Human plasma and serum extracellular small RNA reference profiles and their clinical utility

Area of Science:

• Biochemistry
• Molecular Biology
• Genomics

Background:

• Circulating extracellular RNAs (exRNAs) show promise as biomarkers for various medical conditions.
• Current exRNA isolation methods and understanding of variability parameters limit clinical application.

Purpose of the Study:

• To develop an automated, high-throughput method for exRNA and extracellular DNA (exDNA) recovery from biofluids.
• To characterize exRNA profiles in human plasma and serum samples.

Main Methods:

• Developed an automated method using denaturants, reducing agents, proteolysis, and organic extraction.
• Applied the method to 312 plasma and serum samples from 13 healthy volunteers over 2 months.
• Utilized small RNA cDNA library sequencing for miRNA analysis.

Main Results:

• Identified nearly twofold increased cell-specific miRNAs in females; fasting and hormonal cycle had minimal impact.
• External standardization revealed quantitative differences in miRNA contributions and concentrations between biofluids.
• Discovered a unique exRNA phenotype with significantly elevated endocrine-cell-specific miRNAs and total miRNA concentrations.

Conclusions:

• The developed method enables efficient and quantitative discernment of exRNA phenotypes.
• Plasma and serum RNA profiles are stable over months, suitable for long-term clinical monitoring.