摘要研究内质网应激发生对微囊化细胞脂代谢调节的影响，探讨内质网应激拮抗剂对微囊化细胞生长代谢调控的可行性。采用静电液滴法制备微囊化细胞，Real-time PCR法检测微囊化对葡萄糖调节蛋白78（GRP78）和C/EBP同源蛋白（CHOP）表达影响；通过MTT法检测细胞活性,ELISA法检测白蛋白含量，乙烷-丙酮法抽提测定胞内总胆固醇和甘油三酯含量，并比较拮抗剂四苯基丁酸（4-PBA）干预后相关指标变化。结果显示，微囊细胞中内质网应激标识蛋白GRP78和 CHOP表达量分别为同天数下平面细胞3.6倍和1.9倍（P<0.05），胞内总胆固醇（CHO)和甘油三酯（TG）含量分别为平面细胞1.7倍和3.2倍（P<0.05）。内质网应激拮抗剂4-PBA在1.0 mM 可显著增加微囊化细胞活性。干预后GRP78和CHOP基因表达水平降低50%和30%（P<0.05），胞内CHO和TG含量降低30%和15%（P<0.05），并使白蛋白水平较对照组显著提高（P<0.05）。结果提示微囊内存在内质网应激，且与微囊细胞脂代谢失调有关；内质网应激拮抗剂能缓解微囊对细胞的以上作用。
Abstract：To investigate the relationship of endoplasmic reticulum stress and lipid metabolism imbalance in microencapsulated cells, we compared the expression of glucose regulating protein 78 (GRP78) and C/EBP homologous protein (CHOP) in HepG2 cells under different culture conditions using real-time PCR. Cell viability was measured by MTT and the content of cholesterol (CHO), triglyceride (TG) and albumin were evaluated through ELISA assay. The effect of 4-PBA treatment on above parameters were examined. Results show that the expression levels of GRP78 and CHOP in encapsulated cells were approximately 3.6 and 1.9 times higher than in monolayer cells (P<0.05). As for the contents of CHO and TG, they were elevated to 1.7 and 3.2 times higher than monolayer cells (P<0.05). With 1.0 mM 4-PBA treatment, genes expression of CHO and TG was reduced by 50% and 30%, respectively. Moreover, the contents of CHO and TG were reduced by 30% and 15%. The biosynthetic function was increased since day 10 with 4-PBA (P<0.05). In conclusion, endoplasmic reticulum stress exists in the microcapsules and affects lipid metabolism. Antagonist 4-PBA can prevent the inhibition effects of endoplasmic reticulum stress on cellular growth.
