Mohler E R, Chawla M K, Chang A W, Vyavahare N, Levy R J, Graham L, Gannon F H
Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, USA.
J Heart Valve Dis. 1999 May;8(3):254-60.
Cardiac valve calcification is the predominant pathology in patients needing valve replacement. The aim of this study was to determine if aortic valve cells calcify spontaneously and, if so, to characterize the nodular complex and response to growth factors.
Aortic valves were obtained from humans undergoing surgical valve replacement, and from female dogs. The valvular endothelium was removed and explants cultured in medium.
A population of valvular interstitial cells spontaneously formed distinct calcified nodules containing hydroxyapatite within two to three weeks in canine and within six weeks in human aortic valves. The nodules contained an inner ring of dead cells surrounded by an outer ring of living cells. Cells associated with nodules had osteoblast-like characteristics and stained positively for extracellular bone matrix proteins. Incubating canine cells with potential calcifying stimuli tested the stimulus for calcification. The rate of nodule formation was increased with transforming growth factor beta-1 (+25 nodules), 25-hydroxycholesterol (+9 nodules) and bone morphogenetic protein 2 (+4 nodules) as compared with vehicle control (+3 nodules) over 25 days.
We identified a population of valvular interstitial cells with osteoblast-like characteristics that spontaneously form calcific nodules in cell culture. In addition, the rate of calcific nodule formation was increased with transforming growth factor beta-1 and 25-hydroxycholesterol. Further study of these 'calcifying valve cells' may yield a new in vitro model for testing therapy aimed at preventing calcific valve stenosis.
心脏瓣膜钙化是需要进行瓣膜置换患者的主要病理状况。本研究的目的是确定主动脉瓣细胞是否会自发钙化，若会，则对结节复合体进行特征描述并研究其对生长因子的反应。
从接受外科瓣膜置换手术的人类以及雌性犬类获取主动脉瓣。去除瓣膜内皮并将外植体在培养基中培养。
一群瓣膜间质细胞在犬主动脉瓣中两到三周内、在人主动脉瓣中六周内自发形成了含有羟基磷灰石的明显钙化结节。这些结节包含一个由死细胞构成的内环，其周围是一层活细胞外环。与结节相关的细胞具有成骨细胞样特征，并且细胞外骨基质蛋白染色呈阳性。用潜在钙化刺激物孵育犬类细胞以测试钙化刺激因素。与载体对照（25天内形成3个结节）相比，转化生长因子β-1（增加25个结节）、25-羟基胆固醇（增加9个结节）和骨形态发生蛋白2（增加4个结节）使结节形成速率提高。
我们鉴定出一群具有成骨细胞样特征的瓣膜间质细胞，它们在细胞培养中自发形成钙化结节。此外，转化生长因子β-1和25-羟基胆固醇可提高钙化结节的形成速率。对这些“钙化瓣膜细胞”的进一步研究可能会产生一种新的体外模型，用于测试旨在预防钙化性瓣膜狭窄的治疗方法。
