Oxidative stress and diminished glutathione pools play critical roles in the pathogenesis of
neurodegenerative diseases, including Alzheimer and Parkinson disease. Synthesis of
glutathione, the most abundant mammalian antioxidant, is regulated at the substrate level by
cysteine, which is synthesized from homocysteine via the transsulfuration pathway. Elevated
homocysteine and diminished glutathione levels, seen in Alzheimer and Parkinson disease
patients suggest impairments in the transsulfuration pathway that connects these …