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ABSTRACT: Background & aims
The inflammasome is a well-characterized inducer of inflammation in alcoholic steatohepatitis (ASH). Inflammasome activation requires two signals for mature interleukin (IL)-1β production. Here we asked whether metabolic danger signals trigger inflammasome activation in ASH.Methods
Wild-type mice, ATP receptor 2x7 (P2rx7)-KO mice, or mice overexpressing uricase were fed Lieber-DeCarli ethanol or control diet. We also implemented a pharmacological approach in which mice were treated with probenecid or allopurinol.Results
The sterile danger signals, ATP and uric acid, were increased in the serum and liver of alcohol-fed mice. Depletion of uric acid or ATP, or lack of ATP signaling attenuated ASH and prevented inflammasome activation and its major downstream cytokine, IL-1β. Pharmacological depletion of uric acid with allopurinol provided significant protection from alcohol-induced inflammatory response, steatosis and liver damage, and additional protection was achieved in mice treated with probenecid, which depletes uric acid and blocks ATP-induced P2rx7 signaling. We found that alcohol-damaged hepatocytes released uric acid and ATP in vivo and in vitro and that these sterile danger signals activated the inflammasome in LPS-exposed liver mononuclear cells.Conclusions
Our data indicate that the second signal in inflammasome activation and IL-1β production in ASH results from the endogenous danger signals, uric acid and ATP. Inhibition of signaling triggered by uric acid and ATP may have therapeutic implications in ASH.
SUBMITTER: Iracheta-Vellve A
PROVIDER: S-EPMC4615393 | biostudies-literature | 2015 Nov
REPOSITORIES: biostudies-literature
Iracheta-Vellve Arvin A Petrasek Jan J Satishchandran Abhishek A Gyongyosi Benedek B Saha Banishree B Kodys Karen K Fitzgerald Katherine A KA Kurt-Jones Evelyn A EA Szabo Gyongyi G
Journal of hepatology 20150620 5
<h4>Background & aims</h4>The inflammasome is a well-characterized inducer of inflammation in alcoholic steatohepatitis (ASH). Inflammasome activation requires two signals for mature interleukin (IL)-1β production. Here we asked whether metabolic danger signals trigger inflammasome activation in ASH.<h4>Methods</h4>Wild-type mice, ATP receptor 2x7 (P2rx7)-KO mice, or mice overexpressing uricase were fed Lieber-DeCarli ethanol or control diet. We also implemented a pharmacological approach in whi ...[more]