Metabolic and transcriptional patterns accompanying glutamine depletion and repletion in mouse hepatoma cells: a model for physiological regulatory networks
Open Access
- 15 January 2004
- journal article
- Published by American Physiological Society in Physiological Genomics
- Vol. 16 (2), 247-255
- https://doi.org/10.1152/physiolgenomics.00088.2003
Abstract
An important objective in postgenomic biology is to link gene expression to function by developing physiological networks that include data from the genomic and functional levels. Here, we develop a model for the analysis of time-dependent changes in metabolites, fluxes, and gene expression in a hepatic model system. The experimental framework chosen was modulation of extracellular glutamine in confluent cultures of mouse Hepa1-6 cells. The importance of glutamine has been demonstrated previously in mammalian cell culture by precipitating metabolic shifts with glutamine depletion and repletion. Our protocol removed glutamine from the medium for 24 h and returned it for a second 24 h. Flux assays of glycolysis, the tricarboxylic acid (TCA) cycle, and lipogenesis were used at specified intervals. All of these fluxes declined in the absence of glutamine and were restored when glutamine was repleted. Isotopomer spectral analysis identified glucose and glutamine as equal sources of lipogenic carbon. Metabolite measurements of organic acids and amino acids indicated that most metabolites changed in parallel with the fluxes. Experiments with actinomycin D indicated that de novo mRNA synthesis was required for observed flux changes during the depletion/repletion of glutamine. Analysis of gene expression data from DNA microarrays revealed that many more genes were anticorrelated with the glycolytic flux and glutamine level than were correlated with these indicators. In conclusion, this model may be useful as a prototype physiological regulatory network where gene expression profiles are analyzed in concert with changes in cell function.Keywords
This publication has 23 references indexed in Scilit:
- Modeling transcriptional regulatory networksBioEssays, 2002
- Glutamine Transport and Human Hepatocellular TransformationJournal of Parenteral and Enteral Nutrition, 1999
- Effect of tamoxifen on cholesterol synthesis in HepG2 cells and cultured rat hepatocytesMetabolism, 1998
- Hypoosmolarity and glutamine increased the β-actin gene transcription in isolated rat hepatocytesFEBS Letters, 1996
- Glutamine metabolism in AS-30D hepatoma cells. Evidence for its conversion into lipids via reductive carboxylationMolecular and Cellular Biochemistry, 1995
- Isotopomer Analysis of Citric Acid Cycle and Gluconeogenesis in Rat LiverPublished by Elsevier BV ,1995
- Interleukin-6, but not tumour necrosis factor-α, increases lipogenesis in rat hepatocyte primary culturesBiochemical Journal, 1994
- Glutamine metabolism in lymphocytes of the ratBiochemical Journal, 1983
- Lipid extraction of tissues with a low-toxicity solventAnalytical Biochemistry, 1978
- Energy metabolism in respiration‐deficient and wild type chinese hamster fibroblasts in cultureJournal of Cellular Physiology, 1976