Series: EV Characterization

Speaker:  Juan Pablo Tosar

Affiliation: Analytical Biochemistry Unit, School of Science, Universidad de la República (Uruguay), Functional Genomics Laboratory, Institut Pasteur de Montevideo (Uruguay).

Date and Time: April 10th, 11 am Montevideo/10 am EDT/4 pm CEST

Title: Things are not always what they seem: characterization of vesicular and nonvesicular exRNAs

Abstract: This talk will challenge widespread assumptions on the RNA content of extracellular vesicles (EVs). In particular, the idea that EVs mostly contain miRNAs and tRNA-derived fragments selectively released from their parental cells. Both northern blot and low bias RNA-sequencing methods show that intact tRNAs are more abundant than their fragments in EVs, with tRNA-derived fragments possibly corresponding to nicked tRNA forms. In addition, because these RNAs are also stable and abundant outside EVs, stringent EV purification methods or single EV analysis methods are needed to distinguish between bona fide EV-encapsulated RNAs and nonvesicular contaminants. Regarding miRNAs, their abundance in EVs is low, and while selective miRNA sorting mechanisms might exist, the impact of those hypothetical mechanisms in the definition of EV-RNA profiles has been overestimated, due again to contamination issues. Finally, database annotation problems explain the presence of virtually all extracellular and EV-associated Piwi interacting RNAs, which are probably absent or very lowly abundant in circulating EVs. In summary, this talk will highlight the effects of sequencing bias, survivorship bias, and contamination, in the characterization of EV-RNA profiles. And point toward the integration of orthogonal techniques to achieve a less biased and more comprehensive view of the extracellular RNAome.

Zoom
https://us06web.zoom.us/j/89875776612?pwd=dzbwAwc88zbdS7UbRJGF7rcvSdsCah.1
ID: 898 7577 6612
Code: 853818