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）神经元变性和死亡的分子机制，并利用这些信息反过来设计治疗方法来抑制患者这种疾病的进展。拟议的研究将测试过度假设，即PD中的神经元变性和死亡是由于神经细胞功能和存活所需的关键酶Akt的失活，并且这是由应激反应蛋白Trib 3（Akt激活的抑制剂）的诱导介导的。具体目标将评估四个假设：（1）Trib 3表达在PD模型和PD中升高;（2）Trib 3介导PD模型中的神经元变性和死亡;（3）Trib 3通过干扰Akt的磷酸化/活化促进神经元死亡;以及（4）Trib 3在PD模型和PD中的诱导由转录因子ATF 4介导。将采用多种实验方法。这些将包括评估Trib 3在PD的基于毒素和α-突触核蛋白的细胞培养模型中、在疾病的动物模型中以及在来自PD患者和对照的死后脑组织中的表达;确定Trib 3表达的丧失（通过shRNA或基因缺失）是否保护PD的细胞培养和动物模型中的神经元免于死亡;确定（通过过度表达或功能丧失研究）Trib 3是否负责介导在PD细胞模型中发生的Akt活性丧失;以及确定在培养物和动物模型中操纵ATF 4的表达是否影响PD的培养物和动物模型中的Trib 3诱导。如果成功，这些研究将确定Trib 3是导致PD神经元死亡和变性的机制中的必需元素，并将提供有关其如何做到这一点以及如何在这种疾病中诱导的见解。这些信息将被长期利用，以制定新的方法来抑制患者的PD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.