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Vermijlen D, Braun MY, Marchant A. Do PI3-kinase mutations drive T cells insane? Cell Mol Immunol 2014; 11:320-2. [PMID: 24583713 DOI: 10.1038/cmi.2014.11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 02/02/2014] [Indexed: 01/11/2023] Open
Affiliation(s)
- David Vermijlen
- Institute of Pharmacy, Université Libre de Bruxelles (ULB), Belgium
| | - Michel Y Braun
- Institute for Medical Immunology, Université Libre de Bruxelles (ULB), Belgium
| | - Arnaud Marchant
- Institute for Medical Immunology, Université Libre de Bruxelles (ULB), Belgium
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Tsuchiya A, Kanno T, Nishizaki T. PI3 kinase directly phosphorylates Akt1/2 at Ser473/474 in the insulin signal transduction pathway. J Endocrinol 2014; 220:49-59. [PMID: 24169049 PMCID: PMC3842210 DOI: 10.1530/joe-13-0172] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Insulin stimulated translocation of the glucose transporter GLUT4 from the cytosol to the plasma membrane in a concentration (1 nM-1 μM)-dependent manner and increased glucose uptake in 3T3-L1 adipocytes. Insulin-induced GLUT4 translocation to the cell surface was prevented by the phosphoinositide 3 kinase (PI3K) inhibitor wortmannin, the 3-phosphoinositide-dependent protein kinase 1 (PDK1) inhibitor BX912 or the Akt1/2 inhibitor MK2206, and by knocking-down PI3K, PDK1 or Akt1/2. Insulin increased phosphorylation of Akt1/2 at Thr308/309 and Ser473/474, to activate Akt1/2, in the adipocytes. Insulin-induced phosphorylation of Akt1/2 was suppressed by wortmannin and knocking-down PI3K, while no significant inhibition of the phosphorylation was obtained with BX912 or knocking-down PDK1. In the cell-free Akt assay, PI3K phosphorylated Akt1 both at Thr308 and Ser473 and Akt2 at Ser474 alone. In contrast, PDK1 phosphorylates Akt1 at Thr308 and Akt2 at Thr309. The results of this study indicate that PI3K activates Akt1, independently of PDK1, and Akt2 by cooperating with PDK1 in the insulin signal transduction pathway linked to GLUT4 translocation.
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Affiliation(s)
| | | | - T Nishizaki
- Correspondence should be addressed to T Nishizaki;
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Yang Z, Fujii H, Mohan SV, Goronzy JJ, Weyand CM. Phosphofructokinase deficiency impairs ATP generation, autophagy, and redox balance in rheumatoid arthritis T cells. ACTA ACUST UNITED AC 2013; 210:2119-34. [PMID: 24043759 PMCID: PMC3782046 DOI: 10.1084/jem.20130252] [Citation(s) in RCA: 248] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
In the HLA class II-associated autoimmune syndrome rheumatoid arthritis (RA), CD4 T cells are critical drivers of pathogenic immunity. We have explored the metabolic activity of RA T cells and its impact on cellular function and fate. Naive CD4 T cells from RA patients failed to metabolize equal amounts of glucose as age-matched control cells, generated less intracellular ATP, and were apoptosis-susceptible. The defect was attributed to insufficient induction of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), a regulatory and rate-limiting glycolytic enzyme known to cause the Warburg effect. Forced overexpression of PFKFB3 in RA T cells restored glycolytic flux and protected cells from excessive apoptosis. Hypoglycolytic RA T cells diverted glucose toward the pentose phosphate pathway, generated more NADPH, and consumed intracellular reactive oxygen species (ROS). PFKFB3 deficiency also constrained the ability of RA T cells to resort to autophagy as an alternative means to provide energy and biosynthetic precursor molecules. PFKFB3 silencing and overexpression identified a novel extraglycolytic role of the enzyme in autophagy regulation. In essence, T cells in RA patients, even those in a naive state, are metabolically reprogrammed with insufficient up-regulation of the glycolytic activator PFKFB3, rendering them energy-deprived, ROS- and autophagy-deficient, apoptosis-sensitive, and prone to undergo senescence.
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Affiliation(s)
- Zhen Yang
- Division of Immunology & Rheumatology, Stanford University School of Medicine, Stanford, CA 94305
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Beyoğlu D, Imbeaud S, Maurhofer O, Bioulac-Sage P, Zucman-Rossi J, Dufour JF, Idle JR. Tissue metabolomics of hepatocellular carcinoma: tumor energy metabolism and the role of transcriptomic classification. Hepatology 2013; 58:229-38. [PMID: 23463346 PMCID: PMC3695036 DOI: 10.1002/hep.26350] [Citation(s) in RCA: 165] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 02/19/2013] [Indexed: 12/12/2022]
Abstract
UNLABELLED Hepatocellular carcinoma (HCC) is one of the commonest causes of death from cancer. A plethora of metabolomic investigations of HCC have yielded molecules in biofluids that are both up- and down-regulated but no real consensus has emerged regarding exploitable biomarkers for early detection of HCC. We report here a different approach, a combined transcriptomics and metabolomics study of energy metabolism in HCC. A panel of 31 pairs of HCC tumors and corresponding nontumor liver tissues from the same patients was investigated by gas chromatography-mass spectrometry (GCMS)-based metabolomics. HCC was characterized by ∼2-fold depletion of glucose, glycerol 3- and 2-phosphate, malate, alanine, myo-inositol, and linoleic acid. Data are consistent with a metabolic remodeling involving a 4-fold increase in glycolysis over mitochondrial oxidative phosphorylation. A second panel of 59 HCC that had been typed by transcriptomics and classified in G1 to G6 subgroups was also subjected to GCMS tissue metabolomics. No differences in glucose, lactate, alanine, glycerol 3-phosphate, malate, myo-inositol, or stearic acid tissue concentrations were found, suggesting that the Wnt/β-catenin pathway activated by CTNNB1 mutation in subgroups G5 and G6 did not exhibit specific metabolic remodeling. However, subgroup G1 had markedly reduced tissue concentrations of 1-stearoylglycerol, 1-palmitoylglycerol, and palmitic acid, suggesting that the high serum α-fetoprotein phenotype of G1, associated with the known overexpression of lipid catabolic enzymes, could be detected through metabolomics as increased lipid catabolism. CONCLUSION Tissue metabolomics yielded precise biochemical information regarding HCC tumor metabolic remodeling from mitochondrial oxidation to aerobic glycolysis and the impact of molecular subtypes on this process.
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Affiliation(s)
- Diren Beyoğlu
- Hepatology Research Group, Department of Clinical Research, University of Bern, Switzerland
| | - Sandrine Imbeaud
- Inserm, UMR-674, Génomiquefonctionnelle des tumeurssolides, IUH, Paris, F-75010 France,Université Paris Descartes, LabexImmuno-oncology, Sorbonne Paris Cité, Faculté de Médecine, Assistance Publique-Hôpitaux de Paris, France
| | - Olivier Maurhofer
- Hepatology Research Group, Department of Clinical Research, University of Bern, Switzerland
| | - Paulette Bioulac-Sage
- Inserm, UMR-1053; Université Victor Segalen Bordeaux 2, Bordeaux, F-33076, France,CHU de Bordeaux, Pellegrin Hospital, Department of Pathology, Bordeaux, F-33076, France
| | - Jessica Zucman-Rossi
- Inserm, UMR-674, Génomiquefonctionnelle des tumeurssolides, IUH, Paris, F-75010 France,Université Paris Descartes, LabexImmuno-oncology, Sorbonne Paris Cité, Faculté de Médecine, Assistance Publique-Hôpitaux de Paris, France
| | - Jean-François Dufour
- Hepatology Research Group, Department of Clinical Research, University of Bern, Switzerland
| | - Jeffrey R. Idle
- Hepatology Research Group, Department of Clinical Research, University of Bern, Switzerland
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Kim EH, Suresh M. Role of PI3K/Akt signaling in memory CD8 T cell differentiation. Front Immunol 2013; 4:20. [PMID: 23378844 PMCID: PMC3561661 DOI: 10.3389/fimmu.2013.00020] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 01/10/2013] [Indexed: 11/13/2022] Open
Abstract
The clonal expansion, differentiation into effectors and establishing an immunological memory are crucial components of the adaptive immune response. Following the initial encounter with a pathogen, clonal CD8 T cell expansion yields at least two distinct populations of effector cells, short-lived effector cells (SLECs) and memory precursor effector cells (MPECs). SLECs are the terminally differentiated cells, which play an active role in pathogen clearance and undergo apoptosis once the pathogen is eliminated. In contrast, MPECs persist and give rise to self-renewing memory cells. These memory CD8 T cells maintain a state of heightened alertness and are poised to rapidly respond and swiftly clear the pathogen upon antigen re-encounter. As one of the goals of vaccination is to induce the development of these memory CD8 T cells, understanding the cellular and molecular basis of memory cell differentiation is critical to rational vaccine design. It is clear that memory differentiation is complex and involves multiple interrelated signaling pathways. It is influenced by factors such as the strength and duration of antigen receptor signaling and concurrent exposure to cytokines. Several signaling pathways that influence T cell fate have been recently described, and many culminate in the differential expression of specific transcription factors. Unfortunately, the mechanisms underlying the coordination and confluence of these signaling pathways remain largely unknown. In this review, we will discuss the role of the phosphatidylinositol 3-kinase signaling pathway as a central signaling node, and the function of Akt as a rheostat in orchestrating the differentiation of memory CD8 T cells.
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Affiliation(s)
- Eui Ho Kim
- Department of Pathobiological Sciences, University of Wisconsin-Madison Madison, WI, USA
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Total ginsenosides of Radix Ginseng modulates tricarboxylic acid cycle protein expression to enhance cardiac energy metabolism in ischemic rat heart tissues. Molecules 2012; 17:12746-57. [PMID: 23108293 PMCID: PMC6268387 DOI: 10.3390/molecules171112746] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 10/08/2012] [Accepted: 10/24/2012] [Indexed: 11/17/2022] Open
Abstract
To elucidate the underlying mechanism of cardio-protective activity of the total ginsenosides (TGS) of Radix Ginseng, proteomic analysis using two-dimensional gel electrophoresis (2-DE) and MALDI-TOF-TOF-MS techniques was employed for identifying the underlying targets of TGS on improvement of the energy metabolism of isolated rat heart tissues perfused in Langendorff system under ischemia-reperfusion injury conditions. The image analysis results revealed 11 differentially expressed proteins in the TGS-treated heart tissues; these proteins, including LDHB and ODP-2, were found to be closely related to the function of tricarboxylic acid (TCA) cycle that plays pivotal roles in cardiac energy metabolism. It is thus concluded that improvement of cardiac energy metabolism via activating proteins in TCA cycle could be the major action pathway and targets of TGS activity against rat heart tissue injury.
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