scholarly journals Calcium-sensitive pyruvate dehydrogenase phosphatase is required for energy metabolism, growth, differentiation, and infectivity of Trypanosoma cruzi

2018 ◽  
Vol 293 (45) ◽  
pp. 17402-17417 ◽  
Author(s):  
Noelia Lander ◽  
Miguel A. Chiurillo ◽  
Mayara S. Bertolini ◽  
Melissa Storey ◽  
Anibal E. Vercesi ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Trypanosoma Cruzi ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Phosphatase

scholarly journals Starvation and Diabetes Reduce the Amount of Pyruvate Dehydrogenase Phosphatase in Rat Heart and Kidney

Diabetes ◽  
2003 ◽  
Vol 52 (6) ◽  
pp. 1371-1376 ◽  
Author(s):  
B. Huang ◽  
P. Wu ◽  
K. M. Popov ◽  
R. A. Harris
Keyword(s):  
Pyruvate Dehydrogenase ◽  
Rat Heart ◽  
Pyruvate Dehydrogenase Phosphatase

The relationship between human skeletal muscle pyruvate dehydrogenase phosphatase activity and muscle aerobic capacity

2011 ◽  
Vol 111 (2) ◽  
pp. 427-434 ◽  
Author(s):  
Lorenzo K. Love ◽  
Paul J. LeBlanc ◽  
J. Greig Inglis ◽  
Nicolette S. Bradley ◽  
Jon Choptiany ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Content ◽  
Endurance Training ◽  
Aerobic Capacity ◽  
Pyruvate Dehydrogenase ◽  
Human Skeletal Muscle ◽  
Citrate Synthase ◽  
Tricarboxylic Acid Cycle ◽  
Carbohydrate Oxidation ◽  
Pyruvate Dehydrogenase Phosphatase

Pyruvate dehydrogenase (PDH) is a mitochondrial enzyme responsible for regulating the conversion of pyruvate to acetyl-CoA for use in the tricarboxylic acid cycle. PDH is regulated through phosphorylation and inactivation by PDH kinase (PDK) and dephosphorylation and activation by PDH phosphatase (PDP). The effect of endurance training on PDK in humans has been investigated; however, to date no study has examined the effect of endurance training on PDP in humans. Therefore, the purpose of this study was to examine differences in PDP activity and PDP1 protein content in human skeletal muscle across a range of muscle aerobic capacities. This association is important as higher PDP activity and protein content will allow for increased activation of PDH, and carbohydrate oxidation. The main findings of this study were that 1) PDP activity ( r2 = 0.399, P = 0.001) and PDP1 protein expression ( r2 = 0.153, P = 0.039) were positively correlated with citrate synthase (CS) activity as a marker for muscle aerobic capacity; 2) E1α ( r2 = 0.310, P = 0.002) and PDK2 protein ( r2 = 0.229, P =0.012) are positively correlated with muscle CS activity; and 3) although it is the most abundant isoform, PDP1 protein content only explained ∼18% of the variance in PDP activity ( r2 = 0.184, P = 0.033). In addition, PDP1 in combination with E1α explained ∼38% of the variance in PDP activity ( r2 = 0.383, P = 0.005), suggesting that there may be alternative regulatory mechanisms of this enzyme other than protein content. These data suggest that with higher muscle aerobic capacity (CS activity) there is a greater capacity for carbohydrate oxidation (E1α), in concert with higher potential for PDH activation (PDP activity).

scholarly journals Targeting Altered Energy Metabolism in Colorectal Cancer: Oncogenic Reprogramming, the Central Role of the TCA Cycle and Therapeutic Opportunities

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1731 ◽  
Author(s):  
Carina Neitzel ◽  
Philipp Demuth ◽  
Simon Wittmann ◽  
Jörg Fahrer
Keyword(s):  
Colorectal Cancer ◽  
Energy Metabolism ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Tca Cycle ◽  
Dietary Factors ◽  
Pyruvate Dehydrogenase Kinase ◽  
Driver Mutations ◽  
The Tca Cycle

Colorectal cancer (CRC) is among the most frequent cancer entities worldwide. Multiple factors are causally associated with CRC development, such as genetic and epigenetic alterations, inflammatory bowel disease, lifestyle and dietary factors. During malignant transformation, the cellular energy metabolism is reprogrammed in order to promote cancer cell growth and proliferation. In this review, we first describe the main alterations of the energy metabolism found in CRC, revealing the critical impact of oncogenic signaling and driver mutations in key metabolic enzymes. Then, the central role of mitochondria and the tricarboxylic acid (TCA) cycle in this process is highlighted, also considering the metabolic crosstalk between tumor and stromal cells in the tumor microenvironment. The identified cancer-specific metabolic transformations provided new therapeutic targets for the development of small molecule inhibitors. Promising agents are in clinical trials and are directed against enzymes of the TCA cycle, including isocitrate dehydrogenase, pyruvate dehydrogenase kinase, pyruvate dehydrogenase complex (PDC) and α-ketoglutarate dehydrogenase (KGDH). Finally, we focus on the α-lipoic acid derivative CPI-613, an inhibitor of both PDC and KGDH, and delineate its anti-tumor effects for targeted therapy.

scholarly journals Increased pyruvate dehydrogenase activity in skeletal muscle of growth-restricted ovine fetuses

2019 ◽  
Vol 317 (4) ◽  
pp. R513-R520 ◽  
Author(s):  
Alexander L. Pendleton ◽  
Laurel R. Humphreys ◽  
Melissa A. Davis ◽  
Leticia E. Camacho ◽  
Miranda J. Anderson ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Pyruvate Dehydrogenase ◽  
Intrauterine Growth Restriction ◽  
Citrate Synthase ◽  
Pyruvate Dehydrogenase Kinase ◽  
Semitendinosus Muscle ◽  
Fetal Sheep ◽  
Pyruvate Dehydrogenase Phosphatase ◽  
And Control ◽  
Fetal Muscle

Fetal sheep with placental insufficiency-induced intrauterine growth restriction (IUGR) have lower fractional rates of glucose oxidation and greater gluconeogenesis, indicating lactate shuttling between skeletal muscle and liver. Suppression of pyruvate dehydrogenase ( PDH) activity was proposed because of greater pyruvate dehydrogenase kinase (PDK) 4 and PDK1 mRNA concentrations in IUGR muscle. Although PDK1 and PDK4 inhibit PDH activity to reduce pyruvate metabolism, PDH protein concentrations and activity have not been examined in skeletal muscle from IUGR fetuses. Therefore, we evaluated the protein concentrations and activity of PDH and the kinases and phosphatases that regulate PDH phosphorylation status in the semitendinosus muscle from placenta insufficiency-induced IUGR sheep fetuses and control fetuses. Immunoblots were performed for PDH, phosphorylated PDH (E1α), PDK1, PDK4, and pyruvate dehydrogenase phosphatase 1 and 2 (PDP1 and PDP2, respectively). Additionally, the PDH, lactate dehydrogenase (LDH), and citrate synthase (CS) enzymatic activities were measured. Phosphorylated PDH concentrations were 28% lower (P < 0.01) and PDH activity was 67% greater (P < 0.01) in IUGR fetal muscle compared with control. PDK1, PDK4, PDP1, PDP2, and PDH concentrations were not different between groups. CS and LDH activities were also unaffected. Contrary to the previous speculation, PDH activity was greater in skeletal muscle from IUGR fetuses, which parallels lower phosphorylated PDH. Therefore, greater expression of PDK1 and PDK4 mRNA did not translate to greater PDK1 or PDK4 protein concentrations or inhibition of PDH as proposed. Instead, these findings show greater PDH activity in IUGR fetal muscle, which indicates that alternative regulatory mechanisms are responsible for lower pyruvate catabolism.

scholarly journals A comparison of the regulation of pyruvate dehydrogenase in mitochondria from rat brain and liver

1975 ◽  
Vol 150 (3) ◽  
pp. 397-403 ◽  
Author(s):  
R Jope ◽  
J P Blass
Keyword(s):  
Rat Brain ◽  
Dehydrogenase Activity ◽  
Pyruvate Dehydrogenase ◽  
Active Form ◽  
Energy Charge ◽  
Liver Mitochondria ◽  
Brain Mitochondria ◽  
Ruthenium Red ◽  
Rat Brain And Liver ◽  
Pyruvate Dehydrogenase Phosphatase

The total activity of pyruvate dehydrogenase in mitochondria isolated from rat brain and liver was 53.5 and 14.2nmol/min per mg of protein respectively. Pyruvate dehydrogenase in liver mitochondria incubated for 4 min at 37 degrees C with no additions was 30% in the active form and this activity increased with longer incubations until it was completely in the active form after 20 min. Brain mitochondrial pyruvate dehydrogenase activity was initially high and did not increase with addition of Mg2+ plus Ca2+ or partially purified pyruvate dehydrogenase phosphatase or with longer incubations. The proportion of pyruvate dehydrogenase in the active form in both brain and liver mitochondria changed inversely with changes in mitochondrial energy charge, whereas total pyruvate dehydrogenase did not change. The chelators citrate, isocitrate, EDTA, ethanedioxybis(ethylamine)tetra-acetic acid and Ruthenium Red each lowered pyruvate dehydrogenase activity in brain mitochondria, but only citrate and isocitrate did so in liver mitochondria. These chelators did not affect the energy charge of the mitochondria. Mg2+ plus Ca2+ reversed the pyruvate dehydrogenase inactivation in liver, but not brain, mitochondria. The regulation of the activation-inactivation of pyruvate dehydrogenase in mitochondria from rat brain and liver with respect to energy charge is similar and may be at least partially regulated by this parameter, and the effects of chelators differ in the two types of mitochondria.

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