Figure 8

The p53 inactivators block the negative regulation of zebrafish BIRC2 on the E. piscicida infection. (A) Pifithrin-μ inhibited the zebrafish BIRC2-mediated bacterial proliferation at 24 hpi. (B) The effect of Pifithrin-μ on the survival rates of zebrafish larvae microinjected with p3×FLAG or BIRC2-FLAG in the case of E. piscicida infection. (C) Pifithrin-α inhibited the zebrafish BIRC2-mediated bacterial proliferation at 24 hpi. (D) The effect of Pifithrin-α on the survival rates of zebrafish larvae microinjected with p3×FLAG or BIRC2-FLAG in the case of E. piscicida infection. For (A–D), 4 dpf larvae microinjected with the p3×FLAG or BIRC2-FLAG were treated by adding Pifithrin-μ or Pifithrin-α for 12 h, and then infected with E. piscicida. For (A, C), larvae were collected at 24 hpi, and used for colony count. Data represented the means ± the SEM (n = 3) and were tested for statistical significance using a two-tailed student’s t -test. **p < 0.01. The asterisk above the error bars indicates statistical significance using the group microinjected with empty plasmid and without treatment as the control group. The asterisk above the bracket indicates statistical significance between the two groups connected by the bracket. For (B, D), larvae were monitored for 5 days. Exposures were performed in triplicate with 20 larvae per repetition (n = 60). Statistical differences using the log-rank test were observed between the FLAG/BIRC2-FLAG groups (p < 0.05), BIRC2-FLAG/BIRC2-FLAG+ Pifithrin-μ groups (p < 0.01), and BIRC2-FLAG/BIRC2-FLAG+ Pifithrin-α groups (p < 0.01).