scholarly journals Pyruvate dehydrogenase kinase 1 and 2 deficiency reduces high-fat diet-induced hypertrophic obesity and inhibits the differentiation of preadipocytes into mature adipocytes

2021 ◽  
Author(s):  
Hyeon-Ji Kang ◽  
Byong-Keol Min ◽  
Won-Il Choi ◽  
Jae-Han Jeon ◽  
Dong Wook Kim ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Pyruvate Dehydrogenase ◽  
High Fat Diet ◽  
Critical Role ◽  
Hypoxia Inducible Factor ◽  
Lactate Production ◽  
Human Adipose Tissue ◽  
Pyruvate Dehydrogenase Kinase ◽  
Loss Of Function ◽  
High Fat

AbstractObesity is now recognized as a disease. This study revealed a novel role for pyruvate dehydrogenase kinase (PDK) in diet-induced hypertrophic obesity. Mice with global or adipose tissue-specific PDK2 deficiency were protected against diet-induced obesity. The weight of adipose tissues and the size of adipocytes were reduced. Adipocyte-specific PDK2 deficiency slightly increased insulin sensitivity in HFD-fed mice. In studies with 3T3-L1 preadipocytes, PDK2 and PDK1 expression was strongly increased during adipogenesis. Evidence was found for epigenetic induction of both PDK1 and PDK2. Gain- and loss-of-function studies with 3T3-L1 cells revealed a critical role for PDK1/2 in adipocyte differentiation and lipid accumulation. PDK1/2 induction during differentiation was also accompanied by increased expression of hypoxia-inducible factor-1α (HIF1α) and enhanced lactate production, both of which were absent in the context of PDK1/2 deficiency. Exogenous lactate supplementation increased the stability of HIF1α and promoted adipogenesis. PDK1/2 overexpression-mediated adipogenesis was abolished by HIF1α inhibition, suggesting a role for the PDK-lactate-HIF1α axis during adipogenesis. In human adipose tissue, the expression of PDK1/2 was positively correlated with that of the adipogenic marker PPARγ and inversely correlated with obesity. Similarly, PDK1/2 expression in mouse adipose tissue was decreased by chronic high-fat diet feeding. We conclude that PDK1 and 2 are novel regulators of adipogenesis that play critical roles in obesity.

scholarly journals Helminth infection modulates number and function of adipose tissue Tregs in high fat diet-induced obesity

2021 ◽  
Author(s):  
Camila Queiroz-Glauss ◽  
Mariana Vieira ◽  
Marcela Helena Gonçalves-Pereira ◽  
Stephanie Almeida ◽  
Rachel Freire ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Weight Gain ◽  
High Fat Diet ◽  
Metabolic Diseases ◽  
Experimental Studies ◽  
Treg Cells ◽  
Loss Of Function ◽  
High Fat ◽  
Diet Induced Obesity ◽  
And Function

Background: Epidemiological and experimental studies have shown a protective effect of helminth infections in weight gain and against the development of metabolic dysfunctions in the host. However, the mechanisms induced by the parasite that regulate the development of metabolic diseases in the host are unclear. The present study aimed to verify the influence of Heligmosomoides polygyrus infection in early stages of high fat diet-induced obesity. Principal Findings: The presence of infection was able to prevent exacerbated weight gain in mice fed with high fat diet when compared to non-infected controls. In addition, infected animals displayed improved insulin sensitivity and decreased fat accumulation in the liver. Obesity-associated inflammation was reduced in the presence of infection, demonstrated by higher levels of IL10 and adiponectin, increased infiltration of Th2 and eosinophils in adipose tissue of infected animals. Of note, the parasite infection was associated with increased Treg frequency in adipose tissue which showed higher expression of cell surface markers of function and activation, like LAP and CD134. The infection could also revert the loss of function in Tregs associated with high fat diet. Conclusion: These data suggest that H. polygyrus infection can prevent weight gain and metabolic syndrome in animals fed with high fat diet associated with modulations of adipose tissue Treg cells.

Elevated n-3 fatty acids in a high-fat diet attenuate the increase in PDH kinase activity but not PDH activity in human skeletal muscle

2005 ◽  
Vol 98 (1) ◽  
pp. 350-355 ◽  
Author(s):  
Erin A. Turvey ◽  
George J. F. Heigenhauser ◽  
Michelle Parolin ◽  
Sandra J. Peters
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Pyruvate Dehydrogenase ◽  
High Fat Diet ◽  
Human Skeletal Muscle ◽  
Fat Content ◽  
Pyruvate Dehydrogenase Kinase ◽  
High Fat ◽  
High Fat Diets ◽  
Fat Diets

We tested the hypothesis that a high-fat diet (75% fat; 5% carbohydrates; 20% protein), for which 15% of the fat content was substituted with n-3 fatty acids, would not exhibit the diet-induced increase in pyruvate dehydrogenase kinase (PDK) activity, which is normally observed in human skeletal muscle. The fat content was the same in both the regular high-fat diet (HF) and in the n-3-substituted diet (N3). PDK activity increased after both high-fat diets, but the increase was attenuated after the N3 diet (0.051 ± 0.007 and 0.218 ± 0.047 min−1 for pre- and post-HF, respectively; vs. 0.073 ± 0.016 and 0.133 ± 0.032 min−1 for pre- and post-N3, respectively). However, the active form of pyruvate dehydrogenase (PDHa) activity decreased to a similar extent in both conditions (0.93 ± 0.17 and 0.43 ± 0.09 mmol/kg wet wt pre- and post-HF; vs. 0.87 ± 0.19 and 0.39 ± 0.05 mmol/kg wet wt pre- and post-N3, respectively). This suggested that the difference in PDK activity did not affect PDHa activation in the basal state, and it was regulated by intramitochondrial effectors, primarily muscle pyruvate concentration. Muscle glycogen content was consistent throughout the study, before and after both diet conditions, whereas muscle glucose-6-phosphate, glycerol-3-phosphate, lactate, and pyruvate were decreased after the high-fat diets. Plasma triglycerides decreased after both high-fat diets but decreased to a greater extent after the N3, whereas plasma free fatty acids increased after both diets, but to a lesser extent after the N3. In summary, PDK activity is decreased after a high-fat diet that is rich in n-3 fatty acids, although PDHa activity was unaltered. In addition, our data demonstrated that the hypolipidemic effect of n-3 fatty acids occurs earlier (3 days) than previously reported and is evident even when the diet has 75% of its total energy derived from fat.

scholarly journals PHD2 Is a Regulator for Glycolytic Reprogramming in Macrophages

2016 ◽  
Vol 37 (1) ◽  
Author(s):  
Annemarie Guentsch ◽  
Angelika Beneke ◽  
Lija Swain ◽  
Katja Farhat ◽  
Shunmugam Nagarajan ◽  
...  
Keyword(s):  
Pyruvate Dehydrogenase ◽  
Critical Role ◽  
Hypoxia Inducible Factor ◽  
Pyruvate Dehydrogenase Kinase ◽  
Metabolic Phenotype ◽  
Protein Levels ◽  
Dehydrogenase Enzyme ◽  
Pyruvate Dehydrogenase Kinase 1 ◽  
And Function

ABSTRACT The prolyl-4-hydroxylase domain (PHD) enzymes are regarded as the molecular oxygen sensors. There is an interplay between oxygen availability and cellular metabolism, which in turn has significant effects on the functionality of innate immune cells, such as macrophages. However, if and how PHD enzymes affect macrophage metabolism are enigmatic. We hypothesized that macrophage metabolism and function can be controlled via manipulation of PHD2. We characterized the metabolic phenotypes of PHD2-deficient RAW cells and primary PHD2 knockout bone marrow-derived macrophages (BMDM). Both showed typical features of anaerobic glycolysis, which were paralleled by increased pyruvate dehydrogenase kinase 1 (PDK1) protein levels and a decreased pyruvate dehydrogenase enzyme activity. Metabolic alterations were associated with an impaired cellular functionality. Inhibition of PDK1 or knockout of hypoxia-inducible factor 1α (HIF-1α) reversed the metabolic phenotype and impaired the functionality of the PHD2-deficient RAW cells and BMDM. Taking these results together, we identified a critical role of PHD2 for a reversible glycolytic reprogramming in macrophages with a direct impact on their function. We suggest that PHD2 serves as an adjustable switch to control macrophage behavior.

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 Corrupted adipose tissue endogenous myelopoiesis initiates diet-induced metabolic disease

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Elodie Luche ◽  
Virginie Robert ◽  
Vincent Cuminetti ◽  
Celine Pomié ◽  
Quentin Sastourné-Arrey ◽  
...  
Keyword(s):  
Metabolic Disease ◽  
Adipose Tissue ◽  
Glucose Homeostasis ◽  
High Fat Diet ◽  
Metabolic Diseases ◽  
Loss Of Function ◽  
High Fat ◽  
Hematopoietic Stem ◽  
Promising Therapeutic Target ◽  
Inflammatory Macrophages

Activation and increased numbers of inflammatory macrophages, in adipose tissue (AT) are deleterious in metabolic diseases. Up to now, AT macrophages (ATM) accumulation was considered to be due to blood infiltration or local proliferation, although the presence of resident hematopoietic stem/progenitor cells (Lin-/Sca+/c-Kit+; LSK phenotype) in the AT (AT-LSK) has been reported. By using transplantation of sorted AT-LSK and gain and loss of function studies we show that some of the inflammatory ATM inducing metabolic disease, originate from resident AT-LSK. Transplantation of AT-LSK sorted from high fat diet-fed (HFD) mice is sufficient to induce ATM accumulation, and to transfer metabolic disease in control mice. Conversely, the transplantation of control AT-LSK improves both AT-inflammation and glucose homeostasis in HFD mice. Our results clearly demonstrate that resident AT-LSK are one of the key point of metabolic disease, and could thus constitute a new promising therapeutic target to fight against metabolic disease.

scholarly journals Transcriptional regulation of pyruvate dehydrogenase kinase 4 in skeletal muscle during and after exercise

2004 ◽  
Vol 63 (2) ◽  
pp. 221-226 ◽  
Author(s):  
Henriette Pilegaard ◽  
P. Darrell Neufer
Keyword(s):  
Skeletal Muscle ◽  
Muscle Glycogen ◽  
Pyruvate Dehydrogenase ◽  
High Fat Diet ◽  
Prolonged Exercise ◽  
Pyruvate Dehydrogenase Kinase ◽  
High Fat ◽  
Low Intensity ◽  
Low Intensity Exercise ◽  
The Impact

The pyruvate dehydrogenase complex (PDC) has a key position in skeletal muscle metabolism as it represents the entry of carbohydrate-derived fuel into the mitochondria for oxidation. PDC is regulated by a phosphorylation–dephosphorylation cycle, in which the pyruvate dehydrogenase kinase (PDK) phosphorylates and inactivates the complex. PDK exists in four isoforms, of which the PDK4 isoform is predominantly expressed in skeletal and heart muscle. PDK4 transcription and PDK4 mRNA are markedly increased in human skeletal muscle during prolonged exercise and after both short-term high-intensity and prolonged low-intensity exercise. The exercise-induced transcriptional response of PDK4 is enhanced when muscle glycogen is lowered before the exercise, and intake of a low-carbohydrate high-fat diet during recovery from exercise results in increased transcription and mRNA content of PDK4 when compared with intake of a high-carbohydrate diet. The activity of pyruvate dehydrogenase (PDH) is increased during the first 2 h of low-intensity exercise, followed by a decrease towards resting levels, which is in line with the possibility that the increased PDK4 expressed influences the PDH activity already during prolonged exercise. PDK4 expression is also increased in response to fasting and a high-fat diet. Thus, increased PDK4 expression when carbohydrate availability is low seems to contribute to the sparing of carbohydrates by preventing carbohydrate oxidation. The impact of substrate availability on PDK4 expression during recovery from exercise also underlines the high metabolic priority given to replenishing muscle glycogen stores and re-establishing intracellular homeostasis after exercise.

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