Abstract
RNA motifs may promote interactions with exosomes (EXO-motifs) and lipid rafts (RAFT-motifs) that are enriched in exosomal membranes. These interactions can promote selective RNA loading into exosomes. We quantified the affinity between RNA aptamers containing various EXO- and RAFT-motifs and membrane lipid rafts in a liposome model of exosomes by determining the dissociation constants. Analysis of the secondary structure of RNA molecules provided data about the possible location of EXO- and RAFT-motifs within the RNA structure. The affinity of RNAs containing RAFT-motifs (UUGU, UCCC, CUCC, CCCU) and some EXO-motifs (CCCU, UCCU) to rafted liposomes is higher in comparison to aptamers without these motifs, suggesting direct RNA-exosome interaction. We have confirmed these results through the determination of the dissociation constant values of exosome-RNA aptamer complexes. RNAs containing EXO-motifs GGAG or UGAG have substantially lower affinity to lipid rafts, suggesting indirect RNA-exosome interaction via RNA binding proteins. Bioinformatics analysis revealed RNA aptamers containing both raft- and miRNA-binding motifs and involvement of raft-binding motifs UCCCU and CUCCC. A strategy is proposed for using functional RNA aptamers (fRNAa) containing both RAFT-motif and a therapeutic motif (e.g., miRNA inhibitor) to selectively introduce RNAs into exosomes for fRNAa delivery to target cells for personalized therapy.
Highlights
Exosomes are small (30–100 nm) membrane nanovesicles originating from endosomes, that are released from the parent cell into the extracellular environment [1]
Since the selective binding of RNAs to the membrane of multivesicular body (MVB) may be regulated by the activity of a lipid raft region in the MVB membrane and the presence of the RNA motifs, in this study we investigate the significance of these factors in the RNA-membrane relationship
For each of the individual RNA aptamers, the changes in donor (YOYO-1) emission intensity were measured after incubation with ordered RAFT (DOPC:SM:CHL) and disordered non-RAFT (DOPC) membranes
Summary
Exosomes are small (30–100 nm) membrane nanovesicles originating from endosomes, that are released from the parent cell into the extracellular environment [1]. Their release was reported from various cell types, such as: reticulocytes [1], B and T lymphocytes [2,3], dendritic cells [4] as well as cancer cells [5]. Since the first description of microvesicles produced by platelets in human blood and the discovery of their procoagulant properties [8] the role of exosomes is constantly being explored Their direct function is to transport various molecules such as proteins, lipids, and nucleic acids between cells, and to protect the cargo contained within them. The involvement of exosomes was reported in various pathological conditions such as cardiovascular diseases [12], viral infections [13], neurodegenerative diseases [14], and cancer [15,16,17]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
