scholarly journals Acetate Affects the Process of Lipid Metabolism in Rabbit Liver, Skeletal Muscle and Adipose Tissue

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 799 ◽  
Author(s):  
Lei Liu ◽  
Chunyan Fu ◽  
Fuchang Li
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Fatty Acid Synthesis ◽  
Lipid Accumulation ◽  
Acid Synthesis ◽  
Control Group ◽  
Acid Oxidation ◽  
Signal Pathways ◽  
Peroxisome Proliferator ◽  
Acid Uptake

Short-chain fatty acids (SCFAs) (a microbial fermentation production in the rabbit gut) have an important role in many physiological processes, which may be related to the reduced body fat of rabbits. In the present experiment, we study the function of acetate (a major SCFA in the rabbit gut) on fat metabolism. Ninety rabbits (40 days of age) were randomly divided into three groups: a sham control group (injection of saline for four days); a group experiencing subcutaneous injection of acetate for four days (2 g/kg BM per day, one injection each day, acetate); and a pair-fed sham treatment group. The results show that acetate-inhibited lipid accumulation by promoting lipolysis and fatty acid oxidation and inhibiting fatty acid synthesis. Activated G protein-coupled receptor 41/43, adenosine monophosphate activated protein kinase (AMPK) and extracellular-signal-regulated kinase (ERK) 1/2 signal pathways were likely to participate in the regulation in lipid accumulation of acetate. Acetate reduced hepatic triglyceride content by inhibiting fatty acid synthesis, enhancing fatty acid oxidation and lipid output. Inhibited peroxisome proliferator-activated receptor α (PPARα) and activated AMPK and ERK1/2 signal pathways were related to the process in liver. Acetate reduced intramuscular triglyceride level via increasing fatty acid uptake and fatty acid oxidation. PPARα was associated with the acetate-reduced intracellular fat content.

Regulation of fatty acid synthesis and oxidation by the AMP-activated protein kinase

2002 ◽  
Vol 30 (6) ◽  
pp. 1064-1070 ◽  
Author(s):  
D. G. Hardie ◽  
D. A. Pan
Keyword(s):  
Fatty Acid ◽  
Protein Kinase ◽  
Fatty Acid Oxidation ◽  
Fatty Acid Synthesis ◽  
Cellular Stress ◽  
Energy Charge ◽  
Acid Synthesis ◽  
Atp Depletion ◽  
Acid Oxidation ◽  
Amp Activated Protein Kinase

The AMP-activated protein kinase (AMPK) is a sensor of cellular energy charge and a ‘metabolic master switch’. When activated by ATP depletion, it switches off ATP-consuming processes, while switching on catabolic pathways that generate ATP. AMPK exists as heterotrimeric complexes comprising catalytic α subunits and regulatory β and γ subunits, each of which occurs as multiple isoforms. Rising AMP and falling ATP, brought about by various types of cellular stress (including exercise in skeletal muscle), stimulate the system in an ultrasensitive manner. Acetyl-CoA carboxylase (ACC) exists in mammals as two isoforms, termed ACC-1 and ACC-2 (also known as ACC-α and ACC-β). AMPK phosphorylates and inactivates both isoforms at the equivalent site. Knockout mice, and other approaches, suggest that the malonyl-CoA produced by ACC-2 is exclusively involved in regulation of fatty acid oxidation, whereas that produced by ACC-1 is utilized in fatty acid synthesis. Activation of AMPK by cellular stress or exercise therefore switches on fatty acid oxidation (via phosphorylation of ACC-2) while switching off fatty acid synthesis (via phosphorylation of ACC-1). The Drosophila melanogaster genome contains single genes encoding homologues of the α, β and γ subunits of AMPK (DmAMPK) and of ACC (DmACC). Studies in a Drosophila embryonal cell line show that DmAMPK is activated by stresses that cause ATP depletion (oligomycin, hypoxia or glucose deprivation) and that this is associated with phosphorylation of the site on DmACC equivalent to the AMPK sites on mammalian ACC-1 and ACC-2. This is abolished when expression of DmAMPK is ablated using an RNA interference approach, proving that DmAMPK is necessary for phosphorylation of DmACC in response to ATP depletion.

Effects of 2[5(4-chlorphenyl)pentyl]oxirane-2- carboxylate on fatty acid synthesis and fatty acid oxidation in isolated rat hepatocytes

1985 ◽  
Vol 34 (15) ◽  
pp. 2651-2654 ◽  
Author(s):  
Loranne Agius ◽  
Deenam Pillay ◽  
K. George ◽  
M.M. Alberti ◽  
H. Stanley ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Fatty Acid Synthesis ◽  
Rat Hepatocytes ◽  
Acid Synthesis ◽  
Acid Oxidation ◽  
Isolated Rat Hepatocytes ◽  
Isolated Rat

scholarly journals Impairment of PPARα and the Fatty Acid Oxidation Pathway Aggravates Renal Fibrosis during Aging

2018 ◽  
Vol 29 (4) ◽  
pp. 1223-1237 ◽  
Author(s):  
Ki Wung Chung ◽  
Eun Kyeong Lee ◽  
Mi Kyung Lee ◽  
Goo Taeg Oh ◽  
Byung Pal Yu ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Epithelial Cells ◽  
Fatty Acid Oxidation ◽  
Calorie Restriction ◽  
Lipid Accumulation ◽  
Renal Fibrosis ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Effects Of Aging

Defects in the renal fatty acid oxidation (FAO) pathway have been implicated in the development of renal fibrosis. Although, compared with young kidneys, aged kidneys show significantly increased fibrosis with impaired kidney function, the mechanisms underlying the effects of aging on renal fibrosis have not been investigated. In this study, we investigated peroxisome proliferator–activated receptor α (PPARα) and the FAO pathway as regulators of age-associated renal fibrosis. The expression of PPARα and the FAO pathway–associated proteins significantly decreased with the accumulation of lipids in the renal tubular epithelial region during aging in rats. In particular, decreased PPARα protein expression associated with increased expression of PPARα-targeting microRNAs. Among the microRNAs with increased expression during aging, miR-21 efficiently decreased PPARα expression and impaired FAO when ectopically expressed in renal epithelial cells. In cells pretreated with oleic acid to induce lipid stress, miR-21 treatment further enhanced lipid accumulation. Furthermore, treatment with miR-21 significantly exacerbated the TGF-β–induced fibroblast phenotype of epithelial cells. We verified the physiologic importance of our findings in a calorie restriction model. Calorie restriction rescued the impaired FAO pathway during aging and slowed fibrosis development. Finally, compared with kidneys of aged littermate controls, kidneys of aged PPARα−/− mice showed exaggerated lipid accumulation, with decreased activity of the FAO pathway and a severe fibrosis phenotype. Our results suggest that impaired renal PPARα signaling during aging aggravates renal fibrosis development, and targeting PPARα is useful for preventing age-associated CKD.

scholarly journals Pancreatic Islet Adaptation to Fasting Is Dependent on Peroxisome Proliferator-Activated Receptor α Transcriptional Up-Regulation of Fatty Acid Oxidation

Endocrinology ◽  
2005 ◽  
Vol 146 (1) ◽  
pp. 375-382 ◽  
Author(s):  
Sandrine Gremlich ◽  
Christopher Nolan ◽  
Raphaël Roduit ◽  
Rémy Burcelin ◽  
Marie-Line Peyot ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Pancreatic Islet ◽  
Cellular Response ◽  
Uncoupling Protein ◽  
Acid Oxidation ◽  
Hyperinsulinemic Hypoglycemia ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

The cellular response to fasting and starvation in tissues such as heart, skeletal muscle, and liver requires peroxisome proliferator-activated receptor-α (PPARα)-dependent up-regulation of energy metabolism toward fatty acid oxidation (FAO). PPARα null (PPARαKO) mice develop hyperinsulinemic hypoglycemia in the fasting state, and we previously showed that PPARα expression is increased in islets at low glucose. On this basis, we hypothesized that enhanced PPARα expression and FAO, via depletion of lipid-signaling molecule(s) for insulin exocytosis, are also involved in the normal adaptive response of the islet to fasting. Fasted PPARαKO mice compared with wild-type mice had supranormal ip glucose tolerance due to increased plasma insulin levels. Isolated islets from the PPARα null mice had a 44% reduction in FAO, normal glucose use and oxidation, and enhanced glucose-induced insulin secretion. In normal rats, fasting for 24 h increased islet PPARα, carnitine palmitoyltransferase 1, and uncoupling protein-2 mRNA expression by 60%, 62%, and 82%, respectively. The data are consistent with the view that PPARα, via transcriptionally up-regulating islet FAO, can reduce insulin secretion, and that this mechanism is involved in the normal physiological response of the pancreatic islet to fasting such that hypoglycemia is avoided.

An Increase in Peroxisomal Fatty Acid Oxidation Is Not Sufficient to Prevent Tissue Lipid Accumulation in hHTg Rats

2006 ◽  
Vol 967 (1) ◽  
pp. 71-79 ◽  
Author(s):  
J. UKROPEC ◽  
I. KLIMEŠ ◽  
D. GAŠPERÍKOVÁ ◽  
E. DEMCÁKOVÁ ◽  
C. A. DREVON ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Lipid Accumulation ◽  
Acid Oxidation ◽  
Tissue Lipid ◽  
Peroxisomal Fatty Acid Oxidation ◽  
Peroxisomal Fatty Acid
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