Carotid artery endothelial growth: a novel in vitro assay

Larger species are being used increasingly for cardiovascular research. Pigs have a cardiovascular system with similar anatomy and scale to the human, and a large, gyrencephalic brain. Refinement and reduction of animal numbers is especially important in a large, sentient species, hence in vitro screening tools are vital for optimising protocols, drug doses and transfection methods. For vascular biology, cell lines such as HUVEC and rodent ex vivo cultures are currently available, but we aim to develop an ex vivo system that may be superior to these—a pig carotid ring model of endothelial growth, based on Ottinetti-Nicosia rat aortic ring cultures. This has the advantages of a larger vessel similar in size to human carotid, with multiple cultures produced from a given animal, and direct access for biological reagents (for example, viral vectors, peptides, siRNAs) prior to in vivo use. In this one-year pilot study, we will use surplus carotid tissue to establish the culture system, characterise endothelial cell phenotype, test known modifiers of endothelial proliferation and determine the efficacy of standard lentiviral and HSV-derived vectors. This will allow us to make realistic plans for transgenesis of pig carotid endothelium in vivo.