Effects of sodium arsenite on lipid metabolism in human hepatocytes and regulatory factors
BACKGROUND:The liver,as the main target organ for arsenic toxicity,has become the focus of studies related to the mechanism of action of arsenic toxicity.OBJECTIVE:To investigate the effects of sodium arsenite(NaAsO2)on lipid metabolism,cell proliferation,apoptosis,and expression of related regulatory factors in human normal hepatocytes.METHODS:MIHA normal human hepatocyte cell lines were exposed to 0,10,20,and 30 µmol/L NaAsO2 for 48 hours.Cell morphology changes were observed by light microscopy.Cell viability was detected by CCK-8 assay.The cell serum total cholesterol,triacylglycerol,and total bile acids were detected by single-agent COD-PAP assay,single-agent GPO-PAP assay,and enzyme microplate assay.The intracellular lipid content was detected by oil red O staining.Cell proliferation was detected by Edu-488 infiltration.Cell cycle and apoptosis were detected by PI staining and Annexin V-FITC/PI dual-labeling combined with flow cytometry.The mRNA and protein expression levels of hepatocyte nuclear factor 4 alpha,cholesterol 7α-hydroxylase,and farnesoid X receptor were detected by real-time fluorescence quantitative PCR and western blot assay,respectively.RESULTS AND CONCLUSION:(1)Compared with the control group(0 µmol/L NaAsO2),with the increase of NaAsO2 concentration:MIHA cell viability decreased gradually.The content of total cholesterol and triacylglycerol in cell supernatant increased gradually,while the contents of total bile acids decreased gradually.The content of intracellular lipid increased gradually.The proportion of cells stagnating in S phase and G2/M phase gradually increased,and the apoptosis rate gradually increased.The expression level of hepatocyte nuclear factor 4 alpha mRNA did not show significant changes,while cholesterol 7α-hydroxylase and farnesoid X receptor mRNA expression levels decreased.The protein expression levels of hepatocyte nuclear factor 4 alpha,cholesterol 7α-hydroxylase,and farnesoid X receptor decreased gradually.(2)NaAsO2 has cytotoxicity,significantly reduces MIHA cell viability,induces cell steatosis,inhibits cell proliferation,and induces cell apoptosis.NaAsO2 down-regulates hepatocyte nuclear factor 4 alpha protein expression and the transcription and expression of cholesterol 7α-hydroxylase and farnesoid X receptor,which further induces lipid metabolism disorders in hepatocytes.
sodium arseniteMIHA cellcholesterol 7α-hydroxylasefarnesol X receptorcell cyclecell apoptosisoil red O staininglipid metabolism