Snrk-1 and Dusp-5 co-ordinately regulate vascular development in vertebrates

描述（由申请人提供）：血管异常（VAs），胚胎血管发育中的先天性错误分为两类：血管瘤和血管畸形（vm）。目前的VAs治疗方法疗效有限，且有明显的并发症。因此，为了改善对这些疾病患者的治疗，确定VMs和血管瘤发病的潜在机制至关重要。我们的长期目标是了解导致VAs发病机制的潜在机制，以便针对这种情况产生更好的治疗方法。为了实现这一目标，本文的目的是研究我们小组最近发现的两个基因，即蔗糖非发酵受体激酶-1 (Snrk-1)，一种丝氨酸-苏氨酸激酶，和双特异性磷酸酶-5 (Dusp-5)，一种丝裂原活化蛋白激酶（MAPK）家族，它们在血管瘤和vm患者中发生突变。我们的中心假设是“转化生长因子- β (TGF-)配体与内皮细胞上的特异性受体（ALK-1/ALK-5）相互作用，通过Snrk-1和Dusp-5将信号传递到rho相关的共同底物，盘绕盘绕含有蛋白激酶-1 (Rock-1)，从而在该细胞及其周围细胞中诱导特异性反应。”这一假设是基于我们小组在Snrk-1底物筛选中发现的TGF-信号家族的几个成员（Alk-1、Alk-2、Smad-3、BMPR-2）和Rock-1的初步数据制定的。本研究的基本原理是，一旦确定胚胎发育过程中Snrk-1和ddusp -5如何调节EC和EC前体（成血管细胞）中的TGF-信号通路，我们就可以用fda批准的靶向药物靶向TGF- Snrk-1/ ddusp -5信号通路，从而为VAs患者提供更好的靶向治疗选择。该假设将通过以下三个具体目标进行验证：1)确定细胞自主与非自主Snrk-1/Dusp-5功能的贡献以及Dusp-5突变在VA疾病发病机制中的作用。2)明确Rock-1在Snrk-1/Dusp-5体内外信号通路中的机制作用。3)确定Snrk-1/Dusp-5在体内外参与特定信号通路的机制。在这些目标中，我们将采用多种细胞生物学，分子生物学和发育生物学方法来揭示Snrk-1/Dusp-5到TGF-信号通路的机制基础，包括Rock-1在体内和体外这一过程中的作用。这种方法是创新的，因为它为我们提供了一个前所未有的机会来了解这些基因在体内参与的分子途径，从而有助于我们理解VAs发病机制的机制步骤。这项研究具有重要意义，因为研究参与TGF-信号通路在血管发生中的机制基础的新型细胞内信号分子，消除了这一关键的进展障碍，从而推动了血管生物学领域的发展。

DESCRIPTION (provided by applicant): Vascular anomalies (VAs), inborn errors in embryonic vascular development are classified into two distinct groups: hemangiomas and vascular malformations (VMs). Current therapies for VAs are limited in efficacy and have significant complications. Therefore, to improve therapy for patients afflicted with these conditions, it is critical to identify the underlying mechanism leading to pathogenesis of VMs and hemangiomas. Our long-term goal is to understand the underlying mechanisms that lead to pathogenesis of VAs so that better therapeutics targeting this condition can be generated. In order to pursue that goal, the objective here is to study two recently identified genes by our group namely Sucrose non-fermenting receptor kinase-1 (Snrk-1), a serine- threonine kinase, and dual-specific phosphatase-5 (Dusp-5), a mitogen-activated protein kinase (MAPK) family, which are mutated in patients with hemangiomas and VMs. Our central hypothesis is that "transforming growth factor-beta (TGF-) ligand interacts with specific receptors (ALK-1/ALK-5) on endothelial cells transmitting signals via Snrk-1 and Dusp-5 to common substrate Rho-associated, coiled-coil containing protein kinase-1 (Rock-1) to induce specific responses in that cell and cells surrounding it." This hypothesis is formulated based on preliminary data from our group that identified several members (Alk-1, Alk-2, Smad-3, BMPR-2) of the TGF- signaling family and Rock-1 in a screen for substrates for Snrk-1. The rationale for the proposed research is that once it is determined how Snrk-1 and Dusp-5 modulate TGF- signaling in ECs and EC precursors (angioblasts) during embryonic development, we can target the TGF- Snrk-1/Dusp-5 signaling pathway with repurposed FDA-approved drugs thus providing better target based therapeutic options for VAs patients. The hypothesis will be tested by pursuing three specific aims: 1) Identify the contribution of cell autonomous vs. non-autonomous Snrk-1/Dusp-5 function and the role of Dusp-5 mutations in VA disease pathogenesis. 2) Identify the mechanistic role of Rock-1 in Snrk-1/Dusp-5 signaling in vivo and in vitro. 3) Determine mechanistically how Snrk-1/Dusp-5 participates with specific signaling pathway in vivo and in vitro. In each of these aims, we will employ a variety of cell biology, molecular and developmental biology approaches to unravel the mechanistic underpinnings of Snrk-1/Dusp-5 to TGF- signaling pathway including the role of Rock-1 in this process in vivo and in vitro. The approach is innovative because it provides us an unprecedented opportunity to understand the molecular pathway that these genes participate in vivo thereby contributing to our understanding of the mechanistic steps involved in VAs pathogenesis. The proposed research is significant because studying novel intracellular signaling molecules that participate in the mechanistic underpinnings of the TGF- signaling pathway in vasculogenesis, removes this critical barrier to progress thus moving the field of vascular biology forward. PUBLIC HEALTH RELEVANCE: The proposed research is relevant to public health because vascular anomalies (VAs) represent an important clinical problem that has few therapeutic options. The successful mechanistic understanding of VAs pathogenesis is likely to provide candidate targets for drug development against VAs. Thus, the proposed research is directly relevant to NIH's mission of reducing the burden of debilitating health conditions from diseases affected by deregulated vasculature.