Functional Induction of the Cystine-Glutamate Exchanger System Xc- Activity in SH-SY5Y Cells by Unconjugated Bilirubin

We have previously reported that exposure of SH-SY5Y neuroblastoma cells to unconjugated bilirubin (UCB) resulted in a marked up-regulation of the mRNA encoding for the Na+ -independent cystine∶glutamate exchanger System Xc− (SLC7A11 and SLC3A2 genes). In this study we demonstrate that SH-SY5Y cells treated with UCB showed a higher cystine uptake due to a significant and specific increase in the activity of System Xc−, without the contribution of the others two cystine transporters (XAG− and GGT) reported in neurons. The total intracellular glutathione content was 2 folds higher in the cells exposed to bilirubin as compared to controls, suggesting that the internalized cystine is used for gluthathione synthesis. Interestingly, these cells were significantly less sensitive to an oxidative insult induced by hydrogen peroxide. If System Xc− is silenced the protection is lost. In conclusion, these results suggest that bilirubin can modulate the gluthathione levels in neuroblastoma cells through the induction of the System Xc−, and this renders the cell less prone to oxidative damage

Soil carbon in Mediterranean ecosystems and related management problems

16CBT: S-D-2450reservedInternational coauthor/editorThe Mediterranean region can be considered as a transitional zone between sub-tropical and temperate climates, characterized by dry, hot summers and mild, wet winters. According to the FAO database the prevailing soil type in the Mediterranean region are Cambisols however Fluvisols, Luvisols and Leptosols are also quite common. In order to quantify the soil carbon content of the major Mediterranean ecosystems, a data collection was organized among the partners of the COST 639 action. Moreover, the effects of wildfires on soil carbon loss and organic matter decomposition were investigated together with inorganic contributions to CO2 soil emissions. The average soil carbon content per unit surface area, to a depth of 30 cm, was found to be around 60-70 tC ha-1 for forest and rangeland ecosystems. Lower contents were found for Dehesa and agricultural soils. However, surprisingly high values, up to 200 tC ha-1 were also reported, which seem to be quite uncommon for dry land ecosystems. The main problem in this study was defining exactly what should or should not be included into the definition of "Mediterranean climate". In fact this term is often used with a wide meaning that includes also temperate ecosystems and therefore a consistent analysis to define the baselines of soil carbon content should firstly be based on a climatic classification. For the same reason a comparison between IPCC default values for forest ecosystems and the collected data in this study was found to be difficult. Moreover, common sampling procedures should be applied to guarantee the comparability of data.mixedRodeghiero, M.; Rubio, A.; Díaz-Pinés, E.; Romanyà, J.; Marañón-Jiménez, S.; Levy, G.J.; Fernandez-Getino, A.P.; Sebastià, M.T.; Karyotis, T.; Chiti, T.; Sirca, C.; Martins, A.; Madeira, M.; Zhiyanski, M.; Gristina, L.; Lamantia, T.Rodeghiero, M.; Rubio, A.; Díaz Pinés, E.; Romanyà, J.; Marañón Jiménez, S.; Levy, G.J.; Fernandez Getino, A.P.; Sebastià, M.T.; Karyotis, T.; Chiti, T.; Sirca, C.; Martins, A.; Madeira, M.; Zhiyanski, M.; Gristina, L.; Lamantia, T

ENERGY ENERGY CORRELATIONS IN HADRONIC FINAL-STATES FROM Z0 DECAYS

We have studied the energy-energy angular correlations in hadronic final states from Z0 decay using the DELPHI detector at LEP. From a comparison with Monte Carlo calculations based on the exact second order QCD matrix element and string fragmentation we find that Lambda-MS(5) = 104(-20)+25(stat.)-20(+25)(syst.)-00(+30)(theor.) MeV, which corresponds to alpha-s(91 GeV) = 0.106 +/- 0.003(stat.) +/- 0.003(syst.)-0.000(+0.003)(theor.). The theoretical error stems from different choices for the renormalization scale of alpha-s. In the Monte Carlo simulation the scale of alphA-s as well as the fragmentation parameters have been optimized to described reasonably well as aspects of multihadron production