Glutamyl cysteine synthetase catalytic and regulatory subunits localize to dopaminergic nigral neurons as well as to astrocytes.

Abstract

Glutathione (GSH) is considered one of the primary antioxidant compounds in the brain, important for the removal of peroxides from this organ. GSH levels have been reported to be significantly lower in the substantia nigra (SN) of Parkinson patients vs. age-matched controls. Curiously, GSH has been proposed to be present in brain astrocytes rather than in neurons even though these cells are not lost in Parkinson disease. We report that the catalytic and regulatory subunit proteins of glutamyl cysteine synthetase (GCS), the primary enzyme involved in GSH synthesis, are present not only in astrocytes but also in dopaminergic neurons of the SN. This may have important implications in terms of GSH loss associated with Parkinson disease.