Selective glucocorticoid-induced attenuation of the inflammatory response in zebrafish

In the present study, we have used the zebrafish to investigate the anti-inflammatory effects of glucocorticoids. An inflammatory response was induced by amputation of the tail fin of 3dpf zebrafish larvae, and the effect of treatment with the glucocorticoid beclomethasone was investigated. A microarray study was performed to study transcriptional changes 4 hours after amputation and the beclomethasone-induced effects on these changes. Our results show that beclomethasone attenuates almost the entire transcriptional response to amputation. Interestingly, the amputation-induced expression of genes involved in leukotriene biosynthesis appears to be resistant to beclomethasone treatment. This microarray study was designed to determine the effect of glucocorticoid treatment on amputation-induced transcriptional changes. For this purpose, the tail fin of 3dpf zebrafish larvae was amputated and 4 hours later larvae were collected. Glucocorticoid treament (25 microM beclomethasone) started two hours before the amputation. This resulted in 4 treament groups: con/veh, amp/veh, con/beclo, amp/beclo. RNA was isolated from 20 larvae per treatment group. Four individual experiments were performed, and the resulting quadruplicate samples were analyzed by microarray, using a common reference approach.