title: Increased excitatory amino acid transport into murine prion protein knockout astrocytes cultured in vitro.
abstract: Prion protein (PrP) is expressed on a wide variety of cells and plays an important role in the pathogenesis of transmissible spongiform encephalopathies. However, its normal function remains unclear. Mice that do not express PrP exhibit deficits in spatial memory and abnormalities in excitatory neurotransmission suggestive that PrP may function in the glutamatergic synapse. Here, we show that transport of D-aspartate, a nonmetabolized L-glutamate analog, through excitatory amino acid transporters (EAATs) was faster in astrocytes from PrP knockout (PrPKO) mice than in astrocytes from C57BL/10SnJ wild-type (WT) mice. Experiments using EAAT subtype-specific inhibitors demonstrated that in both WT and PrPKO astrocytes, the majority of transport was mediated by EAAT1. Furthermore, PrPKO astrocytes were more effective than WT astrocytes at alleviating L-glutamate-mediated excitotoxic damage in both WT and PrPKO neuronal cultures. Thus, in this in vitro model, PrPKO astrocytes exerted a functional influence on neuronal survival and may therefore influence regulation of glutamatergic neurotransmission in vivo.
authors.affiliation: Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, NIAID, National Institute of Health, Hamilton, Montana, USA.
authors.forename: Melissa S
authors.initials: MS
authors.lastname: Pathmajeyan
authors.forename: Sarjubhai A
authors.initials: SA
authors.lastname: Patel
authors.forename: James A
authors.initials: JA
authors.lastname: Carroll
authors.forename: Todd
authors.initials: T
authors.lastname: Seib
authors.forename: James F
authors.initials: JF
authors.lastname: Striebel
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Bridges
authors.forename: Bruce
authors.initials: B
authors.lastname: Chesebro
mesh_terms: D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D001253:Astrocytes / Q000378:metabolism*; D015153:Blotting, Western; D002470:Cell Survival; D002478:Cells, Cultured; D018920:Coculture Techniques; D027341:Excitatory Amino Acid Transporter 1 / Q000378:metabolism; D027342:Excitatory Amino Acid Transporter 2 / Q000378:metabolism; D005434:Flow Cytometry; D050491:Glutamate Plasma Membrane Transport Proteins / Q000378:metabolism*; D018698:Glutamic Acid / Q000502:physiology; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009474:Neurons / Q000502:physiology; D011328:Prions / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012964:Sodium / Q000502:physiology
chemical_list: D027341:Excitatory Amino Acid Transporter 1; D027342:Excitatory Amino Acid Transporter 2; D050491:Glutamate Plasma Membrane Transport Proteins; D011328:Prions; D012333:RNA, Messenger; C493396:Slc1a2 protein, mouse; C493393:Slc1a3 protein, mouse; D001224:Aspartic Acid; D018698:Glutamic Acid; D012964:Sodium