Stimulatory state specific genetic regulatory signatures at diabetes GWAS signals

摘要 2型糖尿病(T2D)是一种复杂的疾病，由遗传和环境因素共同引起 各种因素。T2D以前的全基因组关联研究(GWAS)已经确定了600多个独立的 遗传信号，但大多数属于基因组的非编码区，这使得识别 机械装置很难。这些信号可以是特定于细胞类型的，这增加了另一层复杂性 提名机制。该实验室最近的工作已经确定了骨骼肌细胞类型的特定基因 通过研究数百个样本的单核分辨率染色质结构，我们获得了一种新型的调控剂。我们 观察到几个T2D Gwas信号与间充质干细胞(MSC)基因特异性共定位 染色质结构的调节者，它代表一个前体细胞阶段，可能反映一个早期的指标 疾病易感性。实验室之前的工作已经确定了ARL15内含子T2D Gwas信号 特异性为MSCs。染色质环分析表明，这个遗传调节区与 卵泡抑素(FST)启动子约500kb。卵泡抑素促进肌肉生长并影响胰岛素 通过结合激活素A并阻止其抑制mTOR途径而产生的抗性。上调金融服务税 途径与T2D风险增加和影响脂肪细胞分化有关。卵泡抑素有效 对环境刺激，包括炎症、胰岛素和血糖水平。这些观察结果提供了 强有力的证据表明，探索MSC染色质结构的刺激状态特异性遗传学，尤其是在 FST和相关的通路基因，将对T2D有意义。因此，我有兴趣研究 可能影响MSCs中T2D易感性的状态特定的环境，特别是状态特定的遗传 金融服务税的监管格局。先前的研究表明，细胞状态会影响基因调控 基因表达的一部分，处于基础状态的细胞在反应时会显示一种“启动的”染色质构象-- 特定的差异调控基因。这种启动状态反映了一种基础染色质配置，使 反应特异的基因表达发生变化。因此，基因调控的遗传信号在 单元格类型中的单元格状态。为了在T2D中开始研究这一点，我将生成MSCs，诱导不同的 刺激状态，并产生基因表达和染色质结构数据，以建立全基因组 FST途径基因图谱。最后，我将研究FST基因途径，并选择用于验证的基因座 一种新型的可诱导CRISPRi/a平台。总体而言，我将在不同的刺激状态下生成MSC地图并使用 用多重组学方法比较基因表达和染色质结构的遗传控制 在基因FST和相关的途径基因上，目标是在T2D GWAs信号中提名机制。

Abstract Type 2 diabetes (T2D) is a complex disease that arises from a combination of genetic and environmental factors. Previous genome wide association studies (GWAS) of T2D have identified over 600 independent genetic signals, but most fall within non-coding regions of the genome, which makes identifying underlying mechanisms difficult. These signals can be cell-type specific, which adds another layer of complexity to nominating mechanisms. Recent work within the lab has identified skeletal muscle cell-type specific genetic regulators by investigating single-nucleus resolution chromatin structure across hundreds of samples. We observed several T2D GWAS signals colocalize specifically with mesenchymal stem cell (MSC) genetic regulators of chromatin structure, which represents a precursor cell stage that may reflect an early indicator of disease predisposition. Previous work within the lab has identified an ARL15 intronic T2D GWAS signal that is specific to MSCs. Chromatin looping analyses showed that this genetic regulatory region interacts with the follistatin (FST) promoter ~500kb away. The protein follistatin promotes muscle growth and affects insulin resistance by binding activin A and preventing it from inhibiting the mTOR pathway. Up-regulation of the FST pathway has been linked to increased T2D risk and impacts adipocyte differentiation. Follistatin is responsive to environmental stimulation, including inflammation, insulin, and glucose levels. These observations provide strong evidence that exploring the stimulatory state specific genetics of MSC chromatin structure, especially at FST and related pathway genes, will have implications for T2D. As a result, I am interested in studying the state-specific contexts which may influence T2D predisposition in MSCs, especially the state-specific genetic regulatory landscape of FST. Previous studies have shown that cellular state influences the genetic regulation of gene expression, where cells in a basal state display a “primed” chromatin conformation at response- specific differentially regulated genes. This primed state reflected a basal chromatin configuration that enabled the response-specific gene expression change. Therefore, the genetic signals of gene regulation vary across cell states within a cell type. To begin to investigate this within T2D, I will generate MSCs, induce different stimulatory states, and generate gene expression and chromatin structure data to establish genome-wide maps of FST pathway genes. Finally, I will investigate the FST gene pathway and select loci for validation with a novel inducible CRISPRi/a platform. Overall, I will generate MSC maps in different stimulatory states and use a multi-omics approach to compare the genetic control of gene expression and chromatin structure, focusing on the gene FST and related pathway genes, with the goal of nominating mechanisms at T2D GWAS signals.