微囊化对HepG2细胞氧化应激基因表达影响及调控研究

Effect of Microencapsulation on the Expression of the Oxidative Stress Genes of HepG2 Cells and Exogenous Regulation

探讨微囊微环境对HepG2细胞氧化应激基因表达影响及外源性抗氧化物质干预效果。采用静电液滴法制备微囊化细胞,real-time PCR法检测不同培养方式下血红素加氧酶-1(HO-1)和谷胱甘肽转硫酶-A1(GST-A1)表达;通过MTT法检测细胞活性、ELISA法检测白蛋白含量,比较还原型谷胱甘肽(GSH)和N-乙酰半胱氨酸(NAC)干预后指标变化。结果显示,培养第6d和第16d时,微囊细胞中HO-1基因表达水平分别为同天数下平面细胞的4.9倍和3.1倍,GST-A1表达分别为平面细胞的11.2倍和33倍(P<0.05);添加5~10mmol/L NAC后,微囊化细胞活性较对照组增加40%~70%,白蛋白水平增加20%~30%(P<0.05),而GSH在10mmol/L时可使囊内细胞活性增加20%~55%,白蛋白水平增加15%(P<0.05)。结果提示微囊内存在氧化应激因素诱导基因表达改变,NAC和GSH能缓解其对细胞的抑制作用。

Abstract： The aim of this research is to investigate the influence of microencapsulation on the expression of the oxida- tive stress genes and exogenous regulation of HepG2 ceils. We compared the expression of hemeoxygenase-1 （HO-1） and glutathione S-transferases-A1 （GST-A1） in HepG2 ceils under different culture conditions through real-time PCR. The effects of exogenous antioxidants on cell viability and albumin levels were also evaluated through MTT as- say and ELISA assay. The results showed that after culturing for 6 and 16 days, the expression levels of HO-1 in en- capsulated cells were approximately 4. 9 and 3. 1 times higher than that of monolayer cells at the same culture period; As for the expression levels of GST-A1, they were elevated to 11.2 and 33 times of monolayer cells （P^0.05）. Ac- cordingly, we found that NAC at 5-10 mmol/L significantly increased the viability by 40 %-70 % and the biosynthetic function by 20%-30% in microencapsulated HepG2 cells （P^0.05）. GSH increased the viability of the encapsulated cells by 20%-55% and the biosynthetic function by 15% （P^0. 05）. In conclusion, oxidative stress exists in the mi- crocapsules and affects genes expression. Exogenous antioxidants can prevent the inhibition effects of oxidative stress on cellular growth.