MicroRNA biomarkers of tissue function

In recent years circulating miRNAs have been proposed as biomarkers of several diseases in humans. However the origin of these potential biomarkers is not always investigated and recent studies have highlighted the importance of selecting biomarkers which are not blood-cell derived to ensure robust performance. The aim of this study was identify circulating miRNAs which are not blood-cell derived (highly expressed in plasma compared to whole blood cells in cow) and investigate the expression of a selection of those in a range of bovine tissues as a follow-up to these results. Overall design: In this experiment a total of 8 bovine samples (4 blood cell samples and 4 plasma samples) were analysed using Illumina miRNA sequencing. These samples were collected from healthy cycling heifers during a normal oestrous cycle from each of 4 animals (the samples are paired). Therefore this study included 4 biological replicates for each of the two groups analysed.