槲皮素下调人角质形成细胞内NF-κB和IL-6表达的表观遗传学修饰效应

Study on the Epigenetic Effects of Quercetin on Down-regulation of NF-κB and IL-6 Expression in Human Keratinocytes

目的探讨纳米脂质体槲皮素(nanoliposomal quercetin,Q)下调角质形成细胞内核转录因子(NF-κB)和白介素-6(IL-6)表达的表观遗传学修饰效应,并与地塞米松(dexamethasone,D)的效应进行比较。方法将培养的HaCaT角质形成细胞分为三组:①IP-10+Q组:20ng/mL IP-10+40μmol/L Q;②IP-10+D组:20ng/mL IP-10+10-7mol/L D;③对照组(C组):20ng/mL IP-10,三组细胞均培养48h。对各组细胞进行p16INK4ɑ的甲基化特异PCR(MSP),将各组细胞内提取的蛋白质进行DNA甲基化转移酶1(DNMT1),组蛋白脱乙酰化酶1(HDAC1),NF-κBp65,CyclinD1,IL-6及P16的免疫印迹并对各组细胞进行HDAC1,IL-6免疫细胞化学染色,每组实验重复3次。对获得的数据进行相应的统计学处理。结果与C组相比,p16INK4ɑ的MSP显示:①组比②组p16INK4ɑ的DNA甲基化减低显著;免疫印迹显示:①组比②组的DNMT1,HDAC1,NF-κBp65,CyclinD1及IL-6的表达下调显著,p16INK4ɑ的表达上调显著;免疫细胞化学染色显示:①组比②组的IL-6及HDAC1的表达下调显著。以上差异均有统计学意义(P<0.05)。结论 Q和D通过下调p16INK4ɑ甲基化和HDAC1的表观遗传-NF-κB信号途径而下调角质形成细胞增殖的NF-κB和IL-6炎症因子的表达,且Q比D的下调作用更显著。

Objective To study on the epigenetic effects of quercetin （Q） on down-regulation of NF-KB and IL-6 expression in human keratinocytes, and compare the effects of Q with dexamethone （D）. Methods The cul- tured keratinocytes were divided into 3 groups ： （1）IP-10 ＋ Q group ： 20ng/mL IP-10 ＋ 40μmol/L Q ; （2）IP-10 ＋ D group ：20ng/mL IP-10 ＋ 10- 7 mol/L D and （3）control group （C） ：20 ng/mLIP-10. The methylation-specific PCR for p16^INK4a was performed at 48h after cultures. The expression levels of DNMT1, HDAC1, NF-κBp65, CyclinD1, IL-6 and p16^INK4a were assessed by Western blot. In addition, the expression levels of HDAC1 and IL-6 were evaluated by immunocytochemical staining. The dala（x ＋ s） were from three experiments. Results In comparison with the control group, the levels of methylated p16^INK4a were lower in both group （1） and group （2）（P 〈0.05）. The expression levels of DNMT1, HDAC1, NF-κBp65, Cyclin Dl or IL-6 were lower in group （1） than in group （2）（ P 〈 0.05 ）. In contrast, the expression levels of p16^INK4a were higher in group （1） than in group （2）（ P 〈 0.05 ）. Immunocytochemical staining showed that the levels of both HDAC1 and IL-6 expression were lower in groups （1） than in group （2）（ P 〈 0.05 ）. Conclusion Q and D inhibit NF-κB and IL-6 expression via down-regulation of pl 6＋NK4a methylation- and HDACl-associated epigenetic-NF-κB signaling. Quercetin is more effective than dethamethone.