血管紧张素Ⅱ诱导主动脉瓣成肌纤维细胞向成骨细胞样表型转化的机制  

Mechanism of Angiotensin lI promotes an osteoblast- like phenotype in porcine aortic valve myofibroblasts

作　　者：李永胜[1] 胡伟林[1] 陈正平[1] 许高[1] 马春桃[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院重症医学科/急诊科,湖北武汉430030

出　　处：《中国急救医学》2015年第1期48-53,I0005,共7页Chinese Journal of Critical Care Medicine

基　　金：国家自然科学基金（81070190）;湖北省自然科学基金（2014CFB962）

摘　　要：目的通过研究Wnt／β-catenin信号通路在心脏瓣膜成肌纤维细胞向成骨细胞样表型转化的凋控作用，探寻心脏瓣膜钙化的发病机制。方法以原代培养的猪主动脉瓣成肌纤维细胞作为研究对象，用与心脏瓣膜钙化有关的病理因素血管紧张素Ⅱ处理细胞，将细胞随机分为四组：对照组（Ctr）、血管紧张素Ⅱ组（AngⅡ10^-6mol／L）、血管紧张素Ⅱ＋缬沙坦组（AngⅡ10^-6mol／L＋Val10^-5mol／L）、缬沙坦组（Val10^-5mol／L）。通过检测骨形成蛋白2（bone morphogenetic protein2，BMP2）、碱性磷酸酶（alkaline phosphatase，ALP）、Wnt／β-catenin信号通路中Wnt3a和β—catenin的蛋白表达，观察Wnt／β-catenin信号通路的变化以及细胞是否向成骨细胞样表型转化。结果AngⅡ能使成肌纤维细胞a—SMA的表达显著增加而成为活性细胞；骨相关蛋白BMP2、ALP蛋白和mRNA在对照组和缬沙坦组几乎没有表达，而在AngⅡ组表达显著增加（P〈0．01）；Writ／β-catenin信号通路中的配体Wnt3a在对照组和缬沙坦组几乎没有表达，AngⅡ组的Wnt3a和β—catenin基因表达显著上调（P〈0．01）；缬沙坦对AngⅡ的这种病理性影响可以起到-定的抑制作用（P〈0．05）。结论血管紧张素Ⅱ可能经由瓣膜间质细胞上的AngⅡ受体，通过激活Wnt／β-catenin信号通路，促使心脏瓣膜成肌纤维细胞激活、分化、增殖以及向成骨细胞样表型转化，进而导致心脏瓣膜的钙化。Objective The mechanisms for pathogenesis of cardiac valve calcification were explored by studying the regulation of the Wnt signaling pathway during the transformation from cardiac valvular myofibroblasts to osteoblast- like phenotype. Methods Studies were carried on primary cultured prcine aortic valvular myofibroblasts. The cells were randomly divided into four groups and treated with a valvular calcification associated pathological factor （ designated Ang Ⅱ ） according to the following： AngⅡ （ 10-6 mol/1）, Valsartan （Val） （ 10^-5 mol/l）, Ang Ⅱ plus Val （ Ang Ⅱ 10^-6 moll/l ＋ Val 10^- 5 mol/l） or mock treated as the control. Protein expression of Bone morphogenetic protein 2 （BMP2）, Alkaline phosphatase （ALP）, and Wnt pathway components, Wnt3a and β -eatenin, was investigated to assess the activation of the Wnt signaling pathway and determine whether cells undergo the transformation to osteoblast - like phenotype. Results Ang H treatment of myofibroblasts led to significant up - regulation of α - SMA expression and activation of the cells. Neither the BMP2 or ALP proteins nor the mRNA were detectable in the control group or the Val treated group; however, there was a significant increase in Ang Ⅱ treated group （P 〈 0.01 ）. The Wnt/β - eatenin signaling ligand, Wnt3a, was not expressed in the control or Val treated groups. Whereas in Ang Ⅱ treated cells, bothWnt3a and β - catenin gene expression were enhanced （ P 〈 0.01 ）, but was partially inhibited by Valsartan （P 〈 0.05 ）. Conclusion Ang Ⅱ might act on the Ang II receptor on valvular interstitial cells （VICs） and lead to activation of the Wnt/β -catenin pathway and hence cause the activation, differentiation and proliferation of myofibroblasts, and finally, osteoblast - like phenotype transformation, leading to calcification of heart valves.

关 键 词：血管紧张素Ⅱ 瓣膜钙化 成肌纤维细胞 Wnt/β—catenin 

分 类 号：R562.25[医药卫生—呼吸系统]