In Vivo Characterization of Endogenous Cardiovascular Extracellular Vesicles in Larval and Adult Zebrafish

This is the final version. Available on open access from the American Heart Association via the DOI in this recordThe authors declare that all supporting data are available within the article (and its Data Supplement). Please also see the Major Resources Table in the Data Supplement.OBJECTIVE: Extracellular vesicles (EVs) facilitate molecular transport across extracellular space, allowing local and systemic signaling during homeostasis and in disease. Extensive studies have described functional roles for EV populations, including during cardiovascular disease, but the in vivo characterization of endogenously produced EVs is still in its infancy. Because of their genetic tractability and live imaging amenability, zebrafish represent an ideal but under-used model to investigate endogenous EVs. We aimed to establish a transgenic zebrafish model to allow the in vivo identification, tracking, and extraction of endogenous EVs produced by different cell types. APPROACH AND RESULTS: Using a membrane-tethered fluorophore reporter system, we show that EVs can be fluorescently labeled in larval and adult zebrafish and demonstrate that multiple cell types including endothelial cells and cardiomyocytes actively produce EVs in vivo. Cell-type specific EVs can be tracked by high spatiotemporal resolution light-sheet live imaging and modified flow cytometry methods allow these EVs to be further evaluated. Additionally, cryo electron microscopy reveals the full morphological diversity of larval and adult EVs. Importantly, we demonstrate the utility of this model by showing that different cell types exchange EVs in the adult heart and that ischemic injury models dynamically alter EV production. CONCLUSIONS: We describe a powerful in vivo zebrafish model for the investigation of endogenous EVs in all aspects of cardiovascular biology and pathology. A cell membrane fluorophore labeling approach allows cell-type specific tracing of EV origin without bias toward the expression of individual protein markers and will allow detailed future examination of their function

Research on Asian firms : a review and look forward

Asia has a population of approximately 3.5 billion people in over 30 nations spreading east from Europe and Africa, excluding the nations of the Middle East and the Caucasus, and substantive parts of Turkey and Russa. The economic influence of this region is expanding and growing stronger. With China and Japan as two of the world\u27s largest economies, the Four Tigers (i.e., Singapore, South Korea, Hong Kong and Taiwan) as the newly industrialized economies, and India, another emerging economy, the GDP of this region is predicted to exceed that of the United States by 2050