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Vascular endothelial growth factor (VEGF) promotes parenchymal liver cell growth in vivo
172 MOLECULAR
Papers read by title AND CELL BIOLOGY
(GENE EXPRESSION,
SIGNALLING,
FIBROSIS)
THE INTERACTION BETWEEN THE CATION-BINDING SITE AND IRON IN OXIDATIVE MODIFICATION OF Y-NUCLEOTIDASE
VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) PROMOTES PARENCHYMAL LIVER CELL GROWTH IN WV0
G. KociC, D.PavloviC. P. Vlahovic.
Y Baruch’. A Krasik’, G Shoshanv’. L. Shenkaa. N Assv’. M Paiz?, Y Kraize?, G Soira3. ‘Liver Unit and ‘Dept. of Pediatric Surgery, Rambam Medical Center, and 3Dept. of Cell Biology, B. Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
Institut of Biochemistry,
R. KociC. T. Jevtovic. I. Stoianovic
Medical Faculty NiS, Yugoslavia
Although oxidative stress has a pleiotropic effect on liver cell damage the final and irreversible event is altered property of membrane mileu including the modified activity of membrane-bound enzymes. To asses the mechanism responsible for the oxidative modification of ecto-S’mtcleotidase, different free-radical generating systems (FeCl&scorbate, X/X0 and HrOz) were investigated in a dose-dependent manner. Hepatocytes were isolated from male Wistar rats by the collagenase technique and the enzyme activity was measured in b&,-cells and extracellular medium. FeCl&corbate system caused a dramatical fall in enzyme activity (Fig.1 )in cells and ECT. Since it was already documnted that S’NtJ is a metal-protein and that the endogenous cation is essential for its catalytic activity, it means that Fe-induced modification is a site-specific process of the metal-binding site. XIX0 system caused a decrease in enzyme activity in cells, but mainly as a result of the enzvme leakaae. due to the membrane moteolvsis and loss of membrane integri6, because-au increase in ECT was observed (Fig.2). Hz02 system did not cause a ereat inhibition (Fie.3). Ca”chamte1 blocker hra~amil~ was capable of pgtentiating the inbi&i&t in Fe system (by 16.&l.?%) and in X/X0 system (by 13.1*2.4%),indicating that the cation flux can be important for catalytic activity and inhibition. Since highest dose-dependent MDA increase was observed in Hz02 system (by 409.5*15.7%, vs 281&13.4% of Fe, vs 214.3il2.5% of X/X0), but the highest increase in carbonyl group content was observed in XIX0 system (by 172.Oi2.5% vs 169.&10.8% of H202, vs 125.*2.5% of Fe) it can be concluded that neither peroxidation of lipid environment nor protein oxidative modification, but rather the cationbinding site is responsible for the oxidative modification.
We studied the effect of human recombinant VEGF (I~VEGF,~) on liver cell growth using two animal models. Transfected baby hamster kidney (BHK) fibroblasts with the vector to ~~IVEGF,~~(producing 50 pggllto the medium) were transplanted into the peritoneum or spleen of nude mice. Nontransfected BHK cells and saline treatment served as controls. This model exposed the liver to VEGF for a long period. Twenty-four mice (9 died) were transplanted with BHK-165 cells, 12 with BHK (5 died), and 4 with saline. BHK-165transplanted mice produced a tumor within 1 week in 13/l 5 (86%); 11115 produced sanguineous ascites. Of the BHKtransplanted mice, only 4/7 (57%) produced a tumor, and only 2 had ascites. Western blot analysis showed a significant amount of ~~IVEGF,~ protein in the serum and ascitic fluid of the BHK-165 mice. Proliferating cell nuclear antigen (PCNA) immunostaining of hepatocytes was significantly greater in the BHK-165 group than in controls [labeling index (mean*SEM): 12.3Q.3, 3.lfl .l, and 4.2fl.7, respectively; p
1 CO3/004
HEPATIC ANTIFIBROTIC EFFECT OF SUPEROXIDE DISMUTASE (SOD) IN MURINE SCHISTOSOMIASZS S GUERRET”‘. S. RICARD-BLUM’2’. B. DUGAS3’, E. POSTAIRE’4’. D. HARTMANN’2’. M. CHEVALLIER”‘. P. CHOSSEGROS”‘. (1) Laboratoire M. Merieux, LYON ; (2) Universite LYON I, (3) Fractales-Biotech, PARIS ; (4) Danone-CIRDC, PARIS ; (5) Hotel Dieu, LYON, FRANCE. The development of liver fibrosis is the major complication of chronic hepatopathies. Bovine SOD as been proven to have an antitibrotic effect in radiation-induced skin fibrosis. A murine schistosomiasis experimental model, known to lead to an extensive periovular fibrous deposit, was used to test the potential antifibrotic effect of SOD. Material and Methods: Each of 21 female mice were subcutaneously infested by 120 cercariae of Schistosoma mansoni. Simultaneously 13 mice were treated with SOD for 8 weeks, at the dose of 2mg/kg, by intramuscular injection, thrice a week. The control group (8 mice) received 0.9% sodium chloride/injection. Periovular liver fibrosis surface density (%) was assessed by image analysis on 3um picrosirius red stained sections. Results: The number and distribution of granulomas was not modified, but a significant decrease of periovular fibrosis (p
1
Withdrawn
Papers read by title AND CELL BIOLOGY
(GENE EXPRESSION,
SIGNALLING,
FIBROSIS)
THE INTERACTION BETWEEN THE CATION-BINDING SITE AND IRON IN OXIDATIVE MODIFICATION OF Y-NUCLEOTIDASE
VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) PROMOTES PARENCHYMAL LIVER CELL GROWTH IN WV0
G. KociC, D.PavloviC. P. Vlahovic.
Y Baruch’. A Krasik’, G Shoshanv’. L. Shenkaa. N Assv’. M Paiz?, Y Kraize?, G Soira3. ‘Liver Unit and ‘Dept. of Pediatric Surgery, Rambam Medical Center, and 3Dept. of Cell Biology, B. Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
Institut of Biochemistry,
R. KociC. T. Jevtovic. I. Stoianovic
Medical Faculty NiS, Yugoslavia
Although oxidative stress has a pleiotropic effect on liver cell damage the final and irreversible event is altered property of membrane mileu including the modified activity of membrane-bound enzymes. To asses the mechanism responsible for the oxidative modification of ecto-S’mtcleotidase, different free-radical generating systems (FeCl&scorbate, X/X0 and HrOz) were investigated in a dose-dependent manner. Hepatocytes were isolated from male Wistar rats by the collagenase technique and the enzyme activity was measured in b&,-cells and extracellular medium. FeCl&corbate system caused a dramatical fall in enzyme activity (Fig.1 )in cells and ECT. Since it was already documnted that S’NtJ is a metal-protein and that the endogenous cation is essential for its catalytic activity, it means that Fe-induced modification is a site-specific process of the metal-binding site. XIX0 system caused a decrease in enzyme activity in cells, but mainly as a result of the enzvme leakaae. due to the membrane moteolvsis and loss of membrane integri6, because-au increase in ECT was observed (Fig.2). Hz02 system did not cause a ereat inhibition (Fie.3). Ca”chamte1 blocker hra~amil~ was capable of pgtentiating the inbi&i&t in Fe system (by 16.&l.?%) and in X/X0 system (by 13.1*2.4%),indicating that the cation flux can be important for catalytic activity and inhibition. Since highest dose-dependent MDA increase was observed in Hz02 system (by 409.5*15.7%, vs 281&13.4% of Fe, vs 214.3il2.5% of X/X0), but the highest increase in carbonyl group content was observed in XIX0 system (by 172.Oi2.5% vs 169.&10.8% of H202, vs 125.*2.5% of Fe) it can be concluded that neither peroxidation of lipid environment nor protein oxidative modification, but rather the cationbinding site is responsible for the oxidative modification.
We studied the effect of human recombinant VEGF (I~VEGF,~) on liver cell growth using two animal models. Transfected baby hamster kidney (BHK) fibroblasts with the vector to ~~IVEGF,~~(producing 50 pggllto the medium) were transplanted into the peritoneum or spleen of nude mice. Nontransfected BHK cells and saline treatment served as controls. This model exposed the liver to VEGF for a long period. Twenty-four mice (9 died) were transplanted with BHK-165 cells, 12 with BHK (5 died), and 4 with saline. BHK-165transplanted mice produced a tumor within 1 week in 13/l 5 (86%); 11115 produced sanguineous ascites. Of the BHKtransplanted mice, only 4/7 (57%) produced a tumor, and only 2 had ascites. Western blot analysis showed a significant amount of ~~IVEGF,~ protein in the serum and ascitic fluid of the BHK-165 mice. Proliferating cell nuclear antigen (PCNA) immunostaining of hepatocytes was significantly greater in the BHK-165 group than in controls [labeling index (mean*SEM): 12.3Q.3, 3.lfl .l, and 4.2fl.7, respectively; p
1 CO3/004
HEPATIC ANTIFIBROTIC EFFECT OF SUPEROXIDE DISMUTASE (SOD) IN MURINE SCHISTOSOMIASZS S GUERRET”‘. S. RICARD-BLUM’2’. B. DUGAS3’, E. POSTAIRE’4’. D. HARTMANN’2’. M. CHEVALLIER”‘. P. CHOSSEGROS”‘. (1) Laboratoire M. Merieux, LYON ; (2) Universite LYON I, (3) Fractales-Biotech, PARIS ; (4) Danone-CIRDC, PARIS ; (5) Hotel Dieu, LYON, FRANCE. The development of liver fibrosis is the major complication of chronic hepatopathies. Bovine SOD as been proven to have an antitibrotic effect in radiation-induced skin fibrosis. A murine schistosomiasis experimental model, known to lead to an extensive periovular fibrous deposit, was used to test the potential antifibrotic effect of SOD. Material and Methods: Each of 21 female mice were subcutaneously infested by 120 cercariae of Schistosoma mansoni. Simultaneously 13 mice were treated with SOD for 8 weeks, at the dose of 2mg/kg, by intramuscular injection, thrice a week. The control group (8 mice) received 0.9% sodium chloride/injection. Periovular liver fibrosis surface density (%) was assessed by image analysis on 3um picrosirius red stained sections. Results: The number and distribution of granulomas was not modified, but a significant decrease of periovular fibrosis (p
1
Withdrawn