Fig. 2

T-MSCs-Exo could be taken up by MN9D cells via endocytosis and enhanced cell viability in MPP⁺-induced MN9D cells. a T-MSCs-Exo were labelled using the Exosome Tracer Kit and co-cultured with MN9D cells. During this period, five time points (1, 3, 6, 12, and 24 h) were set. Cells from each time point were stained with DAPI and the uptake of T-MSCs-Exo by MN9D cells was observed by confocal microscopy. Scale bars, upper, 20 µm; lower, 5 µm. b CCK-8 was used to evaluate the MPP⁺-induced MN9D cell viability after treatment with 10, 50, 100, 200, and 300 μg/mL T-MSCs-Exo for 24 h. c, d Immunofluorescence staining and quantification of TH expression in MPP⁺-induced MN9D cells after treatment with different concentrations of T-MSCs-Exo for 24 h. e, f Western blotting analysis showed the TH expression on MPP⁺-induced MN9D cells after treatment with T-MSCs-Exo for 24 h. Each experiment was independently repeated three times, and the results are shown as mean ± SD. One-way ANOVA was used to analyze the data. **p < 0.01, ***p < 0.001, ****p < 0.0001