These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: L-cysteine down-regulates SREBP-1c-regulated lipogenic enzymes expression via glutathione in HepG2 cells.
    Author: Bettzieche A, Brandsch C, Hirche F, Eder K, Stangl GI.
    Journal: Ann Nutr Metab; 2008; 52(3):196-203. PubMed ID: 18544973.
    Abstract:
    BACKGROUND/AIM: Protein-associated amino acids are supposed to play a role in sterol regulatory element-binding protein (SREBP)-mediated regulation of lipid metabolism. This study investigates the effects of cysteine on expression of SREBP-regulated hepatic genes. METHODS: HepG2 cells which are an accepted model for the study of the lipid metabolism were treated with L-cysteine under different conditions. RESULTS: Exposure of cells to L-cysteine reduced the mRNA concentrations of SREBP-1c (-35 to -43%) and its target genes fatty acid synthase (FAS; -20 to -50%), glucose-6-phosphate-dehydrogenase (G6PDH; -31 to -35%), and stearoyl-coenzyme A desaturase (SCD)1 (-34 to -50%). Cells treated with L-cysteine had 47% higher glutathione and 47% lower triglyceride concentrations than control cells. In cells which were concurrently treated with L-cysteine and L-buthionine-[S,R]-sulfoximine, an inhibitor of enzymatic glutathione synthesis, no down-regulation of the gene expression was observed. Pro-oxidant CuSO(4) up-regulated SREBP-1c (+71%), FAS (+165%), G6PDH (+84%) and SCD1 (+96%) mRNA abundance compared to control cells, but when cells were concurrently treated with L-cysteine, the gene expression remained at control level. CONCLUSIONS: The results show that L-cysteine rapidly down-regulates the transcription of genes involved in fatty acid biosynthesis via a mechanism that appears to be mediated by an improved glutathione status.
    [Abstract] [Full Text] [Related] [New Search]