Endosomal Escape of Antisense Oligonucleotides Internalized by Stabilin Receptors Is Regulated by Rab5C and EEA1 During Endosomal Maturation

Authors

Colton M. Miller, University of Nebraska - LincolnFollow
W. Brad Wan, Ionis Pharmaceuticals
Punit P. Seth, Ionis Pharmaceuticals
Edward N. Harris, University of Nebraska - LincolnFollow

Date of this Version

2018

Citation

NUCLEIC ACID THERAPEUTICS Volume 28, Number 2, 2018

Comments

Copyright Colton M. Miller et al.

DOI: 10.1089/nat.2017.0694

Abstract

Second-generation (Gen 2) Antisense oligonucleotides (ASOs) show increased nuclease stability and affinity for their RNA targets, which has translated to improved potency and therapeutic index in the clinic. Gen 2 ASOs are typically modified using the phosphorothioate (PS) backbone modification, which enhances ASO interactions with plasma, cell surface, and intracellular proteins. This facilitates ASO distribution to peripheral tissues and also promotes cellular uptake after injection into animals. Previous work identified that Stabilin receptors specifically internalize PS-ASOs in the sinusoidal endothelial cells of the liver and the spleen. By modulating expression of specific proteins involved in the trafficking and maturation of the endolysosomal compartments, we show that Rab5C and EEA1 in the early endosomal pathway, and Rab7A and lysobisphosphatidic acid in the late endosomal pathway, are important for trafficking of PS-ASOs and facilitate their escape from endolysosomal compartments after Stabilin-mediated internalization. In conclusion, this work identifies key ratelimiting proteins in the pathway for PS-ASO translocation and escape from the endosome.