黑木耳多糖对动脉粥样硬化血管平滑肌细胞表型转化及bFGF和PDGF表达变化的研究

Effects of Auricularia Auricula Polysaccharide on the Phenotypes of Vascular Smooth Muscle Cells and the Expression of bFGF and PDGF in Atherogenesis

目的通过黑木耳多糖对血管平滑肌细胞表型转化及bFGF和PDGF表达变化的影响,探讨黑木耳多糖降血脂和抗氧化以外的抗动脉粥样硬化形成作用。方法将30只新西兰白兔随机分为正常对照组、模型组和实验组3组,分别给予普通饲料(正常组)、高胆固醇饲料(模型组)以及高胆固醇加黑木耳多糖饲料(实验组)喂养。第12周末处死动物,取主动脉行组织形态学观察及用透射电镜和免疫组织化学方法分析平滑肌细胞表型转化及bFGF和PDGF表达变化。结果实验组主动脉斑块面积明显小于模型组,模型组和实验组分别为(0.44±0.10)和(0.30±0.83),两组比较差异有统计学意义(P<0.01);透射电镜和免疫组化结果显示:模型组动脉粥样硬化斑块的平滑肌细胞内内质网、线粒体增多,主要为合成表型;而实验组平滑肌细胞内内质网、线粒体少,主要为收缩表型,并且斑块内bFGF和PDGF的表达减少。结论黑木耳多糖可抑制动脉粥样硬化过程中血管平滑细胞从收缩表型向合成表型的转化,从而抑制平滑肌细胞合成和分泌bFGF、PDGF和其他细胞外基质的能力,从而减少动脉粥样硬化形成中血管平滑肌细胞参与的过程。

Objective To explore the effect of auricularia auricula polysaccharide on the phenotypes of vascular smooth muscle cells （VSMCs） and the also expression of basic fibroblast growth factor （bFGF） and platelet-derived growth factor （PDGF） in the formation of atherosclerosis （AS）. Method Thirty New Zealand white rabbits were randomly divided into three groups ： normal group, model group and experimental group. The period of experiment is twelve weeks. Normal group received normal food chow. Model group received normal chow and cholesterol, and the experimental group received normal chow, cholesterol and polysaccharide. Animals were sacrificed after 12 weeks of treatment. Excised artery segments were prepared for histo-morphological observation. Transmission electron microscopy and immunohistochemical methods were used to determine the phenotypes of VSMC and the expression of bFGF and PDGF. Result Compared with the model group, atherosclerotic lesions were alleviated in the experimental group （model group： 0.44 ＋ 0.10, experimental group：0.30 ＋ 0.83, P〈0.01）. Electron microscopy and immunohistochemical studies showed that mitochondria and endoplasmie reticulum of VSMCs were riched in atherosclerotic plaques in the model group, but not in the experimental group. VSMCs were mainly synthesized type in model group, but were mainly contracted type in experiment group, bFGF and PDGF expression were also decreased in the atherosclerotic lesion. Conclusion Auricularia auricula polysaccharide could inhibit the phenotypie conversion of VSMC from contracted type to synthesized type in atherogenesis. It could also inhibit the secretion of bFGF, PDGF and other extracellular matrixs, thus decreased the formation of atherosclerosis.