Tenuated capability of fibroblasts to assistance the formation of vessel-like endothelial structures. Summary/Conclusion: Exosome-induced differentiation of fibroblasts to a pro-angiogenic phenotype is dependent on certain HSPGs present on the exosome surface. HSPGs are required for exosome activation of SMADdependent TGF- signalling. Exosomal-HSPGs might thus represent novel targets for attenuation of fibroblast-assisted tumour growth. Funding: This work was funded by Prostate Cancer UK – Career Development Fellowship (held by Dr J Webber)OF13.CD44 is actually 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) will be the most significant feature regulating EV adhesion and receptorligand interactions together with the target cells. The multifunctional adhesion molecule and principal hyaluronan (HA) ligand CD44 is a single of those 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 in the circulation which makes CD44 called a “homing receptor”. The bonds amongst HA and CD44 are remarkably powerful, which gives resistance to shear throughout adhesion of lymphocytes on endothelial cells. Solutions: Here, we AT1 Receptor Inhibitor Synonyms hypothesized that these similar CB1 Activator Storage & Stability 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 standard type and compared them to cells expressing empty vector pIRES-EGFP2 (MOCK). First, we confirmed the CD44 expression of these cell lines by CDFriday, 04 Mayimmunostainings, western blotting, ELISA and QPCR. Next, the secretion and size distribution of EV secreted by both cell lines was analysed by NTA evaluation, as well as the possible of EV binding to target cells was studied by superresolution microscopy. Outcomes: The outcomes indicated that the MOCK cells have low HA binding capacity in comparison with the CD44 overexpressing cells. In addition, the NTA outcomes showed no variations in EV secretion of CD44-negative and overexpressing cells. These results recommend that CD44 regulates EV interactions with their target cells.Summary/Conclusion: Further studies will show the far more detailed mechanisms of those interactions. Additionally, CD44 and HA are potential multipurpose EV biomarkers, since they are upregulated in inflammatory, injured and cancer cells and accumulate on the surface of EV secreted in these conditions. Funding: This study is funded by Academy of Finland.ISEV 2018 abstract bookSymposium Session 14 – Tissue Injury and Repair Chairs: Bernd Giebel; Mariko Ikuo Location: Space five 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 Scoville1; Tyler Thompson1; Raymond L. Swetenburg1; Franklin West2; Steven SticeArunA Biomedical, Athens, GA, USA; 2Regenerative Bioscience Center, University of Georgia, Athens, GA, USABackground: Current perform fr.