scholarly journals Diversion of Carbon Flux from Sugars to Lipids Improves the Growth of an Arabidopsis Starchless Mutant

Plants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 229 ◽  
Author(s):  
Jilian Fan ◽  
Chao Zhou ◽  
Linhui Yu ◽  
Ping Li ◽  
John Shanklin ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Plant Growth ◽  
Energy Production ◽  
Alternative Energy ◽  
Continuous Light ◽  
Acid Synthesis ◽  
Energy Deficiency ◽  
Similar Growth ◽  
Starchless Mutant

Inactivation of ADP-glucose pyrophosphorylase1 (ADG1) causes a starchless phenotype in Arabidopsis. Mutants defective in ADG1 show severe growth retardation in day/night conditions but exhibit similar growth to wild type under continuous light, implying that starch plays an important role in supporting respiration, metabolism and growth at night. In addition to carbohydrates, lipids and proteins can serve as alternative respiratory substrates for the energy production in mature plants. To test the role of lipids in plant growth, we generated transgenic plants overexpressing phospholipid:diacylglycerol acyltransferase1 (PDAT1) in adg1. We found that PDAT1 overexpression caused an increase in both fatty acid synthesis and turnover and increased the accumulation of triacylglycerol (TAG) at the expense of sugars, and enhanced the growth of adg1. We demonstrated that unlike sugars, which were metabolized within a few hours of darkness, TAG breakdown was slow, occurring throughout the entire dark period. The slow pace of TAG hydrolysis provided a sustained supply of fatty acids for energy production, thereby alleviating energy deficiency at night and thereby improving the growth of the starchless mutants. We conclude that lipids can contribute to plant growth by providing a constant supply of fatty acids as an alternative energy source in mature starchless mutant plants.

scholarly journals FSMP-15. EVALUATING THE ROLE OF LONG-CHAIN FATTY ACID METABOLISM IN PROMOTING GLIOBLASTOMA GROWTH

2021 ◽  
Vol 3 (Supplement_1) ◽  
pp. i19-i19
Author(s):  
Divya Ravi ◽  
Carmen del Genio ◽  
Haider Ghiasuddin ◽  
Arti Gaur
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Survival Rate ◽  
Tumor Progression ◽  
Acid Synthesis ◽  
Normal Brain ◽  
Acid Uptake ◽  
Exogenous Fatty Acid ◽  
Long Chain

Abstract Glioblastomas (GBM) or Stage IV gliomas, are the most aggressive of primary brain tumors and are associated with high mortality and morbidity. Patients diagnosed with this lethal cancer have a dismal survival rate of 14 months and a 5-year survival rate of 5.6% despite a multimodal therapeutic approach, including surgery, radiation therapy, and chemotherapy. Aberrant lipid metabolism, particularly abnormally active de novo fatty acid synthesis, is recognized to have a key role in tumor progression and chemoresistance in cancers. Previous studies have reported a high expression of fatty acid synthase (FASN) in patient tumors, leading to multiple investigations of FASN inhibition as a treatment strategy. However, none of these have developed as efficacious therapies. Furthermore, when we profiled FASN expression using The Cancer Genome Atlas (TCGA) we determined that high FASN expression in GBM patients did not confer a worse prognosis (HR: 1.06; p-value: 0.51) and was not overexpressed in GBM tumors compared to normal brain. Therefore, we need to reexamine the role of exogenous fatty acid uptake over de novofatty acid synthesis as a potential mechanism for tumor progression. Our study aims to measure and compare fatty acid oxidation (FAO) of endogenous and exogenous fatty acids between GBM patients and healthy controls. Using TCGA, we have identified the overexpression of multiple enzymes involved in mediating the transfer and activation of long-chain fatty acids (LCFA) in GBM tumors compared to normal brain tissue. We are currently conducting metabolic flux studies to (1) assess the biokinetics of LCFA degradation and (2) establish exogenous versus endogenous LCFA preferences between patient-derived primary GBM cells and healthy glial and immune cells during steady state and glucose-deprivation.

scholarly journals Studies on the role of insulin in the regulation of glyceride synthesis in rat epididymal adipose tissue

1975 ◽  
Vol 150 (3) ◽  
pp. 441-451 ◽  
Author(s):  
S R Sooranna ◽  
E D Saggerson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Synthesis Process ◽  
Epididymal Adipose Tissue ◽  
Fat Cells ◽  
Fat Cell ◽  
Glyceride Synthesis

1. When rat isolated fat-cells were incubated with fructose and palmitate, insulin significantly stimulated glyceride synthesis as measured by either [14C]fructose incorporation into the glycerol moiety or of [3H]palmitate incorporation into the acyl moiety of tissue glycerides. Under certain conditions the effect of insulin on glyceride synthesis was greater than the effect of insulin on fructose uptake. 2. In the presence of palmitate, insulin slightly stimulated (a) [14C]pyruvate incorporation into glyceride glycerol of fat-cells and (b) 3H2O incorporation into glyceride glycerol of incubated fat-pads. 3. At low extracellular total concentrations of fatty acids (in the presence of albumin), insulin stimulated [14C]fructose, [14C]pyruvate and 3H2O incorporation into fat-cell fatty acids. Increasing the extracellular fatty acid concentration greatly inhibited fatty acid synthesis from these precursors and also greatly decreased the extent of apparent stimulation of fatty acid synthesis by insulin. 4. These results are discussed in relation to the suggestion [A.P. Halestrap & R.M Denton (1974) Biochem. J. 142, 365-377] that the tissue may contain a specific acyl-binding protein which is subject to regulation. It is suggested that an insulin-sensitive enzyme component of the glyceride-synthesis process may play such a role.

scholarly journals Disruption of the FATB Gene in Arabidopsis Demonstrates an Essential Role of Saturated Fatty Acids in Plant Growth

2003 ◽  
Vol 15 (4) ◽  
pp. 1020-1033 ◽  
Author(s):  
Gustavo Bonaventure ◽  
Joaquin J. Salas ◽  
Michael R. Pollard ◽  
John B. Ohlrogge
Keyword(s):  
Fatty Acids ◽  
Plant Growth ◽  
Essential Role ◽  
Saturated Fatty Acids

scholarly journals The manipulation of cellular cytochrome and lipid composition in a haem mutant of Saccharomyces cerevisiae

1977 ◽  
Vol 166 (2) ◽  
pp. 275-285 ◽  
Author(s):  
A M Astin ◽  
J M Haslam
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Protoporphyrin Ix ◽  
Total Sterol ◽  
Acid Synthesis ◽  
Progressive Increase ◽  
Sterol Synthesis ◽  
Early Lesion

1. The ole-3 mutant of Saccharomyces cerevisiae has an early lesion in the pathway of porphyrin biosynthesis. 2. This results in the loss of all haem-containing enzymes, including the mitochondrial cytochromes, and prevents the synthesis of components whose formation requires haem-containing enzymes, including unsaturated fatty acids, ergosterol and methionine. 3. The pleiotropic effects of the primary lesion are reversed by growing mutant ole-3 aerobically in the presence of intermediates of the porphyrin-biosynthetic pathway, and the present work reports the degree of manipulation of lipid and respiratory-cytochrome composition. 4. Supplements of delta-aminolaevulinate in the range 0.5–500 mg/l result in a progressive increase in the cellular content of unsaturated fatty acids and respiratory cytochromes, cause the replacement of lanosterol and squalene by ergosterol, and an increase in total sterol content. 5. Haematoporphyrin and protoporphyrin IX have similar but less extensive effects on cellular composition, whereas haematin allows unsaturated fatty acid synthesis and some sterol synthesis, but has no effect on the formation of respiratory cytochromes. 6. These results suggest that growth of the organism in the presence of defined amounts of delta-aminolaevulinate will be useful in the investigation of the role of lipids and cytochromes in the function and assembly of mitochondrial membranes.

scholarly journals Mitochondria, oxidative stress and the petite phenotype in Saccharomyces cerevisiae

2010 ◽  
Vol 31 (2) ◽  
pp. 82
Author(s):  
Anita Ayer ◽  
Ian W Dawes ◽  
Gabriel G Perrone
Keyword(s):  
Oxidative Stress ◽  
Energy Production ◽  
Acid Synthesis ◽  
Nuclear Space ◽  
Amino Acid Synthesis ◽  
Iron Sulfur Cluster ◽  
Iron Sulfur ◽  
Eukaryotic Organisms ◽  
State Concentration

Oxidative stress has long been recognised as biologically important and is increasingly implicated in a variety of phenomena, such as mutation, carcinogenesis, degenerative and other diseases, inflammation, ageing, and development. The role of the mitochondrion in oxidative stress and the production of reactive oxygen species (ROS) and other radical species is well-established, with mitochondria providing a fascinating area of study within the oxidative stress field. Mitochondria are essential organelles for the viability of all eukaryotic organisms. While mitochondria perform important processes associated with oxidative phosphorylation and energy production, and numerous other metabolic processes, such as iron sulfur cluster biogenesis, lipid and amino acid synthesis, they also appear to be the largest intracellular source of ROS in aerobic cells. The steady state concentration of O2 in the mitochondrial matrix is five- to tenfold higher than in the cytosol or nuclear space according to one estimation. Therefore, mitochondrial macromolecules such as mitochondrial DNA are particularly susceptible to oxidative damage.

scholarly journals The role of dietary coconut for the prevention and treatment of Alzheimer's disease: potential mechanisms of action

2015 ◽  
Vol 114 (1) ◽  
pp. 1-14 ◽  
Author(s):  
W. M. A. D. B. Fernando ◽  
Ian J. Martins ◽  
K. G. Goozee ◽  
Charles S. Brennan ◽  
V. Jayasena ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Fatty Acids ◽  
Alternative Energy ◽  
Cocos Nucifera ◽  
Amyloid Β ◽  
Coconut Oil ◽  
Amyloid Β Peptide ◽  
Chain Fatty Acids

Coconut, Cocos nucifera L., is a tree that is cultivated to provide a large number of products, although it is mainly grown for its nutritional and medicinal values. Coconut oil, derived from the coconut fruit, has been recognised historically as containing high levels of saturated fat; however, closer scrutiny suggests that coconut should be regarded more favourably. Unlike most other dietary fats that are high in long-chain fatty acids, coconut oil comprises medium-chain fatty acids (MCFA). MCFA are unique in that they are easily absorbed and metabolised by the liver, and can be converted to ketones. Ketone bodies are an important alternative energy source in the brain, and may be beneficial to people developing or already with memory impairment, as in Alzheimer's disease (AD). Coconut is classified as a highly nutritious ‘functional food’. It is rich in dietary fibre, vitamins and minerals; however, notably, evidence is mounting to support the concept that coconut may be beneficial in the treatment of obesity, dyslipidaemia, elevated LDL, insulin resistance and hypertension – these are the risk factors for CVD and type 2 diabetes, and also for AD. In addition, phenolic compounds and hormones (cytokinins) found in coconut may assist in preventing the aggregation of amyloid-β peptide, potentially inhibiting a key step in the pathogenesis of AD. The purpose of the present review was to explore the literature related to coconut, outlining the known mechanistic physiology, and to discuss the potential role of coconut supplementation as a therapeutic option in the prevention and management of AD.

Mitochondrial matrix calcium ions regulate energy production in myocardium: A cytochemical study

1990 ◽  
Vol 48 (2) ◽  
pp. 166-167
Author(s):  
W.A. Jacob ◽  
R. Hertsens ◽  
A. Van Bogaert ◽  
M. De Smet
Keyword(s):  
Energy Metabolism ◽  
Calcium Ions ◽  
Energy Production ◽  
Regulation Of Respiration ◽  
Free Calcium ◽  
Mitochondrial Matrix ◽  
Cytochemical Study ◽  
Nmr Techniques

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.

Alcohol intake impairs glucose counterregulation during acute insulin-induced hypoglycemia in IDDM patients. Evidence for a critical role of free fatty acids

Diabetes ◽  
1993 ◽  
Vol 42 (11) ◽  
pp. 1626-1634 ◽  
Author(s):  
A. Avogaro ◽  
P. Beltramello ◽  
L. Gnudi ◽  
A. Maran ◽  
A. Valerio ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Alcohol Intake ◽  
Critical Role
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