Effect of high-glucose (HG) conditions on mitochondrial dynamics, autophagy, apoptosis, and ROS production in human renal proximal tubular cells (RPTCs). (a, A, B, and C) Under high-glucose conditions, the number of MitoTracker Red-labeled mitochondria and the expression of LC3, an autophagy marker, decrease. (a, D and E) However, mitochondrial and cytosolic ROS increase, as detected by MitoSOX (red) or H2-DCFDA (green) staining. (b) Decreased mitochondrial mass, as assessed by the mtDNA/gDNA ratio, in human RPTCs under high-glucose condition. (c) Western blot analyses reveal upregulation of the mitochondrial profission protein Drp1; the profusion protein Mfn1 and the autophagy-related protein LC3II were downregulated. (d) Bax and cytochrome C, apoptosis regulatory proteins, were upregulated in a HG environment, whereas Bcl2, an antiapoptotic protein, was downregulated (∗p < 0.05 versus the 5 mM glucose condition; scale bar 10 μm).