Transcriptional regulation of human angiotensin receptor

描述（由申请人提供）：八肽，血管紧张素- 2 （Ang II）是已知最有效的血管活性物质之一，调节多种生理反应，包括流体稳态，醛固酮产生，肾功能和血管平滑肌（VSM）收缩。血管紧张素受体-1 （AT1R）基因的过度表达会产生高血压，尤其是在雌性转基因小鼠中。这些研究表明，hat1r基因转录增加可能导致高血压。因此，我们分析了hAT1R基因5'侧区单核苷酸多态性（SNPs）在高血压中的作用。我们发现，hat1r基因启动子具有至少5个单倍型片段，包括T/ a - 777， T/G -680, a /C -214， G/C -213和a /G -119。我们的研究表明，变异- 777t、- 680T、- 214a、- 213g和- 119a总是一起出现（分别形成含有TTAGA的单倍型-1和含有AGCCG的单倍型-2）。我们的研究表明，hAT1R基因的单倍型- 1与高加索女性的高血压有关，与单倍型- 1相比，含有hAT1R基因单倍型- 1的报告基因构建体的短暂感染增加了肾上腺皮质细胞和VSMC中的启动子活性。我们的凝胶转移实验表明：(a)转录因子C/EBP与含有- 119a（单倍型-l）的寡核苷酸的结合比- 119g（单倍型-ll）的结合更强；(b)转录因子USF（与E-box基序CANNTG结合）与含有核苷a和G的寡核苷酸在-214和-213（单倍型-l）的结合比含有核苷C的寡核苷酸在-213和-214（单倍型-ll）的结合更强。我们将分析单体型的影响- I和II hAT1R基因的转录调节在一个使用肾上腺皮质和血管平滑肌细胞,体外系统检查haplotypes-l的影响和II hAT1 R mRNA水平和血压使用男性和女性的转基因小鼠,并检查il - 6的影响,糖皮质激素,和雌激素hAT1R mRNA水平转基因老鼠包含单体型R I和II的hAT1基因,并将mRNA水平的潜在变化与转基因小鼠的血压联系起来。

DESCRIPTION (provided by applicant): The octapeptide, angiotensin-ll (Ang II) is one of the most potent vasoactive substances known and regulates a variety of physiological responses, including fluid homeostasis, aldosterone production, renal function and contraction of vascular smooth muscle (VSM). Over-expression of the angiotensin receptor-1 (AT1R) gene produces hypertension especially in female transgenic mice. These studies have suggested that increased transcription of the hAT1 R gene may lead to hypertension. We have therefore analyzed the role of single nucleotide polymorphisms (SNPs) in the 5' flanking region of the hAT1R gene in hypertension. We have found that hAT1 R gene promoter has a haplotype block of at least five SNPs consisting of T/A at - 777, T/G at -680, A/C at -214, G/C at -213, and A/G at -119. Our studies have shown that variants -777T, - 680T, -214A, -213G, and -119A always occur together (creating haplotype-l containing TTAGA and haplotype-ll containing AGCCG respectively). Our studies have shown that haplotype-l of the hAT1R gene is associated with hypertension in Caucasian women and transient transfection of reporter construct containing haplotype-l of the hAT1R gene has increased promoter activity in adrenal cortical cells and VSMC as compared to haplotype-ll. Our gel shift assays have shown that: (a) transcription factor C/EBP binds more strongly to an oligonucleotide containing -119A (haplotype-l) as compared to -119G (haplotype- ll) and (b) transcription factor USF (which binds to an E-box motif CANNTG) binds strongly to an oligonucleotide containing nucleoside A and G at -214 and -213 (haplotype-l) as compared to the same oligonucleotide containing nucleoside C at -213 and -214 (haplotype-ll). We will therefore analyze the effect of haplotypes -I and II on transcriptional regulation of the hAT1R gene in an in-vitro system using adrenocortical and vascular smooth muscle cells, examine the effect of haplotypes-l and II on hAT1 R mRNA level and on blood pressure using male and female transgenic mice, and examine the effect of IL-6, glucocorticoids, and estrogens on hAT1R mRNA level in transgenic mice containing haplotype I and II of the hAT1 R gene, and to correlate potential changes in mRNA levels with blood pressure in transgenic mice.