scholarly journals Activating cardiac E2F1 induces up-regulation of pyruvate dehydrogenase kinase 4 in mice on a short term of high fat feeding

FEBS Letters ◽  
2012 ◽  
Vol 586 (7) ◽  
pp. 996-1003 ◽  
Author(s):  
Liyan Zhang ◽  
Jun Mori ◽  
Cory Wagg ◽  
Gary D. Lopaschuk
Keyword(s):  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Kinase ◽  
High Fat ◽  
Short Term ◽  
Pyruvate Dehydrogenase Kinase 4 ◽  
Fat Feeding

scholarly journals Coenzyme A–mediated degradation of pyruvate dehydrogenase kinase 4 promotes cardiac metabolic flexibility after high-fat feeding in mice

2018 ◽  
Vol 293 (18) ◽  
pp. 6915-6924 ◽  
Author(s):  
Christopher Schafer ◽  
Zachary T. Young ◽  
Catherine A. Makarewich ◽  
Abdallah Elnwasany ◽  
Caroline Kinter ◽  
...  
Keyword(s):  
Pyruvate Dehydrogenase ◽  
Coenzyme A ◽  
Pyruvate Dehydrogenase Kinase ◽  
Metabolic Flexibility ◽  
High Fat ◽  
Pyruvate Dehydrogenase Kinase 4 ◽  
Fat Feeding

scholarly journals Pyruvate dehydrogenase kinase-4 deficiency lowers blood glucose and improves glucose tolerance in diet-induced obese mice

2008 ◽  
Vol 295 (1) ◽  
pp. E46-E54 ◽  
Author(s):  
Nam Ho Jeoung ◽  
Robert A. Harris
Keyword(s):  
Skeletal Muscle ◽  
Blood Glucose ◽  
Glucose Tolerance ◽  
Pyruvate Dehydrogenase ◽  
High Fat Diet ◽  
Pyruvate Dehydrogenase Kinase ◽  
Wild Type ◽  
High Fat ◽  
Pyruvate Dehydrogenase Kinase 4 ◽  
Liver And Kidney

The effect of pyruvate dehydrogenase kinase-4 (PDK4) deficiency on glucose homeostasis was studied in mice fed a high-fat diet. Expression of PDK4 was greatly increased in skeletal muscle and diaphragm but not liver and kidney of wild-type mice fed the high-fat diet. Wild-type and PDK4−/− mice consumed similar amounts of the diet and became equally obese. Insulin resistance developed in both groups. Nevertheless, fasting blood glucose levels were lower, glucose tolerance was slightly improved, and insulin sensitivity was slightly greater in the PDK4−/− mice compared with wild-type mice. When the mice were killed in the fed state, the actual activity of the pyruvate dehydrogenase complex (PDC) was higher in the skeletal muscle and diaphragm but not in the liver and kidney of PDK4−/− mice compared with wild-type mice. When the mice were killed after overnight fasting, the actual PDC activity was higher only in the kidney of PDK4−/− mice compared with wild-type mice. The concentrations of gluconeogenic substrates were lower in the blood of PDK4−/− mice compared with wild-type mice, consistent with reduced formation in peripheral tissues. Diaphragms isolated from PDK4−/− mice oxidized glucose faster and fatty acids slower than diaphragms from wild-type mice. Fatty acid oxidation inhibited glucose oxidation by diaphragms from wild-type but not PDK4−/− mice. NEFA, ketone bodies, and branched-chain amino acids were elevated more in PDK4−/− mice, consistent with slower rates of oxidation. These findings show that PDK4 deficiency lowers blood glucose and slightly improves glucose tolerance and insulin sensitivity in mice with diet-induced obesity.

scholarly journals Investigation of potential mechanisms regulating protein expression of hepatic pyruvate dehydrogenase kinase isoforms 2 and 4 by fatty acids and thyroid hormone

2003 ◽  
Vol 369 (3) ◽  
pp. 687-695 ◽  
Author(s):  
Mark J. HOLNESS ◽  
Karen BULMER ◽  
Nicholas D. SMITH ◽  
Mary C. SUGDEN
Keyword(s):  
Thyroid Hormone ◽  
Protein Expression ◽  
Pyruvate Dehydrogenase ◽  
Hormone Receptors ◽  
Pyruvate Dehydrogenase Complex ◽  
Pyruvate Dehydrogenase Kinase ◽  
Peroxisome Proliferator ◽  
High Fat ◽  
Cpt I ◽  
Fat Feeding

Liver contains two pyruvate dehydrogenase kinases (PDKs), namely PDK2 and PDK4, which regulate glucose oxidation through inhibitory phosphorylation of the pyruvate dehydrogenase complex (PDC). Starvation increases hepatic PDK2 and PDK4 protein expression, the latter occurring, in part, via a mechanism involving peroxisome proliferator-activated receptor-α (PPARα). High-fat feeding and hyperthyroidism, which increase circulating lipid supply, enhance hepatic PDK2 protein expression, but these increases are insufficient to account for observed increases in hepatic PDK activity. Enhanced expression of PDK4, but not PDK2, occurs in part via a mechanism involving PPAR-α. Heterodimerization partners for retinoid X receptors (RXRs) include PPARα and thyroid-hormone receptors (TRs). We therefore investigated the responses of hepatic PDK protein expression to high-fat feeding and hyperthyroidism in relation to hepatic lipid delivery and disposal. High-fat feeding increased hepatic PDK2, but not PDK4, protein expression whereas hyperthyroidism increased both hepatic PDK2 and PDK4 protein expression. Both manipulations decreased the sensitivity of hepatic carnitine palmitoyltransferase I (CPT I) to suppression by malonyl-CoA, but only hyperthyrodism elevated plasma fatty acid and ketone-body concentrations and CPT I maximal activity. Administration of the selective PPAR-α activator WY14,643 significantly increased PDK4 protein to a similar extent in both control and high-fat-fed rats, but WY14,643 treatment and hyperthyroidism did not have additive effects on hepatic PDK4 protein expression. PPARα activation did not influence hepatic PDK2 protein expression in euthyroid rats, suggesting that up-regulation of PDK2 by hyperthyroidism does not involve PPARα, but attenuated the effect of hyperthyroidism to increase hepatic PDK2 expression. The results indicate that hepatic PDK4 up-regulation can be achieved by heterodimerization of either PPARα or TR with the RXR receptor and that effects of PPARα activation on hepatic PDK2 and PDK4 expression favour a switch towards preferential expression of PDK4.

scholarly journals High-Fat/Low-Carbohydrate Diet Reduces Insulin-Stimulated Carbohydrate Oxidation but Stimulates Nonoxidative Glucose Disposal in Humans: An Important Role for Skeletal Muscle Pyruvate Dehydrogenase Kinase 4

2007 ◽  
Vol 92 (1) ◽  
pp. 284-292 ◽  
Author(s):  
K. Chokkalingam ◽  
K. Jewell ◽  
L. Norton ◽  
J. Littlewood ◽  
L. J. C. van Loon ◽  
...  
Keyword(s):  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Glycogen Storage ◽  
Pyruvate Dehydrogenase Kinase ◽  
Whole Body ◽  
Glucose Disposal ◽  
High Fat ◽  
Complex Activity ◽  
Pyruvate Dehydrogenase Kinase 4 ◽  
Low Carbohydrate

Abstract Aim: The aim of this report was to study the effect of high-fat (HF)/low-carbohydrate (CHO) diet on regulation of substrate metabolism in humans. Methods: Ten healthy men consumed either a HF (75% energy as fat) or control (35%) diet for 6 d in random order. On d 7, blood glucose disappearance rate (Rd) was determined before and during a hyperinsulinemic euglycemic clamp. Substrate oxidation was determined by indirect calorimetry. Muscle biopsies were obtained prediet, postdiet, and postclamps. Results: Rd was similar under basal conditions but slightly elevated (∼10%, P < 0.05) during the last 30 min of the clamp after the HF diet. HF diet reduced CHO oxidation under basal (by ∼40%, P < 0.05) and clamp conditions (by ∼20%, P < 0.05), increased insulin-mediated whole-body nonoxidative glucose disposal (by 30%, P < 0.05) and muscle glycogen storage (by ∼25%, P < 0.05). Muscle pyruvate dehydrogenase complex activity was blunted under basal and clamp conditions after HF compared with control (P < 0.05) and was accompanied by an approximately 2-fold increase (P < 0.05) in pyruvate dehydrogenase kinase 4 (PDK4) mRNA and protein expression. Conclusion: Short-term HF/low-CHO dietary intake did not induce whole-body insulin resistance, but caused a shift in im glucose metabolism from oxidation to glycogen storage. Insulin-stimulated CHO oxidation and muscle pyruvate dehydrogenase complex activity were blunted after the HF diet. Up-regulation of muscle PDK4 expression was an early molecular adaptation to these changes, and we showed for the first time in healthy humans, unlike insulin-resistant individuals, that insulin can suppress PDK4 but not PDK2 gene expression in skeletal muscle.

Long-term regulation of pyruvate dehydrogenase kinase by high-fat feeding

FEBS Letters ◽  
1993 ◽  
Vol 336 (3) ◽  
pp. 501-505 ◽  
Author(s):  
Karen A. Orfali ◽  
Lee G.D. Fryer ◽  
Mark J. Holness ◽  
Mary C. Sugden
Keyword(s):  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Kinase ◽  
High Fat ◽  
Fat Feeding

scholarly journals Activation of Liver X Receptor Regulates Substrate Oxidation in White Adipocytes

Endocrinology ◽  
2009 ◽  
Vol 150 (9) ◽  
pp. 4104-4113 ◽  
Author(s):  
Britta M. Stenson ◽  
Mikael Rydén ◽  
Knut R. Steffensen ◽  
Kerstin Wåhlén ◽  
Amanda T. Pettersson ◽  
...  
Keyword(s):  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Substrate Oxidation ◽  
Pyruvate Dehydrogenase Kinase ◽  
Tissue Mass ◽  
Metabolic Complications ◽  
Pyruvate Dehydrogenase Kinase 4 ◽  
White Adipocytes ◽  
X Receptors

Abstract Liver X receptors (LXRs) are nuclear receptors with established roles in cholesterol, lipid, and carbohydrate metabolism, although their function in adipocytes is not well characterized. Increased adipose tissue mass in obesity is associated with increased adipocyte lipolysis. Fatty acids (FA) generated by lipolysis can be oxidized by mitochondrial β-oxidation, reesterified, or released from the adipocyte. The latter results in higher circulating levels of free FAs, in turn causing obesity-related metabolic complications. However, mitochondrial β-oxidation can at least in part counteract an increased output of FA into circulation. In this study, we provide evidence that activation of LXRs up-regulates mitochondrial β-oxidation in both human and murine white adipocytes. We also show that the expression of a kinase regulating the cellular fuel switch, pyruvate dehydrogenase kinase 4 (PDK4), is up-regulated by the LXR agonist GW3965 in both in vitro differentiated human primary adipocytes and differentiated murine 3T3-L1 cells. Moreover, activation of LXR causes PDK4-dependent phosphorylation of the pyruvate dehydrogenase complex, thereby decreasing its activity and attenuating glucose oxidation. The specificity of the GW3965 effect on oxidation was confirmed by RNA interference targeting LXRs. We propose that LXR has an important role in the regulation of substrate oxidation and the switch between lipids and carbohydrates as cellular fuel in both human and murine white adipocytes.

scholarly journals Transforming Growth Factor β Mediates Drug Resistance by Regulating the Expression of Pyruvate Dehydrogenase Kinase 4 in Colorectal Cancer

2016 ◽  
Vol 291 (33) ◽  
pp. 17405-17416 ◽  
Author(s):  
Yang Zhang ◽  
Yi Zhang ◽  
Liying Geng ◽  
Haowei Yi ◽  
Wei Huo ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Drug Resistance ◽  
Cancer Cells ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Kinase ◽  
Dependent Manner ◽  
Colon Cancer Cells ◽  
Pyruvate Dehydrogenase Kinase 4 ◽  
Mouse Xenograft Model

Drug resistance is one of the main causes of colon cancer recurrence. However, our understanding of the underlying mechanisms and availability of therapeutic options remains limited. Here we show that expression of pyruvate dehydrogenase kinase 4 (PDK4) is positively correlated with drug resistance of colon cancer cells and induced by 5-fluorouracil (5-FU) treatment in drug-resistant but not drug-sensitive cells. Knockdown of PDK4 expression sensitizes colon cancer cells to 5-FU or oxaliplatin-induced apoptosis in vitro and increases the effectiveness of 5-FU in the inhibition of tumor growth in a mouse xenograft model in vivo. In addition, we demonstrate for the first time that TGFβ mediates drug resistance by regulating PDK4 expression and that 5-FU induces PDK4 expression in a TGFβ signaling-dependent manner. Mechanistically, knockdown or inhibition of PDK4 significantly increases the inhibitory effect of 5-FU on expression of the anti-apoptotic factors Bcl-2 and survivin. Importantly, studies of patient samples indicate that expression of PDK4 and phosphorylation of Smad2, an indicator of TGFβ pathway activation, show a strong correlation and that both positively associate with chemoresistance in colorectal cancer. These findings indicate that the TGFβ/PDK4 signaling axis plays an important role in the response of colorectal cancer to chemotherapy. A major implication of our studies is that inhibition of PDK4 may have considerable therapeutic potential to overcome drug resistance in colorectal cancer patients, which warrants the development of PDK4-specific inhibitors.

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