Role of N-methyl-D-aspartate receptors in polychlorinated biphenyl mediated neurotoxicity. 2009

Leopold Tchapda Ndountse, and Hing Man Chan
Community Health Sciences Program, University of Northern British Columbia, Prince George, BC, Canada V2N4Z9.

Polychlorinated biphenyls (PCBs) are widespread persistent environmental pollutants. Chronic human and animal exposure to PCBs results in various harmful effects including neurotoxicity. This study investigates the effects of the PCB mixture Aroclor 1254 (A1254) and two PCB congeners (coplanar, non-ortho PCB 126, and non coplanar PCB 99) on the expression of N-methyl-D-aspartate receptors (NMDARs) and the subsequent toxic effects using a human SHS5-SY neuroblastoma cell line. NMDAR was measured using a radiolabeled phencyclidine receptor ligand [(3)H]-MK801, apoptosis was quantified using fluorogenic substrates specific for caspase-3 (DEVD-AFC) and cell death using lactate dehydrogenase (LDH) release. After treatment, a positive dose-response relationship of increasing NMDARS, increasing caspase-3 activity and cell death was observed in all PCB compounds. The non-coplanar PCB compounds were found to be significantly more toxic than the coplanar congener and the PCB mixture A1254. PCB-mediated cell death was attenuated with 10microM NMDAR antagonists: 1-amino-3,5-dimethyladamantane hydrochloride (memantine) and (+)-5-methyl-10,11-dihydro-5H-debenzocyclhepten-5,10-imine maleate ((+)-MK-801), thus demonstrating the importance of NMDAR in PCB neurotoxicity. Intracellular calcium [Ca(2+)](i) chelator BAPTA-AM (1microM) partially attenuated the neurotoxic effect of the PCBs suggesting a role of calcium homeostasis disruption in the neurotoxicity of PCBs. These results suggest that the neurotoxicity of PCBs can be mediated through activation of NMDARs.

UI MeSH Term Description Entries
D007770 L-Lactate Dehydrogenase A tetrameric enzyme that, along with the coenzyme NAD+, catalyzes the interconversion of LACTATE and PYRUVATE. In vertebrates, genes for three different subunits (LDH-A, LDH-B and LDH-C) exist. Lactate Dehydrogenase,Dehydrogenase, L-Lactate,Dehydrogenase, Lactate,L Lactate Dehydrogenase
D008559 Memantine AMANTADINE derivative that has some dopaminergic effects. It has been proposed as an antiparkinson agent. 1,3-Dimethyl-5-aminoadamantane,1-Amino-3,5-dimethyladamantane,Axura,D-145,D145,Ebixa,Memantin,Memantine Hydrochloride,Namenda,D 145
D011078 Polychlorinated Biphenyls Industrial products consisting of a mixture of chlorinated biphenyl congeners and isomers. These compounds are highly lipophilic and tend to accumulate in fat stores of animals. Many of these compounds are considered toxic and potential environmental pollutants. PCBs,Polychlorinated Biphenyl,Polychlorobiphenyl Compounds,Biphenyl, Polychlorinated,Biphenyls, Polychlorinated,Compounds, Polychlorobiphenyl
D004785 Environmental Pollutants Substances or energies, for example heat or light, which when introduced into the air, water, or land threaten life or health of individuals or ECOSYSTEMS. Environmental Pollutant,Pollutant,Pollutants,Pollutants, Environmental,Pollutant, Environmental
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014407 Tumor Cells, Cultured Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely. Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured
D016194 Receptors, N-Methyl-D-Aspartate A class of ionotropic glutamate receptors characterized by affinity for N-methyl-D-aspartate. NMDA receptors have an allosteric binding site for glycine which must be occupied for the channel to open efficiently and a site within the channel itself to which magnesium ions bind in a voltage-dependent manner. The positive voltage dependence of channel conductance and the high permeability of the conducting channel to calcium ions (as well as to monovalent cations) are important in excitotoxicity and neuronal plasticity. N-Methyl-D-Aspartate Receptor,N-Methyl-D-Aspartate Receptors,NMDA Receptor,NMDA Receptor-Ionophore Complex,NMDA Receptors,Receptors, NMDA,N-Methylaspartate Receptors,Receptors, N-Methylaspartate,N Methyl D Aspartate Receptor,N Methyl D Aspartate Receptors,N Methylaspartate Receptors,NMDA Receptor Ionophore Complex,Receptor, N-Methyl-D-Aspartate,Receptor, NMDA,Receptors, N Methyl D Aspartate,Receptors, N Methylaspartate
D016291 Dizocilpine Maleate A potent noncompetitive antagonist of the NMDA receptor (RECEPTORS, N-METHYL-D-ASPARTATE) used mainly as a research tool. The drug has been considered for the wide variety of neurodegenerative conditions or disorders in which NMDA receptors may play an important role. Its use has been primarily limited to animal and tissue experiments because of its psychotropic effects. Dizocilpine,MK-801,MK 801,MK801
D053148 Caspase 3 A short pro-domain caspase that plays an effector role in APOPTOSIS. It is activated by INITIATOR CASPASES such as CASPASE 9. Isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA. CASP3,Apopain,Caspase-3,Pro-Caspase-3,Procaspase-3,Pro Caspase 3,Procaspase 3
D018691 Excitatory Amino Acid Antagonists Drugs that bind to but do not activate excitatory amino acid receptors, thereby blocking the actions of agonists. Amino Acids, Excitatory, Antagonists,Excitatory Amino Acid Antagonist,Glutamate Antagonist,Glutamate Antagonists,Glutamate Receptor Antagonist,Amino Acid Antagonists, Excitatory,Antagonists, Excitatory Amino Acid,EAA Antagonists,Glutamate Receptor Antagonists,Antagonist, Glutamate,Antagonist, Glutamate Receptor,Antagonists, EAA,Antagonists, Glutamate,Antagonists, Glutamate Receptor,Receptor Antagonist, Glutamate,Receptor Antagonists, Glutamate

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