Identification of microRNAs in bovine faeces and their potential as biomarkers of Johne’s Disease

Abstract

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.

Detection of latent forms of Mycobacterium avium subsp. paratuberculosis infection using host biomarker-based ELISAs greatly improves paratuberculosis diagnostic sensitivity

“…The potential of emerging -omic approaches to complement and enhance the diagnosis of MAP infection in cattle has been previously reviewed [23]. Host biomarkers, identified using transcriptomics and proteomics, have been proposed as tools to develop novel diagnostic methods for PTB [25][26][27][28][29][30][31][32][33][34][35][36]. However, the application of those biomarkers for PTB diagnosis has yet to be developed and properly validated for naturally infected cattle in various stages of infection [37].…”

Bovine Intelectin 2 Expression as a Biomarker of Paratuberculosis Disease Progression

“…Consequently, novel diagnostic tools with high sensitivity and specificity are needed to improve the diagnostic and control of the disease. Emerging -omic technologies have been used for the identification of host biomarkers [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ] that could help to understand the factors that determine disease progression from the latent to the patent form of infection and could be used in biomarker-based diagnostic methods for PTB. However, most of these biomarkers have not yet been applied and validated for PTB diagnosis in naturally infected cattle.…”

Johne's Disease in Dairy Cattle: An Immunogenetic Perspective

“…The cows classified as infected were ELISA and fecal culture positive, and both exposed and unexposed cows were ELISA negative but were from JD positive and negative herds, respectively. In another study, three differentially expressed miRNAs were identified in bovine feces with JD diagnostic potential (124). Alongside miRNA, long non-coding RNAs (lncRNA) constitute another type of noncoding RNA that function as regulators of gene expression.…”