The protein phosphatase inhibitor okadaic acid (OA) dose-dependently induced apoptosis in CHP-100 neuroepithelioma cells when administered for 24 h at concentrations ranging from 10 - 100 nM. Apoptosis was largely, albeit not completely, dependent on cystein protease (caspase) activation. CPP32 processing and poly(ADP-ribose) polymerase (PARP) cleavage started to be observed only at 20 nM OA; moreover, the caspase inhibitor Z-Val-Ala-DL-Asp-fluoromethylketone (Z-VAD.fmk) (100 microM) had negligible effect on apoptosis induced by 10 nM OA, but rescued from death an increasing cell fraction as OA concentration was raised from 20 - 100 nM. Cell treatment for 24 h with OA induced ceramide accumulation; the phenomenon started to be evident at 20 nM OA and reached its maximum at 50 - 100 nM OA. In cells exposed to 50 nM OA, ceramide was already elevated by 5 h; at this time, however, PARP cleavage and apoptosis were not yet observed. Z-VAD.fmk (100 microM) had no effect on ceramide elevation induced by 50 nM OA within 5 h, but markedly reduced ceramide accumulation as the incubation was prolonged to 24 h. The latter phenomenon was accompanied by elevation of glucosylceramide levels, thus suggesting that a caspase-dependent reduction of glucosylceramide synthesis might contribute to late ceramide accumulation. Short-chain ceramide (30 microM) induced apoptosis in CHP-100 cells and its effect was additive with that evoked by OA (10 - 20 nM). These results suggest that ceramide generation might be an important mechanism through which sustained protein phosphatase inhibition induces caspase activation and apoptosis in CHP-100 cells.

Spinedi, A., DI BARTOLOMEO, S., DI SANO, F., Rodolfo, C., Ambrosino, A., Piacentini, M. (1999). Ceramide accumulation precedes caspase-dependent apoptosis in CHP-100 neuroepithelioma cells exposed to the protein phosphatase inhibitor okadaic acid. CELL DEATH AND DIFFERENTIATION, 6(7), 618-623 [10.1038/sj.cdd.4400533].

Ceramide accumulation precedes caspase-dependent apoptosis in CHP-100 neuroepithelioma cells exposed to the protein phosphatase inhibitor okadaic acid

SPINEDI, ANGELO;DI BARTOLOMEO, SABRINA;DI SANO, FEDERICA;RODOLFO, CARLO;PIACENTINI, MAURO
1999-07-01

Abstract

The protein phosphatase inhibitor okadaic acid (OA) dose-dependently induced apoptosis in CHP-100 neuroepithelioma cells when administered for 24 h at concentrations ranging from 10 - 100 nM. Apoptosis was largely, albeit not completely, dependent on cystein protease (caspase) activation. CPP32 processing and poly(ADP-ribose) polymerase (PARP) cleavage started to be observed only at 20 nM OA; moreover, the caspase inhibitor Z-Val-Ala-DL-Asp-fluoromethylketone (Z-VAD.fmk) (100 microM) had negligible effect on apoptosis induced by 10 nM OA, but rescued from death an increasing cell fraction as OA concentration was raised from 20 - 100 nM. Cell treatment for 24 h with OA induced ceramide accumulation; the phenomenon started to be evident at 20 nM OA and reached its maximum at 50 - 100 nM OA. In cells exposed to 50 nM OA, ceramide was already elevated by 5 h; at this time, however, PARP cleavage and apoptosis were not yet observed. Z-VAD.fmk (100 microM) had no effect on ceramide elevation induced by 50 nM OA within 5 h, but markedly reduced ceramide accumulation as the incubation was prolonged to 24 h. The latter phenomenon was accompanied by elevation of glucosylceramide levels, thus suggesting that a caspase-dependent reduction of glucosylceramide synthesis might contribute to late ceramide accumulation. Short-chain ceramide (30 microM) induced apoptosis in CHP-100 cells and its effect was additive with that evoked by OA (10 - 20 nM). These results suggest that ceramide generation might be an important mechanism through which sustained protein phosphatase inhibition induces caspase activation and apoptosis in CHP-100 cells.
lug-1999
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore BIO/06 - ANATOMIA COMPARATA E CITOLOGIA
English
Con Impact Factor ISI
Fumonisins; Ceramides; Caspases; Cell Death; Humans; Neuroectodermal Tumors, Primitive, Peripheral; Phosphoprotein Phosphatases; Carboxylic Acids; Enzyme Activation; Apoptosis; Enzyme Inhibitors; Tumor Cells, Cultured; Okadaic Acid
Spinedi, A., DI BARTOLOMEO, S., DI SANO, F., Rodolfo, C., Ambrosino, A., Piacentini, M. (1999). Ceramide accumulation precedes caspase-dependent apoptosis in CHP-100 neuroepithelioma cells exposed to the protein phosphatase inhibitor okadaic acid. CELL DEATH AND DIFFERENTIATION, 6(7), 618-623 [10.1038/sj.cdd.4400533].
Spinedi, A; DI BARTOLOMEO, S; DI SANO, F; Rodolfo, C; Ambrosino, A; Piacentini, M
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/19277
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