Figure 2.

hUC-MSCs-MVs inhibited LO-induced HK-2 cell apoptosis through transferring miR-21. (a) qRT-PCR analysis showed that miR-21 expression was downregulated in MVs derived from miR-21 inhibitor-transfected hUC-MSCs. (b) The MVs derived from FAM (green)-miR-21-transfected hUC-MSCs were labeled with Dil (red), and co-cultured with HK-2 cells (nuclei stained with DAPI, blue). The distribution and intensity of fluorescence were observed to analyze MVs uptake by HK-2 cells. Scale bar: 10 μm. (c-e) HK-2 cells were co-cultured with PBS, hUC-MSCs-MVs, MVs derived from inhibitor NC-transfected hUC-MSCs (inhibitor NC MVs), and MVs derived from miR-21 inhibitor-transfected hUC-MSCs (miR-21 inhibitor MVs), followed by exposure to low oxygen (LO; 1.5 h of hypoxia and then 24 h of reoxygenation). (c) miR-21 expression in HK-2 cells in each group was detected by qRT-PCR. (d) The apoptosis rate of HK-2 cells in each group was examined using flow cytometry after annexin V-FITC/propidium iodide (PI) staining. (e) The protein levels of apoptosis-related proteins (caspase-3, Bax, Bcl-2) in HK-2 cells were analyzed by western blot.