Phospho-RNA-Seq Highlights Specific Small RNA Profiles in Plasma Extracellular Vesicles

Area of Science:

• Biochemistry
• Molecular Biology
• Genomics

Background:

• Small RNAs (sRNAs) in biofluids are potential biomarkers.
• Plasma sRNAs exist in extracellular vesicles (EVs) and extravesicular fractions.
• Standard sequencing often misses many sRNAs.

Purpose of the Study:

• To evaluate phospho-RNA-seq for profiling plasma sRNAs.
• To compare sRNA content in EVs versus extravesicular fractions.
• To assess phospho-RNA-seq's utility for biomarker discovery.

Main Methods:

• Enzymatic treatment of plasma sRNAs with T4 polynucleotide kinase (T4-PNK).
• Deep sequencing of treated and untreated sRNAs from EV and extravesicular fractions.
• Unsupervised clustering analysis of sRNA counts.

Main Results:

• Phospho-RNA-seq increased the proportion and diversity of aligned sRNAs.
• T4-PNK treatment enabled accurate classification of EV and extravesicular samples.
• Specific miRNA variants (5'-isomiRs) and tRNA fragments were emphasized.
• Tissue-specific mRNA fragments were more abundant in EVs using phospho-RNA-seq.

Conclusions:

• Phospho-RNA-seq significantly enhances the detection and characterization of plasma sRNAs.
• The method improves the distinction between EV and extravesicular sRNA profiles.
• Phospho-RNA-seq is valuable for discovering novel RNA-based biomarkers, particularly within EVs.