Synthesis and transport of creatine in the CNS: importance for cerebral functions.
Apart of its well known function of 'energetic buffer' through the creatine/phosphocreatine/creatine kinase system allowing the regeneration of ATP, creatine has been recently suggested as a potential neuromodulator of even true neurotransmitter. Moreover, the recent discovery of primary creatine deficiency syndromes, due to deficiencies in L-arginine : glycine amidinotransferase or guanidinoacetate methyltransferase (the two enzymes allowing creatine synthesis) or in the creatine transporter, has shed new light on creatine synthesis, metabolism and transport, in particular in CNS which appears as the main tissue affected by these creatine deficiencies. Recent data suggest that creatine can cross blood-brain barrier but only with a poor efficiency, and that the brain must ensure parts of its needs in creatine by its own endogenous synthesis. Finally, the recent years have demonstrated the interest to use creatine as a neuroprotective agent in a growing number of neurodegenerative diseases, including Parkinson's and Huntington's diseases. This article aims at reviewing the latest data on creatine metabolism and transport in the brain, in relation to creatine deficiencies and to the potential use of creatine as neuroprotective molecule. Emphasis is also given to the importance of creatine for cerebral function.
Béard
Elidie
E
Inborn Errors of Metabolism, Clinical Chemistry Laboratory, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
Braissant
Olivier
O
D000579:Amidinotransferases / Q000378:metabolism; D000818:Animals; D002490:Central Nervous System / Q000378:metabolism*; D002540:Cerebral Cortex / Q000502:physiology*; D003401:Creatine / Q000096:biosynthesis* / Q000172:deficiency; D050937:Guanidinoacetate N-Methyltransferase / Q000378:metabolism; D006801:Humans; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000378:metabolism; D019636:Neurodegenerative Diseases / Q000378:metabolism / Q000517:prevention & control; D050480:Plasma Membrane Neurotransmitter Transport Proteins / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology
D009419:Nerve Tissue Proteins; D050480:Plasma Membrane Neurotransmitter Transport Proteins; C094770:SLC6A8 protein, human; C494506:GAMT protein, human; D050937:Guanidinoacetate N-Methyltransferase; D000579:Amidinotransferases; C020681:glycine amidinotransferase; D003401:Creatine