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Abstract

Angiogenesis is necessary for tumor growth, making inhibition of vessel formation an excellent target for cancer therapy. Current assays for angiogenesis, however, are too complex to be practical for drug screening. Here, we demonstrate that the zebrafish is a viable whole animal model for screening small molecules that affect blood vessel formation. Blood vessel patterning is highly characteristic in the developing zebrafish embryo and the subintestinal vessels (SIVs) can be stained and visualized microscopically as a primary screen for compounds that affect angiogenesis. Small molecules added directly to the fish culture media diffuse into the embryo and induce observable, dose-dependent effects. To evaluate the zebrafish as a model, we used two angiogenesis inhibitors, SU5416 and TNP470, both of which have been tested in mammalian systems. Both compounds caused a reduction in vessel formation when introduced to zebrafish embryos prior to the onset of angiogenesis. Short duration (1 h) exposure of SU5416 was sufficient to block new angiogenic and vasculogenic vessel formation. In contrast, TNP470 required continuous exposure to block SIV formation and had no apparent effect on vasculogenic vessel formation. To ascertain whether blood vessels in the zebrafish embryo respond to angiogenic compounds, we introduced human VEGF into embryos. Injection of VEGF caused an observable increase in SIV formation.

Distinct genetic interactions between multiple Vegf receptors are required for development of different blood vessel types in zebrafish

“…Interestingly, we find that embryos exposed to the pan-Vegf receptor inhibitor SU5416, which blocks the catalytic activity of the three mammalian Vegf receptors (32) and prevents angiogenesis in zebrafish embryos (33), completely eliminates segmental artery formation at 30 hpf in wild-type TG(fli1:egfp) y1 embryos ( Fig. 1G).…”

Zebrafish as a model system for biomedical studies

“…Сосуды эмбриона могут быть прокрашены и визуализированы под микроскопом. Визуализировать сосудистую систему можно с помощью специфических флуоресцирующих микросфер, которые не проникают внутрь сосудов, но связываются с их поверхностью [23]. Помимо этого, для исследования ангиогенеза используют трансгенных рыбок с экспрессированным зелёным флуоресцентным белком кораллового рифа [2,24,25].…”

Neuropilin-1 is required for vascular development and is a mediator of VEGF-dependent angiogenesis in zebrafish

“…The zebrafish vascular system is advantageous for study because of the transparency of the embryos and the rapid development of a functional circulatory system (16). Functional analysis is facilitated by the ability to readily introduce small compounds into embryos to antagonize protein function-e.g., antisense morpholino oligonucleotides that specifically blocks a protein's translation (17) and VEGFR-2 kinase inhibitors that inhibit VEGF activity (18). Embryos treated with antisense morpholinos targeting VEGF showed a marked loss of developing blood vessels during vascular development (19).…”