Ethanol affects hepatitis C pathogenesis: Humanized SCID Alb-uPA mouse model Natalia A. Osna a,b,⇑ , Kusum K. Kharbanda a,b , Yimin Sun c , Ronda L. Simpson a,b , Larisa E. Poluektova a,d , Murali Ganesan a,b , James L. Wisecarver e , David F. Mercer c a Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA b Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68105, USA c Department of Surgery, University of Nebraska Medical Center, Omaha, NE 68105, USA d Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68105, USA e Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68105, USA article info Article history: Received 22 May 2014 Available online 19 June 2014 Keywords: SCID Alb-uPA mice Hepatitis C virus Alcohol Oxidative stress Proteasome activity abstract Alcohol consumption exacerbates the course of hepatitis C viral (HCV) infection, worsens outcomes and contributes to the development of chronic infection that exhibits low anti-viral treatment efficiency. The lack of suitable in vivo models makes HCV–ethanol studies very difficult. Here, we examine whether chimeric SCID Alb-uPA mice transplanted with human hepatocytes and infected with HCV develop wors- ening pathology when fed ethanol. After 5 weeks of feeding, such mice fed chow + water (control) or chow + 20% ethanol in water (EtOH) diets mice developed oxidative stress, decreased proteasome activity and increased steatosis. Importantly, HCV + mice in the control group cleared HCV RNA after 5 weeks, while the infection persisted in EtOH-fed mice at the same or even higher levels compared with pre- feeding HCV RNA. We conclude that in chimeric SCID Alb-uPA mice, EtOH exposure causes the complex biochemical and histological changes typical for alcoholic liver injury. In addition, ethanol feeding delays the clearance of HCV RNA thereby generating persistent infection and promoting liver injury. Overall, this model is appropriate for conducting HCV–ethanol studies. Published by Elsevier Inc. 1. Introduction Ethanol consumption exacerbates hepatitis C virus (HCV)- infection pathogenesis and decreases the sensitivity of HCV patients to anti-viral treatment. However, the mechanisms of eth- anol–HCV interactions are not clear yet. Moreover, the lack of the adequate animal models makes conducting such studies extremely difficult since HCV is a human virus, which does not infect the rodents. In vitro ethanol studies using hepatoma cells of Huh 7.5 origin are not always successful because these cells while allowing viral replication do not express ethanol-metabolizing enzymes, alcohol dehydrogenase and cytochrome P450 2E1, and do not generate the most toxic ethanol metabolites. Thus, animal studies are critical for examining the true effects of ethanol on HCV path- ogenesis. The most attractive way to solve this problem is using chimeric mice with transplanted human hepatocytes, which can be naturally infected with HCV. Currently, several available mouse strains (SCID Alb-uPA mice, Fah-/-Rag2-/-cg-/-mice, uPA-NOG and TK-NOG) allow up to 70–90% reconstitution of mouse hepatocytes by human ones. Various strategies were used for the robust depletion of mouse liver cells, including transgenic expression of liver damaging enzyme, murine plasminogen urokinase genes, under the control of the albumin promoter (Alb-uPA) on CB-17-scid-bg or NOD- scid-c-/- (NOG) background [1,2], enzymatic deficiency of tyrosine catabolic enzyme fumarylacetoacetate hydrolase (Fah) mutants [3], conditional depletion of mouse hepatocytes expressing FK506 binding protein (FKBP)-caspase 8 fusion gene driven by the albumin enhancer/promoter (AFC8) during first week after birth [4] and depletion of hepatocytes in adult mice carrying her- pes simplex virus thymidine kinase by gancyclovir [5]. Some of these mice were reported to be infected with HCV [1,6,7]. http://dx.doi.org/10.1016/j.bbrc.2014.06.048 0006-291X/Published by Elsevier Inc. Abbreviations: HCV, hepatitis C virus; EtOH, ethanol; ALT, alanine aminotrans- ferase; TBARS, thiobarbituric acid-reactive substances; proteasome ChT-like activ- ity, chymotrypsin-like activity; PCR, polymerase chain reaction. ⇑ Corresponding author at: Research Service (151), Veterans Affairs Nebraska- Western Iowa Health Care System, 4101 Woolworth Ave, Omaha, NE 68105, USA. Fax: +1 (402) 449 0604. E-mail address: nosna@unmc.edu (N.A. Osna). Biochemical and Biophysical Research Communications 450 (2014) 773–776 Contents lists available at ScienceDirect Biochemical and Biophysical Research Communications journal homepage: www.elsevier.com/locate/ybbrc