Domain-Specific Activation of Death-Associated Intracellular Signalling Cascades by the Cellular Prion Protein in Neuroblastoma Cells
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The biological functions of the cellular prion protein remain poorly understood. In fact, numerous studies have aimed to determine specific functions for the different protein domains. Studies of cellular prion protein (PrPC) domains through in vivo expression of molecules carrying internal deletions in a mouse Prnp null background have provided helpful data on the implication of the protein in signalling cascades in affected neurons. Nevertheless, understanding of the mechanisms underlying the neurotoxicity induced by these PrPC deleted forms is far from complete. To better define the neurotoxic or neuroprotective potential of PrPC N-terminal domains, and to overcome the heterogeneity of results due to the lack of a standardized model, we used neuroblastoma cells to analyse the effects of overexpressing PrPC deleted forms. Results indicate that PrPC N-terminal deleted forms were properly processed through the secretory pathway. However, PrPΔF35 and PrPΔCD mutants led to death by different mechanisms sharing loss of alpha-cleavage and activation of caspase-3. Our data suggest that both gain-of-function and loss-of-function pathogenic mechanisms may be associated with N-terminal domains and may therefore contribute to neurotoxicity in prion disease. Dissecting the molecular response induced by PrPΔF35 may be the key to unravelling the physiological and pathological functions of the prion protein.
KeywordsCellular prion protein Neurotoxicity Truncated prion protein
The authors thank Prof. D. Harris (University of Boston) for kindly providing pcDNA-PrP plasmid and Prof. A. Aguzzi (University Hospital of Zurich) for pcDNA-ΔF35 plasmid. The authors thank Tom Yohannan for the editorial advice, M. Martínez-Vicente from M. Vila’s Lab for her guidance in MMP experiments, and M. Segura for the technical assistance. This research was supported by the Spanish Ministry of Science and Innovation (BFU2012-32617), FP7-PRIORITY, the Generalitat de Catalunya (SGR2014-1218), CIBERNED (PI2014/02-4 and PRY-14-114), La Caixa Obra Social Foundation, La Marató de TV3, and the Basque Foundation of Health and Innovation Research (BIO12/AL/004) to JADR. R.G. was supported by Instituto de Salud Carlos Tercero (FIS, PI11-00075). C.V, S.V., and A.M. were supported by the Spanish Ministry of Science and Innovation. O.N. was supported by Fundación Ramón Areces.
- 10.Nicolas O, Gavin R, Braun N, Urena JM, Fontana X, Soriano E, Aguzzi A, del Rio JA (2007) Bcl-2 overexpression delays caspase-3 activation and rescues cerebellar degeneration in prion-deficient mice that overexpress amino-terminally truncated prion. FASEB J 21(12):3107–3117. doi: 10.1096/fj.06-7827com CrossRefPubMedGoogle Scholar
- 14.Gavin R, Braun N, Nicolas O, Parra B, Urena JM, Mingorance A, Soriano E, Torres JM et al (2005) PrP(106-126) activates neuronal intracellular kinases and Egr1 synthesis through activation of NADPH-oxidase independently of PrPc. FEBS Lett 579(19):4099–4106. doi: 10.1016/j.febslet.2005.06.037 CrossRefPubMedGoogle Scholar
- 23.Enguita M, DeGregorio-Rocasolano N, Abad A, Trullas R (2005) Glycogen synthase kinase 3 activity mediates neuronal pentraxin 1 expression and cell death induced by potassium deprivation in cerebellar granule cells. Mol Pharmacol 67(4):1237–1246. doi: 10.1124/mol.104.007062 CrossRefPubMedGoogle Scholar
- 24.Vilches S, Vergara C, Nicolas O, Sanclimens G, Merino S, Varon S, Acosta GA, Albericio F et al (2013) Neurotoxicity of prion peptides mimicking the central domain of the cellular prion protein. PLoS One 8(8):e70881. doi: 10.1371/journal.pone.0070881PONE-D-13-04002 CrossRefPubMedPubMedCentralGoogle Scholar
- 28.Nocentini S, Reginensi D, Garcia S, Carulla P, Moreno-Flores MT, Wandosell F, Trepat X, Bribian A et al (2012) Myelin-associated proteins block the migration of olfactory ensheathing cells: an in vitro study using single-cell tracking and traction force microscopy. Cell Mol Life Sci 69(10):1689–1703. doi: 10.1007/s00018-011-0893-1 CrossRefPubMedGoogle Scholar
- 46.McDonald AJ, Millhauser GL (2014) PrP overdrive: does inhibition of alpha-cleavage contribute to PrP(C) toxicity and prion disease? Prion 8 (2). doi:28796 [pii]Google Scholar
- 48.Guillot-Sestier MV, Sunyach C, Druon C, Scarzello S, Checler F (2009) The alpha-secretase-derived N-terminal product of cellular prion, N1, displays neuroprotective function in vitro and in vivo. J Biol Chem 284(51):35973–35986. doi: 10.1074/jbc.M109.051086M109.051086 CrossRefPubMedPubMedCentralGoogle Scholar