Spatial and temporal dynamics of ATP synthase from mitochondria toward the cell surface.

Ectopic ATP synthase complex (eATP synthase), located on cancer cell surface, has been reported to possess catalytic activity that facilitates the generation of ATP in the extracellular environment to establish a suitable microenvironment and to be a potential target for cancer therapy. However, the mechanism of intracellular ATP synthase complex transport remains unclear. Using a combination of spatial proteomics, interaction proteomics, and transcriptomics analyses, we find ATP synthase complex is first assembled in the mitochondria and subsequently delivered to the cell surface along the microtubule via the interplay of dynamin-related protein 1 (DRP1) and kinesin family member 5B (KIF5B). We further demonstrate that the mitochondrial membrane fuses to the plasma membrane in turn to anchor ATP syntheses on the cell surface using super-resolution imaging and real-time fusion assay in live cells. Our results provide a blueprint of eATP synthase trafficking and contribute to the understanding of the dynamics of tumor progression.

Effects of pyruvate on retinal oxidative damage and retinal ultrastructure in diabetic rats / 国际眼科杂志(Guoji Yanke Zazhi)

AlM:To investigate the changes of retinal histology and oxidative stress in diabetic retinopathy and its reversal by pyruvate in diabetic rats. METHODS: Eighty Wistar rats were divided into 3 groups:control group ( 20 rats ) , model group ( 30 rats ) and treatment group ( 30 rats ) . After streptozotocin ( STZ) induced diabetes mellitus in the model group and the treatment group, the treatment group received 2%pyruvate in diet and drinking. The changes of body weight and blood glucose were observed and the changes of glutathione peroxidase ( GSH-PX ) , malonie dialdehyde ( MDA) , and Na+-K+-ATPase levels of retinal tissue and retinal ultrastructure were investigated in three groups at 12wk after occurrence of diabetes. RESULTS: Compared with control group, the body weight of the model group were significantly decreased, the activities of GSH-PX and ATP in the retina of diabetic rats were significantly lower, the MDA was signigicantly higher and significant changes occurred in retinal ultrastructure. Compared with model group, the blood glucose of the treatment group had no significant changes. However, the activities of GSH and ATP in the retina of diabetic rats were higher, the MDA was lower and the retinal ultrastructure was comparatively mild. CONCLUSlON:Pyruvate can alleviate oxidatie stress reaction, improve the energy metabolism of retina, and delay the development of retinopathy.