School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland.
Biosensia, NovaUCD, Belfield Innovation Park, UCD, Dublin, Ireland.
Sci Rep. 2020 Apr 3;10(1):5908. doi: 10.1038/s41598-020-62843-w.
Extracellular microRNAs (miRNAs) are detectable in the peripheral blood and have been touted as potential biomarkers for a range of maladies. The presence and biomarker potential of miRNAs in other biofluids has been less thoroughly explored, particularly in the veterinary realm. Faecal miRNAs are a case in point; while they have been identified largely in rodents and humans, they have not been reported in cattle but may have prognostic or diagnostic value for Johne's Disease (JD) in cattle, a chronic granulomatous inflammation of the ileum caused by Mycobacterium avium subspecies paratuberculosis (MAP). The aim of this study was thus to characterise the bovine faecal miRNome and to determine the utility of these transcripts as biomarkers for JD. Real-time PCR arrays consisting of 752 miRNA targets, optimised for detection of human miRNA, were used to screen RNA purified from faecal samples obtained from confirmed JD clinical cases vs. healthy controls. Two hundred and fifty-eight miRNAs were detected in bovine faeces, three of which are potentially novel orthologs of known human miRNAs. Differential abundance of three miRNA was evident in animals with clinical JD as compared to healthy controls. Our study has therefore identified a variety of miRNAs in bovine faeces and has demonstrated their utility in differentiating healthy animals from those with late-stage JD, providing potential biomarkers for MAP infection and disease progression.
细胞外 microRNAs（miRNAs）可在外周血液中检测到，并被吹捧为多种疾病的潜在生物标志物。miRNAs 在其他生物体液中的存在和生物标志物潜力尚未得到充分探索，特别是在兽医领域。粪便 miRNAs 就是一个例子；虽然它们在啮齿动物和人类中已被广泛识别，但在牛中尚未报道，但它们可能对牛的副结核病（JD）具有预后或诊断价值，副结核病是由分枝杆菌亚种副结核分枝杆菌（MAP）引起的回肠慢性肉芽肿性炎症。因此，本研究旨在描述牛粪便的 miRNome，并确定这些转录物作为 JD 生物标志物的效用。使用针对人 miRNA 检测进行了优化的包含 752 个 miRNA 靶标的实时 PCR 阵列，筛选从确诊 JD 临床病例与健康对照中获得的粪便样本中纯化的 RNA。在牛粪便中检测到 258 种 miRNA，其中三种是已知人类 miRNA 的潜在新型同源物。与健康对照相比，患有临床 JD 的动物中三种 miRNA 的丰度差异明显。因此，我们的研究在牛粪便中鉴定了多种 miRNA，并证明了它们在区分健康动物和晚期 JD 动物方面的效用，为 MAP 感染和疾病进展提供了潜在的生物标志物。
