scholarly journals Hereditary Nonspherocytic Hemolysis With Erythrocyte Phosphofructokinase Deficiency

Blood ◽  
1972 ◽  
Vol 39 (3) ◽  
pp. 415-425 ◽  
Author(s):  
Larry Waterbury ◽  
Eugene P. Frenkel
Keyword(s):  
Enzyme Activity ◽  
Adenosine Triphosphate ◽  
Lactate Production ◽  
Kinetic Studies ◽  
Glycogen Storage ◽  
Muscle Disease ◽  
Phosphofructokinase Activity ◽  
Phosphofructokinase Deficiency

Abstract Hereditary nonspherocytic hemolysis associated with abnormal erythrocyte phosphofructokinase activity was demonstrated in a young man. Enzyme activity in the propositus, his mother, and maternal grandmother was approximately 60% of normal controls. There was markedly increased lability of enzyme activity on in vitro storage. Kinetic studies revealed increased sensitivity to adenosine triphosphate inhibition. Erythrocyte adenosine triphosphate levels were depressed. The absence of muscle disease and the presence of normal in vivo lactate production following ischemic exercise differentiated this kindred from those with Type VII glycogen storage disease.

scholarly journals Acute effects of phorbol esters on the protein-synthetic rate and carbohydrate metabolism of normal and mdx mouse muscles

1991 ◽  
Vol 275 (2) ◽  
pp. 477-483 ◽  
Author(s):  
P A MacLennan ◽  
A McArdle ◽  
R H Edwards
Keyword(s):  
Glucose Uptake ◽  
Carbohydrate Metabolism ◽  
Phorbol Esters ◽  
Glycogen Synthesis ◽  
Lactate Production ◽  
Kinetic Studies ◽  
Mdx Mouse ◽  
Mdx Mice

1. mdx mice do not express dystrophin, the product of the gene which is defective in Duchenne and Becker muscular dystrophy. We have previously shown that protein-synthetic rates (ks) are increased in mdx mouse muscles [MacLennan & Edwards (1990) Biochem. J. 268, 795-797]. 2. The tumour-promoting stereoisomer of phorbol 12,13-didecanoate (4 beta-PDD) acutely increased the ks of muscles from mdx and wild-type (C57BL/10) mice incubated in vitro in the absence of insulin. The effects of 4 beta-PDD are presumably mediated by activation of protein kinase C (PKC). 3. The muscle glycogen concentrations of mdx mice were higher than those of C57BL/10 mice. Studies performed in vivo and in vitro suggested that the effect might be at least partially due to increased rate of glycogen synthesis in mdx muscle. 4. 4 beta-PDD increased the glycogen-synthetic rates rates of C57BL/10, but not mdx, muscles incubated in vitro in the absence of insulin. 5. In muscles from both species incubated in the absence of insulin, treatment with 4 beta-PDD also induced increased rates of glucose uptake and lactate production. Kinetic studies of C57BL/10 and mdx muscles suggested that 4 beta-PDD raised the Vmax. of glucose uptake, but did not alter the Km for the process. 6. The possible role of PKC in controlling the protein and carbohydrate metabolism of normal and mdx mouse muscles is discussed.

Insulin secretion in the spiny mouse (Acomys cahirinus). Dose and time kinetic studies with glucose in vivo and in vitro

Diabetes ◽  
1975 ◽  
Vol 24 (12) ◽  
pp. 1094-1100 ◽  
Author(s):  
A. Rabinovitch ◽  
A. Gutzeit ◽  
A. E. Renold ◽  
E. Cerasi
Keyword(s):  
Insulin Secretion ◽  
Kinetic Studies ◽  
Spiny Mouse ◽  
Acomys Cahirinus

scholarly journals Lactate secreted by PKM2 upregulation promotes Galectin-9-mediated immunosuppression via inhibiting NF-κB pathway in HNSCC

2021 ◽  
Vol 12 (8) ◽  
Author(s):  
Hanyue Chang ◽  
Qiaoshi Xu ◽  
Jiayi Li ◽  
Mingyu Li ◽  
Zhiyuan Zhang ◽  
...  
Keyword(s):  
Critical Role ◽  
Lactate Production ◽  
Metabolic Reprogramming ◽  
Migration And Invasion ◽  
Histone Deacetylase 3 ◽  
Proliferation And Metastasis ◽  
Immunosuppressive Microenvironment ◽  
Transcriptional Complex

AbstractPyruvate kinase M2 as a key rate-limiting enzyme in glycolysis, it plays a critical role in metabolic reprogramming and carcinogenesis. However, whether PKM2 can promote immunosuppressive microenvironment formation remains unknown in head and neck squamous cell carcinoma (HNSCC). PKM2 expression was detected using immunohistochemical staining. The biological functions of PKM2 were investigated in vitro and in vivo. Lactate production and the expression of Galectin-9, a critical immunosuppression molecule, were detected after PKM2 knockdown and overexpression in HNSCC cells. The mechanism of lactate regulating Galectin-9 expression through NF-κB signaling was explored in vitro. Overexpression of PKM2 correlates with poor prognosis in HNSCC patients. Silencing PKM2 markedly inhibits proliferation and metastasis capacity in vivo and in vitro, and vice versa. The glycolysis and glycolytic capacity are significantly decreased after PKM2 silencing. Lactate secretion induced by PKM2 significantly promotes migration and invasion capacity. Furthermore, a positive correlation between PKM2 and Galectin-9 expression is observed in HNSCC tissues. The induction of Galectin-9 expression by PKM2 can be affected by a lactate transporter inhibitor. Mechanically, lactate impeded the suppressive transcriptional complex formation of NF-κB and histone deacetylase 3 (HDAC3), which released the transcription of Galectin-9 mediated by NF-κB signaling. Our findings demonstrate that lactate produced by PKM2 upregulation promotes tumor progression and Galectin-9-mediated immunosuppression via NF-κB signaling inhibition in HNSCC, which bridges metabolism and immunosuppression. The novel PKM2-lactate-Galectin-9 axis might be a potential therapeutic target in HNSCC.

Metabolic importance of Na+/K+-ATPase activity during sea urchin development.

1997 ◽  
Vol 200 (22) ◽  
pp. 2881-2892 ◽  
Author(s):  
P Leong ◽  
D Manahan
Keyword(s):  
Enzyme Activity ◽  
Atpase Activity ◽  
Sea Urchin ◽  
Sodium Pump ◽  
Sea Water ◽  
Strongylocentrotus Purpuratus ◽  
Lytechinus Pictus ◽  
Stimulation Of

Early stages of animal development have high mass-specific rates of metabolism. The biochemical processes that establish metabolic rate and how these processes change during development are not understood. In this study, changes in Na+/K+-ATPase activity (the sodium pump) and rate of oxygen consumption were measured during embryonic and early larval development for two species of sea urchin, Strongylocentrotus purpuratus and Lytechinus pictus. Total (in vitro) Na+/K+-ATPase activity increased during development and could potentially account for up to 77 % of larval oxygen consumption in Strongylocentrotus purpuratus (pluteus stage) and 80 % in Lytechinus pictus (prism stage). The critical issue was addressed of what percentage of total enzyme activity is physiologically active in living embryos and larvae and thus what percentage of metabolism is established by the activity of the sodium pump during development. Early developmental stages of sea urchins are ideal for understanding the in vivo metabolic importance of Na+/K+-ATPase because of their small size and high permeability to radioactive tracers (86Rb+) added to sea water. A comparison of total and in vivo Na+/K+-ATPase activities revealed that approximately half of the total activity was utilized in vivo. The remainder represented a functionally active reserve that was subject to regulation, as verified by stimulation of in vivo Na+/K+-ATPase activity in the presence of the ionophore monensin. In the presence of monensin, in vivo Na+/K+-ATPase activities in embryos of S. purpuratus increased to 94 % of the maximum enzyme activity measured in vitro. Stimulation of in vivo Na+/K+-ATPase activity was also observed in the presence of dissolved alanine, presumably due to the requirement to remove the additional intracellular Na+ that was cotransported with alanine from sea water. The metabolic cost of maintaining the ionic balance was found to be high, with this process alone accounting for 40 % of the metabolic rate of sea urchin larvae (based on the measured fraction of total Na+/K+-ATPase that is physiologically active in larvae of S. purpuratus). Ontogenetic changes in pump activity and environmentally induced regulation of reserve Na+/K+-ATPase activity are important factors that determine a major proportion of the metabolic costs of sea urchin development.

scholarly journals Epigenetic control via allosteric regulation of mammalian protein arginine methyltransferases

2017 ◽  
Vol 114 (38) ◽  
pp. 10101-10106 ◽  
Author(s):  
Kanishk Jain ◽  
Cyrus Y. Jin ◽  
Steven G. Clarke
Keyword(s):  
Cancer Metastasis ◽  
Gene Activation ◽  
Kinetic Studies ◽  
Arginine Methylation ◽  
Histone H4 ◽  
Protein Arginine Methyltransferases ◽  
Wide Range ◽  
Substrate Concentrations

Arginine methylation on histones is a central player in epigenetics and in gene activation and repression. Protein arginine methyltransferase (PRMT) activity has been implicated in stem cell pluripotency, cancer metastasis, and tumorigenesis. The expression of one of the nine mammalian PRMTs, PRMT5, affects the levels of symmetric dimethylarginine (SDMA) at Arg-3 on histone H4, leading to the repression of genes which are related to disease progression in lymphoma and leukemia. Another PRMT, PRMT7, also affects SDMA levels at the same site despite its unique monomethylating activity and the lack of any evidence for PRMT7-catalyzed histone H4 Arg-3 methylation. We present evidence that PRMT7-mediated monomethylation of histone H4 Arg-17 regulates PRMT5 activity at Arg-3 in the same protein. We analyzed the kinetics of PRMT5 over a wide range of substrate concentrations. Significantly, we discovered that PRMT5 displays positive cooperativity in vitro, suggesting that this enzyme may be allosterically regulated in vivo as well. Most interestingly, monomethylation at Arg-17 in histone H4 not only raised the general activity of PRMT5 with this substrate, but also ameliorated the low activity of PRMT5 at low substrate concentrations. These kinetic studies suggest a biochemical explanation for the interplay between PRMT5- and PRMT7-mediated methylation of the same substrate at different residues and also suggest a general model for regulation of PRMTs. Elucidating the exact relationship between these two enzymes when they methylate two distinct sites of the same substrate may aid in developing therapeutics aimed at reducing PRMT5/7 activity in cancer and other diseases.

scholarly journals The Rhodococcus opacus PD630 Heparin-Binding Hemagglutinin Homolog TadA Mediates Lipid Body Formation

2010 ◽  
Vol 76 (21) ◽  
pp. 7217-7225 ◽  
Author(s):  
Daniel P. MacEachran ◽  
M. E. Prophete ◽  
A. J. Sinskey
Keyword(s):  
Kinetic Studies ◽  
Lipid Body ◽  
Dry Weight ◽  
Rhodococcus Opacus ◽  
Lipid Bodies ◽  
Heparin Binding ◽  
Tag Biosynthesis ◽  
Tag Accumulation

ABSTRACT Generally, prokaryotes store carbon as polyhydroxyalkanoate, starch, or glycogen. The Gram-positive actinomycete Rhodococcus opacus strain PD630 is noteworthy in that it stores carbon in the form of triacylglycerol (TAG). Several studies have demonstrated that R. opacus PD630 can accumulate up to 76% of its cell dry weight as TAG when grown under nitrogen-limiting conditions. While this process is well studied, the underlying molecular and biochemical mechanisms leading to TAG biosynthesis and subsequent storage are poorly understood. We designed a high-throughput genetic screening to identify genes and their products required for TAG biosynthesis and storage in R. opacus PD630. We identified a gene predicted to encode a putative heparin-binding hemagglutinin homolog, which we have termed tadA (triacylglycerol accumulation deficient), as being important for TAG accumulation. Kinetic studies of TAG accumulation in both the wild-type (WT) and mutant strains demonstrated that the tadA mutant accumulates 30 to 40% less TAG than the parental strain (WT). We observed that lipid bodies formed by the mutant strain were of a different size and shape than those of the WT. Characterization of TadA demonstrated that the protein is capable of binding heparin and of agglutinating purified lipid bodies. Finally, we observed that the TadA protein localizes to lipid bodies in R. opacus PD630 both in vivo and in vitro. Based on these data, we hypothesize that the TadA protein acts to aggregate small lipid bodies, found in cells during early stages of lipid storage, into larger lipid bodies and thus plays a key role in lipid body maturation in R. opacus PD630.

scholarly journals Proton export drives the Warburg Effect

2021 ◽  
Author(s):  
Shonagh Russell ◽  
Liping Xu ◽  
Yoonseok Kam ◽  
Dominique Abrahams ◽  
Bryce Ordway ◽  
...  
Keyword(s):  
Warburg Effect ◽  
Cancer Metabolism ◽  
Aerobic Glycolysis ◽  
Lactate Production ◽  
Glycolytic Enzymes ◽  
Hek293 Cells ◽  
Driver Mutations ◽  
The Warburg Effect

Aggressive cancers commonly ferment glucose to lactic acid at high rates, even in the presence of oxygen. This is known as aerobic glycolysis, or the “Warburg Effect”. It is widely assumed that this is a consequence of the upregulation of glycolytic enzymes. Oncogenic drivers can increase the expression of most proteins in the glycolytic pathway, including the terminal step of exporting H+ equivalents from the cytoplasm. Proton exporters maintain an alkaline cytoplasmic pH, which can enhance all glycolytic enzyme activities, even in the absence of oncogene-related expression changes. Based on this observation, we hypothesized that increased uptake and fermentative metabolism of glucose could be driven by the expulsion of H+ equivalents from the cell. To test this hypothesis, we stably transfected lowly-glycolytic MCF-7, U2-OS, and glycolytic HEK293 cells to express proton exporting systems: either PMA1 (yeast H+-ATPase) or CAIX (carbonic anhydrase 9). The expression of either exporter in vitro enhanced aerobic glycolysis as measured by glucose consumption, lactate production, and extracellular acidification rate. This resulted in an increased intracellular pH, and metabolomic analyses indicated that this was associated with an increased flux of all glycolytic enzymes upstream of pyruvate kinase. These cells also demonstrated increased migratory and invasive phenotypes in vitro, and these were recapitulated in vivo by more aggressive behavior, whereby the acid-producing cells formed higher grade tumors with higher rates of metastases. Neutralizing tumor acidity with oral buffers reduced the metastatic burden. Therefore, cancer cells with increased H+ export increase intracellular alkalization, even without oncogenic driver mutations, and this is sufficient to alter cancer metabolism towards a Warburg phenotype.

scholarly journals TOP1MT deficiency promotes GC invasion and migration via the enhancements of LDHA expression and aerobic glycolysis

2017 ◽  
Vol 24 (11) ◽  
pp. 565-578 ◽  
Author(s):  
Hongqiang Wang ◽  
Rui Zhou ◽  
Li Sun ◽  
Jianling Xia ◽  
Xuchun Yang ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Topoisomerase I ◽  
Target Genes ◽  
Aerobic Glycolysis ◽  
Lactate Production ◽  
Migration And Invasion ◽  
Glucose Transporter 1 ◽  
Mesenchymal Transition

Aerobic glycolysis plays an important role in cancer progression. New target genes regulating cancer aerobic glycolysis must be explored to improve patient prognosis. Mitochondrial topoisomerase I (TOP1MT) deficiency suppresses glucose oxidative metabolism but enhances glycolysis in normal cells. Here, we examined the role of TOP1MT in gastric cancer (GC) and attempted to determine the underlying mechanism. Using in vitro and in vivo experiments and analyzing the clinicopathological characteristics of patients with GC, we found that TOP1MT expression was lower in GC samples than in adjacent nonmalignant tissues. TOP1MT knockdown significantly promoted GC migration and invasion in vitro and in vivo. Importantly, TOP1MT silencing increased glucose consumption, lactate production, glucose transporter 1 expression and the epithelial-mesenchymal transition (EMT) in GC. Additionally, regulation of glucose metabolism induced by TOP1MT was significantly associated with lactate dehydrogenase A (LDHA) expression. A retrospective analysis of clinical data from 295 patients with GC demonstrated that low TOP1MT expression was associated with lymph node metastasis, recurrence and high mortality rates. TOP1MT deficiency enhanced glucose aerobic glycolysis by stimulating LDHA to promote GC progression.

scholarly journals Induction of Host Chemotactic Response by Encephalitozoon spp.

2006 ◽  
Vol 75 (4) ◽  
pp. 1619-1625 ◽  
Author(s):  
Jeffrey Fischer ◽  
Jeffrey West ◽  
Nnenaya Agochukwu ◽  
Colby Suire ◽  
Hollie Hale-Donze
Keyword(s):  
Inflammatory Responses ◽  
Kinetic Studies ◽  
Protein Profiling ◽  
Diagnostic Tools ◽  
Emerging Pathogens ◽  
Chemokine Production ◽  
Human Macrophages ◽  
Monocyte Migration

ABSTRACT Microsporidians are a group of emerging pathogens typically associated with chronic diarrhea in immunocompromised individuals. The number of reports of infections with these organisms and the disseminated pathology is growing as diagnostic tools become more readily available. However, little is known about the innate immune response induced by and generated against these parasites. Using a coculture chemotaxis system, primary human macrophages were infected with Encephalitozoon cuniculi or Encephalitozoon intestinalis, and the recruitment of naïve monocytes was monitored. Encephalitozoon spp. induced an average threefold increase in migration of naïve cells 48 h postinfection, which corresponded to optimal infection of monocyte-derived-macrophages. A limited microarray analysis of infected macrophages revealed several chemokines involved in the inflammatory responses whose expression was upregulated, including CCL1, CCL2, CCL3, CCL4, CCL7, CCL15, CCL20, CXCL1, CXCL2, CXCL3, CXCL5, and CXCL8. The levels of 6 of 11 chemokines also present in the microarray were confirmed to be elevated by protein profiling. Kinetic studies confirmed that secreted CCL2, CCL3, and CCL4 were expressed as early as 6 h postinfection, with peak expression at 12 to 24 h and expression remaining until 48 h postinfection. Neutralization of these chemokines, specifically CCL4, significantly reduced the number of migrating cells in vitro, indicating their role in the induction of monocyte migration. This mechanism of recruitment not only supports the evidence that in vivo cellular infiltration occurs but also provides new hosts for the parasites, which escape macrophages by rupturing the host cell. To our knowledge, this is the first documentation that chemokine production is induced by microsporidian infections in human macrophages.

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