Hepatoprotective and anti-fibrotic functions of interleukin-22: Therapeutic potential for the treatment of alcoholic liver disease

Authors

  • Xiaoni Kong,

    Corresponding author
    1. School of Biomedical Engineering and Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China
    • Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
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  • Dechun Feng,

    1. Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
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  • Stephanie Mathews,

    1. Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
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  • Bin Gao

    1. Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
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Correspondence

Dr Xiaoni Kong, School of Biomedical Engineering and Med-X Research Institute, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China. Email: xiaonikong@sjtu.edu.cn

Abstract

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Interleukin-22 (IL-22) plays a key role in promoting antimicrobial immunity and tissue repair at barrier surfaces by binding to the receptors IL-22R1, which is generally thought to be expressed exclusively in epithelial cells, and IL-10R2. Our laboratory previously demonstrated that IL-22 plays an important role in ameliorating liver injury in many rodent models by targeting hepatocytes that express high levels of IL-22R1 and IL-10R2. Recently, we have identified high expression levels of IL-22R1 and IL-10R2 in liver progenitor cells and hepatic stellate cells (HSCs). Overexpression of IL-22 in vivo or treatment with IL-22 in vitro promotes proliferation of liver progenitor cells via a signal transducer and activator of transcription 3 (STAT3)-dependent mechanism. IL-22 treatment also prevents HSC apoptosis in vitro and in vivo. Surprisingly, overexpression of IL-22, via either gene targeting or exogenous administration of adenovirus expressing IL-22, reduces liver fibrosis and accelerates the resolution of liver fibrosis during recovery. The anti-fibrotic effects of IL-22 are mediated via the activation of STAT3 in HSCs and subsequent induction of suppressor of cytokine signaling 3, which induces HSC senescence. Taken together, the hepatoprotective, mitogenic, and anti-fibrotic effects of IL-22 are beneficial in ameliorating alcoholic liver injury. Importantly, due to the restricted expression of IL-22R1, IL-22 therapy is expected to have few side effects, thus making IL-22 a potential candidate for treatment of alcoholic liver disease.

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