Functional induction of the cystine-glutamate exchanger system Xc(-) activity in SH-SY5Y cells by unconjugated bilirubin.

ABSTRACT: 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 X(c)(-) (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 X(c)(-), without the contribution of the others two cystine transporters (X(AG)(-) 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 a

SUBMITTER: Giraudi PJ 

PROVIDER: S-EPMC3246462 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature