scholarly journals AMP-activated protein kinase (AMPK) contributes to the anti-obesity effects and adipose tissue browning of alpha-lipoic acid in ovariectomized rats

2021 ◽  
Author(s):  
Hsin-Hsueh Shen ◽  
Ming-Ting Chung ◽  
Shieh-Yang Huang ◽  
Ching-Wen Kung ◽  
Shu-Ying Chen ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Protein Kinase ◽  
Lipoic Acid ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Ampk Signaling ◽  
Ovx Rats ◽  
Beige Adipocytes ◽  
Amp Activated Protein Kinase ◽  
Tissue Browning

Abstract BackgroundBilateral ovariectomy is an experimental model used to analyze the conditions of menopause and develop strategies for alleviation of the deleterious effects during estrogen deficiency. Brown and beige adipocytes exert thermogenesis capacities and are promising therapeutic strategy for obesity. This study aims to investigate the adipose tissue browning potentials of antioxidant α-lipoic acid (ALA) and underlying mechanisms involved in ovariectomized (Ovx) rats.Methods:Eight weeks old female Wistar rats were randomly divided into Sham or Ovx groups. The Ovx rats were subjected to bilateral ovariectomy and administered with ALA 200 or ALA 300 mg/kg/day (gavage) for 8 weeks. Results:Ovx group significantly increased boy weight (BW) and fat pad mass as compared to Sham group, while ALA supplementation reversed these changes. Lipid profiles including serum triglycerides (TG), total (TC) and low-density lipoprotein cholesterol (LDL-C) levels were significantly elevated in the Ovx group, whereas the ALA treatment showed a significant decrease in these levels. Furthermore, high density lipoprotein cholesterol (HDL-C) and myokine irisin secretion were increased by ALA as well. Morphology results showed ALA treatment reduced Ovx-induced adipocyte hypertrophy and enhanced UCP1 expression by immunohistochemical staining in inguinal WAT. Protein expression of brown fat-specific markers UCP1, PRDM16 and CIDEA was markedly reduced in Ovx rats, whereas ALA treatment reversed these changes. ALA significantly increased liver kinase B1 (LKB1) and phosphorylation of AMP-activated protein kinase (AMPK) and the downstream acetyl-CoA carboxylase (ACC) that were decreased by Ovx, suggesting the browning effects were mediated by AMPK signaling. Conclusions:ALA ameliorates obesity caused by hormone deprivation in menopause via conversion of white to beige adipocytes concomitant with the activation of AMPK signaling.

scholarly journals Effect of Soybean and Soybean Koji on Obesity and Dyslipidemia in Rats Fed a High-Fat Diet: A Comparative Study

2021 ◽  
Vol 18 (11) ◽  
pp. 6032
Author(s):  
Sihoon Park ◽  
Jae-Joon Lee ◽  
Hye-Won Shin ◽  
Sunyoon Jung ◽  
Jung-Heun Ha
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
High Fat Diet ◽  
Unsaturated Fatty Acids ◽  
Density Lipoprotein ◽  
Serum Triglyceride ◽  
Lipoprotein Cholesterol ◽  
Health Concern ◽  
High Fat ◽  
Cholesterol Levels

Soybean koji refers to steamed soybeans inoculated with microbial species. Soybean fermentation improves the health benefits of soybeans. Obesity is a serious health concern owing to its increasing incidence rate and high association with other metabolic diseases. Therefore, we investigated the effects of soybean and soybean koji on high-fat diet-induced obesity in rats. Five-week-old male Sprague-Dawley rats were randomly divided into four groups (n = 8/group) as follows: (1) regular diet (RD), (2) high-fat diet (HFD), (3) HFD + steamed soybean (HFD+SS), and (4) HFD + soybean koji (HFD+SK). SK contained more free amino acids and unsaturated fatty acids than SS. In a rat model of obesity, SK consumption significantly alleviated the increase in weight of white adipose tissue and mRNA expression of lipogenic genes, whereas SS consumption did not. Both SS and SK reduced serum triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels, and increased high-density lipoprotein cholesterol levels. SS and SK also inhibited lipid accumulation in the liver and white adipose tissue and reduced adipocyte size. Although both SS and SK could alleviate HFD-induced dyslipidemia, SK has better anti-obesity effects than SS by regulating lipogenesis. Overall, SK is an excellent functional food that may prevent obesity.

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 The Role of AMPK Signaling in Brown Adipose Tissue Activation

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1122
Author(s):  
Jamie I. van der van der Vaart ◽  
Mariëtte R. Boon ◽  
Riekelt H. Houtkooper
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Whole Body ◽  
Ampk Signaling ◽  
Mitochondrial Homeostasis ◽  
Brown Adipose ◽  
Metabolic Stresses ◽  
Amp Activated Protein Kinase ◽  
Body Energy

Obesity is becoming a pandemic, and its prevalence is still increasing. Considering that obesity increases the risk of developing cardiometabolic diseases, research efforts are focusing on new ways to combat obesity. Brown adipose tissue (BAT) has emerged as a possible target to achieve this for its functional role in energy expenditure by means of increasing thermogenesis. An important metabolic sensor and regulator of whole-body energy balance is AMP-activated protein kinase (AMPK), and its role in energy metabolism is evident. This review highlights the mechanisms of BAT activation and investigates how AMPK can be used as a target for BAT activation. We review compounds and other factors that are able to activate AMPK and further discuss the therapeutic use of AMPK in BAT activation. Extensive research shows that AMPK can be activated by a number of different kinases, such as LKB1, CaMKK, but also small molecules, hormones, and metabolic stresses. AMPK is able to activate BAT by inducing adipogenesis, maintaining mitochondrial homeostasis and inducing browning in white adipose tissue. We conclude that, despite encouraging results, many uncertainties should be clarified before AMPK can be posed as a target for anti-obesity treatment via BAT activation.

scholarly journals Anti-Obesity Effect of Galacto-Oligosaccharides in Obese Rats

2021 ◽  
Author(s):  
Shang Kong ◽  
Xingjun Huang ◽  
Hua Cao ◽  
Yan Bai ◽  
Qishi Che ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Fat Body ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Protective Role ◽  
Lipoprotein Cholesterol ◽  
Fat Cells ◽  
Expression Levels ◽  
Brown Adipose ◽  
Obese Rats

Abstract Background: Galacto-oligosaccharides (GOS) is a commonly used as a prebiotic with a variety of metabolic benefits. Whether GOS plays a protective role in obesity is still unknown. Here we demonstrated that GOS possesses an anti-obesity activity by promoting adipose tissue browning and thermogenesis. Results: Our results showed that GOS effectively slow weight gain of diet-induced obese (DIO) rats without affecting energy intake. GOS significantly suppressed the hypertrophy and hyperplasia of white adipose tissue (WAT), as well as markedly lessened the ratio of fat pad to fat body. Consistently, GOS significantly improved serum total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels, which indicated an appropriate weight loss activity of GOS. Interestingly, GOS also significantly increased the expression levels of browning proteins (UCP1, PPARγ, PGC1α and PRMD16) both in the WAT and brown adipose tissue (BAT). We further found that GOS markedly increased the expression levels of LXRα, PPARα, LDLR and CYP7A1 proteins in the liver of obese rats. Conclusions: Taken together, we concluded that GOS inhibits obesity by accelerating the browning of white fat cells and the thermogenesis of brown fat cells, moreover GOS improves host lipid homeostasis by promoting cholesterol catabolism.

scholarly journals Myeloid deletion and therapeutic activation of AMP-activated protein kinase (AMPK) do not alter atherosclerosis in male or female mice

2020 ◽  
Author(s):  
Nicholas D. LeBlond ◽  
Peyman Ghorbani ◽  
Conor O’Dwyer ◽  
Nia Ambursley ◽  
Julia R. C. Nunes ◽  
...  
Keyword(s):  
Protein Kinase ◽  
First Generation ◽  
Western Diet ◽  
Daily Injection ◽  
Catalytic Subunits ◽  
Male And Female ◽  
Ampk Signaling ◽  
Female Mice ◽  
Amp Activated Protein Kinase ◽  
Progression Of Atherosclerosis

AbstractObjectiveThe dysregulation of myeloid-derived cell metabolism can drive atherosclerosis. AMP-activated protein kinase (AMPK) controls various aspects of macrophage dynamics and lipid homeostasis, which are important during atherogenesis.Approach and ResultsWe aimed to clarify the role of myeloid-specific AMPK signaling by using LysM-Cre to drive the deletion of both the α1 and α2 catalytic subunits (MacKO), in male and female mice made acutely atherosclerotic by PCSK9-AAV and Western diet-feeding. After 6 weeks of Western diet feeding, half received daily injection of either the AMPK activator, A-769662 or a vehicle control for a further 6 weeks. After 12 weeks, myeloid cell populations were not different between genotype or sex. Similarly, aortic sinus plaque size, lipid staining and necrotic area were not different in male and female MacKO mice compared to their littermate floxed controls. Moreover, therapeutic intervention with A-769662 had no effect. There were no differences in the amount of circulating total cholesterol or triglyceride, and only minor differences in the levels of inflammatory cytokines between groups. Finally, CD68+ area or markers of autophagy showed no effect of either lacking AMPK signaling or systemic AMPK activation.ConclusionsOur data suggest that while defined roles for each catalytic AMPK subunit have been identified, global deletion of myeloid AMPK signaling does not significantly impact atherosclerosis. Moreover, we show that intervention with the first-generation AMPK activator, A-769662, was not able to stem the progression of atherosclerosis.Highlights- The deletion of both catalytic subunits of AMPK in myeloid cells has no significant effect on the progression of atherosclerosis in either male or female mice- Therapeutic delivery of a first-generation AMPK activator (A-769662) for the last 6 weeks of 12-week study had no beneficial effect in either male or female mice- Studying total AMPK deletion may mask specific effects of each isoform and highlights the need for targeted disruption of AMPK phosphorylation sites via knock-in mutations, rather than the traditional “sledgehammer” knockout approach

AMP-activated protein kinase (AMPK) signaling in GnRH neurons links energy status and reproduction

Metabolism ◽  
2021 ◽  
Vol 115 ◽  
pp. 154460
Author(s):  
D. Franssen ◽  
A. Barroso ◽  
F. Ruiz-Pino ◽  
M.J. Vázquez ◽  
D. García-Galiano ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Energy Status ◽  
Ampk Signaling ◽  
Gnrh Neurons ◽  
Amp Activated Protein Kinase
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