Figure 4.

Adrb1 signaling does not alter klf2a expression in ccm2 CRISPR embryos. Tg(klf2a:H2b-EGFP; kdrl:mcherry) embryos were injected and nuclear EGFP signal in mcherry labeled vascular endothelial cells is recorded by confocal. Representative images from each group are shown. (A) Control MO alone injected embryos were used as control. (B and C) Ccm2 morphant embryos co-injected with adrb1 MO (B) or control MO (C) both displayed significant increase of endothelial nuclear EGFP intensity (P<0.0001) compared to that of control (A), and there is no significant difference between them. (D and E) All the ccm2 CRISPR embryos were co-injected with tnnt MO, which are absent of blood flow. Compared to that of control (A), ccm2 CRISPR embryos co-injected with adrb1 MO (D) or control MO (E) both displayed a mosaic increase of nuclear EGFP intensity of vascular endothelial cells compared to control (A) (P<0.0001), and there is no significant difference between them. Arrows indicated the endothelial nuclei with significant higher EGFP intensity than those indicated by arrowheads. Scale bar:100μm. (F) EGFP intensity of endothelial nuclei were quantified with Image J. The number of analyzed nuclei were: 63 from 10 embryos (control MO), 70 from 10 embryos (ccm2 MO+adrb1 MO), 77 from 10 embryos (ccm2 MO+control MO), 93 from 13 embryos (ccm2 CRISPR+adrb1 MO), and 94 from 13 embryos (ccm2 CRISPR+control MO). Statistical analysis is performed by one-way ANOVA followed by Tukey’s multiple comparison test. (G) At 2dpf, 2,3-BDM prevented the CVP cavernoma dramatically. 164 embryos in 2,3-BDM treated group and 177 in control group were used for Two-tailed paired t-test. P=0.0013.