The role of NADPH oxidase, neuronal nitric oxide synthase and poly(ADP ribose) polymerase in oxidative neuronal death induced in cortical cultures by brain‐derived neurotrophic factor and neurotrophin‐4/5

• Published in: Journal of neurochemistry Vol. 82; no. 4; pp. 894 - 902
• Main Authors: Hwang, Jung‐Jin, Choi, So‐Young, Koh, Jae‐Young
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.08.2002
• Subjects: Animals; Apoptosis - drug effects; Apoptosis - physiology; Blotting, Western; Brain-Derived Neurotrophic Factor - pharmacology; cell death; Cells, Cultured; Cerebral Cortex - cytology; Enzyme Inhibitors - pharmacology; free radicals; Glycoside Hydrolases - antagonists & inhibitors; lactate dehydrogenase; Mice; NADPH Oxidases - antagonists & inhibitors; NADPH Oxidases - metabolism; Nerve Growth Factors - pharmacology; Neurons - cytology; Neurons - drug effects; Neurons - metabolism; Nitric Oxide Synthase - antagonists & inhibitors; Nitric Oxide Synthase - metabolism; Nitric Oxide Synthase Type I; Oxidation-Reduction; peroxynitrite; Phosphoproteins - metabolism; poly(ADP ribose) glycohydrolase; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases - metabolism; Protein Subunits; Protein Transport - drug effects; TrkB
• ISSN: 0022-3042; 1471-4159
• DOI: 10.1046/j.1471-4159.2002.01040.x

Certain neurotrophins promote or induce oxidative neuronal death in cortical cultures. However, the effector mechanisms mediating this phenomenon have not been delineated. In this study, we investigated the possibility that NADPH oxidase and nitric oxide synthase (NOS) function as such effectors. Western blot analysis showed that treatment with brain‐derived neurotrophic factor (BDNF) and neurotrophin (NT)‐4/5 increased the levels of NADPH oxidase subunits. Moreover, neurotrophin treatment resulted in membrane translocation of p67phox, a characteristic feature of NADPH oxidase activation. Administration of the specific NADPH oxidase inhibitor, 4‐(2‐aminoethyl)benzenesulfonylfluoride (AEBSF), attenuated increases in oxygen free radicals thereby suggesting that NADPH oxidase contributes to the oxidative stress induced by neurotrophins. Furthermore, neuronal death induced by BDNF or NT‐4/5 was significantly attenuated by AEBSF. Treatment with BDNF has previously been shown to induce neuronal NOS (nNOS). Our data indicated that inhibitors of nNOS attenuated neuronal death induced by BDNF or NT‐4/5, consistent with an active role of nNOS in the mediation of neurotrophin neurotoxicity. As in other models of oxidative cell death, BDNF‐induced neuronal death was accompanied by poly(ADP ribose) polymerase (PARP) activation. AEBSF or N‐nitro‐l‐arginine (NNA) reduced BDNF‐mediated PARP activation. PARP and poly(ADP ribose) glycohydrolase (PARG) are actively involved in mediating neurotrophin neurotoxicity since inhibitors of PARP and PARG significantly reduced levels of cell death. These results suggest that NADPH oxidase and nNOS contribute to increased oxidative stress, subsequent activation of PARP/PARG, and neuronal death induced by prolonged neurotrophin exposure.