Molecular regulation of angiogenesis

描述（由申请人提供）：相当多的疾病，包括缺血性心脏和肢体疾病、癌症、糖尿病性失明、年龄相关性黄斑变性和类风湿性关节炎，都以血管生成过多或不足为特征。血管内皮生长因子（VEGF）是调节多种内皮细胞（EC）功能和血管生成的主要生长因子。VEGF在血管生成中的重要性提供了新的治疗机会。然而，对VEGF指导血管生成的信号通路的不完全理解仍然是开发有效的抗血管生成癌症治疗或促进血管生成治疗缺血性心脏和肢体疾病的关键障碍。我的团队和其他人的新证据支持蛋白激酶D （PKD1）在VEGF信号传导和血管生成中的关键作用。PKD1是一个新的丝氨酸/苏氨酸蛋白激酶家族的成员，是潜在的药物治疗靶点。因此，有必要了解PKD1的生物学功能和导致血管生成的特定信号事件。我们首次报道了VEGF通过其受体2刺激血管内皮细胞中PKD1的磷酸化和激活。随后，我们发现PKD1通过磷酸化组蛋白去乙酰化酶，特别是HDAC7，调节EC迁移和管的形成。我的小组的初步观察现在揭示了PKD1，通过对EC存活和新血管形成的平行影响，调节vegf介导的血管生成。具体来说，使用基于PKD1基序的筛选策略，我们发现了一种新的参与凋亡途径的PKD1底物。其次，通过基因谱分析，我们发现PKD1参与VEGF信号和Notch信号的串扰，在EC形态分化、发芽和血管稳定等新血管形成过程中发挥重要作用。最后，我们的初步研究表明，PKD1抑制在体外和体内阻碍血管生成。因此，我们的中心假设是，VEGF激活PKD1促进内皮细胞的存活和功能，从而导致血管生成。提出了三个强有力的和相互关联的目标来检验这一假设：目标1。确定PKD1在vegf诱导的EC存活中的作用和信号机制。目标2。明确PKD1在VEGF和Notch信号相互作用中的作用和分子机制。目标3。研究PKD1及其信号通路在小鼠缺血血管生成模型中的作用。目标4。评估PKD1的生物学作用和特定PKD抑制剂在肿瘤血管生成小鼠模型中的治疗作用。本文提出的研究将提供VEGF-PKD1通路在血管生成中的机制见解和功能重要性。这些研究的结果将促进新的治疗方法的发展，以预防或治疗血管生成相关疾病。

DESCRIPTION (provided by applicant): A considerable number of diseases, including ischemic heart and limb diseases, cancer, diabetic blindness, age-related macular degeneration and rheumatoid arthritis, are characterized by excessive or insufficient angiogenesis. Vascular endothelial growth factor (VEGF) is a major growth factor that regulates multiple endothelial cell (EC) functions and angiogenesis. The importance of VEGF in angiogenesis has offered new therapeutic opportunities. However, the incomplete understanding of the signaling pathways whereby VEGF directs angiogenesis remains a critical barrier to developing efficient anti-angiogenic cancer therapy or pro-angiogenic treatment for ischemic heart and limb diseases. Emerging evidence from my group and others supports a crucial role of protein kinase D (PKD1) in VEGF signaling and angiogenesis. PKD1 is a member of a novel family of serine/threonine protein kinases, which are potential druggable targets for therapeutics. As such, it is imperative to understand the biological functions of PKD1 and specific signaling events leading to angiogenesis. We are the first to report that VEGF via its receptor 2 stimulated PKD1 phosphorylation and activation in vascular ECs. Subsequently, we found that PKD1, via phosphorylation of histone deacetylases specifically HDAC7, regulates EC migration and tube formation. Nascent observations from my group now reveal that PKD1, through parallel effects on EC survival and new vessel formation, regulates VEGF-mediated angiogenesis. Specifically, using a PKD1 motif-based screening strategy, we identified a novel PKD1 substrate that is involved in the apoptosis pathway. Second, using gene profile analysis we have found that PKD1 is involved in the crosstalk of VEGF signaling and Notch signaling, which plays an essential role in new vessel formation including EC morphological differentiation, sprouting and vascular stabilization. Finally, our preliminary studies indicate that PKD1 inhibition impedes angiogenesis in vitro and in vivo. Therefore, our central hypothesis is that PKD1 activation by VEGF promotes endothelial survival and functions leading to angiogenesis. Three robust and interrelated aims are proposed to test this hypothesis: Aim 1. Determine the role and signaling mechanisms for PKD1 in VEGF-induced EC survival. Aim 2. Define the role and molecular mechanisms for PKD1 in the interplay of VEGF and Notch signaling. Aim 3. Study the role of PKD1 and signaling pathways in a mouse model of ischemia angiogenesis. Aim 4. Evaluate the biological role of PKD1 and therapeutic effects of a specific PKD inhibitor in a mouse model of tumor angiogenesis. The studies proposed herein will provide mechanistic insights and functional importance of the VEGF-PKD1 pathway in angiogenesis. The results of these studies will facilitate development of new therapeutic approaches to prevent or treat angiogenesis-related diseases.