Extracellular microRNAs in human circulation are associated with miRISC complexes that are accessible to anti-AGO2 antibody and can bind target mimic oligonucleotides
Authors
Geekiyanage, HiroshaRayatpisheh, Shima
Wohlschlegel, James A.
Brown, Robert H. Jr.
Ambros, Victor R.
Document Type
Journal ArticlePublication Date
2020-09-29Keywords
AGO2Argonaut
cerebrospinal fluid
extracellular microRNA
human plasma
Amino Acids, Peptides, and Proteins
Cell Biology
Cellular and Molecular Physiology
Fluids and Secretions
Hemic and Immune Systems
Molecular Biology
Nervous System Diseases
Nucleic Acids, Nucleotides, and Nucleosides
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MicroRNAs (miRNAs) function cell-intrinsically to regulate gene expression by base-pairing to complementary mRNA targets while in association with Argonaute, the effector protein of the miRNA-mediated silencing complex (miRISC). A relatively dilute population of miRNAs can be found extracellularly in body fluids such as human blood plasma and cerebrospinal fluid (CSF). The remarkable stability of circulating miRNAs in such harsh extracellular environments can be attributed to their association with protective macromolecular complexes, including extracellular vesicles (EVs), proteins such as Argonaut 2 (AGO2), or high-density lipoproteins. The precise origins and the potential biological significance of various forms of miRNA-containing extracellular complexes are poorly understood. It is also not known whether extracellular miRNAs in their native state may retain the capacity for miRISC-mediated target RNA binding. To explore the potential functionality of circulating extracellular miRNAs, we comprehensively investigated the association between circulating miRNAs and the miRISC Argonaute AGO2. Using AGO2 immunoprecipitation (IP) followed by small-RNA sequencing, we find that miRNAs in circulation are primarily associated with antibody-accessible miRISC/AGO2 complexes. Moreover, we show that circulating miRNAs can base-pair with a target mimic in a seed-based manner, and that the target-bound AGO2 can be recovered from blood plasma in an approximately 1:1 ratio with the respective miRNA. Our findings suggest that miRNAs in circulation are largely contained in functional miRISC/AGO2 complexes under normal physiological conditions. However, we find that, in human CSF, the assortment of certain extracellular miRNAs into free miRISC/AGO2 complexes can be affected by pathological conditions such as amyotrophic lateral sclerosis.Source
Geekiyanage H, Rayatpisheh S, Wohlschlegel JA, Brown R Jr, Ambros V. Extracellular microRNAs in human circulation are associated with miRISC complexes that are accessible to anti-AGO2 antibody and can bind target mimic oligonucleotides. Proc Natl Acad Sci U S A. 2020 Sep 29;117(39):24213-24223. doi: 10.1073/pnas.2008323117. Epub 2020 Sep 14. PMID: 32929008; PMCID: PMC7533700. Link to article on publisher's site
DOI
10.1073/pnas.2008323117Permanent Link to this Item
http://hdl.handle.net/20.500.14038/41586PubMed ID
32929008Related Resources
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Copyright © 2020 the Author(s). Published by PNAS. This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).Distribution License
http://creativecommons.org/licenses/by-nc-nd/4.0/ae974a485f413a2113503eed53cd6c53
10.1073/pnas.2008323117
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Except where otherwise noted, this item's license is described as Copyright © 2020 the Author(s). Published by PNAS. This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).