Effects of PPAR-α and -γ Agonists on Fatty Acid Metabolism of Muscle Cells in Hyperlipidemic and Hyperglycemic Conditions

2006 ◽  
Vol 30 (5) ◽  
pp. 324 ◽  
Author(s):  
Yong jik Lee ◽  
Zheng Shan Zhao ◽  
Soo Kyung Kim ◽  
Hae Jin Kim ◽  
Wan Sub Shim ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Muscle Cells

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.

Impaired fatty acid metabolism in type 2 diabetic skeletal muscle cells is reversed by PPARγ agonists

2005 ◽  
Vol 289 (1) ◽  
pp. E151-E159 ◽  
Author(s):  
Bong-Soo Cha ◽  
Theodore P. Ciaraldi ◽  
Kyong-Soo Park ◽  
Leslie Carter ◽  
Sunder R. Mudaliar ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Muscle Cells ◽  
Palmitate Oxidation ◽  
Pparγ Agonists ◽  
Type 2 Diabetic

The impact of type 2 diabetes on the ability of muscle to accumulate and dispose of fatty acids and triglycerides was evaluated in cultured muscle cells from nondiabetic (ND) and type 2 diabetic (T2D) subjects. In the presence of 5 μM palmitate, T2D muscle cells accumulated less lipid than ND cells (11.5 ± 1.2 vs. 15.1 ± 1.4 nmol/mg protein, P < 0.05). Chronic treatment (4 days) with the peroxisome proliferator-activated receptor-γ (PPARγ) agonist troglitazone increased palmitate accumulation, normalizing uptake in T2D cells. There were no significant differences between groups with regard to the relative incorporation of palmitate into neutral lipid species. This distribution was also unaffected by troglitazone treatment. β-Oxidation of both long-chain (palmitate) and medium-chain (octanoate) fatty acids in T2D muscle cells was reduced by ∼40% compared with ND cells. Palmitate oxidation occurred primarily in mitochondrial (∼40–50% of total) and peroxisomal (20–30%) compartments. The diabetes-related defect in palmitate oxidation was localized to the mitochondrial component. Both palmitate and octanoate oxidation were stimulated by a series of thiazolidinediones. Oxidation in T2D muscle cells was normalized after treatment. Troglitazone increased the mitochondrial component of palmitate oxidation. Skeletal muscle cells from T2D subjects express defects in free fatty acid metabolism that are retained in vitro, most importantly defects in β-oxidation. These defects can be corrected by treatment with PPARγ agonists. Augmentation of fatty acid disposal in skeletal muscle, potentially reducing intramyocellular triglyceride content, may represent one mechanism for the lipid-lowering and insulin-sensitizing effects of thiazolidinediones.

scholarly journals 17β-estradiol upregulates oxytocin and the oxytocin receptor in C2C12 myotubes

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3124 ◽  
Author(s):  
Enrica Berio ◽  
Sara Divari ◽  
Laura Starvaggi Cucuzza ◽  
Bartolomeo Biolatti ◽  
Francesca Tiziana Cannizzo
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Fatty Acid Metabolism ◽  
Fatty Acid Binding Protein ◽  
Acid Metabolism ◽  
Muscle Cells ◽  
Oxytocin Receptor ◽  
C2c12 Myotubes ◽  
Fatty Acid Binding ◽  
Acid Binding Protein

BackgroundThe endocrinology of skeletal muscle is highly complex and many issues about hormone action in skeletal muscle are still unresolved. Aim of the work is to improve our knowledge on the relationship between skeletal muscle and 17β-estradiol.MethodsThe skeletal muscle cell line C2C12 was treated with 17β-estradiol, the oxytocin peptide and a combination of the two hormones. The mRNA levels of myogenic regulatory factors, myosin heavy chain, oxytocin, oxytocin receptor and adipogenic factors were analysed in C2C12 myotubes.ResultsIt was demonstrated that C2C12 myoblasts and myotubes express oxytocin and its receptor, in particular the receptor levels physiologically increase in differentiated myotubes. Myotubes treated with 17β-estradiol overexpressed oxytocin and oxytocin receptor genes by approximately 3- and 29-fold, respectively. A decrease in the expression of fatty acid binding protein 4 (0.62-fold), a fat metabolism-associated gene, was observed in oxytocin-treated myotubes. On the contrary, fatty acid binding protein 4 was upregulated (2.66-fold) after the administration of the combination of 17β-estradiol and oxytocin. 17β-estradiol regulates oxytocin and its receptor in skeletal muscle cells and they act in a synergic way on fatty acid metabolism.DiscussionOxytocin and its receptor are physiologically regulated along differentiation. 17β-estradiol regulates oxytocin and its receptor in skeletal muscle cells. 17β-estradiol and oxytocin act in a synergic way on fatty acid metabolism. A better understanding of the regulation of skeletal muscle homeostasis by estrogens and oxytocin peptide could contribute to increase our knowledge of muscle and its metabolism.

The Influence of Lactate and Dipyridamole on Myocardial Fatty Acid Metabolism in Man, Traced with 123l-17-lodo-heptadecanoic Acid

1990 ◽  
Vol 29 (01) ◽  
pp. 28-34 ◽  
Author(s):  
F. C. Visser ◽  
M. J. van Eenige ◽  
G. Westera ◽  
J. P. Roos ◽  
C. M. B. Duwel
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Time Activity ◽  
Time Value ◽  
Myocardial Fatty Acid Metabolism ◽  
Coronary Vasodilatation ◽  
Activity Curve ◽  
Normal Human ◽  
Plasma Lactate Level

Changes in myocardial metabolism can be detected externally by registration of time-activity curves after administration of radioiodinated fatty acids. In this scintigraphic study the influence of lactate on fatty acid metabolism was investigated in the normal human myocardium, traced with 123l-17-iodoheptadecanoic acid (123l-17-HDA). In patients (paired, n = 7) lactate loading decreased the uptake of 123l-17-HDA significantly from 27 (control: 22-36) to 20 counts/min/pixel (16-31; p <0.05 Wilcoxon). The half-time value increased to more than 60 rriin (n = 5), oxidation decreased from 61 to 42%. Coronary vasodilatation, a well-known side effect of lactate loading, was studied separately in a dipyridamole study (paired, n = 6). Coronary vasodilatation did not influence the parameters of the time-activity curve. These results suggest that changes in plasma lactate level as occurring, among other effects, during exercise will influence the parameters of dynamic 123l-17-HDA scintigraphy of the heart.

Sign in / Sign up

Export Citation Format

Share Document