Variation in Chst8 gene expression level affects PrPC to PrPSc conversion efficiency in prion-infected Mov cells

Area of Science:

• Neuroscience
• Biochemistry
• Molecular Biology

Background:

• Transmissible spongiform encephalopathies (TSEs) are linked to the misfolding of cellular prion protein (PrP) into abnormal isoforms.
• Glycosaminoglycans (GAGs) are implicated as potential molecular partners in the PrP misfolding process.
• The Chst8 gene encodes N-acetylgalactosamine 4-O-sulfotransferase 8, an enzyme involved in GAG synthesis.

Purpose of the Study:

• To investigate the relationship between PrP conversion efficiency and the transcript levels of the Chst8 gene.
• To understand how Chst8 influences the glycosaminoglycan environment and its role in prion protein misfolding.

Main Methods:

• Ovine PrP-expressing Mov cells were transfected with shRNA targeting Chst8 transcripts.
• Analysis of Chst8 and Prnp transcript levels in transfected cells.
• Characterization of sulfated glycosaminoglycans, specifically chondroitin sulfates, in the resulting clones.

Main Results:

• Reduced Chst8 transcript levels unexpectedly increased the proportion of chondroitin sulfate among total GAGs.
• A significant increase in 4-O-sulfation of GalNAc residues was observed in Chst8-deficient cells.
• Infection with sheep prion resulted in a transient, low level of PrP(Sc) that disappeared upon subpassaging.

Conclusions:

• Chst8 transcript levels modulate the glycosaminoglycan environment surrounding the cellular prion protein.
• This modulation, in turn, affects the prion protein's susceptibility to conversion into the pathogenic PrP(Sc) form.
• Findings suggest Chst8 plays a role in regulating prion conversion efficiency.