gAcrp increased IL-10 mRNA and protein expression, as well as expression of the IL-10 inducible gene, HO-1; expression was higher in Kupffer cells from ethanol-fed rats compared with pair-fed selleck kinase inhibitor controls. Although IL-10 receptor surface expression on Kupffer cells was not affected by ethanol feeding, IL-10–mediated phosphorylation of STAT3 and expression of HO-1 was higher in Kupffer cells after ethanol feeding. Inhibition of HO-1 activity, either by treatment with the HO-1 inhibitor zinc protoporphyrin or by siRNA knockdown of HO-1, prevented the inhibitory effect of gAcrp on LPS-stimulated

TNF-α expression in Kupffer cells. LPS-stimulated TNF-α expression in liver was increased in mice after chronic ethanol exposure. When mice were treated with cobalt protoporphyrin to induce HO-1 expression, ethanol-induced sensitivity to LPS was ameliorated. Conclusion: gAcrp prevents LPS-stimulated TNF-α expression in Kupffer cells through the activation of the IL-10/STAT3/HO-1 pathway. Kupffer cells from ethanol-fed rats are highly sensitive to the anti-inflammatory effects of gAcrp; this sensitivity is associated with both increased expression and sensitivity to IL-10. (HEPATOLOGY 2010.) selleckchem The innate and adaptive immune systems have been implicated in the progression of alcoholic liver disease. Disruption in the regulation of the innate immune response is thought to be particularly important

in the early stages of ethanol-induced liver injury.1 Accumulating evidence suggests that an imbalance between the activities of

pro-inflammatory and anti-inflammatory mediators contributes to ethanol-induced liver injury. For example, ethanol consumption leads to elevated lipopolysaccharide (LPS)/endotoxin in the portal blood, as well as a sensitization of Kupffer cells to activation, resulting in production of a number of inflammatory mediators, including tumor necrosis factor alpha (TNF-α), interleukin (IL)-6 and reactive oxygen species. Among the pro-inflammatory mediators, TNF-α plays a critical role in the pathogenesis of alcoholic liver disease1; treatment with TNF-α neutralizing antibody reduces find more ethanol-induced liver injury in animals, and TNF-α receptor 1 knockout mice are resistant to the toxic effects of ethanol exposure.1 Loss of anti-inflammatory mediators also may contribute to a pro-inflammatory state in the liver and facilitate injury. For example, IL-10 is an immunomodulatory cytokine with potent anti-inflammatory and immunosuppressive properties. IL-10 decreases production of pro-inflammatory cytokines, including TNF-α and IL-1β.2 Although little is known about the regulation of IL-10 expression and activity in the liver in response to chronic ethanol, impaired expression of IL-10 contributes to inflammation in alcoholic patients with cirrhosis,3 and IL-10–deficient mice are more sensitive to ethanol-induced liver injury.