title: Interleukin-22 treatment ameliorates alcoholic liver injury in a murine model of chronic-binge ethanol feeding: role of signal transducer and activator of transcription 3.
abstract: Interleukin-22 (IL-22), a recently identified member of the IL-10 family of cytokines that is produced by Th17 and natural killer cells, plays an important role in controlling bacterial infection, homeostasis, and tissue repair. Here, we tested the effect of IL-22 on alcohol-induced liver injury in a murine model of chronic-binge ethanol feeding. Feeding male C57BL/6 mice with a Lieber-DeCarli diet containing 5% ethanol for 10 days, followed by a single dose of ethanol (5 g/kg body weight) by gavage, induces significant fatty liver and liver injury with peak serum levels of approximately 250 IU/L alanine aminotransferase and 420 IU/L aspartate aminotransferase 9 hours after gavage. Moreover, chronic-binge ethanol administration increases expression of hepatic and serum inflammatory cytokines and hepatic oxidative stress. Using this model, we demonstrate that treatment with IL-22 recombinant protein activates hepatic signal transducer and activator of transcription 3 (STAT3) and ameliorates alcoholic fatty liver, liver injury, and hepatic oxidative stress. Administration with IL-22 adenovirus also prevents alcohol-induced steatosis and liver injury. Deletion of STAT3 in hepatocytes abolishes the hepatoprotection provided by IL-22 in alcoholic liver injury. In addition, IL-22 treatment down-regulates the hepatic expression of fatty acid transport protein, but up-regulates several antioxidant, antiapoptotic, and antimicrobial genes. Finally, expression of IL-22 receptor 1 is up-regulated whereas IL-22 is undetectable in the livers from mice with chronic-binge ethanol feeding or patients with alcoholic hepatitis.
  
  
  CONCLUSIONS
  Chronic-binge ethanol feeding may be a useful model to study the early stages of alcoholic liver injury. IL-22 treatment could be a potential therapeutic option to ameliorate alcoholic liver disease, due to its antioxidant, antiapoptotic, antisteatotic, proliferative, and antimicrobial effects with the added benefit of potentially few side effects.
authors.affiliation: Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism (NIAAA), National Institutes of Health (NIH), Bethesda, MD 20892, USA.
authors.forename: Sung Hwan
authors.initials: SH
authors.lastname: Ki
authors.forename: Oygi
authors.initials: O
authors.lastname: Park
authors.forename: Mingquan
authors.initials: M
authors.lastname: Zheng
authors.forename: Oriol
authors.initials: O
authors.lastname: Morales-Ibanez
authors.forename: Jay K
authors.initials: JK
authors.lastname: Kolls
authors.forename: Ramon
authors.initials: R
authors.lastname: Bataller
authors.forename: Bin
authors.initials: B
authors.lastname: Gao
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D000437:Alcoholism / Q000378:metabolism; D000818:Animals; D001219:Aspartate Aminotransferases; D004195:Disease Models, Animal; D015536:Down-Regulation; D000431:Ethanol / Q000506:poisoning*; D050612:Fatty Acid Transport Proteins / Q000096:biosynthesis; D005235:Fatty Liver, Alcoholic / Q000517:prevention & control; D006801:Humans; D007378:Interleukins / Q000627:therapeutic use*; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008108:Liver Diseases, Alcoholic / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018123:Receptors, Interleukin / Q000096:biosynthesis; D050796:STAT3 Transcription Factor / Q000172:deficiency / Q000502:physiology*; D015854:Up-Regulation; D000097043:Interleukin-22
chemical_list: D000410:Alanine Transaminase; D001219:Aspartate Aminotransferases; D000431:Ethanol; D050612:Fatty Acid Transport Proteins; D007378:Interleukins; D018123:Receptors, Interleukin; D050796:STAT3 Transcription Factor; D000097043:Interleukin-22; C494087:Stat3 protein, mouse; C415369:interleukin-22 receptor