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Zang J, Liu Y, Li W, Xiao D, Zhang Y, Luo Y, Liang W, Liu F, Wei W. Voluntary exercise increases adult hippocampal neurogenesis by increasing GSK-3β activity in mice. Neuroscience 2017; 354:122-135. [PMID: 28456716 DOI: 10.1016/j.neuroscience.2017.04.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 04/18/2017] [Accepted: 04/18/2017] [Indexed: 02/06/2023]
Abstract
Exercise has been proven to promote learning and memory, and is closely related to increased adult neurogenesis in the hippocampus. In our study, the β subunit of Glycogen synthase kinase-3 (GSK3β) can be significantly regulated by exercise, and the modulation of GSK3β activity can enhance adult neurogenesis and memory. To explore the mechanism by which exercise can improve cognitive function and adult neurogenesis, and the role GSK3β plays in this process, we established a mouse model of voluntary exercise to examine the expression and activity of GSK3β, and its associated signaling pathways, in the hippocampus dentate gyrus. The results showed an obvious increase in adult neurogenesis and cognitive functions, and the up-regulation of GSK3β, after exercise. The activity of the insulin pathway, which negatively regulates GSK3β, was also increased. Moreover, our results showed that the dopamine D1 receptor (DARP D1) pathway and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) were also activated, which indicates a relationship between GSK3β and neurogenesis. Overall, our findings demonstrated that voluntary exercise promotes cognition and neurogenesis in the adult mouse dentate gyrus by the regulation of GSK3β expression and activity, which may be implemented through the DARP D1 receptor-signaling pathway.
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Affiliation(s)
- Jiankun Zang
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou 510632, PR China
| | - Yinghua Liu
- Department of Pharmacology, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou 511436, PR China
| | - Wei Li
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou 510632, PR China
| | - Di Xiao
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou 510632, PR China
| | - Yingcheng Zhang
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou 510632, PR China
| | - Yuxiang Luo
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou 510632, PR China
| | - Wanying Liang
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou 510632, PR China
| | - Fei Liu
- Department of Neurochemistry, Inge-Grundke Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA
| | - Wei Wei
- Key Laboratory of State Administration of Traditional Chinese Medicine of China, Department of Pathophysiology, School of Medicine, Institute of Brain Research, Jinan University, Guangzhou 510632, PR China.
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Holland WL, Xia JY, Johnson JA, Sun K, Pearson MJ, Sharma AX, Quittner-Strom E, Tippetts TS, Gordillo R, Scherer PE. Inducible overexpression of adiponectin receptors highlight the roles of adiponectin-induced ceramidase signaling in lipid and glucose homeostasis. Mol Metab 2017; 6:267-275. [PMID: 28271033 PMCID: PMC5323887 DOI: 10.1016/j.molmet.2017.01.002] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 12/27/2016] [Accepted: 01/05/2017] [Indexed: 02/06/2023] Open
Abstract
Objective Adiponectin and the signaling induced by its cognate receptors, AdipoR1 and AdipoR2, have garnered attention for their ability to promote insulin sensitivity and oppose steatosis. Activation of these receptors promotes the deacylation of ceramide, a lipid metabolite that appears to play a causal role in impairing insulin signaling. Methods Here, we have developed transgenic mice that overexpress AdipoR1 or AdipoR2 under the inducible control of a tetracycline response element. These represent the first inducible genetic models that acutely manipulate adiponectin receptor signaling in adult mouse tissues, which allows us to directly assess AdipoR signaling on glucose and lipid metabolism. Results Overexpression of either adiponectin receptor isoform in the adipocyte or hepatocyte is sufficient to enhance ceramidase activity, whole body glucose metabolism, and hepatic insulin sensitivity, while opposing hepatic steatosis. Importantly, metabolic improvements fail to occur in an adiponectin knockout background. When challenged with a leptin-deficient genetic model of type 2 diabetes, AdipoR2 expression in adipose or liver is sufficient to reverse hyperglycemia and glucose intolerance. Conclusion These observations reveal that adiponectin is critical for AdipoR-induced ceramidase activation which enhances hepatic glucose and lipid metabolism via rapidly acting “cross-talk” between liver and adipose tissue sphingolipids. Adiponectin receptor signaling in adipose prompts beneficial effects on whole-body glucose and lipid metabolism. The small molecule adiponectin receptor antagonist AdipoRon lowers hepatic ceramides. Depletion of ceramides in adipocytes results in diminished hepatic ceramide accumulation. Depletion of ceramides in hepatocytes results in diminished adipose sphingolipid accumulation. Adiponectin is essential for the beneficial effects of adiponectin receptors on glucose, ceramide, and lipid metabolism.
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Affiliation(s)
- William L Holland
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA.
| | - Jonathan Y Xia
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Joshua A Johnson
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Kai Sun
- Center for Metabolic and Degenerative Diseases, Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Mackenzie J Pearson
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Ankit X Sharma
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Ezekiel Quittner-Strom
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Trevor S Tippetts
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Ruth Gordillo
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA; Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
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Vanhoutte PM, Shimokawa H, Feletou M, Tang EHC. Endothelial dysfunction and vascular disease - a 30th anniversary update. Acta Physiol (Oxf) 2017; 219:22-96. [PMID: 26706498 DOI: 10.1111/apha.12646] [Citation(s) in RCA: 556] [Impact Index Per Article: 79.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/27/2015] [Accepted: 12/17/2015] [Indexed: 02/06/2023]
Abstract
The endothelium can evoke relaxations of the underlying vascular smooth muscle, by releasing vasodilator substances. The best-characterized endothelium-derived relaxing factor (EDRF) is nitric oxide (NO) which activates soluble guanylyl cyclase in the vascular smooth muscle cells, with the production of cyclic guanosine monophosphate (cGMP) initiating relaxation. The endothelial cells also evoke hyperpolarization of the cell membrane of vascular smooth muscle (endothelium-dependent hyperpolarizations, EDH-mediated responses). As regards the latter, hydrogen peroxide (H2 O2 ) now appears to play a dominant role. Endothelium-dependent relaxations involve both pertussis toxin-sensitive Gi (e.g. responses to α2 -adrenergic agonists, serotonin, and thrombin) and pertussis toxin-insensitive Gq (e.g. adenosine diphosphate and bradykinin) coupling proteins. New stimulators (e.g. insulin, adiponectin) of the release of EDRFs have emerged. In recent years, evidence has also accumulated, confirming that the release of NO by the endothelial cell can chronically be upregulated (e.g. by oestrogens, exercise and dietary factors) and downregulated (e.g. oxidative stress, smoking, pollution and oxidized low-density lipoproteins) and that it is reduced with ageing and in the course of vascular disease (e.g. diabetes and hypertension). Arteries covered with regenerated endothelium (e.g. following angioplasty) selectively lose the pertussis toxin-sensitive pathway for NO release which favours vasospasm, thrombosis, penetration of macrophages, cellular growth and the inflammatory reaction leading to atherosclerosis. In addition to the release of NO (and EDH, in particular those due to H2 O2 ), endothelial cells also can evoke contraction of the underlying vascular smooth muscle cells by releasing endothelium-derived contracting factors. Recent evidence confirms that most endothelium-dependent acute increases in contractile force are due to the formation of vasoconstrictor prostanoids (endoperoxides and prostacyclin) which activate TP receptors of the vascular smooth muscle cells and that prostacyclin plays a key role in such responses. Endothelium-dependent contractions are exacerbated when the production of nitric oxide is impaired (e.g. by oxidative stress, ageing, spontaneous hypertension and diabetes). They contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive and diabetic patients. In addition, recent data confirm that the release of endothelin-1 can contribute to endothelial dysfunction and that the peptide appears to be an important contributor to vascular dysfunction. Finally, it has become clear that nitric oxide itself, under certain conditions (e.g. hypoxia), can cause biased activation of soluble guanylyl cyclase leading to the production of cyclic inosine monophosphate (cIMP) rather than cGMP and hence causes contraction rather than relaxation of the underlying vascular smooth muscle.
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Affiliation(s)
- P. M. Vanhoutte
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy; Li Ka Shing Faculty of Medicine; The University of Hong Kong; Hong Kong City Hong Kong
| | - H. Shimokawa
- Department of Cardiovascular Medicine; Tohoku University; Sendai Japan
| | - M. Feletou
- Department of Cardiovascular Research; Institut de Recherches Servier; Suresnes France
| | - E. H. C. Tang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy; Li Ka Shing Faculty of Medicine; The University of Hong Kong; Hong Kong City Hong Kong
- School of Biomedical Sciences; Li Ka Shing Faculty of Medicine; The University of Hong Kong; Hong Kong City Hong Kong
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Wang L, Zhang S, Cheng H, Lv H, Cheng G, Ci X. Nrf2-mediated liver protection by esculentoside A against acetaminophen toxicity through the AMPK/Akt/GSK3β pathway. Free Radic Biol Med 2016; 101:401-412. [PMID: 27836781 DOI: 10.1016/j.freeradbiomed.2016.11.009] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 11/01/2016] [Accepted: 11/02/2016] [Indexed: 12/13/2022]
Abstract
Acetaminophen (APAP) overdose accounts for the majority of acute liver failure cases, and oxidative stress plays a key role in its toxic effects. Esculentoside A (EsA) has anti-oxidant activities, but its therapeutic potential for APAP hepatotoxicity remains unknown. This study aimed to assess the protective effects and mechanism of EsA against APAP-induced hepatotoxicity in vitro and in vivo. In vitro, EsA treatment inhibited APAP- or H2O2-induced cytotoxicity, H2O2 and O2- production, glutathione (GSH) depletion and apoptosis dependent on nuclear factor erythroid-2-related factor 2 (Nrf2) activation in HepG2 cells. Moreover, EsA significantly increased the phosphorylation of AMP-activated protein kinase (AMPK) and serine/threonine kinase (Akt), as well as glycogen synthase kinase 3 beta (GSK-3β) inhibitory phosphorylation at Ser9. Furthermore, an AMPK inhibitor (compound c) abolished the effects of EsA on AKT phosphorylation, GSK-3β inactivation, Nrf2 nuclear translocation and cytoprotection. With regard to APAP-induced acute liver injury, EsA attenuated the APAP-stimulated increases in the serum ALT and AST levels, as well as centrilobular necrosis and GSH depletion in the mice. In addition, it decreased the GSSG level, GSSG-to-GSH ratio, and the phosphorylation and mitochondrial translocation of c-Jun N-terminal kinase (JNK). Further, the protective potential of EsA against mitochondrial dysfunction was exhibited not only by inhibiting Bax mitochondrial translocation and the release of mitochondrial inter-membrane proteins, such as apoptosis-inducing factor (AIF), but also by activating Nrf2/HO-1. Collectively, our findings suggest that EsA has protective potential against APAP toxicity by potentiating the Nrf2-regulated survival mechanism through the AMPK/Akt/GSK3β pathway.
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Affiliation(s)
- Lidong Wang
- Institute of Translational Medicine, The First Hospital, Jilin University, Changchun 130001, China
| | - Songling Zhang
- Department of Obstetrics and Gynecology, the First Hospital of Jilin University, Changchun 130021, China
| | - Hang Cheng
- Institute of Translational Medicine, The First Hospital, Jilin University, Changchun 130001, China
| | - Hongming Lv
- Institute of Translational Medicine, The First Hospital, Jilin University, Changchun 130001, China
| | - Genhong Cheng
- Institute of Translational Medicine, The First Hospital, Jilin University, Changchun 130001, China; Center of Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, China; Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA 90095, USA
| | - Xinxin Ci
- Institute of Translational Medicine, The First Hospital, Jilin University, Changchun 130001, China.
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Almabrouk TAM, Ugusman AB, Katwan OJ, Salt IP, Kennedy S. Deletion of AMPKα1 attenuates the anticontractile effect of perivascular adipose tissue (PVAT) and reduces adiponectin release. Br J Pharmacol 2016; 174:3398-3410. [PMID: 27668984 DOI: 10.1111/bph.13633] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 08/23/2016] [Accepted: 08/29/2016] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND AND PURPOSE Perivascular adipose tissue (PVAT) surrounds most blood vessels and secretes numerous active substances, including adiponectin, which produce a net anticontractile effect in healthy individuals. AMPK is a key mediator of cellular energy balance and may mediate the vascular effects of adiponectin. In this study, we investigated the role of AMPK within PVAT in mediating the anticontractile effect of PVAT. EXPERIMENTAL APPROACH Endothelium-denuded aortic rings from wild-type (WT; Sv129) and α1 AMPK knockout (KO) mice were mounted on a wire myograph. Dose-response curves to the AMPK-independent vasodilator cromakalim were studied in vessels with and without PVAT, and effect of pre-incubation with conditioned media and adiponectin on relaxation was also studied. The effect of AMPKα1 KO on the secretory profile of PVAT was assessed by elisa. KEY RESULTS Thoracic aortic PVAT from KO mice was morphologically indistinct from that of WT and primarily composed of brown adipose tissue. PVAT augmented relaxation to cromakalim in WT but not KO aortic rings. Addition of WT PVAT augmented relaxation in KO aortic rings but KO PVAT had no effect in WT rings. PVAT from KO mice secreted significantly less adiponectin and addition of adiponectin to either KO or WT aortic rings without PVAT augmented relaxation to cromakalim. An adiponectin blocking peptide significantly attenuated relaxation in WT rings with PVAT but not in KO rings. CONCLUSIONS AND IMPLICATIONS AMPKα1 has a critical role in maintaining the anticontractile actions of PVAT; an effect independent of the endothelium but likely mediated through altered adiponectin secretion or sensitivity. LINKED ARTICLES This article is part of a themed section on Molecular Mechanisms Regulating Perivascular Adipose Tissue - Potential Pharmacological Targets? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.20/issuetoc.
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Affiliation(s)
- Tarek A M Almabrouk
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.,Department of Pharmacology, School of Medicine, University of Zawia, Zawia, Libya
| | - Azizah B Ugusman
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Omar J Katwan
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.,Department of Biochemistry, College of Medicine, University of Diyala, Baqubah, Iraq
| | - Ian P Salt
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Simon Kennedy
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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Controls of Nuclear Factor-Kappa B Signaling Activity by 5'-AMP-Activated Protein Kinase Activation With Examples in Human Bladder Cancer Cells. Int Neurourol J 2016; 20:182-187. [PMID: 27706018 PMCID: PMC5083836 DOI: 10.5213/inj.1632718.359] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 09/26/2016] [Indexed: 02/02/2023] Open
Abstract
Generally, both lipopolysaccharide (LPS)- and hypoxia-induced nuclear factor kappa B (NF-κB) effects are alleviated through differential posttranslational modification of NF-κB phosphorylation after pretreatment with 5´-AMP-activated protein kinase (AMPK) activators such as 5´-aminoimidazole-4-carboxamide ribonucleotide (AICAR) or the hypoglycemic agent metformin. We found that AICAR or metformin acts as a regulator of LPS/NF-κB-or hypoxia/NF-κB-mediated cyclooxygenase induction by an AMPK-dependent mechanism with interactions between p65-NF-κB phosphorylation and acetylation, including in a human bladder cancer cell line (T24). In summary, we highlighted the regulatory interactions of AMPK activity on NF-κB induction, particularly in posttranslational phosphorylation and acetylation of NF-κB under inflammatory conditions or hypoxia environment.
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Qi D, Tang X, He J, Wang D, Zhao Y, Deng W, Deng X, Zhou G, Xia J, Zhong X, Pu S. Omentin protects against LPS-induced ARDS through suppressing pulmonary inflammation and promoting endothelial barrier via an Akt/eNOS-dependent mechanism. Cell Death Dis 2016; 7:e2360. [PMID: 27607575 PMCID: PMC5059868 DOI: 10.1038/cddis.2016.265] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 07/25/2016] [Accepted: 07/25/2016] [Indexed: 12/18/2022]
Abstract
Acute respiratory distress syndrome (ARDS) is characterized by increased pulmonary inflammation and endothelial barrier permeability. Omentin has been shown to benefit obesity-related systemic vascular diseases; however, its effects on ARDS are unknown. In the present study, the level of circulating omentin in patients with ARDS was assessed to appraise its clinical significance in ARDS. Mice were subjected to systemic administration of adenoviral vector expressing omentin (Ad-omentin) and one-shot treatment of recombinant human omentin (rh-omentin) to examine omentin's effects on lipopolysaccharide (LPS)-induced ARDS. Pulmonary endothelial cells (ECs) were treated with rh-omentin to further investigate its underlying mechanism. We found that a decreased level of circulating omentin negatively correlated with white blood cells and procalcitonin in patients with ARDS. Ad-omentin protected against LPS-induced ARDS by alleviating the pulmonary inflammatory response and endothelial barrier injury in mice, accompanied by Akt/eNOS pathway activation. Treatment of pulmonary ECs with rh-omentin attenuated inflammatory response and restored adherens junctions (AJs), and cytoskeleton organization promoted endothelial barrier after LPS insult. Moreover, the omentin-mediated enhancement of EC survival and differentiation was blocked by the Akt/eNOS pathway inactivation. Therapeutic rh-omentin treatment also effectively protected against LPS-induced ARDS via the Akt/eNOS pathway. Collectively, these data indicated that omentin protects against LPS-induced ARDS by suppressing inflammation and promoting the pulmonary endothelial barrier, at least partially, through an Akt/eNOS-dependent mechanism. Therapeutic strategies aiming to restore omentin levels may be valuable for the prevention or treatment of ARDS.
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Affiliation(s)
- Di Qi
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xumao Tang
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jing He
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Daoxin Wang
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yan Zhao
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Wang Deng
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xinyu Deng
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Guoqi Zhou
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jing Xia
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xi Zhong
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Shenglan Pu
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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Park SY, Park MY, Park HG, Lee KJ, Kook MS, Kim WJ, Jung JY. Nitric oxide-induced autophagy and the activation of activated protein kinase pathway protect against apoptosis in human dental pulp cells. Int Endod J 2016; 50:260-270. [DOI: 10.1111/iej.12616] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 02/07/2016] [Indexed: 01/09/2023]
Affiliation(s)
- S. Y. Park
- Dental Science Research Institute and Medical Research Center for Biomineralization Disorders; Chonnam National University; Gwangju Korea
- Department of Oral Physiology; Chonnam National University; Gwangju Korea
- School of Dentistry; Chonnam National University; Gwangju Korea
| | - M. Y. Park
- Dental Science Research Institute and Medical Research Center for Biomineralization Disorders; Chonnam National University; Gwangju Korea
- Department of Oral Physiology; Chonnam National University; Gwangju Korea
- School of Dentistry; Chonnam National University; Gwangju Korea
| | - H. G. Park
- Dental Science Research Institute and Medical Research Center for Biomineralization Disorders; Chonnam National University; Gwangju Korea
- Department of Oral Physiology; Chonnam National University; Gwangju Korea
- School of Dentistry; Chonnam National University; Gwangju Korea
| | - K. J. Lee
- Department of Convergence Medicine; Asan Institute for Life Sciences; Asan Medical Center; University of Ulsan College of Medicine; Seoul Korea
| | - M. S. Kook
- Dental Science Research Institute and Medical Research Center for Biomineralization Disorders; Chonnam National University; Gwangju Korea
- School of Dentistry; Chonnam National University; Gwangju Korea
- Department of Oral and Maxillofacial Surgery; Chonnam National University; Gwangju Korea
| | - W. J. Kim
- Dental Science Research Institute and Medical Research Center for Biomineralization Disorders; Chonnam National University; Gwangju Korea
- Department of Oral Physiology; Chonnam National University; Gwangju Korea
- School of Dentistry; Chonnam National University; Gwangju Korea
| | - J. Y. Jung
- Department of Oral Physiology; Chonnam National University; Gwangju Korea
- School of Dentistry; Chonnam National University; Gwangju Korea
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Chang W, Li K, Guan F, Yao F, Yu Y, Zhang M, Hatch GM, Chen L. Berberine Pretreatment Confers Cardioprotection Against Ischemia-Reperfusion Injury in a Rat Model of Type 2 Diabetes. J Cardiovasc Pharmacol Ther 2016; 21:486-94. [PMID: 26846272 DOI: 10.1177/1074248415627873] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/28/2015] [Indexed: 11/17/2022]
Abstract
Preclinical and clinical studies have demonstrated that berberine (BBR) improves diabetic complications and reduces mortality of patients with congestive heart failure. The therapeutic effects of BBR have been reported to be mediated by its regulation of adenosine monophosphate (AMP)-activated protein kinase (AMPK). We previously reported that BBR protects against ischemia-reperfusion injury via regulating AMPK activity in both ischemic and nonischemic areas of the rat heart. Since diabetic hearts are more sensitive to ischemia-reperfusion injury, we examined whether BBR treatment exhibited cardioprotective effects in the diabetic heart. Type 2 diabetic rats were pretreated plus or minus BBR for 7 days and subjected to 30-minute ischemia followed by 120-minute reperfusion. Pretreatment of type 2 diabetic rats with BBR reduced ischemia-reperfusion injury infarct size and attenuated arrhythmia compared to untreated diabetic controls. Subsequent to ischemia-reperfusion, serum triglyceride, total cholesterol, and malondialdehyde levels were reduced by pretreatment of type 2 diabetic rats with BBR compared to untreated diabetic controls. In contrast, serum glucose and superoxide dismutase levels were unaltered. The mechanism for the BBR-mediated cardioprotective effect was examined. Pretreatment with BBR did not alter AMPK activity in ischemic areas at risk but increased AMPK activity in nonischemic areas compared to untreated diabetic controls. The increased AMPK activity in nonischemic areas was due an elevated ratio of AMP to adenosine triphosphate (ATP) and adenosine diphosphate to ATP. In addition, pretreatment with BBR increased protein kinase B (AKT) phosphorylation and reduced glycogen synthase kinase 3β (GSK3β) activity in nonischemic areas compared to untreated diabetic controls. These findings indicate that BBR protects the diabetic heart from ischemia-reperfusion injury. In addition, BBR may mediate this cardioprotective effect through AMPK activation, AKT phosphorylation, and GSK3β inhibition in the nonischemic areas of the diabetic heart.
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Affiliation(s)
- Wenguang Chang
- Department of Pharmacology, College of Basic Medical Sciences, School of Nursing, Jilin University, Changchun, China Department of Pharmacology and Therapeutics, Center for Research and Treatment of Atherosclerosis, University of Manitoba, Winnipeg, Manitoba, Canada DREAM Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada
| | - Kun Li
- Department of Pharmacology, College of Basic Medical Sciences, School of Nursing, Jilin University, Changchun, China
| | - Fengying Guan
- Department of Pharmacology, College of Basic Medical Sciences, School of Nursing, Jilin University, Changchun, China
| | - Fan Yao
- Department of Pharmacology, College of Basic Medical Sciences, School of Nursing, Jilin University, Changchun, China
| | - Yang Yu
- Department of Pharmacology, College of Basic Medical Sciences, School of Nursing, Jilin University, Changchun, China
| | - Ming Zhang
- Department of Pharmacology, College of Basic Medical Sciences, School of Nursing, Jilin University, Changchun, China Department of Pharmacology and Therapeutics, Center for Research and Treatment of Atherosclerosis, University of Manitoba, Winnipeg, Manitoba, Canada DREAM Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada
| | - Grant M Hatch
- Department of Pharmacology, College of Basic Medical Sciences, School of Nursing, Jilin University, Changchun, China Department of Pharmacology and Therapeutics, Center for Research and Treatment of Atherosclerosis, University of Manitoba, Winnipeg, Manitoba, Canada DREAM Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada Department of Biochemistry and Medical Genetics, Center for Research and Treatment of Atherosclerosis, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Li Chen
- Department of Pharmacology, College of Basic Medical Sciences, School of Nursing, Jilin University, Changchun, China
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Dasgupta B, Chhipa RR. Evolving Lessons on the Complex Role of AMPK in Normal Physiology and Cancer. Trends Pharmacol Sci 2015; 37:192-206. [PMID: 26711141 DOI: 10.1016/j.tips.2015.11.007] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 02/08/2023]
Abstract
AMP kinase (AMPK) is an evolutionarily conserved enzyme required for adaptive responses to various physiological and pathological conditions. AMPK executes numerous cellular functions, some of which are often perceived at odds with each other. While AMPK is essential for embryonic growth and development, its full impact in adult tissues is revealed under stressful situations that organisms face in the real world. Conflicting reports about its cellular functions, particularly in cancer, are intriguing and a growing number of AMPK activators are being developed to treat human diseases such as cancer and diabetes. Whether these drugs will have only context-specific benefits or detrimental effects in the treatment of human cancer will be a subject of intense research. Here we review the current state of AMPK research with an emphasis on cancer and discuss the yet unresolved context-dependent functions of AMPK in human cancer.
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Affiliation(s)
- Biplab Dasgupta
- Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
| | - Rishi Raj Chhipa
- Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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Donato AJ, Morgan RG, Walker AE, Lesniewski LA. Cellular and molecular biology of aging endothelial cells. J Mol Cell Cardiol 2015; 89:122-35. [PMID: 25655936 PMCID: PMC4522407 DOI: 10.1016/j.yjmcc.2015.01.021] [Citation(s) in RCA: 326] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 01/05/2015] [Accepted: 01/27/2015] [Indexed: 12/29/2022]
Abstract
Cardiovascular disease (CVD) is the leading cause of death in the United States and aging is a major risk factor for CVD development. One of the major age-related arterial phenotypes thought to be responsible for the development of CVD in older adults is endothelial dysfunction. Endothelial function is modulated by traditional CVD risk factors in young adults, but advancing age is independently associated with the development of vascular endothelial dysfunction. This endothelial dysfunction results from a reduction in nitric oxide bioavailability downstream of endothelial oxidative stress and inflammation that can be further modulated by traditional CVD risk factors in older adults. Greater endothelial oxidative stress with aging is a result of augmented production from the intracellular enzymes NADPH oxidase and uncoupled eNOS, as well as from mitochondrial respiration in the absence of appropriate increases in antioxidant defenses as regulated by relevant transcription factors, such as FOXO. Interestingly, it appears that NFkB, a critical inflammatory transcription factor, is sensitive to this age-related endothelial redox change and its activation induces transcription of pro-inflammatory cytokines that can further suppress endothelial function, thus creating a vicious feed-forward cycle. This review will discuss the two macro-mechanistic processes, oxidative stress and inflammation, that contribute to endothelial dysfunction with advancing age as well as the cellular and molecular events that lead to the vicious cycle of inflammation and oxidative stress in the aged endothelium. Other potential mediators of this pro-inflammatory endothelial phenotype are increases in immune or senescent cells in the vasculature. Of note, genomic instability, telomere dysfunction or DNA damage has been shown to trigger cell senescence via the p53/p21 pathway and result in increased inflammatory signaling in arteries from older adults. This review will discuss the current state of knowledge regarding the emerging concepts of senescence and genomic instability as mechanisms underlying oxidative stress and inflammation in the aged endothelium. Lastly, energy sensitive/stress resistance pathways (SIRT-1, AMPK, mTOR) are altered in endothelial cells and/or arteries with aging and these pathways may modulate endothelial function via key oxidative stress and inflammation-related transcription factors. This review will also discuss what is known about the role of "energy sensing" longevity pathways in modulating endothelial function with advancing age. With the growing population of older adults, elucidating the cellular and molecular mechanisms of endothelial dysfunction with age is critical to establishing appropriate and measured strategies to utilize pharmacological and lifestyle interventions aimed at alleviating CVD risk. This article is part of a Special Issue entitled "SI: CV Aging".
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Affiliation(s)
- Anthony J Donato
- University of Utah, Department of Internal Medicine, Division of Geriatrics, Salt Lake City, UT, USA; Veteran's Affairs Medical Center-Salt Lake City, Geriatrics Research Education and Clinical Center, Salt Lake City, UT, USA.
| | - R Garrett Morgan
- University of Washington, Department of Pathology, Seattle, WA, USA
| | - Ashley E Walker
- University of Utah, Department of Internal Medicine, Division of Geriatrics, Salt Lake City, UT, USA
| | - Lisa A Lesniewski
- University of Utah, Department of Internal Medicine, Division of Geriatrics, Salt Lake City, UT, USA; Veteran's Affairs Medical Center-Salt Lake City, Geriatrics Research Education and Clinical Center, Salt Lake City, UT, USA
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Hernández-Díaz A, Arana-Martínez JC, Carbó R, Espinosa-Cervantes R, Sánchez-Muñoz F. [Omentin: Role in insulin resistance, inflammation and cardiovascular protection]. ARCHIVOS DE CARDIOLOGIA DE MEXICO 2015; 86:233-43. [PMID: 26778502 DOI: 10.1016/j.acmx.2015.09.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 08/14/2015] [Accepted: 09/29/2015] [Indexed: 10/22/2022] Open
Abstract
The omentin is an adipokine, which role is due to the capacity of regulate metabolic (insulin sensitivity) and anti-inflammatory activities, thus conferring vascular protection during obesity and diabetes mellitus type 2. By this, it is important to know the mechanisms by which omentin confers cardiovascular protection, with the purpose of establish omentin a possible therapeutic target or molecule on this scenario.
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Affiliation(s)
- Adrián Hernández-Díaz
- Maestría en Farmacología, Escuela Superior de Medicina, Instituto Politécnico Nacional, México, D.F., México; Departamento de Inmunología, Instituto Nacional de Cardiología Ignacio Chávez, México, D.F., México
| | - Julio C Arana-Martínez
- Departamento de Inmunología, Instituto Nacional de Cardiología Ignacio Chávez, México, D.F., México
| | - Roxana Carbó
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiología Ignacio Chávez, México, D.F., México
| | - Román Espinosa-Cervantes
- Departamento de Producción Agrícola y Animal, Universidad Autónoma Metropolitana, Unidad Xochimilco, México, D.F., México
| | - Fausto Sánchez-Muñoz
- Departamento de Inmunología, Instituto Nacional de Cardiología Ignacio Chávez, México, D.F., México.
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63
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Diversity and plasticity of microglial cells in psychiatric and neurological disorders. Pharmacol Ther 2015; 154:21-35. [DOI: 10.1016/j.pharmthera.2015.06.010] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 06/25/2015] [Indexed: 02/07/2023]
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Liu J, Ye C, Liu W, Zhao W, Zhang YJ, Zhang H, Ying H. AICAR enhances insulin signaling via downregulation of miR-29. Can J Physiol Pharmacol 2015; 94:199-205. [PMID: 26359920 DOI: 10.1139/cjpp-2015-0159] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
As an activator of AMPK, the effect of AICAR on insulin signaling has not been investigated extensively. PI3K-Akt is a critical node involved in the insulin signaling pathway. We observed that concomitant with the activation of AMPK by AICAR, the protein level of PI3K p85α and the insulin-induced phosphorylation of Akt were enhanced in mouse primary hepatocytes. Previously, we identified a group of AMPK-regulated miRNAs in hepatocytes. It is not clear whether miRNAs are related to the regulation of insulin signaling by AMPK. Here, we confirmed the negative regulation of miR-29 family members by AICAR treatment in mouse primary hepatocytes. Our results indicated that p85α is a direct target of miR-29 and is negatively regulated by miR-29b in hepatocytes. In agreement with the findings in vitro, we found that the expression of miR-29 and the protein levels of p85α were inversely correlated in the liver of fasted mice. Overexpression of miR-29b reduced the insulin-induced phosphorylation of Akt in hepatocytes, suggesting that miR-29 could serve as a negative regulator of insulin signaling. Furthermore, we found that overexpression of miR-29 could attenuate the effect of AICAR on p85α expression. Taken together, our results indicated that activation of AMPK may enhance insulin signaling via downregulation of miR-29.
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Affiliation(s)
- Jia Liu
- a 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, 66 Tong-an Road, Tianjin 300070, China
| | - Cheng Ye
- b Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-yang Road, Shanghai 200031, China
| | - Wei Liu
- b Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-yang Road, Shanghai 200031, China
| | - Wei Zhao
- a 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, 66 Tong-an Road, Tianjin 300070, China
| | - Ya-Jing Zhang
- a 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, 66 Tong-an Road, Tianjin 300070, China
| | - Hong Zhang
- a 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, 66 Tong-an Road, Tianjin 300070, China
| | - Hao Ying
- b Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-yang Road, Shanghai 200031, China.,c Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing 100021, China
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Xing SS, Yang XY, Zheng T, Li WJ, Wu D, Chi JY, Bian F, Bai XL, Wu GJ, Zhang YZ, Zhang CT, Zhang YH, Li YS, Jin S. Salidroside improves endothelial function and alleviates atherosclerosis by activating a mitochondria-related AMPK/PI3K/Akt/eNOS pathway. Vascul Pharmacol 2015; 72:141-52. [PMID: 26187353 DOI: 10.1016/j.vph.2015.07.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 06/17/2015] [Accepted: 07/11/2015] [Indexed: 10/23/2022]
Abstract
Salidroside (SAL) is a phenylpropanoid glycoside isolated from the medicinal plant Rhodiola rosea. A recent study has reported that SAL can efficiently decrease atherosclerotic plaque formation in low-density lipoprotein receptor-deficient mice. This study was to investigate the molecular mechanism of antiatherogenic effects of SAL. Given the importance of endothelial nitric oxide synthase (eNOS) in atherosclerosis, we sought to elucidate whether SAL could stimulate eNOS activation and also to explore its upstream signaling pathway. Six-week old apoE(-/-) male mice were fed a high-fat diet for 8weeks and then were administered with SAL for another 8weeks. SAL significantly improved endothelial function associated with increasing eNOS activation, thus reduced the atherosclerotic lesion area. SAL increased eNOS-Ser1177 phosphorylation and decreased eNOS-Thr495 phosphorylation, indicative of eNOS activation in endothelium. The aortic sinus lesions in SAL treated mice displayed reduced inflammation. SAL significantly activated AMP-activated protein kinase (AMPK). Both AMPK inhibitor and AMPK small interfering RNA (siRNA) abolished SAL-induced Akt-Ser473 and eNOS-Ser1177 phosphorylation. In contrast, LY294002, the PI3k/Akt pathway inhibitor, abolished SAL-induced phosphorylation and expression of eNOS. High performance liquid chromatography (HPLC) analysis revealed that SAL decreased cellular ATP content and increased the cellular AMP/ATP ratio, which was associated with the activation of AMPK. SAL was found to decrease the mitochondrial membrane potential (ΔΨm), which is a likely consequence of reduced ATP production. The action of SAL to reduce atherosclerotic lesion formation may at least be attributed to its effect on improving endothelial function by promoting nitric oxide (NO) production, which was associated with mitochondrial depolarization and subsequent activation of the AMPK/PI3K/Akt/eNOS pathway. Taken together, our data described the effects of SAL on mitochondria, which played critical roles in improving endothelial function in atherosclerosis.
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Affiliation(s)
- Sha-Sha Xing
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Xiao-Yan Yang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Tao Zheng
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Wen-Jing Li
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Dan Wu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Jiang-Yang Chi
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Fang Bian
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Xiang-Li Bai
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Guang-Jie Wu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - You-Zhi Zhang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Cun-Tai Zhang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Yong-Hui Zhang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Yong-Sheng Li
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - Si Jin
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China; Department of Endocrinology, Institute of Geriatric Medicine, Liyuan Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430077, China.
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66
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Bilirubin exerts pro-angiogenic property through Akt-eNOS-dependent pathway. Hypertens Res 2015; 38:733-40. [PMID: 26134126 DOI: 10.1038/hr.2015.74] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/30/2015] [Accepted: 05/12/2015] [Indexed: 12/19/2022]
Abstract
Low serum bilirubin levels are associated with the risk of cardiovascular diseases including peripheral artery disease. Bilirubin is known to exert its property such as antioxidant effect or the enhancement of flow-mediated vasodilation, however, bilirubin action on angiogenesis remains unclear. To investigate the molecular mechanism of bilirubin on angiogenic effect, we first employed C57BL/6J mice with unilateral hindlimb ischemia surgery and divided the mice into two groups (vehicle-treated group and bilirubin-treated group). The analysis of laser speckle blood flow demonstrated the enhancement of blood flow recovery in response to ischemia of mice with bilirubin treatment. The density of capillaries was significantly higher in ischemic-adductor muscles of bilirubin-treated mice. The phosphorylated levels of endothelial nitric oxide synthase (eNOS) and Akt were increased in ischemic skeletal muscles of mice with bilirubin treatment compared with vehicle treatment. In in vitro experiments by using human aortic endothelial cells, bilirubin augmented eNOS and Akt phosphorylation, cell proliferation, cell migration and tube formation. These bilirubin actions on endothelial cell activation were inhibited by LY294002, a phosphatidylinositol 3-kinase inhibitor. In conclusion, bilirubin promotes angiogenesis through endothelial cells activation via Akt-eNOS-dependent manner.
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67
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Koska J, Sands M, Burciu C, D'Souza KM, Raravikar K, Liu J, Truran S, Franco DA, Schwartz EA, Schwenke DC, D'Alessio D, Migrino RQ, Reaven PD. Exenatide Protects Against Glucose- and Lipid-Induced Endothelial Dysfunction: Evidence for Direct Vasodilation Effect of GLP-1 Receptor Agonists in Humans. Diabetes 2015; 64:2624-35. [PMID: 25720388 PMCID: PMC4477348 DOI: 10.2337/db14-0976] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 02/17/2015] [Indexed: 01/24/2023]
Abstract
GLP-1 receptor (GLP-1R) agonists may improve endothelial function (EF) via metabolic improvement and direct vascular action. The current study determined the effect of GLP-1R agonist exenatide on postprandial EF in type 2 diabetes and the mechanisms underlying GLP-1R agonist-mediated vasodilation. Two crossover studies were conducted: 36 participants with type 2 diabetes received subcutaneous exenatide or placebo for 11 days and EF, and glucose and lipid responses to breakfast and lunch were determined; and 32 participants with impaired glucose tolerance (IGT) or diet-controlled type 2 diabetes had EF measured before and after intravenous exenatide, with or without the GLP-1R antagonist exendin-9. Mechanisms of GLP-1R agonist action were studied ex vivo on human subcutaneous adipose tissue arterioles and endothelial cells. Subcutaneous exenatide increased postprandial EF independent of reductions in plasma glucose and triglycerides. Intravenous exenatide increased fasting EF, and exendin-9 abolished this effect. Exenatide elicited eNOS activation and NO production in endothelial cells, and induced dose-dependent vasorelaxation and reduced high-glucose or lipid-induced endothelial dysfunction in arterioles ex vivo. These effects were reduced with AMPK inhibition. In conclusion, exenatide augmented postprandial EF in subjects with diabetes and prevented high-glucose and lipid-induced endothelial dysfunction in human arterioles. These effects were largely direct, via GLP-1R and AMPK activation.
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Affiliation(s)
- Juraj Koska
- Department of Medicine, Phoenix VA Health Care System, Phoenix, AZ
| | - Michelle Sands
- Department of Medicine, Phoenix VA Health Care System, Phoenix, AZ
| | - Camelia Burciu
- Department of Medicine, Phoenix VA Health Care System, Phoenix, AZ
| | - Karen M D'Souza
- Department of Medicine, Phoenix VA Health Care System, Phoenix, AZ
| | | | - James Liu
- Department of Medicine, Phoenix VA Health Care System, Phoenix, AZ
| | - Seth Truran
- Department of Medicine, Phoenix VA Health Care System, Phoenix, AZ
| | - Daniel A Franco
- Department of Medicine, Phoenix VA Health Care System, Phoenix, AZ
| | - Eric A Schwartz
- Department of Medicine, Phoenix VA Health Care System, Phoenix, AZ
| | - Dawn C Schwenke
- Department of Medicine, Phoenix VA Health Care System, Phoenix, AZ
| | - David D'Alessio
- Division of Endocrinology, Diabetes and Metabolism, Duke University, Durham, NC
| | | | - Peter D Reaven
- Department of Medicine, Phoenix VA Health Care System, Phoenix, AZ
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Sphingosine-1-Phosphate Is a Novel Regulator of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Activity. PLoS One 2015; 10:e0130313. [PMID: 26079370 PMCID: PMC4469317 DOI: 10.1371/journal.pone.0130313] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 05/18/2015] [Indexed: 01/12/2023] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) attenuates sphingosine-1-phosphate (S1P) signaling in resistance arteries and has emerged as a prominent regulator of myogenic vasoconstriction. This investigation demonstrates that S1P inhibits CFTR activity via adenosine monophosphate-activated kinase (AMPK), establishing a potential feedback link. In Baby Hamster Kidney (BHK) cells expressing wild-type human CFTR, S1P (1μmol/L) attenuates forskolin-stimulated, CFTR-dependent iodide efflux. S1P's inhibitory effect is rapid (within 30 seconds), transient and correlates with CFTR serine residue 737 (S737) phosphorylation. Both S1P receptor antagonism (4μmol/L VPC 23019) and AMPK inhibition (80μmol/L Compound C or AMPK siRNA) attenuate S1P-stimluated (i) AMPK phosphorylation, (ii) CFTR S737 phosphorylation and (iii) CFTR activity inhibition. In BHK cells expressing the ΔF508 CFTR mutant (CFTRΔF508), the most common mutation causing cystic fibrosis, both S1P receptor antagonism and AMPK inhibition enhance CFTR activity, without instigating discernable correction. In summary, we demonstrate that S1P/AMPK signaling transiently attenuates CFTR activity. Since our previous work positions CFTR as a negative S1P signaling regulator, this signaling link may positively reinforce S1P signals. This discovery has clinical ramifications for the treatment of disease states associated with enhanced S1P signaling and/or deficient CFTR activity (e.g. cystic fibrosis, heart failure). S1P receptor/AMPK inhibition could synergistically enhance the efficacy of therapeutic strategies aiming to correct aberrant CFTR trafficking.
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69
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Wang W, Fromm M. Sphingolipids are required for efficient triacylglycerol loss in conjugated linoleic Acid treated adipocytes. PLoS One 2015; 10:e0119005. [PMID: 25906159 PMCID: PMC4407960 DOI: 10.1371/journal.pone.0119005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 01/13/2015] [Indexed: 11/19/2022] Open
Abstract
Conjugated linoleic acid (CLA) reduces adiposity in human and mouse adipocytes. This outcome is achieved through a variety of biological responses including increased energy expenditure and fatty acid oxidation, increased inflammation, repression of fatty acid biosynthesis, attenuated glucose transport, and apoptosis. In the current study, profiling of 261 metabolites was conducted to gain new insights into the biological pathways responding to CLA in 3T3-L1 adipocytes. Sphinganine and sphingosine levels were observed to be highly elevated in CLA treated adipocytes. Exogenous chemicals that increased endogenous ceramide levels decreased lipid levels in adipocytes, and activated AMP-activated protein kinase (AMPK) as well as NF-κB, both of which are typically activated in CLA treated adipocytes. Concurrent inhibition of ceramide de novo biosynthesis and recycling from existing sphingolipid pools attenuated the lipid lowering effect normally associated with responses to CLA, implicating ceramides as an important component of the lipid lowering response in CLA treated adipocytes.
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Affiliation(s)
- Wei Wang
- Department of Animal Science, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Michael Fromm
- Center for Biotechnology, University of Nebraska, Lincoln, Nebraska, United States of America
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García-Prieto CF, Gil-Ortega M, Aránguez I, Ortiz-Besoain M, Somoza B, Fernández-Alfonso MS. Vascular AMPK as an attractive target in the treatment of vascular complications of obesity. Vascul Pharmacol 2015; 67-69:10-20. [PMID: 25869500 DOI: 10.1016/j.vph.2015.02.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 12/23/2014] [Accepted: 02/02/2015] [Indexed: 02/06/2023]
Abstract
The key for the survival of all organisms is the regulation and control of energy metabolism. Thus, several strategies have evolved in each tissue in order to balance nutrient supply with energy demand. Adenosine monophosphate-activated protein kinase (AMPK) is now recognized as a key participant in energy metabolism. It ensures an appropriate energetic supply by promoting energy conserving pathways in detriment of anabolic processes not essential for cell survival. Vascular AMPK plays a critical role in the regulation of blood flow and vascular tone through several mechanisms, including vasodilation by stimulating nitric oxide release in endothelial cells. Since obesity leads to endothelial damage and AMPK dysregulation, AMPK activation might be an important strategy to restore vascular function in cardiometabolic alterations. In the present review we focus on the role of vascular AMPK in both endothelial and smooth muscle cells, paying special attention to its dysregulation in obesity- and high-fat diet-related complications, as well as to the mechanisms and benefits of vascular AMPK activation.
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Affiliation(s)
- C F García-Prieto
- Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad CEU-San Pablo, 28668 Madrid, Spain
| | - M Gil-Ortega
- Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad CEU-San Pablo, 28668 Madrid, Spain
| | - I Aránguez
- Instituto Pluridisciplinar and Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain; Departamento de Bioquímica, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain
| | - M Ortiz-Besoain
- Departamento de Ciencias Farmacéuticas, Facultad de Ciencias, Edificio N3, Universidad Católica del Norte de Chile, Angamos, 0610 Antofagasta, Chile
| | - B Somoza
- Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad CEU-San Pablo, 28668 Madrid, Spain
| | - M S Fernández-Alfonso
- Instituto Pluridisciplinar and Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain.
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Wang DT, He J, Wu M, Li SM, Gao Q, Zeng QP. Artemisinin mimics calorie restriction to trigger mitochondrial biogenesis and compromise telomere shortening in mice. PeerJ 2015; 3:e822. [PMID: 25780774 PMCID: PMC4358698 DOI: 10.7717/peerj.822] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 02/16/2015] [Indexed: 12/23/2022] Open
Abstract
Calorie restriction is known to extend lifespan among organisms by a debating mechanism underlying nitric oxide-driven mitochondrial biogenesis. We report here that nitric oxide generators including artemisinin, sodium nitroprusside, and L-arginine mimics calorie restriction and resembles hydrogen peroxide to initiate the nitric oxide signaling cascades and elicit the global antioxidative responses in mice. The large quantities of antioxidant enzymes are correlated with the low levels of reactive oxygen species, which allow the down-regulation of tumor suppressors and accessory DNA repair partners, eventually leading to the compromise of telomere shortening. Accompanying with the up-regulation of signal transducers and respiratory chain signatures, mitochondrial biogenesis occurs with the elevation of adenosine triphosphate levels upon exposure of mouse skeletal muscles to the mimetics of calorie restriction. In conclusion, calorie restriction-triggered nitric oxide provides antioxidative protection and alleviates telomere attrition via mitochondrial biogenesis, thereby maintaining chromosomal stability and integrity, which are the hallmarks of longevity.
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Affiliation(s)
- Da-Ting Wang
- Tropical Medicine Institute, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jiang He
- Tropical Medicine Institute, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Ming Wu
- School of Life Science, Sun Yat-sen University, Guangzhou, China
| | - Si-Ming Li
- The Second Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Qian Gao
- Tropical Medicine Institute, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Qing-Ping Zeng
- Tropical Medicine Institute, Guangzhou University of Chinese Medicine, Guangzhou, China
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72
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Kar R, Kellogg DL, Roman LJ. Oxidative stress induces phosphorylation of neuronal NOS in cardiomyocytes through AMP-activated protein kinase (AMPK). Biochem Biophys Res Commun 2015; 459:393-7. [PMID: 25732085 DOI: 10.1016/j.bbrc.2015.02.113] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 02/19/2015] [Indexed: 02/05/2023]
Abstract
Neuronal nitric oxide synthase (nNOS) plays a critical role in regulating cardiomyocyte function. nNOS was reported to decrease superoxide production in the myocardium by inhibiting the function of xanthine oxidoreductase. However, the effect of oxidative stress on nNOS in cardiomyocytes has not been determined. We report here that brief exposure of HL-1 cardiomyocytes to hydrogen peroxide (H2O2) induces phosphorylation of nNOS at serine 1412. This increase in phosphorylation was concomitant with increased nitric oxide (NO) production. Prolonged exposure to the oxidant, however, resulted in decreased expression of the protein. H2O2 treatment for short periods also stimulated phosphorylation of AKT and AMPK. H2O2-induced phosphorylation of nNOS was reduced when AMPK activity was inhibited by compound C, suggesting that AMPK is a mediator of oxidative stress-induced phosphorylation of nNOS. However, inhibition of AKT activity by the pan AKT inhibitor, AKTi, had no effect on nNOS phosphorylation caused by H2O2. These data demonstrate the novel regulation of nNOS phosphorylation and expression by oxidative stress.
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Affiliation(s)
- Rekha Kar
- Department of Biochemistry, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229, USA.
| | - Dean L Kellogg
- Department of Biochemistry, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229, USA.
| | - Linda J Roman
- Department of Biochemistry, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229, USA.
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Cheng PW, Ho WY, Su YT, Lu PJ, Chen BZ, Cheng WH, Lu WH, Sun GC, Yeh TC, Hsiao M, Tseng CJ. Resveratrol decreases fructose-induced oxidative stress, mediated by NADPH oxidase via an AMPK-dependent mechanism. Br J Pharmacol 2014; 171:2739-50. [PMID: 24547812 DOI: 10.1111/bph.12648] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 12/19/2013] [Accepted: 12/27/2013] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE Oxidative stress is an important pathogenic factor in the development of hypertension. Resveratrol, the main antioxidant in red wine, improves NO bioavailability and prevents cardiovascular disease. The aim of this study was to examine whether resveratrol decreases the generation of reactive oxygen species (ROS), thereby reducing BP in rats with fructose-induced hypertension. EXPERIMENTAL APPROACH Rats were fed 10% fructose with or without resveratrol (10 mg·kg(-1) ·day(-1) ) for 1 week or for 4 weeks with resveratrol treatment beginning at week 2; systolic BP (SBP) was measured by tail-cuff method. Endogenous in vivo O2 (-) production in the nucleus tractus solitarii (NTS) was determined with dihydroethidium. Real-time PCR and immunoblotting analyses were used to quantify RNA and protein expression levels. KEY RESULTS In fructose-fed rats, ROS levels in the NTS were higher, whereas the NO level was significantly decreased. Also, RNA and protein levels of NADPH oxidase subunits (p67, p22-phox) were elevated, superoxide dismutase 2 (SOD2) reduced and AMP-activated PK (AMPK) T172 phosphorylation levels in the NTS were lower in fructose-fed rats. Treatment with the AMPK activator resveratrol decreased levels of NADPH oxidase subunits and ROS, and increased NO and SOD2 levels in the NTS of fructose-fed rats. Administration of resveratrol, in combination with fructose at week 0 and later at week 2, significantly reduced the SBP of fructose-fed rats. CONCLUSIONS AND IMPLICATIONS Collectively, resveratrol decreased BP through the phosphorylation of AMPK, Akt and neuronal NOS in fructose-fed rats. These novel findings suggest that resveratrol may be a potential pharmacological candidate for the treatment of hypertension.
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Affiliation(s)
- Pei-Wen Cheng
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
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García-Prieto CF, Hernández-Nuño F, Rio DD, Ruiz-Hurtado G, Aránguez I, Ruiz-Gayo M, Somoza B, Fernández-Alfonso MS. High-fat diet induces endothelial dysfunction through a down-regulation of the endothelial AMPK-PI3K-Akt-eNOS pathway. Mol Nutr Food Res 2014; 59:520-32. [PMID: 25421217 DOI: 10.1002/mnfr.201400539] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 11/08/2014] [Accepted: 11/13/2014] [Indexed: 11/11/2022]
Abstract
SCOPE Activation of endothelial adenosine monophosphate-activated protein kinase (AMPK) contributes to increase nitric oxide (NO) availability. The aim of this study was to assess if high-fat diet (HFD)-induced endothelial dysfunction is linked to AMPK deregulation. METHODS AND RESULTS Twelve-week-old Sprague Dawley male rats were assigned either to control (10 kcal % from fat) or to HFD (45 kcal % from fat) for 8 wk. HFD rats segregated in obesity-prone (OP) or obesity-resistant (OR) rats according to body weight. HFD triggered an impaired glucose management together with impaired endothelium-dependent relaxation, reduced endothelial AMPK activity and lower NO availability in aortic rings of OP and OR cohorts. Relaxation evoked by AMPK activator, 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR) was reduced in both OP and OR rings, which exhibited lower p-AMPKα-Thr(172) /AMPKα ratios that negatively correlated with plasma non-esterified fatty acids (NEFA) and triglycerides (TG). Inhibition of PI3K (wortmannin, 10(-7) M) or Akt (triciribine, 10(-5) M) reduced relaxation to AICAR only in the control group (p < 0.001). Akt (p-Akt-Ser(473) ) and eNOS phosphorylation (p-eNOS-Ser(1177) ) were significantly reduced in OP and OR (p < 0.01). CONCLUSION Endothelial dysfunction caused by HFD is related to a dysfunctional endothelial AMPK-PI3K-Akt-eNOS pathway correlating with the increase of plasma NEFA, TG, and an impaired glucose management.
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Affiliation(s)
- Concha F García-Prieto
- Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad CEU-San Pablo, Madrid, Spain
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García-Prieto CF, Pulido-Olmo H, Ruiz-Hurtado G, Gil-Ortega M, Aranguez I, Rubio MA, Ruiz-Gayo M, Somoza B, Fernández-Alfonso MS. Mild caloric restriction reduces blood pressure and activates endothelial AMPK-PI3K-Akt-eNOS pathway in obese Zucker rats. Vascul Pharmacol 2014; 65-66:3-12. [PMID: 25530153 DOI: 10.1016/j.vph.2014.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 11/08/2014] [Accepted: 12/04/2014] [Indexed: 10/24/2022]
Abstract
Genetic obesity models exhibit endothelial dysfunction associated to adenosine monophosphate-activated protein kinase (AMPK) dysregulation. This study aims to assess if mild short-term caloric restriction (CR) restores endothelial AMPK activity leading to an improvement in endothelial function. Twelve-week old Zucker lean and obese (fa/fa) male rats had access to standard chow either ad libitum (AL, n=8) or 80% of AL (CR, n=8) for two weeks. Systolic blood pressure was significantly higher in fa/fa AL rats versus lean AL animals, but was normalized by CR. Endothelium-dependent relaxation to acetylcholine (ACh, 10(-9) to 10(-4) M) was reduced in fa/fa AL compared to control lean AL rats (p<0.001), and restored by CR. The AMPK activator AICAR (10(-5) to 8·10(-3) M) elicited a lower relaxation in fa/fa AL rings that was normalized by CR (p<0.001). Inhibition of PI3K (wortmannin, 10(-7) M), Akt (triciribine, 10(-5) M), or eNOS (L-NAME, 10(-4) M) markedly reduced AICAR-induced relaxation in lean AL, but not in fa/fa AL rats. These inhibitions were restored by CR in Zucker fa/fa rings. These data show that mild short-term CR improves endothelial function and lowers blood pressure in obesity due to the activation of the AMPK-PI3K-Akt-eNOS pathway.
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Affiliation(s)
- C F García-Prieto
- Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad CEU-San Pablo, 28668 Madrid, Spain
| | - H Pulido-Olmo
- Instituto Pluridisciplinar and Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain; Unidad de Hipertensión, imas12, Hospital 12 de Octubre, 28041 Madrid, Spain
| | - G Ruiz-Hurtado
- Instituto Pluridisciplinar and Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain; Unidad de Hipertensión, imas12, Hospital 12 de Octubre, 28041 Madrid, Spain
| | - M Gil-Ortega
- Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad CEU-San Pablo, 28668 Madrid, Spain
| | - I Aranguez
- Instituto Pluridisciplinar and Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain; Departamento de Bioquímica, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain
| | - M A Rubio
- Servicio de Endocrinología y Nutrición, Hospital Clínico San Carlos, IdISSC, 28040 Madrid, Spain
| | - M Ruiz-Gayo
- Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad CEU-San Pablo, 28668 Madrid, Spain
| | - B Somoza
- Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad CEU-San Pablo, 28668 Madrid, Spain
| | - M S Fernández-Alfonso
- Instituto Pluridisciplinar and Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain.
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Park DW, Jiang S, Liu Y, Siegal GP, Inoki K, Abraham E, Zmijewski JW. GSK3β-dependent inhibition of AMPK potentiates activation of neutrophils and macrophages and enhances severity of acute lung injury. Am J Physiol Lung Cell Mol Physiol 2014; 307:L735-45. [PMID: 25239914 PMCID: PMC4233296 DOI: 10.1152/ajplung.00165.2014] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Although AMP-activated protein kinase (AMPK) is involved in regulating carbohydrate and lipid metabolism, activated AMPK also plays an anti-inflammatory role in many cell populations. However, despite the ability of AMPK activation to diminish the severity of inflammatory responses, previous studies have found that AMPK activity is diminished in LPS-treated neutrophils and also in lungs of mice with LPS-induced acute lung injury (ALI). Since GSK3β participates in regulating AMPK activity, we examined potential roles for GSK3β in modulating LPS-induced activation of neutrophils and macrophages and in influencing severity of ALI. We found that GSK3β-dependent phosphorylation of T479-AMPK was associated with pT172 dephosphorylation and inactivation of AMPK following TLR4 engagement. GSK3β inhibitors BIO (6-bromoindirubin-3'-oxime), SB216763, or siRNA knockdown of GSK3β, but not the PI3K/AKT inhibitor LY294002, prevented Thr172-AMPK dephosphorylation. Exposure to LPS resulted in rapid binding between IKKβ and AMPKα, and phosphorylation of S485-AMPK by IKKβ. These results suggest that IKKβ-dependent phosphorylation of S485-AMPK was an essential step in subsequent phosphorylation and inactivation AMPK by GSK3β. Inhibition of GSK3β activity delayed IκBα degradation and diminished expression of the proinflammatory TNF-α in LPS-stimulated neutrophils and macrophages. In vivo, inhibition of GSK3β decreased the severity of LPS-induced lung injury as assessed by development of pulmonary edema, production of TNF-α and MIP-2, and release of the alarmins HMGB1 and histone 3 in the lungs. These results show that inhibition of AMPK by GSK3β plays an important contributory role in enhancing LPS-induced inflammatory responses, including worsening the severity of ALI.
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Affiliation(s)
- Dae Won Park
- 1Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; ,2Division of Infectious Diseases, Korea University Ansan Hospital, Ansan, Korea;
| | - Shaoning Jiang
- 1Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama;
| | - Yanping Liu
- 1Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama;
| | - Gene P. Siegal
- 3Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama;
| | - Ken Inoki
- 4University of Michigan Medical School, Ann Arbor, Michigan; and
| | - Edward Abraham
- 5Office of the Dean, Wake Forest University School of Medicine, Winston-Salem, North Carolina
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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: 43] [Impact Index Per Article: 4.3] [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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78
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Genetic dissection of the vav2-rac1 signaling axis in vascular smooth muscle cells. Mol Cell Biol 2014; 34:4404-19. [PMID: 25288640 DOI: 10.1128/mcb.01066-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vascular smooth muscle cells (vSMCs) are key in the regulation of blood pressure and the engagement of vascular pathologies, such as hypertension, arterial remodeling, and neointima formation. The role of the Rac1 GTPase in these cells remains poorly characterized. To clarify this issue, we have utilized genetically engineered mice to manipulate the signaling output of Rac1 in these cells at will using inducible, Cre-loxP-mediated DNA recombination techniques. Here, we show that the expression of an active version of the Rac1 activator Vav2 exclusively in vSMCs leads to hypotension as well as the elimination of the hypertension induced by the systemic loss of wild-type Vav2. Conversely, the specific depletion of Rac1 in vSMCs causes defective nitric oxide vasodilation responses and hypertension. Rac1, but not Vav2, also is important for neointima formation but not for hypertension-driven vascular remodeling. These animals also have allowed us to dismiss etiological connections between hypertension and metabolic disease and, most importantly, identify pathophysiological programs that cooperate in the development and consolidation of hypertensive states caused by local vascular tone dysfunctions. Finally, our results suggest that the therapeutic inhibition of Rac1 will be associated with extensive cardiovascular system-related side effects and identify pharmacological avenues to circumvent them.
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Cheng WH, Ho WY, Chang CF, Lu PJ, Cheng PW, Yeh TC, Hong LZ, Sun GC, Hsiao M, Tseng CJ. Simvastatin induces a central hypotensive effect via Ras-mediated signalling to cause eNOS up-regulation. Br J Pharmacol 2014; 170:847-58. [PMID: 23889671 DOI: 10.1111/bph.12317] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 07/08/2013] [Accepted: 07/21/2013] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND AND PURPOSE Clinical studies indicate that statins have a BP-lowering effect in hypercholesterolemic individuals with hypertension. Specifically, statins modulate BP through the up-regulation of endothelial NOS (eNOS) activation in the brain. However, the signalling mechanisms through which statins enhance eNOS activation remain unclear. Therefore, we examined the possible signalling pathways involved in statin-mediated BP regulation in the nucleus tractus solitarii (NTS). EXPERIMENTAL APPROACH To investigate the involvement of Ras and other signalling pathways in simvastatin-induced effects on BP, BP and renal sympathetic nerve activity (RSNA) were determined in spontaneously hypertensive rats (SHRs) before and after i.c.v. administration of simvastatin in the absence and presence of a Ras-specific inhibitor (farnesyl thiosalicylic acid, FTS), a geranylgeranyltransferase inhibitor (GGTI-2133), a PI3K inhibitor (LY294002) or a MAPK-ERK kinase (MEK) inhibitor (PD98059). KEY RESULTS FTS significantly attenuated the decrease in BP and increased NO evoked by simvastatin and reversed the decrease in basal RSNA induced by simvastatin. Immunoblotting and pharmacological studies showed that inhibition of Ras activity by FTS significantly abolished simvastatin-induced phosphorylation of ERK1/2, ribosomal protein S6 kinase (RSK), Akt and decreased eNOS phosphorylation. Likewise, administration of Akt and ERK1/2 signalling inhibitors, LY294002 and PD98059, attenuated the reduction in BP evoked by simvastatin. Furthermore, i.c.v. simvastatin decreased Rac1 activation and the number of ROS-positive cells in the NTS. CONCLUSIONS AND IMPLICATIONS Simvastatin modulates central BP control in the NTS of SHRs by increasing Ras-mediated activation of the PI3K-Akt and ERK1/2-RSK signalling pathways, which then up-regulates eNOS activation.
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Affiliation(s)
- Wen-Han Cheng
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan; Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
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Kratzer A, Giral H, Landmesser U. High-density lipoproteins as modulators of endothelial cell functions: alterations in patients with coronary artery disease. Cardiovasc Res 2014; 103:350-61. [DOI: 10.1093/cvr/cvu139] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Endothelial PGC-1α mediates vascular dysfunction in diabetes. Cell Metab 2014; 19:246-58. [PMID: 24506866 PMCID: PMC4040246 DOI: 10.1016/j.cmet.2013.12.014] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 10/08/2013] [Accepted: 12/10/2013] [Indexed: 12/26/2022]
Abstract
Endothelial dysfunction is a central hallmark of diabetes. The transcriptional coactivator PGC-1α is a powerful regulator of metabolism, but its role in endothelial cells remains poorly understood. We show here that endothelial PGC-1α expression is high in diabetic rodents and humans and that PGC-1α powerfully blocks endothelial migration in cell culture and vasculogenesis in vivo. Mechanistically, PGC-1α induces Notch signaling, blunts activation of Rac/Akt/eNOS signaling, and renders endothelial cells unresponsive to established angiogenic factors. Transgenic overexpression of PGC-1α in the endothelium mimics multiple diabetic phenotypes, including aberrant re-endothelialization after carotid injury, blunted wound healing, and reduced blood flow recovery after hindlimb ischemia. Conversely, deletion of endothelial PGC-1α rescues the blunted wound healing and recovery from hindlimb ischemia seen in type 1 and type 2 diabetes. Endothelial PGC-1α thus potently inhibits endothelial function and angiogenesis, and induction of endothelial PGC-1α contributes to multiple aspects of vascular dysfunction in diabetes.
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Shiroto T, Romero N, Sugiyama T, Sartoretto JL, Kalwa H, Yan Z, Shimokawa H, Michel T. Caveolin-1 is a critical determinant of autophagy, metabolic switching, and oxidative stress in vascular endothelium. PLoS One 2014; 9:e87871. [PMID: 24498385 PMCID: PMC3912129 DOI: 10.1371/journal.pone.0087871] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 12/30/2013] [Indexed: 01/29/2023] Open
Abstract
Caveolin-1 is a scaffolding/regulatory protein that interacts with diverse signaling molecules. Caveolin-1null mice have marked metabolic abnormalities, yet the underlying molecular mechanisms are incompletely understood. We found the redox stress plasma biomarker plasma 8-isoprostane was elevated in caveolin-1null mice, and discovered that siRNA-mediated caveolin-1 knockdown in endothelial cells promoted significant increases in intracellular H2O2. Mitochondrial ROS production was increased in endothelial cells after caveolin-1 knockdown; 2-deoxy-D-glucose attenuated this increase, implicating caveolin-1 in control of glycolytic pathways. We performed unbiased metabolomic characterizations of endothelial cell lysates following caveolin-1 knockdown, and discovered strikingly increased levels (up to 30-fold) of cellular dipeptides, consistent with autophagy activation. Metabolomic analyses revealed that caveolin-1 knockdown led to a decrease in glycolytic intermediates, accompanied by an increase in fatty acids, suggesting a metabolic switch. Taken together, these results establish that caveolin-1 plays a central role in regulation of oxidative stress, metabolic switching, and autophagy in the endothelium, and may represent a critical target in cardiovascular diseases.
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Affiliation(s)
- Takashi Shiroto
- Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Natalia Romero
- Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Toru Sugiyama
- Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Juliano L. Sartoretto
- Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Hermann Kalwa
- Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Zhonghua Yan
- Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Hiroaki Shimokawa
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Thomas Michel
- Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Jeong KM, Choi JI, Lee SH, Lee HJ, Son JK, Seo CS, Song SW, Kwak SH, Bae HB. Effect of sauchinone, a lignan from Saururus chinensis, on bacterial phagocytosis by macrophages. Eur J Pharmacol 2014; 728:176-82. [PMID: 24486706 DOI: 10.1016/j.ejphar.2014.01.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 01/15/2014] [Accepted: 01/22/2014] [Indexed: 12/13/2022]
Abstract
AMP-activated protein kinase (AMPK) plays an important role in inflammation in various cells and increases the phagocytic ability of macrophages. In this study, we found that sauchinone increased the phosphorylation of AMPK and acetyl-CoA carboxylase (ACC), a downstream target of AMPK, in mouse peritoneal macrophages. Sauchinone increased macrophage phagocytosis of fluorescent Escherichia coli, which was blocked by compound C, an AMPK inhibitor. Sauchinone also increased the phosphorylation of p38 mitogen activated protein kinase (MAPK) in cultured macrophages in a concentration-dependent fashion, which was not blocked by compound C. However, the increase of sauchinone-induced phagocytosis was prevented by SB203580. An inhibitor of the upstream kinase TGF-beta-activated kinase (TAK1), (5z)-7-oxozeaenol, abolished the phosphorylation of ACC and p38 MAPK. Systemic administration of sauchinone to mice led to increased phosphorylation of AMPK and p38 MAPK in the lung, and enhanced phagocytosis of fluorescent E. coli in bronchoalveolar lavage fluid as compared with control mice. These results suggest sauchinone to be a useful adjunctive treatment for bacterial infection.
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Affiliation(s)
- Kyung-Min Jeong
- Center for Creative Biomedical Scientists at Chonnam National University, Republic of Korea; Research Institute of Medical Sciences, Chonnam National University, Republic of Korea
| | - Jeong-Il Choi
- Departments of Anesthesiology and Pain Medicine, Chonnam National University Medical School, 5 Hak-dong, Gwangju 501-746, Republic of Korea; Center for Creative Biomedical Scientists at Chonnam National University, Republic of Korea
| | - Seong-Heon Lee
- Departments of Anesthesiology and Pain Medicine, Chonnam National University Medical School, 5 Hak-dong, Gwangju 501-746, Republic of Korea
| | - Hyun-Jung Lee
- Departments of Anesthesiology and Pain Medicine, Chonnam National University Medical School, 5 Hak-dong, Gwangju 501-746, Republic of Korea
| | - Jong-Keun Son
- College of Pharmacy, Yeungnam University, Gyongsan 712-749, Republic of Korea
| | - Chang-Seob Seo
- Herbal Medicine Formulation Research Group, Korea Institute of Oriental Medicine, Exporo 483, Yusung-gu, Daejeon 305-811, Republic of Korea
| | - Seung-Won Song
- Departments of Anesthesiology and Pain Medicine, Chonnam National University Medical School, 5 Hak-dong, Gwangju 501-746, Republic of Korea
| | - Sang-Hyun Kwak
- Departments of Anesthesiology and Pain Medicine, Chonnam National University Medical School, 5 Hak-dong, Gwangju 501-746, Republic of Korea; Center for Creative Biomedical Scientists at Chonnam National University, Republic of Korea
| | - Hong-Beom Bae
- Departments of Anesthesiology and Pain Medicine, Chonnam National University Medical School, 5 Hak-dong, Gwangju 501-746, Republic of Korea; Center for Creative Biomedical Scientists at Chonnam National University, Republic of Korea.
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Dulovic M, Jovanovic M, Xilouri M, Stefanis L, Harhaji-Trajkovic L, Kravic-Stevovic T, Paunovic V, Ardah MT, El-Agnaf OMA, Kostic V, Markovic I, Trajkovic V. The protective role of AMP-activated protein kinase in alpha-synuclein neurotoxicity in vitro. Neurobiol Dis 2013; 63:1-11. [PMID: 24269733 DOI: 10.1016/j.nbd.2013.11.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 10/30/2013] [Accepted: 11/12/2013] [Indexed: 01/08/2023] Open
Abstract
In the present study, we investigated the role of the main intracellular energy sensor, AMP-activated protein kinase (AMPK), in the in vitro neurotoxicity of α-synuclein (ASYN), one of the key culprits in the pathogenesis of Parkinson's disease. The loss of viability in retinoic acid-differentiated SH-SY5Y human neuroblastoma cells inducibly overexpressing wild-type ASYN was associated with the reduced activation of AMPK and its activator LKB1, as well as AMPK target Raptor. ASYN-overexpressing rat primary neurons also displayed lower activity of LKB1/AMPK/Raptor pathway. Restoration of AMPK activity by metformin or AICAR reduced the in vitro neurotoxicity of ASYN overexpression, acting independently of the prosurvival kinase Akt or the induction of autophagic response. The conditioned medium from ASYN-overexpressing cells, containing secreted ASYN, as well as dopamine-modified or nitrated recombinant ASYN oligomers, all inhibited AMPK activation in differentiated SH-SY5Y cells and reduced their viability, but not in the presence of metformin or AICAR. The RNA interference-mediated knockdown of AMPK increased the sensitivity of SH-SY5Y cells to the harmful effects of secreted ASYN. AMPK-dependent protection from extracellular ASYN was also observed in rat neuron-like pheochromocytoma cell line PC12. These data demonstrate the protective role of AMPK against the toxicity of both intracellular and extracellular ASYN, suggesting that modulation of AMPK activity may be a promising therapeutic strategy in Parkinson's disease.
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Affiliation(s)
- Marija Dulovic
- Institute of Medical and Clinical Biochemistry, School of Medicine, University of Belgrade, Pasterova 2, Belgrade, Serbia
| | - Maja Jovanovic
- Institute of Medical and Clinical Biochemistry, School of Medicine, University of Belgrade, Pasterova 2, Belgrade, Serbia
| | - Maria Xilouri
- Division of Basic Neurosciences, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Leonidas Stefanis
- Division of Basic Neurosciences, Biomedical Research Foundation of the Academy of Athens, Athens, Greece; Second Department of Neurology, University of Athens Medical School, Athens, Greece
| | | | - Tamara Kravic-Stevovic
- Institute of Histology and Embryology, School of Medicine, University of Belgrade, Belgrade, Serbia
| | - Verica Paunovic
- Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade, Serbia
| | - Mustafa T Ardah
- Department of Biochemistry, College of Medicine and Health Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Omar M A El-Agnaf
- Department of Biochemistry, College of Medicine and Health Science, United Arab Emirates University, Al Ain, United Arab Emirates; Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Vladimir Kostic
- Clinic for Neurology CCS, School of Medicine, University of Belgrade, Serbia
| | - Ivanka Markovic
- Institute of Medical and Clinical Biochemistry, School of Medicine, University of Belgrade, Pasterova 2, Belgrade, Serbia.
| | - Vladimir Trajkovic
- Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade, Serbia.
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85
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Guillas I, Puyaubert J, Baudouin E. Nitric oxide-sphingolipid interplays in plant signalling: a new enigma from the Sphinx? FRONTIERS IN PLANT SCIENCE 2013; 4:341. [PMID: 24062754 PMCID: PMC3770979 DOI: 10.3389/fpls.2013.00341] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 08/13/2013] [Indexed: 05/04/2023]
Abstract
Nitric oxide (NO) emerged as one of the major signaling molecules operating during plant development and plant responses to its environment. Beyond the identification of the direct molecular targets of NO, a series of studies considered its interplay with other actors of signal transduction and the integration of NO into complex signaling networks. Beside the close relationships between NO and calcium or phosphatidic acid signaling pathways that are now well-established, recent reports paved the way for interplays between NO and sphingolipids (SLs). This mini-review summarizes our current knowledge of the influence NO and SLs might exert on each other in plant physiology. Based on comparisons with examples from the animal field, it further indicates that, although SL-NO interplays are common features in signaling networks of eukaryotic cells, the underlying mechanisms and molecular targets significantly differ.
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Affiliation(s)
- Isabelle Guillas
- UR 5, Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes, Université Pierre et Marie Curie - Paris 6Paris, France
- EAC 7180, Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes, Centre National de la Recherche ScientifiqueParis, France
| | - Juliette Puyaubert
- UR 5, Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes, Université Pierre et Marie Curie - Paris 6Paris, France
- EAC 7180, Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes, Centre National de la Recherche ScientifiqueParis, France
| | - Emmanuel Baudouin
- UR 5, Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes, Université Pierre et Marie Curie - Paris 6Paris, France
- EAC 7180, Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes, Centre National de la Recherche ScientifiqueParis, France
- *Correspondence: Emmanuel Baudouin, UR 5, Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes, Université Pierre et Marie Curie - Paris 6, Bâtiment C/3 Boîte courrier 156, 4 place Jussieu, F-75252 Paris Cédex 05, France; EAC 7180, Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes, Centre National de la Recherche Scientifique, Bâtiment C/3 Boîte courrier 156, 4 place Jussieu, F-75252 Paris Cédex 05, France e-mail:
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86
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Yoo YM. Melatonin-mediated insulin synthesis during endoplasmic reticulum stress involves HuD expression in rat insulinoma INS-1E cells. J Pineal Res 2013; 55:207-20. [PMID: 23711134 DOI: 10.1111/jpi.12064] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 04/26/2013] [Indexed: 01/12/2023]
Abstract
In this study, we investigated how melatonin mediates insulin synthesis through endoplasmic reticulum (ER) via HuD expression in rat insulinoma INS-1E cells. Under ER stress condition (thapsigargin with/without melatonin, tunicamycin with/without melatonin), phosphorylation of AMP-activated protein kinase (p-AMPK) was significantly increased when compared with only with/without melatonin (control/melatonin). Insulin receptor substrate (IRS) two protein was significantly reduced under conditions of ER stress when compared with control/melatonin, but no expression of IRS1 protein was observed. In thapsigargin treatment, melatonin (10, 50 μm) increased IRS2 protein expression in a dose-dependent manner. p-Akt (Ser473) expression significantly decreased under ER stress condition prior to control/melatonin. Melatonin (10, 50 μm) significantly reduced nuclear and cellular p85α expressions in a dose-dependent manner when compared with only thapsigargin or tunicamycin. These results indicate the activation of the aforementioned expressions under regulation of the pathway, AMPK → IRS2 → Akt/PKB → PI3K (p85α). However, mammalian target of rapamycin and raptor protein, mTORC1, was found to be independent of the ER stress response. In thapsigargin treatment, melatonin increased nuclear mammalian RNA-binding protein (HuD) expression and reduced cellular HuD expression and subsequently resulted in a decrease in cellular insulin level and rise in insulin secretion in a dose-dependent manner. In tunicamycin treatment, HuD and insulin proteins showed similar expression tendencies. These results indicate that ER stress/melatonin, especially thapsigargin/melatonin, increased nuclear HuD expression and subsequently resulted in a decrease in intracellular biosynthesis; it is hypothesized that extracellular secretion of insulin may be regulated by melatonin.
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Affiliation(s)
- Yeong-Min Yoo
- Department of Biomedical Engineering, College of Health Science, Yonsei University, Wonju, Gangwon-do 220-710, Korea.
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87
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Guan TH, Chen G, Gao B, Janssen MR, Uttarwar L, Ingram AJ, Krepinsky JC. Caveolin-1 deficiency protects against mesangial matrix expansion in a mouse model of type 1 diabetic nephropathy. Diabetologia 2013; 56:2068-77. [PMID: 23793581 DOI: 10.1007/s00125-013-2968-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 05/24/2013] [Indexed: 01/10/2023]
Abstract
AIMS/HYPOTHESIS Glomerular matrix protein accumulation, mediated largely by resident mesangial cells (MCs), is central to the pathogenesis of diabetic nephropathy. We previously showed that caveolin (CAV)-1/caveolae mediate matrix upregulation by MCs in response to high glucose and TGFβ, two important pathogenic mediators of diabetic glomerular sclerosis. Here, we evaluated the in vivo role of CAV-1/caveolae in the development of diabetic nephropathy. METHODS Diabetes was induced in Cav1-knockout (KO) mice and their wild-type (WT) counterparts by streptozotocin injection. After 10 months, kidneys were evaluated for the development of nephropathy, including glomerular sclerosis and upregulation of matrix proteins. Parallel experiments assessing glucose-induced matrix upregulation were carried out in MCs isolated from KO mice. RESULTS KO diabetic mice developed hyperglycaemia and renal hypertrophy, but were protected from developing albuminuria and glomerular sclerosis compared with WT mice. KO mice were significantly protected from the upregulation of glomerular collagen I, fibronectin, connective tissue growth factor (CTGF) and TGFβ. In vitro, glucose induced collagen I A1 promoter activation and collagen I, fibronectin and CTGF protein upregulation in WT but not KO MCs. Re-expression of Cav1 in KO cells restored this response. CONCLUSIONS/INTERPRETATION Cav1 deletion rendered significant protection from glomerular matrix accumulation and albuminuria in a mouse model of type 1 diabetes. These studies provide a foundation for the development of renal-targeted interference with CAV-1/caveolae as a novel approach to the treatment of diabetic nephropathy.
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Affiliation(s)
- T H Guan
- Division of Nephrology, McMaster University, St Joseph's Hospital, 50 Charlton Ave East, Rm T3311, Hamilton, ON, Canada L8N 4A6
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88
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Bretón-Romero R, Kalwa H, Lamas S, Michel T. Role of PTEN in modulation of ADP-dependent signaling pathways in vascular endothelial cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:2586-2595. [PMID: 23806663 DOI: 10.1016/j.bbamcr.2013.06.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Revised: 05/20/2013] [Accepted: 06/07/2013] [Indexed: 11/30/2022]
Abstract
ADP plays critical signaling roles in the vascular endothelium. ADP receptors are targeted by several cardiovascular drugs, yet the intracellular pathways modulated by ADP are incompletely understood. These studies have identified important roles for the phosphatase PTEN in ADP-dependent modulation of the endothelial isoform of nitric oxide synthase (eNOS) as well as of lipid and protein kinase pathways in endothelial cells. We find that ADP-promoted eNOS activation as well as phosphorylation of p38 MAPK are enhanced by siRNA-mediated PTEN knockdown. However, the increase in ADP-dependent eNOS activation promoted by PTEN knockdown is abrogated by siRNA-mediated knockdown of p38 MAPK. These findings indicate that PTEN tonically suppresses both p38 phosphorylation as well as ADP-stimulated eNOS activity. A key enzymatic activity of PTEN is its role as a lipid phosphatase, catalyzing the dephosphorylation of phosphoinositol-3,4,5-trisphosphate (PIP3) to phosphoinositol-4,5-bisphosphate (PIP2). We performed biochemical analyses of cellular phospholipids in endothelial cells to show that siRNA-mediated PTEN knockdown leads to a marked increase in PIP3. Because these complex lipids activate the small GTPase Rac1, we explored the role of PTEN in ADP-modulated Rac1 activation. We used a FRET biosensor for Rac1 to show that ADP-dependent Rac1 activation is blocked by siRNA-mediated PTEN knockdown. We then exploited a FRET biosensor for PIP3 to show that the striking ADP-dependent increase in intracellular PIP3 is entirely blocked by PTEN knockdown. These studies identify a key role for PTEN in the modulation of lipid mediators involved in ADP receptor-regulated endothelial signaling pathways involving eNOS activation in vascular endothelial cells.
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Affiliation(s)
- Rosa Bretón-Romero
- Cardiovascular Medicine Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA; Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM). c/ Nicolás Cabrera 1, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Hermann Kalwa
- Cardiovascular Medicine Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | - Santiago Lamas
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM). c/ Nicolás Cabrera 1, Universidad Autónoma de Madrid, 28049 Madrid, Spain..
| | - Thomas Michel
- Cardiovascular Medicine Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
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89
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Triolo M, Annema W, Dullaart RPF, Tietge UJF. Assessing the functional properties of high-density lipoproteins: an emerging concept in cardiovascular research. Biomark Med 2013; 7:457-72. [DOI: 10.2217/bmm.13.35] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Although plasma concentrations of high-density lipoprotein (HDL) cholesterol correlate inversely with the incidence of atherosclerotic cardiovascular disease, results from recent epidemiological, genetic and pharmacological intervention studies resulted in a shift of concept. Rather than HDL cholesterol mass levels, the functionality of HDL particles is increasingly regarded as potentially clinically important. This review provides an overview of four key functional properties of HDL, namely cholesterol efflux and reverse cholesterol transport; antioxidative activities; anti-inflammatory activities; and the ability of HDL to increase vascular nitric oxide production resulting in vasorelaxation. Currently available assays are put into context with different HDL isolation procedures yielding compositional heterogeneity of the particle. Gathered knowledge on the impact of different disease states on HDL function is discussed together with potential underlying causative factors modulating HDL functionalities. In addition, a perspective is provided regarding how a better understanding of the determinants of (dys)functional HDL might impact clinical practice and the future design of rational and specific therapeutic approaches targeting atherosclerotic cardiovascular disease.
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Affiliation(s)
- Michela Triolo
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Wijtske Annema
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
- Top Institute Food & Nutrition, Wageningen, The Netherlands
| | - Robin PF Dullaart
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Uwe JF Tietge
- Top Institute Food & Nutrition, Wageningen, The Netherlands
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
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90
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Takeuchi K, Morizane Y, Kamami-Levy C, Suzuki J, Kayama M, Cai W, Miller JW, Vavvas DG. AMP-dependent kinase inhibits oxidative stress-induced caveolin-1 phosphorylation and endocytosis by suppressing the dissociation between c-Abl and Prdx1 proteins in endothelial cells. J Biol Chem 2013; 288:20581-91. [PMID: 23723070 DOI: 10.1074/jbc.m113.460832] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Caveolin-1 is the primary structural component of endothelial caveolae that is essential for transcellular trafficking of albumin and is also a critical scaffolding protein that regulates the activity of signaling molecules in caveolae. Phosphorylation of caveolin-1 plays a fundamental role in the mechanism of oxidant-induced vascular hyper permeability. However, the regulatory mechanism of caveolin-1 phosphorylation remains unclear. Here we identify a previously unexpected role for AMPK in inhibition of caveolin-1 phosphorylation under oxidative stress. A pharmacological activator of AMPK, 5-amino-4-imidazole carboxamide riboside (AICAR), inhibited oxidative stress-induced phosphorylation of both caveolin-1 and c-Abl, which is the major kinase of caveolin-1, and endocytosis of albumin in human umbilical vein endothelial cell. These effects were abolished by treatment with two specific inhibitors of AICAR, dipyridamole, and 5-iodotubericidin. Consistently, knockdown of the catalytic AMPKα subunit by siRNA abolished the inhibitory effect of AICAR on oxidant-induced phosphorylation of both caveolin-1 and c-Abl. Pretreatment with specific c-Abl inhibitor, imatinib mesylate, and knock down of c-Abl significantly decreased the caveolin-1 phosphorylation after H2O2 exposure and abolished the inhibitory effect of AICAR on the caveolin-1 phosphorylation. Interestingly, knockdown of Prdx-1, an antioxidant enzyme associated with c-Abl, increased phosphorylation of both caveolin-1 and c-Abl and abolished the inhibitory effect of AICAR on the caveolin-1 phosphorylation. Furthermore, co-immunoprecipitation experiment showed that AICAR suppressed the oxidant-induced dissociation between c-Abl and Prdx1. Overall, our results suggest that activation of AMPK inhibits oxidative stress-induced caveolin-1 phosphorylation and endocytosis, and this effect is mediated in part by stabilizing the interaction between c-Abl and Prdx-1.
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Affiliation(s)
- Kimio Takeuchi
- Retina Service, Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114, USA
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91
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Igarashi J, Hashimoto T, Shoji K, Yoneda K, Tsukamoto I, Moriue T, Kubota Y, Kosaka H. Dexamethasone induces caveolin-1 in vascular endothelial cells: implications for attenuated responses to VEGF. Am J Physiol Cell Physiol 2013; 304:C790-800. [DOI: 10.1152/ajpcell.00268.2012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Steroids exert direct actions on cardiovascular cells, although underlying molecular mechanisms remain incompletely understood. We examined if steroids modulate abundance of caveolin-1, a regulatory protein of cell-surface receptor pathways that regulates the magnitudes of endothelial response to vascular endothelial growth factor (VEGF). Dexamethasone, a synthetic glucocorticoid, induces caveolin-1 at both levels of protein and mRNA in a time- and dose-dependent manner in pharmacologically relevant concentrations in cultured bovine aortic endothelial cells. Aldosterone, a mineralocorticoid, but not the sex steroids 17β-estradiol, testosterone, or progesterone, elicits similar caveolin-1 induction. Caveolin-1 induction by dexamethasone and that by aldosterone were abrogated by RU-486, an inhibitor of glucocorticoid receptor, and by spironolactone, a mineralocorticoid receptor inhibitor, respectively. Dexamethasone attenuates VEGF-induced responses at the levels of protein kinases Akt and ERK1/2, small-G protein Rac1, nitric oxide production, and migration. When induction of caveolin-1 by dexamethasone is attenuated either by genetically by transient transfection with small interfering RNA or pharmacologically by RU-486, kinase responses to VEGF are rescued. Dexamethasone also increases expression of caveolin-1 protein in cultured human umbilical vein endothelial cells, associated with attenuated tube formation responses of these cells when cocultured with normal fibroblasts. Immunohistochemical analyses revealed that intraperitoneal injection of dexamethasone induces endothelial caveolin-1 protein in thoracic aorta and in lung artery in healthy male rats. Thus steroids functionally attenuate endothelial responses to VEGF via caveolin-1 induction at the levels of signal transduction, migration, and tube formation, identifying a novel point of cross talk between nuclear and cell-surface receptor signaling pathways.
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Affiliation(s)
- Junsuke Igarashi
- Department of Cardiovascular Physiology, Kagawa University, Kagawa, Japan
| | - Takeshi Hashimoto
- Department of Cardiovascular Physiology, Kagawa University, Kagawa, Japan
| | - Kazuyo Shoji
- Department of Dermatology, Kagawa University, Kagawa, Japan; and
| | - Kozo Yoneda
- Department of Dermatology, Kagawa University, Kagawa, Japan; and
| | - Ikuko Tsukamoto
- Department of Pharmaco-Bio-Informatics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Tetsuya Moriue
- Department of Dermatology, Kagawa University, Kagawa, Japan; and
| | - Yasuo Kubota
- Department of Dermatology, Kagawa University, Kagawa, Japan; and
| | - Hiroaki Kosaka
- Department of Cardiovascular Physiology, Kagawa University, Kagawa, Japan
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92
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Louie SM, Roberts LS, Nomura DK. Mechanisms linking obesity and cancer. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1499-508. [PMID: 23470257 DOI: 10.1016/j.bbalip.2013.02.008] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 02/20/2013] [Accepted: 02/23/2013] [Indexed: 12/31/2022]
Abstract
The incidence of obesity in US adults has been steadily increasing over the past few decades. Many comorbidities associated with obesity have been well-established such as type 2 diabetes and cardiovascular diseases. However, more recently an epidemiological relationship between obesity and the prevalence of a variety of cancers has also been uncovered. The shift of the paradigm surrounding white adipose tissue function from purely an energy storage tissue, to one that has both endocrine and metabolic relevance, has led to several mechanisms implicated in how obesity drives cancer prevalence and cancer deaths. Currently, there are four categories into which these mechanisms fall - increased lipids and lipid signaling, inflammatory responses, insulin resistance, and adipokines. In this review, we examine each of these categories and the mechanisms through which they drive cancer pathogenesis. Understanding the relationship(s) between obesity and cancer and especially the nodal points of control in these cascades will be essential in developing effective therapeutics or interventions for combating this deadly combination. This article is part of a Special Issue entitled Lipid Metabolism in Cancer.
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Affiliation(s)
- Sharon M Louie
- Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, 127 Morgan Hall, Berkeley, CA 94710, USA
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93
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Critical role of endothelial hydrogen peroxide in post-ischemic neovascularization. PLoS One 2013; 8:e57618. [PMID: 23472092 PMCID: PMC3589391 DOI: 10.1371/journal.pone.0057618] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 01/23/2013] [Indexed: 11/19/2022] Open
Abstract
Background Reactive oxygen species (ROS) play an important role in angiogenesis in endothelial cells (ECs) in vitro and neovascularization in vivo. However, little is known about the role of endogenous vascular hydrogen peroxide (H2O2) in postnatal neovascularization. Methodology/Principal Findings We used Tie2-driven endothelial specific catalase transgenic mice (Cat-Tg mice) and hindlimb ischemia model to address the role of endogenous H2O2 in ECs in post-ischemic neovascularization in vivo. Here we show that Cat-Tg mice exhibit significant reduction in intracellular H2O2 in ECs, blood flow recovery, capillary formation, collateral remodeling with larger extent of tissue damage after hindlimb ischemia, as compared to wild-type (WT) littermates. In the early stage of ischemia-induced angiogenesis, Cat-Tg mice show a morphologically disorganized microvasculature. Vascular sprouting and tube elongation are significantly impaired in isolated aorta from Cat-Tg mice. Furthermore, Cat-Tg mice show a decrease in myeloid cell recruitment after hindlimb ischemia. Mechanistically, Cat-Tg mice show significant decrease in eNOS phosphorylation at Ser1177 as well as expression of redox-sensitive vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemotactic protein-1 (MCP-1) in ischemic muscles, which is required for inflammatory cell recruitment to the ischemic tissues. We also observed impaired endothelium-dependent relaxation in resistant vessels from Cat-Tg mice. Conclusions/Significance Endogenous ECs-derived H2O2 plays a critical role in reparative neovascularization in response to ischemia by upregulating adhesion molecules and activating eNOS in ECs. Redox-regulation in ECs is a potential therapeutic strategy for angiogenesis-dependent cardiovascular diseases.
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94
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Ahn YJ, Kim H, Lim H, Lee M, Kang Y, Moon S, Kim HS, Kim HH. AMP-activated protein kinase: implications on ischemic diseases. BMB Rep 2013; 45:489-95. [PMID: 23010169 DOI: 10.5483/bmbrep.2012.45.9.169] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ischemia is a blockage of blood supply due to an embolism or a hemorrhage in a blood vessel. When an organ cannot receive oxygenated blood and can therefore no longer replenish its blood supply due to ischemia, stresses, such as the disruption of blood glucose homeostasis, hypoglycemia and hypoxia, activate the AMPK complex. LKB1 and CaMKKβ are essential activators of the AMPK signaling pathway. AMPK triggers proangiogenic effects through the eNOS protein in tissues with ischemic conditions, where cells are vulnerable to apoptosis, autophagy and necrosis. The AMPK complex acts to restore blood glucose levels and ATP levels back to homeostasis. This review will discuss AMPK, as well as its key activators (LKB1 and CaMKKβ), as a central energy regulator and evaluate the upstream and downstream regulating pathways of AMPK. We will also discuss how we can control this important enzyme in ischemic conditions to prevent harmful effects in patients with vascular damage.
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Affiliation(s)
- Yong-Joo Ahn
- Vascular Medicine Research Unit, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Cambridge, MA 02139, USA
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Bruce CR, Risis S, Babb JR, Yang C, Lee-Young RS, Henstridge DC, Febbraio MA. The sphingosine-1-phosphate analog FTY720 reduces muscle ceramide content and improves glucose tolerance in high fat-fed male mice. Endocrinology 2013. [PMID: 23183172 DOI: 10.1210/en.2012-1847] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
FTY720 is a sphingosine-1-phosphate analog that has been shown to inhibit ceramide synthesis in vitro. Because ceramide accumulation in muscle is associated with insulin resistance, we aimed to examine whether FTY720 would prevent muscle ceramide accumulation in high fat-fed mice and subsequently improve glucose homeostasis. Male C57Bl/6 mice were fed either a chow or high fat-diet (HFD) for 6 wk, after which they were treated with vehicle or FTY720 (5 mg/kg) daily for a further 6 wk. The ceramide content of muscle was examined and insulin action was assessed. Whereas the HFD increased muscle ceramide, this was prevented by FTY720 treatment. This was not associated with alterations in the expression of genes involved in sphingolipid metabolism. Interestingly, the effects of FTY720 on lipid metabolism were not limited to ceramide because FTY720 also prevented the HFD-induced increase in diacylglycerol and triacylglycerol in muscle. Furthermore, the increase in CD36 mRNA expression induced by fat feeding was prevented in muscle of FTY720-treated mice. This was associated with an attenuation of the HFD-induced increase in palmitate uptake and esterification. In addition, FTY720 improved glucose homeostasis as demonstrated by a reduction in plasma insulin, an improvement in whole-body glucose tolerance, an increase in insulin-stimulated glucose uptake, and Akt phosphorylation in muscle. In conclusion, FTY720 exerts beneficial effects on muscle lipid metabolism that prevent lipid accumulation and improve glucose tolerance in high fat-fed mice. Thus, FTY720 and other compounds that target sphingosine-1-phosphate signaling may have therapeutic potential in treating insulin resistance.
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Affiliation(s)
- Clinton R Bruce
- Department of Physiology, Monash University, Clayton 3800, Victoria, Australia.
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96
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Pantovic A, Krstic A, Janjetovic K, Kocic J, Harhaji-Trajkovic L, Bugarski D, Trajkovic V. Coordinated time-dependent modulation of AMPK/Akt/mTOR signaling and autophagy controls osteogenic differentiation of human mesenchymal stem cells. Bone 2013; 52:524-31. [PMID: 23111315 DOI: 10.1016/j.bone.2012.10.024] [Citation(s) in RCA: 187] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 10/17/2012] [Accepted: 10/20/2012] [Indexed: 12/20/2022]
Abstract
We investigated the role of AMP-activated protein kinase (AMPK), Akt, mammalian target of rapamycin (mTOR), autophagy and their interplay in osteogenic differentiation of human dental pulp mesenchymal stem cells. The activation of various members of AMPK, Akt and mTOR signaling pathways and autophagy was analyzed by immunoblotting, while osteogenic differentiation was assessed by alkaline phosphatase staining and real-time RT-PCR/immunoblot quantification of osteocalcin, Runt-related transcription factor 2 and bone morphogenetic protein 2 mRNA and/or protein levels. Osteogenic differentiation of mesenchymal stem cells was associated with early (day 1) activation of AMPK and its target Raptor, coinciding with the inhibition of mTOR and its substrate p70S6 kinase. The early induction of autophagy was demonstrated by accumulation of autophagosome-bound LC3-II, upregulation of proautophagic beclin-1 and a decrease in the selective autophagic target p62. This was followed by the late activation of Akt/mTOR at days 3-7 of differentiation. The RNA interference-mediated silencing of AMPK, mTOR or autophagy-essential LC3β, as well as the pharmacological inhibitors of AMPK (compound C), Akt (10-DEBC hydrochloride), mTOR (rapamycin) and autophagy (bafilomycin A1, chloroquine and ammonium chloride), each suppressed mesenchymal stem cell differentiation to osteoblasts. AMPK knockdown prevented early mTOR inhibition and autophagy induction, as well as late activation of Akt/mTOR signaling, while Akt inhibition suppressed mTOR activation without affecting AMPK phosphorylation. Our data indicate that AMPK controls osteogenic differentiation of human mesenchymal stem cells through both early mTOR inhibition-mediated autophagy and late activation of Akt/mTOR signaling axis.
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Affiliation(s)
- Aleksandar Pantovic
- Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr Subotica 1, 11000 Belgrade, Serbia
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Bruce CR, Risis S, Babb JR, Yang C, Kowalski GM, Selathurai A, Lee-Young RS, Weir JM, Yoshioka K, Takuwa Y, Meikle PJ, Pitson SM, Febbraio MA. Overexpression of sphingosine kinase 1 prevents ceramide accumulation and ameliorates muscle insulin resistance in high-fat diet-fed mice. Diabetes 2012; 61:3148-55. [PMID: 22961081 PMCID: PMC3501880 DOI: 10.2337/db12-0029] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The sphingolipids sphingosine-1-phosphate (S1P) and ceramide are important bioactive lipids with many cellular effects. Intracellular ceramide accumulation causes insulin resistance, but sphingosine kinase 1 (SphK1) prevents ceramide accumulation, in part, by promoting its metabolism into S1P. Despite this, the role of SphK1 in regulating insulin action has been largely overlooked. Transgenic (Tg) mice that overexpress SphK1 were fed a standard chow or high-fat diet (HFD) for 6 weeks before undergoing several metabolic analyses. SphK1 Tg mice fed an HFD displayed increased SphK activity in skeletal muscle, which was associated with an attenuated intramuscular ceramide accumulation compared with wild-type (WT) littermates. This was associated with a concomitant reduction in the phosphorylation of c-jun amino-terminal kinase, a serine threonine kinase associated with insulin resistance. Accordingly, skeletal muscle and whole-body insulin sensitivity were improved in SphK1 Tg, compared with WT mice, when fed an HFD. We have identified that the enzyme SphK1 is an important regulator of lipid partitioning and insulin action in skeletal muscle under conditions of increased lipid supply.
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Affiliation(s)
- Clinton R. Bruce
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Department of Physiology, Monash University, Clayton, Victoria, Australia
- Corresponding author: Mark A. Febbraio, , or Clinton R. Bruce,
| | - Steve Risis
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Joanne R. Babb
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Christine Yang
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Greg M. Kowalski
- Department of Physiology, Monash University, Clayton, Victoria, Australia
| | - Ahrathy Selathurai
- Department of Physiology, Monash University, Clayton, Victoria, Australia
| | - Robert S. Lee-Young
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Jacquelyn M. Weir
- Lipidomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | | | - Yoh Takuwa
- Department of Physiology, Kanazawa University, Kanazawa, Japan
| | - Peter J. Meikle
- Lipidomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Stuart M. Pitson
- Molecular Signalling Laboratory, Centre for Cancer Biology, Adelaide, South Australia, Australia
| | - Mark A. Febbraio
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Corresponding author: Mark A. Febbraio, , or Clinton R. Bruce,
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98
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Ou HC, Hsieh YL, Yang NC, Tsai KL, Chen KL, Tsai CS, Chen IJ, Wu BT, Lee SD. Ginkgo biloba extract attenuates oxLDL-induced endothelial dysfunction via an AMPK-dependent mechanism. J Appl Physiol (1985) 2012. [PMID: 23195633 DOI: 10.1152/japplphysiol.00367.2012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Atherosclerosis is a complex inflammatory arterial disease, and oxidized low-density lipoprotein (oxLDL) is directly associated with chronic vascular inflammation. Previous studies have shown that Ginkgo biloba extract (GbE) acts as a therapeutic agent for neurological and cardiovascular disorders. However, the mechanisms mediating the actions of GbE are still largely unknown. In the present study, we tested the hypothesis that GbE protects against oxLDL-induced endothelial dysfunction via an AMP-activated protein kinase (AMPK)-dependent mechanism. Human umbilical vein endothelial cells were treated with GbE, followed by oxLDL, for indicated time periods. Results from Western blot showed that GbE inhibited the membrane translocation of the NADPH oxidase subunits p47(phox) and Rac-1 and attenuated the increase in protein expression of membrane subunits gp91 and p22(phox) caused by oxLDL-induced AMPK dephosphorylation and subsequent PKC activation. AMPK-α(1)-specific small interfering RNA-transfected cells that had been exposed to GbE followed by oxLDL revealed elevated levels of PKC and p47(phox). In addition, exposure to oxLDL resulted in reduced AMPK-mediated Akt/endothelial nitric oxide (NO) synthase signaling and the induction of phosphorylation of p38 mitogen-activated protein kinase, which, in turn, activated NF-κB-mediated inflammatory responses, such as the release of interleukin-8, the expression of the adhesion molecule, and the adherence of monocytic cells to human umbilical vein endothelial cells. Furthermore, oxLDL upregulated the expression of inducible NO synthase, thereby augmenting the formation of NO and protein nitrosylation. Pretreatment with GbE, however, exerted significant cytoprotective effects in a dose-dependent manner. Results from this study may provide insight into a possible molecular mechanism by which GbE protects against oxLDL-induced endothelial dysfunction.
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Affiliation(s)
- Hsiu-Chung Ou
- Department of Physical Therapy and Graduate Institute of Rehabilitation Science, China Medical University, Taichung, Taiwan
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99
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Traumatic noise activates Rho-family GTPases through transient cellular energy depletion. J Neurosci 2012; 32:12421-30. [PMID: 22956833 DOI: 10.1523/jneurosci.6381-11.2012] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Small GTPases mediate transmembrane signaling and regulate the actin cytoskeleton in eukaryotic cells. Here, we characterize the auditory pathology of adult male CBA/J mice exposed to traumatic noise (2-20 kHz; 106 dB; 2 h). Loss of outer hair cells was evident 1 h after noise exposure in the basal region of the cochlea and spread apically with time, leading to permanent threshold shifts of 35, 60, and 65 dB at 8, 16, and 32 kHz. Several biochemical and molecular changes correlated temporally with the loss of cells. Immediately after exposure, the concentration of ATP decreased in cochlear tissue and reached a minimum after 1 h while the immunofluorescent signal for p-AMPKα significantly increased in sensory hair cells at that time. Levels of active Rac1 increased, whereas those of active RhoA decreased significantly 1 h after noise attaining a plateau at 1-3 h; the formation of a RhoA-p140mDia complex was consistent with an activation of Rho GTPase pathways. Also at 1-3 h after exposure, the caspase-independent cell death marker, Endo G, translocated to the nuclei of outer hair cells. Finally, experiments with the inner ear HEI-OC1 cell line demonstrated that the energy-depleting agent oligomycin enhanced both Rac1 activity and cell death. The sum of the results suggests that traumatic noise induces transient cellular ATP depletion and activates Rho GTPase pathways, leading to death of outer hair cells in the cochlea.
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100
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Teng RJ, Du J, Afolayan AJ, Eis A, Shi Y, Konduri GG. AMP kinase activation improves angiogenesis in pulmonary artery endothelial cells with in utero pulmonary hypertension. Am J Physiol Lung Cell Mol Physiol 2012; 304:L29-42. [PMID: 23103561 DOI: 10.1152/ajplung.00200.2012] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Pulmonary artery endothelial cells (PAEC) isolated from fetal lambs with in utero pulmonary hypertension (IPH) have phenotypical changes that lead to increased reactive oxygen species (ROS) formation and impaired angiogenesis. AMP-activated protein kinase (AMPK) is known to be activated by ROS, which is expected to help angiogenesis in IPH-PAEC. The objectives of this study were to investigate AMPK responses in IPH and its role in angiogenesis. We observed that, compared with control PAEC, IPH-PAEC have decreased phosphorylation of AMPKα catalytic subunit and AMPK downstream enzymes, indicating a decrease in AMPK activity. In addition, the expression of AMPK kinases is decreased, and protein phosphatase 2 is increased in IPH-PAEC, potentially contributing to the decreased AMPK activation. Metformin, an AMPK activator, improved IPH-PAEC angiogenesis while increasing endothelial NO synthase (eNOS) serine(1179) phosphorylation and decreasing the eNOS-caveolin-1 association. Metformin also increased MnSOD activity and the expression of both eNOS and MnSOD. The increase in angiogenesis by Metformin is abolished by pretreatment with AMPK inhibitor, Compound C. Expression of vascular endothelial growth factor (VEGF) and platelet-derived growth factor β (PDGFβ) are decreased in IPH-PAEC compared with control PAEC and were not altered by Metformin. These data indicate that Metformin improves angiogenesis through mechanisms independent of these angiogenic factors. In conclusion, activation of AMPK restores angiogenesis and increases the bioavailability of nitric oxide in IPH. Whether Metformin is beneficial in the management of pulmonary hypertension requires further investigation.
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Affiliation(s)
- Ru-Jeng Teng
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, USA.
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