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

项目总结/摘要 使用生物信息学分析，我们已经确定了病毒胰岛素/IGF 1样肽（VILP）的基因组中， 四种不同但相关的病毒虽然这些病毒是从鱼中分离出来的，但在一个 系统发育背景表明，VILPs与人类和其他物种的关系与鱼类一样密切 胰岛素/IGFs。目前还不知道这些VILPs如何与哺乳动物胰岛素或IGF-1相互作用 受体，以及这些病毒及其胰岛素样肽对糖尿病的潜在影响 发病机制或生物体/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节， 比如生长因子该提案的总体目标是在功能上描述VILPs，定义其 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。的 中心假设是VILPs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信号传导，从而改变细胞代谢，基因 表达和细胞增殖。这一假设是根据令人兴奋的初步数据提出的 在申请人的实验室生产。拟议研究的基本原理是， VILPs在哺乳动物细胞上的功能有可能转化为更好地理解基本的 胰岛素/IGF-1信号传导的机制和早期起源，以及这些肽如何不仅参与 病毒性疾病，还有2型糖尿病（T2 D）、1型糖尿病（T1 D）和肿瘤生长的病症。一起 这些疾病影响着这个国家和全世界数百万人。根据初步数据， 我们将通过以下两个具体目标来验证这一假设：1）确定VILP的分子机制 作为新的胰岛素和IGF-1受体配体的作用和2）探索VILP对 葡萄糖稳态和细胞生长。根据目标1，VILPs的功能表征将是 使用人类、啮齿动物和鱼类细胞进行。除了外源性作用，VILPs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。与合作者，核磁共振 将确定VILPs的结构并与它们的哺乳动物对应物进行比较。根据目标2，我们将 表征VILPs在体内的急性和慢性作用。为此，VILP基因将被转移到 使用腺相关病毒载体系统的小鼠肝脏。VILP过表达对肝脏的局部影响 以及它们对身体的全身影响将被确定。这种方法是创新的，因为它将是第一个 探索VILP作用及其对胰岛素信号传导、代谢、基因表达和生长的影响。的 这项研究意义重大，因为它将是第一项促进我们对VILP理解的研究 功能及其对人类疾病的潜在影响。最终，这些知识有可能帮助我们 不仅要了解这些分子的作用，而且要更好地了解胰岛素/IGF-1的整体作用， 可以用于设计新的、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.