malonyl-coenzyme-a and Disease-Models--Animal

Hypertension and kidney disease have been repeatedly associated with genomic variants and alterations of lysine metabolism. Here, we combined stable isotope labeling with untargeted metabolomics to investigate lysine's metabolic fate in vivo. Dietary

Topics: Albumins; Animals; Carbon; Disease Models, Animal; Hypertension; Kidney; Lysine; Malonyl Coenzyme A; Rats

The histidine nucleotide-binding protein, Hint2, is a mitochondrial phosphoramidase expressed in liver, brown fat, pancreas, and muscle. The livers of Hint2 knockout (Hint2(-/-)) mice accumulate triglycerides and show a pattern of mitochondrial protein lysine hyperacetylation. The extent and nature of the lysine acetylation changes and the response of Hint2(-/-) mice to nutritional challenges that elicit a modification of protein acetylation have not been investigated. To compare the adaptation of Hint2(-/-) and control (Hint2(+/+)) mice with episodes of fasting and high-fat diet (HFD), we subjected animals to either feeding ad libitum or fasting for 24 h, and to either a HFD or control diet for 8 wk. Triglyceride content was higher in Hint2(-/-) than in Hint2(+/+) livers, whereas plasma triglycerides were fourfold lower. Malonyl-CoA levels were increased twofold in Hint2(-/-) livers. After 24 h fasting, Hint2(-/-) displayed a decrease in body temperature, commensurate with a decrease in mass of brown fat and downregulation of uncoupling protein 1. HFD-treated Hint2(-/-) livers showed more steatosis, and plasma insulin and cholesterol were higher than in Hint(+/+) mice. Several proteins identified as substrates of sirtuin 3 and 5 and active in intermediary and ketone metabolism were hyperacetylated in liver and brown fat mitochondria after both HFD and fasting regimens. Glutamate dehydrogenase activity was downregulated in fed and fasted livers, and this was attributed to an increase in acetylation and ADP-ribosylation. The absence of Hint2 deregulates the posttranslational modification of several mitochondrial proteins, which impedes the adaptation to episodes of nutritional stress.

Topics: Acetylation; Adaptation, Physiological; Adenosine Diphosphate Ribose; Adipose Tissue, Brown; Animals; Body Temperature Regulation; Cholesterol; Diet, High-Fat; Disease Models, Animal; Fasting; Fatty Liver; Gene Deletion; Genetic Predisposition to Disease; Glutamate Dehydrogenase; Hydrolases; Insulin; Liver; Malonyl Coenzyme A; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Knockout; Mitochondria, Liver; Mitochondrial Proteins; Nutritional Status; Phenotype; Protein Processing, Post-Translational; Triglycerides; Uncoupling Protein 1

Social stress may precipitate psychiatric disorders such as depression, which is related to the occurrence of the metabolic syndrome, including obesity and type 2 diabetes. We have evaluated the effects of social stress on central and peripheral metabolism using a model of depression in mice. In the present study, we focused on coenzyme A (CoA) molecular species [i.e. non-esterified CoA (CoASH), acetyl-CoA and malonyl-CoA] which play important roles in numerous metabolic pathways, and we analyzed changes in expression of these molecules in the hypothalamus and liver of adult male mice (C57BL/6J) subjected to 10 days of subchronic mild social defeat stress (sCSDS) with ICR mice as aggressors. Mice (n = 12) exposed to showed hyperphagia- and polydipsia-like symptoms and increased body weight gain compared with control mice which were not affected by exposure to ICR mice (n = 12). To elucidate the underlying metabolic features in the sCSDS model, acetyl-CoA, malonyl-CoA and CoASH tissue levels were analyzed using the acyl-CoA cycling method. The levels of hypothalamic malonyl-CoA, which decreases feeding behavior, were not influenced by sCSDS. However, sCSDS reduced levels of acetyl-CoA, malonyl-CoA and total CoA (sum of the three CoA molecular species) in the liver. Hence, hyperphagia-like symptoms in sCSDS mice evidently occurred independently of hypothalamic malonyl-CoA, but might consequently lead to down-regulation of hepatic CoA via altered expression of nudix hydrolase 7. Future studies should investigate the molecular mechanism(s) underlying the down-regulation of liver CoA pools in sCSDS mice.

Topics: Acetyl Coenzyme A; Animals; Body Weight; Coenzyme A; Depression; Disease Models, Animal; Down-Regulation; Hypothalamus; Liver; Male; Malonyl Coenzyme A; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Stress, Psychological; Weight Gain

This study investigated whether cyclophosphamide (CP) and ifosfamide (IFO) therapy alters the expression of the key genes engaged in long-chain fatty acid (LCFA) oxidation outside rat heart mitochondria, and if so, whether these alterations should be viewed as a mechanism during CP- and IFO-induced cardiotoxicity. Adult male Wistar albino rats were assigned to one of the six treatment groups: Rats in group 1 (control) and group 2 (L-carnitine) were injected intraperitoneal (i.p.) with normal saline and L-carnitine (200 mg/kg/day), respectively, for 10 successive days. Animals in group 3 (CP group) were injected i.p. with normal saline for 5 days before and 5 days after a single dose of CP (200 mg/kg, i.p.). Rats in group 4 (IFO group) received normal saline for 5 successive days followed by IFO (50 mg/kg/day, i.p.) for 5 successive days. Rats in group 5 (CP-carnitine supplemented) were given the same doses of L-carnitine as group 2 for 5 days before and 5 days after a single dose of CP as group 3. Rats in group 6 (IFO-carnitine supplemented) were given the same doses of L-carnitine as group 2 for 5 days before and 5 days concomitant with IFO as group 4. Immediately, after the last dose of the treatment protocol, blood samples were withdrawn and animals were killed for biochemical, histopathological and gene expression studies. Treatment with CP and IFO significantly decreased expression of heart fatty acid binding protein (H-FABP) and carnitine palmitoyltransferase I (CPT I) genes in cardiac tissues. Moreover, CP but not IFO significantly increased acetyl-CoA carboxylase2 mRNA expression. Conversely, IFO but not CP significantly decreased mRNA expression of malonyl-CoA decarboxylase. Both CP and IFO significantly increased serum lactate dehydrogenase, creatine kinase isoenzyme MB and malonyl-CoA content and histopathological lesions in cardiac tissues. Interestingly, carnitine supplementation completely reversed all the biochemical, histopathological and gene expression changes induced by CP and IFO to the control values, except CPT I mRNA, and protein expression remained inhibited by IFO. Data from the current study suggest, for the first time, that (1) CP and IFO therapy is associated with the inhibition of the expression of H-FABP and CPT I genes in cardiac tissues with the consequent inhibition of mitochondrial transport and oxidation of LCFA. (2) The progressive increase in cardiotoxicity enzymatic indices and the decrease in H-FABP and CPT I express

Topics: Animals; Antineoplastic Agents, Alkylating; Blotting, Western; Cardiomyopathies; Cardiotoxicity; Carnitine; Carnitine O-Palmitoyltransferase; Creatine Kinase, MB Form; Cyclophosphamide; Disease Models, Animal; Fatty Acid-Binding Proteins; Gene Expression Regulation; Ifosfamide; L-Lactate Dehydrogenase; Male; Malonyl Coenzyme A; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; RNA, Messenger

Muscle carnitine palmitoyltransferase I is predominant in the heart, but the liver isoform (liver carnitine palmitoyltransferase I [L-CPT1]) is elevated in hearts with low long chain fatty acid oxidation, such as fetal and hypertrophied hearts.. This work examined the effect of acute L-CPT1 expression on the regulation of palmitate oxidation and energy metabolism in intact functioning rat hearts for comparison with findings in hypertrophied hearts.. L-CPT1 was expressed in vivo in rat hearts by coronary perfusion of Adv.cmv.L-CPT1 (L-CPT1, n=15) vs. phosphate-buffered saline (PBS) infusion (PBS, n=7) or empty virus (empty, n=5). L-CPT1 was elevated 5-fold at 72 hours after Adv.cmv.L-CPT1 infusion (P<0.05), but muscle carnitine palmitoyltransferase I was unaffected. Despite similar tricarboxylic acid cycle rates, palmitate oxidation rates were reduced with L-CPT1 (1.12 ± 0.29 μmol/min per gram of dry weight, mean±SE) vs. PBS (1.6 ± 0.34). Acetyl CoA production from palmitate was reduced with L-CPT1 (69 ± 0.02%; P<0.05; PBS=79 ± 0.01%; empty=81 ± 0.02%), similar to what occurs in hypertrophied hearts, and with no difference in malonyl CoA content. Glucose oxidation was elevated with L-CPT1 (by 60%). Surprisingly, L-CPT1 hearts contained elevated atrial natriuretic peptide, indicating induction of hypertrophic signaling.. The results link L-CPT1 expression to reduced palmitate oxidation in a nondiseased adult heart, recapitulating the phenotype of reduced long chain fatty acid oxidation in cardiac hypertrophy. The implications are that L-CPT1 expression induces metabolic remodeling hypertrophic signaling and that regulatory factors beyond malonyl CoA in the heart regulate long chain fatty acid oxidation via L-CPT1.

Topics: Acetyl-CoA Carboxylase; Animals; Atrial Natriuretic Factor; Carboxy-Lyases; Cardiomegaly; Carnitine O-Palmitoyltransferase; Disease Models, Animal; Energy Metabolism; Gene Expression Regulation, Enzymologic; Gene Transfer Techniques; Genotype; Liver; Magnetic Resonance Spectroscopy; Male; Malonyl Coenzyme A; Myocardium; Oxidation-Reduction; Palmitic Acid; Phenotype; Rats; Rats, Sprague-Dawley; RNA, Messenger; Time Factors; Up-Regulation

p53 and its transcriptional target miRNA34a have been implicated in the pathogenesis of fatty liver. We tested the efficacy of a p53 inhibitor, pifithrin-α p-nitro (PFT) in attenuating steatosis, associated oxidative stress and apoptosis in a murine model of non-alcoholic fatty liver disease (NAFLD).. C57BL/6 mice were fed a high-fat (HFD) or control diet for 8 weeks; PFT or DMSO (vehicle) was administered three times per week. Markers of oxidative stress and apoptosis as well as mediators of hepatic fatty acid metabolism were assessed by immunohistochemistry, Western blot, real-time PCR, and biochemical assays.. PFT administration suppressed HFD-induced weight gain, ALT elevation, steatosis, oxidative stress, and apoptosis. PFT treatment blunted the HFD-induced upregulation of miRNA34a and increased SIRT1 expression. In the livers of HFD-fed, PFT-treated mice, activation of the SIRT1/PGC1α/PPARα axis increased the expression of malonyl-CoA decarboxylase (MLYCD), an enzyme responsible for malonyl-CoA (mCoA) degradation. Additionally, the SIRT1/LKB1/AMPK pathway (upstream activator of MLYCD) was promoted by PFT. Thus, induction of these two pathways by PFT diminished the hepatic mCoA content by enhancing MLYCD expression and function. Since mCoA inhibits carnitine palmitoyltransferase 1 (CPT1), the decrease of hepatic mCoA in the PFT-treated, HFD-fed mice increased CPT1 activity, favored fatty acid oxidation, and decreased steatosis. Additionally, we demonstrated that PFT abrogated steatosis and promoted MLYCD expression in palmitoleic acid-treated human HepaRG cells.. The p53 inhibitor PFT diminished hepatic triglyceride accumulation and lipotoxicity in mice fed a HFD, by depleting mCoA and favoring the β-oxidation of fatty acids.

Topics: Alanine Transaminase; Animals; Apoptosis; Benzothiazoles; Cell Line; Diet, High-Fat; Disease Models, Animal; Fatty Acids; Fatty Liver; Humans; Liver; Male; Malonyl Coenzyme A; Mice; Mice, Inbred C57BL; MicroRNAs; Models, Biological; Non-alcoholic Fatty Liver Disease; Oxidative Stress; Toluene; Triglycerides; Tumor Suppressor Protein p53; Weight Gain

Although a major mechanism for cardioprotection is altered metabolism, little is known regarding metabolic changes in ischaemic preconditioning and subsequent ischaemia. Our objective was to examine the effects of the second window of preconditioning (SWOP), the delayed phase of preconditioning against infarction and stunning, on long-chain free fatty acid (LCFA) oxidation during ischaemia in chronically instrumented, conscious pigs.. We studied three groups: (i) normal baseline perfusion (n = 5); (ii) coronary artery stenosis (CAS; n = 5); (iii) CAS 24 h following 2 × 10 min coronary occlusions and 10 min reperfusion (n = 7). Ischaemia was induced by a left anterior descending (LAD) stenosis (40% flow reduction) for 90 min, dropping systolic wall thickening by 72%. LCFA oxidation was assessed following LAD infusion of (13)C palmitate, i.e. during control or stenosis, by in vitro nuclear magnetic resonance of the sampled myocardium. Stenosis reduced subendocardial blood flow subendocardially, but not subepicardial, yet induced transmural reductions in LCFA oxidation and increased non-oxidative glycolysis. During stenosis, preconditioned hearts showed normalized contributions of LCFA to oxidative ATP synthesis, despite increased lactate accumulation. SWOP induced a shift towards LCFA oxidation during stenosis, despite increased malonyl-CoA, and marked protection of contractile function with a significant improvement in systolic wall thickening.. Thus, the second window of preconditioning normalized oxidative metabolism of LCFA during subsequent ischaemia despite elevated non-oxidative glycolysis and malonyl-CoA and was linked to protection of regional contractile function resulting in improved mechanical performance. Interestingly, the metabolic responses occurred transmurally while ischaemia was restricted solely to the subendocardium.

Topics: Acetyl Coenzyme A; Animals; Coronary Circulation; Coronary Stenosis; Disease Models, Animal; Energy Metabolism; Glycolysis; Hemodynamics; Ischemic Preconditioning, Myocardial; Malonyl Coenzyme A; Myocardial Contraction; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardial Stunning; Myocardium; Oxidation-Reduction; Palmitic Acid; Recovery of Function; Sus scrofa; Time Factors; Ventricular Function, Left

Acute leptin increase as well as endogenous hyperleptinemia evoked by high-fat diets (HF) activate fatty acid metabolism in nonadipose tissues. This supports the notion that hyperleptinemia is pivotal to prevent/delay steatosis during periods of positive energy balance. We have previously shown that long-term HF spares ectopic accumulation of lipids specifically in the miocardium. Because carnitine palmitoyltransferase I (CPT-I) allows mitochondrial uptake/oxidation of fatty acids, we have hypothesized that leptin drives cardiac CPT-I activity. In the current study, hyperleptinemia was induced in C57BL/6J mice either by exogenous leptin administration or by means of HF, and the ability of malonyl-coenzyme A (malonyl-CoA) (the main endogenous inhibitor of CPT-I) to inhibit cardiac CPT was analyzed. IC(50) values of malonyl-CoA were 8.1 +/- 1.5 micromol/liter in controls vs. 69.3 +/- 5.2 micromol/liter (P < 0.01) in leptin-treated mice. This effect was also observed in cardiac explants incubated with leptin and was blocked by triciribine, a compound shown to inhibit protein kinase B (Akt) phosphorylation (pAkt). In accordance, acute leptin evoked an increase of cardiac pAkt levels, which correlated with CPT sensitivity to malonyl-CoA. Otherwise, the inhibitory effect of malonyl-CoA was hindered in HF hyperleptinemic mice, and in this case, pAkt levels also correlated with CPT sensitivity to malonyl-CoA. Our data show that leptin reduces the sensitivity of cardiac CPT-I to malonyl-CoA and suggest the involvement of an Akt-related signaling pathway in this effect. This mechanism appears to be sensitive to both acute and chronic hyperleptinemia. We conclude that this action of leptin is pivotal to drive cardiac metabolism under situations associated to hyperleptinemia.

Topics: Animals; Carnitine O-Palmitoyltransferase; Dietary Fats; Disease Models, Animal; Heart Diseases; Leptin; Lipid Metabolism; Male; Malonyl Coenzyme A; Mice; Mice, Inbred C57BL; Myocardium; Phosphorylation; Proto-Oncogene Proteins c-akt; Ribonucleosides; STAT3 Transcription Factor; Triglycerides

The alterations of enzymatic activities involved in lipid degradation in cancer cachexia have not been fully elucidated. One of the two subclones of colon 26 adenocarcinoma, clone 20, with a potent ability to induce cachexia, or clone 5, without such an activity, was transplanted in to CDF-1 male mice. Murine livers were extirpated for analyses on the 14th day after tumor inoculation. The body weights and food intake of mice bearing clone 20 were all significantly lower than those of non-tumor bearing mice and mice bearing the clone 5 tumor. The decline of body weight was accompanied by a shrinkage of epididymal fat pads. Expression of spermidine/spermine N-1 acetyl transferase (SSAT) assessed by real-time PCR was significantly increased in cachectic mice. Conversely, acetyl-CoA carboxylase (ACC) measured by Western blotting and malonyl-CoA levels determined by malonyl-CoA:acetyl-CoA cycling procedures were decreased in cachectic mice. Indomethacin in drinking water reversed the clone 20 induced decrease in body and fat weight and food intake, and simultaneously negated the clone 20 induced increase of SSAT expressions and decrease of ACC and malonyl-CoA amounts. Because malonyl-CoA inhibits the rate-limiting step in the beta-oxidation of fatty acids, the decreased malonyl-CoA and the background metabolic alterations may contribute to the accelerated lipolysis of cancer cachexia.

Topics: Acetyl-CoA Carboxylase; Acetyltransferases; Animals; Body Weight; Cachexia; Disease Models, Animal; Eating; Liver; Male; Malonyl Coenzyme A; Mice; Mice, Inbred BALB C; Mice, Inbred DBA; Neoplasms; Polymerase Chain Reaction

Leptin stimulates fatty acid oxidation via the phosphorylation of AMPK (AMP-activated protein kinase) and ACC (acetyl-CoA carboxylase). Obesity is associated with resistance to the effects of leptin. We determined the action of leptin on AMPKalpha and ACCbeta phosphorylation and lipid metabolism in soleus (SOL) and extensor digitorum longus (EDL) muscles from lean and obese Wistar rats after 1 and 100 nM leptin. Both leptin doses stimulated phosphorylation of AMPKalpha and ACCbeta (P

Topics: Acetyl-CoA Carboxylase; Acyl Coenzyme A; Adipose Tissue; AMP-Activated Protein Kinases; Animals; Body Weight; Dietary Fats; Disease Models, Animal; Dose-Response Relationship, Drug; Energy Metabolism; Enzyme Activation; Fatty Acids; Glycolysis; Humans; Insulin; Leptin; Male; Malonyl Coenzyme A; Multienzyme Complexes; Muscle Fibers, Skeletal; Muscle, Skeletal; Obesity; Oxidation-Reduction; Phosphorylation; Protein Serine-Threonine Kinases; Rats; Rats, Wistar

Peroxisomal oxidation yields metabolites that are more efficiently utilized by mitochondria. This is of potential clinical importance because reduced fatty acid oxidation is suspected to promote excess lipid accumulation in obesity-associated insulin resistance. Our purpose was to assess peroxisomal contributions to mitochondrial oxidation in mixed gastrocnemius (MG), liver, and left ventricle (LV) homogenates from lean and fatty (fa/fa) Zucker rats. Results indicate that complete mitochondrial oxidation (CO(2) production) using various lipid substrates was increased approximately twofold in MG, unaltered in LV, and diminished approximately 50% in liver of fa/fa rats. In isolated mitochondria, malonyl-CoA inhibited CO(2) production from palmitate 78%, whereas adding isolated peroxisomes reduced inhibition to 21%. These data demonstrate that peroxisomal products may enter mitochondria independently of CPT I, thus providing a route to maintain lipid disposal under conditions where malonyl-CoA levels are elevated, such as in insulin-resistant tissues. Peroxisomal metabolism of lignoceric acid in fa/fa rats was elevated in both liver and MG (LV unaltered), but peroxisomal product distribution varied. A threefold elevation in incomplete oxidation was solely responsible for increased hepatic peroxisomal oxidation (CO(2) unaltered). Alternatively, only CO(2) was detected in MG, indicating that peroxisomal products were exclusively partitioned to mitochondria for complete lipid disposal. These data suggest tissue-specific destinations for peroxisome-derived products and emphasize a potential role for peroxisomes in skeletal muscle lipid metabolism in the obese, insulin-resistant state.

Topics: Animals; Disease Models, Animal; Epoxy Compounds; Glucose Tolerance Test; Hypoglycemic Agents; Insulin Resistance; Lipids; Liver; Male; Malonyl Coenzyme A; Mitochondria, Liver; Mitochondria, Muscle; Obesity; Oxidation-Reduction; Peroxisomes; Rats; Rats, Sprague-Dawley; Rats, Zucker

The expression of fatty acid synthase (FAS) in rat and mouse sciatic nerves during postnatal development was investigated. FAS activity was not sensitive to the nutritional status of the animals. During development, the specific activity of FAS was low in rat and mouse nerves immediately after birth. Then, there was a steady increase in the activity (8- to 10-fold) which reached a maximal level around postnatal day 11, plateaued till day 32, and decreased to reach 30% of the maximum at day 80. A similar developmental profile was obtained when the amount of FAS protein was quantified, thus suggesting that the variations in activity observed during sciatic nerve development are mainly due to variations in FAS protein content. Northern blot analysis showed that the mRNA levels for FAS parallels those of the ceramide galactosyl transferase (CGT) during mouse sciatic nerve development and in a rat demyelination-nerve regeneration model. In addition, we measured FAS expression in the sciatic nerves of the trembler mutant, which is a mouse model of PNS dysmyelination. In 20-day-old trembler nerves, FAS specific activity, protein amount and mRNA levels represented only 25% of the normal values. Altogether, our data indicate that FAS expression is linked to the PNS myelination process, and that the main regulation occurs at the level of the gene expression.

Topics: Aging; Animals; Animals, Newborn; Brain; Demyelinating Diseases; Disease Models, Animal; Fatty Acid Synthases; Galactosyltransferases; Gene Expression Regulation, Enzymologic; Liver; Malonyl Coenzyme A; Membrane Lipids; Mice; Mice, Neurologic Mutants; Myelin Sheath; N-Acylsphingosine Galactosyltransferase; Nerve Regeneration; Rats; Rats, Sprague-Dawley; Rats, Wistar; RNA, Messenger; Schwann Cells; Sciatic Nerve; Up-Regulation; Wallerian Degeneration