scholarly journals Control of mitochondrial gene expression in the aging rat myocardium

2006 ◽  
Vol 84 (2) ◽  
pp. 191-198 ◽  
Author(s):  
Christophe M.R LeMoine ◽  
Grant B McClelland ◽  
Carrie N Lyons ◽  
Odile Mathieu-Costello ◽  
Christopher D Moyes
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Transcriptional Regulators ◽  
Acid Oxidation ◽  
Mitochondrial Enzymes ◽  
Mrna Levels ◽  
Α Subunit ◽  
Transcript Levels ◽  
Nuclear Respiratory Factor ◽  
Age Dependent

Aging induces complex changes in myocardium bioenergetic and contractile properties. Using F344BNF1rats, we examined age-dependent changes in myocardial bioenergetic enzymes (catalytic activities and transcript levels) and mRNA levels of putative transcriptional regulators of bioenergetic genes. Very old rats (35 months) showed a 22% increase in ventricular mass with no changes in DNA or RNA per gram. Age-dependent cardiac hypertrophy was accompanied by complex changes in mitochondrial enzymes. Enzymes of the Krebs cycle and electron transport system remained within 15% of the values measured in adult heart, significant decreases occurring in citrate synthase (10%) and aconitase (15%). Transcripts for these enzymes were largely unaffected by aging, although mRNA levels of putative transcriptional regulators of the enzymes (nuclear respiratory factor (NRF) 1 and 2 α subunit) increased by about 30%–50%. In contrast, enzymes of fatty acid oxidation exhibited a more diverse pattern, with a 50% decrease in β-hydroxyacyl-CoA dehydrogenase (HOAD) and no change in long-chain acyl-CoA dehydrogenase or carnitine palmitoyltransferase. Transcript levels for fatty acid oxidizing enzymes covaried with HOAD, which declined significantly by 30%. There were no significant changes in the relative transcript levels of regulators of genes for fatty acid oxidizing enzymes: peroxisome proliferator-activated receptor-α (PPARα), PPARβ, or PPARγ coactivator-1α (PGC-1α). There were no changes in the mRNA levels of Sirt1, a histone-modifying enzyme that interacts with PGC-1α. Collectively, these data suggest that aging causes complex changes in the enzymes of myocardial energy metabolism, triggered in part by NRF-independent pathways as well as post-transcriptional regulation.Key words: PGC-1a, fatty acid oxidation, nuclear respiratory factor (NRF), PPAR, coactivator, transcriptional regulation.

scholarly journals Interrelated effects of dihomo-γ-linolenic and arachidonic acids, and sesamin on hepatic fatty acid synthesis and oxidation in rats

2012 ◽  
Vol 108 (11) ◽  
pp. 1980-1993 ◽  
Author(s):  
Takashi Ide ◽  
Yoshiko Ono ◽  
Hiroshi Kawashima ◽  
Yoshinobu Kiso
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Dietary Fat ◽  
Acid Synthesis ◽  
Acid Oxidation ◽  
Mrna Levels ◽  
Lipogenic Enzymes ◽  
Hepatic Fatty Acid ◽  
Hepatic Fatty Acid Oxidation ◽  
Maize Oil

Interrelated effects of dihomo-γ-linolenic acid (DGLA) and arachidonic acid (ARA), and sesamin, a sesame lignan, on hepatic fatty acid synthesis and oxidation were examined in rats. Rats were fed experimental diets supplemented with 0 or 2 g/kg sesamin (1:1 mixture of sesamin and episesamin), containing 100 g/kg of maize oil or fungal oil rich in DGLA or ARA for 16 d. Among the groups fed sesamin-free diets, oils rich in DGLA or ARA, especially the latter, compared with maize oil strongly reduced the activity and mRNA levels of various lipogenic enzymes. Sesamin, irrespective of the type of fat, reduced the parameters of lipogenic enzymes except for malic enzyme. The type of dietary fat was rather irrelevant in affecting hepatic fatty acid oxidation among rats fed the sesamin-free diets. Sesamin increased the activities of enzymes involved in fatty acid oxidation in all groups of rats given different fats. The extent of the increase depended on the dietary fat type, and the values became much higher with a diet containing sesamin and oil rich in ARA in combination than with a diet containing lignan and maize oil. Analyses of mRNA levels revealed that the combination of sesamin and oil rich in ARA compared with the combination of lignan and maize oil markedly increased the gene expression of various peroxisomal fatty acid oxidation enzymes but not mitochondrial enzymes. The enhancement of sesamin action on hepatic fatty acid oxidation was also confirmed with oil rich in DGLA but to a lesser extent.

Bezafibrate Reduces mRNA Levels of Adipocyte Markers and Increases Fatty Acid Oxidation in Primary Culture of Adipocytes

Diabetes ◽  
2001 ◽  
Vol 50 (8) ◽  
pp. 1883-1890 ◽  
Author(s):  
A. Cabrero ◽  
M. Alegret ◽  
R. M. Sanchez ◽  
T. Adzet ◽  
J. C. Laguna ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Primary Culture ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Mrna Levels

scholarly journals Acetylation of Mitochondrial Trifunctional Protein α-Subunit Enhances Its Stability To Promote Fatty Acid Oxidation and Is Decreased in Nonalcoholic Fatty Liver Disease

2016 ◽  
Vol 36 (20) ◽  
pp. 2553-2567 ◽  
Author(s):  
Liang Guo ◽  
Shui-Rong Zhou ◽  
Xiang-Bo Wei ◽  
Yuan Liu ◽  
Xin-Xia Chang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Acid Oxidation ◽  
Fatty Liver Disease ◽  
Acid Oxidation ◽  
Α Subunit ◽  
Nonalcoholic Fatty Liver ◽  
Mitochondrial Trifunctional Protein

Nonalcoholic fatty liver disease (NAFLD) has become the most common liver disease, and decreased fatty acid oxidation is one of the important contributors to NAFLD. Mitochondrial trifunctional protein α-subunit (MTPα) functions as a critical enzyme for fatty acid β-oxidation, but whether dysregulation of MTPα is pathogenically connected to NAFLD is poorly understood. We show that MTPα is acetylated at lysine residues 350, 383, and 406 (MTPα-3K), which promotes its protein stability by antagonizing its ubiquitylation on the same three lysines (MTPα-3K) and blocking its subsequent degradation. Sirtuin 4 (SIRT4) has been identified as the deacetylase, deacetylating and destabilizing MTPα. Replacement of MTPα-3K with either MTPα-3KR or MTPα-3KQ inhibits cellular lipid accumulation both in free fatty acid (FFA)-treated alpha mouse liver 12 (AML12) cells and primary hepatocytes and in the livers of high-fat/high-sucrose (HF/HS) diet-fed mice. Moreover, knockdown of SIRT4 could phenocopy the effects of MTPα-3K mutant expression in mouse livers, and MTPα-3K mutants more efficiently attenuate SIRT4-mediated hepatic steatosis in HF/HS diet-fed mice. Importantly, acetylation of both MTPα and MTPα-3K is decreased while SIRT4 is increased in the livers of mice and humans with NAFLD. Our study reveals a novel mechanism of MTPα regulation by acetylation and ubiquitylation and a direct functional link of this regulation to NAFLD.

scholarly journals The PPARβ/δ Activator GW501516 Prevents the Down-Regulation of AMPK Caused by a High-Fat Diet in Liver and Amplifies the PGC-1α-Lipin 1-PPARα Pathway Leading to Increased Fatty Acid Oxidation

Endocrinology ◽  
2011 ◽  
Vol 152 (5) ◽  
pp. 1848-1859 ◽  
Author(s):  
Emma Barroso ◽  
Ricardo Rodríguez-Calvo ◽  
Lucía Serrano-Marco ◽  
Alma M. Astudillo ◽  
Jesús Balsinde ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
High Fat Diet ◽  
Plasma Lipoproteins ◽  
Acid Oxidation ◽  
Mrna Levels ◽  
High Fat ◽  
Hepatic Fatty Acid ◽  
Lipin 1 ◽  
Hepatic Fatty Acid Oxidation

Metabolic syndrome-associated dyslipidemia is mainly initiated by hepatic overproduction of the plasma lipoproteins carrying triglycerides. Here we examined the effects of the peroxisome proliferator-activated receptors (PPAR)-β/δ activator GW501516 on high-fat diet (HFD)-induced hypertriglyceridemia and hepatic fatty acid oxidation. Exposure to the HFD caused hypertriglyceridemia that was accompanied by reduced hepatic mRNA levels of PPAR-γ coactivator 1 (PGC-1)-α and lipin 1, and these effects were prevented by GW501516 treatment. GW501516 treatment also increased nuclear lipin 1 protein levels, leading to amplification in the PGC-1α-PPARα signaling system, as demonstrated by the increase in PPARα levels and PPARα-DNA binding activity and the increased expression of PPARα-target genes involved in fatty acid oxidation. These effects of GW501516 were accompanied by an increase in plasma β-hydroxybutyrate levels, demonstrating enhanced hepatic fatty acid oxidation. Moreover, GW501516 increased the levels of the hepatic endogenous ligand for PPARα, 16:0/18:1-phosphatidilcholine and markedly enhanced the expression of the hepatic Vldl receptor. Interestingly, GW501516 prevented the reduction in AMP-activated protein kinase (AMPK) phosphorylation and the increase in phosphorylated levels of ERK1/2 caused by HFD. In addition, our data indicate that the activation of AMPK after GW501516 treatment in mice fed HFD might be the result of an increase in the AMP to ATP ratio in hepatocytes. These findings indicate that the hypotriglyceridemic effect of GW501516 in HFD-fed mice is accompanied by an increase in phospho-AMPK levels and the amplification of the PGC-1α-lipin 1-PPARα pathway.

scholarly journals Fenofibrate Reverses Palmitate Induced Impairment in Glucose Uptake in Skeletal Muscle Cells by Preventing Cytosolic Ceramide Accumulation

2015 ◽  
Vol 37 (4) ◽  
pp. 1315-1328 ◽  
Author(s):  
Sudarshan Bhattacharjee ◽  
Nabanita Das ◽  
Ashok Mandala ◽  
Satinath Mukhopadhyay ◽  
Sib Sankar Roy
Keyword(s):  
Insulin Resistance ◽  
Fatty Acid ◽  
Glucose Uptake ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Stoichiometric Ratio ◽  
Mrna Levels ◽  
L6 Myotubes ◽  
Hypolipidemic Agents ◽  
Ceramide Accumulation

Backgrounds/Aims: The lipid induced insulin resistance is a major pathophysiologic mechanism underlying glucose intolerance of varying severity. PPARα-agonists are proven as effective hypolipidemic agents. The aim of this study was to see if impaired glucose uptake in palmitate treated myotubes is reversed by fenofibrate. Methods: Palmitate-treated myotubes were used as a model for insulin resistance, impaired glucose uptake, fatty acid oxidation and ceramide synthesis. mRNA levels of CPT1 and CPT2 were determined by PCR array and Q-PCR. Results: The incubation of myotubes with 750 uM palmitate not only reduced glucose uptake but also impaired fatty acid oxidation and cytosolic ceramide accumulation. Palmitate upregulated CPT1b expression in L6 myotubes, while CPT2 expression level remained unchanged. The altered stoichiometric ratio between the two CPT isoforms led to reduced fatty acid oxidation (FAO), ceramide accumulation and impaired glucose uptake, whereas administration of 200 µM fenofibrate signifcantly reversed the above abnormalities by increasing CPT2 mRNA levels and restoring CPT1b to CPT2 ratio. Conclusion: Palmitate-induced alteration in the stoichiometric ratio of mitochondrial CPT isoforms leads to incomplete FAO and enhanced cytosolic ceramide accumulation that lead to insulin resistance. Fenofibrate ameliorated insulin resistance by restoring the altered stoichiometry by upregulating CPT2 and preventing, cytoplasmic ceramide accumulation.

scholarly journals Effect of Continuous Feeding of Ayu-Narezushi on Lipid Metabolism in a Mouse Model of Metabolic Syndrome

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Takeshi Nishida ◽  
Koichi Tsuneyama ◽  
Yasuhiko Tago ◽  
Koji Nomura ◽  
Makoto Fujimoto ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Serum Triglyceride ◽  
Fermented Food ◽  
Control Group ◽  
Acid Oxidation ◽  
Mrna Levels ◽  
Mice Model ◽  
Continuous Feeding

Ayu-narezushi, a traditional Japanese fermented food, comprises abundant levels of lactic acid bacteria (LAB) and free amino acids. This study aimed to examine the potential beneficial effects of ayu-narezushi and investigated whether ayu-narezushi led to improvements in the Tsumura Suzuki obese diabetes (TSOD) mice model of spontaneous metabolic syndrome because useful LAB are known as probiotics that regulate intestinal function. In the present study, the increased body weight of the TSOD mice was attenuated in those fed the ayu-narezushi-comprised chow (ayu-narezushi group) compared with those fed the normal rodent chow (control group). Serum triglyceride and cholesterol levels were significantly lower in the Ayu-narezushi group than in the control group at 24 weeks of age. Furthermore, hepatic mRNA levels of carnitine-palmitoyl transferase 1 and acyl-CoA oxidase, which related to fatty acid oxidation, were significantly increased in the ayu-narezushi group than in the control group at 24 weeks of age. In conclusion, these results suggested that continuous feeding with ayu-narezushi improved obesity and dyslipidemia in the TSOD mice and that the activation of fatty acid oxidation in the liver might contribute to these improvements.

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