Fig. 1

BMSCs produce functional extracellular mitochondria particles transferred into neurons. a Mitochondria in BMSCs visualized using Mito Tracker Red CMXRos. The red dots represent mitochondria. Scale bar, 200 μm. b Representative TEM images of extracellular mitochondria derived from BMSCs. Scale bar, 200 nm. c FACS results of extracellular mitochondria particles pre-stained using Mito Tracker Red CMXRos. Control group, BMSC medium without staining. Md-BCM group, the mitochondria depleted medium; BCM group, the normal pre-stained medium. d Extracellular mitochondria ratio in medium (n = 5). *p < 0.05. e Quantification of ATP content in medium (n = 6, fold of Md-BCM). **p < 0.01. f Statistics for extracellular mitochondria membrane potential (n = 8). ***p < 0.001. g Quantification of internalized mitochondria in VSC4.1 motor neurons w/o OGD (fold of control). Image J was used to measure IOD. **p < 0.01. h Representative fluorescence images of internalized mitochondria in VSC4.1 motor neurons co-cultured with BMSCs. In the directly group, BMSCs were pre-stained using CFSE. The purple arrows indicate VSC4.1 motor neurons and the white arrows indicate co-cultured BMSCs. Scale bar, 50 μm. In the transwell system, VSC4.1 motor neurons were pre-stained using CFSE. Scale bar, 100 μm. i Representative fluorescence images of VSC4.1 motor neurons. All VSC4.1 motor neurons were co-cultured with BMSCs in the transwell system. Control group, normal VSC4.1 motor neurons; OGD group, VSC4.1 motor neurons with oxygen and glucose deprivation treatment. Scale bar, 50 μm