Intracellular and extracellular microRNAs expressed by HEK293T cells

MicroRNAs (miRNAs) are a class of small RNA molecules that regulate expression of specific mRNA targets. They can be released from cells, often encapsulated within extracellular vesicles (EVs), and therefore have the potential to mediate intercellular communication. It has been suggested that certain miRNAs may be selectively exported, although the mechanism has yet to be identified. Manipulation of the miRNA content of EVs will be important for future therapeutic applications. We therefore wished to assess which endogenous miRNAs are enriched in EVs and how effectively an overexpressed miRNA would be exported. Small RNA libraries from HEK293T cells and vesicles before or after transfection with a vector for miR-146 overexpression were analysed by deep sequencing. A subset of miRNAs was found to be enriched in EVs. The global expression data provided by deep sequencing confirms that specific miRNAs are enriched in EVs released by HEK293T cells. Overall design: Cells were transfected with a plasmid to direct overexpression of miR-146a. Extracellular vesicles were isolated by ultracentrifugation from untreated and transfected cells. RNA was isolated from one sample each of untreated and transfected cells and vesicles.Small RNA libraries were prepared for sequencing.

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Guduric-Fuchs J, O'Connor A, Camp B, O'Neill CL, Medina RJ, Simpson DA