Helicobacter hepaticus infection induces chronic hepatitis and fibrosis in male BALB/c mice via the activation of NF-κB, Stat3, and MAPK signaling pathways

Helicobacter. 2020 Apr;25(2):e12677. doi: 10.1111/hel.12677. Epub 2019 Dec 27.

Abstract

Background: It has been documented that Helicobacter hepaticus (H hepaticus) infection is linked to chronic hepatitis and liver cancer. However, our understanding of the molecular mechanisms underlying progression of the H hepaticus-induced hepatic inflammation to cellular hepatocarcinoma is still limited.

Materials and methods: In our study, male BALB/c mice were infected by H hepaticus for 8, 12, 16, 20, and 24 weeks. Histopathology, H hepaticus colonization dynamics, select signaling pathways, and expression of key inflammatory cytokines in the liver were examined.

Results: We found that H hepaticus was detectible in feces of mice at 7 days postinfection (DPI) by PCR, but it was not detected in the livers by PCR until 8 weeks postinfection (WPI). In addition, abundance of colonic and hepatic H hepaticus was progressively increased over the infection duration. H hepaticus-induced hepatic inflammation and fibrosis were aggravated over the infection duration, and necrosis or cirrhosis developed in the infected liver at 24 WPI H hepaticus infection increased levels of alanine aminotransferase and aspartate aminotransferase. Moreover, mRNA levels of Il-6 and Tnf-α were significantly elevated in the livers of H hepaticus-infected mice compared to uninfected control from 8 WPI to 24 WPI. Furthermore, Stat3, nuclear factor-κB (p65), and MAPK (Erk1/2 and p38) were activated by H hepaticus infection.

Conclusions: These data demonstrated that male BALB/c mice can be used as a new mouse model of H hepaticus-induced liver diseases and that the H hepaticus-induced liver injury is triggered by NF-κB, Jak-Stat, and MAPK signaling pathways.

Keywords: H hepaticus; BALB/c mice; NF-κB/stat3/MAPK; hepatic fibrosis/cirrhosis.

MeSH terms

  • Animals
  • Cytokines / biosynthesis
  • Feces / microbiology
  • Fibrosis / microbiology*
  • Helicobacter Infections / pathology
  • Helicobacter hepaticus* / genetics
  • Helicobacter hepaticus* / isolation & purification
  • Hepatitis, Chronic / microbiology*
  • Liver / microbiology
  • Liver / pathology
  • Liver Neoplasms / microbiology
  • MAP Kinase Signaling System*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Models, Animal
  • NF-kappa B / metabolism*
  • STAT3 Transcription Factor / metabolism*
  • Signal Transduction
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Cytokines
  • NF-kappa B
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • p38 Mitogen-Activated Protein Kinases