Discrepant roles of CpG ODN on acute alcohol-induced liver injury in mice

Increasing evidence suggests that the alcoholic liver injury is associated with activation of Toll-like receptors (TLRs) and the consequent over-production of inflammatory cytokines such as TNF-α. However, few studies have evaluated the effect of CpG ODN, a TLR9 agonist, on alcoholic liver injury. In this study, an animal model of acute alcohol-induced liver injury was established by administering the mice with alcohol at 7 g/kg intragastrically once. Using the model, 2216, an A-type CpG ODN, was found able to dramatically elevate serum ALT levels and aggravate pathological changes of liver in mice. In contrast, 2006, a B-type CpG ODN, caused elevation of serum ALT levels with no visible aggravation of liver pathological changes; YW002, a C-type CpG ODN, caused no elevation of serum ALT levels and seemed able to lessen pathological changes in the liver of the mice. Real-time RT-PCR revealed that 2216 dramatically up-regulated the expression of TLR9 and TNF-α and YW002 was unable to up-regulate expression of TLR9 and TNF-α, instead up-regulate the expression of IFN-α in the livers of the model mice. The data suggest that 2216 could aggravate alcohol-induced liver injury by inducing the up-regulation of hepatic TLR9 and TNF-α and that YW002 could alleviate the pathological changes induced by acute alcohol intake by up-regulating IFN-α, possibly.

► Administration of alcohol at 7 g/kg could cause acute alcohol-induced liver injury in mice.
► CpG ODN of different types has distinct effect on acute alcohol-induced liver injury in mice.
► A-type CpG ODN could aggravate acute alcohol-induced liver injury in mice.
► C-type CpG ODN trended to alleviate acute alcohol-induced liver injury in mice.