Establishment of a standardized mouse model of hepatic fibrosis for biomedical research

Liver injury causes nodule and scar tissue formation and diffuse fibrosis, which are characteristic of liver cirrhosis. Since there are currently no efficacious therapies to prevent fibrosis, the development of animal models of liver fibrosis is necessary to facilitate further in vivo studies of this pathology. In this study, a mouse model of liver fibrosis was generated using Swiss mice and carbon tetrachloride (CCl4) treatment. Induction of liver fibrosis was analyzed using 0.8, 1.0, or 1.2 mL/kg CCl4 to determine the effective dose. In this study, we aimed to develop a standardized hepatic fibrosis mouse model by using CCl4 induction to facilitate further studies in this field. In Swiss mice, we evaluated the dose of CCl4 and the criteria of fibrosis, such as serum markers, fibrosis marker genes, and histopathology. Mice were administered CCl4 three times per week for 8 consecutive weeks. Body weights, survival rates, levels of serum markers (aspartate aminotransferase/alanine aminotransferase [AST/ALT]) and fibrosis markers (fibronectin, procollagen, nt5e, transforming growth factor-beta [TGF-β], and integrin), and histopathology (using hematoxylin and eosin [H&E] staining) were analyzed to determine the optimal dose of CCl4 for induction of liver fibrosis. Results showed that 1.0 mL/kg CCl4 was the most efficient dose for the establishment of a liver fibrosis mouse model. In a standardized liver fibrosis model, mice were treated with 1.0 mL/kg CCl4 three times per week for 11 consecutive weeks, and levels of serum markers (AST, ALT, bilirubin, and albumin), expression of fibrosis marker genes (using quantitative reverse transcription polymerase chain reaction [RT-PCR]), histopathology (using Hematoxylin and eosin staining), and connective tissue formation (using Massive trichrome staining) were analyzed. The outcomes showed that serum markers and the levels of fibrosis marker genes were significantly increased in the standardized liver fibrosis model. Additionally, we observed sharp increases in fibronectin and procollagen expression (1222.40 ± 4.20 and 241.35 ± 1.18, respectively), and the development of cirrhosis (fibrosis stage 3–5/6) in liver tissues of the standardized mouse model of hepatic fibrosis.