摘要目的:观察亚砷酸钠（NaAsO 2）对人正常肝细胞（L-02细胞）脂代谢基因固醇调节元件结合蛋白-1c（SREBP-1c）、过氧化物酶体增殖物激活受体α（PPARα）和脂肪酸合成酶（FAS）表达的影响。 方法:体外培养L-02细胞，分别以0（对照）、2、4、8、16、32、64、128 μmol/L NaAsO 2染砷24 h，采用CCK-8法检测细胞存活率，并制作拟合曲线计算半抑制浓度（IC 50），以IC 50的0、1/8、1/4、1/2作为染砷剂量进行后续实验。采用甘油磷酸氧化酶-过氧化氢酶（GPO-PAP）法检测细胞甘油三酯（TG）含量；实时荧光定量PCR检测SREBP-1c、PPARα、FAS mRNA表达水平；蛋白质印迹法（Western blot）检测SREBP-1c和PPARα蛋白表达水平。 结果:8、16、32、64、128 μmol/L NaAsO 2组细胞存活率[（92.000 ± 1.414）%、（91.000 ± 0.000）%、（76.500 ± 0.707）%、（53.000 ± 1.412）%、（47.000 ± 1.412）%]明显低于对照组[（100.000 ± 0.000）%， P均< 0.01]，IC 50为64 μmol/L，以0（对照）、8、16、32 μmol/L NaAsO 2进行后续实验。与对照组[（1.000 ± 0.000）mmol/g prot]比较，8、16、32 μmol/L NaAsO 2组TG含量[（0.691 ± 0.064）、（0.474 ± 0.162）、（0.184 ± 0.045）mmol/g prot]显著降低（ P均< 0.01）。与对照组比较，各染砷组SREBP-1c、PPARα、FAS mRNA表达水平，SREBP-1c、PPARα蛋白表达水平显著降低（ P < 0.01或< 0.05）。相关性分析可见，NaAsO 2含量与细胞TG含量，SREBP-1c和PPARα蛋白表达水平呈负相关（ r =-0.954、- 0.875、- 0.965， P均< 0.01）。 结论:NaAsO 2可引起L-02细胞TG含量减少及脂代谢相关基因SREBP-1c、PPARα和FAS表达降低，提示砷致肝损伤过程中可引起脂代谢障碍发生。

abstractsObjective:To investigate the effects of sodium arsenite (NaAsO 2) on the expression of sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator activated receptor α (PPARα) and fatty acid synthase (FAS) in human liver cells (L-02 cells). Methods:L-02 cells were cultured in vitro, and exposed to NaAsO 2 at 0 (control), 2, 4, 8, 16, 32, 64 and 128 μmol/L for 24 h, respectively, and the cell survival rate was determined by CCK-8 method. And a fitting curve was made to calculate the half inhibitory concentration (IC 50), subsequent experiments were carried out with 0, 1/8, 1/4 and 1/2 of IC 50 as arsenic exposure doses. Glycerol phosphate oxidase-catalase (GPO-PAP) method was used to detect the content of triglyceride (TG) in cells; the mRNA expression levels of SREBP-1c, PPARα and FAS were detected by Real-time PCR; and the protein expression levels of SREBP-1c and PPARα were detected by Western blotting. Results:The cell survival rates of 8, 16, 32, 64 and 128 μmol/L NaAsO 2 groups [(92.000 ± 1.414)%, (91.000 ± 0.000)%, (76.500 ± 0.707)%, (53.000 ± 1.412)%, (47.000 ± 1.412)%] were significantly lower than that of the control group [(100.000 ± 0.000)%, P < 0.01]. The IC 50 was 64 μmol/L, and subsequent experiments were conducted with 0 (control), 8, 16 and 32 μmol/L NaAsO 2, respectively. Compared with the control group [(1.000 ± 0.000) mmol/g prot], TG contents of 8, 16 and 32 μmol/L NaAsO 2 groups [(0.691 ± 0.064), (0.474 ± 0.162), (0.184 ± 0.045) mmol/g prot] were significant decreased ( P < 0.01). Compared with the control group, the mRNA expression levels of SREBP-1c, PPARα, FAS, and the protein expression levels of SREBP-1c and PPARα in NaAsO 2 groups were significantly decreased ( P < 0.01 or < 0.05). Correlation analysis showed that NaAsO 2 content was negatively correlated with TG content, SREBP-1c and PPARα protein expression levels ( r =-0.954,- 0.875,-0.965, P < 0.01). Conclusion:NaAsO 2 can reduce the TG content and the expression of lipid metabolism related genes SREBP-1c, PPARα and FAS in L-02 cells, suggesting that arsenic-induced liver injury can cause lipid metabolism disorders.