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Glycerol To Glucose

Bmbr Metabolic Pathways

Bmbr Metabolic Pathways

All Rights Reserved. All trademarks and copyrights are the property of their respective owners. Simplified metabolic pathways are summarized in this section. For more detailed information, please see any biochemistry textbook or use Biochemistry Animations or The Medical Biochemistry Page . Please note that red indicates molecule is used while green indicates molecule is produced. Glycolysis is responsible for the oxidation of glucose into pyruvate. Pentose phosphate pathway serves several purposes, production of ribose-5-phosphate, NADPH and glycolytic intermediates (fructose and glyceraldehyde-3-phosphate). Glycogenesis and glycogenolysis are processes that synthesize the glucose storage macromolecule glycogen and degrade glycogen into glucose-1-phosphate (and glucose), respectively. Fructose metabolism occurs in muscle and liver. Tricarboxylic acid cycle generates reducing equivalents for the electron transport chain and processes various metabolytes from other pathways. The electron transport chain couples reducing equivalents with ATP production. Gluconeogenesis uses metabolytes to synthesize new glucose. Lipogenesis and lipolysis are processes that synthesize and degrade fatty acids. β-oxidation is responsible for the complete oxidation of fatty acids. This process, which may occur in all cells, involves splitting the 6-carbon monosaccharide into two 2-carbon molecules, dihydroxyacetone phosphate and glyceraldehyde-3-phosphate. Two ATP molecules are invested initially (hexokinase and phosphofructokinase-1) with the eventual net production of 2 ATP molecules (3-phosphoglycerate kinase and pyruvate kinase). Two NADH are produced by glyceraldehyde-3-phosphate dehydrogenase. The resulting NADH may be reoxidized by lactate dehydrogenase such that NAD+ is regener Continue reading >>

Glycerol Kinase Interacts With Nuclear Receptor Nr4a1 And Regulates Glucose Metabolism In The Liver

Glycerol Kinase Interacts With Nuclear Receptor Nr4a1 And Regulates Glucose Metabolism In The Liver

Glycerol kinase interacts with nuclear receptor NR4A1 and regulates glucose metabolism in the liver *Beijing Institute of Radiation Medicine, Beijing, China; Graduate School, Anhui Medical University, Hefei, China; 1These authors contributed equally to this work. Institute of AcuMoxibustion, China Academy of Chinese Medical Sciences, Beijing, China; State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences, Beijing Institute of Lifeomics, Beijing, China; and 1These authors contributed equally to this work. *Beijing Institute of Radiation Medicine, Beijing, China; Department of Pharmaceutical Engineering, Tianjin University, Tianjin, China *Beijing Institute of Radiation Medicine, Beijing, China; Graduate School, Anhui Medical University, Hefei, China; State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences, Beijing Institute of Lifeomics, Beijing, China; and Department of Pharmaceutical Engineering, Tianjin University, Tianjin, China *Beijing Institute of Radiation Medicine, Beijing, China; Graduate School, Anhui Medical University, Hefei, China; Glycerol kinase (Gyk), consisting of 4 isoforms, plays a critical role in metabolism by converting glycerol to glycerol 3-phosphate in an ATP-dependent reaction. Only Gyk isoform b is present in whole cells, but its function in the nucleus remains elusive. Previous studies have shown that nuclear orphan receptor subfamily 4 group A member (NR4A)-1 is an important regulator of hepatic glucose homeostasis and lipid metabolism in adipose tissue. We aimed to elucidate the functional interaction between nuclear Gyk and NR4A1 during hepatic gluconeogenesis in the unfed state and diabetes. We identified nuclear Gyk as a novel corepress Continue reading >>

Formation Of Glycerol From Glucose In Rat Brain And Cultured Brain Cells. Augmentation With Kainate Or Ischemia

Formation Of Glycerol From Glucose In Rat Brain And Cultured Brain Cells. Augmentation With Kainate Or Ischemia

Ischemic stroke and neonatal hypoxic-ischemic encephalopathy are two of the leading causes of disability in adults and infants. The energy demands of the brain are provided by mitochondrial oxidative phosphorylation. Ischemia/reperfusion (I/R) affects the production of ATP in brain mitochondria, leading to energy failure and death of the affected tissue. Among the enzymes of the mitochondrial respiratory chain, mitochondrial complex I is the most sensitive to I/R; however, the mechanisms of its inhibition are poorly understood. This article reviews some of the existing data on the mitochondria impairment during I/R and proposes two distinct mechanisms of complex I damage emerging from recent studies. One mechanism is a reversible dissociation of natural flavin mononucleotide cofactor from the enzyme I after ischemia. Another mechanism is a modification of critical cysteine residue of complex I involved into the active/deactive conformational transition of the enzyme. I describe potential effects of these two processes in the development of mitochondrial I/R injury and briefly discuss possible neuroprotective strategies to ameliorate I/R brain injury. Reactive oxygen species (ROS) are byproducts of physiological mitochondrial metabolism that are involved in several cellular signaling pathways as well as tissue injury and pathophysiological processes, including brain ischemiareperfusion injury. The mitochondrial respiratory chain is considered a major source of ROS; however, there is little agreement on how ROS release depends on oxygen concentration.The rate of H2O2 release by intact brain mitochondria was measured with an Amplex UltraRed assay using a highresolution respirometer (Oroboros) equipped with a fluorescent optical module and a system of controlled gas flow f Continue reading >>

Nutrients | Free Full-text | Insulin Controls Triacylglycerol Synthesis Through Control Of Glycerol Metabolism And Despite Increased Lipogenesis | Html

Nutrients | Free Full-text | Insulin Controls Triacylglycerol Synthesis Through Control Of Glycerol Metabolism And Despite Increased Lipogenesis | Html

Insulin Controls Triacylglycerol Synthesis through Control of Glycerol Metabolism and Despite Increased Lipogenesis Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain Faculty of Medicine, Universidad Nacional del Centro del Per, 12006 Huancayo, Per Institute of Biomedicine, University of Barcelona, 08028 Barcelona, Spain Centro de Investigacin Biomdica en Red Fisiopatologa de la Obesidad y Nutricin (CIBER-OBN), 08028 Barcelona, Spain Author to whom correspondence should be addressed. Received: 7 February 2019 / Accepted: 22 February 2019 / Published: 28 February 2019 Under normoxic conditions, adipocytes in primary culture convert huge amounts of glucose to lactate and glycerol. This wasting of glucose may help to diminish hyperglycemia. Given the importance of insulin in the metabolism, we have studied how it affects adipocyte response to varying glucose levels, and whether the high basal conversion of glucose to 3-carbon fragments is affected by insulin. Rat fat cells were incubated for 24 h in the presence or absence of 175 nM insulin and 3.5, 7, or 14 mM glucose; half of the wells contained 14C-glucose. We analyzed glucose label fate, medium metabolites, and the expression of key genes controlling glucose and lipid metabolism. Insulin increased both glucose uptake and the flow of carbon through glycolysis and lipogenesis. Lactate excretion was related to medium glucose levels, which agrees with the purported role of disposing excess (circulating) glucose. When medium glucose was low, most basal glycerol came from lipolysis, but when glucose was high, release of glycerol via breakup of glycerol-3P was predominant. Although insulin promotes lipogenesis, it also limited the synthesis of glycerol-3P Continue reading >>

Glucose Can Be Synthesized From Noncarbohydrate Precursors - Biochemistry - Ncbi Bookshelf

Glucose Can Be Synthesized From Noncarbohydrate Precursors - Biochemistry - Ncbi Bookshelf

Glucose is formed by hydrolysis of glucose 6-phosphate in a reaction catalyzed by glucose 6-phosphatase. We will examine each of these steps in turn. 16.3.2. The Conversion of Pyruvate into Phosphoenolpyruvate Begins with the Formation of Oxaloacetate The first step in gluconeogenesis is the carboxylation of pyruvate to form oxaloacetate at the expense of a molecule of ATP . Then, oxaloacetate is decarboxylated and phosphorylated to yield phosphoenolpyruvate, at the expense of the high phosphoryl-transfer potential of GTP . Both of these reactions take place inside the mitochondria. The first reaction is catalyzed by pyruvate carboxylase and the second by phosphoenolpyruvate carboxykinase. The sum of these reactions is: Pyruvate carboxylase is of special interest because of its structural, catalytic, and allosteric properties. The N-terminal 300 to 350 amino acids form an ATP -grasp domain ( Figure 16.25 ), which is a widely used ATP-activating domain to be discussed in more detail when we investigate nucleotide biosynthesis ( Section 25.1.1 ). The C -terminal 80 amino acids constitute a biotin-binding domain ( Figure 16.26 ) that we will see again in fatty acid synthesis ( Section 22.4.1 ). Biotin is a covalently attached prosthetic group, which serves as a carrier of activated CO2. The carboxylate group of biotin is linked to the -amino group of a specific lysine residue by an amide bond ( Figure 16.27 ). Note that biotin is attached to pyruvate carboxylase by a long, flexible chain. The carboxylation of pyruvate takes place in three stages: Recall that, in aqueous solutions, CO2 exists as HCO3- with the aid of carbonic anhydrase (Section 9.2). The HCO3- is activated to carboxyphosphate. This activated CO2 is subsequently bonded to the N-1 atom of the biotin ring to Continue reading >>

Comparison Of The Effects Of Pre-exercise Feeding Of Glucose, Glycerol And Placebo On Endurance And Fuel Homeostasis In Man

Comparison Of The Effects Of Pre-exercise Feeding Of Glucose, Glycerol And Placebo On Endurance And Fuel Homeostasis In Man

Comparison of the effects of pre-exercise feeding of glucose, glycerol and placebo on endurance and fuel homeostasis in man Six men were studied during exercise to exhaustion on a cycle ergometer at 73% of \(\dot V_{O_{2max} } \) following ingestion of glycerol, glucose or placebo. Five of the subjects exercised for longer on the glucose trial compared to the placebo trial (p<0.1; 108.8 vs 95.9 min). Exercise time to exhaustion on the glucose trial was longer (p<0.01) than on the glycerol trial (86.0 min). No difference in performance was found between the glycerol and placebo trials. The ingestion of glucose (lg kg1 body weight) 45 min before exercise produced a 50% rise in blood glucose and a 3-fold rise in plasma insulin at zero min of exercise. Total carbohydrate oxidation was increased by 26% compared to placebo and none of the subjects exhibited a fall in blood glucose below 4 mmol l1 during the exercise. The ingestion of glycerol (lg kg1 body weight) 45 min before exercise produced a 340-fold increase in blood glycerol concentration at zero min of exercise, but did not affect resting blood glucose or plasma insulin levels; blood glucose levels were up to 14% higher (p<0.05) in the later stages of exercise and at exhaustion compared to the placebo or glucose trials. Both glycerol and glucose feedings lowered the magnitude of the rise in plasma FFA during exercise compared to placebo. Levels of blood lactate and alanine during exercise were not different on the 3 dietary treatments. These data contrast with previous reports that have indicated glucose feeding pre-exercise produces hypoglycaemia during strenuous submaximal exercise and reduces endurance performance. It appears that man cannot use glycerol as a gluconeogenic substrate rapidly enough to serve as a ma Continue reading >>

Glycerol-mediated Repression Of Glucose Metabolism And Glycerol Kinase As The Sole Route Of Glycerol Catabolism In The Haloarchaeon Haloferax Volcanii

Glycerol-mediated Repression Of Glucose Metabolism And Glycerol Kinase As The Sole Route Of Glycerol Catabolism In The Haloarchaeon Haloferax Volcanii

List of strains and plasmids used in this study For growth assays, cells were grown in yeast extract-peptone-Casamino Acids, Gly MM, Gly Glu MM, and Glu MM as indicated below. Cells from 80C glycerol stocks were freshly inoculated onto the appropriate agar-based media on plates. Cells were thrice subcultured and used as inocula for the final analyses of growth under various conditions as described below. Each subculture was inoculated to a final optical density at 600 nm (OD600) of 0.03 to 0.04. For the analyses of growth rates and cell yields, cells were grown in 20 ml of medium in 250-ml baffled Erlenmeyer flasks. For enzyme activity assays, cells were grown in 100 ml of Gly MM, Glu MM, or Gly Glu MM in 1,000-ml flasks. For RNA preparation, cells were grown in 3 ml of medium in 13- by 100-cm2 culture tubes. Cell growth was monitored by an increase in OD600 (where 1 OD600 unit equals approximately 109 CFUml1 for all strains used in this study). All experiments were performed at least in triplicate. DNA isolation and analysis.DNA was separated by electrophoresis using 0.8% (wt/vol) agarose gels in 1 TAE electrophoresis buffer (40 mM Tris acetate, 2 mM EDTA, pH 8.5). Plasmid DNA was isolated from E. coli strains by using the QIAprep spin miniprep kit (Qiagen, Valencia, CA). PCR products were purified by using the MinElute kit (Qiagen) prior to modification by a restriction enzyme (BamHI, HindIII, KpnI, XbaI, HpaI, or NdeI) or T4 DNA polynucleotide kinase. For rapid PCR screening, template DNA was extracted from H. volcanii mutant and parent strains and recombinant E. coli DH5 as described previously ( 28 ). For Southern blotting, H. volcanii genomic DNA was isolated from 5-ml cultures by DNA spooling ( 9 ). PCRs.High-fidelity double-stranded DNA used for the constructio Continue reading >>

Jci -interstitial Fluid Concentrations Of Glycerol, Glucose, And Amino Acids In Human Quadricep Muscle And Adipose Tissue. Evidence For Significant Lipolysis In Skeletal Muscle.

Jci -interstitial Fluid Concentrations Of Glycerol, Glucose, And Amino Acids In Human Quadricep Muscle And Adipose Tissue. Evidence For Significant Lipolysis In Skeletal Muscle.

Interstitial fluid concentrations of glycerol, glucose, and amino acids in human quadricep muscle and adipose tissue. Evidence for significant lipolysis in skeletal muscle. D G Maggs, , W V Tamborlane, R S Sherwin J Clin Invest. 1995; 96(1) :370-377. . To determine the relationship between circulating metabolic fuels and their local concentrations in peripheral tissues we measured glycerol, glucose, and amino acids by microdialysis in muscle and adipose interstitium of 10 fasted, nonobese human subjects during (a) baseline, (b) euglycemic hyperinsulinemia (3 mU/kg per min for 3 h) and, (c) local norepinephrine reuptake blockade (NOR). At baseline, interstitial glycerol was strikingly higher (P < 0.0001) in muscle (3710 microM) and adipose tissue (2760 microM) compared with plasma (87 microM), whereas interstitial glucose (muscle 3.3, fat 3.6 mM) was lower (P < 0.01) than plasma levels (4.8 mM). Taurine, glutamine, and alanine levels were higher in muscle than in adipose or plasma (P < 0.05). Euglycemic hyperinsulinemia did not affect interstitial glucose, but induced a fall in plasma glycerol and amino acids paralleled by similar changes in the interstitium of both tissues. Local NOR provoked a fivefold increase in glycerol (P < 0.001) and twofold increase in norepinephrine (P < 0.01) in both muscle and adipose tissues. To conclude, interstitial substrate levels in human skeletal muscle and adipose tissue differ substantially from those in the circulation and this disparity is most pronounced for glycerol which is raised in muscle as well as adipose tissue. In muscle, insulin suppressed and NOR increased interstitial glycerol concentrations. Our data suggest unexpectedly high rates of [] Continue reading >>

Propionic Acid Fermentation Of Glycerol And Glucose By Propionibacterium Acidipropionici And Propionibacterium Freudenreichii Ssp.shermanii

Propionic Acid Fermentation Of Glycerol And Glucose By Propionibacterium Acidipropionici And Propionibacterium Freudenreichii Ssp.shermanii

A comparative study was carried out in anaerobic batch cultures on 20 g/l of either glycerol or glucose using two propionibacteria strains, Propionibacterium acidipropionici and Propionibacterium freudenreichii ssp. shermanii. In all cases, fermentation end-products were the same and consisted of propionic acid as the major product, acetic acid as the main by-product and two minor metabolites, n-propanol and succinic acid. Evidence was provided that greater production of propionic acid by propionibacteria was obtained with glycerol as carbon and energy sources. P. acidipropionici showed higher efficiency in glycerol conversion to propionic acid with a faster substrate consumption (0.64 g l1 h1) and a higher propionic acid production (0.42 g l1 h1 and 0.79 mol/mol). The almost exclusive production of propionic acid from glycerol by this bacterium suggested an homopropionic tendency of this fermentation. Acetic acid final concentration was two times lower on glycerol (2 g/l) than on glucose (4 g/l) for both micro-organisms. P. freudenreichii ssp. shermanii exhibited a glycerol fermentation pattern typical of non-associated glycerol-consumption-product formation. This could indicate a particular metabolism for P. freudenreichii ssp. shermanii oriented towards the production of other specific components. These results tend to show that glycerol could be an excellent alternative to conventional carbon sources such as carbohydrates for propionic acid production. FermentationPropionic AcidSuccinic AcidGlycerol ConversionExclusive Production These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves. Received: 21 May 1999 / Accepted: 1 November 1999 This is a preview of subscripti Continue reading >>

Effects Of Insulin, Glucose And Glycerol On Fat Metabolism In Alloxan-diabetic Sheep

Effects Of Insulin, Glucose And Glycerol On Fat Metabolism In Alloxan-diabetic Sheep

EFFECTS OF INSULIN, GLUCOSE AND GLYCEROL ON FAT METABOLISM IN ALLOXAN-DIABETIC SHEEP The effects of insulin, glucose injection and oral glycerol on blood or plasma levels of glucose, free fatty acids (FFA), acetic acid and ketone bodies have been studied in alloxan-diabetic sheep. Insulin (05 i.u./kg.) lowered glucose levels only slightly, but induced a prompt and marked fall in FFA and acetate levels; ketones declined steadily after the first hour. The rate of utilization of injected glucose was considerably slower in diabetic than in non-diabetic sheep. FFA levels did not decline after glucose injection, while acetate levels declined slowly. Ketone levels were not affected significantly. Glycerol (180 ml.) per os reduced acetate and ketone levels, while tending to increase FFA values. Blood glucose also increased considerably. These data are consistent with present knowledge of the metabolic lesions in severe diabetes. However, it is concluded that there is impairment of acetate and, probably, ketone oxidation in severe diabetic ketosis. Finally, the metabolic changes recorded are compared with those which occur after insulin, glucose or glycerol administration to ewes showing clinical signs of ovine pregnancy toxaemia following severe and prolonged undernourishment in late pregnancy. Continue reading >>

Gluconeogenesis: Endogenous Glucose Synthesis

Gluconeogenesis: Endogenous Glucose Synthesis

Reactions of Gluconeogenesis: Gluconeogenesis from two moles of pyruvate to two moles of 1,3-bisphosphoglycerate consumes six moles of ATP. This makes the process of gluconeogenesis very costly from an energy standpoint considering that glucose oxidation to two moles of pyruvate yields two moles of ATP. The major hepatic substrates for gluconeogenesis (glycerol, lactate, alanine, and pyruvate) are enclosed in red boxes for highlighting. The reactions that take place in the mitochondria are pyruvate to OAA and OAA to malate. Pyruvate from the cytosol is transported across the inner mitochondrial membrane by the pyruvate transporter. Transport of pyruvate across the plasma membrane is catalyzed by the SLC16A1 protein (also called the monocarboxylic acid transporter 1, MCT1) and transport across the outer mitochondrial membrane involves a voltage-dependent porin transporter. Transport across the inner mitochondrial membrane requires a heterotetrameric transport complex (mitochondrial pyruvate carrier) consisting of the MPC1 gene and MPC2 gene encoded proteins. Following reduction of OAA to malate the malate is transported to the cytosol by the malate transporter (SLC25A11). In the cytosol the malate is oxidized to OAA and the OOA then feeds into the gluconeogenic pathway via conversion to PEP via PEPCK. The PEPCK reaction is another site for consumption of an ATP equivalent (GTP is utilized in the PEPCK reaction). The reversal of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) reaction requires a supply of NADH. When lactate is the gluconeogenic substrate the NADH is supplied by the lactate dehydrogenase (LDH) reaction (indicated by the dashes lines), and it is supplied by the malate dehydrogenase reaction when pyruvate and alanine are the substrates. Secondly, one mo Continue reading >>

Gluconeogenesis

Gluconeogenesis

Not to be confused with Glycogenesis or Glyceroneogenesis. Simplified Gluconeogenesis Pathway Gluconeogenesis (GNG) is a metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates. From breakdown of proteins, these substrates include glucogenic amino acids (although not ketogenic amino acids); from breakdown of lipids (such as triglycerides), they include glycerol (although not fatty acids); and from other steps in metabolism they include pyruvate and lactate. Gluconeogenesis is one of several main mechanisms used by humans and many other animals to maintain blood glucose levels, avoiding low levels (hypoglycemia). Other means include the degradation of glycogen (glycogenolysis)[1] and fatty acid catabolism. Gluconeogenesis is a ubiquitous process, present in plants, animals, fungi, bacteria, and other microorganisms.[2] In vertebrates, gluconeogenesis takes place mainly in the liver and, to a lesser extent, in the cortex of the kidneys. In ruminants, this tends to be a continuous process.[3] In many other animals, the process occurs during periods of fasting, starvation, low-carbohydrate diets, or intense exercise. The process is highly endergonic until it is coupled to the hydrolysis of ATP or GTP, effectively making the process exergonic. For example, the pathway leading from pyruvate to glucose-6-phosphate requires 4 molecules of ATP and 2 molecules of GTP to proceed spontaneously. Gluconeogenesis is often associated with ketosis. Gluconeogenesis is also a target of therapy for type 2 diabetes, such as the antidiabetic drug, metformin, which inhibits glucose formation and stimulates glucose uptake by cells.[4] In ruminants, because dietary carbohydrates tend to be metabolized by rumen organisms, gluconeogenesis occurs Continue reading >>

Production Of Glycerol From Glucose By Coexpressing Glycerol-3-phosphate Dehydrogenase And Glycerol-3-phosphatase In Klebsiella Pneumoniae

Production Of Glycerol From Glucose By Coexpressing Glycerol-3-phosphate Dehydrogenase And Glycerol-3-phosphatase In Klebsiella Pneumoniae

Volume 105, Issue 5 , May 2008, Pages 508-512 Production of glycerol from glucose by coexpressing glycerol-3-phosphate dehydrogenase and glycerol-3-phosphatase in Klebsiella pneumoniae Author links open overlay panel YuZheng LiZhao JianguoZhang HaiyiZhang XingyuanMa DongzhiWei Get rights and content As a valuable chemical, 1,3-propanediol (1,3-PD) could be biosynthesized by glycerol fermentation. However, no natural microorganisms that could directly convert glucose into 1,3-PD have been found so far. In this work, genes coding for two enzymes, glycerol-3-phosphate dehydrogenase (GPD, EC 1.1.1.8) and glycerol-3-phosphatase (GPP, EC 3.1.3.21), which were responsible for glycerol production, were organized into the plasmid pUC18K under control of the respective lac promoters. Two recombinant proteins were expressed successfully in wild-type Klebsiella pneumoniae. A glycerol concentration of 6.8 g l1 was obtained in flask culture. When glucose was exhausted, dihydroxyacetone was added and medium pH was adjusted to 7.0, and then a 1,3-PD concentration of 0.58 g l1 was achieved with engineered K. pneumoniae from glucose. Continue reading >>

Glycerol Production From Glucose And Fructose By 3t3-l1 Cells: A Mechanism Of Adipocyte Defense From Excess Substrate

Glycerol Production From Glucose And Fructose By 3t3-l1 Cells: A Mechanism Of Adipocyte Defense From Excess Substrate

Click through the PLOS taxonomy to find articles in your field. For more information about PLOS Subject Areas, click here . Glycerol Production from Glucose and Fructose by 3T3-L1 Cells: A Mechanism of Adipocyte Defense from Excess Substrate Affiliations Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Av.Diagonal 643, 08028, Barcelona, Spain, Institute of Biomedicine, University of Barcelona, Barcelona, Spain, CIBER Obesity and Nutrition, Barcelona, Spain Affiliation Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Av.Diagonal 643, 08028, Barcelona, Spain Affiliations Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Av.Diagonal 643, 08028, Barcelona, Spain, Institute of Biomedicine, University of Barcelona, Barcelona, Spain, CIBER Obesity and Nutrition, Barcelona, Spain Affiliations Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Av.Diagonal 643, 08028, Barcelona, Spain, Institute of Biomedicine, University of Barcelona, Barcelona, Spain, CIBER Obesity and Nutrition, Barcelona, Spain Continue reading >>

Glucose-to-glycerol Conversion In Long-lived Yeast Provides Anti-aging Effects

Glucose-to-glycerol Conversion In Long-lived Yeast Provides Anti-aging Effects

Cell biologists have found a more filling substitute for caloric restriction in extending the life span of simple organisms. Researchers show that yeast cells maintained on a glycerol diet live twice as long as normal -- as long as yeast cells on a severe caloric-restriction diet. They are also more resistant to cell damage. Cell biologists have found a more filling substitute for caloric restriction in extending the life span of simple organisms. In a study published May 8 in the open-access journal PLoS Genetics, researchers from the University of Southern California Andrus Gerontology Center show that yeast cells maintained on a glycerol diet live twice as long as normal -- as long as yeast cells on a severe caloric-restriction diet. They are also more resistant to cell damage. Many studies have shown that caloric restriction can extend the life span of a variety of laboratory animals. Caloric restriction is also known to cause major improvements in a number of markers for cardiovascular diseases in humans. This study is the first to propose that "dietary substitution" can replace "dietary restriction" in a living species. "If you add glycerol, or restrict caloric intake, you obtain the same effect," said senior author Valter Longo. "It's as good as calorie restriction, yet cells can take it up and utilize it to generate energy or for the synthesis of cellular components." Longo and colleagues Min Wei and Paola Fabrizio introduced a glycerol diet after discovering that genetically engineered long-lived yeast cells that survive up to 5-fold longer than normal have increased levels of the genes that produce glycerol. In fact, they convert virtually all the glucose and ethanol into glycerol. Notably, these cells have a reduced activity in the TOR1/SCH9 pathway, which i Continue reading >>

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