Investigating Ptpn18 as a regulator of diet induced obesity, cell proliferation, and insulin resistance

项目摘要/摘要 世界已经跨过了一个门槛，在那里，患有营养过剩疾病的人现在超过了 那些营养不良的人。世界肥胖症的流行导致了前所未有的糖尿病 流行病。在基因筛查中，我们的实验室最近发现了一个基因(Ptpn18)，它影响着 西方饮食(高脂肪/高蔗糖)导致的身体脂肪。在我们学习之前，一个 PTPN18在饮食诱导的肥胖中的生理作用尚未被描述。然而，在乳腺癌中， PTPN18通过去磷酸化和抑制人EGF调节EGF信号转导 受体2(HER2)。通过CRSPR/Cas9基因编辑，我们实验室获得了一只带有单一氨基酸的敲入小鼠 Ptpn18；D197A中的酸取代，使其磷酸酶活性丧失。敲入的老鼠有一种 对饮食引起的肥胖的戏剧性抵抗。因此，我推测Ptpn18是一个关键的调节因子。 脂肪组织内的体重增加和细胞增殖。我建议：1)确定直接的生理学 Ptpn18在脂肪组织中的底物，2)评价PTPn18在脂肪内细胞增殖中的作用 组织和脂肪组织炎症，以及3)Ptpn18D197A的能量消耗和食物摄入量的特征 老鼠。所提出的实验结果将极大地促进我们对 Ptpn18及其与饮食诱导的肥胖的联系。通过发现Ptpn18的直接底物，我希望 为调节脂肪组织功能及其对饮食的反应寻找新的途径。虽然Ptpn18不太可能 作为一个直接的治疗靶点，我发现的途径有可能被挖掘出来作为治疗靶点。 阿蒂实验室的总体研究主题是肥胖症和2型糖尿病的遗传学。我们的实验室 利用小鼠遗传学识别导致肥胖、2型糖尿病和代谢紊乱的基因座 与肥胖和糖尿病有关；例如肝脏脂肪变性和血脂异常。在我成为一名 博士后，我将接受新的实验方法的培训，包括质谱学，流动 细胞学和大规模数据分析。我还将在老鼠生理学方面获得新的专业知识，同时完善 那些我已经拥有的技能和技巧。阿蒂博士还将指导我发展一种教学哲学 报告和教学组合，并在获得独立资金方面提供指导。威斯康星大学麦迪逊分校 有出色的培训环境，致力于并支持合作努力。我要一份 作为一名独立研究人员发展所需的支持和培训。

Project Summary/Abstract The world has crossed a threshold where people suffering from diseases of overnutrition now outnumber those who suffer from undernutrition. The world obesity epidemic has resulted in an unprecedented diabetes epidemic. In a genetic screen, our laboratory recently identified a gene (Ptpn18) that affects the increase in body fat that results from consumption of a Western (high-fat/high-sucrose) diet. Prior to our studies, a physiological role for PTPN18 in diet-induced obesity had not been described. However, in breast cancer, PTPN18 regulates epithelial growth factor (EGF) signaling by dephosphorylating and repressing human EGF receptor 2 (HER2). Through CRSPR/Cas9 gene editing, our lab derived a knock-in mouse with a single amino acid substitution in Ptpn18; D197A, which abolishes its phosphatase activity. The knock-in mice have a dramatic resistance to diet-induced obesity. Therefore, I hypothesize that Ptpn18 is a critical regulator of weight gain and cell proliferation within adipose tissue. I propose to: 1) Identify the direct physiological substrates of Ptpn18 in adipose tissue, 2) Evaluate the role of PTPN18 in cell proliferation within adipose tissue and adipose tissue inflammation, and 3) Characterize energy expenditure and food intake in Ptpn18D197A mice. The results of the proposed experiments will significantly advance our understanding of the function of Ptpn18 and its link to diet-induced obesity. Through the discovery of direct substrates of Ptpn18, I expect to find a novel pathway for regulation of adipose tissue function and its response to diet. While Ptpn18 is unlikely to be a direct therapeutic target, it is possible that the pathway I discover can be mined for therapeutic targets. The overall theme of research in the Attie lab is the genetics of obesity and type 2 diabetes. Our laboratory uses mouse genetics to identify gene loci that contribute to obesity, type 2 diabetes, and metabolic disorders related to obesity and diabetes; e.g. hepatic steatosis and dyslipidemia. During the time in which I am a postdoctoral fellow, I will be trained in new experimental methods, including mass spectrometry, flow cytometry, and large-scale data analysis. I will also gain new expertise in mouse physiology, while refining those skills and techniques I already possess. Dr. Attie will also guide me in developing a teaching philosophy statement and teaching portfolio, as well as providing guidance in securing independent funding. UW-Madison has an outstanding training environment, dedicated to and supportive of collaborative efforts. I will have the support and training necessary to develop as an independent researcher.