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Archive - Jul 22, 2020

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“EVs in Neurological Diseases,” with Focus on Rett Syndome, Is Second Plenary Address on Opening Day of International Society for Extracellular Vesicles (ISEV) 2020 Virtual Annual Meeting (July 20-22) for 1,600 Virtual Attendees from 52 Countries

(Written for BioQuick News by Michael A. Goldman, PhD, Professor & Former Chair, Biology, San Francisco State University, https://faculty.sfsu.edu/~goldman/) The International Society for Extracellular Vesicles (ISEV) 2020 Virtual Annual Meeting (July 20-22) (https://www.eventscribe.com/2020/ISEV/), with a record 1,600 virtual attendees from 52 countries around the world, and offering ~600 presentations of various types (Plenary Addresses, “Hot-Topic” Panel Sessions, Featured Abstracts, Oral Abstract Talks, Poster Chats, & Education Sessions), both live-streamed and on-demand, showcased its second Plenary Address on Monday, July 20. This address was titled “EVs in Neurological Diseases,” and was delivered by Hollis Cline (photo), PhD, the Hahn Professor of Neuroscience and Co-Chair of the Department of Neuroscience at Scripps Research in La Jolla, California, USA. Dr. Cline (https://www.scripps.edu/faculty/cline/) is also a Counselor for the National Institute of Neurological Disorders and Stroke (NINDS) and a Past President of the Society for Neuroscience. She received her BA from Bryn Mawr College and her PhD from the University of California at Berkeley, followed by postdoctoral training at Yale University and Stanford University. Dr. Cline has served on the faculty of the University of Iowa and the Cold Spring Harbor Laboratory, where she served as the Director of Research from 2002-2006. Dr. Cline’s research has demonstrated the roles of a variety of activity-dependent mechanisms in controlling structural plasticity of neuronal dendrites and axons, synaptic maturation, and topographic map formation. This body of work has helped to generate a comprehensive understanding of the role of experience in shaping brain development.

Fourth Featured Abstract at ISEV 2020 Virtual Annual Meeting Reports That, Following Endocytosis by Acceptor Cells, Extracellular Vesicles (EVs) Release Their Cargo from Endosomes; New Analytical Methodology Enables Key Finding

Today (Wednesday, June 22), in the last of four Featured Abstracts presented by graduate students during the ISEV 2020 Virtual Annual Meeting (July 20-22) (https://www.eventscribe.com/2020/ISEV/), Bhagyashree Joshi (photo), of the Department of Biomedical Engineering, University of Groningen, University Medical Center Groningen, The Netherlands, presented her group’s abstract (FA03) “Genetically Encoded Probes Provide Insight into Extracellular Vesicle Cargo Release in Cells.” Ms. Joshi is a PhD candidate in the laboratory of Inge Zuhorn, PhD, Associate Professor, Department of Biomedical Engineering, University of Groningen, University Medical Center Groningen University Medical Center Groningen. In her introduction, Ms. Joshi noted that extracellular vesicles (EVs) are known to modulate tissue development, regeneration, and disease through the transfer of proteins, nucleic acids, and lipids between cells. Currently, however, the mechanism of cytosolic delivery of EV cargo is largely unknown, she said. It has been speculated that EVs undergo back fusion at multi-vesicular bodies (MVBs) in recipient cells to release their functional cargo. However, Ms. Joshi said, evidence for this is lacking. She remarked that tracing the cellular uptake of EVs with high resolution, as well as acquiring direct evidence for the release of EV cargo, is challenging, chiefly because of technical limitations. To address this problem, Ms. Joshi and colleagues developed an analytical methodology that combined state-of-the-art molecular tools and correlative light and electron microscopy (CLEM) to identify the intracellular site for EV cargo release. Green fluorescent protein (GFP) was loaded inside EVs through the expression of GFP-CD63, a fusion of GFP to the cytosolic tail of CD63, in EV producer cells.

Third Featured Abstract at ISEV 2020 Virtual Annual Meeting Reports That Expression of Tetraspanin 8 (Tspan8) Causes Nuclear Proteins to Be Incorporated into Tumor-Derived Extracellular Vesicles (EVs); Results Suggest New Mechanism of Action for Tspan8

On Tuesday, June 21, in the third of four Featured Abstracts being presented by junior investigators during the ISEV 2020 Virtual Annual Meeting (July 20-22) (https://www.eventscribe.com/2020/ISEV/), Elena Grueso Navarro (photo), a Marie Curie Fellow at TRAIN-EV* at the Institute for Infection Prevention and Hospital Epidemiology, Medical Center-University of Freiburg, Breisgau, German, presented her group’s abstract (FA02) “Nuclear Proteins Are Recruited into Tumor-Derived Extracellular Vesicles Upon Expression of Tetraspanin Tspan8.” Ms. Navarro is a PhD candidate in the laboratory of Irina Nazarenko, PhD, Head, Exosomes & Tumor Group, Institute for Infection Prevention and Hospital Epidemiology, Medical Center-University of Freiburg. In her introduction, Ms. Grueso Navarro noted that tetraspanin 8 (Tspan8) is a transmembrane protein that exhibits a unique expression pattern, being overexpressed in many cancer types, but undetectable in a majority of healthy tissues. When overexpressed, Tspan8 facilitates cell motility, and, in tumor models, it supports invasion and metastasis. In addition, Tspan8 is recruited to the extracellular vesicles (EVs). Previous work in Dr. Nazarenko's laboratory has shown that Tspan8 affects EV content and mediates the EVs’ function in metastasis and angiogenesis. These data suggest that Tspan8 may be a promising therapeutic target in cancer.