title: Basal metallothionein-I/II protects against NMDA-mediated oxidative injury in cortical neuron/astrocyte cultures.
abstract: N-Methyl-D-aspartate (NMDA) receptor overactivation-mediated oxidative stress has been proposed to contribute to brain injury. Metallothionein-I/II (MT-I/II), a member of cysteine-rich metalloproteins, has been found to express in the central nervous system primarily in cortical tissues and be upregulated following brain injury. To address the role of MT-I/II on NMDA-mediated oxidative injury, we established primary cortical neuron/astrocyte cultures from neonatal MT-I/II deficient (MT⁻/⁻) and wild type (MT+/+) mice to test whether basal MT-I/II protects cortical cultures against NMDA-mediated injury. We found that MT-I/II expression was increased by NMDA in MT+/+ cultures but was not detectable in MT⁻/⁻ cultures. NMDA concentration-dependently induced oxidative injury in both MT+/+ and MT⁻/⁻ cultures as evidenced by decrease of cell viability, increases of lipid peroxidation and DNA damage. However, these toxic effects were greater in MT⁻/⁻ than MT+/+ cultures. NMDA significantly increased reactive oxygen species (ROS) generation and disrupted mitochondrial membrane potential in neurons in MT+/+ cultures, and these effects were exaggerated in MT⁻/⁻ cultures. Our findings clearly show that basal MT-I/II provides protection against NMDA-mediated oxidative injury in cortical neuron/astrocyte cultures, and suggest that the protective effects are possibly associated with inhibition of ROS generation and preservation of mitochondrial membrane potential.
authors.affiliation: Evaluation and Research Centre for Toxicology, Institute of Disease Control and Prevention, Academy of Military Medical Sciences, 20# Dongdajie Rd, Fengtai District, Beijing 100071, PR China.
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Yu
authors.forename: Jiabin
authors.initials: J
authors.lastname: Guo
authors.forename: Houhua
authors.initials: H
authors.lastname: Fang
authors.forename: Shuangqing
authors.initials: S
authors.lastname: Peng
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D001930:Brain Injuries / Q000378:metabolism; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D015536:Down-Regulation / Q000187:drug effects; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016202:N-Methylaspartate / Q000633:toxicity; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
chemical_list: C491054:Mt2 protein, mouse; D009419:Nerve Tissue Proteins; D017382:Reactive Oxygen Species; C525355:metallothionein-1, mouse; D016202:N-Methylaspartate; D008668:Metallothionein