Mitochondrial Transfer from Wharton’s Jelly Mesenchymal Stem Cell to MERRF Cybrid Reduces Oxidative Stress and Improves Mitochondrial Bioenergetics

Figure 5

Partly reduced mtDNA mutation load by mitochondrial transfer is sufficient to improve mitochondrial bioenergetics long term. (a) Mitochondrial membrane potential probed with TMRE was imaged using a fluorescence microscope. Heat map reflecting the fluorescent intensity was analyzed using ImageJ. (b) Quantitative TMRE fluorescence was analyzed using flow cytometer. (c) Mitochondrial membrane potential probed with JC-1 was analyzed using flow cytometer. (d–f) representative polarography of OCR measurement. Substrates and inhibitors were sequentially added to a cell-containing oximeter chamber, including glutamate/malate (G/M), ADP (A), oligomycin (O), FCCP (F), and rotenone (R). (g) Basal respiration was calculated by OCR in the presence of G/M. (h) ADP-stimulated respiration was calculated by OCR in the presence of ADP. (i) Respiration related to ATP turnover was determined by the difference between ADP-stimulated OCR and oligomycin-suppressed OCR. (j) Maximal respiration was calculated by OCR in the presence of FCCP. (k) Respiratory reserve was determined by the difference between maximal and basal OCR. (l) ATP level was measured in the presence of DMSO or oligomycin. (m-n) Cytochrome c oxidase subunit 2 (COX2) expression level was determined using immunoblotting. β-Actin as a loading control. (o–r) Mitochondria-dependent cellular viability was examined by growing cell in galactose medium. Viable cells were observed under microscope and counted by trypan blue assay. , significantly different when compared to indicated group. CT, control; MF, MERRF; MF+WJ, MERRF cybrid-plus-WJMSC.

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