Expression of fibrillin-1 in congenital bicuspid aortic valves

Abstract

To detect the expression of fibrillin-1 in congenital bicuspid aortic valves, and to investigate the molecular mechanism of congenital bicuspid aortic valves. Specimens of aortic valve were obtained from 12 pediatric patients with congenital bicuspid aortic valve, 11 boys and 1 girl, aged 16.7 (10 - 18), including 5 cases of aortic stenosis (AS), 8 of aortic insufficiency (AI), and 1 of AS and AI, undergoing valve replacement, 8 children who died accidentally without cardiovascular system and collagen system diseases, 6 boys and 2 girls, aged 9.1 (1 - 17), collected in autopsy [normal (tricuspid) aortic valve controls], and 18 pediatric patients of rheumatic valvular heart disease with diseased tricuspid aortic valves who underwent aortic valve replacement, 13 boys and 5 girls, aged 16.5 (12 - 18) (rheumatic valvular heart disease controls). HE staining and light microscopy were conducted. Immunohistochemistry was used to detect the expression of fibrillin-1 in the aortic valves. Microscopy showed that the tissue structure of the congenital bicuspid aortic valves was unclear with hyperplasia of fibrous tissue. The grey degree value of fibrillin-1 of the congenital bicuspid aortic valve group was 170 +/- 10, significantly lower than those of normal aortic valve group and diseased tricuspid aortic valve group (126 +/- 8 and 73 +/- 16 respectively, both P < 0.05). There were not significant difference in the grey degree value of fibrillin-1 among the patients of congenital bicuspid aortic valves with AS, AI, and AS + AI (167 +/- 6, 171 +/- 8, and 168 +/- 6 respectively). The expression of fibrillin-1 is significantly reduced in congenital bicuspid aortic valves which may contribute to the morphological changes of the aortic valve leaflets and their resultant functional failure in congenital bicuspid aortic valves.