Related Experiment Video
Updated: Sep 23, 2025
Prion Safety Laboratory Swipe Test
Published on: February 14, 2025
Pentosan polysulfate induces low-level persistent prion infection keeping measurable seeding activity without PrP-res
Hanae Takatsuki1, Morikazu Imamura1, Tsuyoshi Mori1
1Division of Microbiology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake-cho, Miyazaki, 889-1692, Japan.
Abstract:
Each prion strain has its own characteristics and the efficacy of anti-prion drugs varies. Screening of prion disease therapeutics is typically evaluated by measuring amounts of protease-resistant prion protein (PrP-res). However, it remains unclear whether such measurements correlate with seeding activity, which is evaluated by real-time quaking-induced conversion (RT-QuIC). In this study, the effects of anti-prion compounds pentosan polysulfate (PPS), Congo red, and alprenolol were measured in N2a58 cells infected with Fukuoka-1 (FK1) or 22L strain. The compounds abolished PrP-res and seeding activity, except for N2a58/FK1 treated with PPS. Interestingly, the seeding activity of N2a58/FK1, which was reduced in the presence of PPS, was not lost and remained at low levels. However, upon removal of PPS, both were gradually restored to their original levels. These results indicate that low-level persistent prion infection keeping measurable seeding activity is induced by PPS in a strain-dependent manner. Furthermore, for protein misfolding cyclic amplification (PMCA), the anti-prion effect of PPS decreased in FK1 compared to 22L, suggesting that the differences occur at the level of the direct conversion. Our findings demonstrate that the advantages of RT-QuIC and PMCA can be exploited for more accurate assessment of therapeutic drug screening, reflecting strain differences.
Insights
This study reveals that prion drug screening needs to consider prion strain differences. Real-time quaking-induced conversion (RT-QuIC) and protein misfolding cyclic amplification (PMCA) offer better therapeutic assessment than protease-resistant prion protein (PrP-res) measurements.
Area of Science:
- Neuroscience
- Biochemistry
- Infectious Diseases
Background:
- Prion strains exhibit unique characteristics, influencing anti-prion drug efficacy.
- Current prion disease therapeutic screening relies on protease-resistant prion protein (PrP-res) quantification.
- The correlation between PrP-res levels and prion seeding activity, assessed by real-time quaking-induced conversion (RT-QuIC), is not fully understood.
Purpose of the Study:
- To investigate the impact of anti-prion compounds (pentosan polysulfate, Congo red, alprenolol) on different prion strains (Fukuoka-1 and 22L).
- To compare the effectiveness of PrP-res measurement versus seeding activity (RT-QuIC) in evaluating drug efficacy.
- To explore the strain-dependent effects of pentosan polysulfate (PPS) on persistent prion infection.
Main Methods:
- Treatment of prion-infected N2a58 cells (Fukuoka-1 and 22L strains) with PPS, Congo red, and alprenolol.
- Quantification of protease-resistant prion protein (PrP-res).
- Assessment of prion seeding activity using real-time quaking-induced conversion (RT-QuIC) and protein misfolding cyclic amplification (PMCA).
Main Results:
- Compounds abolished PrP-res and seeding activity, except for PPS on N2a58/Fukuoka-1 cells.
- PPS treatment resulted in persistent low-level seeding activity in N2a58/Fukuoka-1 cells, which was restored upon drug removal.
- PPS showed reduced anti-prion effects against the Fukuoka-1 strain compared to the 22L strain in PMCA, indicating strain-specific direct conversion differences.
Conclusions:
- Pentosan polysulfate can induce a strain-dependent persistent prion infection with measurable seeding activity.
- RT-QuIC and PMCA are superior methods for assessing prion therapeutics, accurately reflecting strain-specific drug responses.
- Therapeutic drug screening for prion diseases requires consideration of prion strain characteristics for accurate evaluation.
