FisMat2017 - Submission - View

Abstract's title: Generating microvesicles from astrocytes with unconventional stimuli to challenge this intercellular communication system in cultured cortex cells
Submitting author: Mattia Musto
Affiliation: Scuola Internazionale degli Studi Avanzati (SISSA)
Affiliation Address: Via Bonomea 265
Country: Italy
Oral presentation/Poster (Author's request): Poster
Other authors and affiliations: Laura Ballerini (Scuola Internazionale degli Studi Avanzati, SISSA) Loredana Casalis (Elettra-Sincrotrone)

Recently a novel aspect of intercellular communication has been described, which imply the involvement of extracellular vesicles (EVs). EVs can deliver molecules that usually are not readily passing the plasma membrane, such as membrane and cytosolic proteins, mRNAs and non-coding RNAs and bioactive lipids, exposed on the EVs surface. There are three classes of EVs: exosomes, microvesicles that are involved in intercellular signalling and the apoptotic bodies that are released by dying cells and probably do not take part to the crosstalk between cells. Exosomes and microvesicles differ mostly for the size and the mechanism of biogenesis and release. The former range from 30 nm to 100 nm in diameter, while the latter are more heterogeneous and fluctuate between 100 nm and 1 μm. The formation and release of EVs into the extracellular environment relies on the endosomal sorting complex required for transport (ESCRT) or on lipid-dependent processes. Exosomes originate from the inward budding of some endosomes called multi vesicular bodies (MVB) that, once they fuse with the plasma membrane, release their vesicles outside the cell. On the other side, microvesicles are formed through outward budding and vesicle shedding at the plasma membrane at membrane microdomains called lipid rafts. Aim of the study is to characterize the morphology and content of microvesicles released from glia, in particular astrocytes. In that aim we used conventional and unconventional tools to induce microvesicles release. We used graphene oxide (GO) nanosheets, which can stick or pierce the plasma membrane and we demonstrated for the first time that exposition of astrocytes to GO flakes, alone or in synergy with the pharmacological stimulation with bzATP, induces the release of microvesicles. Moreover we observed by infrared spectroscopy the macromolecular composition of both the subpopulation of vesicles, highlightinga slight difference in genetic material cargo, mostly RNA, and proteic. Even if the processes involved are still unclear,these results represent a starting point for a new approach in the study of neuron-glia signalling and for the developing of therapeutic application like drug or gene delivery.