摘要
为研究氧化型低密度脂蛋白致U937细胞凋亡时泛素—蛋白酶体通路中泛素缀合酶、p5 3与泡沫细胞凋亡之间的关系 ,用氧化型低密度脂蛋白处理人单核细胞U937细胞 ,诱导其凋亡 ,采用DNA琼脂糖凝胶电泳和流式细胞术检测细胞凋亡 ,逆转录聚合酶链反应检测泛素缀合酶和p5 3的基因表达 ;流式细胞术分析泛素缀合酶、载脂蛋白B和P5 3的蛋白表达。结果发现 ,氧化型低密度脂蛋白可以诱导U937细胞凋亡 ,在U937细胞凋亡过程中泛素缀合酶表达降低 ,p5 3表达增高 ,而且细胞内载脂蛋白B也增加。结果提示 ,泛素缀合酶的表达降低可能使P5 3和载脂蛋白B经泛素—蛋白酶体通路的降解减慢 ,从而引起P5 3和载脂蛋白B在细胞内积聚 。
Aim To investigate expression of ubiquitin conjugating enzyme (Ubc E2) and p53 in the apoptosis of human monocyte cell line U937 induced by oxidized low density lipoprotein (ox LDL). Methods U937 cells were incubated with ox LDL. The apoptotic cells were determined by DNA fragment analysis and flow cytometric analysis. The level of p53 and ubiquitin conjugating enzyme mRNA were quantified by reverse transcription polymerase chain reaction (RT PCR). The protein contents of ubiquitin conjugating enzyme, P53 and apolipoprotein B (apo B) were analyzed by immunofluoresence staining and flow cytometric method. Results The results showed that the increase of the degree of U937 cell apoptosis was concentration dependent. Ox LDL could down regulate the gene/protein expression of ubiquitin conjugating enzyme and up regulate the gene/protein expression of P53, meanwhile, the apo B accumulated in U937 cells. Conclusion The results implicated that ox LDL induced U937 cell apoptosis by accumulation of P53 and apo B through down regulating ubiquitin conjugating enzyme. Cellular defense system, either dependent or independent on the ubiquitin system, was weakened by the ox LDL induced toxicity.
出处
《中国动脉硬化杂志》
CAS
CSCD
2003年第4期287-290,共4页
Chinese Journal of Arteriosclerosis
基金
国家自然科学基金 ( 3 0 0 2 10 3 )
湖南省自然科学基金( 0 0JJY2 0 2 7
0 2JJY40 11)资助
