Depleting prion protein using splice-switching small molecules

Liu, B.; Fair, B. J.; Kuang, Z.; Tang, Z.; Zhao, J.; Zhou, L.; Kong, Q.; Solanki, A.; Kenny, C.; Mastrianni, J. A.; Zhao, R.; Li, Y.; Wang, J.

doi:10.64898/2026.06.26.734742

bioRxiv · 10.64898/2026.06.26.734742

Depleting prion protein using splice-switching small molecules

Liu, B.·Fair, B. J.·Kuang, Z.·Tang, Z.·Zhao, J.·Zhou, L.·Kong, Q.·Solanki, A.·Kenny, C.·Mastrianni, J. A.·Zhao, R.·Li, Y.·Wang, J.

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Abstract

Prion diseases are fatal neurodegenerative disorders driven by prion protein (PrP) misfolding, and lowering cellular PrP represents a promising therapeutic strategy. Here we report a small-molecule approach that reduces PrP by modulating pre-mRNA splicing of the PRNP gene. Through chemical modification of the clinically approved splicing modulator risdiplam, we generated CP3, the first class of compounds that selectively activate a cryptic exon in PRNP and routes its mRNA product for degradation, reducing PrP by [~]70% in cells. We demonstrate that CP3 activity critically depends on alternative splicing factor Luc7L, revealing a novel requirement for alternative splicing factors in small molecule splicing modulation. Strikingly, co-administration of CP3 with a Luc7L activator PTC258 significantly lowers PrP levels in the brains of transgenic mice. These results establish splicing modulation as a powerful strategy for PrP reduction and highlight the potential of small-molecule cooperativity for therapeutic RNA targeting.

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Liu, B., Fair, B. J., Kuang, Z., Tang, Z., Zhao, J., Zhou, L., Kong, Q., Solanki, A., Kenny, C., Mastrianni, J. A., Zhao, R., Li, Y., Wang, J.. 2026-06-27. Depleting prion protein using splice-switching small molecules. https://doi.org/10.64898/2026.06.26.734742

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