Identification and characterization of modulators affecting Amyloid precursor protein (APP) family members synaptogenic activity

影响淀粉样前体蛋白 (APP) 家族成员突触活性的调节剂的鉴定和表征

• 批准号: 325768783
• 负责人: Professor Dr. Stefan Kins
• 金额: --
• 依托单位: Fachgebiet Humanbiologie und Humangenetik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/325768783?language=en
• 关键词: Identification; characterization; modulators; affecting; Amyloid

Besides its fundamental role in Alzheimer Disease pathology, the Amyloid precursor protein (APP) has important physiological functions at the synapse. Interestingly, actual data suggest that APP and its homologues APLP1 and APLP2 act together in different synaptic processes and in doing so secreted (sAPP) and full-length APP fulfill different functions. So deficits in synapse formation and LTP observed in APP/APL2 knockout mice can only partly be rescued by sAPP. We and others have shown that full-length APP, APLP1 and APLP2 can dimerize in trans-orientation and could show that expression of APP in HEK293 cells co-cultured with primary neurons potently promotes synaptogenesis in contacting axons, similar to other synaptic adhesion molecules, such as Neuroligins/Neurexins. In a pre-screen based on in vitro trans-dimerization of purified APP/APLPs we observed that different cell types, including neurons and glia cells secrete diverse protein components modulating APP trans-directed dimerization. In first biochemical analysis we could identify one of those modulators affecting trans-directed interaction of APP and APLP1. In context of this application we intend to screen for additional modulators of APP/APLPs trans-interaction and like to analyze their function in APP/APLPs synapse formation. For this purpose we intend to analyze the impact of those modulators on APP/APLPs-mediated synapse formation in primary neurons, on hemi-synapses in the mixed co-culture assay and on synapse dynamics by long-term in vivo two-photon live cell imaging. In this context we will also use neuronal cultures from different single or double knockouts of APP, APLP1 and APLP2. Together these studies will help to increase our understanding of APP/APLPs physiological function in interplay with other synaptic proteins in synapse modulation.

除了在阿尔茨海默病病理学中的基本作用外，淀粉样前体蛋白 (APP) 在突触中还具有重要的生理功能。有趣的是，实际数据表明 APP 及其同源物 APLP1 和 APLP2 在不同的突触过程中共同作用，并且在此过程中分泌的 (sAPP) 和全长 APP 履行不同的功能。因此，在 APP/APL2 敲除小鼠中观察到的突触形成和 LTP 缺陷只能通过 sAPP 部分修复。我们和其他人已经证明，全长 APP、APLP1 和 APLP2 可以反式二聚化，并且可以表明与原代神经元共培养的 HEK293 细胞中 APP 的表达有效促进接触轴突的突触发生，类似于其他突触粘附分子，例如 Neuroligins/Neurexins。在基于纯化 APP/APLP 体外反式二聚化的预筛选中，我们观察到不同的细胞类型，包括神经元和神经胶质细胞，分泌调节 APP 反式二聚化的不同蛋白质成分。在第一个生化分析中，我们可以识别出影响 APP 和 APLP1 反式相互作用的调节剂之一。在此应用中，我们打算筛选 APP/APLP 反式相互作用的其他调节剂，并分析它们在 APP/APLP 突触形成中的功能。为此，我们打算分析这些调节剂对原代神经元中 APP/APLP 介导的突触形成、混合共培养测定中的半突触以及通过长期体内双光子活细胞成像对突触动力学的影响。在这种情况下，我们还将使用来自 APP、APLP1 和 APLP2 的不同单敲除或双敲除的神经元培养物。这些研究将有助于加深我们对 APP/APLP 在突触调节中与其他突触蛋白相互作用的生理功能的理解。

项目成果

Dimerization leads to changes in APP (amyloid precursor protein) trafficking mediated by LRP1 and SorLA

• DOI: 10.1007/s00018-017-2625-7
• 发表时间: 2018-01-01
• 期刊: CELLULAR AND MOLECULAR LIFE SCIENCES
• 影响因子: 8
• 作者: Eggert, Simone;Gonzalez, A. C.;Kins, Stefan
• 通讯作者: Kins, Stefan