A Monkey Model of Human mu-Opioid Receptor Physiogenetics

描述(申请人提供)：在人类中，阿片受体基因包含许多单核苷酸多态(SNP)，其中至少有7个位于改变受体中氨基酸的编码区。其中，N40D(或DNA中的A118G)的新出现相关性源于它与阿片类药物、酒精和阿片类药物的敏感性和依赖性、甲基苯丙胺精神病、下丘脑-垂体-肾上腺(HPA)轴功能异常和癫痫的临床反应有关。我们在恒河猴体内发现了一种新的P26R SNP-阿片受体，它在功能和表型上都与人类N40D相似。人类和恒河猴的等位基因对p-内啡肽的敏感性都是后者的3.5倍，并与下丘脑-垂体-肾上腺(HPA)轴功能改变有关。基于这些数据，我们将把恒河猴作为与人类阿片受体多样性相关的人类基因/表型关系的自然模型。我们将确定发生在编码区内的SNPs，并在体外将它们的功能结果与人类SNPs进行比较。由于获得性免疫缺陷综合征(AIDS)在人类和恒河猴之间最显著和最显著的生物医学共性之一是艾滋病的发病机制和疾病进展，我们包括了免疫细胞中？阿片受体的表达及其与CCR5的已知相互作用，CCR5是人类和猿类免疫缺陷病毒(HIV/SIV)进入细胞的主要共同受体。随着阿片受体激动剂影响CCR5信号转导，调节CCR5基因表达，调节SIV/HIV感染性，我们将探索一个未知的领域：阿片受体中的SNPs是否在艾滋病中起到宿主因子的作用？因此，这笔赠款的目的是：1)鉴定影响蛋白质结构的恒河猴α-阿片受体的等位基因变异，并建立基因分型分析以筛选常见的等位基因；2)克隆恒河猴α-阿片受体的全长变异编码区，表达每个克隆，并与人类变异一起评估其药理学；以及3)探索β-阿片受体的基因型是否影响内源性阿片肽、常见阿片类药物和临床相关阿片类药物如何调节CCR5，从而在艾滋病感染和进展中起到相关宿主因素的作用。人类和恒河猴阿片受体的结构相似，以及两个物种共有的功能和表型特征，可能会使恒河猴发展成为最准确地代表人类阿片受体生理学和药物遗传学的无与伦比的自然主义模型。

DESCRIPTION (provided by applicant): In the human, the ¿-opioid receptor gene contains numerous single nucleotide polymorphisms (SNPs), including at least seven in the coding region that alter amino acids in the receptor. Among these, an emerging relevance for N40D (or A118G in the DNA) stems from its association with clinical responses to opioidergics, alcohol and opiate sensitivity and dependence, methamphetamine psychosis, aberrant hypothalamic-pituitary- adrenal (HPA) axis function and epilepsy. We discovered a novel P26R SNP in the rhesus monkey ¿-opioid receptor that both functionally and phenotypically parallels human N40D. Both human and rhesus monkey alleles have 3.5-fold greater sensitivity to p-endorphin, and associate with altered hypothalamic-pituitary- adrenal (HPA) axis function. Based on these data, we will develop the rhesus monkey as a naturalistic model of human genotype/phenotype relationships relevant to ¿-opioid receptor diversity in humans. We will identify SNPs occurring within the coding region and compare their functional consequences to human SNPs in vitro. Because one of the most prominent and biomedically significant commonalities among humans and rhesus monkeys is the parallel pathogenesis and disease progression of Acquired Immune Deficiency Syndrome (AIDS), we include a focus on ¿-opioid receptor expression in immune cells and its documented interaction with CCR5, the major co-receptor for Human and Simian Immunodeficiency Virus (HIV/SIV) entry into cells. As ¿-opioid receptor agonists affect CCR5 signaling, modulate CCR5 gene expression and regulate SIV/HIV infectivity, we will explore an unknown area: do SNPs in the ¿-opioid receptor contribute as a host factor in AIDS? Accordingly, the Aims of this grant are to: 1) identify allelic variants of the rhesus monkey |a-opioid receptor that affect protein structure, and develop genotyping assays to screen for the common alleles; 2) clone full-length variant coding regions of the rhesus monkey ¿-opioid receptor, express each clone and assess its pharmacology along side human variants; and 3) explore whether ¿-opioid receptor genotype influences how endogenous opioid peptides, common opiates and clinically relevant opioidergic drugs regulate CCR5 and thereby contribute as a relevant host factor in AIDS infection and progression. The structural similarity of human and rhesus monkey ¿-opioid receptors and the functional and phenotypic characteristics that are common to both species may permit the development of rhesus monkeys as an unparalleled naturalistic model that most accurately represents human ¿-opioid receptor physiogenetics and pharmacogenetics.