Fig. 5

miR-320a from EVs alleviates mitochondrial dysfunction and apoptosis. A Changes in cellular oxidative phosphorylation were detected by extracellular flux analysis. B and C ATP production and mtDNA expression in A549 cells after transfection with miR-320a inhibitor and miR-320a mimics. D Mito Tracker Red staining of mitochondria in A549 cells. Scale bar, 20 μm. Mito Tracker Red: red, DAPI: blue. E The quantitative analysis of mitochondrial fluorescence intensity. F The mitochondrial potential was observed via JC-1 staining. G The red to green fluorescence ratio was recorded to quantify the mitochondrial potential (rate). Scale bar, 20 μm. H ROS levels were assessed. I The relative fluorescence intensity ratio shown in (H) was analyzed. Scale bar, 20 μm. J qRT-PCR was performed to determine mRNA levels of mitochondrial fragmentation-related genes, including Drp1, Mfn1, and Mfn2. K CCK-8 assay was used to determine the Cell proliferation. (L) Caspase 3 activity was measured in the control, miR-320a mimics, and miR-320a inhibitor groups. (M) The expressions of Caspase 3, Bcl-2, and Bax were analyzed by Western blotting. Fluorescence images and blots were representative of six independent experiments. All data are presented as the mean ± SEM of n = 6. ***p < 0.001, **p < 0.01, *p < 0.05, ns, no significance