Using zebrafish embryos to find mechanically-regulated genes involved in cardiovascular disease
Atherosclerosis is a chronic disease of the arteries and the leading cause of death in the UK. Atherosclerotic lesions occur at regions of arteries exposed to complex, disturbed blood flow patterns, such as branches and bends. These lesions are initiated by injury and death of vascular endothelial cells lining the inner surface of arteries.
In the arterial regions that are prone to developing atherosclerosis, disturbed flow leads to expression of genes that promote endothelial cell death, whereas in the regions that are protected against atherosclerosis, non-disturbed laminar flow activates protective genes. In this study, Dr Jovana Serbanovic-Canic, John Stokes Postdoctoral Fellow in Professor Paul Evans’ group from the Department of Infection, Immunity & Cardiovascular Disease, tested whether zebrafish embryos can be used as a model for the functional screening of these mechanically-regulated genes.
Researchers discovered that blood flow regulates survival of endothelial cells in the developing vasculature of zebrafish embryos. To select candidates for the functional screening in the zebrafish model, the authors conducted a microarray study to compare gene expression between endothelial cells from non-disturbed and disturbed flow region of the pig aorta. The study found >50 genes regulating cell death to be differentially regulated between the two aortic regions in pigs. Subsequently, 11 genes that showed highest differential expression and possessed a homologue in zebrafish were chosen for the screening study in zebrafish embryos. As a result, 4 genes were identified to be able to protect from (ANGPTL4, CDH13) or promote (PDCD2L, PERP) endothelial cell death in response to blood flow. The findings were validated by studying the expression of these molecules in mouse aortas and by studying their function in human endothelial cells exposed to different flow conditions.
In conclusion, this study has established a novel zebrafish-based model for functional screening of flow-sensitive genes in endothelial cells, thus providing potential therapeutic targets to prevent or treat endothelial injury at athero-prone sites.
The study has been published in journal Arteriosclerosis, Thrombosis and Vascular Biology.
This work was funded by the British Heart Foundation and the University of Sheffield.