Gene Expression Profiling in Spleens of Deoxynivalenol-Exposed Mice: Immediate Early Genes as Primary Targets

Abstract

Exposure to the trichothecene mycotoxin deoxynivalenol (DON) alters immune functions in vitro and in vivo. To gain further insight into DON's immunotoxic effects, microarrays were used to determine how acute exposure to this mycotoxin modulates gene expression profiles in murine spleen. B6C3F1 mice were treated orally with 25mg/kg body weight DON, and 2h later spleens were collected for macroarray analysis. Following normalization using a local linear regression model, expression of 116 out of 1176 genes was significantly altered compared to average expression levels in all treatment groups. When genes were arranged into an ontology tree to facilitate comparison of expression profiles between treatment groups, DON was found primarily to modulate genes associated with immunity, inflammation, and chemotaxis. Real-time polymerase chain reaction was used to confirm modulation for selected genes. DON was found to induce the cytokines interleukin (IL)-1alpha, IL-1beta, IL-6 and IL-11. In analogous fashion, DON upregulated expression of the chemokines macrophage inhibitory protein-2 (MIP-2), cytokine-induced chemoattractant protein-1 (CINC-1), monocyte chemoattractant protein (MCP)-1, MCP-3, and cytokine-responsive gene-2 (CRG-2). c-Fos, Fra-, c-Jun, and JunB, components of the activator protein-1 (AP-1) transcription factor complex, were induced by DON as well as another transcription factor, NR4A1. Four hydrolases were found to be upregulated by DON, including mitogen-activated protein kinase phosphatase 1 (MKP1), catalytic subunit beta isoform (CnAbeta), protein tyrosine phosphatase receptor type J (Ptprj), and protein tyrosine phosphatase nonreceptor type 8 (Ptpn8), whereas three other hydrolases, microsomal epoxide hydrolase (Eph) 1, histidine triad nucleotide binding protein (Hint), and proteosome subunit beta type 8 (Psmb8) were significantly decreased by the toxin. Finally, cysteine-rich protein 61 (CRP61) and heat-shock protein 40 (Hsp40), genes associated with signaling, were increased, while Jun kinase 2 (JNK2) was decreased. Taken together, data suggest that DON upregulated the expression of multiple immediate early genes, many of which are likely to contribute to the complex immunological effects reported for this and other trichothecenes.

The In Vitro Approach to the Cytotoxicity of a Trichothecene Mycotoxin Nivalenol

“…Kinser et al reported that deoxynivalenol upregulated the MCP-1 mRNA in mouse spleen cells 4 , however, they did not document the secretion of MCP-1.…”

Toxicogenomics and cancer pathogenesis

“…DON was found to induce the cytokines interleukin (IL)-1alpha, IL-1beta, IL-6 and IL-11.DON upregulated expression of the chemokines macrophage inhibitory protein-2 (MIP-2), cytokine-induced chemoattractant protein-1 (CINC-1), monocyte chemoattractant protein (MCP)-1, MCP-3, and cytokine-responsive gene-2 (CRG-2). c-Fos, Fra-, c-Jun, and JunB, components of the activator protein-1 (AP-1) transcription factor complex, were induced by DON as well as another transcription factor, NR4A1 [41,44].…”

Immuno-Modulatory Effects of Phytomedicines Evaluated Using Omics Approaches

“…Many differentially expressed genes are known to play a role in apoptosis, host defense, cell growth and differentiation, and trafficking of specific cells in body fluid systems. In the spleen, these may include the up-regulation of IL-18, lymphotoxin B receptor, and colonystimulating factor receptor, and down-regulation of RANTES and histocompatibility antigens [15,[33][34][35]. In the thymus, gene changes included the down-regulation of nuclear factor of activated T cells, interferon gamma receptor, and T cell transcription factor 7, and the up-regulation of caspase 1 and ApoE.…”

“…Gene chips or microarrays are already employed in immunotoxicology research to identify biochemical pathways that are altered by specific chemical exposures. For example, trichothecene mycotoxin deoxynivalenol has been shown in mice to modulate splenic early responsive genes, which are functionally related to immunity, inflammation and chemotaxis [15,26], indicating the importance of innate immune systems, including macrophages, granulocytes, neutrophils and various soluble mediators released in the inflammatory response activated by the hexachlorobenzene treatment. For basic research, a number of mechanistic studies have been performed towards gaining a comprehensive understanding of the immunomodulatory properties of potential new drugs or drug leads.…”

“…Published online 15 Whereas some â€oemicroarray†or â€oebioinformatics†scientists among us may have been criticized as doing â€oecataloging research†, the majority of us believe that we are sincerely exploring new scientific and technological systems to benefit human health, human food and animal feed production, and environmental protections. Indeed, we are humbled by the complexity, extent and beauty of cross-talks in various biological systems; on the other hand, we are becoming more educated and are able to start addressing honestly and skillfully the various important issues concerning translational medicine, global agriculture, and the environment.…”