Profile of energy metabolism in a murine hybridoma: Glucose and glutamine utilization

Petch, Donna; Butler, Michael

doi:10.1002/jcp.1041610110

Cited by 66 publications

(67 citation statements)

References 25 publications

(22 reference statements)

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“…To distinguish these possibilities, we asked if the gene expression profile induced by rapamycin resembles those induced by starvation for individual nutrients. We generated expression profiles from cells cultured in media with low concentrations of glucose or glutamine, the principal energy, carbon, and nitrogen sources for mammalian cells (31). Glutamine is particularly important for lymphocytes, and decreased blood levels lead to immunosuppression in human beings (6,30).…”

Section: Resultsmentioning

confidence: 99%

The Immunosuppressant Rapamycin Mimics a Starvation-Like Signal Distinct from Amino Acid and Glucose Deprivation

Peng

Golub

Sabatini

2002

Molecular and Cellular Biology

362

299

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RAFT1/FRAP/mTOR is a key regulator of cell growth and division and the mammalian target of rapamycin, an immunosuppressive and anticancer drug. Rapamycin deprivation and nutrient deprivation have similar effects on the activity of S6 kinase 1 (S6K1) and 4E-BP1, two downstream effectors of RAFT1, but the relationship between nutrient-and rapamycin-sensitive pathways is unknown. Using transcriptional profiling, we show that, in human BJAB B-lymphoma cells and murine CTLL-2 T lymphocytes, rapamycin treatment affects the expression of many genes involved in nutrient and protein metabolism. The rapamycin-induced transcriptional profile is distinct from those induced by glucose, glutamine, or leucine deprivation but is most similar to that induced by amino acid deprivation. In particular, rapamycin treatment and amino acid deprivation up-regulate genes involved in nutrient catabolism and energy production and down-regulate genes participating in lipid and nucleotide synthesis and in protein synthesis, turnover, and folding. Surprisingly, however, rapamycin had effects opposite from those of amino acid starvation on the expression of a large group of genes involved in the synthesis, transport, and use of amino acids. Supported by measurements of nutrient use, the data suggest that RAFT1 is an energy and nutrient sensor and that rapamycin mimics a signal generated by the starvation of amino acids but that the signal is unlikely to be the absence of amino acids themselves. These observations underscore the importance of metabolism in controlling lymphocyte proliferation and offer a novel explanation for immunosuppression by rapamycin.Rapamycin is an immunosuppressive drug used to prevent the rejection of transplanted organs and a promising anticancer agent (18,26,27,32). Studies of its mechanism of action have led to the discovery of the TOR pathway, an evolutionarily conserved signaling network that plays critical roles in eukaryotic cell growth and cell cycle progression. In mammalian cells, the complex of rapamycin with its receptor, FKBP12, binds directly to the central component of the pathway, a large protein kinase called RAFT1/FRAP/mTOR (5, 33, 34). Exactly how the rapamycin-FKBP12 complex perturbs the function of RAFT1 is not well understood. Work in yeast, Drosophila, and mammals suggests that the TOR proteins participate in nutrient-sensitive signaling. Treatment of yeast and Drosophila larvae with rapamycin causes a starvation-like phenotype (2,7,17,39), and in mammalian cells, extracellular amino acids regulate the activity of two translational regulators downstream of RAFT1, S6 kinase 1 (S6K1), and 4E-BP1 (15). Recent studies indicate that the levels of ATP and phosphatidic acid may regulate the TOR pathway in mammalian cells (11,13), but the connection to nutrient signaling is not clear.Available evidence indicates that the TOR pathway is ubiquitously expressed in mammalian cell types, and it is not known why rapamycin causes immunosuppression in human beings and other mammals without significantly affecti...

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Section: Resultsmentioning

confidence: 99%

The Immunosuppressant Rapamycin Mimics a Starvation-Like Signal Distinct from Amino Acid and Glucose Deprivation

Peng

Golub

Sabatini

2002

Molecular and Cellular Biology

362

299

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“…Despite the observation of significant pyruvate recycling via the action of malic enzyme, the use of uniformly labeled substrate revealed that glutamine did not significantly contribute to lactate formation, due to its comparatively small uptake rate. This is not a universal finding, as glioblastoma cells were shown to metabolize 60% of glutamine to lactate (DeBerardinis et al, 2007), human diploid fibroblasts about 13% (Zielke et al, 1980) and hybridoma cells approximately 9% (Petch and Butler, 1994). Other than the changes observed in the intracellular flux distribution, one of the key difference between the two clones lies in the reduced specific consumption rate of glucose by the PYC-expressing cells.…”

Section: O Henry Y Durocher / Metabolic Engineering ] (]]]]) ]]]-]mentioning

confidence: 99%

Enhanced glycoprotein production in HEK-293 cells expressing pyruvate carboxylase

Henry

Durocher

2011

Metabolic Engineering

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“…Acetate was extracted from the plasma using the freeze-transferring technique of Pethick et al (1981) and measured by GLC at 120°C (Pethick et al, 1993). One sample was measured in duplicate, standards were added before extraction, and recoveries (1 22 YJ and 1 16 %) were used in the calculations.…”

Section: Measurements Of Metabolites In Plasmamentioning

confidence: 99%

“…This approach results in overestimates of the contributions of particular fuels and pathways to total ATP turnover as the 'total ATP turnover' figure is too low. For example Petch and Butler (1994) and Neermann and Wagner (1996) conclude that the various pathways of glucose and glutamine utilization account for 100% of ATP turnover in various cell lines in the presence of glucose, glutamine and fetal calf serum. Oxygen consumption was not measured and would almost certainly demonstrate the oxidation of other fuels.…”

mentioning

confidence: 99%

Fuel Choices by Human Platelets in Human Plasma

Guppy

Abas

Neylon

et al. 1997

European Journal of Biochemistry

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Despite the fact that homogeneous preparations of isolated cells are now being used very effectively to study a range of important biochemical questions, it is still not known what combination of fuels and energy-producing pathways is used by cells when offered the complex mixture characteristic of plasma or extracellular fluid. We have developed an in vitro system whereby highly purified and functional human platelets are incubated in human plasma that has been minimally modified from its native state. The concentration of platelets and fuels, and the complexity of fuels in the incubation are similar to those in vivo. The preparation thus represents a reasonable approximation of the physiological condition, considering the complex nature of the system being studied. Measurements carried out simultaneously during the incubation are rates of oxygen consumption, lactate production and fuel oxidation. The data allow the calculation of total ATP turnover, and contributions to this turnover by lactate production and the oxidation of individual fuels. Lactate production accounts for 24% of the ATP turnover. The oxidation of glucose and 3-hydroxybutyrate each account for under S%, palmitate for 21 %, oleate for 7% and acetate for 9%, leaving 32% of the ATP turnover as yet unaccounted for. The results confirm some previous measurements in the literature, but show that data collected under non-physiological experimental conditions can be misleading.Keywords: platelet; oxygen consumption ; plasma; glycolysis ; oxidation.The preparations used for the study of cellular metabolism have progressed over the last 40 years from tissue homogenates and slices to homogeneous preparations of isolated cells. The latter systems are now being used very effectively to study a range of important biochemical questions. However, there is still a question that has never really been adequately addressed, which could have important implications for the relevance of these preparations, and which is fundamental to our understanding of cell biology. This question concerns the combination of fuels and energy-producing pathways used by a cell when it is offered the complex mixture characteristic of plasma or extracellular fluid.Where energy budgets have been presented previously, it is often the case that total ATP turnover has been underestimated due to the omission of any measurement of oxygen consumption. This approach results in overestimates of the contributions of particular fuels and pathways to total ATP turnover as the 'total ATP turnover' figure is too low. For example Petch and Butler (1994) and Neermann and Wagner (1996) conclude that the various pathways of glucose and glutamine utilization account for 100% of ATP turnover in various cell lines in the presence of glucose, glutamine and fetal calf serum. Oxygen consumption was not measured and would almost certainly demonstrate the oxidation of other fuels. Similarly it is now obvious that aerobic glycolysis contributes significantly (20 -50%) to ATP production under aerobic conditions...

show abstract

Profile of energy metabolism in a murine hybridoma: Glucose and glutamine utilization

Cited by 66 publications

References 25 publications

The Immunosuppressant Rapamycin Mimics a Starvation-Like Signal Distinct from Amino Acid and Glucose Deprivation

The Immunosuppressant Rapamycin Mimics a Starvation-Like Signal Distinct from Amino Acid and Glucose Deprivation

Enhanced glycoprotein production in HEK-293 cells expressing pyruvate carboxylase

Fuel Choices by Human Platelets in Human Plasma

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