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Rudraraju M, Narayanan SP, Somanath PR. Regulation of blood-retinal barrier cell-junctions in diabetic retinopathy. Pharmacol Res 2020; 161:105115. [PMID: 32750417 PMCID: PMC7755666 DOI: 10.1016/j.phrs.2020.105115] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/22/2020] [Accepted: 07/27/2020] [Indexed: 12/15/2022]
Abstract
Loss of the blood-retinal barrier (BRB) integrity and subsequent damage to the neurovascular unit in the retina are the underlying reasons for diabetic retinopathy (DR). Damage to BRB eventually leads to severe visual impairment in the absence of prompt intervention. Diabetic macular edema and proliferative DR are the advanced stages of the disease where BRB integrity is altered. Primary mechanisms contributing to BRB dysfunction include loss of cell-cell barrier junctions, vascular endothelial growth factor, advanced glycation end products-induced damage, and oxidative stress. Although much is known about the involvement of adherens and tight-junction proteins in the regulation of vascular permeability in various diseases, there is a significant gap in our knowledge on the junctional proteins expressed in the BRB and how BRB function is modulated in the diabetic retina. In this review article, we present our current understanding of the molecular composition of BRB, the changes in the BRB junctional protein turnover in DR, and how BRB functional modulation affects vascular permeability and macular edema in the diabetic retina.
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Affiliation(s)
- Madhuri Rudraraju
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, GA 30912, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA 30912, United States
| | - S Priya Narayanan
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, GA 30912, United States; Vascular Biology Center, Augusta University, Augusta, GA 30912, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA 30912, United States
| | - Payaningal R Somanath
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, GA 30912, United States; Vascular Biology Center, Augusta University, Augusta, GA 30912, United States; Department of Medicine, Augusta University, Augusta, GA 30912, United States.
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2
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Liu X, Wilson MW, Liu K, Lee P, Yeomans L, Hagen SE, Lin CM, Wen B, Sun D, White AD, Showalter HD, Antonetti DA. Synthesis and structure-activity relationships of thieno[2,3-d]pyrimidines as atypical protein kinase C inhibitors to control retinal vascular permeability and cytokine-induced edema. Bioorg Med Chem 2020; 28:115480. [PMID: 32327351 DOI: 10.1016/j.bmc.2020.115480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 03/25/2020] [Accepted: 03/27/2020] [Indexed: 11/28/2022]
Abstract
Studies demonstrate that small molecule targeting of atypical protein kinase C (aPKC) may provide an effective means to control vascular permeability, prevent edema, and reduce inflammation providing novel and important alternatives to anti-VEGF therapies for certain blinding eye diseases. Based on a literature tricyclic thieno[2,3-d]pyrimidine lead (1), an ATP-competitive inhibitor of the aPKC iota (ι) and aPKC zeta (ζ) isoforms, we have synthesized a small series of compounds in 1-2 steps from a readily available chloro intermediate. A single pyridine congener was also made using 2D NMR to assign regiochemistry. Within the parent pyrimidine series, a range of potencies was observed against aPKCζ whereas the pyridine congener was inactive. Selected compounds were also tested for their effect toward VEGF-induced permeability in BREC cells. The most potent of these (7l) was further assayed against the aPKCι isoform and showed a favorable selectivity profile against a panel of 31 kinases, including kinases from the AGC superfamily, with a focus on PKC isoforms and kinases previously shown to affect permeability. Further testing of 7l in a luciferase assay in HEK293 cells showed an ability to prevent TNF-α induced NFκB activation while not having any effect on cell survival. Intravitreal administration of 7l to the eye yielded a complete reduction in permeability in a test to determine whether the compound could block VEGF- and TNFα-induced permeability across the retinal vasculature in a rat model. The compound in mice displayed good microsomal stability and in plasma moderate exposure (AUC and Cmax), low clearance, a long half-life and high oral bioavailability. With IV dosing, higher levels were observed in the brain and eye relative to plasma, with highest levels in the eye by either IV or PO dosing. With a slow oral absorption profile, 7l accumulates in the eye to maintain a high concentration after dosing with higher levels than in plasma. Compound 7l may represent a class of aPKC inhibitors for further investigation.
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Affiliation(s)
- Xuwen Liu
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Michael W Wilson
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, USA; Vahlteich Medicinal Chemistry Core, University of Michigan, Ann Arbor, MI 48109, USA
| | - Kun Liu
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, USA; Vahlteich Medicinal Chemistry Core, University of Michigan, Ann Arbor, MI 48109, USA
| | - Pil Lee
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, USA; Vahlteich Medicinal Chemistry Core, University of Michigan, Ann Arbor, MI 48109, USA
| | - Larisa Yeomans
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Susan E Hagen
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, USA; Vahlteich Medicinal Chemistry Core, University of Michigan, Ann Arbor, MI 48109, USA
| | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Bo Wen
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA
| | - Duxin Sun
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA
| | - Andrew D White
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, USA; Vahlteich Medicinal Chemistry Core, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hollis D Showalter
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA.
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3
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Downregulation of S1P Lyase Improves Barrier Function in Human Cerebral Microvascular Endothelial Cells Following an Inflammatory Challenge. Int J Mol Sci 2020; 21:ijms21041240. [PMID: 32069843 PMCID: PMC7072972 DOI: 10.3390/ijms21041240] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/30/2020] [Accepted: 02/10/2020] [Indexed: 01/08/2023] Open
Abstract
Sphingosine 1-phosphate (S1P) is a key bioactive lipid that regulates a myriad of physiological and pathophysiological processes, including endothelial barrier function, vascular tone, vascular inflammation, and angiogenesis. Various S1P receptor subtypes have been suggested to be involved in the regulation of these processes, whereas the contribution of intracellular S1P (iS1P) through intracellular targets is little explored. In this study, we used the human cerebral microvascular endothelial cell line HCMEC/D3 to stably downregulate the S1P lyase (SPL-kd) and evaluate the consequences on endothelial barrier function and on the molecular factors that regulate barrier tightness under normal and inflammatory conditions. The results show that in SPL-kd cells, transendothelial electrical resistance, as a measure of barrier integrity, was regulated in a dual manner. SPL-kd cells had a delayed barrier build up, a shorter interval of a stable barrier, and, thereafter, a continuous breakdown. Contrariwise, a protection was seen from the rapid proinflammatory cytokine-mediated barrier breakdown. On the molecular level, SPL-kd caused an increased basal protein expression of the adherens junction molecules PECAM-1, VE-cadherin, and β-catenin, increased activity of the signaling kinases protein kinase C, AMP-dependent kinase, and p38-MAPK, but reduced protein expression of the transcription factor c-Jun. However, the only factors that were significantly reduced in TNFα/SPL-kd compared to TNFα/control cells, which could explain the observed protection, were VCAM-1, IL-6, MCP-1, and c-Jun. Furthermore, lipid profiling revealed that dihydro-S1P and S1P were strongly enhanced in TNFα-treated SPL-kd cells. In summary, our data suggest that SPL inhibition is a valid approach to dampenan inflammatory response and augmente barrier integrity during an inflammatory challenge.
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Raghavan S, Singh NK, Gali S, Mani AM, Rao GN. Protein Kinase Cθ Via Activating Transcription Factor 2-Mediated CD36 Expression and Foam Cell Formation of Ly6C hi Cells Contributes to Atherosclerosis. Circulation 2019; 138:2395-2412. [PMID: 29991487 DOI: 10.1161/circulationaha.118.034083] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Although the role of thrombin in atherothrombosis is well studied, its role in the pathogenesis of diet-induced atherosclerosis is not known. METHODS Using a mouse model of diet-induced atherosclerosis and molecular biological approaches, here we have explored the role of thrombin and its G protein-coupled receptor signaling in diet-induced atherosclerosis. RESULTS In exploring the role of G protein-coupled receptor signaling in atherogenesis, we found that thrombin triggers foam cell formation via inducing CD36 expression, and these events require Par1-mediated Gα12-Pyk2-Gab1-protein kinase C (PKC)θ-dependent ATF2 activation. Genetic deletion of PKCθ in apolipoprotein E (ApoE)-/- mice reduced Western diet-induced plaque formation. Furthermore, thrombin induced Pyk2, Gab1, PKCθ, and ATF2 phosphorylation, CD36 expression, and foam cell formation in peritoneal macrophages of ApoE-/- mice. In contrast, thrombin only stimulated Pyk2 and Gab1 but not ATF2 phosphorylation or its target gene CD36 expression in the peritoneal macrophages of ApoE-/-:PKCθ-/- mice, and it had no effect on foam cell formation. In addition, the aortic root cross-sections of Western diet-fed ApoE-/- mice showed increased Pyk2, Gab1, PKCθ, and ATF2 phosphorylation and CD36 expression as compared with ApoE-/-:PKCθ-/- mice. Furthermore, although the monocytes from peripheral blood and the aorta of Western diet-fed ApoE-/- mice were found to contain more of Ly6Chi cells than Ly6Clo cells, the monocytes from Western diet-fed ApoE-/-:PKCθ-/- mice were found to contain more Ly6Clo cells than Ly6Chi cells. It is interesting to note that the Ly6Chi cells showed higher CD36 expression with enhanced capacity to form foam cells as compared with Ly6Clo cells. CONCLUSIONS These findings reveal for the first time that thrombin-mediated Par1-Gα12 signaling via targeting Pyk2-Gab1-PKCθ-ATF2-dependent CD36 expression might be playing a crucial role in diet-induced atherogenesis.
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Affiliation(s)
| | - Nikhlesh K Singh
- Department of Physiology, University of Tennessee Health Science Center, Memphis
| | - Sivaiah Gali
- Department of Physiology, University of Tennessee Health Science Center, Memphis
| | - Arul M Mani
- Department of Physiology, University of Tennessee Health Science Center, Memphis
| | - Gadiparthi N Rao
- Department of Physiology, University of Tennessee Health Science Center, Memphis
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5
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Lin CM, Titchenell PM, Keil JM, Garcia-Ocaña A, Bolinger MT, Abcouwer SF, Antonetti DA. Inhibition of Atypical Protein Kinase C Reduces Inflammation-Induced Retinal Vascular Permeability. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 188:2392-2405. [PMID: 30220554 DOI: 10.1016/j.ajpath.2018.06.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 06/01/2018] [Accepted: 06/13/2018] [Indexed: 01/14/2023]
Abstract
Changes in permeability of retinal blood vessels contribute to macular edema and the pathophysiology of numerous ocular diseases, including diabetic retinopathy, retinal vein occlusions, and macular degeneration. Vascular endothelial growth factor (VEGF) induces retinal permeability and macular thickening in these diseases. However, inflammatory agents, such as tumor necrosis factor-α (TNF-α), also may drive vascular permeability, specifically in patients unresponsive to anti-VEGF therapy. Recent evidence suggests VEGF and TNF-α induce permeability through distinct mechanisms; however, both require the activation of atypical protein kinase C (aPKC). We provide evidence, using genetic mouse models and therapeutic intervention with small molecules, that inhibition of aPKC prevented or reduced vascular permeability in animal models of retinal inflammation. Expression of a kinase-dead aPKC transgene, driven by a vascular and hematopoietic restricted promoter, reduced retinal vascular permeability in an ischemia-reperfusion model of retinal injury. This effect was recapitulated with a small-molecule inhibitor of aPKC. Expression of the kinase-dead aPKC transgene dramatically reduced the expression of inflammatory factors and blocked the attraction of inflammatory monocytes and granulocytes after ischemic injury. Coinjection of VEGF with TNF-α was sufficient to induce permeability, edema, and retinal inflammation, and treatment with an aPKC inhibitor prevented VEGF/TNF-α-induced permeability. These data suggest that aPKC contributes to inflammation-driven retinal vascular pathology and may be an attractive target for therapeutic intervention.
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Affiliation(s)
- Cheng-Mao Lin
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Paul M Titchenell
- The Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jason M Keil
- Molecular and Behavioral Neuroscience Institute, Department of Human Genetics and Medical Scientist Training Program, University of Michigan, Ann Arbor, Michigan
| | - Adolfo Garcia-Ocaña
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Mark T Bolinger
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Steven F Abcouwer
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - David A Antonetti
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan.
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6
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Amado-Azevedo J, de Menezes RX, van Nieuw Amerongen GP, van Hinsbergh VWM, Hordijk PL. A functional siRNA screen identifies RhoGTPase-associated genes involved in thrombin-induced endothelial permeability. PLoS One 2018; 13:e0201231. [PMID: 30048510 PMCID: PMC6062096 DOI: 10.1371/journal.pone.0201231] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 07/11/2018] [Indexed: 12/18/2022] Open
Abstract
Thrombin and other inflammatory mediators may induce vascular permeability through the disruption of adherens junctions between adjacent endothelial cells. If uncontrolled, hyperpermeability leads to an impaired barrier, fluid leakage and edema, which can contribute to multi-organ failure and death. RhoGTPases control cytoskeletal dynamics, adhesion and migration and are known regulators of endothelial integrity. Knowledge of the precise role of each RhoGTPase, and their associated regulatory and effector genes, in endothelial integrity is incomplete. Using a combination of a RNAi screen with electrical impedance measurements, we quantified the effect of individually silencing 270 Rho-associated genes on the barrier function of thrombin-activated, primary endothelial cells. Known and novel RhoGTPase-associated regulators that modulate the response to thrombin were identified (RTKN, TIAM2, MLC1, ARPC1B, SEPT2, SLC9A3R1, RACGAP1, RAPGEF2, RHOD, PREX1, ARHGEF7, PLXNB2, ARHGAP45, SRGAP2, ARHGEF5). In conclusion, with this siRNA screen, we confirmed the roles of known regulators of endothelial integrity but also identified new, potential key players in thrombin-induced endothelial signaling.
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Affiliation(s)
- Joana Amado-Azevedo
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Renee X. de Menezes
- Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands
| | | | - Victor W. M. van Hinsbergh
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Peter L. Hordijk
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
- * E-mail:
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7
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A positive circuit of VEGF increases Glut-1 expression by increasing HIF-1α gene expression in human retinal endothelial cells. Arch Pharm Res 2017; 40:1433-1442. [DOI: 10.1007/s12272-017-0971-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 10/07/2017] [Indexed: 01/07/2023]
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8
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IP 3 receptor signaling and endothelial barrier function. Cell Mol Life Sci 2017; 74:4189-4207. [PMID: 28803370 DOI: 10.1007/s00018-017-2624-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 07/18/2017] [Accepted: 08/08/2017] [Indexed: 12/14/2022]
Abstract
The endothelium, a monolayer of endothelial cells lining vessel walls, maintains tissue-fluid homeostasis by restricting the passage of the plasma proteins and blood cells into the interstitium. The ion Ca2+, a ubiquitous secondary messenger, initiates signal transduction events in endothelial cells that is critical to control of vascular tone and endothelial permeability. The ion Ca2+ is stored inside the intracellular organelles and released into the cytosol in response to environmental cues. The inositol 1,4,5-trisphosphate (IP3) messenger facilitates Ca2+ release through IP3 receptors which are Ca2+-selective intracellular channels located within the membrane of the endoplasmic reticulum. Binding of IP3 to the IP3Rs initiates assembly of IP3R clusters, a key event responsible for amplification of Ca2+ signals in endothelial cells. This review discusses emerging concepts related to architecture and dynamics of IP3R clusters, and their specific role in propagation of Ca2+ signals in endothelial cells.
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9
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Escue R, Kandasamy K, Parthasarathi K. Thrombin Induces Inositol Trisphosphate-Mediated Spatially Extensive Responses in Lung Microvessels. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:921-935. [PMID: 28188112 DOI: 10.1016/j.ajpath.2016.12.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 12/09/2016] [Accepted: 12/20/2016] [Indexed: 12/20/2022]
Abstract
Activation of plasma membrane receptors initiates compartmentalized second messenger signaling. Whether this compartmentalization facilitates the preferential intercellular diffusion of specific second messengers is unclear. Toward this, the receptor-mediated agonist, thrombin, was instilled into microvessels in a restricted region of isolated blood-perfused mouse lungs. Subsequently, the thrombin-induced increase in endothelial F-actin was determined using confocal fluorescence microscopy. Increased F-actin was evident in microvessels directly treated with thrombin and in those located in adjoining thrombin-free regions. This increase was abrogated by inhibiting inositol trisphosphate-mediated calcium release with Xestospongin C (XeC). XeC also inhibited the thrombin-induced increase in the amplitude of endothelial cytosolic Ca2+ oscillations. Instillation of thrombin and XeC into adjacent restricted regions increased F-actin in microvessels in the thrombin-treated and adjacent regions but not in those in the XeC-treated region. Thus, inositol trisphosphate, and not calcium, diffused interendothelially to the spatially remote thrombin-free microvessels. Thus, activation of plasma membrane receptors increased the ambit of inflammatory responses via a second messenger different from that used by stimuli that induce cell-wide increases in second messengers. Thrombin however failed to induce the spatially extensive response in microvessels of mice lacking endothelial connexin43, suggesting a role for connexin43 gap junctions. Compartmental second messenger signaling and interendothelial communication define the specific second messenger involved in exacerbating proinflammatory responses to receptor-mediated agonists.
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Affiliation(s)
- Rachel Escue
- Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Kathirvel Kandasamy
- Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Kaushik Parthasarathi
- Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee.
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10
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Li C, Miao X, Li F, Wang S, Liu Q, Wang Y, Sun J. Oxidative Stress-Related Mechanisms and Antioxidant Therapy in Diabetic Retinopathy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:9702820. [PMID: 28265339 PMCID: PMC5317113 DOI: 10.1155/2017/9702820] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/27/2016] [Accepted: 12/27/2016] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes and is the leading cause of blindness in young adults. Oxidative stress has been implicated as a critical cause of DR. Metabolic abnormalities induced by high-glucose levels are involved in the development of DR and appear to be influenced by oxidative stress. The imbalance between reactive oxygen species (ROS) production and the antioxidant defense system activates several oxidative stress-related mechanisms that promote the pathogenesis of DR. The damage caused by oxidative stress persists for a considerable time, even after the blood glucose concentration has returned to a normal level. Animal experiments have proved that the use of antioxidants is a beneficial therapeutic strategy for the treatment of DR, but more data are required from clinical trials. The aims of this review are to highlight the improvements to our understanding of the oxidative stress-related mechanisms underlying the development of DR and provide a summary of the main antioxidant therapy strategies used to treat the disease.
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Affiliation(s)
- Cheng Li
- The First Hospital of Jilin University, Changchun 130021, China
| | - Xiao Miao
- The Second Hospital of Jilin University, Changchun 130041, China
| | - Fengsheng Li
- General Hospital of the PLA Rocket Force, Beijing 100088, China
| | - Shudong Wang
- The First Hospital of Jilin University, Changchun 130021, China
| | - Quan Liu
- The First Hospital of Jilin University, Changchun 130021, China
| | - Yonggang Wang
- The First Hospital of Jilin University, Changchun 130021, China
| | - Jian Sun
- The First Hospital of Jilin University, Changchun 130021, China
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11
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Zhang J, Yang GM, Zhu Y, Peng XY, Li T, Liu LM. Role of connexin 43 in vascular hyperpermeability and relationship to Rock1-MLC20 pathway in septic rats. Am J Physiol Lung Cell Mol Physiol 2015; 309:L1323-32. [PMID: 26342084 DOI: 10.1152/ajplung.00016.2015] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 08/31/2015] [Indexed: 12/27/2022] Open
Abstract
Connexin (Cx)43 has been shown to participate in several cardiovascular diseases. Increased vascular permeability is a common and severe complication in sepsis or septic shock. Whether or not Cx43 takes part in the regulation of vascular permeability in severe sepsis is not known, and the underlying mechanism has not been described. With cecal ligation and puncture-induced sepsis in rats and lipopolysaccharide (LPS)-treated vascular endothelial cells (VECs) from pulmonary veins, the role of Cx43 in increased vascular permeability and its relationship to the RhoA/Rock1 pathway were studied. It was shown that vascular permeability in the lungs, kidneys, and mesentery in sepsis rats and LPS-stimulated monolayer pulmonary vein VECs was significantly increased and positively correlated with the increased expression of Cx43 and Rock1 in these organs and cultured pulmonary vein VECs. The connexin inhibitor carbenoxolone (10 mg/kg iv) and the Rock1 inhibitor Y-27632 (2 mg/kg iv) alleviated the vascular leakage of lung, mesentery, and kidney in sepsis rats. Overexpressed Cx43 increased the phosphorylation of 20-kDa myosin light chain (MLC20) and the expression of Rock1 and increased the vascular permeability and decreased the transendothelial electrical resistance of pulmonary vein VECs. Cx43 RNA interference decreased the phosphorylation of MLC20 and the expression of Rock1 and decreased LPS-stimulated hyperpermeability of cultured pulmonary vein VECs. The Rock1 inhibitor Y-27632 alleviated LPS- and overexpressed Cx43-induced hyperpermeability of monolayer pulmonary vein VECs. This report shows that Cx43 participates in the regulation of vascular permeability in sepsis and that the mechanism is related to the Rock1-MLC20 phosphorylation pathway.
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Affiliation(s)
- Jie Zhang
- State Key Laboratory of Trauma, Burns, and Combined Injury, Second Department of Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Guang-Ming Yang
- State Key Laboratory of Trauma, Burns, and Combined Injury, Second Department of Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Yu Zhu
- State Key Laboratory of Trauma, Burns, and Combined Injury, Second Department of Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Xiao-Yong Peng
- State Key Laboratory of Trauma, Burns, and Combined Injury, Second Department of Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Tao Li
- State Key Laboratory of Trauma, Burns, and Combined Injury, Second Department of Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Liang-Ming Liu
- State Key Laboratory of Trauma, Burns, and Combined Injury, Second Department of Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, People's Republic of China
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12
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Sukriti S, Tauseef M, Yazbeck P, Mehta D. Mechanisms regulating endothelial permeability. Pulm Circ 2015; 4:535-51. [PMID: 25610592 DOI: 10.1086/677356] [Citation(s) in RCA: 196] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 03/03/2014] [Indexed: 12/26/2022] Open
Abstract
The endothelial monolayer partitioning underlying tissue from blood components in the vessel wall maintains tissue fluid balance and host defense through dynamically opening intercellular junctions. Edemagenic agonists disrupt endothelial barrier function by signaling the opening of the intercellular junctions leading to the formation of protein-rich edema in the interstitial tissue, a hallmark of tissue inflammation that, if left untreated, causes fatal diseases, such as acute respiratory distress syndrome. In this review, we discuss how intercellular junctions are maintained under normal conditions and after stimulation of endothelium with edemagenic agonists. We have focused on reviewing the new concepts dealing with the alteration of adherens junctions after inflammatory stimulus.
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Affiliation(s)
- Sukriti Sukriti
- Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois, USA
| | - Mohammad Tauseef
- Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois, USA
| | - Pascal Yazbeck
- Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois, USA
| | - Dolly Mehta
- Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois, USA
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13
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Mehta D, Ravindran K, Kuebler WM. Novel regulators of endothelial barrier function. Am J Physiol Lung Cell Mol Physiol 2014; 307:L924-35. [PMID: 25381026 PMCID: PMC4269690 DOI: 10.1152/ajplung.00318.2014] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 11/05/2014] [Indexed: 12/15/2022] Open
Abstract
Endothelial barrier function is an essential and tightly regulated process that ensures proper compartmentalization of the vascular and interstitial space, while allowing for the diffusive exchange of small molecules and the controlled trafficking of macromolecules and immune cells. Failure to control endothelial barrier integrity results in excessive leakage of fluid and proteins from the vasculature that can rapidly become fatal in scenarios such as sepsis or the acute respiratory distress syndrome. Here, we highlight recent advances in our understanding on the regulation of endothelial permeability, with a specific focus on the endothelial glycocalyx and endothelial scaffolds, regulatory intracellular signaling cascades, as well as triggers and mediators that either disrupt or enhance endothelial barrier integrity, and provide our perspective as to areas of seeming controversy and knowledge gaps, respectively.
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Affiliation(s)
- Dolly Mehta
- Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois;
| | - Krishnan Ravindran
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
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Barvitenko NN, Aslam M, Filosa J, Matteucci E, Nikinmaa M, Pantaleo A, Saldanha C, Baskurt OK. Tissue oxygen demand in regulation of the behavior of the cells in the vasculature. Microcirculation 2014; 20:484-501. [PMID: 23441854 DOI: 10.1111/micc.12052] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 02/19/2013] [Indexed: 12/20/2022]
Abstract
The control of arteriolar diameters in microvasculature has been in the focus of studies on mechanisms matching oxygen demand and supply at the tissue level. Functionally, important vascular elements include EC, VSMC, and RBC. Integration of these different cell types into functional units aimed at matching tissue oxygen supply with tissue oxygen demand is only achieved when all these cells can respond to the signals of tissue oxygen demand. Many vasoactive agents that serve as signals of tissue oxygen demand have their receptors on all these types of cells (VSMC, EC, and RBC) implying that there can be a coordinated regulation of their behavior by the tissue oxygen demand. Such functions of RBC as oxygen carrying by Hb, rheology, and release of vasoactive agents are considered. Several common extra- and intracellular signaling pathways that link tissue oxygen demand with control of VSMC contractility, EC permeability, and RBC functioning are discussed.
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15
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Mittal M, Siddiqui MR, Tran K, Reddy SP, Malik AB. Reactive oxygen species in inflammation and tissue injury. Antioxid Redox Signal 2014; 20:1126-67. [PMID: 23991888 PMCID: PMC3929010 DOI: 10.1089/ars.2012.5149] [Citation(s) in RCA: 2672] [Impact Index Per Article: 267.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Abstract Reactive oxygen species (ROS) are key signaling molecules that play an important role in the progression of inflammatory disorders. An enhanced ROS generation by polymorphonuclear neutrophils (PMNs) at the site of inflammation causes endothelial dysfunction and tissue injury. The vascular endothelium plays an important role in passage of macromolecules and inflammatory cells from the blood to tissue. Under the inflammatory conditions, oxidative stress produced by PMNs leads to the opening of inter-endothelial junctions and promotes the migration of inflammatory cells across the endothelial barrier. The migrated inflammatory cells not only help in the clearance of pathogens and foreign particles but also lead to tissue injury. The current review compiles the past and current research in the area of inflammation with particular emphasis on oxidative stress-mediated signaling mechanisms that are involved in inflammation and tissue injury.
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Affiliation(s)
- Manish Mittal
- 1 Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, Illinois
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16
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Song HB, Jun HO, Kim JH, Yu YS, Kim KW, Kim JH. Suppression of protein kinase C-ζ attenuates vascular leakage via prevention of tight junction protein decrease in diabetic retinopathy. Biochem Biophys Res Commun 2014; 444:63-8. [DOI: 10.1016/j.bbrc.2014.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 01/07/2014] [Indexed: 01/17/2023]
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17
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Ong SP, Ng ML, Chu JJH. Differential regulation of angiopoietin 1 and angiopoietin 2 during dengue virus infection of human umbilical vein endothelial cells: implications for endothelial hyperpermeability. Med Microbiol Immunol 2013; 202:437-52. [DOI: 10.1007/s00430-013-0310-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 08/19/2013] [Indexed: 12/17/2022]
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18
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Xu H, Song J, Gao X, Xu Z, Xu X, Xia Y, Dai Y. Paeoniflorin attenuates lipopolysaccharide-induced permeability of endothelial cells: involvements of F-actin expression and phosphorylations of PI3K/Akt and PKC. Inflammation 2013; 36:216-25. [PMID: 23053726 DOI: 10.1007/s10753-012-9537-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This study aimed to investigate the effects of paeoniflorin, the main active ingredient of the medicinal plant Paeonia lactiflora Pall., on the permeability of endothelial cells induced by lipopolysaccharide (LPS) and the underlying mechanisms. Human umbilical vein endothelial cells (HUVECs) were stimulated by LPS. Extravasated FITC-dextran reflecting permeability was assessed by multimode microplate reader, and the migration of bis-carboxyethyl-carboxyfluorescein acetoxy-methyl-labeled human acute monocytic leukemia cell line and leukemia cell line cells through HUVECs were analyzed by fluorescence microscopy. The phosphorylations of phosphatidylinositol 3-kinase (PI3K)/Akt, protein kinase C (PKC), and cofilin in HUVECs were assessed by western blotting, and the F-actin level was detected by laser scanning confocal microscopy. After LPS stimulation, inflammatory endothelial cells exhibited significantly increased permeability. Paeoniflorin (10, 30, and 100 μM) inhibited dextran extravasation and leukocyte migration through HUVECs induced by LPS in a concentration-dependent manner. Moreover, paeoniflorin was able to suppress the phosphorylations of PI3K/Akt, PKC, and cofilin, as well as F-actin reorganization in HUVECs induced by LPS. These findings revealed that paeoniflorin partly blocked LPS-induced endothelium permeability, supporting a new explanation for its anti-inflammatory effects.
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Affiliation(s)
- Huan Xu
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing, 210009, China
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19
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Titchenell PM, Antonetti DA. Using the past to inform the future: anti-VEGF therapy as a road map to develop novel therapies for diabetic retinopathy. Diabetes 2013; 62:1808-15. [PMID: 23704522 PMCID: PMC3661651 DOI: 10.2337/db12-1744] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Therapies targeting vascular endothelial growth factor (VEGF) are revolutionizing the treatment of diabetic retinopathy (DR) and diabetic macular edema (DME). In August 2012, ranibizumab, a monoclonal antibody fragment targeting VEGF designed for ocular use, became the first and only U.S. Food and Drug Administration-approved medical therapy for DME and the first approved treatment in over 25 years. This approval was based on strong preclinical data followed by numerous clinical trials that demonstrate an essential role of VEGF in vascular permeability and angiogenesis in both normal physiology and disease pathology. In this Perspective, we will examine the experimental studies and scientific data that aided in the success of the development of therapies targeting VEGF and consider how these approaches may inform the development of future therapeutics for diabetic eye disease. A multipoint model is proposed, based on well-established drug development principles, with the goal of improving the success of clinical drug development. This model suggests that to provide a validated preclinical target, investigators should demonstrate the following: the role of the target in normal physiology, a causal link to disease pathogenesis, correlation to human disease, and the ability to elicit clinically relevant improvements of disease phenotypes in animal models with multiple, chemically diverse interventions. This model will provide a framework to validate the current preclinical targets and identify novel targets to improve drug development success for DR.
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Affiliation(s)
- Paul M. Titchenell
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, Pennsylvania
| | - David A. Antonetti
- Departments of Ophthalmology and Visual Sciences and Molecular and Integrative Physiology, The University of Michigan, Ann Arbor, Michigan
- Corresponding author: David A. Antonetti,
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20
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Adyshev DM, Dudek SM, Moldobaeva N, Kim KM, Ma SF, Kasa A, Garcia JGN, Verin AD. Ezrin/radixin/moesin proteins differentially regulate endothelial hyperpermeability after thrombin. Am J Physiol Lung Cell Mol Physiol 2013; 305:L240-55. [PMID: 23729486 DOI: 10.1152/ajplung.00355.2012] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Endothelial cell (EC) barrier disruption induced by inflammatory agonists such as thrombin leads to potentially lethal physiological dysfunction such as alveolar flooding, hypoxemia, and pulmonary edema. Thrombin stimulates paracellular gap and F-actin stress fiber formation, triggers actomyosin contraction, and alters EC permeability through multiple mechanisms that include protein kinase C (PKC) activation. We previously have shown that the ezrin, radixin, and moesin (ERM) actin-binding proteins differentially participate in sphingosine-1 phosphate-induced EC barrier enhancement. Phosphorylation of a conserved threonine residue in the COOH-terminus of ERM proteins causes conformational changes in ERM to unmask binding sites and is considered a hallmark of ERM activation. In the present study we test the hypothesis that ERM proteins are phosphorylated on this critical threonine residue by thrombin-induced signaling events and explore the role of the ERM family in modulating thrombin-induced cytoskeletal rearrangement and EC barrier function. Thrombin promotes ERM phosphorylation at this threonine residue (ezrin Thr567, radixin Thr564, moesin Thr558) in a PKC-dependent fashion and induces translocation of phosphorylated ERM to the EC periphery. Thrombin-induced ERM threonine phosphorylation is likely synergistically mediated by protease-activated receptors PAR1 and PAR2. Using the siRNA approach, depletion of either moesin alone or of all three ERM proteins significantly attenuates thrombin-induced increase in EC barrier permeability (transendothelial electrical resistance), cytoskeletal rearrangements, paracellular gap formation, and accumulation of phospho-myosin light chain. In contrast, radixin depletion exerts opposing effects on these indexes. These data suggest that ERM proteins play important differential roles in the thrombin-induced modulation of EC permeability, with moesin promoting barrier dysfunction and radixin opposing it.
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Affiliation(s)
- Djanybek M Adyshev
- Institute for Personalized Respiratory Medicine, Department of Medicine, Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, COMRB 3154, MC 719, 909 S. Wolcott Ave., Chicago, IL 60612, USA.
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21
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Usatyuk PV, Kotha SR, Parinandi NL, Natarajan V. Phospholipase D signaling mediates reactive oxygen species-induced lung endothelial barrier dysfunction. Pulm Circ 2013; 3:108-15. [PMID: 23662182 PMCID: PMC3641713 DOI: 10.4103/2045-8932.109925] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Reactive oxygen species (ROS) have emerged as critical players in the pathophysiology of pulmonary disorders and diseases. Earlier, we have demonstrated that ROS stimulate lung endothelial cell (EC) phospholipase D (PLD) that generates phosphatidic acid (PA), a second messenger involved in signal transduction. In the current study, we investigated the role of PLD signaling in the ROS-induced lung vascular EC barrier dysfunction. Our results demonstrated that hydrogen peroxide (H2O2), a typical physiological ROS, induced PLD activation and altered the barrier function in bovine pulmonary artery ECs (BPAECs). 1-Butanol, the quencher of PLD, generated PA leading to the formation of physiologically inactive phosphatidyl butanol but not its biologically inactive analog, 2-butanol, blocked the H2O2-mediated barrier dysfunction. Furthermore, cell permeable C2 ceramide, an inhibitor of PLD but not the C2 dihydroceramide, attenuated the H2O2-induced PLD activation and enhancement of paracellular permeability of Evans blue conjugated albumin across the BPAEC monolayers. In addition, transfection of BPAECs with adenoviral constructs of hPLD1 and mPLD2 mutants attenuated the H2O2-induced barrier dysfunction, cytoskeletal reorganization and distribution of focal adhesion proteins. For the first time, this study demonstrated that the PLD-generated intracellular bioactive lipid signal mediator, PA, played a critical role in the ROS-induced barrier dysfunction in lung vascular ECs. This study also underscores the importance of PLD signaling in vascular leak and associated tissue injury in the etiology of lung diseases among critically ill patients encountering oxygen toxicity and excess ROS production during ventilator-assisted breathing.
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Affiliation(s)
- Peter V Usatyuk
- Department of Pharmacology and Institute for Personalized Respiratory Medicine, University of Illinois, Chicago, IL, USA
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22
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Titchenell PM, Showalter HD, Pons JF, Barber AJ, Jin Y, Antonetti DA. Synthesis and structure-activity relationships of 2-amino-3-carboxy-4-phenylthiophenes as novel atypical protein kinase C inhibitors. Bioorg Med Chem Lett 2013; 23:3034-8. [PMID: 23566515 DOI: 10.1016/j.bmcl.2013.03.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 02/27/2013] [Accepted: 03/04/2013] [Indexed: 12/19/2022]
Abstract
Recent evidence suggests atypical protein kinase C (aPKC) isoforms are required for both TNF- and VEGF-induced breakdown of the blood-retinal barrier (BRB) and endothelial permeability to 70kDa dextran or albumin. A chemical library screen revealed a series of novel small molecule phenylthiophene based inhibitors of aPKC isoforms that effectively block permeability in cell culture and in vivo. In an effort to further elucidate the structural requirements of this series of inhibitors, we detail in this study a structure-activity relationship (SAR) built on screening hit 1, which expands on our initial pharmacophore model. The biological activity of our analogues was evaluated in models of bona fide aPKC-dependent signaling including NFκB driven-gene transcription as a marker for an inflammatory response and VEGF/TNF-induced vascular endothelial permeability. The EC50 for the most efficacious inhibitors (6, 32) was in the low nanomolar range in these two cellular assays. Our study demonstrates the key structural elements that confer inhibitory activity and highlights the requirement for electron-donating moieties off the C-4 aryl moiety of the 2-amino-3-carboxy-4-phenylthiophene backbone. These studies suggest that this class has potential for further development into small molecule aPKC inhibitors with therapeutic efficacy in a host of diseases involving increased vascular permeability and inflammation.
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Affiliation(s)
- Paul M Titchenell
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, PA 17033, USA
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23
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Novel atypical PKC inhibitors prevent vascular endothelial growth factor-induced blood-retinal barrier dysfunction. Biochem J 2012; 446:455-67. [PMID: 22721706 DOI: 10.1042/bj20111961] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Pro-inflammatory cytokines and growth factors such as VEGF (vascular endothelial growth factor) contribute to the loss of the BRB (blood-retinal barrier) and subsequent macular oedema in various retinal pathologies. VEGF signalling requires PKCβ [conventional PKC (protein kinase C)] activity; however, PKCβ inhibition only partially prevents VEGF-induced endothelial permeability and does not affect pro-inflammatory cytokine-induced permeability, suggesting the involvement of alternative signalling pathways. In the present study, we provide evidence for the involvement of aPKC (atypical PKC) signalling in VEGF-induced endothelial permeability and identify a novel class of inhibitors of aPKC that prevent BRB breakdown in vivo. Genetic and pharmacological manipulations of aPKC isoforms were used to assess their contribution to endothelial permeability in culture. A chemical library was screened using an in vitro kinase assay to identify novel small-molecule inhibitors, and further medicinal chemistry was performed to delineate a novel pharmacophore. We demonstrate that aPKC isoforms are both sufficient and required for VEGF-induced endothelial permeability. Furthermore, these specific, potent, non-competitive, small-molecule inhibitors prevented VEGF-induced tight junction internalization and retinal endothelial permeability in response to VEGF in both primary culture and in rodent retina. The results of the present study suggest that aPKC inhibition with 2-amino-4-phenyl-thiophene derivatives may be developed to preserve the BRB in retinal diseases such as diabetic retinopathy or uveitis, and the BBB (blood-brain barrier) in the presence of brain tumours.
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24
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Ruiz-Loredo AY, López E, López-Colomé AM. Thrombin stimulates stress fiber assembly in RPE cells by PKC/CPI-17-mediated MLCP inactivation. Exp Eye Res 2012; 96:13-23. [DOI: 10.1016/j.exer.2012.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 01/11/2012] [Accepted: 01/17/2012] [Indexed: 12/29/2022]
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25
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Central nervous system inflammation in disease related conditions: Mechanistic prospects. Brain Res 2012; 1446:144-55. [DOI: 10.1016/j.brainres.2012.01.061] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 01/24/2012] [Accepted: 01/24/2012] [Indexed: 12/24/2022]
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26
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Hyperglycemia and endothelial dysfunction in atherosclerosis: lessons from type 1 diabetes. Int J Vasc Med 2012; 2012:569654. [PMID: 22489274 PMCID: PMC3303762 DOI: 10.1155/2012/569654] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 10/27/2011] [Indexed: 12/18/2022] Open
Abstract
A clear relationship between diabetes and cardiovascular disease has been established for decades. Despite this, the mechanisms by which diabetes contributes to plaque formation remain in question. Some of this confusion derives from studies in type 2 diabetics where multiple components of metabolic syndrome show proatherosclerotic effects independent of underlying diabetes. However, the hyperglycemia that defines the diabetic condition independently affects atherogenesis in cell culture systems, animal models, and human patients. Endothelial cell biology plays a central role in atherosclerotic plaque formation regulating vessel permeability, inflammation, and thrombosis. The current paper highlights the mechanisms by which hyperglycemia affects endothelial cell biology to promote plaque formation.
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27
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Thennes T, Mehta D. Heterotrimeric G proteins, focal adhesion kinase, and endothelial barrier function. Microvasc Res 2011; 83:31-44. [PMID: 21640127 DOI: 10.1016/j.mvr.2011.05.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 05/04/2011] [Accepted: 05/12/2011] [Indexed: 12/18/2022]
Abstract
Ligands by binding to G protein coupled receptors (GPCRs) stimulate dissociation of heterotrimeric G proteins into Gα and Gβγ subunits. Released Gα and Gβγ subunits induce discrete signaling cues that differentially regulate focal adhesion kinase (FAK) activity and endothelial barrier function. Activation of G proteins downstream of receptors such as protease activated receptor 1 (PAR1) and histamine receptors rapidly increases endothelial permeability which reverses naturally within the following 1-2 h. However, activation of G proteins coupled to the sphingosine-1-phosphate receptor 1 (S1P1) signal cues that enhance basal barrier endothelial function and restore endothelial barrier function following the increase in endothelial permeability by edemagenic agents. Intriguingly, both PAR1 and S1P1 activation stimulates FAK activity, which associates with alteration in endothelial barrier function by these agonists. In this review, we focus on the role of the G protein subunits downstream of PAR1 and S1P1 in regulating FAK activity and endothelial barrier function.
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Affiliation(s)
- Tracy Thennes
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612, USA
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28
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Han J, Shuvaev VV, Muzykantov VR. Catalase and superoxide dismutase conjugated with platelet-endothelial cell adhesion molecule antibody distinctly alleviate abnormal endothelial permeability caused by exogenous reactive oxygen species and vascular endothelial growth factor. J Pharmacol Exp Ther 2011; 338:82-91. [PMID: 21474567 DOI: 10.1124/jpet.111.180620] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Reactive oxygen species (ROS) superoxide anion (O(2)()) and hydrogen peroxide (H(2)O(2)) produced by activated leukocytes and endothelial cells in sites of inflammation or ischemia cause endothelial barrier dysfunction that may lead to tissue edema. Antioxidant enzymes (AOEs) catalase and superoxide dismutase (SOD) conjugated with antibodies to platelet-endothelial cell adhesion molecule-1 (PECAM-1) specifically bind to endothelium, quench the corresponding ROS, and alleviate vascular oxidative stress and inflammation. In the present work, we studied the effects of anti-PECAM/catalase and anti-PECAM/SOD conjugates on the abnormal permeability manifested by transendothelial electrical resistance decline, increased fluorescein isothiocyanate-dextran influx, and redistribution of vascular endothelial-cadherin in human umbilical vein endothelial cell (HUVEC) monolayers. Anti-PECAM/catalase protected HUVEC monolayers against H(2)O(2)-induced endothelial barrier dysfunction. Polyethylene glycol-conjugated catalase exerted orders of magnitude lower endothelial uptake and no protective effect, similarly to IgG/catalase. Anti-PECAM/catalase, but not anti-PECAM/SOD, alleviated endothelial hyperpermeability caused by exposure to hypoxanthine/xanthine oxidase, implicating primarily H(2)O(2) in the disruption of the endothelial barrier in this model. Thrombin-induced endothelial permeability was not affected by treatment with anti-PECAM/AOEs or the NADPH oxidase inhibitor apocynin or overexpression of AOEs, indicating that the endogenous ROS play no key role in thrombin-mediated endothelial barrier dysfunction. In contrast, anti-PECAM/SOD, but not anti-PECAM/catalase, inhibited a vascular endothelial growth factor (VEGF)-induced increase in endothelial permeability, identifying a key role of endogenous O(2)() in the VEGF-mediated regulation of endothelial barrier function. Therefore, AOEs targeted to endothelial cells provide versatile molecular tools for testing the roles of specific ROS in vascular pathology and may be translated into remedies for these ROS-induced abnormalities.
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Affiliation(s)
- Jingyan Han
- Institute for Translational Medicine and Therapeutics, Institute for Environmental Medicine, and Department of Pharmacology, University of Pennsylvania, School of Medicine, Philadelphia, Pennsylvania 19104-6068, USA
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