Characterization of glucocorticoid receptor 1 and 2 under stress in Orange-spotted grouper (Epinephelus coioides)

Orange-spotted grouper, Epinephelus coioides, is one of the commercially important aquaculture fish in Asia. For successful aquaculture it is important to minimize stress. Due to inflammation is one of the important innate immunity in fish and tumor necrosis factor (TNF1) is first been expressed under stress in teleosts. The aim is to understand the characterization of the modulation of glucocorticoid pathway involved in modulating inflammation cytokine under stress condition.

GR1 and GR2 are cloned from Epinephelus coioides. Cortisol produce their effect on responsive cells by acting through the glucocorticoid receptor, which regulates the transcription of target genes. Upon hormone binding, the GR translocates to the nucleus, where it acts as a transcription factor. The GR binds DNA at glucocorticoid response elements in the promoter regions of corticosteroid responsive genes, inducing transcription. Two GR gene regulations in response to cortisol treatment was analysis by real-time PCR. Immune stimulate of tumor necrosis factor 1, GR1 and GR2 in cortisol-treatment grouper compared with healthy grouper during 48 hours post-treatment. We used to FRET experiment conclude that cortisol exerts their influences by binding to the grouper GR and associating with HSP90AB, capable of regulating several genes. These findings have implications that biological effects of cortisol involve cross-talk with inflammatory and immune responses during nodavirus infection.