Caspase-independent cell death and neurodegeneration

描述(由申请人提供)：本项目的总体目标是 描述一种新的细胞死亡途径，称为“细胞坏死”，并确定 它在神经退行性变中的作用。在最近的几年中产生了大量的证据 多年来表明有两条“经典”的细胞死亡途径，即细胞凋亡和 坏死，不能解释细胞的生理和病理变化 死亡机制。第三种途径的存在，称为“细胞坏死”，是 建议。该途径在被诱导经历的细胞中被激活 细胞凋亡，但仍未完成。建议代表一个 旨在消除损坏和潜在危险的新型安全机制 危险的牢房。粒细胞坏死与程序性细胞死亡本质相同 细胞凋亡和执行子程序以及坏死的表型特征。 利用高通量筛选小分子文库中的几种化合物 分离出了抗细胞坏死的抑制剂。这些化合物被发现是 选择性地抑制细胞坏死，但不能抑制细胞凋亡，强调了独特的 无凋亡性细胞死亡过程的机制。使用选定的抑制剂 细胞坏死表现为一种主要的细胞死亡过程。 体外caspase非依赖性细胞死亡范例。无核细胞坏死也是 与PC12细胞的淀粉样β蛋白毒性和脑缺血损伤有关 活着。选定缓蚀剂在不同体系中的作用分析 提示其中两个靶细胞类型特定的信号通路， 而另一个复合体阻止统一的下游执行步骤，提供 有机会描述坏死的各个步骤 单独的抑制剂。两种促凋亡调节因子(p38激酶和组织蛋白酶B) 都被发现了。本研究的具体目的如下：1)评价 神经细胞坏死在体外和体内神经细胞死亡中的作用 鉴定与细胞坏死有关的分子事件；3)鉴定新的 利用化学、细胞和分子生物学研究与细胞坏死相关的基因 接近了。 这项研究将在哈佛大学细胞生物学系进行 袁俊英医生和蒂莫西医生共同指导的医学院 米奇森。袁俊英博士是公认的神经学领域的领军人物 细胞死亡。蒂莫西·米奇森博士是一位杰出的细胞生物学家， 也是化学生物学方法的先驱之一。袁博士将提供 前两个目标的资源和指导，部分用于第三个目标。 蒂莫西·米奇森博士将提供培训和监督以及 哈佛大学化学与细胞生物学研究所的化学资源 生物学是该项目的一部分。细胞生物学系全力致力于 申请人发展成为该领域完全独立的研究人员 与衰老相关的神经退行性变。 阿列克谢·德格特里耶夫博士立志成为一项完全独立的研究 衰老相关神经细胞死亡领域的科学家将使用 K01训练期，以发展和提高表演所需的技能 在这一领域独立研究，并开发研究项目，将从 为他未来的独立研究奠定了基础。

DESCRIPTION (provided by applicant): The overall goal of this project is to characterize a novel cell death pathway, termed "aponecrosis", and determine its role in neurodegeneration. Extensive evidence was generated in recent years suggesting that two "classic" cell death pathways, apoptosis and necrosis, do not explain the variety of physiological and pathological cell death mechanisms. Existence of the third pathway, termed "aponecrosis", is proposed. This pathway is activated in cells that are induced to undergo apoptosis, yet prevented from its completion. It is proposed to represent a novel safety mechanism aimed at elimination of damaged and potentially dangerous cells. Aponecrosis shares programmed cell death nature with apoptosis and execution subroutines and phenotypic features with necrosis. Using high throughput screening of small molecule library several chemical inhibitors of aponecrosis were isolated. These compounds were found to selectively inhibit aponecrosis, but not apoptosis, underscoring distinct mechanism of the aponecrotic cell death process. Using selected inhibitors aponecrosis was shown to represent a major cell death process in a variety of caspase-independent cell death paradigms in vitro. Aponecrosis was also implicated in amyloid-beta toxicity in PC12 cells and ischemic brain damage in vivo. Analysis of the effects of selected inhibitors in various systems suggests that two of them target cell type specific signaling pathways, whereas another compound blocks uniform downstream execution step, providing the opportunity to characterize various steps in aponecrosis with the help of individual inhibitors. Two aponecrotic regulators (p38 kinase and cathepsin B) were discovered. Specific aims of this study are as follows: 1 ) To evaluate the role of aponecrosis in neuronal cell death in vitro and in vivo; 2) To characterize molecular events involved in aponecrosis; 3) To identify novel genes involved in aponecrosis using chemical, cell and molecular biology approaches. The research will be conducted in the Department of Cell Biology at Harvard Medical School under the joint guidance of Dr. Junying Yuan and Dr. Timothy Mitchison. Dr. Junying Yuan is a recognized leader in the field of neuronal cell death. Dr. Timothy Mitchison is an outstanding cell biologist, who is also one of the pioneers of chemical biology approach. Dr. Yuan will provide resources and mentorship for the first two and partially for the third aim. Dr. Timothy Mitchison will provide training and supervision as well as resources of Harvard Institute of Chemistry and Cell Biology for the chemical biology part of the project. Department of Cell Biology is fully committed to the applicant's development into a fully independent researcher in the field of aging-related neurodegeneration. Dr. Alexei Degterev is aspiring to become a fully independent research scientist in the field of aging-associated neuronal cell death and would use K01 training period to develop and enhance the skills needed to perform independent research in this area and develop research project that will from the basis for his future independent research.