1
|
Tan TE, Jampol LM, Ferris FL, Tadayoni R, Sadda SR, Chong V, Domalpally A, Blodi BL, Duh EJ, Curcio CA, Antonetti DA, Dutta S, Levine SR, Sun JK, Gardner TW, Wong TY. Imaging Modalities for Assessing the Vascular Component of Diabetic Retinal Disease: Review and Consensus for an Updated Staging System. Ophthalmol Sci 2024; 4:100449. [PMID: 38313399 PMCID: PMC10837643 DOI: 10.1016/j.xops.2023.100449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 12/05/2023] [Accepted: 12/05/2023] [Indexed: 02/06/2024]
Abstract
Purpose To review the evidence for imaging modalities in assessing the vascular component of diabetic retinal disease (DRD), to inform updates to the DRD staging system. Design Standardized narrative review of the literature by an international expert workgroup, as part of the DRD Staging System Update Effort, a project of the Mary Tyler Moore Vision Initiative. Overall, there were 6 workgroups: Vascular Retina, Neural Retina, Systemic Health, Basic and Cellular Mechanisms, Visual Function, and Quality of Life. Participants The Vascular Retina workgroup, including 16 participants from 4 countries. Methods Literature review was conducted using standardized evidence grids for 5 modalities: standard color fundus photography (CFP), widefield color photography (WFCP), standard fluorescein angiography (FA), widefield FA (WFFA), and OCT angiography (OCTA). Summary levels of evidence were determined on a validated scale from I (highest) to V (lowest). Five virtual workshops were held for discussion and consensus. Main Outcome Measures Level of evidence for each modality. Results Levels of evidence for standard CFP, WFCP, standard FA, WFFA, and OCTA were I, II, I, I, and II respectively. Traditional vascular lesions on standard CFP should continue to be included in an updated staging system, but more studies are required before they can be used in posttreatment eyes. Widefield color photographs can be used for severity grading within the area covered by standard CFPs, although these gradings may not be directly interchangeable with each other. Evaluation of the peripheral retina on WFCP can be considered, but the method of grading needs to be clarified and validated. Standard FA and WFFA provide independent prognostic value, but the need for dye administration should be considered. OCT angiography has significant potential for inclusion in the DRD staging system, but various barriers need to be addressed first. Conclusions This study provides evidence-based recommendations on the utility of various imaging modalities for assessment of the vascular component of DRD, which can inform future updates to the DRD staging system. Although new imaging modalities offer a wealth of information, there are still major gaps and unmet research needs that need to be addressed before this potential can be realized. Financial Disclosures Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
Collapse
Affiliation(s)
- Tien-En Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Programme (EYE ACP), Duke-National University of Singapore Medical School, Singapore
| | - Lee M. Jampol
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | | | - Ramin Tadayoni
- Ophthalmology Department, Lariboisière, AP-HP, Saint Louis and Fondation Adolphe de Rothschild Hospitals, Université Paris Cité, Paris, France
| | - Srinivas R. Sadda
- Doheny Eye Institute, Pasadena, California
- Department of Ophthalmology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
| | - Victor Chong
- UCL Institute of Ophthalmology, University College London, London, UK
| | - Amitha Domalpally
- Department of Ophthalmology and Visual Sciences, Wisconsin Reading Center, University of Wisconsin-Madison, Madison, Wisconsin
| | - Barbara L. Blodi
- Department of Ophthalmology and Visual Sciences, Wisconsin Reading Center, University of Wisconsin-Madison, Madison, Wisconsin
| | - Elia J. Duh
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama
| | - David A. Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan
| | | | - S. Robert Levine
- The Mary Tyler Moore & S. Robert Levine, MD Charitable Foundation, Greenwich, Connecticut
| | - Jennifer K. Sun
- Joslin Diabetes Center, Beetham Eye Institute, Harvard Medical School, Boston, Massachusetts
| | - Thomas W. Gardner
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Programme (EYE ACP), Duke-National University of Singapore Medical School, Singapore
- Tsinghua Medicine, Tsinghua University, Beijing, China
| |
Collapse
|
2
|
Díaz-Coránguez M, González-González L, Wang A, Liu X, Antonetti DA. Disheveled-1 Interacts with Claudin-5 and Contributes to Norrin-Induced Endothelial Barrier Restoration. Cells 2023; 12:2402. [PMID: 37830616 PMCID: PMC10571979 DOI: 10.3390/cells12192402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 09/27/2023] [Accepted: 09/29/2023] [Indexed: 10/14/2023] Open
Abstract
Previous studies have revealed that norrin can reverse vascular endothelial-growth-factor (VEGF)-induced permeability in a β-catenin-dependent pathway. Here, we have explored the contribution of disheveled-1 (DVL1) in norrin-induced blood-retinal barrier (BRB) restoration. We provide evidence that in addition to canonical signaling, DVL1 promotes tight junction (TJ) stabilization through a novel, non-canonical signaling pathway involving direct claudin-5 (CLDN5) binding. Immunofluorescence staining of rat retinal cross-sections showed enriched expression of DVL1 and 3 at endothelial capillaries and co-localization with CLDN5 and ZO-1 at the TJ complex in primary bovine retinal endothelial cells (BRECs). Barrier properties of BRECs were determined via measurements of trans-endothelial electrical resistance (TEER) or permeability to 70 kDa RITC-dextran. These studies demonstrated that norrin restoration of barrier properties after VEGF treatment required DVL1 as an siRNA knockdown of Dvl1 but not Dvl2 or Dvl3, reduced basal barrier properties and ablated norrin-induced barrier restoration. However, loss of Dvl1 did not decrease β-catenin signaling activity as measured by Axin2 mRNA expression, suggesting the contribution of a non-canonical pathway. DVL and TJ protein interactions were analyzed via co-immunoprecipitation of endogenous protein in BRECs, which demonstrated that DVL1 interacts with both CLDN5 and ZO-1, while DVL3 interacts only with ZO-1. These interactions were most abundant after inducing BRB restoration by treating BRECs with VEGF and norrin. DVL has previously been shown to form intramolecular bindings between the C-terminal PDZ-binding motif (PDZ-BM) with an internal PDZ domain. Co-transfection of HEK293 cells with DVL1 and CLDN5 or relevant mutants revealed that DVL1 interacts with CLDN5 through the DVL PDZ domain binding, CLDN5 PDZ-BM, in competition with DVL1 PDZ-BM, since DVL/CLDN5 interaction increases with deletion of the DVL1 PDZ-BM and decreases by co-expressing the C-terminal fragment of DVL1 containing the PDZ-BM or through deletion of CLDN5 PDZ-BM. In BREC cells, transfection of the C-terminal fragment of DVL1 downregulates the expression of CLDN5 but does not affect the expression of other proteins of the TJs, including ZO-1, occludin, CLDN1 or VE-cadherin. Blocking DVL1/CLDN5 interaction increased basal permeability and prevented norrin induction of barrier properties after VEGF. Combined with previous data, these results demonstrate that norrin signals through both a canonical β-catenin pathway and a non-canonical signaling pathway by which DVL1 directly binds to CLDN5 to promote barrier properties.
Collapse
Affiliation(s)
- Mónica Díaz-Coránguez
- Department of Pharmacobiology, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), Mexico City 07360, Mexico;
| | - Laura González-González
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA; (L.G.-G.); (A.W.); (X.L.)
| | - Amy Wang
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA; (L.G.-G.); (A.W.); (X.L.)
| | - Xuwen Liu
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA; (L.G.-G.); (A.W.); (X.L.)
| | - David A. Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA; (L.G.-G.); (A.W.); (X.L.)
| |
Collapse
|
3
|
Canonica J, Foxton R, Garrido MG, Lin CM, Uhles S, Shanmugam S, Antonetti DA, Abcouwer SF, Westenskow PD. Delineating effects of angiopoietin-2 inhibition on vascular permeability and inflammation in models of retinal neovascularization and ischemia/reperfusion. Front Cell Neurosci 2023; 17:1192464. [PMID: 37377777 PMCID: PMC10291265 DOI: 10.3389/fncel.2023.1192464] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 05/26/2023] [Indexed: 06/29/2023] Open
Abstract
Introduction Clinical trials demonstrated that co-targeting angiopoietin-2 (Ang-2) and vascular endothelial growth factor (VEGF-A) with faricimab controls anatomic outcomes and maintains vision improvements, with strong durability, through 2 years in patients with neovascular age-related macular degeneration and diabetic macular edema. The mechanism(s) underlying these findings is incompletely understood and the specific role that Ang-2 inhibition plays requires further investigation. Methods We examined the effects of single and dual Ang-2/VEGF-A inhibition in diseased vasculatures of JR5558 mice with spontaneous choroidal neovascularization (CNV) and in mice with retinal ischemia/reperfusion (I/R) injuries. Results In JR5558 mice, Ang-2, VEGF-A, and dual Ang-2/VEGF-A inhibition reduced CNV area after 1 week; only dual Ang-2/VEGF-A inhibition decreased neovascular leakage. Only Ang-2 and dual Ang-2/VEGF-A inhibition maintained reductions after 5 weeks. Dual Ang-2/VEGF-A inhibition reduced macrophage/microglia accumulation around lesions after 1 week. Both Ang-2 and dual Ang-2/VEGF-A inhibition reduced macrophage/microglia accumulation around lesions after 5 weeks. In the retinal I/R injury model, dual Ang-2/VEGF-A inhibition was statistically significantly more effective than Ang-2 or VEGF-A inhibition alone in preventing retinal vascular leakage and neurodegeneration. Discussion These data highlight the role of Ang-2 in dual Ang-2/VEGF-A inhibition and indicate that dual inhibition has complementary anti-inflammatory and neuroprotective effects, suggesting a mechanism for the durability and efficacy of faricimab in clinical trials.
Collapse
Affiliation(s)
- Jérémie Canonica
- Roche Pharma Research and Early Development, Roche Innovation Center, Basel, Switzerland
| | - Richard Foxton
- Roche Pharma Research and Early Development, Roche Innovation Center, Basel, Switzerland
| | - Marina Garcia Garrido
- Roche Pharma Research and Early Development, Roche Innovation Center, Basel, Switzerland
| | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, Ann Arbor, MI, United States
| | - Sabine Uhles
- Roche Pharma Research and Early Development, Roche Innovation Center, Basel, Switzerland
| | - Sumathi Shanmugam
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, Ann Arbor, MI, United States
| | - David A. Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, Ann Arbor, MI, United States
| | - Steven F. Abcouwer
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, Ann Arbor, MI, United States
| | - Peter D. Westenskow
- Roche Pharma Research and Early Development, Roche Innovation Center, Basel, Switzerland
| |
Collapse
|
4
|
Goncalves A, Antonetti DA. Transgenic animal models to explore and modulate the blood brain and blood retinal barriers of the CNS. Fluids Barriers CNS 2022; 19:86. [PMID: 36320068 PMCID: PMC9628113 DOI: 10.1186/s12987-022-00386-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 10/03/2022] [Indexed: 11/18/2022] Open
Abstract
The unique environment of the brain and retina is tightly regulated by blood-brain barrier and the blood-retinal barrier, respectively, to ensure proper neuronal function. Endothelial cells within these tissues possess distinct properties that allow for controlled passage of solutes and fluids. Pericytes, glia cells and neurons signal to endothelial cells (ECs) to form and maintain the barriers and control blood flow, helping to create the neurovascular unit. This barrier is lost in a wide range of diseases affecting the central nervous system (CNS) and retina such as brain tumors, stroke, dementia, and in the eye, diabetic retinopathy, retinal vein occlusions and age-related macular degeneration to name prominent examples. Recent studies directly link barrier changes to promotion of disease pathology and degradation of neuronal function. Understanding how these barriers form and how to restore these barriers in disease provides an important point for therapeutic intervention. This review aims to describe the fundamentals of the blood-tissue barriers of the CNS and how the use of transgenic animal models led to our current understanding of the molecular framework of these barriers. The review also highlights examples of targeting barrier properties to protect neuronal function in disease states.
Collapse
Affiliation(s)
- Andreia Goncalves
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, 1000 Wall St Rm, Ann Arbor, MI, 7317, USA
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, 1000 Wall St Rm, Ann Arbor, MI, 7317, USA.
| |
Collapse
|
5
|
Kern TS, Du Y, Tang J, Lee CA, Liu H, Dreffs A, Leinonen H, Antonetti DA, Palczewski K. Regulation of Adrenergic, Serotonin, and Dopamine Receptors to Inhibit Diabetic Retinopathy: Monotherapies versus Combination Therapies. Mol Pharmacol 2021; 100:470-479. [PMID: 34393108 PMCID: PMC9175131 DOI: 10.1124/molpharm.121.000278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 08/03/2021] [Indexed: 11/22/2022] Open
Abstract
We compared monotherapies and combinations of therapies that regulate G-protein-coupled receptors (GPCRs) with respect to their abilities to inhibit early stages of diabetic retinopathy (DR) in streptozotocin-diabetic mice. Metoprolol (MTP; 0.04-1.0 mg/kg b.wt./day), bromocriptine (BRM; 0.01-0.1 mg/kg b.wt./day), doxazosin (DOX; 0.01-1.0 mg/kg b.wt./day), or tamsulosin (TAM; 0.05-0.25 mg/kg b.wt./day) were injected individually daily for 2 months in dose-response studies to assess their effects on the diabetes-induced increases in retinal superoxide and leukocyte-mediated cytotoxicity against vascular endothelial cells, both of which abnormalities have been implicated in the development of DR. Each of the individual drugs inhibited the diabetes-induced increase in retinal superoxide at the higher concentrations tested, but the inhibition was lost at lower doses. To determine whether combination therapies had superior effects over individual drugs, we intentionally selected for each drug a low dose that had little or no effect on the diabetes-induced retinal superoxide for use separately or in combinations in 8-month studies of retinal function, vascular permeability, and capillary degeneration in diabetes. At the low doses used, combinations of the drugs generally were more effective than individual drugs, but the low-dose MTP alone totally inhibited diabetes-induced reduction in a vision task, BRM or DOX alone totally inhibited the vascular permeability defect, and DOX alone totally inhibited diabetes-induced degeneration of retinal capillaries. Although low-dose MTP, BRM, DOX, or TAM individually had beneficial effects on some endpoints, combination of the therapies better inhibited the spectrum of DR lesions evaluated. SIGNIFICANCE STATEMENT: The pathogenesis of early stages of diabetic retinopathy remains incompletely understood, but multiple different cell types are believed to be involved in the pathogenic process. We have compared the effects of monotherapies to those of combinations of drugs that regulate GPCR signaling pathways with respect to their relative abilities to inhibit the development of early diabetic retinopathy.
Collapse
Affiliation(s)
- Timothy S Kern
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Yunpeng Du
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Jie Tang
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Chieh Allen Lee
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Haitao Liu
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Alyssa Dreffs
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Henri Leinonen
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - David A Antonetti
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Krzysztof Palczewski
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| |
Collapse
|
6
|
Abcouwer SF, Shanmugam S, Muthusamy A, Lin CM, Kong D, Hager H, Liu X, Antonetti DA. Inflammatory resolution and vascular barrier restoration after retinal ischemia reperfusion injury. J Neuroinflammation 2021; 18:186. [PMID: 34446062 PMCID: PMC8394696 DOI: 10.1186/s12974-021-02237-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 08/11/2021] [Indexed: 02/08/2023] Open
Abstract
Background Several retinal pathologies exhibit both inflammation and breakdown of the inner blood-retinal barrier (iBRB) resulting in vascular permeability, suggesting that treatments that trigger resolution of inflammation may also promote iBRB restoration. Methods Using the mouse retinal ischemia-reperfusion (IR) injury model, we followed the time course of neurodegeneration, inflammation, and iBRB disruption and repair to examine the relationship between resolution of inflammation and iBRB restoration and to determine if minocycline, a tetracycline derivative shown to reverse microglial activation, can hasten these processes. Results A 90-min ischemic insult followed by reperfusion in the retina induced cell apoptosis and inner retina thinning that progressed for approximately 2 weeks. IR increased vascular permeability within hours, which resolved between 3 and 4 weeks after injury. Increased vascular permeability coincided with alteration and loss of endothelial cell tight junction (TJ) protein content and disorganization of TJ protein complexes. Shunting of blood flow away from leaky vessels and dropout of leaky capillaries were eliminated as possible mechanisms for restoring the iBRB. Repletion of TJ protein contents occurred within 2 days after injury, long before restoration of the iBRB. In contrast, the eventual re-organization of TJ complexes at the cell border coincided with restoration of the barrier. A robust inflammatory response was evident a 1 day after IR and progressed to resolution over the 4-week time course. The inflammatory response included a rapid and transient infiltration of granulocytes and Ly6C+ classical inflammatory monocytes, a slow accumulation of Ly6Cneg monocyte/macrophages, and activation, proliferation, and mobilization of resident microglia. Extravasation of the majority of CD45+ leukocytes occurred from the superficial plexus. The presence of monocyte/macrophages and increased numbers of microglia were sustained until the iBRB was eventually restored. Intervention with minocycline to reverse microglial activation at 1 week after injury promoted early restoration of the iBRB coinciding with decreased expression of mRNAs for the microglial M1 markers TNF-α, IL-1β, and Ptgs2 (Cox-2) and increased expression of secreted serine protease inhibitor Serpina3n mRNA. Conclusions These results suggest that iBRB restoration occurs as TJ complexes are reorganized and that resolution of inflammation and restoration of the iBRB following retinal IR injury are functionally linked. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02237-5.
Collapse
Affiliation(s)
- Steven F Abcouwer
- Department of Ophthalmology and Visual Sciences, Michigan Medicine, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, 48105, USA.
| | - Sumathi Shanmugam
- Department of Ophthalmology and Visual Sciences, Michigan Medicine, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, 48105, USA
| | | | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, Michigan Medicine, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Dejuan Kong
- Department of Ophthalmology and Visual Sciences, Michigan Medicine, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Heather Hager
- Department of Ophthalmology and Visual Sciences, Michigan Medicine, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Xuwen Liu
- Department of Ophthalmology and Visual Sciences, Michigan Medicine, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, 48105, USA
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, Michigan Medicine, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, 48105, USA.,Department of Molecular and Integrative Physiology, Ann Arbor, MI, 48109, USA
| |
Collapse
|
7
|
Sheskey SR, Antonetti DA, Rentería RC, Lin CM. Correlation of Retinal Structure and Visual Function Assessments in Mouse Diabetes Models. Invest Ophthalmol Vis Sci 2021; 62:20. [PMID: 34410299 PMCID: PMC8383928 DOI: 10.1167/iovs.62.10.20] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Purpose Diabetic retinopathy results in vision loss with changes to both retinal blood vessels and neural retina. Recent studies have revealed that animal models of diabetes demonstrate early loss of visual function. We explored the time course of retinal change in three different mouse models of diabetes in a longitudinal study using in vivo measures of retinal structure (optical coherence tomography [OCT]) and visual function (optomotor and pupillary responses). Methods OCT analysis of retinal microstructure, optokinetic response as a measure of visual acuity, and pupillary response to light stimulation were compared among the db/db, Ins2Akita, and streptozotocin (STZ)-induced mouse models of diabetes at 1.5, 3, 6, and 9 months of diabetes. Results The db/db, Ins2Akita, and STZ-induced models of diabetes all exhibited vision loss and retinal thinning as disease progressed. Both structural changes and functional measures were significantly correlated with the blood glucose levels. Despite this, vision loss and retinal thinning were not consistently correlated, except for the inner retinal layer thickness at 6 months of diabetes. Conclusions This longitudinal study compiled structural measures and functional outcome data for type 1 and 2 diabetes mouse models commonly used for diabetes studies and demonstrated an overall decline in retinal-related health in conjunction with weight change and blood glucose alterations. The relationship between the structural change and functional outcome could be correlative but is not necessarily causative, as retinal thinning was not sufficient to explain visual acuity decline.
Collapse
Affiliation(s)
- Sarah R Sheskey
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - René C Rentería
- Department of Clinical and Applied Science Education, School of Osteopathic Medicine, University of the Incarnate Word, San Antonio, Texas, United States
| | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| |
Collapse
|
8
|
Goncalves A, Dreffs A, Lin CM, Sheskey S, Hudson N, Keil J, Campbell M, Antonetti DA. Vascular Expression of Permeability-Resistant Occludin Mutant Preserves Visual Function in Diabetes. Diabetes 2021; 70:1549-1560. [PMID: 33883214 PMCID: PMC8336002 DOI: 10.2337/db20-1220] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 04/01/2021] [Indexed: 12/20/2022]
Abstract
Diabetic retinopathy is one of the leading causes of vision loss and blindness. Extensive preclinical and clinical evidence exists for both vascular and neuronal pathology. However, the relationship of these changes in the neurovascular unit and impact on vision remains to be determined. Here, we investigate the role of tight junction protein occludin phosphorylation at S490 in modulating barrier properties and its impact on visual function. Conditional vascular expression of the phosphorylation-resistant Ser490 to Ala (S490A) form of occludin preserved tight junction organization and reduced vascular endothelial growth factor (VEGF)-induced permeability and edema formation after intraocular injection. In the retinas of streptozotocin-induced diabetic mice, endothelial-specific expression of the S490A form of occludin completely prevented diabetes-induced permeability to labeled dextran and inhibited leukostasis. Importantly, vascular-specific expression of the occludin mutant completely blocked the diabetes-induced decrease in visual acuity and contrast sensitivity. Together, these results reveal that occludin acts to regulate barrier properties downstream of VEGF in a phosphorylation-dependent manner and that loss of inner blood-retinal barrier integrity induced by diabetes contributes to vision loss.
Collapse
Affiliation(s)
- Andreia Goncalves
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI
| | - Alyssa Dreffs
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI
| | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI
| | - Sarah Sheskey
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI
| | - Natalie Hudson
- Neurovascular Genetics Unit, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Jason Keil
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI
| | - Matthew Campbell
- Neurovascular Genetics Unit, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI
| |
Collapse
|
9
|
Abstract
Diabetes mellitus has profound effects on multiple organ systems; however, the loss of vision caused by diabetic retinopathy might be one of the most impactful in a patient's life. The retina is a highly metabolically active tissue that requires a complex interaction of cells, spanning light sensing photoreceptors to neurons that transfer the electrochemical signal to the brain with support by glia and vascular tissue. Neuronal function depends on a complex inter-dependency of retinal cells that includes the formation of a blood-retinal barrier. This dynamic system is negatively affected by diabetes mellitus, which alters normal cell-cell interactions and leads to profound vascular abnormalities, loss of the blood-retinal barrier and impaired neuronal function. Understanding the normal cell signalling interactions and how they are altered by diabetes mellitus has already led to novel therapies that have improved visual outcomes in many patients. Research highlighted in this Review has led to a new understanding of retinal pathophysiology during diabetes mellitus and has uncovered potential new therapeutic avenues to treat this debilitating disease.
Collapse
Affiliation(s)
- David A Antonetti
- Department of Ophthalmology and Visual Sciences, Department of Molecular and Integrative Physiology, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, USA.
| | - Paolo S Silva
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
- Beetham Eye Institute, Joslin Diabetes Center, Boston, MA, USA
| | - Alan W Stitt
- Centre for Experimental Medicine, Queen's University, Belfast, UK
| |
Collapse
|
10
|
Abstract
Diabetic retinopathy remains a leading cause of blindness despite recent advance in therapies. Traditionally, this complication of diabetes was viewed predominantly as a microvascular disease but research has pointed to alterations in ganglion cells, glia, microglia, and photoreceptors as well, often occurring without obvious vascular damage. In neural tissue, the microvasculature and neural tissue form an intimate relationship with the neural tissue providing signaling cues for the vessels to form a distinct barrier that helps to maintain the proper neuronal environment for synaptic signaling. This relationship has been termed the neurovascular unit (NVU). Research is now focused on understanding the cellular and molecular basis of the neurovascular unit and how diabetes alters the normal cellular communications and disrupts the cellular environment contributing to loss of vision in diabetes.
Collapse
Affiliation(s)
- David A Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| |
Collapse
|
11
|
Sun JK, Aiello LP, Abràmoff MD, Antonetti DA, Dutta S, Pragnell M, Levine SR, Gardner TW. Updating the Staging System for Diabetic Retinal Disease. Ophthalmology 2020; 128:490-493. [PMID: 33218709 DOI: 10.1016/j.ophtha.2020.10.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 01/13/2023] Open
|
12
|
Dreffs A, Lin CM, Liu X, Shanmugam S, Abcouwer SF, Kern TS, Antonetti DA. All-trans-Retinaldehyde Contributes to Retinal Vascular Permeability in Ischemia Reperfusion. Invest Ophthalmol Vis Sci 2020; 61:8. [PMID: 32492112 PMCID: PMC7415894 DOI: 10.1167/iovs.61.6.8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 04/17/2020] [Indexed: 01/28/2023] Open
Abstract
Purpose Extracellular accumulation of all-trans-retinaldehyde (atRAL), a highly reactive visual cycle intermediate, is toxic to cells of the outer retina and contributes to retinal and macular degenerations. However, the contribution of atRAL to retinal capillary function has not been studied. We hypothesized that atRAL released from the outer retina can contribute to retinal vascular permeability. We, therefore, tested the contribution of atRAL to retinal ischemia-reperfusion (IR)-induced vascular permeability. Methods IR was induced in mice by transient increase in intraocular pressure followed by natural reperfusion. The visual cycle was ablated in the Lrat-/- mice, reduced by dark adaptation or the use of the RPE65 inhibitor and atRAL scavenger emixustat. Accumulation of FITC-BSA was used to assess vascular permeability and DNA fragmentation quantified cell death after IR. Primary bovine retinal endothelial cell (BREC) culture was used to measure the direct effects of atRAL on endothelial permeability and cell death. Results Inhibition of the visual cycle by Lrat-/-, dark adaptation, or with emixustat, all reduced approximately half of IR induced vascular permeability at 48 hours. An increase in BREC permeability with atRAL coincided with lactate dehydrogenase (LDH) release, a measure of cell death. Both permeability and toxicity were blocked by emixustat. Conclusions Outer retinal pathology may contribute to vascular permeability by release of atRAL, which can act directly on vascular endothelial cells to alter barrier properties and induce cell death. These studies may have implications for a variety of blinding eye diseases that include outer retinal damage and retinal vascular permeability.
Collapse
Affiliation(s)
- Alyssa Dreffs
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Xuwen Liu
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Sumathi Shanmugam
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Steven F. Abcouwer
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Timothy S. Kern
- Center for Translational Vision Research, Department of Ophthalmology, Gavin Herbert Eye Institute, School of Medicine, University of California-Irvine, Gillespie Neuroscience Research Facility, Irvine, California, United States
| | - David A. Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| |
Collapse
|
13
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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.
| |
Collapse
|
14
|
Fu Z, Sun Y, Cakir B, Tomita Y, Huang S, Wang Z, Liu CH, S. Cho S, Britton W, S. Kern T, Antonetti DA, Hellström A, E.H. Smith L. Targeting Neurovascular Interaction in Retinal Disorders. Int J Mol Sci 2020; 21:E1503. [PMID: 32098361 PMCID: PMC7073081 DOI: 10.3390/ijms21041503] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/13/2020] [Accepted: 02/21/2020] [Indexed: 02/07/2023] Open
Abstract
The tightly structured neural retina has a unique vascular network comprised of three interconnected plexuses in the inner retina (and choroid for outer retina), which provide oxygen and nutrients to neurons to maintain normal function. Clinical and experimental evidence suggests that neuronal metabolic needs control both normal retinal vascular development and pathological aberrant vascular growth. Particularly, photoreceptors, with the highest density of mitochondria in the body, regulate retinal vascular development by modulating angiogenic and inflammatory factors. Photoreceptor metabolic dysfunction, oxidative stress, and inflammation may cause adaptive but ultimately pathological retinal vascular responses, leading to blindness. Here we focus on the factors involved in neurovascular interactions, which are potential therapeutic targets to decrease energy demand and/or to increase energy production for neovascular retinal disorders.
Collapse
Affiliation(s)
- Zhongjie Fu
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Ye Sun
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Bertan Cakir
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Yohei Tomita
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Shuo Huang
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Zhongxiao Wang
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Chi-Hsiu Liu
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Steve S. Cho
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - William Britton
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Timothy S. Kern
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Irvine, CA 92697, USA;
| | - David A. Antonetti
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA;
| | - Ann Hellström
- Section for Ophthalmology, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 405 30 Göteborg, Sweden;
| | - Lois E.H. Smith
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| |
Collapse
|
15
|
Díaz-Coránguez M, Lin CM, Liebner S, Antonetti DA. Norrin restores blood-retinal barrier properties after vascular endothelial growth factor-induced permeability. J Biol Chem 2020; 295:4647-4660. [PMID: 32086377 DOI: 10.1074/jbc.ra119.011273] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 02/11/2020] [Indexed: 12/25/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) contributes to blood-retinal barrier (BRB) dysfunction in several blinding eye diseases, including diabetic retinopathy. Signaling via the secreted protein norrin through the frizzled class receptor 4 (FZD4)/LDL receptor-related protein 5-6 (LRP5-6)/tetraspanin 12 (TSPAN12) receptor complex is required for developmental vascularization and BRB formation. Here, we tested the hypothesis that norrin restores BRB properties after VEGF-induced vascular permeability in diabetic rats or in animals intravitreally injected with cytokines. Intravitreal co-injection of norrin with VEGF completely ablated VEGF-induced BRB permeability to Evans Blue-albumin. Likewise, 5-month diabetic rats exhibited increased permeability of FITC-albumin, and a single norrin injection restored BRB properties. These results were corroborated in vitro, where co-stimulation of norrin with VEGF or stimulation of norrin after VEGF exposure restored barrier properties, indicated by electrical resistance or 70-kDa RITC-dextran permeability in primary endothelial cell culture. Interestingly, VEGF promoted norrin signaling by increasing the FZD4 co-receptor TSPAN12 at cell membranes in an MAPK/ERK kinase (MEK)/ERK-dependent manner. Norrin signaling through β-catenin was required for BRB restoration, but glycogen synthase kinase 3 α/β (GSK-3α/β) inhibition did not restore BRB properties. Moreover, levels of the tight junction protein claudin-5 were increased with norrin and VEGF or with VEGF alone, but both norrin and VEGF were required for enriched claudin-5 localization at the tight junction. These results suggest that VEGF simultaneously induces vascular permeability and promotes responsiveness to norrin. Norrin, in turn, restores tight junction complex organization and BRB properties in a β-catenin-dependent manner.
Collapse
Affiliation(s)
- Mónica Díaz-Coránguez
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48105
| | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48105
| | - Stefan Liebner
- Institute of Neurology (Edinger Institute), University Hospital, Goethe University, 60538 Frankfurt, Germany
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48105
| |
Collapse
|
16
|
Bendriem RM, Singh S, Aleem AA, Antonetti DA, Ross ME. Tight junction protein occludin regulates progenitor Self-Renewal and survival in developing cortex. eLife 2019; 8:49376. [PMID: 31794381 PMCID: PMC6890460 DOI: 10.7554/elife.49376] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Accepted: 11/18/2019] [Indexed: 12/31/2022] Open
Abstract
Occludin (OCLN) mutations cause human microcephaly and cortical malformation. A tight junction component thought absent in neuroepithelium after neural tube closure, OCLN isoform-specific expression extends into corticogenesis. Full-length and truncated isoforms localize to neuroprogenitor centrosomes, but full-length OCLN transiently localizes to plasma membranes while only truncated OCLN continues at centrosomes throughout neurogenesis. Mimicking human mutations, full-length OCLN depletion in mouse and in human CRISPR/Cas9-edited organoids produce early neuronal differentiation, reduced progenitor self-renewal and increased apoptosis. Human neural progenitors were more severely affected, especially outer radial glial cells, which mouse embryonic cortex lacks. Rodent and human mutant progenitors displayed reduced proliferation and prolonged M-phase. OCLN interacted with mitotic spindle regulators, NuMA and RAN, while full-length OCLN loss impaired spindle pole morphology, astral and mitotic microtubule integrity. Thus, early corticogenesis requires full-length OCLN to regulate centrosome organization and dynamics, revealing a novel role for this tight junction protein in early brain development.
Collapse
Affiliation(s)
- Raphael M Bendriem
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, United States.,Graduate School of Medical Sciences, Weill Cornell Medicine, New York, United States
| | - Shawn Singh
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, United States
| | | | - David A Antonetti
- Kellogg Eye Center, Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, United States
| | - M Elizabeth Ross
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, United States.,Graduate School of Medical Sciences, Weill Cornell Medicine, New York, United States
| |
Collapse
|
17
|
Kern TS, Antonetti DA, Smith LEH. Pathophysiology of Diabetic Retinopathy: Contribution and Limitations of Laboratory Research. Ophthalmic Res 2019; 62:196-202. [PMID: 31362288 DOI: 10.1159/000500026] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 03/29/2019] [Indexed: 12/11/2022]
Abstract
Preclinical models of diabetic retinopathy are indispensable in the drug discovery and development of new therapies. They are, however, imperfect facsimiles of diabetic retinopathy in humans. This chapter discusses the advantages, limitations, and physiological and pathological relevance of preclinical models of diabetic retinopathy. The judicious interpretation and extrapolation of data derived from these models to humans and a correspondingly greater emphasis placed on translational medical research in early-stage clinical trials are essential to more successfully inhibit the development and progression of diabetic retinopathy in the future.
Collapse
Affiliation(s)
- Timothy S Kern
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, USA, .,Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA,
| | - David A Antonetti
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Lois E H Smith
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
18
|
Ragelle H, Goncalves A, Kustermann S, Antonetti DA, Jayagopal A. Organ-On-A-Chip Technologies for Advanced Blood-Retinal Barrier Models. J Ocul Pharmacol Ther 2019; 36:30-41. [PMID: 31140899 PMCID: PMC6985766 DOI: 10.1089/jop.2019.0017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 04/02/2019] [Indexed: 12/16/2022] Open
Abstract
The blood-retinal barrier (BRB) protects the retina by maintaining an adequate microenvironment for neuronal function. Alterations of the junctional complex of the BRB and consequent BRB breakdown in disease contribute to a loss of neuronal signaling and vision loss. As new therapeutics are being developed to prevent or restore barrier function, it is critical to implement physiologically relevant in vitro models that recapitulate the important features of barrier biology to improve disease modeling, target validation, and toxicity assessment. New directions in organ-on-a-chip technology are enabling more sophisticated 3-dimensional models with flow, multicellularity, and control over microenvironmental properties. By capturing additional biological complexity, organs-on-chip can help approach actual tissue organization and function and offer additional tools to model and study disease compared with traditional 2-dimensional cell culture. This review describes the current state of barrier biology and barrier function in ocular diseases, describes recent advances in organ-on-a-chip design for modeling the BRB, and discusses the potential of such models for ophthalmic drug discovery and development.
Collapse
Affiliation(s)
- Héloïse Ragelle
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Andreia Goncalves
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Harbor, Michigan
| | - Stefan Kustermann
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - David A. Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Harbor, Michigan
| | - Ashwath Jayagopal
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| |
Collapse
|
19
|
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. Am J Pathol 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] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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.
| |
Collapse
|
20
|
Keep RF, Andjelkovic AV, Xiang J, Stamatovic SM, Antonetti DA, Hua Y, Xi G. Brain endothelial cell junctions after cerebral hemorrhage: Changes, mechanisms and therapeutic targets. J Cereb Blood Flow Metab 2018; 38:1255-1275. [PMID: 29737222 PMCID: PMC6092767 DOI: 10.1177/0271678x18774666] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/09/2018] [Indexed: 11/15/2022]
Abstract
Vascular disruption is the underlying cause of cerebral hemorrhage, including intracerebral, subarachnoid and intraventricular hemorrhage. The disease etiology also involves cerebral hemorrhage-induced blood-brain barrier (BBB) disruption, which contributes an important component to brain injury after the initial cerebral hemorrhage. BBB loss drives vasogenic edema, allows leukocyte extravasation and may lead to the entry of potentially neurotoxic and vasoactive compounds into brain. This review summarizes current information on changes in brain endothelial junction proteins in response to cerebral hemorrhage (and clot-related factors), the mechanisms underlying junction modification and potential therapeutic targets to limit BBB disruption and, potentially, hemorrhage occurrence. It also addresses advances in the tools that are now available for assessing changes in junctions after cerebral hemorrhage and the potential importance of such junction changes. Recent studies suggest post-translational modification, conformational change and intracellular trafficking of junctional proteins may alter barrier properties. Understanding how cerebral hemorrhage alters BBB properties beyond changes in tight junction protein loss may provide important therapeutic insights to prevent BBB dysfunction and restore normal function.
Collapse
Affiliation(s)
- Richard F Keep
- Department of Neurosurgery, University of Michigan Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, University of Michigan Ann Arbor, MI, USA
| | - Anuska V Andjelkovic
- Department of Neurosurgery, University of Michigan Ann Arbor, MI, USA
- Department of Pathology, University of Michigan Ann Arbor, MI, USA
| | - Jianming Xiang
- Department of Neurosurgery, University of Michigan Ann Arbor, MI, USA
| | | | - David A Antonetti
- Department of Molecular and Integrative Physiology, University of Michigan Ann Arbor, MI, USA
- Department of Ophthalmology & Visual Science Medical School, University of Michigan Ann Arbor, MI, USA
| | - Ya Hua
- Department of Neurosurgery, University of Michigan Ann Arbor, MI, USA
| | - Guohua Xi
- Department of Neurosurgery, University of Michigan Ann Arbor, MI, USA
| |
Collapse
|
21
|
Abstract
PURPOSE Changes in retinal pH may contribute to a variety of eye diseases. To study the effect of acidosis alone, we induced systemic metabolic acidosis and hypothesized that the retina would respond with altered expression of genes involved in acid/base regulation. METHODS Systemic metabolic acidosis was induced in Long-Evans rats for up to 2 weeks by adding NH4Cl to the drinking water. After 2 weeks, venous pH was 7.25 ± 0.08 (SD) and [HCO3-] was 21.4 ± 4.6 mM in acidotic animals; pH was 7.41 ± 0.03 and [HCO3-] was 30.5 ± 1.0 mM in controls. Retinal mRNAs were quantified by quantitative reverse transcription polymerase chain reaction. Protein was quantified with Western blots and localized by confocal microscopy. Retinal [H+]o was measured in vivo with pH microelectrodes in animals subjected to metabolic acidosis and in controls. RESULTS NH4Cl in drinking water or given intravenous was effective in acidifying the retina. Cariporide, a blocker of Na+/H+ exchange, further acidified the retina. Metabolic acidosis for 2 weeks led to increases of 40-100% in mRNA for carbonic anhydrase isoforms II (CA-II) and XIV (CA-XIV) and acid-sensing ion channels 1 and 4 (ASIC1 and ASIC4) (all p < 0.005). Expression of anion exchange protein 3 (AEP-3) and Na+/H+ exchanger (NHE)-1 also increased by ≥50% (both p < 0.0001). Changes were similar after 1 week of acidosis. Protein for AEP-3 doubled. NHE-1 co-localized with vascular markers, particularly in the outer plexiform layer. CA-II was located in the neural parenchyma of the ganglion cell layer and diffusely in the rest of the inner retina. CONCLUSIONS The retina responds to systemic acidosis with increased expression of proton and bicarbonate exchangers, carbonic anhydrase, and ASICs. While responses to acidosis are usually associated with renal regulation, these studies suggest that the retina responds to changes in local pH presumably to control its acid/base environment in response to systemic acidosis.
Collapse
Affiliation(s)
- Alyssa Dreffs
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI
| | - Desmond Henderson
- Department of Biomedical Engineering, Northwestern University, Evanston and Chicago, IL
| | - Andrey V. Dmitriev
- Department of Biomedical Engineering, Northwestern University, Evanston and Chicago, IL
| | - David A. Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI
| | - Robert A. Linsenmeier
- Department of Biomedical Engineering, Northwestern University, Evanston and Chicago, IL
- Department of Neurobiology, Northwestern University, Evanston and Chicago, IL
- Department of Ophthalmology, Northwestern University, Evanston and Chicago, IL
| |
Collapse
|
22
|
Kady NM, Liu X, Lydic TA, Syed MH, Navitskaya S, Wang Q, Hammer SS, O'Reilly S, Huang C, Seregin SS, Amalfitano A, Chiodo VA, Boye SL, Hauswirth WW, Antonetti DA, Busik JV. ELOVL4-Mediated Production of Very Long-Chain Ceramides Stabilizes Tight Junctions and Prevents Diabetes-Induced Retinal Vascular Permeability. Diabetes 2018; 67:769-781. [PMID: 29362226 PMCID: PMC5860862 DOI: 10.2337/db17-1034] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 01/08/2018] [Indexed: 12/25/2022]
Abstract
Tight junctions (TJs) involve close apposition of transmembrane proteins between cells. Although TJ proteins have been studied in detail, the role of lipids is largely unknown. We addressed the role of very long-chain (VLC ≥26) ceramides in TJs using diabetes-induced loss of the blood-retinal barrier as a model. VLC fatty acids that incorporate into VLC ceramides are produced by elongase elongation of very long-chain fatty acids protein 4 (ELOVL4). ELOVL4 is significantly reduced in the diabetic retina. Overexpression of ELOVL4 significantly decreased basal permeability, inhibited vascular endothelial growth factor (VEGF)- and interleukin-1β-induced permeability, and prevented VEGF-induced decrease in occludin expression and border staining of TJ proteins ZO-1 and claudin-5. Intravitreal delivery of AAV2-hELOVL4 reduced diabetes-induced increase in vascular permeability. Ultrastructure and lipidomic analysis revealed that ω-linked acyl-VLC ceramides colocalize with TJ complexes. Overall, normalization of retinal ELOVL4 expression could prevent blood-retinal barrier dysregulation in diabetic retinopathy through an increase in VLC ceramides and stabilization of TJs.
Collapse
Affiliation(s)
- Nermin M Kady
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Xuwen Liu
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI
| | - Todd A Lydic
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Meesum H Syed
- Department of Physiology, Michigan State University, East Lansing, MI
| | | | - Qi Wang
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Sandra S Hammer
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Sandra O'Reilly
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Chao Huang
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Sergey S Seregin
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI
| | - Andrea Amalfitano
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI
| | - Vince A Chiodo
- Ophthalmology and Molecular Genetics and Retina Gene Therapy Group, University of Florida, Gainesville, FL
| | - Sanford L Boye
- Ophthalmology and Molecular Genetics and Retina Gene Therapy Group, University of Florida, Gainesville, FL
| | - William W Hauswirth
- Ophthalmology and Molecular Genetics and Retina Gene Therapy Group, University of Florida, Gainesville, FL
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI
| | - Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, MI
| |
Collapse
|
23
|
Ramos CJ, Lin C, Liu X, Antonetti DA. The EPAC-Rap1 pathway prevents and reverses cytokine-induced retinal vascular permeability. J Biol Chem 2017; 293:717-730. [PMID: 29158262 DOI: 10.1074/jbc.m117.815381] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/15/2017] [Indexed: 12/31/2022] Open
Abstract
Increased retinal vascular permeability contributes to macular edema, a leading cause of vision loss in eye pathologies such as diabetic retinopathy, age-related macular degeneration, and central retinal vein occlusions. Pathological changes in vascular permeability are driven by growth factors such as VEGF and pro-inflammatory cytokines such as TNF-α. Identifying the pro-barrier mechanisms that block vascular permeability and restore the blood-retinal barrier (BRB) may lead to new therapies. The cAMP-dependent guanine nucleotide exchange factor (EPAC) exchange-protein directly activated by cAMP promotes exchange of GTP in the small GTPase Rap1. Rap1 enhances barrier properties in human umbilical endothelial cells by promoting adherens junction assembly. We hypothesized that the EPAC-Rap1 signaling pathway may regulate the tight junction complex of the BRB and may restore barrier properties after cytokine-induced permeability. Here, we show that stimulating EPAC or Rap1 activation can prevent or reverse VEGF- or TNF-α-induced permeability in cell culture and in vivo Moreover, EPAC activation inhibited VEGF receptor (VEGFR) signaling through the Ras/MEK/ERK pathway. We also found that Rap1B knockdown or an EPAC antagonist increases endothelial permeability and that VEGF has no additive effect, suggesting a common pathway. Furthermore, GTP-bound Rap1 promoted tight junction assembly, and loss of Rap1B led to loss of junctional border organization. Collectively, our results indicate that the EPAC-Rap1 pathway helps maintain basal barrier properties in the retinal vascular endothelium and activation of the EPAC-Rap1 pathway may therefore represent a potential therapeutic strategy to restore the BRB.
Collapse
Affiliation(s)
- Carla J Ramos
- From the Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan 48105
| | - Chengmao Lin
- From the Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan 48105
| | - Xuwen Liu
- From the Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan 48105
| | - David A Antonetti
- From the Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan 48105
| |
Collapse
|
24
|
Małecki A, Skipor-Lahuta J, Toborek M, Abbott NJ, Antonetti DA, Su EJ, Lawrence DA, Atış M, Akcan U, Yılmaz CU, Orhan N, Düzgün P, Ceylan UD, Arıcan N, Karahüseyinoğlu S, Şahin GN, Ahıshalı B, Kaya M, Aydin S, Klopstein A, Engelhardt B, Baumann J, Tsao CC, Huang SF, Ogunshola O, Boytsova EB, Morgun AV, Khilazheva ED, Pozhilenkova EA, Gorina YV, Martynova GP, Salmina AB, Bueno D, Garcia-Fernàndez J, Castro V, Skowronska M, Toborek M, Chupel MU, Minuzzi LG, Filaire E, Teixeira AM, Corsi M, Versele R, Fuso A, Sevin E, Di Lorenzo C, Businaro R, Fenart L, Gosselet F, Candela P, Deli MA, Delaney C, O’Keefe E, Farrell M, Doyle S, Campbell M, Drewes LR, Appelt-Menzel A, Cubukova A, Metzger M, Fischer R, Francisco DMF, Bruggmann R, Fries A, Blecharz KG, Wagner J, Winkler L, Schneider U, Vajkoczy P, Furuse M, Gabbert L, Dilling C, Sisario D, Soukhoroukov V, Burek M, Guérit S, Fidan E, Devraj K, Czupalla CJ, Macas J, Thom S, Plate KH, Gerhardt H, Liebner S, Harazin A, Bocsik A, Váradi J, Fenyvesi F, Tubak V, Vecsernyés M, Helms HC, Waagepetersen HS, Nielsen CU, Brodin B, Hoyk Z, Tóth ME, Lénárt N, Dukay B, Kittel Á, Vígh J, Veszelka S, Walter F, Zvara Á, Puskás L, Sántha M, Engelhardt S, Ogunshola OO, Huber A, Reitner A, Osmen S, Hahn K, Bounzina N, Gerhartl A, Schönegger A, Steinkellner H, Laccone F, Neuhaus W, Hudson N, Celkova L, Iltzsche A, Drndarski S, Begley DJ, Janiurek MM, Kucharz K, Christoffersen C, Nielsen LB, Lauritzen M, Johnson RH, Kho DT, O’Carroll SJ, Angel CE, Graham ES, Pereira J, Karali CS, Cheng V, Zarghami N, Soto MS, Couch Y, Anthony DC, Sibson NR, Kealy J, Keep RF, Routhe LJ, Xiang J, Ye H, Hua Y, Moos T, Xi G, Kristensen M, Bach A, Strømgaard K, Kutuzov N, Lopes-Pinheiro MA, Lim J, Kamermans A, van Horssen J, Unger WW, Fontijn R, de Vries HE, Majerova P, Garruto RM, Marchetti L, Francisco D, Gruber I, Lyck R, Mészáros M, Porkoláb G, Kiss L, Pilbat AM, Török Z, Bozsó Z, Fülöp L, Michalicova A, Galba J, Mihaljevic S, Novak M, Kovac A, Morofuji Y, Fujimoto T, Watanabe D, Nakagawa S, Ujifuku K, Horie N, Izumo T, Anda T, Matsuo T, Niu F, Buch S, Nyúl-Tóth Á, Kozma M, Nagyőszi P, Nagy K, Fazakas C, Haskó J, Molnár K, Farkas AE, Galajda P, Wilhelm I, Krizbai IA, Kelly E, Wallace E, Greene C, Hughes S, Kealy J, Doyle N, Humphries MM, Grant GA, Friedman A, Veksler R, Molloy MG, Meaney JF, Pender N, Doherty CP, Park M, Liskiewicz A, Przybyla M, Kasprowska-Liśkiewicz D, Nowacka-Chmielewska M, Malecki A, Pombero A, Garcia-Lopez R, Martinez-Morga M, Martinez S, Prager O, Solomon-Kamintsky L, Schoknecht K, Bar-Klein G, Milikovsky D, Vazana U, Rosenbach D, Kovács R, Friedman A, Radak Z, Rodríguez-Lorenzo S, Bruggmann R, Kooij G, de Vries HE, Oxana SG, Denis B, Elena V, Anna A, Alla S, Vladimir S, Andrey M, Nataliya M, Elena K, Elizaveta B, Alexander S, Nikita N, Alla B, Yirong Y, Arkady A, Artem G, Mariya U, Anastasia S, Madina B, Artem S, Alexander K, Esmat SA, Valery P, Artem T, Jürgen K, de Abreu MS, Calpena AC, Espina M, García ML, Romero IA, Male D, Storck S, Hartz A, Pahnke J, Surma CU, Surma M, Giżejewski Z, Zieliński H, Szczepkowska A, Kowalewska M, Krawczynska A, Herman AP, Skipor J, Kachappilly N, Veenstra M, Rivera RL, Williams DW, Morgello S, Berman JW, Wyneken U, Batiz LF, Temizyürek A, Khodadust R, Küçük M, Gürses C, Emik S, Zielińska M, Obara-Michlewska M, Milewski K, Skonieczna E, Fręśko I, Neuwelt EA, Maria ARS, Bras AR, Lipka D, Valkai S, Kincses A, Dér A, Deli MA. Abstracts from the 20th International Symposium on Signal Transduction at the Blood-Brain Barriers. Fluids Barriers CNS 2017. [PMCID: PMC5667590 DOI: 10.1186/s12987-017-0071-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
25
|
Díaz-Coránguez M, Ramos C, Antonetti DA. The inner blood-retinal barrier: Cellular basis and development. Vision Res 2017; 139:123-137. [PMID: 28619516 DOI: 10.1016/j.visres.2017.05.009] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/26/2017] [Accepted: 05/30/2017] [Indexed: 01/01/2023]
Abstract
The blood-retinal barrier (BRB) regulates transport across retinal capillaries maintaining proper neural homeostasis and protecting the neural tissue from potential blood borne toxicity. Loss of the BRB contributes to the pathophysiology of a number of blinding retinal diseases including diabetic retinopathy. In this review, we address the basis of the BRB, including the molecular mechanisms that regulate flux across the retinal vascular bed. The routes of transcellular and paracellular flux are described as well as alterations in these pathways in response to permeabilizing agents in diabetes. Finally, we provide information on exciting new studies that help to elucidate the process of BRB development or barriergenesis and how understanding this process may lead to new opportunities for barrier restoration in diabetic retinopathy.
Collapse
Affiliation(s)
- Mónica Díaz-Coránguez
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, United States
| | - Carla Ramos
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, United States
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, United States.
| |
Collapse
|
26
|
Gonçalves A, Lin CM, Muthusamy A, Fontes-Ribeiro C, Ambrósio AF, Abcouwer SF, Fernandes R, Antonetti DA. Protective Effect of a GLP-1 Analog on Ischemia-Reperfusion Induced Blood-Retinal Barrier Breakdown and Inflammation. Invest Ophthalmol Vis Sci 2017; 57:2584-92. [PMID: 27163772 PMCID: PMC4868093 DOI: 10.1167/iovs.15-19006] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Inflammation associated with blood–retinal barrier (BRB) breakdown is a common feature of several retinal diseases. Therefore, the development of novel nonsteroidal anti-inflammatory approaches may provide important therapeutic options. Previous studies demonstrated that inhibition of dipeptidyl peptidase-IV, the enzyme responsible for the degradation of glucagon-like peptide-1 (GLP-1), led to insulin-independent prevention of diabetes-induced increases in BRB permeability, suggesting that incretin-based drugs may have beneficial pleiotropic effects in the retina. In the current study, the barrier protective and anti-inflammatory properties of exendin-4 (Ex-4), an analog of GLP-1, after ischemia-reperfusion (IR) injury were examined. Methods Ischemia-reperfusion injury was induced in rat retinas by increasing the intraocular pressure for 45 minutes followed by 48 hours of reperfusion. Rats were treated with Ex-4 prior to and following IR. Blood–retinal barrier permeability was assessed by Evans blue dye leakage. Retinal inflammatory gene expression and leukocytic infiltration were measured by qRT-PCR and immunofluorescence, respectively. A microglial cell line was used to determine the effects of Ex-4 on lipopolysaccharide (LPS)-induced inflammatory response. Results Exendin-4 dramatically reduced the BRB permeability induced by IR injury, which was associated with suppression of inflammatory gene expression. Moreover, in vitro studies showed that Ex-4 also reduced the inflammatory response to LPS and inhibited NF-κB activation. Conclusions The present work suggests that Ex-4 can prevent IR injury–induced BRB breakdown and inflammation through inhibition of inflammatory cytokine production by activated microglia and may provide a novel option for therapeutic intervention in diseases involving retinal inflammation.
Collapse
Affiliation(s)
- Andreia Gonçalves
- Institute for Biomedical Imaging and Life Sciences (IBILI) Faculty of Medicine, University of Coimbra, Coimbra, Portugal 3CNC.IBILI, University of Coimbra, Coimbra, Portugal
| | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Arivalagan Muthusamy
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Carlos Fontes-Ribeiro
- Institute for Biomedical Imaging and Life Sciences (IBILI) Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - António F Ambrósio
- Institute for Biomedical Imaging and Life Sciences (IBILI) Faculty of Medicine, University of Coimbra, Coimbra, Portugal 3CNC.IBILI, University of Coimbra, Coimbra, Portugal 4Association for Innovation and Biomedical Research on Light, Coimbra, Portugal
| | - Steven F Abcouwer
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Rosa Fernandes
- Institute for Biomedical Imaging and Life Sciences (IBILI) Faculty of Medicine, University of Coimbra, Coimbra, Portugal 3CNC.IBILI, University of Coimbra, Coimbra, Portugal
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| |
Collapse
|
27
|
Abstract
Maintenance and regulation of the vascular endothelial cell junctional complex is critical for proper barrier function of the blood-brain barrier (BBB) and the highly related blood-retinal barrier (BRB) that help maintain proper neuronal environment. Recent research has demonstrated that the junctional complex is actively maintained and can be dynamically regulated. Studies focusing on the mechanisms of barrier formation, maintenance, and barrier disruption have been of interest to understanding development of the BBB and BRB and identifying a means for therapeutic intervention for diseases ranging from brain tumors and dementia to blinding eye diseases. Research has increasingly revealed that small GTPases play a critical role in both barrier formation and disruption mechanisms. This review will summarize the current data on small GTPases in barrier regulation with an emphasis on the EPAC-Rap1 signaling pathway to Rho in endothelial barriers, as well as explore its potential involvement in paracellular flux and transcytosis regulation.
Collapse
Affiliation(s)
- Carla J Ramos
- a Department of Ophthalmology and Visual Sciences , University of Michigan , Ann Arbor , MI USA
| | - David A Antonetti
- a Department of Ophthalmology and Visual Sciences , University of Michigan , Ann Arbor , MI USA
| |
Collapse
|
28
|
Bolinger MT, Antonetti DA. Moving Past Anti-VEGF: Novel Therapies for Treating Diabetic Retinopathy. Int J Mol Sci 2016; 17:E1498. [PMID: 27618014 PMCID: PMC5037775 DOI: 10.3390/ijms17091498] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 08/22/2016] [Accepted: 08/30/2016] [Indexed: 12/25/2022] Open
Abstract
Diabetic retinopathy is the leading cause of blindness in working age adults, and is projected to be a significant future health concern due to the rising incidence of diabetes. The recent advent of anti-vascular endothelial growth factor (VEGF) antibodies has revolutionized the treatment of diabetic retinopathy but a significant subset of patients fail to respond to treatment. Accumulating evidence indicates that inflammatory cytokines and chemokines other than VEGF may contribute to the disease process. The current review examines the presence of non-VEGF cytokines in the eyes of patients with diabetic retinopathy and highlights mechanistic pathways in relevant animal models. Finally, novel drug targets including components of the kinin-kallikrein system and emerging treatments such as anti-HPTP (human protein tyrosine phosphatase) β antibodies are discussed. Recognition of non-VEGF contributions to disease pathogenesis may lead to novel therapeutics to enhance existing treatments for patients who do not respond to anti-VEGF therapies.
Collapse
Affiliation(s)
- Mark T Bolinger
- Departments of Ophthalmology and Visual Sciences, Kellogg Eye Center, and Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, USA.
| | - David A Antonetti
- Departments of Ophthalmology and Visual Sciences, Kellogg Eye Center, and Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, USA.
| |
Collapse
|
29
|
Liu X, Dreffs A, Díaz-Coránguez M, Runkle EA, Gardner TW, Chiodo VA, Hauswirth WW, Antonetti DA. Occludin S490 Phosphorylation Regulates Vascular Endothelial Growth Factor-Induced Retinal Neovascularization. Am J Pathol 2016; 186:2486-99. [PMID: 27423695 DOI: 10.1016/j.ajpath.2016.04.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 04/07/2016] [Accepted: 04/26/2016] [Indexed: 01/01/2023]
Abstract
Occludin is a transmembrane tight junction protein that contributes to diverse cellular functions, including control of barrier properties, cell migration, and proliferation. Vascular endothelial growth factor (VEGF) induces phosphorylation of occludin at S490, which is required for VEGF-induced endothelial permeability. Herein, we demonstrate that occludin S490 phosphorylation also regulates VEGF-induced retinal endothelial cell proliferation and neovascularization. Using a specific antibody, phospho-occludin was located in centrosomes in endothelial cell cultures, animal models, and human surgical samples of retinal neovessels. Occludin S490 phosphorylation was found to increase with endothelial tube formation in vitro and in vivo during retinal neovascularization after induction of VEGF expression. More important, expression of occludin mutated at S490 to Ala, completely inhibited angiogenesis in cell culture models and in vivo. Collectively, these data suggest a novel role for occludin in regulation of endothelial proliferation and angiogenesis in a phosphorylation-dependent manner. These findings may lead to methods of regulating pathological neovascularization by specifically targeting endothelial cell proliferation.
Collapse
Affiliation(s)
- Xuwen Liu
- Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan
| | - Alyssa Dreffs
- Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan
| | - Monica Díaz-Coránguez
- Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan
| | - E Aaron Runkle
- Department of Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Thomas W Gardner
- Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan
| | - Vince A Chiodo
- Department of Ophthalmology, University of Florida, Gainesville, Florida
| | | | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan.
| |
Collapse
|
30
|
Korot E, Comer G, Steffens T, Antonetti DA. Algorithm for the Measure of Vitreous Hyperreflective Foci in Optical Coherence Tomographic Scans of Patients With Diabetic Macular Edema. JAMA Ophthalmol 2016; 134:15-20. [PMID: 26502148 DOI: 10.1001/jamaophthalmol.2015.3949] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
IMPORTANCE Developing a noninvasive measure of diabetic retinopathy disease progression may provide physicians with information needed for patient-specific intervention. OBJECTIVE To develop an algorithm to measure vitreous hyperreflective foci (VHRF) from standard, 3-dimensional optical coherence tomographic (OCT) images in an unbiased manner. DESIGN, SETTING, AND PARTICIPANTS We retrospectively analyzed OCT scans from 97 patients who were evaluated at the Kellogg Eye Center, University of Michigan. Patients with diabetes mellitus without signs of retinopathy (n = 9) and patients with diabetic macular edema (DME) (n = 31) were compared with healthy control participants (n = 37). The algorithm was used to determine whether the VHRF score is associated with DME and may serve as a noninvasive measure of inflammation. The study was conducted from November 14, 2011, to August 5, 2015. Data analysis was performed from May 15, 2014, to August 13, 2015. MAIN OUTCOMES AND MEASURES An algorithm was developed to enhance the vitreous imaging from OCT to allow automated quantification of VHRF and calculation of a VHRF score. This score was compared between the healthy control, diabetes without retinopathy, and DME groups. RESULTS In the 97 scans evaluated, VHRF scores, reported as mean (SD), were increased in patients with DME by 2.95-fold (5.60 [8.65]) compared with healthy controls (1.90 [3.42]; 95% CI, 0.75-7.45; P = .012) and by 6.83-fold compared with patients with diabetes without retinopathy (0.82 [1.26]; 95% CI, 1.46-8.82; P = .005). CONCLUSIONS AND RELEVANCE Scores obtained using the VHRF algorithm may be obtained from OCT images that include the vitreous and could provide a rapid, noninvasive clinical correlate for ocular inflammation. Higher VHRF scores in patients with DME compared with controls and diabetic patients without retinopathy warrant further population-based and longitudinal studies to help determine the value of the VHRF score in selecting therapeutic intervention.
Collapse
Affiliation(s)
- Edward Korot
- Beaumont Eye Institute, Royal Oak, Michigan2Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor
| | - Grant Comer
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor
| | - Timothy Steffens
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor
| |
Collapse
|
31
|
Liu H, Tang J, Du Y, Lee CA, Golczak M, Muthusamy A, Antonetti DA, Veenstra AA, Amengual J, von Lintig J, Palczewski K, Kern TS. Retinylamine Benefits Early Diabetic Retinopathy in Mice. J Biol Chem 2015; 290:21568-79. [PMID: 26139608 DOI: 10.1074/jbc.m115.655555] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Indexed: 12/12/2022] Open
Abstract
Recent evidence suggests an important role for outer retinal cells in the pathogenesis of diabetic retinopathy (DR). Here we investigated the effect of the visual cycle inhibitor retinylamine (Ret-NH2) on the development of early DR lesions. Wild-type (WT) C57BL/6J mice (male, 2 months old when diabetes was induced) were made diabetic with streptozotocin, and some were given Ret-NH2 once per week. Lecithin-retinol acyltransferase (LRAT)-deficient mice and P23H mutant mice were similarly studied. Mice were euthanized after 2 (WT and Lrat(-/-)) and 8 months (WT) of study to assess vascular histopathology, accumulation of albumin, visual function, and biochemical and physiological abnormalities in the retina. Non-retinal effects of Ret-NH2 were examined in leukocytes treated in vivo. Superoxide generation and expression of inflammatory proteins were significantly increased in retinas of mice diabetic for 2 or 8 months, and the number of degenerate retinal capillaries and accumulation of albumin in neural retina were significantly increased in mice diabetic for 8 months compared with nondiabetic controls. Administration of Ret-NH2 once per week inhibited capillary degeneration and accumulation of albumin in the neural retina, significantly reducing diabetes-induced retinal superoxide and expression of inflammatory proteins. Superoxide generation also was suppressed in Lrat(-/-) diabetic mice. Leukocytes isolated from diabetic mice treated with Ret-NH2 caused significantly less cytotoxicity to retinal endothelial cells ex vivo than did leukocytes from control diabetics. Administration of Ret-NH2 once per week significantly inhibited the pathogenesis of lesions characteristic of early DR in diabetic mice. The visual cycle constitutes a novel target for inhibition of DR.
Collapse
Affiliation(s)
| | - Jie Tang
- From the Departments of Medicine and
| | | | | | - Marcin Golczak
- Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Arivalagan Muthusamy
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan 48105, and
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan 48105, and
| | | | - Jaume Amengual
- Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | | | | | - Timothy S Kern
- From the Departments of Medicine and Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106, Veterans Affairs Medical Center, Cleveland, Ohio 44106
| |
Collapse
|
32
|
Du Y, Cramer M, Lee CA, Tang J, Muthusamy A, Antonetti DA, Jin H, Palczewski K, Kern TS. Adrenergic and serotonin receptors affect retinal superoxide generation in diabetic mice: relationship to capillary degeneration and permeability. FASEB J 2015; 29:2194-204. [PMID: 25667222 DOI: 10.1096/fj.14-269431] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 01/13/2015] [Indexed: 12/22/2022]
Abstract
Reactive oxygen species play an important role in the pathogenesis of diabetic retinopathy. We studied the role of adrenergic and serotonin receptors in the generation of superoxide by retina and 661W retinal cells in high glucose and of the α1-adrenergic receptor (AR) on vascular lesions of the retinopathy in experimentally diabetic C57Bl/6J mice (and controls) after 2 and 8 months. Compared with 5 mM glucose, incubating cells or retinal explants in 30 mM glucose induced superoxide generation. This response was reduced or ablated by pharmacologic inhibition of the α1-AR (a Gq-coupled receptor) or Gs-coupled serotonin (5-HT2, 5-HT4, 5-HT6, and 5-HT7) receptors or by activation of the Gi-coupled α2-AR. In elevated glucose, the α1-AR produced superoxide via phospholipase C, inositol triphosphate-induced Ca(2+) release, and NADPH oxidase, and pharmacologic inhibition of these reactions prevented the superoxide increase. Generation of retinal superoxide, expression of proinflammatory proteins, and degeneration of retinal capillaries in diabetes all were significantly inhibited with daily doxazosin or apocynin (inhibitors of α1-AR and NADPH oxidase, respectively), but increased vascular permeability was not significantly affected. Adrenergic receptors, and perhaps other GPCRs, represent novel targets for inhibiting the development of important features of diabetic retinopathy.
Collapse
Affiliation(s)
- Yunpeng Du
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Megan Cramer
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Chieh Allen Lee
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Jie Tang
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Arivalagan Muthusamy
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - David A Antonetti
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Hui Jin
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Krzysztof Palczewski
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Timothy S Kern
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| |
Collapse
|
33
|
Abstract
Diabetic retinopathy is the leading cause of visual impairment and preventable blindness, and represents a significant socioeconomic cost for health care systems worldwide. Therefore, new approaches beyond current standards of diabetes care are needed. Based on the crucial pathogenic role of vascular endothelial growth factor (VEGF) in the development of diabetic macular edema (DME), intravitreal anti-VEGF agents have emerged as new treatments. To provide an understanding of the rationale for use and clinical efficacy of anti-VEGF treatment, we examine this topic in a two-part Bench to Clinic narrative. In the Bench narrative, we provide an overview of the role of VEGF in the pathogenesis of diabetic retinopathy, the molecular characteristics of anti-VEGF agents currently used, and future perspectives and challenges in this area. In the Clinic narrative that follows our contribution, Cheung et al. provide an overview of the current evidence from clinical trials on anti-VEGF therapy for diabetic retinopathy.
Collapse
|
34
|
Muthusamy A, Lin CM, Shanmugam S, Lindner HM, Abcouwer SF, Antonetti DA. Ischemia-reperfusion injury induces occludin phosphorylation/ubiquitination and retinal vascular permeability in a VEGFR-2-dependent manner. J Cereb Blood Flow Metab 2014; 34:522-31. [PMID: 24398936 PMCID: PMC3948134 DOI: 10.1038/jcbfm.2013.230] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 11/05/2013] [Accepted: 11/25/2013] [Indexed: 02/02/2023]
Abstract
Retinal ischemia-reperfusion (IR) induces neurodegenaration as well as blood-retinal barrier (BRB) breakdown causing vascular permeability. Whereas the neuronal death has been extensively studied, the molecular mechanisms related to BRB breakdown in IR injury remain poorly understood. In this study, we investigated the early changes in tight junctional (TJ) proteins in response to IR injury. Ischemia-reperfusion injury was induced in male rat retinas by increasing the intraocular pressure for 45 minutes followed by natural reperfusion. The results demonstrate that IR injury induced occludin Ser490 phosphorylation and ubiquitination within 15 minutes of reperfusion with subsequent vascular permeability. Immunohistochemical analysis revealed a rapid increase in occludin Ser490 phosphorylation and loss of Zonula occludens-1 (ZO-1) protein, particularly in arterioles. Ischemia-reperfusion injury also rapidly induced the activation and phosphorylation of vascular endothelial growth factor receptor-2 (VEGFR-2) at tyrosine 1175. Blocking vascular endothelial growth factor (VEGF) function by intravitreal injection of bevacizumab prevented VEGFR-2 activation, occludin phosphorylation, and vascular permeability. These studies suggest a novel mechanism of occludin Ser490 phosphorylation and ubiquitination downstream of VEGFR2 activation associated with early IR-induced vascular permeability.
Collapse
Affiliation(s)
- Arivalagan Muthusamy
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, USA
| | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, USA
| | - Sumathi Shanmugam
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, USA
| | - Heather M Lindner
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, USA
| | - Steven F Abcouwer
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, USA
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, USA
| |
Collapse
|
35
|
Zinnanti WJ, Lazovic J, Housman C, Antonetti DA, Koeller DM, Connor JR, Steinman L. Mechanism of metabolic stroke and spontaneous cerebral hemorrhage in glutaric aciduria type I. Acta Neuropathol Commun 2014; 2:13. [PMID: 24468193 PMCID: PMC3940023 DOI: 10.1186/2051-5960-2-13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 01/18/2014] [Indexed: 12/28/2022] Open
Abstract
Background Metabolic stroke is the rapid onset of lasting central neurological deficit associated with decompensation of an underlying metabolic disorder. Glutaric aciduria type I (GA1) is an inherited disorder of lysine and tryptophan metabolism presenting with metabolic stroke in infancy. The clinical presentation includes bilateral striatal necrosis and spontaneous subdural and retinal hemorrhages, which has been frequently misdiagnosed as non-accidental head trauma. The mechanisms underlying metabolic stroke and spontaneous hemorrhage are poorly understood. Results Using a mouse model of GA1, we show that metabolic stroke progresses in the opposite sequence of ischemic stroke, with initial neuronal swelling and vacuole formation leading to cerebral capillary occlusion. Focal regions of cortical followed by striatal capillaries are occluded with shunting to larger non-exchange vessels leading to early filling and dilation of deep cerebral veins. Blood–brain barrier breakdown was associated with displacement of tight-junction protein Occludin. Conclusion Together the current findings illuminate the pathophysiology of metabolic stroke and vascular compromise in GA1, which may translate to other neurometabolic disorders presenting with stroke.
Collapse
|
36
|
Abcouwer SF, Lin CM, Shanmugam S, Muthusamy A, Barber AJ, Antonetti DA. Minocycline prevents retinal inflammation and vascular permeability following ischemia-reperfusion injury. J Neuroinflammation 2013; 10:149. [PMID: 24325836 PMCID: PMC3866619 DOI: 10.1186/1742-2094-10-149] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 11/24/2013] [Indexed: 12/21/2022] Open
Abstract
Background Many retinal diseases are associated with vascular dysfunction accompanied by neuroinflammation. We examined the ability of minocycline (Mino), a tetracycline derivative with anti-inflammatory and neuroprotective properties, to prevent vascular permeability and inflammation following retinal ischemia-reperfusion (IR) injury, a model of retinal neurodegeneration with breakdown of the blood-retinal barrier (BRB). Methods Male Sprague–Dawley rats were subjected to 45 min of pressure-induced retinal ischemia, with the contralateral eye serving as control. Rats were treated with Mino prior to and following IR. At 48 h after reperfusion, retinal gene expression, cellular inflammation, Evan’s blue dye leakage, tight junction protein organization, caspase-3 activation, and DNA fragmentation were measured. Cellular inflammation was quantified by flow-cytometric evaluation of retinal tissue using the myeloid marker CD11b and leukocyte common antigen CD45 to differentiate and quantify CD11b+/CD45low microglia, CD11b+/CD45hi myeloid leukocytes and CD11bneg/CD45hi lymphocytes. Major histocompatibility complex class II (MHCII) immunoreactivity was used to determine the inflammatory state of these cells. Results Mino treatment significantly inhibited IR-induced retinal vascular permeability and disruption of tight junction organization. Retinal IR injury significantly altered mRNA expression for 21 of 25 inflammation- and gliosis-related genes examined. Of these, Mino treatment effectively attenuated IR-induced expression of lipocalin 2 (LCN2), serpin peptidase inhibitor clade A member 3 N (SERPINA3N), TNF receptor superfamily member 12A (TNFRSF12A), monocyte chemoattractant-1 (MCP-1, CCL2) and intercellular adhesion molecule-1 (ICAM-1). A marked increase in leukostasis of both myeloid leukocytes and lymphocytes was observed following IR. Mino treatment significantly reduced retinal leukocyte numbers following IR and was particularly effective in decreasing the appearance of MHCII+ inflammatory leukocytes. Surprisingly, Mino did not significantly inhibit retinal cell death in this model. Conclusions IR induces a retinal neuroinflammation within hours of reperfusion characterized by inflammatory gene expression, leukocyte adhesion and invasion, and vascular permeability. Despite Mino significantly inhibiting these responses, it failed to block neurodegeneration.
Collapse
Affiliation(s)
- Steven F Abcouwer
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, 1000 Wall Street, Ann Arbor, MI 48105, USA.
| | | | | | | | | | | |
Collapse
|
37
|
Tari SR, Youssif M, Samson CM, Harris RL, Lin CM, Kompella UB, Antonetti DA, Barile GR. Polychromatic angiography for the assessment of VEGF-induced BRB dysfunction in the rabbit retina. Invest Ophthalmol Vis Sci 2013; 54:5550-8. [PMID: 23882687 DOI: 10.1167/iovs.13-12144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine the utility of polychromatic angiography (PCA) in the assessment of VEGF-induced blood retinal barrier (BRB) dysfunction in rabbits. METHODS Twenty-six eyes of 24 Dutch Belted rabbits were injected intravitreally with 1.25 μg (group A, n = 5), 10 μg (group C, n = 7), or 4 μg (group B, n = 6; group D, n = 4; and group E, n = 4) of VEGF on day 0. Groups D and E were also injected intravitreally with 1.25 μg and 12.5 μg bevacizumab, respectively, on day 2. On days 0, 2, 4, 7, 11, and 14, PCA was performed using a contrast agent mixture composed of fluorescein sodium, indocyanine green, PCM102, and PCM107 and imaged with a modified fundus camera. PCA scores were based on detected leaking fluorophores. RESULTS On day 7, there was a statistically significant difference between PCA scores of group A (0.6 ± 0.89) and both groups B (2.67 ± 1.37, P = 0.0154) and C (3.33 ± 0.52, P = 0.00085). There was also a statistically significant difference between groups B and E (PCA score 0.75 ± 0.96, P = 0.032) on day 7. On day 11, there was statistically significant difference between group C (1.80 ± 1.1) and both groups A (0, P = 0.021) and B (0.33 ± 0.52, P = 0.037). CONCLUSIONS A differential response to both increasing VEGF dose and administration of bevacizumab could be discerned using the PCA. PCA allowed stratification of VEGF-induced BRB dysfunction and inhibitory effects of bevacizumab therapy in the rabbit retina.
Collapse
Affiliation(s)
- Samir R Tari
- PCAsso Diagnostics LLC, North Brunswick, New Jersey 08902, USA
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Keil JM, Liu X, Antonetti DA. Glucocorticoid induction of occludin expression and endothelial barrier requires transcription factor p54 NONO. Invest Ophthalmol Vis Sci 2013; 54:4007-15. [PMID: 23640037 PMCID: PMC3681474 DOI: 10.1167/iovs.13-11980] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 04/26/2013] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Glucocorticoids (GCs) effectively reduce retinal edema and induce vascular barrier properties but possess unwanted side effects. Understanding GC induction of barrier properties may lead to more effective and specific therapies. Previous work identified the occludin enhancer element (OEE) as a GC-responsive cis-element in the promoters of multiple junctional genes, including occludin, claudin-5, and cadherin-9. Here, we identify two OEE-binding factors and determine their contribution to GC induction of tight junction (TJ) gene expression and endothelial barrier properties. METHODS OEE-binding factors were isolated from human retinal endothelial cells (HREC) using DNA affinity purification followed by MALDI-TOF MS/MS. Chromatin immunoprecipitation (ChIP) assays determined in situ binding. siRNA was used to evaluate the role of trans-acting factors in transcription of TJ genes in response to GC stimulation. Paracellular permeability was determined by quantifying flux through a cell monolayer, whereas transendothelial electrical resistance (TER) was measured using the ECIS system. RESULTS MS/MS analysis of HREC nuclear extracts identified the heterodimer of transcription factors p54/NONO (p54) and polypyrimidine tract-binding protein-associated splicing factor (PSF) as OEE-binding factors, which was confirmed by ChIP assay from GC-treated endothelial cells and rat retina. siRNA knockdown of p54 demonstrated that this factor is necessary for GC induction of occludin and claudin-5 expression. Further, p54 knockdown ablated the pro-barrier effects of GC treatment. CONCLUSIONS p54 is essential for GC-mediated expression of occludin, claudin-5, and barrier induction, and the p54/PSF heterodimer may contribute to normal blood-retinal barrier (BRB) induction in vivo. Understanding the mechanism of GC induction of BRB properties may provide novel therapies for macular edema.
Collapse
Affiliation(s)
- Jason M Keil
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, USA
| | | | | |
Collapse
|
39
|
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.
Collapse
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,
| |
Collapse
|
40
|
|
41
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
Affiliation(s)
- Paul M Titchenell
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, PA 17033, USA
| | | | | | | | | | | |
Collapse
|
42
|
Runkle EA, Rice SJ, Qi J, Masser D, Antonetti DA, Winslow MM, Mu D. Occludin is a direct target of thyroid transcription factor-1 (TTF-1/NKX2-1). J Biol Chem 2012; 287:28790-801. [PMID: 22761434 DOI: 10.1074/jbc.m112.367987] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The thyroid transcription factor 1 gene (TTF-1 or NKX2-1) is essential to lung development; however, it is also a critical factor in lung cancer. TTF-1 is amplified in lung cancers, suggesting that it is a gain-of-function lung oncogene. Conversely, TTF-1 counters epithelial to mesenchymal transition in cell-based studies and inhibits progression of primary lung adenocarcinomas to metastases in an animal model of lung adenocarcinomas. The unifying theory regarding TTF-1 is that it exhibits both pro-oncogenic and anti-metastatic function depending on the cellular context. Occludin is the first discovered constituent of the epithelial tight junction; in recent years, a functional role of occludin as a tumor suppressor has begun to emerge. Here, we demonstrate that TTF-1 transactivated the expression of the epithelial tight junction molecules occludin (OCLN) and claudin-1 (CLDN1). We show that transcriptional activation occurred through a direct interaction of TTF-1 with the OCLN and CLDN1 promoters. Furthermore, in cells that lack TTF-1, exogenous TTF-1 expression dampened the inhibitory effect of TGF-β on occludin and claudin-1 content. Using cells derived from a genetically engineered mouse model of lung adenocarcinomas, we observed that silenced TTF-1 expression down-regulated occludin, which we supported with additional siRNA experiments. Finally, TTF-1 knockdown conferred human lung cancer cells resistance to anoikis, and expression of occludin restored cellular sensitivity to anoikis. Overexpression of occludin impeded migration and induced anoikis in lung carcinoma cells. Collectively, these data suggest that TTF-1 transcriptionally regulates occludin, which represents another avenue of TTF-1-mediated metastasis suppression.
Collapse
Affiliation(s)
- E Aaron Runkle
- Department of Pathology, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania 17033, USA
| | | | | | | | | | | | | |
Collapse
|
43
|
Murakami T, Frey T, Lin C, Antonetti DA. Protein kinase cβ phosphorylates occludin regulating tight junction trafficking in vascular endothelial growth factor-induced permeability in vivo. Diabetes 2012; 61:1573-83. [PMID: 22438576 PMCID: PMC3357276 DOI: 10.2337/db11-1367] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 01/28/2012] [Indexed: 11/21/2022]
Abstract
Vascular endothelial growth factor (VEGF)-induced breakdown of the blood-retinal barrier requires protein kinase C (PKC)β activation. However, the molecular mechanisms related to this process remain poorly understood. In this study, the role of occludin phosphorylation and ubiquitination downstream of PKCβ activation in tight junction (TJ) trafficking and endothelial permeability was investigated. Treatment of bovine retinal endothelial cells and intravitreal injection of PKCβ inhibitors as well as expression of dominant-negative kinase was used to determine the contribution of PKCβ to endothelial permeability and occludin phosphorylation at Ser490 detected with a site-specific antibody. In vitro kinase assay was used to demonstrate direct occludin phosphorylation by PKCβ. Ubiquitination was measured by immunoblotting after occludin immunoprecipitation. Confocal microscopy revealed organization of TJ proteins. The results reveal that inhibition of VEGF-induced PKCβ activation blocks occludin Ser490 phosphorylation, ubiquitination, and TJ trafficking in retinal vascular endothelial cells both in vitro and in vivo and prevents VEGF-stimulated vascular permeability. Occludin Ser490 is a direct target of PKCβ, and mutating Ser490 to Ala (S490A) blocks permeability downstream of PKCβ. Therefore, PKCβ activation phosphorylates occludin on Ser490, leading to ubiquitination required for VEGF-induced permeability. These data demonstrate a novel mechanism for PKCβ targeted inhibitors in regulating vascular permeability.
Collapse
Affiliation(s)
- Tomoaki Murakami
- Department of Cellular and Molecular Physiology and Ophthalmology, Penn State College of Medicine, Hershey, Pennsylvania
| | - Tiffany Frey
- Department of Cellular and Molecular Physiology and Ophthalmology, Penn State College of Medicine, Hershey, Pennsylvania
| | - Chengmao Lin
- Department of Cellular and Molecular Physiology and Ophthalmology, Penn State College of Medicine, Hershey, Pennsylvania
| | - David A. Antonetti
- Department of Cellular and Molecular Physiology and Ophthalmology, Penn State College of Medicine, Hershey, Pennsylvania
| |
Collapse
|
44
|
Affiliation(s)
- David A Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, USA
| | | | | |
Collapse
|
45
|
Abstract
Diabetic retinopathy (DR) is a leading cause of blindness in Western society. Since the prevalence of diabetes continues to increase dramatically, the impact of DR will only worsen unless new therapeutic options are developed. Recent data demonstrate that oxidative stress contributes to the pathology of DR and inhibition of oxidative stress reduces retinal vascular permeability. However, direct mechanisms by which oxidative stress alters the blood-retinal barrier (BRB) and increases vascular permeability remain to be elucidated. A large body of evidence demonstrates a clear role for altered expression of cytokines and growth factors in DR, resulting in increased vascular permeability, and the molecular mechanisms for these processes are beginning to emerge. The pathology of DR is likely a result of metabolic dysregulation contributing to both oxidative stress and cytokine production. This review will examine the evidence for oxidative stress, growth factors, and other cytokines in tight junction regulation and vascular permeability in DR.
Collapse
Affiliation(s)
- Tiffany Frey
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | | |
Collapse
|
46
|
Abstract
Proper control of cell cycle progression and barrier function are essential processes to the maintenance of epithelial cell homeostasis. The contribution of tight junction proteins to barrier function is well established, whereas their contribution to cell cycle control is only beginning to be understood. Centrosomes are the principal microtubule organizing centers in eukaryotic cells and centrosome duplication and separation are linked to the cell cycle and mitotic entry. Here we demonstrate that occludin localizes with centrosomes in Madin-Darby canine kidney cells. Immunocytochemistry and biochemical fractionation studies reveal occludin localizes with centrosomes during interphase and occludin Ser-490 phosphorylation at centrosomes increases with mitotic entry. Stable expression of aspartic acid phosphomimetic (S490D) results in centrosomal localization of occludin and increases cell numbers. Furthermore, we provide evidence that occludin regulates centrosome separation and mitotic entry as the nonphosphorylatable alanine mutation (S490A) impedes centrosome separation, delays mitotic entry, and reduces proliferation. Collectively, these studies demonstrate a novel location and function for occludin in centrosome separation and mitosis.
Collapse
Affiliation(s)
- E Aaron Runkle
- Departments of Cellular and Molecular Physiology, Hershey, Pennsylvania 17033
| | - Jeffrey M Sundstrom
- Ophthalmology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033
| | - Kristin B Runkle
- Departments of Cellular and Molecular Physiology, Hershey, Pennsylvania 17033
| | - Xuwen Liu
- University of Michigan Kellogg Eye Center, Ann Arbor, Michigan 48105
| | - David A Antonetti
- University of Michigan Kellogg Eye Center, Ann Arbor, Michigan 48105.
| |
Collapse
|
47
|
Lopez-Quintero SV, Ji XY, Antonetti DA, Tarbell JM. A three-pore model describes transport properties of bovine retinal endothelial cells in normal and elevated glucose. Invest Ophthalmol Vis Sci 2011; 52:1171-80. [PMID: 21357410 DOI: 10.1167/iovs.10-5971] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Changes in blood vessel barrier properties contribute to retinal edema in diabetic retinopathy (DR). However, limited data are available to describe the routes of transport for fluids and solutes across the inner blood-retinal barrier (iBRB). In this study, a three-pore model was developed to characterize such routes in normal and elevated glucose levels. METHODS Diffusive and apparent permeabilities to TAMRA (467 Da), dextran (70 kDa), and LDL (2000 kDa), as well as hydraulic conductivity, were measured across bovine retinal endothelial cell (BREC) monolayers after exposure to normal- and high-glucose media for 6 days. The data were used to develop a model of transport dynamics. Claudin 5 and eNOS Western blot analysis were used to measure changes in expression and phosphorylation. Immunolocalization of ZO-1 and VE-cadherin demonstrated organization of the junctional complex. Apoptosis was measured by TUNEL assay. RESULTS A three-pore model describes the fractional transport of water and molecular tracers across the retinal endothelial barrier. No change in permeability or hydraulic conductivity was observed after exposure to high glucose, whereas VEGF increased permeability in both normal- and high-glucose environments. The transport results were consistent with ZO-1 and VE-cadherin immunocytochemistry and expression of claudin-5, which were all unaltered by high glucose. CONCLUSIONS The data describe, for the first time, a model for transport of various size solutes and fluids across endothelial cells of the iBRB. Further, the results support the existence of an indirect pathway by which iBRB permeability is increased through the upregulation of retinal VEGF in response to hyperglycemia.
Collapse
Affiliation(s)
- Sandra V Lopez-Quintero
- Department of Biomedical Engineering, The City College of The City University of New York, New York, New York 10031, USA
| | | | | | | |
Collapse
|
48
|
Abstract
Formation and maintenance of the blood-retinal barrier is required for proper vision and loss of this barrier contributes to the pathology of a wide number of retinal diseases. The retina is responsible for converting visible light into the electrochemical signal interpreted by the brain as vision. Multiple cell types are required for this function, which are organized into eight distinct cell layers. These neural and glial cells gain metabolic support from a unique vascular structure that provides the necessary nutrients while minimizing interference with light sensing. In addition to the vascular contribution, the retina also possesses an epithelial barrier, the retinal pigment epithelium, which is located at the posterior of the eye and controls exchange of nutrients with the choroidal vessels. Together the vascular and epithelial components of the blood-retinal barrier maintain the specialized environment of the neural retina. Both the vascular endothelium and pigment epithelium possess a well-developed junctional complex that includes both adherens and tight junctions conferring a high degree of control of solute and fluid permeability. Understanding induction and regulation of the blood-retinal barrier will allow the development of therapies aimed at restoring the barrier when compromised in disease or allowing the specific transport of therapies across this barrier when needed. This chapter will highlight the anatomical structure of the blood-retinal barrier and explore the molecular structure of the tight junctions that provide the unique barrier properties of the blood--retinal barrier.
Collapse
Affiliation(s)
- E Aaron Runkle
- Department of Ophthalmology, Penn State College of Medicine, Hershey, PA, USA
| | | |
Collapse
|
49
|
Aveleira CA, Lin CM, Abcouwer SF, Ambrósio AF, Antonetti DA. TNF-α signals through PKCζ/NF-κB to alter the tight junction complex and increase retinal endothelial cell permeability. Diabetes 2010; 59:2872-82. [PMID: 20693346 PMCID: PMC2963546 DOI: 10.2337/db09-1606] [Citation(s) in RCA: 302] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Tumor necrosis factor-α (TNF-α) and interleukin-1 beta (IL-1β) are elevated in the vitreous of diabetic patients and in retinas of diabetic rats associated with increased retinal vascular permeability. However, the molecular mechanisms underlying retinal vascular permeability induced by these cytokines are poorly understood. In this study, the effects of IL-1β and TNF-α on retinal endothelial cell permeability were compared and the molecular mechanisms by which TNF-α increases cell permeability were elucidated. RESEARCH DESIGN AND METHODS Cytokine-induced retinal vascular permeability was measured in bovine retinal endothelial cells (BRECs) and rat retinas. Western blotting, quantitative real-time PCR, and immunocytochemistry were performed to determine tight junction protein expression and localization. RESULTS IL-1β and TNF-α increased BREC permeability, and TNF-α was more potent. TNF-α decreased the protein and mRNA content of the tight junction proteins ZO-1 and claudin-5 and altered the cellular localization of these tight junction proteins. Dexamethasone prevented TNF-α-induced cell permeability through glucocorticoid receptor transactivation and nuclear factor-kappaB (NF-κB) transrepression. Preventing NF-κB activation with an inhibitor κB kinase (IKK) chemical inhibitor or adenoviral overexpression of inhibitor κB alpha (IκBα) reduced TNF-α-stimulated permeability. Finally, inhibiting protein kinase C zeta (PKCζ) using both a peptide and a novel chemical inhibitor reduced NF-κB activation and completely prevented the alterations in the tight junction complex and cell permeability induced by TNF-α in cell culture and rat retinas. CONCLUSIONS These results suggest that PKCζ may provide a specific therapeutic target for the prevention of vascular permeability in retinal diseases characterized by elevated TNF-α, including diabetic retinopathy.
Collapse
Affiliation(s)
- Célia A Aveleira
- Centre of Ophthalmology and Vision Sciences, Institute of Biomedical Research in Light and Image, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
| | | | | | | | | |
Collapse
|
50
|
Schrufer TL, Antonetti DA, Sonenberg N, Kimball SR, Gardner TW, Jefferson LS. Ablation of 4E-BP1/2 prevents hyperglycemia-mediated induction of VEGF expression in the rodent retina and in Muller cells in culture. Diabetes 2010; 59:2107-16. [PMID: 20547975 PMCID: PMC2927931 DOI: 10.2337/db10-0148] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Vascular endothelial growth factor (VEGF) contributes to diabetic retinopathy, but control of its expression is not well understood. Here, we tested the hypothesis that hyperglycemia mediates induction of VEGF expression in a eukaryotic initiation factor 4E (eIF4E) binding protein (4E-BP) 1 and 2 dependent manner. RESEARCH DESIGN AND METHODS The retina was harvested from control and type 1 diabetic rats and mice and analyzed for VEGF mRNA and protein expression as well as biomarkers of translational control mechanisms. Similar analyses were performed in Müller cell cultures exposed to hyperglycemic conditions. The effect of 4E-BP1 and 4E-BP2 gene deletion on VEGF expression was examined in mice and in mouse embryo fibroblasts (MEFs). RESULTS Whereas VEGF mRNA in the retina remained constant, VEGF expression was increased as early as 2 weeks after the onset of diabetes. Increases in expression of 4E-BP1 protein mirrored those of VEGF and expression of 4E-BP1 mRNA was unchanged. Similar results were observed after 10 h of exposure of cells in culture to hyperglycemic conditions. Importantly, the diabetes-induced increase in VEGF expression was not observed in mice deficient in 4E-BP1 and 4E-BP2, nor in MEFs lacking the two proteins. CONCLUSIONS Hyperglycemia induces VEGF expression through cap-independent mRNA translation mediated by increased expression of 4E-BP1. Because the VEGF mRNA contains two internal ribosome entry sites, the increased expression is likely a consequence of ribosome loading at these sites. These findings provide new insights into potential targets for treatment of diabetic retinopathy.
Collapse
Affiliation(s)
- Tabitha L. Schrufer
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - David A. Antonetti
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Nahum Sonenberg
- Department of Biochemistry, McIntyre Medical Science Bldg., Montreal, Quebec, Canada
| | - Scot R. Kimball
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
- Corresponding author: Scot R. Kimball,
| | - Thomas W. Gardner
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
- Department of Ophthalmology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Leonard S. Jefferson
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| |
Collapse
|