Alzheimer’s disease (AD) is the most common neurodegenerative disorder, with significant research efforts devoted to identifying new biomarkers for clinical diagnosis and treatment. MicroRNAs have emerged as likely disease regulators and biomarkers for AD, now implicated as having roles in several biological processes related to progression of the disease. In this work, we use the miRacles assay (microRNA activated conditional looping of engineered switches) for single-step detection of AD-related microRNAs. The technology is based on conformationally responsive DNA nanoswitches that loop upon recognition of a target microRNA and report their on/off status through an electrophoretic readout. Unlike many methods, our approach directly detects native microRNAs without amplification or labeling, eliminating the need for expensive enzymes, reagents, and equipment. For known AD-related microRNA miR-107, we demonstrated sensitivity of ∼8 fM, specificity among four similar microRNAs of the same family, and simultaneous multiplexed detection of those four microRNA targets. Toward clinical use, we screened 56 AD-related microRNAs and found four that showed detectable differences between total RNA extracts derived from human healthy and AD brain samples. In the context of AD, this “smart reagent” could facilitate biomarker discovery, accelerate efforts to understand the role of microRNAs in AD, and have clinical potential as a diagnostic or monitoring tool for validated biomarkers.

中文翻译：

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用于检测阿尔茨海默病相关 microRNA 的基于 DNA 的智能试剂

阿尔茨海默病 (AD) 是最常见的神经退行性疾病，大量研究工作致力于确定用于临床诊断和治疗的新生物标志物。MicroRNA 已成为可能的 AD 疾病调节剂和生物标志物，现在被认为在与疾病进展相关的几个生物学过程中发挥作用。在这项工作中，我们使用了miRacles测定法（micro R NA激活条件循环工程女巫）用于单步检测 AD 相关的 microRNA。该技术基于构象响应 DNA 纳米开关，该开关在识别目标 microRNA 时循环并通过电泳读数报告其开/关状态。与许多方法不同，我们的方法无需扩增或标记即可直接检测天然 microRNA，无需昂贵的酶、试剂和设备。对于已知的与 AD 相关的 microRNA miR-107，我们展示了约 8 fM 的灵敏度、同一家族的四个相似 microRNA 之间的特异性，以及这四个 microRNA 靶标的同时多重检测。在临床应用方面，我们筛选了 56 种与 AD 相关的 microRNA，发现其中 4 种在来自人类健康和 AD 脑样本的总 RNA 提取物中显示出可检测的差异。在 AD 的背景下，