Vitamin D Deficiency Aggravates Hepatic Oxidative Stress and Inflammation during Chronic Alcohol-Induced Liver Injury in Mice

Abstract

Vitamin D deficiency has been reported in alcoholics. This study is aimed at evaluating the effects of vitamin D deficiency on chronic alcohol-induced liver injury in mice. Mice were fed with modified Lieber-DeCarli liquid diets for 6 weeks to establish an animal model of chronic alcohol-induced liver injury. In the VDD+EtOH group, mice were fed with modified diets, in which vitamin D was depleted. Vitamin D deficiency aggravated alcohol-induced liver injury. Furthermore, vitamin D deficiency aggravated hepatocyte apoptosis during alcohol-induced liver injury. Although it has a little effect on hepatic TG content, vitamin D deficiency promoted alcohol-induced hepatic GSH depletion and lipid peroxidation. Further analysis showed that vitamin D deficiency further increased alcohol-induced upregulation of hepatic inducible nitric oxide synthase (<i>inos</i>), two NADPH oxidase subunits <i>p47phox</i> and <i>gp91phox</i>, and heme oxygenase- (HO-) 1. By contrast, vitamin D deficiency attenuated alcohol-induced upregulation of hepatic antioxidant enzyme genes, such as superoxide dismutase (<i>sod</i>) 1 and <i>gshpx</i>. In addition, vitamin D deficiency significantly elevated alcohol-induced upregulation of hepatic proinflammatory cytokines and chemokines. Taken together, these results suggest that vitamin D deficiency aggravates hepatic oxidative stress and inflammation during chronic alcohol-induced liver injury.