Viral Insulin-like Peptides (VILPs) and Their Activities on Mammalian Cells

项目摘要/摘要 利用生物信息学分析，我们在猪的基因组中发现了病毒胰岛素/IGF1样多肽(VILPs)。 四种不同但相关的病毒。虽然这些病毒是从鱼类中分离出来的，但对一种 系统发育背景表明，VILP与人类和其他物种的亲缘关系与鱼类一样 胰岛素/IGFS。关于这些VILP如何与哺乳动物的胰岛素或IGF-1相互作用尚不清楚 受体，以及这些病毒及其胰岛素样肽在糖尿病方面的潜在影响 发病机制或器官/肿瘤生长，所有过程都受到哺乳动物胰岛素和胰岛素的高度调控- 比如增长因素。这项提案的首要目标是从功能上描述VILP的特征，定义其 作用机制，了解它们的效力，并确定它们是否影响哺乳动物的病理生理学。这个 核心假设是VILP是胰岛素超家族的新成员，可以与哺乳动物相互作用 胰岛素和IGF-1受体并激活胰岛素/IGF-1信号从而改变细胞代谢基因 表达与细胞增殖的关系。这一假设是在令人兴奋的初步数据的基础上提出的 在申请人的实验室生产。提出这项研究的理由是，理解 VILPs在哺乳动物细胞上的功能有可能转化为更好地理解基础 胰岛素/IGF-1信号的机制和早期起源，以及这些多肽如何不仅参与 病毒性疾病，但也有2型糖尿病(T2D)、1型糖尿病(T1D)和肿瘤生长条件。同舟共济 这些疾病影响着这个国家和世界各地的数百万人。根据我们的初步数据，这 假说将通过追求两个特定的目标来检验：1)确定VILP的分子机制 作为新的胰岛素和IGF-1受体配体的作用；2)探讨VILPs对血管内皮细胞的病理生理影响 小鼠的葡萄糖稳态与细胞生长。在目标1下，VILP的功能特征将是 使用人类、啮齿动物和鱼类细胞进行实验。除了外源效应，VILP还将被克隆到 将评估哺乳动物细胞及其作为内源性配体的作用。有了合作者，核磁共振 VILP的结构将被确定，并与它们的哺乳动物同行进行比较。在目标2下，我们将 描述VILPs在体内的急性和慢性影响。为此，VILP基因将转移到 使用腺相关病毒载体系统的小鼠肝脏。VILP过表达对肝脏局部影响的研究 它们对身体的系统影响将被确定这种方法是创新的，因为它将是第一个 探讨VILP的作用及其对胰岛素信号、代谢、基因表达和生长的影响。这个 提出的研究具有重要意义，因为这将是第一个促进我们对VILP的理解的研究 功能及其对人类疾病的潜在影响。归根结底，这样的知识有可能帮助我们 不仅要了解这些分子的作用，而且要从整体上更好地了解胰岛素/IGF-1的作用 可能有助于设计新的、独特的胰岛素类似物。

PROJECT SUMMARY/ABSTRACT Using a bioinformatics analysis, we have identified viral insulin/IGF1-like peptides (VILPs) in the genomes of four different, but related, viruses. Although these viruses were isolated from fish, assessment of the VILPs in a phylogenetic context showed that VILPs are equally well-related to humans and other species as to fish insulins/IGFs. Nothing is known about how these VILPs might interact with mammalian insulin or IGF-1 receptors, and about the potential impact of these viruses and their insulin-like peptides in terms of diabetes pathogenesis or organismal/tumor growth, all processes highly regulated by mammalian insulins and insulin- like growth factors. The overarching goal of this proposal is to functionally characterize the VILPs, define their mechanism of action, understand their potency and determine if they affect mammalian pathophysiology. The central hypothesis is that VILPs are new members of the insulin super-family that can interact with mammalian insulin and IGF-1 receptors and activate insulin/IGF-1 signaling thereby altering cellular metabolism, gene expression and cell proliferation. This hypothesis has been formulated on the basis of exciting preliminary data produced in the applicant's laboratory. The rationale for the proposed research is that understanding the functions of VILPs on mammalian cells has the potential to translate into better understanding of fundamental mechanisms and early origins of insulin/IGF-1 signaling, and how these peptides may be involved in not only viral diseases, but also type 2 diabetes (T2D), type 1 diabetes (T1D) and conditions of tumor growth. Together these disorders affect millions of people in this country and worldwide. Guided by our preliminary data, this hypothesis will be tested by pursuing two specific aims: 1) Determine the molecular mechanisms of VILP action as novel insulin and IGF-1 receptor ligands and 2) explore the pathophysiologic effects of VILPs on glucose homeostasis and cell growth in mice. Under Aim 1, functional characterization of VILPs will be performed using human, rodent and fish cells. In addition to exogenous effects, VILPs will be cloned into mammalian cells and their effects as endogenous ligands will be assessed. With collaborators, the NMR structures of VILPs will be determined and compared to their mammalian counterparts. Under Aim 2, we will characterize the acute and chronic effects of VILPs in vivo. To this end, VILP genes will be transferred to the liver of mice using an adeno-associated viral vector system. The local effects of VILP overexpression on liver and their systemic effects on the body will be determined This approach is innovative since it will be the first exploration of VILP action and their impact on insulin signaling, metabolism, gene expression and growth. The proposed research is significant, because it will be the first study that advances our understanding of VILP function and their potential impact on human disease. Ultimately, such knowledge has the potential to help us not only understand the role of these molecules, but to better understand insulin/IGF-1 action overall, which may be useful in designing new, unique insulin analogs.