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

描述（由申请人提供）：血管异常（VA），胚胎血管发育中的先天性缺陷分为两个不同的组：血管瘤和血管畸形（VM）。目前VA的治疗方法疗效有限，并有严重的并发症。因此，为了改善对患有这些疾病的患者的治疗，确定导致VM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VA发病机制的潜在机制，以便能够产生针对这种情况的更好的治疗方法。为了实现这一目标，本文的目标是研究我们小组最近鉴定的两个基因，即蔗糖非发酵受体激酶-1（Snrk-1），丝氨酸-苏氨酸激酶，和双特异性磷酸酶-5（Dusp-5），丝裂原活化蛋白激酶（MAPK）家族，其在血管瘤和VM患者中突变。我们的中心假设是“转化生长因子-β（TGF-β）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将信号传递给共同底物Rho相关的、含有卷曲螺旋的蛋白激酶-1（Rock-1），以诱导该细胞及其周围细胞的特异性反应。“这一假设是基于我们小组的初步数据制定的，这些数据在Snrk-1底物的筛选中鉴定了TGF-信号家族和Rock-1的几个成员（Alk-1，Alk-2，Smad-3，BMPR-2）。提出的研究的基本原理是，一旦确定Snrk-1和Dusp-5如何在胚胎发育期间调节EC和EC前体（成血管细胞）中的TGF-β信号传导，我们就可以用FDA批准的药物靶向TGF- Snrk-1/Dusp-5信号传导途径，从而为VA患者提供更好的基于靶点的治疗选择。将通过追求三个具体目标来测试该假设：1）鉴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)确定Rock-1在体内和体外Snrk-1/Dusp-5信号传导中的机制作用。3)确定Snrk-1/Dusp-5在体内和体外如何参与特异性信号通路的机制。在这些目标中的每一个中，我们将采用各种细胞生物学、分子和发育生物学方法来解开Snrk-1/Dusp-5对TGF-β信号传导通路的机制基础，包括Rock-1在体内和体外该过程中的作用。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，了解这些基因在体内参与的分子途径，从而有助于我们了解VA发病机制中涉及的机制步骤。拟议的研究是重要的，因为研究参与血管发生中TGF-信号通路的机制基础的新型细胞内信号分子，消除了这一关键障碍，从而推动了血管生物学领域的发展。 公共卫生相关性：拟议的研究与公共卫生有关，因为血管异常（VA）是一个重要的临床问题，几乎没有治疗选择。对VA发病机制的成功理解可能为针对VA的药物开发提供候选靶点。因此，拟议的研究与NIH的使命直接相关，即减少因血管系统失调而导致的疾病所造成的健康状况恶化的负担。

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.