Activation of the Secretin Receptor as a Strategy for the Treatment of Heart Failure

项目摘要/摘要 心力衰竭是人口发病率和死亡率的主要原因， 肥胖症及相关的2型肥胖症发病率上升导致的心血管疾病 糖尿病。虽然现有的药物在纠正失代偿性心力衰竭方面是有效的，但这 仍然与令人无法接受的再住院率和死亡率有关。一种新的药物组合 这增加了奈普利辛的抑制作用，增加了目前治疗心力衰竭的标准，血管紧张素受体阻断， FDA在延长心输出量减少患者寿命的基础上批准了该药。 然而，在理论上，肽酶抑制剂在这种组合中的非常广泛的作用可以得到改善， 从而减少可能的副作用，提高治疗效果。特定的酶底物 目前还不清楚这种药物的有益效果。虽然它被认为是利钠药 多肽，其他多肽也被切割，其中许多具有潜在的抵消和/或副作用。另一个 奈普利辛的主要潜在有益底物是分泌素，这是一种多肽激素，对 心脏收缩能力和射血分数，冠脉血流灌注，外周血管阻力，脑缺血后饱足感， 和对葡萄糖敏感的胰岛素作用。目前还没有已知的针对分泌素受体的药物， 提供这些效果。该提案旨在开发适当的分析方法并筛选候选人。 使用高通量筛查(HTS)有可能影响这一重大公共卫生问题。这个 目的是确定在促胰液素受体上增强信号的分子，或者通过作为阳性分子 作为分泌素作用的变构调节剂或作为这一潜在重要治疗靶点的直接激动剂。这 代表了拥有丰富促胰液素受体经验的米勒博士和塞尔吉延科博士之间的合作伙伴关系， 拥有HTS和化学基因组方面的专业知识。有三个具体目标：(一)一级和二级化验 实施和优化，(Ii)HTS使用表达人分泌素受体的细胞和HIT确认， 以及(Iii)HIT验证和表征。主要的检测将集中在细胞内cAMP反应 稳定表达野生型人分泌素受体的CHO-SECR细胞株 分泌素亚极量刺激和激动剂模式下的正变构调节剂模式 不会接触到分泌素。在确认期间，将以化合物浓度重复进行分析- 依赖性评估和使用自然表达生理密度的分泌素的神经细胞系 受体，NG-108细胞。亲本CHO细胞和表达Gs偶联2型加压素的CHO细胞系 受体将作为对照进行研究，以确定观察到的反应是由分泌素受体介导的。 将使用其他B类GPCR表达细胞和其他信号事件的调查来探索选择性， 将进行内化、细胞毒性和增殖。目标将是确定候选人与 足够的活性在临床前系统中进行概念验证，并最终在临床试验中进行测试。

PROJECT SUMMARY/ABSTRACT Heart failure is a major cause of morbidity and mortality in the population, with the rising incidence of cardiovascular disease contributed to by epidemic increases in the incidence of obesity and associated type 2 diabetes mellitus. Although existing drugs are effective in acutely correcting decompensated heart failure, this continues to be associated with unacceptable rates of rehospitalization and mortality. A new drug combination that adds neprilysin inhibition to the current standard-of-care for heart failure, angiotensin receptor blockade, was approved by the FDA on the basis of extension of the life of patients with reduced cardiac output. However, the very broad action of the peptidase inhibitor in this combination theoretically could be improved, thereby reducing possible side effects and increasing therapeutic effectiveness. The specific enzyme substrate responsible for the beneficial effects of this drug is not yet clear. While it has been assumed to be natriuretic peptides, other peptides are also cleaved, many of which have potential offsetting and/or side effects. Another prominent potentially beneficial substrate of neprilysin is secretin, a peptide hormone with useful effects on cardiac contractility and ejection fraction, coronary perfusion, peripheral vascular resistance, post-cibal satiety, and glucose-sensitive incretin action. There are currently no known drugs that target the secretin receptor, providing these effects. This proposal is designed to develop appropriate assays and to screen for candidates with potential to impact this major public health problem using high throughput screening (HTS). The OBJECTIVE is to identify molecules that enhance signaling at the secretin receptor, either by acting as positive allosteric modulators of secretin action or as direct agonists of this potentially important therapeutic target. This represents a partnership between Dr. Miller, with extensive secretin receptor experience, and Dr. Sergienko, with HTS and chemical genomic expertise. There are three specific aims: (i) Primary and secondary assay implementation and optimization, (ii) HTS using cells expressing human secretin receptor and hit confirmation, and (iii) Hit validation and characterization. The primary assays will focus on intracellular cAMP responses in the CHO-SecR cell line stably expressing wild type human secretin receptor, with the assays run in both positive allosteric modulator mode in the presence of submaximal secretin stimulation and in agonist mode without exposure to secretin. During confirmation, the assays will be repeated with compound concentration- dependency evaluated and using a neuronal cell line that naturally expresses a physiologic density of secretin receptor, NG-108 cells. Parental CHO cells and a CHO cell line expressing the Gs-coupled type 2 vasopressin receptor will be studied as controls to be certain that observed responses are secretin receptor-mediated. Selectivity will be explored using other class B GPCR-expressing cells, and a survey of other signaling events, internalization, cell cytotoxicity, and proliferation will be performed. The goal will be to identify candidates with adequate activity to be tested in pre-clinical systems for proof-of-concept, and ultimately in clinical trials.