氧化型低密度脂蛋白诱导3T3-L1脂肪细胞内质网应激相关标志物p-eIF2a、CHOP表达

目的 观察氧化型低密度脂蛋白(oxidized low density lipoprotein,ox-LDL)诱导3T3-L1脂肪细胞内质网应激相关标志物p-eIF2a、CHOP的表达,探讨ox-LDL对3T3-L1脂肪细胞内质网应激的诱导作用.方法 体外培养3T3-L1脂肪细胞,用ox-LDL分别干预脂肪细胞6小时、12小时、24小时,用RT-PCR检测CHOP mRNA表达,用Western blot检测p-eIF2a、CHOP蛋白表达.结果 ox-LDL可诱导脂肪细胞p-eIF2a、CHOP表达,p-eIF2a表达发生在ox-LDL作用早期(6小时,12小时),24小时表达有所下降,而CHOP的表达强度随时间增加,24小时表达达到高峰.结论 ox-LDL可诱导3T3-L1脂肪细胞发生内质网应激,激活未折叠蛋白反应信号通路.p-eIF2a表达发生在ox-LDL作用早期,而CHOP的表达强度呈时间依赖性.

Oxidized Low Density Lipoprotein Induces the Expression of Endoplasmic Reticulum Stress Related Molecules p-eIF2a and CHOP in 3T3-L1 Adipocytes

Objective The purpose of the study is to observe the expression of endoplasmic reticulum stress （ ER stress, ERS） related molecules phosphorylation of eukaryotic translational initiation factor 2a （p-elF2a） and C/EBP homologous protein （CHOP） in 3T3-L1 adipocytes treated with oxidized low density lipoprotein （ox-LDL） ,and to investigate the effect of ox-LDL on the induction of ERS in 3T3-L1 adipo- cytes. Methods 3T3-L1 adipocytes were cultured and treated with ox-LDL for 6 hours, 12 hours and 24 hours, respectively. RT-PCR was used to detect the mRNA expression of CHOP, and Western blotting was used to exam the expression of p-elF2a and CHOP. Results The ox-LDL up-regulated the expression of p-elF2a and CHOP. The expression of p-elF2a was induced in early stage of ox-LDL stimulation （6 hours, 12 hours ） , decreased gradually after 24 hours, while the expression of CHOP was increased with time extended, peaked at 24 hours. Conclusion ox-LDL may induce ERS and activate the unfolded protein response in 3T3-L1 adipocytes. The expression of p-elF2a was induced in early stage of ox-LDL stimulation,while the expression of CHOP was induced in time-depended manner.