Fig. 9

Overexpression of PKA restores excessive mitochondrial elongation in RTECs. A Schematic diagram of treatment. Along with 3 days of chronic hypoxia, HK-2 cells were subjected to PKA overexpression (PKA plasmid) with or without MSC-CM continuously before harvest. Cells were subsequently harvested for morphological and immunoblot analysis (n = 3 experiments). OD: 72 h of oxygen deprivation. MSC-CM: conditioned medium collected and concentrated from hUC-MSCs. PKA-OE: PKA plasmid. B Immunoblot of PKA overexpression at consistent enzyme activity. C Quantitative protein expression level of PKA and phosphor-Drp1ser637. D Images of Mito-Tracker Green staining. Scale bar: 20 μm. Representative different mitochondrial morphologies are shown below. Among them, intermediate mitochondria had both punctate fragments and elongated twisted filaments. E Quantitative mitochondrial morphology analysis of Mito-Tracker staining. F Western blot images of cytosolic (cyto) and mitochondrial (mito) drp1 showing its subcellular localization. The GAPDH level was monitored as a cytosol internal loading control. COX IV is used as a mitochondrial internal loading control. After PKA overexpression, drp1 remains in the cytoplasm rather than mitochondria. Data are presented as mean ± SD. **P < 0.01; *P < 0.05. ns, not significant