The role of glucose, insulin and NEFA in regulating tissue triglyceride accumulation: Substrate cooperation in adipose tissue versus substrate competition in skeletal muscle

2017 ◽  
Vol 27 (11) ◽  
pp. 956-963
Author(s):  
M.A. Guzzardi ◽  
L. Hodson ◽  
L. Guiducci ◽  
F. La Rosa ◽  
P.A. Salvadori ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Triglyceride Accumulation ◽  
Substrate Competition

Role of the AMP-activated protein kinase in regulating fatty acid metabolism during exerciseThis paper 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. 315-322 ◽  
Author(s):  
Gregory R. Steinberg
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Protein Kinase ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Moderate Intensity ◽  
Amp Activated Protein Kinase

During moderate-intensity exercise, fatty acids are the predominant substrate for working skeletal muscle. The release of fatty acids from adipose tissue stores, combined with the ability of skeletal muscle to actively fine tune the gradient between fatty acid and carbohydrate metabolism, depending on substrate availability and energetic demands, requires a coordinated system of metabolic control. Over the past decade, since the discovery that AMP-activated protein kinase (AMPK) was increased in accordance with exercise intensity, there has been significant interest in the proposed role of this ancient stress-sensing kinase as a critical integrative switch controlling metabolic responses during exercise. In this review, studies examining the role of AMPK as a regulator of fatty acid metabolism in both adipose tissue and skeletal muscle during exercise will be discussed. Exercise induces activation of AMPK in adipocytes and regulates triglyceride hydrolysis and esterfication through phosphorylation of hormone sensitive lipase (HSL) and glycerol-3-phosphate acyl-transferase, respectively. In skeletal muscle, exercise-induced activation of AMPK is associated with increases in fatty acid uptake, phosphorylation of HSL, and increased fatty acid oxidation, which is thought to occur via the acetyl-CoA carboxylase-malony-CoA-CPT-1 signalling axis. Despite the importance of AMPK in regulating fatty acid metabolism under resting conditions, recent evidence from transgenic models of AMPK deficiency suggest that alternative signalling pathways may also be important for the control of fatty acid metabolism during exercise.

scholarly journals Collagen 24 α1 Is Increased in Insulin-Resistant Skeletal Muscle and Adipose Tissue

2020 ◽  
Vol 21 (16) ◽  
pp. 5738
Author(s):  
Xiong Weng ◽  
De Lin ◽  
Jeffrey T. J. Huang ◽  
Roland H. Stimson ◽  
David H. Wasserman ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Insulin Resistant ◽  
Global View ◽  
Novel Association ◽  
Visceral Adipose ◽  
Subcutaneous Adipose

Aberrant extracellular matrix (ECM) remodelling in muscle, liver and adipose tissue is a key characteristic of obesity and insulin resistance. Despite its emerging importance, the effective ECM targets remain largely undefined due to limitations of current approaches. Here, we developed a novel ECM-specific mass spectrometry-based proteomics technique to characterise the global view of the ECM changes in the skeletal muscle and liver of mice after high fat (HF) diet feeding. We identified distinct signatures of HF-induced protein changes between skeletal muscle and liver where the ECM remodelling was more prominent in the muscle than liver. In particular, most muscle collagen isoforms were increased by HF diet feeding whereas the liver collagens were differentially but moderately affected highlighting a different role of the ECM remodelling in different tissues of obesity. Moreover, we identified a novel association between collagen 24α1 and insulin resistance in the skeletal muscle. Using quantitative gene expression analysis, we extended this association to the white adipose tissue. Importantly, collagen 24α1 mRNA was increased in the visceral adipose tissue, but not the subcutaneous adipose tissue of obese diabetic subjects compared to lean controls, implying a potential pathogenic role of collagen 24α1 in obesity and type 2 diabetes.

Postprandial leg uptake of triglyceride is greater in women than in men

2002 ◽  
Vol 283 (6) ◽  
pp. E1192-E1202 ◽  
Author(s):  
Tracy J. Horton ◽  
S. Renee Commerford ◽  
Michael J. Pagliassotti ◽  
Daniel H. Bessesen
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Test Meal ◽  
Dietary Fat ◽  
Nutritional State ◽  
Lipid Uptake ◽  
Postprandial Metabolism ◽  
Men And Women ◽  
Main Effect

The postprandial excursion of plasma triglyceride (TG) concentration is greater in men than in women. In this study, the disposition of dietary fat was examined in lean healthy men and women ( n = 8/group) in either the overnight-fasted or fed (4.5 h after breakfast) states. A [14C]oleate tracer was incorporated into a test meal, providing 30% of total daily energy requirements. After ingestion of the test meal, measures of arteriovenous differences in TG and14C across the leg were combined with needle biopsies of skeletal muscle and adipose tissue and respiratory gas collections to define the role of skeletal muscle in the clearance of dietary fat. The postprandial plasma TG and14C tracer excursions were lower ( P = 0.04) in women than in men in the overnight-fasted and fed states. Women, however, had significantly greater limb uptake of total TG compared with men on both the fasted (3,849 ± 846 vs. 528 ± 221 total μmol over 6 h) and fed (4,847 ± 979 vs. 1,571 ± 334 total μmol over 6 h) days. This was also true for meal-derived14C lipid uptake.14C content of skeletal muscle tissue (μCi/g tissue) was significantly greater in women than in men 6 h after ingestion of the test meal. In contrast,14C content of adipose tissue was not significantly different between men and women at 6 h. The main effect of nutritional state, fed vs. fasted, was to increase the postmeal glucose ( P = 0.01) excursion (increase from baseline) and decrease the postmeal TG excursion ( P = 0.02). These results support the notion that enhanced skeletal muscle clearance of lipoprotein TG in women contributes to their reduced postprandial TG excursion. Questions remain as to the mechanisms causing these sex-based differences in skeletal muscle TG uptake and metabolism. Furthermore, nutritional state can significantly impact postprandial metabolism in both men and women.

scholarly journals Catalase deficiency facilitates the shuttling of free fatty acid to brown adipose tissue through lipolysis mediated by ROS during sustained fasting

2021 ◽  
Author(s):  
Raghbendra Kumar Dutta ◽  
Joon No Lee ◽  
Yunash Maharjan ◽  
Channy Park ◽  
Seong-Kyu Choe ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Lipid Metabolism ◽  
Brown Adipose Tissue ◽  
Energy Homeostasis ◽  
Redox Homeostasis ◽  
Ros Generation ◽  
Peroxisomal Enzyme ◽  
Triglyceride Accumulation ◽  
Brown Adipose

Abstract Background Fatty acids (FA) derived from adipose tissue and liver serve as the main fuel in thermogenesis of brown adipose tissue (BAT). Catalase, a peroxisomal enzyme, plays an important role in maintaining intracellular redox homeostasis by decomposing hydrogen peroxide to either water or oxygen that oxidize and provide fuel for cellular metabolism. Although the antioxidant enzymatic activity of catalase is well known, its role in the metabolism and maintenance of energy homeostasis has not yet been revealed. The present study investigated the role of catalase in lipid metabolism and thermogenesis during nutrient deprivation in catalase-knockout (KO) mice. Results We found that hepatic triglyceride accumulation in KO mice decreased during sustained fasting due to lipolysis through reactive oxygen species (ROS) generation in adipocytes. Furthermore, the free FA released from lipolysis were shuttled to BAT through the activation of CD36 and catabolized by lipoprotein lipase in KO mice during sustained fasting. Although the exact mechanism for the activation of the FA receptor enzyme is still unclear, we found that ROS generation in adipocytes mediated the shuttling of FA to BAT. Conclusions Taken together, our findings uncover the novel role of catalase in lipid metabolism and thermogenesis in BAT, which may be useful in understanding metabolic dysfunction.

Polymorphic Role of P2Y6Receptor in Insulin Sensitive Organs—Adipose Tissue and Skeletal Muscle

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1769-P
Author(s):  
SHANU JAIN ◽  
JÜRGEN WESS ◽  
KENNETH A. JACOBSON
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue

scholarly journals Increased AQP7 abundance in skeletal muscle from obese men with type 2 diabetes

2018 ◽  
Vol 315 (3) ◽  
pp. E367-E373 ◽  
Author(s):  
Janne Lebeck ◽  
Esben Søndergaard ◽  
Søren Nielsen
Keyword(s):  
Type 2 Diabetes ◽  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Protein Abundance ◽  
Tissue Samples ◽  
Triglyceride Accumulation ◽  
Meal Intake ◽  
Fasting And Refeeding ◽  
Subcutaneous Adipose

Aquaglyceroporin 7 (AQP7) facilitates the transport of glycerol across cell membranes. In mice, fasting and refeeding regulate adipose tissue AQP7 abundance, and a role in controlling triglyceride accumulation in adipose tissue has been proposed. AQP7 is also expressed in skeletal muscle, where its function remains to be determined. Here, the abundance of AQP7 in abdominal subcutaneous adipose tissue (SAT) and skeletal muscle was evaluated in the overnight fasted and postprandial state in eight lean and eight obese men with type 2 diabetes (T2D). A biopsy from SAT and muscle was collected after an overnight fast and 2 h after ingestion of a low-fat test meal. Palmitate turnover was evaluated using a [9,10-3H] palmitate dilution technique. Tissue samples were analyzed by immunoblotting. Meal intake did not affect AQP7 expression in SAT or skeletal muscle. No association between the SAT AQP7 abundance and palmitate turnover was found. SAT AQP7 abundance was similar in lean and obese T2D men, whereas muscle AQP7 abundance was more than fourfold higher in obese T2D men. In conclusion, meal intake did not affect AQP7 protein abundance in SAT or skeletal muscle. In addition, SAT AQP7 expression does not appear to be involved in the regulation of adipose tissue lipolysis. However, in contrast to SAT AQP7, skeletal muscle AQP7 protein abundance is markedly increased in obese T2D men, potentially contributing to the excess lipid accumulation in skeletal muscle in type 2 diabetes.

Role of Cardiotrophin-1 in Regulating Insulin Sensitivity in Skeletal Muscle, Adipose Tissue and Liver

2011 ◽  
pp. P3-401-P3-401
Author(s):  
Matilde Bustos ◽  
Maria J Moreno-Aliaga ◽  
Nerea Perez-Echarri ◽  
Beatriz Gomez-Marcos ◽  
Esperanza Lopez-Franco ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Insulin Sensitivity
Sign in / Sign up

Export Citation Format

Share Document