In vitro exposure to copper induced changes in immune and steroidogenic gene expression in sparus aurata head kidney cells

Changes in the transcription of selected genes in fish can be used as indicators of the sublethal impact of metals. In this study, head kidney cells of Sparus aurata (Gilthead sea bream) were exposed to copper in vitro to evaluate steroidogenic and immune functions by measuring changes in gene transcription of steroidogenic acute regulatory protein (StAR) and in cytokines, respectively. Cortisol was measured in the incubation medium. As a preliminary step, a cell viability experiment set LC50-1h for copper at 3.55 mM. After incubating the head kidney cells for 1 h with 0.001 or 0.1 mM of copper, the previous parameters were assessed. Exposure to the highest copper concentration caused an upregulation of StAR gene transcription, whereas the Cortisol levels in the incubation medium remained unaltered. Copper also caused changes in immune related genes, as the expression of interleukin-lß and transforming growth factor-ß1 was increased at 0.001 and 0.1 mM of copper, respectively. On the other hand, both copper concentrations induced a decrease in the transcription of interleukin-6. These results reveal an altered immune function, giving new insights onto the mechanisms involved. © by PSP.