早期自噬在非酒精性脂肪肝中的保护作用

目的 探讨非酒精性脂肪肝细胞模型中早期自噬的发生及作用.方法 用含浓度为400μmol/L油酸的DMEM高糖培养基培养肝癌HepG2细胞,制作体外非酒精性脂肪肝细胞模型.向肝癌HepG2细胞转染GFP-LC3质粒,通过观察LC3Ⅱ绿色荧光斑点确定自噬的发生.采用PI3k抑制剂LY294002抑制自噬.Calcein A...

The protective role of early autophagy in nonalcoholic fatty liver

Objective To study the role of autophagy in nonalcoholic fatty liver (NAFL). Methods The in vitro model of NAFL of HepG2 cells was made by culturing cells in DMEM which contained 400μmol/L oleate. Transient transfection of GFP-LC3 plasmid was performed with Fugenes and autophagy was detected by whether LC3 puncta had formed. The PI3K inhibitor LY294002 was used to inhibit autophagy. Calcein AM and propidium iodide (PI) were used to detect whether apoptosis had developed. Real-time PCR was employed to detect the level of BAX mRNA. Results A bold autophagy could be detected in HepG2 cells cultured with oleate at 8 hours and there were little positive responses of LC3 puncta in HepG2 cells without oleate stimulus. Apoptosis development was not found by using Calcein AM/PI in HepG2 cells cultured with oleate at 8 hours. However, LY294002 treatment could decrease the level of autophagy and induce apoptosis development among 7.8% HepG2 cells. Real-time PCR revealed that LY294002 inhibited autophagy could induce a high expression of BAX at 8 hours in HepG2 cells cultured with oleate. Conclusion At early stage of culturing with oleate, autophagy development could protect HepG2 cells from apoptosis and the mechanism might be associated to decrease the expression of pro-apoptotic genes.