NADPH Oxidase 1 in Liver Macrophages Promotes Inflammation and Tumor Development in Mice

Shuang Liang, Hsiao Yen Ma, Zhenyu Zhong, Debanjan Dhar, Xiao Liu, Jun Xu, Yukinori Koyama, Takahiro Nishio, Daniel Karin, Gabriel Karin, Ryan Mccubbin, Cuili Zhang, Ronglin Hu, Guizhi Yang, Li Chen, Souradipta Ganguly, Tian Lan, Michael Karin, Tatiana Kisseleva, David A. Brenner

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9 Scopus citations

Abstract

Background & Aims: Although there are associations among oxidative stress, reduced nicotinamide adenine dinucleotide phosphate oxidase (NOX) activation, and hepatocellular carcinoma (HCC) development, it is not clear how NOX contributes to hepatocarcinogenesis. We studied the functions of different NOX proteins in mice after administration of a liver carcinogen. Methods: Fourteen-day-old Nox1 –/– mice, Nox4 –/– mice, Nox1 –/– Nox4 –/– (double-knockout) mice, and wild-type (WT) C57BL/6 mice were given a single intraperitoneal injection of diethylnitrosamine (DEN) and liver tumors were examined at 9 months. We also studied the effects of DEN in mice with disruption of Nox1 specifically in hepatocytes (Nox1 ΔHep ), hepatic stellate cells (Nox1 ΔHep ), or macrophages (Nox1 ΔMac ). Some mice were also given injections of the NOX1-specific inhibitor ML171. To study the acute effects of DEN, 8–12-week-old mice were given a single intraperitoneal injection, and liver and serum were collected at 72 hours. Liver tissues were analyzed by histologic examination, quantitative polymerase chain reaction, and immunoblots. Hepatocytes and macrophages were isolated from WT and knockout mice and analyzed by immunoblots. Results: Nox4 –/– mice and WT mice developed liver tumors within 9 months after administration of DEN, whereas Nox1 –/– mice developed 80% fewer tumors, which were 50% smaller than those of WT mice. Nox1 ΔHep and Nox1 ΔHSC mice developed liver tumors of the same number and size as WT mice, whereas Nox1 ΔMac developed fewer and smaller tumors, similar to Nox1 –/– mice. After DEN injection, levels of tumor necrosis factor, interleukin 6 (IL6), and phosphorylated signal transducer and activator of transcription 3 were increased in livers from WT, but not Nox1 –/– or Nox1 ΔMac , mice. Conditioned medium from necrotic hepatocytes induced expression of NOX1 in cultured macrophages, followed by expression of tumor necrosis factor, IL6, and other inflammatory cytokines; this medium did not induce expression of IL6 or cytokines in Nox1 ΔMac macrophages. WT mice given DEN followed by ML171 developed fewer and smaller liver tumors than mice given DEN followed by vehicle. Conclusions: In mice given injections of a liver carcinogen (DEN), expression of NOX1 by macrophages promotes hepatic tumorigenesis by inducing the production of inflammatory cytokines. We propose that upon liver injury, damage-associated molecular patterns released from dying hepatocytes activate liver macrophages to produce cytokines that promote tumor development. Strategies to block NOX1 or these cytokines might be developed to slow hepatocellular carcinoma progression.

Original languageEnglish (US)
Pages (from-to)1156-1172.e6
JournalGastroenterology
Volume156
Issue number4
DOIs
StatePublished - Mar 2019
Externally publishedYes

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Keywords

  • Hepatocellular carcinoma
  • Inflammation
  • Macrophage
  • Reactive oxygen species

ASJC Scopus subject areas

  • Hepatology
  • Gastroenterology

Cite this

Liang, S., Ma, H. Y., Zhong, Z., Dhar, D., Liu, X., Xu, J., Koyama, Y., Nishio, T., Karin, D., Karin, G., Mccubbin, R., Zhang, C., Hu, R., Yang, G., Chen, L., Ganguly, S., Lan, T., Karin, M., Kisseleva, T., & Brenner, D. A. (2019). NADPH Oxidase 1 in Liver Macrophages Promotes Inflammation and Tumor Development in Mice. Gastroenterology, 156(4), 1156-1172.e6. https://doi.org/10.1053/j.gastro.2018.11.019