叶酸降低高同型半胱氨酸血症大鼠单核细胞趋化蛋白-1的表达

Folate Reduces Monocyte Chemoattractant Protein-1 Expression in Rats with Hyperhomocysteinemia

目的探讨补充叶酸对高蛋氨酸喂养所致的高同型半胱氨酸血症(Hhcy)大鼠主动脉内皮及外周血单个核细胞(PBMC)单核细胞趋化蛋白-1(MCP-1)表达和释放的影响。方法健康清洁级SD雄性大鼠30只随机分为3组:正常对照(Control)组、高同型半胱氨酸(Hhcy)组、补充叶酸(FA)组。每组10只,分别给予普通饲料;普通饲料加1.7%蛋氨酸;普通饲料加1.7%蛋氨酸和0.006%叶酸。饲养45d,采用高效液相色谱法测定血浆总同型半胱氨酸浓度,用双抗体夹心ELISA方法测定3组大鼠氧化型低密度脂蛋白诱导后PBMC释放炎症趋化因子MCP-1的含量,免疫组织化学染色法及蛋白免疫印迹(Westernblot)法检测大鼠主动脉MCP-1的表达。结果大鼠喂以高蛋氨酸饲料45d可诱导高同型半胱氨酸血症,同时补充叶酸可显著降低血浆总同型半胱氨酸水平(P<0.01);与Control组相比,Hhcy组大鼠血浆总同型半胱氨酸升高,主动脉内皮MCP-1的表达和氧化型低密度脂蛋白诱导的PBMC释放的MCP-1水平均显著升高(P<0.05,P<0.01);FA组大鼠血浆总同型半胱氨酸水平降低,主动脉内皮MCP-1的表达及氧化型低密度脂蛋白诱导的PBMC释放的MCP-1水平较Hhcy组显著降低(P<0.05,P<0.01)。结论叶酸治疗Hhcy大鼠可以降低血同型半胱氨酸水平,同时降低主动脉内皮细胞和外周血PBMC炎症趋化因子MCP-1的表达与释放。

Objective To investigate effects of supplementation of folate on the expression of monocyte chemoattractant protein-1 （MCP-1） in aortic endothelium and release from peripheral blood mononuclear cells （PBMC） in rats with hyperhomocysteinemia induced by ingestion of excess methionine. Methods Thirty male SD rats were randomly divided into 3 groups （n = 10 for each group）： control group （Control）, high homocysteinemia group （Hhcy）, and folate supplementation group （FA）. They were fed with nomal diet, normal diet enriched by 1.7% methionine, and normal diet plus 1.7% methionine and 0.006% folate, respectively, for 45 days. The levels of total plasma homocysteine （Thcy） were measured by high performance liquid chromatography and the concentrations of chemokine MCP-1 released from PBMC stimulated by oxidized low density lipoprotein were detected by enzyme immunoassays. The expression of MCP-1 on aortas of rats was detected by immunohistochemistry and Western blot. Results A high methionine diet for 45 days induced hyperhomocysteinemia. Folate supplementation to highmethionine diet significantly decreased plasma Thcy levels （P 〈 0.01）. The expression of MCP-1 in aortic endothelium and the levels of MCP-1 released from PBMC stimulated by oxidized low densitylipoprotein were significantly higher in rats of Hhcy group than in rats of control group （P 〈 0.05, P 〈 0.01）. During supplementation of folate, normalization of Thcy levels was accompanied by a marked reduction of MCP-1 expression in aortic endothelium and by a significant decrease of MCP-1 released from PBMC stimulated by oxidized low density lipoprotein （P〈 0.05, P 〈 0.01）. Conclusion Folate supplementation can prevent an elevation of homocysteine levels in the blood and decrease the expression MCP-1 in aortic endothelium and release of MCP-1 from PBMC in rats with hyperhomocysteinemia.