Effects of Kudoa septempunctata infections in a human intestinal epithelial model (Caco-2): a DNA microarray study.

ABSTRACT

Kudoa septempunctata, a myxosporean parasite infecting the trunk muscles of olive flounder (Paralichthys olivaceus), is reported to cause food poisoning in humans. The molecular mechanisms underlying the toxicity of K. septempunctata spores remain largely unknown. In the present study, we examine the molecular basis of such toxicity using DNA microarray analysis of K. septempunctata-inoculated human colon adenocarcinoma cells (Caco-2). We observed that the transepithelial resistance of the K. septempunctata-inoculated Caco-2 cell monolayers decreased markedly. DNA microarray analysis revealed that the mRNA expression profiles of control and inoculated cells clearly differed. Inflammatory and bacteria-related pathways, such as interleukin-8 (IL-8) production and MAPK/NF-kappa B pathway, were enriched. The concentrations of IL-8 and serotonin (5-HT) were higher in inoculated cells than in controls. K. septempunctata invasion damages the human intestinal epithelium, causing increased production of IL-8 and 5-HT, which likely results in the vomiting associated with K. septempunctata invasion.Abbreviations AP-1 activator protein 1; DAVID Database for Annotation, Visualization and Integrated Discovery; ENS enteric nervous system; FARMS Factor Analysis for Robust Microarray Summarization; FDR false discovery rate; GO Gene Ontology; 5-HT 5-hydroxytryptamine; IL-8 Interleukin-8; KEGG Kyoto Encyclopedia of Genes and Genomes; K. septempunctata Kudoa septempunctata; NF-kappa B nuclear factor-kappa B; TJ tight junction; TER transepithelial electrical resistance.