Fig. 1

Identification of exosomes isolated from NK cells and the uptake analysis of exosomes by astrocytes. a Transmission electronic microscopy (TEM) analysis of the exosomes secreted by NK cells. Scale bars indicate 200 nm and 100 nm, respectively. b Measurement of particle size of the vesicles secreted from NK cells by qNano Gold analysis. c Western blot analysis of the expression of the exosomal markers CD63 and CD81 in NK cell-derived exosomes. d Exosomes from NK cells were labeled with PKH26 and were taken up by astrocytes extracted from neonatal mice for 24 h. The red fluorescence signal in astrocytes was detected with a fluorescence microscope (bar = 50 μm). e Fluorescence distribution in the mouse brain was detected 12 h after exosomes that were stained with PKH26 fluorescent dye were intravenously injected into mice. 12h-PKH26 indicates the fluorescence distribution in the brain 12 h after PKH26 fluorescent dye was injected into mice; 12h-exosomes-PKH26 indicates the fluorescence distribution in the brain, and 12 h after exosomes marked by PKH26 dye were injected into mice. The left mouse in both pictures was used as a control mouse; these mice were injected with normal saline without dye molecules. f Fluorescence distribution in the brain 24 h after exosomes that were stained with PKH26 fluorescent dye were injected into the tail vein of mice. 24 h-PKH26 indicates the fluorescence distribution in the brain 24 h after PKH26 fluorescent dye was injected into mice; 24h-exosomes-PKH26 indicates the fluorescence distribution in the brain 24 h after exosomes that were marked by PKH26 dye were injected into mice. The left mouse in both pictures was used as a control mouse; these mice were injected with normal saline without dye molecules