Chronic exposure to low concentration of MC-LR caused hepatic lipid metabolism disorder

Microcystin-LR (MC-LR), a potent hepatotoxin can cause liver damages. However, research on hepatic lipid metabolism caused by long-term exposure to environmental concentrations MC-LR is limited. In the current study, mice were exposed to various low concentrations of MC-LR (0, 1, 30, 60, 90, 120 mu g/L in the drinking water) for 9 months. The general parameters, serum and liver lipids, liver tissue pathology, lipid metabolismrelated genes and proteins of liver were investigated. The results show that chronic MC-LR exposure had increased the levels of triglyceride (TG) and total cholesterol (TC) in serum and liver. In addition, histological observation revealed that hepatic lobules were disordered with obvious inflammatory cell infiltration and lipid droplets. More importantly, the mRNA and proteins expression levels of lipid synthesis-related nuclear sterol regulatory element binding protein-1c (nSREBP-1c), SREBP-1c, cluster of differentiation 36 (CD36), acetyl-CoAcarboxylase1 (ACC1), stearoyl-CoA desaturase1 (SCD1) and fatty acid synthase (FASN) were increased in MC-LR treated groups, the expression levels of fatty acids I3-oxidation related genes peroxisomal acyl-coenzyme A oxidase 1 (ACOX1) was decreased after exposure to 60-120 mu g/L MC-LR. Furthermore, the inflammatory factors interleukin 6 (IL-6) and tumor necrosis factor-a (TNF-alpha) were higher than that in the control group. All the findings indicated that mice were exposed to chronic low concentrations MC-LR caused liver inflammation and hepatic lipid metabolism disorder .

Automated summary

This study found that chronic exposure to low concentrations of MC-LR caused a disorder in hepatic lipid metabolism and liver inflammation, indicating potential harm to liver health from MC-LR.