Development of Anorexigenic and Glucoregulatory Chimeric Peptides

项目摘要 目前的肥胖药物治疗长期疗效有限，对疾病影响很小或没有影响 逆转这项研究的重点是肥胖的病理生理学是由以下因素驱动的： 多个但相互关联的通路的失调。因此，我们假设，成功的治疗， 肥胖症将需要新一代的治疗方法，靶向多种互补的受体， 调节能量平衡的神经回路。虽然相当大的兴趣集中在 胰高血糖素样肽1受体激动剂单独，最近的证据也表明，Y1-R激动促进反式- 胰腺α细胞分化为β细胞，从而增加胰岛素分泌和减少胰高血糖素分泌， 而神经肽Y2-受体（Y2-R）激动剂PYY 3 -36的外周给药已显示 减少热量摄入。我们最近开发了第一个GLP-1 R、Y1-R和Y2-R的三效激动剂（GEP 44）， 在瘦型和DIO啮齿动物（小鼠和大鼠）和哺乳动物（麝香鼩）研究中进行广泛研究后获得 食物摄入、体重减轻、葡萄糖摄取、恶心和呕吐。GEP 44在瘦肉型小鼠中显示出有效的厌食作用。 以及在急性和慢性研究中饮食诱导的肥胖大鼠和小鼠，食物摄入减少高达80%， 体重减轻比已知GLP-1 RA（包括利拉鲁肽）更强，且无内脏不适 （仅与GLP-1 RA常见）。我们已经证明GEP 44可以穿透脑干并与GLP-1 R结合， Y家族受体在最后区和孤束核，并促进葡萄糖进入肌肉 通过Y1-R。我们的成功与这一创新的三重agonism导致我们进一步发展和完善， 单体肽，包括开发一种长效形式，我们计划在体内测试， 项目为了进一步测试这三种受体的同时激动作用，这三种受体在葡萄糖调节、食物摄入、 和能量平衡，我们建议由一个多PI团队建立的研究者进行补充研究， 广泛的合作经验，以调查以下目标：目标1将阐明组织特异性 三受体激动与单受体激动的协同作用和GEP 44集中于脑的功效的靶点 能量平衡的区域。其中包括一项无偏倚的细胞转录组学研究，以测试对 脑干回路，GEP 44在饮食诱导的肥胖（DIO）大鼠。此外，不同脂化的特征 在两个主要位置的长效类似物，重点是受体激动和结合、内化、β-抑制蛋白 募集、白蛋白结合和蛋白水解保护将在体外建立。目标2将侧重于 药代动力学和测试长效GEP 44相对于GEP 44的能量消耗，体重变化， 摄食量、胃排空和潜在不良反应，以确定大鼠的急性和慢性效应。目的 3将建立长效GEP 44对餐后葡萄糖水平、肠促胰岛素非依赖性胰岛素水平和胰岛素抵抗的影响。 分泌、胰岛素敏感性和对糖尿病肥胖大鼠葡萄糖摄取的影响。这些研究将大大提高 用于治疗肥胖症和相关代谢紊乱的改进的、临床上有益的新疗法。

PROJECT SUMMARY Current pharmacological obesity treatments have limited long-term efficacy with little or no impact on disease reversal. The proposed research focuses on the fact that the pathophysiology of obesity is driven by dysregulation of multiple, but inter-related pathways. As such, we hypothesize that successful treatments for obesity will require a new generation of therapeutics that target multiple receptors of complementary neurocircuits regulating the controls of energy balance. While considerable interest has focused on glucagon-like peptide 1 receptor agonists alone, recent evidence also shows that Y1-R agonism facilitates trans- differentiation of pancreatic α-cells to β-cells, thus increasing insulin secretion and reducing glucagon secretion, while peripheral administration of the neuropeptide Y2-receptor (Y2-R) agonist PYY3-36 has been shown to reduce caloric intake. We recently developed the first tri-agonist of GLP-1R, Y1-R and Y2-R (GEP44), obtained after extensive studies in lean and DIO rodent (mice and rats) and mammalian (musk shrew) studies of food intake, weight loss, glucose uptake, nausea, and emesis. GEP44 shows potent anorectic effects in lean and diet-induced obese rats and mice in acute and chronic studies with up to 80 % reduction of food intake and stronger reductions of body weight than known GLP-1RAs, including liraglutide, and without visceral malaise (common to GLP-1RAs alone). We have shown GEP44 can penetrate the brainstem and bind to GLP-1R, and Y-family receptors in the area postrema and nucleus tractus solitarius, and facilitate glucose entry into muscle via the Y1-R. Our success with this innovative triple agonism led us to further development and refinements of monomeric peptides, including the development of a long-acting form, which we plan to test in vivo with this project. To further test the simultaneous agonism of these three receptors, critical in glucoregulation, food intake, and energy balance, we propose complimentary studies by a multi-PI team of established investigators with extensive collaborative experience to investigate the following aims: Aim 1 will elucidate tissue-specific synergism of tri- vs. single- receptor agonism and targets underlying the efficacy of GEP44 focusing on brain areas of energy homeostasis. Included therein is an unbiased cell transcriptomics study to test the effects, on brainstem circuitry, of GEP44 in diet-induced obese (DIO) rats. Furthermore, characteristics of different lipidated long-acting analogs at two primary positions focusing on receptor agonism and binding, internalization, β-arrestin recruitment, albumin binding, and proteolysis protection will be established in vitro. Aim 2 will focus on pharmacokinetics and on testing long-acting GEP44 vs. GEP44 on energy expenditure, body weight change, food intake, gastric emptying, and potential adverse effects to determine acute and chronic effects in rats. Aim 3 will establish the effects of long-acting GEP44 on post meal glucose levels, incretin independent insulin secretion, insulin sensitivity, and on glucose uptake in diabetic obese rats. Such studies will lead to significantly improved, clinically beneficial novel therapeutics for the treatment of obesity and associated metabolic disorders.