Viability of the isolated soleus muscle during long-term incubation

2006 ◽  
Vol 31 (4) ◽  
pp. 467-476 ◽  
Author(s):  
Hakam Alkhateeb ◽  
Adrian Chabowski ◽  
Arend Bonen
Keyword(s):  
Fatty Acid ◽  
Protein Expression ◽  
Glucose Transport ◽  
Fatty Acid Metabolism ◽  
Soleus Muscle ◽  
Glucose Transporter ◽  
Acid Metabolism ◽  
Insulin Signalling ◽  
Low Concentrations

Skeletal muscle metabolism has been examined in perfused hindlimb muscles and in isolated muscle preparations. While long-term viability of the fast-twitch epitrochlearis has been documented with respect to glucose transport, it appears that long-term incubated soleus muscles are less stable when incubated ex vivo for many hours. Therefore, in the present study, we have examined whether the isolated soleus muscle remains metabolically viable for up to 18 h with respect to maintaining ATP and phosphocreatine (PCr) concentrations, carbohydrate and fatty-acid metabolism, insulin signalling, and protein expression. Soleus muscles were incubated in well-oxygenated Medium 199 (M199) supplemented with low concentrations of insulin (14.3 µU/mL) for 0, 6, 12, and 18 h. During this incubating period the concentrations of ATP and PCr were stable, indicating that oxygenation and substrate supply were being maintained. In addition, the concentrations of proglycogen and macroglycogen were not altered, whereas an increase (+30%) in intramuscular triacylglycerol concentration was observed at the end of 18 h of incubation (p < 0.05). Complex molecular processes in the long-term incubated muscles were also stable. This was shown by maintenance of basal as well as insulin-stimulated rates of 3-O-methyl glucose transport, and by the maintenance of protein expression of the glucose transporter GLUT4 and the fatty acid transporters FAT/CD36 and FABPpm. In addition, the insulin-stimulated translocation of GLUT4 to the plasma membrane, which involves a complex signalling cascade, was fully preserved. In conclusion, in well-oxygenated soleus muscles maintained in M199 supplemented with extremely low concentrations of insulin, ATP and PCr concentrations, carbohydrate and fatty acid metabolism, insulin signalling, and protein expression were stably maintained for up to 18 h. This provides for opportunities to examine muscle metabolic function under very highly controlled conditions.

scholarly journals Coordinated multitissue transcriptional and plasma metabonomic profiles following acute caloric restriction in mice

2006 ◽  
Vol 27 (3) ◽  
pp. 187-200 ◽  
Author(s):  
Colin Selman ◽  
Nicola D. Kerrison ◽  
Anisha Cooray ◽  
Matthew D. W. Piper ◽  
Steven J. Lingard ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fatty Acid ◽  
Caloric Restriction ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Proton Nuclear Magnetic Resonance ◽  
Cellular Transport ◽  
Expression Of Genes ◽  
Transcriptional Changes

Caloric restriction (CR) increases healthy life span in a range of organisms. The underlying mechanisms are not understood but appear to include changes in gene expression, protein function, and metabolism. Recent studies demonstrate that acute CR alters mortality rates within days in flies. Multitissue transcriptional changes and concomitant metabolic responses to acute CR have not been described. We generated whole genome RNA transcript profiles in liver, skeletal muscle, colon, and hypothalamus and simultaneously measured plasma metabolites using proton nuclear magnetic resonance in mice subjected to acute CR. Liver and muscle showed increased gene expressions associated with fatty acid metabolism and a reduction in those involved in hepatic lipid biosynthesis. Glucogenic amino acids increased in plasma, and gene expression for hepatic gluconeogenesis was enhanced. Increased expression of genes for hormone-mediated signaling and decreased expression of genes involved in protein binding and development occurred in hypothalamus. Cell proliferation genes were decreased and cellular transport genes increased in colon. Acute CR captured many, but not all, hepatic transcriptional changes of long-term CR. Our findings demonstrate a clear transcriptional response across multiple tissues during acute CR, with congruent plasma metabolite changes. Liver and muscle switched gene expression away from energetically expensive biosynthetic processes toward energy conservation and utilization processes, including fatty acid metabolism and gluconeogenesis. Both muscle and colon switched gene expression away from cellular proliferation. Mice undergoing acute CR rapidly adopt many transcriptional and metabolic changes of long-term CR, suggesting that the beneficial effects of CR may require only a short-term reduction in caloric intake.

Differential effects of short- and long-term high-fat diet feeding on hepatic fatty acid metabolism in rats

2011 ◽  
Vol 1811 (7-8) ◽  
pp. 441-451 ◽  
Author(s):  
Jolita Ciapaite ◽  
Nicole M. van den Broek ◽  
Heleen te Brinke ◽  
Klaas Nicolay ◽  
Jeroen A. Jeneson ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Metabolism ◽  
High Fat Diet ◽  
Acid Metabolism ◽  
High Fat ◽  
Differential Effects ◽  
Hepatic Fatty Acid ◽  
Short And Long Term

Impact on fatty acid metabolism and differential localization of FATP1 and FAT/CD36 proteins delivered in cultured human muscle cells

2005 ◽  
Vol 288 (6) ◽  
pp. C1264-C1272 ◽  
Author(s):  
Cèlia García-Martínez ◽  
Mario Marotta ◽  
Rodrigo Moore-Carrasco ◽  
Maria Guitart ◽  
Marta Camps ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Fluorescent Protein ◽  
Intracellular Localization ◽  
Muscle Cells ◽  
Human Muscle ◽  
Transporter Protein ◽  
Human Muscle Cells

We compared the intracellular distribution and regulatory role of fatty acid transporter protein (FATP1) and fatty acid translocase (FAT/CD36) on muscle cell fatty acid metabolism. With the use of adenoviruses, FATP1 and FAT genes were delivered to primary cultured human muscle cells. FATP1 and FAT moderately enhanced palmitate and oleate transport evenly at concentrations of 0.05, 0.5, and 1 mM. Long-term (16 h) consumption of palmitate and oleate from the media, and particularly incorporation into triacylglyceride (TAG), was stimulated equivalently by FATP1 and FAT at all fatty acid concentrations tested. In contrast, long-term CO2 production was reduced by FATP1 and FAT at all doses of palmitate and at the lower concentrations of oleate. Neither FATP1 nor FAT markedly altered the production of acid-soluble metabolic intermediates from palmitate or oleate. The intracellular localization of fusion constructs of FATP1 and FAT with enhanced green fluorescent protein (EGFP) was examined. Independently of fatty acid treatment, FATPGFP was observed throughout the cytosol in a reticular pattern and concentrated in the perinuclear region, partly overlapping with the Golgi marker GM-130. FATGFP was found in the extracellular membrane and in cytosolic vesicles not coincident with GM-130. Neither FATP1 nor FAT proteins colocalized with lipid droplets in oleate-treated cells. We conclude that whereas FAT is localized on the extracellular membrane, FATP1 is active in the cytosol and imports fatty acids into myotubes. Overall, both FATP1 and FAT stimulated transport and consumption of palmitate and oleate, which they channeled away from complete oxidation and toward TAG synthesis.

Mechanisms of impaired hepatic fatty acid metabolism in rats with long-term bile duct ligation

Hepatology ◽  
1994 ◽  
Vol 19 (5) ◽  
pp. 1272-1281
Author(s):  
Stephan Krähenbühl ◽  
Christine Talos ◽  
Jürg Reichen
Keyword(s):  
Fatty Acid ◽  
Bile Duct ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Bile Duct Ligation ◽  
Hepatic Fatty Acid ◽  
Duct Ligation

Abstract 17827: Klf5 Mediates Glucose-driven Changes ofCcardiac Pparα in Diabetes

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Konstantinos Drosatos ◽  
Nina M Pollak ◽  
Florian Willecke ◽  
Panagiotis Ntziachristos ◽  
Chad M Trent ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fatty Acid ◽  
Fatty Acid Metabolism ◽  
Plasma Glucose ◽  
Binding Sites ◽  
Glucose Transporter ◽  
Acid Metabolism ◽  
In Silico Analysis ◽  
Dependent Manner ◽  
Glucose Transporter 2

Krüppel-like factors (KLF) affect metabolism. Lipopolysaccharide-induced sepsis reduced cardiac PPARα and increased KLF5 (8-fold) more than any cardiac KLF isoform detected by whole genome microarray analysis. In silico analysis of ppara gene promoter predicted two KLF5 binding sites that overlap with c-Jun (AP-1) binding sites: -792/-772 bp and -719/-698 bp. Infection of a mouse cardiomyocyte cell line (HL-1) with adenovirus expressing constitutively active c-Jun reduced, while Ad-KLF5 increased PPARα mRNA in a dose-dependent manner. Chromatin immunoprecipitation (ChIP) showed that c-Jun binds both -792/-772 bp and -719/-698 on ppara promoter while KLF5 binds on -792/-772 bp. ChIP on LPS-treated HL-1 cells showed that c-Jun binding on -792/-772 bp prohibits KLF5 binding. We generated a cardiomyocyte-specific KLF5 knockout mouse (αMHC-KLF5-/-), which had 50% normal cardiac function. Cardiomyocyte-specific KLF5 ablation reduced PPARα (50%) and several fatty acid metabolism-associated genes such as CD36 (40%), LpL (20%), PGC1α (45%), AOX (28%) and Cpt1 (45%). As PPARα regulates cardiac fatty acid metabolism, we tested whether cardiac KLF5 is modulated in diabetes, when cardiac PPARα and lipid changes occur. I.p. injection of streptozotocin (STZ) in C57BL/6 mice increased plasma glucose (2.9-fold) and reduced cardiac KLF5 and PPARα gene expression; similar to STZ-treated rats but unlike what had been found in a different mouse strain (C57BL/6 x DBA2) treated with STZ. Treatment of HL-1 cells with increased glucose-containing medium (1 mg/ml) reduced KLF5 (80%) and PPARα (65%), as well as fatty acid metabolism markers, such as AOX (85%), Cpt1β (70%), LCAD (80%) and VLCAD (85%). On the other hand GLUT1 and GLUT4 were increased (30% and 20%) and PDK4 was reduced (65%) indicating increased glucose utilization. A model of non-insulin dependent hyperglycemia (ob/ob mice) had reduced cardiac KLF5 (60%) and PPARα (65%). Correction of hyperglycemia in STZ-treated C57BL/6 mice by pharmacological (dapagliflozin) or antisense oligonucleotide inhibition of kidney’s sodium glucose transporter 2 (SGLT2), restored KLF5 and PPARα gene expression. Thus, KLF5 is a transcriptional regulator of cardiac PPARα that is driven by changes in plasma glucose levels

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