Recent studies indicate that the Kupffer cell plays a major role in the production of liver injury induced by a number of hepatotoxins and pathological conditions. Obliteration of Kupffer cells virtually abolishes cell necrosis and inflammation induced by xenobiotics such as ethanol, carbon tetrachloride and acetaminophen. Similarly, liver damage induced by endotoxemia or liver storage prior to transplantation is markedly reduced by experimental conditions that reduce Kupffer cell function. Data suggest that tumor necrosis factor-alpha released by Kupffer cells plays a major role in cell damage. The synthesis of tumor necrosis factor- alpha is initiated by gene-transcription factors, which are activated by oxygen radicals and endotoxin. Tumor necrosis factor-alpha triggers a cytokine cascade involving cytotoxic, inflammatory and fibrogenic mediators. The studies proposed (a) test the hypothesis that triple-helix targeting of the tumor necrosis factor-alpha gene in Kupffer cells results in marked reduction of liver damage induced by a number of hepatotoxins and pathogenic conditions; (b) develop methodologies for the design and delivery of triple-helix forming oligonucleotide drugs into Kupffer cells, for possible therapeutic use. Kupffer cells are specialized in the phagocytic removal of particulate matter from the circulation. Studies in this application utilize this phagocytic action to deliver liposome-entrapped triple-helix antigene oligonucleotides into Kupffer cells. The proposed research is designed to (i) suppress the synthesis of tumor necrosis factor-a and the cytokine transcription factor NF-kappaB in Kupffer cells, (ii) reduce the expression of genes involved in the generation of oxygen-radicals in Kupffer cells, and (iii) test the protection afforded by triple-helix drugs against liver necrosis and inflammation induced by the chronic administration of ethanol and other hepatotoxins. Overall, the proposed research investigates at the gene level the existence of central mechanisms of liver injury by new approaches with therapeutic potential for alcoholic liver disease in humans.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Research Project (R01)
Project #
5R01AA010967-03
Application #
2732459
Study Section
Special Emphasis Panel (SRCA (53))
Project Start
1996-07-01
Project End
1999-06-30
Budget Start
1998-07-01
Budget End
1999-06-30
Support Year
3
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Thomas Jefferson University
Department
Pathology
Type
Schools of Medicine
DUNS #
061197161
City
Philadelphia
State
PA
Country
United States
Zip Code
19107
Ponnappa, Biddanda C; Israel, Yedy; Aini, Maria et al. (2005) Inhibition of tumor necrosis factor alpha secretion and prevention of liver injury in ethanol-fed rats by antisense oligonucleotides. Biochem Pharmacol 69:569-77
Ezquer, Fernando; Nunez, Marco Tulio; Israel, Yedy (2005) Antisense gene delivered by an adenoassociated viral vector inhibits iron uptake in human intestinal cells: potential application in hemochromatosis. Biochem Pharmacol 69:1559-66
Rodriguez, Diego A; Moncada, Claudio; Nunez, Marco T et al. (2004) Ethanol increases tumor necrosis factor-alpha receptor-1 (TNF-R1) levels in hepatic, intestinal, and cardiac cells. Alcohol 33:9-15
Ponnappa, Biddanda C; Israel, Yedy (2002) Targeting Kupffer cells with antisense oligonucleotides. Front Biosci 7:e223-33
Ponnappa, B C; Dey, I; Tu , G C et al. (2001) In vivo delivery of antisense oligonucleotides in pH-sensitive liposomes inhibits lipopolysaccharide-induced production of tumor necrosis factor-alpha in rats. J Pharmacol Exp Ther 297:1129-36
Ponnappa, B C; Rubin, E (2000) Modeling alcohol's effects on organs in animal models. Alcohol Res Health 24:93-104
Ross, A D; Dey, I; Janes, N et al. (1998) Effect of antithyroid drugs on hydroxyl radical formation and alpha-1-proteinase inhibitor inactivation by neutrophils: therapeutic implications. J Pharmacol Exp Ther 285:1233-8