Roles of DNA Fragmentation Factor and Poly(ADP-ribose) Polymerase-1 in Sensitization of Fibroblasts to Tumor Necrosis Factor-Induced Apoptosis
| Autor: | A. Hamid Boulares, Mark E. Smulson, Alexander G. Yakovlev, Zaki A. Sherif, Anna J. Zoltoski |
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| Rok vydání: | 2002 |
| Předmět: |
Poly ADP ribose polymerase
Biophysics Gene Expression Apoptosis Cytochrome c Group DNA Fragmentation Biology Mitochondrion Transfection Biochemistry Mice chemistry.chemical_compound Adenosine Triphosphate Animals Humans Poly-ADP-Ribose Binding Proteins Molecular Biology Cells Cultured Deoxyribonucleases Caspase 3 Tumor Necrosis Factor-alpha Cytochrome c Intracellular Signaling Peptides and Proteins Proteins Cell Biology Fibroblasts NAD Molecular biology Mice Mutant Strains Enzyme Activation Protein Subunits chemistry Caspases biology.protein DNA fragmentation Tumor necrosis factor alpha NAD+ kinase Poly(ADP-ribose) Polymerases Apoptosis Regulatory Proteins DNA |
| Zdroj: | Biochemical and Biophysical Research Communications. 290:796-801 |
| ISSN: | 0006-291X |
| DOI: | 10.1006/bbrc.2001.6280 |
| Popis: | DNA fragmentation factor (DFF) comprises DFF45 and DFF40 subunits, the former of which acts as an inhibitor of the latter (the catalytic subunit) and whose cleavage by caspase-3 results in DFF activation. Disruption of the DFF45 gene blocks the generation of 50-kb DNA fragments and confers resistance to apoptosis. We recently suggested that the early fragmentation of DNA by DFF and the consequent activation of poly(ADP-ribose) polymerase–1 (PARP-1), mitochondrial dysfunction, and activation of caspase-3 contribute to an amplification loop in the apoptotic process. To verify the existence of such a loop, we have now examined the effects of restoring DFF expression in DFF45-deficient fibroblasts. Co-transfection of mouse DFF45−/− fibroblasts with plasmids encoding human DFF40 and DFF45 reversed the apoptosis resistance normally observed in these cells. The DFF45−/− cells regained the ability to fragment their DNA into 50-kb pieces in response to TNF, which resulted in a marked activation of PARP-1 and a concomitant depletion of intracellular NAD. DFF expression also resulted in an increase both in cytochrome c release into the cytosol and in caspase-3 activation triggered by TNF. These results support the importance of DFF, PARP-1, mitochondria, and caspase-3 in an amplification phase of TNF–induced apoptosis. |
| Databáze: | OpenAIRE |
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