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Xu L, Wang S, Li B, Sun A, Zou Y, Ge J. A protective role of ciglitazone in ox-LDL-induced rat microvascular endothelial cells via modulating PPARγ-dependent AMPK/eNOS pathway. J Cell Mol Med 2014; 19:92-102. [PMID: 25388834 PMCID: PMC4288353 DOI: 10.1111/jcmm.12463] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 09/19/2014] [Indexed: 01/10/2023] Open
Abstract
Thiazolidinediones, the antidiabetic agents such as ciglitazone, has been proved to be effective in limiting atherosclerotic events. However, the underlying mechanism remains elucidative. Ox-LDL receptor-1 (LOX-1) plays a central role in ox-LDL-mediated atherosclerosis via endothelial nitric oxide synthase (eNOS) uncoupling and nitric oxide reduction. Therefore, we tested the hypothesis that ciglitazone, the PPARγ agonist, protected endothelial cells against ox-LDL through regulating eNOS activity and LOX-1 signalling. In the present study, rat microvascular endothelial cells (RMVECs) were stimulated by ox-LDL. The impact of ciglitazone on cell apoptosis and angiogenesis, eNOS expression and phosphorylation, nitric oxide synthesis and related AMPK, Akt and VEGF signalling pathway were observed. Our data showed that both eNOS and Akt phosphorylation, VEGF expression and nitric oxide production were significantly decreased, RMVECs ageing and apoptosis increased after ox-LDL induction for 24 hrs, all of which were effectively reversed by ciglitazone pre-treatment. Meanwhile, phosphorylation of AMP-activated protein kinase (AMPK) was suppressed by ox-LDL, which was also prevented by ciglitazone. Of interest, AMPK inhibition abolished ciglitazone-mediated eNOS function, nitric oxide synthesis and angiogenesis, and increased RMVECs ageing and apoptosis. Further experiments showed that inhibition of PPARγ significantly suppressed AMPK phosphorylation, eNOS expression and nitric oxide production. Ciglitazone-mediated angiogenesis and reduced cell ageing and apoptosis were reversed. Furthermore, LOX-1 protein expression in RMVECs was suppressed by ciglitazone, but re-enhanced by blocking PPARγ or AMPK. Ox-LDL-induced suppression of eNOS and nitric oxide synthesis were largely prevented by silencing LOX-1. Collectively, these data demonstrate that ciglitazone-mediated PPARγ activation suppresses LOX-1 and moderates AMPK/eNOS pathway, which contributes to endothelial cell survival and function preservation.
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Affiliation(s)
- Lei Xu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China; Institutes of Biomedical Science, Fudan University, Shanghai, China
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Ma X, Zhang J, Deng R, Ding S, Gu N, Guo X. Synergistic effect of smoking with genetic variants in the AMPKα1 gene on the risk of coronary artery disease in type 2 diabetes. Diabetes Metab Res Rev 2014; 30:483-8. [PMID: 24395629 DOI: 10.1002/dmrr.2520] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 12/01/2013] [Accepted: 12/19/2013] [Indexed: 11/11/2022]
Abstract
BACKGROUND Increasing evidence suggests that adenosine monophosphate-activated protein kinase (AMPK) plays a critical physiological role in the cardiovascular system. The objective of this study was to assess the possible correlation between the genetic variability of the AMPKα1 (PRKAA1) gene and the risk of cardiovascular disease, as well as the interactive effects of the genetic variations and environmental factors, on the risk in Chinese patients with type 2 diabetes. METHODS Five haplotype-tagging single nucleotide polymorphisms (SNPs) at the AMPKα1 locus and 404 unrelated Chinese Han subjects with type 2 diabetes were studied; 260 individuals with coronary artery disease and 144 non-coronary artery disease controls were genotyped using the polymerase chain reaction-restriction fragment length polymorphism assay. RESULTS Minor allele C at rs3805489 was protective from coronary artery disease in type 2 diabetic subjects compared with allele A (OR 0.67, 95% CI 0.48-0.92, p = 0.015). There was no significant correlation between the genotypes at five SNPs and the risk of coronary artery disease. In addition, a significant interaction was identified between smoking status and rs3805489 (p = 0.018 for interaction). The smokers with genotype AA at the SNP had a three-fold higher risk of coronary artery disease compared with non-smokers with genotypes AC or CC (OR' 3.02, 95% CI' 1.39-6.57, p' = 0.005, after adjustment for other known coronary artery disease risk factors). CONCLUSIONS The genetic variability at the AMPKα1 locus has synergetic effects with smoking to increase the risk of coronary artery disease in the Chinese Han population with type 2 diabetes.
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Affiliation(s)
- Xiaowei Ma
- Department of Endocrinology, Peking University First Hospital, Beijing, China
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53
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Hamdulay SS, Wang B, Calay D, Kiprianos AP, Cole J, Dumont O, Dryden N, Randi AM, Thornton CC, Al-Rashed F, Hoong C, Shamsi A, Liu Z, Holla VR, Boyle JJ, Haskard DO, Mason JC. Synergistic Therapeutic Vascular Cytoprotection against Complement-Mediated Injury Induced via a PKCα-, AMPK-, and CREB-Dependent Pathway. THE JOURNAL OF IMMUNOLOGY 2014; 192:4316-27. [DOI: 10.4049/jimmunol.1301702] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Venna VR, Li J, Hammond MD, Mancini NS, McCullough LD. Chronic metformin treatment improves post-stroke angiogenesis and recovery after experimental stroke. Eur J Neurosci 2014; 39:2129-38. [PMID: 24649970 DOI: 10.1111/ejn.12556] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 02/09/2014] [Accepted: 02/12/2014] [Indexed: 02/06/2023]
Abstract
Metformin is currently the first-line treatment drug for type 2 diabetes. Metformin is a well-known activator of AMP-activated protein kinase (AMPK). In experimental studies, metformin has been shown to exert direct vascular effects by increasing vascular endothelial growth factor expression and improving microvascular density. As stroke is the leading cause of long-term disability and angiogenesis is implicated as an important mechanism in functional recovery, we hypothesized that chronic metformin treatment would improve post-stroke functional recovery by enhancing functional microvascular density. For this study, C57BL/6N male mice were subjected to a 60-min middle cerebral artery occlusion, and were given 50 mg/kg/day metformin beginning 24 h post-stroke for 3 weeks. Behavioral recovery was assessed using adhesive-tape removal and the apomorphine-induced turning test. The role of angiogenesis was assessed by counting vessel branch points from fluorescein-conjugated lectin-perfused brain sections. Importantly even if metformin treatment was initiated 24 h after injury it enhanced recovery and significantly improved stroke-induced behavioral deficits. This recovery occurred in parallel with enhanced angiogenesis and with restoration of endogenous cerebral dopaminergic tone and revascularization of ischemic tissue. We assessed if the effects on recovery and angiogenesis were mediated by AMPK. When tested in AMPK α-2 knockout mice, we found that metformin treatment did not have the same beneficial effects on recovery and angiogenesis, suggesting that metformin-induced angiogenic effects are mediated by AMPK. The results from this study suggest that metformin mediates post-stroke recovery by enhancing angiogenesis, and these effects are mediated by AMPK signaling.
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Affiliation(s)
- Venugopal R Venna
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, USA
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55
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Soares H, Marinho HS, Real C, Antunes F. Cellular polarity in aging: role of redox regulation and nutrition. GENES AND NUTRITION 2013; 9:371. [PMID: 24306961 DOI: 10.1007/s12263-013-0371-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 11/19/2013] [Indexed: 02/06/2023]
Abstract
Cellular polarity concerns the spatial asymmetric organization of cellular components and structures. Such organization is important not only for biological behavior at the individual cell level, but also for the 3D organization of tissues and organs in living organisms. Processes like cell migration and motility, asymmetric inheritance, and spatial organization of daughter cells in tissues are all dependent of cell polarity. Many of these processes are compromised during aging and cellular senescence. For example, permeability epithelium barriers are leakier during aging; elderly people have impaired vascular function and increased frequency of cancer, and asymmetrical inheritance is compromised in senescent cells, including stem cells. Here, we review the cellular regulation of polarity, as well as the signaling mechanisms and respective redox regulation of the pathways involved in defining cellular polarity. Emphasis will be put on the role of cytoskeleton and the AMP-activated protein kinase pathway. We also discuss how nutrients can affect polarity-dependent processes, both by direct exposure of the gastrointestinal epithelium to nutrients and by indirect effects elicited by the metabolism of nutrients, such as activation of antioxidant response and phase-II detoxification enzymes through the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2). In summary, cellular polarity emerges as a key process whose redox deregulation is hypothesized to have a central role in aging and cellular senescence.
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Affiliation(s)
- Helena Soares
- Departamento de Química e Bioquímica, Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
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56
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Pisanti S, Picardi P, Ciaglia E, Margarucci L, Ronca R, Giacomini A, Malfitano AM, Casapullo A, Laezza C, Gazzerro P, Bifulco M. Antiangiogenic effects of N6-isopentenyladenosine, an endogenous isoprenoid end product, mediated by AMPK activation. FASEB J 2013; 28:1132-44. [PMID: 24265487 DOI: 10.1096/fj.13-238238] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
N6-isopentenyladenosine (iPA), an end product of the mevalonate pathway with an isopentenyl chain, is already known to exert a suppressor effect against various tumors. In this work, we investigated whether iPA also directly interferes with the angiogenic process, which is fundamental to tumor growth and progression. To this end, using human umbilical vein endothelial cells (HUVECs) as a suitable in vitro model of angiogenesis, we evaluated their viability, proliferation, migration, invasion, tube formation in response to iPA, and molecular mechanisms involved. Data were corroborated in mice by using a gel plug assay. iPA dose- and time-dependently inhibited all the neoangiogenesis stages, with an IC50 of 0.98 μM. We demonstrated for the first time, by liquid chromatography-coupled tandem mass spectrometry (LC-MS/MS), that iPA was monophosphorylated into 5'-iPA-monophosphate (iPAMP) by the adenosine kinase (ADK) inside the cells. iPAMP is the active form that inhibits angiogenesis through the direct activation of AMP-kinase (AMPK). Indeed, all effects were completely reversed by pretreatment with 5-iodotubercidin (5-Itu), an ADK inhibitor. The isoprenoid intermediate isopentenyl pyrophosphate (IPP), which shares the isopentenyl moiety with iPA, was ineffective in the inhibition of angiogenesis, thus showing that the iPA structure is specific for the observed effects. In conclusion, iPA is a novel AMPK activator and could represent a useful tool for the treatment of diseases where excessive neoangiogenesis is the underlying pathology.
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Affiliation(s)
- Simona Pisanti
- 2University of Salerno, Via Giovanni Paolo II, 84084 Fisciano, Salerno, Italy. S.P.,
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Berchtold MW, Villalobo A. The many faces of calmodulin in cell proliferation, programmed cell death, autophagy, and cancer. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1843:398-435. [PMID: 24188867 DOI: 10.1016/j.bbamcr.2013.10.021] [Citation(s) in RCA: 230] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Revised: 10/24/2013] [Accepted: 10/26/2013] [Indexed: 12/21/2022]
Abstract
Calmodulin (CaM) is a ubiquitous Ca(2+) receptor protein mediating a large number of signaling processes in all eukaryotic cells. CaM plays a central role in regulating a myriad of cellular functions via interaction with multiple target proteins. This review focuses on the action of CaM and CaM-dependent signaling systems in the control of vertebrate cell proliferation, programmed cell death and autophagy. The significance of CaM and interconnected CaM-regulated systems for the physiology of cancer cells including tumor stem cells, and processes required for tumor progression such as growth, tumor-associated angiogenesis and metastasis are highlighted. Furthermore, the potential targeting of CaM-dependent signaling processes for therapeutic use is discussed.
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Key Words
- (4-[3,5-bis-[2-(4-hydroxy-3-methoxy-phenyl)-ethyl]-4,5-dihydro-pyrazol-1-yl]-benzoic acid
- (4-[3,5-bis-[2-(4-hydroxy-3-methoxy-phenyl)-vinyl]-4,5-dihydro-pyrazol-1-yl]-phenyl)-(4-methyl-piperazin-1-yl)-methanone
- (−) enantiomer of dihydropyrine 3-methyl-5-3-(4,4-diphenyl-1-piperidinyl)-propyl-1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-piridine-3,5-dicarboxylate-hydrochloride (niguldipine)
- 1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-l-tyrosyl]-4-phenylpiperazine
- 12-O-tetradecanoyl-phorbol-13-acetate
- 2-chloro-(ε-amino-Lys(75))-[6-(4-(N,N′-diethylaminophenyl)-1,3,5-triazin-4-yl]-CaM adduct
- 3′-(β-chloroethyl)-2′,4′-dioxo-3,5′-spiro-oxazolidino-4-deacetoxy-vinblastine
- 7,12-dimethylbenz[a]anthracene
- Apoptosis
- Autophagy
- B859-35
- CAPP(1)-CaM
- Ca(2+) binding protein
- Calmodulin
- Cancer biology
- Cell proliferation
- DMBA
- EBB
- FL-CaM
- FPCE
- HBC
- HBCP
- J-8
- KAR-2
- KN-62
- KN-93
- N-(4-aminobutyl)-2-naphthalenesulfonamide
- N-(4-aminobutyl)-5-chloro-2-naphthalenesulfonamide
- N-(6-aminohexyl)-1-naphthalenesulfonamide
- N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide
- N-8-aminooctyl-5-iodo-naphthalenesulfonamide
- N-[2-[N-(4-chlorocinnamyl)-N-methylaminomethyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide
- O-(4-ethoxyl-butyl)-berbamine
- RITC-CaM
- TA-CaM
- TFP
- TPA
- W-12
- W-13
- W-5
- W-7
- fluorescein-CaM adduct
- fluphenazine-N-2-chloroethane
- norchlorpromazine-CaM adduct
- rhodamine isothiocyanate-CaM adduct
- trifluoperazine
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Affiliation(s)
- Martin W Berchtold
- Department of Biology, University of Copenhagen, Copenhagen Biocenter 4-2-09 Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
| | - Antonio Villalobo
- Instituto de Investigaciones Biomédicas, Department of Cancer Biology, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, c/Arturo Duperier 4, E-28029 Madrid, Spain.
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58
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Manwani B, McCullough LD. Function of the master energy regulator adenosine monophosphate-activated protein kinase in stroke. J Neurosci Res 2013; 91:1018-29. [PMID: 23463465 PMCID: PMC4266469 DOI: 10.1002/jnr.23207] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Revised: 12/24/2012] [Accepted: 01/05/2013] [Indexed: 01/09/2023]
Abstract
Adenosine monophosphate-activated protein kinase (AMPK) is an evolutionarily conserved signaling molecule that is emerging as one of the most important energy sensors in the body. AMPK monitors cellular energy status and is activated via phosphorylation when energy stores are low. This allows for maintenance of energy homeostasis by promoting catabolic pathways for ATP production and limiting processes that consume ATP. Growing number of stimuli have been shown to activate AMPK, and AMPK has been implicated in many diverse biological processes, including cell polarity, autophagy, and senescence. The effect of AMPK activation and its biological functions are extremely diverse and depend on both the overall energy "milieu" and the location and duration of activation. AMPK has tissue- and isoform-specific functions in the brain vs. periphery. These functions and the pathways activated also appear to differ by cell location (hypothalamus vs. cortex), cell type (astrocyte vs. neuron), and duration of exposure. Short bursts of AMPK activation have been found to be involved in ischemic preconditioning and neuronal survival; however, prolonged AMPK activity during ischemia leads to neuronal cell death. AMPK may also underlie some of the beneficial effects of hypothermia, a potential therapy for ischemic brain injury. This review discusses the role of AMPK in ischemic stroke, a condition of severe energy depletion.
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Affiliation(s)
- Bharti Manwani
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut
| | - Louise D. McCullough
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut
- Department of Neurology, University of Connecticut Health Center, Farmington, Connecticut
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59
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O'Neill HM, Holloway GP, Steinberg GR. AMPK regulation of fatty acid metabolism and mitochondrial biogenesis: implications for obesity. Mol Cell Endocrinol 2013; 366:135-51. [PMID: 22750049 DOI: 10.1016/j.mce.2012.06.019] [Citation(s) in RCA: 241] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Revised: 03/13/2012] [Accepted: 06/21/2012] [Indexed: 12/25/2022]
Abstract
Skeletal muscle plays an important role in regulating whole-body energy expenditure given it is a major site for glucose and lipid oxidation. Obesity and type 2 diabetes are causally linked through their association with skeletal muscle insulin resistance, while conversely exercise is known to improve whole body glucose homeostasis simultaneously with muscle insulin sensitivity. Exercise activates skeletal muscle AMP-activated protein kinase (AMPK). AMPK plays a role in regulating exercise capacity, skeletal muscle mitochondrial content and contraction-stimulated glucose uptake. Skeletal muscle AMPK is also thought to be important for regulating fatty acid metabolism; however, direct genetic evidence in this area is currently lacking. This review will discuss the current paradigms regarding the influence of AMPK in regulating skeletal muscle fatty acid metabolism and mitochondrial biogenesis at rest and during exercise, and highlight the potential implications in the development of insulin resistance.
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Affiliation(s)
- Hayley M O'Neill
- University of Melbourne, Department of Medicine, St. Vincent's Institute of Medical Research, Melbourne, Victoria, Australia.
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60
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Abstract
In this review we summarize the current understanding of signal transduction downstream of vascular endothelial growth factor A (VEGFA) and its receptor VEGFR2, and the relationship between these signal transduction pathways and the hallmark responses of VEGFA, angiogenesis and vascular permeability. These physiological responses involve a number of effectors, including extracellular signal-regulated kinases (ERKs), Src, phosphoinositide 3 kinase (PI3K)/Akt, focal adhesion kinase (FAK), Rho family GTPases, endothelial NO and p38 mitogen-activated protein kinase (MAPK). Several of these factors are involved in the regulation of both angiogenesis and vascular permeability. Tumour angiogenesis primarily relies on VEGFA-driven responses, which to a large extent result in a dysfunctional vasculature. The reason for this remains unclear, although it appears that certain aspects of the VEGFA-stimulated angiogenic milieu (high level of microvascular density and permeability) promote tumour expansion. The high degree of redundancy and complexity of VEGFA-driven tumour angiogenesis may explain why tumours commonly develop resistance to anti-angiogenic therapy targeting VEGFA signal transduction.
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Affiliation(s)
- L Claesson-Welsh
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.
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61
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Feng Y, Wang Y, Wang Z, Fang Z, Li F, Gao Y, Liu H, Xiao T, Li F, Zhou Y, Zhai Q, Liu X, Sun Y, Bardeesy N, Wong KK, Chen H, Xiong ZQ, Ji H. The CRTC1-NEDD9 signaling axis mediates lung cancer progression caused by LKB1 loss. Cancer Res 2012; 72:6502-11. [PMID: 23074285 DOI: 10.1158/0008-5472.can-12-1909] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Somatic mutation of the tumor suppressor gene LKB1 occurs frequently in lung cancer where it causes tumor progression and metastasis, but the underlying mechanisms remain mainly unknown. Here, we show that the oncogene NEDD9 is an important downstream mediator of lung cancer progression evoked by LKB1 loss. In de novo mouse models, RNAi-mediated silencing of Nedd9 inhibited lung tumor progression, whereas ectopic NEDD9 expression accelerated this process. Mechanistically, LKB1 negatively regulated NEDD9 transcription by promoting cytosolic translocation of CRTC1 from the nucleus. Notably, ectopic expression of either NEDD9 or CRTC1 partially reversed the inhibitory function of LKB1 on metastasis of lung cancer cells. In clinical specimens, elevated expression of NEDD9 was associated with malignant progression and metastasis. Collectively, our results decipher the mechanism through which LKB1 deficiency promotes lung cancer progression and metastasis, and provide a mechanistic rationale for therapeutic attack of these processes.
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Affiliation(s)
- Yan Feng
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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62
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Su KH, Yu YB, Hou HH, Zhao JF, Kou YR, Cheng LC, Shyue SK, Lee TS. AMP-activated protein kinase mediates erythropoietin-induced activation of endothelial nitric oxide synthase. J Cell Physiol 2012; 227:3053-62. [PMID: 22021095 DOI: 10.1002/jcp.23052] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We investigated whether AMP-activated protein kinase (AMPK), a multi-functional regulator of energy homeostasis, participates in the regulation of erythropoietin (EPO)-mediated activation of endothelial nitric oxide synthase (eNOS) in endothelial cells (ECs) and mice. In ECs, treatment with EPO increased the phosphorylation of AMPK, acetyl-CoA carboxylase (ACC), and eNOS, as revealed by Western blot analysis. Inhibition of AMPK activation by compound C or dominant-negative AMPK mutant abrogated the EPO-induced increase in the phosphorylation of AMPK, ACC, and eNOS, as well as nitric oxide (NO) production. Additionally, suppression of AMPK activation abolished EPO-induced EC proliferation, migration and tube formation. Immunoprecipitation analysis demonstrated that AMPK mediated the EPO-induced increase in the phosphorylation of β common receptor (βCR) and the formation of a βCR-AMPK-eNOS complex. In mice, inhibition of AMPK activation by compound C markedly decreased EPO-elicited angiogenesis in Matrigel plugs. Furthermore, the phosphorylation of AMPK and eNOS was significantly higher in aortas from EPO transgenic mice than wild-type mice. Moreover, treatment with EPO neutralizing antibody greatly reduced the exercise training-induced increase in phosphorylation of AMPK and eNOS in aortas of wild-type mice. Taken together, EPO may trigger AMPK-dependent signaling, which leads to enhanced phosphorylation of βCR and eNOS, increased βCR-AMPK-eNOS complex formation, NO production, and, ultimately, angiogenesis.
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Affiliation(s)
- Kuo-Hui Su
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
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63
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Peyton KJ, Liu XM, Yu Y, Yates B, Durante W. Activation of AMP-activated protein kinase inhibits the proliferation of human endothelial cells. J Pharmacol Exp Ther 2012; 342:827-34. [PMID: 22700432 DOI: 10.1124/jpet.112.194712] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
AMP-activated protein kinase (AMPK) is an evolutionary conserved energy-sensing enzyme that regulates cell metabolism. Emerging evidence indicates that AMPK also plays an important role in modulating endothelial cell function. In the present study, we investigated whether AMPK modulates endothelial cell growth. Treatment of cultured human umbilical vein endothelial cells with the AMPK activators 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR), 6,7-dihydro-4-hydroxy-3-(2'-hydroxy[1,1'-biphenyl]-4-yl)-6-oxo-thieno[2,3-b]pyridine-5-carbonitrile (A-769662), or metformin inhibited cell proliferation and DNA synthesis. The antiproliferative action of AICAR was largely prevented by the adenosine kinase inhibitor 5'-iodotubercidin and mimicked by infecting endothelial cells with an adenovirus expressing constitutively active AMPK. In contrast, pharmacological blockade of endothelial nitric oxide synthase or heme oxygenase-1 activity failed to reverse the inhibition of endothelial cell growth by AICAR. Flow cytometry experiments revealed that pharmacological activation of AMPK arrested endothelial cells in the G₀/G₁ phase of the cell cycle, and this was associated with increases in p53 phosphorylation and p53, p21, and p27 protein expression and decreases in cyclin A protein expression and retinoblastoma protein phosphorylation. In addition, silencing p21 and p27 expression partially restored the mitogenic response of AMPK-activated cells. Finally, activation of AMPK by AICAR blocked the migration of endothelial cells after scrape injury and stimulated tube formation by endothelial cells plated onto Matrigel-coated plates. In conclusion, these studies demonstrate that AMPK activation inhibits endothelial cell proliferation by elevating p21 and p27 expression. In addition, they show that AMPK regulates endothelial cell migration and differentiation and identify AMPK as an attractive therapeutic target in treating diseases associated with aberrant endothelial cell growth.
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Affiliation(s)
- Kelly J Peyton
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
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64
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Lee JA, Uhlik MT, Moxham CM, Tomandl D, Sall DJ. Modern phenotypic drug discovery is a viable, neoclassic pharma strategy. J Med Chem 2012; 55:4527-38. [PMID: 22409666 DOI: 10.1021/jm201649s] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jonathan A Lee
- Department of Quantitative Biology, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA.
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Kvietys PR, Granger DN. Role of reactive oxygen and nitrogen species in the vascular responses to inflammation. Free Radic Biol Med 2012; 52:556-592. [PMID: 22154653 PMCID: PMC3348846 DOI: 10.1016/j.freeradbiomed.2011.11.002] [Citation(s) in RCA: 213] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 11/04/2011] [Accepted: 11/04/2011] [Indexed: 12/23/2022]
Abstract
Inflammation is a complex and potentially life-threatening condition that involves the participation of a variety of chemical mediators, signaling pathways, and cell types. The microcirculation, which is critical for the initiation and perpetuation of an inflammatory response, exhibits several characteristic functional and structural changes in response to inflammation. These include vasomotor dysfunction (impaired vessel dilation and constriction), the adhesion and transendothelial migration of leukocytes, endothelial barrier dysfunction (increased vascular permeability), blood vessel proliferation (angiogenesis), and enhanced thrombus formation. These diverse responses of the microvasculature largely reflect the endothelial cell dysfunction that accompanies inflammation and the central role of these cells in modulating processes as varied as blood flow regulation, angiogenesis, and thrombogenesis. The importance of endothelial cells in inflammation-induced vascular dysfunction is also predicated on the ability of these cells to produce and respond to reactive oxygen and nitrogen species. Inflammation seems to upset the balance between nitric oxide and superoxide within (and surrounding) endothelial cells, which is necessary for normal vessel function. This review is focused on defining the molecular targets in the vessel wall that interact with reactive oxygen species and nitric oxide to produce the characteristic functional and structural changes that occur in response to inflammation. This analysis of the literature is consistent with the view that reactive oxygen and nitrogen species contribute significantly to the diverse vascular responses in inflammation and supports efforts that are directed at targeting these highly reactive species to maintain normal vascular health in pathological conditions that are associated with acute or chronic inflammation.
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Affiliation(s)
- Peter R Kvietys
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - D Neil Granger
- Department of Molecular & Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130-3932, USA.
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Nagai A, Sado T, Naruse K, Noguchi T, Haruta S, Yoshida S, Tanase Y, Tsunemi T, Kobayashi H. Antiangiogenic-Induced Hypertension: The Molecular Basis of Signaling Network. Gynecol Obstet Invest 2012; 73:89-98. [DOI: 10.1159/000334458] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 10/16/2011] [Indexed: 01/09/2023]
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67
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Zhang QX, Nakhaei-Nejad M, Haddad G, Wang X, Loutzenhiser R, Murray AG. Glomerular endothelial PI3 kinase-α couples to VEGFR2, but is not required for eNOS activation. Am J Physiol Renal Physiol 2011; 301:F1242-50. [DOI: 10.1152/ajprenal.00662.2010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Vascular endothelial growth factor (VEGF)-dependent signals are central to many endothelial cell (EC) functions, including survival and regulation of vascular tone. Akt and endothelial nitric oxide synthase (eNOS) activity are implicated to mediate these effects. Dysregulated signaling is characteristic of endothelial dysfunction that sensitizes the glomerular microvasculature to injury. Signaling intermediates that couple VEGF stimulation to eNOS activity remain unclear; hence, we examined the PI3 kinase isoforms implicated to regulate these enzymes. Using a combination of small molecule inhibitors and RNAi to study responses to VEGF in glomerular EC, we observed that the PI3 kinase p110α catalytic isoform is coupled to VEGFR2 and regulates the bulk of Akt activity. Coimmunoprecipitation experiments support a physical association of p110α with VEGFR2. Downstream, Akt-mediated FOXO1 phosphorylation in EC is regulated by p110α. The p110δ isoform contributes a minor amount of VEGF-stimulated Akt activation. However, we observe no effect of p110α or p110δ to regulate VEGF-stimulated eNOS activation via Akt-mediated phosphorylation on eNOS Ser1177, or NO-mediated vasodilation of the afferent arteriole ex vivo. VEGFR2-stimulated eNOS activation and NO production are inhibited by Compound C, an inhibitor of AMP-stimulated kinase, independent of PI3 kinase signaling. PI3 kinase-α/δ-mediated signaling downstream of VEGFR2 activation regulates Akt-dependent survival signals, but our data suggest it is not required to activate eNOS or to elicit NO production in glomerular EC.
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Affiliation(s)
- Qiu-Xia Zhang
- Department of Medicine, University of Alberta, Edmonton; and
| | | | - George Haddad
- Department of Medicine, University of Alberta, Edmonton; and
| | - Xuemei Wang
- Department of Pharmacology and Therapeutics, University of Calgary, Calgary, AB
| | - Rodger Loutzenhiser
- Department of Pharmacology and Therapeutics, University of Calgary, Calgary, AB
| | - Allan G. Murray
- Department of Medicine, University of Alberta, Edmonton; and
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Hardie DG. AMP-activated protein kinase: an energy sensor that regulates all aspects of cell function. Genes Dev 2011; 25:1895-908. [PMID: 21937710 DOI: 10.1101/gad.17420111] [Citation(s) in RCA: 1212] [Impact Index Per Article: 93.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
AMP-activated protein kinase (AMPK) is a sensor of energy status that maintains cellular energy homeostasis. It arose very early during eukaryotic evolution, and its ancestral role may have been in the response to starvation. Recent work shows that the kinase is activated by increases not only in AMP, but also in ADP. Although best known for its effects on metabolism, AMPK has many other functions, including regulation of mitochondrial biogenesis and disposal, autophagy, cell polarity, and cell growth and proliferation. Both tumor cells and viruses establish mechanisms to down-regulate AMPK, allowing them to escape its restraining influences on growth.
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Affiliation(s)
- D Grahame Hardie
- Division of Cell Signalling and Immunology, College of Life Science, University of Dundee, Scotland, United Kingdom.
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AMP-activated protein kinase (AMPK) beta1beta2 muscle null mice reveal an essential role for AMPK in maintaining mitochondrial content and glucose uptake during exercise. Proc Natl Acad Sci U S A 2011; 108:16092-7. [PMID: 21896769 DOI: 10.1073/pnas.1105062108] [Citation(s) in RCA: 329] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
AMP-activated protein kinase (AMPK) β1 or β2 subunits are required for assembling of AMPK heterotrimers and are important for regulating enzyme activity and cellular localization. In skeletal muscle, α2β2γ3-containing heterotrimers predominate. However, compensatory up-regulation and redundancy of AMPK subunits in whole-body AMPK α2, β2, and γ3 null mice has made it difficult to determine the physiological importance of AMPK in regulating muscle metabolism, because these models have normal mitochondrial content, contraction-stimulated glucose uptake, and insulin sensitivity. In the current study, we generated mice lacking both AMPK β1 and β2 isoforms in skeletal muscle (β1β2M-KO). β1β2M-KO mice are physically inactive and have a drastically impaired capacity for treadmill running that is associated with reductions in skeletal muscle mitochondrial content but not a fiber-type switch. Interestingly, young β1β2M-KO mice fed a control chow diet are not obese or insulin resistant but do have impaired contraction-stimulated glucose uptake. These data demonstrate an obligatory role for skeletal muscle AMPK in maintaining mitochondrial capacity and contraction-stimulated glucose uptake, findings that were not apparent in mice with single mutations or deletions in muscle α, β, or γ subunits.
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Zhu Z, Fu C, Li X, Song Y, Li C, Zou M, Guan Y, Zhu Y. Prostaglandin E2 promotes endothelial differentiation from bone marrow-derived cells through AMPK activation. PLoS One 2011; 6:e23554. [PMID: 21876756 PMCID: PMC3158081 DOI: 10.1371/journal.pone.0023554] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Accepted: 07/20/2011] [Indexed: 01/08/2023] Open
Abstract
Prostaglandin E2 (PGE2) has been reported to modulate angiogenesis, the process of new blood vessel formation, by promoting proliferation, migration and tube formation of endothelial cells. Endothelial progenitor cells are known as a subset of circulating bone marrow mononuclear cells that have the capacity to differentiate into endothelial cells. However, the mechanism underlying the stimulatory effects of PGE2 and its specific receptors on bone marrow-derived cells (BMCs) in angiogenesis has not been fully characterized. Treatment with PGE2 significantly increased the differentiation and migration of BMCs. Also, the markers of differentiation to endothelial cells, CD31 and von Willebrand factor, and the genes associated with migration, matrix metalloproteinases 2 and 9, were significantly upregulated. This upregulation was abolished by dominant-negative AMP-activated protein kinase (AMPK) and AMPK inhibitor but not protein kinase, a inhibitor. As a functional consequence of differentiation and migration, the tube formation of BMCs was reinforced. Along with altered BMCs functions, phosphorylation and activation of AMPK and endothelial nitric oxide synthase, the target of activated AMPK, were both increased which could be blocked by EP4 blocking peptide and simulated by the agonist of EP4 but not EP1, EP2 or EP3. The pro-angiogenic role of PGE2 could be repressed by EP4 blocking peptide and retarded in EP4+/− mice. Therefore, by promoting the differentiation and migration of BMCs, PGE2 reinforced their neovascularization by binding to the receptor of EP4 in an AMPK-dependent manner. PGE2 may have clinical value in ischemic heart disease.
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Affiliation(s)
- Zhenjiu Zhu
- Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
| | - Chenglai Fu
- Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
| | - Xiaoxia Li
- Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
| | - Yimeng Song
- Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
| | - Chenghong Li
- Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
| | - Minghui Zou
- Division of Endocrinology and Diabetes, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Youfei Guan
- Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
- * E-mail: (YZ); (YG)
| | - Yi Zhu
- Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
- * E-mail: (YZ); (YG)
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71
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Reihill JA, Ewart MA, Salt IP. The role of AMP-activated protein kinase in the functional effects of vascular endothelial growth factor-A and -B in human aortic endothelial cells. Vasc Cell 2011; 3:9. [PMID: 21507243 PMCID: PMC3094250 DOI: 10.1186/2045-824x-3-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 04/20/2011] [Indexed: 02/08/2023] Open
Abstract
Background Vascular endothelial growth factors (VEGFs) are key regulators of endothelial cell function and angiogenesis. We and others have previously demonstrated that VEGF-A stimulates AMP-activated protein kinase (AMPK) in cultured endothelial cells. Furthermore, AMPK has been reported to regulate VEGF-mediated angiogenesis. The role of AMPK in the function of VEGF-B remains undetermined, as does the role of AMPK in VEGF-stimulated endothelial cell proliferation, a critical process in angiogenesis. Methods Human aortic endothelial cells (HAECs) were incubated with VEGF-A and VEGF-B prior to examination of HAEC AMPK activity, proliferation, migration, fatty acid oxidation and fatty acid transport. The role of AMPK in the functional effects of VEGF-A and/or VEGF-B was assessed after downregulation of AMPK activity with chemical inhibitors or infection with adenoviruses expressing a dominant negative mutant AMPK. Results Incubation of HAECs with VEGF-B rapidly stimulated AMPK activity in a manner sensitive to an inhibitor of Ca2+/calmodulin-dependent kinase kinase (CaMKK), without increasing phosphorylation of endothelial NO synthase (eNOS) phosphorylation at Ser1177. Downregulation of AMPK abrogated HAEC proliferation in response to VEGF-A or VEGF-B. However, activation of AMPK by agents other than VEGF inhibited proliferation. Downregulation of AMPK abrogated VEGF-A-stimulated HAEC migration, whereas infection with adenoviruses expressing constitutively active mutant AMPK stimulated chemokinesis. Neither VEGF-A nor VEGF-B had any significant effect on HAEC fatty acid oxidation, yet prolonged incubation with VEGF-A stimulated fatty acid uptake in an AMPK-dependent manner. Inhibition of eNOS abrogated VEGF-mediated proliferation and migration, but was without effect on VEGF-stimulated fatty acid transport, ERK or Akt phosphorylation. Conclusions These data suggest that VEGF-B stimulates AMPK by a CaMKK-dependent mechanism and stimulation of AMPK activity is required for proliferation in response to either VEGF-A or VEGF-B and migration in response to VEGF-A. AMPK activation alone was not sufficient, however, to stimulate proliferation in the absence of VEGF. VEGF-stimulated NO synthesis is required for the stimulation of proliferation by VEGF-A or VEGF-B, yet this may be independent of eNOS Ser1177 phosphorylation.
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Affiliation(s)
- James A Reihill
- Institute of Cardiovascular & Medical Sciences, College of Medicine, Veterinary & Life Sciences, University of Glasgow, Glasgow UK.
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Kim M, Tian R. Targeting AMPK for cardiac protection: opportunities and challenges. J Mol Cell Cardiol 2010; 51:548-53. [PMID: 21147121 DOI: 10.1016/j.yjmcc.2010.12.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 11/30/2010] [Accepted: 12/06/2010] [Indexed: 01/01/2023]
Abstract
AMP-activated protein kinase (AMPK) regulates cellular energy homeostasis and multiple biological processes in cell growth and survival, hence an attractive drug target. AMPK is a heterotrimeric protein consisting of α catalytic, β and γ regulatory subunits; two isoforms of each subunit are present in the heart. Studies using both genetic and pharmacological approaches have demonstrated important roles of AMPK in protecting the heart during ischemia/reperfusion injury as well as in pathological hypertrophy and failure. There is also emerging evidence suggesting isoform-specific function of AMPK, e.g. mutations of the γ2 subunit cause human cardiomyopathy. Thus, strategies avoiding the undesirable effects of altering γ2-AMPK activity, such as isoform selective activation of AMPK may lead to cardioprotective therapies with greater efficacy and safety. This article is part of a special issue entitled "Key Signaling Molecules in Hypertrophy and Heart Failure."
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Affiliation(s)
- Maengjo Kim
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA
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Thors B, Halldórsson H, Thorgeirsson G. eNOS activation mediated by AMPK after stimulation of endothelial cells with histamine or thrombin is dependent on LKB1. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1813:322-31. [PMID: 21145922 DOI: 10.1016/j.bbamcr.2010.12.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 11/26/2010] [Accepted: 12/01/2010] [Indexed: 10/18/2022]
Abstract
Reports on the role of AMP-activated protein kinase (AMPK) in thrombin-mediated activation of endothelial nitric-oxide synthase (eNOS) in endothelial cells have been conflicting. Previously, we have shown that under culture conditions that allow reduction of ATP-levels after stimulation, activation of AMPK contributes to eNOS phosphorylation and activation in endothelial cells after treatment with thrombin. In this paper we examined the signaling pathways mediating phosphorylation and activation of eNOS after stimulation of cultured human umbilical vein endothelial cells (HUVEC) with histamine and the role of LKB1-AMPK in the signaling. In Morgan's medium 199 intracellular ATP was lowered by treatment with histamine or the ionophore A23187 while in medium RMPI 1640 ATP was unchanged after identical treatment. In medium 199 inhibition of Ca(+2)/CaM kinase kinase (CaMKK) by STO-609 only partially inhibited AMPK phosphorylation but after gene silencing of LKB1 with siRNA there was a total inhibition of AMPK phosphorylation by STO-609 after treatment with either histamine or thrombin, demonstrating phosphorylation of AMPK by both upstream kinases, LKB1 and CaMKK. Downregulation of AMPK with siRNA partially inhibited eNOS phosphorylation caused by histamine in cells maintained in medium 199. Downregulation of LKB1 by siRNA inhibited both phosphorylation and activity of eNOS and addition of the AMPK inhibitor Compound C had no further effect on eNOS phosphorylation. When experiments were carried out in medium 1640, STO-609 totally prevented the phosphorylation of AMPK without affecting eNOS phosphorylation. AMPKα2 downregulation resulted in a loss of the integrity of the endothelial monolayer and increased expression of GRP78, indicative of endoplasmic reticular (ER) stress. Downregulation of AMPKα1 had no such effect. The results show that culture conditions affect endothelial signal transduction pathways after histamine stimulation. Under conditions where intracellular ATP is lowered by histamine, AMPK is activated by both LKB1 and CaMKK and, in turn, mediates eNOS phosphorylation in an LKB1 dependent manner. Both AMPKα1 and -α2 are involved in the signaling. Under conditions where intracellular ATP is unchanged after histamine treatment, CaMKK alone activates AMPK and eNOS is phosphorylated and activated independent of AMPK.
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Affiliation(s)
- Brynhildur Thors
- Institute of Pharmacy, Pharmacology and Toxicology, University of Iceland, Hagi Hofsvallagotu 53, Reykjavik, Iceland; Faculty of Medicine, University of Iceland, Reykjavik, Iceland
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Ewart MA, Kennedy S. AMPK and vasculoprotection. Pharmacol Ther 2010; 131:242-53. [PMID: 21111758 DOI: 10.1016/j.pharmthera.2010.11.002] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 11/10/2010] [Indexed: 01/25/2023]
Abstract
AMP-activated protein kinase (AMPK) is proposed to be a key regulator of cellular and organismal metabolism and has reported vasculoprotective effects. In addition, many therapeutic agents used in the treatment of diabetes and atherosclerosis such as metformin, thiazolidinediones and statins may exert their vasculoprotective effects through activation of AMPK. Activation of AMPK has a number of potentially beneficial anti-atherosclerotic effects including reducing adhesion of inflammatory cells to the blood vessel endothelium, reducing lipid accumulation and the proliferation of inflammatory cells caused by oxidised lipids, stimulation of gene expression responsible for cellular antioxidant defenses and stimulation of enzymes responsible for nitric oxide formation. In humans and animals the AMPK cascade triggers vascular protective mechanisms that have been shown to reduce myocardial ischaemic injury and mutations in AMPK can cause familial hypertrophic cardiomyopathy. Taken together, these data suggest that activation and function of AMPK contributes to cardiovascular health. In this review we propose to focus on the vasculoprotective effects of AMPK, the evidence for AMPK activation with currently used therapeutic agents and the potential for agents which specifically activate AMPK as a treatment for vascular disease.
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Affiliation(s)
- Marie-Ann Ewart
- College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
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Viollet B, Horman S, Leclerc J, Lantier L, Foretz M, Billaud M, Giri S, Andreelli F. AMPK inhibition in health and disease. Crit Rev Biochem Mol Biol 2010; 45:276-95. [PMID: 20522000 DOI: 10.3109/10409238.2010.488215] [Citation(s) in RCA: 304] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
All living organisms depend on dynamic mechanisms that repeatedly reassess the status of amassed energy, in order to adapt energy supply to demand. The AMP-activated protein kinase (AMPK) alphabetagamma heterotrimer has emerged as an important integrator of signals managing energy balance. Control of AMPK activity involves allosteric AMP and ATP regulation, auto-inhibitory features and phosphorylation of its catalytic (alpha) and regulatory (beta and gamma) subunits. AMPK has a prominent role not only as a peripheral sensor but also in the central nervous system as a multifunctional metabolic regulator. AMPK represents an ideal second messenger for reporting cellular energy state. For this reason, activated AMPK acts as a protective response to energy stress in numerous systems. However, AMPK inhibition also actively participates in the control of whole body energy homeostasis. In this review, we discuss recent findings that support the role and function of AMPK inhibition under physiological and pathological states.
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Affiliation(s)
- Benoit Viollet
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, Paris, France.
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