title: Enhanced susceptibility of Prnp-deficient mice to kainate-induced seizures, neuronal apoptosis, and death: Role of AMPA/kainate receptors.
abstract: Normal physiologic functions of the cellular prion protein (PrPc) are still elusive. This GPI-anchored protein exerts many functions, including roles in neuron proliferation, neuroprotection or redox homeostasis. There are, however, conflicting data concerning its role in synaptic transmission. Although several studies report that PrPc participates in NMDA-mediated neurotransmission, parallel studies describe normal behavior of PrPc-mutant mice. Abnormal axon connections have been described in the dentate gyrus of the hippocampi of PrPc-deficient mice similar to those observed in epilepsy. A study indicates increased susceptibility to kainate (KA) in these mutant mice. We extend the observation of these studies by means of several histologic and biochemical analyses of KA-treated mice. PrPc-deficient mice showed increased sensitivity to KA-induced seizures in vivo and in vitro in organotypic slices. In addition, we show that this sensitivity is cell-specific because interference experiments to abolish PrPc expression increased susceptibility to KA in PrPc-expressing cells. We indicate a correlation of susceptibility to KA in cells lacking PrPc with the differential expression of GluR6 and GluR7 KA receptor subunits using real-time RT-PCR methods. These results indicate that PrPc exerts a neuroprotective role against KA-induced neurotoxicity, probably by regulating the expression of KA receptor subunits.
authors.affiliation: Cellular and Molecular Basis of Neurodegeneration and Neurorepair, Department of Cell Biology, University of Barcelona, Spain.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Rangel
authors.forename: Ferran
authors.initials: F
authors.lastname: Burgaya
authors.forename: Rosalina
authors.initials: R
authors.lastname: Gavín
authors.forename: Eduardo
authors.initials: E
authors.lastname: Soriano
authors.forename: Adriano
authors.initials: A
authors.lastname: Aguzzi
authors.forename: José A
authors.initials: JA
authors.lastname: Del Río
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D004198:Disease Susceptibility; D005452:Fluoresceins; D006624:Hippocampus / Q000473:pathology; D007608:Kainic Acid; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009474:Neurons / Q000473:pathology*; D009924:Organ Culture Techniques; D009930:Organic Chemicals; D000072002:Prion Proteins; D011328:Prions / Q000235:genetics; D034741:RNA, Small Interfering / Q000378:metabolism; D018091:Receptors, AMPA / Q000502:physiology*; D012640:Seizures / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology*; D014162:Transfection / Q000379:methods
chemical_list: D005452:Fluoresceins; D009930:Organic Chemicals; D000072002:Prion Proteins; D011328:Prions; C512657:Prnp protein, mouse; D034741:RNA, Small Interfering; D018091:Receptors, AMPA; C435731:fluoro jade; D007608:Kainic Acid