Translational analysis of functional variation in human dopamine beta?hydroxylase

描述(由申请人提供)： 项目摘要：多巴胺2-羟基酶(DBH)催化从多巴胺(DA)合成神经递质去甲肾上腺素(NE)，从而调节这两个分子的水平。在人血清中可以检测到DBH，其活性在很大程度上反映了DBH结构位点的序列变异。我们在转录起始点(-970C&GT；T)上游发现了一个单核苷酸多态(SNP)，它占血清DBH活性总变异的30-50%，“T”等位基因的活性低于“C”等位基因，呈共显性模式。我们在群体遗传水平上的工作和来自另一个实验室的分子实验提供了强有力的证据，证明-970C&gt；T是一个真正的调节变异体，影响胸径的转录。然而，分子实验表明，低血清白蛋白T等位基因与较高的转录水平相关。因此，-970C&gt；T如何在体内调节DBH的表达尚不清楚。本项目建议利用BAC转基因，然后与缺乏内源性DBH表达的DBH/-小鼠杂交，在约170kb的相同人类序列背景下，研究与T或C等位基因相关的DBH在脑、肾上腺髓质和血清中的表达。该项目将为公共卫生研究的多个领域提供信息，包括精神病、情绪障碍、药物成瘾、神经退行性疾病和人类血压障碍的研究，因为血清DBH和/或-970C&gt；T的变化与与所有这些疾病相关的人类表型的重要方面有关。这项拟议的工作将为研究NE介导的神经传递中的许多方面的遗传变异提供一个有价值的创新动物模型。 公共卫生相关性： 项目简介：多巴胺2-羟基酶(DBH)是一种合成神经信号分子去甲肾上腺素(NE)的酶，去甲肾上腺素反过来参与人类精神、神经和血压相关的疾病。人类胸腺激素基因的一个序列变异(多态)强烈调节胸径水平，并影响所有上述人类疾病。该项目将把人类胸径基因的两个版本(等位基因)放入缺乏自身胸径的小鼠体内。这将允许在小鼠模型中对这种重要的人类多态进行功能研究。

DESCRIPTION (provided by applicant): Project Summary: Dopamine 2-hydroxylase (DBH) catalyzes synthesis of the neurotransmitter norepinephrine (NE) from dopamine (DA), and thereby regulates levels of both molecules. DBH is detectable in human serum, where its activity largely reflects sequence variation at the structural locus DBH. We identified a single nucleotide polymorphism (SNP) 970 bp upstream of the transcriptional start site (-970C>T) that accounts for 30-50% of the total variance in serum DBH activity, with the "T" allele being associated with lower activity than the "C" allele, in a co-dominant pattern. Our work on a population-genetic level, and molecular experiments from another laboratory provide strong evidence that -970C>T is a true regulatory variant, affecting transcription of DBH. However, the molecular experiments suggested that the low-serum-DBH T allele associates with greater transcription. Thus, how -970C>T regulates DBH expression in vivo is not clear. The present project proposes to use BAC transgenesis, followed by crossing with Dbh -/- mice lacking endogenous DBH expression, to investigate DBH expression in brain, adrenal medulla and serum, associated with either the T or C allele in an otherwise identical human-sequence context of ~170 kb. This project will inform multiple areas of public health research, including studies of psychosis, mood disorders, drug addiction, neuro-degenerative disorders, and disorders of human blood pressure, as variation in serum DBH and/or -970C>T associates with important aspects of human phenotypes related to all of those disorders. The proposed work will produce a valuable and innovative animal model for investigation of many aspects of genetic variation in NE-mediated neurotransmission. PUBLIC HEALTH RELEVANCE: Project Narrative: Dopamine 2-hydroxylase (DBH) is an enzyme that synthesizes the neural signaling molecule norepinephrine (NE), which is in turn involved in human psychiatric, neurological and blood-pressure related disorders. A sequence variant (polymorphism) in the human DBH gene strongly regulates levels of DBH, and influences all of the foregoing human disorders. This project will put the two versions (alleles) of the human DBH gene into mice that lack their own Dbh. This will allow functional study of this important human polymorphism in a mouse model.