Hology and exosomal generation and release in neurodegenerative problems Efrat Levy1; Rocio Perez-Gonzalez2; Katherine Y. Peng2; Paul M. MathewsDepartments of Psychiatry, Biochemistry Molecular Pharmacology, as well as the Neuroscience Institute, NYU Langone Medical Center, Orangeburg, USA; 2 Center for Dementia Research, Nathan S. Kline Institute for Psychiatric Investigation, Orangeburg, USAOF15.Conditional deletion of Rab35 and Alix in mice to study exosomes in neuron-glia interaction in vivo Kerstin Miebach1; Christina M ler2; Anja Schneider3; Wiebke M ius4; Anja Scheller5; Laura Stopper5; Frank Kirchhoff5; Remy Sadoul6; Eva-Maria Kr er-AlbersUniversity of Mainz, IDN, Molecular Cell Biology, Mainz, Germany, Mainz, Germany; 2IDN, Molecular Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany; 3German Center for Neurodegenerative Leukocyte Immunoglobulin Like Receptor A3 Proteins Recombinant Proteins Diseases (DZNE), Bonn, Bonn, Germany; 4MPI for Experimental Medicine, G tingen, G tingen, Germany; 5Molecular Physiology, CIPMM, University of Saarland, Homburg, Germany; 6Institute of Neurosciences, Grenoble, Grenoble, FranceBackground: In the CNS, myelinating oligodendrocytes (OLs) offer trophic assistance and mediate long-term neuronal integrity. We showed that neuronal activity triggers the release of oligodendroglial exosomes from multi-vesicular bodies (MVB) which can be subsequently internalized by neurons. Oligodendroglial exosomes promote neuronal metabolic activity and transport of cargo along axons, indicating their value in glial assistance. To examine the part of exosomes in neuron-glia communication, we’re studying transgenic mouse models having a potential defect in OL exosome secretion resulting from conditional deletion of Rab35 and Alix. Approaches: We are analysing transgenic mice floxed within the gene locus of Rab35- and Alix and crossed to oligodendroglial Cre-drivers mediating deletion (KO) especially in oligodendroglial precursor cells and mature OLs. To confirm impaired exosome release by OLs we quantified isolated exosomes by western blotting (WB) making use of distinct markers and nanoparticle tracking analysis (NTA). Additionally, we determined the ultrastructure and quantity of MVBs in optic nerves by electron microscopy (EM). We at the moment apply stress paradigms to KIR2DS3 Proteins custom synthesis neurons and examine the possible of KO-derived exosomes to enhance metabolic activity of neurons. To decide exosome transfer to neurons in vivo, we are utilizing CreERT2-mediated reporter gene recombination subjected to a distinct tamoxifen injection-protocol to visualize and quantify exosome delivery from OLs to neurons in unique brain locations. Outcomes: NTA and WB of exosomes derived from wild-type versus KOmice offer proof that exosome secretion is impacted by Rab35- and Alix-deletion in OLs. EM analyses of optical nerve cross sections demonstrate a compartment specific boost of MVBs in Rab35-KO OLs. Functional evaluation elucidating exosome delivery to neurons and their ability to mediate metabolic help is ongoing and will give insight into the roles of Rab35 and Alix to generate functionally competent exosomes. Summary/Conclusion: Conditional deletion of Rab35 and Alix delivers a useful means to examine the precise function of oligodendroglia-derivedBackground: Dysfunction from the neuronal endosomal pathway is usually a characteristic of down syndrome (DS) and Alzheimer’s disease (AD) and of carriers on the AD-risk apolipoprotein E four allele (APOE4). We hypothesized that the efficient release of endosomal material via exosomes in to the ext.