miRNA Regulatory Functions in Farm Animal Diseases, and Biomarker Potentials for Effective Therapies

Abstract

MicroRNAs (miRNAs) are small endogenous RNAs that regulate gene expression post-transcriptionally by targeting either the 3′ untranslated or coding regions of genes. They have been reported to play key roles in a wide range of biological processes. The recent remarkable developments of transcriptomics technologies, especially next-generation sequencing technologies and advanced bioinformatics tools, allow more in-depth exploration of messenger RNAs (mRNAs) and non-coding RNAs (ncRNAs), including miRNAs. These technologies have offered great opportunities for a deeper exploration of miRNA involvement in farm animal diseases, as well as livestock productivity and welfare. In this review, we provide an overview of the current knowledge of miRNA roles in major farm animal diseases with a particular focus on diseases of economic importance. In addition, we discuss the steps and future perspectives of using miRNAs as biomarkers and molecular therapy for livestock disease management as well as the challenges and opportunities for understanding the regulatory mechanisms of miRNAs related to disease pathogenesis.

Potential Novel Biomarkers for Mastitis Diagnosis in Sheep

“…MicroRNAs are short, non-coding RNAs, 18-25 nucleotides in length [78], which are known to regulate biological processes. They are responsible for controlling the expression of protein-coding genes and participate in the regulation of many cellular processes in animals; miRNAs regulate gene expression by inhibiting translation initiation or elongation and inducing co-translational protein degradation and premature termination of translation [79]. It includes immune system activity, which in turn makes miRNAs having specific roles in disease and inflammation pathogenesis.…”

“…In farm animal diseases, the miRNA's utility as a biomarker has been recently reviewed [79]. The authors point out that in cattle miRNA can be used in diagnostics (as well as management) of Johne's diseases (JD), bovine viral diarrhea (BVD), and mastitis, while in pigs, miRNAs have been investigated in the case of the porcine reproductive and respiratory syndrome (PRRS), swine influenza and, to a lesser extent, salmonellosis, adenomatosis and colibacillosis [79]. In poultry diseases, the literature describes miRNAs shifts in Marek disease, avian leukosis, bursal disease, and avian influenza [79].…”

“…The authors point out that in cattle miRNA can be used in diagnostics (as well as management) of Johne's diseases (JD), bovine viral diarrhea (BVD), and mastitis, while in pigs, miRNAs have been investigated in the case of the porcine reproductive and respiratory syndrome (PRRS), swine influenza and, to a lesser extent, salmonellosis, adenomatosis and colibacillosis [79]. In poultry diseases, the literature describes miRNAs shifts in Marek disease, avian leukosis, bursal disease, and avian influenza [79]. There are also reports from equine veterinary medicine, that miRNAs can be useful diagnostic tools in different pathologies in horses including osteochondrosis, myopathies, and infertility [81].…”

“…The reports suggest that miRNA profiles might be pathogen-specific demonstrating unique miRNA biomarkers depending on bacteria species. However, these are most in vitro studies performed on bovine epithelial cells [79].…”

“…Although Hao et al [97] studied the profiles of lncRNAs in the mammary gland from ewes and revealed their comprehensive expression to better understand their functions in ovine lactation, there is still a small number of reports on the roles of lncRNAs in ovine mammary gland tissues. As Do et al [79] noticed, there is a downward trend in the sequencing expenses, which may in the future lead to creating more opportunities for sequencing multiple types of molecules such as ncRNAs, miRNAs, mRNAs, and others. This may contribute to increased detection and a better understanding of mastitis pathogenesis among small ruminants, as well as selection and prediction of treatment response.…”