A mouse model of aortic angioplasty for genomic studies of neointimal hyperplasia

We describe here a mouse model of diffuse aortic remodelling triggered by combined endothelial denudation/vascular distension injury using a novel balloon microcatheter. We validated this model in both outbred (NMRI) and inbred (BALB/c, C57BL/6) mouse strains and found evidence for differential strain susceptibility to neointimal hyperplasia, possibly attributable to genetic factors. Neointimal lesions were approximately 50% smaller in the inbred strains, a finding associated with profound cell loss in the aortic media at the early stages of the response to injury. A further insight from this model suggests an essential role for platelets in the initiation of neointimal hyperplasia, which apparently progresses through monocyte influx from the peripheral circulation. Our findings are consistent with monocyte recruitment driving neointimal growth, a minority expressing the endothelial cell marker FVIII. Overall, the time course and gross histological features of vascular remodelling seen here resemble those seen in other rodent models. However, this new mouse model offers distinct advantages over existing ones in that it involves the actual use of a catheter in a clinical manner, and because it allows the recovery of intact RNA from injured vessels in sufficient quantities for downstream molecular analyses.