Fig. 4

BM-MSCs, LT-MSCs and BAL-MSCs donate mitochondria to BEAS2B epithelial cells. Mitochondrial transfer between mesenchymal stromal cells (MSCs) and BEAS2B bronchial epithelial cells was measured by flow cytometry and confocal microscopy. a Representative flow cytometry plot of transfer after MSCs were labelled with Mitotracker Green and co-cultured with BEAS2B cells for 4 hours. Blue line represents co-cultured BEAS2B cells, red line represents unstained control. b To assess whether epithelial cells were capable of donating mitochondrial to MSCs, BEAS2B cells were labelled with Mitotracker Green and co-cultured with MSCs for 4 h. Blue line represents co-cultured MSCs, red line represents unstained control. c Representative flow cytometry plot of transfer after MSCs were labelled with Mitotracker Green and co-cultured with BEAS2B cells within a transwell configuration. d Grouped data of mitochondrial transfer by bone marrow-derived (BM-MSCs), lung tissue-derived (LT-MSCs) and bronchoalveolar fluid-derived (BAL-MSCs) MSCs. Y axis represents the fold-change increase in Mitotracker Green mean fluorescent intensity (MFI) of BEAS2B cells after co-culture with each respective MSC population. Horizontal bars represent median. e–g Confocal microscopy images of mitochondrial transfer by BM-MSCs (e), LT-MSCs (f) and BAL-MSCs (g). MSCs were pre-labelled with Mitotracker Green (green) and co-cultured with BEAS2B epithelial cells labelled with DiD (red). Images are shown at 630× magnification with an oil immersion lens. White arrows point to microvesicles containing mitochondria, white arrowhead points to an endocytosed MSC-derived mitochondria