Live Tracking of Inter-organ Communication by Endogenous Exosomes In Vivo

Abstract

Highlights d Single endogenous EVs can be live-visualized in the zebrafish embryo with CD63-pHluorin d Syntenin in the YSL regulates exosome release into the blood for further dissemination d YSL exosomes are taken up by macrophages and endothelial cells in the tail of the embryo d Uptake is scavenger receptor-and dynamin-dependent and provides trophic support

Inflammatory Responses during Tumour Initiation: From Zebrafish Transgenic Models of Cancer to Evidence from Mouse and Man

“…Cancer-derived EVs have been shown to promote M2 polarisation of TAMs in some cases, and the expression of pro-inflammatory cytokines in others [252][253][254]. Recently, both a fluorescent probe [255,256] and a transgenic line [257] have been developed that specifically label EVs in zebrafish, making it possible to track their transit in a live in vivo model. For example, one study showed that tumour-derived EVs activated macrophages, resulting in a macrophage-dependent promotion of metastatic outgrowth at distal sites [255].…”

Origin of the bidirectionality of cerebrospinal fluid flow and impact on long-range transport between brain and spinal cord

“…We identify many vesicles with high lipids or proteins content floating in central canal, in agreement with previous observations 31 . The presence of dense exosomes is confirmed using fluorescence labeling ( Supplementary Movie S10, Methods ), and electron microscopy with immunogold labeling of exosomes ( Figure 7h, Methods ) 30 . Note that both optical techniques show similar bidirectional flow of endogenous extracellular vesicles in the CC ( Supplementary Movies S10, S11 ).…”

“…On the next day, embryos were anesthetized with tricaine and embedded in 1.5% low melting point agarose. Live imaging recordings were performed at 28°C using a Nikon TSi spinningwide (Yokagawa CSUW1) microscope 30 . Other embryos were used for ultrathin cryosectioning and immunogold labeling, in which case they were fixed in 2% PFA, 0.2% glutaraldehyde in 0.1M phosphate buffer pH 7.4 at 3 dpf.…”

“…All samples were examined with a FEI Tecnai Spirit electron microscope (FEI Company), and digital acquisitions were made with a numeric camera (Quemesa; Soft Imaging System). 30 Computational Fluid Dynamics (CFD) and numerical methods for solving the equations . For the numerical resolution of the system of three coupled equations detailed in the "Results" Figure 2B1.…”

“…Understanding CSF circulation throughout the body is crucial as this biological fluid plays numerous roles in the development of brain and spinal cord. The CSF provides the hydromechanical protection of the brain 25 , enables the transport of nutrients and waste 25,26 , exosomes [27][28][29][30][31] , and signaling molecules impacting neurogenesis and neuronal migration in the brain [32][33][34][35] . The CSF circulation has recently been linked to body axis formation in the embryo and spine morphogenesis in juveniles/adults 21,36,37 .…”