Venardos Neil, Bennett Daine, Weyant Michael J, Reece Thomas Brett, Meng Xianzhong, Fullerton David A
Department of Surgery, Division of Cardiothoracic Surgery, University of Colorado School of Medicine, Aurora, Colorado.
Department of Surgery, Division of Cardiothoracic Surgery, University of Colorado School of Medicine, Aurora, Colorado.
J Surg Res. 2015 Nov;199(1):1-6. doi: 10.1016/j.jss.2015.04.076. Epub 2015 Apr 25.
The aortic valve interstitial cell (AVIC) has been implicated in the pathogenesis of aortic stenosis. In response to proinflammatory stimulation, the AVIC undergoes a phenotypic change from that of a myofibroblast phenotype to that of osteoblast-like cell. Matrix Gla-protein (MGP) has been identified as an important inhibitor of vascular calcification. We therefore hypothesized that MGP expression is reduced in diseased AVICs, and loss of this protective protein contributes to calcification of the aortic valve. Our purpose was to compare MGP expression in normal versus diseased AVICs.
Human AVICs were isolated from normal aortic valves from explanted hearts (n = 6) at the time of heart transplantation. AVICs were also isolated from calcified, diseased valves of patients (n = 6) undergoing aortic valve replacement. AVICs were grown in culture until they reached passages 2-6 before experimentation. Immunofluorescent staining, reverse transcriptase-polymerase chain reaction, immunoblotting, and enzyme-linked immunosorbent assay were used to compare levels of MGP in normal and diseased AVICs. Statistics were performed using the Mann-Whitney U test (P < 0.05).
MGP expression was significantly decreased in diseased AVICs relative to normal AVICs by immunofluorescent staining, reverse transcriptase-polymerase chain reaction, immunoblotting, and enzyme-linked immunosorbent assay.
An important anti-calcification defense mechanism is deficient in calcified aortic valves. MGP expression is significantly lower in diseased relative to normal AVICs. Lack of this important "anti-calcification" protein may contribute to calcification of the aortic valve.
主动脉瓣间质细胞（AVIC）与主动脉瓣狭窄的发病机制有关。在促炎刺激下，AVIC会发生表型变化，从肌成纤维细胞表型转变为成骨样细胞表型。基质Gla蛋白（MGP）已被确定为血管钙化的重要抑制剂。因此，我们推测在患病的AVIC中MGP表达降低，而这种保护蛋白的缺失会导致主动脉瓣钙化。我们的目的是比较正常与患病AVIC中MGP的表达。
在心脏移植时，从移植心脏的正常主动脉瓣中分离出人AVIC（n = 6）。还从接受主动脉瓣置换术的患者（n = 6）的钙化病变瓣膜中分离出AVIC。在实验前，将AVIC培养至传代2 - 6代。采用免疫荧光染色、逆转录聚合酶链反应、免疫印迹和酶联免疫吸附测定法比较正常和患病AVIC中MGP的水平。使用Mann-Whitney U检验进行统计学分析（P < 0.05）。
通过免疫荧光染色、逆转录聚合酶链反应、免疫印迹和酶联免疫吸附测定法发现，与正常AVIC相比，患病AVIC中MGP表达显著降低。
钙化主动脉瓣中一种重要的抗钙化防御机制存在缺陷。与正常AVIC相比，患病AVIC中MGP表达显著降低。缺乏这种重要的“抗钙化”蛋白可能导致主动脉瓣钙化。
