In Vitro Seeding Activity of Glycoform-Deficient Prions from Variably Protease-Sensitive Prionopathy and Familial CJD Associated with PrPV180I Mutation
Résumé
Both sporadic variably protease-sensitive prionopathy (VPSPr) and familial Creutzfeldt-Jakob disease linked to the prion protein (PrP) V180I mutation (fCJD V180I) have been found to share a unique pathological prion protein (PrP Sc) that lacks the protease-resistant PrP Sc glycosylated at residue 181 because two of four PrP glycoforms are apparently not converted into the PrP Sc from their cellular PrP (PrP C). To investigate the seeding activity of these unique PrP Sc molecules, we conducted in vitro prion conversion experiments using serial protein misfolding cyclic amplification (sPMCA) and real-time quaking-induced conversion (RT-QuIC) assays with different PrP C substrates. We observed that the seeding of PrP Sc from VPSPr or fCJD V180I in the sPMCA reaction containing normal human or humanized transgenic (Tg) mouse brain homogenates generated PrP Sc molecules that unexpectedly exhibited a dominant diglycosylated PrP isoform along with PrP monoglycosylated at residue 181. The efficiency of PrP Sc amplification was significantly higher in non-CJDMM than in non-CJDVV human brain homogenate, whereas it was higher in normal TgVV than in TgMM mouse brain homogenate. PrP C from the mixture of normal TgMM and Tg mouse brain expressing PrP V180I mutation (Tg180) but not TgV180I alone was converted into PrP Sc by seeding with the VPSPr or fCJD V180I. The RT-QuIC seeding activity of PrP Sc from VPSPr and fCJD V180I was significantly lower than that of sCJD. Our results suggest that the formation of glycoform-selective prions may be associated with an unidentified factor in the affected brain and the glycoform-deficiency of PrP Sc does not affect the glycoforms of in vitro newly amplified PrP Sc. Electronic supplementary material The online version of this article (https://doi.
Domaines
Sciences du Vivant [q-bio]
Origine : Fichiers produits par l'(les) auteur(s)
Loading...
