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O'Leary F, Campbell M. The blood-retina barrier in health and disease. FEBS J 2023; 290:878-891. [PMID: 34923749 DOI: 10.1111/febs.16330] [Citation(s) in RCA: 48] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/05/2021] [Accepted: 12/17/2021] [Indexed: 12/20/2022]
Abstract
The blood-retina barrier (BRB) is the term used to define the properties of the retinal capillaries and the retinal pigment epithelium (RPE), which separate the systemic circulation from the retina. More specifically, the inner blood-retina barrier (iBRB) is used to describe the properties of the endothelial cells that line the microvasculature of the inner retina, while the outer blood-retina barrier (oBRB) refers to the properties of the RPE cells that separate the fenestrated choriocapillaris from the retina. The BRB is not a fixed structure; rather, it is dynamic, with its components making unique contributions to its function and structural integrity, and therefore the retina. For example, while tight junction (TJ) proteins between retinal endothelial cells are the key molecular structures in the maintenance of the iBRB, other cell types surrounding endothelial cells are also important. In fact, this overall structure is termed the neurovascular unit (NVU). The integrity of the BRB is crucial in the maintenance of a 'dry', tightly regulated retinal microenvironment through the regulation of transcellular and paracellular transport. Specifically, breakdown of TJs can result in oedema formation, a hallmark feature of many retinal diseases. Here, we will describe the oBRB briefly, with a more in-depth focus on the structure and function of the iBRB in health and diseased states. Finally, the contribution of the BRB to the pathophysiology of age-related macular degeneration (AMD), diabetic retinopathy (DR) and other rarer retinal diseases will be discussed.
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Affiliation(s)
- Fionn O'Leary
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Matthew Campbell
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
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2
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Abstract
The antihypertrophic effect of nebivolol over cardioselective beta-blockers (β-blockers) is attributed to the activation of cardiac nitric oxide signaling. However, the precise role of nebivolol on hypertrophied cardiomyocytes remains unclear. In the current study, in vitro cardiomyocyte hypertrophy model was induced with isoprenaline (10 μM), angiotensin II (1 μM), and phenylephrine (20 μM) in neonatal cardiomyocytes isolated from 0- to 2-day-old Sprague-Dawley rats. In addition to hypertrophic agents, cardiomyocytes were treated with nebivolol (1 μM), metoprolol (10 μM), N(ω)-nitro-L-arginine methyl ester (L-NAME) (100 μM), KT5823 (1 μM), DETA-NONOate (1-10 μM), and BAY412272 (10 μM). After 24 hours of treatment, cardiomyocyte size and transcriptional changes in cardiac hypertrophy markers were evaluated. Cardiomyocyte size increased equally in response to all hypertrophic agents. Nebivolol reduced the enhancement in cell size in response to both isoprenaline and angiotensin II; metoprolol did not. The antihypertrophic effect of nebivolol was prevented with L-NAME blockage indicating the role of NOS signaling on cardiomyocyte hypertrophy. The increased mRNA levels of atrial natriuretic peptide induced by isoprenaline decreased with nebivolol, but both β-blockers reduced the angiotensin II-induced increase in atrial natriuretic peptide expression. Combined, these results reveal that by activating NOS signaling, nebivolol exerts antihypertrophic effects on neonatal cardiomyocytes independent from the action mechanism of hypertrophic stimulus.
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Lu H, Sun J, Liang W, Zhang J, Rom O, Garcia-Barrio MT, Li S, Villacorta L, Schopfer FJ, Freeman BA, Chen YE, Fan Y. Novel gene regulatory networks identified in response to nitro-conjugated linoleic acid in human endothelial cells. Physiol Genomics 2019; 51:224-233. [PMID: 31074702 PMCID: PMC6620647 DOI: 10.1152/physiolgenomics.00127.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/05/2019] [Accepted: 04/24/2019] [Indexed: 12/11/2022] Open
Abstract
Endothelial cell (EC) dysfunction is a crucial initiation event in the development of atherosclerosis and is associated with diabetes mellitus, hypertension, and heart failure. Both digestive and oxidative inflammatory conditions lead to the endogenous formation of nitrated derivatives of unsaturated fatty acids (FAs) upon generation of the proximal nitrating species nitrogen dioxide (·NO2) by nitric oxide (·NO) and nitrite-dependent reactions. Nitro-FAs (NO2-FAs) such as nitro-oleic acid (NO2-OA) and nitro-linoleic acid (NO2-LA) potently inhibit inflammation and oxidative stress, regulate cellular functions, and maintain cardiovascular homeostasis. Recently, conjugated linoleic acid (CLA) was identified as the preferential FA substrate of nitration in vivo. However, the functions of nitro-CLA (NO2-CLA) in ECs remain to be explored. In the present study, a distinct transcriptome regulated by NO2-CLA was revealed in primary human coronary artery endothelial cells (HCAECs) through RNA sequencing. Differential gene expression and pathway enrichment analysis identified numerous regulatory networks including those related to the modulation of inflammation, oxidative stress, cell cycle, and hypoxic responses by NO2-CLA, suggesting a diverse impact of NO2-CLA and other electrophilic nitrated FAs on cellular processes. These findings extend the understanding of the protective actions of NO2-CLA in cardiovascular diseases and provide new insight into the underlying mechanisms that mediate the pleiotropic cellular responses to NO2-CLA.
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Affiliation(s)
- Haocheng Lu
- Frankel Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center , Ann Arbor, Michigan
| | - Jinjian Sun
- Frankel Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center , Ann Arbor, Michigan
| | - Wenying Liang
- Frankel Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center , Ann Arbor, Michigan
| | - Jifeng Zhang
- Frankel Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center , Ann Arbor, Michigan
| | - Oren Rom
- Frankel Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center , Ann Arbor, Michigan
| | - Minerva T Garcia-Barrio
- Frankel Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center , Ann Arbor, Michigan
| | - Shengdi Li
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL) , Heidelberg , Germany
| | - Luis Villacorta
- Frankel Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center , Ann Arbor, Michigan
| | - Francisco J Schopfer
- Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Bruce A Freeman
- Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Y Eugene Chen
- Frankel Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center , Ann Arbor, Michigan
| | - Yanbo Fan
- Frankel Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center , Ann Arbor, Michigan
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4
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Melo T, Montero-Bullón JF, Domingues P, Domingues MR. Discovery of bioactive nitrated lipids and nitro-lipid-protein adducts using mass spectrometry-based approaches. Redox Biol 2019; 23:101106. [PMID: 30718106 PMCID: PMC6859590 DOI: 10.1016/j.redox.2019.101106] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 01/08/2019] [Accepted: 01/10/2019] [Indexed: 01/01/2023] Open
Abstract
Nitro-fatty acids (NO2-FA) undergo reversible Michael adduction reactions with cysteine and histidine residues leading to the post-translational modification (PTM) of proteins. This electrophilic character of NO2-FA is strictly related to their biological roles. The NO2-FA-induced PTM of signaling proteins can lead to modifications in protein structure, function, and subcellular localization. The nitro lipid-protein adducts trigger a series of downstream signaling events that culminates with anti-inflammatory, anti-hypertensive, and cytoprotective effects mediated by NO2-FA. These lipoxidation adducts have been detected and characterized both in model systems and in biological samples by using mass spectrometry (MS)-based approaches. These MS approaches allow to unequivocally identify the adduct together with the targeted residue of modification. The identification of the modified proteins allows inferring on the possible impact of the NO2-FA-induced modification. This review will focus on MS-based approaches as valuable tools to identify NO2-FA-protein adducts and to unveil the biological effect of this lipoxidation adducts.
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Affiliation(s)
- Tânia Melo
- Centro de Espectrometria de Massa, Departamento de Química & QOPNA, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; Departamento de Química & CESAM & ECOMARE, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
| | - Javier-Fernando Montero-Bullón
- Centro de Espectrometria de Massa, Departamento de Química & QOPNA, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
| | - Pedro Domingues
- Centro de Espectrometria de Massa, Departamento de Química & QOPNA, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
| | - M Rosário Domingues
- Centro de Espectrometria de Massa, Departamento de Química & QOPNA, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; Departamento de Química & CESAM & ECOMARE, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
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Freeman BA, O'Donnell VB, Schopfer FJ. The discovery of nitro-fatty acids as products of metabolic and inflammatory reactions and mediators of adaptive cell signaling. Nitric Oxide 2018; 77:106-111. [PMID: 29742447 DOI: 10.1016/j.niox.2018.05.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/04/2018] [Indexed: 01/06/2023]
Abstract
Foundational advances in eicosanoid signaling, the free radical biology of oxygen and nitric oxide and mass spectrometry all converged to enable the discovery of nitrated unsaturated fatty acids. Due to the unique biochemical characteristics of fatty acid nitroalkenes, these species undergo rapid and reversible Michael addition of biological nucleophiles such as cysteine, leading to the post-translational modification of low molecular weight and protein thiols. This capability has led to the present understanding that nitro-fatty acid reaction with the alkylation-sensitive cysteine proteome leads to physiologically-beneficial alterations in transcriptional regulatory protein function, gene expression and in vivo rodent model responses to metabolic and inflammatory stress. These findings motivated the preclinical and clinical development of nitro-fatty acids as new drug candidates for treating acute and chronic metabolic and inflammatory disorders.
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Affiliation(s)
- Bruce A Freeman
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Valerie B O'Donnell
- Systems Immunity Research Institute and Division of Infection and Immunity, Cardiff University, Cardiff, UK
| | - Francisco J Schopfer
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.
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Mollenhauer M, Mehrkens D, Rudolph V. Nitrated fatty acids in cardiovascular diseases. Nitric Oxide 2018; 78:S1089-8603(17)30292-6. [PMID: 29588164 DOI: 10.1016/j.niox.2018.03.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 03/21/2018] [Accepted: 03/21/2018] [Indexed: 11/26/2022]
Abstract
Cardiovascular disease (CVD) is the leading cause of death and accounts for one third of disease-related mortality worldwide. Dysregulated redox mechanisms, in particular the formation of reactive oxygen species (ROS) play a pivotal pathogenetic role in CVD. Nitro-fatty acids (NO2-FAs) are electrophilic molecules which have a NO2-group bound to one of their olefinic carbons. They are endogenously formed by the reaction of reactive nitrogen species with unsaturated fatty acids. Basal levels of NO2-FAs are in the low nanomolar range and higher concentrations can be encountered under acidic (stomach) and inflammatory (e.g. ischemia/reperfusion) conditions. Dietary intake of polyunsaturated fatty acids in combination with nitrites raises circulating NO2-FAs to a clinically relevant level in mice. NO2-FAs undergo reversible covalent binding to cysteine residues and by virtue of these posttranslational protein modifications act as potent anti-inflammatory signaling mediators via modulation of various critical pathways like nuclear factor E2-related factor 2 (Nrf2)- and peroxisome proliferator-activated receptor γ (PPARγ) activation, nuclear factor-kappa B (NF-κB) inhibition and hem oxygenase-1 (HO-1)- and heat shock protein (HSP) induction. In this review article, we summarize recent findings about the effects and underlying molecular mechanisms of NO2-FAs from a variety of pre-clinical cardiovascular disease models. The described findings suggest the potential of NO2-FAs to emerge as therapeutic agents with a broad range of potential clinical applications for CVD.
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Affiliation(s)
- Martin Mollenhauer
- Department of Cardiology, Heart Center, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Dennis Mehrkens
- Department of Cardiology, Heart Center, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Volker Rudolph
- Department of Cardiology, Heart Center, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.
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7
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D'Amore A, Fazzari M, Jiang HB, Luketich SK, Luketich ME, Hoff R, Jacobs DL, Gu X, Badylak SF, Freeman BA, Wagner WR. Nitro-Oleic Acid (NO 2-OA) Release Enhances Regional Angiogenesis in a Rat Abdominal Wall Defect Model. Tissue Eng Part A 2018; 24:889-904. [PMID: 29187125 DOI: 10.1089/ten.tea.2017.0349] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Ventral hernia is often addressed surgically by the placement of prosthetic materials, either synthetic or from allogeneic and xenogeneic biologic sources. Despite advances in surgical approaches and device design, a number of postsurgical limitations remain, including hernia recurrence, mesh encapsulation, and reduced vascularity of the implanted volume. The in situ controlled release of angiogenic factors from a scaffold facilitating abdominal wall repair might address some of these issues associated with suboptimal tissue reconstruction. Furthermore, a biocomposite material that combines the favorable mechanical properties achievable with synthetic materials and the bioactivity associated with xenogeneic tissue sources would be desirable. In this report, an abdominal wall repair scaffold has been designed based on a microfibrous, elastomeric poly(ester carbonate)urethane urea matrix integrated with a hydrogel derived from decellularized porcine dermis (extracellular matrix [ECM] gel) and poly(lactic-co-glycolic acid) (PLGA) microspheres loaded with nitro-oleic acid (NO2-OA). NO2-OA is an electrophilic fatty acid nitro-alkene derivative that, under hypoxic conditions, induces angiogenesis. This scaffold was utilized to repair a rat abdominal wall partial thickness defect, hypothesizing that the nitro-fatty acid release would facilitate increased angiogenesis at the 8-week endpoint. The quantification of neovascularization was conducted by novel methodologies to assess vessel morphology and spatial distribution. The repaired abdominal wall defects were evaluated by histopathologic methods, including quantification of the foreign body response and cellular ingrowth. The results showed that NO2-OA release was associated with significantly improved regional angiogenesis. The combined biohybrid scaffold and NO2-OA-controlled release strategy also reduced scaffold encapsulation, increased wall thickness, and enhanced cellular infiltration. More broadly, the three components of the composite scaffold design (ECM gel, polymeric fibers, and PLGA microparticles) enable the tuning of performance characteristics, including scaffold bioactivity, degradation, mechanics, and drug release profile, all decisive factors to better address current limitations in abdominal wall repair or other soft tissue augmentation procedures.
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Affiliation(s)
- Antonio D'Amore
- 1 Departments of Bioengineering and Surgery, McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania.,2 Fondazione RiMED , Palermo, Italy .,3 Dipartimento Innovazione Industriale e Digitale (DIID), Università di Palermo , Palermo, Italy
| | - Marco Fazzari
- 2 Fondazione RiMED , Palermo, Italy .,4 Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Hong-Bin Jiang
- 1 Departments of Bioengineering and Surgery, McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Samuel K Luketich
- 5 Department of Chemical Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Michael E Luketich
- 5 Department of Chemical Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Richard Hoff
- 1 Departments of Bioengineering and Surgery, McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Daniel L Jacobs
- 1 Departments of Bioengineering and Surgery, McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Xinzhu Gu
- 1 Departments of Bioengineering and Surgery, McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Stephen F Badylak
- 1 Departments of Bioengineering and Surgery, McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Bruce A Freeman
- 4 Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - William R Wagner
- 1 Departments of Bioengineering and Surgery, McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania.,5 Department of Chemical Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania
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8
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Mathers AR, Carey CD, Killeen ME, Salvatore SR, Ferris LK, Freeman BA, Schopfer FJ, Falo LD. Topical electrophilic nitro-fatty acids potentiate cutaneous inflammation. Free Radic Biol Med 2018; 115:31-42. [PMID: 29132974 PMCID: PMC5767521 DOI: 10.1016/j.freeradbiomed.2017.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 11/07/2017] [Accepted: 11/09/2017] [Indexed: 11/18/2022]
Abstract
Endogenous electrophilic fatty acids mediate anti-inflammatory responses by modulating metabolic and inflammatory signal transduction and gene expression. Nitro-fatty acids and other electrophilic fatty acids may thus be useful for the prevention and treatment of immune-mediated diseases, including inflammatory skin disorders. In this regard, subcutaneous (SC) injections of nitro oleic acid (OA-NO2), an exemplary nitro-fatty acid, inhibit skin inflammation in a model of allergic contact dermatitis (ACD). Given the nitration of unsaturated fatty acids during metabolic and inflammatory processes and the growing use of fatty acids in topical formulations, we sought to further study the effect of nitro-fatty acids on cutaneous inflammation. To accomplish this, the effect of topically applied OA-NO2 on skin inflammation was evaluated using established murine models of contact hypersensitivity (CHS). In contrast to the effects of subcutaneously injected OA-NO2, topical OA-NO2 potentiated hapten-dependent inflammation inducing a sustained neutrophil-dependent inflammatory response characterized by psoriasiform histological features, increased angiogenesis, and an inflammatory infiltrate that included neutrophils, inflammatory monocytes, and γδ T cells. Consistent with these results, HPLC-MS/MS analysis of skin from psoriasis patients displayed a 56% increase in nitro-conjugated linoleic acid (CLA-NO2) levels in lesional skin compared to non-lesional skin. These results suggest that nitro-fatty acids in the skin microenvironment are products of cutaneous inflammatory responses and, in high local concentrations, may exacerbate inflammatory skin diseases.
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Affiliation(s)
- Alicia R Mathers
- Departments of Dermatology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213. USA; Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213. USA.
| | - Cara D Carey
- Departments of Dermatology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213. USA
| | - Meaghan E Killeen
- Departments of Dermatology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213. USA
| | - Sonia R Salvatore
- Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213. USA
| | - Laura K Ferris
- Departments of Dermatology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213. USA
| | - Bruce A Freeman
- Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213. USA
| | - Francisco J Schopfer
- Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213. USA
| | - Louis D Falo
- Departments of Dermatology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213. USA; Bioengineering, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213. USA
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Eshaq RS, Aldalati AMZ, Alexander JS, Harris NR. Diabetic retinopathy: Breaking the barrier. PATHOPHYSIOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY FOR PATHOPHYSIOLOGY 2017; 24:229-241. [PMID: 28732591 PMCID: PMC5711541 DOI: 10.1016/j.pathophys.2017.07.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 06/26/2017] [Accepted: 07/04/2017] [Indexed: 12/28/2022]
Abstract
Diabetic retinopathy (DR) remains a major complication of diabetes and a leading cause of blindness among adults worldwide. DR is a progressive disease affecting both type I and type II diabetic patients at any stage of the disease, and targets the retinal microvasculature. DR results from multiple biochemical, molecular and pathophysiological changes to the retinal vasculature, which affect both microcirculatory functions and ultimately photoreceptor function. Several neural, endothelial, and support cell (e.g., pericyte) mechanisms are altered in a pathological fashion in the hyperglycemic environment during diabetes that can disturb important cell surface components in the vasculature producing the features of progressive DR pathophysiology. These include loss of the glycocalyx, blood-retinal barrier dysfunction, increased expression of inflammatory cell markers and adhesion of blood leukocytes and platelets. Included in this review is a discussion of modifications that occur at or near the surface of the retinal vascular endothelial cells, and the consequences of these alterations on the integrity of the retina.
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Affiliation(s)
- Randa S Eshaq
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center -Shreveport, 1501 Kings Highway, Shreveport, LA 71130, United States
| | - Alaa M Z Aldalati
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center -Shreveport, 1501 Kings Highway, Shreveport, LA 71130, United States
| | - J Steven Alexander
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center -Shreveport, 1501 Kings Highway, Shreveport, LA 71130, United States
| | - Norman R Harris
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center -Shreveport, 1501 Kings Highway, Shreveport, LA 71130, United States.
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Woodcock CSC, Huang Y, Woodcock SR, Salvatore SR, Singh B, Golin-Bisello F, Davidson NE, Neumann CA, Freeman BA, Wendell SG. Nitro-fatty acid inhibition of triple-negative breast cancer cell viability, migration, invasion, and tumor growth. J Biol Chem 2017; 293:1120-1137. [PMID: 29158255 DOI: 10.1074/jbc.m117.814368] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/05/2017] [Indexed: 12/31/2022] Open
Abstract
Triple-negative breast cancer (TNBC) comprises ∼20% of all breast cancers and is the most aggressive mammary cancer subtype. Devoid of the estrogen and progesterone receptors, along with the receptor tyrosine kinase ERB2 (HER2), that define most mammary cancers, there are no targeted therapies for patients with TNBC. This, combined with a high metastatic rate and a lower 5-year survival rate than for other breast cancer phenotypes, means there is significant unmet need for new therapeutic strategies. Herein, the anti-neoplastic effects of the electrophilic fatty acid nitroalkene derivative, 10-nitro-octadec-9-enoic acid (nitro-oleic acid, NO2-OA), were investigated in multiple preclinical models of TNBC. NO2-OA reduced TNBC cell growth and viability in vitro, attenuated TNFα-induced TNBC cell migration and invasion, and inhibited the tumor growth of MDA-MB-231 TNBC cell xenografts in the mammary fat pads of female nude mice. The up-regulation of these aggressive tumor cell growth, migration, and invasion phenotypes is mediated in part by the constitutive activation of pro-inflammatory nuclear factor κB (NF-κB) signaling in TNBC. NO2-OA inhibited TNFα-induced NF-κB transcriptional activity in human TNBC cells and suppressed downstream NF-κB target gene expression, including the metastasis-related proteins intercellular adhesion molecule-1 and urokinase-type plasminogen activator. The mechanisms accounting for NF-κB signaling inhibition by NO2-OA in TNBC cells were multifaceted, as NO2-OA (a) inhibited the inhibitor of NF-κB subunit kinase β phosphorylation and downstream inhibitor of NF-κB degradation, (b) alkylated the NF-κB RelA protein to prevent DNA binding, and (c) promoted RelA polyubiquitination and proteasomal degradation. Comparisons with non-tumorigenic human breast epithelial MCF-10A and MCF7 cells revealed that NO2-OA more selectively inhibited TNBC function. This was attributed to more facile mechanisms for maintaining redox homeostasis in normal breast epithelium, including a more favorable thiol/disulfide balance, greater extents of multidrug resistance protein-1 (MRP1) expression, and greater MRP1-mediated efflux of NO2-OA-glutathione conjugates. These observations reveal that electrophilic fatty acid nitroalkenes react with more alkylation-sensitive targets in TNBC cells to inhibit growth and viability.
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Affiliation(s)
- Chen-Shan Chen Woodcock
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Yi Huang
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260.,the Women's Cancer Research Center of the UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania 15232, and
| | - Steven R Woodcock
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Sonia R Salvatore
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Bhupinder Singh
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Franca Golin-Bisello
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Nancy E Davidson
- the Fred Hutchinson Cancer Research Center and Department of Medicine, University of Washington, Seattle, Washington 98109
| | - Carola A Neumann
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260.,the Women's Cancer Research Center of the UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania 15232, and
| | - Bruce A Freeman
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260,
| | - Stacy G Wendell
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260,
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11
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Koudelka A, Ambrozova G, Klinke A, Fidlerova T, Martiskova H, Kuchta R, Rudolph TK, Kadlec J, Kuchtova Z, Woodcock SR, Freeman BA, Kubala L, Pekarova M. Nitro-Oleic Acid Prevents Hypoxia- and Asymmetric Dimethylarginine-Induced Pulmonary Endothelial Dysfunction. Cardiovasc Drugs Ther 2017; 30:579-586. [PMID: 27858190 DOI: 10.1007/s10557-016-6700-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
RATIONALE Pulmonary hypertension (PH) represents a serious health complication accompanied with hypoxic conditions, elevated levels of asymmetric dimethylarginine (ADMA), and overall dysfunction of pulmonary vascular endothelium. Since the prevention strategies for treatment of PH remain largely unknown, our study aimed to explore the effect of nitro-oleic acid (OA-NO2), an exemplary nitro-fatty acid (NO2-FA), in human pulmonary artery endothelial cells (HPAEC) under the influence of hypoxia or ADMA. METHODS HPAEC were treated with OA-NO2 in the absence or presence of hypoxia and ADMA. The production of nitric oxide (NO) and interleukin-6 (IL-6) was monitored using the Griess method and ELISA, respectively. The expression or activation of different proteins (signal transducer and activator of transcription 3, STAT3; hypoxia inducible factor 1α, HIF-1α; endothelial nitric oxide synthase, eNOS; intercellular adhesion molecule-1, ICAM-1) was assessed by the Western blot technique. RESULTS We discovered that OA-NO2 prevents development of endothelial dysfunction induced by either hypoxia or ADMA. OA-NO2 preserves normal cellular functions in HPAEC by increasing NO production and eNOS expression. Additionally, OA-NO2 inhibits IL-6 production as well as ICAM-1 expression, elevated by hypoxia and ADMA. Importantly, the effect of OA-NO2 is accompanied by prevention of STAT3 activation and HIF-1α stabilization. CONCLUSION In summary, OA-NO2 eliminates the manifestation of hypoxia- and ADMA-mediated endothelial dysfunction in HPAEC via the STAT3/HIF-1α cascade. Importantly, our study is bringing a new perspective on molecular mechanisms of NO2-FAs action in pulmonary endothelial dysfunction, which represents a causal link in progression of PH. Graphical Abstract ᅟ.
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Affiliation(s)
- Adolf Koudelka
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Kralovopolska 135, 612 65, Brno, Czech Republic
| | - Gabriela Ambrozova
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Kralovopolska 135, 612 65, Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic
| | - Anna Klinke
- International Clinical Research Center, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic.,Department of Experimental Cardiology, University Hospital of Cologne, Kerpener Str. 62, 50924, Cologne, Germany
| | - Tana Fidlerova
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Kralovopolska 135, 612 65, Brno, Czech Republic.,Faculty of Science, Institute of Experimental Biology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Hana Martiskova
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Kralovopolska 135, 612 65, Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic.,Faculty of Science, Institute of Experimental Biology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Radek Kuchta
- Faculty of Electrical Engineering and Communication, Brno University of Technology, Technicka 3058/10, 616 00, Brno, Czech Republic
| | - Tanja K Rudolph
- Department of Experimental Cardiology, University Hospital of Cologne, Kerpener Str. 62, 50924, Cologne, Germany
| | - Jaroslav Kadlec
- Faculty of Electrical Engineering and Communication, Brno University of Technology, Technicka 3058/10, 616 00, Brno, Czech Republic
| | - Zdenka Kuchtova
- Faculty of Electrical Engineering and Communication, Brno University of Technology, Technicka 3058/10, 616 00, Brno, Czech Republic
| | - Steven R Woodcock
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, 4200 Fifth Ave, Pittsburgh, PA, 15260, USA
| | - Bruce A Freeman
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, 4200 Fifth Ave, Pittsburgh, PA, 15260, USA
| | - Lukas Kubala
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Kralovopolska 135, 612 65, Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic
| | - Michaela Pekarova
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Kralovopolska 135, 612 65, Brno, Czech Republic. .,International Clinical Research Center, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic.
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12
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Villacorta L, Gao Z, Schopfer FJ, Freeman BA, Chen YE. Nitro-fatty acids in cardiovascular regulation and diseases: characteristics and molecular mechanisms. Front Biosci (Landmark Ed) 2016; 21:873-89. [PMID: 26709810 DOI: 10.2741/4425] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Electrophilic nitro-fatty acids (NO2-FAs) are endogenously formed by redox reactions of nitric oxide ((.)NO)- and nitrite ((.)NO2)- derived nitrogen dioxide with unsaturated fatty acids. Nitration preferentially occurs on polyunsaturated fatty acids with conjugated dienes under physiological or pathophysiological conditions such as during digestion, metabolism and as adaptive inflammatory processes. Nitro-fatty acids are present in free and esterified forms achieving broad biodistribution in humans and experimental models. Structural, functional and biological characterization of NO2-FAs has revealed clinically relevant protection from inflammatory injury in a number of cardiovascular, renal and metabolic experimental models. NO2-FAs are engaged in posttranslational modifications (PTMs) of a selective redox sensitive pool of proteins and regulate key adaptive signaling pathways involved in cellular homeostasis and inflammatory response. Here, we review and update the biosynthesis, metabolism and signaling actions of NO2-FAs, highlighting their diverse protective roles relevant to the cardiovascular system.
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Affiliation(s)
- Luis Villacorta
- Cardiovascular Center, Department of Internal Medicine, University of Michigan, North Campus Research Complex 26, 2800 Plymouth Road, Ann Arbor, MI 48109,,
| | - Zhen Gao
- Cardiovascular Center, Department of Internal Medicine, University of Michigan, North Campus Research Complex 26, 2800 Plymouth Road, Ann Arbor, MI 48109
| | - Francisco J Schopfer
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, E1343 Thomas E. Starzl Biomedical Science Tower, 200 Lothrop Street, Pittsburgh, PA 15213
| | - Bruce A Freeman
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, E1343 Thomas E. Starzl Biomedical Science Tower, 200 Lothrop Street, Pittsburgh, PA 15213
| | - Y Eugene Chen
- Cardiovascular Center, Department of Internal Medicine, University of Michigan, North Campus Research Complex 26, 2800 Plymouth Road, Ann Arbor, MI 48109
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13
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Ibrahim M, Jang M, Park M, Gobianand K, You S, Yeon SH, Park S, Kim MJ, Lee HJ. Capsaicin inhibits the adipogenic differentiation of bone marrow mesenchymal stem cells by regulating cell proliferation, apoptosis, oxidative and nitrosative stress. Food Funct 2015; 6:2165-78. [DOI: 10.1039/c4fo01069h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Suppression of the maturation of pre-adipocytes into adipocytes and inhibition of the differentiation of mesenchymal stem cells into adipocytes by capsaicin.
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Affiliation(s)
- Muhammed Ibrahim
- Animal Nutritional & Physiology Team
- National Institute of Animal Science
- Jeollabuk-do
- Republic of Korea
- Department of Anatomy
| | - Mi Jang
- Division of Animal Genomics and Bioinformatics
- National Institute of Animal Science
- Rural Development Administration
- Suwon
- Republic of Korea
| | - Mina Park
- Division of Animal Genomics and Bioinformatics
- National Institute of Animal Science
- Rural Development Administration
- Suwon
- Republic of Korea
| | - Kuppannan Gobianand
- Division of Animal Genomics and Bioinformatics
- National Institute of Animal Science
- Rural Development Administration
- Suwon
- Republic of Korea
| | - Seungkwon You
- The Laboratory of Cell Growth and Function Regulation
- Division of Bioscience and Technology
- College of Life and Environmental Sciences
- Korea University
- Seoul 136-701
| | - Sung-Heom Yeon
- Division of Animal Genomics and Bioinformatics
- National Institute of Animal Science
- Rural Development Administration
- Suwon
- Republic of Korea
| | - Sungkwon Park
- Animal Nutritional & Physiology Team
- National Institute of Animal Science
- Jeollabuk-do
- Republic of Korea
| | - Min Ji Kim
- Animal Nutritional & Physiology Team
- National Institute of Animal Science
- Jeollabuk-do
- Republic of Korea
| | - Hyun-Jeong Lee
- Animal Nutritional & Physiology Team
- National Institute of Animal Science
- Jeollabuk-do
- Republic of Korea
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14
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Zheng R, Heck DE, Black AT, Gow A, Laskin DL, Laskin JD. Regulation of keratinocyte expression of stress proteins and antioxidants by the electrophilic nitrofatty acids 9- and 10-nitrooleic acid. Free Radic Biol Med 2014; 67:1-9. [PMID: 24140437 PMCID: PMC4391631 DOI: 10.1016/j.freeradbiomed.2013.10.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 09/15/2013] [Accepted: 10/08/2013] [Indexed: 10/26/2022]
Abstract
Nitric oxide and various by-products including nitrite contribute to tissue injury by forming novel intermediates via redox-mediated nitration reactions. Nitration of unsaturated fatty acids generates electrophilic nitrofatty acids such as 9-nitrooleic acid (9-NO) and 10-nitrooleic acid (10-NO), which are known to initiate intracellular signaling pathways. In these studies, we characterized nitrofatty acid-induced signaling and stress protein expression in mouse keratinocytes. Treatment of keratinocytes with 5-25μM 9-NO or 10-NO for 6h upregulated mRNA expression of heat shock proteins (hsp's) 27 and 70; primary antioxidants heme oxygenase-1 (HO-1) and catalase; secondary antioxidants glutathione S-transferase (GST) A1/2, GSTA3, and GSTA4; and Cox-2, a key enzyme in prostaglandin biosynthesis. The greatest responses were evident with HO-1, hsp27, and hsp70. In keratinocytes, 9-NO activated JNK and p38 MAP kinases. JNK inhibition suppressed 9-NO-induced HO-1, hsp27, and hsp70 mRNA and protein expression, whereas p38 MAP kinase inhibition suppressed HO-1. In contrast, inhibition of constitutive expression of Erk1/2 suppressed only hsp70, indicating that 9-NO modulates expression of stress proteins by distinct mechanisms. 9-NO and 10-NO also upregulated expression of caveolin-1, the major structural component of caveolae. Western blot analysis of caveolar membrane fractions isolated by sucrose density centrifugation revealed that HO-1, hsp27, and hsp70 were localized within caveolae after nitrofatty acid treatment of keratinocytes, suggesting a link between induction of stress response proteins and caveolin-1 expression. These data indicate that nitrofatty acids are effective signaling molecules in keratinocytes. Moreover, caveolae seem to be important in the localization of stress proteins in response to nitrofatty acids.
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Affiliation(s)
- Ruijin Zheng
- Pharmacology & Toxicology and Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Diane E Heck
- Environmental Health Science, New York Medical College, Valhalla, NY 10595, USA
| | - Adrienne T Black
- Pharmacology & Toxicology and Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Andrew Gow
- Pharmacology & Toxicology and Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Debra L Laskin
- Pharmacology & Toxicology and Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Jeffrey D Laskin
- Environmental & Occupational Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA.
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15
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Vitturi DA, Chen CS, Woodcock SR, Salvatore SR, Bonacci G, Koenitzer JR, Stewart NA, Wakabayashi N, Kensler TW, Freeman BA, Schopfer FJ. Modulation of nitro-fatty acid signaling: prostaglandin reductase-1 is a nitroalkene reductase. J Biol Chem 2013; 288:25626-25637. [PMID: 23878198 DOI: 10.1074/jbc.m113.486282] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Inflammation, characterized by the activation of both resident and infiltrated immune cells, is accompanied by increased production of oxidizing and nitrating species. Nitrogen dioxide, the proximal nitrating species formed under these conditions, reacts with unsaturated fatty acids to yield nitroalkene derivatives. These electrophilic products modulate protein function via post-translational modification of susceptible nucleophilic amino acids. Nitroalkenes react with Keap1 to instigate Nrf2 signaling, activate heat shock response gene expression, and inhibit NF-κB-mediated signaling, inducing net anti-inflammatory and tissue-protective metabolic responses. We report the purification and characterization of a NADPH-dependent liver enzyme that reduces the nitroalkene moiety of nitro-oleic acid, yielding the inactive product nitro-stearic acid. Prostaglandin reductase-1 (PtGR-1) was identified as a nitroalkene reductase by protein purification and proteomic studies. Kinetic measurements, inhibition studies, immunological and molecular biology approaches as well as clinical analyses confirmed this identification. Overexpression of PtGR-1 in HEK293T cells promoted nitroalkene metabolism to inactive nitroalkanes, an effect that abrogated the Nrf2-dependent induction of heme oxygenase-1 expression by nitro-oleic acid. These results situate PtGR-1 as a critical modulator of both the steady state levels and signaling activities of fatty acid nitroalkenes in vivo.
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Affiliation(s)
| | - Chen-Shan Chen
- From the Department of Pharmacology and Chemical Biology
| | | | | | | | | | - Nicolas A Stewart
- Biomedical Mass Spectrometry Center. University of Pittsburgh, Pittsburgh, Pennsylvania 15261
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16
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Hypoxia mediated expression of stem cell markers in VHL-associated hemangioblastomas. Biochem Biophys Res Commun 2013; 438:71-7. [PMID: 23872148 DOI: 10.1016/j.bbrc.2013.07.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 07/09/2013] [Indexed: 11/24/2022]
Abstract
Hemangioblastomas of the retina, central nervous system, and kidney are observed in patients with mutations in the von Hippel-Lindau (VHL) tumor suppressor gene. Mutations in the VHL lead to constitutive activation of hypoxia-inducible-factor (HIF) pathway. HIF-mediated expression of pro-angiogenic genes causes extensive pathological neovascularization in hemangioblastomas. A number of studies have shown coexistence of pro-angiogenic and stem cell markers in 'tumorlet-like stromal cells' in the retinal and optic nerve hemangioblastomas, leading to suggestions that hemangioblastomas originate from developmentally arrested stem cells or embryonic progenitors. Since recent studies have shown that the HIF pathway also plays a role in the maintenance/de-differentiation of normal and cancerous stem cells, we evaluated the role of the HIF pathway in the expression of stem cell markers in VHL-/- renal cell carcinoma cells under normoxia or VHL+/+ retinal pigment epithelial cells under hypoxia. Here we show that the expression of stem cell markers in hemangioblastomas is due to activation of the HIF pathway. Further, we show that honokiol, digoxin, and doxorubicin, three recently identified HIF inhibitors from natural sources, blocks the expression of stem cell markers. Our results show the mechanism for the cytological origin of neoplastic stromal cells in hemangioblastomas, and suggest that inhibition of the HIF pathway is an attractive strategy for the treatment of hemangioblastomas.
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Villacorta L, Chang L, Salvatore SR, Ichikawa T, Zhang J, Petrovic-Djergovic D, Jia L, Carlsen H, Schopfer FJ, Freeman BA, Chen YE. Electrophilic nitro-fatty acids inhibit vascular inflammation by disrupting LPS-dependent TLR4 signalling in lipid rafts. Cardiovasc Res 2013; 98:116-24. [PMID: 23334216 DOI: 10.1093/cvr/cvt002] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
AIMS Electrophilic fatty acid nitroalkene derivatives, products of unsaturated fatty acid nitration, exert long-term cardiovascular protection in experimental models of metabolic and cardiovascular diseases. The goal of this study is to examine the effects of nitro-fatty acids in the regulation of upstream signalling events in nuclear factor-κB (NF-κB) activation and determine whether low-dose acute administration of nitro-fatty acids reduces vascular inflammation in vivo. METHODS AND RESULTS Using NF-κB-luciferase transgenic mice, it was determined that pre-emptive treatment with nitro-oleic acid (OA-NO2), but not oleic acid (OA) inhibits lipopolysaccharide (LPS)-induced NF-κB activation both in vivo and in isolated macrophages. Acute intravenous administration of OA-NO2 was equally effective to inhibit leukocyte recruitment to the vascular endothelium assessed by intravital microscopy and significantly reduces aortic expression of adhesion molecules. An acute treatment with OA-NO2 in vivo yielding nanomolar concentrations in plasma, is sufficient to inhibit LPS-induced Toll-like receptor 4 (TLR4)-induced cell surface expression in leukocytes and NF-κB activation. In vitro experiments reveal that OA-NO2 suppresses LPS-induced TLR4 signalling, inhibitor of κB (IκBα) phosphorylation and ubiquitination, phosphorylation of the IκB kinase (IKK), impairing the recruitment of the TLR4 and TNF receptor associated factor 6 (TRAF6) to the lipid rafts compartments. CONCLUSION These studies demonstrate that acute administration of nitro-fatty acids is effective to reduce vascular inflammation in vivo. These findings reveal a direct role of nitro-fatty acids in the disruption of the TLR4 signalling complex in lipid rafts, upstream events of the NF-κB pathway, leading to resolution of pro-inflammatory activation of NF-κB in the vasculature.
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Affiliation(s)
- Luis Villacorta
- Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center, North Campus Research Complex Building 26 Room 355S, 2800 Plymouth Road, Ann Arbor, MI, USA.
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