Glutamate receptors modulate oxidative stress in neuronal cells. A mini-review.

ABSTRACT

Multiple lines of evidence demonstrate that reactive oxygen species (ROS) are involved in regulation of normal cell metabolism as second messengers. Under extreme conditions, these molecules induce oxidative stress, which may stimulate (or accompany) a number of neurodegenerative processes. In the glutamatergic system, ROS levels are under control of ionotropic and metabotropic glutamate receptors, which modulate ion fluxes through the neuronal membrane. The Na+/K(+)-pump is also one of the important participants affecting stationary ROS levels through several distinct mechanisms. This review describes the involvement of the Na+/K(+)-pump in intracellular signaling mechanisms via cross-talk between the pump and glutamate receptors in cerebellum granule cells. Selective dysfunction of mGlu II receptors may also lead to abnormal protein phosphorylation (i.e., tau phosphorylation), culminating in neurodegenerative disorders (i.e., Alzheimer disease). Also, unregulated production of intracellular ROS resulting from an imbalance of ionotropic and metabotropic receptors may activate one or more protein kinases. In summary, Glu receptor dysfunction, leading to a deficit in glutamate-mediated signal transduction may represent one of the earliest stages of neurodegenerative disorders. The Na+/K(+)-pump is able to prevent over-production of intracellular ROS, thus increasing oxidative stability of neuronal cells.