葛根通脉饮对HCY家兔AS斑块和环磷酸腺苷反应元件结合转录因子同源蛋白表达的影响

目的:观察葛根通脉饮对同型半胱氨酸(homocysteine,HCY)所致家兔动脉粥样硬化(atherosclerosis,AS)血管损伤和内质网应激(ERS)相关分子C/EBP环磷酸腺苷反应元件结合转录因子同源蛋白(C/EBP-homologousprotein,CHOP)表达的影响,并探讨其分子机制。方法:将36只日本大耳白兔随机等分成6组。对照组饲喂基础饲料,模型组饲喂高脂饲料(基础饲料+1%胆固醇及0.02%蛋氨酸),可定组(1 mg·kg-1+高脂饲料)、葛根通脉饮低、中、高剂量组(5,7.5,10 g·kg-1+高脂饲料),通过高脂饮食9周复制兔动脉粥样硬化模型。取胸主动脉观察其病理改变,用组织原位杂交和Western-blotting检测胸主动脉CHOP分子表达水平。结果:形态学显示模型组血管内膜下形成典型的脂质斑块,可定组内膜下有少量的斑块形成,病变较模型组轻,葛根通脉饮低剂量组血管局部区域出现脂质斑块,葛根通脉饮中剂量组血管内膜结构紊乱,葛根通脉饮高剂量组血管内膜下有少量平滑肌细胞增生。组织原位杂交结果显示,各组中CHOP基因在血管内膜和中膜层细胞胞质中均有表达,对照组内皮细胞和平滑肌细胞胞质中可见少量棕黄色颗粒。模型组斑块结构中平滑肌细胞和泡沫细胞胞质中棕黄色颗粒高表达。与模型组比葛根通脉饮组平滑肌细胞阳性信号表达下降。Western-blotting杂交结果显示,CHOP蛋白在各组中均有表达,与对照组比较模型组CHOP蛋白表达增多,差异有统计学意义(P<0.01);与模型组比较在葛根通脉饮低、中、高剂量组中CHOP蛋白表达减少,差异均显著(P<0.01)。结论:葛根通脉饮抗AS作用机制可能与ERS相关分子CHOP的表达密切相关。可通过拮抗HCY所诱导AS的血管损伤,降低ERS相关分子CHOP在家兔胸主动脉中的表达。

Effect of Gegen Tongmai Yin on CHOP Expression Induced by HCY in AS Rabbit Model

Objective: To observe the effect of Gegen Tongmai Yin on the endoplasmic reticulum stress related C/EBP-homologousprotein (CHOP) expression induced by homocysteine (HCY), in order to discuss anti-atherosclerosis (AS) molecular mechanism. Method: Thirty-six rabbits were randomly divided into 6 groups, the normal control group (the normal feed), the high-fat group (the normal feed+1% cholesterol+0.02% methionine), the rosuvastatin group (1 mg·kg^-1+high-fat feed), the Gegen Tongmai Yin low, middle and high dose group (5,7.5,10 g·kg^-1+high-fat feed).The rabbit AS model was induced by feeding the high-fat diet for 9 weeks. The superior segment of thoracic aorta was taken for the pathological observation, the CHOP expression was detected by situ hybridization and Western-blotting hybridization. Result: Pathological observation showed that the typical lipid plaque formed under the tunica intima in high-fat group, the pathological changes in the Rosuvastatin group were weaker than high-fat group, with small lipid plaque formed. The lipid plaque only formed in local areas in the Gegen Tongmai Yin low-dose group, the tunica intima structural disordered in the middle-dose group, only a small quantity cellular proliferation of smooth muscle in the high-dose group. Tissue in situ hybridization detection showed that CHOP gene expressed in the cytoplasm of tunica intima and tunica media in all groups. Small brownish yellow granules appeared in the endothelial cells and smooth muscle cells in normal control group. The brownish yellow granules were strongly expressed in the smooth muscle cells and foam cells in the high-fat group. The positive signal decreased expression in the smooth muscle cells in Gegen Tongmai Yin groups compared with the high-fat group. Western-blotting hybridization showed that CHOP protein were all expressed in 6 groups, CHOP protein expression increased in high-fat group compared with normal group. The difference was statistically significant(P<0.01);CHOP protein expression decreased in Gegen Tongmai Yin low, middle and high dose groups, the difference was significant(P<0.01). Conclusion: The Gegen Tongmai Yin's anti-AS mechanism may be correlated with the CHOP expression. The Gegen Tongmai Yin can improve the injury of blood vessel induced by HCY and depress the CHOP expression in the rabbit's thoracic aorta.