Glycosaminoglycan myxomatous mitral profiles of leaflets and chordae parallel the severity of mechanical alterations
Glycosaminoglycan myxomatous mitral profiles of leaflets and chordae parallel the severity of mechanical alterations
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DOI：
10.1016/s0735-1097(03)00626-0
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发表时间：
2003-07-16
影响因子：
24
通讯作者：
Vesely, I
中科院分区：
文献类型：
--
作者：
Grande-Allen, KJ;Griffin, BP;Vesely, I
本生物化学研究比较了正常二尖瓣和粘液瘤二尖瓣的细胞外基质与单叶脱垂（ULP）或双叶脱垂（BLP）。背景粘液瘤二尖瓣比正常瓣膜更脆弱和更可伸展，粘液瘤腱索比小叶更机械受损。尽管组织学证据表明，糖胺聚糖（GAG）积累在粘液瘤瓣膜，以前的生化分析没有充分研究不同的GAG classes.METHODS小叶和腱索粘液瘤瓣膜（n = 41 ULP，31 BLP）和正常瓣膜（n = 27）进行干燥，溶解，并测定脱氧核糖核酸，胶原蛋白和总GAG。用选择性酶标记和荧光辅助糖电泳分析特异性GAG类。结果腱索的生化变化比小叶更明显。粘液瘤小叶和腱索的含水量比正常值高3%至9%，GAG浓度高30%至150%。粘液瘤瓣膜中胶原蛋白浓度略有升高。腱索从ULP有62%以上的糖胺聚糖比那些从BLP，主要是从透明质酸和软骨素-6-sulfate.CONCLUSIONS的水平升高的GAG类升高粘液瘤腱索与基质的微观结构和弹性纤维的缺陷，并可能影响这些组织的水化相关的“软”的性质。这些异常可能与粘液瘤腱索的机械性无力有关。ULP和BLP之间的生化差异证实了以前的机械和超声心动图的区别。(C)2003年由美国心脏病学会基金会。
OBJECTIVES This biochemical study compared the extracellular matrix of normal mitral valves and myxomatous mitral valves with either unileaflet prolapse (ULP) or bileaflet prolapse (BLP).BACKGROUND Myxomatous mitral valves are weaker and more extensible than normal valves, and myxomatous chordae are more mechanically compromised than leaflets. Despite histological evidence that glycosaminoglycans (GAGs) accumulate in myxomatous valves, previous biochemical analyses have not adequately examined the different GAG classes.METHODS Leaflets and chordae from myxomatous valves (n = 41 ULP, 31 BLP) and normal valves (n = 27) were dried, dissolved, and assayed for deoxyribonucleic acid, collagen, and total GAGs. Specific GAG classes were analyzed with selective enzyme digestions and fluorophore-assisted carbohydrate electrophoresis.RESULTS Biochemical changes were more pronounced in chordae than in leaflets. Myxomatous leaflets and chordae had 3% to 9% more water content and 30% to 150% higher GAG concentrations than normal. Collagen concentration was slightly elevated in the myxomatous valves. Chordae from ULP had 62% more GAGs than those from BLP, primarily from elevated levels of hyaluronan and chondroitin-6-sulfate.CONCLUSIONS The GAG classes elevated in the myxomatous chordae are associated with matrix microstructure and elastic fiber deficiencies and may influence the hydration-related "floppy" nature of these tissues. These abnormalities may be related to the reported mechanical weakness of myxomatous chordae. The biochemical differences between ULP and BLP confirm previous mechanical and echocardiographic distinctions. (C) 2003 by the American College of Cardiology Foundation.