Objective: To establish an in vitro model applicable for fatty liver lipotoxicity pharmacological research.
Methods: HepG2 cells were cultured with rat serum instead of fetal bovine serum and with long-chain free fatty acid (FFA) added. The tested indices were: the content of serum TNFa, cellular triglycerides (TG) content, Oil Red staining and ultrastructural changes; protein expression and gene expression of cellular TNFa, and the expression and distribution of cathepsin B (Ctsb).
Results: After incubation with FFA for 24 hours, the TG deposition of HepG2 in the model group increased markedly and TG content was 627.24 mg/g protein (t = 23.6, P less than 0.01), TNFa content in the cell supernatant also increased to 52.04 pg/mg protein (t = 2.6, P less than 0.05). Compared with those of the normal group, the protein expression and mRNA expression of cellular TNFa and Ctsb also increased significantly.
Conclusion: FFA could induce a model of HepG2 steatosis with TNFa secretion through the Ctsb signal pathway using rat serum in the culture media. The method is simple and economical, which is an ideal model applicable for fatty liver lipotoxicity pharmacological research.