101
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O’Rourke RW. Endometrial hyperplasia, endometrial cancer, and obesity: convergent mechanisms regulating energy homeostasis and cellular proliferation. Surg Obes Relat Dis 2014; 10:926-8. [DOI: 10.1016/j.soard.2014.03.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 03/27/2014] [Indexed: 12/19/2022]
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102
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Cheng G, Zielonka J, McAllister D, Tsai S, Dwinell MB, Kalyanaraman B. Profiling and targeting of cellular bioenergetics: inhibition of pancreatic cancer cell proliferation. Br J Cancer 2014; 111:85-93. [PMID: 24867695 PMCID: PMC4090735 DOI: 10.1038/bjc.2014.272] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/21/2014] [Accepted: 04/24/2014] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Targeting both mitochondrial bioenergetics and glycolysis pathway is an effective way to inhibit proliferation of tumour cells, including those that are resistant to conventional chemotherapeutics. METHODS In this study, using the Seahorse 96-well Extracellular Flux Analyzer, we mapped the two intrinsic cellular bioenergetic parameters, oxygen consumption rate and proton production rate in six different pancreatic cancer cell lines and determined their differential sensitivity to mitochondrial and glycolytic inhibitors. RESULTS There exists a very close relationship among intracellular bioenergetic parameters, depletion of ATP and anti-proliferative effects (inhibition of colony-forming ability) in pancreatic cancer cells derived from different genetic backgrounds treated with the glycolytic inhibitor, 2-deoxyglucose (2-DG). The most glycolytic pancreatic cancer cell line was exquisitely sensitive to 2-DG, whereas the least glycolytic pancreatic cancer cell was resistant to 2-DG. However, when combined with metformin, inhibitor of mitochondrial respiration and activator of AMP-activated protein kinase, 2-DG synergistically enhanced ATP depletion and inhibited cell proliferation even in poorly glycolytic, 2-DG-resistant pancreatic cancer cell line. Furthermore, treatment with conventional chemotherapeutic drugs (e.g., gemcitabine and doxorubicin) or COX-2 inhibitor, celecoxib, sensitised the cells to 2-DG treatment. CONCLUSIONS Detailed profiling of cellular bioenergetics can provide new insight into the design of therapeutic strategies for inhibiting pancreatic cancer cell metabolism and proliferation.
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Affiliation(s)
- G Cheng
- Department of Biophysics and Free Radical Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - J Zielonka
- Department of Biophysics and Free Radical Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - D McAllister
- Department of Biophysics and Free Radical Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - S Tsai
- Department of Surgery/Surgical Oncology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - M B Dwinell
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - B Kalyanaraman
- Department of Biophysics and Free Radical Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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103
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Metformin and phenformin deplete tricarboxylic acid cycle and glycolytic intermediates during cell transformation and NTPs in cancer stem cells. Proc Natl Acad Sci U S A 2014; 111:10574-9. [PMID: 25002509 DOI: 10.1073/pnas.1409844111] [Citation(s) in RCA: 211] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Metformin, a first-line diabetes drug linked to cancer prevention in retrospective clinical analyses, inhibits cellular transformation and selectively kills breast cancer stem cells (CSCs). Although a few metabolic effects of metformin and the related biguanide phenformin have been investigated in established cancer cell lines, the global metabolic impact of biguanides during the process of neoplastic transformation and in CSCs is unknown. Here, we use LC/MS/MS metabolomics (>200 metabolites) to assess metabolic changes induced by metformin and phenformin in an Src-inducible model of cellular transformation and in mammosphere-derived breast CSCs. Although phenformin is the more potent biguanide in both systems, the metabolic profiles of these drugs are remarkably similar, although not identical. During the process of cellular transformation, biguanide treatment prevents the boost in glycolytic intermediates at a specific stage of the pathway and coordinately decreases tricarboxylic acid (TCA) cycle intermediates. In contrast, in breast CSCs, biguanides have a modest effect on glycolytic and TCA cycle intermediates, but they strongly deplete nucleotide triphosphates and may impede nucleotide synthesis. These metabolic profiles are consistent with the idea that biguanides inhibit mitochondrial complex 1, but they indicate that their metabolic effects differ depending on the stage of cellular transformation.
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104
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Knockdown of malic enzyme 2 suppresses lung tumor growth, induces differentiation and impacts PI3K/AKT signaling. Sci Rep 2014; 4:5414. [PMID: 24957098 PMCID: PMC4067620 DOI: 10.1038/srep05414] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 06/02/2014] [Indexed: 12/30/2022] Open
Abstract
Mitochondrial malic enzyme 2 (ME2) catalyzes the oxidative decarboxylation of malate to yield CO2 and pyruvate, with concomitant reduction of dinucleotide cofactor NAD+ or NADP+. We find that ME2 is highly expressed in many solid tumors. In the A549 non-small cell lung cancer (NSCLC) cell line, ME2 depletion inhibits cell proliferation and induces cell death and differentiation, accompanied by increased reactive oxygen species (ROS) and NADP+/NADPH ratio, a drop in ATP, and increased sensitivity to cisplatin. ME2 knockdown impacts phosphoinositide-dependent protein kinase 1 (PDK1) and phosphatase and tensin homolog (PTEN) expression, leading to AKT inhibition. Depletion of ME2 leads to malate accumulation and pyruvate decrease, and exogenous cell permeable dimethyl-malate (DMM) mimics the ME2 knockdown phenotype. Both ME2 knockdown and DMM treatment reduce A549 cell growth in vivo. Collectively, our data suggest that ME2 is a potential target for cancer therapy.
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105
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Vogt JA, Wachter U, Wagner K, Calzia E, Gröger M, Weber S, Stahl B, Georgieff M, Asfar P, Fontaine E, Radermacher P, Leverve XM, Wagner F. Effects of glycemic control on glucose utilization and mitochondrial respiration during resuscitated murine septic shock. Intensive Care Med Exp 2014; 2:19. [PMID: 26266919 PMCID: PMC4678133 DOI: 10.1186/2197-425x-2-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 04/08/2014] [Indexed: 12/13/2022] Open
Abstract
Background This study aims to test the hypothesis whether lowering glycemia improves mitochondrial function and thereby attenuates apoptotic cell death during resuscitated murine septic shock. Methods Immediately and 6 h after cecal ligation and puncture (CLP), mice randomly received either vehicle or the anti-diabetic drug EMD008 (100 μg · g-1). At 15 h post CLP, mice were anesthetized, mechanically ventilated, instrumented and rendered normo- or hyperglycemic (target glycemia 100 ± 20 and 180 ± 50 mg · dL-1, respectively) by infusing stable, non-radioactive isotope-labeled 13C6-glucose. Target hemodynamics was achieved by colloid fluid resuscitation and continuous i.v. noradrenaline, and mechanical ventilation was titrated according to blood gases and pulmonary compliance measurements. Gluconeogenesis and glucose oxidation were derived from blood and expiratory glucose and 13CO2 isotope enrichments, respectively; mathematical modeling allowed analyzing isotope data for glucose uptake as a function of glycemia. Postmortem liver tissue was analyzed for HO-1, AMPK, caspase-3, and Bax (western blotting) expression as well as for mitochondrial respiratory activity (high-resolution respirometry). Results Hyperglycemia lowered mitochondrial respiratory capacity; EMD008 treatment was associated with increased mitochondrial respiration. Hyperglycemia decreased AMPK phosphorylation, and EMD008 attenuated both this effect as well as the expression of activated caspase-3 and Bax. During hyperglycemia EMD008 increased HO-1 expression. During hyperglycemia, maximal mitochondrial oxidative phosphorylation rate was directly related to HO-1 expression, while it was unrelated to AMPK activation. According to the mathematical modeling, EMD008 increased the slope of glucose uptake plotted as a function of glycemia. Conclusions During resuscitated, polymicrobial, murine septic shock, glycemic control either by reducing glucose infusion rates or EMD008 improved glucose uptake and thereby liver tissue mitochondrial respiratory activity. EMD008 effects were more pronounced during hyperglycemia and coincided with attenuated markers of apoptosis. The effects of glucose control were at least in part due to the up-regulation of HO-1 and activation of AMPK. Electronic supplementary material The online version of this article (doi:10.1186/2197-425X-2-19) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Josef A Vogt
- Sektion Anästhesiologische Pathophysiologie und Verfahrensentwicklung, Klinik für Anästhesiologie, Universitätsklinikum, Helmhotzstrasse 8-1, Ulm, 89081, Germany,
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106
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Kim HY, Cha HJ, Kim HS. CCL5 upregulates activation of AMP-activated protein kinases in vascular smooth muscle cells of spontaneously hypertensive rats. Cytokine 2014; 67:77-84. [DOI: 10.1016/j.cyto.2014.02.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 01/15/2014] [Accepted: 02/25/2014] [Indexed: 11/25/2022]
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107
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Involvement of the AMPK–PTEN pathway in insulin resistance induced by high glucose in cultured rat podocytes. Int J Biochem Cell Biol 2014; 51:120-30. [DOI: 10.1016/j.biocel.2014.04.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 03/28/2014] [Accepted: 04/09/2014] [Indexed: 11/17/2022]
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108
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Qi X, Xu J, Gu P, Yang X, Gao X. PTEN in smooth muscle cells is essential for colonic immune homeostasis. Int J Biochem Cell Biol 2014; 53:108-14. [PMID: 24819541 DOI: 10.1016/j.biocel.2014.04.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 04/14/2014] [Accepted: 04/29/2014] [Indexed: 12/25/2022]
Abstract
Colonic immune homeostasis is essential for normal gastrointestinal tract functioning. In this study, we report that specific gene targeting of phosphatase and tensin homolog (PTEN) in smooth muscle cells caused age-related colonic lymphoid hyperplasia followed by global immune activation in mice. Beginning at 5 weeks of age, these mutant mice displayed massive neutrophil infiltration in the colonic lamina propria. The gene expression levels of pro-inflammatory cytokines and chemokines, including those code for monocyte chemotactic protein-1 (Mcp-1), stromal cell-derived factor 1α (Sdf-1α), and chemokine (C-C motif) ligand 28 (Ccl-28), were upregulated in the colon. Accordingly, permeability and proliferation of the colonic epithelium was compromised. These abnormalities were alleviated to a great extent when the mutants were crossed with Akt1-null mice, indicating that the pathogenesis was mediated by Akt1 signaling. Our results suggest that in smooth muscle cells, PTEN is crucial for maintaining colonic immune homeostasis.
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Affiliation(s)
- Xin Qi
- Genetic Laboratory of Development and Diseases, Institute of Biotechnology, Beijing 100071, PR China; MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, 12 Xuefu Road, Nanjing 210061, China
| | - Jingyue Xu
- Genetic Laboratory of Development and Diseases, Institute of Biotechnology, Beijing 100071, PR China
| | - Pengyu Gu
- Genetic Laboratory of Development and Diseases, Institute of Biotechnology, Beijing 100071, PR China
| | - Xiao Yang
- Genetic Laboratory of Development and Diseases, Institute of Biotechnology, Beijing 100071, PR China
| | - Xiang Gao
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, 12 Xuefu Road, Nanjing 210061, China.
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109
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Wu WY, Yan H, Wang XB, Gui YZ, Gao F, Tang XL, Qin YL, Su M, Chen T, Wang YP. Sodium tanshinone IIA silate inhibits high glucose-induced vascular smooth muscle cell proliferation and migration through activation of AMP-activated protein kinase. PLoS One 2014; 9:e94957. [PMID: 24739942 PMCID: PMC3989257 DOI: 10.1371/journal.pone.0094957] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 03/21/2014] [Indexed: 11/30/2022] Open
Abstract
The proliferation of vascular smooth muscle cells may perform a crucial role in the pathogenesis of diabetic vascular disease. AMPK additionally exerts several salutary effects on vascular function and improves vascular abnormalities. The current study sought to determine whether sodium tanshinone IIA silate (STS) has an inhibitory effect on vascular smooth muscle cell (VSMC) proliferation and migration under high glucose conditions mimicking diabetes without dyslipidemia, and establish the underlying mechanism. In this study, STS promoted the phosphorylation of AMP-activated protein kinase (AMPK) at T172 in VSMCs. VSMC proliferation was enhanced under high glucose (25 mM glucose, HG) versus normal glucose conditions (5.5 mM glucose, NG), and this increase was inhibited significantly by STS treatment. We utilized western blotting analysis to evaluate the effects of STS on cell-cycle regulatory proteins and found that STS increased the expression of p53 and the Cdk inhibitor, p21, subsequent decreased the expression of cell cycle-associated protein, cyclin D1. We further observed that STS arrested cell cycle progression at the G0/G1 phase. Additionally, expression and enzymatic activity of MMP-2, translocation of NF-κB, as well as VSMC migration were suppressed in the presence of STS. Notably, Compound C (CC), a specific inhibitor of AMPK, as well as AMPK siRNA blocked STS-mediated inhibition of VSMC proliferation and migration. We further evaluated its potential for activating AMPK in aortas in animal models of type 2 diabetes and found that Oral administration of STS for 10 days resulted in activation of AMPK in aortas from ob/ob or db/db mice. In conclusion, STS inhibits high glucose-induced VSMC proliferation and migration, possibly through AMPK activation. The growth suppression effect may be attributable to activation of AMPK-p53-p21 signaling, and the inhibitory effect on migration to the AMPK/NF-κB signaling axis.
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MESH Headings
- AMP-Activated Protein Kinases/genetics
- AMP-Activated Protein Kinases/metabolism
- Abietanes/pharmacology
- Animals
- Aorta/enzymology
- Blotting, Western
- Cell Cycle Checkpoints/drug effects
- Cell Movement/drug effects
- Cell Proliferation/drug effects
- Diabetes Mellitus, Type 2/enzymology
- Diabetes Mellitus, Type 2/genetics
- Dose-Response Relationship, Drug
- Drugs, Chinese Herbal/pharmacology
- Enzyme Activation/drug effects
- Flow Cytometry
- Glucose/pharmacology
- Male
- Mice
- Mice, Mutant Strains
- Mice, Obese
- Muscle, Smooth, Vascular/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Phosphorylation/drug effects
- Primary Cell Culture
- RNA Interference
- Rats, Sprague-Dawley
- Threonine/metabolism
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Affiliation(s)
- Wen-yu Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Hong Yan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xin-bo Wang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yu-zhou Gui
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Fei Gao
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xi-lan Tang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yin-lin Qin
- Carefree Pharmaceutical Co., Ltd, Nanjing, China
| | - Mei Su
- Carefree Pharmaceutical Co., Ltd, Nanjing, China
| | - Tao Chen
- Carefree Pharmaceutical Co., Ltd, Nanjing, China
| | - Yi-ping Wang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
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110
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Bułdak Ł, Łabuzek K, Bułdak RJ, Kozłowski M, Machnik G, Liber S, Suchy D, Duława-Bułdak A, Okopień B. Metformin affects macrophages' phenotype and improves the activity of glutathione peroxidase, superoxide dismutase, catalase and decreases malondialdehyde concentration in a partially AMPK-independent manner in LPS-stimulated human monocytes/macrophages. Pharmacol Rep 2014; 66:418-29. [PMID: 24905518 DOI: 10.1016/j.pharep.2013.11.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 10/22/2013] [Accepted: 11/18/2013] [Indexed: 12/18/2022]
Abstract
BACKGROUND Diabetic patients experience accelerated atherosclerosis. Metformin is a cornerstone of the current therapy of type 2 diabetes. Macrophages are the key cells associated with the development of atherosclerotic plaques. Therefore, our aim was to assess the in vitro effects of metformin on macrophages and its influence on the mechanisms involved in the development of atherosclerosis. MATERIALS AND METHODS Peripheral blood mononuclear cells were obtained from the group including 16 age-matched healthy non-smoking volunteers aged 18-40 years. Monocytes were further incubated with metformin, LPS and compound C--a pharmacological inhibitor of AMPK. The impact of metformin on oxidative stress markers, antioxidative properties, inflammatory cytokines and phenotypical markers of macrophages was studied. RESULTS We showed that macrophages treated with metformin expressed less reactive oxygen species (ROS), which resulted from increased antioxidative potential. Furthermore, a reduction in inflammatory cytokines was observed. We also observed a phenotypic shift toward the alternative activation of macrophages that was induced by metformin. All the aforementioned results resulted from AMPK activation, but a residual activity of metformin after AMPK blockade was still noticeable even after inhibition of AMPK by compound C. CONCLUSIONS Authors believe that metformin-based therapy, a cornerstone in diabetes therapy, not only improves the prognosis of diabetics by reducing blood glucose but also by reducing oxidative stress, inflammatory cytokine production and the shift toward alternative activation of macrophages.
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Affiliation(s)
- Łukasz Bułdak
- Department of Internal Medicine and Clinical Pharmacology, Medical University of Silesia, Katowice, Poland.
| | - Krzysztof Łabuzek
- Department of Internal Medicine and Clinical Pharmacology, Medical University of Silesia, Katowice, Poland
| | - Rafał Jakub Bułdak
- Department of Physiology, Medical University of Silesia, Zabrze, Poland.
| | - Michał Kozłowski
- Department of Internal Medicine and Clinical Pharmacology, Medical University of Silesia, Katowice, Poland
| | - Grzegorz Machnik
- Department of Internal Medicine and Clinical Pharmacology, Medical University of Silesia, Katowice, Poland
| | - Sebastian Liber
- Department of Internal Medicine and Clinical Pharmacology, Medical University of Silesia, Katowice, Poland
| | - Dariusz Suchy
- Department of Internal Medicine and Clinical Pharmacology, Medical University of Silesia, Katowice, Poland
| | - Anna Duława-Bułdak
- Department of Anesthesiology and Intensive Care, Medical University of Silesia, Katowice, Poland
| | - Bogusław Okopień
- Department of Internal Medicine and Clinical Pharmacology, Medical University of Silesia, Katowice, Poland
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111
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Venna VR, Li J, Hammond MD, Mancini NS, McCullough LD. Chronic metformin treatment improves post-stroke angiogenesis and recovery after experimental stroke. Eur J Neurosci 2014; 39:2129-38. [PMID: 24649970 DOI: 10.1111/ejn.12556] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 02/09/2014] [Accepted: 02/12/2014] [Indexed: 02/06/2023]
Abstract
Metformin is currently the first-line treatment drug for type 2 diabetes. Metformin is a well-known activator of AMP-activated protein kinase (AMPK). In experimental studies, metformin has been shown to exert direct vascular effects by increasing vascular endothelial growth factor expression and improving microvascular density. As stroke is the leading cause of long-term disability and angiogenesis is implicated as an important mechanism in functional recovery, we hypothesized that chronic metformin treatment would improve post-stroke functional recovery by enhancing functional microvascular density. For this study, C57BL/6N male mice were subjected to a 60-min middle cerebral artery occlusion, and were given 50 mg/kg/day metformin beginning 24 h post-stroke for 3 weeks. Behavioral recovery was assessed using adhesive-tape removal and the apomorphine-induced turning test. The role of angiogenesis was assessed by counting vessel branch points from fluorescein-conjugated lectin-perfused brain sections. Importantly even if metformin treatment was initiated 24 h after injury it enhanced recovery and significantly improved stroke-induced behavioral deficits. This recovery occurred in parallel with enhanced angiogenesis and with restoration of endogenous cerebral dopaminergic tone and revascularization of ischemic tissue. We assessed if the effects on recovery and angiogenesis were mediated by AMPK. When tested in AMPK α-2 knockout mice, we found that metformin treatment did not have the same beneficial effects on recovery and angiogenesis, suggesting that metformin-induced angiogenic effects are mediated by AMPK. The results from this study suggest that metformin mediates post-stroke recovery by enhancing angiogenesis, and these effects are mediated by AMPK signaling.
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Affiliation(s)
- Venugopal R Venna
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, USA
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112
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Zippel N, Malik RA, Frömel T, Popp R, Bess E, Strilic B, Wettschureck N, Fleming I, Fisslthaler B. Transforming Growth Factor-β–Activated Kinase 1 Regulates Angiogenesis via AMP-Activated Protein Kinase-α1 and Redox Balance in Endothelial Cells. Arterioscler Thromb Vasc Biol 2013; 33:2792-9. [DOI: 10.1161/atvbaha.113.301848] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Objective—
Transforming growth factor-β–activated kinase 1 (TAK1) is a mitogen-activated protein 3-kinase and an AMP-activated protein kinase (AMPK) kinase in some cell types. Although TAK1
−/−
mice display defects in developmental vasculogenesis, the role of TAK1 in endothelial cells has not been investigated in detail.
Approach and Results—
TAK1 downregulation (small interfering RNA) in human endothelial cells attenuated proliferation without inducing apoptosis and diminished endothelial cell migration, as well as tube formation. Cytokine- and vascular endothelial growth factor (VEGF)–induced endothelial cell sprouting in a modified spheroid assay were abrogated by TAK1 downregulation. Moreover, VEGF–induced endothelial sprouting was impaired in aortic rings from mice lacking TAK1 in endothelial cells (TAK
ΔEC
). TAK1 inhibition and downregulation also inhibited VEGF–stimulated phosphorylation of several kinases, including AMPK. Proteomic analyses revealed that superoxide dismutase 2 (SOD2) expression was reduced in TAK1-deficient endothelial cells, resulting in attenuated hydrogen peroxide production but increased mitochondrial superoxide production. Endothelial cell SOD2 expression was also attenuated by AMPK inhibition and in endothelial cells from AMPKα1
−/−
mice but was unaffected by inhibitors of c-Jun N-terminal kinase, p38, extracellular signal–regulated kinase 1/2, or phosphatidylinositol 3-kinase/Akt. Moreover, the impaired endothelial sprouting from TAK
ΔEC
aortic rings was abrogated in the presence of polyethylene glycol-SOD, and tube formation was normalized by the overexpression of SOD2. A similar rescue of angiogenesis was observed in polyethylene glycol-SOD–treated aortic rings from mice with endothelial cell–specific deletion of the AMPKα1.
Conclusions—
These results establish TAK1 as an AMPKα1 kinase that regulates vascular endothelial growth factor–induced and cytokine-induced angiogenesis by modulating SOD2 expression and the superoxide anion:hydrogen peroxide balance.
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Affiliation(s)
- Nina Zippel
- From the Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt, Germany and DZHK (German Centre for Cardiovascular Research) partner site Rhine-Main (N.Z., R.A.M., T.F., R.P., E.B., I.F., B.F.); and Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (B.S., N.W.)
| | - Randa Abdel Malik
- From the Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt, Germany and DZHK (German Centre for Cardiovascular Research) partner site Rhine-Main (N.Z., R.A.M., T.F., R.P., E.B., I.F., B.F.); and Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (B.S., N.W.)
| | - Timo Frömel
- From the Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt, Germany and DZHK (German Centre for Cardiovascular Research) partner site Rhine-Main (N.Z., R.A.M., T.F., R.P., E.B., I.F., B.F.); and Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (B.S., N.W.)
| | - Rüdiger Popp
- From the Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt, Germany and DZHK (German Centre for Cardiovascular Research) partner site Rhine-Main (N.Z., R.A.M., T.F., R.P., E.B., I.F., B.F.); and Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (B.S., N.W.)
| | - Elke Bess
- From the Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt, Germany and DZHK (German Centre for Cardiovascular Research) partner site Rhine-Main (N.Z., R.A.M., T.F., R.P., E.B., I.F., B.F.); and Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (B.S., N.W.)
| | - Boris Strilic
- From the Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt, Germany and DZHK (German Centre for Cardiovascular Research) partner site Rhine-Main (N.Z., R.A.M., T.F., R.P., E.B., I.F., B.F.); and Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (B.S., N.W.)
| | - Nina Wettschureck
- From the Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt, Germany and DZHK (German Centre for Cardiovascular Research) partner site Rhine-Main (N.Z., R.A.M., T.F., R.P., E.B., I.F., B.F.); and Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (B.S., N.W.)
| | - Ingrid Fleming
- From the Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt, Germany and DZHK (German Centre for Cardiovascular Research) partner site Rhine-Main (N.Z., R.A.M., T.F., R.P., E.B., I.F., B.F.); and Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (B.S., N.W.)
| | - Beate Fisslthaler
- From the Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt, Germany and DZHK (German Centre for Cardiovascular Research) partner site Rhine-Main (N.Z., R.A.M., T.F., R.P., E.B., I.F., B.F.); and Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (B.S., N.W.)
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113
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Lin CF, Young KC, Bai CH, Yu BC, Ma CT, Chien YC, Su HC, Wang HY, Liao CS, Lai HW, Tsao CW. Blockade of reactive oxygen species and Akt activation is critical for anti-inflammation and growth inhibition of metformin in phosphatase and tensin homolog-deficient RAW264.7 cells. Immunopharmacol Immunotoxicol 2013; 35:669-77. [PMID: 24053326 DOI: 10.3109/08923973.2013.837059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
CONTEXT Metformin is widely used for treatment of type 2 diabetes and has a potential application on the treatment of inflammation and cancer. Phosphatase and tensin homolog (PTEN) plays a critical role in cancer cell growth and inflammation; however, precise mechanisms remain unclear. OBJECTIVE We aimed to investigate the possible mechanisms of how PTEN regulates metformin against cell growth and inflammation. MATERIALS AND METHODS We established PTEN knockdown in RAW264.7 murine macrophages (shPTEN cells) to detect inflammatory mediators using commercial kits, production of reactive oxygen species (ROS) by flow cytometry, cell growth by MTT assay and phosphorylated levels of signal molecules by western blot. RESULTS The shPTEN cells had a significant large amount of inflammatory mediators, such as inducible nitric oxide synthase (iNOS)/nitric oxide (NO) and cyclooxygenase-2 (COX-2)/prostaglandin E(2) (PGE(2)); and also elevated the production of ROS and increased cell proliferation. These effects were accompanied with the activation of Akt and p38 mitogen-activated protein kinase (MAPK), and the inactivation of an AMP-activated protein kinase (AMPK) activator and extracellular signal-regulated kinase 1/2. Pretreatment with metformin not only blocked these inflammatory mediators, but also caused growth inhibition induced by significant apoptosis. Furthermore, inactivation of Akt, blockade of ROS generation and independence of activations of AMPK and MAPK by metformin were also observed. CONCLUSION Macrophages with PTEN deficiency developed a continuous inflammatory microenvironment, which further aggravated tumor cell growth. Moreover, metformin affected PTEN-deficient cells dependent of inhibition of ROS production and Akt activation against enlarged inflammatory mediators and/or cell growth in shPTEN cells.
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Paintlia AS, Paintlia MK, Mohan S, Singh AK, Singh I. AMP-activated protein kinase signaling protects oligodendrocytes that restore central nervous system functions in an experimental autoimmune encephalomyelitis model. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 183:526-41. [PMID: 23759513 DOI: 10.1016/j.ajpath.2013.04.030] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Revised: 04/22/2013] [Accepted: 04/29/2013] [Indexed: 12/12/2022]
Abstract
AMP-activated protein kinase (AMPK) signaling is reported to protect neurons under pathologic conditions; however, its effect on oligodendrocytes (OLs) remains to be elucidated. We investigated whether AMPK signaling protects OLs to restore central nervous system (CNS) functions in an experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis. Increased inflammation and demyelination in the CNS and peripheral immune responses were consistent with the observed clinical impairments in EAE animals, which were attenuated by treatment with metformin compared with vehicle. In addition, expressions of neurotrophic factors and of signatory genes of OL lineages were increased in the CNS of metformin-treated EAE animals. Likewise, metformin attenuated inflammatory response and enhanced expressions of neurotrophic factors, thereby protecting OLs via AMPK activation in mixed glial cultures stimulated with lipopolysaccharide/interferon γ in vitro, as evidenced by analysis of the expression of signatory genes of O1(+)/MBP(+) OLs and their cellular populations. Metformin also attenuated oxidative stress and malondialdehyde-containing protein levels, with corresponding induction of antioxidative defenses in OLs exposed to cytokines via AMPK activation. These effects of metformin were evident in the CNS of EAE animals. These data provide evidence that AMPK signaling is crucial to protect OLs and, thus, CNS functions in EAE animals. We conclude that AMPK activators, including metformin, have the potential to limit neurologic deficits in multiple sclerosis and related neurodegenerative disorders.
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Affiliation(s)
- Ajaib S Paintlia
- Darby Children's Research Institute, Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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Baars T, Konorza T, Kahlert P, Möhlenkamp S, Erbel R, Heusch G, Kleinbongard P. Coronary aspirate TNFα reflects saphenous vein bypass graft restenosis risk in diabetic patients. Cardiovasc Diabetol 2013; 12:12. [PMID: 23305356 PMCID: PMC3560373 DOI: 10.1186/1475-2840-12-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 01/08/2013] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Patients with diabetes mellitus (DM) have an increased risk for periprocedural complications and adverse cardiac events after percutaneous coronary intervention. We addressed the potential for coronary microvascular obstruction and restenosis in patients with and without DM undergoing stenting for saphenous vein bypass graft (SVG) stenosis under protection with a distal occlusion/aspiration device. METHODS SVG plaque volume and composition were analyzed using intravascular ultrasound before stent implantation. Percent diameter stenosis was determined from quantitative coronary angiography before, immediately after and 6 months after stent implantation. Coronary aspirate was retrieved during stent implantation and divided into particulate debris and plasma. Total calcium, several vasoconstrictors, and tumor necrosis factor (TNF)α in particulate debris and coronary aspirate plasma were determined. RESULTS Patients with and without DM had similar plaque volume, but larger necrotic core and greater particulate debris release in patients with than without DM (20.3±2.7 vs. 12.7±2.6% and 143.9±19.3 vs. 75.1±10.4 mg, P<0.05). The TNFα concentration in particulate debris and coronary aspirate plasma was higher in patients with than without DM (15.9±6.6 vs. 5.1±2.4 pmol/mg and 2.2±0.7 vs. 1.1±0.2 pmol/L, P<0.05), whereas total calcium and vasoconstrictors were not different. Patients with DM had a greater percent diameter stenosis 6 months after stent implantation than those without DM (22.17±5.22 vs. 6.34±1.11%, P<0.05). The increase in TNFα immediately after stent implantation correlated with restenosis 6 months later (r=0.69, P<0.05). CONCLUSION In diabetics, particulate debris and coronary aspirate plasma contained more TNFα, which might reflect the activity of the underlying atherosclerotic process. TRIAL REGISTRATION URL: http://www.clinicaltrials.gov/ct2/results?term=NCT01430884; unique identifier: NCT01430884.
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Affiliation(s)
- Theodor Baars
- Institut für Pathophysiologie, Universitätsklinikum Essen, Hufelandstr 55, 45122 Essen, Germany
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Paintlia AS, Mohan S, Singh I. Combinatorial Effect of Metformin and Lovastatin Impedes T-cell Autoimmunity and Neurodegeneration in Experimental Autoimmune Encephalomyelitis. ACTA ACUST UNITED AC 2013; 4. [PMID: 24324917 DOI: 10.4172/2155-9899.1000149] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Multiple Sclerosis (MS) is an incurable central nervous system (CNS) demyelinating disease affecting several million people worldwide. Due to the multifactorial and complex pathology of MS, FDA approved drugs often show limited efficacy inpatients. We earlier documented that both lovastatin (cholesterol lowering drug) and metformin (anti-diabetic drug) attenuate experimental autoimmune encephalomyelitis (EAE), a widely used model of MS via different mechanisms of action. Since combination therapy of two or more agents has advantage over monotherapy, we here assessed the therapeutic efficacy of metformin and lovastatin combination in EAE. We found that suboptimal doses of these drugs in combination had additive effect to attenuate established EAE in treated animals than their individual treatments. Histological, immunohistochemistry and western blotting analyses revealed that the observed demyelination and axonal loss as evident from reduced levels of myelin and neurofilament proteins in the spinal cords of EAE animals were attenuated by treatment with these drugs in combination. Accordingly, the observed infiltration of myelin reactive T cells (CD4 and CD8) and macrophages (CD68) as well as the increased expression of their signatory cytokines in the spinal cords of EAE animals were attenuated by this regimen as revealed by enzyme-linked immune-sorbent assay and real-time PCR analyses. In the periphery, this regimen biased the class of elicited anti-myelin basic protein immunoglobulins from IgG2a to IgG1 and IgG2b, suggesting a Th1 to Th2 shift which was further supported by the increased expression of their signatory cytokines in EAE animals. Taken together, these data imply that metformin and lovastatin combination attenuates T-cell autoimmunity and neurodegeneration in treated EAE animals thereby suggesting that the oral administration of these FDA approved drugs in combination has potential to limit MS pathogenesis.
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Affiliation(s)
- Ajaib S Paintlia
- Darby Children's Research Institute, Department of Pediatrics, Medical University of South Carolina Charleston, South Carolina 29425, USA
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Metformin inhibits the inflammatory response associated with cellular transformation and cancer stem cell growth. Proc Natl Acad Sci U S A 2012; 110:972-7. [PMID: 23277563 DOI: 10.1073/pnas.1221055110] [Citation(s) in RCA: 337] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Metformin, the first-line drug for treating diabetes, inhibits cellular transformation and selectively kills cancer stem cells in breast cancer cell lines. In a Src-inducible model of cellular transformation, metformin inhibits the earliest known step in the process, activation of the inflammatory transcription factor NF-κB. Metformin strongly delays cellular transformation in a manner similar to that occurring upon a weaker inflammatory stimulus. Conversely, inhibition of transformation does not occur if metformin is added after the initial inflammatory stimulus. The antitransformation effect of metformin can be bypassed by overexpression of Lin28B or IL1β, downstream targets of NF-κB. Metformin preferentially inhibits nuclear translocation of NF-κB and phosphorylation of STAT3 in cancer stem cells compared with non-stem cancer cells in the same population. The ability of metformin to block tumor growth and prolong remission in xenografts in combination with doxorubicin is associated with decreased function of the inflammatory feedback loop. Lastly, metformin-based combinatorial therapy is effective in xenografts involving inflammatory prostate and melanoma cell lines, whereas it is ineffective in noninflammatory cell lines from these lineages. Taken together, our observations suggest that metformin inhibits a signal transduction pathway that results in an inflammatory response. As metformin alters energy metabolism in diabetics, we speculate that metformin may block a metabolic stress response that stimulates the inflammatory pathway associated with a wide variety of cancers.
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