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Fevereiro-Martins M, Marques-Neves C, Guimarães H, Bicho M. Retinopathy of prematurity: A review of pathophysiology and signaling pathways. Surv Ophthalmol 2023; 68:175-210. [PMID: 36427559 DOI: 10.1016/j.survophthal.2022.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 11/15/2022] [Accepted: 11/18/2022] [Indexed: 11/25/2022]
Abstract
Retinopathy of prematurity (ROP) is a vasoproliferative disorder of the retina and a leading cause of visual impairment and childhood blindness worldwide. The disease is characterized by an early stage of retinal microvascular degeneration, followed by neovascularization that can lead to subsequent retinal detachment and permanent visual loss. Several factors play a key role during the different pathological stages of the disease. Oxidative and nitrosative stress and inflammatory processes are important contributors to the early stage of ROP. Nitric oxide synthase and arginase play important roles in ischemia/reperfusion-induced neurovascular degeneration. Destructive neovascularization is driven by mediators of the hypoxia-inducible factor pathway, such as vascular endothelial growth factor and metabolic factors (succinate). The extracellular matrix is involved in hypoxia-induced retinal neovascularization. Vasorepulsive molecules (semaphorin 3A) intervene preventing the revascularization of the avascular zone. This review focuses on current concepts about signaling pathways and their mediators, involved in the pathogenesis of ROP, highlighting new potentially preventive and therapeutic modalities. A better understanding of the intricate molecular mechanisms underlying the pathogenesis of ROP should allow the development of more effective and targeted therapeutic agents to reduce aberrant vasoproliferation and facilitate physiological retinal vascular development.
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Affiliation(s)
- Mariza Fevereiro-Martins
- Laboratório de Genética and Grupo Ecogenética e Saúde Humana, Instituto de Saúde Ambiental, Faculdade de Medicina, Universidade de Lisboa, Portugal; Instituto de Investigação Científica Bento da Rocha Cabral, Lisboa, Portugal; Departamento de Oftalmologia, Hospital Cuf Descobertas, Lisboa, Portugal.
| | - Carlos Marques-Neves
- Centro de Estudos das Ci.¼ncias da Visão, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Grupo Ecogenética e Saúde Humana, Instituto de Saúde Ambiental, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
| | - Hercília Guimarães
- Departamento de Ginecologia-Obstetrícia e Pediatria, Faculdade de Medicina, Universidade do Porto, Porto, Portugal.
| | - Manuel Bicho
- Laboratório de Genética and Grupo Ecogenética e Saúde Humana, Instituto de Saúde Ambiental, Faculdade de Medicina, Universidade de Lisboa, Portugal; Instituto de Investigação Científica Bento da Rocha Cabral, Lisboa, Portugal.
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2
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Antenatal and Postnatal Sequelae of Oxidative Stress in Preterm Infants: A Narrative Review Targeting Pathophysiological Mechanisms. Antioxidants (Basel) 2023; 12:antiox12020422. [PMID: 36829980 PMCID: PMC9952227 DOI: 10.3390/antiox12020422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/01/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
The detrimental effects of oxidative stress (OS) can start as early as after conception. A growing body of evidence has shown the pivotal role of OS in the development of several pathological conditions during the neonatal period, which have been therefore defined as OS-related neonatal diseases. Due to the physiological immaturity of their antioxidant defenses and to the enhanced antenatal and postnatal exposure to free radicals, preterm infants are particularly susceptible to oxidative damage, and several pathophysiological cascades involved in the development of prematurity-related complications are tightly related to OS. This narrative review aims to provide a detailed overview of the OS-related pathophysiological mechanisms that contribute to the main OS-related diseases during pregnancy and in the early postnatal period in the preterm population. Particularly, focus has been placed on pregnancy disorders typically associated with iatrogenic or spontaneous preterm birth, such as intrauterine growth restriction, pre-eclampsia, gestational diabetes, chorioamnionitis, and on specific postnatal complications for which the role of OS has been largely ascertained (e.g., respiratory distress, bronchopulmonary dysplasia, retinopathy of prematurity, periventricular leukomalacia, necrotizing enterocolitis, neonatal sepsis). Knowledge of the underlying pathophysiological mechanisms may increase awareness on potential strategies aimed at preventing the development of these conditions or at reducing the ensuing clinical burden.
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Fu Z, Nilsson AK, Hellstrom A, Smith LEH. Retinopathy of prematurity: Metabolic risk factors. eLife 2022; 11:e80550. [PMID: 36420952 PMCID: PMC9691009 DOI: 10.7554/elife.80550] [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: 05/25/2022] [Accepted: 11/16/2022] [Indexed: 11/25/2022] Open
Abstract
At preterm birth, the retina is incompletely vascularized. Retinopathy of prematurity (ROP) is initiated by the postnatal suppression of physiological retinal vascular development that would normally occur in utero. As the neural retina slowly matures, increasing metabolic demand including in the peripheral avascular retina, leads to signals for compensatory but pathological neovascularization. Currently, only late neovascular ROP is treated. ROP could be prevented by promoting normal vascular growth. Early perinatal metabolic dysregulation is a strong but understudied risk factor for ROP and other long-term sequelae of preterm birth. We will discuss the metabolic and oxygen needs of retina, current treatments, and potential interventions to promote normal vessel growth including control of postnatal hyperglycemia, dyslipidemia and hyperoxia-induced retinal metabolic alterations. Early supplementation of missing nutrients and growth factors and control of supplemental oxygen promotes physiological retinal development. We will discuss the current knowledge gap in retinal metabolism after preterm birth.
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Affiliation(s)
- Zhongjie Fu
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical SchoolBostonUnited States
| | - Anders K Nilsson
- The Sahlgrenska Centre for Pediatric Ophthalmology Research, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of GothenburgGothenburgSweden
| | - Ann Hellstrom
- The Sahlgrenska Centre for Pediatric Ophthalmology Research, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of GothenburgGothenburgSweden
| | - Lois EH Smith
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical SchoolBostonUnited States
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4
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The Role and Regulation of Thromboxane A2 Signaling in Cancer-Trojan Horses and Misdirection. Molecules 2022; 27:molecules27196234. [PMID: 36234768 PMCID: PMC9573598 DOI: 10.3390/molecules27196234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/09/2022] [Accepted: 09/09/2022] [Indexed: 11/24/2022] Open
Abstract
Over the last two decades, there has been an increasing awareness of the role of eicosanoids in the development and progression of several types of cancer, including breast, prostate, lung, and colorectal cancers. Several processes involved in cancer development, such as cell growth, migration, and angiogenesis, are regulated by the arachidonic acid derivative thromboxane A2 (TXA2). Higher levels of circulating TXA2 are observed in patients with multiple cancers, and this is accompanied by overexpression of TXA2 synthase (TBXAS1, TXA2S) and/or TXA2 receptors (TBXA2R, TP). Overexpression of TXA2S or TP in tumor cells is generally associated with poor prognosis, reduced survival, and metastatic disease. However, the role of TXA2 signaling in the stroma during oncogenesis has been underappreciated. TXA2 signaling regulates the tumor microenvironment by modulating angiogenic potential, tumor ECM stiffness, and host immune response. Moreover, the by-products of TXA2S are highly mutagenic and oncogenic, adding to the overall phenotype where TXA2 synthesis promotes tumor formation at various levels. The stability of synthetic enzymes and receptors in this pathway in most cancers (with few mutations reported) suggests that TXA2 signaling is a viable target for adjunct therapy in various tumors to reduce immune evasion, primary tumor growth, and metastasis.
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Rovati G, Contursi A, Bruno A, Tacconelli S, Ballerini P, Patrignani P. Antiplatelet Agents Affecting GPCR Signaling Implicated in Tumor Metastasis. Cells 2022; 11:725. [PMID: 35203374 PMCID: PMC8870128 DOI: 10.3390/cells11040725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/10/2022] [Accepted: 02/16/2022] [Indexed: 11/16/2022] Open
Abstract
Metastasis requires that cancer cells survive in the circulation, colonize distant organs, and grow. Despite platelets being central contributors to hemostasis, leukocyte trafficking during inflammation, and vessel stability maintenance, there is significant evidence to support their essential role in supporting metastasis through different mechanisms. In addition to their direct interaction with cancer cells, thus forming heteroaggregates such as leukocytes, platelets release molecules that are necessary to promote a disseminating phenotype in cancer cells via the induction of an epithelial-mesenchymal-like transition. Therefore, agents that affect platelet activation can potentially restrain these prometastatic mechanisms. Although the primary adhesion of platelets to cancer cells is mainly independent of G protein-mediated signaling, soluble mediators released from platelets, such as ADP, thromboxane (TX) A2, and prostaglandin (PG) E2, act through G protein-coupled receptors (GPCRs) to cause the activation of more additional platelets and drive metastatic signaling pathways in cancer cells. In this review, we examine the contribution of the GPCRs of platelets and cancer cells in the development of cancer metastasis. Finally, the possible use of agents affecting GPCR signaling pathways as antimetastatic agents is discussed.
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Affiliation(s)
- Gianenrico Rovati
- Department of Pharmaceutical Sciences, University of Milan, 20122 Milan, Italy;
| | - Annalisa Contursi
- Laboratory of Systems Pharmacology and Translational Therapies, Center for Advanced Studies and Technology (CAST), School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy; (A.C.); (A.B.); (S.T.); (P.B.)
- Department of Neuroscience, Imaging and Clinical Science, School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy
| | - Annalisa Bruno
- Laboratory of Systems Pharmacology and Translational Therapies, Center for Advanced Studies and Technology (CAST), School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy; (A.C.); (A.B.); (S.T.); (P.B.)
- Department of Neuroscience, Imaging and Clinical Science, School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy
| | - Stefania Tacconelli
- Laboratory of Systems Pharmacology and Translational Therapies, Center for Advanced Studies and Technology (CAST), School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy; (A.C.); (A.B.); (S.T.); (P.B.)
- Department of Neuroscience, Imaging and Clinical Science, School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy
| | - Patrizia Ballerini
- Laboratory of Systems Pharmacology and Translational Therapies, Center for Advanced Studies and Technology (CAST), School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy; (A.C.); (A.B.); (S.T.); (P.B.)
- Department of Innovative Technologies in Medicine and Dentistry, “G. d’Annunzio” University, 66100 Chieti, Italy
| | - Paola Patrignani
- Laboratory of Systems Pharmacology and Translational Therapies, Center for Advanced Studies and Technology (CAST), School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy; (A.C.); (A.B.); (S.T.); (P.B.)
- Department of Neuroscience, Imaging and Clinical Science, School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy
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6
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Lewandowski D, Sander CL, Tworak A, Gao F, Xu Q, Skowronska-Krawczyk D. Dynamic lipid turnover in photoreceptors and retinal pigment epithelium throughout life. Prog Retin Eye Res 2021; 89:101037. [PMID: 34971765 PMCID: PMC10361839 DOI: 10.1016/j.preteyeres.2021.101037] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 12/13/2022]
Abstract
The retinal pigment epithelium-photoreceptor interphase is renewed each day in a stunning display of cellular interdependence. While photoreceptors use photosensitive pigments to convert light into electrical signals, the RPE supports photoreceptors in their function by phagocytizing shed photoreceptor tips, regulating the blood retina barrier, and modulating inflammatory responses, as well as regenerating the 11-cis-retinal chromophore via the classical visual cycle. These processes involve multiple protein complexes, tightly regulated ligand-receptors interactions, and a plethora of lipids and protein-lipids interactions. The role of lipids in maintaining a healthy interplay between the RPE and photoreceptors has not been fully delineated. In recent years, novel technologies have resulted in major advancements in understanding several facets of this interplay, including the involvement of lipids in phagocytosis and phagolysosome function, nutrient recycling, and the metabolic dependence between the two cell types. In this review, we aim to integrate the complex role of lipids in photoreceptor and RPE function, emphasizing the dynamic exchange between the cells as well as discuss how these processes are affected in aging and retinal diseases.
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Affiliation(s)
- Dominik Lewandowski
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Christopher L Sander
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Aleksander Tworak
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Fangyuan Gao
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Qianlan Xu
- Department of Physiology and Biophysics, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Dorota Skowronska-Krawczyk
- Department of Physiology and Biophysics, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA.
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7
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Beharry KD, Cai CL, Siddiqui F, D’Agrosa C, Zangaladze A, Mustafa G, Qadri A, Duggan TJ, Aranda JV. Combination Antioxidant/NSAID Therapies and Oral/Topical Ocular Delivery Modes for Prevention of Oxygen-Induced Retinopathy in a Rat Model. Nutrients 2020; 12:nu12071980. [PMID: 32635350 PMCID: PMC7400869 DOI: 10.3390/nu12071980] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 11/17/2022] Open
Abstract
Given the complexity of oxygen-induced retinopathy (OIR), we tested the hypothesis that combination therapies and modes of administration would synergistically optimize efficacy for prevention of OIR. Newborn rats were exposed to neonatal intermittent hypoxia (IH) from the first day of life (P0) until P14 during which they received: (1) oral glutathione nanoparticles (nGSH) with topical ocular phosphate buffered saline (PBS); (2) nGSH with topical ocular Acuvail (ACV); (3) oral coenzyme Q10 (CoQ10) + ACV; (4) oral omega 3 polyunsaturated fatty acids (n-3 PUFAs) + ACV; (5) CoQ10 + n-3 PUFAs + PBS; or (6) CoQ10 + n-3 PUFAs + ACV. Treated groups raised in room air (RA) served as controls. At P14, pups were placed in RA with no treatment until P21. Retinal vascular pathology, ocular angiogenesis biomarkers, histopathology, and morphometry were determined. All combination treatments in IH resulted in the most beneficial retinal outcomes consistent with suppression of angiogenesis growth factors during reoxygenation/reperfusion and no significant adverse effects on somatic growth. nGSH + PBS also reversed IH-induced retinopathy, but had negative effects on growth. Simultaneously targeting oxidants, inflammation, and poor growth mitigates the damaging effects of neonatal IH on the developing retina. Therapeutic synergy with combination delivery methods enhance individual attributes and simultaneously target multiple pathways involved in complex diseases such as OIR.
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Affiliation(s)
- Kay D. Beharry
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA; (C.L.C.); (F.S.); (A.Z.); (G.M.); (A.Q.); (T.J.D.); (J.V.A.)
- Department of Ophthalmology, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA
- SUNY Eye Institute, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA
- Correspondence: ; Tel.: +01-718-270-1475
| | - Charles L. Cai
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA; (C.L.C.); (F.S.); (A.Z.); (G.M.); (A.Q.); (T.J.D.); (J.V.A.)
| | - Faisal Siddiqui
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA; (C.L.C.); (F.S.); (A.Z.); (G.M.); (A.Q.); (T.J.D.); (J.V.A.)
| | - Christina D’Agrosa
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA; (C.L.C.); (F.S.); (A.Z.); (G.M.); (A.Q.); (T.J.D.); (J.V.A.)
| | - Anano Zangaladze
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA; (C.L.C.); (F.S.); (A.Z.); (G.M.); (A.Q.); (T.J.D.); (J.V.A.)
| | - Ghassan Mustafa
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA; (C.L.C.); (F.S.); (A.Z.); (G.M.); (A.Q.); (T.J.D.); (J.V.A.)
| | - Areej Qadri
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA; (C.L.C.); (F.S.); (A.Z.); (G.M.); (A.Q.); (T.J.D.); (J.V.A.)
| | - Thomas J. Duggan
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA; (C.L.C.); (F.S.); (A.Z.); (G.M.); (A.Q.); (T.J.D.); (J.V.A.)
| | - Jacob V. Aranda
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA; (C.L.C.); (F.S.); (A.Z.); (G.M.); (A.Q.); (T.J.D.); (J.V.A.)
- Department of Ophthalmology, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA
- SUNY Eye Institute, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA
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8
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Is There A Role for Abscisic Acid, A Proven Anti-Inflammatory Agent, in the Treatment of Ischemic Retinopathies? Antioxidants (Basel) 2019; 8:antiox8040104. [PMID: 30999583 PMCID: PMC6523110 DOI: 10.3390/antiox8040104] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/03/2019] [Accepted: 04/13/2019] [Indexed: 02/06/2023] Open
Abstract
Ischemic retinopathies (IRs) are the main cause of severe visual impairment and sight loss, and are characterized by loss of blood vessels, accompanied by hypoxia, and neovascularization. Actual therapies, based on anti-vascular endothelial growth factor (VEGF) strategies, antioxidants or anti-inflammatory therapies are only partially effective or show some adverse side effects. Abscisic acid (ABA) is a phytohormone present in vegetables and fruits that can be naturally supplied by the dietary intake and has been previously studied for its benefits to human health. It has been demonstrated that ABA plays a key role in glucose metabolism, inflammation, memory and tumor growth. This review focuses on a novel and promising role of ABA as a potential modulator of angiogenesis, oxidative status and inflammatory processes in the retina, which are the most predominant characteristics of the IRs. Thus, this nutraceutical compound might shed some light in new therapeutic strategies focused in the prevention or amelioration of IRs-derived pathologies.
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Bernabe-García M, Villegas-Silva R, Villavicencio-Torres A, Calder PC, Rodríguez-Cruz M, Maldonado-Hernández J, Macías-Loaiza D, López-Alarcón M, Inda-Icaza P, Cruz-Reynoso L. Enteral Docosahexaenoic Acid and Retinopathy of Prematurity: A Randomized Clinical Trial. JPEN J Parenter Enteral Nutr 2019; 43:874-882. [PMID: 30614004 DOI: 10.1002/jpen.1497] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/01/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Retinopathy of prematurity (ROP) is a disorder of the retina of low-birth-weight preterm infants that potentially leads to blindness. Docosahexaenoic acid (DHA), is protective in experimental models, but its administration as part of parenteral nutrition has shown inconsistent results. We test the effect of enteral DHA to prevent ROP and/or severity and to reduce hospital stay. METHODS This was a double-blind parallel clinical trial. Preterm infants (n = 110; 55 per group) with birth weight <1500 g but ≥1000 g were recruited in a neonatal intensive care unit. Infants were randomized to receive 75 mg of DHA/kg/d (DHA group) or high oleic sunflower oil (control group) for 14 days by enteral feeding. The effect of DHA was evaluated on any stage of ROP, severe ROP (stage ≥3) incidence, and hospital stay. Groups were compared with relative risk (RR) and 95% confidence interval (CI), Fisher's exact test, Student's t-test, or Mann-Whitney U-test, as appropriate. Logistic regression was applied to adjust for confounders. RESULTS There was no difference between the DHA and control groups in ROP risk (RR for DHA = 0.79; 95% CI, 0.49-1.27; P = 0.33). However, patients who received DHA showed lower risk for stage 3 ROP (RR for DHA = 0.66; 95% CI, 0.44-0.99; P = 0.03). After adjusting for confounders, this decreased risk remained significant (adjusted odds ratio = 0.10; 95% CI, 0.011-0.886; P = 0.04). Hospital stay was similar between groups. CONCLUSION Enteral DHA may reduce the incidence of stage 3 ROP.
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Affiliation(s)
- Mariela Bernabe-García
- Unidad de Investigación Médica en Nutrición, Hospital de Pediatría, Centro Médico Nacional, Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Raúl Villegas-Silva
- Neonatología, Hospital Infantil de México Federico Gómez, México City, México
| | - Astrid Villavicencio-Torres
- Oftalmología Pediátrica, General Hospital, Centro Médico Nacional La Raza, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Philip C Calder
- Human Development and Health Academic Unit, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK.,National Institute for Health Research Southampton Biomedical Research Centre, University Hospital Southampton National Health Service Foundation Trust and University of Southampton, Southampton, UK
| | - Maricela Rodríguez-Cruz
- Unidad de Investigación Médica en Nutrición, Hospital de Pediatría, Centro Médico Nacional, Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Jorge Maldonado-Hernández
- Unidad de Investigación Médica en Nutrición, Hospital de Pediatría, Centro Médico Nacional, Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Denisse Macías-Loaiza
- Unidad de Investigación Médica en Nutrición, Hospital de Pediatría, Centro Médico Nacional, Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Mardia López-Alarcón
- Unidad de Investigación Médica en Nutrición, Hospital de Pediatría, Centro Médico Nacional, Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Patricia Inda-Icaza
- Nutrición, Universidad Anáhuac México, Campus Norte, Huixquilucan, Estado de México, México
| | - Leonardo Cruz-Reynoso
- División de Pediatría, Hospital de Gineco-Obstetricia No.3, Centro Médico Nacional La Raza, Instituto Mexicano del Seguro Social, Ciudad de México, México
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Ischemic Retinopathies: Oxidative Stress and Inflammation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:3940241. [PMID: 29410732 PMCID: PMC5749295 DOI: 10.1155/2017/3940241] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 11/20/2017] [Indexed: 12/15/2022]
Abstract
Ischemic retinopathies (IRs), such as retinopathy of prematurity (ROP), diabetic retinopathy (DR), and (in many cases) age-related macular degeneration (AMD), are ocular disorders characterized by an initial phase of microvascular changes that results in ischemia, followed by a second phase of abnormal neovascularization that may culminate into retinal detachment and blindness. IRs are complex retinal conditions in which several factors play a key role during the development of the different pathological stages of the disease. Increasing evidence reveals that oxidative stress and inflammatory processes are important contributors to the pathogenesis of IRs. Despite the beneficial effects of the photocoagulation and anti-VEGF therapy during neovascularization phase, the need to identify novel targets to prevent initial phases of these ocular pathologies is still needed. In this review, we provide an update on the involvement of oxidative stress and inflammation in the progression of IRs and address some therapeutic interventions by using antioxidants and anti-inflammatory agents.
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11
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Gong Y, Fu Z, Liegl R, Chen J, Hellström A, Smith LEH. ω-3 and ω-6 long-chain PUFAs and their enzymatic metabolites in neovascular eye diseases. Am J Clin Nutr 2017; 106:16-26. [PMID: 28515072 PMCID: PMC5486202 DOI: 10.3945/ajcn.117.153825] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 04/18/2017] [Indexed: 01/01/2023] Open
Abstract
Neovascular eye diseases, including retinopathy of prematurity, diabetic retinopathy, and age-related macular degeneration, threaten the visual health of children and adults. Current treatment options, including anti-vascular endothelial growth factor therapy and laser retinal photocoagulation, have limitations and are associated with adverse effects; therefore, the identification of additional therapies is highly desirable. Both clinical and experimental studies show that dietary ω-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFAs) reduce retinal and choroidal angiogenesis. The ω-3 LC-PUFA metabolites from 2 groups of enzymes, cyclooxygenases and lipoxygenases, inhibit [and the ω-6 (n-6) LC-PUFA metabolites promote] inflammation and angiogenesis. However, both of the ω-3 and the ω-6 lipid products of cytochrome P450 oxidase 2C promote neovascularization in both the retina and choroid, which suggests that inhibition of this pathway might be beneficial. This review summarizes our current understanding of the roles of ω-3 and ω-6 LC-PUFAs and their enzymatic metabolites in neovascular eye diseases.
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Affiliation(s)
- Yan Gong
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA; and
| | - Zhongjie Fu
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA; and
| | - Raffael Liegl
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA; and
| | - Jing Chen
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA; and
| | - Ann Hellström
- Department of Ophthalmology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Lois EH Smith
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA; and
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12
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Rivera JC, Madaan A, Zhou TE, Chemtob S. Review of the mechanisms and therapeutic avenues for retinal and choroidal vascular dysfunctions in retinopathy of prematurity. Acta Paediatr 2016; 105:1421-1433. [PMID: 27620714 DOI: 10.1111/apa.13586] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 07/04/2016] [Accepted: 09/09/2016] [Indexed: 12/23/2022]
Abstract
Retinopathy of prematurity (ROP) is a multifactorial disease and the main cause of visual impairment and blindness in premature neonates. The inner retina has been considered the primary region affected in ROP, but choroidal vascular degeneration and progressive outer retinal dysfunctions have also been observed. This review focuses on observations regarding neurovascular dysfunctions in both the inner and outer immature retina, the mechanisms and the neuronal-derived factors implicated in the development of ROP, as well potential therapeutic avenues for this disorder. CONCLUSION Alterations in the neurovascular integrity of the inner and outer retina contribute to the development of ROP.
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Affiliation(s)
- José Carlos Rivera
- Department of Pediatrics, Ophthalmology and Pharmacology; Centre Hospitalier Universitaire Sainte-Justine Research Center; Montréal QC Canada
- Department of Ophthalmology; Maisonneuve-Rosemont Hospital Research Center; University of Montréal; Montréal QC Canada
| | - Ankush Madaan
- Department of Pediatrics, Ophthalmology and Pharmacology; Centre Hospitalier Universitaire Sainte-Justine Research Center; Montréal QC Canada
- Department of Pharmacology and Therapeutics; McGill University; Montréal QC Canada
| | - Tianwei Ellen Zhou
- Department of Ophthalmology; Maisonneuve-Rosemont Hospital Research Center; University of Montréal; Montréal QC Canada
- Department of Pharmacology and Therapeutics; McGill University; Montréal QC Canada
| | - Sylvain Chemtob
- Department of Pediatrics, Ophthalmology and Pharmacology; Centre Hospitalier Universitaire Sainte-Justine Research Center; Montréal QC Canada
- Department of Ophthalmology; Maisonneuve-Rosemont Hospital Research Center; University of Montréal; Montréal QC Canada
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13
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Capozzi ME, McCollum GW, Penn JS. The role of cytochrome P450 epoxygenases in retinal angiogenesis. Invest Ophthalmol Vis Sci 2014; 55:4253-60. [PMID: 24917142 DOI: 10.1167/iovs.14-14216] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The purpose of this study was to investigate the role(s) of cytochrome P450 epoxygenases (CYPs) and their products, the epoxyeicosatrienoic acids (EETs), in hypoxia-induced VEGF production and pathologic retinal angiogenesis. METHODS Human retinal astrocytes, Müller cells, and retinal microvascular endothelial cells (HRMEC) were exposed to hypoxia, and relative CYP2C expression was measured by RT-PCR. Astrocyte and Müller cell VEGF production was measured by ELISA after exposure to hypoxia and treatment with the general CYP inhibitor, SKF-525a. Human retinal microvascular endothelial cells were treated with the CYP product, 11,12-epoxyeicosatrienoic acid [EET], or SKF-525a in the presence or absence of VEGF. Proliferation of HRMEC and tube formation were assayed. Oxygen-induced retinopathy (OIR) was induced in newborn rats. Retinal CYP2C11 and CYP2C23 expression were measured by RT-PCR. The OIR rats received SKF-525a by intravitreal injection and preretinal neovascularization (NV) was quantified. Retinal VEGF protein levels were measured by ELISA. RESULTS Human retinal astrocytes were the only cells to exhibit significant induction of CYP2C8 and CYP2C9 mRNA expression by hypoxia. Astrocytes, but not Müller cells, exhibited reduced hypoxia-induced VEGF production when treated with SKF-525a. 11,12-EET induced HRMEC proliferation and tube formation, and SKF-525a inhibited VEGF-induced proliferation. Oxygen-induced retinopathy induced expression of CYP2C23, but had no effect on CYP2C11. SKF-525a inhibited retinal NV and reduced retinal VEGF levels in OIR rats. CONCLUSIONS The CYP-derived 11,12-EET may exhibit a proangiogenic biological function in the retina following stimulation by hypoxia in astrocytes. Inhibition of CYP may provide a rational therapy against retinal NV, because it can reduce VEGF production and VEGF-induced angiogenic responses in endothelial cells.
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Affiliation(s)
- Megan E Capozzi
- Departments of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Gary W McCollum
- Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - John S Penn
- Departments of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
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14
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Capra V, Bäck M, Angiolillo DJ, Cattaneo M, Sakariassen KS. Impact of vascular thromboxane prostanoid receptor activation on hemostasis, thrombosis, oxidative stress, and inflammation. J Thromb Haemost 2014; 12:126-37. [PMID: 24298905 DOI: 10.1111/jth.12472] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Indexed: 12/13/2022]
Abstract
The activation of thromboxane prostanoid (TP) receptor on platelets, monocytes/macrophages, endothelial cells, and vascular smooth muscle cells (SMC) plays important roles in regulating platelet activation and vascular tone and in the pathogenesis of thrombosis and vascular inflammation. Oxidative stress and vascular inflammation increase the formation of TP receptor agonists, which promote initiation and progression of atherogenesis and thrombosis. Furthermore, TP receptor activation promotes angiogenesis and vessel wall constriction. Besides thromboxane A₂ and its endoperoxide precursors, prostaglandin G₂ and H₂, isoprostanes, and 20-hydroxyeicosatetraenoic acid also activate TP receptor as autocrine or paracrine ligands. These additional TP activators play a role in pathological conditions such as diabetes, obesity, and hypertension, and their biosynthesis is not inhibited by aspirin, at variance with that of thromboxane A₂. The understanding of TP receptor function increased our current knowledge of the pathogenesis of atherosclerosis and thrombosis, highlighting the great impact that this receptor has in cardiovascular disorders.
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Affiliation(s)
- V Capra
- Department of Pharmacology and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
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15
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Narayanan SP, Rojas M, Suwanpradid J, Toque HA, Caldwell RW, Caldwell RB. Arginase in retinopathy. Prog Retin Eye Res 2013; 36:260-80. [PMID: 23830845 PMCID: PMC3759622 DOI: 10.1016/j.preteyeres.2013.06.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 06/14/2013] [Accepted: 06/25/2013] [Indexed: 12/12/2022]
Abstract
Ischemic retinopathies, such as diabetic retinopathy (DR), retinopathy of prematurity and retinal vein occlusion are a major cause of blindness in developed nations worldwide. Each of these conditions is associated with early neurovascular dysfunction. However, conventional therapies target clinically significant macula edema or neovascularization, which occur much later. Intra-ocular injections of anti-VEGF show promise in reducing retinal edema, but the effects are usually transient and the need for repeated injections increases the risk of intraocular infection. Laser photocoagulation can control pathological neovascularization, but may impair vision and in some patients the retinopathy continues to progress. Moreover, neither treatment targets early stage disease or promotes repair. This review examines the potential role of the ureahydrolase enzyme arginase as a therapeutic target for the treatment of ischemic retinopathy. Arginase metabolizes l-arginine to form proline, polyamines and glutamate. Excessive arginase activity reduces the l-arginine supply for nitric oxide synthase (NOS), causing it to become uncoupled and produce superoxide and less NO. Superoxide and NO react and form the toxic oxidant peroxynitrite. The catabolic products of polyamine oxidation and glutamate can induce more oxidative stress and DNA damage, both of which can cause cellular injury. Studies indicate that neurovascular injury during retinopathy is associated with increased arginase expression/activity, decreased NO, polyamine oxidation, formation of superoxide and peroxynitrite and dysfunction and injury of both vascular and neural cells. Furthermore, data indicate that the cytosolic isoform arginase I (AI) is involved in hyperglycemia-induced dysfunction and injury of vascular endothelial cells whereas the mitochondrial isoform arginase II (AII) is involved in neurovascular dysfunction and death following hyperoxia exposure. Thus, we postulate that activation of the arginase pathway causes neurovascular injury by uncoupling NOS and inducing polyamine oxidation and glutamate formation, thereby reducing NO and increasing oxidative stress, all of which contribute to the retinopathic process.
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Affiliation(s)
- S. Priya Narayanan
- Vision Discovery Institute, Georgia Regents University, 1459 Laney Walker Boulevard, Augusta, 30912, USA
- Vascular Biology Center, Georgia Regents University, 1459 Laney Walker Boulevard, Augusta, 30912, USA
| | - Modesto Rojas
- Vision Discovery Institute, Georgia Regents University, 1459 Laney Walker Boulevard, Augusta, 30912, USA
- Vascular Biology Center, Georgia Regents University, 1459 Laney Walker Boulevard, Augusta, 30912, USA
| | - Jutamas Suwanpradid
- Vision Discovery Institute, Georgia Regents University, 1459 Laney Walker Boulevard, Augusta, 30912, USA
- Vascular Biology Center, Georgia Regents University, 1459 Laney Walker Boulevard, Augusta, 30912, USA
| | - Haroldo A. Toque
- Department of Pharmacology & Toxicology, Georgia Regents University, 1459 Laney Walker Boulevard, Augusta, 30912, USA
| | - R. William Caldwell
- Vision Discovery Institute, Georgia Regents University, 1459 Laney Walker Boulevard, Augusta, 30912, USA
- Department of Pharmacology & Toxicology, Georgia Regents University, 1459 Laney Walker Boulevard, Augusta, 30912, USA
| | - Ruth B. Caldwell
- Vision Discovery Institute, Georgia Regents University, 1459 Laney Walker Boulevard, Augusta, 30912, USA
- Vascular Biology Center, Georgia Regents University, 1459 Laney Walker Boulevard, Augusta, 30912, USA
- VA Medical Center, One Freedom Way, Augusta, GA, USA
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16
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Majed BH, Khalil RA. Molecular mechanisms regulating the vascular prostacyclin pathways and their adaptation during pregnancy and in the newborn. Pharmacol Rev 2012; 64:540-82. [PMID: 22679221 DOI: 10.1124/pr.111.004770] [Citation(s) in RCA: 173] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Prostacyclin (PGI(2)) is a member of the prostanoid group of eicosanoids that regulate homeostasis, hemostasis, smooth muscle function and inflammation. Prostanoids are derived from arachidonic acid by the sequential actions of phospholipase A(2), cyclooxygenase (COX), and specific prostaglandin (PG) synthases. There are two major COX enzymes, COX1 and COX2, that differ in structure, tissue distribution, subcellular localization, and function. COX1 is largely constitutively expressed, whereas COX2 is induced at sites of inflammation and vascular injury. PGI(2) is produced by endothelial cells and influences many cardiovascular processes. PGI(2) acts mainly on the prostacyclin (IP) receptor, but because of receptor homology, PGI(2) analogs such as iloprost may act on other prostanoid receptors with variable affinities. PGI(2)/IP interaction stimulates G protein-coupled increase in cAMP and protein kinase A, resulting in decreased [Ca(2+)](i), and could also cause inhibition of Rho kinase, leading to vascular smooth muscle relaxation. In addition, PGI(2) intracrine signaling may target nuclear peroxisome proliferator-activated receptors and regulate gene transcription. PGI(2) counteracts the vasoconstrictor and platelet aggregation effects of thromboxane A(2) (TXA(2)), and both prostanoids create an important balance in cardiovascular homeostasis. The PGI(2)/TXA(2) balance is particularly critical in the regulation of maternal and fetal vascular function during pregnancy and in the newborn. A decrease in PGI(2)/TXA(2) ratio in the maternal, fetal, and neonatal circulation may contribute to preeclampsia, intrauterine growth restriction, and persistent pulmonary hypertension of the newborn (PPHN), respectively. On the other hand, increased PGI(2) activity may contribute to patent ductus arteriosus (PDA) and intraventricular hemorrhage in premature newborns. These observations have raised interest in the use of COX inhibitors and PGI(2) analogs in the management of pregnancy-associated and neonatal vascular disorders. The use of aspirin to decrease TXA(2) synthesis has shown little benefit in preeclampsia, whereas indomethacin and ibuprofen are used effectively to close PDA in the premature newborn. PGI(2) analogs have been used effectively in primary pulmonary hypertension in adults and have shown promise in PPHN. Careful examination of PGI(2) metabolism and the complex interplay with other prostanoids will help design specific modulators of the PGI(2)-dependent pathways for the management of pregnancy-related and neonatal vascular disorders.
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Affiliation(s)
- Batoule H Majed
- Harvard Medical School, Brigham and Women's Hospital, Division of Vascular Surgery, 75 Francis St., Boston, MA 02115, USA
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17
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Ekambaram P, Lambiv W, Cazzolli R, Ashton AW, Honn KV. The thromboxane synthase and receptor signaling pathway in cancer: an emerging paradigm in cancer progression and metastasis. Cancer Metastasis Rev 2012; 30:397-408. [PMID: 22037941 DOI: 10.1007/s10555-011-9297-9] [Citation(s) in RCA: 263] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Thromboxane A(2) (TXA(2)) is a biologically active metabolite of arachidonic acid formed by the action of the terminal synthase, thromboxane A(2) synthase (TXA(2)S), on prostaglandin endoperoxide (PGH(2)). TXA(2) is responsible for multiple biological processes through its cell surface receptor, the T-prostanoid (TP) receptor. Thromboxane A(2) synthase and TP are the two necessary components for the functioning of this potent bioactive lipid. Thromboxane A(2) is widely implicated in a range of cardiovascular diseases, owing to its acute and chronic effects in promoting platelet aggregation, vasoconstriction, and proliferation. In recent years, additional functional roles for both TXA(2)S and TP in cancer progression have been indicated. Increased cyclooxygenase (COX)-2 expression has been described in a variety of human cancers, which has focused attention on TXA(2) as a downstream metabolite of the COX-2-derived PGH(2). Several studies suggest potential involvement of TXA(2)S and TP in tumor progression, especially tumor cell proliferation, migration, and invasion that are key steps in cancer progression. In addition, the regulation of neovascularization by TP has been identified as a potent source of control during oncogenesis. There have been several recent reviews of TXA(2)S and TP but thus far none have discussed its role in cancer progression and metastasis in depth. This review will focus on some of the more recent findings and advances with a significant emphasis on understanding the functional role of TXA(2)S and TP in cancer progression and metastasis.
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Affiliation(s)
- Prasanna Ekambaram
- Department of Oncology, School of Medicine, Wayne State University, Detroit, MI 48202, USA
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18
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Kermorvant-Duchemin E, Sennlaub F, Behar-Cohen F, Chemtob S. Épidémiologie et physiopathologie de la rétinopathie du prématuré. Arch Pediatr 2011; 18 Suppl 2:S79-85. [DOI: 10.1016/s0929-693x(11)71095-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Stahl A, Krohne TU, Sapieha P, Chen J, Hellstrom A, Chew E, Holz FG, Smith LEH. Lipid metabolites in the pathogenesis and treatment of neovascular eye disease. Br J Ophthalmol 2011; 95:1496-501. [PMID: 21421650 DOI: 10.1136/bjo.2010.194241] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Lipids and lipid metabolites have long been known to play biological roles that go beyond energy storage and membrane structure. In age-related macular degeneration and diabetes, for example, dysregulation of lipid metabolism is closely associated with disease onset and progression. At the same time, some lipids and their metabolites can exert beneficial effects in the same disorders. This review summarises our current knowledge of the contributions of lipids to both the pathogenesis and treatment of neovascular eye disease. The clinical entities covered are exudative age-related macular degeneration, diabetic retinopathy and retinopathy of prematurity, with a special emphasis on the potential therapeutic effects of ω3- (also known as n-3) polyunsaturated fatty acids.
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Affiliation(s)
- Andreas Stahl
- Department of Ophthalmology, Harvard Medical School, Children's Hospital, Boston, Massachusetts 02115, USA
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20
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Rivera JC, Sapieha P, Joyal JS, Duhamel F, Shao Z, Sitaras N, Picard E, Zhou E, Lachapelle P, Chemtob S. Understanding retinopathy of prematurity: update on pathogenesis. Neonatology 2011; 100:343-53. [PMID: 21968165 DOI: 10.1159/000330174] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Retinopathy of prematurity (ROP), an ocular disease characterized by the onset of vascular abnormalities in the developing retina, is the major cause of visual impairment and blindness in premature neonates. ROP is a complex condition in which various factors participate at different stages of the disease leading to microvascular degeneration followed by neovascularization, which in turn predisposes to retinal detachment. Current ablative therapies (cryotherapy and laser photocoagulation) used in the clinic for the treatment of ROP have limitations and patients can still have long-term effects even after successful treatment. New treatment modalities are still emerging. The most promising are the therapies directed against VEGF; more recently the use of preventive dietary supplementation with ω-3 polyunsaturated fatty acid may also be promising. Other than pharmacologic and nutritional approaches, cell-based strategies for vascular repair are likely to arise from advances in regenerative medicine using stem cells. In addition to all of these, a greater understanding of other factors involved in regulating pathologic retinal angiogenesis continues to emerge, suggesting potential targets for therapeutic approaches. This review summarizes an update on the current state of knowledge on ROP from our and other laboratories, with particular focus on the role of nitro-oxidative stress and notably trans-arachidonic acids in microvascular degeneration, semaphorin 3 operating as vasorepulsive molecules in the avascular hypoxic retina and in turn impairing revascularization, succinate and its receptor GPR91 in neuron-mediated retinal neovascularization, and ω-3 lipids as modulators of preretinal neovascularization.
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Affiliation(s)
- José Carlos Rivera
- Department of Pediatrics, Ophthalmology and Pharmacology, Centre Hospitalier Universitaire Sainte-Justine Research Center, Montréal, Qué., Canada
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21
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Sapieha P, Joyal JS, Rivera JC, Kermorvant-Duchemin E, Sennlaub F, Hardy P, Lachapelle P, Chemtob S. Retinopathy of prematurity: understanding ischemic retinal vasculopathies at an extreme of life. J Clin Invest 2010; 120:3022-32. [PMID: 20811158 DOI: 10.1172/jci42142] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Retinopathy of prematurity (ROP) is a major complication of preterm birth. It encompasses a spectrum of pathologies that affect vision, from mild disease that resolves spontaneously to severe disease that causes retinal detachment and subsequent blindness. The pathologies are characterized by an arrest in normal retinal vascular development associated with microvascular degeneration. The resulting ischemia and retinal hypoxia lead to excessive abnormal compensatory blood vessel growth. However, this neovascularization can lead to fibrous scar formation and culminate in retinal detachment. Present therapeutic modalities to limit the adverse consequences of aberrant neovascularization are invasive and/or tissue-destructive. In this Review, we discuss current concepts on retinal microvascular degeneration, neovascularization, and available treatments, as well as present future perspectives toward more profound elucidation of the pathogenesis of ROP.
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Affiliation(s)
- Przemyslaw Sapieha
- Department of Ophthalmology, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts, USA
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22
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Honoré JC, Kooli A, Hou X, Hamel D, Rivera JC, Picard É, Hardy P, Tremblay S, Varma DR, Jankov RP, Mancini JA, Balazy M, Chemtob S. Sustained hypercapnia induces cerebral microvascular degeneration in the immature brain through induction of nitrative stress. Am J Physiol Regul Integr Comp Physiol 2010; 298:R1522-30. [DOI: 10.1152/ajpregu.00807.2009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Hypercapnia is regularly observed in chronic lung disease, such as bronchopulmonary dysplasia in preterm infants. Hypercapnia results in increased nitric oxide synthase activity and in vitro formation of nitrates. Neural vasculature of the immature subject is particularly sensitive to nitrative stress. We investigated whether exposure to clinically relevant sustained high CO2 causes microvascular degeneration in the newborn brain by inducing nitrative stress, and whether this microvascular degeneration has an impact on brain growth. Newborn rat pups were exposed to 10% CO2 as inspired gas (PaCO2 = 60–70 mmHg) starting within 24 h of birth until postnatal day 7 (P7). Brains were notably collected at different time points to measure vascular density, determine brain cortical nitrite/nitrate, and trans-arachidonic acids (TAAs; products of nitration) levels as effectors of vessel damage. Chronic exposure of rat pups to high CO2 (PaCO2 ≈ 65 mmHg) induced a 20% loss in cerebrovascular density at P3 and a 15% decrease in brain mass at P7; at P30, brain mass remained lower in CO2-exposed animals. Within 24 h of exposure to CO2, brain eNOS expression and production of nitrite/nitrate doubled, lipid nitration products (TAAs) increased, and protein nitration (3-nitrotyrosine immunoreactivity) was also coincidently augmented on brain microvessels (lectin positive). Intracerebroventricular injection of TAAs (10 μM) replicated cerebrovascular degeneration. Treatment of rat pups with NOS inhibitor (l-Nω-nitroarginine methyl ester) or a peroxynitrite decomposition catalyst (FeTPPS) prevented hypercapnia-induced microvascular degeneration and preserved brain mass. Cytotoxic effects of high CO2 were reproduced in vitro /ex vivo on cultured endothelial cells and sprouting microvessels. In summary, hypercapnia at values frequently observed in preterm infants with chronic lung disease results in increased nitrative stress, which leads to cerebral cortical microvascular degeneration and curtails brain growth.
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Affiliation(s)
- Jean-Claude Honoré
- Department of Pediatrics, Research Center-Centre Hospitalier Universitaire Ste-Justine, Montréal, Quebec, Canada
- Department of Pharmacology, Université de Montréal, Quebec, Canada
| | - Amna Kooli
- Department of Pediatrics, Research Center-Centre Hospitalier Universitaire Ste-Justine, Montréal, Quebec, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Xin Hou
- Department of Pediatrics, Research Center-Centre Hospitalier Universitaire Ste-Justine, Montréal, Quebec, Canada
| | - David Hamel
- Department of Pediatrics, Research Center-Centre Hospitalier Universitaire Ste-Justine, Montréal, Quebec, Canada
- Department of Pharmacology, Université de Montréal, Quebec, Canada
| | - José Carlos Rivera
- Department of Pediatrics, Research Center-Centre Hospitalier Universitaire Ste-Justine, Montréal, Quebec, Canada
- Department of Pharmacology, Université de Montréal, Quebec, Canada
| | - Émilie Picard
- Department of Pediatrics, Research Center-Centre Hospitalier Universitaire Ste-Justine, Montréal, Quebec, Canada
- Department of Pharmacology, Université de Montréal, Quebec, Canada
| | - Pierre Hardy
- Department of Pediatrics, Research Center-Centre Hospitalier Universitaire Ste-Justine, Montréal, Quebec, Canada
- Department of Pharmacology, Université de Montréal, Quebec, Canada
| | - Sophie Tremblay
- Department of Pediatrics, Research Center-Centre Hospitalier Universitaire Ste-Justine, Montréal, Quebec, Canada
| | - Daya R. Varma
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Robert P. Jankov
- Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada; and
| | - Joseph A. Mancini
- Department of Pediatrics, Research Center-Centre Hospitalier Universitaire Ste-Justine, Montréal, Quebec, Canada
| | - Michael Balazy
- Department of Pathology, New York Medical College, New York, New York
| | - Sylvain Chemtob
- Department of Pediatrics, Research Center-Centre Hospitalier Universitaire Ste-Justine, Montréal, Quebec, Canada
- Department of Pharmacology, Université de Montréal, Quebec, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
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Bovenzi V, Savard M, Morin J, Cuerrier CM, Grandbois M, Gobeil F. Bradykinin protects against brain microvascular endothelial cell death induced by pathophysiological stimuli. J Cell Physiol 2009; 222:168-76. [PMID: 19780024 DOI: 10.1002/jcp.21933] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The morphological and functional integrity of the microcirculation is compromised in many cardiovascular diseases such as hypertension, diabetes, stroke, and sepsis. Angiotensin converting enzyme inhibitors (ACEi), which are known to favor bradykinin (BK) bioactivity by reducing its metabolism, may have a positive impact on preventing the microvascular structural rarefaction that occurs in these diseases. Our study was designed to test the hypothesis that BK, via B2 receptors (B2R), protects the viability of the microvascular endothelium exposed to the necrotic and apoptotic cell death inducers H(2)O(2) and LPS independently of hemodynamics. Expression (RT-PCR and radioligand binding) and functional (calcium mobilization with fura-2AM, and p42/p44MAPK and Akt phosphorylation assays) experiments revealed the presence of functional B2R in pig cerebral microvascular endothelial cells (pCMVEC). In vitro results showed that the cytocidal effects of H(2)O(2) and LPS on pCMVEC were significantly decreased by a BK pretreatment (MTT and crystal violet tests, annexin-V staining/FACS analysis), which was countered by the B2R antagonist HOE 140. BK treatment coincided with enhanced expression of the cytoprotective proteins COX-2, Bcl-2, and (Cu/Zn)SOD. Ex vivo assays on rat brain explants showed that BK impeded (by approximately 40%) H(2)O(2)-induced microvascular degeneration (lectin-FITC staining). The present study proposes a novel role for BK in microvascular endothelial protection, which may be pertinent to the complex mechanism of action of ACEi explaining their long-term beneficial effects in maintaining vascular integrity.
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Affiliation(s)
- Veronica Bovenzi
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, Québec, Canada
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24
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Balazy M, Chemtob S. Trans-arachidonic acids: new mediators of nitro-oxidative stress. Pharmacol Ther 2008; 119:275-90. [PMID: 18606454 DOI: 10.1016/j.pharmthera.2008.05.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Accepted: 05/14/2008] [Indexed: 10/22/2022]
Abstract
A reaction of arachidonic acid with the nitrogen dioxide radical (*NO2) or its precursors (peroxynitrite, nitrous acid, nitrogen trioxide) generates a group of nitro lipids named nitroeicosanoids. A distinct feature of this reaction is abundant formation of four trans isomers of arachidonic acid (TAA) via reversible addition of the NO2 radical to the arachidonic acid cis double bonds. This cis-trans isomerization is biologically relevant because many pathologies that involve NO formation such as inflammation, hyperoxia, hypercapnia or exposure to cigarette smoke increase the TAA levels in cells, tissues and in the systemic circulation. Inflammatory conditions have been known to stimulate formation of a variety of oxidized lipids from unsaturated fatty acid precursors via lipid peroxidation mechanisms; however, nitration-dependent cis-trans-isomerization of arachidonic acid is a characteristic process for *NO2. TAA are likely to function as specific and selective biomarkers of the pathologic conditions that define nitro-oxidative stress. Diet independent biosynthesis of trans fatty acids as a result of disease is our new observation. In the past, experimental feeding and clinical studies have supported the concerns that dietary trans fatty acids are cardiovascular risk factors, however, clinical consequences of the endogenous formation of trans fatty acids are not known but potentially important given available studies on TAA. This review aims to summarize the emerging role of TAA as a unique group of biomarkers that target microcirculation and other systems. A biological mechanism that generates endogenous trans fatty acids poses new challenges for pharmacologic intervention and we suggest approaches that may limit TAA effects.
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Wiswedel I, Peter D, Gardemann A, Carluccio F, Hampl H, Siems W. Serum Concentrations of F2-Isoprostanes and 4-Hydroxynonenal in Hemodialysis Patients in Relation to Inflammation and Renal Anemia. Biomark Insights 2008; 3:419-428. [PMID: 19578522 PMCID: PMC2688378 DOI: 10.4137/bmi.s363] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background Patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD) are apparently exposed to enhanced oxidative stress and to inflammation. It was the aim of this study to characterize the state of systemic oxidative stress of ESRD patients before and following HD using highly specific biomarkers, F2-isoprostanes and 4-hydroxynonenal (HNE). Furthermore the question should be answered, if there are associations between inflammation and systemic oxidative stress and/or between systemic oxidative stress and renal anemia, which is more or less typical for HD patients. Patients and methods Concentrations of F2-isoprostanes, HNE, C-reactive protein (CRP) as marker of inflammation, and hemoglobin were measured in serum samples of patients with ESRD before and after HD and of healthy control persons for comparison. Total (esterified plus free) F2-isoprostanes were quantified by highly sensitive gas chromatography/mass spectrometry technique, HNE by thin layer chromatography and HPLC/UV detection, CRP by immunoturbidimetry and hemoglobin by clinico-chemical routine assay. Results 1. HD patients showed significantly higher serum concentrations of F2-isoprostanes and HNE than healthy human control subjects. 2. Total (esterified plus free) F2-isoprostane levels before HD were not significantly different from those after HD, whereas HNE levels were significantly decreased in patients after HD. 3. F2-isoprostane concentrations in HD patients correlated with the levels of CRP, whereas HNE concentrations inversely correlated with the content of hemoglobin. Conclusion Both, F2-isoprostanes and HNE serum concentrations are useful oxidative stress parameters in ESRD patients undergoing HD. Whereas HNE strongly correlates with the severity of renal anemia, leading to left heart insufficiency, F2-isoprostanes (sum of free plus esterified) highly correlate with the degree of inflammation.
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Affiliation(s)
- Ingrid Wiswedel
- Department of Pathological Biochemistry, Otto-von-Guericke-University of Magdeburg
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The effect of oxygen and light on the structure and function of the neonatal rat retina. Doc Ophthalmol 2008; 118:37-54. [DOI: 10.1007/s10633-008-9128-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Accepted: 04/07/2008] [Indexed: 10/22/2022]
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Al-Amro SA, Al-Kharfi TM, Thabit AA, Al-Mofada SM. Risk factors for acute retinopathy of prematurity. ACTA ACUST UNITED AC 2008; 33:73-7. [PMID: 18004017 DOI: 10.1007/s12019-007-8008-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 11/30/1999] [Accepted: 01/05/2007] [Indexed: 11/26/2022]
Abstract
We prospectively studied the risk factors and the incidence of retinopathy of prematurity (ROP) in 195 consecutive preterm infants. Birth weight and duration of mechanical ventilation were the only factors that were significantly associated with the incidence of ROP. While indomethacin increases the risk of developing ROP, maternal antenatal steroids have a protective effect against the development of severe stages of ROP. The presence of intraventricular hemorrhage increases the risk of severe ROP.
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Affiliation(s)
- Saleh A Al-Amro
- Department of Ophthalmology, King Abdulaziz University Hospital, Riyadh, 11411, Saudi Arabia.
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Al-Amro SA, Al-Kharfi TM, Thabit AA, Al-Mofada SM. Risk factors for acute retinopathy of prematurity. ANNALS OF OPHTHALMOLOGY (SKOKIE, ILL.) 2007; 39:107-111. [PMID: 17984498 DOI: 10.1007/s12009-007-0015-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 11/30/1999] [Accepted: 01/05/2007] [Indexed: 05/25/2023]
Abstract
We prospectively studied the risk factors and the incidence of retinopathy of prematurity (ROP) in 195 consecutive preterm infants. Birth weight and duration of mechanical ventilation were the only factors significantly associated with the incidence of ROP. While indomethacin increases the risk of developing ROP, maternal antenatal steroids have a protective effect against the development of severe stages of ROP. The presence of intraventricular hemorrhage increases the risk of severe ROP.
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Affiliation(s)
- Saleh A Al-Amro
- Department of Ophthalmology, King Abdulaziz University, Riyadh, 11411, Kingdom of Saudi Arabia.
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29
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Brault S, Gobeil F, Fortier A, Honoré JC, Joyal JS, Sapieha PS, Kooli A, Martin E, Hardy P, Ribeiro-da-Silva A, Peri K, Lachapelle P, Varma D, Chemtob S. Lysophosphatidic acid induces endothelial cell death by modulating the redox environment. Am J Physiol Regul Integr Comp Physiol 2006; 292:R1174-83. [PMID: 17122328 DOI: 10.1152/ajpregu.00619.2006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Oxidant stress plays a significant role in hypoxic-ischemic injury to the susceptible microvascular endothelial cells. During oxidant stress, lysophosphatidic acid (LPA) concentrations increase. We explored whether LPA caused cytotoxicity to neuromicrovascular cells and the potential mechanisms thereof. LPA caused a dose-dependent death of porcine cerebral microvascular as well as human umbilical vein endothelial cells; cell death appeared oncotic rather than apoptotic. LPA-induced cell death was mediated via LPA(1) receptor, because the specific LPA(1) receptor antagonist THG1603 fully abrogated LPA's effects. LPA decreased intracellular GSH levels and induced a p38 MAPK/JNK-dependent inducible nitric oxide synthase (NOS) expression. Pretreatment with the antioxidant GSH precursor N-acetyl-cysteine (NAC), as well as with inhibitors of NOS [N(omega)-nitro-l-arginine (l-NNA); 1400W], significantly prevented LPA-induced endothelial cell death (in vitro) to comparable extents; as expected, p38 MAPK (SB203580) and JNK (SP-600125) inhibitors also diminished cell death. LPA did not increase indexes of oxidation (isoprostanes, hydroperoxides, and protein nitration) but did augment protein nitrosylation. Endothelial cytotoxicity by LPA in vitro was reproduced ex vivo in brain and in vivo in retina; THG1603, NAC, l-NNA, and combined SB-203580 and SP600125 prevented the microvascular rarefaction. Data implicate novel properties for LPA as a modulator of the cell redox environment, which partakes in endothelial cell death and ensued neuromicrovascular rarefaction.
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Affiliation(s)
- Sonia Brault
- Department of Pediatrics, Research Center, Hôpital Sainte-Justine, 3175 Côte Sainte-Catherine, Montréal, Québec, Canada H3T 1C5
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van Albada ME, Berger RMF, Niggebrugge M, van Veghel R, Cromme-Dijkhuis AH, Schoemaker RG. Prostacyclin therapy increases right ventricular capillarisation in a model for flow-associated pulmonary hypertension. Eur J Pharmacol 2006; 549:107-16. [PMID: 16978602 DOI: 10.1016/j.ejphar.2006.08.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Revised: 07/24/2006] [Accepted: 08/02/2006] [Indexed: 11/17/2022]
Abstract
Pulmonary hypertension, and consequently right ventricular failure, complicates several congenital heart defects. Although intervention in the prostacyclin-thromboxane ratio is known to improve outcome, the underlying mechanism is not clear. Therefore, effects of acetyl salicylic acid and iloprost are studied in an animal model for flow-associated pulmonary hypertension. Male Wistar rats with flow-associated pulmonary hypertension, an aortocaval shunt in addition to monocrotaline induced pulmonary hypertension, were treated with low-dose aspirin (25 mg/kg/day) or iloprost (72 microg/kg/day). Effects on pulmonary hemodynamics and pulmonary vascular remodeling as well as right ventricular hemodynamics and remodeling were evaluated. Ninety percent (n=7/8) of the untreated pulmonary hypertensive rats developed dyspnea and pleural fluid, whereas this was seen in 50% (n=4/8, ns) and 10% (n=1/8, P<0.05 vs. untreated animals) of the aspirin and iloprost-treated rats, respectively. This could not be attributed to changes in pulmonary artery pressure, wall-lumen ratio of the pulmonary vasculature or right ventricular hypertrophy. However, both therapies restored reduced right ventricular capillary to myocyte ratio in pulmonary hypertensive rats (0.95+/-0.10 in untreated rats vs. 1.38+/-0.18 in control animals; P<0.05, and 1.32+/-0.11 in aspirin-treated and 1.29+/-0.9 in iloprost-treated rats; both P<0.05 vs. non-treated animals), which was associated with improved right ventricular contractility (iloprost). Thus, interventions in the prostacyclin-thromboxane metabolism improve outcome in rats with flow-associated pulmonary hypertension. However, these effects may be attributed to effects on cardiac rather than on pulmonary vascular remodeling.
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Affiliation(s)
- Mirjam E van Albada
- Department of Pediatrics, Division of Pediatric Cardiology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
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Kermorvant-Duchemin E, Sennlaub F, Chemtob S, Behar-Cohen F. Physiopathologie de la rétinopathie du prématuré. Arch Pediatr 2006; 13:566-8. [PMID: 16690308 DOI: 10.1016/j.arcped.2006.03.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Kermorvant-Duchemin E, Sennlaub F, Sirinyan M, Brault S, Andelfinger G, Kooli A, Germain S, Ong H, D'Orleans-Juste P, Gobeil F, Zhu T, Boisvert C, Hardy P, Jain K, Falck J, Balazy M, Chemtob S. Trans-arachidonic acids generated during nitrative stress induce a thrombospondin-1-dependent microvascular degeneration. Nat Med 2005; 11:1339-45. [PMID: 16311602 PMCID: PMC4850227 DOI: 10.1038/nm1336] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Accepted: 11/01/2005] [Indexed: 12/17/2022]
Abstract
Nitrative stress has an important role in microvascular degeneration leading to ischemia in conditions such as diabetic retinopathy and retinopathy of prematurity. Thus far, mediators of nitrative stress have been poorly characterized. We recently described that trans-arachidonic acids are major products of NO(2)(*)-mediated isomerization of arachidonic acid within the cell membrane, but their biological relevance is unknown. Here we show that trans-arachidonic acids are generated in a model of retinal microangiopathy in vivo in a NO(*)-dependent manner. They induce a selective time- and concentration-dependent apoptosis of microvascular endothelial cells in vitro, and result in retinal microvascular degeneration ex vivo and in vivo. These effects are mediated by an upregulation of the antiangiogenic factor thrombospondin-1, independently of classical arachidonic acid metabolism. Our findings provide new insight into the molecular mechanisms of nitrative stress in microvascular injury and suggest new therapeutic avenues in the management of disorders involving nitrative stress, such as ischemic retinopathies and encephalopathies.
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Affiliation(s)
| | - Florian Sennlaub
- Department of Pediatrics, Ophthalmology and Pharmacology
Hôpital Sainte-JustineMontréal, Québec
- Physiopathologie des Maladies Oculaires : Innovations Thérapeutiques
InsermIFR58Université Pierre et Marie Curie - Paris 6Institut Biomédical Des Cordeliers 15 Rue de L'Ecole de Médecine 75270 Paris Cedex 06
- * Correspondence should be addressed to Florian Sennlaub
| | - Mirna Sirinyan
- Department of Pediatrics, Ophthalmology and Pharmacology
Hôpital Sainte-JustineMontréal, Québec
- Department of Pharmacology and Therapeutics
McGill University [Montreal]Montréal, Québec
| | - Sonia Brault
- Department of Pediatrics, Ophthalmology and Pharmacology
Hôpital Sainte-JustineMontréal, Québec
- Department of Pharmacology and Therapeutics
McGill University [Montreal]Montréal, Québec
| | - Gregor Andelfinger
- Department of Pediatrics, Ophthalmology and Pharmacology
Hôpital Sainte-JustineMontréal, Québec
| | - Amna Kooli
- Department of Pediatrics, Ophthalmology and Pharmacology
Hôpital Sainte-JustineMontréal, Québec
- Department of Pharmacology and Therapeutics
McGill University [Montreal]Montréal, Québec
| | - Stéphane Germain
- Pathologie Vasculaire et Endocrinologie Rénale
InsermCollège de FranceCollège de France 11 Place Marcelin Berthelot 75231 Paris Cedex 05
| | - Huy Ong
- Faculty of Pharmacy
Université de MontréalMontréal Québec
| | | | - Fernand Gobeil
- Department of Pharmacology
Université de SherbrookeQuebec
| | - Tang Zhu
- Department of Pediatrics, Ophthalmology and Pharmacology
Hôpital Sainte-JustineMontréal, Québec
| | - Chantal Boisvert
- Department of Pediatrics, Ophthalmology and Pharmacology
Hôpital Sainte-JustineMontréal, Québec
| | - Pierre Hardy
- Department of Pediatrics, Ophthalmology and Pharmacology
Hôpital Sainte-JustineMontréal, Québec
| | - Kavita Jain
- Department of Pharmacology
New York Medical CollegeNew York
| | - John Falck
- Department of Biochemistry
University of Texas
| | - Michael Balazy
- Department of Pharmacology
New York Medical CollegeNew York
| | - Sylvain Chemtob
- Department of Pediatrics, Ophthalmology and Pharmacology
Hôpital Sainte-JustineMontréal, Québec
- Department of Pharmacology and Therapeutics
McGill University [Montreal]Montréal, Québec
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Quiniou C, Sennlaub F, Beauchamp MH, Checchin D, Lahaie I, Brault S, Gobeil F, Sirinyan M, Kooli A, Hardy P, Pshezhetsky A, Chemtob S. Dominant Role for Calpain in Thromboxane-Induced Neuromicrovascular Endothelial Cytotoxicity. J Pharmacol Exp Ther 2005; 316:618-27. [PMID: 16214879 DOI: 10.1124/jpet.105.093898] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Thromboxane A(2) (TXA(2)) is an important lipid mediator generated during oxidative stress and implicated in ischemic neural injury. This autacoid was recently shown to partake in this injury process by directly inducing endothelial cytotoxicity. We explored the mechanisms for this TXA(2)-evoked neural microvascular endothelial cell death. Stable TXA(2) mimetics 5-heptenoic acid, 7-[6-(3-hydroxy-1-octenyl)-2-oxabicyclo[2.2.1]hept-5-yl]-[1R-[1alpha,4alpha,5beta(Z),6alpha,(1E,3S)]]-9,11-dedioxy-9alpha,11alpha-methanolpoxy (U-46619) [as well as [1S-[1alpha,2alpha(Z),3beta(1E,3S(*)),4alpha]]-7-[3-[3-hydroxy-4-(4-iodophenoxy)-1-butenyl]-7-oxabicyclo[2.1.1]-hept-2-yl]-5-heptenoic acid; I-BOP] induced a retinal microvascular degeneration in rat pups in vivo and in porcine retinal explants ex vivo and death of porcine brain endothelial cells (in culture). TXA(2) dependence of these effects was corroborated by antagonism using the selective TXA(2) receptor blocker (-)-6,8-difluoro-9-p-methyl-sulfonyl-benzyl-1,2,3,4-tetrahydrocarbazol-1-yl-acetic acid (L670596). In all cases, neurovascular endothelial cell death was prevented by pan-calpain and specific m-calpain inhibitors but not by caspase-3 or pan-caspase inhibitors. Correspondingly, TXA(2) (mimetics) augmented generation of known active m-calpain (but not mu-calpain) form and increased the activity of m-calpain (cleavage of fluorogenic substrate N-succinyl-Leu-Leu-Val-Tyr-7-amino-4-methylcoumarin; and of alpha-spectrin into specific fragments) but not of pan-caspase or specific caspase-3 (respectively, using sulforhodamine-Val-Arg-Asp-fluoromethyl ketone and detecting its active 17- and 12-kDa fragments). Interestingly, these effects were phospholipase C (PLC)-dependent [associated with increase in inositol triphosphate and inhibited by PLC blocker 1-[6-[[17beta-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U73122)] and required calcium but were not associated with increased intracellular calcium. U-46619-induced calpain activation resulted in translocation of Bax to the mitochondria, loss of polarization of the latter (using potentiometric probe 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide; JC-1) and in turn release of cytochrome c into the cytosol and depletion of cellular ATP; these effects were all blocked by calpain inhibitors. Overall, this work identifies (specifically) m-calpain as a dominant protease in TXA(2)-induced neurovascular endothelial cell death.
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Affiliation(s)
- Christiane Quiniou
- Department of Pediatrics, Centre de Recherche de l'Hôpital Ste-Justine, Université de Montréal, Québec, Canada
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Abstract
Some years ago it was discovered that prostaglandin F2-like compounds are formed in vivo by nonenzymatic free radical-catalyzed peroxidation of arachidonic acid. Because these compounds are a series of isomers that contain the prostane ring of prostaglandins, they were termed F2-isoprostanes. Intermediates in the isoprostane pathway are prostaglandin H2-like compounds that become reduced to form F2-isoprostanes but also undergo rearrangement in vivo to form E2-, D2-, A2-, J2-isoprostanes, isothromboxanes, and highly reactive gamma-ketoaldehydes, termed isoketals. Analogous compounds have also been shown to be formed from free radical mediated oxidation of docosoahexaenoic acid. Because docosahexaenoic acid is highly enriched in neurons, these compounds have been termed neuroprostanes and neuroketals. An important aspect of the discovery of isoprostanes is that measurement of F2-isoprostanes has emerged as one of the most reliable approaches to assess oxidative stress status in vivo, providing an important tool to explore the role of oxidative stress in the pathogenesis of human disease. Measurement of F4-neuroprostanes has also proved of value in exploring the role of oxidative stress in neurodegenerative diseases. Products of the isoprostane pathway have been found to exert potent biological actions and therefore may participate as physiological mediators of disease.
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Affiliation(s)
- Paolo Montuschi
- Department of Pharmacology, School of Medicine, Catholic University of the Sacred Heart, Rome, Italy
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35
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Hardy P, Beauchamp M, Sennlaub F, Gobeil F, Tremblay L, Mwaikambo B, Lachapelle P, Chemtob S. New insights into the retinal circulation: inflammatory lipid mediators in ischemic retinopathy. Prostaglandins Leukot Essent Fatty Acids 2005; 72:301-25. [PMID: 15850712 DOI: 10.1016/j.plefa.2005.02.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2004] [Revised: 12/21/2004] [Accepted: 02/11/2005] [Indexed: 10/25/2022]
Abstract
Ischemic proliferative retinopathy develops in various retinal disorders, including retinal vein occlusion, diabetic retinopathy and retinopathy of prematurity. Ischemic retinopathy remains a common cause of visual impairment and blindness in the industrialized world due to relatively ineffective treatment. Oxygen-induced retinopathy (OIR) is an established model of retinopathy of prematurity associated with vascular cell injury culminating in microvascular degeneration, which precedes an abnormal neovascularization. The retina is a tissue particularly rich in polyunsaturated fatty acids and the ischemic retina becomes highly sensitive to lipid peroxidation initiated by oxygenated free radicals. Consequently, the retina constitutes an excellent model for testing the functional consequences of membrane lipid peroxidation. Retinal tissue responds to physiological and pathophysiological stimuli by the activation of phospholipases and the consequent release from membrane phospholipids of biologically active metabolites. Activation of phospholipase A(2) is the first step in the synthesis of two important classes of lipid second messengers, the eicosanoids and a membrane-derived phospholipid mediator platelet-activating factor (PAF). These lipid mediators accumulate in the retina in response to injury and a physiologic role of these metabolites in retinal vasculature remains for the most part to be determined; albeit proposed roles have been suggested for some. The eicosanoids, in particular the prostanoids, thromboxane (TXA2) and PAF are abundantly generated following an oxidant stress and contribute to neurovascular injury. TXA2 and PAF play an important role in the retinal microvacular degeneration of OIR by directly inducing endothelial cell death and potentially could contribute to the pathogenesis of ischemic retinopathies. Despite these advances there are still a number of important questions that remain to be answered before we can confidently target pathological signals. This review focuses on mechanisms that precede the development of neovascularization, most notably regarding the role of lipid mediators that partake in microvascular degeneration.
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Affiliation(s)
- Pierre Hardy
- Department of Obstetrics, Research Center Sainte-Justine Hospital and University of Montreal, Montreal, Quebec, Canada, H3T 1C5.
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Beauchamp MH, Sennlaub F, Speranza G, Gobeil F, Checchin D, Kermorvant-Duchemin E, Abran D, Hardy P, Lachapelle P, Varma DR, Chemtob S. Redox-dependent effects of nitric oxide on microvascular integrity in oxygen-induced retinopathy. Free Radic Biol Med 2004; 37:1885-94. [PMID: 15528047 DOI: 10.1016/j.freeradbiomed.2004.09.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2004] [Revised: 08/10/2004] [Accepted: 09/02/2004] [Indexed: 11/19/2022]
Abstract
Opposing effects have been ascribed to nitric oxide (NO) on retinal microvascular survival. We investigated whether changes in the redox state may contribute to explain apparent conflicting actions of NO in a model of oxygen-induced retinal vasoobliteration. Retinal microvascular obliteration was induced by exposing 7-day-old rat pups (P7) for 2 or 5 days to 80% O(2). The redox state of the retina was assessed by measuring reduced glutathione and oxidative and nitrosative products malondialdehyde and nitrotyrosine. The role of NO on vasoobliteration was evaluated by treating animals with nitric oxide synthase (NOS) inhibitors (N-nitro-l-arginine; L-NA) and by determining NOS isoform expression and activity; the contribution of nitrosative stress was also determined in animals treated with the degradation catalyst of peroxynitrite FeTPPS or with the superoxide dismutase mimetic CuDIPS. eNOS, but not nNOS or iNOS, expression and activity were increased throughout the exposure to hyperoxia. These changes were associated with an early (2 days hyperoxia) decrease in reduced glutathione and increases in malondialdehyde and nitrotyrosine. CuDIPS, FeTPPS, and L-NA treatments for these 2 days of hyperoxia nearly abolished the vasoobliteration. In contrast, during 5 days exposure to hyperoxia when the redox state rebalanced, L-NA treatment aggravated the vasoobliteration. Interestingly, VEGFR-2 expression was respectively increased by NOS inhibition after short-term (2 days) exposure to hyperoxia and decreased during the longer hyperoxia exposure. Data disclose that the dual effects of NO on newborn retinal microvascular integrity in response to hyperoxia in vivo depend on the redox state and seem mediated at least in part by VEGFR-2.
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Affiliation(s)
- Martin H Beauchamp
- Department of Pediatrics, Ophthalmology, and Pharmacology, Research Center of Hôpital Ste-Justine, Montréal, Québec H3T 1C5, Canada
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Brault S, Martinez-Bermudez AK, Roberts J, Cui QL, Fragoso G, Hemdan S, Liu HN, Gobeil F, Quiniou C, Kermorvant-Duchemin E, Lachance C, Almazan G, Varma DR, Chemtob S. Cytotoxicity of the E(2)-isoprostane 15-E(2t)-IsoP on oligodendrocyte progenitors. Free Radic Biol Med 2004; 37:358-66. [PMID: 15223069 DOI: 10.1016/j.freeradbiomed.2004.05.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2003] [Revised: 04/28/2004] [Accepted: 05/07/2004] [Indexed: 10/26/2022]
Abstract
Oxidant stress plays a significant role in the pathogenesis of periventricular leukomalacia (PVL). Isoprostanes (IsoPs) are bioactive products of lipid peroxidation abundantly generated during hypoxic-ischemic injuries. Because loss of oligodendrocytes (OLs) occurs early in PVL, we hypothesized that IsoPs could induce progenitor OL death. 15-E(2t)-IsoP but not 15-F(2t)-IsoP elicited a concentration-dependent death of progenitor OLs by oncosis and not by apoptosis, but exerted minimal effects on mature OLs. 15-E(2t)-IsoP-induced cytotoxicity could not be explained by its conversion into cyclopentenones, because PGA(2) was hardly cytotoxic. On the other hand, thromboxane A(2) (TxA(2)) synthase inhibitor CGS12970 and cyclooxygenase inhibitor ibuprofen attenuated 15-E(2t)-IsoP-induced cytotoxicity. Susceptibility of progenitor OLs was independent of TxA(2) receptor (TP) expression, which was far less in progenitor than in mature OLs. However, TxA(2) synthase was detected in precursor but not in mature OLs, and TxA(2) mimetic U46619 induced hydroperoxides generation and progenitor OL death. The glutathione synthesis enhancer N-acetylcysteine prevented 15-E(2t)-IsoP-induced progenitor cell death. Depletion of glutathione in mature OLs with buthionine sulfoximine rendered them susceptible to cytotoxicity of 15-E(2t)-IsoP. These novel data implicate 15-E(2t)-IsoP as a product of oxidative stress that may contribute in the genesis of PVL.
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Affiliation(s)
- Sonia Brault
- Research Center of Hôpital Sainte-Justine, Department of Pediatrics and Pharmacology, Université de Montréal, Québec, Canada
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Crane GJ, Garland CJ. Thromboxane receptor stimulation associated with loss of SKCa activity and reduced EDHF responses in the rat isolated mesenteric artery. Br J Pharmacol 2004; 142:43-50. [PMID: 15051624 PMCID: PMC1574933 DOI: 10.1038/sj.bjp.0705756] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. The possibility that thromboxane (TXA(2)) receptor stimulation causes differential block of the SK(Ca) and IK(Ca) channels which underlie EDHF-mediated vascular smooth muscle hyperpolarization and relaxation was investigated in the rat isolated mesenteric artery. 2. Acetylcholine (30 nm-3 microm ACh) or cyclopiazonic acid (10 microm CPA, SERCA inhibitor) were used to stimulate EDHF-evoked smooth muscle hyperpolarization. In each case, this led to maximal hyperpolarization of around 20 mV, which was sensitive to block with 50 nm apamin and abolished by repeated stimulation of mesenteric arteries with the thromboxane mimetic, U46619 (30 nm-0.1 microm), but not the alpha(1)-adrenoceptor agonist phenylephrine (PE). 3. The ability of U46619 to abolish EDHF-evoked smooth muscle hyperpolarization was prevented by prior exposure of mesenteric arteries to the TXA(2) receptor antagonist 1 microm SQ29548. 4. Similar-sized smooth muscle hyperpolarization evoked with the SK(Ca) activator 100 microm riluzole was also abolished by prior stimulation with U46619, while direct muscle hyperpolarization in response to either levcromakalim (1 microm, K(ATP) activator) or NS1619 (40 microm, BK(Ca) activator) was unaffected. 5. During smooth muscle contraction and depolarization to either PE or U46619, ACh evoked concentration-dependent hyperpolarization (to -67 mV) and complete relaxation. These responses were well maintained during repeated stimulation with PE, but with U46619 there was a progressive decline, so that during a third exposure to U46619 maximum hyperpolarization only reached -52 mV and relaxation was reduced by 20%. This relaxation could now be blocked with charybdotoxin alone. The latter responses could be mimicked with 300 microm 1-EBIO (IK(Ca) activator), an action not modified by exposure to U46619. 6. An early consequence of TXA(2) receptor stimulation is a reduction in the arterial hyperpolarization and relaxation attributed to EDHF. This effect appears to reflect a loss of SK(Ca) activity.
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Affiliation(s)
- G J Crane
- Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY
| | - C J Garland
- Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY
- Author for correspondence:
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39
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Brault S, Martinez-Bermudez AK, Marrache AM, Gobeil F, Hou X, Beauchamp M, Quiniou C, Almazan G, Lachance C, Roberts J, Varma DR, Chemtob S. Selective neuromicrovascular endothelial cell death by 8-Iso-prostaglandin F2alpha: possible role in ischemic brain injury. Stroke 2003; 34:776-82. [PMID: 12624307 DOI: 10.1161/01.str.0000055763.76479.e6] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Free radical-induced peroxidation is an important factor in the genesis of hypoxic-ischemic encephalopathy, including that of the preterm infant. Isoprostanes are major peroxidation products. Since microvascular dysfunction seems to contribute to ischemic encephalopathies, we studied the cytotoxicity of 8-iso-prostaglandin F2alpha (PGF2alpha) on cerebral microvascular cells. METHODS Microvascular endothelial, astroglial, and smooth muscle cells from newborn brain were cultured. The cytotoxicity of 8-iso-PGF2alpha on these cells was determined by MTT assays and lactate dehydrogenase (LDH) release, propidium iodide incorporation, and DNA fragmentation (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling [TUNEL]). In addition, effects of intraventricular injections of 8-iso-PGF2alpha and possible involvement of thromboxane in 8-iso-PGF2alpha-induced cytotoxicity were determined. RESULTS 8-Iso-PGF2alpha induced time- and concentration-dependent endothelial cell death (EC50=0.1 nmol/L) but exerted little effect on smooth muscle and astroglial cells; endothelial cell death seemed mostly of oncotic nature (propidium iodide incorporation and LDH release). Cell death was associated with increased endothelial thromboxane A2 (TXA2) formation and was prevented by TXA2 synthase inhibitors (CGS12970 and U63557A); TXA2 mimetics U46619 and I-BOP also caused endothelial cell death. Intraventricular injection of 8-iso-PGF2alpha induced periventricular damage, which was attenuated by CGS12970 pretreatment. CONCLUSIONS These data disclose a novel action of 8-iso-PGF2alpha involving TXA2 in oxidant stress-induced cerebral microvascular injury and brain damage.
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MESH Headings
- Animals
- Astrocytes/cytology
- Astrocytes/drug effects
- Astrocytes/metabolism
- Brain/blood supply
- Brain/drug effects
- Brain/pathology
- Brain Ischemia/metabolism
- Cell Death/drug effects
- Cell Survival/drug effects
- Cells, Cultured
- DNA Fragmentation/drug effects
- Dinoprost/analogs & derivatives
- Dinoprostone/analogs & derivatives
- Dinoprostone/pharmacology
- Dose-Response Relationship, Drug
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Enzyme Inhibitors/pharmacology
- F2-Isoprostanes/pharmacology
- In Vitro Techniques
- Injections, Intraventricular
- Isoprostanes/pharmacology
- L-Lactate Dehydrogenase/metabolism
- Microcirculation/cytology
- Microcirculation/drug effects
- Microcirculation/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Necrosis
- Rats
- Rats, Sprague-Dawley
- Swine
- Thromboxane A2/metabolism
- Thromboxane-A Synthase/antagonists & inhibitors
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Affiliation(s)
- Sonia Brault
- Centre de Recherche de l'Hôpital Sainte-Justine, Department of Pediatrics and Pharmacology, Université de Montréal, Montréal, Québec, Canada
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40
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Hatae T, Wada M, Yokoyama C, Shimonishi M, Tanabe T. Prostacyclin-dependent apoptosis mediated by PPAR delta. J Biol Chem 2001; 276:46260-7. [PMID: 11551955 DOI: 10.1074/jbc.m107180200] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prostacyclin (PGI(2)) plays important roles in hemostasis both as a vasodilator and an endogenous inhibitor of platelet aggregation. PGI(2) functions in these roles through a specific IP receptor, a G protein-coupled receptor linked to G(s) and increases in cAMP. Here, we report that intracellular prostacyclin formed by expressing prostacyclin synthase in human embryonic kidney 293 cells promotes apoptosis by activating endogenous peroxisome proliferator-activated receptor delta (PPAR delta). In contrast, treatment of cells with extracellular prostacyclin or dibutyryl cAMP actually reduced apoptosis. On the contrary, treatment of the cells with RpcAMP (adenosine 3',5'-cyclic monophosphothioate, Rp-isomer), an antagonist of cAMP, enhanced prostacyclin-mediated apoptosis. The expression of an L431A/G434A mutant of PPAR delta completely blocked prostacyclin-mediated PPAR delta activation and apoptosis. These observations indicate that prostacyclin can act through endogenous PPAR delta as a second signaling pathway that controls cell fate.
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Affiliation(s)
- T Hatae
- Department of Pharmacology, National Cardiovascular Center Research Institute, Fujishiro-dai, Suita, Osaka 565-8565, Japan
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41
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Abstract
The incidence of ROP is birth weight dependent and restricting therapeutic oxygen levels has dramatically reduced the incidence of ROP in infants of birth weight >1000 g. However, the incidence of ROP has remained high in very low birth weight (VLBW) infants and this appears to be related to these babies being more ill. Several risk factors have been identified in this group, however oxygen variability, rather than high levels, has been correlated with severity of disease in recent clinical and animal studies. Difficulties in defining 'normal' oxygen in this group has meant the optimal range of oxygen therapy has not yet been defined. Clinical studies are now underway using even lower oxygen therapy ranges. The impact this may have on ROP, neurological and respiratory outcomes will require further study.
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Affiliation(s)
- J R Mccolm
- Child Life & Health, Reproductive and Developmental Sciences, Edinburgh University, Edinburgh, UK
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42
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Wright DH, Abran D, Bhattacharya M, Hou X, Bernier SG, Bouayad A, Fouron JC, Vazquez-Tello A, Beauchamp MH, Clyman RI, Peri K, Varma DR, Chemtob S. Prostanoid receptors: ontogeny and implications in vascular physiology. Am J Physiol Regul Integr Comp Physiol 2001; 281:R1343-60. [PMID: 11641101 DOI: 10.1152/ajpregu.2001.281.5.r1343] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Prostanoids exert significant effects on circulatory beds. They play a role in the response of the vasculature to adjustments in perfusion pressure and oxygen and carbon dioxide tension, and they mediate the actions of numerous factors. The role of prostanoids in governing circulation of the perinate is suggested to surpass that in the adult. Prostanoids are abundantly generated in the perinate. They have been implicated in autoregulation of blood flow as studied in brain and eyes. Prostaglandins are also dominant regulators of ductus arteriosus tone. The effects of these autacoids are mediated through specific G protein-coupled receptors. In addition to the pharmacological characterization of the prostanoid receptors, important advances in understanding the biology of these receptors have been made in the last decade. Their cloning and the development of animals with disrupted genes of these receptors have been very informative. The involvement of prostanoid receptors in the developing subject, especially on brain and ocular vasculature and on ductus arteriosus, has also begun to be investigated; the expression of these receptors changes with development. Some but not all of the ontogenic changes in these receptors are attributed to homologous regulation. Interestingly, in the process of elucidating their effects, functional perinuclear prostaglandin E2 receptors have been uncovered. This article reviews prostanoid receptors and addresses implications on the developing subject with attention to vascular physiology.
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Affiliation(s)
- D H Wright
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G-1Y6, Canada
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Hou X, Roberts LJ, Taber DF, Morrow JD, Kanai K, Gobeil F, Beauchamp MH, Bernier SG, Lepage G, Varma DR, Chemtob S. 2,3-Dinor-5,6-dihydro-15-F(2t)-isoprostane: a bioactive prostanoid metabolite. Am J Physiol Regul Integr Comp Physiol 2001; 281:R391-400. [PMID: 11448840 DOI: 10.1152/ajpregu.2001.281.2.r391] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
15-F(2t)-isoprostane (15-F(2t)-IsoP), also termed 8-isoprostaglandin F(2alpha), is one of a series of prostanoids formed by free radical-mediated peroxidation of arachidonic acid and exerts potent biological actions such as vasoconstriction. We recently demonstrated that 15-F(2t)-IsoP is metabolized in humans to a major metabolite, 2,3-dinor-5,6-dihydro-15-F(2t)-IsoP (15-F(2t)-IsoP-M). 15-F(2t)-IsoP-M can also potentially be formed as a product of free radical-induced oxidation of the low abundance fatty acid gamma-linolenic acid. We confirmed that 15-F(2t)-IsoP-M is generated during oxidation of gamma-linolenic acid and explored whether it may exhibit biological activity. 15-F(2t)-IsoP-M caused marked constriction of porcine surface retinal and intraparenchymal brain microvessels, comparable to that observed with 15-F(2t)-IsoP. These effects were associated with increased thromboxane A(2) (TXA(2)) formation and were virtually abolished by TXA(2)-synthase and -receptor inhibitors (CGS-12970 and L-670596). Vasoconstriction induced by either 15-F(2t)-IsoP or 15-F(2t)-IsoP-M on perfused ocular choroid was also abrogated by TXA(2)-synthase inhibition as well as by removal of endothelium. Similar to 15-F(2t)-IsoP, 15-F(2t)-IsoP-M evoked vasoconstriction and TXA(2) generation by activating Ca(2+) influx from nonvoltage-gated channels (SK&F96365 sensitive) in the retina and from both nonvoltage- and N-type voltage-gated Ca(2+) channels (omega-conotoxin MVIIA sensitive), respectively, in brain endothelial and astroglial cells; smooth muscle cells were unresponsive to both agents. Cross-desensitization experiments further suggest that 15-F(2t)-IsoP and 15-F(2t)-IsoP-M act on the same receptor mechanism. Findings reveal a novel concept by which a beta-oxidation metabolite of 15-F(2t)-IsoP that can also be formed by nonenzymatic oxidation of gamma-linolenic acid is equivalently bioactive to 15-F(2t)-IsoP and may prolong the vascular actions of F(2)-IsoPs.
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Affiliation(s)
- X Hou
- Departments of Pediatrics and Pharmacology, Centre de Recherche de l'Hôpital Sainte-Justine, Université de Montréal, Montréal, Québec H3T 1C5, Canada
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