scholarly journals Niche-selective inhibition of pathogenic Th17 cells by targeting metabolic redundancy

2019 ◽  
Author(s):  
Lin Wu ◽  
Kate E.R. Hollinshead ◽  
Yuhan Hao ◽  
Christy Au ◽  
Lina Kroehling ◽  
...  
Keyword(s):  
Mitochondrial Respiration ◽  
Th17 Cells ◽  
Selective Inhibition ◽  
Glycolytic Enzyme ◽  
Pentose Phosphate ◽  
Glucose Phosphate ◽  
Selective Targeting ◽  
Effective Therapeutic Strategy ◽  
Partial Blockade ◽  
Pathway Flux

SummaryTargeting glycolysis has been considered therapeutically intractable owing to its essential housekeeping role. However, the context-dependent requirement for individual glycolytic steps has not been fully explored. We show that CRISPR-mediated targeting of glycolysis in T cells in mice results in global loss of Th17 cells, whereas deficiency of the glycolytic enzyme glucose phosphate isomerase (Gpi1) selectively eliminates inflammatory encephalitogenic and colitogenic Th17 cells, without substantially affecting homeostatic microbiota-specific Th17 cells. In homeostatic Th17 cells, partial blockade of glycolysis upon Gpi1 inactivation was compensated by pentose phosphate pathway flux and increased mitochondrial respiration. In contrast, inflammatory Th17 cells experience a hypoxic microenvironment known to limit mitochondrial respiration, which is incompatible with loss of Gpi1. Our study suggests that inhibiting glycolysis by targeting Gpi1 could be an effective therapeutic strategy with minimum toxicity for Th17-mediated autoimmune diseases, and, more generally, that metabolic redundancies can be exploited for selective targeting of disease processes.

scholarly journals Targeting PFKFB3 alleviates cerebral ischemia-reperfusion injury in mice

2019 ◽  
Author(s):  
Olga Burmistrova ◽  
Ana Olias-Arjona ◽  
Tatiana Eremeeva ◽  
Dmitry Shishov ◽  
Kristina Zakurdaeva ◽  
...  
Keyword(s):  
Ischemia Reperfusion Injury ◽  
Neurological Diseases ◽  
Ischemia Reperfusion ◽  
Selective Inhibition ◽  
Redox Status ◽  
Artery Occlusion ◽  
Glycolytic Enzyme ◽  
Pentose Phosphate ◽  
Redox Stress

The glycolytic rate in neurons is low in order to allow glucose to be metabolized through the pentose-phosphate pathway (PPP), which regenerates NADPH to preserve the glutathione redox status and survival. This is controlled by 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3), the pro-glycolytic enzyme that forms fructose-2,6-bisphosphate, a powerful allosteric activator of 6-phosphofructo-1-kinase. In neurons, PFKFB3 protein is physiologically inactive due to its proteasomal degradation. However, upon an excitotoxic stimuli, PFKFB3 becomes stabilized to activate glycolysis, thus hampering PPP mediated protection of redox status leading to neurode-generation. Here, we show that selective inhibition of PFKFB3 activity in neurons by the small molecule AZ67 prevents the NADPH oxidation, redox stress and apoptotic neuronal death caused by activation of glycolysis upon excitotoxic stimuli. Furthermore, in vivo administration of AZ67 to mice significantly alleviated the motor discoordination and brain infarct injury in the middle carotid artery occlusion ischemia/reperfusion model. These results show that pharmacological inhibition of PFKFB3 is a suitable neuroprotective therapeutic strategy for excitotoxic-related neurological diseases.

scholarly journals Phosphofructokinase deficiency impairs ATP generation, autophagy, and redox balance in rheumatoid arthritis T cells

2013 ◽  
Vol 210 (10) ◽  
pp. 2119-2134 ◽  
Author(s):  
Zhen Yang ◽  
Hiroshi Fujii ◽  
Shalini V. Mohan ◽  
Jorg J. Goronzy ◽  
Cornelia M. Weyand
Keyword(s):  
Rheumatoid Arthritis ◽  
T Cells ◽  
Cd4 T Cells ◽  
Redox Balance ◽  
Glycolytic Enzyme ◽  
Pentose Phosphate ◽  
Glycolytic Flux ◽  
Alternative Means ◽  
Atp Generation ◽  
Phosphofructokinase Deficiency

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.

scholarly journals THE SELECTIVE INHIBITION OF MACROPHAGE PHAGOCYTIC RECEPTORS BY ANTI-MEMBRANE ANTIBODIES

1972 ◽  
Vol 135 (3) ◽  
pp. 458-475 ◽  
Author(s):  
Phillip Holland ◽  
Nancy H Holland ◽  
Zanvil A. Cohn
Keyword(s):  
Plasma Membrane ◽  
Selective Inhibition ◽  
Morphological Evidence ◽  
Igg Antibodies ◽  
High Concentration ◽  
Mouse Macrophages ◽  
Γ Globulins ◽  
Membrane Attachment ◽  
Common Antigens ◽  
Partial Blockade

Rabbit antibodies were prepared against purified mouse macrophages, erythrocytes, and liver lysosomes. In the presence of complement each of these reagents was capable of lysing mouse erythrocytes and macrophages. In the absence of complement, all antisera agglutinated mouse erythrocytes and at high concentration produced a cytotoxic effect on macrophages. At IgG concentrations of 100 µg/ml, no morphological evidence of cytotoxicity was evident. These data suggest the presence of common antigens on the erythrocyte and macrophage plasma membrane. Anti-macrophage, anti-erythrocyte, and anti-lysosomal γ-globulins and IgG, employed at subtoxic concentrations, all inhibited the attachment and ingestion of opsonized erythrocytes and mycoplasma. This occurred without significant reduction in the phagocytosis of polystyrene particles, formalinized erythrocytes, and yeast cell walls. Each of the anti-membrane IgG antibodies was capable of blocking the Fc receptor on the macrophage plasma membrane. Attachment to the macrophage membrane occurred by means of the Fab region. However, a role for the Fc portion of the molecule was suggested since pepsin-digested IgG was unable to block the receptor. Each of the IgG antibodies produced a partial blockade of the complement receptor and reduced the ingestion of EAC1,4,2,3 by approximately 50%.

Genome-wide analysis of Kluyveromyces lactis in wild-type and rag2 mutant strains

Genome ◽  
2004 ◽  
Vol 47 (5) ◽  
pp. 970-978 ◽  
Author(s):  
Manuel Becerra ◽  
Nuria Tarrío ◽  
M Isabel González-Siso ◽  
M Esperanza Cerdán
Keyword(s):  
Kluyveromyces Lactis ◽  
Glycolytic Enzyme ◽  
Pentose Phosphate ◽  
Phosphoglucose Isomerase ◽  
Transcriptional Level ◽  
Dna Arrays ◽  
Gene Coding ◽  
Genome Wide ◽  
Rag2 Gene ◽  
Interesting Alternative

The use of heterologous DNA arrays from Saccharomyces cerevisiae has been tested and revealed as a suitable tool to compare the transcriptomes of S. cerevisiae and Kluyveromyces lactis, two yeasts with notable differences in their respirofermentative metabolism. The arrays have also been applied to study the changes in the K. lactis transcriptome owing to mutation in the RAG2 gene coding for the glycolytic enzyme phosphoglucose isomerase. Comparison of the rag2 mutant growing in 2% glucose versus 2% fructose has been used as a model to elucidate the importance of transcriptional regulation of metabolic routes, which may be used to reoxidize the NADPH produced in the pentose phosphate pathway. At this transcriptional level, routes related to the oxidative stress response become an interesting alternative for NADPH use.Key words: Kluyveromyces lactis, transcription, phosphoglucose isomerase, carbohydrate use.

scholarly journals Death of mouse embryos that lack a functional gene for glucose phosphate isomerase

1990 ◽  
Vol 56 (2-3) ◽  
pp. 223-236 ◽  
Author(s):  
John D. West ◽  
Jean H. Flockhart ◽  
Josephine Peters ◽  
Simon T. Ball
Keyword(s):  
Null Allele ◽  
Phosphoglycerate Kinase ◽  
Maternal Blood ◽  
Pentose Phosphate ◽  
Glucose Phosphate Isomerase ◽  
Lethal Mutant ◽  
Glucose Phosphate ◽  
Extraembryonic Membranes ◽  
Mutant Cells ◽  
Better Than

SummaryA null allele of theGpi-1sstructural gene, that encodes glucose phosphate isomerase (GPI-1;E.C.5.3.1.9), arose in a mutation experiment and was designatedGpi-1sa-m1H. The viability of homozygotes has been investigated. No offspring homozygous for the null allele were produced by intercrossing two heterozygotes, so the homozygous condition was presumed to be embryonic lethal. Embryos were produced by crossingGpi-1sa/null heterozygous females andGpi-1sb/null heterozygous males. Homozygous null embryos were identified at different stages of development by electrophoresis and staining either for GPI-1 alone or GPI-1 plus phosphoglycerate kinase (PGK) activity. At 6½ and 7½ dayspost coitumhomozygous null embryos were present at approximately the expected 25% frequency (37/165; 22·4% overall) although at 7½ days the homozygous null embryos tended to be small. By 8½ days most homozygous null embryos were developmentally retarded and had not developed significantly further than at 7½ days; some were dead or dying. By 9½ days the homozygous null conceptus was characterised by a small implantation site that contained trophoblast and often a small amount of extraembryonic membrane. Surviving trophoblast tissue was also detectable at 10½ days. Previous studies have shown that oocyte-coded GPI-1 persists only until 5½ or 6½ days. Survival of homozygous null embryos to 7½ or 8½ days and survival of certain extraembryonic tissue to 10½ days suggests that the homozygous null condition may not be cell-lethal although it is certainly embryo-lethal. Mutant cells that are deficient in glycolysis may use the pentose phosphate shunt to bypass the block in glycolysis created by the deficiency of glucose phosphate isomerase, and/or might be rescued by the transport, from the maternal blood, of energy sources other than glucose (such as glutamine). Either strategy may only permit slow cell growth that would not be adequate to support normal embryogenesis. Transport of maternal nutrients would be more efficient to the trophoblast and extraembryonic membranes and this may help to explain why these tissues survive for longer than the embryo itself. The morphological similarity between homozygous nulls and androgenetic conceptuses, where the trophoblast also survives better than the embryo, is discussed.

scholarly journals PKM2 promotes Th17 cell differentiation and autoimmune inflammation by fine-tuning STAT3 activation

2020 ◽  
Vol 217 (10) ◽  
Author(s):  
Luis Eduardo Alves Damasceno ◽  
Douglas Silva Prado ◽  
Flavio Protasio Veras ◽  
Miriam M. Fonseca ◽  
Juliana E. Toller-Kawahisa ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Th17 Cell ◽  
Th17 Cells ◽  
Glycolytic Enzyme ◽  
Metabolic Reprogramming ◽  
Fine Tuning ◽  
Autoimmune Inflammation ◽  
Th17 Cell Differentiation ◽  
Key Factor

Th17 cell differentiation and pathogenicity depend on metabolic reprogramming inducing shifts toward glycolysis. Here, we show that the pyruvate kinase M2 (PKM2), a glycolytic enzyme required for cancer cell proliferation and tumor progression, is a key factor mediating Th17 cell differentiation and autoimmune inflammation. We found that PKM2 is highly expressed throughout the differentiation of Th17 cells in vitro and during experimental autoimmune encephalomyelitis (EAE) development. Strikingly, PKM2 is not required for the metabolic reprogramming and proliferative capacity of Th17 cells. However, T cell–specific PKM2 deletion impairs Th17 cell differentiation and ameliorates symptoms of EAE by decreasing Th17 cell–mediated inflammation and demyelination. Mechanistically, PKM2 translocates into the nucleus and interacts with STAT3, enhancing its activation and thereby increasing Th17 cell differentiation. Thus, PKM2 acts as a critical nonmetabolic regulator that fine-tunes Th17 cell differentiation and function in autoimmune-mediated inflammation.

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