Abstract
Diabetes and obesity have been associated with nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) and increased incidence of hepatocellular carcinoma (HCC). Here we use optically transparent zebrafish to visualize liver inflammation and disease progression in a NAFLD/NASH-HCC model. We combined a high-cholesterol diet (HCD) with a transgenic zebrafish HCC model induced by hepatocyte-specific activated β-catenin and found that diet induced an increase in liver size and enhanced angiogenesis and neutrophil infiltration in the liver. Although macrophage number was not affected by diet, HCD induced changes in macrophage morphology and polarization with an increase in liver associated TNFα-positive macrophages. Treatment with metformin altered macrophage polarization and reduced liver size in NAFLD/NASH-associated HCC larvae. Moreover, ablation of macrophages limited progression in NAFLD/NASH-associated HCC larvae but not in HCC alone. These findings suggest that HCD alters macrophage polarization and exacerbates the liver inflammatory microenvironment and cancer progression in a zebrafish model of NAFLD/NASH-associated HCC.
- Abbreviations used in this paper
- NAFLD
- Nonalcoholic fatty liver disease
- NASH
- nonalcoholic steatohepatitis
- HCC
- hepatocellular carcinoma
- HCD
- high-cholesterol diet
- TME
- tumor microenvironment
- TNF
- tumor necrosis factor
- dpf
- days post-fertilization
- ND
- normal diet
- MTZ
- metronidazole
- NTR
- nitroreductase.
Authors Contribution
Conceived and designed experiments: SDO and AH. Performed experiments: SDO, RAH, AG, NG, BGK and VM. Performed analysis: SDO, RAH, AG and VM. Wrote the manuscript: SDO. Critically reviewed and edited the manuscript: RAH, NG, VM and AH
Footnotes
Grant Support: AH was funded by NCI CA085862; SDO is supported by EMBO ALTF 620-2015 and Cancer Research Institute/Fibrolamellar Cancer Foundation; NG is supported by Molecular Biosciences Training Grant T32-GM07215 and Laboratory for Optical and Computational Instrumentation and the Morgridge Institute for Research (KE); VM is supported by American Heart Association (17POST33410970)
Disclosures: The authors disclose no conflicts.