scholarly journals ADCK2 Haploinsufficiency Reduces Mitochondrial Lipid Oxidation and Causes Myopathy Associated with CoQ Deficiency

2019 ◽  
Vol 8 (9) ◽  
pp. 1374 ◽  
Author(s):  
Vázquez-Fonseca ◽  
Schaefer ◽  
Navas-Enamorado ◽  
Santos-Ocaña ◽  
Hernández-Camacho ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Mouse Model ◽  
Fatty Acid Oxidation ◽  
Physical Performance ◽  
Liver Dysfunction ◽  
Mitochondrial Myopathy ◽  
Integrated Analysis ◽  
Acid Oxidation ◽  
Mitochondrial Fatty Acid

Fatty acids and glucose are the main bioenergetic substrates in mammals. Impairment of mitochondrial fatty acid oxidation causes mitochondrial myopathy leading to decreased physical performance. Here, we report that haploinsufficiency of ADCK2, a member of the aarF domain-containing mitochondrial protein kinase family, in human is associated with liver dysfunction and severe mitochondrial myopathy with lipid droplets in skeletal muscle. In order to better understand the etiology of this rare disorder, we generated a heterozygous Adck2 knockout mouse model to perform in vivo and cellular studies using integrated analysis of physiological and omics data (transcriptomics–metabolomics). The data showed that Adck2+/− mice exhibited impaired fatty acid oxidation, liver dysfunction, and mitochondrial myopathy in skeletal muscle resulting in lower physical performance. Significant decrease in Coenzyme Q (CoQ) biosynthesis was observed and supplementation with CoQ partially rescued the phenotype both in the human subject and mouse model. These results indicate that ADCK2 is involved in organismal fatty acid metabolism and in CoQ biosynthesis in skeletal muscle. We propose that patients with isolated myopathies and myopathies involving lipid accumulation be tested for possible ADCK2 defect as they are likely to be responsive to CoQ supplementation.

scholarly journals ADCK2 Haploinsufficiency Reduces Mitochondrial Lipid Oxidation and Causes Myopathy Associated with CoQ Deficiency

2019 ◽  
Author(s):  
Luis Vázquez-Fonseca ◽  
Jochen Schäfer ◽  
Ignacio Navas-Enamorado ◽  
Carlos Santos-Ocaña ◽  
Juan D. Hernández-Camacho ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Mouse Model ◽  
Fatty Acid Oxidation ◽  
Physical Performance ◽  
Liver Dysfunction ◽  
Mitochondrial Myopathy ◽  
Integrated Analysis ◽  
Acid Oxidation ◽  
Mitochondrial Fatty Acid

Fatty acids and glucose are the main bioenergetic substrates in mammals that are alternatively used during the transition between fasting and feeding. Impairment of mitochondrial fatty acid oxidation causes mitochondrial myopathy leading to decreased physical performance. Here, we report that haploinsufficiency of ADCK2, a member of the aarF domain-containing mitochondrial protein kinase family, in human is associated with liver dysfunction and severe mitochondrial myopathy with lipid droplets in skeletal muscle. In order to better understand the etiology of this rare disorder, we generated a heterozygous Adck2 knockout mouse model to perform in vivo and cellular studies using integrated analysis of physiological and omics data (transcriptomics-metabolomics). The data show that Aldh2+/- mice exhibits impaired fatty acid oxidation, liver dysfunction, and mitochondrial myopathy in skeletal muscle resulting in lower physical performance. Significant decrease in CoQ biosynthesis was observed and supplementation with CoQ partially rescued the phenotype both in the human subject and mouse model. These results indicate that ADCK2 is involved in organismal fatty acid metabolism and in CoQ biosynthesis in skeletal muscle. We propose that patients with isolated myopathies and myopathies involving lipid accumulation be tested for possible ADCK2 defect as they are likely to be responsive to CoQ supplementation.

scholarly journals Overexpression of Long-Chain Acyl-CoA Synthetase 5 Increases Fatty Acid Oxidation and Free Radical Formation While Attenuating Insulin Signaling in Primary Human Skeletal Myotubes

2019 ◽  
Vol 16 (7) ◽  
pp. 1157 ◽  
Author(s):  
Hyo-Bum Kwak ◽  
Tracey Woodlief ◽  
Thomas Green ◽  
Julie Cox ◽  
Robert Hickner ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Free Radical ◽  
Fatty Acid Oxidation ◽  
Insulin Signaling ◽  
Human Skeletal Muscle ◽  
Acid Oxidation ◽  
Protein Levels ◽  
Human Skeletal Muscle Cells ◽  
Mitochondrial Fatty Acid

In rodent skeletal muscle, acyl-coenzyme A (CoA) synthetase 5 (ACSL-5) is suggested to localize to the mitochondria but its precise function in human skeletal muscle is unknown. The purpose of these studies was to define the role of ACSL-5 in mitochondrial fatty acid metabolism and the potential effects on insulin action in human skeletal muscle cells (HSKMC). Primary myoblasts isolated from vastus lateralis (obese women (body mass index (BMI) = 34.7 ± 3.1 kg/m2)) were transfected with ACSL-5 plasmid DNA or green fluorescent protein (GFP) vector (control), differentiated into myotubes, and harvested (7 days). HSKMC were assayed for complete and incomplete fatty acid oxidation ([1-14C] palmitate) or permeabilized to determine mitochondrial respiratory capacity (basal (non-ADP stimulated state 4), maximal uncoupled (carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone (FCCP)-linked) respiration, and free radical (superoxide) emitting potential). Protein levels of ACSL-5 were 2-fold higher in ACSL-5 overexpressed HSKMC. Both complete and incomplete fatty acid oxidation increased by 2-fold (p < 0.05). In permeabilized HSKMC, ACSL-5 overexpression significantly increased basal and maximal uncoupled respiration (p < 0.05). Unexpectedly, however, elevated ACSL-5 expression increased mitochondrial superoxide production (+30%), which was associated with a significant reduction (p < 0.05) in insulin-stimulated p-Akt and p-AS160 protein levels. We concluded that ACSL-5 in human skeletal muscle functions to increase mitochondrial fatty acid oxidation, but contrary to conventional wisdom, is associated with increased free radical production and reduced insulin signaling.

Mitochondrial function and dysfunction in exercise and insulin resistanceThis paper article is one of a selection of papers published in this Special Issue, entitled 14th International Biochemistry of Exercise Conference – Muscles as Molecular and Metabolic Machines, and has undergone the Journal’s usual peer review process.

2009 ◽  
Vol 34 (3) ◽  
pp. 440-446 ◽  
Author(s):  
Graham P. Holloway
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Peer Review Process ◽  
Acid Oxidation ◽  
Fatty Acid Transport ◽  
Acid Transport ◽  
Mitochondrial Content ◽  
Mitochondrial Fatty Acid

Fatty acid translocase (FAT/CD36) represents a novel flexible regulatory system, influencing rates of mitochondrial fatty acid metabolism in both human and rodent skeletal muscle. During exercise, the subcellular redistribution of FAT/CD36 provides a mechanism to increase not only plasma membrane fatty acid transport, but also mitochondrial fatty acid oxidation. This FAT/CD36-mediated coordination of long chain fatty acid (LCFA) transport and oxidation is an intriguing model in the context of insulin resistance. It was believed for almost a decade that reductions in fatty acid oxidation increased intramuscular lipids, thereby contributing to insulin resistance. A reduction in mitochondrial content may reduce the capacity of skeletal muscle LCFA oxidation; however, work from my laboratory has shown that, in some insulin-resistant muscles, mitochondrial content and fatty acid oxidation are both increased, yet these muscles accumulate lipids because of a considerably greater increase in fatty acid transport. Therefore, an alternative model is being considered, in which the balance between LCFA uptake and oxidation is a determining factor in the development of insulin resistance. A permanent redistribution of the LCFA transport protein FAT/CD36 to the sarcolemmal has been consistently found, which results in an increased rate of LCFA transport. This work suggests that the accumulation of skeletal muscle lipids, regardless of changes in mitochondria, is attributable to an increased rate of LCFA transport that exceeds the capacity for oxidation.

3,5-Diiodo-l-thyronine rapidly enhances mitochondrial fatty acid oxidation rate and thermogenesis in rat skeletal muscle: AMP-activated protein kinase involvement

2009 ◽  
Vol 296 (3) ◽  
pp. E497-E502 ◽  
Author(s):  
A. Lombardi ◽  
P. de Lange ◽  
E. Silvestri ◽  
R. A. Busiello ◽  
A. Lanni ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Energy Metabolism ◽  
Fatty Acid Oxidation ◽  
Atp Synthesis ◽  
Acid Oxidation ◽  
Mitochondrial Fatty Acid Oxidation ◽  
Mitochondrial Fatty Acid ◽  
Amp Activated Protein Kinase

Triiodothyronine regulates energy metabolism and thermogenesis. Among triiodothyronine derivatives, 3,5-diiodo-l-thyronine (T2) has been shown to exert marked effects on energy metabolism by acting mainly at the mitochondrial level. Here we investigated the capacity of T2 to affect both skeletal muscle mitochondrial substrate oxidation and thermogenesis within 1 h after its injection into hypothyroid rats. Administration of T2 induced an increase in mitochondrial oxidation when palmitoyl-CoA (+104%), palmitoylcarnitine (+80%), or succinate (+30%) was used as substrate, but it had no effect when pyruvate was used. T2 was able to 1) activate the AMPK-ACC-malonyl-CoA metabolic signaling pathway known to direct lipid partitioning toward oxidation and 2) increase the importing of fatty acids into the mitochondrion. These results suggest that T2 stimulates mitochondrial fatty acid oxidation by activating several metabolic pathways, such as the fatty acid import/β-oxidation cycle/FADH2-linked respiratory pathways, where fatty acids are imported. T2 also enhanced skeletal muscle mitochondrial thermogenesis by activating pathways involved in the dissipation of the proton-motive force not associated with ATP synthesis (“proton leak”), the effect being dependent on the presence of free fatty acids inside mitochondria. We conclude that skeletal muscle is a target for T2, and we propose that, by activating processes able to enhance mitochondrial fatty acid oxidation and thermogenesis, T2 could play a role in protecting skeletal muscle against excessive intramyocellular lipid storage, possibly allowing it to avoid functional disorders.

Phenotyping a new mitochondrial fatty acid oxidation deficient mouse model

2013 ◽  
Vol 81 (S1) ◽  
pp. 33-33
Author(s):  
E.F. Diekman ◽  
M. Weeghel ◽  
R.J. Wanders ◽  
G. Visser ◽  
S.M. Houten
Keyword(s):  
Fatty Acid ◽  
Mouse Model ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Deficient Mouse ◽  
Mitochondrial Fatty Acid Oxidation ◽  
Mitochondrial Fatty Acid

High-intensity interval training increases intrinsic rates of mitochondrial fatty acid oxidation in rat red and white skeletal muscle

2013 ◽  
Vol 38 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Daisuke Hoshino ◽  
Yuko Yoshida ◽  
Yu Kitaoka ◽  
Hideo Hatta ◽  
Arend Bonen
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
High Intensity ◽  
Interval Training ◽  
Acid Oxidation ◽  
Mitochondrial Fatty Acid Oxidation ◽  
Mitochondrial Fatty Acid ◽  
Mitochondrial Volume ◽  
High Intensity Interval

High-intensity interval training (HIIT) can increase mitochondrial volume in skeletal muscle. However, it is unclear whether HIIT alters the intrinsic capacity of mitochondrial fatty acid oxidation, or whether such changes are associated with changes in mitochondrial FAT/CD36, a regulator of fatty acid oxidation, or with reciprocal changes in the nuclear receptor coactivator (peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α)) and the corepressor (receptor-interacting protein 140 (RIP140)). We examined whether HIIT alters fatty acid oxidation rates in the isolated subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria of red and white skeletal muscle and (or) induces changes in muscle PGC-1α and RIP140 proteins and mitochondrial FAT/CD36 protein content. Rats were divided into untrained or HIIT-trained groups. HIIT animals performed 10 bouts of 1-min high-intensity treadmill running (30–55 m·min–1), separated by 2 min of rest, for 5 days a week for 4 weeks. As expected, after the training period, HIIT increased mitochondrial enzymes (citrate synthase, COXIV, and β-hydroxyacyl CoA dehydrogenase) in red and white muscle, indicating that muscle mitochondrial volume had increased. HIIT also increased the rates of palmitate oxidation in mitochondria of red (37% for SS and 19% for IMF) and white (36% for SS and 12% for IMF) muscle. No changes occurred in SS and IMF mitochondrial FAT/CD36 proteins, despite increasing FAT/CD36 at the whole-muscle level (27% for red and 22% for white). Concurrently, muscle PGC-1α protein was increased in red (22%) and white (16%) muscle, but RIP140 was not altered. These results indicate that increases in SS and IMF mitochondrial fatty acid oxidation induced by HIIT are accompanied by an increase in PGC-1α, but not RIP140 or FAT/CD36.

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