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Lee JH, Ha DH, Go HK, Youn J, Kim HK, Jin RC, Miller RB, Kim DH, Cho BS, Yi YW. Reproducible Large-Scale Isolation of Exosomes from Adipose Tissue-Derived Mesenchymal Stem/Stromal Cells and Their Application in Acute Kidney Injury. Int J Mol Sci 2020; 21:E4774. [PMID: 32635660 PMCID: PMC7370182 DOI: 10.3390/ijms21134774] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/03/2020] [Accepted: 07/03/2020] [Indexed: 12/18/2022] Open
Abstract
Acute kidney injury (AKI) is a fatal medical episode caused by sudden kidney damage or failure, leading to the death of patients within a few hours or days. Previous studies demonstrated that exosomes derived from various mesenchymal stem/stromal cells (MSC-exosomes) have positive effects on renal injuries in multiple experimental animal models of kidney diseases including AKI. However, the mass production of exosomes is a challenge not only in preclinical studies with large animals but also for successful clinical applications. In this respect, tangential flow filtration (TFF) is suitable for good manufacturing practice (GMP)-compliant large-scale production of high-quality exosomes. Until now, no studies have been reported on the use of TFF, but rather ultracentrifugation has been almost exclusively used, to isolate exosomes for AKI therapeutic application in preclinical studies. Here, we demonstrated the reproducible large-scale production of exosomes derived from adipose tissue-derived MSC (ASC-exosomes) using TFF and the lifesaving effect of the ASC-exosomes in a lethal model of cisplatin-induced rat AKI. Our results suggest the possibility of large-scale stable production of ASC-exosomes without loss of function and their successful application in life-threatening diseases.
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Affiliation(s)
- Jun Ho Lee
- ExoCoBio Exosome Institue (EEI), ExoCoBio Inc., Seoul 08594, Korea; (J.H.L.); (D.H.H.); (J.Y.); (H.-k.K.)
| | - Dae Hyun Ha
- ExoCoBio Exosome Institue (EEI), ExoCoBio Inc., Seoul 08594, Korea; (J.H.L.); (D.H.H.); (J.Y.); (H.-k.K.)
| | | | - Jinkwon Youn
- ExoCoBio Exosome Institue (EEI), ExoCoBio Inc., Seoul 08594, Korea; (J.H.L.); (D.H.H.); (J.Y.); (H.-k.K.)
| | - Hyun-keun Kim
- ExoCoBio Exosome Institue (EEI), ExoCoBio Inc., Seoul 08594, Korea; (J.H.L.); (D.H.H.); (J.Y.); (H.-k.K.)
| | | | | | | | - Byong Seung Cho
- ExoCoBio Exosome Institue (EEI), ExoCoBio Inc., Seoul 08594, Korea; (J.H.L.); (D.H.H.); (J.Y.); (H.-k.K.)
| | - Yong Weon Yi
- ExoCoBio Exosome Institue (EEI), ExoCoBio Inc., Seoul 08594, Korea; (J.H.L.); (D.H.H.); (J.Y.); (H.-k.K.)
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White K, Lu Y, Annis S, Hale AE, Chau BN, Dahlman JE, Hemann C, Opotowsky AR, Vargas SO, Rosas I, Perrella MA, Osorio JC, Haley KJ, Graham BB, Kumar R, Saggar R, Saggar R, Wallace WD, Ross DJ, Khan OF, Bader A, Gochuico BR, Matar M, Polach K, Johannessen NM, Prosser HM, Anderson DG, Langer R, Zweier JL, Bindoff LA, Systrom D, Waxman AB, Jin RC, Chan SY. Genetic and hypoxic alterations of the microRNA-210-ISCU1/2 axis promote iron-sulfur deficiency and pulmonary hypertension. EMBO Mol Med 2015; 7:695-713. [PMID: 25825391 PMCID: PMC4459813 DOI: 10.15252/emmm.201404511] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Revised: 02/20/2015] [Accepted: 02/23/2015] [Indexed: 12/03/2022] Open
Abstract
Iron-sulfur (Fe-S) clusters are essential for mitochondrial metabolism, but their regulation in pulmonary hypertension (PH) remains enigmatic. We demonstrate that alterations of the miR-210-ISCU1/2 axis cause Fe-S deficiencies in vivo and promote PH. In pulmonary vascular cells and particularly endothelium, hypoxic induction of miR-210 and repression of the miR-210 targets ISCU1/2 down-regulated Fe-S levels. In mouse and human vascular and endothelial tissue affected by PH, miR-210 was elevated accompanied by decreased ISCU1/2 and Fe-S integrity. In mice, miR-210 repressed ISCU1/2 and promoted PH. Mice deficient in miR-210, via genetic/pharmacologic means or via an endothelial-specific manner, displayed increased ISCU1/2 and were resistant to Fe-S-dependent pathophenotypes and PH. Similar to hypoxia or miR-210 overexpression, ISCU1/2 knockdown also promoted PH. Finally, cardiopulmonary exercise testing of a woman with homozygous ISCU mutations revealed exercise-induced pulmonary vascular dysfunction. Thus, driven by acquired (hypoxia) or genetic causes, the miR-210-ISCU1/2 regulatory axis is a pathogenic lynchpin causing Fe-S deficiency and PH. These findings carry broad translational implications for defining the metabolic origins of PH and potentially other metabolic diseases sharing similar underpinnings.
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Affiliation(s)
- Kevin White
- Divisions of Cardiovascular Medicine and Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Yu Lu
- Divisions of Cardiovascular Medicine and Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Sofia Annis
- Divisions of Cardiovascular Medicine and Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Andrew E Hale
- Divisions of Cardiovascular Medicine and Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - James E Dahlman
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Craig Hemann
- The Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Alexander R Opotowsky
- Divisions of Cardiovascular Medicine and Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA Department of Cardiology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Sara O Vargas
- Department of Pathology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ivan Rosas
- Division of Pulmonary/Critical Care Medicine, Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Mark A Perrella
- Division of Pulmonary/Critical Care Medicine, Department of Medicine, Harvard Medical School, Boston, MA, USA Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Juan C Osorio
- Division of Pulmonary/Critical Care Medicine, Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Kathleen J Haley
- Division of Pulmonary/Critical Care Medicine, Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Brian B Graham
- Program in Translational Lung Research, University of Colorado, Denver, Aurora, CO, USA
| | - Rahul Kumar
- Program in Translational Lung Research, University of Colorado, Denver, Aurora, CO, USA
| | - Rajan Saggar
- Departments of Medicine and Pathology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Rajeev Saggar
- Department of Cardiothoracic Surgery, University of Arizona College of Medicine, Phoenix, AZ, USA
| | - W Dean Wallace
- Departments of Medicine and Pathology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - David J Ross
- Departments of Medicine and Pathology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Omar F Khan
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Andrew Bader
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Bernadette R Gochuico
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | | | | | | | - Haydn M Prosser
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Daniel G Anderson
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Robert Langer
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jay L Zweier
- The Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Laurence A Bindoff
- Department of Clinical Medicine, University of Bergen, Bergen, Norway Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - David Systrom
- Division of Pulmonary/Critical Care Medicine, Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Aaron B Waxman
- Division of Pulmonary/Critical Care Medicine, Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Richard C Jin
- Divisions of Cardiovascular Medicine and Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Stephen Y Chan
- Divisions of Cardiovascular Medicine and Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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Jin RC, Min PK, Chan SY. MicroRNA in the Diseased Pulmonary Vasculature: Implications for the Basic Scientist and Clinician. J Korean Soc Hypertens 2013; 19:1-16. [PMID: 26705533 PMCID: PMC4687897 DOI: 10.5646/jksh.2013.19.1.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Since the first descriptions of their active functions more than ten years ago, small non-coding RNA species termed microRNA (miRNA) have emerged as essential regulators in a broad range of adaptive and maladaptive cellular processes. With an exceptionally rapid pace of discovery in this field, the dysregulation of many individual miRNAs has been implicated in the development and progression of various cardiovascular diseases. MiRNA are also expected to play crucial regulatory roles in the progression of pulmonary vascular diseases such as pulmonary hypertension (PH), yet direct insights in this field are only just emerging. This review will provide an overview of pulmonary hypertension and its molecular mechanisms, tailored for both basic scientists studying pulmonary vascular biology and physicians who manage PH in their clinical practice. We will describe the pathobiology of pulmonary hypertension and mechanisms of action of miRNA relevant to this disease. Moreover, we will summarize the potential roles of miRNA as biomarkers and therapeutic targets as well as future strategies for defining the cooperative actions of these powerful effectors in pulmonary vascular disease.
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Affiliation(s)
- Richard C. Jin
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA, 02115
| | - Pil-Ki Min
- Cardiology Division, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 135-720, South Korea
| | - Stephen Y. Chan
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA, 02115
- Corresponding Author: Stephen Y. Chan, M.D., Ph.D. Brigham and Women's Hospital, New Research Building, Room 630N, 77 Avenue Louis Pasteur, Boston, MA USA 02115, Tel: +1-617-525-4844, Fax: +1-617-525-4830,
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Parikh VN, Jin RC, Rabello S, Gulbahce N, White K, Hale A, Cottrill KA, Shaik RS, Waxman AB, Zhang YY, Maron BA, Hartner JC, Fujiwara Y, Orkin SH, Haley KJ, Barabási AL, Loscalzo J, Chan SY. MicroRNA-21 integrates pathogenic signaling to control pulmonary hypertension: results of a network bioinformatics approach. Circulation 2012; 125:1520-32. [PMID: 22371328 DOI: 10.1161/circulationaha.111.060269] [Citation(s) in RCA: 208] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Pulmonary hypertension (PH) is driven by diverse pathogenic etiologies. Owing to their pleiotropic actions, microRNA molecules are potential candidates for coordinated regulation of these disease stimuli. METHODS AND RESULTS Using a network biology approach, we identify microRNA associated with multiple pathogenic pathways central to PH. Specifically, microRNA-21 (miR-21) is predicted as a PH-modifying microRNA, regulating targets integral to bone morphogenetic protein (BMP) and Rho/Rho-kinase signaling as well as functional pathways associated with hypoxia, inflammation, and genetic haploinsufficiency of BMP receptor type 2. To validate these predictions, we have found that hypoxia and BMP receptor type 2 signaling independently upregulate miR-21 in cultured pulmonary arterial endothelial cells. In a reciprocal feedback loop, miR-21 downregulates BMP receptor type 2 expression. Furthermore, miR-21 directly represses RhoB expression and Rho-kinase activity, inducing molecular changes consistent with decreased angiogenesis and vasodilation. In vivo, miR-21 is upregulated in pulmonary tissue from several rodent models of PH and in humans with PH. On induction of disease in miR-21-null mice, RhoB expression and Rho-kinase activity are increased, accompanied by exaggerated manifestations of PH. CONCLUSIONS A network-based bioinformatic approach coupled with confirmatory in vivo data delineates a central regulatory role for miR-21 in PH. Furthermore, this study highlights the unique utility of network biology for identifying disease-modifying microRNA in PH.
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Affiliation(s)
- Victoria N Parikh
- Brigham and Women's Hospital, New Research Building, 77 Ave. Louis Pasteur, Boston, MA 02115, USA
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Jin RC, Mahoney CE, Coleman Anderson L, Ottaviano F, Croce K, Leopold JA, Zhang YY, Tang SS, Handy DE, Loscalzo J. Glutathione peroxidase-3 deficiency promotes platelet-dependent thrombosis in vivo. Circulation 2011; 123:1963-73. [PMID: 21518981 DOI: 10.1161/circulationaha.110.000034] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Glutathione peroxidase-3 (GPx-3) is a selenocysteine-containing plasma protein that scavenges reactive oxygen species in the extracellular compartment. A deficiency of this enzyme has been associated with platelet-dependent thrombosis, and a promoter haplotype with reduced function has been associated with stroke risk. METHODS AND RESULTS We recently developed a genetic mouse model to assess platelet function and thrombosis in the setting of GPx-3 deficiency. The GPx-3((-/-)) mice showed an attenuated bleeding time and an enhanced aggregation response to the agonist ADP compared with wild-type mice. GPx-3((-/-)) mice displayed increased plasma levels of soluble P-selectin and decreased plasma cyclic cGMP compared with wild-type mice. ADP infusion-induced platelet aggregation in the pulmonary vasculature produced a more robust platelet activation response in the GPx-3((-/-)) than wild-type mice; histological sections from the pulmonary vasculature of GPx-3((-/-)) compared with wild-type mice showed increased platelet-rich thrombi and a higher percentage of occluded vessels. Cremaster muscle preparations revealed endothelial dysfunction in the GPx-3((-/-)) compared with wild-type mice. With a no-flow ischemia-reperfusion stroke model, GPx-3((-/-)) mice had significantly larger cerebral infarctions compared with wild-type mice and platelet-dependent strokes. To assess the neuroprotective role of antioxidants in this model, we found that manganese(III) meso-tetrakis(4-benzoic acid)porphyrin treatment reduced stroke size in GPx-3((-/-)) mice compared with vehicle-treated controls. CONCLUSIONS These findings demonstrate that GPx-3 deficiency results in a prothrombotic state and vascular dysfunction that promotes platelet-dependent arterial thrombosis. These data illustrate the importance of this plasma antioxidant enzyme in regulating platelet activity, endothelial function, platelet-dependent thrombosis, and vascular thrombotic propensity.
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Affiliation(s)
- Richard C Jin
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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Abstract
Nitric oxide (NO) is a structurally simple, highly versatile molecule that was originally discovered over 30 years ago as an endothelium-derived relaxing factor. In addition to its vasorelaxing effects, NO is now recognized as a key determinant of vascular health, exerting antiplatelet, antithrombotic, and anti-inflammatory properties within the vasculature. This short-lived molecule exerts its inhibitory effect on vascular smooth muscle cells and platelets largely through cyclic guanosine monophosphate-dependent mechanisms, resulting in a multitude of molecular effects by which platelet activation and aggregation are prevented. The biosynthesis of NO occurs via the catalytic activity of NO synthase, an oxidoreductase found in many cell types. NO insufficiency can be attributed to limited substrate/cofactor availability as well as interactions with reactive oxygen species. Impaired NO bioavailability represents the central feature of endothelial dysfunction, a common abnormality found in many vascular diseases. In this review, we present an overview of NO synthesis and biochemistry, discuss the mechanisms of action of NO in regulating platelet and endothelial function, and review the effects of vascular disease states on NO bioavailability.
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Affiliation(s)
- Richard C Jin
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
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Voetsch B, Jin RC, Bierl C, Deus-Silva L, Camargo ECS, Annichino-Bizacchi JM, Handy DE, Loscalzo J. Role of promoter polymorphisms in the plasma glutathione peroxidase (GPx-3) gene as a risk factor for cerebral venous thrombosis. Stroke 2007; 39:303-7. [PMID: 18096833 DOI: 10.1161/strokeaha.107.490094] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Plasma glutathione peroxidase (GPx-3) is a major antioxidant enzyme in plasma and the extracellular space that scavenges reactive oxygen species produced during normal metabolism or after oxidative insult. A deficiency of this enzyme increases extracellular oxidant stress, promotes platelet activation, and may promote oxidative posttranslational modification of fibrinogen. We recently identified a haplotype (H(2)) in the GPx-3 gene promoter that increases the risk of arterial ischemic stroke among children and young adults. METHODS The aim of this study is to identify possible relationships between promoter haplotypes in the GPx-3 gene and cerebral venous thrombosis (CVT). We studied the GPx-3 gene promoter from 23 patients with CVT and 123 young controls (18 to 45 years) by single-stranded conformational polymorphism and sequencing analysis. RESULTS Over half of CVT patients (52.1%) were heterozygous (H(1)H(2)) or homozygous (H(2)H(2)) carriers of the H(2) haplotype compared with 12.2% of controls, yielding a more than 10-fold independent increase in the risk of CVT (OR=10.7; 95% CI, 2.70 to 42.36; P<0.0001). Among women, the interaction of the H(2) haplotype with hormonal risk factors increased the OR of CVT to almost 70 (P<0.0001). CONCLUSIONS These findings show that a novel GPx-3 promoter haplotype is a strong, independent risk factor for CVT. As we have previously shown that this haplotype is associated with a reduction in transcriptional activity, which compromises antioxidant activity and antithrombotic benefits of the enzyme, these results suggest that a deficiency of GPx-3 leads to a cerebral venous thrombophilic state.
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Affiliation(s)
- Barbara Voetsch
- Whitaker Cardiovascular Institute and Evans Department of Medicine, Boston University School of Medicine, Boston, MA 02115, USA
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Voetsch B, Jin RC, Bierl C, Benke KS, Kenet G, Simioni P, Ottaviano F, Damasceno BP, Annichino-Bizacchi JM, Handy DE, Loscalzo J. Promoter polymorphisms in the plasma glutathione peroxidase (GPx-3) gene: a novel risk factor for arterial ischemic stroke among young adults and children. Stroke 2006; 38:41-9. [PMID: 17122425 PMCID: PMC1781064 DOI: 10.1161/01.str.0000252027.53766.2b] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Plasma glutathione peroxidase (GPx-3)-deficiency increases extracellular oxidant stress, decreases bioavailable nitric oxide, and promotes platelet activation. The aim of this study is to identify polymorphisms in the GPx-3 gene, examine their relationship to arterial ischemic stroke (AIS) in a large series of children and young adults, and determine their functional molecular consequences. METHODS We studied the GPx-3 gene promoter from 123 young adults with idiopathic AIS and 123 age- and gender-matched controls by single-stranded conformational polymorphism and sequencing analysis. A second, independent population with childhood stroke was used for a replication study. We identified 8 novel, strongly linked polymorphisms in the GPx-3 gene promoter that formed 2 main haplotypes (H1 and H2). The transcriptional activity of the 2 most prevalent haplotypes was studied with luciferase reporter gene constructs. RESULTS The H2 haplotype was over-represented in both patient populations and associated with an independent increase in the risk of AIS in young adults (odds ratio=2.07, 95% CI=1.03 to 4.47; P=0.034) and children (odds ratio=2.13, 95% CI=1.23 to 4.90; P=0.027). In adults simultaneously exposed to vascular risk factors, the risk of AIS approximately doubled (odds ratio=5.18, 95% CI=1.82 to 15.03; P<0.001). Transcriptional activity of the H2 haplotype was lower than that of the H1 haplotype, especially after upregulation by hypoxia (normalized relative luminescence: 3.54+/-0.32 versus 2.47+/-0.26; P=0.0083). CONCLUSIONS These findings indicate that a novel GPx-3 promoter haplotype is an independent risk factor for AIS in children and young adults. This haplotype reduces the gene's transcriptional activity, thereby compromising gene expression and plasma antioxidant and antithrombotic activities.
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Affiliation(s)
- Barbara Voetsch
- Whitaker Cardiovascular Institute and Evans Department of
Medicine, Boston University School of Medicine, Boston, MA
- Department of Neurology, State University of Campinas, Brazil
| | - Richard C. Jin
- Whitaker Cardiovascular Institute and Evans Department of
Medicine, Boston University School of Medicine, Boston, MA
- Department of Medicine, Brigham and Women’s
Hospital, Harvard Medical School, Boston, MA
| | - Charlene Bierl
- Whitaker Cardiovascular Institute and Evans Department of
Medicine, Boston University School of Medicine, Boston, MA
| | - Kelly S. Benke
- Bloomberg School of Public Health, Johns Hopkins University,
Baltimore, MD
| | - Gili Kenet
- Institute of Thrombosis and Haemostasis, Sheba Medical Center,
Israel
| | - Paolo Simioni
- Department of Medical and Surgical Sciences, University of
Padua, Italy
| | - Filomena Ottaviano
- Whitaker Cardiovascular Institute and Evans Department of
Medicine, Boston University School of Medicine, Boston, MA
- Department of Medicine, Brigham and Women’s
Hospital, Harvard Medical School, Boston, MA
| | | | | | - Diane E. Handy
- Whitaker Cardiovascular Institute and Evans Department of
Medicine, Boston University School of Medicine, Boston, MA
- Department of Medicine, Brigham and Women’s
Hospital, Harvard Medical School, Boston, MA
| | - Joseph Loscalzo
- Whitaker Cardiovascular Institute and Evans Department of
Medicine, Boston University School of Medicine, Boston, MA
- Department of Medicine, Brigham and Women’s
Hospital, Harvard Medical School, Boston, MA
- Address for correspondence: Joseph Loscalzo, M.D., Ph.D., 77
Avenue Louis Pasteur, NRB, Rm 630 Brigham and Women’s Hospital,
Boston, MA 02115, Phone: 617-525-4833, Fax: 617-525-4830,
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Abstract
Platelets play an important role in coagulation, in maintenance of hemostasis, and in the pathophysiology of thrombotic diseases. In response to blood vessel injury, platelets accumulate at the site, recruit other platelets, promote clotting, and form a hemostatic plug to prevent hemorrhage. By contrast, several inhibitory mechanisms modulate platelet function and act in a synergistic manner to prevent pathologic thrombus formation. This review focuses on the principal endogenous inhibitors of platelet function and the central role of the normal endothelium in these inhibitory processes. The main endothelium-derived platelet inhibitors include nitric oxide, prostacyclin, and Ecto-ADPase/CD39/NTPDase. Each of these factors is discussed in turn, and the specific mechanisms by which they inhibit platelet function are reviewed.
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Affiliation(s)
- Richard C Jin
- Whitaker Cardiovascular Institute, Evans Department of Medicine, Boston University School of Medicine, MA 02118, USA
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10
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Abstract
Nitric oxide (NO) is a structurally simple compound that participates in a wide range of biological reactions to maintain normal endothelial function and an antithrombotic intravascular milieu. Among its principal effects are the regulation of vascular tone, vascular smooth muscle cell proliferation, endothelial-leukocyte interactions, and the antiplatelet effects of the endothelium. Impaired NO bioavailability represents the central feature of endothelial dysfunction, the earliest stage in the atherosclerotic process, and also contributes to the pathogenesis of acute vascular syndromes by predisposing to intravascular thrombosis. The causes of NO insufficiency can be grouped into two fundamental mechanisms: inadequate synthesis and increased inactivation of NO. Polymorphisms in the endothelial NO synthase gene and decreased substrate or cofactor availability for this enzyme are the main mechanisms that compromise the synthesis of NO. Inactivation of NO occurs mainly through its interaction with reactive oxygen species and can be favored by a deficiency of antioxidant enzymes such as glutathione peroxidase. In this review, we present an overview of NO synthesis and biological chemistry, discuss the mechanisms of action of NO in regulating endothelial and platelet function, and explore the causes of NO insufficiency, as well as the evidence linking these causes to the pathophysiology of endothelial dysfunction and atherothrombosis.
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Affiliation(s)
- Barbara Voetsch
- Whitaker Cardiovascular Institute, Evans Department of Medicine, Boston University School of Medicine, 715 Albany Street, W507, Boston, MA 02118, USA
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11
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Abstract
Plasma glutathione peroxidase (GPx-3) is a selenocysteine-containing protein with antioxidant properties. GPx-3 deficiency has been associated with cardiovascular disease and stroke. The regulation of GPx-3 expression remains largely uncharacterized, however, and we studied its transcriptional and translational determinants in a cultured cell system. In transient transfections of a renal cell line (Caki-2), the published sequence cloned upstream of a luciferase reporter gene produced minimal activity (relative luminescence (RL) = 0.6 +/- 0.4). Rapid amplification of cDNA ends was used to identify a novel transcription start site that is located 233 bp downstream (3') of the published site and that produced a >25-fold increase in transcriptional activity (RL = 16.8 +/- 1.9; p < 0.0001). Analysis of the novel GPx-3 promoter identified Sp-1- and hypoxia-inducible factor-1-binding sites, as well as the redox-sensitive metal response element and antioxidant response element. Hypoxia was identified as a strong transcriptional regulator of GPx-3 expression, in part through the presence of the hypoxia-inducible factor-1-binding site, leading to an almost 3-fold increase in expression levels after 24 h compared with normoxic conditions (normalized RL = 3.5 +/- 0.3 versus 1.2 +/- 0.1; p < 0.001). We also investigated the role of the translational cofactors tRNA(Sec), SECIS-binding protein-2, and SelD (selenophosphate synthetase D) in GPx-3 protein expression. tRNA(Sec) and SelD significantly enhanced GPx-3 expression, whereas SECIS-binding protein-2 showed a trend toward increased expression. These results demonstrate the presence of a novel functional transcription start site for the human GPx-3 gene with a promoter regulated by hypoxia, and identify unique translational determinants of GPx-3 expression.
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Affiliation(s)
- Charlene Bierl
- Whitaker Cardiovascular Institute and the Evans Department of Medicine, Boston, MA 02118, USA
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