Targeting Abnormal Calcium Cycling Using Novel Gene Therapy Vectors

使用新型基因治疗载体靶向异常钙循环

基本信息

批准号：
8788952
负责人：
FADI GABRIEL AKAR
金额：
$ 72.28万
依托单位：
ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-01-02 至 2017-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8788952
关键词：
Accounting Acute Address Amiodarone Animal Model Anti-Arrhythmia Agents Antibodies Arrhythmia Biological Markers Ca(2+)-Transporting ATPase Calcium Cardiac Cause of Death Chronic Clinical Clinical Trials Congestive Heart Failure Coronary Coronary Arteriosclerosis Coronary artery Coupled Development Disease Dominant-Negative Mutation Effectiveness Etiology Exhibits FKBP1B gene Family suidae Functional disorder Gene Delivery Gene Transduction Agent Gene Transfer Gene Transfer Techniques Health Heart Heart failure Hour Human Hybrids Incidence Individual Injury International Investigation Ion Channel Protein Left Ventricular Dysfunction Macromolecular Complexes Mechanics Mediating Modeling Molecular Molecular Target Myocardial Infarction Myocardial Ischemia Myocardial dysfunction Myocardium Nature Outcome Patients Pharmaceutical Preparations Pharmacotherapy Phase Phosphorylation Post-Translational Protein Processing Pre-Clinical Model Prevention Prevention strategy Property Protein-Serine-Threonine Kinases Proteins Pump Randomized Clinical Trials Recombinants Regulation Reperfusion Therapy Reporting Research Design Risk Risk Factors Ryanodine Receptor Calcium Release Channel SERCA2a Sarcoplasmic Reticulum Serotyping Small Interfering RNA Testing Therapeutic Time Translations Tropism United States Up-Regulation Ventricular Arrhythmia adeno-associated viral vector base clinically relevant constriction design gene delivery system gene therapy hemodynamics high risk improved inhibitor/antagonist innovation man mortality neutralizing antibody novel overexpression patient population phospholamban preclinical study sudden cardiac death treatment strategy uptake vector

项目摘要

DESCRIPTION (provided by applicant): Most sudden cardiac deaths occur in patients with coronary artery disease and associated left ventricular dysfunction. Epicardial coronary artery abnormalities resulting in acute or chronic ischemic insults account for up to 80% of clinical arrhythmias. Randomized trials and clinical electrophysiological studies have demonstrated the ineffectiveness of anti-arrhythmic drug therapy in reducing mortality in this high-risk patient population. Paradoxically, conventional pharmacotherapies targeting ion channel proteins are often associated with increased rather than decreased mortality, possibly due to a potent pro-arrhythmic effect of these drugs. Numerous studies have established the importance of abnormal intracellular calcium (Ca2+) cycling in mechano-electrical dysfunction. Defective sequestration of Ca2+ by the sarcoplasmic reticulum (SR) Ca2+ ATPase (SERCA2a), coupled with increased diastolic SR Ca2+ leak via the ryanodine receptor (RYR2), result in cytosolic Ca2+ overload and associated dysfunction in ischemic heart disease. Key molecular targets that modulate SR Ca2+uptake and release include: 1) SERCA2a and its newly discovered post-translational modification by SUMO1, 2) Phospholamban (PLB), an endogenous inhibitor of SERCA2a, 3) FKBP12.6, a key component of the RYR2 macromolecular complex which stabilizes RYR2 activity, and 4) CAMKII¿c, a serine/threonine protein kinase which regulates intracellular Ca2+ cycling, including SR Ca2+ leak through RYR2 phosphorylation. The development of novel gene-based therapies that target these central components of intracellular Ca2+ cycling requires the investigation of their electrophysiological consequences, including pro- arrhythmic risk, in clinically relevant large animal models that closely mimic human ischemic heart disease. A major obstacle that has hindered the translation of these potentially effective molecular therapies has been the availability of adequate vectors for long-term gene transfer. Although AAV vectors were found to be safe in multiple clinical trials, their widespread use for gene delivery is limited by: 1) non-specificity to the heart and 2) pre-existing neutralizig antibodies to conventional AAV serotypes in <50% of candidates. A major innovation of the current application is the proposed use of chimeric AAV based bionanoparticles that exhibit superior cardiac tropism while escaping inherent immunological limitations in patients. We will take advantage of clinically relevant porcine models and gene delivery systems to test the central hypothesis that: a) SUMO1 ¿ SERCA2a overexpression, b) PLB silencing, c) FKBP12.6 overexpression, and d) CAMKII¿c inhibition are associated with distinct electrophysiological consequences in preclinical models of CAD. These studies will reveal the electrophysiological benefits and potential pitfalls associated with novel (e.g. SERCA2a + SUMO1) molecular therapies for CAD.

描述（由申请人提供）：大多数心脏性猝死发生在患有冠状动脉疾病和相关左心室功能障碍的患者中，导致急性或慢性缺血性损伤的心外膜冠状动脉异常占临床心律失常的 80%。研究表明，抗心律失常药物治疗在降低这一高危患者群体的死亡率方面无效，但矛盾的是，针对传统离子通道蛋白的药物治疗。通常与死亡率增加而不是降低有关，这可能是由于这些药物具有强效的促心律失常作用，大量研究已证实细胞内钙 (Ca2+) 循环异常在肌浆钙离子封存缺陷中的重要性。网状 (SR) Ca2+ ATP 酶 (SERCA2a)，加上通过兰尼碱受体 (RYR2) 增加舒张期 SR Ca2+ 渗漏，导致缺血性心脏病中胞浆 Ca2+ 超载和相关功能障碍，调节 SR Ca2+ 摄取和释放的关键分子靶点包括：1) SERCA2a 及其新发现的 SUMO1 翻译后修饰，2) Phospholamban (PLB)，一种内源性抑制剂。 SERCA2a，3) FKBP12.6，稳定 RYR2 活性的 RYR2 大分子复合物的关键成分，以及4）CAMKII?? c，一种丝氨酸/苏氨酸蛋白激酶，可调节细胞内 Ca2+ 循环，包括通过 RYR2 磷酸化进行 SR Ca2+ 渗漏。针对细胞内 Ca2+ 循环的这些核心成分的新型基因疗法的开发需要研究其电生理学后果，包括促电生理学后果。在与人类缺血性心脏病密切相关的临床相关大型动物模型中，心律失常风险阻碍了这些潜在有效分子疗法转化的主要障碍是可用性。尽管在多项临床试验中发现 AAV 载体是安全的，但它们在递送基因方面的广泛使用受到以下因素的限制：1) 对心脏的非特异性；2) 预先存在的中和抗体。当前应用的一个主要创新是基于嵌合 AAV 的生物纳米颗粒的使用，该纳米颗粒表现出优异的心脏趋向性，同时避免了患者固有的免疫学限制。利用临床相关的猪模型和基因传递系统来测试中心假设：a) SUMO1 ¿ SERCA2a 过表达，b) PLB 沉默，c) FKBP12.6 过表达，以及 d) CAMKII¿ c 抑制与 CAD 临床前模型中独特的电生理学后果相关。这些研究将揭示与 CAD 新型分子疗法（例如 SERCA2a + SUMO1）相关的电生理学益处和潜在缺陷。