Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA.
Department of Physiology & Biophysics, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Center for Mitochondrial Diseases, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA.
Mol Cell Proteomics. 2022 Sep;21(9):100280. doi: 10.1016/j.mcpro.2022.100280. Epub 2022 Aug 6.
Mouse models of Alzheimer's disease (AD) show progression through stages reflective of human pathology. Proteomics identification of temporal and sex-linked factors driving AD-related pathways can be used to dissect initiating and propagating events of AD stages to develop biomarkers or design interventions. In the present study, we conducted label-free proteome measurements of mouse hippocampus tissue with variables of time (3, 6, and 9 months), genetic background (5XFAD versus WT), and sex (equal males and females). These time points are associated with well-defined phenotypes with respect to the following: Aβ42 plaque deposition, memory deficits, and neuronal loss, allowing correlation of proteome-based molecular signatures with the mouse model stages. Our data show 5XFAD mice exhibit increases in known human AD biomarkers as amyloid-beta peptide, APOE, GFAP, and ITM2B are upregulated across all time points/stages. At the same time, 23 proteins are here newly associated with Alzheimer's pathology as they are also dysregulated in 5XFAD mice. At a pathways level, the 5XFAD-specific upregulated proteins are significantly enriched for DNA damage and stress-induced senescence at 3-month only, while at 6-month, the AD-specific proteome signature is altered and significantly enriched for membrane trafficking and vesicle-mediated transport protein annotations. By 9-month, AD-specific dysregulation is also characterized by significant neuroinflammation with innate immune system, platelet activation, and hyper-reactive astrocyte-related enrichments. Aside from these temporal changes, analysis of sex-linked differences in proteome signatures uncovered novel sex and AD-associated proteins. Pathway analysis revealed sex-linked differences in the 5XFAD model to be involved in the regulation of well-known human AD-related processes of amyloid fibril formation, wound healing, lysosome biogenesis, and DNA damage. Verification of the discovery results by Western blot and parallel reaction monitoring confirm the fundamental conclusions of the study and poise the 5XFAD model for further use as a molecular tool for understanding AD.
阿尔茨海默病（AD）的小鼠模型表现出与人类病理学相关的阶段进展。通过对驱动 AD 相关途径的时间和性别相关因素进行蛋白质组学鉴定，可以用于剖析 AD 阶段的起始和传播事件，以开发生物标志物或设计干预措施。在本研究中，我们对具有时间变量（3、6 和 9 个月）、遗传背景（5XFAD 与 WT）和性别的小鼠海马组织进行了无标记蛋白质组测量（雄性和雌性各占一半）。这些时间点与以下方面的明确表型相关：Aβ42 斑块沉积、记忆缺陷和神经元丢失，允许将基于蛋白质组的分子特征与小鼠模型阶段相关联。我们的数据显示，5XFAD 小鼠表现出已知的人类 AD 生物标志物的增加，如淀粉样β肽、APOE、GFAP 和 ITM2B 在所有时间点/阶段均上调。与此同时，有 23 种蛋白质在这里与阿尔茨海默病病理学新相关，因为它们在 5XFAD 小鼠中也失调。在途径水平上，5XFAD 特异性上调的蛋白质仅在 3 个月时显著富集与 DNA 损伤和应激诱导的衰老相关，而在 6 个月时，AD 特异性蛋白质组特征发生改变，并且显著富集与膜转运和囊泡介导的转运蛋白注释相关。到 9 个月时，AD 特异性失调还以固有免疫系统、血小板激活和高反应性星形胶质细胞相关丰度的显著神经炎症为特征。除了这些时间变化外，对蛋白质组特征中性别差异的分析揭示了新的性别和 AD 相关蛋白。途径分析显示，5XFAD 模型中的性别差异涉及调节已知的人类 AD 相关过程，如淀粉样纤维形成、伤口愈合、溶酶体生物发生和 DNA 损伤。通过 Western blot 和平行反应监测对发现结果的验证证实了该研究的基本结论，并为进一步将 5XFAD 模型用作理解 AD 的分子工具奠定了基础。
