Gong Chunmei, Yang Linqing, Tao Gonghua, Liu Qingcheng, Liu Jianjun, Zhuang Zhixiong
Shenzhen Center for Chronic Disease Control, Shenzhen 518020, China.
Wei Sheng Yan Jiu. 2013 Mar;42(2):179-84.
To observe the effect of SiO2 nanoparticles on genome DNA methylation profile in cultured cells.
HaCaT cells were treated with nm-SiO2 at 2.5, 5 and 10 microg/ml and micro-SiO2 at 10 microg/ml for 24h and DAC treatment was given at 10 microg/ml group for 48h. The mC/(mC + C) percent was quantified by high performance capillary electrophoresis (HPCE) assay, and the expression level of mRNA and protein was detected by Real-time Q-PCR and westernblot assay. The activity of DNMTs was determined by DNA Methyltransferase Activity/Inhibition Assay Kit.
HPCE assay showed that nm-SiO2-treated cells were decreased in some degree. An average proportion of methylated mC/ (mC + C) was 4.82% in control, 2.7% in 2.5 microg/ml and 2.17% in 10 microg/ml groups, while 3.1% in micro-SiO2 groups, which got the consistent downtrend of genome methylation level during increasing nm-SiO2 dose nanoparticles. The mRNA expression level for DNMT1 decreased gradually with increased dose of nm-SiO2 nanoparticles. The alterations at protein level were similar to those at the mRNA level.
Genomic DNA methylation levels were decreased in HaCaT cells after short-term exposure to SiO2 nanoparticles.
观察二氧化硅纳米颗粒对培养细胞基因组DNA甲基化谱的影响。
将HaCaT细胞分别用2.5、5和10μg/ml的纳米二氧化硅以及10μg/ml的微米二氧化硅处理24小时，对10μg/ml组给予48小时的地西他滨（DAC）处理。通过高效毛细管电泳（HPCE）测定法对甲基化胞嘧啶（mC）/（mC + C）百分比进行定量，并通过实时定量聚合酶链反应（Real-time Q-PCR）和蛋白质免疫印迹法检测mRNA和蛋白质的表达水平。使用DNA甲基转移酶活性/抑制测定试剂盒测定DNA甲基转移酶（DNMTs）的活性。
HPCE测定显示纳米二氧化硅处理的细胞在一定程度上有所下降。对照组中甲基化的mC/（mC + C）平均比例为4.82%，2.5μg/ml组为2.7%，10μg/ml组为2.17%，而微米二氧化硅组为3.1%，随着纳米二氧化硅剂量增加，基因组甲基化水平呈一致的下降趋势。DNMT1的mRNA表达水平随着纳米二氧化硅纳米颗粒剂量的增加而逐渐降低。蛋白质水平的变化与mRNA水平相似。
短期暴露于二氧化硅纳米颗粒后，HaCaT细胞的基因组DNA甲基化水平降低。
