NR AUAR
AU Hetz,C.A.; Russelakis-Carneiro,M.; Walchli,S.; Carboni,S.; Vial-Knecht,E.; Maundrell,K.; Castilla,J.; Soto,C.
TI The disulfide isomerase Grp58 is a protective factor against prion neurotoxicity
QU Journal of Neuroscience 2005 Mar 16; 25(11): 2793-802
IA http://www.jneurosci.org/cgi/reprint/25/11/2793
PT journal article
AB Prion diseases are transmissible neurodegenerative disorders characterized by extensive neuronal apoptosis and accumulation of misfolded prion protein (PrPsc). Recent reports indicate that PrPsc induces neuronal apoptosis via activation of the endoplasmic reticulum (ER) stress pathway and activation of the ER resident caspase-12. Here, we investigate the relationship between prion replication and induction of ER stress during different stages of the disease in a murine scrapie model. The first alteration observed consists of the upregulation of the ER chaperone of the glucose-regulated protein Grp58, which was detected during the presymptomatic phase and followed closely the formation of PrPsc. An increase in Grp58 expression correlated with PrPsc accumulation at all stages of the disease in different brain areas, suggesting that this chaperone may play an important role in the cellular response to prion infection. Indeed, in vitro studies using N2a neuroblastoma cells demonstrated that inhibition of Grp58 expression with small interfering RNA led to a significant enhancement of PrPsc toxicity. Conversely, overexpression of Grp58 protected cells against PrPsc toxicity and decreased the rate of caspase-12 activation. Grp58 and PrP were shown to interact by coimmunoprecipitation, observing a higher interaction in cells infected with scrapie prions. Our data indicate that expression of Grp58 is an early cellular response to prion replication, acting as a neuroprotective factor against prion neurotoxicity. Our findings suggest that targeting Grp58 interaction may have applications for developing novel strategies for treatment and early diagnosis of prion diseases.
MH Analysis of Variance; Animals; Anti-Bacterial Agents/pharmacology; Blotting, Western/methods; Brain/metabolism/pathology; Calcimycin/pharmacology; Calcium Signaling/genetics/physiology; Carcinoma; Cell Line, Tumor; Cell Survival/drug effects; Comparative Study; Disease Models, Animal; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel/methods; Gene Expression Regulation/drug effects/physiology; HSP70 Heat-Shock Proteins/metabolism; Heat-Shock Proteins/genetics/metabolism/*therapeutic use; Humans; Immunohistochemistry/methods; Immunoprecipitation/methods; Membrane Proteins/metabolism; Mice; Mice, Inbred C57BL; Phosphopyruvate Hydratase/metabolism; Prion Diseases/*etiology/*prevention & control; Prions/metabolism/*pathogenicity; Protein Disulfide-Isomerase/genetics/metabolism/*therapeutic use; RNA, Small Interfering/metabolism; Research Support, Non-U.S. Gov't; Transfection/methods
AD Serono Pharmaceutical Research Institute, 1228 Plan-les-Ouates, Geneva, Switzerland.
SP englisch
PO USA