NMDA-Receptors Are Involved in Cu²⁺/Paraquat-Induced Death of Cultured Cerebellar Granule Neurons

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E. V. Stelmashook^1*, E. E. Genrikhs¹, O. P. Aleksandrova¹, G. A. Amelkina², E. A. Zelenova^1,2, and N. K. Isaev^1,2*

¹Neurology Research Center, 125367 Moscow, Russia; E-mail: estelmash@mail.ru

²Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; E-mail: isaev@genebee.msu.ru

^* To whom correspondence should be addressed.

Received March 4, 2016; Revision received May 17, 2016

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Rat cultured cerebellar granule neurons (CGNs) were not sensitive to CuCl₂ (1-10 µM, 24 h), whereas paraquat (150 µM) decreased neuronal survival to 79 ± 3% of control level. Simultaneous treatment of CGNs with paraquat and CuCl₂ (2, 5, or 10 µM Cu²⁺/paraquat) caused significant copper dose-dependent death, lowering their survival to 56 ± 4, 37 ± 3, or 16 ± 2%, respectively, and stimulating elevated production of free radicals in CGNs. Introduction of vitamin E, a non-competitive antagonist of NMDA subtype of glutamate receptors (MK-801), and also removal of glutamine from the incubation medium decreased toxicity of Cu²⁺/paraquat mixture. However, addition of Cu²⁺ into the incubation medium did not affect CGNs death caused by glutamate. These data emphasize that excessive copper in the brain may trigger oxidative stress, which in turn results in release of glutamate, overstimulation of glutamate receptors, and neuronal death.

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KEY WORDS: copper, paraquat, cerebellar granule neurons, free radicals, glutamate

DOI: 10.1134/S0006297916080113

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