Altered Expression of beta3 Integrin on Sclerotic Aortic Valves in a Hypercholesterolemic Rabbit Model / 대한흉부외과학회지

ABSTRACT

BACKGROUND: Although aortic valve sclerosis causes no significant hemodynamic alterations, it is associated with an increased risk of cardiovascular death and myocardial infarction. However, the role of beta3 integrin in aortic valve sclerosis remains unclear. MATERIAL AND METHOD: Twenty male New Zealand rabbits were divided into two groups. Group 1 rabbits (n=10) received a normal chow diet, while group 2 (n=10) rabbits received a diet containing 1% cholesterol for 12 weeks. After the rabbits were euthanized, their aortic valves and ascending aortas were excised for analysis. RESULT: Total serum cholesterol (2,148.3+/-1,012.5 mg/dL versus 53.7+/-31.8 mg/dL, p<0.05), triglyceride (240.4+/-218.3 mg/dL versus 31.6+/-6.4 mg/dL, p<0.05), and low density lipoprotein (LDL)-cholesterol (2,065.3+/-960.9 mg/dL versus 29.1+/-30.9 mg/dL, p<0.05) levels were significantly higher in the cholesterol diet group compared with the normal diet group. Myofibroblasts and macrophages were more highly expressed in the aortic valve leaflets of rabbits in the cholesterol diet group than of those in the normal diet group. A real-time polymerase chain reaction revealed decreased beta3 integrin mRNA levels in the hypercholesterolemic aortic valves and aortas. CONCLUSION: The present study shows that hypercholesterolemia induces aortic valve sclerosis. These findings suggest that alterations in beta3 integrin may play a role in the development of aortic valve sclerosis.