氧化低密度脂蛋白诱导Zucker肥胖大鼠肾小球系膜细胞AP-1活性的变化

Enhancement of Ox-LDL on activator protein-1 activation in glomerular mesangial cells from Zucker rats

目的 :研究氧化低密度脂蛋白 (oxidizedlow densitylipoprotein ,Ox LDL)对体外培养的Zucker大鼠肾小球系膜细胞 (glomerularmesangialcell,GMC)中核转录因子激活蛋白 1(activatorprotein 1,AP 1)活化的影响 ,以及观察Ox LDL诱导的AP 1活性的变化与Zucker大鼠鼠龄以及基因型的相关性。 方法 :①采用Zucker肥胖大鼠 (3月龄和 10月龄 )及Zucker瘦型大鼠 (3月龄和 10月龄 )的 4种GMC株 (O3m,O10m,L3m,L10m)进行传代培养。②利用凝胶迁移率实验 (EMSA)和超迁移率实验检测不同浓度及不同时相Ox LDL对Zucker大鼠GMCAP 1活性的影响 ,以及AP 1二聚体中c jun和c fos成分的变化。 结果 :①经Ox LDL诱导后 ,4个组GMC内AP 1活性均较对照组明显增强 (F =177 84 ,P <0 0 1) ;②随着Ox LDL刺激浓度增加和时间的延长 ,GMC内AP 1活性相应增强 ,5 0mg/L的Ox LDL刺激 8h时 ,AP 1活性强度达最高峰 ;③Ox LDL主要激活AP 1二聚体成分中的c jun ;④O10m组AP 1的活性显著高于O3m组 (P <0 0 1) ,L10m组AP 1的活性显著高于L3m组 (P <0 0 1) ,O10m组显著高于L10m组 (P <0 0 1) ,O3m组显著高于L3m组 (P <0 0 1)。 结论 :Ox LDL可诱导Zucker大鼠GMC内AP 1活化 ,其活化方式呈时间和剂量依赖 ;活化强度与大鼠的基因型及鼠龄?

Objective: To study the effect of oxidized low density lipoprotein (Ox LDL) on activator protein 1 (AP 1) activation in glomerular mesangial cells of the Zucker rats and investigate the correlation between the activity of AP 1 induced by Ox LDL to the ages and genotype of Zucker rats. Methodology: Four groups of cultured GMCs (O 3m , O 10m , L 3m , L 10m ) from the Zucker obese rats (3 months and 10 months old) and Zucker lean rats (3 months and 10 months old) were stimulated by Ox LDL. Electrophoretic mobility shift assay (EMSA) was used to determine the activity of AP 1. Gel super shift assay was used to detect the subunit of AP 1 dimer. Results: ① AP 1 activity in 4 groups GMCs was significantly higher than that in control group after induced of Ox LDL ( F =177.84, P < 0.01). ② With the increase of stimulation concentration and time of Ox LDL, the AP 1 activity was elevated accordingly. The level of AP 1 activity was the highest when GMCs were stimulated by Ox LDL 50 mg/L, 8h. ③ Super shift assay demonstrated that c Jun was the predominant subunit involved. ④ The AP 1 activity in O 10m was higher than that in O 3m ( P <0.01), L 10m was higher than that in L 3m (P<0.01),O 10m was higher than that in L 10m ( P <0.01), and O 3m was also higher than that in L 3m ( P <0.01). Conclusion: Ox LDL significantly activated AP 1 in GMCs of Zucker rats, present time and dose dependent manier. There is a close correlation between the activity of AP 1 induced by Ox LDL to the ages and genotype, which plays an important role in the lately renal lesion of diabetes mellitus that enhance effect of Ox LDL on AP 1 activation in GMCs of the Zucker rats.