The role of Spry2 in beta cell function and the unfolded protein response

 描述(申请人提供)胰腺β细胞是胰岛素生理水平的唯一产生者。当胰岛β细胞在胰岛素抵抗增加的情况下失效时，就会发生2型糖尿病。目前没有一种糖尿病药物可以预防胰岛细胞衰竭。 我们认为，进一步了解控制正常β细胞功能的途径将有助于更合理地设计能够防止β细胞衰竭的糖尿病治疗方法。为此，我们进行了全基因组RNA干扰筛选，并确定SPRY2是一种新的胰岛素产生调节因子。有趣的是，SPRY2附近的单核苷酸多态性(SNP)与2型糖尿病有关，这表明它在糖尿病的发病机制中发挥了作用。我们制作了胰岛素转录顶级调控因子之间的系统遗传相互作用图，以了解SPRY2可能的功能。这张图预测SPRY2可能与Wfs1相互作用，Wfs1是一种已知通过激活未折叠蛋白反应(UPR)而导致人类糖尿病的基因。事实上，我们表明SPRY2受普遍定期审议的调节和调节。这项提案的总体目标是确定SPRY2在β细胞功能、UPR和人类糖尿病中的作用和机制。具体地说，我们假设SPRY2通过与Wfs1的相互作用对β细胞功能和UPR是重要的。我们的具体目标是：目标1：证明SPRY2在体内β细胞功能中的作用。我们将描述一个贝塔细胞特异性的SPRY2基因敲除。目的2：阐明SPRY2对UPR的作用机制。我们将测试Wfs1/SPRY2相互作用的功能重要性，并绘制其调节UPR所需的SPRY2位点。目的3：检测SPRY2在人胰岛中的功能，确定SPRY2附近调控SPRY2表达的SNP。在目标的第一部分，我们将减少人类胰岛中SPRY2的表达，并测量胰岛素的产生、分泌和未折叠的蛋白质反应。在目标的第二部分，我们将使用基因组编辑来测试潜在的致病2型糖尿病SNPs调节SPRY2表达的能力。这项建议的贡献是确立了SPRY2作为β细胞UPR和2型糖尿病发病机制中的新参与者。

 DESCRIPTION (provided by applicant) The pancreatic beta cell is the sole producer of physiologic levels of insulin. Type 2 diabetes develops when the pancreatic beta cell fails in the setting of increased insulin resistance. No current diabetes medication prevents beta cell failure. We propose that further understanding the pathways that control normal beta cell function will allow the more rational design of diabetes therapies that can prevent beta cell failure. To that end, we performed a whole genome RNA interference screen and identified Spry2 as a novel regulator of insulin production. Intriguingly, a single nucleotide polymorphism (SNP) near Spry2 is associated with type 2 diabetes, suggesting that it plays a role in diabetes pathogenesis. We generated a systemic genetic interaction map between top regulators of insulin transcription to understand how Spry2 might function. This map predicts that Spry2 may interact with Wfs1, a gene known to cause human diabetes via activation of the unfolded protein response (UPR). Indeed, we show that Spry2 is regulated by and regulates the UPR. The overall objective of this proposal is to define the role and mechanism of Spry2 in beta cell function, the UPR, and human diabetes. Specifically, we hypothesize that Spry2 is important for beta cell function and the UPR through an interaction with Wfs1. Our specific aims are: Aim 1: Demonstrate a role for Spry2 in beta cell function in vivo. We will characterize a beta cell specific knockout of Spry2. Aim 2: Elucidate the mechanism of Spry2 action on the UPR. We will test the functional importance of a Wfs1/Spry2 interaction and map the sites of Spry2 that are required for its modulation of the UPR. Aim 3: Test the function of Spry2 in human islets and identify the causative SNP near Spry2 that controls Spry2 expression. In the first part of the aim we will reduce Spry2 expression in human islets and measure insulin production, secretion and the unfolded protein response. In the second part of the aim, we will use genome editing to test potential causative type 2 diabetes SNPs for their ability to modulate Spry2 expression. The contribution of this proposal is the establishment of Spry2 as a new player in the beta cell UPR and in the pathogenesis of type 2 diabetes.