Regulation of Akt-integrin pathway in endothelial function and neovasculature

Akt-整合素通路在内皮功能和新血管系统中的调节

• 批准号: 9307929
• 负责人: Tatiana V Byzova
• 金额: $ 39.63万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-14 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9307929
• 关键词: Address; Adhesions; Adult; Affect; Binding; Biology; Blood Vessels; Cell Adhesion; Cell Adhesion Molecules; Cell Proliferation; Cell Survival; Cell membrane; Cessation of life; Characteristics; Clinical Trials; Complex; Cytoplasmic Tail; Data; Development; Disease; Endothelial Cells; Endothelium; Goals; Growth; Growth Factor; Health; Heart; Homeostasis; Human Development; Individual; Integrins; Ischemia; KDR gene; Knock-in; Knock-out; Knowledge; LIMS1 gene; Life; Maintenance; Mediating; Modeling; Molecular; Mus; Myocardial Ischemia; Pathologic; Pathology; Pathway interactions; Patients; Peripheral Vascular Diseases; Phosphotransferases; Process; Protein Isoforms; Recruitment Activity; Regulation; Retina; Role; Series; Signal Transduction; Stroke; Structure; TLR2 gene; Technology; Testing; Therapeutic; Time; Tissues; Vascular Diseases; Vascularization; angiogenesis; base; cell motility; experimental study; in vivo; innovation; migration; mutant; neovasculature; novel; postnatal; public health relevance; response; scaffold; success; tumor

DESCRIPTION (provided by applicant): Despite the considerable progress in vascular biology and development, there is a lack of technologies preserving endothelial function, as well as deficits in understanding how stable and mature neovasculature is formed. The main goal of these studies is to dissect the detailed molecular mechanisms and identify novel targets regulating endothelial function and neoangiogenesis. This is a resubmission of our project focused on the role of integrin-Akt signaling axis in vascular biology. We have demonstrated that integrin activation on endothelium is essential for angiogenesis and vascular homeostasis and have identified key molecules regulating this process. Mechanistically, we have identified integrin/Akt axis as an important driver of vascular growth and maturation, suggesting that this pathway can act as an on/off switch for tissue specific angiogenesis. Our preliminary data demonstrate that Akt in endothelium controls vascular functions and angiogenesis. We will focus on the role of Akt in endothelial migration and integrin function and will determine molecular interactions controlling this interplay. The main hypothesis is: endothelial Akt1 is recruited to integrins via heterotrimeric complex of PINCH, ILK, Parvin, and serves as an essential regulator of integrin inside-out signaling, which, in turn, controls endothelial migratio and angiogenesis in vivo. While other parallel pathways might mediate cell survival and proliferation in the absence of Akt, it is indispensable for the endothelial attachment and migration. The following specific Aims are proposed: Aim 1. To establish the role for endothelial Akt in integrin-dependent functions in angiogenesis: We will determine the levels of Akt activity which are sufficient to support integrin functions in vivo during angiogenic responses. We will assess how and why Akt deletion in endothelium affects the key characteristics of neovasculature. Aim 2. To determine the levels of Akt activity and Akt isoforms required for integrin inside-out vs. outside-in signaling in EC. We will compare the direct involvement of individual Akt isoforms in the regulation of integrin inside-out signaling triggered either by VEGFR or by TLR2 activation (as an example of a novel VEGF- independent pathway in endothelium). Rescue experiments with constitutively active integrins or forced integrin activation will be performed. Aim 3. To establish a detailed molecular mechanism of Akt1 recruitment to integrin complex and the role for this complex in integrin function in endothelium. We will focus on the direct recruitment of Akt1 to integrin-associated complex (ILK/ PINCH/Parvin and Kindlin) and determine how this complex coordinates integrin functions on endothelium. To this end, we will determine the structural determinants of this complex (residues within Akt1 required to interact with Parvin, which is a prerequisite for the formation o the entire complex) and show how disruption of the individual interactions affects bidirectional integrin signaling. Together, our studies will show how the Akt-integrin axis regulates vascular homeostasis and angiogenesis in a complexity of in vivo settings, and reveal the molecular determinants connecting Akt signaling to integrin function. These studies will identify novel cellular and molecular mechanisms underlying endothelial functions in health and disease.

描述（由申请人提供）：尽管在血管生物学和发育方面取得了相当大的进展，但仍然缺乏保护内皮功能的技术，以及对稳定和成熟的新血管如何形成的理解不足。这些研究的主要目的是剖析详细的分子机制，并确定调节内皮功能和新生血管生成的新靶点。这是我们关于整合素- akt信号轴在血管生物学中的作用的项目的重新提交。我们已经证明了内皮上整合素的激活对血管生成和血管稳态至关重要，并确定了调节这一过程的关键分子。在机制上，我们已经确定整合素/Akt轴是血管生长和成熟的重要驱动因素，这表明该途径可以作为组织特异性血管生成的开关。我们的初步数据表明，内皮细胞中的Akt控制着血管功能和血管生成。我们将重点关注Akt在内皮迁移和整合素功能中的作用，并将确定控制这种相互作用的分子相互作用。主要假设是：内皮细胞Akt1通过PINCH、ILK、Parvin的异源三聚体复合物募集到整合素中，并作为整合素内向外信号传导的重要调节因子，进而控制体内内皮细胞的迁移和血管生成。虽然其他平行通路可能在Akt缺失的情况下介导细胞存活和增殖，但它对于内皮细胞的附着和迁移是必不可少的。提出了以下具体目标：目标1。为了确定内皮Akt在血管生成中整合素依赖功能中的作用：我们将确定在血管生成反应中足以支持体内整合素功能的Akt活性水平。我们将评估内皮细胞中Akt缺失如何以及为什么会影响血管系统的关键特征。目标2。测定EC中整合素内向外与外向内信号通路所需的Akt活性水平和Akt亚型。我们将比较单个Akt亚型在由VEGFR或TLR2激活触发的整合素内外信号的调节中的直接参与（作为内皮中新的VEGF独立通路的一个例子）。将进行本构活性整合素或强制整合素激活的救援实验。目标3。建立Akt1向整合素复合体募集的详细分子机制以及该复合体在内皮细胞整合素功能中的作用。我们将重点关注Akt1对整合素相关复合体（ILK/ PINCH/Parvin和Kindlin）的直接募集，并确定该复合体如何协调整合素在内皮细胞上的功能。为此，我们将确定该复合体的结构决定因素（Akt1内的残基需要与Parvin相互作用，这是形成整个复合体的先决条件），并展示个体相互作用的破坏如何影响双向整合素信号传导。总之，我们的研究将揭示Akt-整合素轴如何在复杂的体内环境中调节血管稳态和血管生成，并揭示Akt信号传导与整合素功能之间的分子决定因素。这些研究将确定健康和疾病中内皮功能的新细胞和分子机制。