TNF-α,ox-LDL对人单核细胞株U937胆固醇酰基转移酶1表达的影响

Effects of Tumor Necrosis Factor-alpha and Oxidized Low Density Lipoprotein on the Synthesis of Acyl-Coenzyme A: Cholesterol Acyltransferase 1 mRNA and Protein in Human Monocytic U937 Cells

目的 观察肿瘤坏死因子 α (TNF α)和氧化型低密度脂蛋白 (ox LDL)对人单核细胞U937酰基辅酶A :胆固醇酰基转移酶 1(ACAT1)mRNA表达和蛋白质翻译的影响。方法 U937细胞培养到足够数量后 ,细胞计数传代分组 :①对照组 :加等量的培养基 ;②TNF α组 :加入TNF α ,使其终浓度为 10ng/ml;③ox LDL组 :加入ox LDL ,终浓度为 10 0 μg/ml。应用RT PCR检测ACAT1mRNA表达 ,蛋白定量应用免疫印迹法。 结果 与对照组相比 ,TNF α组ACAT1mRNA表达显著增加 (0 5 73± 0 0 32vs0 990± 0 0 2 2 ,P <0 0 1) ,而ox LDL组ACAT1mRNA表达水平 (0 5 5 4± 0 0 2 6 )无显著变化。 3组之间ACAT1酶蛋白含量差异无显著性意义。结论 TNF α能促进A CAT1mRNA表达 ,但未见TNF α和ox

Objective To investigate the regulation of acyl-coenzyme A: cholesterol acyltransferase 1 (ACAT1) gene expression and protein synthesis by tumor necrosis factor-alpha (TNF-α) and oxidized low density lipoprotein (ox-LDL) in the human monocytic cell line U937. Methods The U937 cells were incubated in treatment medium alone (control group) or in the medium containing either TNF-α (TNF-α group) or ox-LDL (ox-LDL group). The ACAT1 mRNA level of cells was determined by RT-PCR. The content of ACAT1 protein was detected by immunoblotting. Results The ACAT1 mRNA level in TNF-α-treated cells was significantly increased compared to that of the control group. In contrast, the ACAT1 mRNA synthesis was not significantly stimulated by ox-LDL. In addition, no statistical difference in the amount of ACAT1 protein was found among any of the three groups studied. Conclusion TNF-α can induce ACAT1 gene expression at mRNA level. However, neither TNF-α nor ox-LDL had effect on the amount of ACAT1 protein.