Extracellular vesicles as an emerging mechanism of cell-to-cell communication

Abstract

The concept that extracellular vesicles may act as paracrine/endocrine effectors is based on the evidence that they are able to transport bioactive molecules between cells, either within a defined microenvironment or remotely, by entering the biologic fluids. Extracellular vesicles, including exosomes and microvesicles, may deliver lipids and various functional transcripts, released from the cell of origin, to target cells. Since extracellular vesicles contain defined patterns of mRNA, microRNA, long non-coding RNA, and occasionally genomic DNA, they may transfer genetic information which induces transient or persistent phenotypic changes in recipient cells. In this review, we will discuss potential physiologic and pathological implications of extracellular vesicles, as well as the diagnostic and therapeutic opportunities that they may provide.

Fig. 1

Differential effects of stem cell-derived EVs. The effects of EVs not only depend on their content but also on which pathways are activated in the recipient cells. In particular, the miRNA contents of EVs have different effects depending on the state of activation of their targets. The same EVs released from stem cells may stimulate activation of regenerative programs in injured cells leading to their dedifferentiation, cell cycle re-entry with proliferation, and promoting cell survival. Conversely, the same EVs may reprogram cancer cells by delivering tumor suppressive miRNAs which inhibit tumor cell growth and promote apoptosis