Plasma microRNAs as non-invasive biomarkers in bovine endometritis caused by Gram-negative and Gram-positive bacteria

The purpose was to identify differentially expressed plasma microRNAs (miRNAs) in cows with clinical and subclinical endometritis. In this study clinical endometritis (CE; n = ۲۳) based on vaginal discharge score (VDS), subclinical endometritis (SCE; n = ۱۷) based on VDS (۰), and endometrial cytology (the presence of ۸.۰۰% polymorphonuclear neutrophils (PMN) on days ۲۱-۳۱ and ۵.۰۰% on days ۴۱-۵۱ days in milk (DIM) and healthy cows (n = ۲۱) based on vaginal discharge score (۰), and endometrial cytology (< ۵.۰۰% PMN on days ۲۱ - ۳۱ and < ۵.۰۰% on days ۴۱ - ۵۱ DIM) were selected. The results showed that the expression level of miR-۱۴۶a was significantly higher in the CE (۱۹.۱۷-fold), and SCE (۶.۲۲-fold) groups than those of healthy cows. The relative transcript abundance of miR-۲۲۳ was considerably down-regulated in the CE (۰.۲۶-fold) and SCE (۰.۰۶-fold) compared to the healthy cows. The expression levels of miR-۱۴۶a and miR-۲۲۳ were significantly higher in the CE group which could be caused by Gram-negative bacterial infection. Our results showed that the expression level of plasma miRNAs postpartum could be used as a reliable marker to distinguish between SCE, CE and healthy cows.

Keywords:

Bacteria , Dairy cattle , Endometritis , MicroRNAs , Plasma