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    PI3K/AKT/GSK-3β信号通路在转录后水平调控ICAM-1的表达

    PI3K/AKT/GSK-3(HUVEC)ICAM-1mRNA PI3K/AKT/GSK-3 signaling pathways regulate ICAM-1 expression at the post transcriptional level

    • 摘要: 目的 探讨PI3K/AKT/GSK-3β信号通路调控脂多糖诱导的人脐静脉内皮细胞(HUVEC)ICAM-1的表达及其机制。方法1.LPS(10μg/ml)刺激HUVEC 0、6、12和24h或者0、4、8和12h或者0、30、60和120min后,western blot检测ICAM-1、PI3K、p-PI3K、AKT、p-AKT、GSK-3β和p-GSK-3β的表达,实时荧光定量PCR(qPCR)检测ICAM-1 mRNA的表达;2.将40、80和100nM 浓度的PI3K、AKT和GSK-3β siRNA分别转染HUVEC,对照组转染control siRNA,western blot检测PI3K、AKT和GSK-3β总蛋白的表达;3.将PI3K、AKT和GSK-3β的siRNA分别转染HUVEC,对照组转染control siRNA,LPS刺激细胞30min、60min、8h和12h,western blot检测p-AKT、 p-GSK-3β和ICAM-1的表达,qPCR检测ICAM-1 mRNA的表达;4.转染方法同上,LPS刺激HUVEC 8h后加入放线菌素D(5μg/ml)抑制转录,于0、1、2、3和4h收集细胞,qPCR检测ICAM-1 mRNA 的表达并计算mRNA的半衰期。 结果 1.LPS刺激HUVEC后可诱导ICAM-1的表达,其中12h表达量最高,与6h和24h相比差异有统计学意义(P<0.01,P<0.05);可增强ICAM-1 mRNA的转录,其中8h mRNA表达量最高,与4h和12h相比差异有统计学意义(P<0.01,P<0.05); LPS 刺激HUVEC后可诱导PI3K、AKT和GSK-3β蛋白的磷酸化,且三者的磷酸化水平分别在刺激后30min、60min和60min最高;2. PI3K、AKT和GSK-3β转染组的最适转染浓度为100nM;3. PI3K转染组的p-AKT和p-GSK-3β水平下降(P<0.01),AKT转染组p-GSK-3β水平下降(P<0.01),PI3K和AKT转染组ICAM-1的蛋白和mRNA水平均显著增加(P<0.05,P<0.01;P<0.01,P<0.01),而GSK-3β转染组ICAM-1的蛋白和mRNA水平均显著降低(P<0.01);4. PI3K、AKT和GSK-3β的沉默表达显著降低ICAM-1的mRNA半衰期(P<0.01)。结论1. LPS刺激HUVEC后可诱导ICAM-1的表达;2. LPS通过激活PI3K/AKT/GSK-3β信号通路负向调控HUVEC表达ICAM-1;3. PI3K、AKT和GSK-3β在转录后水平调控ICAM-1的mRNA稳定性。

       

      Abstract: Objective To explore the effect and the mechanism of PI3K/AKT/GSK-3β signaling pathways on the expression of intercellular adhesion molecule-1 (ICAM-1) induced by lipopolysaccharides (LPS) in h uman umbilical vein endothelial cells (HUVECs). Methods 1. HUVECs were treated with LPS(10 μg/ml) for 0 , 6,12 and 24hours , 0, 4, 8 and 12hours, and 0, 30, 60 and 120minutes, the protein and mRNA levels of ICAM-1 were measured by western blot and real-time quantitative PCR ( qPCR) respectively, the expression of PI3K, phospho-PI3K, AKT, phospho-AKT, GSK-3β and pho spho-GSK-3β were measured by western blot; 2. HUVECs were transfected by PI3K, AKT, GSK-3 β and control siRNA respectively, the t ransfection concentration gradient was 40, 80 and 100nM, the expression of PI3K, AKT and GSK-3β were measured by western blot; 3. HUVECs were transfected by PI3K, AKT, GSK-3β and control siRNA respectively, then stimulated with LPS for 30min, 60min, 8hours and 12hours, the expression of phospho-AKT, phospho-GSK-3β and ICAM-1 were measured by western blot, and mRNA levels of ICAM-1 was measured by qPCR; 4. The transfection method is same as above, the transfected cells were stimulated with LPS for 8 hours, then incubated with ActD (5μg/ml ) for 0, 1, 2, 3 and 4hours, mRNA levels of ICAM-1 was measured by qPCR , then calculated t he half-life of mRNAs. Results 1. HUVEC s could be induced the expression of ICAM-1 by LPS, and t he expression of 12h group reached at the peak value, and the difference was statistically significant compared with that of 6h and 24h group (P<0.01, P<0.05); the mRNA transcriptions of ICAM-1 induced by LPS in HUVECs were enhanced, and the expression of 8h group reached at the peak value, and the difference was statistically significant compared with that of 4h and 12h group (P<0.01,P<0.05); the phosphorylation of PI3K, AKT and GSK-3β could be induced by LPS in HUVECs, and the phosphorylation of them were highest at 30min, 60min and 60min respectively; 2. The optimal transfection concentration of PI3K, AKT and GSK-3β siRNA transfect ed group s were 100nM; 3. The PI3K transfected group decreased the expression of p-AKT, p-GSK-3β in HUVECs (P<0.01), the AKT transfected group decreased the expression of p-GSK-3β in HUVECs (P<0.01), PI3K and AKT transfected groups significantly enhanced the protein and mRNA levels of ICAM-1(P<0.05,P<0.01;P<0.01,P<0.01), but the GSK-3β transfected group significantly decreased the protein and mRNA levels of ICAM-1 (P<0.01); 4. The silent expression of PI3K, AKT and GSK-3β significantly reduced the mRNA half-life of ICAM-1 (P<0.01). Conclusion 1. LPS could induce the expression of ICAM-1 in HUVECs; 2. LPS negatively regulates the expression of ICAM-1 by activating the PI3K/AKT/GSK-3β signaling pathway in HUVECs; 3. PI3K , AKT and GSK-3β could regulate the mRNA stability of ICAM-1 at the post-transcriptional level .

       

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