NR AWDJ
AU Christensen,H.M.; Harris,D.A.
TI Cellular lifesaver: exploring the role of the cellular prion protein in neuroprotection
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions CE-06
PT Konferenz-Poster
AB Several lines of in vivo and in vitro evidence suggest that PrPc plays a role in protection of neurons from apoptotic cell death. Wild type PrPc rescues transgenic mice from neurotoxicity induced by PrP(32-134) and Doppel expression (Behrens, A. and Aguzzi, A. (2002) Trends Neurosci. 25(3): 150-4). Work in our laboratory has shown that PrPc efficiently rescues S. cerevisiae from cell death induced by Bax (Li, A. and Harris, D.A. (2005) J Biol Chem. 280(17): 17430-4). Since the ability of PrPc to protect cells from toxic insults has been demonstrated in transgenic mouse models and yeast, we explored in vitro systems previously described in the literature to establish a mammalian cell system to further investigate PrPc-mediated neuroprotection. PrPc was reported to rescue MCF-7 cells (Diarra-Mehrpour, M. et al. (2004) Cancer Res. 64(2): 719-27) and immortalized Prnp-/hippocampal neurons (HpL3-4 cells; Kuwahara, C. et al. (1999) Nature. 400(6741): 225-6) from death stimulated by TNF-alpha and serum deprivation, respectively. TNF-alpha treated MCF-7 cells stably expressing human PrPc displayed only a slight decrease in cell death compared with vector controls. Stable expression of PrPc in HpL3-4 cells did not produce any consistent effect. In addition, the HpL3-4 cell morphology was not consistent with their being of neuronal origin. Quantitative RT-PCR analysis revealed that the HpL3-4 cell line did not express neurofilament light chain or GFAP. Surprisingly, these cells did not express Doppel, which was unexpected since they were derived from the Rikn Prnp-/- mice that ectopically express Doppel in the brain. In striking contrast, a PrPc-mediated rescue effect was observed in cerebellar granule neurons (CGNs) that were transiently transfected to express mouse Bax. CGNs derived from Prnp-/- mice had increased sensitivity to Bax-mediated cell death compared with those expressing PrPc. Introduction of Bax into cerebellar granule neurons constitutes a tractable system for investigations into the mechanism of PrPc-mediated rescue.
AD Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 USA. E-mail. dharris@wustl.edu
SP englisch
PO Italien