Bax deletion further orders the cell death pathway in cerebellar granule cells and suggests a caspase-independent pathway to cell death

Timothy M. Miller, Krista L. Moulder, C. Michael Knudson, Douglas J. Creedon, Mohanish Deshmukh, Stanley J. Korsmeyer, Eugene M. Johnson

Producción científica: Articlerevisión exhaustiva

361 Citas (Scopus)

Resumen

Dissociated cerebellar granule cells maintained in medium containing 25 mM potassium undergo an apoptotic death when switched to medium with 5 mM potassium. Granule cells from mice in which Bax, a proapoptotic Bcl-2 family member, had been deleted, did not undergo apoptosis in 5 mM potassium, yet did undergo an excitotoxic cell death in response to stimulation with 30 or 100 μM NMDA. Within 2 h after switching to 5 mM K+, both wild-type and Bax- deficient granule cells decreased glucose uptake to <20% of control. Protein synthesis also decreased rapidly in both wild-type and Bax-deficient granule cells to 50% of control within 12 h after switching to 5 mM potassium. Both wild-type and Bax -/- neurons increased mRNA levels of c-jun, and caspase 3 (CPP32) and increased phosphorylation of the transactivation domain of c-Jun after K+ deprivation. Wild-type granule cells in 5 mM K+ increased cleavage of DEVD-aminomethyl-coumarin (DEVD-AMC), a fluorogenic substrate for caspases 2, 3, and 7; in contrast, Bax-deficient granule cells did not cleave DEVD- AMC. These results place BAX downstream of metabolic changes, changes in mRNA levels, and increased phosphorylation of c-Jun, yet upstream of the activation of caspases and indicate that BAX is required for apoptotic, but not excitotoxic, cell death. In wild-type cells, Boc-Asp-FMK and ZVAD-FMK, general inhibitors of caspases, blocked cleavage of DEVD-AMC and blocked the increase in TdT-mediated dUTP nick end labeling (TUNEL) positivity. However, these inhibitors had only a marginal effect on preventing cell death, suggesting a caspase-independent death pathway downstream of BAX in cerebellar granule cells.

Idioma originalEnglish (US)
Páginas (desde-hasta)205-217
Número de páginas13
PublicaciónJournal of Cell Biology
Volumen139
N.º1
DOI
EstadoPublished - oct 6 1997
Publicado de forma externa

ASJC Scopus subject areas

  • Cell Biology

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