Proteomic analysis of the postsynaptic density-95 interactome in schizophrenia

项目摘要： 这是一个创新的R21应用程序，研究精神分裂症中蛋白质-蛋白质相互作用的异常。这是一 保守地说，在过去的20年里，自2000年以来， 非典型抗精神病药物的发展。有广泛的共识，这些新的药物不延长 药物治疗对认知和阴性/缺陷症状的疗效，这些症状导致严重残疾， 精神分裂症患者因此，迫切需要更深入地了解 这种疾病的病理生理学，以开发新的治疗策略。越来越多的证据表明， 精神分裂症是一种神经可塑性障碍，涉及突触功能的病理生理变化， 认知缺陷遍布大脑的突触包含称为突触后密度的微区，它们是动态的 受体、结构和信号蛋白的聚集。兴奋性突触中的突触后密度包含 离子型谷氨酸受体，包括NMDA和AMPA受体，以及多能支架分子，如 突触后密度-95（PSD-95）。PSD-95通过调节突触后密度成分的运输和组装， 蛋白质相互作用受体通过支架蛋白在突触后致密物中的共定位 与学习和记忆相关的分子，如长时程增强（LTP）和长时程抑制（LTD）。 越来越多的证据表明精神分裂症患者突触后密度的含量和功能异常， 还没有对精神分裂症中突触后密度的关键要素进行研究。我们假设， 是这种疾病中突触后蛋白复合物成分的深刻变化。我们特别假设 PSD-95蛋白-蛋白相互作用组的异常是慢性脑梗死中发现的神经可塑性缺陷的基础。 精神分裂症我们建议亲和纯化PSD-95蛋白复合物从背外侧前额叶皮层， 慢性精神分裂症受试者（n = 20）和对照组（n = 20），并检查PSD-95相互作用组使用 液相色谱-质谱法（LCMS/MS）。我们将用靶向LCMS/MS跟踪这些研究， 蛋白质印迹分析以证实我们最初研究中蛋白质表达和浓度的变化。我们将使用 途径分析和网络建模，以确定参与的生物过程和上游调节剂， 精神分裂症的病理生理学最后，我们建议确认研究，包括评估同一依赖 在突触断裂的动物模型以及抗精神病药物治疗的啮齿动物中进行测量。本申请提出 这些实验将扩展我们对精神分裂症病理生理学的理解，并确定新的底物 可以用来治疗这种毁灭性的疾病

Project Summary: This is an innovative R21 application to investigate abnormalities of protein-protein interactions in schizophrenia. It is an understatement to say that the treatment of schizo-spectrum disorders has not progressed in the past 20 years since the development of atypical antipsychotics. There is broad consensus that these newer medications do not extend the efficacy of pharmacological treatments to cognitive and negative/deficit symptoms, which lead to profound disability in persons afflicted with schizophrenia. Thus, there is a pressing need to develop a more sophisticated understanding of the pathophysiology of this illness in order to develop new treatment strategies. Converging evidence suggests that schizophrenia is a disorder of neuroplasticity, involving pathophysiological changes in synaptic function that lead to cognitive deficits. Synapses throughout the brain contain microdomains called postsynaptic densities, which are dynamic aggregations of receptor, structural, and signaling proteins. Postsynaptic densities in excitatory synapses contain ionotropic glutamate receptors, including NMDA and AMPA receptors, and multipotent scaffolding molecules, such as postsynaptic density-95 (PSD-95). PSD-95 regulates trafficking and assembly of postsynaptic density constituents via protein-protein interactions. Co-localization of receptors in the postsynaptic density via scaffolding proteins underlies molecular correlates of learning and memory, such as long-term potentiation (LTP) and long-term depression (LTD). Accumulating evidence implicates abnormalities of postsynaptic density content and function in schizophrenia, but studies on key elements of the postsynaptic density in schizophrenia have not been performed. We postulate that there are profound changes in the constituents of postsynaptic protein complexes in this illness. We specifically hypothesize that abnormalities of the PSD-95 protein-protein interactome underlie the neuroplastic defects found in chronic schizophrenia. We propose to affinity purify PSD-95 protein complexes from the dorsolateral prefrontal cortex in subjects with chronic schizophrenia (n = 20) and a control group (n = 20), and examine the PSD-95 interactome using liquid chromatography-mass spectrometry (LCMS/MS). We will follow up these studies with targeted LCMS/MS and western blot analyses to confirm changes in protein expression and concentration from our initial studies. We will use pathway analyses and network modeling to identify biological processes and upstream modulators involved in the pathophysiology of schizophrenia. Finally, we propose confirmation studies that include assessing the same dependent measures in an animal model of broken synapses, as well as antipsychotic treated rodents. This application proposes experiments that will extend our understanding of the pathophysiology of schizophrenia and identify novel substrates that may be targeted for the treatment of this often devastating illness.