氧化型低密度脂蛋白诱导U937细胞凋亡及其对p53、p21和Bcl-2表达的影响

Effect of Oxidized Low Density Lipoprotein on Apoptosis and Expression of p53, p21 and Bcl-2 Gene in U937 Cells

为研究单核细胞源性泡沫细胞凋亡机制 ,以氧化型低密度脂蛋白诱导人髓系白血病细胞U937凋亡 ,观察p5 3、p2 1和Bcl- 2的表达。用流式细胞术和DNA断裂分析检测细胞凋亡 ;用细胞免疫荧光标记结合流式细胞术检测p5 3、p2 1和Bcl- 2蛋白表达 ,反转录聚合酶链反应显示p5 3、p2 1和Bcl- 2mRNA表达水平。结果表明氧化型低密度脂蛋白可致U937细胞凋亡 ,其作用具有浓度效应 ;氧化型低密度脂蛋白诱导U937细胞凋亡过程中 ,p5 3、p2 1mRNA和蛋白表达增加 ,Bcl- 2mRNA和蛋白表达减少。提示氧化型低密度脂蛋白可能通过上调p5 3、p2 1基因表达 ,下调Bcl- 2基因 ,导致U937细胞凋亡。

Aim [WT5”BZ]To investigate the mechanism involved in the apoptosis of human myeloid leukemia U937 cells induced by oxidized low density lipoprotein (ox-LDL).[WT5”HZ] Methods[WT5”BZ] The apoptotic cells were determined by flow cytometry and DNA fragmentation assay. The content of p53, p21 and Bcl-2 protein were analyzed by immunofluoresence staining and flow cytometric analysis. The level of p53,p21 and Bcl-2 mRNA were quantified by reverse transcription-polymerase chain reaction (RT-PCR). [WT5”HZ]Results [WT5”BZ]Ox-LDL induced apoptosis of U937,which is concentration dependent,and upregulate the level of p53 and p21 mRNA and protein as detected by RT-PCR and flow cytometric analysis.However,expression of Bcl-2 was downregulated after treatment with ox-LDL. [WT5”HZ]Conclusion [WT5”BZ]Ox-LDL upregulated the gene expression of p53, p21 and downregulated Bcl-2 expression, which induced apoptosis of U937 cells.