【摘要】 【目的】观察TNF-α对3T3-L1脂肪细胞葡萄糖转运蛋白4(GLUT4)mRNA与蛋白表达的作用,并探讨核因子-κB(NF-κB)对上述作用的影响。【方法】成熟的3T3-L1脂肪细胞分成3组:A组正常对照组,B组肿瘤坏死因子α(TNF-α)组,C组吡咯烷二硫基甲酸酯(NF-κB活性抑制剂)+TNF-α组。各组干预48h后检测phospho-NF-κBp65(Ser536)的蛋白水平、GLUT4mRNA及蛋白水平。蛋白检测采用Western法,mRNA检测采用RT-PCR法。【结果】B组phospho-NF-κBp65蛋白水平(71.1±5.9)高于A组(41.3±1.7,P<0.001)和C组(25.4±4.7,P<0.001)。B组GLUT4的mRNA水平(0.86±0.14,P<0.001)与蛋白水平(31.6±7.2,P<0.001)低于A组(2.01±0.65;60.7±8.4),C组mRNA水平(0.46±0.12)与B组比较有下降趋势但无统计学意义(P=0.100),C组蛋白水平(9.5±3.0)低于B组(P=0.001)。【结论】TNF-α下调3T3-L1脂肪细胞的GLUT4表达,抑制NF-κB活性后GLUT4表达进一步下调。这提示了TNF-α可能不是通过激活NF-κB而使GLUT4的表达下调。更多还原

【Abstract】 【Objective】 To observe the regulating actions of tumor necrosis factor-α (TNF-α) on the mRNA and protein expression of glucose transporter 4 (GLUT4) in 3T3-L1 adipocytes, and to investigate the effects of nuclear factor kappa B (NF-κB) on these actions. 【Methods】 The fully differentiated 3T3-L1 adipocytes were divided into three groups. Group A was the control group. Group B was treated with TNF-α. Group C was treated with pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB activity) and TNF-α. After the adipocytes were treated for 48 h, the protein expression of phospho-NF-κB p65 (Ser536) and GLUT4 were tested by Western blot, and mRNA expression of GLUT4 was tested by RT-PCR. 【Results】 The phospho-NF-κB p65 protein expression in group B (71.1 ± 5.9) was significantly higher than those in group A (41.3 ± 1.7, P < 0.001) and in group C (25.4 ± 4.7, P < 0.001). The expression of the GLUT4 mRNA (0.86 ± 0.14, P < 0.001) and protein (31.6 ± 7.2, P < 0.001) in group B were significantly lower than those in group A (2.01 ± 0.65; 60.7 ± 8.4). Though the GLUT4 mRNA expression in group C (0.46 ± 0.12) was decreasing compared with that in Group B, there was no statistical significance between them (P = 0.100). The GLUT4 protein (9.5 ± 3.0) expression in group C was significantly lower than that in group B (P = 0.001). 【Conclusion】 In 3T3-L1 adipocytes, GLUT4 expression is down-regulated by TNF-α, and down-regulated more by inhibiting NF-κB activity. This indicates that TNF-α may down-regulate the expression of GLUT4 not by activating NF-κB.更多还原