; Pathology; Pathway interactions; Patients; Phenotype; Platelet-Derived Growth Factor; Prevention therapy; Procedures; Process; Proteins; Regulation; Role; Sampling; Sirolimus; Smooth Muscle; Smooth Muscle Myocytes; Stem Cell Factor; Stem cells; Testing; Therapeutic; Transplantation; Vascular Diseases; Viral; c-myc Genes; cell dedifferentiation; femoral artery; graft failure; healing; improved; in vivo; in vivo Model; inhibitor/antagonist; myocardin; novel; overexpression; pluripotency; programs; promoter; response; restenosis; stem cell differentiation

DESCRIPTION (provided by applicant): Regulation of VSMC phenotype remains a key unanswered question in vascular smooth muscle cell (VSMC) biology. VSMC retain a remarkable plasticity to de-differentiate and re-enter the cell cycle allowing for growth and healing. However, such plasticity can also contribute to severe vascular pathologies, including restenosis, graft failure, atherosclerosis, and transplant vasculopathy. Remarkably, despite intense study, the process regulating VSMC plasticity is largely unknown with few therapies successfully targeting this process. With the growing numbers of patients suffering from vascular disease the discovery of novel targets is urgently warranted. We have made the exciting discovery that de-differentiated VSMC express genes associated with stem cell pluripotency, including Sox2, Oct4, Nanog, and KLF4. We propose that these stem cell-associated genes account for the unique plasticity of mature VSMC. Recent groundbreaking studies have identified the TET (ten-eleven translocations) family of chromatin modifying proteins as key mediators of pluripotency in embryonic and hematopoietic stem cells. Our Preliminary Results implicate TET2 as an epigenetic master regulator of VSMC phenotype. Importantly, we find that TET2 inhibits expression of stem cell-associated genes and classic markers of the de-differentiated phenotype. We previously discovered that the mTORC1 inhibitor, rapamycin, promotes VSMC differentiation. We now find that rapamycin regulates TET2 expression. Remarkably, we find that TET2 also regulates miRNAs that can modulate both differentiation-specific and stem cell-associated gene expression. We hypothesize that TET2 is a master regulator of VSMC phenotype through its coordinated regulation of the promoters of contractile and stem cell-associated genes, as well as of miRNAs. In Specific Aim 1, we will determine the role of stem cell-associated genes in VSMC phenotype. In Specific Aim 2, we will determine the role of TET2-regulated miRNAs in VSMC phenotype. In Specific Aim 3, we will determine whether targeting TET2 or stem cell-associated genes has therapeutic utility in in vivo models of intimal hyperplasia. If our goals are achieved, we will have identified a nove mechanism underlying VSMC plasticity. Understanding the critical mechanisms by which mTORC1 regulates VSMC phenotype will lead to improved cardiovascular therapeutics.

描述（由申请人提供）：VSMC 表型的调节仍然是血管平滑肌细胞（VSMC）生物学中尚未解答的关键问题。 VSMC 保留了显着的可塑性，可以去分化并重新进入细胞周期，从而实现生长和愈合。然而，这种可塑性也会导致严重的血管病变，包括再狭窄、移植失败、动脉粥样硬化和移植血管病变。值得注意的是，尽管进行了深入的研究，但调节 VSMC 可塑性的过程在很大程度上仍是未知的，很少有疗法能成功针对这一过程。随着患有血管疾病的患者数量不断增加，迫切需要发现新的靶点。 我们取得了令人兴奋的发现，去分化的 VSMC 表达与干细胞多能性相关的基因，包括 Sox2、Oct4、Nanog 和 KLF4。我们认为这些干细胞相关基因解释了成熟 VSMC 的独特可塑性。最近的突破性研究已确定染色质修饰蛋白 TET（10-11 易位）家族是胚胎干细胞和造血干细胞多能性的关键介质。我们的初步结果表明 TET2 是 VSMC 表型的表观遗传主调节因子。重要的是，我们发现 TET2 抑制干细胞相关基因和去分化表型经典标记的表达。我们之前发现 mTORC1 抑制剂雷帕霉素可促进 VSMC 分化。我们现在发现雷帕霉素调节 TET2 表达。值得注意的是，我们发现 TET2 还调节 miRNA，从而调节分化特异性和干细胞相关基因表达。我们假设 TET2 通过协调调节收缩基因和干细胞相关基因以及 miRNA 的启动子，成为 VSMC 表型的主要调节因子。在具体目标 1 中，我们将确定干细胞相关基因在 VSMC 表型中的作用。在具体目标 2 中，我们将确定 TET2 调节的 miRNA 在 VSMC 表型中的作用。在具体目标 3 中，我们将确定靶向 TET2 或干细胞相关基因在内膜增生的体内模型中是否具有治疗效用。如果我们的目标实现，我们将确定 VSMC 可塑性背后的新机制。了解 mTORC1 调节 VSMC 表型的关键机制将有助于改善心血管治疗。