Fig. 2

Mechanisms of RNA transfer in cell-to-cell communication. Mechanisms underlying the transfer of RNA molecules between cells are mainly based on two systems, vesicle- and protein-mediated transport. (1,2,3) After exosome release from donor cell, RNA content is delivered into recipient cell by (1) the fusion of the exosome with the recipient cell membrane, by (2) phagocytosis- or (3) endocytosis-like internalization of the exosome. RNA molecules can be exported and transported out of the cells by microvesicles also as (4) shedding ectosomes or (5) apoptotic bodies. (6,7) Different protein complexes (violet boxes) including Argonaute, NPM1 and HDL proteins, bind miRNAs and are transferred out of the cell through (6) transporter-mediated release (ABCA1) and are translocated to target cell by (7) receptor-mediated uptake (SR-B1). All these pathways result in the delivery of microRNA or mRNA molecules to the cytosol of the recipient cell where they may contribute to post translational gene regulation. E: Endosome; EE: Early Endosome; G: Golgi; L: Lysosome; MVB: Multivesicular Bodies; N: Nucleus; P: Protein; UP: Undigested Protein