Targeting Apoptosis by Chemical Design

描述(由申请人提供)： 细胞凋亡是细胞在特定的内部和外部信号作用下自毁的精心安排的过程。细胞程序性死亡受到一个复杂的制衡网络的调控，该网络由“bcl2家族”蛋白质控制。在多种血液系统疾病和其他疾病的发病机制中，细胞凋亡通路的错误调控是一个重要事件。BCL-2是一种生存蛋白，其过度生产促进了病理性细胞的存活死亡。触发线粒体凋亡的特定分子编排仍不清楚。BID的结构由8个阿尔法螺旋定义，其中一个是关键的死亡效应器螺旋。我们假设BID中特定的α-螺旋结构域参与了不同的相互作用，这有助于其整体功能。本研究的目的是融合化学和生物学技术来阐明Bid诱导细胞凋亡的机制，并开发在体内操纵细胞凋亡的分子。因此，这项建议的具体目的是：1)合成和表征稳定的BIDα螺旋(SAHBs)，2)确定BID的α螺旋结构域在触发线粒体凋亡中的作用(S)，以及3)利用SAHBs在培养细胞和小鼠模型中验证和操纵BID的活性。 以Bid的死亡效应螺旋为模型的SAHBs的初步面板已经合成。与未经修饰的多肽相比，其中两种SAHBs显示：(A)α-螺旋性增加5倍以上；(B)对蛋白酶的抵抗力提高3.5倍；(C)线粒体细胞色素c释放能力增加25倍，这是细胞凋亡的关键步骤；以及(D)诱导培养的Jurkat细胞凋亡。SAHBs具有双重潜力，既可以作为解剖细胞凋亡途径的生物工具，也可以作为以异常细胞低或增殖为特征的疾病的原型疗法。 由在合成化学、结构生物学、细胞凋亡生物学和临床血液学/肿瘤学领域拥有专业知识的国际公认的导师、合作者和顾问组成的多元化团队将为瓦伦斯基博士作为这些著名领域的独立研究员的发展提供一个理想的培训环境。

DESCRIPTION (provided by applicant): Apoptosis is the orchestrated process by which cells self-destruct in response to specific internal and external signals. Programmed cell death is regulated by a complex network of checks and balances governed by the "BCL-2 family" of proteins. Faulty regulation of apoptotic pathways is a seminal event in the pathogenesis of a variety of hematologic and other diseases. BCL-2 is a survival protein, and its overproduction facilitates pathologic cell survival death. The specific molecular choreography that triggers mitochondrial apoptosis remains unknown. Bid's structure is defined by 8 alpha-helices, one of which is a critical death effector helix. We hypothesize that specific alpha-helical domains within BID engage in distinct interactions that contribute to its overall function. The goal of this research is to fuse chemical and biological techniques to elucidate the mechanism of BID-induced apoptosis and develop molecules to manipulate apoptosis in vivo. Thus, the specific aims of this proposal are: 1) Synthesize and characterize Stabilized Alpha Helices of BID (SAHBs), 2) Define the role(s) of BID's alpha-helical domains in triggering mitochondrial apoptosis, and 3) Utilize SAHBs to validate and manipulate BID activities in cultured cells and mouse models. A preliminary panel of SAHBs modeled after BID's death effector helix has been synthesized. Compared to unmodified peptide, two of these SAHBs demonstrate: (a) more than 5-fold increase in alpha-helicity; (b) up to 3.5-fold enhancement in protease resistance; (c) up to 25-fold increased potency in mitochondrial cytochrome c release, a key step in apoptosis; and (d) apoptosis induction in cultured Jurkat cells. SAHBs have the dual potential to serve as biological tools to dissect apoptotic pathways, and as prototype therapeutics for diseases characterized by aberrant cellular hypo- or hyperplasia. A diverse team of internationally recognized mentors, collaborators, and advisors with expertise in the fields of synthetic chemistry, structural biology, apoptosis biology, and clinical hematology/oncology will provide an idea training environment for Dr. Walensky's development as an independent investigator at the interface of these notable fields.