First Author | Rüdiger HA | Year | 2002 |
Journal | Gastroenterology | Volume | 122 |
Issue | 1 | Pages | 202-10 |
PubMed ID | 11781294 | Mgi Jnum | J:73631 |
Mgi Id | MGI:2156114 | Doi | 10.1053/gast.2002.30304 |
Citation | Rudiger HA, et al. (2002) Tumor necrosis factor alpha, but not Fas, mediates hepatocellular apoptosis in the murine ischemic liver. Gastroenterology 122(1):202-10 |
abstractText | BACKGROUND & AIMS: Apoptosis of hepatocytes is a central feature of ischemic injury in the liver. The aim of this study was to identify extracellular inducers of apoptosis in the murine ischemic liver. METHODS: Involvement of tumor necrosis factor (TNF)-alpha and Fas signaling was evaluated using various knockout mice (TNF-receptor 1 [TNF-R1]-/-, Fas[lpr]-/-, and Fas ligand[gld]-/-) and wild-type mice pretreated with pentoxifylline, an inhibitor of TNF-alpha synthesis. RESULTS: Expression of TNF-alpha was increased after ischemia and reperfusion in wild-type mice and TNF-R1-deficient mice when compared with sham-operated animals. Pentoxifylline prevented up-regulation of TNF-alpha expression. Inhibition of TNF-alpha resulted in significant decrease of serum aspartate aminotransferase levels and prolonged animal survival. Markers of apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining, cytochrome C release, and caspase 3 activity) were consistently decreased, and animal survival was prolonged after blocking TNF-alpha. In contrast, inhibition of Fas signaling did not alter parameters of tissue injury or apoptosis, and animal survival remained unchanged. CONCLUSIONS: We identify TNF-alpha as a crucial inducer of apoptotic cell death in the ischemic liver. A role for Fas could not be identified. These findings may lead to novel strategies to prevent ischemic injury of the liver. |