Expression and activation of caspase 3 following status epilepticus in the rat.

Autor: Narkilahti, Susanna, Pirttilä, Terhi J., Lukasiuk, Katarzyna, Tuunanen, Jarkko, Pitkänen, Asla
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Zdroj: European Journal of Neuroscience; Sep2003, Vol. 18 Issue 6, p1486-1496, 0p
Abstrakt: Abstract It is in dispute whether caspase 3 contributes to status epilepticus (SE)-induced cell loss. We hypothesized that caspase 3-mediated cell death continues beyond the acute phase of SE. We induced SE with either kainic acid or electrical stimulation of the amygdala in Wistar and Sprague-Dawley rats. Caspase 3 immunohistochemistry, Western blot analysis and enzyme activity measurements were used to determine cellular localization and the time course of caspase 3 expression and activation. Immunohistochemistry indicated that caspase 3 protein expression increased following SE, peaking at 16–24 h. Cleavage of procaspase 3 to active fragments (p20–17) was detected 2–7 days after SE. Caspase 3 enzyme activity was elevated at 8 h and further increased up to 19.4-fold at 7 days following SE. Activation of caspase 3 after SE occurred in the hippocampus and the extrahippocampal temporal lobe but not in the thalamus. Caspase 3-immunoreactive cells represented only a minority of degenerating cells as assessed by Fluoro-Jade B and TUNEL staining. Analysis of double-labelled sections indicated that active caspase 3 was located in astrocytes rather than neurons or microglia. There was increased caspase 3 expression in both rat strains, and it was independent of the method used to induce SE. These data demonstrate that caspase 3 contributes to the cell death occurring within the first week after SE, but in only a small proportion of degenerating cells. These results suggest that, contrary to expectations, caspase 3 inhibitors would have only limited benefits in the treatment of SE. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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