Ceramide reproduces late appearance of oxidative stress during TNF-mediated cell death in L929 cells.
Tumor necrosis factor alpha mediated cell death in L929 cells correlates with a late increase in reduction of the superoxide scavenger 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), suggesting an increase in MTT reduction per viable cell. This effect was studied in two TNF-sensitive and in five different TNF-resistant clones. Within 36 hrs TNF promoted a 7-fold increase in the reduction of MTT in TNF-sensitive cells. Exogenous ceramide induced a similar effect prior to cell death. Four of the five TNF-resistant clones were also resistant to ceramide and displayed no increase in MTT reduction with either TNF or ceramide. The remaining TNF-resistant clone was sensitive to ceramide, displaying an increase in MTT reduction. Our results suggest a late increase in superoxide production prior to cellular destruction during TNF and ceramide mediated cell death and support the notion that ceramide can serve as a second messenger for TNF in cell death.
Gómez
E O
EO
Departamento de Biología Celular, Instituto de Fisiología Celular, UNAM, México DF, Mexico.
Mendoza-Milla
C
C
Ibarra-Sánchez
M J
MJ
Ventura-Gallegos
J L
JL
Zentella
A
A
D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002518:Ceramides / Q000494:pharmacology*; D002999:Clone Cells; D004396:Coloring Agents; D004351:Drug Resistance; D016166:Free Radical Scavengers; D007700:Kinetics; D007739:L Cells; D051379:Mice; D016296:Mutagenesis; D018384:Oxidative Stress / Q000187:drug effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis; D011691:Puromycin / Q000494:pharmacology; D011994:Recombinant Proteins / Q000096:biosynthesis; D013778:Tetrazolium Salts; D013844:Thiazoles; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000633:toxicity*
D002518:Ceramides; D004396:Coloring Agents; D016166:Free Radical Scavengers; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins; D013778:Tetrazolium Salts; D013844:Thiazoles; D014409:Tumor Necrosis Factor-alpha; D011691:Puromycin; C022616:thiazolyl blue