氧化修饰低密度脂蛋白对培养人动脉平滑肌细胞周期及增殖细胞核抗原的影响

应用流式细胞仪对氧化修饰低密度脂蛋白（Ｏｘ－ＬＤＬ）刺激动脉平滑肌细胞（ＳＭＣ）增殖、细胞周期及增殖细胞核抗原（ＰＣＮＡ）、Ｐ５３、Ｐ２７及ｃ－ｅｒｂＢ蛋白表达的影响进行了观察。结果发现：Ｏｘ－ＬＤＬ和天然低密度脂蛋白（Ｎ－ＬＤＬ）刺激培养人动脉ＳＭＣ细胞增殖时其Ｓ期细胞百分率增加，且Ｏｘ－ＬＤＬ的作用比Ｎ－ＬＤＬ强，表明Ｏｘ－ＬＤＬ和Ｎ－ＬＤＬ刺激ＳＭＣ细胞增殖时与Ｓ期细胞的增加有关；Ｏｘ－ＬＤＬ刺激ＳＭＣ增殖的同时ＰＣＮＡ蛋白阳性率增加，而与Ｐ５３、Ｐ２７和ｃ－ｅｒｂＢ－２蛋白的表达无关。提示ＰＣＮＡ可能参与了Ｏｘ－ＬＤＬ刺激ＳＭＣ的细胞增殖作用；特异性蛋白激酶Ｃ（ＰＫＣ）抑制剂ＧＦ１０９２０３Ｘ能降低Ｏｘ－ＬＤＬ刺激ＳＭＣ增殖过程中ＰＣＮＡ的阳性率，表明该细胞增殖过程中ＰＣＮＡ表达的抑制可能与ＰＫＣ信号传递通路有关。

Effect of Ox LDL on Cell Cycling Phases and PCNA,P53,P27 and c erbB 2 Expression in Cultured Human Arterial Smooth Muscle Cells

It was found in our previous study that oxidative modification LDL(Ox LDL) could stimulate the proliferation of cultured human arterial smooth muscle cells (SMC). Yet, the mechanism responsible for the SMC proliferation induced by Ox LDL is not clear. Proliferating cell nuclear antiger(PCNA), P53 and P27 are the key regulatory factors of cell replication. In order to observe the effects of Ox LDL on cell cycling phase and PCNA, P53,P27 and c erb B 2 expression in SMC, we used the flow cytometric method in the present study on the proliferation of cultured human SMC induced by Ox LDL. The results showed a relation between the Ox LDL mediated SMC proliferation and the cycling phase shifting. The relative number of S phase cells in the Ox LDL group was higher than that of the control group (22.9% vs 15.7%). Ox LDL mediated SMC proliferation was accompanied with the increasing expression of PCNA. The percentage of specific PCNA positive FITC cells in the Ox LDL group was significantly higher than that of the control group (12 6% vs 6.5%).PMA, an activitor of protein kinase C(PKC), stimulated SMC proliferation and increased the PCNA exression in cultured SMC, while the PKC inhibitor, F109203X, significantly decreased the PCNA expression in SMC(PCNA positive cells 13 4% vs 0.4%).No changes were observed in the expression of P53,P27 and c erb B 2 in the cultured proliferating SMC induced by Ox LDL. In all, the results suggest that the Ox LDL mediated SMC proliferation is related to increasing S Phase Cells and involved in the PCNA expression which might undergo the PKC cellular signal transduction pathway.