Alcoholic liver disease (ALD) is an important public health problem. Patients with alcoholic hepatitis (AH) frequently have endotoxemia and elevated plasma tumor necrosis factor (TNF) levels which correlate with clinical indicators of liver dysfunction and mortality. Hepatic neutrophil (PMN) infiltration is an early manifestation of AH. Interleukin-8 (IL-8), a cytokine also known as neutrophil chemotactic factor, is an 8 kDa polypeptide produced by monocytes and hepatocytes in response to endotoxin (LPS) and TNF. We recently reported elevated IL-8 levels in acute AH that decreased as patients improved clinically. The grade of immunohistochemical staining for IL-8 in liver tissue correlates with the degree of hepatic PMN infiltration in AH. A positive effect of treatment with corticosteroids in AH can be predicted by hepatic PMN infiltration, and corticosteroids downregulate IL-8 production. Ethanol metabolism produces reactive oxygen intermediates and chronic alcohol abuse is associated with decreased levels of nutritionally dependent free radical scavengers such as glutathione. NF(kappa)B is a transcription factor for several cytokines including IL-8. NF(kappa)B is activated by reactive oxygen intermediates and its activation can be blocked by antioxidants. It is our working hypothesis that IL-8 plays an etiologic role in the neutrophilia, hepatic PMN infiltration and PMN-induced liver damage in AH. The overall research goals of our laboratory are to further define mechanisms and modulatory pathways whereby cytokines such as IL-8 induce metabolic disturbances and liver injury in ALD, with the ultimate goal being to develop a specific and anti-cytokine therapy for ALD. In this proposal, we will evaluate the role of oxidative stress and antioxidants in regulating IL-8 gene expression. We will determine whether plasma IL-8 levels increase in normal volunteers given alcohol or LPS, and if so, can this response be decreased by giving antioxidants such as vitamin E. We will also determine whether the moderately increased plasma levels of IL-8 present in alcohol-dependent patients without clinical liver disease normalized with abstinence. In vitro, we will determine whether or not Hep G2 liver cells cultured in alcohol, have increased NF(kappa)B activity, mRNA for IL-8 and secreted IL-8 protein in response to recombinant human TNF or monocyte supernatants (containing TNF) from patients with AH. We will also study Hep G2 cells transfected to overexpress cytochrome P450 2E1 to determine if they have increased production of reactive oxygen intermediates, NF(kappa)B activity and IL-8 gene expression when cultured with alcohol. These studies should provide new insights into the mechanism(s) of the increased IL-8 activity seen in ALD, both in vivo and in vitro on the transcription factor level. The knowledge gained should be useful in the development of """"""""anticytokine"""""""" therapy for ALD.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Unknown (K20)
Project #
5K20AA000190-05
Application #
2732412
Study Section
Biochemistry, Physiology and Medicine Subcommittee (ALCB)
Project Start
1994-07-01
Project End
2000-02-29
Budget Start
1998-07-01
Budget End
2000-02-29
Support Year
5
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Kentucky
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
832127323
City
Lexington
State
KY
Country
United States
Zip Code
40506
Deaciuc, I V; Nikolova-Karakashian, M; Fortunato, F et al. (2000) Apoptosis and dysregulated ceramide metabolism in a murine model of alcohol-enhanced lipopolysaccharide hepatotoxicity. Alcohol Clin Exp Res 24:1557-65
Hill, D B; Barve, S; Joshi-Barve, S et al. (2000) Increased monocyte nuclear factor-kappaB activation and tumor necrosis factor production in alcoholic hepatitis. J Lab Clin Med 135:387-95
Hill, K K; Hill, D B; Humphries, L L et al. (1999) A role for Helicobacter pylori in the gastrointestinal complaints of eating disorder patients? Int J Eat Disord 25:109-12
Hill, D B; Devalaraja, R; Joshi-Barve, S et al. (1999) Antioxidants attenuate nuclear factor-kappa B activation and tumor necrosis factor-alpha production in alcoholic hepatitis patient monocytes and rat Kupffer cells, in vitro. Clin Biochem 32:563-70
Hill, D B; Awad, J A (1999) Increased urinary F2-isoprostane excretion in alcoholic liver disease. Free Radic Biol Med 26:656-60
Deaciuc, I V; Fortunato, F; D'Souza, N B et al. (1999) Modulation of caspase-3 activity and Fas ligand mRNA expression in rat liver cells in vivo by alcohol and lipopolysaccharide. Alcohol Clin Exp Res 23:349-56
McClain, C J; Barve, S; Deaciuc, I et al. (1999) Cytokines in alcoholic liver disease. Semin Liver Dis 19:205-19
McClain, C J; Price, S; Barve, S et al. (1999) Acetaminophen hepatotoxicity: An update. Curr Gastroenterol Rep 1:42-9
Deaciuc, I V; D'Souza, N B; Sarphie, T G et al. (1999) Effects of exogenous superoxide anion and nitric oxide on the scavenging function and electron microscopic appearance of the sinusoidal endothelium in the isolated, perfused rat liver. J Hepatol 30:213-21
Devalaraja, M N; Mcclain, C J; Barve, S et al. (1999) Increased monocyte MCP-1 production in acute alcoholic hepatitis. Cytokine 11:875-81

Showing the most recent 10 out of 15 publications