A Monkey Model of Human mu-Opioid Receptor Physiogenetics

描述（由申请人提供）：在人类中，-阿片受体基因包含许多单核苷酸多态性（snp），包括至少7个在改变受体氨基酸的编码区。其中，N40D（或DNA中的A118G）与阿片类药物的临床反应、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）轴功能异常和癫痫有关。我们在恒河猴阿片受体中发现了一个新的P26R SNP，在功能和表型上与人类N40D相似。人类和恒河猴的等位基因对p-内啡肽的敏感性都高出3.5倍，并与改变的下丘脑-垂体-肾上腺（HPA）轴功能有关。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型/表型关系的自然模型。我们将鉴定编码区域内发生的snp，并将其与体外人类snp的功能后果进行比较。由于人类和恒河猴之间最显著的生物医学共性之一是获得性免疫缺陷综合征（AIDS）的平行发病机制和疾病进展，我们将重点关注免疫细胞中的¿-阿片受体表达及其与CCR5的相互作用，CCR5是人类和猴免疫缺陷病毒（HIV/SIV）进入细胞的主要共受体。由于-阿片受体激动剂影响CCR5信号，调节CCR5基因表达并调节SIV/HIV感染，我们将探索一个未知的领域：-阿片受体的snp是否作为艾滋病的宿主因子起作用？因此，该基金的目的是：1)鉴定恒河猴|a-阿片受体影响蛋白质结构的等位基因变异，并开发基因分型分析以筛选常见等位基因；2)克隆恒河猴阿片受体全长变异编码区，表达每个克隆并与人类变异进行药理学评估；3)探讨-阿片受体基因型是否影响内源性阿片肽、常见阿片药物和临床相关阿片能药物调节CCR5，从而作为相关宿主因子参与艾滋病感染和进展。人类和恒河猴-阿片受体的结构相似性，以及两种物种共同的功能和表型特征，可能使恒河猴成为一种无与伦比的自然模型，最准确地代表了人类-阿片受体的生理遗传学和药物遗传学。

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.