Padronização de um modelo in vitro da doença hepática gordurosa associada ao metabolismo e caracterização do estresse oxidativo

Abstract

Metabolism-associated fatty liver disease (MAFLD) represents a wide spectrum of clinical and pathological conditions of the liver characterized by the accumulation of triacylglycerols in hepatocytes, which may progress to steatohepatitis, fibrosis and eventually to cirrhosis and hepatocellular carcinoma. The etiopathogenesis of MAFLD is multifactorial and asymptomatic and, although its molecular mechanisms are not yet understood, oxidative stress is considered the main determinant. Therefore, the aim of this study was to establish an in vitro model of MAFLD in HepG2 cells. To fat-overloading induction, cells were kept in DMEM medium, deprived of fetal bovine serum for 24 hours and then incubated with fatty acids, palmitic (0.7mM) or mixture of oleic and palmitic acids (1mM and 2mM) in proportion 2: 1, respectively. To quantify the intracellular lipid content, cells were stained with Oil red O, cell viability and cytotoxicity were evaluated using the MTT and LDH release techniques, respectively, hepatocellular damage by the release of liver aminotransferases and oxidative stress through quantification of lipid peroxidation biomarkers and total glutathione levels. The lipid content was significantly higher in cells exposed to a mixture of fatty acids at concentrations of 1 and 2mM, with no reduction in viability or increased levels of aminotransferases and LDH release. The lipid peroxidation biomarker also did not increase after treatment, but reduced levels of total glutathione were evidenced. The results obtained demonstrate that the proposed model was efficient in inducing steatosis and oxidative stress in HepG2 cells, especially when exposed to concentrations of 1 and 2mM of the lipid mixture.