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Seong H, Song JW, Lee KH, Jang G, Shin DM, Shon WJ. Taste receptor type 1 member 3 regulates Western diet-induced male infertility. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159433. [PMID: 38007088 DOI: 10.1016/j.bbalip.2023.159433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 11/05/2023] [Accepted: 11/20/2023] [Indexed: 11/27/2023]
Abstract
Western diet (WD), characterized by a high intake of fats and sugary drinks, is a risk factor for male reproductive impairment. However, the molecular mechanisms underlying this remain unclear. Taste receptor type 1 member 3 (TAS1R3), activated by ligands of WD, is highly expressed in extra-oral tissues, particularly in the testes. Here, we investigated to determine the effects of WD intake on male reproduction and whether TAS1R3 mediates WD-induced impairment in male reproduction. Male C57BL/6 J wild-type (WT) and Tas1r3 knockout (KO) mice were fed either a normal diet and plain water (ND) or a 60 % high-fat-diet and 30 % (w/v) sucrose water (WD) for 18 weeks (n = 7-9/group). Long-term WD consumption significantly impaired sperm count, motility and testicular morphology in WT mice with marked Tas1r3 overexpression, whereas Tas1r3 KO mice were protected from WD-induced reproductive impairment. Testicular transcriptome analysis revealed downregulated AMP-activated protein kinase (AMPK) signaling and significantly elevated AMPK-targeted nuclear receptor 4A1 (Nr4a1) expression in WD-fed Tas1r3 KO mice. In vitro studies further validated that Tas1r3 knockdown in Leydig cells prevented the suppression of Nr4a1 and downstream steroidogenic genes (Star, Cyp11a1, Cyp17a1, and Hsd3b1) caused by high glucose, fructose, and palmitic acid levels, and maintained the levels of testosterone. Additionally, we analyzed the public human dataset to assess the clinical implications of our findings and confirmed a significant association between TAS1R3 and male-infertility-related diseases. Our findings suggest that TAS1R3 regulates WD-induced male reproductive impairment via the AMPK/NR4A1 signaling and can be a novel therapeutic target for male infertility.
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Affiliation(s)
- Hobin Seong
- Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea
| | - Jae Won Song
- Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea
| | - Keon-Hee Lee
- Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea
| | - Goo Jang
- Department of Veterinary Clinical Science, College of Veterinary Medicine and the Research Institute of Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea; Comparative Medicine Disease Research Center, Seoul National University, Seoul 08826, Republic of Korea
| | - Dong-Mi Shin
- Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea; Research Institute of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea.
| | - Woo-Jeong Shon
- Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea; Research Institute of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea.
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Lu YY, Cheng CC, Chen YC, Lin YK, Higa S, Kao YH, Chen YJ. Adenosine monophosphate-regulated protein kinase inhibition modulates electrophysiological characteristics and calcium homeostasis of rabbit right ventricular outflow tract. Fundam Clin Pharmacol 2024; 38:262-275. [PMID: 37664898 DOI: 10.1111/fcp.12953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 07/23/2023] [Accepted: 08/20/2023] [Indexed: 09/05/2023]
Abstract
BACKGROUND Metabolic stress predisposes to ventricular arrhythmias and sudden cardiac death. Right ventricular outflow tract (RVOT) is the common origin of ventricular arrhythmias. Adenosine monophosphate-regulated protein kinase (AMPK) activation is an important compensatory mechanism for cardiac remodeling during metabolic stress. OBJECTIVES The purpose of this study was to access whether AMPK inhibition would modulate RVOT electrophysiology, calcium (Ca2+ ) regulation, and RVOT arrhythmogenesis or not. METHODS Conventional microelectrodes were used to record electrical activity before and after compound C (10 µM, an AMPK inhibitor) in isoproterenol (1 µM)-treated rabbit RVOT tissue preparations under electrical pacing. Whole-cell patch-clamp and confocal microscopic examinations were performed in baseline and compound C-treated rabbit RVOT cardiomyocytes to investigate ionic currents and intracellular Ca2+ transients in isolated rabbit RVOT cardiomyocytes. RESULTS Compound C decreased RVOT contractility, and reversed isoproterenol increased RVOT contractility. Compound C decreased the incidence, rate, and duration of isoproterenol-induced RVOT burst firing under rapid pacing. Compared to baseline, compound C-treated RVOT cardiomyocytes had a longer action potential duration, smaller intracellular Ca2+ transients, late sodium (Na+ ), peak L-type Ca2+ current density, Na+ -Ca2+ exchanger, transient outward potassium (K+ ) current, and rapid and slow delayed rectifier K+ currents. CONCLUSION AMPK inhibition modulates RVOT electrophysiological characteristics and Ca2+ homeostasis, contributing to lower RVOT arrhythmogenic activity. Accordingly, AMPK inhibition might potentially reduce ventricular tachyarrhythmias.
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Affiliation(s)
- Yen-Yu Lu
- Division of Cardiology, Department of Internal Medicine, Sijhih Cathay General Hospital, New Taipei City, Taiwan
- School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Chen-Chuan Cheng
- Department of Cardiology, Chi-Mei Medical Center, Tainan, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, and Institute of Physiology, National Defense Medical Center, Taipei, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Taipei Heart Institute, Taipei Medical University, Taipei, Taiwan
| | - Satoshi Higa
- Cardiac Electrophysiology and Pacing Laboratory, Division of Cardiovascular Medicine, Makiminato Central Hospital, Okinawa, Japan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Cardiovascular Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
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Li XJ, Suo P, Wang YN, Zou L, Nie XL, Zhao YY, Miao H. Arachidonic acid metabolism as a therapeutic target in AKI-to-CKD transition. Front Pharmacol 2024; 15:1365802. [PMID: 38523633 PMCID: PMC10957658 DOI: 10.3389/fphar.2024.1365802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 02/06/2024] [Indexed: 03/26/2024] Open
Abstract
Arachidonic acid (AA) is a main component of cell membrane lipids. AA is mainly metabolized by three enzymes: cyclooxygenase (COX), lipoxygenase (LOX) and cytochrome P450 (CYP450). Esterified AA is hydrolysed by phospholipase A2 into a free form that is further metabolized by COX, LOX and CYP450 to a wide range of bioactive mediators, including prostaglandins, lipoxins, thromboxanes, leukotrienes, hydroxyeicosatetraenoic acids and epoxyeicosatrienoic acids. Increased mitochondrial oxidative stress is considered to be a central mechanism in the pathophysiology of the kidney. Along with increased oxidative stress, apoptosis, inflammation and tissue fibrosis drive the progressive loss of kidney function, affecting the glomerular filtration barrier and the tubulointerstitium. Recent studies have shown that AA and its active derivative eicosanoids play important roles in the regulation of physiological kidney function and the pathogenesis of kidney disease. These factors are potentially novel biomarkers, especially in the context of their involvement in inflammatory processes and oxidative stress. In this review, we introduce the three main metabolic pathways of AA and discuss the molecular mechanisms by which these pathways affect the progression of acute kidney injury (AKI), diabetic nephropathy (DN) and renal cell carcinoma (RCC). This review may provide new therapeutic targets for the identification of AKI to CKD continuum.
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Affiliation(s)
- Xiao-Jun Li
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
- Department of Nephrology, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Ping Suo
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Yan-Ni Wang
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Liang Zou
- School of Food and Bioengineering, Chengdu University, Chengdu, Sichuan, China
| | - Xiao-Li Nie
- Department of Nephrology, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Ying-Yong Zhao
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Hua Miao
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
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Xiong J, Wang Z, Bai J, Cheng K, Liu Q, Ni J. Calcitonin gene-related peptide: a potential protective agent in cerebral ischemia-reperfusion injury. Front Neurosci 2023; 17:1184766. [PMID: 37529236 PMCID: PMC10387546 DOI: 10.3389/fnins.2023.1184766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 06/29/2023] [Indexed: 08/03/2023] Open
Abstract
Ischemic stroke is the most common type of cerebrovascular disease with high disability and mortality rates, which severely burdens patients, their families, and society. At present, thrombolytic therapy is mainly used for the treatment of ischemic strokes. Even though it can achieve a good effect, thrombolytic recanalization can cause reperfusion injury. Calcitonin gene-related peptide (CGRP) is a neuropeptide that plays a neuroprotective role in the process of ischemia-reperfusion injury. By combining with its specific receptors, CGRP can induce vasodilation of local cerebral ischemia by directly activating the cAMP-PKA pathway in vascular smooth muscle cells and by indirectly activating the NO-cGMP pathway in an endothelial cell-dependent manner,thus rapidly increasing ischemic local blood flow together with reperfusion. CGRP, as a key effector molecule of neurogenic inflammation, can reduce the activation of microglia, downregulates Th1 classical inflammation, and reduce the production of TNF-α, IL-2, and IFN-γ and the innate immune response of macrophages, leading to the reduction of inflammatory factors. CGRP can reduce the overexpression of the aquaporin-4 (AQP-4) protein and its mRNA in the cerebral ischemic junction, and play a role in reducing cerebral edema. CGRP can protect endothelial cells from angiotensin II by reducing the production of oxidants and protecting antioxidant defense. Furthermore, CGRP-upregulated eNOS can further induce VEGF expression, which then promotes the survival and angiogenesis of vascular endothelial cells. CGRP can also reduce apoptosis by promoting the expression of Bcl-2 and inhibiting the expression of caspase-3. These effects suggest that CGRP can reduce brain injury and repair damaged nerve function. In this review, we focused on the role of CGRP in cerebral ischemia-reperfusion injury.
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Affiliation(s)
- Jie Xiong
- Department of Rehabilitation, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Zhiyong Wang
- Department of Rehabilitation, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Junhui Bai
- Department of Rehabilitation, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Keling Cheng
- Department of Rehabilitation, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Qicai Liu
- Department of Reproductive Medicine Centre, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Jun Ni
- Department of Rehabilitation, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, China
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Gutiérrez-Casares JR, Quintero J, Segú-Vergés C, Rodríguez Monterde P, Pozo-Rubio T, Coma M, Montoto C. In silico clinical trial evaluating lisdexamfetamine's and methylphenidate's mechanism of action computational models in an attention-deficit/hyperactivity disorder virtual patients' population. Front Psychiatry 2023; 14:939650. [PMID: 37333910 PMCID: PMC10273406 DOI: 10.3389/fpsyt.2023.939650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 04/21/2023] [Indexed: 06/20/2023] Open
Abstract
Introduction Attention-deficit/hyperactivity disorder (ADHD) is an impairing psychiatric condition with the stimulants, lisdexamfetamine (LDX), and methylphenidate (MPH), as the first lines pharmacological treatment. Methods Herein, we applied a novel in silico method to evaluate virtual LDX (vLDX) and vMPH as treatments for ADHD applying quantitative systems pharmacology (QSP) models. The objectives were to evaluate the model's output, considering the model characteristics and the information used to build them, to compare both virtual drugs' efficacy mechanisms, and to assess how demographic (age, body mass index, and sex) and clinical characteristics may affect vLDX's and vMPH's relative efficacies. Results and Discussion We molecularly characterized the drugs and pathologies based on a bibliographic search, and generated virtual populations of adults and children-adolescents totaling 2,600 individuals. For each virtual patient and virtual drug, we created physiologically based pharmacokinetic and QSP models applying the systems biology-based Therapeutic Performance Mapping System technology. The resulting models' predicted protein activity indicated that both virtual drugs modulated ADHD through similar mechanisms, albeit with some differences. vMPH induced several general synaptic, neurotransmitter, and nerve impulse-related processes, whereas vLDX seemed to modulate neural processes more specific to ADHD, such as GABAergic inhibitory synapses and regulation of the reward system. While both drugs' models were linked to an effect over neuroinflammation and altered neural viability, vLDX had a significant impact on neurotransmitter imbalance and vMPH on circadian system deregulation. Among demographic characteristics, age and body mass index affected the efficacy of both virtual treatments, although the effect was more marked for vLDX. Regarding comorbidities, only depression negatively impacted both virtual drugs' efficacy mechanisms and, while that of vLDX were more affected by the co-treatment of tic disorders, the efficacy mechanisms of vMPH were disturbed by wide-spectrum psychiatric drugs. Our in silico results suggested that both drugs could have similar efficacy mechanisms as ADHD treatment in adult and pediatric populations and allowed raising hypotheses for their differential impact in specific patient groups, although these results require prospective validation for clinical translatability.
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Affiliation(s)
- José Ramón Gutiérrez-Casares
- Unidad Ambulatoria de Psiquiatría y Salud Mental de la Infancia, Niñez y Adolescencia, Hospital Perpetuo Socorro, Badajoz, Spain
| | - Javier Quintero
- Servicio de Psiquiatría, Hospital Universitario Infanta Leonor, Universidad Complutense, Madrid, Spain
| | - Cristina Segú-Vergés
- Anaxomics Biotech, Barcelona, Spain
- Structural Bioinformatics Group, Research Programme on Biomedical Informatics, Department of Medicine and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | | | | | | | - Carmen Montoto
- Medical Department, Takeda Farmacéutica España, Madrid, Spain
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Novel role of AMPK in cocaine reinforcement via regulating CRTC1. Transl Psychiatry 2022; 12:530. [PMID: 36587026 PMCID: PMC9805446 DOI: 10.1038/s41398-022-02299-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 12/16/2022] [Accepted: 12/21/2022] [Indexed: 01/01/2023] Open
Abstract
Repeated cocaine exposure causes compensatory neuroadaptations in neurons in the nucleus accumbens (NAc), a region that mediates reinforcing effects of drugs. Previous studies suggested a role for adenosine monophosphate-activated protein kinase (AMPK), a cellular energy sensor, in modulating neuronal morphology and membrane excitability. However, the potential involvement of AMPK in cocaine use disorder is still unclear. The present study employed a cocaine self-administration model in rats to investigate the effect of AMPK and its target cyclic adenosine monophosphate response element binding protein-regulated transcriptional co-activator 1 (CRTC1) on cocaine reinforcement and the motivation for cocaine. We found that intravenous cocaine self-administration significantly decreased AMPK activity in the NAc shell (NAcsh), which persisted for at least 7 days of withdrawal. Cocaine reinforcement, reflected by self-administration behavior, was significantly prevented or enhanced by augmenting or suppressing AMPK activity pharmacologically and genetically, respectively. No difference in sucrose self-administration behavior was found after the same manipulations. The inhibition of AMPK activity in the NAcsh also increased the motivation for cocaine in progressive-ratio schedules of reinforcement, whereas the activation of AMPK had no effect. The knockdown of CRTC1 in the NAcsh significantly impaired cocaine reinforcement, which was rescued by pharmacologically increasing AMPK activity. Altogether, these results indicate that AMPK in the NAcsh is critical for cocaine reinforcement, possibly via the regulation of CRTC1 signaling. These findings may help reveal potential therapeutic targets and have important implications for the treatment of cocaine use disorder and relapse.
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Honsho M, Mawatari S, Fujino T. Transient Ca2+ entry by plasmalogen-mediated activation of receptor potential cation channel promotes AMPK activity. Front Mol Biosci 2022; 9:1008626. [PMID: 36406270 PMCID: PMC9672372 DOI: 10.3389/fmolb.2022.1008626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022] Open
Abstract
Ethanolamine-containing alkenyl ether glycerophospholipids, plasmalogens, are major cell membrane components of mammalian cells that activate membrane protein receptors such as ion transporters and G-protein coupled receptors. However, the mechanism by which plasmalogens modulate receptor function is unknown. Here, we found that exogenously added plasmalogens activate transient receptor potential cation channel subfamily C member 4 (TRPC4) to increase Ca2+ influx, followed by calcium/calmodulin-dependent protein kinase 2-mediated phosphorylation of AMP-activated protein kinase (AMPK). Upon topical application of plasmalogens to the skin of mice, AMPK activation was observed in TRPC4-expressing hair bulbs and hair follicles. Here, TRPC4 was co-localized with the leucine-rich repeat containing G protein-coupled receptor 5, a marker of hair-follicle stem cells, leading to hair growth. Collectively, this study indicates that plasmalogens could function as gate openers for TRPC4, followed by activating AMPK, which likely accelerates hair growth in mice.
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Affiliation(s)
- Masanori Honsho
- Department of Neuroinflammation and Brain Fatigue Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
- *Correspondence: Masanori Honsho,
| | - Shiro Mawatari
- Institute of Rheological Functions of Food, Fukuoka, Japan
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Courant F, Maravat M, Chen W, Gosset D, Blot L, Hervouet-Coste N, Sarou-Kanian V, Morisset-Lopez S, Decoville M. Expression of the Human Serotonin 5-HT 7 Receptor Rescues Phenotype Profile and Restores Dysregulated Biomarkers in a Drosophila melanogaster Glioma Model. Cells 2022; 11:1281. [PMID: 35455961 PMCID: PMC9028361 DOI: 10.3390/cells11081281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 03/30/2022] [Accepted: 04/06/2022] [Indexed: 02/01/2023] Open
Abstract
Gliomas are the most common primary brain tumors in adults. Significant progress has been made in recent years in identifying the molecular alterations involved in gliomas. Among them, an amplification/overexpression of the EGFR (Epidermal Growth Factor Receptor) proto-oncogene and its associated signaling pathways have been widely described. However, current treatments remain ineffective for glioblastomas, the most severe forms. Thus, the identification of other pharmacological targets could open new therapeutic avenues. We used a glioma model in Drosophila melanogaster that results from the overexpression of constitutively active forms of EGFR and PI3K specifically in glial cells. We observed hyperproliferation of glial cells that leads to an increase in brain size and lethality at the third instar larval stage. After expression of the human serotonin 5-HT7 receptor in this glioma model, we observed a decrease in larval lethality associated with the presence of surviving adults and a return to a normal morphology of brain for some Drosophila. Those phenotypic changes are accompanied by the normalization of certain metabolic biomarkers measured by High-Resolution Magic Angle Spinning NMR (HR-MAS NMR). The 5-HT7R expression in glioma also restores some epigenetic modifications and characteristic markers of the signaling pathways associated with tumor growth. This study demonstrates the role of the serotonin 5-HT7 receptor as a tumor suppressor gene which is in agreement with transcriptomic analysis obtained on human glioblastomas.
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Affiliation(s)
- Florestan Courant
- Centre de Biophysique Moléculaire—CBM, UPR 4301, CNRS, Rue Charles Sadron, CEDEX 02, F-45071 Orléans, France; (F.C.); (W.C.); (D.G.); (L.B.); (N.H.-C.); (M.D.)
| | - Marion Maravat
- Conditions Extrêmes et Matériaux: Haute Température et Irradiation—CEMHTI-CNRS UPR 3079, CEDEX 02, F-45071 Orléans, France; (M.M.); (V.S.-K.)
| | - Wanyin Chen
- Centre de Biophysique Moléculaire—CBM, UPR 4301, CNRS, Rue Charles Sadron, CEDEX 02, F-45071 Orléans, France; (F.C.); (W.C.); (D.G.); (L.B.); (N.H.-C.); (M.D.)
| | - David Gosset
- Centre de Biophysique Moléculaire—CBM, UPR 4301, CNRS, Rue Charles Sadron, CEDEX 02, F-45071 Orléans, France; (F.C.); (W.C.); (D.G.); (L.B.); (N.H.-C.); (M.D.)
| | - Lauren Blot
- Centre de Biophysique Moléculaire—CBM, UPR 4301, CNRS, Rue Charles Sadron, CEDEX 02, F-45071 Orléans, France; (F.C.); (W.C.); (D.G.); (L.B.); (N.H.-C.); (M.D.)
| | - Nadège Hervouet-Coste
- Centre de Biophysique Moléculaire—CBM, UPR 4301, CNRS, Rue Charles Sadron, CEDEX 02, F-45071 Orléans, France; (F.C.); (W.C.); (D.G.); (L.B.); (N.H.-C.); (M.D.)
| | - Vincent Sarou-Kanian
- Conditions Extrêmes et Matériaux: Haute Température et Irradiation—CEMHTI-CNRS UPR 3079, CEDEX 02, F-45071 Orléans, France; (M.M.); (V.S.-K.)
| | - Séverine Morisset-Lopez
- Centre de Biophysique Moléculaire—CBM, UPR 4301, CNRS, Rue Charles Sadron, CEDEX 02, F-45071 Orléans, France; (F.C.); (W.C.); (D.G.); (L.B.); (N.H.-C.); (M.D.)
| | - Martine Decoville
- Centre de Biophysique Moléculaire—CBM, UPR 4301, CNRS, Rue Charles Sadron, CEDEX 02, F-45071 Orléans, France; (F.C.); (W.C.); (D.G.); (L.B.); (N.H.-C.); (M.D.)
- UFR Sciences et Techniques, Université d’Orléans, 6 Avenue du Parc Floral, F-45100 Orléans, France
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Hou W, Hao Y, Sun L, Zhao Y, Zheng X, Song L. The dual roles of autophagy and the GPCRs-mediating autophagy signaling pathway after cerebral ischemic stroke. Mol Brain 2022; 15:14. [PMID: 35109896 PMCID: PMC8812204 DOI: 10.1186/s13041-022-00899-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 01/20/2022] [Indexed: 12/17/2022] Open
Abstract
Ischemic stroke, caused by a lack of blood supply in brain tissues, is the third leading cause of human death and disability worldwide, and usually results in sensory and motor dysfunction, cognitive impairment, and in severe cases, even death. Autophagy is a highly conserved lysosome-dependent process in which eukaryotic cells removal misfolded proteins and damaged organelles in cytoplasm, which is critical for energy metabolism, organelle renewal, and maintenance of intracellular homeostasis. Increasing evidence suggests that autophagy plays important roles in pathophysiological mechanisms under ischemic conditions. However, there are still controversies about whether autophagy plays a neuroprotective or damaging role after ischemia. G-protein-coupled receptors (GPCRs), one of the largest protein receptor superfamilies in mammals, play crucial roles in various physiological and pathological processes. Statistics show that GPCRs are the targets of about one-fifth of drugs known in the world, predicting potential values as targets for drug research. Studies have demonstrated that nutritional deprivation can directly or indirectly activate GPCRs, mediating a series of downstream biological processes, including autophagy. It can be concluded that there are interactions between autophagy and GPCRs signaling pathway, which provides research evidence for regulating GPCRs-mediated autophagy. This review aims to systematically discuss the underlying mechanism and dual roles of autophagy in cerebral ischemia, and describe the GPCRs-mediated autophagy, hoping to probe promising therapeutic targets for ischemic stroke through in-depth exploration of the GPCRs-mediated autophagy signaling pathway.
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Affiliation(s)
- Weichen Hou
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Xinmin Street 71#, Changchun, 130021, China
| | - Yulei Hao
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Xinmin Street 71#, Changchun, 130021, China
| | - Li Sun
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Xinmin Street 71#, Changchun, 130021, China
| | - Yang Zhao
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Xinmin Street 71#, Changchun, 130021, China
| | - Xiangyu Zheng
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Xinmin Street 71#, Changchun, 130021, China.
| | - Lei Song
- Department of Respiratory Medicine, Center for Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, The First Hospital of Jilin University, Xinmin Street 71#, Changchun, 130021, China.
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Meister J, Bone DBJ, Knudsen JR, Barella LF, Velenosi TJ, Akhmedov D, Lee RJ, Cohen AH, Gavrilova O, Cui Y, Karsenty G, Chen M, Weinstein LS, Kleinert M, Berdeaux R, Jensen TE, Richter EA, Wess J. Clenbuterol exerts antidiabetic activity through metabolic reprogramming of skeletal muscle cells. Nat Commun 2022; 13:22. [PMID: 35013148 PMCID: PMC8748640 DOI: 10.1038/s41467-021-27540-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 11/24/2021] [Indexed: 12/14/2022] Open
Abstract
Activation of the sympathetic nervous system causes pronounced metabolic changes that are mediated by multiple adrenergic receptor subtypes. Systemic treatment with β2-adrenergic receptor agonists results in multiple beneficial metabolic effects, including improved glucose homeostasis. To elucidate the underlying cellular and molecular mechanisms, we chronically treated wild-type mice and several newly developed mutant mouse strains with clenbuterol, a selective β2-adrenergic receptor agonist. Clenbuterol administration caused pronounced improvements in glucose homeostasis and prevented the metabolic deficits in mouse models of β-cell dysfunction and insulin resistance. Studies with skeletal muscle-specific mutant mice demonstrated that these metabolic improvements required activation of skeletal muscle β2-adrenergic receptors and the stimulatory G protein, Gs. Unbiased transcriptomic and metabolomic analyses showed that chronic β2-adrenergic receptor stimulation caused metabolic reprogramming of skeletal muscle characterized by enhanced glucose utilization. These findings strongly suggest that agents targeting skeletal muscle metabolism by modulating β2-adrenergic receptor-dependent signaling pathways may prove beneficial as antidiabetic drugs.
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Affiliation(s)
- Jaroslawna Meister
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA.
| | - Derek B J Bone
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Jonas R Knudsen
- Departments of Nutrition, Exercise and Sports, University of Copenhagen, København, Denmark
| | - Luiz F Barella
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Thomas J Velenosi
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Dmitry Akhmedov
- Departments of Integrative Biology and Pharmacology, Houston Medical School, Houston, TX, 77030, USA
| | - Regina J Lee
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Amanda H Cohen
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Oksana Gavrilova
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Yinghong Cui
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Gerard Karsenty
- Departments of Genetics and Development, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Min Chen
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Lee S Weinstein
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Maximilian Kleinert
- Departments of Nutrition, Exercise and Sports, University of Copenhagen, København, Denmark
- Muscle Physiology and Metabolism Group, German Institute of Human Nutrition, Potsdam-Rehbrücke, Nuthetal, Germany
| | - Rebecca Berdeaux
- Departments of Integrative Biology and Pharmacology, Houston Medical School, Houston, TX, 77030, USA
| | - Thomas E Jensen
- Departments of Nutrition, Exercise and Sports, University of Copenhagen, København, Denmark
| | - Erik A Richter
- Departments of Nutrition, Exercise and Sports, University of Copenhagen, København, Denmark
| | - Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA.
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11
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Cho KM, Kim YS, Lee M, Lee HY, Bae YS. Isovaleric acid ameliorates ovariectomy-induced osteoporosis by inhibiting osteoclast differentiation. J Cell Mol Med 2021; 25:4287-4297. [PMID: 33768674 PMCID: PMC8093970 DOI: 10.1111/jcmm.16482] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 03/03/2021] [Accepted: 03/12/2021] [Indexed: 12/13/2022] Open
Abstract
Osteoclasts (OCs) play important roles in bone remodelling and contribute to bone loss by increasing bone resorption activity. Excessively activated OCs cause diverse bone disorders including osteoporosis. Isovaleric acid (IVA), also known as 3-methylbutanoic acid is a 5-carbon branched-chain fatty acid (BCFA), which can be generated by bacterial fermentation of a leucine-rich diet. Here, we find that IVA suppresses differentiation of bone marrow-derived macrophages into OCs by RANKL. IVA inhibited the expression of OC-related genes. IVA-induced inhibitory effects on OC generation were attenuated by pertussis toxin but not by H89, suggesting a Gi -coupled receptor-dependent but protein kinase A-independent response. Moreover, IVA stimulates AMPK phosphorylation, and treatment with an AMPK inhibitor blocks IVA-induced inhibition of OC generation. In an ovariectomized mouse model, addition of IVA to the drinking water resulted in significant decrease of body weight gain and inhibited the expression of not only OC-related genes but also fusogenic genes in the bone tissue. IVA exposure also blocked bone destruction and OC generation in the bone tissue of ovariectomized mice. Collectively, the results demonstrate that IVA is a novel bioactive BCFA that inhibits OC differentiation, suggesting that IVA can be considered a useful material to control osteoclast-associated bone disorders, including osteoporosis.
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Affiliation(s)
- Kwang Min Cho
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Ye Seon Kim
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Mingyu Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea
| | - Ha Young Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Yoe-Sik Bae
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea.,Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea
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12
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Kurakami K, Norota I, Nasu F, Ohshima S, Nagasawa Y, Konno Y, Obara Y, Ishii K. KCNQ1 is internalized by activation of α1 adrenergic receptors. Biochem Pharmacol 2019; 169:113628. [DOI: 10.1016/j.bcp.2019.113628] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 08/30/2019] [Indexed: 01/25/2023]
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13
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Li Y, Ruan X, Xu X, Li C, Qiang T, Zhou H, Gao J, Wang X. Shengmai Injection Suppresses Angiotensin II-Induced Cardiomyocyte Hypertrophy and Apoptosis via Activation of the AMPK Signaling Pathway Through Energy-Dependent Mechanisms. Front Pharmacol 2019; 10:1095. [PMID: 31616303 PMCID: PMC6764192 DOI: 10.3389/fphar.2019.01095] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 08/26/2019] [Indexed: 01/05/2023] Open
Abstract
Shengmai injection (SMI), a traditional Chinese herbal medicine extracted from Panax ginseng C.A. Mey., Ophiopogon japonicus (Thunb.) Ker Gawl., and Schisandra chinensis (Turcz.) Baill., has been used to treat acute and chronic heart failure. This study aimed to further clarify the effects of SMI on energy metabolism. SMI could improve cell-survival rate and also reduce myocardial cell hypertrophy and apoptosis. Mitochondria are important sites of cellular energy metabolism, and SMI protects mitochondrial function which was evaluated by mitochondrial ultrastructure, mitochondrial respiratory control ratio (RCR), and mitochondrial membrane potential (ΔΨm) in this study. The expression levels of adenosine triphosphate (ATP), adenosine diphosphate (ADP), and phosphocreatine (PCr) increased. The expression levels of free fatty acid oxidation [carnitine palmitoyltransferase-1 (CPT-1)], glucose oxidation [glucose transporter-4 (GLUT-4)], and mitochondrial biogenesis-related genes (peroxisome proliferator-activated receptor-γ coactivator-1α [PGC-1α]) were upregulated after SMI treatment. AMP-activated protein kinase (AMPK) is an important signaling pathway regulating energy metabolism and also can regulate the above-mentioned indicators. In the present study, SMI was found to promote phosphorylation of AMPK. However, the effects of SMI on fatty acid, glucose oxidation, mitochondrial biogenesis, as well as inhibiting apoptosis of hypertrophic cardiomyocytes were partly blocked by AMPK inhibitor–compound C. Moreover, decreased myocardial hypertrophy and apoptosis treated by SMI were inhibited by AMPK knockdown with shAMPK to a certain degree and AMPK knockdown almost abolished the SMI-induced increase in the expression of GLUT-4, CPT-1, and PGC-1α. These data suggest that SMI suppressed Ang II–induced cardiomyocyte hypertrophy and apoptosis via activation of the AMPK signaling pathway through energy-dependent mechanisms.
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Affiliation(s)
- Yiping Li
- Cardiovascular Department of Traditional Chinese Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Cardiovascular Research Institute of Traditional Chinese Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiaofen Ruan
- Cardiovascular Department of Traditional Chinese Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Cardiovascular Research Institute of Traditional Chinese Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiaowen Xu
- Cardiovascular Research Institute of Traditional Chinese Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Cha Li
- Cardiovascular Research Institute of Traditional Chinese Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Tingting Qiang
- Cardiovascular Research Institute of Traditional Chinese Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Hua Zhou
- Cardiovascular Department of Traditional Chinese Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Cardiovascular Research Institute of Traditional Chinese Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Junjie Gao
- Cardiovascular Department of Traditional Chinese Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiaolong Wang
- Cardiovascular Department of Traditional Chinese Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Cardiovascular Research Institute of Traditional Chinese Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
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14
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Propionate suppresses hepatic gluconeogenesis via GPR43/AMPK signaling pathway. Arch Biochem Biophys 2019; 672:108057. [PMID: 31356781 DOI: 10.1016/j.abb.2019.07.022] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 07/23/2019] [Accepted: 07/25/2019] [Indexed: 12/18/2022]
Abstract
Short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate are generated by gut microbial fermentation of dietary fiber. SCFAs may exert multiple beneficial effects on human lipid and glucose metabolism. However, their actions and underlying mechanisms are not fully elucidated. In this study, we examined the direct effects of propionate on hepatic glucose and lipid metabolism using human HepG2 hepatocytes. Here, we demonstrate that propionate at a physiologically-relevant concentration effectively suppresses palmitate-enhanced glucose production in HepG2 cells but does not affect intracellular neutral lipid levels. Our results indicated that propionate can decline in gluconeogenesis by down-regulation of glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK) through activation of AMP-activated protein kinase (AMPK), which is a major regulator of the hepatic glucose metabolism. Mechanistic studies also revealed that propionate-stimulated AMPK phosphorylation can be ascribed to Ca2+/calmodulin-dependent protein kinase kinase β (CaMKKβ) activation in response to an increase in intracellular Ca2+ concentration. Moreover, siRNA-mediated knockdown of the propionate receptor GPR43 prevented propionate-inducible activation of AMPK and abrogates the gluconeogenesis-inhibitory action. Thus, our data indicate that the binding of propionate to hepatic GPR43 elicits CaMKKβ-dependent activation of AMPK through intracellular Ca2+ increase, leading to suppression of gluconeogenesis. The present study suggests the potential efficacy of propionate in preventive and therapeutic management of diabetes.
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15
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AMPK Activation of PGC-1α/NRF-1-Dependent SELENOT Gene Transcription Promotes PACAP-Induced Neuroendocrine Cell Differentiation Through Tolerance to Oxidative Stress. Mol Neurobiol 2018; 56:4086-4101. [DOI: 10.1007/s12035-018-1352-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 09/13/2018] [Indexed: 12/19/2022]
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16
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Moonwiriyakit A, Wattanaphichet P, Chatsudthipong V, Muanprasat C. GPR40 receptor activation promotes tight junction assembly in airway epithelial cells via AMPK-dependent mechanisms. Tissue Barriers 2018; 6:1-12. [PMID: 29913106 DOI: 10.1080/21688370.2018.1480741] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Tight junctions play key roles in the regulation of airway epithelial barrier function and promotion of tight junction integrity is beneficial to lung health. G-protein coupled receptor (GPR) 40 has been identified as a receptor of polyunsaturated fatty acids. This study aimed to investigate the function of GPR40 in regulating tight junction assembly in human airway epithelial cells (Calu-3 cells) using GW9508, a GPR40 agonist. Immunoblotting and immunofluorescence analyses showed that Calu-3 cells expressed both types of polyunsaturated fatty acid receptors including GPR40 and GPR120. Intracellular Ca2+ measurements confirmed that GW9508 stimulated GPR40, but not GPR120. In Ca2+ switch assays, GW9508 promoted the recovery of transepithelial electrical resistance and re-localization of zonula occludens (ZO)-1 to intercellular areas. These effects were suppressed by inhibitors of GPR40 and phospholipase C (PLC). Interestingly, GW9508 enhanced tight junction assembly in an AMP-activated protein kinase (AMPK)-dependent manner. The effect of GW9508 on inducing tight junction assembly was also confirmed in 16HBE14o- cells. Our results indicate that GPR40 stimulation by GW9508 leads to AMPK activation via calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ). Collectively, this study reveals an unprecedented role of GPR40 in facilitating airway epithelial tight junction assembly via PLC-CaMKKβ-AMPK pathways. GPR40 represents a novel regulator of airway epithelial integrity and its stimulation may be beneficial in the treatment of airway diseases.
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Affiliation(s)
- Aekkacha Moonwiriyakit
- a Department of Physiology , Faculty of Science, Mahidol University , Rajathevi, Bangkok , Thailand
| | - Panisara Wattanaphichet
- b Faculty of Medicine Ramathibodi Hospital, Mahidol University , Rajathevi, Bangkok , Thailand
| | - Varanuj Chatsudthipong
- a Department of Physiology , Faculty of Science, Mahidol University , Rajathevi, Bangkok , Thailand.,d Research Center of Transport Protein for Medical Innovation, Faculty of Science, Mahidol University , Rajathevi, Bangkok , Thailand
| | - Chatchai Muanprasat
- a Department of Physiology , Faculty of Science, Mahidol University , Rajathevi, Bangkok , Thailand.,c Excellent Center for Drug Discovery (ECDD), Mahidol University , Rajathevi, Bangkok , Thailand.,d Research Center of Transport Protein for Medical Innovation, Faculty of Science, Mahidol University , Rajathevi, Bangkok , Thailand
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17
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Fang Y, Liu X, Zhao L, Wei Z, Jiang D, Shao H, Zang Y, Xu J, Wang Q, Liu Y, Peng Y, Yin X. RhGLP-1 (7-36) protects diabetic rats against cerebral ischemia-reperfusion injury via up-regulating expression of Nrf2/HO-1 and increasing the activities of SOD. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2017; 21:475-485. [PMID: 28883752 PMCID: PMC5587598 DOI: 10.4196/kjpp.2017.21.5.475] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 11/14/2016] [Accepted: 11/14/2016] [Indexed: 12/13/2022]
Abstract
The present study aimed to explore the neuroprotective effect and possible mechanisms of rhGLP-1 (7–36) against transient ischemia/reperfusion injuries induced by middle cerebral artery occlusion (MCAO) in type 2 diabetic rats. First, diabetic rats were established by a combination of a high-fat diet and low-dose streptozotocin (STZ) (30 mg/kg, intraperitoneally). Second, they were subjected to MCAO for 2 h, then treated with rhGLP-1 (7–36) (10, 20, 40 µg/kg i.p.) at the same time of reperfusion. In the following 3 days, they were injected with rhGLP-1 (7–36) at the same dose and route for three times each day. After 72 h, hypoglycemic effects were assessed by blood glucose changes, and neuroprotective effects were evaluated by neurological deficits, infarct volume and histomorphology. Mechanisms were investigated by detecting the distribution and expression of the nuclear factor erythroid-derived factor 2 related factor 2 (Nrf2) in ischemic brain tissue, the levels of phospho-PI3 kinase (PI3K)/PI3K ratio and heme-oxygenase-1 (HO-l), as well as the activities of superoxide dismutase (SOD) and the contents of malondialdehyde (MDA). Our results showed that rhGLP-1 (7–36) significantly reduced blood glucose and infarction volume, alleviated neurological deficits, enhanced the density of surviving neurons and vascular proliferation. The nuclear positive cells ratio and expression of Nrf2, the levels of P-PI3K/PI3K ratio and HO-l increased, the activities of SOD increased and the contents of MDA decreased. The current results indicated the protective effect of rhGLP-1 (7–36) in diabetic rats following MCAO/R that may be concerned with reducing blood glucose, up-regulating expression of Nrf2/HO-1 and increasing the activities of SOD.
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Affiliation(s)
- Yi Fang
- Department of Pharmacy, Peking University People's Hospital, Beijing 100044, China
| | - Xiaofang Liu
- Zhongda Hospital, School of Medicine, Southeast University, Nanjing 210009, China
| | - Libo Zhao
- Department of Pharmacy, Peking University People's Hospital, Beijing 100044, China
| | - Zhongna Wei
- Department of Pharmacy, Guizhou Orthopedics Hospital, Guizhou 550002, China
| | - Daoli Jiang
- Department of Pharmacy, Xuzhou Medical University, Xuzhou 221004, China
| | - Hua Shao
- Zhongda Hospital, School of Medicine, Southeast University, Nanjing 210009, China
| | - Yannan Zang
- Department of Pharmacy, Peking University People's Hospital, Beijing 100044, China
| | - Jia Xu
- Department of Pharmacy, Mawangdui Hospital, Changsha 410016, China
| | - Qian Wang
- Department of Pharmacy, Peking University People's Hospital, Beijing 100044, China
| | - Yang Liu
- Department of Pharmacy, Peking University People's Hospital, Beijing 100044, China
| | - Ye Peng
- Department of oncology, Harrison International Peace Hospital, Hengshui 053000, China
| | - Xiaoxing Yin
- Department of Pharmacy, Xuzhou Medical University, Xuzhou 221004, China
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18
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Ekstrand B, Young JF, Rasmussen MK. Taste receptors in the gut - A new target for health promoting properties in diet. Food Res Int 2017; 100:1-8. [PMID: 28888429 DOI: 10.1016/j.foodres.2017.08.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/07/2017] [Accepted: 08/12/2017] [Indexed: 12/17/2022]
Abstract
In this review we describe a new target for food functionality, the taste receptors in the gastrointestinal tract. These receptors are involved in an intricate signalling network for monitoring of taste and nutrient intake, homeostasis and energy metabolism, and they are also an early warning system for toxic substances in our diet. Especially the receptors for bitter taste provide a new possibility to activate a number of health related signalling pathways, already at low concentrations of the active substance, without requiring uptake into the body and transport via the circulation. When ligands bind to these receptors, signalling is induced either via peptide hormones into the circulation to other organs in the body, or via nerve fibers directly to the brain.
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Affiliation(s)
- Bo Ekstrand
- Chalmers University of Technology, Department of Biology and Biological Engineering, Food and Nutrition Science, SE-412 96 Gothenburg, Sweden
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19
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Kim MS, Lee GH, Kim YM, Lee BW, Nam HY, Sim UC, Choo SJ, Yu SW, Kim JJ, Kim Kwon Y, Who Kim S. Angiotensin II Causes Apoptosis of Adult Hippocampal Neural Stem Cells and Memory Impairment Through the Action on AMPK-PGC1α Signaling in Heart Failure. Stem Cells Transl Med 2017; 6:1491-1503. [PMID: 28244243 PMCID: PMC5689768 DOI: 10.1002/sctm.16-0382] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 12/21/2016] [Indexed: 11/07/2022] Open
Abstract
Data are limited on the mechanisms underlying memory impairment in heart failure (HF). We hypothesized that angiotensin II (Ang II) may determine the fate of adult hippocampal neural stem cells (HCNs), a cause of memory impairment in HF. HCNs with neurogenesis potential were isolated and cultured from adult rat hippocampi. Ang II decreased HCN proliferation in dose- and time-dependent manners. Moreover, Ang II treatment (1 µM) for 48 hours induced apoptotic death, which was attenuated by pretreatment with Ang II receptor blockers (ARBs). Ang II increased mitochondrial reactive oxygen species (ROS) levels, which was related to mitochondrial morphological changes and functional impairment. Moreover, ROS activated the AMP-activated protein kinase (AMPK) and consequent peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) expression, causing cell apoptosis. In the HF rat model induced by left anterior descending artery ligation, ARB ameliorated the spatial memory ability which decreased 10 weeks after ischemia. In addition, neuronal cell death, especially of newly born mature neurons, was observed in HF rat hippocampi. ARB decreased cell death and promoted the survival of newly born neural precursor cells and mature neurons. In conclusion, Ang II caused HCN apoptosis through mitochondrial ROS formation and subsequent AMPK-PGC1α signaling. ARB improved learning and memory behaviors impaired by neuronal cell death in the HF animal model. These findings suggest that HCN is one treatment target for memory impairment in HF and that ARBs have additional benefits in HF combined with memory impairment. Stem Cells Translational Medicine 2017;6:1491-1503.
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Affiliation(s)
- Min-Seok Kim
- Department of Internal Medicine, University of Ulsan College of Medicine, Seoul, Korea
| | - Geun-Hee Lee
- Department of Biochemistry and Molecular Biology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Yong-Min Kim
- Department of Biology and Department of Life and Nanopharmaceutical Sciences, Kyunghee University, Seoul, Korea
| | - Byoung-Wook Lee
- Department of Biochemistry and Molecular Biology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Hae Yun Nam
- Department of Biochemistry and Molecular Biology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - U-Cheol Sim
- Department of Biology and Department of Life and Nanopharmaceutical Sciences, Kyunghee University, Seoul, Korea
| | - Suk-Jung Choo
- Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Seong-Woon Yu
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Korea
| | - Jae-Joong Kim
- Department of Internal Medicine, University of Ulsan College of Medicine, Seoul, Korea
| | - Yunhee Kim Kwon
- Department of Biology and Department of Life and Nanopharmaceutical Sciences, Kyunghee University, Seoul, Korea
| | - Seong Who Kim
- Department of Biochemistry and Molecular Biology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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20
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Hao Y, Liu C, Yin F, Zhang Y, Liu J. 5′-AMP-activated protein kinase plays an essential role in geniposide-regulated glucose-stimulated insulin secretion in rat pancreatic INS-1 β cells. J Nat Med 2016; 71:123-130. [DOI: 10.1007/s11418-016-1038-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/24/2016] [Indexed: 11/28/2022]
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21
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Salminen A, Kaarniranta K, Kauppinen A. Age-related changes in AMPK activation: Role for AMPK phosphatases and inhibitory phosphorylation by upstream signaling pathways. Ageing Res Rev 2016; 28:15-26. [PMID: 27060201 DOI: 10.1016/j.arr.2016.04.003] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 03/18/2016] [Accepted: 04/05/2016] [Indexed: 02/07/2023]
Abstract
AMP-activated protein kinase (AMPK) is a fundamental regulator of energy metabolism, stress resistance, and cellular proteostasis. AMPK signaling controls an integrated signaling network which is involved in the regulation of healthspan and lifespan e.g. via FoxO, mTOR/ULK1, CRCT-1/CREB, and SIRT1 signaling pathways. Several studies have demonstrated that the activation capacity of AMPK signaling declines with aging, which impairs the maintenance of efficient cellular homeostasis and enhances the aging process. However, it seems that the aging process affects AMPK activation in a context-dependent manner since occasionally, it can also augment AMPK activation, possibly attributable to the type of insult and tissue homeostasis. Three protein phosphatases, PP1, PP2A, and PP2C, inhibit AMPK activation by dephosphorylating the Thr172 residue of AMPKα, required for AMPK activation. In addition, several upstream signaling pathways can phosphorylate Ser/Thr residues in the β/γ interaction domain of the AMPKα subunit that subsequently blocks the activation of AMPK. These inhibitory pathways include the insulin/AKT, cyclic AMP/PKA, and RAS/MEK/ERK pathways. We will examine the evidence whether the efficiency of AMPK responsiveness declines during the aging process. Next, we will review the mechanisms involved in curtailing the activation of AMPK. Finally, we will elucidate the potential age-related changes in the inhibitory regulation of AMPK signaling that might be a part of the aging process.
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Affiliation(s)
- Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland; Department of Ophthalmology, Kuopio University Hospital, P.O. Box 100, FI-70029 KYS, Finland
| | - Anu Kauppinen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
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22
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Edwards A, Abizaid A. Driving the need to feed: Insight into the collaborative interaction between ghrelin and endocannabinoid systems in modulating brain reward systems. Neurosci Biobehav Rev 2016; 66:33-53. [PMID: 27136126 DOI: 10.1016/j.neubiorev.2016.03.032] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 03/08/2016] [Accepted: 03/31/2016] [Indexed: 01/29/2023]
Abstract
Independent stimulation of either the ghrelin or endocannabinoid system promotes food intake and increases adiposity. Given the similar distribution of their receptors in feeding associated brain regions and organs involved in metabolism, it is not surprising that evidence of their interaction and its importance in modulating energy balance has emerged. This review documents the relationship between ghrelin and endocannabinoid systems within the periphery and hypothalamus (HYP) before presenting evidence suggesting that these two systems likewise work collaboratively within the ventral tegmental area (VTA) to modulate non-homeostatic feeding. Mechanisms, consistent with current evidence and local infrastructure within the VTA, will be proposed.
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Affiliation(s)
- Alexander Edwards
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.
| | - Alfonso Abizaid
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.
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23
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Li M, Meng X, Xu J, Huang X, Li H, Li G, Wang S, Man Y, Tang W, Li J. GPR40 agonist ameliorates liver X receptor-induced lipid accumulation in liver by activating AMPK pathway. Sci Rep 2016; 6:25237. [PMID: 27121981 PMCID: PMC4848522 DOI: 10.1038/srep25237] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 04/11/2016] [Indexed: 01/13/2023] Open
Abstract
Hepatic steatosis is strongly linked to insulin resistance and type 2 diabetes. GPR40 is a G protein-coupled receptor mediating free fatty acid-induced insulin secretion and thus plays a beneficial role in the improvement of diabetes. However, the impact of GPR40 agonist on hepatic steatosis still remains to be elucidated. In the present study, we found that activation of GPR40 by its agonist GW9508 attenuated Liver X receptor (LXR)-induced hepatic lipid accumulation. Activation of LXR in the livers of C57BL/6 mice fed a high-cholesterol diet and in HepG2 cells stimulated by chemical agonist caused increased expression of its target lipogenic genes and subsequent lipid accumulation. All these effects of LXR were dramatically downregulated after GW9508 supplementation. Moreover, GPR40 activation was accompanied by upregulation of AMPK pathway, whereas the inhibitive effect of GPR40 on the lipogenic gene expression was largely abrogated by AMPK knockdown. Taken together, our results demonstrated that GW9508 exerts a beneficial effect to ameliorate LXR-induced hepatic steatosis through regulation of AMPK signaling pathway.
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Affiliation(s)
- Meng Li
- Peking University Fifth School of Clinical Medicine (Beijing Hospital), Beijing, China.,The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics &Beijing Hospital, Ministry of Health, Beijing, China
| | - Xiangyu Meng
- Peking University Fifth School of Clinical Medicine (Beijing Hospital), Beijing, China.,The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics &Beijing Hospital, Ministry of Health, Beijing, China
| | - Jie Xu
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics &Beijing Hospital, Ministry of Health, Beijing, China
| | - Xiuqing Huang
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics &Beijing Hospital, Ministry of Health, Beijing, China
| | - Hongxia Li
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics &Beijing Hospital, Ministry of Health, Beijing, China
| | - Guoping Li
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics &Beijing Hospital, Ministry of Health, Beijing, China
| | - Shu Wang
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics &Beijing Hospital, Ministry of Health, Beijing, China
| | - Yong Man
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics &Beijing Hospital, Ministry of Health, Beijing, China
| | - Weiqing Tang
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics &Beijing Hospital, Ministry of Health, Beijing, China
| | - Jian Li
- Peking University Fifth School of Clinical Medicine (Beijing Hospital), Beijing, China.,The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics &Beijing Hospital, Ministry of Health, Beijing, China
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Jian MY, Liu Y, Li Q, Wolkowicz P, Alexeyev M, Zmijewski J, Creighton J. N-cadherin coordinates AMP kinase-mediated lung vascular repair. Am J Physiol Lung Cell Mol Physiol 2015; 310:L71-85. [PMID: 26545901 DOI: 10.1152/ajplung.00227.2015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 10/30/2015] [Indexed: 01/24/2023] Open
Abstract
Injury to the pulmonary circulation compromises endothelial barrier function and increases lung edema. Resolution of lung damage involves restoring barrier integrity, a process requiring reestablishment of endothelial cell-cell adhesions. However, mechanisms underlying repair in lung endothelium are poorly understood. In pulmonary microvascular endothelium, AMP kinase α1 (AMPKα1) stimulation enhances recovery of the endothelial barrier after LPS-induced vascular damage. AMPKα1 colocalizes to a discrete membrane compartment with the adhesion protein neuronal cadherin (N-cadherin). This study sought to determine N-cadherin's role in the repair process. Short-hairpin RNA against full-length N-cadherin or a C-terminally truncated N-cadherin, designed to disrupt the cadherin's interactions with intracellular proteins, were expressed in lung endothelium. Disruption of N-cadherin's intracellular domain caused translocation of AMPK away from the membrane and attenuated AMPK-mediated restoration of barrier function in LPS-treated endothelium. AMPK activity measurements indicated that lower basal AMPK activity in cells expressing the truncated N-cadherin compared with controls. Moreover, the AMPK stimulator 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) failed to increase AMPK activity in cells expressing the modified N-cadherin, indicating uncoupling of a functional association between AMPK and the cadherin. Isolated lung studies confirmed a physiologic role for this pathway in vivo. AMPK activation reversed LPS-induced increase in permeability, whereas N-cadherin inhibition hindered AMPK-mediated repair. Thus N-cadherin coordinates the vascular protective actions of AMPK through a functional link with the kinase. This study provides insight into intrinsic repair mechanisms in the lung and supports AMPK stimulation as a modality for treating vascular disease.
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Affiliation(s)
- Ming-Yuan Jian
- Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine, Center for Lung Injury and Repair
| | - Yanping Liu
- Division of Endocrinology, Diabetes, and Metabolism
| | - Qian Li
- Division of Pediatric Neonatology, and
| | | | - Mikhail Alexeyev
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile
| | - Jaroslaw Zmijewski
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Judy Creighton
- Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine, Center for Lung Injury and Repair,
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A hypothesis for a possible synergy between ghrelin and exercise in patients with cachexia: Biochemical and physiological bases. Med Hypotheses 2015; 85:927-33. [PMID: 26404870 DOI: 10.1016/j.mehy.2015.09.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 09/07/2015] [Accepted: 09/07/2015] [Indexed: 12/15/2022]
Abstract
This article reviews the biochemical and physiological observations underpinning the synergism between ghrelin and ghrelin agonists with exercise, especially progressive resistance training that has been shown to increase muscle mass. The synergy of ghrelin agonists and physical exercise could be beneficial in conditions where muscle wasting is present, such as that found in patients with advanced cancer. The principal mechanism that controls muscle anabolism following the activation of the ghrelin receptor in the central nervous system involves the release of growth hormone/insulin-like growth factor-1 (GH/IGF-1). GH/IGF-1 axis has a dual pathway of action on muscle growth: (a) a direct action on muscle, bone and fat tissue and (b) an indirect action via the production of both muscle-restricted mIGF-1 and anti-cachectic cytokines. Progressive resistance training is a potent inducer of the secretion the muscle-restricted IGF-1 (mIGF-1) that enhances protein synthesis, increases lean body mass and eventually leads to the improvement of muscle strength. Thus, the combination of ghrelin administration with progressive resistance training may serve to circumvent ghrelin resistance and further reduce muscle wasting, which are commonly associated with cachexia.
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26
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Shin DJ, Kim JE, Lim TG, Jeong EH, Park G, Kang NJ, Park JS, Yeom MH, Oh DK, Bode AM, Dong Z, Lee HJ, Lee KW. 20-O-β-D-glucopyranosyl-20(S)-protopanaxadiol suppresses UV-Induced MMP-1 expression through AMPK-mediated mTOR inhibition as a downstream of the PKA-LKB1 pathway. J Cell Biochem 2015; 115:1702-11. [PMID: 24821673 DOI: 10.1002/jcb.24833] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 05/08/2014] [Indexed: 12/11/2022]
Abstract
Various health effects have been attributed to the ginsenoside metabolite 20-O-β-D-glucopyranosyl-20(S)-protopanaxadiol (GPD); however, its effect on ultraviolet (UV)-induced matrix metalloproteinase (MMP)-1 expression and the mechanism underlying this effect are unknown. We examined the inhibitory effect of GPD on UV-induced MMP-1 expression and its mechanisms in human dermal fibroblasts (HDFs). GPD attenuated UV-induced MMP-1 expression in HDFs and suppressed the UV-induced phosphorylation of mammalian target of rapamycin (mTOR) and p70(S6K) without inhibiting the activity of phosphatidylinositol 3-kinase and Akt, which are well-known upstream kinases of mTOR. GPD augmented the phosphorylation of liver kinase B1 (LKB1) and adenosine monophosphate-activated protein kinase (AMPK), which are inhibitors of mTOR, to a greater extent than UV treatment alone. Similar to GPD, 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranosyl 5'-monophosphate (AICAR), an activator of AMPK, augmented UV-induced AMPK phosphorylation to a greater extent than UV treatment alone, resulting in the inhibition of MMP-1 expression. AICAR also decreased the phosphorylation of mTOR and p70(S6K). However, compound C, an antagonist of AMPK, increased MMP-1 expression. In HDF cells with AMPK knock-down using shRNA, MMP-1 expression was increased. These results indicate that AMPK activation plays a key role in MMP-1 suppression. Additionally, the cAMP-dependent protein kinase (PKA) inhibitor, H-89, antagonized GPD-mediated MMP-1 suppression via the inhibition of LKB1. Our results suggest that the suppressive activity of GPD on UV-induced MMP-1 expression is due to the activation of AMPK as a downstream of the PKA-LKB1 pathway.
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Affiliation(s)
- Dong Joo Shin
- WCU Biomodulation Major, Department of Agricultural Biotechnology and Center for Food and Bioconvergence, Seoul National University, Seoul, 151-921, Republic of Korea
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27
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Wauson EM, Dbouk HA, Ghosh AB, Cobb MH. G protein-coupled receptors and the regulation of autophagy. Trends Endocrinol Metab 2014; 25:274-82. [PMID: 24751357 PMCID: PMC4082244 DOI: 10.1016/j.tem.2014.03.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 03/14/2014] [Accepted: 03/17/2014] [Indexed: 01/06/2023]
Abstract
Autophagy is an important catabolic cellular process that eliminates damaged and unnecessary cytoplasmic proteins and organelles. Basal autophagy occurs during normal physiological conditions, but the activity of this process can be significantly altered in human diseases. Thus, defining the regulatory inputs and signals that control autophagy is essential. Nutrients are key modulators of autophagy. Although autophagy is generally accepted to be regulated in a cell-autonomous fashion, recent studies suggest that nutrients can modulate autophagy in a systemic manner by inducing the secretion of hormones and neurotransmitters that regulate G protein-coupled receptors (GPCRs). Emerging studies show that GPCRs also regulate autophagy by directly detecting extracellular nutrients. We review the role of GPCRs in autophagy regulation, highlighting their potential as therapeutic drug targets.
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Affiliation(s)
- Eric M Wauson
- Department of Physiology and Pharmacology, Des Moines University, Des Moines, IA 50312, USA.
| | - Hashem A Dbouk
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9041, USA
| | - Anwesha B Ghosh
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9041, USA
| | - Melanie H Cobb
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9041, USA.
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Chamulitrat W, Liebisch G, Xu W, Gan-Schreier H, Pathil A, Schmitz G, Stremmel W. Ursodeoxycholyl lysophosphatidylethanolamide inhibits lipoapoptosis by shifting fatty acid pools toward monosaturated and polyunsaturated fatty acids in mouse hepatocytes. Mol Pharmacol 2013; 84:696-709. [PMID: 23974795 DOI: 10.1124/mol.113.088039] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Ursodeoxycholyl lysophosphatidylethanolamide (UDCA-LPE) is a hepatoprotectant in inhibiting apoptosis, inflammation, and hyperlipidemia in mouse models of nonalcoholic steatohepatitis (NASH). We studied the ability of UDCA-LPE to inhibit palmitate (Pal)-induced apoptosis in primary hepatocytes and delineate cytoprotective mechanisms. We showed that lipoprotection by UDCA-LPE was mediated by cAMP and was associated with increases in triglycerides (TGs) and phospholipids (PLs). An inhibitor of cAMP-effector protein kinase A partially reversed the protective effects of UDCA-LPE. Lipidomic analyses of fatty acids and PL composition revealed a shift of lipid metabolism from saturated Pal to monounsaturated and polyunsaturated fatty acids, mainly, oleate, docosapentaenoate, and docosahexaenoate. The latter two ω-3 fatty acids were particularly found in phosphatidylcholine and phosphatidylserine pools. The catalysis of Pal by stearoyl-CoA desaturase-1 (SCD-1) is a known mechanism for the channeling of Pal away from apoptosis. SCD-1 protein was upregulated during UDCA-LPE lipoprotection. SCD-1 knockdown of Pal-treated cells showed further increased apoptosis, and the extent of UDCA-LPE protection was reduced. Thus, the major mechanism of UDCA-LPE lipoprotection involved a metabolic shift from toxic saturated toward cytoprotective unsaturated fatty acids in part via SCD-1. UDCA-LPE may thus be a therapeutic agent for treatment of NASH by altering distinct pools of fatty acids for storage into TGs and PLs, and the latter may protect lipotoxicity at the membrane levels.
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Affiliation(s)
- Walee Chamulitrat
- Department of Internal Medicine IV, Gastroenterology and Infectious Diseases, Im Neuenheimer Feld, Heidelberg, Germany (W.C., H.G.-S., A.P., W.S.); Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Regensburg, Germany (G.L., G.S.); and Department of Gastroenterology, Hangzhou First People's Hospital, Hangzhou, Zhejiang, People's Republic of China (W.X.)
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29
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Hwang JA, Hwang MK, Jang Y, Lee EJ, Kim JE, Oh MH, Shin DJ, Lim S, Ji GO, Oh U, Bode AM, Dong Z, Lee KW, Lee HJ. 20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol, a metabolite of ginseng, inhibits colon cancer growth by targeting TRPC channel-mediated calcium influx. J Nutr Biochem 2013; 24:1096-104. [DOI: 10.1016/j.jnutbio.2012.08.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 07/18/2012] [Accepted: 08/13/2012] [Indexed: 10/27/2022]
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30
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Balasubramanian R, Maruoka H, Jayasekara PS, Gao ZG, Jacobson KA. AMP-activated protein kinase as regulator of P2Y(6) receptor-induced insulin secretion in mouse pancreatic β-cells. Biochem Pharmacol 2013; 85:991-8. [PMID: 23333427 PMCID: PMC3594329 DOI: 10.1016/j.bcp.2012.11.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 11/23/2012] [Accepted: 11/26/2012] [Indexed: 10/27/2022]
Abstract
5'-AMP-activated protein kinase (AMPK) and its pharmacological modulators have been targeted for treating type 2 diabetes. Extracellular uridine 5'-diphosphate (UDP) activates P2Y6 receptors (P2Y6Rs) in pancreatic β-cells to release insulin and reduce apoptosis, which would benefit diabetes. Here, we studied the role of P2Y6R in activation of AMPK in MIN6 mouse pancreatic β-cells and insulin secretion. Treatment with a potent P2Y6R dinucleotide agonist MRS2957 (500nM) activated AMPK, which was blocked by P2Y6R-selective antagonist MRS2578. Also, MRS2957 induced phosphorylation of acetyl-coenzyme A carboxylase (ACC), a marker of AMPK activity. Calcium chelator BAPTA-AM, calmodulin-dependent protein kinase kinase (CaMKK) inhibitor STO-069 and IP3 receptor antagonist 2-APB attenuated P2Y6R-mediated AMPK phosphorylation revealing involvement of intracellular Ca(2+) pathways. P2Y6R agonist induced insulin secretion at high glucose, which was reduced by AMPK siRNA. Thus, P2Y6R has a crucial role in β-cell function, suggesting its potential as a therapeutic target in diabetes.
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Affiliation(s)
- Ramachandran Balasubramanian
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Hiroshi Maruoka
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - P. Suresh Jayasekara
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
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Acute regulation of 5'-AMP-activated protein kinase by long-chain fatty acid, glucose and insulin in rat primary adipocytes. Biosci Rep 2012; 33:71-82. [PMID: 23095119 PMCID: PMC3522478 DOI: 10.1042/bsr20120031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Palmitate increased AMPK (5'-AMP-activated protein kinase) activity, glucose utilization and 2-DOG (2-deoxyglucose) transport in rat adipocytes. All three effects were blocked by the AMPK inhibitor Compound C, leading to the conclusion that in response to an increase in long-chain NEFA (non-esterified fatty acid) concentration AMPK mediated an enhancement of adipocyte glucose transport, thereby providing increased glycerol 3-phosphate for FA (fatty acid) esterification to TAG (triacylglycerol). Activation of AMPK in response to palmitate was not due to an increase in the adipocyte AMP:ATP ratio. Glucose decreased AMPK activity and effects of palmitate and glucose on AMPK activity were antagonistic. While insulin had no effect on basal AMPK activity insulin did decrease AMPK activity in the presence of palmitate and also decreased the percentage effectiveness of palmitate to increase the transport of 2-DOG. It is suggested that activation of adipocyte AMPK by NEFA, as well as decreasing the activity of hormone-sensitive lipase, could modulate adipose tissue dynamics by increasing FA esterification and, under certain circumstances, FA synthesis.
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32
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Berberoglu Z, Yazici AC, Bayraktar N, Demirag NG. Rosiglitazone decreases fasting plasma peptide YY3-36 in type 2 diabetic women: a possible role in weight gain? Acta Diabetol 2012; 49 Suppl 1:S115-22. [PMID: 22101910 DOI: 10.1007/s00592-011-0352-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Accepted: 11/05/2011] [Indexed: 10/15/2022]
Abstract
Rosiglitazone often results in weight gain. We hypothesized that rosiglitazone may modulate circulating levels of ghrelin and peptide YY(3-36) and this modulation may be related to weight-gaining effect of this agent. This study was designed as an open-label, randomized, controlled trial of 3-month duration. Women with newly diagnosed type 2 diabetes were studied. Twenty-eight of the 55 eligible participants were randomly assigned to receive rosiglitazone (4 mg/d). Twenty-seven patients with diabetes matched for age and body mass index served as controls on diet alone. We evaluated the effects of 3 months of rosiglitazone treatment on fasting peptide YY(3-36) and ghrelin levels, and anthropometric measurements. The 3-month administration of rosiglitazone reduced fasting plasma peptide YY(3-36) levels by 25%, the between-group difference was statistically significant. No effect of this thiazolidinedione compound on fasting ghrelin concentrations was observed at the end of study. The ghrelin/body mass index ratio also did not change significantly after treatment. Seventy-five percent of the women with diabetes complained of increased hunger at the end of study. Nevertheless, all subjects exhibited a decrease in fasting PYY levels after 3 months of rosiglitazone therapy, irrespective of the levels of hunger. There was no significant correlation between changes in peptide YY(3-36) and those in anthropometric parameters and insulin sensitivity at the end of the study. Rosiglitazone-induced decrease in fasting peptide YY(3-36) levels may in part contribute to orexigenic and weight-gaining effect of this thiazolidinedione derivative.
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Affiliation(s)
- Zehra Berberoglu
- Department of Endocrinology and Metabolism, Turkiye Yuksek Ihtisas Education and Research Hospital, Kızılay sokak, 06100 Sihhiye, Ankara, Turkey.
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33
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Chen G, Xu R, Wang Y, Wang P, Zhao G, Xu X, Gruzdev A, Zeldin DC, Wang DW. Genetic disruption of soluble epoxide hydrolase is protective against streptozotocin-induced diabetic nephropathy. Am J Physiol Endocrinol Metab 2012; 303:E563-75. [PMID: 22739108 PMCID: PMC3774327 DOI: 10.1152/ajpendo.00591.2011] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cytochrome P-450 (CYP) epoxygenases metabolize arachidonic acid into epoxyeicosatrienoic acids (EETs), which play important roles in regulating cardiovascular functions. The anti-inflammatory, antiapoptotic, proangiogenic, and antihypertensive properties of EETs suggest a beneficial role for EETs in diabetic nephropathy. Endogenous EET levels are maintained by a balance between synthesis by CYP epoxygenases and hydrolysis by epoxide hydrolases into physiologically less active dihydroxyeicosatrienoic acids. Genetic disruption of soluble epoxide hydrolase (sEH/EPHX2) results in increased EET levels through decreased hydrolysis. This study investigated the effects of sEH gene disruption on diabetic nephropathy in streptozotocin-induced diabetic mice. Streptozotocin-induced diabetic manifestations were attenuated in sEH-deficient mice relative to wild-type controls, with significantly decreased levels of Hb A(1c), creatinine, and blood urea nitrogen and urinary microalbumin excretion. The sEH-deficient diabetic mice also had decreased renal tubular apoptosis that coincided with increased levels of antiapoptotic Bcl-2 and Bcl-xl, and decreased levels of the proapoptotic Bax. These effects were associated with activation of the PI3K-Akt-NOS3 and AMPK signaling cascades. sEH gene inhibition and exogenous EETs significantly protected HK-2 cells from TNFα-induced apoptosis in vitro. These findings highlight the beneficial role of the CYP epoxygenase-EETs-sEH system in the pathogenesis of diabetic nephropathy and suggest that the sEH inhibitors available may be potential therapeutic agents for this condition.
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MESH Headings
- 8,11,14-Eicosatrienoic Acid/analogs & derivatives
- 8,11,14-Eicosatrienoic Acid/metabolism
- 8,11,14-Eicosatrienoic Acid/pharmacology
- 8,11,14-Eicosatrienoic Acid/urine
- Albuminuria/prevention & control
- Animals
- Apoptosis/drug effects
- Apoptosis Regulatory Proteins/metabolism
- Cell Line, Transformed
- Cytoplasm/drug effects
- Cytoplasm/enzymology
- Cytoplasm/metabolism
- Diabetic Nephropathies/blood
- Diabetic Nephropathies/drug therapy
- Diabetic Nephropathies/metabolism
- Diabetic Nephropathies/urine
- Disease Models, Animal
- Epoxide Hydrolases/antagonists & inhibitors
- Epoxide Hydrolases/genetics
- Epoxide Hydrolases/metabolism
- Gene Silencing
- Humans
- Hyperglycemia/prevention & control
- Kidney Cortex/drug effects
- Kidney Cortex/metabolism
- Kidney Cortex/pathology
- Kidney Tubules, Proximal/drug effects
- Kidney Tubules, Proximal/metabolism
- Kidney Tubules, Proximal/pathology
- Mice
- Molecular Targeted Therapy
- RNA, Small Interfering
- Signal Transduction/drug effects
- Streptozocin
- Tumor Necrosis Factor-alpha
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Affiliation(s)
- Guangzhi Chen
- Department of Internal Medicine and Gene Therapy Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Cells lacking the fumarase tumor suppressor are protected from apoptosis through a hypoxia-inducible factor-independent, AMPK-dependent mechanism. Mol Cell Biol 2012; 32:3081-94. [PMID: 22645311 DOI: 10.1128/mcb.06160-11] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Loss-of-function mutations of the tumor suppressor gene encoding fumarase (FH) occur in individuals with hereditary leiomyomatosis and renal cell cancer syndrome (HLRCC). We found that loss of FH activity conferred protection from apoptosis in normal human renal cells and fibroblasts. In FH-defective cells, both hypoxia-inducible factor 1α (HIF-1α) and HIF-2α accumulated, but they were not required for apoptosis protection. Conversely, AMP-activated protein kinase (AMPK) was activated and required, as evidenced by the finding that FH inactivation failed to protect AMPK-null mouse embryo fibroblasts (MEFs) and AMPK-depleted human renal cells. Activated AMPK was detected in renal cysts, which occur in mice with kidney-targeted deletion of Fh1 and in kidney cancers of HLRCC patients. In Fh1-null MEFs, AMPK activation was sustained by fumarate accumulation and not by defective energy metabolism. Addition of fumarate and succinate to kidney cells led to extracellular signal-regulated kinase 1/2 (ERK1/2) and AMPK activation, probably through a receptor-mediated mechanism. These findings reveal a new mechanism of tumorigenesis due to FH loss and an unexpected pro-oncogenic role for AMPK that is important in considering AMPK reactivation as a therapeutic strategy against cancer.
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35
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5'-AMP-activated protein kinase is inactivated by adrenergic signalling in adult cardiac myocytes. Biosci Rep 2012; 32:197-213. [PMID: 21851339 DOI: 10.1042/bsr20110076] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In adult rat cardiac myocytes adrenaline decreased AMPK (AMP-activated protein kinase) activity with a half-time of approximately 4 min, decreased phosphorylation of AMPK (α-Thr172) and decreased phosphorylation of ACC (acetyl-CoA carboxylase). Inactivation of AMPK by adrenaline was through both α1- and β-ARs (adrenergic receptors), but did not involve cAMP or calcium signalling, was not blocked by the PKC (protein kinase C) inhibitor BIM I (bisindoylmaleimide I), by the ERK (extracellular-signal-regulated kinase) cascade inhibitor U0126 or by PTX (pertussis toxin). Adrenaline caused no measurable change in LKB1 activity. Adrenaline decreased AMPK activity through a process that was distinct from AMPK inactivation in response to insulin or PMA. Neither adrenaline nor PMA altered the myocyte AMP:ATP ratio although the adrenaline effect was attenuated by oligomycin and by AICAR (5-amino-4-imidazolecarboxamide-1-β-D-ribofuranoside), agents that mimic 'metabolic stress'. Inactivation of AMPK by adrenaline was abolished by 1 μM okadaic acid suggesting that activation of PP2A (phosphoprotein phosphatase 2A) might mediate the adrenaline effect. However, no change in PP2A activity was detected in myocyte extracts. Adrenaline increased phosphorylation of the AMPK β-subunit in vitro but there was no detectable change in vivo in phosphorylation of previously identified AMPK sites (β-Ser24, β-Ser108 or β-Ser182) suggesting that another site(s) is targeted.
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36
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Abstract
AbstractThe changes in hormone-regulated adenylyl cyclase (AC) signaling system implicated in control of the nervous, cardiovascular and reproductive systems may contribute to complications of diabetes mellitus (DM). We investigated the functional state of AC system in the brain, myocardium, ovary and uterus of rats with neonatal DM and examined the influence of intranasally administered insulin on the sensitivity of this system to biogenic amines and polypeptide hormones. The regulatory effects of somatostatin and 5-HT1BR-agonist 5-nonyloxytryptamine acting via Gi protein-coupled receptors were significantly decreased in DM and partially restored in insulin-treated rats. The effects of hormones, activators of AC, are changed in tissue- and receptorspecific manner, and intranasal insulin restored the effects rather close to the level in control. In insulin-treated non-diabetic rats, AC stimulating effects of isoproterenol and relaxin in the myocardium and of human chorionic gonadotropin in the ovaries were decreased, while the effects of hormones, inhibitors of AC, were increased. These data indicate that with intranasal insulin, Gi protein-mediated signaling pathways continue to gain strength. The obtained data on the influence of hormones on AC system in the brain, myocardium, ovary and uterus allow looking anew into the mechanisms of therapeutic effects of intranasal insulin.
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37
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Morgado M, Cairrão E, Santos-Silva AJ, Verde I. Cyclic nucleotide-dependent relaxation pathways in vascular smooth muscle. Cell Mol Life Sci 2012; 69:247-66. [PMID: 21947498 PMCID: PMC11115151 DOI: 10.1007/s00018-011-0815-2] [Citation(s) in RCA: 135] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 08/21/2011] [Accepted: 08/23/2011] [Indexed: 02/07/2023]
Abstract
Vascular smooth muscle tone is controlled by a balance between the cellular signaling pathways that mediate the generation of force (vasoconstriction) and release of force (vasodilation). The initiation of force is associated with increases in intracellular calcium concentrations, activation of myosin light-chain kinase, increases in the phosphorylation of the regulatory myosin light chains, and actin-myosin crossbridge cycling. There are, however, several signaling pathways modulating Ca(2+) mobilization and Ca(2+) sensitivity of the contractile machinery that secondarily regulate the contractile response of vascular smooth muscle to receptor agonists. Among these regulatory mechanisms involved in the physiological regulation of vascular tone are the cyclic nucleotides (cAMP and cGMP), which are considered the main messengers that mediate vasodilation under physiological conditions. At least four distinct mechanisms are currently thought to be involved in the vasodilator effect of cyclic nucleotides and their dependent protein kinases: (1) the decrease in cytosolic calcium concentration ([Ca(2+)]c), (2) the hyperpolarization of the smooth muscle cell membrane potential, (3) the reduction in the sensitivity of the contractile machinery by decreasing the [Ca(2+)]c sensitivity of myosin light-chain phosphorylation, and (4) the reduction in the sensitivity of the contractile machinery by uncoupling contraction from myosin light-chain phosphorylation. This review focuses on each of these mechanisms involved in cyclic nucleotide-dependent relaxation of vascular smooth muscle under physiological conditions.
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Affiliation(s)
- Manuel Morgado
- Health Sciences Research Centre (CICS-UBI), University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Elisa Cairrão
- Health Sciences Research Centre (CICS-UBI), University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - António José Santos-Silva
- Health Sciences Research Centre (CICS-UBI), University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Ignacio Verde
- Health Sciences Research Centre (CICS-UBI), University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
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Inactivation of the AMP-activated protein kinase by glucose in cardiac myocytes: a role for the pentose phosphate pathway. Biosci Rep 2011; 32:229-39. [DOI: 10.1042/bsr20110075] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Incubation of adult rat cardiac myocytes with increasing glucose concentrations decreased phosphorylation (αThr172) and activity of AMPK (AMP-activated protein kinase). The effect could be demonstrated without measurable changes in adenine nucleotide contents. The glucose effect was additive to the decrease in AMPK activity caused by insulin, was attenuated by adrenaline, was not mimicked by glucose analogues, lactate or pyruvate and was not due to changes in myocyte glycogen content. AMPK activity was decreased by xylitol and PMS (phenazine methosulfate) and was increased by the glucose-6-phosphate dehydrogenase inhibitor DHEA (dehydroepiandrosterone) and by thiamine. PMS and DHEA respectively, increased and decreased CO2 formation by the PPP (pentose phosphate pathway). AMPK activity was inversely related to the myocyte content of Xu5P (xylulose 5-phosphate), an intermediate of the non-oxidative arm of the PPP. Endothall, an inhibitor of PP2A (protein phosphatase 2A), abolished the glucose effect on AMPK activity. Further studies are needed to define the ‘active component’ that mediates the glucose effect and whether its site of action is PP2A.
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Olianas MC, Dedoni S, Olianas A, Onali P. δ-Opioid Receptors Stimulate the Metabolic Sensor AMP-Activated Protein Kinase through Coincident Signaling with Gq/11-Coupled Receptors. Mol Pharmacol 2011; 81:154-65. [DOI: 10.1124/mol.111.075267] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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Day RM, Lee YH, Han L, Kim YC, Feng YH. Angiotensin II activates AMPK for execution of apoptosis through energy-dependent and -independent mechanisms. Am J Physiol Lung Cell Mol Physiol 2011; 301:L772-81. [PMID: 21856818 DOI: 10.1152/ajplung.00072.2011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
At the cellular level, 5'-AMP-activated protein kinase (AMPK) serves as a critical link between energy homeostasis and the regulation of fundamental biological activities, including apoptosis. Angiotensin (Ang) II plays a key role in fibrotic lung remodeling. We recently demonstrated that Ang II induces apoptosis in pulmonary artery endothelial cells (PAEC) through the Ang type 2 receptor (AT(2)). AT(2) activates Src-homology two-domain-containing phosphatase-2 (SHP-2) in a signaling cascade leading to Bcl-x(L) mRNA destabilization and initiation of intrinsic apoptosis. We investigated the requirement of AMPK and ATP generation for Ang II-induced apoptosis in PAEC. Ang II activated AMPK, which was required for ATP generation. Inhibition of ATP production by compound C, an AMPK inhibitor, or by oligomycin suppressed Ang II-induced apoptosis. Experiments in Chinese hamster ovary-K1 cells expressing ectopic AT(2) (wild-type, mutant D90A, or carboxy terminal truncated mutant tC319) demonstrated that AT(2) activation of AMPK required the active conformation of the receptor and the carboxy terminal 44 amino acids. AMPK associated with and activated SHP-2 and was required for Bcl-x(L) mRNA destabilization. These are the first findings demonstrating that AMPK is activated by Ang II to produce ATP required for apoptosis. Our data also indicate that AMPK plays an energy-independent role by mediating SHP-2 activation.
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Affiliation(s)
- Regina M Day
- Dept. of Pharmacology, Uniformed Services Univ. of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, MD 20814-4799, USA.
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41
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Öberg AI, Yassin K, Csikasz RI, Dehvari N, Shabalina IG, Hutchinson DS, Wilcke M, Östenson CG, Bengtsson T. Shikonin increases glucose uptake in skeletal muscle cells and improves plasma glucose levels in diabetic Goto-Kakizaki rats. PLoS One 2011; 6:e22510. [PMID: 21818330 PMCID: PMC3144218 DOI: 10.1371/journal.pone.0022510] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 06/28/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND There is considerable interest in identifying compounds that can improve glucose homeostasis. Skeletal muscle, due to its large mass, is the principal organ for glucose disposal in the body and we have investigated here if shikonin, a naphthoquinone derived from the Chinese plant Lithospermum erythrorhizon, increases glucose uptake in skeletal muscle cells. METHODOLOGY/PRINCIPAL FINDINGS Shikonin increases glucose uptake in L6 skeletal muscle myotubes, but does not phosphorylate Akt, indicating that in skeletal muscle cells its effect is medaited via a pathway distinct from that used for insulin-stimulated uptake. Furthermore we find no evidence for the involvement of AMP-activated protein kinase in shikonin induced glucose uptake. Shikonin increases the intracellular levels of calcium in these cells and this increase is necessary for shikonin-mediated glucose uptake. Furthermore, we found that shikonin stimulated the translocation of GLUT4 from intracellular vesicles to the cell surface in L6 myoblasts. The beneficial effect of shikonin on glucose uptake was investigated in vivo by measuring plasma glucose levels and insulin sensitivity in spontaneously diabetic Goto-Kakizaki rats. Treatment with shikonin (10 mg/kg intraperitoneally) once daily for 4 days significantly decreased plasma glucose levels. In an insulin sensitivity test (s.c. injection of 0.5 U/kg insulin), plasma glucose levels were significantly lower in the shikonin-treated rats. In conclusion, shikonin increases glucose uptake in muscle cells via an insulin-independent pathway dependent on calcium. CONCLUSIONS/SIGNIFICANCE Shikonin increases glucose uptake in skeletal muscle cells via an insulin-independent pathway dependent on calcium. The beneficial effects of shikonin on glucose metabolism, both in vitro and in vivo, show that the compound possesses properties that make it of considerable interest for developing novel treatment of type 2 diabetes.
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Affiliation(s)
- Anette I. Öberg
- Department of Physiology, Arrhenius Laboratories F3, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Kamal Yassin
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Robert I. Csikasz
- Department of Physiology, Arrhenius Laboratories F3, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Nodi Dehvari
- Department of Physiology, Arrhenius Laboratories F3, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Irina G. Shabalina
- Department of Physiology, Arrhenius Laboratories F3, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Dana S. Hutchinson
- Department of Pharmacology, Monash University, Parkville, Victoria, Australia
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | | | - Claes-Göran Östenson
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Tore Bengtsson
- Department of Physiology, Arrhenius Laboratories F3, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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Creighton J, Jian M, Sayner S, Alexeyev M, Insel PA. Adenosine monophosphate-activated kinase alpha1 promotes endothelial barrier repair. FASEB J 2011; 25:3356-65. [PMID: 21680893 DOI: 10.1096/fj.10-179218] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The vascular endothelium responds to damage through activation of multiple signaling events that restore cell-cell adhesion and vascular integrity. However, the molecular mechanisms that integrate these events are not clearly defined. Herein, we identify a previously unexpected role for adenosine monophosphate-activated protein kinase (AMPK) in pulmonary microvascular endothelial cell (PMVEC) repair. PMVECs selectively express the AMPKα1 catalytic subunit, pharmacological and short hairpin RNA-mediated inhibition of which attenuates Ca(2+) entry in these cells induced by the inflammatory Ca(2+)-signaling mimetic thapsigargin. We find that AMPKα1 activity is required for the formation of PMVEC cell-cell networks in a prorepair environment and for monolayer resealing after wounding. Decreasing AMPKα1 expression reduces barrier resistance in PMVEC monolayers, results consistent with a role for AMPKα1 in cell-cell adhesion. AMPKα1 colocalizes and coimmunoprecipitates with the adherens junction protein N-cadherin and cofractionates with proteins selectively expressed in caveolar membranes. Assessment of permeability, by measuring the filtration coefficient (K(f)) in isolated perfused lungs, confirmed that AMPK activation contributes to barrier repair in vivo. Our findings thus provide novel evidence for AMPKα1 in Ca(2+) influx-mediated signaling and wound repair in the endothelium.
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Affiliation(s)
- Judy Creighton
- Department of Anesthesiology, University of Alabama, Birmingham, Alabama, USA
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43
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Tong X, Smith KA, Pelling JC. Apigenin, a chemopreventive bioflavonoid, induces AMP-activated protein kinase activation in human keratinocytes. Mol Carcinog 2011; 51:268-79. [PMID: 21538580 DOI: 10.1002/mc.20793] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 04/01/2011] [Accepted: 04/08/2011] [Indexed: 12/19/2022]
Abstract
AMP-activated protein kinase (AMPK) is a cellular energy sensor that is conserved in eukaryotes. Although AMPK is traditionally thought to play a major role in the regulation of cellular lipid and protein metabolism, recent discoveries reveal that AMPK inhibits mammalian target of rapamycin (mTOR) signaling and connects with several tumor suppressors such as liver kinase B1 (LKB1), p53, and tuberous sclerosis complex 2 (TSC2), indicating that AMPK may be a potential target for cancer prevention and treatment. For the first time, we demonstrated that apigenin, a naturally occurring nonmutagenic flavonoid, induced AMPK activation in human keratinocytes (both cultured HaCaT cell line and primary normal human epidermal keratinocytes). Through experiments with over-expression of constitutively active Akt and knockdown of LKB1 expression by siRNAs, we further found that the activation of AMPK by apigenin was not dependent on its inhibition of Akt, and was independent of the activation of upstream kinase LKB1. Instead, another upstream kinase of AMPK, calcium/calmodulin-dependent protein kinase kinase-β (CaMKKβ), was required for apigenin-induced AMPK activation. We have demonstrated that knockdown of CaMKKβ expression by siRNA or inhibition of CaMKKβ activity by either CaMKK inhibitor STO-609 or BAPTA-AM (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester; a chelator of intracellular Ca(2+)) prevented apigenin-induced AMPK activation. Apigenin-induced AMPK activation inhibited mTOR signaling and further induced autophagy in human keratinocytes. These results suggest that one of the mechanisms by which apigenin exerts its chemopreventive action may be through activation of AMPK and induction of autophagy in human keratinocytes.
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Affiliation(s)
- Xin Tong
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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44
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Luo ZF, Fang XL, Shu G, Wang SB, Zhu XT, Gao P, Chen LL, Chen CY, Xi QY, Zhang YL, Jiang QY. Sorbic acid improves growth performance and regulates insulin-like growth factor system gene expression in swine. J Anim Sci 2011; 89:2356-64. [PMID: 21421836 DOI: 10.2527/jas.2010-3677] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Sorbic acid (SA) is a PUFA with a conjugated double bond. The conjugated fatty acids, including CLA, are multifunctional bioactive fatty acids with the ability to improve growth performance. The effect of SA on pig growth performance was examined to determine its mechanism of action. The ADG, ADFI, and serum IGF-I concentration were examined, as were IGF-I secretion and IGF system gene expression in hepatocytes. Two hundred forty 21-d-old Duroc × Landrace × Yorkshire weaned piglets (6.86 ± 0.02 kg) were randomly divided into 4 groups, each consisting of 3 pens of 20 piglets (10 female and 10 male). The 4 groups of piglets were kept in a temperature-controlled room (26 to 28 °C), and feed and water were provided to the pigs ad libitum. Weanling piglets were fed diets that included 0, 0.5, 2, or 4 g of SA/kg for 42 d. The diet supplemented with 0.5 g/kg of SA improved (P < 0.05) ADG, BW, and G:F, whereas supplementation with all 3 SA doses increased (P < 0.05) ADG and G:F at 21 to 42 d of age. The greatest concentration of plasma triglycerides was observed (P < 0.05) in the 4 g/kg of SA group. The SA increased (0.5 g of SA/kg, P > 0.05; 1 g of SA/kg, P < 0.05; and 2 g of SA/kg, P < 0.05, respectively) plasma total serum protein and globulin concentrations in a dose-dependent manner. It was noted that the smallest SA treatment dose (0.5 g/kg) dramatically increased (P < 0.05) serum IGF-I concentration but decreased (P < 0.05) the concentrations of blood urea N and cortisol. The SA increased (P < 0.05) IGF-I, IGF-II, IGF-I receptor (IGF-IR), and PPARα gene mRNA expression and IGF-I secretion, but not (P > 0.05) IGFBP or PPARγ mRNA expression, in pig primary hepatocytes. These results indicate that SA improves growth performance by regulating IGF system gene expression and hormone secretion.
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Affiliation(s)
- Z-F Luo
- College of Animal Science, South China Agricultural University, Guangzhou, China 510640
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45
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Mokni W, Keravis T, Etienne-Selloum N, Walter A, Kane MO, Schini-Kerth VB, Lugnier C. Concerted regulation of cGMP and cAMP phosphodiesterases in early cardiac hypertrophy induced by angiotensin II. PLoS One 2010; 5:e14227. [PMID: 21151982 PMCID: PMC2997062 DOI: 10.1371/journal.pone.0014227] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Accepted: 11/12/2010] [Indexed: 12/13/2022] Open
Abstract
Left ventricular hypertrophy leads to heart failure and represents a high risk leading to premature death. Cyclic nucleotides (cAMP and cGMP) play a major role in heart contractility and cyclic nucleotide phosphodiesterases (PDEs) are involved in different stages of advanced cardiac diseases. We have investigated their contributions in the very initial stages of left ventricular hypertrophy development. Wistar male rats were treated over two weeks by chronic infusion of angiotensin II using osmotic mini-pumps. Left cardiac ventricles were used as total homogenates for analysis. PDE1 to PDE5 specific activities and protein and mRNA expressions were explored. Rats developed arterial hypertension associated with a slight cardiac hypertrophy (+24%). cAMP-PDE4 activity was specifically increased while cGMP-PDE activities were broadly increased (+130% for PDE1; +76% for PDE2; +113% for PDE5) and associated with increased expressions for PDE1A, PDE1C and PDE5A. The cGMP-PDE1 activation by Ca2+/CaM was reduced. BNP expression was increased by 3.5-fold, while NOX2 expression was reduced by 66% and AMP kinase activation was increased by 64%. In early cardiac hypertrophy induced by angiotensin II, all specific PDE activities in left cardiac ventricles were increased, favoring an increase in cGMP hydrolysis by PDE1, PDE2 and PDE5. Increased cAMP hydrolysis was related to PDE4. We observed the establishment of two cardioprotective mechanisms and we suggest that these mechanisms could lead to increase intracellular cGMP: i) increased expression of BNP could increase “particulate” cGMP pool; ii) increased activation of AMPK, subsequent to increase in PDE4 activity and 5′AMP generation, could elevate “soluble” cGMP pool by enhancing NO bioavailability through NOX2 down-regulation. More studies are needed to support these assumptions. Nevertheless, our results suggest a potential link between PDE4 and AMPK/NOX2 and they point out that cGMP-PDEs, especially PDE1 and PDE2, may be interesting therapeutic targets in preventing cardiac hypertrophy.
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Affiliation(s)
- Walid Mokni
- CNRS UMR 7213, Biophotonique et Pharmacologie, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
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46
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Chai B, Li JY, Zhang W, Wu X, Zhang C, Mulholland MW. Melanocortin-4 receptor activation promotes insulin-stimulated mTOR signaling. Peptides 2010; 31:1888-93. [PMID: 20603172 PMCID: PMC3282553 DOI: 10.1016/j.peptides.2010.06.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 06/23/2010] [Accepted: 06/24/2010] [Indexed: 01/13/2023]
Abstract
The melanocortin signaling system is integral in regulating energy homeostasis. The melanocortin-4 receptor (MC4R) activates several signaling pathways in performance of this function. The effect of MC4R on insulin-stimulated mammalian target of rapamycin (mTOR), a cellular energy sensor, signaling was investigated. The GT1-1 cell line which expresses MC4R expression was utilized. mTOR signaling was measured by Western blotting analysis using Phospho-mTOR (Ser2448) antibody. NDP-MSH dose-dependently enhanced insulin-stimulated mTOR phosphorylation. The MC4R antagonist SHU9119 blocked this effect, demonstrating specificity. The protein kinase A - cyclic AMP pathway and the MAP kinase pathway were not involved in NDP-MSH actions on insulin-stimulated mTOR phosphorylation. In contrast, the AMP-activated protein kinase agonist, AICAR, attenuated this effect. MC4R activation potentiates insulin-stimulated mTOR signaling via the AMPK pathway.
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Affiliation(s)
| | | | | | | | | | - Michael W. Mulholland
- Corresponding Author: Michael W. Mulholland, M.D., Ph.D., 2101 Taubman Center, 1500 E. Medical Center Dr., Ann Arbor, MI 48109-0346, Tel.: +1 734 936 3236; fax: +1 734 763 5625,
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47
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Zheng S, Li W, Xu M, Bai X, Zhou Z, Han J, Shyy JYJ, Wang X. Calcitonin gene-related peptide promotes angiogenesis via AMP-activated protein kinase. Am J Physiol Cell Physiol 2010; 299:C1485-92. [PMID: 20881236 DOI: 10.1152/ajpcell.00173.2010] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ischemia induces angiogenesis as a compensatory response. Although ischemia is known to causes synthesis and release of calcitonin gene-related peptide (CGRP), it is not clear whether CGRP regulates angiogenesis under ischemia and how does it function. Thus we investigated the role of CGRP in angiogenesis and the involved mechanisms. We found that CGRP level was increased in the rat hindlimb ischemic tissue. The expression of exogenous CGRP by adenovirus vectors enhanced blood flow recovery and increased capillary density in ischemic hindlimbs. In vitro, CGRP promoted human umbilical vein endothelial cell (HUVEC) tube formation and migration. Further more, CGRP activated AMP-activated protein kinase (AMPK) both in vivo and in vitro, and pharmacological inhibition of CGRP and cAMP attenuated the CGRP-activated AMPK in vitro. CGRP also induced endothelial nitric oxide synthase (eNOS) phosphorylation in HUVECs at Ser1177 and Ser633 in a time-dependent manner, and such effects were abolished by AMPK inhibitor Compound C. As well, Compound C blocked CGRP-enhanced HUVEC tube formation and migration. These findings indicate that CGRP promotes angiogenesis by activating the AMPK-eNOS pathway in endothelial cells.
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Affiliation(s)
- Shuai Zheng
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, Peoples Republic of China
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48
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Jaswal JS, Lund CR, Keung W, Beker DL, Rebeyka IM, Lopaschuk GD. Isoproterenol stimulates 5'-AMP-activated protein kinase and fatty acid oxidation in neonatal hearts. Am J Physiol Heart Circ Physiol 2010; 299:H1135-45. [PMID: 20656883 DOI: 10.1152/ajpheart.00186.2010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Isoproterenol increases phosphorylation of LKB, 5'-AMP-activated protein kinase (AMPK), and acetyl-CoA carboxylase (ACC), enzymes involved in regulating fatty acid oxidation. However, inotropic stimulation selectively increases glucose oxidation in adult hearts. In the neonatal heart, fatty acid oxidation becomes a major energy source, while glucose oxidation remains low. This study tested the hypothesis that increased energy demand imposed by isoproterenol originates from fatty acid oxidation, secondary to increased LKB, AMPK, and ACC phosphorylation. Isolated working hearts from 7-day-old rabbits were perfused with Krebs solution (0.4 mM palmitate, 11 mM glucose, 0.5 mM lactate, and 100 mU/l insulin) with or without isoproterenol (300 nM). Isoproterenol increased myocardial O(2) consumption (in J·g dry wt(-1)·min(-1); 11.0 ± 1.4, n = 8 vs. 7.5 ± 0.8, n = 6, P < 0.05), and the phosphorylation of LKB (in arbitrary density units; 0.87 ± 0.09, n = 6 vs. 0.59 ± 0.08, n = 6, P < 0.05), AMPK (0.82 ± 0.08, n = 6 vs. 0.51 ± 0.06, n = 6, P < 0.05), and ACC-β (1.47 ± 0.14, n = 6 vs. 0.97 ± 0.07, n = 6, P < 0.05), with a concomitant decrease in malonyl-CoA levels (in nmol/g dry wt; 0.9 ± 0.9, n = 8 vs. 7.5 ± 1.3, n = 8, P < 0.05) and increase in palmitate oxidation (in nmol·g dry wt(-1)·min(-1); 272 ± 45, n = 8 vs. 114 ± 9, n = 6, P < 0.05). Glucose and lactate oxidation were increased (in nmol·g dry wt(-1)·min(-1); 253 ± 75, n = 8 vs. 63 ± 15, n = 9, P < 0.05 and 246 ± 43, n = 8 vs. 82 ± 11, n = 6, P < 0.05, respectively), independent of alterations in pyruvate dehydrogenase phosphorylation, but occurred secondary to a decrease in acetyl-CoA content and acetyl-CoA-to-free CoA ratio. As acetyl-CoA levels decrease in response to isoproterenol, despite an acceleration of the rates of palmitate and carbohydrate oxidation, these data suggest net rates of acetyl-CoA utilization exceed the net rates of acetyl-CoA generation.
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Affiliation(s)
- Jagdip S Jaswal
- Department of Pediatrics, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
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Interaction between age and obesity on cardiomyocyte contractile function: role of leptin and stress signaling. PLoS One 2010; 5:e10085. [PMID: 20396382 PMCID: PMC2852499 DOI: 10.1371/journal.pone.0010085] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 03/17/2010] [Indexed: 12/31/2022] Open
Abstract
Objectives This study was designed to evaluate the interaction between aging and obesity
on cardiac contractile and intracellular Ca2+
properties. Methods Cardiomyocytes from young (4-mo) and aging (12- and 18-mo) male lean and the
leptin deficient ob/ob obese mice were treated with leptin
(0.5, 1.0 and 50 nM) for 4 hrs in vitro. High fat diet
(45% calorie from fat) and the leptin receptor mutant
db/db obesity models at young and older age were used
for comparison. Cardiomyocyte contractile and intracellular
Ca2+ properties were evaluated including peak
shortening (PS), maximal velocity of shortening/relengthening (±
dL/dt), time-to-PS (TPS), time-to-90% relengthening
(TR90), intracellular Ca2+ levels and
decay. O2− levels were measured by
dihydroethidium fluorescence. Results Our results revealed reduced survival in ob/ob mice. Aging
and obesity reduced PS, ± dL/dt, intracellular
Ca2+ rise, prolonged TR90 and
intracellular Ca2+ decay, enhanced
O2− production and
p47phox expression
without an additive effect of the two, with the exception of intracellular
Ca2+ rise. Western blot analysis exhibited reduced
Ob-R expression and STAT-3 phosphorylation in both young and aging
ob/ob mice, which was restored by leptin. Aging and
obesity reduced phosphorylation of Akt, eNOS and p38 while promoting pJNK
and pIκB. Low levels of leptin reconciled contractile, intracellular
Ca2+ and cell signaling defects as well as
O2− production and
p47phox upregulation in
young but not aging ob/ob mice. High level of leptin (50
nM) compromised contractile and intracellular Ca2+
response as well as O2− production and
stress signaling in all groups. High fat diet-induced and
db/db obesity displayed somewhat comparable
aging-induced mechanical but not leptin response. Conclusions Taken together, our data suggest that aging and obesity compromise cardiac
contractile function possibly via phosphorylation of Akt, eNOS and stress
signaling-associated O2− release.
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50
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Xu X, Zhao CX, Wang L, Tu L, Fang X, Zheng C, Edin ML, Zeldin DC, Wang DW. Increased CYP2J3 expression reduces insulin resistance in fructose-treated rats and db/db mice. Diabetes 2010; 59:997-1005. [PMID: 20068141 PMCID: PMC2844847 DOI: 10.2337/db09-1241] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Accumulating evidence suggests that cytochrome P450 (CYP) epoxygenases metabolize arachidonic acid into epoxyeicosatrienoic acids (EETs), which play crucial and diverse roles in cardiovascular homeostasis. The anti-inflammatory, antihypertensive, and pro-proliferative effects of EETs suggest a possible beneficial role for EETs on insulin resistance and diabetes. RESEARCH DESIGN AND METHODS This study investigated the effects of CYP2J3 epoxygenase gene therapy on insulin resistance and blood pressure in diabetic db/db mice and in a model of fructose-induced hypertension and insulin resistance in rats. RESULTS CYP2J3 gene delivery in vivo increased EET generation, reduced blood pressure, and reversed insulin resistance as determined by plasma glucose levels, homeostasis model assessment insulin resistance index, and glucose tolerance test. Furthermore, CYP2J3 treatment prevented fructose-induced decreases in insulin receptor signaling and phosphorylation of AMP-activated protein kinases (AMPKs) in liver, muscle, heart, kidney, and aorta. Thus, overexpression of CYP2J3 protected against diabetes and insulin resistance in peripheral tissues through activation of insulin receptor and AMPK pathways. CONCLUSIONS These results highlight the beneficial roles of the CYP epoxygenase-EET system in diabetes and insulin resistance.
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Affiliation(s)
- Xizhen Xu
- Department of Internal Medicine and The Institute of Hypertension, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Chun Xia Zhao
- Department of Internal Medicine and The Institute of Hypertension, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Luyun Wang
- Department of Internal Medicine and The Institute of Hypertension, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Ling Tu
- Department of Internal Medicine and The Institute of Hypertension, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Xiaosai Fang
- Department of Internal Medicine and The Institute of Hypertension, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Changlong Zheng
- Department of Internal Medicine and The Institute of Hypertension, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Matthew L. Edin
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Darryl C. Zeldin
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Dao Wen Wang
- Department of Internal Medicine and The Institute of Hypertension, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, People's Republic of China
- Corresponding author: Dao Wen Wang,
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