One-Carbon Metabolism and Midbrain Dopaminergic Cells in Lesch-Nyhan Disease.

Background: Lesch-Nyhan disease (LND) is characterized by severe motor problems, self-injury, and gout. LND is caused by loss of function of HPRT which functions to salvage purine nucleotides, but the link between purine recycling and the neurological phenotypes remains unknown. One-carbon metabolism (OCM) is the utilization of single-carbon units for important cellular pathways such as de novo purine synthesis, the methionine cycle, and the transsulfuration pathway. Since purine salvage is lost in LND and one-carbon groups are required for de novo purine synthesis, there is an obligate need to re-route one-carbon flux in LND. Midbrain dopaminergic neurons have been associated with LND and may represent an important intersection point for OCM and LND. Summary: In this review, we analyze the relationships between HPRT loss, OCM, and the unique metabolic features of midbrain dopaminergic cells. Our hope is to better understand how changes to metabolic flux in OCM might affect midbrain dopaminergic cells and ultimately lead to the neurological phenotypes of LND. Key Messages: OCM provides important components for different processes and pathways including de novo purine synthesis, methionine cycle, transsulfuration pathway, and polyamine synthesis. Changes in flux toward de novo purine synthesis in LND may affect these interconnected processes and have potential effects on dopaminergic cells as discussed in this review.