title: Characterisation of a novel class of polyamine-based neuroprotective compounds.
abstract: Prolonged cerebral ischaemia initiates complex intra- and inter-cellular signalling cascades ultimately resulting in neuronal death. Well-characterised mediators of ischaemic cell death are glutamate, free radicals and nitric oxide. Many drugs that block these mechanisms are neuroprotective in vitro, but have unfavourable side-effect profiles in man. We have recently demonstrated that the compound L-arginyl-3,4-spermidine (L-Arg3,4) is neuroprotective in vitro through an interaction with several of these mechanisms, and prevents ischaemic neurodegeneration in vivo with no gross side effects. In this study, we have used solid-phase combinatorial chemistry, to synthesise a number of analogues of L-Arg3,4, and investigate the structure-activity relationship using an in vitro, organotypic hippocampal slice culture model of cerebral ischaemia. A number of molecular features were identified which were essential for the neuroprotective activity including the requirement for a positive charge and an amino acid in the L-configuration. Relatively minor alterations to both the terminal arginine and polyamine moieties significantly attenuated neuroprotective efficacy. Our data implies that these compounds are neuroprotective through a currently undefined mechanism rather than non-specific ionic interactions described previously for other polyamine-containing compounds.
authors.affiliation: Clinical Neurosciences, University of Southampton, Biomedical Sciences Building, Bassett Crescent East, SO16 7PX, Southampton, UK. akp1@soton.ac.uk
authors.forename: Ashley K
authors.initials: AK
authors.lastname: Pringle
authors.forename: Barclay
authors.initials: B
authors.lastname: Morrison
authors.forename: Mark
authors.initials: M
authors.lastname: Bradley
authors.forename: Fausto
authors.initials: F
authors.lastname: Iannotti
authors.forename: Lars E
authors.initials: LE
authors.lastname: Sundstrom
mesh_terms: D000818:Animals; D015687:Cell Hypoxia / Q000187:drug effects; D046508:Culture Techniques; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D018696:Neuroprotective Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D011073:Polyamines / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013095:Spermidine / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: C488298:L-arginyl-3,4-spermidine; D018696:Neuroprotective Agents; D011073:Polyamines; D013095:Spermidine