Functional Characterization of Phosphodiesterase 1 in Single Ventricle Heart Disease

项目摘要 这个指导临床科学家发展奖的建议描述了一个5年的培训计划，让博士。 中野（PI）有机会在儿科心力衰竭领域发展学术生涯。中野博士 在科罗拉多大学完成了临床儿科心脏病学奖学金， 通过T32机制进行研究培训。中野博士的职业抱负是成为一名独立的 医生科学家和改善儿童心力衰竭的结果通过分子研究。 单心室心脏病（SV）是先天性心脏病的一个子集， 干预进行性心力衰竭（HF）是一种常见的死亡原因和心脏移植的适应症 在SV患儿中。SV HF的确切机制尚不清楚，限制了其治疗的能力。 确定有效的治疗方法。经证实的成人HF药物外推至儿童SV HF人群 目前还不成功，因此需要新的治疗模式。 选择性磷酸二酯酶（PDE）的药理学抑制已变得越来越普遍 SV HF的治疗，主要目的是通过增加环腺苷来增强收缩力 单磷酸（cAMP）与PDE 3抑制（PDE 3 i）。但是我们的研究表明，在分子水平上， PDE 3 i在SV HF中不是有效治疗;这与PDE 3 i在儿科中的发现形成鲜明对比 扩张型心肌病导致的HF患者。因此，有必要阐明其他偏微分方程在 1）PDE 1是主要的cAMP-和环鸟苷一磷酸（cGMP）- 2）PDE 1定位于肌节，并可能靶向一个独特的细胞池， cAMP，和3）PDE 1抑制（PDE 1 i）减少通过cGMP途径介导的肥大。在这 我们将确定：1）PDE 1在收缩的SV心肌中的定位和活性，并测量 急性PDE 1 i在SV小梁中的功能作用; 2）PDE 1在钙敏感性和舒张中的作用 从SV心肌分离的肌细胞和肌原纤维中的动力学;和3）PDE 1在病理学上的贡献。 使用来自SV受试者的血清处理的新生大鼠心室肌细胞进行重构。阐明 PDE 1在SV心肌中的分子和功能作用将为开发PDE 1 i提供依据 目前的结果是令人无法接受的差。PDE 1 i治疗可以 可能会预防这些高风险SV患者发生HF或延迟心脏移植的需要。 在一个最佳的，指导的环境中，中野博士将获得新的研究专业知识，这将是必不可少的， 作为独立研究者开展未来的转化性心血管研究。中野医生 临床，研究，儿科和成人心脏病学专业知识和资源的支持， 科罗拉多，包括大学的大型人类心脏组织库。中野博士将继续与她合作 目前在科罗拉多大学的导师团队，谁是致力于她的成功。

Project Summary This Mentored Clinical Scientist Development Award proposal describes a 5-year training program to allow Dr. Nakano (PI) the opportunity to develop an academic career in the field of pediatric heart failure. Dr. Nakano has completed clinical pediatric cardiology fellowship at the University of Colorado and basic cardiovascular research training through a T32 mechanism. Dr. Nakano’s career aspiration is to become an independent physician scientist and improve outcomes in pediatric heart failure through molecular investigations. Single ventricle heart disease (SV) is a subset of congenital heart defects that are universally fatal without intervention. Progressive heart failure (HF) is a common cause of death and indication for heart transplantation in children with SV. The exact mechanisms underlying SV HF are poorly understood, limiting the ability to identify effective therapies. The extrapolation of proven adult HF medications to the pediatric SV HF population has been unsuccessful, consequently novel treatment paradigms are needed. Pharmacologic inhibition of select phosphodiesterase (PDE) enzymes has become increasingly common therapy for SV HF, with the primary goal of augmenting contractility through increasing cyclic adenosine monophosphate (cAMP) with PDE3 inhibition (PDE3i). However our studies suggest that, on a molecular level, PDE3i is not effective therapy in SV HF; this is in stark contrast to what is found with PDE3i in pediatric patients with HF due to dilated cardiomyopathy. Thus, it is necessary to elucidate the role of other PDEs in the heart, particularly PDE1: 1) PDE1 is the predominant cAMP- and cyclic guanosine monophosphate (cGMP)- hydrolyzing PDE in the cytosol, 2) PDE1 is localized to the sarcomere and likely targets a unique pool of cAMP, and 3) PDE1 inhibition (PDE1i) decreases hypertrophy mediated through cGMP pathways. In this proposal, we will determine: 1) PDE1 localization and activity in explanted SV myocardium, and measure the functional effects of acute PDE1i in SV trabeculae; 2) the role of PDE1 in calcium sensitivity and relaxation kinetics in myocytes and myofibrils isolated from SV myocardium; and 3) the contribution of PDE1 in pathologic remodeling using neonatal rat ventricular myocytes treated with sera from SV subjects. Elucidating the molecular and functional role of PDE1 in the SV myocardium would provide justification for developing PDE1i for clinical use in this population, where current outcomes are unacceptably poor. PDE1i therapy could potentially prevent HF development or delay the need for heart transplantation in these high-risk, SV patients. Within an optimal, mentored environment, Dr. Nakano will gain new research expertise that will be essential to conducting future translational cardiovascular research as an independent investigator. Dr. Nakano has the support of clinical, research, pediatric, and adult cardiology expertise and resources at the University of Colorado, including the University’s large human heart tissue bank. Dr. Nakano will continue to work with her current mentor team at the University of Colorado, who are committed to her success.