Discovering genetic and hormonal mechanisms underlying diabetes risk from flies to humans

我们建议开发和使用创新的体内和人类胰岛细胞系统来研究糖尿病风险的遗传基础。尽管GWAS和其他现代基因组规模的发现已经将数十个基因座和数百个位置候选基因（如转录调节因子SIX3和BCL 11A）与糖尿病风险增加相关联，但我们对受影响基因的理解，对基因功能的影响以及对特定组织或细胞类型的影响仍然很差。新出现的数据表明，大多数常见的变异型2型糖尿病GWAS信号是由胰岛β细胞或α细胞的失调驱动的。目前的系统，包括小鼠，已经推进了我们对胰腺β细胞和α细胞特性的理解。然而，糖尿病研究缺乏体内系统来进行组织特异性遗传功能丧失和获得的研究，其规模或效率可以改变我们对糖尿病风险遗传学的理解。幸运的是，基于我们在果蝇中的发现，我们已经产生了真正创新的体内遗传系统，以发现影响胰岛素转录、翻译、加工、储存、分泌和稳定性的糖尿病风险基因功能。基于这个工作流程，我们已经确定了几个有前途的风险基因，包括SIX3和BCL 11A，用于原代人类胰岛的互补遗传研究。为了研究优先考虑的人类候选糖尿病风险基因的功能，我们创造了允许在人类原代β细胞中进行功能丧失和获得分析的创新方法。 我们拥有强大的科学团队，在人类胰岛生物学和遗传学、果蝇遗传学和生理学、胰腺和胰岛生物学、发育生物学和糖尿病研究方面具有广泛的互补专业知识。我们在可靠地获取和使用原代人类胰岛进行基因功能研究方面拥有丰富的经验。在此，我们建议：（1）在全面的体内研究中使用强大的、创新的遗传和生理学测定，以鉴定调节果蝇中胰岛素生物学和代谢的糖尿病风险基因，以及（2）使用和开发定量测定，以评估人类胰岛中同源风险基因的功能。这些拟议的研究可以改变对人类胰岛功能性糖尿病遗传学的理解，因此与改善人类健康高度相关。

We propose to develop and use innovative in vivo and human islet cell systems to investigate the genetic basis of diabetes risk. Although dozens of loci and perhaps hundreds of positional-candidate genes, like the transcriptional regulators SIX3 and BCL11A, have been previously associated to increased diabetes risk by GWAS and other modern genome-scale findings, our understanding of the affected gene, impact on gene function, and impact on specific tissue(s) or cell-type(s) remains poor. Emerging data indicate that most of the common variant type 2 diabetes GWAS signals are driven by dysregulation of islet β-cells or α-cells. Current systems, including mice, have advanced our understanding of the properties of pancreatic β-cells and α-cells. However, diabetes research lacks in vivo systems to perform tissue-specific genetic loss- and gain-of-function studies on a scale or with the efficiency that could transform our understanding of diabetes risk genetics. Fortunately, based on our discoveries in the fruit fly Drosophila melanogaster, we have generated truly innovative in vivo genetic systems to discover with diabetes risk gene functions impacting insulin transcription, translation, processing, storage, secretion, and stability. Based on this workflow, we have identified several promising risk genes, including SIX3 and BCL11A, for complementary genetic studies in primary human islets. To investigate the function of prioritized human candidate diabetes-risk genes, we have created innovative methods permitting loss- and gain-of-function analysis in human primary β-cells. We have a strong scientific team with broad complementary expertise in human pancreatic islet biology and genetics, Drosophila genetics and physiology, pancreas and islet biology, developmental biology, and diabetes research. We have substantial experience in reliably procuring and using primary human islets for gene function studies. Here we propose to: (1) use powerful, innovative genetic and physiological assays in comprehensive in vivo studies to identify diabetes risk genes that regulate insulin biology and metabolism in Drosophila, and (2) use and develop quantitative assays for assessing cognate risk gene function in human islets. Together the proposed studies could transform understanding of functional diabetes genetics in human islets, and are therefore highly relevant to improving human health.