title: The role of kynurenines in the pathomechanism of amyotrophic lateral sclerosis and multiple sclerosis: therapeutic implications.
abstract: Tryptophan is one of the essential amino acids, 80% of which is catabolised in the extrahepatic tissues by indoleamine-2,3-dioxygenase (IDO), the rate-limiting enzyme of the kynurenine pathway. Metabolites along the kynurenine pathway have been implicated to play a role in the pathomechanism of neuroinflammatory and neurodegenerative disorders. Changes in the concentration levels of kynurenines can shift the balance to pathological conditions. The ability to influence the metabolism towards the neuroprotective branch of the kynurenine pathway, i.e. towards kynurenic acid (KYNA) synthesis, may be one option in preventing neurodegenerative diseases. Three potential therapeutic strategies could be feasible to develop drugs to live up to expectations: (1) chemically related drugs with better bioavailability and higher affinity to the binding sites of excitatory receptors; (2) prodrugs of KYNA, which easily cross the blood-brain barrier combined with an inhibitor of organic acid transport for enhancement of the brain KYNA concentration; (3) inhibitors of enzymes of the kynurenine pathway. In this review, we focus on aspects of the pathomechanism and therapeutic possibilities of amyotrophic lateral sclerosis and multiple sclerosis that may be influenced by kynurenines.
authors.affiliation: Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Centre, University of Szeged, Semmelweis u. 6, Szeged, 6725, Hungary.
authors.forename: Judit
authors.initials: J
authors.lastname: Füvesi
authors.forename: Cecilia
authors.initials: C
authors.lastname: Rajda
authors.forename: Krisztina
authors.initials: K
authors.lastname: Bencsik
authors.forename: József
authors.initials: J
authors.lastname: Toldi
authors.forename: László
authors.initials: L
authors.lastname: Vécsei
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000188:drug therapy* / Q000473:pathology* / Q000503:physiopathology; D000818:Animals; D006801:Humans; D007737:Kynurenine / Q000008:administration & dosage / Q000502:physiology*; D009103:Multiple Sclerosis / Q000188:drug therapy* / Q000473:pathology* / Q000503:physiopathology; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology; D011355:Prodrugs / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D011355:Prodrugs; D007737:Kynurenine