Effect of Nanoformulated Copper/Zinc Superoxide Dismutase on Chronic Ethanol-Induced Alterations in Liver and Adipose Tissue.

BACKGROUND: We previously reported that nanoformulated copper/zinc superoxide dismutase (Nano) attenuates non-alcoholic fatty liver disease and adipose tissue (AT) inflammation in obese animals. Here, we sought to determine whether Nano treatment attenuates alcohol-associated liver disease (AALD) and AT inflammation in alcohol-fed mice.

METHODS: We pre-treated E-47 cells (HepG2 cells that over-express CYP2E1) with native- or nano- SOD for 6 h, followed by treatment with ethanol and/or linoleic acid (LA), a free fatty acid. For in vivo studies, male C57BL/6 mice were fed the Lieber-DeCarli control or ethanol liquid diet for 4 wk. The mice received Nano once every two days during the last 2 wk of ethanol feeding.

RESULTS: Our in vitro studies revealed that Nano pretreatment reduced LA+ethanol-induced oxidative stress in E-47 cells. Our in vivo experiments showed that ethanol-fed Nano-treated mice had 22% lower hepatic triglyceride levels than mice fed ethanol alone. Nano-treated ethanol-fed mice also had 2-fold lower levels of Cd68 and similarly-reduced levels of Ccl2 and Mmp12 mRNAs, than in untreated ethanol-fed mice. We also noted that ethanol feeding caused a remarkable increase in hepatic and/or plasma MCP-1 and CCR2 protein which was blunted in ethanol+Nano-treated animals. The hepatic content of SREBP-1c a transcription factor that promotes lipogenesis, was higher in ethanol-fed mice than controls but was attenuated in ethanol+Nano-treated animals. Further, livers of ethanol+Nano-treated mice had significantly higher levels of phosphorylated AMPK than both control and ethanol-fed mice. In AT, the level of Il6 mRNA a hepatoprotective cytokine, and that of Arg1, a marker of anti-inflammatory macrophages, were significantly increased in ethanol+Nano-treated mice compared with control mice.

CONCLUSION: Our data indicate that Nano treatment attenuates ethanol-induced steatohepatitis and this effect is associated with an apparent activation of AMPK signaling. Our data also suggest that Nano induces Arg1 and IL-6 expression in AT suggesting anti-inflammatory effects in this tissue.