Transient oxidative stress in SH-SY5Y human neuroblastoma cells results in caspase dependent and independent cell death and tau proteolysis
| Autor: | P K, Krishnamurthy, J L, Mays, G N, Bijur, G V, Johnson |
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| Rok vydání: | 2000 |
| Předmět: |
L-Lactate Dehydrogenase
Caspase 3 Cell Survival Hydrolysis Apoptosis tau Proteins Cysteine Proteinase Inhibitors Caspase Inhibitors Amino Acid Chloromethyl Ketones Substrate Specificity Necrosis Neuroblastoma Oxidative Stress tert-Butylhydroperoxide Caspases Tumor Cells Cultured Humans Poly(ADP-ribose) Polymerases |
| Zdroj: | Journal of neuroscience research. 61(5) |
| ISSN: | 0360-4012 |
| Popis: | The effects of an oxidative insult on cell survival and tau metabolism were investigated in human neuroblastoma SH-SY5Y cells. In this treatment paradigm cells were exposed to the membrane permeant oxidant tert-butylhydroperoxide (tBHP) for 40 min, returned to fresh media and cell survival/death was monitored during the post-treatment period. Cell viability decreased significantly by 6 hr after tBHP exposure, and by 24 hr lactate dehydrogenase (LDH) release was 40.1 +/- 8.8% in tBHP treated cells compared to 8.1 +/- 4.7% in control cells. This oxidative stress paradigm also resulted in significant activation of caspase-3 by 2 hr post-treatment and nuclear apoptotic morphology. Furthermore, tBHP treatment also resulted in delayed tau proteolysis that was first evident 2 hr post-treatment. Treatment of the cells with the general caspase inhibitor Boc-Asp(OMe)-Fluoromethylketone (BAF) completely inhibited caspase-3 activation in response to tBHP, and delayed, but did not prevent cell death. BAF treatment also decreased tau proteolysis. In vitro, recombinant tau was readily proteolyzed by active recombinant caspase-3 into a stable breakdown product. Further tau in the cell lysates was cleaved by active recombinant caspase-3 at a rate, and to an extent similar to that observed for the well-established caspase-3 substrate poly(ADP-ribose)polymerase (PARP). These results suggest that oxidative stress-induced cell death occurs through both caspase-dependent and-independent pathways, and that tau is likely an in situ substrate of caspase-3. |
| Databáze: | OpenAIRE |
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