Ab125011

Protein was isolated through lysis with radioimmunoprecipitation assay (RIPA) buffer supplemented with 1:100 protease inhibitor (Solarbio, Beijing, China). The BCA protein assay kit (BOSTER, Wuhan, China) was used for protein quantification. Samples were separated by SDS-PAGE gels and transferred onto a PVDF membrane (Millipore). The membranes were blocked for 1 h with 5% skimmed milk and incubated overnight at 4 °C with primary antibodies: anti-CD9 (1:1000, ab92726, System Biosciences), anti-TSG101(1:2000, ab125011, System Bioscienc-es),anti-COL1A1(1:2000, ab260043, abcam), anti-α-SMA (1:5000, ab124964, abcam), GAPDH (1:1000, 41,549, CST). Then, after 3 times wash, the membranes were incubated with the HRP-conjugated secondary anti-Rabbit antibody for 1 h at room temperature. Immunoreactive bands were visualized using Immobilon Western HRP (GeneBank; USA) and analyzed in Image J software.

Cell culture medium was centrifuged at 500 g for 10 min, then the supernatant was centrifuged at 20 000 g for 20 min. The supernatant was transferred to a fresh tube, filtered through a 0.22 µm filter and pelleted by ultracentrifugation (Beckman Optima L‐100 XP, Beckman Coulter) at 100 000 g for 70 min. Exosome pellets were washed in a large volume of PBS and recovered by centrifugation at 100 000 g for 70 min. The particle concentration and size distribution of the purified exosomes were determined using NTA in ZetaView (Particle Metrix). The morphology and size of the exosomes were determined using SEM. Purified exosomes were characterized by western blotting using antibodies against TSG101 (Abcam, ab125011), CD9 (System Biosciences, ExoAB‐CD9A‐1), Calnexin (Cell Signaling Technology, 2679), Flotillin1 (Proteintech, 15571‐1), and CD81 (Proteintech, 66866‐1).