Brain G-alpha subunit protein mediated neural control of blood pressure

描述（由申请人提供）：在本次K02申请中，杰出且独立获得R01资助的PI，已转移到世界一流的研究环境波士顿大学医学院（BUSM）发展他的独立研究生涯，将验证PVN g αi2亚基蛋白门控通路在中枢神经控制钠和水排泄以及全身动脉血压调节中发挥关键作用的整体假设。内源性上调PVN Gαi2蛋白以响应盐摄入量的增加，将增强内源性交感病理抑制机制，以对抗盐敏感性高血压的发展，而内源性上调PVN Gαi2蛋白将加剧血压失调。具体目的如下：目的1：确定1)脑g αi2亚基蛋白门控通路介导中央诱发的肾对生理和药理学刺激的交感抑制反应；2)中枢g αi2亚基蛋白作为一种反调控机制，内源性上调，以减轻Sprague-Dawley大鼠盐敏感性高血压的发生。SA2：建立下丘脑PVN作为内源性上调g α 2亚基蛋白以增强肾交感神经抑制和尿钠通路的特异性脑部位，以维持液体和电解质稳态，并对抗Sprague-Dawley大鼠盐敏感性高血压的发展。SA3：确定1)高盐摄入导致PVN Gαi2亚基蛋白上调失败，导致Dahl盐敏感大鼠内源性反调节性肾交感抑制和利钠反应和盐敏感性高血压减弱；2)PVN特异性基因治疗过表达Gαi2亚基蛋白将恢复肾脏交感抑制和利钠机制，减轻Dahl盐敏感性高血压的发生。新的K02 SA4：建立心室周围器官作为一个关键的中央钠敏感机制，激活内源性PVN g αi2亚基蛋白门控的肾脏交感抑制和尿钠途径，以对抗盐敏感性高血压的发展。SA's1和2将利用寡脱氧核苷酸（ODN's）消除脑，特别是PVN， Gαi2蛋白的影响，以确定Gαi2蛋白在Sprague-Dawley大鼠对急性药理学和生理刺激以及高盐饮食慢性综合生理刺激下中枢神经调节体液和电解质稳态和血压的作用。sa3将通过ODN和慢病毒基因治疗方法确定PVN g αi2亚基蛋白在盐敏感性高血压Dahl大鼠模型中的作用。SA4将整合心室周围器官在PVN Gαi2蛋白介导的血压神经控制中的作用。在K02职业发展计划期间，PI将在Cunningham博士（UNTHSC心血管研究所主任）的实验室接受培训，以获得AV3V病变的手术技术，并将参加BUSM医学教育教师发展计划办公室。

DESCRIPTION (provided by applicant): In this K02 application, the outstanding and independently R01 funded PI, who has relocated to the world class research environment at the Boston University School of Medicine (BUSM) to develop his independent research career, will test the overall hypothesis that PVN Gαi2-subunit protein-gated pathways play a critical role in the central neural control of sodium and water excretion and systemic arterial blood pressure regulation. Endogenous up-regulation of PVN Gαi2 proteins in response to increased salt-intake will potentiate endogenous sympathoinhibitory mechanisms to counter the development of salt-sensitive hypertension whereas failure to endogenously up-regulate PVN Gαi2 proteins will exacerbate blood pressure dysregulation. The following Specific Aims (SA) will be conducted: SA1: To establish that 1) brain Gαi2-subunit protein-gated pathways mediate centrally-evoked renal sympathoinhibitory responses to physiological and pharmacological stimuli and, 2) central Gαi2-subunit proteins are endogenously up-regulated as a counter regulatory mechanism to attenuate the development of salt-sensitive hypertension in Sprague-Dawley rats. SA2: To establish the hypothalamic PVN as a specific brain site in which Gαi2-subunit proteins are endogenously up- regulated to potentiate renal sympathoinhibitory and natriuretic pathways to maintain fluid and electrolyte homeostasis and counter the development of salt-sensitive hypertension in Sprague-Dawley rats. SA3: To establish that 1) failure to up-regulate PVN Gαi2-subunit proteins, in response to high-salt intake, leads to attenuation of endogenous counter-regulatory renal sympathoinhibitory and natriuretic responses and salt- sensitive hypertension in Dahl salt-sensitive rats, and 2) PVN specific gene therapy to over express Gαi2- subunit proteins will restore renal sympathoinhibitory and natriuretic mechanisms and attenuate the development of Dahl salt-sensitive hypertension. New K02 SA4: To establish the circumventricular organs as a critical central sodium sensing mechanism that activates endogenous PVN Gαi2-subunit protein gated renal sympathoinhibitory and natriuretic pathways to counter the development of salt-sensitive hypertension. SA's1 & 2 will remove the influence of brain, and specifically PVN, Gαi2 proteins using oligodeoxynucleotides (ODN's) to determine the role(s) of Gαi2 proteins in the central neural regulation of fluid and electrolyte homeostasis and blood pressure in response to acute pharmacological & physiological stimuli and the chronic integrated physiological stimulus of high dietary salt-intake in Sprague-Dawley rats. SA 3 will define the role of PVN Gαi2-subunit proteins, via an ODN and lentiviral gene therapy approach, in the Dahl rat model of salt-sensitive hypertension. SA4 will integrate the role of the circumventricular organs in PVN Gαi2 protein mediated neural control of blood pressure. During the K02 Career Development plan the PI will train in the lab of Dr. Cunningham (Director UNTHSC Cardiovascular Research Institute) to acquire the surgical technique of AV3V lesions and will participate in the BUSM Office of Medical Education Faculty Development Program.