Signal integration of the death receptor pathways

生物系统在许多方面都是复杂的，特别是涉及到多个途径 启动和调节病理生理过程。我们感兴趣的是， 可以与这些过程中重要的细胞死亡机制相互作用。在早期的研究中，我们定义了 Bid是一种促死亡Bcl-2家族蛋白，在死亡受体途径和凋亡之间的交叉作用中起着关键作用。 肝损伤和肝细胞凋亡小鼠模型中的线粒体途径。从那时起， 发现新的信号事件参与了这一途径，特别是当TNF-R1参与时。基于 在我们的初步研究中，我们假设JNK和活性氧（ROS）是两个重要的 这些机制可以独立于Bid与线粒体激活整合。我们将解决 JNK在促进TNF α诱导的肝细胞凋亡和肝损伤中的作用（目的1）以及JNK如何 以不依赖Bid的方式激活线粒体（Aim 2）。在目标3中，我们将研究ROS在 TNF α诱导的肝损伤和肝细胞凋亡，它们通过NF-κ B途径的调节以及它们如何 以不依赖Bid的方式激活线粒体。将采取各种方法，包括 利用基因敲除小鼠和通过RNA干扰进行体内基因敲除、体外原代细胞的体内模型 培养和生化分析。虽然这项建议的重点是在整合的一些关键 TNF α刺激后线粒体水平的信号传导过程，我们的长期目标是了解 如何整合不同的信号通路以确定病理过程的最终结果， 这对新疗法的发展很重要。

The biology system is complicated in many senses, in particular regarding to the multiple pathways involved in initiating and regulating pathophysiological processes. We are interested in how different signaling events could interact with the cell death machinery important to these processes. In earlier studies, we defined the critical role of Bid, a pro-death Bcl-2 family protein, in the cross-talk between the death receptor pathway and the mitochondria pathway in a murine model of liver injury and hepatocyte apoptosis. We have since then found that novel signaling events are involved in the pathways, particularly when TNF-R1 is engaged. Based on our preliminary studies, we hypothesize that JNK and reactive oxygen species (ROS) are two important mechanisms that could integrate with the mitochondrial activation independently of Bid. We will address the function of JNK in promoting TNFa-induced hepatocyte apoptosis and liver injury (Aim 1) and how JNK may activate the mitochondria in a Bid-independent way (Aim 2). In Aim 3, we will investigate the role of ROS in TNFa induced liver injury and hepatocyte apoptosis, their regulation by the NF-KB pathway and how they may activate the mitochondria in a Bid-independent manner. A variety of approaches will be taken, including the in vivo models that utilize gene knockout mice and in vivo gene knockdown by RNAi, in vitro primary cell cultures and biochemistry analysis. While the focus of this proposal is at the integration of some of the key signaling processes at the mitochondria level following TNFa stimulation, our long-term goal is to understand how different signal pathways can be integrated to determine the final outcome of a pathological process, which would be important to the development of novel therapeutics.