Molecular Genetics of the ET-1/AngII Receptor

性状（由申请方提供）：内皮素-1（ET-1）和血管紧张素II （AngII）是维持血管内皮细胞正常功能所必需的关键激素。 心血管系统，作用于中枢和外周。都是荷尔蒙 系统与心血管病理学有关--高血压， 内皮功能障碍、心脏肥大和衰竭。几种同种受体 对于ET-1和AngII两者，最近已经被表征。其中，Dual ET-1/AngII受体，我们通过基于并支持 分子识别理论阐明了新的信息， 提出新的假设和问题这项建议的长远目标是 为了分析ET-1/AngII受体基因对血液的特异性贡献， 在正常和病理生理状态如高血压中的压力调节。 在本研究中，我们将测试以下假设：1）基于 我们的初步数据显示a）ET-II共分离的性别偏见 /AngII受体基因座与F2（Dahl S x Dahl R）杂交中的高血压， 和B）Dahl盐敏感型和Dahl盐敏感型之间的结构差异 抗盐大鼠ET-1/AngII受体，我们假设ET-1/AngII受体 受体以性别特异性方式影响血压， 达尔大鼠模型。2)基于ET-1/AngII受体的检测丰度 mRNA在脑和心血管组织中的表达，我们假设这种受体是 这些器官中ET- 1和AngII的重要生理靶点， 因此在血压调节中起重要作用。调查 以下具体目标将检验这些假设：1。性别角色 ET-1/AngII受体在盐敏感性高血压易感性中的作用 1A）Dahl S和Dahl R ET-1/AngII受体的功能表征 有两种氨基酸不同1B）三个近交转基因的建立 携带外源Dahl R ET-1/AngII受体的Dahl S大鼠系， Tg[RET-1/AngIIr]和三个携带外源Dahl S的对照Dahl S大鼠系 ET- 1/AngII受体，Tg[SET- 1/AngIr]，由同源Dahl R 5'驱动 侧翼调控区。1C）确定转基因分子表型， 即外源性（转基因）Dahl R和Dahl S ET-1的相对量。 1/AngII受体mRNA和内源性Dahl S ET-1/AngII受体mRNA表达 分别在Tg[RET-1/AngIIr]和Tg[SET-1/AngIIr]大鼠中的水平。1D） 确定Dahl R和Dahl S ET- 1/AngII的生理效应 通过分析年龄匹配的非转基因 近交系Dahl S大鼠（雄性和雌性）和转基因近交系Tg[RET- 1/AnglIr] 和Tg[SET 1 I AngIIr] Dahl S大鼠系关于1）发病、病程和 高血压程度; 2）寿命; 3）高血压肾病的严重程度。 2. ET-1/AngII受体生理作用的剖析。2A）组织 特定的，空间和时间的表达模式，在发展中的 ET-1/AngII受体基因。2B）ET- 1/AngII受体的靶向破坏 基因和“敲除”小鼠模型的发展，以确定其 在综合生物实验系统中的生理作用。我们提出的 研究将阐明ET- 1 /AngII受体的生理作用 在整个发展中。此外，它还将显示性别特异性 ET- 1/AngII受体参与盐敏感性高血压的研究 Dahl大鼠模型，从而提供了一个有效的优先方案，以调查 该受体在人类原发性高血压中的潜在作用。

DESCRIPTION (provided by the applicant): Endothelin-1 (ET-1) and angiotensin II (AngII) are critical hormones necessary for the appropriate function of the cardiovascular system, acting centrally as well as peripherally. Both hormonal systems have been implicated in cardiovascular pathology -- hypertension, endothelial dysfunction, cardiac hypertrophy and failure. Several isoreceptors for both ET-1 and AngII have been recently characterized. Of these, the dual ET-1/AngII receptor, isolated by us via an approach based on and supporting the molecular recognition theory elucidates novel information providing the bases for new hypotheses and questions. The long-term objective of this proposal is to dissect the specific contribution of the ET-l/AngII receptor gene to blood pressure regulation in normal and pathophysiological states like hypertension. In this research proposal, we will test the following hypotheses: 1) Based on our preliminary data showing a) gender-bias o 1I the cosegregation of the ET-II /AngII receptor locus with hypertension in an F2 (Dahl S x Dahl R) intercross, and b) structural differences between the Dahl salt-sensitive and the Dahl salt-resistant rat ET-1/AngII receptors, we hypothesize that the ET-1/AngII receptor acts in a gender specific manner influencing blood pressure in the Dahl rat model. 2) Based on the detected abundance of the ET-l/AngII receptor mRNA in brain and cardiovascular tissues, we hypothesize that this receptor is a prominent physiologic target for ET- 1 and AngII in these organs, and therefore plays an important role in blood pressure regulation. Investigating the following specific aims will test these hypotheses: 1. Gender specific role of the ET-1/AngII receptor in susceptibility to salt-sensitive hypertension. 1A) Functional characterization of the Dahl S and Dahl R ET-1/AngII receptors that differ in two amino acids. 1B) Establishment of three inbred trans genie Dahl S rat lines bearing exogenous Dahl R ET-1/AngII receptor, Tg[RET-1/AngIIr], and three control Dahl S rat lines bearing exogenous Dahl S ET- 1/AngIl receptor, Tg[SET- 1/AnglIr], driven by the cognate Dahl R 5' flanking regulatory region. 1C) Determine the transgenic molecular phenotype, that is the relative amounts of exogenous (transgenic) Dahl R and Dahl S ET- 1/Angll receptor mRNA and endogenous Dahl S ET-1/AngIl receptor mRNA expression levels in Tg[RET-1/AngIIr] and Tg[SET-1/AngIIr} rats respectively. 1D) Determine the physiological effects of the Dahl R and Dahl S ET- 1/AngII receptor transgene by analyzing differences between age-matched non-transgenic inbred Dahl S rats (males and females) and transgenic inbred Tg[RET- 1/AnglIr] and Tg[SET1I AngIIr] Dahl S rat lines with respect to 1) the onset, course and degree of hypertension; 2) lifespan; 3) severity of hypertensive renal disease. 2. Dissection of physiologic role(s) of the ET-1/AngII receptor. 2A) Tissue specific, spatial and temporal expression patterns in development of the ET-1/AngII receptor gene. 2B) Targeted disruption of the ET- 1/AngIl receptor gene and development of "knockout" mouse model in order to define its physiologic role in an integrated biologic experimental system. Our proposed studies will elucidate the physiological role of the ET- 1 /AngII receptor throughout development. Furthermore, it will demonstrate the gender specific involvement of the ET- 1/AngII receptor in salt-sensitive hypertension in the Dahl rat model, thus providing a validated prioritization scheme to investigate the potential role of this receptor in human essential hypertension.