Analysis of the miRNA Expression Profiles in the Zearalenone-Exposed TM3 Leydig Cell Line.

Mingyang Wang,Weiwei Wu,Si Chen,Jia Chen,Sheng Huang,Lin Li,Shuhua Yang,Peng Li,Jianbin He,Miao Long

doi:10.3390/ijms20030635

Abstract

Zearalenone (ZEN), an important environmental pollutant, can cause serious harm to human and animal health. The aim of our study was to examine the effect of zearalenone (ZEN) on miRNA expression profiles in the mouse Leydig cell line (TM3 Leydig cell line) by miRNA sequencing. The effect of ZEN on the viability of TM3 Leydig cells was verified by Cell Counting Kit-8 (CCK-8). MiRNA sequencing was performed 24 h after the exposure of TM3 Leydig cells with 50 μmol/L of ZEN. Bioinformatics predicted the miRNA target genes, performed Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, and conducted miRNA-gene-pathway mapping to show the relationship between miRNA, the target gene, and the signalling pathway. The expression levels of miRNA and the miRNA target genes associated with ZEN toxicology were verified by quantitative real-time polymerase chain reaction. The miRNA sequencing revealed a significant change (p < 0.05) in the 197 miRNAs in the ZEN-treated and control groups, among which 86 were up-regulated and 111 were down-regulated. GO analysis of the target genes of these miRNAs indicated various biological functions. KEGG analysis showed that the predicted miRNA target genes were involved in signalling pathways, such as cancer, apoptosis, and oxidation, namely, the Ras signalling pathway, Rap1 signalling pathway, PI3K-AKT signalling pathway, Foxo signalling pathway, and AMPK signalling pathway. These results suggest that ZEN, as an estrogen-like toxin, is regulated by microRNAs. Our results can help to examine the toxicological effects of ZEN-regulated miRNAs on germ cells.

Highlights

Zearalenone (ZEN) is a mycotoxin produced by Fusarium fungi [1,2]
The miRNA deep sequencing analysis was used to identify the differential expression of miRNAs in the TM3 Leydig cells between the ZEN-treated and control groups
No studies have shown that ZEN induces germ cell apoptosis through the PI3K-AKT signalling pathway and the Foxo signalling pathway, our study provides strong evidence of ZEN being able to induce germ cell apoptosis through the PI3K-AKT signalling pathway and the Foxo signalling pathway

Summary

Introduction

Zearalenone (ZEN) is a mycotoxin produced by Fusarium fungi [1,2]. The structure of ZEN is similar to that of 17β-oestradiol: ZEN competitively binds to estrogen receptors and activates the transcription of estrogen-responsive genes [3,4]. ZEN may cause reproductive problems, such as ovarian dysfunction, decreased fertility, early abortion, reduced litter size, lower testicular weight, decreased motility of spermatozoa, and a lower total motile sperm count [5,6,7]. These reproductive toxicities are all related to the ZEN interference with the binding site of estrogen. Fan et al demonstrated that ZEN-induced intestinal inflammation was mediated by NLRP3 and that ZEN could affect cell apoptosis and autophagy by regulating target genes and signalling pathways [9]. The toxic effects of ZEN on animal organisms, such as oxidative stress, inflammatory response, apoptosis, and autophagy, need to be explained further by toxicological mechanisms

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