NR AKFM
AU Rubenstein,R.; Deng,H.; Race,R.E.; Ju,W.; Scalici,C.; Papini,M.; Rubenstein,A.; Kascsak,R.; Carp,R.I.
TI Scrapie strain infection in vitro induces changes in neuronal cells
QU Molecular Neurobiology 1994 Apr-Jun; 8(2-3): 129-38
PT journal article; review; review, tutorial
AB PC12 cells, in the presence of nerve growth factor (NGF), support replication of the mouse-derived scrapie strains 139A and ME7, with the former yielding 100-1000-fold higher levels of infectivity. Infectivity remained cell-associated and cells did not show any gross morphological alterations, although changes were observed by electron microscopy in the form of an increased number of lipid droplets in 139A-infected cultures. Analysis of phospholipid metabolism in 139A infected cells indicated that scrapie replication did not change the inositol phosphate levels, but did stimulate phosphoinositide synthesis. Replication was not detected in PC12 cells infected with either the hamster-derived 263K or rat-derived 139R scrapie strains. Since scrapie-infected cultures did not exhibit cell death or any gross changes, any scrapie-induced effects would probably be manifested in nonvital cellular functions. When compared to controls, infection with the 139A scrapie strain resulted in decreased activity of the cholinergic pathway-related enzymes, as well as the GABA synthetic pathway; however, the adrenergic pathway was unaffected by scrapie infection. The effects of the 139A scrapie strain on the cholinergic system appeared to be dose-dependent and were first detected prior to the detection of scrapie agent replication in these cells. No neurotransmitter-related enzymatic changes were detected in 263K- or 139R-infected PC12 cells. The enzymatic changes observed in ME7-infected PC12 cells and in Chandler agent-infected mouse neuroblastoma cells suggest that the significant changes in neurotransmitter levels in cultures exhibiting low infectivity titers must involve factors other than, but not excluding, replication of the agent. The role of additional factors is also suggested in studies of protein kinase C activity in 139A- and 139R-infected PC12 cells. These studies emphasize the value of the PC12 cell model system in examining the scrapie strain-host cell interaction and, in addition, support the concept of variation among scrapie strains.
IN In Kulturen von PC12-Zellen vermehrt sich nach Zugabe von Maus-Scrapieerregern der Stämme 139A und ME7 deren die Infektivität vermutlich durch die Umformung normaler Prionproteine um 2-3 Größenordnungen. Dagegen wurde beim Hamster-Scrapiestamm 263K und beim Ratten-Scrapiestamm 139R in PC12-Zellkulturen keine Infektivitätszunahme beobachtet. Die Infektivität ist zellgebunden und richtet bei den PC12-Zellen keine offensichtlichen Schäden an. Die Scrapie-Replikation beeinflußt nicht die Synthese und den Abbau von Phosphatidylinositol. Mit dem Scrapiestamm 139A infizierte PC12-Zellen zeigen aber eine verminderte Aktivität von Enzymen des cholinergen und des GABA Syntheseweges, während der adrenerge Pfad unbeeinflußt bleibt. Der Einfluß auf das cholinerge System ist dosisabhängig und ist bereits vor der Vermehrung der Scrapieerreger zu beobachten. Der Hamster-Scrapiestamm 263K und der Ratten-Scrapiestamm 139R haben in PC12-Zellkulturen keinen Einfluß auf die Neurotransmitter. Auch die enzymatischen Veränderungen bei mit dem ME7-Scrapiestamm infizierten PC12 Zellen und in mit dem Chandler-Scrapie-Agens infizierten Mausneuroblastomzellen verändern die Neurotransmitterkonzentrationen anscheinend schon vor der Vermehrung der Prionproteine.
ZR 46
MH Acetylcholinesterase/metabolism; Animal; Brain/metabolism; Choline O-Acetyltransferase/metabolism; Mice; Nerve Growth Factors/pharmacology; Neuroblastoma; Neurons/*metabolism; Neurotransmitters/biosynthesis; PC12 Cells; PrPsc Proteins/*metabolism/*pathogenicity; Rats; Scrapie/*metabolism; Support, Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.; Tumor Cells, Cultured; Virus Replication; gamma-Aminobutyric Acid/biosynthesis
AD Department of Virology, New York State Office of Mental Retardation and Developmental Disabilities, Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314.
SP englisch
PO USA