A Complex Extracellular Sphingomyelinase of Pseudomonas aeruginosa Inhibits Angiogenesis by Selective Cytotoxicity to Endothelial Cells
Figure 8
PlcHR causes cardiovascular effects in the zebrafish.
Transgenic zebrafish embryos expressing EGFP in endothelial cells, (Tg(Fli:EGFP) [41]) were utilized to examine PlcHR effects. (A–H) Embryos at 48 hpf (hours post-fertilization) were injected with 2 ng of PlcHR, or a catalytically inactive mutant PlcHR T178A, and examined over the next 24 h. PlcHR T178A-injected embryos appeared phenotypically similar to controls (A,B). Prime panels denote visualization of EGFP-labeled endothelial cells in the same embryo. (C) At 6 hpi (hours post-injection), embryos injected with PlcHR had little or no circulation and pericardial edema (black arrows). (D) Effects became more pronounced by 24 hpi as intersegmental vessels regress (ISV, white arrows). (E–H) Higher magnification of the ISVs revealed that their lumens collapsed before endothelial cell regression. Representative pictures of embryos from one of three independent experiments; n>20 per condition. Scale bars indicate 250 µm for (A–D), 50 µm for (E–H).