Tenuated capacity of fibroblasts to help the formation of vessel-like endothelial structures. Summary/Conclusion: Exosome-induced differentiation of fibroblasts to a pro-angiogenic phenotype is dependent on specific HSPGs present around the exosome surface. HSPGs are necessary for exosome activation of TrkC Proteins web SMADdependent TGF- signalling. Exosomal-HSPGs could as a result represent novel targets for attenuation of fibroblast-assisted tumour growth. Funding: This function was funded by Prostate Cancer UK – Career Development Fellowship (held by Dr J Webber)OF13.CD44 is a novel homing receptor for extracellular vesicles Kai H k en1; Silja Pyysalo1; Sini Hakkola1; Kirsi Ketola1; Carla Oliveira2; Sanna Oikari1; Kirsi Rilla1Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland; i3S – Instituto de Investiga o e Inova o em Sa e, Universidade do Porto, Porto, PortugalBackground: The surface molecular composition of extracellular vesicles (EV) could be the most important function regulating EV adhesion and receptorligand interactions using the target cells. The multifunctional adhesion molecule and principal hyaluronan (HA) ligand CD44 is 1 of these surface receptors binding also to other extracellular matrix components which includes collagen, fibronectin, and laminin. HA-CD44 interactions mediate the recruitment of activated leucocytes stem cells and tumour cells from the circulation which tends to make CD44 called a “homing receptor”. The bonds among HA and CD44 are remarkably powerful, which supplies resistance to shear in the course of adhesion of lymphocytes on endothelial cells. Techniques: Right here, we hypothesized that these very same mechanisms of HACD44 interactions regulate the homing of EV to reprogram other cells and to prepare a favourable niche for metastasis of cancer cells. To answer this hypothesis, we utilized a CD44-negative human gastric cancer line MKN74 stably expressing CD44 normal type and compared them to cells expressing empty vector pIRES-EGFP2 (MOCK). First, we confirmed the CD44 expression of those cell lines by CDFriday, 04 Mayimmunostainings, western blotting, ELISA and QPCR. Next, the secretion and size distribution of EV secreted by each cell lines was analysed by NTA analysis, and also the potential of EV binding to target cells was studied by superresolution microscopy. Outcomes: The results indicated that the MOCK cells have low HA binding capacity compared to the CD44 overexpressing cells. Moreover, the NTA outcomes showed no differences in EV secretion of CD44-negative and overexpressing cells. These outcomes recommend that CD44 regulates EV interactions with their target cells.Summary/Conclusion: Additional studies will show the a lot more detailed mechanisms of those interactions. Furthermore, CD44 and HA are prospective multipurpose EV biomarkers, because they are upregulated in inflammatory, injured and cancer cells and accumulate on the surface of EV secreted in these scenarios. Funding: This study is funded by Academy of Finland.ISEV 2018 abstract bookSymposium Session 14 – Tissue Injury and Repair Chairs: Bernd Giebel; Mariko Ikuo Place: Area 5 13:45 – 15:OF14.Human neural stem cell extracellular vesicles enhance recovery in a porcine model of ischemic stroke Robin Webb1; Erin E. Kaiser2; Brian J. Jurgielewicz2; Samantha Spellicy2; Shelley Activated Cdc42-Associated Kinase 1 (ACK1) Proteins Biological Activity Scoville1; Tyler Thompson1; Raymond L. Swetenburg1; Franklin West2; Steven SticeArunA Biomedical, Athens, GA, USA; 2Regenerative Bioscience Center, University of Georgia, Athens, GA, USABackground: Current work fr.