微纤维蛋白1在先天性二叶型主动脉瓣中的表达

目的检测微纤维蛋白1在先天性二叶型主动脉瓣中的表达,探讨先天性二叶型主动脉瓣的分子学机制。方法选取因先天性二叶型主动脉瓣伴主动脉瓣狭窄（AS）和／或主动脉瓣关闭不全（AI）行主动脉瓣置换术切取的儿童二叶型主动脉瓣为研究组（男11例,女1例,年龄10～18岁,平均16．7岁,其中单纯AS 3例、单纯AI 8例、AS-AI 1例）,同期、性别、年龄相近、无心血管系统及胶原系统疾病、意外死亡患儿的正常三叶型主动脉瓣（健康对照组,男6例,女2例,年龄1～17岁,平均9．1岁）和性别、年龄相近风湿性心脏病患儿的主动脉瓣（风心病组,男13例,女5例,年龄12～18岁,平均16．5岁）为对照组,采用免疫组织化学方法检测主动脉瓣标本中微纤维蛋白1表达,经Image-Pro Plus Version 5．0彩色图像分析系统测定标本免疫组织化学染色灰度值,染色越深,灰度值越小,表明阳性越强。结果微纤维蛋白1在主动脉瓣中的表达平均灰度值为：先天性二叶型主动脉瓣组170±10、正常对照组126±8、风心病组73±16,先天性二叶型主动脉瓣组微纤维蛋白1表达显著低于正常对照组和风心病组（均P〈0．05）,风心病组微纤维蛋白1表达显著高于先天性二叶型主动脉瓣组和正常对照组（均P〈0．05）。先天性二叶型主动脉瓣中单纯AS、单纯AI、AS-AI微纤维蛋白1表达的平均灰度值分别为167±6、171±8、168±6,三者之间差异无统计学意义。结论先天性二叶型主动脉瓣微纤维蛋白1表达降低,可能由于先天性合成不足和（或）降解过多所致,因而主动脉瓣形态改变、功能障碍。

Expression of fibrillin-1 in congenital bicuspid aortic valves

OBJECTIVE: To detect the expression of fibrillin-1 in congenital bicuspid aortic valves, and to investigate the molecular mechanism of congenital bicuspid aortic valves. METHODS: 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. RESULTS: 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). CONCLUSION: 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.