Hsp90/Client Protein Interactions in the Newborn Lung

描述（由申请人提供）：调节出生时肺循环适应的信号机制和导致婴儿肺动脉高压（PH）发展的信号机制尚未完全了解，这是我实验室的长期目标。该提议提出了以下假设：热休克蛋白90（Hsp 90）及其客户信号蛋白之间的相互作用调节正常新生儿肺循环中的血管反应，Hsp 90/客户蛋白相互作用的成熟变化有助于出生后早期肺循环适应，慢性缺氧改变了Hsp 90/客户蛋白的相互作用，扰乱了新生儿肺中扩张信号通路的成熟和功能。生理测量和生物化学技术将用于实现以下具体目标：（1A）确定Hsp 90/客户蛋白相互作用对新生仔猪肺中血管功能和信号传导的影响，（1B）确定在常氧下饲养的健康仔猪中在生命第2-4天和第12-14天之间发生的Hsp 90/客户蛋白相互作用的成熟变化，以及（2）确定Hsp 90/客户蛋白相互作用中的紊乱，这些紊乱导致慢性（10天）缺氧诱导的PH仔猪肺中血管反应性和信号传导的改变。我们的调查集中在热休克蛋白90和其已知的客户蛋白，内皮型一氧化氮合酶（NOS）和Akt激酶之间的相互作用，以及新的相互作用与胞质前列腺素E2合酶和血栓素合酶。我们方法的核心是测量从健康仔猪和患有缺氧诱导PH的仔猪中分离的插管肺阻力动脉中的血管反应。继发于慢性肺或心脏疾病的PH很少对目前可用的疗法有反应，并且经常是致命的。这些研究将提高对新生儿肺动脉高压对慢性缺氧反应的理解，并对制定PH婴儿的新治疗策略至关重要。

DESCRIPTION (provided by applicant): The signaling mechanisms regulating pulmonary circulatory adaptation at birth and those contributing to the development of pulmonary hypertension (PH) in infants are incompletely understood and are the long-term objectives of my laboratory. This proposal addresses the hypothesis that interactions between heat shock protein 90 (Hsp90) and its client signaling proteins regulate vascular responses in the normal newborn pulmonary circulation, that maturational changes in Hsp90/client protein interactions contribute to early postnatal pulmonary circulatory adaptation, and that chronic hypoxia alters Hsp90/client protein interactions disrupting the maturation and function of dilator signaling pathways in the neonatal lung. Physiological measurements and biochemical techniques will be used to address the following specific aims: (1A) Determine the impact of Hsp90/client protein interactions on vascular function and signaling in the lungs of newborn piglets, (1B) Determine the maturational changes in Hsp90/client protein interactions that occur between day of life 2-4 and 12-14 in healthy piglets raised in normoxia and (2) Determine the derangements in Hsp90/client protein interactions that contribute to altered vascular reactivity and signaling in the lungs of piglets with PH induced by chronic (10 days) hypoxia. Our investigations focus on interactions between Hsp90 and its known client proteins, endothelial nitric oxide synthase (NOS) and Akt kinase, as well as novel interactions with cytosolic prostaglandin E2 synthase and thromboxane synthase. At the core of our methodology is measurement of vascular responses in cannulated pulmonary resistance arteries isolated from healthy piglets and piglets with hypoxia-induced PH. PH that develops secondary to chronic pulmonary or cardiac conditions is rarely responsive to currently available therapies and is frequently lethal. These studies will improve understanding of the neonatal pulmonary hypertensive response to chronic hypoxia and are critical to the formulation of novel treatment strategies for infants with PH.