Derived EVs in comparison with typical hepatocyte-derived EV controls, including let-7 members of the family. Treatment of human HSCs with TGF-/LPS (20 ng/ ml) for 72 h induced a important lower of let-7a and let-7b in both activated and handle states. Transfection of let-7a and let-7b precursors in human HSCs markedly induced the expression of cellular senescence IgG1 Proteins Species markers p16 and CCl2, and blunted the enhanced expression of -SMA, collagen a1, MMP-2 and MMP9 (key genes involved inside the activation of HHSCs) by TGF-/LPS therapy. Treatment with MSC/LSC derived EVs (30 g/ml, 72 h) phenocopied the senescence/anti-fibrosis effects of let-7 overexpression in activated HHSCs by TGF-/LPS. A complementary mass spectrometry-based proteomics strategy with luciferase reporter assay identified TLR4, the key LPS receptor, as putative let-7 cluster target. In addition, the expressions of senescent hepatic stellate markersIntroduction: MSC-based cell therapy has received excellent interest within the previous years, in particular in regenerative medicine and tissue repair. The concept of priming consists in preconditioning the cells for the duration of the culture phase (usually with cytokines or hypoxia) to enhance their effects. The literature shows that MSC EVs can recapitulate a substantial part of your useful effects on the cells they originate from, and that miRNAs are key players in EVs action. For that reason, within the present operate, our aim was to establish if IFN or hypoxia priming of MSC could modify their EVs miRNA content. Strategies: Human bone marrow MSC from five wholesome donors had been CD326/EpCAM Proteins Formulation isolated and cultured at 20 of O2 in MEM-alpha/FBS medium till 600 confluence, then with (IFN) or without (CONT) interferongamma (25ng/ml, 48 h) or in hypoxia (3 O2 all through the duration of the culture course of action). Then the cells were rinced with PBS and placed in serum free of charge MEM for 48 h. The conditioned media was collected and EV had been isolated by ultracentrifugation (100 000g for 1h10). Total RNA was isolated and reverse transcribed. Pools of CONT, IFN and HYP cDNA have been prepared, miRNA profiling was performed applying Exiqon miRnome PCR panel I and II. Then, chosen miRNAs were measured on every sample. Final results: A set of 89 miRNAs was detected (quantification cycle 35) in a minimum of one of the pools of MSC EVs. They had been measured on each and every individual sample. 41 miRNAs had been measured in all samples; benefits wereJOURNAL OF EXTRACELLULAR VESICLESnormalized with five endogenous miRNAs. Hypoxia induced no substantial modification of EVs miRNA content material. IFN priming induced a important boost in hsa-miR-106a-5p, 25-3p, 126-3p, 451a and 665. Their validated targets have been determined with miRTarBase and also the proteins have been analysed with Panther classification system. Amongst probably the most cited pathways, we discovered p53, inflammation, Wnt signalling, Apoptosis signalling and Angiogenesis.Summary/conclusion: MSC priming can modify the miRNA landscape of their EVs. IFN priming modifies MSCs EVs miRNA involved in biological pathways relevant to tissue repair. Functional analysis of those EVs with selected miRNAs inhibition is necessary to evaluate the biological effects of such an method. Funding: This perform has been funded by the french Path G ale de l’Armement, Biomedef PDH-1SMO-1ISEV2019 ABSTRACT BOOKIndustry Poster Session Thursday 25 April 2019 Place: Level three, Hall AIP.01 IP.Standardizing F-NTA measurements: evaluation of four-wavelengths nanoparticle tracking analysis with cell-line derived EVs Clemens Helmbrechta and Pao.