Small RNA sequencing reveals new mode of action and potential biomarkers for the mycotoxin Zearalenone. Small RNA sequencing reveals new mode of action and potential biomarkers for the mycotoxin Zearalenone

Purpose: The mycotoxin zearalenone (ZEN) poses a risk to animal health because of its estrogenic effects. Diagnosis of ZEN-induced disorders in animal production remains challenging due to the lack of appropriate non-invasive biomarkers. Thus, we combined untargeted and targeted transcriptomics approaches to investigate the effects of ZEN on the microRNA expression in porcine uterus, jejunum and serum. Methods: twenty-four piglets received either uncontaminated feed (Control) or feed containing 0.17 mg/kg ZEN (ZEN low), 1.46 mg/kg ZEN (ZEN medium) and 4.58 mg/kg ZEN (ZEN high) for 28 days. microRNA from uterus and jejunum tissues were profiled by next-generation small RNA sequencing. Serum microRNA expression was analyzed by RT-qPCR analysis. Results: the microRNA expression in the jejunum remained unaffected, while significant changes in the uterine microRNA profile were observed. Importantly, 14 microRNAs were commonly and in a dose-dependent manner affected in both the ZEN medium and ZEN high group, including microRNAs from the miR-503 cluster. Although the effects in the serum were less pronounced, the receiver operating characteristic analysis revealed that several microRNA ratios were able to discriminate properly between non-exposed and ZEN-exposed pigs (e.g. ssc-miR-135a-5p/ssc-miR-432-5p, ssc-miR-542-3p/ssc-miR-493-3p). Conclusions: This work sheds some new light on the molecular mechanisms of ZEN, and fosters biomarker discovery. Overall design: Uterus and jejunum microRNA profiles at 28 days post weaned piglets. For each tissue, 6 biological replicates (= 6 pigs) from Control, 4 from ZEN low, 4 from ZEN medium, and 4 from ZEN high were used for library preparation. The final multiplexed (n=18) libraries were sequenced on a NextSeq 500