Department of Medicine, Institute for Genomic Medicine, University of California at San Diego, VA San Diego Healthcare System, La Jolla, California 92093-0838, USA.
J Hypertens. 2013 Jan;31(1):123-33. doi: 10.1097/HJH.0b013e32835b053d.
The neuropeptide Y(2) G-protein-coupled receptor (NPY2R) relays signals from PYY or neuropeptide Y toward satiety and control of body mass. Targeted ablation of the NPY2R locus in mice yields obesity, and studies of NPY2R promoter genetic variation in more than 10,000 human participants indicate its involvement in control of obesity and BMI. Here we searched for genetic variation across the human NPY2R locus and probed its functional effects, especially in the proximal promoter.
Twin pair studies indicated substantial heritability for multiple cardiometabolic traits, including BMI, SBP, DBP, and PYY, an endogenous agonist at NPY2R. Systematic polymorphism discovery by resequencing across NPY2R uncovered 21 genetic variants, 10 of which were common [minor allele frequency (MAF) >5%], creating one to two linkage disequilibrium blocks in multiple biogeographic ancestries. In vivo, NPY2R haplotypes were associated with both BMI (P = 3.75E-04) and PYY (P = 4.01E-06). Computational approaches revealed that proximal promoter variants G-1606A, C-599T, and A-224G disrupt predicted IRF1 (A>G), FOXI1 (T>C), and SNAI1 (A>G) response elements. In neuroendocrine cells transfected with NPY2R promoter/luciferase reporter plasmids, all three variants and their resulting haplotypes influenced transcription (G-1606A, P < 2.97E-06; C-599T, P < 1.17E-06; A-224G, P < 2.04E-06), and transcription was differentially augmented or impaired by coexpression of either the cognate full-length transcription factors or their specific siRNAs at each site. Endogenous expression of transcripts for NPY2R, IRF1, and SNAI1 was documented in neuroendocrine cells, and the NPY2R mRNA was differentially expressed in two neuroendocrine tissues (adrenal gland, brainstem) of a rodent model of hypertension and the metabolic syndrome, the spontaneously hypertensive rat.
We conclude that common genetic variation in the proximal NPY2R promoter influences transcription factor binding so as to alter gene expression in neuroendocrine cells, and consequently cardiometabolic traits in humans. These results unveil a novel control point, whereby cis-acting genetic variation contributes to control of complex cardiometabolic traits, and point to new transcriptional strategies for intervention into neuropeptide actions and their cardiometabolic consequences.
神经肽 Y(2)G 蛋白偶联受体 (NPY2R) 将 PYY 或神经肽 Y 的信号传递至饱腹感和体重控制。在小鼠中靶向敲除 NPY2R 基因座会导致肥胖,对超过 10000 名人类参与者的 NPY2R 启动子遗传变异的研究表明,它参与了肥胖和 BMI 的控制。在这里,我们在人类 NPY2R 基因座上搜索遗传变异,并探究其功能效应,尤其是在近端启动子上。
双胞胎研究表明,多种心脏代谢特征(包括 BMI、SBP、DBP 和 NPY2R 的内源性激动剂 PYY)具有显著的遗传度。通过在 NPY2R 上进行测序发现了 21 种遗传变异,其中 10 种是常见的(次要等位基因频率(MAF)>5%),在多种生物地理祖源中创建了一个或两个连锁不平衡块。在体内,NPY2R 单倍型与 BMI(P=3.75E-04)和 PYY(P=4.01E-06)均相关。计算方法表明,近端启动子变异 G-1606A、C-599T 和 A-224G 破坏了预测的 IRF1(A>G)、FOXI1(T>C)和 SNAI1(A>G)反应元件。在转染了 NPY2R 启动子/荧光素酶报告质粒的神经内分泌细胞中,所有三种变体及其产生的单倍型均影响转录(G-1606A,P<2.97E-06;C-599T,P<1.17E-06;A-224G,P<2.04E-06),并且通过在每个位点共表达同源全长转录因子或其特异性 siRNA,转录被不同程度地增强或抑制。在神经内分泌细胞中记录了 NPY2R、IRF1 和 SNAI1 的转录本的内源性表达,并且 NPY2R mRNA 在高血压和代谢综合征的啮齿动物模型即自发性高血压大鼠的两种神经内分泌组织(肾上腺、脑干)中表现出差异表达。
我们得出的结论是,近端 NPY2R 启动子的常见遗传变异影响转录因子结合,从而改变神经内分泌细胞中的基因表达,进而影响人类的心脏代谢特征。这些结果揭示了一个新的调控点,即顺式作用遗传变异有助于控制复杂的心脏代谢特征,并为干预神经肽作用及其心脏代谢后果的新转录策略指明了方向。