Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA; The Research Center for Healthy Metabolism, University of Kentucky, Lexington, Kentucky, USA.
Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA; Department of Neurology, University of Kentucky, Lexington, Kentucky, USA.
J Biol Chem. 2023 May;299(5):104682. doi: 10.1016/j.jbc.2023.104682. Epub 2023 Apr 6.
Islet amyloid polypeptide (amylin) secreted from the pancreas crosses from the blood to the brain parenchyma and forms cerebral mixed amylin-β amyloid (Aβ) plaques in persons with Alzheimer's disease (AD). Cerebral amylin-Aβ plaques are found in both sporadic and early-onset familial AD; however, the role of amylin-Aβ co-aggregation in potential mechanisms underlying this association remains unknown, in part due to lack of assays for detection of these complexes. Here, we report the development of an ELISA to detect amylin-Aβ hetero-oligomers in brain tissue and blood. The amylin-Aβ ELISA relies on a monoclonal anti-Aβ mid-domain antibody (detection) and a polyclonal anti-amylin antibody (capture) designed to recognize an epitope that is distinct from the high affinity amylin-Aβ binding sites. The utility of this assay is supported by the analysis of molecular amylin-Aβ codeposition in postmortem brain tissue obtained from persons with and without AD pathology. By using transgenic AD-model rats, we show that this new assay can detect circulating amylin-Aβ hetero-oligomers in the blood and is sensitive to their dissociation to monomers. This is important because therapeutic strategies to block amylin-Aβ co-aggregation could reduce or delay the development and progression of AD.
胰岛淀粉样多肽（amylin）由胰腺分泌，从血液穿过血脑屏障进入脑实质，在阿尔茨海默病（AD）患者中形成脑混合淀粉样蛋白-β 淀粉样（Aβ）斑块。脑淀粉样蛋白-Aβ 斑块存在于散发性和早发性家族性 AD 中；然而，淀粉样蛋白-Aβ 共聚集在潜在机制中的作用尚不清楚，部分原因是缺乏检测这些复合物的方法。在这里，我们报告了一种用于检测脑组织和血液中淀粉样蛋白-Aβ 异源寡聚体的 ELISA 方法的开发。该淀粉样蛋白-Aβ ELISA 依赖于一种单克隆抗 Aβ 中段抗体（检测）和一种多克隆抗淀粉样蛋白抗体（捕获），旨在识别与高亲和力淀粉样蛋白-Aβ 结合位点不同的表位。该检测方法的实用性得到了从有和没有 AD 病理学的人死后脑组织中淀粉样蛋白-Aβ 共沉积的分子分析的支持。通过使用转基因 AD 模型大鼠，我们表明该新检测方法可以检测血液中的循环淀粉样蛋白-Aβ 异源寡聚体，并且对其单体的解离敏感。这很重要，因为阻断淀粉样蛋白-Aβ 共聚集的治疗策略可以减少或延迟 AD 的发展和进展。
