Understanding the functional impacts of Aβ variants in Alzheimer's disease with human brain organoids

虽然AD的病因在很大程度上仍不清楚，但没有有效的策略来阻止AD的持续发展 目前的证据表明，这种疾病与早期疾病进展有关，淀粉样蛋白-β(Aβ)是一种40/42氨基酸的多肽。 这种多肽的折叠可能会如何产生异质组装(菌株)，这些组装(菌株)会以类Pron的形式传播 整个大脑的感染仍然是一个核心问题。因此，我们建议将这些机制联系起来。 蛋白病型Aβ菌株的分化和繁殖与其生化表现的关系 人脑器官中具有疾病病因学的应变模式的结构基础。因为菌株会影响 疾病病因学的致病特性以及聚集的Aβ蛋白也可能主导治疗 对于疾病的治疗(如免疫治疗)，必须从结构和功能上描述 我们现在所理解的是蛋白质病Aβ传播的动态性质。在当前的应用程序中，我们 将结合我们互补的专业知识领域来分析Aβ菌株的组装和繁殖 它们对人脑有机体的影响(Z.wen)，动态组装网络的光谱分析 成员(D.Lynn)，并使用高分辨率和低分辨率低温EM重建(B.梁)来定义关键 疾病传播者。我们的主要假设是，β组件的多维动力学定义了 阿尔茨海默病自持性淀粉样变的病理生物学基础的动态动力学稳定性。首先，我们将 识别β在细胞内形成和繁殖的菌株特定模式以关联分子 Aβ菌株结构差异的基础(目标1)。第二，我们将测定生化 A-β菌株的临床表现及致病机制探讨 人脑皮质类器官模型(目标2)。最后，我们将描述与β相关的分子签名 人类皮质类器官中的菌株(目标3)。通过结合先进的人类诱导多能干细胞 技术与全面的结构和功能分析，我们的调查将揭示关键的结构 阿尔茨海默病中错误折叠的蛋白质聚集体传播的潜在特征，允许我们 最终确定早期神经退行性AD的病因学靶点进行治疗干预。

While the AD etiology remains largely unknown, with no effective strategy to arrest the relentless progression of the disease, current evidence connects amyloid-β (Aβ), a 40/42 amino acid peptide, to early disease progression. How folding of this peptide might create the heterogeneous assemblies (strains) that propagate as a prion-like infection throughout the brain remains a central question. Accordingly, we propose to connect the mechanisms of diversification and propagation of proteopathic Aβ strains to their biochemical manifestation to connect the structural foundation of strain patterns with disease etiology in human brain organoids. Because strains influence the pathogenic properties of disease etiology and because aggregated Aβ proteins may also govern therapeutic approaches to the diseases (such as immunotherapy), it is essential to structurally and functionally characterize what we now understand to be the dynamic nature of proteopathic Aβ propagons. In the current application, we will combine our complementary areas of expertise to analyze the assembly and propagation of Aβ strains with their impact in human brain organoids (Z. Wen), spectroscopic analyses of the dynamic assembly network members (D. Lynn), and with high- and low-resolution cryo-EM reconstructions (B. Liang) to define critical disease propagons. Our overarching hypothesis is that the multidimensional dynamics of Aβ assemblies define dynamic kinetic stability underlying the pathobiology of the self-perpetuating amyloid strains of AD. First, we will identify strain-specific patterns of Aβ intracellular formation and propagation to correlate the molecular foundations of structural differences among Aβ strains (Aim 1). Second, we will determine the biochemical manifestation of Aβ strains and elucidate the underlying mechanisms by which aberrant strains function in the human cortical organoid model (Aim 2). Lastly, we will delineate the molecular signatures associated with Aβ strains in human cortical organoids (Aim 3). By combining the advanced human induced pluripotent stem cell technology with comprehensive structural and functional analyses, our investigation will reveal key structural features underlying the propagation of misfolded protein aggregates in Alzheimer’s disease, allowing us ultimately to identify early neurodegenerative AD etiology targets for therapeutic intervention.