BALB/c Mouse Model of Liver Fibrosis

Normal male BALB/c mice, aged 6 weeks and initially weighing 18 − 20 g, were purchased from the Laboratory Animal Center (Guangxi Medical University, Nanning, China). All animals received humane care. All experimental procedures on mice were approved by the ethics committee of The First Affiliated Hospital of Guangxi Medical University. The animals were housed in a controlled environment (12 h light/dark cycle; temperature: 22 − 24 °C) and received water ad libitum in the Animal Care Facility Service (Guangxi Medical University). The mice were divided into three groups, with six mice in each group: (1) the mice in group 1 were control animals and received a vehicle (olive oil); (2) the mice in group 2 were injected intraperitoneally with CCl4 (Sigma-Aldrich, St. Louis, MO, USA) (0.1 mL of a solution containing 20 g of CCl4 dissolved in olive oil at a 1:10 ratio) three times per week for 4 or 6 weeks to induce liver fibrosis; and (3) the mice in group 3 were injected intraperitoneally with CCl4 (0.1 mL of a solution containing 20 g of CCl4 dissolved in olive oil at a 1:10 ratio) three times per week for 4 or 6 weeks to induce liver fibrosis. All mice were killed under light ether anesthesia 72 h after the final dose of CCl4 or olive oil. The liver was immediately removed. All samples were kept on ice until analysis. First, the liver was cut into fragments. Then, liver samples were either stored in formaldehyde or snap-frozen in liquid nitrogen and stored at − 80 °C.