Fig. 7

Upregulated activity of LTB4R promoted inflammatory response and vascular alteration in akr7a3^−/− zebrafish. (A–D) The expression of leukotriene receptors was examined. It revealed that the expression of CysLT1R (A), CysLT2R (B), and CysLT3R (C) were not altered but most gene showed an upregulated trend in akr7a3^−/− group whereas LTB4R (D) was significantly overexpressed. n = 5 clutches with 30 larvae. (E–F) Rescue experiment using antagonist for LTB4R and CysLTs: Antagonists of LTB4R (U-75032) and CysLTs (Quininib) were used to incubate akr7a3^−/− larvae. Treatment with U-75032 significantly reduced the retinal vessel diameter in akr7a3^−/− larvae, whereas Quininib had no significant effect on the retinal vessel diameter in these larvae. n = 20 larvae. (G–J) Representative inflammatory factors were also analyzed with RT-qPCR. IL-1β (G) and TNF-α (H) were significantly overexpressed while IL-6 (I) and M-CSF (J) were increased non-sigificantly in akr7a3^−/− group. n = 5 clutches with 30 larvae.The bars indicate mean ± SD values. Statistical analysis was performed by one-way ANOVA or Student's t-test. CysLTs, Cysteinyl leukotriene receptor 1 (CysLT1R), 2 (CysLT2R), and 3 (CysLT3R); LTB4R, Leukotriene B4 receptor; IL-1β, Interleukin-1 beta; TNF-α, Tumor Necrosis Factor-alpha; M-CSF, IL-6, interleukin 6; Macrophage Colony-Stimulating Factor.