Abstract
Purpose:
In our previous work, we have demonstrated that the blood-retinal barrier (BRB) is established in zebrafish at 3 days postfertilization (dpf), and integrity of the BRB can be visualized in vivo using a transgenic zebrafish line, Tg(l-fabp:DBP-EGFP). The purpose of this study is to determine whether retinoic acid (RA) signaling is important for the BRB.
Methods:
The l-fabp:DBP-EGFP embryos were treated with 5-20 uM DEAB or BMS 493, two specific inhibitors of the RA signaling, with or without all-trans retinoic acid (ATRA) from 2 dpf. From 5 to 7 dpf, leakage of the EGFP was detected under a fluorescent microscope. The RA signaling was also knocked down in the Tg(hsp:Cyp26a1) zebrafish to test its function the BRB.
Results:
The treatment of DEAB or BMS 493, results in non-functional BRB in 63-95% fish, while 0.5 uM ATRA can effectively rescue the BRB development. Similarly, the BRB can be disrupted in the Tg(hsp:Cyp26a1) zebrafish, either at embryonic or larval stage. The expression of the claudin-5 and ZO-1, two markers of the BRB, is also decreased in the fish treated with the inhibitors.
Conclusions:
These results demonstrate that the RA signaling is essential in development and maintenance of the zebrafish BRB.
Keywords: 698 retinal development •
452 choroid