异鼠李素对氧化型低密度脂蛋白所致内皮细胞凋亡的影响

Effects of Isorhamnetin on Oxidized Low Density Lipoprotein Induced Endothelial Cell Apoptosis

目的观察异鼠李素对氧化型低密度脂蛋白所致内皮细胞凋亡的保护作用,并对其作用机制进行探讨。方法采用MTT法测定细胞活力,试剂盒测定乳酸脱氢酶含量,Griess法测定一氧化氮含量,JC-1、吖啶橙和溴化乙啶荧光染色法对其线粒体膜电位及细胞存活情况进行分析,流式细胞术评价细胞凋亡率,半定量RT-PCR法检测凝集素样氧化型低密度脂蛋白受体1和Caspase-3 mRNA的表达。结果异鼠李素(10-7μmol/L、10-6μmol/L和10-5μmol/L)预培养能显著抑制氧化型低密度脂蛋白所致内皮细胞活力降低、线粒体乳酸脱氢酶释放增加及一氧化氮释放降低(P<0.05),明显抑制氧化型低密度脂蛋白所致线粒体膜电位降低和细胞凋亡,并呈剂量依赖性;异鼠李素(10-7μmol/L、10-6μmol/L和10-5μmol/L)能显著抑制氧化型低密度脂蛋白所致凝集素样氧化型低密度脂蛋白受体1和Caspase-3 mRNA表达升高(P<0.01),并呈一定的量效关系。结论异鼠李素对氧化型低密度脂蛋白所致内皮细胞凋亡呈现显著的保护作用,其机制可能与抑制氧化型低密度脂蛋白损伤引起的凝集素样氧化型低密度脂蛋白受体1和Caspase-3 mRNA表达上调以及一氧化氮释放降低有关。

Aim To investigate the protective effects of isorhamnetin against oxidized low density lipoprotein （ox-LDL） induced apoptosis of endothelial cells and to figure out some of the underlying mechanisms of these effects. Methods Changes in cell viability were measured by the MTT method, the lactate dehydrogenase （LDH） release was evaluated by assay kits, and nitric oxide （NO） release was detected by the Griess assay. JC-1 staining was used to evaluate the mitochondrial membrane potential alteration, AO/EB staining was used to observe the morphological changes of apoptotic ceils, and flow cytometry was employed to detect the apoptotic rate of the cells. RT-PCR was used to detect the leetin-like low density lipoprotein receptor-1 （ LOX-1 ） and Caspase-3 mRNA expression. Results With the pretreat- ment by isohamnetin （10-7 μmol/L, 10-6 μmol/L and 10-5 μmol/L） , the decrease in endothelial cell viability and NO release as well as the increase in LDH induced by ox-LDL were significantly suppressed （ P 〈 0.05 ）. The ox-LDL-in- duced mitochondrial membrane potential alteration and apoptosis were also considerably inhibited. All these suppressive effects exhibited concentration-dependant behaviors. Pretreatment by isohamnetin （ 10 -7μmol/L, 10 -6 μmol/L and 10 -5μmol/L） significantly （P 〈 0.01 ） inhibited the ox-LDL induced LOX-1 and Caspase-3 mRNA upregnlation in a concentra- tion-dependant manner. Conclusions The results show the protective effects of isorhamnetin on endothelial cells from ox-LDL induced apoptosis. These effects may be related to the inhibition of ox-LDL induced LOX-1 and Caspase-3 mRNA upregulation and the decrease of NO release.