scholarly journals Resistin Regulates Fatty Acid Β Oxidation by Suppressing Expression of Peroxisome Proliferator Activator Receptor Gamma-Coactivator 1α (PGC-1α)

2018 ◽  
Vol 46 (5) ◽  
pp. 2165-2172 ◽  
Author(s):  
Fang He ◽  
Jie-Qiong Jin ◽  
Qing-Qing Qin ◽  
Yong-Qin Zheng ◽  
Ting-Ting Li ◽  
...  

Background/Aims: Abnormal fatty acid β oxidation has been associated with obesity and type 2 diabetes. Resistin is an adipokine that has been considered as a potential factor in obesity-mediated insulin resistance and type 2 diabetes. However, the effect of resistin on fatty acid β oxidation needs to be elucidated. Methods: We detected the effects of resistin on the expression of fatty acid oxidation (FAO) transcriptional regulatory genes, the fatty acid transport gene, and mitochondrial β-oxidation genes using real-time PCR. The rate of FAO was measured using 14C-palmitate. Immunofluorescence assay and western blot analysis were used to explore the underlying molecular mechanisms. Results: Resistin leads to a reduction in expression of the FAO transcriptional regulatory genes ERRα and NOR1, the fatty acid transport gene CD36, and the mitochondrial β-oxidation genes CPT1, MCAD, and ACO. Importantly, treatment with resistin led to a reduction in the rate of cellular fatty acid oxidation. In addition, treatment with resistin reduced phosphorylation of acetyl CoA carboxylase (ACC) (inhibitory). Mechanistically, resistin inhibited the activation of CREB, resulting in suppression of PGC-1α. Importantly, overexpressing PGC-1α can rescue the inhibitory effects of resistin on fatty acid β oxidation. Conclusions: Activating the transcriptional activity of CREB using small molecular chemicals is a potential pharmacological strategy for preventing the inhibitory effects of resistin on fatty acid β oxidation.

2006 ◽  
Vol 42 ◽  
pp. 47-59 ◽  
Author(s):  
Arend Bonen ◽  
G. Lynis Dohm ◽  
Luc J.C. van Loon

Skeletal muscle constitutes 40% of body mass and takes up 80% of a glucose load. Therefore, impaired glucose removal from the circulation, such as that which occurs in obesity and type 2 diabetes, is attributable in large part to the insulin resistance in muscle. Recent research has shown that fatty acids, derived from adipose tissue, can interfere with insulin signalling in muscle. Hence, insulin-stimulated GLUT4 translocation to the cell surface is impaired, and therefore, the rate of glucose removal from the circulation into muscle is delayed. The mechanisms provoking lipid-mediated insulin resistance are not completely understood. In sedentary individuals, excess intramyocellular accumulation of triacylglycerols is only modestly associated with insulin resistance. In contrast, endurance athletes, despite accumulating large amounts of intramyocellular triacylglycerols, are highly insulin sensitive. Thus it appears that lipid metabolites, other than triacylglycerols, interfere with insulin signalling. These metabolites, however, are not expected to accumulate in athletic muscles, as endurance training increases the capacity for fatty acid oxidation by muscle. These observations, and others in severely obese individuals and type 2 diabetes patients, suggest that impaired rates of fatty acid oxidation are associated with insulin resistance. In addition, in obesity and type 2 diabetes, the rates of fatty acid transport into muscle are also increased. Thus, excess intracellular lipid metabolite accumulation, which interferes with insulin signalling, can occur as a result of impaired rates of fatty acid oxidation and/or increased rates of fatty acid transport into muscle. Accumulation of excess intramyocellular lipid can be avoided by exercise, which improves the capacity for fatty acid oxidation.


Placenta ◽  
2014 ◽  
Vol 35 (9) ◽  
pp. A29
Author(s):  
Charlotte Hulme ◽  
Melissa Westwood ◽  
Alexander E.P. Heazell ◽  
Jenny Myers

2016 ◽  
Vol 310 (6) ◽  
pp. E452-E460 ◽  
Author(s):  
K. J. Mather ◽  
G. D. Hutchins ◽  
K. Perry ◽  
W. Territo ◽  
R. Chisholm ◽  
...  

Altered myocardial fuel selection likely underlies cardiac disease risk in diabetes, affecting oxygen demand and myocardial metabolic flexibility. We investigated myocardial fuel selection and metabolic flexibility in human type 2 diabetes mellitus (T2DM), using positron emission tomography to measure rates of myocardial fatty acid oxidation {16-[18F]fluoro-4-thia-palmitate (FTP)} and myocardial perfusion and total oxidation ([11C]acetate). Participants underwent paired studies under fasting conditions, comparing 3-h insulin + glucose euglycemic clamp conditions (120 mU·m−2·min−1) to 3-h saline infusion. Lean controls ( n = 10) were compared with glycemically controlled volunteers with T2DM ( n = 8). Insulin augmented heart rate, blood pressure, and stroke index in both groups (all P < 0.01) and significantly increased myocardial oxygen consumption ( P = 0.04) and perfusion ( P = 0.01) in both groups. Insulin suppressed available nonesterified fatty acids ( P < 0.0001), but fatty acid concentrations were higher in T2DM under both conditions ( P < 0.001). Insulin-induced suppression of fatty acid oxidation was seen in both groups ( P < 0.0001). However, fatty acid oxidation rates were higher under both conditions in T2DM ( P = 0.003). Myocardial work efficiency was lower in T2DM ( P = 0.006) and decreased in both groups with the insulin-induced increase in work and shift in fuel utilization ( P = 0.01). Augmented fatty acid oxidation is present under baseline and insulin-treated conditions in T2DM, with impaired insulin-induced shifts away from fatty acid oxidation. This is accompanied by reduced work efficiency, possibly due to greater oxygen consumption with fatty acid metabolism. These observations suggest that improved fatty acid suppression, or reductions in myocardial fatty acid uptake and retention, could be therapeutic targets to improve myocardial ischemia tolerance in T2DM.


2013 ◽  
Vol 37 ◽  
pp. S62
Author(s):  
Fatima-Zahra Bouchouirab ◽  
Mélanie Fortin ◽  
Frédérique Frish ◽  
Jean Dubé ◽  
André Carpentier

2009 ◽  
Vol 296 (4) ◽  
pp. E738-E747 ◽  
Author(s):  
Graham P. Holloway ◽  
Carley R. Benton ◽  
Kerry L. Mullen ◽  
Yuko Yoshida ◽  
Laelie A. Snook ◽  
...  

Intramuscular triacylglycerol (IMTG) accumulation in obesity has been attributed to increased fatty acid transport and/or to alterations in mitochondrial fatty acid oxidation. Alternatively, an imbalance in these two processes may channel fatty acids into storage. Therefore, in red and white muscles of lean and obese Zucker rats, we examined whether the increase in IMTG accumulation was attributable to an increased rate of fatty acid transport rather than alterations in subsarcolemmal (SS) or intermyofibrillar (IMF) mitochondrial fatty acid oxidation. In obese animals selected parameters were upregulated, including palmitate transport (red: +100%; white: +51%), plasmalemmal FAT/CD36 (red: +116%; white: +115%; not plasmalemmal FABPpm, FATP1, or FATP4), IMTG concentrations (red: ∼2-fold; white: ∼4-fold), and mitochondrial content (red +30%). Selected mitochondrial parameters were also greater in obese animals, namely, palmitate oxidation (SS red: +91%; SS white: +26%; not IMF mitochondria), FAT/CD36 (SS: +65%; IMF: +65%), citrate synthase (SS: +19%), and β-hydroxyacyl-CoA dehydrogenase activities (SS: +20%); carnitine palmitoyltransferase-I activity did not differ. A comparison of lean and obese rat muscles revealed that the rate of change in IMTG concentration was eightfold greater than that of fatty acid oxidation (SS mitochondria), when both parameters were expressed relative to fatty transport. Thus fatty acid transport, esterification, and oxidation (SS mitochondria) are upregulated in muscles of obese Zucker rats, with these effects being most pronounced in red muscle. The additional fatty acid taken up is channeled primarily to esterification, suggesting that upregulation in fatty acid transport as opposed to altered fatty acid oxidation is the major determinant of intramuscular lipid accumulation.


2009 ◽  
Vol 34 (3) ◽  
pp. 440-446 ◽  
Author(s):  
Graham P. Holloway

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.


2009 ◽  
Vol 297 (4) ◽  
pp. R1202-R1212 ◽  
Author(s):  
Arend Bonen ◽  
Graham P. Holloway ◽  
Narendra N. Tandon ◽  
Xiao-Xia Han ◽  
Jay McFarlan ◽  
...  

We examined fatty acid transporters, transport, and metabolism in hearts and red and white muscles of lean and insulin-resistant ( week 6) and type 2 diabetic ( week 24) Zucker diabetic fatty (ZDF) rats. Cardiac fatty acid transport was similar in lean and ZDF hearts at week 6 but was reduced at week 24 (−40%) in lean but not ZDF hearts. Red muscle of ZDF rats exhibited an early susceptibility to upregulation (+66%) of fatty acid transport at week 6 that was increased by 50% in lean and ZDF rats at week 24 but remained 44% greater in red muscle of ZDF rats. In white muscle, no differences were observed in fatty acid transport between groups or from week 6 to week 24. In all tissues (heart and red and white muscle), FAT/CD36 protein and plasmalemmal content paralleled the changes in fatty acid transport. Triacylglycerol content in red and white muscles, but not heart, in lean and ZDF rats correlated with fatty acid transport ( r = 0.91) and sarcolemmal FAT/CD36 ( r = 0.98). Red and white muscle fatty acid oxidation by isolated mitochondria was not impaired in ZDF rats but was reduced by 18–24% in red muscle of lean rats at week 24. Thus, in red, but not white, muscle of insulin-resistant and type 2 diabetic animals, a marked upregulation in fatty acid transport and intramuscular triacylglycerol was associated with increased levels of FAT/CD36 expression and plasmalemmal content. In heart, greater rates of fatty acid transport and FAT/CD36 in ZDF rats ( week 24) were attributable to the inhibition of age-related reductions in these parameters. However, intramuscular triacylglycerol did not accumulate in hearts of ZDF rats. Thus insulin resistance and type 2 diabetes are accompanied by tissue-specific differences in FAT/CD36 and fatty acid transport and metabolism. Upregulation of fatty acid transport increased red muscle, but not cardiac, triacylglycerol accumulation. White muscle lipid metabolism dysregulation was not observed.


2004 ◽  
Vol 18 (10) ◽  
pp. 1144-1146 ◽  
Author(s):  
Arend Bonen ◽  
Michelle L. Parolin ◽  
Gregory R. Steinberg ◽  
Jorge Calles‐Escandon ◽  
Narendra N. Tandon ◽  
...  

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