Familial CJD Associated PrP Mutants within Transmembrane Region Induced Ctm-PrP Retention in ER and Triggered Apoptosis by ER Stress in SH-SY5Y CellsReportar como inadecuado




Familial CJD Associated PrP Mutants within Transmembrane Region Induced Ctm-PrP Retention in ER and Triggered Apoptosis by ER Stress in SH-SY5Y Cells - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Background

Genetic prion diseases are linked to point and inserted mutations in the prion protein PrP gene that are presumed to favor conversion of the cellular isoform of PrP PrPC to the pathogenic one PrPSc. The pathogenic mechanisms and the subcellular sites of the conversion are not completely understood. Here we introduce several PRNP gene mutations such as, PrP-KDEL, PrP-3AV, PrP-A117V, PrP-G114V, PrP-P102L and PrP-E200K into the cultured cells in order to explore the pathogenic mechanism of familial prion disease.

Methodology-Principal Findings

To address the roles of aberrant retention of PrP in endoplasmic reticulum ER, the recombinant plasmids expressing full-length human PrP tailed with an ER signal peptide at the COOH-terminal PrP-KDEL and PrP with three amino acids exchange in transmembrane region PrP-3AV were constructed. In the preparations of transient transfections, 18-kD COOH-terminal proteolytic resistant fragments Ctm-PrP were detected in the cells expressing PrP-KDEL and PrP-3AV. Analyses of the cell viabilities in the presences of tunicamycin and brefeldin A revealed that expressions of PrP-KDEL and PrP-3AV sensitized the transfected cells to ER stress stimuli. Western blots and RT-PCR identified the clear alternations of ER stress associated events in the cells expressing PrP-KDEL and PrP-3AV that induced ER mediated apoptosis by CHOP and capase-12 apoptosis pathway. Moreover, several familial CJD related PrP mutants were transiently introduced into the cultured cells. Only the mutants within the transmembrane region G114V and A117V induced the formation of Ctm-PrP and caused the ER stress, while the mutants outside the transmembrane region P102L and E200K failed.

Conclusions-Significance

The data indicate that the retention of PrP in ER through formation of Ctm-PrP results in ER stress and cell apoptosis. The cytopathic activities caused by different familial CJD associated PrP mutants may vary, among them the mutants within the transmembrane region undergo an ER-stress mediated cell apoptosis.



Autor: Xin Wang, Qi Shi, Kun Xu, Chen Gao, Cao Chen, Xiao-Li Li, Gui-Rong Wang, Chan Tian, Jun Han, Xiao-Ping Dong

Fuente: http://plos.srce.hr/



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