AICAR and Compound C regulate food intake independently of AMP-activated protein kinase in lines of chickens selected for high or low body weight

It has been suggested a role of fatty acid ethanolamides in control of feeding behavior. Among these, palmitoylethanolamide (PEA) has not been directly implicated in appetite regulation and weight gain. The aim of this study was to investigate the effect of PEA on food intake and body weight and the interaction between PEA and hypothalamic leptin signaling in ovariectomized rats. Ovariectomy produced hyperphagia and increased weight gain, making it an useful model of mild obesity. Ovariectomized rats were treated with PEA (30 mg/kg sc) for 5 weeks. Then, blood was collected, and hypothalamus and adipose tissue were removed for histological, cellular, and molecular measurements. We showed that PEA caused a reduction of food intake, body weight, and fat mass. The mechanisms underlying PEA effects involved an improvement in hypothalamic leptin signaling, through a raise in signal transducer and activator of transcription 3 phosphorylation. We also reported that PEA reduced AMP-activated protein kinase-α phosphorylation and modulated transcription of anorectic and orexigenic neuropeptides in the hypothalamus. Moreover, PEA increased AMP-activated protein kinase-α phosphorylation and carnitine palmitoyltransferase 1 transcription in adipose tissue, suggesting an increase in ATP-producing catabolic pathway. PEA also polarized adipose tissue macrophages to M2 lean phenotype, associated to a reduction of inflammatory cytokines/adipokines. To demonstrate the direct effect of PEA on leptin sensitivity without interference of adiposity loss, we obtained consistent data in PEA-treated sham-operated animals and in vitro in SH-SY5Y neuroblastoma cell line. Therefore, our data provide a rationale for the therapeutic use of PEA in obese postmenopausal woman.

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C75, a Fatty Acid Synthase Inhibitor, Reduces Food Intake via Hypothalamic AMP-activated Protein Kinase

Journal of Biological Chemistry ◽

10.1074/jbc.m402165200 ◽

2004 ◽

Vol 279 (19) ◽

pp. 19970-19976 ◽

Cited By ~ 213

Author(s):

Eun-Kyoung Kim ◽

Ian Miller ◽

Susan Aja ◽

Leslie E. Landree ◽

Michael Pinn ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Fatty Acid ◽

Energy Balance ◽

Protein Kinase ◽

Food Intake ◽

Fatty Acid Synthase ◽

Α Subunit ◽

Compound C ◽

Amp Activated Protein Kinase

Energy homeostasis and feeding are regulated by the central nervous system. C75, a fatty acid synthase (FAS) inhibitor, causes weight loss and anorexia, implying a novel central nervous system pathway(s) for sensing energy balance. AMP-activated protein kinase (AMPK), a sensor of peripheral energy balance, is phosphorylated and activated when energy sources are low. Here, we identify a role for hypothalamic AMPK in the regulation of feeding behavior and in mediating the anorexic effects of C75. 5-Aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR), an activator of AMPK, increased food intake, whereas compound C, an inhibitor of AMPK, decreased food intake. C75 rapidly reduced the level of the phosphorylated AMPK α subunit (pAMPKα) in the hypothalamus, even in fasted mice that had elevated hypothalamic pAMPKα levels. Furthermore, AICAR reversed both the C75-induced anorexia and the decrease in hypothalamic pAMPKα levels. C75 elevated hypothalamic neuronal ATP levels, which may contribute to the mechanism by which C75 decreased AMPK activity. C75 reduced the levels of pAMPKα and phosphorylated cAMP response element-binding protein (pCREB) in the arcuate nucleus neurons of the hypothalamus, suggesting a mechanism for the reduction in NPY expression seen with C75 treatment. These data indicate that modulation of FAS activity in the hypothalamus can alter energy perception via AMPK, which functions as a physiological energy sensor in the hypothalamus.

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Adrenaline is a critical mediator of acute exercise-induced AMP-activated protein kinase activation in adipocytes

Biochemical Journal ◽

10.1042/bj20061479 ◽

2007 ◽

Vol 403 (3) ◽

pp. 473-481 ◽

Cited By ~ 81

Author(s):

Ho-Jin Koh ◽

Michael F. Hirshman ◽

Huamei He ◽

Yangfeng Li ◽

Yasuko Manabe ◽

...

Keyword(s):

Protein Kinase ◽

Protein Kinase Activity ◽

Chronic Exercise ◽

Rat Adipocytes ◽

Compound C ◽

Isolated Adipocytes ◽

Ampk Activity ◽

Exercise Induced ◽

Amp Activated Protein Kinase

Exercise increases AMPK (AMP-activated protein kinase) activity in human and rat adipocytes, but the underlying molecular mechanisms and functional consequences of this activation are not known. Since adrenaline (epinephrine) concentrations increase with exercise, in the present study we hypothesized that adrenaline activates AMPK in adipocytes. We show that a single bout of exercise increases AMPKα1 and α2 activities and ACC (acetyl-CoA carboxylase) Ser79 phosphorylation in rat adipocytes. Similarly to exercise, adrenaline treatment in vivo increased AMPK activities and ACC phosphorylation. Pre-treatment of rats with the β-blocker propranolol fully blocked exercise-induced AMPK activation. Increased AMPK activity with exercise and adrenaline treatment in vivo was accompanied by an increased AMP/ATP ratio. Adrenaline incubation of isolated adipocytes also increased the AMP/ATP ratio and AMPK activities, an effect blocked by propranolol. Adrenaline incubation increased lipolysis in isolated adipocytes, and Compound C, an AMPK inhibitor, attenuated this effect. Finally, a potential role for AMPK in the decreased adiposity associated with chronic exercise was suggested by marked increases in AMPKα1 and α2 activities in adipocytes from rats trained for 6 weeks. In conclusion, both acute and chronic exercise are significant regulators of AMPK activity in rat adipocytes. Our findings suggest that adrenaline plays a critical role in exercise-stimulated AMPKα1 and α2 activities in adipocytes, and that AMPK can function in the regulation of lipolysis.

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Abstract 337: Activation of Myocardial AMP-activated Protein Kinase by Metformin Prevents Progression of Heart Failure in Dogs; Involvement of eNOS Activation

Circulation ◽

10.1161/circ.118.suppl_18.s_286-c ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Hideyuki Sasaki ◽

Hiroshi Asanuma ◽

Masashi Fujita ◽

Hiroyuki Takahama ◽

Masanori Asakura ◽

...

Keyword(s):

Oxidative Stress ◽

Nitric Oxide ◽

Heart Failure ◽

Cell Death ◽

Protein Kinase ◽

Left Ventricular ◽

Vehicle Group ◽

Mrna Levels ◽

Compound C ◽

Amp Activated Protein Kinase

Background; Several studies have shown that metformin activates AMP-activated protein kinase (AMPK), which mediates potent cardioprotection against ischemia-reperfusion injury. AMPK is also activated in experimental failing myocardium, suggesting that activation of AMPK is beneficial for the pathophysiology of heart failure. We investigated whether metformin prevents oxidative stress-induced cell death in rat cardiomyocytes and attenuates the progression of heart failure in dogs. Methods and Results; The treatment with metformin (10 μmol/L) protected the rat cultured cardiomyocytes against cell death due to H 2 O 2 exposure (50 μmol/L) as indicated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), TUNEL staining, and flow cytometry. These effects were blunted by an AMPK inhibitor, compound-C (20 μmol/L), suggesting that the activation of AMPK decreased the extent of apoptosis-induced cell death due to H 2 O 2 exposure. Continuous rapid ventricular pacing (230/min for 4 weeks) in dogs caused heart failure and the treatment with metformin (100 mg/kg/day PO, n=8) decreased left ventricular (LV) end-diastolic dimension (32.8±0.4 vs. 36.5±1.0 mm, p< 0.01) and pressure (11.8±1.1 vs. 22±0.9 mmHg, p< 0.01), and increased LV fractional shortening (18.6±1.8 vs. 9.6±0.7 %, p< 0.01) along with enhanced phosphorylation of AMPK and the decreased the number of TUNEL-positive cells of the LV myocardium compared with the vehicle group (n=8). Interestingly, metformin increased the protein and mRNA levels of endothelial nitric oxide synthase of the LV myocardium and plasma nitric oxide levels. Metformin improved the plasma insulin resistance without increased myocardial GLUT-4 translocation. Furthermore, the subcutaneous administration of AICAR (50 mg/kg/every other day), another AMPK activator mediated the equivalent effects to metformin, strengthening the pivotal role of AMPK in reduction of apoptosis and prevention of heart failure. Conclusions; Activation of myocardial AMPK attenuated the oxidative stress-induced cardiomyocyte apoptosis and prevented the progression of heart failure in dogs, along with eNOS activation. Thus, metformin or AICAR may be applicable as a novel therapy for heart failure.

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Involvement of AMP-activated protein kinase in thrombin-stimulated interleukin 6 synthesis in osteoblasts

Journal of Molecular Endocrinology ◽

10.1530/jme-11-0165 ◽

2012 ◽

Vol 49 (1) ◽

pp. 47-55 ◽

Cited By ~ 5

Author(s):

H Tokuda ◽

K Kato ◽

H Natsume ◽

A Kondo ◽

G Kuroyanagi ◽

...

Keyword(s):

Protein Kinase ◽

Map Kinase ◽

Interleukin 6 ◽

P38 Map Kinase ◽

Thrombin Time ◽

Rt Pcr ◽

Α Subunit ◽

Compound C ◽

Kinase C ◽

Amp Activated Protein Kinase

We previously demonstrated that thrombin stimulates synthesis of interleukin 6 (IL6), a potent bone resorptive agent, in part via p44/p42 MAP kinase and p38 MAP kinase but not through stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) among the MAP kinase superfamily in osteoblast-like MC3T3-E1 cells. In this study, we investigated the involvement of AMP-activated protein kinase (AMPK), a regulator of energy metabolism, in thrombin-stimulated IL6 synthesis in MC3T3-E1 cells. The phosphorylation of p44/p42 MAP kinase, p38 MAP kinase, SAPK/JNK, or AMPK was determined by western blot analysis. The release of IL6 was determined by the measurement of IL6 concentration in the conditioned medium using an ELISA kit. The expression ofIL6mRNA was determined by RT-PCR. Thrombin time dependently induced the phosphorylation of AMPK α-subunit (Thr-172). Compound C, an inhibitor of AMPK, dose-dependently suppressed the thrombin-stimulated IL6 release in the range between 0.3 and 10 μM. Compound C reduced thrombin-induced acetyl-CoA carboxylase phosphorylation. TheIL6mRNA expression induced by thrombin was markedly reduced by compound C. Downregulation of AMPK by siRNA suppressed the thrombin-stimulated IL6 release. The thrombin-induced phosphorylation of p44/p42 MAP kinase and p38 MAP kinase was inhibited by compound C, which failed to affect SAPK/JNK phosphorylation. These results strongly suggest that AMPK regulates thrombin-stimulated IL6 synthesis via p44/p42 MAP kinase and p38 MAP kinase in osteoblasts.

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Adiponectin Stimulates AMP-Activated Protein Kinase in the Hypothalamus and Increases Food Intake

Cell Metabolism ◽

10.1016/j.cmet.2007.06.003 ◽

2007 ◽

Vol 6 (1) ◽

pp. 55-68 ◽

Cited By ~ 480

Author(s):

Naoto Kubota ◽

Wataru Yano ◽

Tetsuya Kubota ◽

Toshimasa Yamauchi ◽

Shinsuke Itoh ◽

...

Keyword(s):

Protein Kinase ◽

Food Intake ◽

Amp Activated Protein Kinase

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AMP-activated protein kinase agonists increase mRNA content of the muscle-specific ubiquitin ligases MAFbx and MuRF1 in C2C12 cells

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00622.2006 ◽

2007 ◽

Vol 292 (6) ◽

pp. E1555-E1567 ◽

Cited By ~ 93

Author(s):

Brian J. Krawiec ◽

Gerald J. Nystrom ◽

Robert A. Frost ◽

Leonard S. Jefferson ◽

Charles H. Lang

Keyword(s):

Skeletal Muscle ◽

Protein Kinase ◽

Mrna Expression ◽

Muscle Atrophy ◽

Ubiquitin Ligases ◽

C2c12 Cells ◽

Skeletal Muscle Atrophy ◽

Compound C ◽

Mrna Content ◽

Amp Activated Protein Kinase

The hypothesis of the present study was that exposure of differentiated muscle cells to agonists of the AMP-activated protein kinase (AMPK) would increase the mRNA content of the muscle-specific ubiquitin ligases muscle atrophy F-box (MAFbx) and muscle RING finger 1 (MuRF1). C2C12 cells were incubated with incremental doses of 5-aminoimidazol-4-carboximide ribonucleoside (AICAR) or metformin for 24 h. Both MAFbx and MuRF1 mRNA increased dose dependently in response to these AMPK activators. AICAR, metformin, and 2-deoxy-d-glucose produced time-dependent alterations in ubiquitin ligase expression, typified by a biphasic pattern of expression marked by an acute repression followed by a sustained induction. AMPK-activating treatments in conjunction with dexamethasone produced a pronounced synergistic effect on ligase mRNA expression at later time points. This cooperative response occurred in the absence of a dexamethasone-dependent increase in AMPK expression or activity, as determined by immunoblotting for phosphorylation and expression of AMPKα and its downstream target acetyl-CoA carboxylase (ACC). These responses elicited by AMPK activation singly or in combination with dexamethasone did not extend to the mRNA expression of the UBR box family E3s UBR1/E3αI and UBR2/E3αII. Treatment with the AMPK inhibitor compound C prevented increases in MAFbx and MuRF1 mRNA in response to serum deprivation, as well as AICAR and dexamethasone treatment individually or jointly. Stimulation of AMPK activity in vivo via AICAR injection increased both MAFbx and MuRF1 mRNA in murine skeletal muscle. These data suggest that activation of AMPK in skeletal muscle results in a specific upregulation of MAFbx and MuRF1, responses that are reminiscent of the proposed atrophic transcriptional program executed under various conditions of skeletal muscle wasting. Therefore, AMPK may be a critical component of the intercalated network of signaling pathways governing skeletal muscle atrophy, where its input acts to modify anti- and proatrophic signals to influence gene expression in reaction to catabolic perturbations.

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Abstract 565: The Activation of AMP-Activated Protein Kinase Ameliorates the Severity of Heart Failure in Dogs

Circulation ◽

10.1161/circ.116.suppl_16.ii_102-a ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Hideyuki Sasaki ◽

Hiroshi Asanuma ◽

Masashi Fujita ◽

Hiroyuki Takahama ◽

Masakatsu Wakeno ◽

...

Keyword(s):

Heart Failure ◽

Protein Kinase ◽

Cardiac Myocytes ◽

Left Ventricular ◽

Neonatal Rat ◽

Cellular Damage ◽

Control Group ◽

Compound C ◽

Rapid Pacing ◽

Amp Activated Protein Kinase

Backgrounds; Since AMP-activated protein kinase (AMPK) is activated in the pressure-overloaded hypertrophic hearts, we investigated whether the activation of AMPK caused by metformin attenuates the progression of heart failure induced by rapid pacing in dogs and decreases cellular damage caused by oxidative stress in neonatal rat cardiac myocytes. Methods and Results; Heart failure was induced by right ventricular (RV) pacing at 230 bpm for 4 weeks in dogs. Treatment of dogs with metformin (100mg/kg/day, orally, n=8, Met group) for 4 weeks prevented significantly the progression of pacing-induced heart failure evaluated by echocardiographical and hemodynamic measurement compared with the control group (n=8). Left ventricular (LV) diastolic and systolic dimension (LVDd and LVDs) were smaller (32.8±0.4 and 26.7±0.9 mm, respectively) and fractional shortening (FS) and ejection fraction (EF) were preserved in Met group (18.6±1.8 and 45.5±3.5 %, respectively) compared with the control group (LVDd and LVDs; 36.5±1.0 and 33.0±1.0 mm, FS and EF; 9.6±0.7 and 27.0±1.9 %, p<0.05 vs. Met group each). Furthermore, both pulmonary capillary wedge pressure (PCWP) and mean pulmonary arterial pressure (mPA) were significantly lower in Met group (11.1±0.9 and 18.1±1.4 mmHg, respectively) compared with the control group (21.0±2.2 and 26.8±2.8 mmHg, respectively). Treatment of cultured cardiac myocytes with a maximal physiological concentration of metformin (10μmol/L) attenuated the cellular damage against H 2 O 2 exposure (50μmol/L). These effects were blunted by an AMPK inhibitor, compound-C (20μmol/L), suggesting that the activation of AMPK increased the cellular viability during H 2 O 2 exposure. Conclusions; Metformin that activates AMPK prevented the progression of heart failure induced by rapid pacing in dogs and attenuated the cellular damage against H 2 O 2 exposure in cardiac myocytes. AMPK may be one of new targets for preventing heart failure in clinical settings.

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PRKAA1 Promotes Proliferation and Inhibits Apoptosis of Gastric Cancer Cells Through Activating JNK1 and Akt Pathways

Oncology Research Featuring Preclinical and Clinical Cancer Therapeutics ◽

10.3727/096504019x15668125347026 ◽

2020 ◽

Vol 28 (3) ◽

pp. 213-223 ◽

Cited By ~ 2

Author(s):

Yangmei Zhang ◽

Xichang Zhou ◽

Long Cheng ◽

Xiang Wang ◽

Qinglin Zhang ◽

...

Keyword(s):

Gastric Cancer ◽

Protein Kinase ◽

Cancer Cells ◽

Akt Signaling ◽

Catalytic Subunit ◽

Gastric Cancer Cells ◽

In Vivo Experiments ◽

Compound C ◽

Amp Activated Protein Kinase

PRKAA1 (protein kinase AMP-activated catalytic subunit α 1) is a catalytic subunit of AMP-activated protein kinase (AMPK), which plays a key role in regulating cellular energy metabolism through phosphorylation, and genetic variations in the PRKAA1 have been found to be associated with gastric cancer risk. However, the effect and underlying molecular mechanism of PRKAA1 on gastric cancer tumorigenesis, especially the proliferation and apoptosis, are not fully understood. Our data showed that PRKAA1 is highly expressed in BGC-823 and MKN45 cells and is expressed low in SGC-7901 and MGC-803 cells in comparison with the other gastric cancer cells. PRKAA1 downregulation by shRNA or treatment of AMPK inhibitor compound C significantly inhibited proliferation as well as promoted cell cycle arrest and apoptosis of BGC-823 and MKN45 cells. Moreover, the expression of PCNA and Bcl-2 and the activity of JNK1 and Akt signaling were also reduced in BGC-823 and MKN45 cells after PRKAA1 downregulation. In vivo experiments demonstrated that tumor growth in nude mice was significantly inhibited after PRKAA1 silencing. Importantly, inactivation of JNK1 or Akt signaling pathway significantly inhibited PRKAA1 overexpression-induced increased cell proliferation and decreased cell apoptosis in MGC-803 cells. In conclusion, our findings suggest that PRKAA1 increases proliferation and restrains apoptosis of gastric cancer cells through activating JNK1 and Akt pathways.

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