Artículos de revistas
Ethanol increases tumor necrosis factor-alpha receptor-1 (TNF-R1) levels in hepatic, intestinal, and cardiac cells
Fecha
2004-05Registro en:
ALCOHOL 33 (1): 9-15 MAY 2004
0741-8329
Autor
Rodríguez, Diego A.
Moncada, Claudio
Núñez González, Marco
Lavandero González, Sergio
Ponnappa, Biddanda C.
Israel Jacard, Yedy
Institución
Resumen
Chronic ethanol consumption leads to cell injury in virtually every tissue. Tumor necrosis factor-alpha (TNF-alpha) constitutes a major factor in the development of alcohol-induced liver injury. In alcohol-dependent subjects, elevated levels of plasma TNF-alpha are strongly predictive of mortality. Binding of TNF-alpha to TNF-alpha receptor-1 (TNF-R1) activates death domain pathways, leading to necrosis and apoptosis in most tissues, and it also increases the expression of intercellular adhesion molecules (i.e., ICAM-1), which promote inflammation. We determined whether ethanol exposure leads to increases in cellular TNF-R1. We incubated HepG2 human hepatoma cells and H4-IIE-C3 rat hepatoma cells with 25, 50, and 100 mM ethanol for various intervals of time up to 48 It. Human colonic adenocarcinoma cells (Caco-2 cells) and neonatal rat primary cardiomyocytes were also incubated with different concentrations of ethanol. Levels of TNF-R1 were measured either by a sandwich enzyme-linked immunosorbent assay (ELISA) method or by determining the extracellular transmembrane domain of TNF-R1 by an intact-cell ELISA method. Ethanol exposure for 48 h increased TNF-R1 levels in human hepatoma cells in a dose-dependent manner. Levels increased significantly by 164% at 50 mM and by 240% at 100 mM ethanol. Effects were time dependent and did not reach a plateau at 48 h. Similar increases in TNF-R1 were also observed in rat hepatoma cells (90% at 50 MM and 230% at 100 mM ethanol). Under similar conditions, Caco-2 cells showed a significant 80% increase in TNF-R1 levels at 200 mM ethanol, a concentration found in intestine. Neonatal rat primary cardiomyocytes showed TNF-R1 increases of 36% at 50 mM and 44% at 100 mM ethanol. These results indicate that exposure of different cell types to pharmacologic concentrations of ethanol increases TNF-R1 levels and may augment TNF-alpha-mediated cell injury in different tissues.