Microarray based gene expression analysis of Sus Scrofa duodenum exposed to zearalenone: significance to human health

Abstract

BackgroundZearalenone (ZEA) is a secondary metabolite produced by Fusarium species. ZEA was proved to exert a wide range of unwanted side effects, but its mechanism of action, particularly at duodenum levels, remains unclear. In our study based on the microarray technology we assessed the alteration of gene expression pattern Sus scrofa duodenum which has been previously exposed to ZEA. Gene expression data was validated by qRT-PCR and ELISA. The gene expression data were further extrapolated the results to their human orthologues and analyzed the data in the context of human health using IPA (Ingenuity Pathways Analysis).ResultsUsing Agilent microarray technology, we found that gene expression pattern was significantly affected by ZEA exposure, considering a 2-fold expression difference as a cut-off level and a p-value < 0.05. In total, we found 1576 upregulated and 2446 downregulated transcripts. About 1084 genes (764 downregulated and 751 overexpressed) were extrapolated to their human orthologues. IPA analysis showed various altered key cellular and molecular pathways. As expected, we observed a significant alteration of immune response related genes, MAPK (mitogen activate protein kinases) pathways or Toll-Like Receptors (TLRs). What captured our attention was the modulation of pathways related to the activation of early carcinogenesis.ConclusionsOur data demonstrate that ZEA has a complex effect at duodenum level. ZEA is able to activate not only the immune response related genes, but also those relate to colorectal carcinogenesis. The effects can be more dramatic when connected with the exposure to other environmental toxic agents or co-occurrence with different microorganisms.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-2984-8) contains supplementary material, which is available to authorized users.

Acute Exposure to Zearalenone Disturbs Intestinal Homeostasis by Modulating the Wnt/β-Catenin Signaling Pathway

“…No information is available on how signaling is regulated in pig, but up-regulation of the most important target genes, such as c-Myc and Cyclin D1, confirms that down-regulation of TCF4 is not essential for β-catenin-mediated transcriptional activation. We also observed significant up-regulation of the expression of ATP6AP2, a protein that is necessary for the facilitation of the transmission of Wnt/β-catenin signaling [35], and whose ZEN-dependent up-regulation has already been observed in the pig duodenum [12]. Our results suggest that the activation of Wnt signaling could be mediated by the up-accumulated ERα, since it is known that ERα down-regulates the Wnt inhibitor DKK1.…”

“…We observed no signs of inflammation either at the gene expression level (interleukins 8, 17, 18, 22, TNF-α, interferon gamma, Lipocalin 2, S100A8, S100A12) or at the protein level (IL-17α, IL-8, serum amyloid A3 and alpha-acid glycoprotein alpha 1). Significant down-regulation of inflammatory cytokines has also been reported in the duodenum of pigs exposed to ZEN [12]. These results could be linked to the ZEN-induced activation of ERα signaling, which has anti-inflammatory effects [60,61].…”

“…The ZEN-mediated induction of inflammation has already been studied in different tissues in immune cells [10,11], the spleen [57,58], the liver, [11] and the intestine [8,12,30,59]. We observed no signs of inflammation either at the gene expression level (interleukins 8, 17, 18, 22, TNF-α, interferon gamma, Lipocalin 2, S100A8, S100A12) or at the protein level (IL-17α, IL-8, serum amyloid A3 and alpha-acid glycoprotein alpha 1).…”

“…ZEN is more dependent on the activation of the estrogen receptor (ER) signaling pathway, which has an anti-inflammatory [8,11,12], anti-apoptotic and proliferating effect [3,13,14]. ER is a ligand-activated transcriptional factor, and signaling is mainly activated directly upon DNA binding in the estrogen response elements located in target genes, but also indirectly (not involving DNA binding) through interaction with other signaling pathways [15][16][17].…”

“…In vivo, whereas some authors found no morphologic changes [28,29], others found that chronic exposure of pigs to ZEN led to transient morphological modifications in the small intestine during the first weeks of exposure [29], or to an increase in the number of Paneth cells at the bottom of the intestinal crypts [28]. At the cellular and molecular level, several reports have described changes in the gene expression of pro-inflammatory cytokines, genes implicated in the induction of a proliferative state such as Dickkopf-related protein 1 (DKK1), β-catenin or the proto-oncogene c-Myc [8,12,30]. Taken together, these results suggest that ZEN can induce transient proliferation in the small intestinal crypt, which could be connected with pro-cancerogenic changes in wingless-type MMTV integration site family (Wnt)/β-catenin and transforming growth factor β (TGF-β) signaling pathways.…”