Tumor necrosis factor-a (TNF-alpha) is a cytokine required for cell replication. However, when its production is upregulated it triggers an inflammatory response and cell injury. Kupffer cells are the main producers of TNF-alpha. In endothelial cells and hepatocytes, TNF-alpha: (i) activates the production of leukocyte chemoattractants and (ii) increases the expression of intercellular adhesion molecules (ICAM-1) which anchors leukocytes. Anchored leukocytes (neutrophils/monocytes) are stimulated to (iii) release latent proteolytic enzymes that become activated by the concerted action of myeloperoxidase and hydrogen peroxide, leading to cell damage. Several approaches can prevent cell injury. Obliteration of Kupffer cells reduces liver injury elicited by a number of hepatotoxins. Antibodies that bind TNF-a, ICAM-1, or anchoring receptors in neutrophils and monocytes (CD11b/CD18) protect against cell injury in different experimental conditions in vitro and in vivo, including liver injury induced by chronic ethanol administration. While these approaches have contributed an important insight to the pathogenesis of liver injury they cannot be used clinically in chronic conditions. Recent studies show that antisense oligonucleotides are viable therapeutic alternatives in chronic inflammatory conditions. Studies proposed test the general hypothesis that liver injury induced by chronic ethanol treatment can be suppressed by antisense oligonucleotides that act at three steps of the cytotoxic cascade: (i) TNF-alpha production by Kupffer cells (ii) ICAM-1 generation by hepatocytes and endothelial cells and (iii) myeloperoxidase-mediated cytotoxicity. Overall, the proposed research investigates the effectiveness of new genotypic drugs that act on central mechanisms of hepatocellular injury that may have therapeutic potential for alcoholic liver disease.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Research Project (R01)
Project #
5R01AA010967-07
Application #
6509241
Study Section
Special Emphasis Panel (ZRG1-ALTX-4 (01))
Program Officer
Purohit, Vishnu
Project Start
1996-07-01
Project End
2004-05-31
Budget Start
2002-06-01
Budget End
2003-05-31
Support Year
7
Fiscal Year
2002
Total Cost
$341,031
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
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