Premium
Polarized provision of cysteine affects glutathione biosynthesis without impacting gene expression pathways responsive to oxidative stress in intestinal epithelial cells
Author(s) -
Chowdhury Shankar R,
Conour John E,
Gaskins H Rex
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a1075-d
Subject(s) - gclc , gclm , glutathione , oxidative stress , microbiology and biotechnology , cysteine , intracellular , biochemistry , chemistry , homeostasis , biology , enzyme
To address the working hypothesis that the lack of luminal cysteine with parenteral nutrition perturbs intestinal redox homeostasis, polarized Caco‐2BBe and HT‐29C1.16E epithelial cells were seeded on cell culture inserts, grown to confluence and subsequently provided cysteine in apical, basal, both, or neither compartments. Cells were also treated with a prototypical pro‐oxidant (H 2 O 2 ) and antioxidant (TBHQ) to examine the induction of pathways responsive to oxidative stress. Cysteine uptake and reduced but not oxidized glutathione concentrations were decreased with basal versus apical provision of cysteine resulting in a decreased intracellular redox potential. However, the extent of intracellular oxidation was not sufficient to activate RNA expression of genes contributing to redox homeostasis (GCLC, GCLM, GPX2, NQO1, xCT) in either cell line. Treatment with H 2 O 2 and TBHQ upregulated the RNA expression of GCLC, GCLM, NQO1, and xCT and this response was not affected by the polarized provision of cysteine. Overall, these data indicate that the polarized provision of cysteine diminishes glutathione biosynthesis without impacting gene expression pathways for redox homeostasis in Caco‐2BBe and HT‐29C1.16E cells. Supported by NIH DK061568.