Nitric oxide induces caspase-dependent apoptosis and necrosis in neonatal rat cardiomyocytes.

Abstract

Excessive nitric oxide (NO) production has been implicated in the pathophysiology of cardiomyocyte (CMC) apoptosis and necrosis induced by ischemia/reperfusion, inflammation and NO-donating chemicals. Although caspases are known to be involved in apoptosis, the present study examined whether caspases also play a role in NO-induced CMC necrosis. Neonatal rat CMCs were labeled with Annexin-V and propidium iodide, and apoptosis and necrosis were analyzed by confocal images and fluorescence activated cell sorter analysis. CMC apoptosis and necrosis were also evaluated by determining DNA fragmentation in the cell and the supernatant fractions. Treatment of CMCs with the NO donor, diethylenetriamine NO (DETA/NO) or S-nitroso-N-acetyl-penicillamine (SNAP) at concentrations of 10 and 100 microM for 24h induced predominantly apoptosis over necrosis, but a higher concentration (1mM) of DETA/NO or SNAP provoked both apoptosis and necrosis. The lower doses of DETA/NO-induced apoptosis was associated with a gradual increase in caspase-3 activity over 24h without appreciable activation of poly ADP-ribose polymerase (PARP), while the higher dose of DETA/NO induced a marked increase in caspase-3 activity and CMC apoptosis until 2h after the treatment, and increased necrotic CMCs thereafter associated with robust activation of PARP. The caspase inhibitor Z-DEVD-FMK but not the poly ADP-ribose polymerase (PARP) inhibitor 3-aminobenzamide (3-AB) abolished caspase-3 activation and CMC apoptosis induced by 100 microM DETA/NO. However, both Z-DEVD-FMK and 3-AB abolished PARP activation and CMC necrosis induced by 1mM DETA/NO. The amount of nicotinamide adenine dinucleotide (NAD) and adenine nucleotides in CMCs was not significantly affected by treatment with 10 and 100 microM DETA/NO, but was significantly reduced by treatment with 1mM DETA/NO without a decline of adenylate energy charge. The depletion of NAD and adenine nucleotides was abrogated by Z-DEVD-FMK and 3-AB. These results suggest that caspase activation play a crucial role in CMC apoptosis induced by lower concentrations of NO as well as in CMC necrosis induced by a higher concentration of and a longer exposure to NO. NO-induced CMC necrosis is likely mediated by PARP activation which occurs as a consequence of caspase activation.

• Authors: Takamichi Uchiyama, Hajime Otani, Takayuki Okada, Hideki Ninomiya, Masakuni Kido, Hiroji Imamura, Shunji Nogi, Yonosuke Kobayashi
• Journal: Journal of molecular and cellular cardiology (J Mol Cell Cardiol) Vol. 34 Issue 8 Pg. 1049-61 (Aug 2002) ISSN: 0022-2828 [Print] England
• PMID: 12234774 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 1-hydroxy-2-oxo-3,3-bis(2-aminoethyl)-1-triazene
• Benzamides
• Cytochrome c Group
• Oligopeptides
• Triazenes
• benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone
• NAD
• Nitric Oxide
• 3-aminobenzamide
• Casp3 protein, rat
• Caspase 3
• Caspases

Topics

• Animals
• Apoptosis (drug effects, physiology)
• Benzamides (pharmacology)
• Caspase 3
• Caspases (drug effects, physiology)
• Cytochrome c Group (drug effects, metabolism)
• Mitochondria (drug effects, metabolism)
• Myocytes, Cardiac (physiology)
• NAD (drug effects)
• Necrosis
• Nitric Oxide (physiology)
• Oligopeptides (pharmacology)
• Rats
• Rats, Sprague-Dawley
• Triazenes (pharmacology)