Angiotensin II attenuates chemical hypoxia-induced caspase-3 activation in primary cortical neuronal cultures.
In this study we determined whether caspase-3 is required in mouse cortical neurons for sodium azide-mediated apoptosis. Primary cortical neuronal cultures were treated with a cell permeable caspase-3 inhibitor, DEVD (1 nM-100 fM), prior to sodium azide-induced hypoxia. Treatment with the caspase-3 inhibitor resulted in a dose-dependent decrease in apoptosis, suggesting that sodium azide-induced apoptosis is mediated through a caspase-3 dependent pathway. Levels of cytochrome-c release and caspase-3 cleavage were assayed by Western analysis. Cytochrome-c release and caspase-3 cleavage were observed at 5 h (85.3+/-5.8%) and 8 h (53.4+/-14.9%), respectively. We have previously reported that angiotensin II, acting through the AT(2) receptor subtype, protects cultured mouse cortical neurons from sodium azide-induced apoptosis. We also examined whether the protective effect of angiotensin II is mediated through modulation of caspase-3. Pre-treatment of cells with angiotensin II and the AT(1) receptor antagonist, losartan, reduced levels of sodium azide-induced caspase-3 cleavage by 95.0+/-4.0%. Cells pre-treated with the AT(2) receptor antagonist, PD123319 showed a smaller reduction of caspase-3 cleavage (53.8+/-3.4%). Our findings indicate that sodium azide-induced apoptosis is caspase-3 dependent and that angiotensin II protects cortical neurons from chemical-induced apoptosis by reducing caspase-3 cleavage.
Grammatopoulos
Tom N
TN
Department of Cell and Structural Biology, University of Illinois, 126 Chemical Life Sciences Laboratory, 506 South Goodwin Avenue, Urbana, IL 61801, USA.
Morris
Katherine
K
Bachar
Cheryl
C
Moore
Steve
S
Andres
Robert
R
Weyhenmeyer
James A
JA
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D053148:Caspase 3; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D015687:Cell Hypoxia / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects / Q000201:enzymology*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D009474:Neurons / Q000187:drug effects / Q000201:enzymology*
D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D000804:Angiotensin II; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases