NR AIEQ
AU McHattie,S.J.; Brown,D.R.; Bird,M.M.
TI Cellular uptake of the prion protein fragment PrP106-126 in vitro
QU Journal of Neurocytology 1999 Feb; 28(2): 149-59
PT journal article
AB The aetiological agent of prion disease is proposed to be an aberrant isoform of the cell surface glycoprotein known as the prion protein (PrPc). This pathological isoform (PrPsc) is abnormally deposited in the extracellular space of diseased CNS. Neurodegeneration in these disease has been shown to be associated with accumulation of PrPsc in affected tissue. To investigate the possible uptake mechanisms that may be required for PrPsc-induced neurodegeneration we studied the cellular trafficking of the neurotoxic fragment, PrP106-126. We were able to detect, by fluorescence microscopy, PrP106-126 inclusions in murine neurones, astrocytes and microglia in vitro. These inclusions were abundant after 24 hour exposure and still present 48h post-exposure. Shorter exposure times yielded only occasional cells with inclusions. Large extracellular aggregates of PrP106-126 could also be detected, which appeared in a time dependent manner. The appearance of inclusions or aggregates was not dependent on PrPc expression as determined by exposure of peptides from PrP-null mice. Using transmission electron microscopy and gold particle detection, positively labelled osmiophilic inclusions of peptide could be detected in the cytoplasm of exposed cells. These results demonstrate that cultured cells are capable of sequestering PrP106-126 and may indicate uptake pathways for PrPsc in various cell types. Toxicity of PrP106-126 may thus be mediated via a sequestration pathway that is not effective for this peptide in PrP-null cells.
MH Animal; Cell Count; Cells, Cultured; Cerebellum/cytology/metabolism; Immunohistochemistry; Mice; Mice, Inbred C57BL; Microglia/chemistry/ultrastructure; Microscopy, Confocal; Microscopy, Electron; Neurofibrils/metabolism/ultrastructure; Neurons/chemistry/ultrastructure; Peptide Fragments/analysis/metabolism/*pharmacokinetics; Prions/analysis/metabolism/*pharmacokinetics; Support, Non-U.S. Gov't
AD Biomedical Sciences, Queen Mary and Westfield College, Mile End Road, London E1 4NS, UK
SP englisch
PO USA