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Johnson RT, Solanki R, Wostear F, Ahmed S, Taylor JCK, Rees J, Abel G, McColl J, Jørgensen HF, Morris CJ, Bidula S, Warren DT. Piezo1-mediated regulation of smooth muscle cell volume in response to enhanced extracellular matrix rigidity. Br J Pharmacol 2024; 181:1576-1595. [PMID: 38044463 DOI: 10.1111/bph.16294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 11/06/2023] [Accepted: 11/23/2023] [Indexed: 12/05/2023] Open
Abstract
BACKGROUND AND PURPOSE Decreased aortic compliance is a precursor to numerous cardiovascular diseases. Compliance is regulated by the rigidity of the aortic wall and the vascular smooth muscle cells (VSMCs). Extracellular matrix stiffening, observed during ageing, reduces compliance. In response to increased rigidity, VSMCs generate enhanced contractile forces that result in VSMC stiffening and a further reduction in compliance. Mechanisms driving VSMC response to matrix rigidity remain poorly defined. EXPERIMENTAL APPROACH Human aortic-VSMCs were seeded onto polyacrylamide hydrogels whose rigidity mimicked either healthy (12 kPa) or aged/diseased (72 kPa) aortae. VSMCs were treated with pharmacological agents prior to agonist stimulation to identify regulators of VSMC volume regulation. KEY RESULTS On pliable matrices, VSMCs contracted and decreased in cell area. Meanwhile, on rigid matrices VSMCs displayed a hypertrophic-like response, increasing in area and volume. Piezo1 activation stimulated increased VSMC volume by promoting calcium ion influx and subsequent activation of PKC and aquaporin-1. Pharmacological blockade of this pathway prevented the enhanced VSMC volume response on rigid matrices whilst maintaining contractility on pliable matrices. Importantly, both piezo1 and aquaporin-1 gene expression were up-regulated during VSMC phenotypic modulation in atherosclerosis and after carotid ligation. CONCLUSIONS AND IMPLICATIONS In response to extracellular matrix rigidity, VSMC volume is increased by a piezo1/PKC/aquaporin-1 mediated pathway. Pharmacological targeting of this pathway specifically blocks the matrix rigidity enhanced VSMC volume response, leaving VSMC contractility on healthy mimicking matrices intact. Importantly, upregulation of both piezo1 and aquaporin-1 gene expression is observed in disease relevant VSMC phenotypes.
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Affiliation(s)
| | - Reesha Solanki
- School of Pharmacy, University of East Anglia, Norwich, UK
| | - Finn Wostear
- School of Pharmacy, University of East Anglia, Norwich, UK
| | - Sultan Ahmed
- School of Pharmacy, University of East Anglia, Norwich, UK
| | - James C K Taylor
- Section of Cardiorespiratory Medicine, University of Cambridge, VPD Heart and Lung Research Institute, Cambridge, UK
| | - Jasmine Rees
- School of Pharmacy, University of East Anglia, Norwich, UK
| | - Geraad Abel
- School of Pharmacy, University of East Anglia, Norwich, UK
| | - James McColl
- Henry Wellcome Laboratory for Cell Imaging, University of East Anglia, Norfolk, UK
| | - Helle F Jørgensen
- Section of Cardiorespiratory Medicine, University of Cambridge, VPD Heart and Lung Research Institute, Cambridge, UK
| | - Chris J Morris
- School of Pharmacy, University College London, London, UK
| | - Stefan Bidula
- School of Pharmacy, University of East Anglia, Norwich, UK
| | - Derek T Warren
- School of Pharmacy, University of East Anglia, Norwich, UK
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2
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Shen A, Wu M, Ali F, Guo Z, Fang Y, Zhou Y, Zhang S, Zhang W, Wen Y, Yu M, Peng J, Chen K. Based on network pharmacology, gastrodin attenuates hypertension-induced vascular smooth muscle cell proliferation and PI3K/AKT pathway activation. Sci Rep 2023; 13:12140. [PMID: 37495624 PMCID: PMC10372005 DOI: 10.1038/s41598-023-39202-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 07/21/2023] [Indexed: 07/28/2023] Open
Abstract
The effects and underlying mechanisms of gastrodin treatment on hypertensive vascular dysfunction and proliferation of vascular smooth muscle cells (VSMCs) were determined in vitro and in vivo. Using a pharmacological target network interaction analysis, 151 common targets and a PPI network were identified containing the top 10 hub genes. Kyoto encyclopedia of genes and genomes (KEGG) analysis identified the PI3K/AKT pathway as a significantly enriched pathway. Both spontaneous hypertensive rats (SHRs) and Wistar Kyoto rats were used to assess the therapeutic effects of gastrodin on hypertension. Gastrodin treatment of the SHRs resulted in a marked attenuation of elevated blood pressure, pulse wave velocity, and pathological changes in the abdominal aorta. Moreover, gastrodin treatment significantly inhibited cell growth and downregulated the expression of PCNA as well as the p-PI3K/PI3K and p-AKT/AKT levels in angiotensin II-stimulated VSMCs. Taken together, gastrodin treatment attenuates blood pressure elevation, vascular dysfunction, and proliferation of VSMCs and inhibits the activation of the PI3K/AKT pathway.
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Affiliation(s)
- Aling Shen
- Postdoctoral Workstation, Department of Research and development, Tianjiang Pharmaceutical Co., Ltd., No.1 Xin Sheng Road, Jiangyin, 214400, Jiangsu, China
- Department of Cardiology, Xiyuan Hospital of China Academy of Chinese Medical Sciences, 1 XiyuanCaochang, Hai Dian District, Beijing, 100091, China
- National Clinical Research Center for Cardiovascular Diseases of Traditional Chinese Medicine, Beijing, 100091, China
- Clinical Research Institute, The Second Affiliated Hospital & Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, 1 Qiuyang Road, MinhouShangjie, Fuzhou, 350122, Fujian, China
- Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China
- Fujian Collaborative Innovation Center for Integrative Medicine in Prevention and Treatment of Major Chronic Cardiovascular Diseases, Fuzhou, 350122, Fujian, China
| | - Meizhu Wu
- Clinical Research Institute, The Second Affiliated Hospital & Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, 1 Qiuyang Road, MinhouShangjie, Fuzhou, 350122, Fujian, China
- Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China
- Fujian Collaborative Innovation Center for Integrative Medicine in Prevention and Treatment of Major Chronic Cardiovascular Diseases, Fuzhou, 350122, Fujian, China
| | - Farman Ali
- Clinical Research Institute, The Second Affiliated Hospital & Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, 1 Qiuyang Road, MinhouShangjie, Fuzhou, 350122, Fujian, China
- Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China
- Fujian Collaborative Innovation Center for Integrative Medicine in Prevention and Treatment of Major Chronic Cardiovascular Diseases, Fuzhou, 350122, Fujian, China
| | - Zhi Guo
- Clinical Research Institute, The Second Affiliated Hospital & Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, 1 Qiuyang Road, MinhouShangjie, Fuzhou, 350122, Fujian, China
- Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China
| | - Yi Fang
- Clinical Research Institute, The Second Affiliated Hospital & Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, 1 Qiuyang Road, MinhouShangjie, Fuzhou, 350122, Fujian, China
- Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China
- Fujian Collaborative Innovation Center for Integrative Medicine in Prevention and Treatment of Major Chronic Cardiovascular Diseases, Fuzhou, 350122, Fujian, China
| | - Yuting Zhou
- Clinical Research Institute, The Second Affiliated Hospital & Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, 1 Qiuyang Road, MinhouShangjie, Fuzhou, 350122, Fujian, China
- Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China
| | - Siyu Zhang
- Clinical Research Institute, The Second Affiliated Hospital & Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, 1 Qiuyang Road, MinhouShangjie, Fuzhou, 350122, Fujian, China
- Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China
| | - Wenqiang Zhang
- Clinical Research Institute, The Second Affiliated Hospital & Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, 1 Qiuyang Road, MinhouShangjie, Fuzhou, 350122, Fujian, China
- Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China
| | - Ying Wen
- Clinical Research Institute, The Second Affiliated Hospital & Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, 1 Qiuyang Road, MinhouShangjie, Fuzhou, 350122, Fujian, China
- Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China
- Fujian Collaborative Innovation Center for Integrative Medicine in Prevention and Treatment of Major Chronic Cardiovascular Diseases, Fuzhou, 350122, Fujian, China
| | - Min Yu
- Postdoctoral Workstation, Department of Research and development, Tianjiang Pharmaceutical Co., Ltd., No.1 Xin Sheng Road, Jiangyin, 214400, Jiangsu, China.
| | - Jun Peng
- Clinical Research Institute, The Second Affiliated Hospital & Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, 1 Qiuyang Road, MinhouShangjie, Fuzhou, 350122, Fujian, China.
- Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China.
- Fujian Collaborative Innovation Center for Integrative Medicine in Prevention and Treatment of Major Chronic Cardiovascular Diseases, Fuzhou, 350122, Fujian, China.
| | - Keji Chen
- Postdoctoral Workstation, Department of Research and development, Tianjiang Pharmaceutical Co., Ltd., No.1 Xin Sheng Road, Jiangyin, 214400, Jiangsu, China.
- Department of Cardiology, Xiyuan Hospital of China Academy of Chinese Medical Sciences, 1 XiyuanCaochang, Hai Dian District, Beijing, 100091, China.
- National Clinical Research Center for Cardiovascular Diseases of Traditional Chinese Medicine, Beijing, 100091, China.
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3
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Elia A, Mohsin S, Khan M. Cardiomyocyte Ploidy, Metabolic Reprogramming and Heart Repair. Cells 2023; 12:1571. [PMID: 37371041 DOI: 10.3390/cells12121571] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/27/2023] [Accepted: 04/29/2023] [Indexed: 06/29/2023] Open
Abstract
The adult heart is made up of cardiomyocytes (CMs) that maintain pump function but are unable to divide and form new myocytes in response to myocardial injury. In contrast, the developmental cardiac tissue is made up of proliferative CMs that regenerate injured myocardium. In mammals, CMs during development are diploid and mononucleated. In response to cardiac maturation, CMs undergo polyploidization and binucleation associated with CM functional changes. The transition from mononucleation to binucleation coincides with unique metabolic changes and shift in energy generation. Recent studies provide evidence that metabolic reprogramming promotes CM cell cycle reentry and changes in ploidy and nucleation state in the heart that together enhances cardiac structure and function after injury. This review summarizes current literature regarding changes in CM ploidy and nucleation during development, maturation and in response to cardiac injury. Importantly, how metabolism affects CM fate transition between mononucleation and binucleation and its impact on cell cycle progression, proliferation and ability to regenerate the heart will be discussed.
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Affiliation(s)
- Andrea Elia
- Center for Metabolic Disease Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Sadia Mohsin
- Cardiovascular Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Mohsin Khan
- Center for Metabolic Disease Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
- Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
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4
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Lee K, Gusella GL, He JC. Epithelial proliferation and cell cycle dysregulation in kidney injury and disease. Kidney Int 2021; 100:67-78. [PMID: 33831367 PMCID: PMC8855879 DOI: 10.1016/j.kint.2021.03.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 03/05/2021] [Accepted: 03/11/2021] [Indexed: 02/08/2023]
Abstract
Various cellular insults and injury to renal epithelial cells stimulate repair mechanisms to adapt and restore the organ homeostasis. Renal tubular epithelial cells are endowed with regenerative capacity, which allows for a restoration of nephron function after acute kidney injury. However, recent evidence indicates that the repair is often incomplete, leading to maladaptive responses that promote the progression to chronic kidney disease. The dysregulated cell cycle and proliferation is also a key feature of renal tubular epithelial cells in polycystic kidney disease and HIV-associated nephropathy. Therefore, in this review, we provide an overview of cell cycle regulation and the consequences of dysregulated cell proliferation in acute kidney injury, polycystic kidney disease, and HIV-associated nephropathy. An increased understanding of these processes may help define better targets for kidney repair and combat chronic kidney disease progression.
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Affiliation(s)
- Kyung Lee
- Department of Medicine, Nephrology Division, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
| | - G Luca Gusella
- Department of Medicine, Nephrology Division, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - John Cijiang He
- Department of Medicine, Nephrology Division, Icahn School of Medicine at Mount Sinai, New York, New York, USA; Renal Program, James J. Peters Veterans Affairs Medical Center, Bronx, New York, USA.
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5
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Truong V, Anand-Srivastava MB, Srivastava AK. Role of cyclic AMP response element binding protein (CREB) in angiotensin II-induced responses in vascular smooth muscle cells. Can J Physiol Pharmacol 2020; 99:30-35. [PMID: 33091310 DOI: 10.1139/cjpp-2020-0531] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cyclic AMP response element (CRE) binding protein (CREB) is a nuclear transcription factor that regulates the transcription of several genes containing the CRE sites on their promoters. CREB is activated by phosphorylation on a key serine residue, Ser311, in response to a wide variety of extracellular stimuli including angiotensin II (Ang II). Ang II is an important vasoactive peptide and mitogen for vascular smooth muscle cells (VSMC) that in addition to regulating the contractile response in VSMC also plays an important role in phenotypic switch of VSMC from contractile to a synthetic state. The synthetic VSMC are known to exhibit proliferative and migratory properties due to hyperactivation of Ang II-induced signaling events. Ang II has been shown to induce CREB phosphorylation/activation and transcription of genes implicated in proliferation, growth, and migration. Here, we have highlighted some key studies that have demonstrated an important role of CREB in Ang II-mediated gene transcription, proliferation, hypertrophy, and migration of VSMC.
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Affiliation(s)
- Vanessa Truong
- Laboratory of Cellular Signaling, Montreal Diabetes Research Center and Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC H2X 0A9, Canada
| | - Madhu B Anand-Srivastava
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montreal, H3C 3J7, Canada
| | - Ashok K Srivastava
- Laboratory of Cellular Signaling, Montreal Diabetes Research Center and Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC H2X 0A9, Canada.,Department of Medicine, Faculty of Medicine, Université de Montréal, Montreal, QC H3C 3J7, Canada
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6
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Aherrahrou R, Guo L, Nagraj VP, Aguhob A, Hinkle J, Chen L, Yuhl Soh J, Lue D, Alencar GF, Boltjes A, van der Laan SW, Farber E, Fuller D, Anane-Wae R, Akingbesote N, Manichaikul AW, Ma L, Kaikkonen MU, Björkegren JLM, Önengüt-Gümüşcü S, Pasterkamp G, Miller CL, Owens GK, Finn A, Navab M, Fogelman AM, Berliner JA, Civelek M. Genetic Regulation of Atherosclerosis-Relevant Phenotypes in Human Vascular Smooth Muscle Cells. Circ Res 2020; 127:1552-1565. [PMID: 33040646 DOI: 10.1161/circresaha.120.317415] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
RATIONALE Coronary artery disease (CAD) is a major cause of morbidity and mortality worldwide. Recent genome-wide association studies revealed 163 loci associated with CAD. However, the precise molecular mechanisms by which the majority of these loci increase CAD risk are not known. Vascular smooth muscle cells (VSMCs) are critical in the development of CAD. They can play either beneficial or detrimental roles in lesion pathogenesis, depending on the nature of their phenotypic changes. OBJECTIVE To identify genetic variants associated with atherosclerosis-relevant phenotypes in VSMCs. METHODS AND RESULTS We quantified 12 atherosclerosis-relevant phenotypes related to calcification, proliferation, and migration in VSMCs isolated from 151 multiethnic heart transplant donors. After genotyping and imputation, we performed association mapping using 6.3 million genetic variants. We demonstrated significant variations in calcification, proliferation, and migration. These phenotypes were not correlated with each other. We performed genome-wide association studies for 12 atherosclerosis-relevant phenotypes and identified 4 genome-wide significant loci associated with at least one VSMC phenotype. We overlapped the previously identified CAD loci with our data set and found nominally significant associations at 79 loci. One of them was the chromosome 1q41 locus, which harbors MIA3. The G allele of the lead risk single nucleotide polymorphism (SNP) rs67180937 was associated with lower VSMC MIA3 expression and lower proliferation. Lentivirus-mediated silencing of MIA3 (melanoma inhibitory activity protein 3) in VSMCs resulted in lower proliferation, consistent with human genetics findings. Furthermore, we observed a significant reduction of MIA3 protein in VSMCs in thin fibrous caps of late-stage atherosclerotic plaques compared to early fibroatheroma with thick and protective fibrous caps in mice and humans. CONCLUSIONS Our data demonstrate that genetic variants have significant influences on VSMC function relevant to the development of atherosclerosis. Furthermore, high MIA3 expression may promote atheroprotective VSMC phenotypic transitions, including increased proliferation, which is essential in the formation or maintenance of a protective fibrous cap.
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MESH Headings
- Animals
- Aryl Hydrocarbon Receptor Nuclear Translocator/genetics
- Aryl Hydrocarbon Receptor Nuclear Translocator/metabolism
- Atherosclerosis/genetics
- Atherosclerosis/metabolism
- Atherosclerosis/pathology
- Cell Movement
- Cell Proliferation
- Cells, Cultured
- Disease Models, Animal
- Female
- Fibrosis
- Genetic Predisposition to Disease
- Genetic Variation
- Genome-Wide Association Study
- Humans
- Male
- Mice, Knockout, ApoE
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Phenotype
- Plaque, Atherosclerotic
- Polymorphism, Single Nucleotide
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Affiliation(s)
- Redouane Aherrahrou
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
| | - Liang Guo
- CVPath Institute, Inc, Gaithersburg, MD (L.G., D.F., A.F.)
| | - V Peter Nagraj
- School of Medicine Research Computing (V.P.N.), University of Virginia, Charlottesville
| | - Aaron Aguhob
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
- Biomedical Engineering (A.A., L.C., D.L., R.A.-W., M.C.), University of Virginia, Charlottesville
| | - Jameson Hinkle
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
| | - Lisa Chen
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
- Biomedical Engineering (A.A., L.C., D.L., R.A.-W., M.C.), University of Virginia, Charlottesville
| | - Joon Yuhl Soh
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
| | - Dillon Lue
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
- Biomedical Engineering (A.A., L.C., D.L., R.A.-W., M.C.), University of Virginia, Charlottesville
| | - Gabriel F Alencar
- Molecular Physiology, Biological Physics, Medicine, Division of Cardiology, Robert M. Berne Cardiovascular Research Center (G.F.A., G.K.O.), University of Virginia, Charlottesville
| | - Arjan Boltjes
- Laboratory of Clinical Chemistry and Hematology, University Medical Center Utrecht, University of Utrecht (A.B., S.W.v.d.L., G.P.)
| | - Sander W van der Laan
- Laboratory of Clinical Chemistry and Hematology, University Medical Center Utrecht, University of Utrecht (A.B., S.W.v.d.L., G.P.)
| | - Emily Farber
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
| | - Daniela Fuller
- CVPath Institute, Inc, Gaithersburg, MD (L.G., D.F., A.F.)
| | - Rita Anane-Wae
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
- Biomedical Engineering (A.A., L.C., D.L., R.A.-W., M.C.), University of Virginia, Charlottesville
| | - Ngozi Akingbesote
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
| | - Ani W Manichaikul
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
| | - Lijiang Ma
- Genetics and Genomic Sciences (L.M., J.L.M.B.), Icahn School of Medicine at Mount Sinai, NY
- Icahn Institute of Genomics and Multiscale Biology (L.M., J.L.M.B.), Icahn School of Medicine at Mount Sinai, NY
| | - Minna U Kaikkonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland (M.U.K.)
| | - Johan L M Björkegren
- Genetics and Genomic Sciences (L.M., J.L.M.B.), Icahn School of Medicine at Mount Sinai, NY
- Icahn Institute of Genomics and Multiscale Biology (L.M., J.L.M.B.), Icahn School of Medicine at Mount Sinai, NY
- Integrated Cardio Metabolic Centre, Department of Medicine, Karolinska Institutet (J.L.M.B.)
| | - Suna Önengüt-Gümüşcü
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
| | - Gerard Pasterkamp
- Laboratory of Clinical Chemistry and Hematology, University Medical Center Utrecht, University of Utrecht (A.B., S.W.v.d.L., G.P.)
| | - Clint L Miller
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
| | - Gary K Owens
- Molecular Physiology, Biological Physics, Medicine, Division of Cardiology, Robert M. Berne Cardiovascular Research Center (G.F.A., G.K.O.), University of Virginia, Charlottesville
| | - Aloke Finn
- CVPath Institute, Inc, Gaithersburg, MD (L.G., D.F., A.F.)
| | - Mohamad Navab
- Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F., J.A.B.)
| | - Alan M Fogelman
- Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F., J.A.B.)
| | - Judith A Berliner
- Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F., J.A.B.)
| | - Mete Civelek
- Center for Public Health Genomics (R.A., A.A., J.H., L.C., J.Y.S., D.L., E.F., R.A.-W., N.A., A.W.M., S.O.-G., C.L.M., M.C.), University of Virginia, Charlottesville
- Biomedical Engineering (A.A., L.C., D.L., R.A.-W., M.C.), University of Virginia, Charlottesville
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7
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Molecular Mechanisms of Adiponectin-Induced Attenuation of Mechanical Stretch-Mediated Vascular Remodeling. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:6425782. [PMID: 32566092 DOI: 10.1155/2020/6425782] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 04/12/2020] [Accepted: 04/17/2020] [Indexed: 12/30/2022]
Abstract
Hypertension induces vascular hypertrophy, which changes blood vessels structurally and functionally, leading to reduced tissue perfusion and further hypertension. It is also associated with dysregulated levels of the circulating adipokines leptin and adiponectin (APN). Leptin is an obesity-associated hormone that promotes vascular smooth muscle cell (VSMC) hypertrophy. APN is a cardioprotective hormone that has been shown to attenuate hypertrophic cardiomyopathy. In this study, we investigated the molecular mechanisms of hypertension-induced VSMC remodeling and the involvement of leptin and APN in this process. To mimic hypertension, the rat portal vein (RPV) was mechanically stretched, and the protective effects of APN on mechanical stretch-induced vascular remodeling and the molecular mechanisms involved were examined by using 10 μg/ml APN. Mechanically stretching the RPV significantly decreased APN protein expression after 24 hours and APN mRNA expression in a time-dependent manner in VSMCs. The mRNA expression of the APN receptors AdipoR1, AdipoR2, and T-cadherin significantly increased after 15 hours of stretch. The ratio of APN/leptin expression in VSMCs significantly decreased after 24 hours of mechanical stretch. Stretching the RPV for 3 days increased the weight and [3H]-leucine incorporation significantly, whereas APN significantly reduced hypertrophy in mechanically stretched vessels. Stretching the RPV for 10 minutes significantly decreased phosphorylation of LKB1, AMPK, and eNOS, while APN significantly increased p-LKB1, p-AMPK, and p-eNOS in stretched vessels. Mechanical stretch significantly increased p-ERK1/2 after 10 minutes, whereas APN significantly reduced stretch-induced ERK1/2 phosphorylation. Stretching the RPV also significantly increased ROS generation after 1 hour, whereas APN significantly decreased mechanical stretch-induced ROS production. Exogenous leptin (3.1 nM) markedly increased GATA-4 nuclear translocation in VSMCs, whereas APN significantly attenuated leptin-induced GATA-4 nuclear translocation. Our results decipher molecular mechanisms of APN-induced attenuation of mechanical stretch-mediated vascular hypertrophy, with the promising potential of ultimately translating this protective hormone into the clinic.
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8
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The role of traditional Chinese medicine in the treatment of atherosclerosis through the regulation of macrophage activity. Biomed Pharmacother 2019; 118:109375. [PMID: 31548175 DOI: 10.1016/j.biopha.2019.109375] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/16/2019] [Accepted: 08/22/2019] [Indexed: 12/27/2022] Open
Abstract
Atherosclerosis (AS) is the main cause of ischemic cardiovascular, cerebrovascular and peripheral vascular diseases. Macrophage activity has been proven to play a critical role during the AS pathological process, which involves the adhesion, aggregation of mononuclear-macrophages, cell differentiation of M1/M2 macrophages as part of complex mechanisms occurring during lipid metabolism, apoptosis, autophagy, inflammation and immune reaction. Therefore, the development of effective AS treatments is likely to target macrophage activity. Certain herbal extracts (such as Salvia miltiorrhiza) have exhibited enormous potential for AS treatment in the past. Here, we aim to provide a summary on the current understanding of the type of action and the underlying target/pathway in macrophage regulation of certain herbal extracts used in Traditional Chinese Medicine for treatment of AS.
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Guo X, Fereydooni A, Isaji T, Gorecka J, Liu S, Hu H, Ono S, Alozie M, Lee SR, Taniguchi R, Yatsula B, Nassiri N, Zhang L, Dardik A. Inhibition of the Akt1-mTORC1 Axis Alters Venous Remodeling to Improve Arteriovenous Fistula Patency. Sci Rep 2019; 9:11046. [PMID: 31363142 PMCID: PMC6667481 DOI: 10.1038/s41598-019-47542-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 07/19/2019] [Indexed: 01/06/2023] Open
Abstract
Arteriovenous fistulae (AVF) are the most common access created for hemodialysis, but up to 60% do not sustain dialysis within a year, suggesting a need to improve AVF maturation and patency. In a mouse AVF model, Akt1 regulates fistula wall thickness and diameter. We hypothesized that inhibition of the Akt1-mTORC1 axis alters venous remodeling to improve AVF patency. Daily intraperitoneal injections of rapamycin reduced AVF wall thickness with no change in diameter. Rapamycin decreased smooth muscle cell (SMC) and macrophage proliferation; rapamycin also reduced both M1 and M2 type macrophages. AVF in mice treated with rapamycin had reduced Akt1 and mTORC1 but not mTORC2 phosphorylation. Depletion of macrophages with clodronate-containing liposomes was also associated with reduced AVF wall thickness and both M1- and M2-type macrophages; however, AVF patency was reduced. Rapamycin was associated with improved long-term patency, enhanced early AVF remodeling and sustained reduction of SMC proliferation. These results suggest that rapamycin improves AVF patency by reducing early inflammation and wall thickening while attenuating the Akt1-mTORC1 signaling pathway in SMC and macrophages. Macrophages are associated with AVF wall thickening and M2-type macrophages may play a mechanistic role in AVF maturation. Rapamycin is a potential translational strategy to improve AVF patency.
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Affiliation(s)
- Xiangjiang Guo
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA.,Department of Vascular Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Arash Fereydooni
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - Toshihiko Isaji
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - Jolanta Gorecka
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - Shirley Liu
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - Haidi Hu
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - Shun Ono
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - Michelle Alozie
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - Shin Rong Lee
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - Ryosuke Taniguchi
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - Bogdan Yatsula
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - Naiem Nassiri
- Division of Vascular and Endovascular Surgery, Department of Surgery, Yale School of Medicine, New Haven, CT, USA
| | - Lan Zhang
- Department of Vascular Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Alan Dardik
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA. .,Division of Vascular and Endovascular Surgery, Department of Surgery, Yale School of Medicine, New Haven, CT, USA.
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10
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Yan Y, Ye W, Chen Q, Yang L, Zhang L, Liu Y, Zhou X, Wang G. Differential expression profile of long non-coding RNA in the stenosis tissue of arteriovenous fistula. Gene 2018; 664:127-138. [PMID: 29655896 DOI: 10.1016/j.gene.2018.04.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Revised: 04/09/2018] [Accepted: 04/11/2018] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To analyze and preliminarily validate the lncRNA expression profiles in the stenosis tissue of arteriovenous fistula (AVF). METHODS A total of 54 uremic patients administered in the department of nephrology in the First Affiliated Hospital of Nanchang University between February 2017 and March 2017 were included in the study and subsequently categorized as experimental group, which included 12 patients with confirmed diagnosis of AVF, and control group which included 42 patients with no vascular stenosis. The experimental group inclusion criteria include: AVF used >3 months; The blood flow of AVF <200 mL/min; the degree of the stenosis was >50%, excluded obvious thrombosis; The ultrasonographic data of AVF stenosis is complete. The controls were randomly selected from uremic patients who were primary AVF operation, excluded obvious vascular stenosis and vascular diseases. Among them, 4 sample in the experimental group and 4 controls were used in LncRNA sequencing. RNA in vascular tissue was extracted by Trizol and IncRNA sequencing was used to establish the expression profiles of lncRNA in the stenosis tissue of AVF.9 difference expression lncRNA were collected for validating in AVF stenosis cases by using quantitative real-time polymerase chain reaction (qRT-PCR). Moreover, Cluster analysis, gene functional analysis and pathway analysis were used to explore the function of difference expression lncRNA. RESULTS Among the 27,692 lncRNA transcripts examined, 247 lncRNAs were found to be significantly differentially expressed (P < 0.05, fold change ≥2) in the experimental group and control group, with 141 being up-regulated and 106 down-regulated. The expression levels of 9 lncRNAs validated by subsequent qRT-PCR were shown to be highly consistent with the sequencing data. CONCLUSION Our study revealed lncRNAs expression profiles in the stenosis tissue of AVF by LncRNA sequencing. These lncRNAs and its related signaling pathways may play a key role in the occurrence and progression of AVF stenosis.
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Affiliation(s)
- Yan Yan
- Department of Nephrology, First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People's Republic of China
| | - Wen Ye
- Department of Nephrology, First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People's Republic of China
| | - Qinkai Chen
- Department of Nephrology, First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People's Republic of China
| | - Liu Yang
- Department of Nephrology, First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People's Republic of China
| | - Li Zhang
- Department of Nephrology, First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People's Republic of China
| | - Yu Liu
- Department of Nephrology, First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People's Republic of China
| | - Xiaochen Zhou
- Department of Urology, First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People's Republic of China
| | - Gongxian Wang
- Department of Urology, First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People's Republic of China.
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11
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Umesalma S, Houwen FK, Baumbach GL, Chan SL. Roles of Caveolin-1 in Angiotensin II-Induced Hypertrophy and Inward Remodeling of Cerebral Pial Arterioles. Hypertension 2016; 67:623-9. [PMID: 26831194 DOI: 10.1161/hypertensionaha.115.06565] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 12/03/2015] [Indexed: 11/16/2022]
Abstract
Angiotensin II (Ang II) is a major determinant of inward remodeling and hypertrophy in pial arterioles that may have an important role in stroke during chronic hypertension. Previously, we found that epidermal growth factor receptor is critical in Ang II-mediated hypertrophy that may involve caveolin-1 (Cav-1). In this study, we examined the effects of Cav-1 and matrix metalloproteinase-9 (MMP9) on Ang II-mediated structural changes in pial arterioles. Cav-1-deficient (Cav-1(-/-)), MMP9-deficient (MMP9(-/-)), and wild-type mice were infused with either Ang II (1000 ng/kg per minute) or saline via osmotic minipumps for 28 days (n=6-8 per group). Systolic arterial pressure was measured by a tail-cuff method. Pressure and diameter of pial arterioles were measured through an open cranial window in anesthetized mice. Cross-sectional area of the wall was determined histologically in pressurized fixed pial arterioles. Expression of Cav-1, MMP9, phosphorylated epidermal growth factor receptor, and Akt was determined by Western blotting and immunohistochemistry. Deficiency of Cav-1 or MMP9 did not affect Ang II-induced hypertension. Ang II increased the expression of Cav-1, phosphorylated epidermal growth factor receptor, and Akt in wild-type mice, which was attenuated in Cav-1(-/-) mice. Ang II-induced hypertrophy, inward remodeling, and increased MMP9 expression in pial arterioles were prevented in Cav-1(-/-) mice. Ang II-mediated increases in MMP9 expression and inward remodeling, but not hypertrophy, were prevented in MMP9(-/-) mice. In conclusion, Cav-1 is essential in Ang II-mediated inward remodeling and hypertrophy in pial arterioles. Cav-1-induced MMP9 is exclusively involved in inward remodeling, not hypertrophy. Further studies are needed to determine the role of Akt in Ang II-mediated hypertrophy.
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Affiliation(s)
- Shaikamjad Umesalma
- From the Department of Pathology, University of Iowa College of Medicine, Iowa City (S.U., F.K.H., G.L.B.); and Department of Neurological Sciences, University of Vermont, Burlington (S.-L.C.)
| | - Frederick Keith Houwen
- From the Department of Pathology, University of Iowa College of Medicine, Iowa City (S.U., F.K.H., G.L.B.); and Department of Neurological Sciences, University of Vermont, Burlington (S.-L.C.)
| | - Gary L Baumbach
- From the Department of Pathology, University of Iowa College of Medicine, Iowa City (S.U., F.K.H., G.L.B.); and Department of Neurological Sciences, University of Vermont, Burlington (S.-L.C.).
| | - Siu-Lung Chan
- From the Department of Pathology, University of Iowa College of Medicine, Iowa City (S.U., F.K.H., G.L.B.); and Department of Neurological Sciences, University of Vermont, Burlington (S.-L.C.).
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Takegahara N, Kim H, Mizuno H, Sakaue-Sawano A, Miyawaki A, Tomura M, Kanagawa O, Ishii M, Choi Y. Involvement of Receptor Activator of Nuclear Factor-κB Ligand (RANKL)-induced Incomplete Cytokinesis in the Polyploidization of Osteoclasts. J Biol Chem 2015; 291:3439-54. [PMID: 26670608 PMCID: PMC4751386 DOI: 10.1074/jbc.m115.677427] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Indexed: 12/21/2022] Open
Abstract
Osteoclasts are specialized polyploid cells that resorb bone. Upon stimulation with receptor activator of nuclear factor-κB ligand (RANKL), myeloid precursors commit to becoming polyploid, largely via cell fusion. Polyploidization of osteoclasts is necessary for their bone-resorbing activity, but the mechanisms by which polyploidization is controlled remain to be determined. Here, we demonstrated that in addition to cell fusion, incomplete cytokinesis also plays a role in osteoclast polyploidization. In in vitro cultured osteoclasts derived from mice expressing the fluorescent ubiquitin-based cell cycle indicator (Fucci), RANKL induced polyploidy by incomplete cytokinesis as well as cell fusion. Polyploid cells generated by incomplete cytokinesis had the potential to subsequently undergo cell fusion. Nuclear polyploidy was also observed in osteoclasts in vivo, suggesting the involvement of incomplete cytokinesis in physiological polyploidization. Furthermore, RANKL-induced incomplete cytokinesis was reduced by inhibition of Akt, resulting in impaired multinucleated osteoclast formation. Taken together, these results reveal that RANKL-induced incomplete cytokinesis contributes to polyploidization of osteoclasts via Akt activation.
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Affiliation(s)
- Noriko Takegahara
- From the Next Generation Optical Immune-imaging, WPI-Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan, the Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104,
| | - Hyunsoo Kim
- the Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - Hiroki Mizuno
- the Department of Immunology and Cell Biology, Graduate School of Medicine and Frontier Biosciences, WPI-Immunology Frontier Research Center, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan, the CREST, Japan Science and Technology Agency, 5 Sanban-cho, Chiyoda-ku, Tokyo 102-0075, Japan
| | - Asako Sakaue-Sawano
- the Laboratory for Cell Function and Dynamics, Advanced Technology Development Group, Brain Science Institute, RIKEN, Wako-city, Saitama 351-0198, Japan
| | - Atsushi Miyawaki
- the Laboratory for Cell Function and Dynamics, Advanced Technology Development Group, Brain Science Institute, RIKEN, Wako-city, Saitama 351-0198, Japan
| | - Michio Tomura
- the Laboratory for Autoimmune Regulation, Research Center for Allergy and Immunology, RIKEN, Yokohama City, Kanagawa 230-0045, Japan, the Laboratory of Immunology, Faculty of Pharmacy, Osaka-Ohtani University, 3-11-1 Nishikiorikita, Tondabayashi-city, Osaka 584-8540, Japan, and
| | - Osami Kanagawa
- the Department of Molecular Preventive Medicine, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-033, Japan
| | - Masaru Ishii
- the Department of Immunology and Cell Biology, Graduate School of Medicine and Frontier Biosciences, WPI-Immunology Frontier Research Center, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan, the CREST, Japan Science and Technology Agency, 5 Sanban-cho, Chiyoda-ku, Tokyo 102-0075, Japan
| | - Yongwon Choi
- the Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104,
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Tormos AM, Taléns-Visconti R, Sastre J. Regulation of cytokinesis and its clinical significance. Crit Rev Clin Lab Sci 2015; 52:159-67. [DOI: 10.3109/10408363.2015.1012191] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Yu H, Littlewood T, Bennett M. Akt isoforms in vascular disease. Vascul Pharmacol 2015; 71:57-64. [PMID: 25929188 PMCID: PMC4728195 DOI: 10.1016/j.vph.2015.03.003] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 03/31/2015] [Indexed: 11/05/2022]
Abstract
The mammalian serine/threonine Akt kinases comprise three closely related isoforms: Akt1, Akt2 and Akt3. Akt activation has been implicated in both normal and disease processes, including in development and metabolism, as well as cancer and cardiovascular disease. Although Akt signalling has been identified as a promising therapeutic target in cancer, its role in cardiovascular disease is less clear. Importantly, accumulating evidence suggests that the three Akt isoforms exhibit distinct tissue expression profiles, localise to different subcellular compartments, and have unique modes of activation. Consistent with in vitro findings, genetic studies in mice show distinct effects of individual Akt isoforms on the pathophysiology of cardiovascular disease. This review summarises recent studies of individual Akt isoforms in atherosclerosis, vascular remodelling and aneurysm formation, to provide a comprehensive overview of Akt function in vascular disease.
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Affiliation(s)
- Haixiang Yu
- Division of Cardiovascular Medicine, University of Cambridge, Box 110, Addenbrooke's Centre for Clinical Investigation, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK.
| | - Trevor Littlewood
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Martin Bennett
- Division of Cardiovascular Medicine, University of Cambridge, Box 110, Addenbrooke's Centre for Clinical Investigation, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
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15
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Gentric G, Desdouets C. Polyploidization in liver tissue. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 184:322-31. [PMID: 24140012 DOI: 10.1016/j.ajpath.2013.06.035] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 06/17/2013] [Accepted: 06/20/2013] [Indexed: 12/14/2022]
Abstract
Polyploidy (alias whole genome amplification) refers to organisms containing more than two basic sets of chromosomes. Polyploidy was first observed in plants more than a century ago, and it is known that such processes occur in many eukaryotes under a variety of circumstances. In mammals, the development of polyploid cells can contribute to tissue differentiation and, therefore, possibly a gain of function; alternately, it can be associated with development of disease, such as cancer. Polyploidy can occur because of cell fusion or abnormal cell division (endoreplication, mitotic slippage, or cytokinesis failure). Polyploidy is a common characteristic of the mammalian liver. Polyploidization occurs mainly during liver development, but also in adults with increasing age or because of cellular stress (eg, surgical resection, toxic exposure, or viral infections). This review will explore the mechanisms that lead to the development of polyploid cells, our current state of understanding of how polyploidization is regulated during liver growth, and its consequence on liver function.
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Affiliation(s)
- Géraldine Gentric
- French Institute of Health and Medical Research (INSERM), U1016, Cochin Institute, Department of Development, Reproduction and Cancer, Paris, France; French National Centre for Scientific Research (CNRS), UMR 8104, Paris, France; Paris Descartes University, Sorbonne Paris Cité, Paris, France
| | - Chantal Desdouets
- French Institute of Health and Medical Research (INSERM), U1016, Cochin Institute, Department of Development, Reproduction and Cancer, Paris, France; French National Centre for Scientific Research (CNRS), UMR 8104, Paris, France; Paris Descartes University, Sorbonne Paris Cité, Paris, France.
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16
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Youreva V, Kapakos G, Srivastava AK. Insulin-like growth-factor-1-induced PKB signaling and Egr-1 expression is inhibited by curcumin in A-10 vascular smooth muscle cells. Can J Physiol Pharmacol 2013; 91:241-7. [DOI: 10.1139/cjpp-2012-0267] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Insulin-like growth factor 1 (IGF-1) is a mitogenic factor that stimulates the signaling pathways responsible for inducing hypertrophic and proliferative responses in vascular smooth muscle cells (VSMC). We have previously demonstrated that IGF-1 receptor (IGF-1R) plays a key role in transducing the hypertrophic and proliferative responses of angiotensin II (Ang-II) and endothelin-1 (ET-1). Curcumin, a polyphenolic compound derived from the spice turmeric is known to possess antiproliferative properties and exerts vasculoprotective effects. However, the ability of curcumin to modulate IGF-1-induced signaling responses in VSMC remains to be investigated. In this study, we determined the effect of curcumin on IGF-1-induced phosphorylation of protein kinase B (PKB), glycogen synthase kinase-3β (GSK-3β), and IGF-1R in VSMC. Curcumin inhibited IGF-1-induced phosphorylation of PKB and GSK-3β as well as the IGF-1R β subunit in a dose-dependent fashion. In addition, IGF-1-induced expression of early growth response protein 1 (Egr-1) which plays a pathogenic role in vascular dysfunctions, was also attenuated by curcumin. In conclusion, these results indicate that curcumin is a potent inhibitor of key components of the IGF-1-induced mitogenic and proliferative signaling system in VSMC, and suggest that curcumin-induced attenuation of these signaling components may constitute a potential mechanism for its vasculoprotective effects.
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Affiliation(s)
- Viktoria Youreva
- Laboratory of Cell Signaling, Montreal Diabetes Research Center, Research Centre of Centre Hospitalier de l'Université de Montréal (CRCHUM) – Angus Campus, 2901 Rachel Est, and Department of Medicine, Université de Montréal, Montréal, QC H1W 4A4, Canada
| | - Georgia Kapakos
- Laboratory of Cell Signaling, Montreal Diabetes Research Center, Research Centre of Centre Hospitalier de l'Université de Montréal (CRCHUM) – Angus Campus, 2901 Rachel Est, and Department of Medicine, Université de Montréal, Montréal, QC H1W 4A4, Canada
| | - Ashok K. Srivastava
- Laboratory of Cell Signaling, Montreal Diabetes Research Center, Research Centre of Centre Hospitalier de l'Université de Montréal (CRCHUM) – Angus Campus, 2901 Rachel Est, and Department of Medicine, Université de Montréal, Montréal, QC H1W 4A4, Canada
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Yih LH, Hsu NC, Wu YC, Yen WY, Kuo HH. Inhibition of AKT enhances mitotic cell apoptosis induced by arsenic trioxide. Toxicol Appl Pharmacol 2013; 267:228-37. [PMID: 23352504 DOI: 10.1016/j.taap.2013.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 01/06/2013] [Accepted: 01/10/2013] [Indexed: 11/18/2022]
Abstract
Accumulated evidence has revealed a tight link between arsenic trioxide (ATO)-induced apoptosis and mitotic arrest in cancer cells. AKT, a serine/threonine kinase frequently over-activated in diverse tumors, plays critical roles in stimulating cell cycle progression, abrogating cell cycle checkpoints, suppressing apoptosis, and regulating mitotic spindle assembly. Inhibition of AKT may therefore enhance ATO cytotoxicity and thus its clinical utility. We show that AKT was activated by ATO in HeLa-S3 cells. Inhibition of AKT by inhibitors of the phosphatidyl inositol 3-kinase/AKT pathway significantly enhanced cell sensitivity to ATO by elevating mitotic cell apoptosis. Ectopic expression of the constitutively active AKT1 had no effect on ATO-induced spindle abnormalities but reduced kinetochore localization of BUBR1 and MAD2 and accelerated mitosis exit, prevented mitotic cell apoptosis, and enhanced the formation of micro- or multi-nuclei in ATO-treated cells. These results indicate that AKT1 activation may prevent apoptosis of ATO-arrested mitotic cells by attenuating the function of the spindle checkpoint and therefore allowing the formation of micro- or multi-nuclei in surviving daughter cells. In addition, AKT1 activation upregulated the expression of aurora kinase B (AURKB) and survivin, and depletion of AURKB or survivin reversed the resistance of AKT1-activated cells to ATO-induced apoptosis. Thus, AKT1 activation suppresses ATO-induced mitotic cell apoptosis, despite the presence of numerous spindle abnormalities, probably by upregulating AURKB and survivin and attenuating spindle checkpoint function. Inhibition of AKT therefore effectively sensitizes cancer cells to ATO by enhancing mitotic cell apoptosis.
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Affiliation(s)
- Ling-Huei Yih
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan, ROC.
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Wang B, Sun L, Tian Y, Li Z, Wei H, Wang D, Yang Z, Chen J, Zhang J, Jiang R. Effects of atorvastatin in the regulation of circulating EPCs and angiogenesis in traumatic brain injury in rats. J Neurol Sci 2012; 319:117-23. [DOI: 10.1016/j.jns.2012.04.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Revised: 03/16/2012] [Accepted: 04/12/2012] [Indexed: 12/20/2022]
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19
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Gentric G, Celton-Morizur S, Desdouets C. Polyploidy and liver proliferation. Clin Res Hepatol Gastroenterol 2012; 36:29-34. [PMID: 21778131 DOI: 10.1016/j.clinre.2011.05.011] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 05/23/2011] [Accepted: 05/25/2011] [Indexed: 02/04/2023]
Abstract
Organisms containing an increase in DNA content by whole number multiples of the entire set of chromosomes are defined as polyploid. Cells that contain more than two sets of chromosomes were first observed in plants about a century ago, and it is now recognized that polyploid cells form in many eukaryotes under a wide variety of circumstances. Although it is less common in mammals, some tissues, including the liver, show a high percentage of polyploid cells. Thus, during post-natal growth, the liver parenchyma undergoes dramatic changes characterized by gradual polyploidization during which hepatocytes of several ploidy classes emerge as a result of modified cell-division cycles. Liver cell polyploidy is generally considered to indicate terminal differentiation and senescence and to both lead to a progressive loss of cell pluripotency and to a markedly decreased replication capacity. In adults, liver polyploidization is differentially regulated upon loss of liver mass and liver damage. Here we review the current state of understanding about how polyploidization is regulated during normal and pathological liver growth, and detail by which mechanisms hepatocytes become polyploid.
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Affiliation(s)
- G Gentric
- Inserm, U1016, Institut Cochin, 75014 Paris, France
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Hepatocytes polyploidization and cell cycle control in liver physiopathology. Int J Hepatol 2012; 2012:282430. [PMID: 23150829 PMCID: PMC3485502 DOI: 10.1155/2012/282430] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 09/10/2012] [Indexed: 01/06/2023] Open
Abstract
Most cells in mammalian tissues usually contain a diploid complement of chromosomes. However, numerous studies have demonstrated a major role of "diploid-polyploid conversion" during physiopathological processes in several tissues. In the liver parenchyma, progressive polyploidization of hepatocytes takes place during postnatal growth. Indeed, at the suckling-weaning transition, cytokinesis failure events induce the genesis of binucleated tetraploid liver cells. Insulin signalling, through regulation of the PI3K/Akt signalling pathway, is essential in the establishment of liver tetraploidization by controlling cytoskeletal organisation and consequently mitosis progression. Liver cell polyploidy is generally considered to indicate terminal differentiation and senescence, and both lead to a progressive loss of cell pluripotency associated to a markedly decreased replication capacity. Although adult liver is a quiescent organ, it retains a capacity to proliferate and to modulate its ploidy in response to various stimuli or aggression (partial hepatectomy, metabolic overload (i.e., high copper and iron hepatic levels), oxidative stress, toxic insult, and chronic hepatitis etc.). Here we review the mechanisms and functional consequences of hepatocytes polyploidization during normal and pathological liver growth.
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Ma L, Brown M, Kogut P, Serban K, Li X, McConville J, Chen B, Bentley JK, Hershenson MB, Dulin N, Solway J, Camoretti-Mercado B. Akt activation induces hypertrophy without contractile phenotypic maturation in airway smooth muscle. Am J Physiol Lung Cell Mol Physiol 2011; 300:L701-9. [PMID: 21378028 DOI: 10.1152/ajplung.00119.2009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Airway smooth muscle (ASM) hypertrophy is a cardinal feature of severe asthma, but the underlying molecular mechanisms remain uncertain. Forced protein kinase B/Akt 1 activation is known to induce myocyte hypertrophy in other muscle types, and, since a number of mediators present in asthmatic airways can activate Akt signaling, we hypothesized that Akt activation could contribute to ASM hypertrophy in asthma. To test this hypothesis, we evaluated whether Akt activation occurs naturally within airway myocytes in situ, whether Akt1 activation is sufficient to cause hypertrophy of normal airway myocytes, and whether such hypertrophy is accompanied by excessive accumulation of contractile apparatus proteins (contractile phenotype maturation). Immunostains of human airway sections revealed concordant activation of Akt (reflected in Ser(473) phosphorylation) and of its downstream effector p70(S6Kinase) (reflected in Thr(389) phosphorylation) within airway muscle bundles, but there was no phosphorylation of the alternative Akt downstream target glycogen synthase kinase (GSK) 3β. Artificial overexpression of constitutively active Akt1 (by plasmid transduction or lentiviral infection) caused a progressive increase in size and protein content of cultured canine tracheal myocytes and increased p70(S6Kinase) phosphorylation but not GSK3β phosphorylation; however, constitutively active Akt1 did not cause disproportionate overaccumulation of smooth muscle (sm) α-actin and SM22. Furthermore, mRNAs encoding sm-α-actin and SM22 were reduced. These results indicate that forced Akt1 signaling causes hypertrophy of cultured airway myocytes without inducing further contractile phenotypic maturation, possibly because of opposing effects on contractile protein gene transcription and translation, and suggest that natural activation of Akt1 plays a similar role in asthmatic ASM.
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Affiliation(s)
- Lan Ma
- Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
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22
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Chang T, Wang R, Olson DJ, Mousseau DD, Ross AR, Wu L. Modification of Akt1 by methylglyoxal promotes the proliferation of vascular smooth muscle cells. FASEB J 2011; 25:1746-57. [DOI: 10.1096/fj.10-178053] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Tuanjie Chang
- Department of PharmacologyCollege of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Rui Wang
- Department of BiologyFaculty of Science and Environmental StudyLakehead UniversityThunder BayOntarioCanada
| | - Douglas J.H. Olson
- Plant Biotechnology InstituteNational Research CouncilSaskatoonSaskatchewanCanada
| | - Darrell D. Mousseau
- Cell Signalling LaboratoryUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Andrew R.S. Ross
- Institute of Ocean SciencesFisheries and Oceans CanadaSidneyBritish ColumbiaCanada
| | - Lingyun Wu
- Department of PharmacologyCollege of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada
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23
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Knecht H, Brüderlein S, Wegener S, Lichtensztejn D, Lichtensztejn Z, Lemieux B, Möller P, Mai S. 3D nuclear organization of telomeres in the Hodgkin cell lines U-HO1 and U-HO1-PTPN1: PTPN1 expression prevents the formation of very short telomeres including "t-stumps". BMC Cell Biol 2010; 11:99. [PMID: 21144060 PMCID: PMC3018409 DOI: 10.1186/1471-2121-11-99] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 12/14/2010] [Indexed: 01/04/2023] Open
Abstract
Background In cancer cells the three-dimensional (3D) telomere organization of interphase nuclei into a telomeric disk is heavily distorted and aggregates are found. In Hodgkin's lymphoma quantitative FISH (3D Q-FISH) reveals a major impact of nuclear telomere dynamics during the transition form mononuclear Hodgkin (H) to diagnostic multinuclear Reed-Sternberg (RS) cells. In vitro and in vivo formation of RS-cells is associated with the increase of very short telomeres including "t-stumps", telomere loss, telomeric aggregate formation and the generation of "ghost nuclei". Results Here we analyze the 3D telomere dynamics by Q-FISH in the novel Hodgkin cell line U-HO1 and its non-receptor protein-tyrosine phosphatase N1 (PTPN1) stable transfectant U-HO1-PTPN1, derived from a primary refractory Hodgkin's lymphoma. Both cell lines show equally high telomerase activity but U-HO1-PTPN differs from U-HO1 by a three times longer doubling time, low STAT5A expression, accumulation of RS-cells (p < 0.0001) and a fourfold increased number of apoptotic cells. As expected, multinuclear U-HO1-RS-cells and multinuclear U-HO1-PTPN1-RS-cells differ from their mononuclear H-precursors by their nuclear volume (p < 0.0001), the number of telomeres (p < 0.0001) and the increase in telomere aggregates (p < 0.003). Surprisingly, U-HO1-RS cells differ from U-HO1-PTPN1-RS-cells by a highly significant increase of very short telomeres including "t-stumps" (p < 0.0001). Conclusion Abundant RS-cells without additional very short telomeres including "t-stumps", high rate of apoptosis, but low STAT5A expression, are hallmarks of the U-HO1-PTPN1 cell line. These characteristics are independent of telomerase activity. Thus, PTPN1 induced dephosphorylation of STAT5 with consecutive lack of Akt/PKB activation and cellular arrest in G2, promoting induction of apoptosis, appears as a possible pathogenetic mechanism deserving further experimental investigation.
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Affiliation(s)
- Hans Knecht
- CHUS, Université de Sherbrooke, Québec, Canada.
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24
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Park HJ, Choi YH, Cho YJ, Henson PM, Kang JL. RhoA-mediated signaling up-regulates hepatocyte growth factor gene and protein expression in response to apoptotic cells. J Leukoc Biol 2010; 89:399-411. [PMID: 21148681 DOI: 10.1189/jlb.0710414] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Clearance of apoptotic cells by macrophages induces HGF secretion. We examined the regulatory mechanisms of HGF mRNA and protein expression in macrophages upon exposure to apoptotic cells. The interaction of RAW 264.7 macrophages with apoptotic Jurkat cells, but not with viable cells, resulted in expression of HGF mRNA and protein. Exposure of RAW 264.7 cells to apoptotic cells induced activation of RhoA, the PI3K/Akt pathway, and MAPKs, including p38 MAPK, ERK, and JNK. Down-regulation of the RhoA/Rho kinase pathway by pharmacological inhibitors or a RhoA-specific siRNA suppressed HGF mRNA and protein expression by macrophages in response to apoptotic cells through the phosphorylation of Akt and the MAPKs. Inhibition of PI3K decreased phosphorylation of Akt and the MAPKs. Inhibition of JNK, but not p38 MAPK and ERK, reduced Akt phosphorylation. The pharmacological inhibitor of PI3K and the MAPKs blocked HGF mRNA and protein expression. Other types of apoptotic cells, such as HeLa cells and murine thymocytes, could also induce HGF mRNA through the RhoA-dependent pathway. Likely, the RhoA-dependent signaling pathway was required for HGF mRNA induction in primary cells of peritoneal macrophages in response to apoptotic cells. An HGFR-blocking antibody did not alter apoptotic cell-induced activation of RhoA, Akt, and the MAPKs, as well as HGF production. Overall, the data provide evidence that activation of the RhoA/Rho kinase pathway up-regulates transcriptional HGF production in response to apoptotic cells.
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Affiliation(s)
- Hyun-Jung Park
- Department of Physiology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul, Korea
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25
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Mechanical stretch potentiates angiotensin II-induced proliferation in spontaneously hypertensive rat vascular smooth muscle cells. Hypertens Res 2010; 33:1250-7. [DOI: 10.1038/hr.2010.187] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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26
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Zhou T, Bao Y, Ye S, Weng D, Chen G, Lu Y, Ma D, Wang S. Effect of spindle checkpoint on Akt2-mediated paclitaxel-resistance in A2780 ovarian cancer cells. ACTA ACUST UNITED AC 2010; 30:206-11. [PMID: 20407875 DOI: 10.1007/s11596-010-0215-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Indexed: 12/21/2022]
Abstract
Recent evidence has suggested that Akt2 plays an important role in the protection of cells from paclitaxel (PTX)-induced apoptosis and control of the cell cycle. In addition, some scholars suggested that the PTX sensitivity depends on a functional spindle assembly checkpoint. In the present study, we investigated the role of the Akt2/Bub1 cross-talking in apoptosis and cell cycle after exposure of the A2780 ovarian cancer cells to paclitaxel (PTX). Recombinant expression plasmid WT-Akt2 was transfected into A2780 cells by lipofectamine2000, and then the expression level of Akt2 gene was detected by using RT-PCR and Western blotting. Cell apoptosis and cell cycle were detected by flow cytometry and Hoechst 33342 staining after treatment with PTX. Moreover, we compared the expression level of Bub1 in different groups by Western blotting. Our study showed that up-regulation of Akt2 contributed to A2780 ovarian cancer cells overriding PTX-induced G(2)/M arrest, and inhibited Bub1 expression. Our findings might shed light on the molecular mechanism of PTX-induced resistance in ovarian cancer and help develop novel anti-neoplastic strategies.
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Affiliation(s)
- Ting Zhou
- Cancer Biology Research Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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27
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Liu Z, Yue S, Chen X, Kubin T, Braun T. Regulation of cardiomyocyte polyploidy and multinucleation by CyclinG1. Circ Res 2010; 106:1498-506. [PMID: 20360255 DOI: 10.1161/circresaha.109.211888] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
RATIONALE Polyploidy and multinucleation are characteristic features of mammalian cardiomyocytes, which develop shortly after birth when most differentiated cardiomyocytes become acytokinetic. Cardiac overload and hypertrophy further increase the degree of polyploidy of cardiomyocytes, suggesting a role in cell type-specific responses to physiological and pathological stimuli. OBJECTIVE We sought to study the function of cyclinG1 in the regulation of polyploidy and multinucleation in cardiomyocytes. METHODS AND RESULTS We found that expression of cyclinG1, a transcriptional target of p53, coincides with arrest of cardiomyocyte proliferation and onset of polyploidization. Overexpression of cyclinG1 promoted DNA synthesis but inhibited cytokinesis in neonatal cardiomyocytes leading to an enlarged population of binuclear cardiomyocytes. Reciprocally, inactivation of the cyclinG1 gene in mice lowered the degree of polyploidy and multinucleation in cardiomyocytes. Moreover, lack of cyclinG1 prevented the increase of polynucleated cardiomyocytes in response to pressure overload and hypertrophy. CONCLUSIONS CyclinG1 is an important player for the regulation of polyploidy and multinucleation in cardiomyocytes probably by inhibition of apoptosis caused by checkpoint activation.
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Affiliation(s)
- Zhipei Liu
- Max-Planck-Institut for Heart und Lung Research, D-61231 Bad Nauheim, Germany
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28
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Wible EF, Laskowitz DT. Statins in traumatic brain injury. Neurotherapeutics 2010; 7:62-73. [PMID: 20129498 PMCID: PMC5084113 DOI: 10.1016/j.nurt.2009.11.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2009] [Revised: 11/17/2009] [Accepted: 11/18/2009] [Indexed: 10/20/2022] Open
Abstract
Traumatic brain injury (TBI) is a common cause of long-term neurological morbidity, with devastating personal and societal consequences. At present, no pharmacological intervention clearly improves outcomes, and therefore a compelling unmet clinical need remains. 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or "statins," offer a potential novel therapeutic strategy for TBI. Statins are well tolerated, easy to administer, and have a long clinical track record in critically ill patients. Their side effects are well defined and easily monitored. Preclinical studies have shown significant benefit of statins in models of TBI and related disease processes, including cerebral ischemia, intracerebral hemorrhage, and subarachnoid hemorrhage. In fact, multiple mechanisms have been defined by which statins may exert benefit after acute brain injury. Statins are currently positioned to be translated into clinical trials in acute brain injury and have the potential to improve outcomes after TBI.
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Affiliation(s)
- Elissa F. Wible
- grid.26009.3d0000000419367961Department of Medicine (Neurology), Duke University School of Medicine, 27710 Durham, North Carolina
| | - Daniel T. Laskowitz
- grid.26009.3d0000000419367961Department of Medicine (Neurology), Duke University School of Medicine, 27710 Durham, North Carolina
- grid.26009.3d0000000419367961Department of Anesthesiology, Duke University School of Medicine, 27710 Durham, North Carolina
- grid.26009.3d0000000419367961Department of Neurobiology, Duke University School of Medicine, 27710 Durham, North Carolina
- grid.189509.c0000000100241216Duke University Medical Center, Box 2900, 27710 Durham, NC
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29
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Owens AP, Subramanian V, Moorleghen JJ, Guo Z, McNamara CA, Cassis LA, Daugherty A. Angiotensin II induces a region-specific hyperplasia of the ascending aorta through regulation of inhibitor of differentiation 3. Circ Res 2009; 106:611-9. [PMID: 20019328 DOI: 10.1161/circresaha.109.212837] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
RATIONALE Angiotensin II (Ang II) has diverse effects on smooth muscle cells (SMCs). The diversity of effects may relate to the regional location of this cell type. OBJECTIVE The aim of this study was to define whether Ang II exerted divergent effects on smooth muscle cells in the aorta and determine the role of blood pressure and specific oxidant mechanisms. METHODS AND RESULTS Ang II (1000 ng/kg per minute) infusion for 28 days into mice increased systolic blood pressure and promoted medial expansion of equivalent magnitude throughout the entire aorta. Both effects were ablated by angiotensin II type 1a (AT(1a)) receptor deficiency. Similar increases in systolic blood pressure by administration of norepinephrine promoted no changes in aortic medial thickness. Increased medial thickness was attributable to SMC expansion owing to hypertrophy in most aortic regions, with the exception of hyperplasia of the ascending aorta. Deficiency of the p47(phox) component of NADPH oxidase ablated Ang II-induced medial expansion in all aortic regions. Analysis of mRNA and protein throughout the aorta revealed a much higher abundance of the inhibitor of differentiation 3 (Id3) in the ascending aorta compared to all other regions. A functional role was demonstrated by Id3 deficiency inhibiting Ang II-induced SMC hyperplasia of the ascending aorta. CONCLUSIONS In conclusion, Ang II promotes both aortic medial hypertrophy and hyperplasia in a region-specific manner via an oxidant mechanism. The ascending aortic hyperplasia is dependent on Id3.
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Affiliation(s)
- A Phillip Owens
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY 40536-0509, USA
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30
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Rzucidlo EM. Signaling pathways regulating vascular smooth muscle cell differentiation. Vascular 2009; 17 Suppl 1:S15-20. [PMID: 19426604 DOI: 10.2310/6670.2008.00089] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Vascular smooth muscle cell (VSMC) differentiation is an essential component of vascular development. These cells perform biosynthetic, proliferative, and contractile roles in the vessel wall. VSMCs are not terminally differentiated and are able to modulate their phenotype in response to changing local environmental cues. There is clear evidence that alterations in the differentiated state of the VSMC play a critical role in the pathogenesis of atherosclerosis and intimal hyperplasia, as well as in a variety of other major human diseases, including hypertension, asthma, atherosclerosis and vascular aneurysms. The focus of this review is to provide an overview of the current state of knowledge of molecular mechanisms involved in controlling phenotypic switching of VSMCs, with particular focus on examination of the signaling pathways that regulate this process.
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Affiliation(s)
- Eva M Rzucidlo
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Dartmouth Medical School, Lebanon, NH 03756, USA.
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31
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McCrann DJ, Yang D, Chen H, Carroll S, Ravid K. Upregulation of Nox4 in the aging vasculature and its association with smooth muscle cell polyploidy. Cell Cycle 2009; 8:902-8. [PMID: 19221493 DOI: 10.4161/cc.8.6.7900] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Our recent reports indicated that polyploidization of aortic vascular smooth muscle cells (VSMC) serves as a biomarker for aging, and that the polyploid state is linked to a higher incidence of senescence in vivo. Here, we found that NADPH oxidase 4 (Nox4) expression is augmented in VSMC from aortas of old rats and that Nox4 levels are increased in polyploid VSMC in comparison to diploid cells in vivo. Seeking to determine if Nox4 upregulation plays a causal role in the accumulation of polyploid cells, we performed ploidy analysis on primary VSMC transduced with Nox4 adenovirus. We observed a consistent accumulation of polyploid cells and a concomitant decrease in the percentage of diploid cells in Nox4 overexpressing cells in comparison to controls or to cells overexpressing dominant negative Nox4. Further exploration of this phenomenon in VSMC cultures identified a Nox4-induced decrease in the chromosome passenger protein, survivin, whose absence and mislocalization during polyploidization was previously shown to induce VSMC polyploidy. Taken together, our study is the first to show increased Nox4 levels in VSMC during aging, and to demonstrate its role in induction of polyploidy in this lineage.
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Affiliation(s)
- Donald J McCrann
- Department of Biochemistry and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts, USA
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32
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Tang YB, Liu YJ, Zhou JG, Wang GL, Qiu QY, Guan YY. Silence of ClC-3 chloride channel inhibits cell proliferation and the cell cycle via G/S phase arrest in rat basilar arterial smooth muscle cells. Cell Prolif 2008; 41:775-85. [PMID: 18823498 DOI: 10.1111/j.1365-2184.2008.00551.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVES Previously, we have found that the ClC-3 chloride channel is involved in endothelin-1 (ET-1)-induced rat aortic smooth muscle cell proliferation. The present study was to investigate the role of ClC-3 in cell cycle progression/distribution and the underlying mechanisms of proliferation. MATERIALS AND METHODS Small interference RNA (siRNA) is used to silence ClC-3 expression. Cell proliferation, cell cycle distribution and protein expression were measured or detected with cell counting, bromodeoxyuridine (BrdU) incorporation, Western blot and flow cytometric assays respectively. RESULTS ET-1-induced rat basilar vascular smooth muscle cell (BASMC) proliferation was parallel to a significant increase in endogenous expression of ClC-3 protein. Silence of ClC-3 by siRNA inhibited expression of ClC-3 protein, prevented an increase in BrdU incorporation and cell number induced by ET-1. Silence of ClC-3 also caused cell cycle arrest in G(0)/G(1) phase and prevented the cells' progression from G(1) to S phase. Knockdown of ClC-3 potently inhibited cyclin D1 and cyclin E expression and increased cyclin-dependent kinase inhibitors (CDKIs) p27(KIP) and p21(CIP) expression. Furthermore, ClC-3 knockdown significantly attenuated phosphorylation of Akt and glycogen synthase kinase-3beta (GSK-3beta) induced by ET-1. CONCLUSION Silence of ClC-3 protein effectively suppressed phosphorylation of the Akt/GSK-3beta signal pathway, resulting in down-regulation of cyclin D1 and cyclin E, and up-regulation of p27(KIP) and p21(CIP). In these BASMCs, integrated effects lead to cell cycle G(1)/S arrest and inhibition of cell proliferation.
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Affiliation(s)
- Y-B Tang
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
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33
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McCrann DJ, Nguyen HG, Jones MR, Ravid K. Vascular smooth muscle cell polyploidy: An adaptive or maladaptive response? J Cell Physiol 2008; 215:588-92. [DOI: 10.1002/jcp.21363] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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34
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Martin KA, Merenick BL, Ding M, Fetalvero KM, Rzucidlo EM, Kozul CD, Brown DJ, Chiu HY, Shyu M, Drapeau BL, Wagner RJ, Powell RJ. Rapamycin Promotes Vascular Smooth Muscle Cell Differentiation through Insulin Receptor Substrate-1/Phosphatidylinositol 3-Kinase/Akt2 Feedback Signaling. J Biol Chem 2007; 282:36112-20. [PMID: 17908691 DOI: 10.1074/jbc.m703914200] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The phenotypic plasticity of mature vascular smooth muscle cells (VSMCs) facilitates angiogenesis and wound healing, but VSCM dedifferentiation also contributes to vascular pathologies such as intimal hyperplasia. Insulin/insulin-like growth factor I (IGF-I) is unique among growth factors in promoting VSMC differentiation via preferential activation of phosphatidylinositol 3-kinase (PI3K) and Akt. We have previously reported that rapamycin promotes VSMC differentiation by inhibiting the mammalian target of rapamycin (mTOR) target S6K1. Here, we show that rapamycin activates Akt and induces contractile protein expression in human VSMC in an insulin-like growth factor I-dependent manner, by relieving S6K1-dependent negative regulation of insulin receptor substrate-1 (IRS-1). In skeletal muscle and adipocytes, rapamycin relieves mTOR/S6K1-dependent inhibitory phosphorylation of IRS-1, thus preventing IRS-1 degradation and enhancing PI3K activation. We report that this mechanism is functional in VSMCs and crucial for rapamycin-induced differentiation. Rapamycin inhibits S6K1-dependent IRS-1 serine phosphorylation, increases IRS-1 protein levels, and promotes association of tyrosine-phosphorylated IRS-1 with PI3K. A rapamycin-resistant S6K1 mutant prevents rapamycin-induced Akt activation and VSMC differentiation. Notably, we find that rapamycin selectively activates only the Akt2 isoform and that Akt2, but not Akt1, is sufficient to induce contractile protein expression. Akt2 is required for rapamycin-induced VSMC differentiation, whereas Akt1 appears to oppose contractile protein expression. The anti-restenotic effect of rapamycin in patients may be attributable to this unique pattern of PI3K effector regulation wherein anti-differentiation signals from S6K1 are inhibited, but pro-differentiation Akt2 activity is promoted through an IRS-1 feedback signaling mechanism.
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MESH Headings
- Antibiotics, Antineoplastic/pharmacology
- Cell Differentiation/drug effects
- Cell Differentiation/physiology
- Elafin/genetics
- Elafin/metabolism
- Enzyme Activation/drug effects
- Enzyme Activation/physiology
- Humans
- Hyperplasia/genetics
- Hyperplasia/metabolism
- Hyperplasia/pathology
- Insulin Receptor Substrate Proteins
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Muscle Proteins/biosynthesis
- Muscle Proteins/genetics
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/metabolism
- Neovascularization, Physiologic/drug effects
- Neovascularization, Physiologic/physiology
- Phosphoproteins/genetics
- Phosphoproteins/metabolism
- Phosphorylation/drug effects
- Protein Kinases/genetics
- Protein Kinases/metabolism
- Proto-Oncogene Proteins c-akt/genetics
- Proto-Oncogene Proteins c-akt/metabolism
- Ribosomal Protein S6 Kinases, 70-kDa/genetics
- Ribosomal Protein S6 Kinases, 70-kDa/metabolism
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Sirolimus/pharmacology
- TOR Serine-Threonine Kinases
- Tunica Intima/metabolism
- Tunica Intima/pathology
- Wound Healing/drug effects
- Wound Healing/physiology
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Affiliation(s)
- Kathleen A Martin
- Division of Vascular Surgery, Dartmouth Medical School, Lebanon, New Hampshire 03756, USA.
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Enhanced sterol response element-binding protein in postintervention restenotic blood vessels plays an important role in vascular smooth muscle proliferation. Life Sci 2007; 82:174-81. [PMID: 18068195 DOI: 10.1016/j.lfs.2007.10.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Revised: 10/30/2007] [Accepted: 10/31/2007] [Indexed: 01/01/2023]
Abstract
Postintervention restenosis (PIRS) after balloon angioplasty or stent implantation is a limitation for these interventional procedures even with the advent of new drug-eluting stents. Sterol regulatory element-binding proteins (SREBP) are transcription factors governing cellular lipid biosynthesis and thus critical in the regulation of the lipid-rich cell membranes. PIRS following injury results partially from newly proliferating cells expressing vascular smooth muscle cell (VSMC) markers. Platelet-derived growth factor (PDGF), lysophosphatidic acid (LPA) and alpha(1)-adrenergic receptor stimulation are well recognized diverse mitogens for VSMC activation in PIRS. We examined whether PDGF, LPA and alpha(1)-adrenergic receptor stimulation with phenylephrine (PE) regulate SREBP expression and subsequently, VSMC proliferation. Our results show that PDGF, LPA and PE upregulate SREBP-1 in a time- and dose-dependent manner. PDGF, LPA and PE-mediated proliferation is dependent on SREBP since inhibition of SREBP expression using targeted knockdown of the SREBP precursor SREBP activating protein (SCAP) by siRNA led to an attenuation of SREBP expression and decreased PDGF, LPA and PE induced proliferation. In two different in vivo PIRS models we found that SREBP-1 was enhanced in the injured blood vessel wall, especially within the neointima and co-localized with alpha-smooth muscle actin positive cells. Thus, SREBP is enhanced in the vessel wall following PIRS and is important in the regulation of pro-hyperplasia molecular signaling. SREBP inhibition may be a powerful tool to limit PIRS.
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Gui Y, He GH, Walsh MP, Zheng XL. Predisposition to tetraploidy in pulmonary vascular smooth muscle cells derived from the Eker rats. Am J Physiol Lung Cell Mol Physiol 2007; 293:L702-11. [PMID: 17575014 DOI: 10.1152/ajplung.00016.2007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Somatic mutations in the tuberous sclerosis complex-2 (TSC2) gene are associated with pulmonary lymphangioleiomyomatosis (LAM), a disorder characterized by benign lesions of smooth muscle and/or smooth muscle-like cells in the lung. However, the cellular mechanisms underlying LAM disease are largely unknown. Given that the TSC2 gene product tuberin is involved in the regulation of cell growth and proliferation, the present study was designed to investigate the potential roles of TSC2 in regulation of the cell cycle. We studied cell cycle profiles of pulmonary vascular smooth muscle cells (SMCs) derived from Eker rats (Tsc2(+/EK)), a genetic model carrying a germline insertional deletion in one copy of the Tsc2 gene, and the wild-type rats (Tsc2(+/+)), a noncarrier counterpart. We found that Tsc2(+/EK), but not Tsc2(+/+), SMCs displayed increases in cells with > or =4N DNA content (> or =4N cells) and in the bromodeoxyuridine (BrdU) incorporation of > or =4N cells. Centrosome number was also increased in Tsc2(+/EK) SMCs, but the mitotic index was comparable between Tsc2(+/+) and Tsc2(+/EK) SMCs. Furthermore, Tsc2(+/EK) SMCs showed elevated phosphorylation of p70S6K and increased expression of cell cycle regulatory proteins Cdk1, cyclin B, Cdk2, and cyclin E. Inhibition of the mammalian target of rapamycin (mTOR) pathway by rapamycin not only inhibited the phosphorylation of p70(S6K) and the expression of cell cycle regulatory proteins but also reduced accumulation of > or =4N cells and BrdU incorporation of >4N cells. Therefore, our results demonstrate that Tsc2(+/EK) SMCs are predisposed to undergo tetraploidization, involving activation of the mTOR pathway. These findings suggest an important role of Tsc2 in regulation of the cell cycle.
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MESH Headings
- Animals
- Cell Cycle
- Centrosome/metabolism
- Cyclin B/genetics
- Cyclin E/genetics
- Cyclin-Dependent Kinases/genetics
- DNA/biosynthesis
- Female
- Male
- Mitogen-Activated Protein Kinases/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/enzymology
- Myocytes, Smooth Muscle/metabolism
- Polyploidy
- Protein Kinases/metabolism
- Pulmonary Artery/cytology
- Pulmonary Artery/metabolism
- Rats
- Rats, Inbred Strains
- Rats, Long-Evans
- Ribosomal Protein S6 Kinases/metabolism
- TOR Serine-Threonine Kinases
- Tuberous Sclerosis Complex 2 Protein
- Tumor Suppressor Proteins/metabolism
- Up-Regulation/genetics
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Affiliation(s)
- Yu Gui
- Smooth Muscle Research Group, Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada
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37
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Zeidan A, Paylor B, Steinhoff KJ, Javadov S, Rajapurohitam V, Chakrabarti S, Karmazyn M. Actin cytoskeleton dynamics promotes leptin-induced vascular smooth muscle hypertrophy via RhoA/ROCK- and phosphatidylinositol 3-kinase/protein kinase B-dependent pathways. J Pharmacol Exp Ther 2007; 322:1110-6. [PMID: 17562852 DOI: 10.1124/jpet.107.122440] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Obesity is associated with increased leptin production that may contribute to cardiovascular pathology through a multiplicity of effects. Leptin has been shown to contribute to vascular remodeling through various mechanisms, including production of vascular smooth muscle (VSMC) hypertrophy; however, the mechanisms underlying the vascular hypertrophic effect of leptin remain unknown. In the present study, we investigated the contributions of the RhoA/Rho kinase (ROCK) and phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathways, actin dynamics, and the expression of serum-response factor (SRF) in the hypertrophic effects of leptin on vascular tissue. Strips of rat portal vein (RPV) were cultured with or without leptin at 3.1 nM for 1 to 3 days. Leptin significantly increased RhoA activity by 163 +/- 20%, whereas phosphorylation of downstream factors, including LIM kinase 1 and cofilin-2, was increased by 160 +/- 25 and 290 +/- 25%, respectively. Leptin also significantly phosphorylated Akt by 130 +/- 30%, which was inhibited by the PI3K inhibitor 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002). RhoA/ROCK and PI3K/Akt activation was associated with a significant increase in RPV wet weight (11 +/- 1%), protein synthesis (45 +/- 7%), SRF expression (136 +/- 11%), and polymerization of actin, as reflected by an increase in the F-/G-actin ratio, effects that were significantly attenuated by a leptin receptor (leptin obese receptor) antibody, the ROCK inhibitor (+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl) (Y-27632) as well as the PI3K inhibitor LY294002. Our results indicate that the activation of RhoA/ROCK and PI3K/Akt plays a pivotal role in leptin signaling, leading to the development of VSMC hypertrophy through a mechanism involving altered actin dynamics.
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Affiliation(s)
- Asad Zeidan
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
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38
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Guilluy C, Rolli-Derkinderen M, Tharaux PL, Melino G, Pacaud P, Loirand G. Transglutaminase-dependent RhoA activation and depletion by serotonin in vascular smooth muscle cells. J Biol Chem 2006; 282:2918-28. [PMID: 17142836 DOI: 10.1074/jbc.m604195200] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The small G protein RhoA plays a major role in several vascular processes and cardiovascular disorders. Here we analyze the mechanisms of RhoA regulation by serotonin (5-HT) in arterial smooth muscle. 5-HT (0.1-10 microM) induced activation of RhoA followed by RhoA depletion at 24-72 h. Inhibition of 5-HT1 receptors reduced the early phase of RhoA activation but had no effect on 5-HT-induced delayed RhoA activation and depletion, which were suppressed by the 5-HT transporter inhibitor fluoxetine and the transglutaminase inhibitor monodansylcadaverin and in type 2 transglutaminase-deficient smooth muscle cells. Coimmunoprecipitations demonstrated that 5-HT associated with RhoA both in vitro and in vivo. This association was calcium-dependent and inhibited by fluoxetine and monodansylcadaverin. 5-HT promotes the association of RhoA with the E3 ubiquitin ligase Smurf1, and 5-HT-induced RhoA depletion was inhibited by the proteasome inhibitor MG132 and the RhoA inhibitor Tat-C3. Simvastatin, the Rho kinase inhibitor Y-27632, small interfering RNA-mediated RhoA gene silencing, and long-term 5-HT stimulation induced Akt activation. In contrast, inhibition of 5-HT-mediated RhoA degradation by MG132 prevented 5-HT-induced Akt activation. Long-term 5-HT stimulation also led to the inhibition of the RhoA/Rho kinase component of arterial contraction. Our data provide evidence that 5-HT, internalized through the 5-HT transporter, is transamidated to RhoA by transglutaminase. Transamidation of RhoA leads to RhoA activation and enhanced proteasomal degradation, which in turn is responsible for Akt activation and contraction inhibition. The observation of transamidation of 5-HT to RhoA in pulmonary artery of hypoxic rats suggests that this process could participate in pulmonary artery remodeling and hypertension.
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Affiliation(s)
- Christophe Guilluy
- INSERM U533 Institut du Thorax, Université de Nantes, 44322 Nantes cedex 3, France
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39
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Li M, Chiu JF, Mossman BT, Fukagawa NK. Down-regulation of manganese-superoxide dismutase through phosphorylation of FOXO3a by Akt in explanted vascular smooth muscle cells from old rats. J Biol Chem 2006; 281:40429-39. [PMID: 17079231 DOI: 10.1074/jbc.m606596200] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Manganese-superoxide dismutase (MnSOD) is one of the major cellular antioxidant defense systems. To study the effect of age on the regulation of MnSOD in the vasculature, we compared MnSOD expression and its transcriptional regulation in explanted vascular smooth muscle cells (VSMC) isolated from old (24 months old) versus young (6 months old) rats and grown in a normal (5 mM) or high (12.5 and 25 mM) glucose or tumor necrosis factor alpha (5 ng/ml) environment to induce oxidative stress. Both MnSOD protein and activity were reduced in VSMC from old compared with young animals. FOXO3a, a member of the family of Forkhead transcription factors, interacted with the promoter of the rat MnSOD gene at a specific binding site. Inhibition of FOXO3a transcription with small interfering RNA led to a reduction in MnSOD gene expression. VSMC from old rats had increased phosphorylated FOXO3a at Ser(253), which paralleled the reduction of MnSOD protein. Treatment of VSMC with 5 nm insulin-like growth factor-1 induced phosphorylation of Akt and FOXO3a over time, repressing FOXO3a DNA binding and consequently MnSOD gene expression. Furthermore, Akt activity was selectively increased in VSMC from the old, supporting the hypothesis that increased age-related Akt activity might be responsible for the phosphorylation and inactivation of FOXO3a, which in turn down-regulates MnSOD transcription.
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Affiliation(s)
- Muyao Li
- Departments of Medicine, Pathology, and Biochemistry, University of Vermont College of Medicine, Burlington, Vermont 05405, USA
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40
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Gervais M, Dugourd C, Muller L, Ardidie C, Canton B, Loviconi L, Corvol P, Chneiweiss H, Monnot C. Akt down-regulates ERK1/2 nuclear localization and angiotensin II-induced cell proliferation through PEA-15. Mol Biol Cell 2006; 17:3940-51. [PMID: 16822839 PMCID: PMC1593169 DOI: 10.1091/mbc.e06-06-0501] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Angiotensin II (AngII) type 1 receptors (AT1) regulate cell growth through the extracellular signal-regulated kinase (ERK)1/2 and phosphatidylinositol 3-kinase (PI3K) pathways. ERK1/2 and Akt/protein kinase B, downstream of PI3K, are independently activated but both required for mediating AngII-induced proliferation when expressed at endogenous levels. We investigate the effect of an increase in the expression of wild-type Akt1 by using Chinese hamster ovary (CHO)-AT1 cells. Unexpectedly, Akt overexpression inhibits the AT1-mediated proliferation. This effect could be generated by a cross-talk between the PI3K and ERK1/2 pathways. A functional partner is the phosphoprotein enriched in astrocytes of 15 kDa (PEA-15), an Akt substrate known to bind ERK1/2 and to regulate their nuclear translocation. We report that Akt binds to PEA-15 and that Akt activation leads to PEA-15 stabilization, independently of PEA-15 interaction with ERK1/2. Akt cross-talk with PEA-15 does not affect ERK1/2 activation but decreases their nuclear activity as a result of the blockade of ERK1/2 nuclear accumulation. In response to AngII, PEA-15 overexpression displays the same functional consequences on ERK1/2 signaling as Akt overactivation. Thus, Akt overactivation prevents the nuclear translocation of ERK1/2 and the AngII-induced proliferation through interaction with and stabilization of endogenous PEA-15.
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Affiliation(s)
- Marianne Gervais
- *Institut National de la Santé et de la Recherche Médicale U36 and
| | - Céline Dugourd
- *Institut National de la Santé et de la Recherche Médicale U36 and
| | - Laurent Muller
- *Institut National de la Santé et de la Recherche Médicale U36 and
| | - Corinne Ardidie
- *Institut National de la Santé et de la Recherche Médicale U36 and
| | - Brigitte Canton
- Institut National de la Santé et de la Recherche Médicale U114, Collège de France, 75231 Paris, France
| | | | - Pierre Corvol
- *Institut National de la Santé et de la Recherche Médicale U36 and
| | - Hervé Chneiweiss
- Institut National de la Santé et de la Recherche Médicale U114, Collège de France, 75231 Paris, France
| | - Catherine Monnot
- *Institut National de la Santé et de la Recherche Médicale U36 and
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41
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Kim NH, Rincon-Choles H, Bhandari B, Choudhury GG, Abboud HE, Gorin Y. Redox dependence of glomerular epithelial cell hypertrophy in response to glucose. Am J Physiol Renal Physiol 2005; 290:F741-51. [PMID: 16234311 DOI: 10.1152/ajprenal.00313.2005] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Podocytes or glomerular epithelial cells (GECs) are important targets of the diabetic microenvironment. Podocyte foot process effacement and widening, loss of GECs and hypertrophy are pathological features of this disease. ANG II and oxidative stress are key mediators of renal hypertrophy in diabetes. The cellular mechanisms responsible for GEC hypertrophy in diabetes are incompletely characterized. We investigated the effect of high glucose on protein synthesis and GEC hypertrophy. Exposure of GECs to high glucose dose dependently stimulated [(3)H]leucine incorporation, but not [(3)H]thymidine incorporation. High glucose resulted in the activation of ERK1/2 and Akt/PKB. ERK1/2 pathway inhibitor or the dominant negative mutant of Akt/PKB inhibited high glucose-induced protein synthesis. High glucose elicited a rapid generation of reactive oxygen species (ROS). The stimulatory effect of high glucose on ROS production, ERK1/2, and Akt/PKB activation was prevented by the antioxidants catalase, diphenylene iodonium, and N-acetylcysteine. Exposure of the cells to hydrogen peroxide mimicked the effects of high glucose. In addition, ANG II resulted in the activation of ERK1/2 and Akt/PKB and GEC hypertrophy. Moreover, high glucose and ANG II exhibited additive effects on ERK1/2 and Akt/PKB activation as well as protein synthesis. These additive responses were abolished by treatment of the cells with the antioxidants. These data demonstrate that high glucose stimulates GEC hypertrophy through a ROS-dependent activation of ERK1/2 and Akt/PKB. Enhanced ROS generation accounts for the additive effects of high glucose and ANG II, suggesting that this signaling cascade contributes to GEC injury in diabetes.
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Affiliation(s)
- Nam-Ho Kim
- University of Texas Health Science Center, Department of Medicine, Division of Nephrology, MC 7882, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA
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42
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Gorin Y, Block K, Hernandez J, Bhandari B, Wagner B, Barnes JL, Abboud HE. Nox4 NAD(P)H oxidase mediates hypertrophy and fibronectin expression in the diabetic kidney. J Biol Chem 2005; 280:39616-26. [PMID: 16135519 DOI: 10.1074/jbc.m502412200] [Citation(s) in RCA: 408] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Renal hypertrophy and extracellular matrix accumulation are early features of diabetic nephropathy. We investigated the role of the NAD(P)H oxidase Nox4 in generation of reactive oxygen species (ROS), hypertrophy, and fibronectin expression in a rat model of type 1 diabetes induced by streptozotocin. Phosphorothioated antisense (AS) or sense oligonucleotides for Nox4 were administered for 2 weeks with an osmotic minipump 72 h after streptozotocin treatment. Nox4 protein expression was increased in diabetic kidney cortex compared with non-diabetic controls and was down-regulated in AS-treated animals. AS oligonucleotides inhibited NADPH-dependent ROS generation in renal cortical and glomerular homogenates. ROS generation by intact isolated glomeruli from diabetic animals was increased compared with glomeruli isolated from AS-treated animals. AS treatment reduced whole kidney and glomerular hypertrophy. Moreover, the increased expression of fibronectin protein was markedly reduced in renal cortex including glomeruli of AS-treated diabetic rats. Akt/protein kinase B and ERK1/2, two protein kinases critical for cell growth and hypertrophy, were activated in diabetes, and AS treatment almost abolished their activation. In cultured mesangial cells, high glucose increased NADPH oxidase activity and fibronectin expression, effects that were prevented in cells transfected with AS oligonucleotides. These data establish a role for Nox4 as the major source of ROS in the kidneys during early stages of diabetes and establish that Nox4-derived ROS mediate renal hypertrophy and increased fibronectin expression.
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Affiliation(s)
- Yves Gorin
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas 78229-3900, USA.
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43
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Ko MA, Rosario CO, Hudson JW, Kulkarni S, Pollett A, Dennis JW, Swallow CJ. Plk4 haploinsufficiency causes mitotic infidelity and carcinogenesis. Nat Genet 2005; 37:883-8. [PMID: 16025114 DOI: 10.1038/ng1605] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2004] [Accepted: 05/18/2005] [Indexed: 02/07/2023]
Abstract
The polo-like kinase Plk4 (also called Sak) is required for late mitotic progression, cell survival and postgastrulation embryonic development. Here we identified a phenotype resulting from Plk4 haploinsufficiency in Plk4 heterozygous cells and mice. Plk4+/- embryonic fibroblasts had increased centrosomal amplification, multipolar spindle formation and aneuploidy compared with wild-type cells. The incidence of spontaneous liver and lung cancers was approximately 15 times high in elderly Plk4+/- mice than in Plk4+/+ littermates. Using the in vivo model of partial hepatectomy to induce synchronous cell cycle entry, we determined that the precise regulation of cyclins D1, E and B1 and of Cdk1 was impaired in Plk4+/- regenerating liver, and p53 activation and p21 and BubR1 expression were suppressed. These defects were associated with progressive cell cycle delays, increased spindle irregularities and accelerated hepatocellular carcinogenesis in Plk4+/- mice. Loss of heterozygosity occurs frequently (approximately 60%) at polymorphic markers adjacent to the PLK4 locus in human hepatoma. Reduced Plk4 gene dosage increases the probability of mitotic errors and cancer development.
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Affiliation(s)
- Michael A Ko
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Ave. R988, Toronto, Ontario M5G 1X5, Canada
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44
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Frank GD, Eguchi S, Motley ED. The role of reactive oxygen species in insulin signaling in the vasculature. Antioxid Redox Signal 2005; 7:1053-61. [PMID: 15998260 DOI: 10.1089/ars.2005.7.1053] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Although there is an abundance of evidence suggesting that insulin resistance plays a significant role in the vasculature, the precise mechanistic role involved still remains unclear. In this review, we discuss the current background of insulin resistance in the context of insulin signaling and action in the vasculature. Also, studies suggest that insulin resistance, diabetes, and cardiovascular disease all share a common involvement with oxidative stress. Recently, we reported that lysophosphatidylcholine, a major bioactive product of oxidized low-density lipoprotein, and angiotensin II, a vasoactive hormone and a potent inducer of reactive oxygen species (ROS), negatively regulate insulin signaling in vascular smooth muscle cells (VSMCs). In endothelial cells, insulin stimulates the release of nitric oxide, which results in VSMC relaxation and inhibition of atherosclerosis. Other data suggest that angiotensin II inhibits the vasodilator effects of insulin through insulin receptor substrate-1 phosphorylation at Ser312 and Ser616. Moreover, ROS impair insulin-induced vasorelaxation by neutralizing nitric oxide to form peroxynitrite. Thus, evidence is growing to enable us to better understand mechanistically the relationship between insulin/insulin resistance and ROS in the vasculature, and the impact they have on cardiovascular disease.
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Affiliation(s)
- Gerald D Frank
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
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45
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Nagata Y, Jones MR, Nguyen HG, McCrann DJ, St Hilaire C, Schreiber BM, Hashimoto A, Inagaki M, Earnshaw WC, Todokoro K, Ravid K. Vascular smooth muscle cell polyploidization involves changes in chromosome passenger proteins and an endomitotic cell cycle. Exp Cell Res 2005; 305:277-91. [PMID: 15817153 DOI: 10.1016/j.yexcr.2004.12.028] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2004] [Revised: 12/18/2004] [Accepted: 12/20/2004] [Indexed: 02/06/2023]
Abstract
Vascular smooth muscle cell polyploidization occurs during normal development and is enhanced under physiologic stress, but the mechanism of this cell cycle has not been explored. We show via time-lapse video imaging and immunofluorescence analyses that primary vascular smooth muscle cells (VSMC) undergo an endomitotic-type cell cycle, including a normal progression through part of mitosis. Mononuclear polyploid cells are generated by defects in sister chromatid separation and/or segregation, and cellular binucleation occurs by reversal of cytokinesis. To obtain further leads to regulators involved, we examined the chromosomal passenger proteins, Aurora B, inner centromere protein and Survivin, and concluded that Aurora B and inner centromere protein are normally colocalized in centromeres, the midzone, and the midbody during mitosis. Survivin, however, is dim and diffused; it does not colocalize with either Aurora B or inner centromere protein in VSMC, which could account for defects in sister chromatid separation and/or segregation and reversal of cytokinesis. In accordance with the reported dependency of Aurora B activity on Survivin, the Aurora B substrate, vimentin, is not phosphorylated during cytokinesis. Finally, the data show that ectopically expressed Survivin inhibits polyploidization in vascular smooth muscle cells. Hence, aberrant chromosome passenger protein activity and endomitosis are associated with VSMC polyploidization.
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Affiliation(s)
- Yuka Nagata
- Recognition and Formation, Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Japan
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46
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Extracellular matrix gene expression in the developing mouse aorta. EXTRACELLULAR MATRIX IN DEVELOPMENT AND DISEASE 2005. [DOI: 10.1016/s1574-3349(05)15003-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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47
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Deblois D, Tea BS, Beaudry D, Hamet P. Regulation of therapeutic apoptosis: a potential target in controlling hypertensive organ damage. Can J Physiol Pharmacol 2005; 83:29-41. [PMID: 15759048 DOI: 10.1139/y05-001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cell growth and survival are potential therapeutic targets for the control of complications associated with hypertension. In most cardiovascular disorders, cardiac fibroblasts and large-vessel smooth muscle cells can replicate and thus contribute to the disease. We propose that cardiovascular hyperplasia may be reversed via therapeutic apoptosis induction with drugs that are safe and already used in the clinic. We first reported that, irrespective of the drug class, those drugs that are able to induce regression of cardiovascular hypertrophy are also able to reverse cardiovascular hyperplasia via apoptosis. Drugs active in this regard include inhibitors of the renin-angiotensin system, calcium channel blockers, and beta-blockers. Moreover, the effects of these drugs on cell survival is not merely secondary to blood pressure reduction. Therapeutic apoptosis in the cardiovascular system of the spontaneously hypertensive rat is characterized by a rapid and transient onset following initiation of antihypertensive treatment. Herein, the induction and termination of therapeutic apoptosis during drug treatment of hypertension will be briefly reviewed and supported by novel data suggesting that reversal of cardiovascular hyperplasia is associated with reduced cell growth and a resistance to further induction of therapeutic apoptosis, as shown in spontaneously hypertensive rats receiving an intermittent regime of nifedipine therapy. We propose that the presence of a cell subpopulation with defective cell cycle regulation may determine organ susceptibility to undergo therapeutic apoptosis.Key words: apoptosis, hypertension, hyperplasia, growth, nifedipine.
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Affiliation(s)
- Denis Deblois
- University of Montreal Hospital Research Center, Montreal, QC, Canada.
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48
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Guo DF, Tardif V, Ghelima K, Chan JSD, Ingelfinger JR, Chen X, Chenier I. A novel angiotensin II type 1 receptor-associated protein induces cellular hypertrophy in rat vascular smooth muscle and renal proximal tubular cells. J Biol Chem 2004; 279:21109-20. [PMID: 14985364 DOI: 10.1074/jbc.m401544200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Angiotensin II stimulates cellular hypertrophy in cultured vascular smooth muscle and renal proximal tubular cells. This effect is believed to be one of earliest morphological changes of heart and renal failure. However, the precise molecular mechanism involved in angiotensin II-induced hypertrophy is poorly understood. In the present study we report the isolation of a novel angiotensin II type 1 receptor-associated protein. It encodes a 531-amino acid protein. Its mRNA is detected in all human tissues examined but highly expressed in the human kidney, pancreas, heart, and human embryonic kidney cells as well as rat vascular smooth muscle and renal proximal tubular cells. Protein synthesis and relative cell size analyzed by flow cytometry studies indicate that overexpression of the novel angiotensin II type 1 receptor-associated protein induces cellular hypertrophy in cultured rat vascular smooth muscle and renal proximal tubular cells. In contrast, the hypertrophic effects was reversed in renal proximal tubular cell lines expressing the novel gene in the antisense orientation and its dominant negative mutant, which lacks the last 101 amino acids in its carboxyl-terminal tail. The hypertrophic effects are at least in part mediated via protein kinase B activation or cyclin-dependent kinase inhibitor, p27(kip1) protein expression level in vascular smooth muscle, and renal proximal tubular cells. Moreover, angiotensin II could not stimulate cellular hypertrophy in renal proximal tubular cells expressing the novel gene in the antisense orientation and its mutant. These findings may provide new molecular mechanisms to understand hypertrophic agents such as angiotensin II-induced cellular hypertrophy.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Amino Acid Sequence
- Animals
- Base Sequence
- Cells, Cultured
- Consensus Sequence
- DNA Primers
- Humans
- Hypertrophy
- Kidney Tubules, Proximal/pathology
- Kidney Tubules, Proximal/physiology
- Molecular Sequence Data
- Muscle, Smooth, Vascular/pathology
- Muscle, Smooth, Vascular/physiology
- RNA, Messenger/genetics
- Rats
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/physiology
- Receptors, Angiotensin/genetics
- Receptors, Angiotensin/physiology
- Repetitive Sequences, Amino Acid
- Sequence Alignment
- Sequence Homology, Amino Acid
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Affiliation(s)
- Deng-Fu Guo
- Department of Medicine, University of Montreal and Research Center, CHUM-Hotel-Dieu Hospital, 3850 St.-Urbain, Montreal, Quebec H2W 1T8, Canada.
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49
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Jones MR, Ravid K. Vascular Smooth Muscle Polyploidization as a Biomarker for Aging and Its Impact on Differential Gene Expression. J Biol Chem 2004; 279:5306-13. [PMID: 14634004 DOI: 10.1074/jbc.m308406200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Polyploidy is characterized by a greater than diploid content of DNA in a cell. Previous measurements of ploidy level in different organs of humans and rodents, including the aorta, indicated an increase in old versus young. We hypothesized that aortic vascular smooth muscle polyploidy is a biomarker for aging and that the augmented DNA dosage affects selective gene-specific transcript expression. Our results demonstrate that tetraploidy increases exponentially over the life span of the animal, serving as an indicator of age. Approximately 60% of the vascular smooth muscle cells in the thoracic aorta of 36-month-old Brown Norway rats are tetraploid compared with 8% in their 3-month-old counterparts. Microarray analysis and reverse transcriptase-PCR was performed with mRNA isolated from sorted diploid (2N) and tetraploid (4N) vascular smooth muscle cells from old rats to identify differentially expressed transcripts. For the majority of detectable transcripts, an increase in DNA content led to a proportional increase in mRNA. A select group of transcripts, however, were reduced in tetraploid compared with diploid cells. These mRNAs correspond to guanine deaminase, to the matrix proteins rat glypican 3 (OCI-5) and decorin, as well as to the inflammation-associated transcripts, insulin-like growth factor-binding protein 6, macrophage inflammatory protein 2 precursor, macrophage galactose N-acetylgalactoseamine-specific lectin, and complement component C4. Our study is the first to describe aortic ploidy level as a biomarker for aging and to indicate that changes associated with increased DNA content per cell may selectively suppress the expression of specific genes.
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Affiliation(s)
- Matthew R Jones
- Department of Biochemistry, Boston University, Boston, Massachusetts 02118, USA
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50
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Lu D, Goussev A, Chen J, Pannu P, Li Y, Mahmood A, Chopp M. Atorvastatin Reduces Neurological Deficit and Increases Synaptogenesis, Angiogenesis, and Neuronal Survival in Rats Subjected to Traumatic Brain Injury. J Neurotrauma 2004; 21:21-32. [PMID: 14987462 DOI: 10.1089/089771504772695913] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Statins administered postischemia promote functional improvement in rats, independent of their capability to lower cholesterol. We therefore tested the effect of statin treatment on traumatic brain injury (TBI) in rats. Atorvastatin was orally administered (1 mg/kg/day) to Wistar rats starting 1 day after TBI for 7 consecutive days. Control animals received saline. Modified Neurological Severity Scores and Corner tests were utilized to evaluate functional response to treatment. Bromodeoxyuridine (BrdU, 100 mg/kg) was also intraperitoneally injected daily for 14 consecutive days to label the newly generated endothelial cells. Rats were sacrificed at day 14 after TBI, and the brain samples were processed for immunohistochemical staining. Atorvastatin administration after brain injury significantly reduced the neurological functional deficits, increased neuronal survival and synaptogenesis in the boundary zone of the lesion and in the CA3 regions of the hippocampus, and induced angiogenesis in these regions. The results suggest that atorvastatin may provide beneficial effects in experimental TBI.
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Affiliation(s)
- Dunyue Lu
- Department of Neurosurgery, Henry Ford Health Sciences Center, Detroit, MI 48202, USA
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