Resistance of neonatal primary astrocytes against Fas-induced apoptosis depends on silencing of caspase 8.
In the present report, we have found that primary fetal astrocytes express caspase 8 and undergo apoptosis in response to Fas ligation. In contrast, neonatal astrocytes do not express detectable levels of the enzyme and are resistant to Fas killing. Fas-induced apoptosis can be restored in these cells by up-regulation of caspase 8 expression by means of transient transfection with a caspase 8-encoding plasmid. Furthermore, treatment of primary astrocytes with the demethylating agent 5-Aza-dC restores caspase 8 expression and increases the sensibility of neonatal astrocytes to the cytotoxic effect of Fas activation. Altogether, our findings indicate that silencing of caspase 8 gene is a key factor controlling the outcome of neonatal astrocytes upon Fas engagement.
Departamento de Fisioloxía, Facultade de Medicina, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Olga
O
Barca
Carmen
C
Carneiro
José A
JA
Costoya
Rosa M
RM
Señarís
Víctor M
VM
Arce
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis; D001253:Astrocytes / Q000166:cytology*; D053181:Caspase 8 / Q000096:biosynthesis / Q000235:genetics*; D002540:Cerebral Cortex / Q000166:cytology; D020868:Gene Silencing; D051381:Rats; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation
D053181:Caspase 8