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Merk H, Zhang S, Lehr T, Müller C, Ulrich M, Bibb JA, Adams RH, Bracher F, Zahler S, Vollmar AM, Liebl J. Inhibition of endothelial Cdk5 reduces tumor growth by promoting non-productive angiogenesis. Oncotarget 2017; 7:6088-104. [PMID: 26755662 PMCID: PMC4868742 DOI: 10.18632/oncotarget.6842] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 12/29/2015] [Indexed: 11/25/2022] Open
Abstract
Therapeutic success of VEGF-based anti-angiogenic tumor therapy is limited due to resistance. Thus, new strategies for anti-angiogenic cancer therapy based on novel targets are urgently required. Our previous in vitro work suggested that small molecule Cdk5 inhibitors affect angiogenic processes such as endothelial migration and proliferation. Moreover, we recently uncovered a substantial role of Cdk5 in the development of lymphatic vessels. Here we pin down the in vivo impact of endothelial Cdk5 inhibition in angiogenesis and elucidate the underlying mechanism in order to judge the potential of Cdk5 as a novel anti-angiogenic and anti-cancer target. By the use of endothelial-specific Cdk5 knockout mouse models and various endothelial and tumor cell based assays including human tumor xenograft models, we show that endothelial-specific knockdown of Cdk5 results in excessive but non-productive angiogenesis during development but also in tumors, which subsequently leads to inhibition of tumor growth. As Cdk5 inhibition disrupted Notch function by reducing the generation of the active Notch intracellular domain (NICD) and Cdk5 modulates Notch-dependent endothelial cell proliferation and sprouting, we propose that the Dll4/Notch driven angiogenic signaling hub is an important and promising mechanistic target of Cdk5. In fact, Cdk5 inhibition can sensitize tumors to conventional anti-angiogenic treatment as shown in tumor xenograft models. In summary our data set the stage for Cdk5 as a drugable target to inhibit Notch-driven angiogenesis condensing the view that Cdk5 is a promising target for cancer therapy.
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Affiliation(s)
- Henriette Merk
- Department of Pharmacy, Pharmaceutical Biology, Ludwig-Maximilians-University, 81377 Munich, Germany
| | - Siwei Zhang
- Department of Pharmacy, Pharmaceutical Biology, Ludwig-Maximilians-University, 81377 Munich, Germany
| | - Thorsten Lehr
- Clinical Pharmacy, Saarland University, 66123 Saarbrücken, Germany
| | - Christoph Müller
- Department of Pharmacy, Pharmaceutical Chemistry, Ludwig-Maximilians-University, 81377 Munich, Germany
| | - Melanie Ulrich
- Department of Pharmacy, Pharmaceutical Biology, Ludwig-Maximilians-University, 81377 Munich, Germany
| | - James A Bibb
- Department of Psychiatry and Neurology and Neurotherapeutics, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Ralf H Adams
- Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany.,University of Münster, Faculty of Medicine, 48149 Münster, Germany
| | - Franz Bracher
- Department of Pharmacy, Pharmaceutical Chemistry, Ludwig-Maximilians-University, 81377 Munich, Germany
| | - Stefan Zahler
- Department of Pharmacy, Pharmaceutical Biology, Ludwig-Maximilians-University, 81377 Munich, Germany
| | - Angelika M Vollmar
- Department of Pharmacy, Pharmaceutical Biology, Ludwig-Maximilians-University, 81377 Munich, Germany
| | - Johanna Liebl
- Department of Pharmacy, Pharmaceutical Biology, Ludwig-Maximilians-University, 81377 Munich, Germany
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Leung SWS, Vanhoutte PM. Endothelium-dependent hyperpolarization: age, gender and blood pressure, do they matter? Acta Physiol (Oxf) 2017; 219:108-123. [PMID: 26548576 DOI: 10.1111/apha.12628] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 09/21/2015] [Accepted: 11/02/2015] [Indexed: 12/14/2022]
Abstract
Under physiological conditions, the endothelium generates vasodilator signals [prostacyclin, nitric oxide NO and endothelium-dependent hyperpolarization (EDH)], for the regulation of vascular tone. The relative importance of these two signals depends on the diameter of the blood vessels: as the diameter of the arteries decreases, the contribution of EDH to the regulation of vascular tone increases. The mechanism involved in EDH varies with species and blood vessel types; nevertheless, activation of endothelial intermediate- and small-conductance calcium-activated potassium channels (IKCa and SKCa , respectively) is characteristic of the EDH pathway. IKCa - and SKCa -mediated EDH are reduced with endothelial dysfunction, which develops with ageing and hypertension, and is less pronounced in female than in age-matched male until after menopause. Impaired EDH-mediated relaxation is related to a reduced involvement of SKCa , so that the response becomes more dependent on IKCa . The latter depends on the activation of adenosine monophosphate-activated protein kinase (AMPK) and silent information regulator T1 (SIRT1), proteins associated with the process of cellular senescence and vascular signalling in response to the female hormone. An understanding of the role of AMPK and/or SIRT1 in EDH-like responses may help identifying effective pharmacological strategies to prevent the development of vascular complications of different aetiologies.
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Affiliation(s)
- S. W. S. Leung
- Department of Pharmacology & Pharmacy; University of Hong Kong; Hong Kong Hong Kong SAR China
| | - P. M. Vanhoutte
- Department of Pharmacology & Pharmacy; University of Hong Kong; Hong Kong Hong Kong SAR China
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Kong D, Zhan Y, Liu Z, Ding T, Li M, Yu H, Zhang L, Li H, Luo A, Zhang D, Wang Y, Wang S, Zhang Z, Zhang H, Huang X, Yao P, Ding Y, Liu Z. SIRT1-mediated ERβ suppression in the endothelium contributes to vascular aging. Aging Cell 2016; 15:1092-1102. [PMID: 27470296 PMCID: PMC6398526 DOI: 10.1111/acel.12515] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2016] [Indexed: 01/23/2023] Open
Abstract
SIRT1 has many important molecular functions in aging, and the estrogen receptors (ERs) have a vasculoprotective effect, although the detailed mechanism for the roles of SIRT1 and ERs in vascular aging remains unclear. We found that ERβ expression in the endothelium was reduced in aging mice, and the expression of ERα and SIRT1 did not change, while SIRT1 activity declined. Further investigation showed that the ERβ expression was regulated by SIRT1 through complexes of SIRT1‐PPARγ/RXR‐p300 that bind to a PPRE (PPAR response element) site on the ERβ promoter, and the declined SIRT1 function in aging mice was due to compromised phosphorylation at S154. A single‐mutant SIRT1‐C152(D) restored the reduced ERβ expression in the endothelium with minimized reactive oxygen species generation and DNA damage and increased mitochondrial function and fatty acid metabolism. In high‐fat diet aging mice, the endothelium‐specific delivery of ERβ or SIRT1‐C152(D) on the vascular wall reduced the circulating lipids with ameliorated vascular damage, including the restored vessel tension and blood pressure. We conclude that SIRT1‐mediated ERβ suppression in the endothelium contributes to vascular aging, and the modulation of SIRT1 phosphorylation through a single‐mutant SIRT1‐C152(D) restores this effect.
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Affiliation(s)
- Danli Kong
- School of Public Health Guangdong Medical College Dongguan 523808 China
| | - Ying Zhan
- Tongji Wenchang Hospital Huazhong University of Science and Technology Wenchang 571321 China
- Tongji Hospital Huazhong University of Science and Technology Wuhan 430030 China
| | - Zhaoyu Liu
- Tongji Hospital Huazhong University of Science and Technology Wuhan 430030 China
| | - Ting Ding
- Tongji Hospital Huazhong University of Science and Technology Wuhan 430030 China
| | - Min Li
- Tongji Wenchang Hospital Huazhong University of Science and Technology Wenchang 571321 China
- Inner Mongolia University for the Nationalities #1742 Huolinhe Str. Tongliao Inner Mongolia 028000 China
| | - Haibing Yu
- School of Public Health Guangdong Medical College Dongguan 523808 China
| | - Laxi Zhang
- Tongji Hospital Huazhong University of Science and Technology Wuhan 430030 China
| | - Huawen Li
- School of Public Health Guangdong Medical College Dongguan 523808 China
| | - Aiyue Luo
- Tongji Hospital Huazhong University of Science and Technology Wuhan 430030 China
| | - Dongwei Zhang
- Inner Mongolia University for the Nationalities #1742 Huolinhe Str. Tongliao Inner Mongolia 028000 China
| | - Yifei Wang
- Guangzhou Biomedical Research and Development Center Jinan University Guangzhou 510632 China
| | - Shixuan Wang
- Tongji Hospital Huazhong University of Science and Technology Wuhan 430030 China
| | - Zhefan Zhang
- Personalized Treatment Research Center The Third Hospital of Wuhan Wuhan 430060 China
| | - Hongyu Zhang
- Department of Hematology Peking University ShenZhen Hospital ShenZhen 518036 China
| | - Xiaodong Huang
- Personalized Treatment Research Center The Third Hospital of Wuhan Wuhan 430060 China
| | - Paul Yao
- School of Public Health Guangdong Medical College Dongguan 523808 China
- Tongji Wenchang Hospital Huazhong University of Science and Technology Wenchang 571321 China
| | - Yuanling Ding
- School of Public Health Guangdong Medical College Dongguan 523808 China
| | - Zhengxiang Liu
- Tongji Wenchang Hospital Huazhong University of Science and Technology Wenchang 571321 China
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Zhou Z, Yin Y, Chang Q, Sun G, Lin J, Dai Y. Downregulation of B-myb promotes senescence via the ROS-mediated p53/p21 pathway, in vascular endothelial cells. Cell Prolif 2016; 50. [PMID: 27878894 DOI: 10.1111/cpr.12319] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 10/18/2016] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVES To reveal whether B-myb is involved in preventing senescence of vascular endothelial cells, and if so, to identify possible mechanisms for it. MATERIALS AND METHODS C57/BL6 male mice and primary human aortic endothelial cells (HAECs) were used. Bleomycin was applied to induce stress-related premature senescence. B-myb knockdown was achieved using an siRNA technique and cell senescence was assessed using the senescence-associated β-galactosidase (SA-β-gal) assay. Intracellular reactive oxygen species (ROS) production was analysed using an ROS assay kit and cell proliferation was evaluated using KFluor488 EdU kit. Capillary tube network formation was determined by Matrigel assay. Expressions of mRNA and protein levels were detected by real-time PCR and western blotting. RESULTS B-myb expression significantly decreased, while p53 and p21 expressions increased in the aortas of aged mice. This expression pattern was also found in replicative senescent HAECs and senescent HAECs induced by bleomycin. B-myb knockdown resulted in upregulation of p22phox , ROS accumulation and cell senescence of HAECs. Downregulation of B-myb significantly inhibited cell proliferation and capillary tube network formation and activated the p53/p21 signalling pathway. Blocking ROS production or inhibiting p53 activation remarkably attenuated SA-β-gal activity and delayed cell senescence induced by B-myb-silencing. CONCLUSION Downregulation of B-myb induced senescence by upregulation of p22phox and activation of the ROS/p53/p21 pathway, in our vascular endothelial cells, suggesting that B-myb may be a novel candidate for regulating cell senescence to protect against endothelial senescence-related cardiovascular diseases.
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Affiliation(s)
- Zhihui Zhou
- Department of Cardiology, Shanghai East Hospital and Immunology Department, Tongji University School of Medicine, Shanghai, China
| | - Yanlin Yin
- Department of Cardiology, Shanghai East Hospital and Immunology Department, Tongji University School of Medicine, Shanghai, China
| | - Qun Chang
- Department of Cardiology, Shanghai East Hospital and Immunology Department, Tongji University School of Medicine, Shanghai, China
| | - Guanqun Sun
- Department of Cardiology, Shanghai East Hospital and Immunology Department, Tongji University School of Medicine, Shanghai, China
| | - Jiahui Lin
- Department of Cardiology, Shanghai East Hospital and Immunology Department, Tongji University School of Medicine, Shanghai, China
| | - Yalei Dai
- Department of Cardiology, Shanghai East Hospital and Immunology Department, Tongji University School of Medicine, Shanghai, China
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Serum from Varicose Patients Induces Senescence-Related Dysfunction of Vascular Endothelium Generating Local and Systemic Proinflammatory Conditions. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:2069290. [PMID: 27994710 PMCID: PMC5141312 DOI: 10.1155/2016/2069290] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 10/25/2016] [Accepted: 11/01/2016] [Indexed: 11/17/2022]
Abstract
Although the role of endothelium in varicose vein development is indisputable, the effect of the pathology on biological properties of endothelial cells remains unclear. Here we examined if the presence of varicose veins affects senescence of endothelial cells (HUVECs) and, if so, what will be the local and systemic outcome of this effect. Experiments showed that HUVECs subjected to serum from varicose patients display improved proliferation, increased expression of senescence marker, SA-β-Gal, and increased generation of reactive oxygen species (ROS), as compared with serum from healthy donors. Both increased SA-β-Gal activity and ROS release were mediated by TGF-β1, the concentration of which in varicose serum was elevated and the activity of which in vitro was prevented using specific neutralizing antibody. Senescent HUVECs exposed to varicose serum generated increased amounts of ICAM-1, VCAM-1, P-selectin, uPA, PAI-1, and ET-1. Direct comparison of sera from varicose and healthy donors showed that pathological serum contained increased level of ICAM-1, VCAM-1, P-selectin, uPA, and ET-1. Calendar age of healthy subjects correlated positively with serum uPA and negatively with P-selectin. Age of varicose patients correlated positively with ICAM-1, VCAM-1, and ET-1. Collectively, our findings indicate that the presence of varicose veins causes a senescence-related dysfunction of vascular endothelium, which leads to the development of local and systemic proinflammatory environment.
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Bochenek ML, Schütz E, Schäfer K. Endothelial cell senescence and thrombosis: Ageing clots. Thromb Res 2016; 147:36-45. [DOI: 10.1016/j.thromres.2016.09.019] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 09/16/2016] [Accepted: 09/17/2016] [Indexed: 01/28/2023]
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Li Q, Kim YR, Vikram A, Kumar S, Kassan M, Gabani M, Lee SK, Jacobs JS, Irani K. P66Shc-Induced MicroRNA-34a Causes Diabetic Endothelial Dysfunction by Downregulating Sirtuin1. Arterioscler Thromb Vasc Biol 2016; 36:2394-2403. [PMID: 27789474 DOI: 10.1161/atvbaha.116.308321] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 10/14/2016] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Diabetes mellitus causes vascular endothelial dysfunction and alters vascular microRNA expression. We investigated whether endothelial microRNA-34a (miR-34a) leads to diabetic vascular dysfunction by targeting endothelial sirtuin1 (Sirt1) and asked whether the oxidative stress protein p66Shc governs miR-34a expression in the diabetic endothelium. APPROACH AND RESULTS MiR-34a is upregulated, and Sirt1 downregulated, in aortic endothelium of db/db and streptozotocin-induced diabetic mice. Systemic administration of miR-34a inhibitor, or endothelium-specific knockout of miR-34a, prevents downregulation of aortic Sirt1 and rescues impaired endothelium-dependent aortic vasorelaxation induced by diabetes mellitus. Moreover, overexpression of Sirt1 mitigates impaired endothelium-dependent vasorelaxation caused by miR-34a mimic ex vivo. Systemic infusion of miR-34a inhibitor or genetic ablation of endothelial miR-34a prevents downregulation of endothelial Sirt1 by high glucose. MiR-34a is upregulated, Sirt1 is downregulated, and oxidative stress (hydrogen peroxide) is induced in endothelial cells incubated with high glucose or the free fatty acid palmitate in vitro. Increase of hydrogen peroxide and induction of endothelial miR-34a by high glucose or palmitate in vitro is suppressed by knockdown of p66shc. In addition, overexpression of wild-type but not redox-deficient p66Shc upregulates miR-34a in endothelial cells. P66Shc-stimulated upregulation of endothelial miR-34a is suppressed by cell-permeable antioxidants. Finally, mice with global knockdown of p66Shc are protected from diabetes mellitus-induced upregulation of miR-34a and downregulation of Sirt1 in the endothelium. CONCLUSIONS These data show that hyperglycemia and elevated free fatty acids in the diabetic milieu recruit p66Shc to upregulate endothelial miR-34a via an oxidant-sensitive mechanism, which leads to endothelial dysfunction by targeting Sirt1.
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Affiliation(s)
- Qiuxia Li
- From the Cardiovascular Division, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (Q.L., Y.-R.K., A.V., S.K., M.K., M.G., J.S.J., K.I.); and Department of Sports Science, Chungnam National University, Daejeon, Korea (S.K.L.)
| | - Young-Rae Kim
- From the Cardiovascular Division, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (Q.L., Y.-R.K., A.V., S.K., M.K., M.G., J.S.J., K.I.); and Department of Sports Science, Chungnam National University, Daejeon, Korea (S.K.L.)
| | - Ajit Vikram
- From the Cardiovascular Division, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (Q.L., Y.-R.K., A.V., S.K., M.K., M.G., J.S.J., K.I.); and Department of Sports Science, Chungnam National University, Daejeon, Korea (S.K.L.)
| | - Santosh Kumar
- From the Cardiovascular Division, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (Q.L., Y.-R.K., A.V., S.K., M.K., M.G., J.S.J., K.I.); and Department of Sports Science, Chungnam National University, Daejeon, Korea (S.K.L.)
| | - Modar Kassan
- From the Cardiovascular Division, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (Q.L., Y.-R.K., A.V., S.K., M.K., M.G., J.S.J., K.I.); and Department of Sports Science, Chungnam National University, Daejeon, Korea (S.K.L.)
| | - Mohanad Gabani
- From the Cardiovascular Division, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (Q.L., Y.-R.K., A.V., S.K., M.K., M.G., J.S.J., K.I.); and Department of Sports Science, Chungnam National University, Daejeon, Korea (S.K.L.)
| | - Sang Ki Lee
- From the Cardiovascular Division, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (Q.L., Y.-R.K., A.V., S.K., M.K., M.G., J.S.J., K.I.); and Department of Sports Science, Chungnam National University, Daejeon, Korea (S.K.L.)
| | - Julia S Jacobs
- From the Cardiovascular Division, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (Q.L., Y.-R.K., A.V., S.K., M.K., M.G., J.S.J., K.I.); and Department of Sports Science, Chungnam National University, Daejeon, Korea (S.K.L.)
| | - Kaikobad Irani
- From the Cardiovascular Division, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (Q.L., Y.-R.K., A.V., S.K., M.K., M.G., J.S.J., K.I.); and Department of Sports Science, Chungnam National University, Daejeon, Korea (S.K.L.).
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Senthil KK, Gokila VM, Mau JL, Lin CC, Chu FH, Wei CC, Liao VHC, Wang SY. A steroid like phytochemical Antcin M is an anti-aging reagent that eliminates hyperglycemia-accelerated premature senescence in dermal fibroblasts by direct activation of Nrf2 and SIRT-1. Oncotarget 2016; 7:62836-62861. [PMID: 27542238 PMCID: PMC5325331 DOI: 10.18632/oncotarget.11229] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 07/27/2016] [Indexed: 12/14/2022] Open
Abstract
The present study revealed the anti-aging properties of antcin M (ANM) and elucidated the molecular mechanism underlying the effects. We found that exposure of human normal dermal fibroblasts (HNDFs) to high-glucose (HG, 30 mM) for 3 days, accelerated G0/G1 phase arrest and senescence. Indeed, co-treatment with ANM (10 µM) significantly attenuated HG-induced growth arrest and promoted cell proliferation. Further molecular analysis revealed that ANM blocked the HG-induced reduction in G1-S transition regulatory proteins such as cyclin D, cyclin E, CDK4, CDK6, CDK2 and protein retinoblastoma (pRb). In addition, treatment with ANM eliminated HG-induced reactive oxygen species (ROS) through the induction of anti-oxidant genes, HO-1 and NQO-1 via transcriptional activation of Nrf2. Moreover, treatment with ANM abolished HG-induced SIPS as evidenced by reduced senescence-associated β-galactosidase (SA-β-gal) activity. This effect was further confirmed by reduction in senescence-associated marker proteins including, p21CIP1, p16INK4A, and p53/FoxO1 acetylation. Also, the HG-induced decline in aging-related marker protein SMP30 was rescued by ANM. Furthermore, treatment with ANM increased SIRT-1 expression, and prevented SIRT-1 depletion. This protection was consistent with inhibition of SIRT-1 phosphorylation at Ser47 followed by blocking its upstream kinases, p38 MAPK and JNK/SAPK. Further analysis revealed that ANM partially protected HG-induced senescence in SIRT-1 silenced cells. A similar effect was also observed in Nrf2 silenced cells. However, a complete loss of protection was observed in both Nrf2 and SIRT-1 knockdown cells suggesting that both induction of Nrf2-mediated anti-oxidant defense and SIRT-1-mediated deacetylation activity contribute to the anti-aging properties of ANM in vitro. Result of in vivo studies shows that ANM-treated C. elegens exhibits an increased survival rate during HG-induced oxidative stress insult. Furthermore, ANM significantly extended the life span of C. elegans. Taken together, our results suggest the potential application of ANM in age-related diseases or as a preventive reagent against aging process.
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Affiliation(s)
- Kumar K.J. Senthil
- Department of Forestry, National Chung Hsing University, Taichung, Taiwan
| | - Vani M. Gokila
- Department of Forestry, National Chung Hsing University, Taichung, Taiwan
- National Chung Hsing University/University of California at Davis, Plant and Food Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
| | - Jeng-Leun Mau
- National Chung Hsing University/University of California at Davis, Plant and Food Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung, Taiwan
| | | | - Fang-Hua Chu
- School of Forestry and Resource Conservation, National Taiwan University, Taipei, Taiwan
| | - Chia-Cheng Wei
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan
| | - Vivian Hsiu-Chuan Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan
| | - Sheng-Yang Wang
- Department of Forestry, National Chung Hsing University, Taichung, Taiwan
- National Chung Hsing University/University of California at Davis, Plant and Food Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
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Cai Y, Sukhova GK, Wong HK, Xu A, Tergaonkar V, Vanhoutte PM, Tang EHC. Rap1 induces cytokine production in pro-inflammatory macrophages through NFκB signaling and is highly expressed in human atherosclerotic lesions. Cell Cycle 2016; 14:3580-92. [PMID: 26505215 DOI: 10.1080/15384101.2015.1100771] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Repressor activator protein 1 (Rap1) is essential for maintaining telomere length and structural integrity, but it also exerts other non-telomeric functions. The present study tested the hypothesis that Rap1 is released into the cytoplasm and induces production of pro-inflammatory cytokines via nuclear factor kappa B (NFκB) signaling in macrophages, a cell type involved in the development and progression of atherosclerotic lesions. Western blotting analysis confirmed that Rap1 was present in the cytoplasm of differentiated human monocytic leukemia cells (THP-1, a macrophage-like cell line). Co-immunoprecipitation assay revealed a direct interaction between Rap1 and I kappa B kinase (IKK). Knockdown of Rap1 suppressed lipopolysaccharide-mediated activation of NFκB, and phosphorylation of inhibitor of kappa B α (IκBα) and p65 in THP-1 macrophages. The reduction of NFκB activity was paralleled by a decreased production of NFκB-dependent pro-inflammatory cytokines and an increased expression of IκBα (native NFκB inhibitor) in various macrophage models with pro-inflammatory phenotype, including THP-1, mouse peritoneal macrophages and bone marrow-derived M1 macrophages. These changes were observed selectively in pro-inflammatory macrophages but not in bone marrow-derived M2 macrophages (with an anti-inflammatory phenotype), mouse lung endothelial cells, human umbilical vein endothelial cells or human aortic smooth muscle cells. Immunostaining revealed that Rap1 was localized mainly in macrophage-rich areas in human atherosclerotic plaques and that the presence of Rap1 was positively correlated with the advancement of the disease process. In pro-inflammatory macrophages, Rap1 promotes cytokine production via NFκB activation favoring a pro-inflammatory environment which may contribute to the development and progression of atherosclerosis.
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Affiliation(s)
- Yin Cai
- a Department of Pharmacology and Pharmacy and State Key Laboratory of Pharmaceutical Biotechnology ; Li Ka Shing Faculty of Medicine; The University of Hong Kong ; Hong Kong , China
| | - Galina K Sukhova
- b Division of Cardiovascular Medicine; Brigham and Women's Hospital; Harvard Medical School ; Boston , MA USA
| | - Hoi Kin Wong
- a Department of Pharmacology and Pharmacy and State Key Laboratory of Pharmaceutical Biotechnology ; Li Ka Shing Faculty of Medicine; The University of Hong Kong ; Hong Kong , China
| | - Aimin Xu
- a Department of Pharmacology and Pharmacy and State Key Laboratory of Pharmaceutical Biotechnology ; Li Ka Shing Faculty of Medicine; The University of Hong Kong ; Hong Kong , China.,c Department of Medicine ; Li Ka Shing Faculty of Medicine; The University of Hong Kong ; Hong Kong , China
| | - Vinay Tergaonkar
- d Institute of Molecular and Cell Biology ; Biopolis A*STAR, Singapore
| | - Paul M Vanhoutte
- a Department of Pharmacology and Pharmacy and State Key Laboratory of Pharmaceutical Biotechnology ; Li Ka Shing Faculty of Medicine; The University of Hong Kong ; Hong Kong , China
| | - Eva Hoi Ching Tang
- a Department of Pharmacology and Pharmacy and State Key Laboratory of Pharmaceutical Biotechnology ; Li Ka Shing Faculty of Medicine; The University of Hong Kong ; Hong Kong , China.,e School of Biomedical Sciences; Li Ka Shing Faculty of Medicine; The University of Hong Kong ; Hong Kong , China
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Mesenchymal stem cell-conditioned media ameliorate diabetic endothelial dysfunction by improving mitochondrial bioenergetics via the Sirt1/AMPK/PGC-1α pathway. Clin Sci (Lond) 2016; 130:2181-2198. [PMID: 27613156 DOI: 10.1042/cs20160235] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 09/05/2016] [Indexed: 02/05/2023]
Abstract
Vasculopathy is a major complication of diabetes. Impaired mitochondrial bioenergetics and biogenesis due to oxidative stress are a critical causal factor for diabetic endothelial dysfunction. Sirt1, an NAD+-dependent enzyme, is known to play an important protective role through deacetylation of many substrates involved in oxidative phosphorylation and reactive oxygen species generation. Mesenchymal stem cell-conditioned medium (MSC-CM) has emerged as a promising cell-free therapy due to the trophic actions of mesenchymal stem cell (MSC)-secreted molecules. In the present study, we investigated the therapeutic potential of MSC-CMs in diabetic endothelial dysfunction, focusing on the Sirt1 signalling pathway and the relevance to mitochondrial function. We found that high glucose-stimulated MSC-CM attenuated several glucotoxicity-induced processes, oxidative stress and apoptosis of endothelial cells of the human umbilical vein. MSC-CM perfusion in diabetic rats ameliorated compromised aortic vasodilatation and alleviated oxidative stress in aortas. We further demonstrated that these effects were dependent on improved mitochondrial function and up-regulation of Sirt1 expression. MSC-CMs activated the phosphorylation of phosphoinositide 3-kinase (PI3K) and protein kinase B (Akt), leading to direct interaction between Akt and Sirt1, and subsequently enhanced Sirt1 expression. In addition, both MSC-CM and Sirt1 activation could increase the expression of peroxisome proliferator-activated receptor γ co-activator-1α (PGC-1α), as well as increase the mRNA expression of its downstream, mitochondrial, biogenesis-related genes. This indirect regulation was mediated by activation of AMP-activated protein kinase (AMPK). Overall our findings indicated that MSC-CM had protective effects on endothelial cells, with respect to glucotoxicity, by ameliorating mitochondrial dysfunction via the PI3K/Akt/Sirt1 pathway, and Sirt1 potentiated mitochondrial biogenesis, through the Sirt1/AMPK/PGC-1α pathway.
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Cloning and Characterization of Sirtuin3 (SIRT3). Methods Mol Biol 2016. [PMID: 27246217 DOI: 10.1007/978-1-4939-3667-0_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Mitochondria play a pivotal role in maintaining cellular homeostasis and regulating longevity. SIRT3 is a mitochondrial sirtuin mediating the deacetylation of various metabolic and antioxidant enzymes, in turn controlling energy metabolism, stress resistance, and the pace of ageing. To study the function of SIRT3, a proteomics-based approach is employed for identifying the protein-binding partners of this enzyme in mitochondria.
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Yuan Y, Cruzat VF, Newsholme P, Cheng J, Chen Y, Lu Y. Regulation of SIRT1 in aging: Roles in mitochondrial function and biogenesis. Mech Ageing Dev 2016; 155:10-21. [DOI: 10.1016/j.mad.2016.02.003] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 12/28/2015] [Accepted: 02/05/2016] [Indexed: 12/13/2022]
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Kida Y, Goligorsky MS. Sirtuins, Cell Senescence, and Vascular Aging. Can J Cardiol 2015; 32:634-41. [PMID: 26948035 DOI: 10.1016/j.cjca.2015.11.022] [Citation(s) in RCA: 193] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 11/10/2015] [Accepted: 11/29/2015] [Indexed: 01/03/2023] Open
Abstract
The sirtuins (SIRTs) constitute a class of proteins with nicotinamide adenine dinucleotide-dependent deacetylase or adenosine diphosphate-ribosyltransferase activity. Seven SIRT family members have been identified in mammals, from SIRT1, the best studied for its role in vascular aging, to SIRT7. SIRT1 and SIRT2 are localized in the nucleus and cytoplasm. SIRT3, SIRT4, and SIRT5 are mitochondrial, and SIRT6 and SIRT7 are nuclear. Extensive studies have clearly revealed that SIRT proteins regulate diverse cell functions and responses to stressors. Vascular aging involves the aging process (senescence) of endothelial and vascular smooth muscle cells. Two types of cell senescence have been identified: (1) replicative senescence with telomere attrition; and (2) stress-induced premature senescence without telomere involvement. Both types of senescence induce vascular cell growth arrest and loss of vascular homeostasis, and contribute to the initiation and progression of cardiovascular diseases. Previous mechanistic studies have revealed in detail that SIRT1, SIRT3, and SIRT6 show protective functions against vascular aging, and definite vascular function of other SIRTs is under investigation. Thus, direct SIRT modulation and nicotinamide adenine dinucleotide stimulation of SIRT are promising candidates for cardiovascular disease therapy. A small number of pilot studies have been conducted to assess SIRT modulation in humans. These clinical studies have not yet provided convincing evidence that SIRT proteins alleviate morbidity and mortality in patients with cardiovascular diseases. The outcomes of multiple ongoing clinical trials are awaited to define the efficacy of SIRT modulators and SIRT activators in cardiovascular diseases, along with the potential adverse effects of chronic SIRT modulation.
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Affiliation(s)
- Yujiro Kida
- Departments of Medicine, Pharmacology, and Physiology, Renal Research Institute, New York Medical College, Valhalla, New York, USA.
| | - Michael S Goligorsky
- Departments of Medicine, Pharmacology, and Physiology, Renal Research Institute, New York Medical College, Valhalla, New York, USA
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Vascular Ageing and Exercise: Focus on Cellular Reparative Processes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2016:3583956. [PMID: 26697131 PMCID: PMC4678076 DOI: 10.1155/2016/3583956] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 08/17/2015] [Accepted: 08/20/2015] [Indexed: 12/20/2022]
Abstract
Ageing is associated with an increased risk of developing noncommunicable diseases (NCDs), such as diabetes and cardiovascular disease (CVD). The increased risk can be attributable to increased prolonged exposure to oxidative stress. Often, CVD is preceded by endothelial dysfunction, which carries with it a proatherothrombotic phenotype. Endothelial senescence and reduced production and release of nitric oxide (NO) are associated with “vascular ageing” and are often accompanied by a reduced ability for the body to repair vascular damage, termed “reendothelialization.” Exercise has been repeatedly shown to confer protection against CVD and diabetes risk and incidence. Regular exercise promotes endothelial function and can prevent endothelial senescence, often through a reduction in oxidative stress. Recently, endothelial precursors, endothelial progenitor cells (EPC), have been shown to repair damaged endothelium, and reduced circulating number and/or function of these cells is associated with ageing. Exercise can modulate both number and function of these cells to promote endothelial homeostasis. In this review we look at the effects of advancing age on the endothelium and these endothelial precursors and how exercise appears to offset this “vascular ageing” process.
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Sphingosine-1-Phosphate Receptor Subtype 2 Signaling in Endothelial Senescence-Associated Functional Impairments and Inflammation. Curr Atheroscler Rep 2015; 17:504. [DOI: 10.1007/s11883-015-0504-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Cencioni C, Spallotta F, Mai A, Martelli F, Farsetti A, Zeiher AM, Gaetano C. Sirtuin function in aging heart and vessels. J Mol Cell Cardiol 2015; 83:55-61. [PMID: 25579854 DOI: 10.1016/j.yjmcc.2014.12.023] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 12/04/2014] [Accepted: 12/30/2014] [Indexed: 12/22/2022]
Abstract
Age is the most important risk factor for metabolic alterations and cardiovascular accidents. Although class III histone deacetylases, alias Sirtuins, have been appealed as "the fountain of youth" their role in longevity control and prevention of aging-associated disease is still under debate. Indeed, several lines of evidence indicate that sirtuin activity is strictly linked to metabolism and dependent on NAD(+) synthesis both often altered as aging progresses. During aging the cardiovascular system is attacked by a variety of environmental stresses, including those determined by high blood glucose and lipid levels, or by the presence of oxidized lipoproteins which, among others, determine important oxidative stress signals. In such a milieu, heart and vessels develop a functional impairment leading to atherosclerosis, ischemia, heart insufficiency and failure. Sirtuins, which are believed to have a positive impact on cardiovascular physiology and physiopathology, are distributed in different subcellular compartments including the nucleus, the cytoplasm and the mitochondria, where they regulate expression and function of a large variety of target genes and proteins. Remarkably, experimental animal models indicate resveratrol, the first natural compound described to positively regulate the activity of sirtuins, as able to protect the endothelium and the heart exposed to a variety of stress agents. This review will focus on the regulation and function of mammalian sirtuins with special attention paid to their role as cardiovascular "defenders" giving indication of their targets of potential relevance for the development of future therapeutics. This article is part of a Special Issue entitled CV Aging.
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Affiliation(s)
- Chiara Cencioni
- Division of Cardiovascular Epigenetics, Department of Cardiology, Goethe University, Frankfurt am Main 60596, Germany.
| | - Francesco Spallotta
- Division of Cardiovascular Epigenetics, Department of Cardiology, Goethe University, Frankfurt am Main 60596, Germany.
| | - Antonello Mai
- Pasteur Institute - Cenci-Bolognetti Foundation, Department of Drug Chemistry and Technologies, Sapienza University of Rome, Rome, Italy.
| | - Fabio Martelli
- Molecular Cardiology Laboratory, IRCCS-Policlinico San Donato, San Donato Milanese, Milan 20,097, Italy.
| | - Antonella Farsetti
- Consiglio Nazionale delle Ricerche, Istituto di Biologia Cellulare e Neurobiologia, Roma, Italy.
| | - Andreas M Zeiher
- Internal Medicine Clinic III, Department of Cardiology, Goethe University, Frankfurt am Main 60,596, Germany.
| | - Carlo Gaetano
- Division of Cardiovascular Epigenetics, Department of Cardiology, Goethe University, Frankfurt am Main 60596, Germany.
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Song Z, Liu Y, Hao B, Yu S, Zhang H, Liu D, Zhou B, Wu L, Wang M, Xiong Z, Wu C, Zhu J, Qian X. Ginsenoside Rb1 prevents H2O2-induced HUVEC senescence by stimulating sirtuin-1 pathway. PLoS One 2014; 9:e112699. [PMID: 25386949 PMCID: PMC4227851 DOI: 10.1371/journal.pone.0112699] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 10/10/2014] [Indexed: 11/19/2022] Open
Abstract
Purposes We have previously reported that Ginsenoside Rb1 may effectively prevent HUVECs from senescence, however, the detailed mechanism has not demonstrated up to now. Recent studies have shown that sirtuin-1 (Sirt1) plays an important role in the development of endothelial senescence. The purpose of this study was to explore whether Sirt1 is involved in the action of Ginsenoside Rb1 regarding protection against H2O2-induced HUVEC Senescence. Methods and Results Senescence induced by hydrogen peroxide (H2O2) in human umbilical vein endothelial cells (HUVECs) was examined by analyzing plasminogen activator inhibitor-1 (PAI-1) expression, cell morphology, and senescence-associated beta-galactosidase (SA-β-gal) activity. The results revealed that 42% of control-treated HUVECs were SA-β-gal positive after treatment by 60 µmol/L H2O2, however, this particular effect of H2O2 was decreased more than 2-fold (19%) in the HUVECs when pretreated with Rb1 (20 µmol/L) for 30 min. Additionally, Rb1 decreased eNOS acetylation, as well as promoted more NO production that was accompanied by an increase in Sirt1 expression. Furthermore, upon knocking down Sirt1, the effect of Rb1 on HUVEC senescence was blunted. Conclusions The present study indicated that Ginsenoside Rb1 acts through stimulating Sirt1 in order to protect against endothelial senescence and dysfunction. As such, Sirt1 appears to be of particular importance in maintaining endothelial functions and delaying vascular aging.
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Affiliation(s)
- Zhiming Song
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yong Liu
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Baoshun Hao
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Shujie Yu
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Hui Zhang
- Department of Ultrasonography, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Dinghui Liu
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Bin Zhou
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Lin Wu
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Min Wang
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zhaojun Xiong
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Chaodong Wu
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, United States of America
| | - Jieming Zhu
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
- * E-mail: (JZ); (XQ)
| | - Xiaoxian Qian
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
- Institute Integrated Traditional Chinese and Western Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- * E-mail: (JZ); (XQ)
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Abstract
Ageing is the most significant risk factor for a range of prevalent diseases, including cancer, cardiovascular disease, and diabetes. Accordingly, interventions are needed for delaying or preventing disorders associated with the ageing process, i.e., promotion of healthy ageing. Calorie restriction is the only nongenetic and the most robust approach to slow the process of ageing in evolutionarily divergent species, ranging from yeasts, worms, and flies to mammals. Although it has been known for more than 80 years that calorie restriction increases lifespan, a mechanistic understanding of this phenomenon remains elusive. Yeast silent information regulator 2 (Sir2), the founding member of the sirtuin family of protein deacetylases, and its mammalian homologue Sir2-like protein 1 (SIRT1), have been suggested to promote survival and longevity of organisms. SIRT1 exerts protective effects against a number of age-associated disorders. Caloric restriction increases both Sir2 and SIRT1 activity. This review focuses on the mechanistic insights between caloric restriction and Sir2/SIRT1 activation. A number of molecular links, including nicotinamide adenine dinucleotide, nicotinamide, biotin, and related metabolites, are suggested to be the most important conduits mediating caloric restriction-induced Sir2/SIRT1 activation and lifespan extension.
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Affiliation(s)
- Yu Wang
- Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China
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Wan Y, Gao P, Zhou S, Zhang Z, Hao D, Lian L, Li Y, Chen H, Liu D. SIRT1-mediated epigenetic downregulation of plasminogen activator inhibitor-1 prevents vascular endothelial replicative senescence. Aging Cell 2014; 13:890-9. [PMID: 25040736 PMCID: PMC4331759 DOI: 10.1111/acel.12247] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2014] [Indexed: 12/20/2022] Open
Abstract
The inactivation of plasminogen activator inhibitor-1 (PAI-1) has been shown to exert beneficial effects in age-related vascular diseases. Limited information is available on the molecular mechanisms regarding the negatively regulated expression of PAI-1 in the vascular system. In this study, we observed an inverse correlation between SIRT1, a class III histone deacetylase, and PAI-1 expression in human atherosclerotic plaques and the aortas of old mice, suggesting that internal negative regulation exists between SIRT1 and PAI-1. SIRT1 overexpression reversed the increased PAI-1 expression in senescent human umbilical vein endothelial cells (HUVECs) and aortas of old mice, accompanied by decreased SA-β-gal activity in vitro and improved endothelial function and reduced arterial stiffness in vivo. Moreover, the SIRT1-mediated inhibition of PAI-1 expression exerted an antisenescence effect in HUVECs. Furthermore, we demonstrated that SIRT1 is able to bind to the PAI-1 promoter, resulting in a decrease in the acetylation of histone H4 lysine 16 (H4K16) on the PAI-1 promoter region. Thus, our findings suggest that the SIRT1-mediated epigenetic inhibition of PAI-1 expression exerts a protective effect in vascular endothelial senescence.
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Affiliation(s)
- Yan‐Zhen Wan
- State Key Laboratory of Medical Molecular Biology Institute of Basic Medical Sciences Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China
| | - Peng Gao
- State Key Laboratory of Medical Molecular Biology Institute of Basic Medical Sciences Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China
| | - Shuang Zhou
- State Key Laboratory of Medical Molecular Biology Institute of Basic Medical Sciences Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China
| | - Zhu‐Qin Zhang
- State Key Laboratory of Medical Molecular Biology Institute of Basic Medical Sciences Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China
| | - De‐Long Hao
- State Key Laboratory of Medical Molecular Biology Institute of Basic Medical Sciences Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China
| | - Li‐Shan Lian
- Department of Vascular Surgery Peking Union Medical College Hospital Peking Union Medical College Chinese Academy of Medical Science Beijing 100730 China
| | - Yong‐Jun Li
- Department of Vascular Surgery Peking Union Medical College Hospital Peking Union Medical College Chinese Academy of Medical Science Beijing 100730 China
| | - Hou‐Zao Chen
- State Key Laboratory of Medical Molecular Biology Institute of Basic Medical Sciences Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China
| | - De‐Pei Liu
- State Key Laboratory of Medical Molecular Biology Institute of Basic Medical Sciences Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China
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Jin J, Lv X, Chen L, Zhang W, Li J, Wang Q, Wang R, Lu X, Miao D. Bmi-1 plays a critical role in protection from renal tubulointerstitial injury by maintaining redox balance. Aging Cell 2014; 13:797-809. [PMID: 24915841 PMCID: PMC4331754 DOI: 10.1111/acel.12236] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2014] [Indexed: 12/18/2022] Open
Abstract
To determine whether Bmi-1 deficiency could lead to renal tubulointerstitial injury by mitochondrial dysfunction and increased oxidative stress in the kidney, 3-week-old Bmi-1-/- mice were treated with the antioxidant N-acetylcysteine (NAC, 1 mg mL−1) in their drinking water, or pyrro-quinoline quinone (PQQ, 4 mg kg−1 diet) in their diet for 2 weeks, and their renal phenotypes were compared with vehicle-treated Bmi1-/- and wild-type mice. Bmi-1 was knocked down in human renal proximal tubular epithelial (HK2) cells which were treated with 1 mm NAC for 72 or 96 h, and their phenotypes were compared with control cells. Five-week-old vehicle-treated Bmi-1-/- mice displayed renal interstitial fibrosis, tubular atrophy, and severe renal function impairment with decreased renal cell proliferation, increased renal cell apoptosis and senescence, and inflammatory cell infiltration. Impaired mitochondrial structure, decreased mitochondrial numbers, and increased oxidative stress occurred in Bmi-1-/- mice; subsequently, this caused DNA damage, the activation of TGF-β1/Smad signaling, and the imbalance between extracellular matrix synthesis and degradation. Oxidative stress-induced epithelial-to-mesenchymal transition of renal tubular epithelial cells was enhanced in Bmi-1 knocked down HK2 cells. All phenotypic alterations caused by Bmi-1 deficiency were ameliorated by antioxidant treatment. These findings indicate that Bmi-1 plays a critical role in protection from renal tubulointerstitial injury by maintaining redox balance and will be a novel therapeutic target for preventing renal tubulointerstitial injury.
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Affiliation(s)
- Jianliang Jin
- The State Key Laboratory of Reproductive Medicine Department of Anatomy Histology and Embryology Nanjing Medical University Nanjing China
| | - Xianhui Lv
- The State Key Laboratory of Reproductive Medicine Department of Anatomy Histology and Embryology Nanjing Medical University Nanjing China
| | - Lulu Chen
- The State Key Laboratory of Reproductive Medicine Department of Anatomy Histology and Embryology Nanjing Medical University Nanjing China
| | - Wei Zhang
- The State Key Laboratory of Reproductive Medicine Department of Anatomy Histology and Embryology Nanjing Medical University Nanjing China
| | - Jinbo Li
- The State Key Laboratory of Reproductive Medicine Department of Anatomy Histology and Embryology Nanjing Medical University Nanjing China
| | - Qian Wang
- The State Key Laboratory of Reproductive Medicine Department of Anatomy Histology and Embryology Nanjing Medical University Nanjing China
| | - Rong Wang
- The State Key Laboratory of Reproductive Medicine Department of Anatomy Histology and Embryology Nanjing Medical University Nanjing China
| | - Xiang Lu
- Department of Gerontology The Second Affiliated Hospital of Nanjing Medical University Nanjing China
| | - Dengshun Miao
- The State Key Laboratory of Reproductive Medicine Department of Anatomy Histology and Embryology Nanjing Medical University Nanjing China
- Department of Gerontology The Second Affiliated Hospital of Nanjing Medical University Nanjing China
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Arunachalam G, Samuel SM, Marei I, Ding H, Triggle CR. Metformin modulates hyperglycaemia-induced endothelial senescence and apoptosis through SIRT1. Br J Pharmacol 2014; 171:523-35. [PMID: 24372553 PMCID: PMC3904269 DOI: 10.1111/bph.12496] [Citation(s) in RCA: 175] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 10/20/2013] [Accepted: 10/28/2013] [Indexed: 12/14/2022] Open
Abstract
Background and Purpose: Endothelial dysfunction can be detected at an early stage in the development of diabetes-related microvascular disease and is associated with accelerated endothelial senescence and ageing. Hyperglycaemia-induced oxidative stress is a major contributing factor to the development of endothelial dysfunction. Clinical data indicate that the hypoglycaemic agent, metformin, has an endothelial protective action; however, its molecular and cellular mechanisms remain elusive. In the present study, we have investigated the protective effect of metformin during hyperglycaemia-induced senescence in mouse microvascular endothelial cells (MMECs). Experimental Approach: MMECs were cultured in normal glucose (11 mM) and high glucose (HG; 40 mM) in the presence and absence of metformin (50 μM) for 72 h. The expression of sirtuin-1 (SIRT1) and senescence/apoptosis-associated markers was determined by immunoblotting and immunocyto techniques. SIRT1 expression was inhibited with appropriate siRNA. Key Results: Exposure of MMECs to HG significantly reduced SIRT1 protein expression, increased forkhead box O1 (FoxO-1) and p53 acetylation, increased p21 and decreased Bcl2 expression. In addition, senescence-associated β-galactosidase activity in MMECs was increased in HG. Treatment with metformin attenuated the HG-induced reduction of SIRT1 expression, modulated the SIRT1 downstream targets FoxO-1 and p53/p21, and protected endothelial cells from HG-induced premature senescence. However, following gene knockdown of SIRT1 the effects of metformin were lost. Conclusions and Implications: HG-induced down-regulation of SIRT1 played a crucial role in diabetes-induced endothelial senescence. Furthermore, the protective effect of metformin against HG-induced endothelial dysfunction was partly due to its effects on SIRT1 expression and/or activity.
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Liang Y, Huang B, Song E, Bai B, Wang Y. Constitutive activation of AMPK α1 in vascular endothelium promotes high-fat diet-induced fatty liver injury: role of COX-2 induction. Br J Pharmacol 2014; 171:498-508. [PMID: 24372551 DOI: 10.1111/bph.12482] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Revised: 09/24/2013] [Accepted: 10/16/2013] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND AND PURPOSE AMP-activated protein kinase (AMPK), an important regulator of energy metabolism, comprises three (α, β and γ) subunits, each with a unique tissue distribution. As AMPK has a wide range of protein and gene targets, defining its role has been difficult. Here, we have studied a transgenic mouse model overexpressing the constitutively active α1 subunit of AMPK in endothelial cells (EC-AMPK) to elucidate its role in energy homeostasis. EXPERIMENTAL APPROACH Wild-type and EC-AMPK mice were fed with a high fat diet for 16 weeks. Drugs (or vehicles) were given daily by oral gavage. Body weight, fat mass composition, glucose and lipid levels were monitored regularly. Tissues including aortae and liver were collected for quantitative RT-PCR, Western blotting, elisa, histological and biochemical evaluations. KEY RESULTS Compared with wild-type animals, high fat diet caused more severe metabolic defects in EC-AMPK mice, which exhibited increased body weight and fat mass, elevated blood pressure, augmented glucose and lipid levels, impaired glucose tolerance, hepatomegaly and steatohepatitis. Constitutive activation of AMPK α1 in endothelial cells induced COX-2 expression and arterial inflammation. Genes involved in lipid metabolism were down-regulated in aortae and livers of EC-AMPK mice. Chronic treatment with selective COX-2 inhibitors, celecoxib or nimesulide, significantly ameliorated arterial inflammation, steatohepatitis and hyperlipidaemia in EC-AMPK mice, without altering their blood pressure or clotting. CONCLUSIONS AND IMPLICATIONS Constitutive activation of endothelial AMPK α1 promotes vascular inflammation and the development of obesity-induced fatty livers largely via induction of COX-2.
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Affiliation(s)
- Yan Liang
- Department of Pharmacology and Pharmacy, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
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Wang P, Xu TY, Guan YF, Zhao Y, Li ZY, Lan XH, Wang X, Yang PY, Kang ZM, Vanhoutte PM, Miao CY. Vascular smooth muscle cell apoptosis is an early trigger for hypothyroid atherosclerosis. Cardiovasc Res 2014; 102:448-59. [PMID: 24604622 DOI: 10.1093/cvr/cvu056] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AIMS Endothelial dysfunction is an initial and vascular smooth muscle cell (VSMC) apoptosis, a later step of atherosclerosis. Hypothyroidism accelerates atherosclerosis. However, the early events responsible for this pro-atherosclerotic effect are unclear. METHODS AND RESULTS Rats were resistant to induction of atherosclerosis by high cholesterol diet alone, but became susceptible in hypothyroid state achieved by administration of propylthiouracil (PTU) for 6 weeks. VSMC dysfunction and apoptosis were obvious within 1 week after PTU treatment, without signs of endothelial dysfunction. This early VSMC damage was caused by hypothyroidism but not the high cholesterol diet. In ApoE knockout mice, PTU-induced hypothyroidism triggered early VSMC apoptosis, increased oxidative stress, and accelerated atherosclerosis development. Thyroid hormone supplementation (T4, 10, or 50 μg/kg) prevented atherogenic phenotypes in hypothyroid rats and mice. In rats, thyroidectomy caused severe hypothyroidism 5 days after operation, which also led to rapid VSMC dysfunction and apoptosis. In vitro studies did not show a direct toxic effect of PTU on VSMCs. In contrast, thyroid hormone (T3, 0.75 μg/L plus T4, 50 nmol/L) exerted a direct protection against VSMC apoptosis, which was reduced by knockdown of TRα1, rather than TRβ1 and TRβ2 receptors. TRα1-mediated inhibition of apoptotic signalling of JNKs and caspase-3 contributed to the anti-apoptotic action of thyroid hormone. CONCLUSION These findings provide an in vivo example for VSMC apoptosis as an early trigger of hypothyroidism-associated atherosclerosis, and reveal activation of TRα1 receptors to prevent VSMC apoptosis as a therapeutic strategy in this disease.
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Affiliation(s)
- Pei Wang
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Tian-Ying Xu
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Yun-Feng Guan
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Yan Zhao
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Zhi-Yong Li
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Xiao-Hong Lan
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Xia Wang
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Peng-Yuan Yang
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Zhi-Min Kang
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Paul M Vanhoutte
- Department of Pharmacology, Second Military Medical University, Shanghai, China Department of Pharmacology and Pharmacy and State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China
| | - Chao-Yu Miao
- Department of Pharmacology, Second Military Medical University, Shanghai, China Center of Stroke, Beijing Institute for Brain Disorders, Beijing, China
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Bai B, Vanhoutte PM, Wang Y. Loss-of-SIRT1 function during vascular ageing: Hyperphosphorylation mediated by cyclin-dependent kinase 5. Trends Cardiovasc Med 2014; 24:81-4. [DOI: 10.1016/j.tcm.2013.07.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 07/01/2013] [Accepted: 07/02/2013] [Indexed: 10/26/2022]
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Hwang JW, Yao H, Caito S, Sundar IK, Rahman I. Redox regulation of SIRT1 in inflammation and cellular senescence. Free Radic Biol Med 2013; 61:95-110. [PMID: 23542362 PMCID: PMC3762912 DOI: 10.1016/j.freeradbiomed.2013.03.015] [Citation(s) in RCA: 373] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 12/06/2012] [Accepted: 03/20/2013] [Indexed: 12/31/2022]
Abstract
Sirtuin 1 (SIRT1) regulates inflammation, aging (life span and health span), calorie restriction/energetics, mitochondrial biogenesis, stress resistance, cellular senescence, endothelial functions, apoptosis/autophagy, and circadian rhythms through deacetylation of transcription factors and histones. SIRT1 level and activity are decreased in chronic inflammatory conditions and aging, in which oxidative stress occurs. SIRT1 is regulated by a NAD(+)-dependent DNA repair enzyme, poly(ADP-ribose) polymerase-1 (PARP1), and subsequent NAD(+) depletion by oxidative stress may have consequent effects on inflammatory and stress responses as well as cellular senescence. SIRT1 has been shown to undergo covalent oxidative modifications by cigarette smoke-derived oxidants/aldehydes, leading to posttranslational modifications, inactivation, and protein degradation. Furthermore, oxidant/carbonyl stress-mediated reduction of SIRT1 leads to the loss of its control on acetylation of target proteins including p53, RelA/p65, and FOXO3, thereby enhancing the inflammatory, prosenescent, and apoptotic responses, as well as endothelial dysfunction. In this review, the mechanisms of cigarette smoke/oxidant-mediated redox posttranslational modifications of SIRT1 and its roles in PARP1 and NF-κB activation, and FOXO3 and eNOS regulation, as well as chromatin remodeling/histone modifications during inflammaging, are discussed. Furthermore, we have also discussed various novel ways to activate SIRT1 either directly or indirectly, which may have therapeutic potential in attenuating inflammation and premature senescence involved in chronic lung diseases.
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Affiliation(s)
- Jae-woong Hwang
- Lung Biology and Disease Program, Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Hongwei Yao
- Lung Biology and Disease Program, Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Samuel Caito
- Lung Biology and Disease Program, Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Isaac K Sundar
- Lung Biology and Disease Program, Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Irfan Rahman
- Lung Biology and Disease Program, Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA.
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Ca2+/calmodulin-dependent protein kinase kinase β phosphorylation of Sirtuin 1 in endothelium is atheroprotective. Proc Natl Acad Sci U S A 2013; 110:E2420-7. [PMID: 23754392 DOI: 10.1073/pnas.1309354110] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Atheroprotective flow exerts antioxidative and anti-inflammatory effects on vascular endothelial cells (ECs), in part through the induction of Sirtuin 1 (SIRT1), a class III histone deacetylase. The role of Ca(2+)/calmodulin-dependent protein kinase kinase (CaMKK)β in flow induction of SIRT1 both in vitro and in vivo was investigated. Pulsatile shear stress mimicking atheroprotective flow increased the level of SIRT1 in cultured ECs by enhancing its stability, and this effect was abolished by inhibition or knockdown of CaMKKβ. Flow-enhanced SIRT1 stability was primarily mediated by CaMKKβ phosphorylation of SIRT1 at Ser-27 and Ser-47, as evidenced by in vitro kinase assay, mass spectrometry, and experiments using loss- or gain-of-function SIRT1 mutants. Flow-induced CaMKKβ phosphorylation of SIRT1 Ser-27 and Ser-47 increased antioxidative and anti-inflammatory capacities. Ablation of CaMKKβ or SIRT1 in mice with an apolipoprotein E-null background showed increased atherosclerosis both in athero-prone and in athero-protective areas. The results suggest that the CaMKKβ-SIRT1 axis in ECs is mechanosensitive, antioxidative, and anti-inflammatory.
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78
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Deregulations in the cyclin-dependent kinase-9-related pathway in cancer: implications for drug discovery and development. ISRN ONCOLOGY 2013; 2013:305371. [PMID: 23840966 PMCID: PMC3690251 DOI: 10.1155/2013/305371] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 05/19/2013] [Indexed: 12/21/2022]
Abstract
The CDK9-related pathway is an important regulator of mammalian cell biology and is also involved in the replication cycle of several viruses, including the human immunodeficiency virus type 1. CDK9 is present in two isoforms termed CDK9-42 and CDK9-55 that bind noncovalently type T cyclins and cyclin K. This association forms a heterodimer, where CDK9 carries the enzymatic site and the cyclin partner functions as a regulatory subunit. This heterodimer is the main component of the positive transcription elongation factor b, which stabilizes RNA elongation via phosphorylation of the RNA pol II carboxyl terminal domain. Abnormal activities in the CDK9-related pathway were observed in human malignancies and cardiac hypertrophies. Thus, the elucidation of the CDK9 pathway deregulations may provide useful insights into the pathogenesis and progression of human malignancies, cardiac hypertrophy, AIDS and other viral-related maladies. These studies may lead to the improvement of kinase inhibitors for the treatment of the previously mentioned pathological conditions. This review describes the CDK9-related pathway deregulations in malignancies and the development of kinase inhibitors in cancer therapy, which can be classified into three categories: antagonists that block the ATP binding site of the catalytic domain, allosteric inhibitors, and small molecules that disrupt protein-protein interactions.
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