Maitotoxin induces calpain activation in SH-SY5Y neuroblastoma cells and cerebrocortical cultures.
Arch Biochem Biophys
; 331(2): 208-14, 1996 Jul 15.
Article
em En
| MEDLINE
| ID: mdl-8660700
ABSTRACT
Maitotoxin (MTX) is a highly potent marine toxin that activates both voltage-sensitive and receptor-operated calcium channels in the plasma membrane. This results in calcium overload that rapidly leads to cell death. We now report that maitotoxin (0.1-1 nM) induces calpain activation in both SH-SY5Y neuroblastoma cells and fetal rat cerebrocortical cultures. MTX-induced calpain activation was confirmed by the presence of autolytic fragmentation of both subunits of calpain. Secondly, the formation of calpain-produced alpha-spectrin breakdown products (150 and 145 kDa) was observed. We were also able to detect intracellular hydrolysis of a peptide substrate (succinyl-Leu-Leu-Val-Tyr-7-amido-4-methylcoumarin) by activated calpain in MTX-treated cells. Calpain inhibitors (calpain inhibitor I, MDL28170 and PD150606) inhibited spectrin breakdown and SLLVY-AMC hydrolysis in MTX-treated SY5Y cells. Our results suggest that (i) calpain is activated as a result of the maitotoxin-induced calcium influx; and (ii) coupling with the in situ calpain assays, maitotoxin would be a useful tool in investigating the physiologic and pathophysiologic roles of calpain in neuronal cells.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Calpaína
/
Oxocinas
/
Toxinas Marinhas
/
Neurônios
Limite:
Animals
Idioma:
En
Revista:
Arch Biochem Biophys
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Estados Unidos