ABSTRACT
BACKGROUND:At present, the proteome is a mature technology that has been applied in basic research fields related to liver transplantation. But, it has been not reported in research related to reduced-size liver transplantation. OBJECTIVE:To explore the expression of differential proteins related to hepatic energy metabolism fol owing reduce-size liver transplantation in rats by using by proteomic technology. METHODS:The improved model of reduced-size liver transplantation was used in this experiment. The donor was health female Lewis rats and the recipient was male Wistar rats for liver transplantation. The difference between the donor and the recipient was about 20 g. The weight of donor liver/the weight of recipient donor was approximately equal to 50%. The donor liver tissue was harvested and trimmed to the required size. The portal vein and infrahepatic vena cava were cannulated, and the biliary tract was implanted into the donor bile duct for transplantation. Then the donor was transplanted into the recipient after the removal of original liver tissue. Hepatic specimens were harvested by 1, 3 and 7 days after reduced-size liver transplantation. Then, the harvested specimens were compared with the normal donor and recipient liver tissue that were previously harvested and frozen, to generate two-dimensional gel electrophoresis profile using proteome technology. Then tandem mass spectrometry and databases analysis were performed after two-dimensional electrophoresis for identifying differential protein stains. RESULTS AND CONCLUSION:In this experiment, 72 differential protein stains with over lo-fold changes were selected. After identification, 32 proteins showed clear functions, and among them three differential proteins (ATP synthase beta subunit, electron-transferring flavoprotein beta peptide and proton-transferring ATP synthase) were involved in the process of cel energy metabolism. The proteins were distributed on 1 and 7 days after reduce-size liver transplantation, accounting for 6%.
ABSTRACT
Mitochondrial biogenesis is known to accompany adipogenesis to complement ATP and acetyl-CoA required for lipogenesis. Here, we demonstrated that mitochondrial proteins such as ATP synthase alpha and beta, and cytochrome c were highly expressed during the 3T3-L1 differentiation into adipocytes. Fully-differentiated adipocytes showed a significant increase of mitochondria under electron microscopy. Analysis by immunofluorescence, cellular fractionation, and surface biotinylation demonstrated the elevated levels of ATP synthase complex found not only in the mitochondria but also on the cell surface (particularly lipid rafts) of adipocytes. High rate of ATP (more than 30 micrometer) synthesis from the added ADP and Pi in the adipocyte media suggests the involvement of the surface ATP synthase complex for the exracellular ATP synthesis. In addition, this ATP synthesis was significantly inhibited in the presence of oligomycin, an ATP synthase inhibitor, and carbonyl cyanide m-chlorophenylhydrazone (CCCP), an ATP synthase uncoupler. Decrease of extracellular ATP synthesis in acidic but not in basic media further indicates that the surface ATP synthase may also be regulated by proton gradient through the plasma membrane.