Neuron death in Parkinson's disease: The role of Trib3

描述（由申请人提供）：该项目的长期目标是了解帕金森病（PD）神经元退化和死亡的分子机制，并利用这些信息设计出抑制患者这种疾病进展的治疗方法。这些研究将验证一个重要的假设，即PD患者的神经元退化和死亡是由于神经细胞功能和存活所需的关键酶Akt失活，而这是通过诱导应激反应蛋白Trib3 （Akt激活抑制剂）介导的。具体目的将评估四个假设：(1)Trib3表达在PD模型和PD中升高；(2) Trib3介导PD模型神经元变性和死亡；(3) Trib3通过干扰Akt的磷酸化/激活促进神经元死亡；(4) PD模型和PD中Trib3的诱导是由转录因子ATF4介导的。将采用多种实验方法。这些将包括评估基于毒素和α -突触核蛋白的PD细胞培养模型、疾病动物模型以及PD患者和对照组死后脑组织中的Trib3表达；在细胞培养和PD动物模型中，通过shrna或基因缺失来确定Trib3表达缺失是否能保护神经元免于死亡；确定（通过过表达或功能丧失研究）Trib3是否介导PD细胞模型中Akt活性的丧失；并确定在培养和动物模型中操纵ATF4的表达是否会影响PD培养和动物模型中Trib3的诱导。如果成功，这些研究将确定Trib3是导致帕金森病神经元死亡和退化机制的必要元素，并将提供关于它是如何做到这一点的见解，以及它是如何在这种疾病中被诱导的。从长远来看，这些信息将被用来制定新的方法来抑制PD患者的进展。

DESCRIPTION (provided by applicant): The long-term goals of this project are to understand the molecular mechanisms that underlie the degeneration and death of neurons in Parkinson's Disease (PD) and to use this information in turn to devise treatments to suppress the progression of this disorder in patients. The proposed studies will test the over-arching hypothesis that neuron degeneration and death in PD are due to inactivation of the key enzyme Akt which is required for nerve cell function and survival, and that this is mediated by induction of the stress-responsive protein Trib3, an inhibitor of Akt activation. The specific aims will assess four hypotheses: (1) that Trib3 expression is elevated in PD models and in PD; (2) that Trib3 mediates neuron degeneration and death in models of PD; (3) that Trib3 promotes neuron death by interfering with phosphorylation/activation of Akt; and (4) that induction of Trib3 in PD models and PD is mediated by the transcription factor ATF4. Multiple experimental approaches will be employed. These will include assessing Trib3 expression in toxin- and alpha- synuclein based cell culture models of PD, in animal models of the disease and in post-mortem brain tissues from PD patients and controls; determining whether loss of Trib3 expression, either via shRNAs or gene deletion, protects neurons from death in cell culture and animal models of PD; ascertaining (by over- expression or loss-of function studies) whether Trib3 is responsible for mediating the loss of Akt activity that occurs in cellular models of PD; and establishing whether manipulating expression of ATF4 in culture and animal models influences Trib3 induction in culture and animal models of PD. If successful, these studies will establish Trib3 as a required element in the mechanism that leads to neuron death and degeneration in PD and will provide insight as to how it does this, and how it is induced in this disorder. Such information will be exploited in the long term to formulate new approaches to suppress progression of PD in patients.