An animal model of coronary heart disease has been developed where
myocardial infarct can be induced by altering the animal's diet. In all
embodiments, this animal model is a result of reduced activity of
scavenger receptor class BI (SR-BI) and apolipoprotein E (ApoE). In a
preferred embodiment, the model is a result of crossbreeding two
transgenic mouse lines: a knockout of SR-BI (SR-BI-/-) and an impaired
ApoE expressor (hypoE). The impaired ApoE gene results in only 2-5%
expression of ApoE and a reduction in cholesterol homeostasis. Resulting
animals are predisposed to hypercholesterolemia but can live longer than
a year on a normal low fat diet. Serum plasma levels can be significantly
elevated by changing the animal's diet to one containing high levels of
fat and cholesterol. Within a month on a high fat, high cholesterol diet,
animals develop atherosclerosis and myocardial infarction occurs.
Survival depends on the nature of the diet and the conditions of animal
husbandry and can typically be around 20-30 days after administration of
the modified diet depending on the specific conditions. Housing the
animals alone or in groups significantly affects survival of these
animals on a high fat diet. Analysis of B- and T-cell deficient
SR-BI/ApoE/RAG2 triple knockout mice established that B- and
T-lymphocytes do not play a key role in the pathophysiology of the SR-BI
ApoE dKO model of human disease. These animal models can be used to study
mechanisms and progression of CHD as a function of diet, treatment with
drugs to be screened for efficacy or undesirable side effects, and social
environmental effects.