Mechanism of DNA Fragmentation During Hypoxia in the Cerebral Cortex of Newborn Piglets

• Published in: Neurochemical research 2008-07, Vol.33 (7), p.1232-1237
• Main Authors: Chiang, Ming-Chou, Ashraf, Qazi M., Mishra, Om P., Delivoria-Papadopoulos, Maria
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - metabolism; Animals; Animals, Newborn - physiology; Apoptosis Regulatory Proteins - biosynthesis; Apoptosis Regulatory Proteins - genetics; Biochemistry; Biomedical and Life Sciences; Biomedicine; Caspase 3 - metabolism; Caspase 9 - physiology; Caspase Inhibitors; Cell Biology; Cell Nucleus - drug effects; Cell Nucleus - enzymology; Cell Nucleus - metabolism; Cerebral Cortex - metabolism; Cytosol - drug effects; Cytosol - enzymology; Cytosol - metabolism; Deoxyribonucleases - biosynthesis; Deoxyribonucleases - genetics; DNA Fragmentation; Electrophoresis, Agar Gel; Enzyme Activation - physiology; Enzyme Inhibitors - pharmacology; Hypoxia - metabolism; Nerve Tissue Proteins - metabolism; Neurochemistry; Neurology; Neurons - metabolism; Neurons - ultrastructure; Neurosciences; Oligopeptides - pharmacology; Original Paper; Phosphocreatine - metabolism; Swine
• ISSN: 0364-3190; 1573-6903
• DOI: 10.1007/s11064-007-9574-8

We have previously shown that hypoxia results in increased activity of caspase-9, caspase-3 and fragmentation of nuclear DNA in the cerebral cortex of newborn piglets. The present study tested the hypothesis that mechanism of DNA fragmentation during hypoxia in the cerebral cortex of newborn piglets is mediated by caspase-9-dependent caspase-3 activation. Newborn piglets were randomly assigned to normoxic, hypoxic, and hypoxic pretreated with a highly selective caspase-9 inhibitor, Z-LEHD-FMK groups. The data showed that cerebral tissue hypoxia results in increased expression of caspase-activated DNase (CAD) protein in the nucleus and fragmentation of nuclear DNA. A pretreatment with Z-LEHD-FMK attenuated the expression of CAD protein in the nucleus and the fragmentation of nuclear DNA. Based on these results, we conclude that the mechanism by which the nuclear DNA was fragmented is mediated by caspase-9-dependent caspase-3 activation and the consequence of caspase-activated DNase activation in the cerebral cortex of newborn piglets.