Ethanol-inducible cytochrome P450 2E1 (CYP2E1) contributes to increased oxidative stress and steatosis in chronic alcohol-exposure models. However, its role in binge ethanol-induced gut leakiness and hepatic injury is unclear. This study was aimed to investigate the role of CYP2E1 in binge alcohol-induced gut leakiness and the mechanisms of steatohepatitis. Female wild-type (WT) and Cyp2e1-null mice were treated with three doses of binge ethanol (WT-EtOH or Cyp2e1-null-EtOH) (6 g/kg oral gavage at 12-h intervals) or dextrose (negative control). Intestinal histology of only WT-EtOH exhibited epithelial alteration and blebbing of lamina propria while liver histology obtained at 6 h after the last ethanol dose showed elevated steatosis with scattered inflammatory foci. These were accompanied by increased levels of serum endotoxin, hepatic enterobacteria and triglycerides. All these changes including the intestinal histology and hepatic apoptosis, determined by TUNEL assay, were significantly reversed when WT-EtOH mice were treated with the specific inhibitor of CYP2E1 chlormethiazole and the antioxidant N-acetyl-cysteine, both of which suppressed the oxidative markers including intestinal CYP2E1. WT-EtOH also exhibited elevated amounts of serum TNF-α, hepatic cytokines, CYP2E1 and lipid peroxidation with decreased levels of mitochondrial superoxide dismutase and suppressed aldehyde dehydrogenase 2 activity. Increased hepatocyte apoptosis with elevated levels of pro-apoptotic proteins and decreased levels of active (phosphorylated) p-AKT, p-AMPK and peroxisome proliferator-activated receptor-alpha (PPAR-α), all of which are involved in fat metabolism and inflammation, were observed in WT-EtOH. These changes were significantly attenuated in the corresponding Cyp2e1-null-EtOH mice. These data indicate that both intestinal and hepatic CYP2E1 induced by binge alcohol seem critical in the binge alcohol-mediated increased nitroxidative stress, gut leakage, endotoxemia, and altered fat metabolism, and inflammation, contributing to hepatic apoptosis and steatohepatitis.

Background & Aims Ethanol-inducible cytochrome P450 2E1 (CYP2E1) activity contributes to oxidative stress. However, CYP2E1 may have an important role in the pathogenesis of high-fat mediated nonalcoholic steatohepatitis (NASH). Thus, the role of CYP2E1 in high-fat mediated NASH development was evaluated. Methods Male wild-type (WT) and Cyp2e1-null mice were fed a low-fat diet (LFD, 10% energy-derived) or high-fat diet (HFD, 60% energy-derived) for 10 weeks. Liver histology and tissue homogenates were examined for various parameters of oxidative stress and inflammation. Results Liver histology showed that only WT mice fed a HFD developed NASH despite increased steatosis in both WT and Cyp2e1-null mice fed HFD. Markers of oxidative stress such as elevated CYP2E1 activity and protein amounts, lipid peroxidation, protein carbonylation, nitration, and glycation with increased phospho-JNK were all markedly elevated only in the livers of HFD-fed WT mice. Furthermore, while the levels of inflammation markers osteopontin and F4/80 were higher in HFD-fed WT mice, TNFα and MCP-1 contents were lower compared to the corresponding LFD-fed WT. Finally, only HFD-fed WT mice exhibited increased insulin resistance and impaired glucose tolerance. Conclusions These data suggest that CYP2E1 is critically important in NASH development by promoting oxidative/nitrosative stress, protein modifications, inflammation and insulin resistance.

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An increased risk of HIV-1 associated dementia (HAD) has been observed in patients abusing methamphetamine (METH). Since both HIV viral proteins (gp120, Tat) and METH induce oxidative stress, drug abusing patients are at a greater risk of oxidative stress-induced damage. The objective of this study was to determine if N-acetylcysteine amide (NACA) protects the blood brain barrier (BBB) from oxidative stress-induced damage in animals exposed to gp120, Tat and METH. To study this, CD-1 mice pre-treated with NACA/saline, received injections of gp120, Tat, gp120 + Tat or saline for 5 days, followed by three injections of METH/saline on the fifth day, and sacrificed 24 h after the final injection. Various oxidative stress parameters were measured, and animals treated with gp120+Tat+Meth were found to be the most challenged group, as indicated by their GSH and MDA levels. Treatment with NACA significantly rescued the animals from oxidative stress. Further, NACA-treated animals had significantly higher expression of TJ proteins and BBB permeability as compared to the group treated with gp120+Tat+METH alone, indicating that NACA can protect the BBB from oxidative stress-induced damage in gp120, Tat and METH exposed animals, and thus could be a viable therapeutic option for patients with HAD.

Alcoholic liver disease (ALD) is a major public health problem in the United States and women are known to be more susceptible to ALD. However, the precise mechanism for increased susceptibility of females to ALD is not completely understood. The present study is based on the hypothesis that induction of osteopontin (OPN), a matricellular protein, is the likely contributing factor for higher neutrophil recruitment in females during alcoholic steatohepatitis (ASH). ASH was induced in male and female Sprague-Dawley rats by feeding them a Lieber-DeCarli diet containing ethanol (EtOH) for 6 weeks, followed by a single injection of lipopolysaccharide (LPS, 10 mg/kg, ip). Liver injury, measured by plasma transaminase elevations and confirmed by haematoxylin and eosin-stained liver sections, revealed approximately 25-fold higher liver injury in the female ASH model compared with the males. Although steatosis, necrosis, and neutrophil infiltration were evident in both male and female rats, hepatic neutrophilic necrotic foci were noted as early as 2 h after LPS injection in the EtOH-treated female rats. Hepatic neutrophil infiltration correlated with higher expression of cleaved (cOPN) and uncleaved OPN in the EtOH + LPS-treated female rats compared with the males. OPN secretion was localized predominantly in the biliary epithelium and females had significantly higher OPN mRNA than their male counterparts in the ASH model. The ability of OPN to attract neutrophils was further confirmed in vivo, in a peritonitis rat model, and by neutralizing OPN (nOPN) antibody experiments. Hepatic neutrophil infiltration was largely inhibited ( approximately 50%) by nOPN antibody. Flow cytometry experiments revealed OPN-mediated up-regulation of the CD11b neutrophil adhesion molecule. In conclusion, these data suggest that higher hepatic expression of OPN is the likely reason for higher and early hepatic neutrophil infiltration making females more susceptible to ALD during ASH.