Localization of active form of caspase-8 in mouse L929 cells induced by TNF treatment and polyglutamine aggregates.
The relation between activation of caspase-8 and polyglutamine aggregates has been focused. We prepared an antiserum (anti-m8D387) that recognizes the active form but not the proform of mouse caspase-8. We used immunostaining with anti-m8D387 antiserum to compare the localizations of activated mcaspase-8 in L929 (clone 1422) cells induced by TNF and polyglutamine aggregates. Anti-m8D387 was positive throughout cytoplasm of the TUNEL-positive cells induced by TNF treatment, whereas the anti-m8D387 reactivity was not positive throughout cytoplasm of the cells expressing polyglutamine but was restricted to polyglutamine aggregates. In contrast with TNF-treated cells, cells expressing anti-m8D387-positive cytoplasmic polyglutamine aggregates did not undergo TUNEL-positive apoptosis. Thus activated caspase-8 associated with polyglutamine aggregates alone was not sufficient to induce TUNEL-positive apoptosis of L929 (clone 1422) cells. The distribution of activated caspase-8 associated with polyglutamine aggregates may be essential for the polyglutamine-mediated cell death or downstream of caspase-8 may be different in the TNF-treated cells and cells expressing polyglutamine.
Kouroku
Y
Y
Division of Development and Differentiation, National Institute of Neuroscience, NCNP, Kodaira, Tokyo, 187-8502, Japan.
Fujita
E
E
Jimbo
A
A
Mukasa
T
T
Tsuru
T
T
Momoi
M Y
MY
Momoi
T
T
D000818:Animals; D019556:COS Cells; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000032:analysis / Q000378:metabolism*; D005354:Fibrosarcoma; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000032:analysis; D051379:Mice; D010455:Peptides / Q000032:analysis / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D008164:Luminescent Proteins; D010455:Peptides; D011993:Recombinant Fusion Proteins; D014409:Tumor Necrosis Factor-alpha; D049452:Green Fluorescent Proteins; C097188:polyglutamine; C505526:Casp8 protein, mouse; C506434:Casp9 protein, mouse; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases