佛波酯慢性处理对大鼠血管平滑肌细胞各亚型蛋白激酶C表达的影响

目的观察佛波酯（PMA）慢性处理大鼠血管平滑肌细胞各亚型蛋白激酶C（PKCs）表达的影响。方法原代培养大鼠m管平滑肌细胞，①按照PMA处理浓度将细胞随机分为空白组、0．25％eDMSO组和PMAI、5、10μmol／L组，各组细胞均处理4h；②按照PMA处理时间将细胞随机分为空白组、0．25％eDMSO组和PMA1、4和24h组，PMA组的药物浓度均为10μmol／L。采用Western blotting技术榆测各亚型PKCs蛋白的表达。结果PMA浓度〈10μmol／L处理细胞时间〈4h不影响PKC—α的表达（P〉0．05），10pmlol／LPMA处理24h能抑制PKC—α的表达（P〈0．05）；PMA浓度〉5μmol／L处理细胞时间〉4h可明显抑制PKC-δ的表达（P〈0．01），PMA浓度〈5μmlol／L处理细胞时间〈4h对PKC-δ的表达无显著影响（P〉0．05），10μmol／LPMA处理细胞1h即可明显抑制PKC-δ的表达（P〈0．01）；PMA浓度〉5pμmol／L处理细胞时间〉4h可以明显抑制PKC-θ的表达（P〈0．01）；10μmol／L的PMA处理细胞24h对PKC．∈的表达无明显影响（P〉0．05）。结论PMA慢性处理大鼠血管平滑肌细胞可抑制传统型PKC—α和新型PKC-δ、ε、θ的表达，对非典型PKC-ζ的表达没有影响。

Changes of protein kinase C isoforms in rat vascular smooth muscle cells treated with prolonged incubation of PMA

Objective To investigate the changes of protein kinase C （PKC） isoforms in rat vascular smooth muscle cells （VSMCs） treated with prolonged incubation of phorbol-12-myristate-13-acetate （PMA）. Methods Primary rat vascular smooth muscle cells cultured in vitro were divided into blank group, 1, 5, and 10 μmol/L PMA-treated groups, and 0.25%v DMSO-treated group, and all cells were treated for 4 h. The other cells were treated with 10 μmol/L PMA for 1, 4, and 24 h and with 0.25% DMSO for 24 h. The levels of PKCs were measured using Western blotting. Results In 1, 5, and 10 μmol/L PMA-treated groups for 4 h, the levels of PKC-α had no significant changes （P 〉 0.05）, while in 10 μmol/L PMA-treated group for 24 h, PKC-α was down-regulated significantly （P 〈 0.05）. PKC-α expression was down-regulated obviously in VSMCs treated with PMA （〉5 μmol/L for over 4 h）（P 〈 0.01）. PKC-α expression had no changes in PMA- treated groups （〈 5 μmol/L shorter than 4 h） （P 〉 0.05）, while PKC-α decreased remarkably in PMA group （ 10μmol/L for 1 h） （P 〈 0.01）. PKC-0 expression was down-regulated obviously in VSMCs treated with PMA （ 〉 5 μmol/L for over 4 h）（P 〈 0.01）. Level of PKC-μ had no changes in PMA group （10 μmol/L for 24 h）（P 〉 0.05）. Conclusion Prolonged treatment with PMA down-regulated classical PKC-α and novel PKC- δ, ε, and θ in VSMCs, while had no effect on atypical PKC-ζ.