Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark.
Sino-Danish College (SDC), University of Chinese Academy of Sciences, 380 Huaibeizhuang, Beijing 100101, China.
Cells. 2022 Oct 13;11(20):3216. doi: 10.3390/cells11203216.
Non-alcoholic fatty liver disease affects one-fourth of the world's population. Central to the disease progression is lipid accumulation in the liver, followed by inflammation, fibrosis and cirrhosis. The underlying mechanism behind the early stages of the disease is poorly understood. We have exposed human hepatic HepG2/C3A cells-based spheroids to 65 μM oleic acid and 45 μM palmitic acid and employed proteomics and lipidomics analysis to investigate their effect on hepatocytes. The treatment successfully induced in vivo hallmarks of NAFLD, as evidenced by intracellular lipid accumulation and increased ATP levels. Quantitative lipidome analysis revealed an increase in ceramides, LPC and saturated triglycerides and a decrease in the ratio of PC/PE, similar to the changes observed in patients' liver biopsies. The proteomics analysis combined with qPCR showed increased epithelial to mesenchymal transition (EMT) signalling. Activation of EMT was further validated by transcriptomics in TGF-β treated spheroids, where an increase in mesenchymal cell markers (N-cadherin and collagen expression) was found. Our study demonstrates that this model system thus closely echoes several of the clinical features of non-alcoholic fatty liver disease and can be used to investigate the underlying molecular changes occurring in the condition.
非酒精性脂肪性肝病影响了世界四分之一的人口。该疾病进展的核心是肝脏中的脂质积累，随后是炎症、纤维化和肝硬化。该疾病早期的潜在机制尚未得到很好的理解。我们将基于人肝 HepG2/C3A 细胞的球体暴露于 65 μM 油酸和 45 μM 棕榈酸，并采用蛋白质组学和脂质组学分析来研究它们对肝细胞的影响。该治疗成功地诱导了体内非酒精性脂肪性肝病的特征，如细胞内脂质积累和 ATP 水平增加。定量脂质组学分析显示神经酰胺、LPC 和饱和甘油三酯增加，PC/PE 比值降低，与患者肝活检中观察到的变化相似。蛋白质组学分析结合 qPCR 显示上皮间质转化 (EMT) 信号增加。在 TGF-β处理的球体中转录组学进一步验证了 EMT 的激活，发现间充质细胞标志物（N-钙黏蛋白和胶原蛋白表达）增加。我们的研究表明，该模型系统因此紧密反映了非酒精性脂肪性肝病的一些临床特征，可用于研究该疾病中发生的潜在分子变化。
