Diagnostic marker development of tRNA-derived fragments in cerebrospinal fluid and blood serum. Diagnostic marker development of tRNA-derived fragments in cerebrospinal fluid and blood serum

The development of non-invasive diagnostic methods is crucial in early disease detection and thus better treatment options. Small RNAs have been identified as good candidates for such diagnostic markers due to their small size, which allows ease of transport from live cells. Correlating small RNAs in bodily fluid with those in tissue cells of interest may even shed light on disease mechanisms and the development of therapeutic targets. tRNA-derived RNA fragments (tRFs), a family of recently discovered small non-coding RNAs (sncRNAs), have been found to be significantly changed in various disease states, including Alzheimer's disease (AD), the most common type of dementia. Previously, tRFs have been found to be significantly enhanced in human AD hippocampus tissues. However, whether tRFs change in body fluids is unknown. In this study, we planned to identify baselines for potential usage of tRFs as biomarkers in cerebrospinal fluid and blood serum for future development of AD biomarkers. Towards this goal, we used T4 polynucleotide kinase-RNA-seq, a modified next-generation sequencing technique, to identify detectable tRFs in human cerebrospinal fluid (CSF) and serum samples. Interestingly, we found an abundance of tRFs in both CSF and serum samples in comparison to microRNAs, well-known small RNAs (about 3-10 times higher in read counts). This clearly indicates the significant potential of tRFs as non-invasive biomarkers in CSF and serum. Overall design: We obtained CSF samples through the National Institutes of Health (NIH) NeuroBioBank (https://neurobiobank.nih.gov/). Serum samples were requested and obtained from the Texas Alzheimer's Research and Care Consortium (TARCC).

无创诊断方法的开发对于疾病早期检测并优化治疗方案至关重要。小RNA（small RNAs）因体积小巧、可轻松从活细胞中释放转运，已被证实为理想的诊断标志物候选对象。将体液中的小RNA与目标组织细胞中的小RNA进行关联分析，甚至可为阐明疾病发病机制及开发治疗靶点提供新思路。tRNA衍生RNA片段（tRNA-derived RNA fragments, tRFs）是一类新近发现的小型非编码RNA（small non-coding RNAs, sncRNAs）家族，研究发现其在包括阿尔茨海默病（Alzheimer's disease, AD）在内的多种疾病状态中存在显著异常表达——阿尔茨海默病是最常见的痴呆类型。既往研究已证实，tRFs在人类阿尔茨海默病海马组织中呈显著高表达。然而，体液中的tRFs是否会发生类似变化仍属未知。本研究旨在确立tRFs作为脑脊液与血清生物标志物的应用基线，以推动未来阿尔茨海默病生物标志物的开发工作。为此，我们采用T4多核苷酸激酶-RNA测序（T4 polynucleotide kinase-RNA-seq）这一改良型下一代测序技术，对人类脑脊液（cerebrospinal fluid, CSF）与血清样本中的可检测tRFs进行鉴定。有趣的是，相较于广为人知的microRNAs（miRNAs），我们在脑脊液与血清样本中均检测到了大量的tRFs，其读段计数约为microRNAs的3至10倍。这一结果清晰表明，tRFs作为脑脊液与血清无创生物标志物具备巨大应用潜力。整体实验设计：我们通过美国国立卫生研究院（National Institutes of Health, NIH）神经生物样本库（https://neurobiobank.nih.gov/）获取脑脊液样本。血清样本则由德克萨斯阿尔茨海默病研究与护理联盟（Texas Alzheimer's Research and Care Consortium, TARCC）提供并获取。