scholarly journals Role of TRIB3 in regulation of insulin sensitivity and nutrient metabolism during short-term fasting and nutrient excess

2012 ◽  
Vol 303 (7) ◽  
pp. E908-E916 ◽  
Author(s):  
Jiarong Liu ◽  
Wei Zhang ◽  
Gin C. Chuang ◽  
Helliner S. Hill ◽  
Ling Tian ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Consumption ◽  
Insulin Sensitivity ◽  
Glucose Uptake ◽  
Glucose Transport ◽  
Oxygen Consumption Rate ◽  
Glucose Oxidation ◽  
Consumption Rate ◽  
Negative Regulator ◽  
Short Term

We have suggested previously that Tribbles homolog 3 (TRIB3), a negative regulator of Akt activity in insulin-sensitive tissues, could mediate glucose-induced insulin resistance in muscle under conditions of chronic hyperglycemia (Liu J, Wu X, Franklin JL, Messina JL, Hill HS, Moellering DR, Walton RG, Martin M, Garvey WT. Am J Physiol Endocrinol Metab 298: E565–E576, 2010). In the current study, we have assessed short-term physiological regulation of TRIB3 in skeletal muscle and adipose tissues by nutrient excess and fasting as well as TRIB3's ability to modulate glucose transport and mitochondrial oxidation. In Sprague-Dawley rats, we found that short-term fasting enhanced insulin sensitivity concomitantly with decrements in TRIB3 mRNA (66%, P < 0.05) and protein (81%, P < 0.05) in muscle and increments in TRIB3 mRNA (96%, P < 0.05) and protein (∼10-fold, P < 0.05) in adipose tissue compared with nonfasted controls. On the other hand, rats fed a Western diet for 7 days became insulin resistant concomitantly with increments in TRIB3 mRNA (155%, P < 0.05) and protein (69%, P = 0.0567) in muscle and a decrease in the mRNA (76%, P < 0.05) and protein (70%, P < 0.05) in adipose. In glucose transport and mitochondria oxidation studies using skeletal muscle cells, we found that stable TRIB3 overexpression impaired insulin-stimulated glucose uptake without affecting basal glucose transport and increased both basal glucose oxidation and the maximal uncoupled oxygen consumption rate. With stable knockdown of TRIB3, basal and insulin-stimulated glucose transport rates were increased, whereas basal glucose oxidation and the maximal uncoupled oxygen consumption rate were decreased. In conclusion, TRIB3 impacts glucose uptake and oxidation oppositely in muscle and fat according to levels of nutrient availability. The above data for the first time implicate TRIB3 as a potent physiological regulator of insulin sensitivity and mitochondrial glucose oxidation under conditions of nutrient deprivation and excess.

Metabolic Physiology of Euthermic and Torpid Honey Possums, Tarsipes-Rostratus

1989 ◽  
Vol 37 (6) ◽  
pp. 685 ◽  
Author(s):  
PC Withers ◽  
KC Richardson ◽  
RD Wooller
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Thermal Conductance ◽  
Short Term ◽  
Apparent Absence ◽  
Metabolic Physiology ◽  
Fat Stores ◽  
Torpor Bouts

Euthermic honey possums have a higher body temperature (Tb), basal metabolic rate and wet thermal conductance than other marsupials of similar mass. Honey possums enter torpor when cold-stressed and deprived of food. The pattern of decline in body temperature and oxygen consumption during torpor generally resembles that of other heterothermic endotherms. The duration of torpor bouts in honey possums was about 10 h; torpor bouts longer than one day were not observed. The Tb declined during torpor to within 1-2�C of ambient temperature (Ta>5�C) and oxygen consumption rate declined dramatically. The minimal body temperature (Tb,min) measured for torpid honey possums was about 5�C, because Tb was regulated at about 5�C by honey possums torpid at Ta<5�C, by an elevation of oxygen consumption rate. Previous studies of small marsupials have delineated two basic patterns of torpor: (1) shallow (Tb,min>10-15�C) and short-term torpor cycles (e.g. in dasyurids); (2) deep (Tb,min<10�C) and multi-day torpor cycles (e.g. in burramyids). Honey possums appear to have a third pattern of deep (Tb,min=5�C) but short-term torpor. The ecological reasons for this pattern of deep torpor and the apparent absence of multi-day torpor in honey possums may be related to their nectarivorous diet and lack of extensive fat stores.

Prolonged increase in insulin-stimulated glucose transport in muscle after exercise

1989 ◽  
Vol 256 (4) ◽  
pp. E494-E499 ◽  
Author(s):  
G. D. Cartee ◽  
D. A. Young ◽  
M. D. Sleeper ◽  
J. Zierath ◽  
H. Wallberg-Henriksson ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Glucose Transport ◽  
Muscle Glycogen ◽  
Caloric Intake ◽  
Carbohydrate Intake ◽  
Dietary Carbohydrate ◽  
Short Term ◽  
Insulin Responsiveness ◽  
Muscle Glucose Transport

Exercise can induce short-term increases in the sensitivity and responsiveness of skeletal muscle glucose transport to insulin. The purpose of this study was to determine the effect of carbohydrate deprivation on the persistence of increased insulin sensitivity and responsiveness after a bout of exercise. Three hours after a bout of exercise, epitrochlearis muscles from carbohydrate-deprived (fat fed) rats showed a 25% greater increase in 3-O-methylglucose (3-MG) transport in response to a maximal insulin stimulus compared with muscles of nonexercised rats; this increase in insulin responsiveness had reversed 18 h postexercise. Muscles of rats fed carbohydrate showed no increase in insulin responsiveness 3 h after exercise. The effect of 60 microU/ml of insulin on 3-MG transport was approximately twofold greater in muscles studied 3 h after exercise than in nonexercised controls regardless of dietary carbohydrate intake. This increase in insulin sensitivity was lost within 18 h in carbohydrate-fed rats but persisted for at least 48 h in carbohydrate-deprived rats. Muscle glycogen increased approximately 41 mumol/g in the rats fed carbohydrate for 18 h, and only approximately 14.5 mumol/g in the rats fed fat for 48 h, after exercise. The persistent increase in insulin sensitivity after exercise in carbohydrate-deprived rats was unrelated to caloric intake, as muscles of fasted and fat-fed rats behaved similarly.

scholarly journals Tristetraprolin-mediated hexokinase 2 expression regulation contributes to glycolysis in cancer cells

2019 ◽  
Vol 30 (5) ◽  
pp. 542-553 ◽  
Author(s):  
Dong Jun Kim ◽  
Mai-Tram Vo ◽  
Seong Hee Choi ◽  
Ji-Heon Lee ◽  
So Yeon Jeong ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Glucose Metabolism ◽  
Cancer Cells ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Ectopic Expression ◽  
Mrna Degradation ◽  
Negative Regulator ◽  
Extracellular Acidification ◽  
Hexokinase 2

Hexokinase 2 (HK2) catalyzes the first step of glycolysis and is up-regulated in cancer cells. The mechanism has not been fully elucidated. Tristetraprolin (TTP) is an AU-rich element (ARE)-binding protein that inhibits the expression of ARE-containing genes by enhancing mRNA degradation. TTP expression is down-regulated in cancer cells. We demonstrated that TTP is critical for down-regulation of HK2 expression in cancer cells. HK2 mRNA contains an ARE within its 3′-UTR. TTP binds to HK2 3′-UTR and enhances degradation of HK2 mRNA. TTP overexpression decreased HK2 expression and suppressed the glycolytic capacity of cancer cells, measured as glucose uptake and production of glucose-6-phosphate, pyruvate, and lactate. TTP overexpression reduced both the extracellular acidification rate (ECAR) and the oxygen consumption rate (OCR) of cancer cells. Ectopic expression of HK2 in cancer cells attenuated the reduction in glycolytic capacity, ECAR, and OCR from TTP. Taken together, these findings suggest that TTP acts as a negative regulator of HK2 expression and glucose metabolism in cancer cells.

Microbial efficiency in a meromictic reservoir

2008 ◽  
Vol 37 (2) ◽  
Author(s):  
Grażyna Mazurkiewicz-Boroń ◽  
Teresa Bednarz ◽  
Elżbieta Wilk-Woźniak
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Release Rate ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Metabolic Efficiency ◽  
Sulphur Compounds ◽  
Carbon Dioxide Release ◽  
Microbial Efficiency ◽  
Ion Contents

Microbial efficiency in a meromictic reservoirIndices of microbial efficiency (expressed as oxygen consumption and carbon dioxide release) were determined in the water column of the meromictic Piaseczno Reservoir (in an opencast sulphur mine), which is rich in sulphur compounds. Phytoplankton abundances were low in both the mixolimnion (up to 15 m depth) and monimolimnion (below 15 m depth). In summer and winter, carbon dioxide release was 3-fold and 5-fold higher, respectively, in the monimolimnion than in the mixolimnion. Laboratory enrichments of the sulphur substrate of the water resulted in a decrease in oxygen consumption rate of by about 42% in mixolimnion samples, and in the carbon dioxide release rate by about 69% in monimolimnion samples. Water temperature, pH and bivalent ion contents were of major importance in shaping the microbial metabolic efficiency in the mixolimnion, whilst in the monimolimnion these relationships were not evident.

scholarly journals Correction: Paszkiewicz et al. A Peripheral CB1R Antagonist Increases Lipolysis, Oxygen Consumption Rate, and Markers of Beiging in 3T3-L1 Adipocytes Similar to RIM, Suggesting That Central Effects Can Be Avoided. Int. J. Mol. Sci. 2020, 21, 6639

2021 ◽  
Vol 22 (9) ◽  
pp. 4366
Author(s):  
Rebecca L. Paszkiewicz ◽  
Richard N. Bergman ◽  
Roberta S. Santos ◽  
Aaron P. Frank ◽  
Orison O. Woolcott ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Central Effects

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