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Chucair-Elliott AJ, Ocañas SR, Pham K, Machalinski A, Plafker S, Stout MB, Elliott MH, Freeman WM. Age- and sex- divergent translatomic responses of the mouse retinal pigmented epithelium. Neurobiol Aging 2024; 140:41-59. [PMID: 38723422 PMCID: PMC11173338 DOI: 10.1016/j.neurobiolaging.2024.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 05/18/2024]
Abstract
Aging is the main risk factor for age-related macular degeneration (AMD), a retinal neurodegenerative disease that leads to irreversible blindness, particularly in people over 60 years old. Retinal pigmented epithelium (RPE) atrophy is an AMD hallmark. Genome-wide chromatin accessibility, DNA methylation, and gene expression studies of AMD and control RPE demonstrate epigenomic/transcriptomic changes occur during AMD onset and progression. However, mechanisms by which molecular alterations of normal aging impair RPE function and contribute to AMD pathogenesis are unclear. Here, we specifically interrogate the RPE translatome with advanced age and across sexes in a novel RPE reporter mouse model. We find differential age- and sex- associated transcript expression with overrepresentation of pathways related to inflammation in the RPE. Concordant with impaired RPE function, the phenotypic changes in the aged translatome suggest that aged RPE becomes immunologically active, in both males and females, with some sex-specific signatures, which supports the need for sex representation for in vivo studies.
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Affiliation(s)
- Ana J Chucair-Elliott
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.
| | - Sarah R Ocañas
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Kevin Pham
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Adeline Machalinski
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Scott Plafker
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Michael B Stout
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Michael H Elliott
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Willard M Freeman
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA; Oklahoma City Veterans Affairs Medical Center, Oklahoma City, OK, USA.
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2
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Luo S, Hu Q, Jiang B, Zhang Z, Sun D. Bioinformatics analysis for constructing a cellular senescence-related age-related macular degeneration diagnostic model and identifying relevant disease subtypes to guide treatment. Aging (Albany NY) 2024; 16:8044-8069. [PMID: 38742956 PMCID: PMC11131993 DOI: 10.18632/aging.205804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 04/10/2024] [Indexed: 05/16/2024]
Abstract
Age-related macular degeneration (AMD) is a condition causing progressive central vision loss. Growing evidence suggests a link between cellular senescence and AMD. However, the exact mechanism by which cellular senescence leads to AMD remains unclear. Employing machine learning, we established an AMD diagnostic model. Through unsupervised clustering, two distinct AMD subtypes were identified. GO, KEGG, and GSVA analyses explored the diverse biological functions associated with the two subtypes. By WGCNA, we constructed a coexpression network of differential genes between the subtypes, revealing the regulatory role of hub genes at the level of transcription factors and miRNAs. We identified 5 genes associated with inflammation for the construction of the AMD diagnostic model. Additionally, we observed that the level of cellular senescence and pathways related to programmed cell death (PCD), such as ferroptosis, necroptosis, and pyroptosis, exhibited higher expression levels in subtype B than A. Immune microenvironments also differed between the subtypes, indicating potentially distinct pathogenic mechanisms and therapeutic targets. In summary, by leveraging cellular senescence-associated gene expression, we developed an AMD diagnostic model. Furthermore, we identified two subtypes with varying expression patterns of senescence genes, revealing their differential roles in programmed cell death, disease progression, and immune microenvironments within AMD.
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Affiliation(s)
- Shan Luo
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Qiang Hu
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Bo Jiang
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Zhongyu Zhang
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Dawei Sun
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
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3
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Ridley RB, Bowman BM, Lee J, Walsh E, Massengill MT, Lewin AS, Ildefonso CJ. Modulation of Retinal Inflammation Delays Degeneration in a Mouse Model of Geographic Atrophy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.08.527757. [PMID: 36798403 PMCID: PMC9934704 DOI: 10.1101/2023.02.08.527757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The advanced form of AMD, geographic atrophy, is associated with increased RPE oxidative stress and chronic inflammation. Here we evaluated the effects of delivering an anti-inflammatory viral gene by an AAV-vector in a mouse model of geographic atrophy. We measured changes in retinal function, structure, and morphology over nine months with electroretinography, optical coherence tomography, and fundoscopy, respectively. In addition, we used retinal tissue to quantify changes in markers of inflammation by multiplex ELISA, RT-qPCR, and immunofluorescence staining. Our AAV significantly delayed the loss of retinal function and structure and decreased retinal inflammation compared to the control AAV treatment. Our results suggest that modulating retinal inflammation could significantly slow the progression of geographic atrophy.
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Li P, Li Q, Biswas N, Xin H, Diemer T, Liu L, Perez Gutierrez L, Paternostro G, Piermarocchi C, Domanskyi S, Wang RK, Ferrara N. LIF, a mitogen for choroidal endothelial cells, protects the choriocapillaris: implications for prevention of geographic atrophy. EMBO Mol Med 2022; 14:e14511. [PMID: 34779136 PMCID: PMC8749470 DOI: 10.15252/emmm.202114511] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 10/21/2021] [Accepted: 10/25/2021] [Indexed: 12/18/2022] Open
Abstract
In the course of our studies aiming to discover vascular bed-specific endothelial cell (EC) mitogens, we identified leukemia inhibitory factor (LIF) as a mitogen for bovine choroidal EC (BCE), although LIF has been mainly characterized as an EC growth inhibitor and an anti-angiogenic molecule. LIF stimulated growth of BCE while it inhibited, as previously reported, bovine aortic EC (BAE) growth. The JAK-STAT3 pathway mediated LIF actions in both BCE and BAE cells, but a caspase-independent proapoptotic signal mediated by cathepsins was triggered in BAE but not in BCE. LIF administration directly promoted activation of STAT3 and increased blood vessel density in mouse eyes. LIF also had protective effects on the choriocapillaris in a model of oxidative retinal injury. Analysis of available single-cell transcriptomic datasets shows strong expression of the specific LIF receptor in mouse and human choroidal EC. Our data suggest that LIF administration may be an innovative approach to prevent atrophy associated with AMD, through protection of the choriocapillaris.
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Affiliation(s)
- Pin Li
- Department of PathologyUniversity of California San DiegoLa JollaCAUSA
| | - Qin Li
- Department of OphthalmologyUniversity of California San DiegoLa JollaCAUSA
| | - Nilima Biswas
- Department of PathologyUniversity of California San DiegoLa JollaCAUSA
| | - Hong Xin
- Department of PathologyUniversity of California San DiegoLa JollaCAUSA
| | - Tanja Diemer
- Department of PathologyUniversity of California San DiegoLa JollaCAUSA
| | - Lixian Liu
- Department of PathologyUniversity of California San DiegoLa JollaCAUSA
| | | | | | - Carlo Piermarocchi
- Department of Physics and AstronomyMichigan State UniversityEast LansingMIUSA
| | - Sergii Domanskyi
- Department of Physics and AstronomyMichigan State UniversityEast LansingMIUSA
| | - Ruikang K Wang
- Department of BioengineeringUniversity of WashingtonSeattleWAUSA
| | - Napoleone Ferrara
- Department of PathologyUniversity of California San DiegoLa JollaCAUSA
- Department of OphthalmologyUniversity of California San DiegoLa JollaCAUSA
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5
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Naguib SA, Bernardo-Colón A, Rex TS. Intravitreal injection worsens outcomes in a mouse model of indirect traumatic optic neuropathy from closed globe injury. Exp Eye Res 2021; 202:108369. [PMID: 33238184 PMCID: PMC8117180 DOI: 10.1016/j.exer.2020.108369] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/13/2020] [Accepted: 11/20/2020] [Indexed: 10/22/2022]
Abstract
It is well established that an intravitreal needle poke or injection of buffer is protective to the retina in models of photoreceptor degeneration due to release of endogenous neurotrophic factors. Here we assess the effect of intravitreal injection of buffer in a model of closed globe trauma that causes air-blast induced indirect traumatic optic neuropathy (bITON). We injected animals 1-day after the last bITON or sham procedure and performed assessments 1-month later. Surprisingly, we detected a lower electroretinogram (ERG), greater optic nerve damage, and increased levels of pro-inflammatory cytokines in animals given an intravitreal injection. The effect was sometimes independent of bITON and sometimes exacerbated by the injury. Retina histology appeared normal, however the total number of axons in the optic nerve was lower even in uninjured animals that were injected. The number of degenerative axons was further increased in injured animals that were injected. In contrast, we detected a decrease in the ERG a wave and b wave amplitudes, but no effect on the visual evoked potential. Levels of the pro-inflammatory cytokines, IL-1α and IL-1β were elevated in the mice that received an intravitreal injection. This increase was even greater in animals that also had a bITON. This suggests that intravitreal injections may be injurious to the optic nerve particularly during the acute stage of optic nerve injury. In addition, the data suggests a role for IL-1α and IL-1β in this response.
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Affiliation(s)
- Sarah A. Naguib
- Department of Ophthalmology & Visual Sciences, Vanderbilt University School of Medicine
| | | | - Tonia S. Rex
- Department of Ophthalmology & Visual Sciences, Vanderbilt University School of Medicine;,Vanderbilt Eye Institute, Vanderbilt University Medical Center,Corresponding Author,
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Light stress affects cones and horizontal cells via rhodopsin-mediated mechanisms. Exp Eye Res 2019; 186:107719. [PMID: 31291592 DOI: 10.1016/j.exer.2019.107719] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/04/2019] [Accepted: 07/04/2019] [Indexed: 01/20/2023]
Abstract
Retinal degenerations are a major cause of blindness in human patients. The identification of endogenous mechanisms involved in neurodegeneration or neuroprotection helps to understand the response of the retina to stress and provides essential information not only for basic retinal physiology but also for defining molecular targets for neuroprotective strategies. Here we used excessive light exposure as a model system to study mechanisms of photoreceptor degeneration in mice. Using one wild type and four genetically modified mouse strains, we demonstrate that light exposure resulted not only in the degeneration of rods but also in an early but transient repression of several cone-specific genes, in a reversible hyperreflectivity of the outer retina including the outer plexiform layer, and in the loss of horizontal cells. The effects on cones, horizontal cells and the inner retina depended on light absorption by rhodopsin and, at least partially, on leukemia inhibitory factor. This demonstrates the existence of intercellular communication routes that transduce rod stress to other cells, likely to provide support for photoreceptors and increase cell survival in the injured retina.
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7
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Muhammad F, Trivett A, Wang D, Lee DJ. Tissue-specific production of MicroRNA-155 inhibits melanocortin 5 receptor-dependent suppressor macrophages to promote experimental autoimmune uveitis. Eur J Immunol 2019; 49:2074-2082. [PMID: 31177529 DOI: 10.1002/eji.201848073] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 05/16/2019] [Accepted: 06/03/2019] [Indexed: 12/16/2022]
Abstract
Tissue-specific immune regulation is an important component of the immune response relevant to many areas of immunology. The focus of this study is on tissue-specific mechanisms that contribute to autoimmune uveitis. Precise gene regulation is necessary for the proper expression of an inflammatory or regulatory response. This precision gene regulation can be accomplished by microRNA at the level of the mRNA transcript. miR-155, in particular, has a complicated role in the immune response with positive and negative inflammatory effects. In this work, we identify a decrease in miR-155 in suppressor macrophages and further examine how tissue-specific production of miR-155 impacts experimental autoimmune uveitis. Importantly, we show that eliminating miR-155 expression by the target tissue before initiation reduces disease severity, but elimination of miR-155 after the onset of inflammation does not alter the course of disease. Additionally, expression of miR-155 by the target tissue before initiation is necessary for the induction of regulatory immunity that protects from further autoimmune disease, but not after the onset of inflammation. In summary, we find a MC5r-dependent decrease in miR-155 in postexperimental autoimmune uveitis APC, miR-155 production by the target tissue is necessary for the initiation of autoimmune uveitis, and may have a role in establishing protective regulatory immunity.
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Affiliation(s)
- Fauziyya Muhammad
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Anna Trivett
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, Frederick National Laboratory for Cancer Research (FNLCR), Frederick, MD
| | - Dawei Wang
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Darren J Lee
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK.,Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK
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8
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Massengill MT, Young B, Patel D, Jafri F, Sabogal E, Ash N, Li H, Ildefonso CJ, Lewin AS. Clinically Relevant Outcome Measures for the I307N Rhodopsin Mouse: A Model of Inducible Autosomal Dominant Retinitis Pigmentosa. Invest Ophthalmol Vis Sci 2019; 59:5417-5430. [PMID: 30452595 PMCID: PMC6237214 DOI: 10.1167/iovs.18-25345] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Purpose The I307N rhodopsin (Rho) mouse is a light-inducible model of autosomal dominant retinitis pigmentosa (adRP) that may be useful in testing therapies. We investigated the time-course of retinal changes of the I307N Rho mouse with spectral-domain optical coherence tomography (SD-OCT). Methods SD-OCT was performed up to day 30 after light damage; electroretinography (ERG) was employed to evaluate photoreceptor function. We utilized ImageJ to analyze reflectivity of the retina. We used light and electron microscopy to assess retinal organization. We stained synaptophysin and zonula occludins-1 with immunohistochemistry to determine injury to the plexiform layers and retinal pigment epithelium (RPE). We performed lectin staining to evaluate retinal blood vessels. Results Retinal degeneration increased with longer exposures to light. An increase in retinal thickness was detected by SD-OCT on day 1 after light challenge followed by loss of the outer nuclear layer (ONL) by day 8. Degeneration was most severe in the nasal and inferior retina. Hyper-reflectivity on SD-OCT developed as early as 1 day after light exposure. Disorganization of the ONL, condensation of photoreceptor chromatin, disruption of the outer limiting membrane, and disarray of outer segments were associated with the hyper-reflectivity. Retraction of the outer plexiform synapses and resorption of the subretinal detachment contributed to retinal thinning. The RPE remained intact, whereas atrophied major retinal vessels were evident after light damage. Conclusions Our time-course analysis of retinal degeneration in the I307N Rho mouse with SD-OCT and other outcome measures should enable the use of the mouse model in preclinical efficacy studies and mechanistic studies.
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Affiliation(s)
- Michael T Massengill
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Brianna Young
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Deep Patel
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Farwa Jafri
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Ernesto Sabogal
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Neil Ash
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Hong Li
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Cristhian J Ildefonso
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
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9
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Yang XF, Huang YX, Lan M, Zhang TR, Zhou J. Protective Effects of Leukemia Inhibitory Factor on Retinal Vasculature and Cells in Streptozotocin-induced Diabetic Mice. Chin Med J (Engl) 2019; 131:75-81. [PMID: 29271384 PMCID: PMC5754962 DOI: 10.4103/0366-6999.221263] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Leukemia inhibitory factor (LIF) has been reported to possess various pharmacological effects, including displaying vascular and neuroprotective properties, during retinal disease. The aim of this study was to investigate the vascular and structural changes in the retina of diabetic mice and to explore whether LIF prevents experimental diabetes-induced retinal injury in the early stages. METHODS Diabetes was induced in C57Bl/6J mice with streptozotocin (STZ) injections. Successful diabetic animal models were randomly separated into two groups: the diabetic group (n = 15) and the LIF-treated group (n = 15). Normal C57BL/6 mice served as the normal control group (n = 14). Recombinant human LIF was intravitreally injected 8 weeks after the diabetic model was successfully established. Retinas were collected and evaluated using histological and immunohistochemical techniques, and flat-mounted retinas and Western blotting were performed at 18 weeks after the induction of diabetes and 2 days after the intravitreal injection of LIF. The analysis of variance test were used. RESULTS Histological analysis showed that there were fewer retinal ganglion cells (RGCs) and the inner nuclear layer (INL) became thinner in the diabetic model group (RGC 21.8 ± 4.0 and INL 120.2 ± 4.6 μm) compared with the normal control group (RGC 29.0 ± 6.7, t = -3.02, P = 0.007; INL 150.7 ± 10.6 μm, t = -8.88, P < 0.001, respectively). After LIF treatment, the number of RGCs (26.9 ± 5.3) was significantly increased (t = 3.39, P = 0.030) and the INL (134.5 ± 14.2 μm) was thicker compared to the diabetic group (t = 2.75, P = 0.013). In the anti-Brn-3a-labeled retinas, the number of RGCs in the LIF-treated group (3926.0 ± 143.9) was obviously increased compared to the diabetic group (3507.7 ± 286.1, t = 2.38, P = 0.030), while no significance was found between the LIF-treated group and the control group (4188.3 ± 114.7, t = -2.47, P = 0.069). Flat-mounted retinas demonstrated that a disorganized, dense distribution of the vessel was prominent in the diabetic model group. Vessel distribution in the LIF-treated mouse group was typical and the thickness was uniform. The levels of phosphosignal transducer and activator of transcription 3 activation were obviously higher in the LIF-injected retinas than those in the diabetic control group (t = 3.85, P = 0.019) and the normal control (t = -3.20, P = 0.019). CONCLUSION The present study provides evidence that LIF treatment protects the integrity of the vasculature and prevents retinal injury in the early stages of diabetic retinopathy in STZ-induced diabetic models.
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Affiliation(s)
- Xiu-Fen Yang
- Department of Ophthalmology, The Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Ying-Xiang Huang
- Department of Ophthalmology, The Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Ming Lan
- Institute of Laboratory Animals of Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China
| | - Tao-Ran Zhang
- Department of Ophthalmology, The Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Jie Zhou
- Department of Ophthalmology, The Friendship Hospital, Capital Medical University, Beijing 100050, China
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10
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Li S, Sato K, Gordon WC, Sendtner M, Bazan NG, Jin M. Ciliary neurotrophic factor (CNTF) protects retinal cone and rod photoreceptors by suppressing excessive formation of the visual pigments. J Biol Chem 2018; 293:15256-15268. [PMID: 30115683 DOI: 10.1074/jbc.ra118.004008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 08/15/2018] [Indexed: 12/25/2022] Open
Abstract
The retinal pigment epithelium (RPE)-dependent visual cycle provides 11-cis-retinal to opsins in the photoreceptor outer segments to generate functional visual pigments that initiate phototransduction in response to light stimuli. Both RPE65 isomerase of the visual cycle and the rhodopsin visual pigment have recently been identified as critical players in mediating light-induced retinal degeneration. These findings suggest that the expression and function of RPE65 and rhodopsin need to be coordinately controlled to sustain normal vision and to protect the retina from photodamage. However, the mechanism controlling the development of the retinal visual system remains poorly understood. Here, we show that deficiency in ciliary neurotrophic factor (CNTF) up-regulates the levels of rod and cone opsins accompanied by an increase in the thickness of the outer nuclear layers and the lengths of cone and rod outer segments in the mouse retina. Moreover, retinoid isomerase activity, expression levels of RPE65 and lecithin:retinol acyltransferase (LRAT), which synthesizes the RPE65 substrate, were also significantly increased in the Cntf -/- RPE. Rod a-wave and cone b-wave amplitudes of electroretinograms were increased in Cntf -/- mice, but rod b-wave amplitudes were unchanged compared with those in WT mice. Up-regulated RPE65 and LRAT levels accelerated both the visual cycle rate and recovery rate of rod light sensitivity in Cntf -/- mice. Of note, rods and cones in Cntf -/- mice exhibited hypersusceptibility to light-induced degeneration. These results indicate that CNTF is a common extracellular factor that prevents excessive production of opsins, the photoreceptor outer segments, and 11-cis-retinal to protect rods and cones from photodamage.
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Affiliation(s)
- Songhua Li
- From the Neuroscience Center of Excellence and
| | - Kota Sato
- From the Neuroscience Center of Excellence and
| | - William C Gordon
- From the Neuroscience Center of Excellence and.,Department of Ophthalmology, Louisiana State University School of Medicine, New Orleans, Louisiana 70112 and
| | - Michael Sendtner
- the Institute of Clinical Neurobiology, University Hospital Würzburg, D-97078 Würzburg, Germany
| | - Nicolas G Bazan
- From the Neuroscience Center of Excellence and.,Department of Ophthalmology, Louisiana State University School of Medicine, New Orleans, Louisiana 70112 and
| | - Minghao Jin
- From the Neuroscience Center of Excellence and .,Department of Ophthalmology, Louisiana State University School of Medicine, New Orleans, Louisiana 70112 and
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11
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Damage-associated molecular pattern recognition is required for induction of retinal neuroprotective pathways in a sex-dependent manner. Sci Rep 2018; 8:9115. [PMID: 29904087 PMCID: PMC6002365 DOI: 10.1038/s41598-018-27479-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 06/04/2018] [Indexed: 12/29/2022] Open
Abstract
Retinal degeneration is a common cause of irreversible blindness and is caused by the death of retinal light-sensitive neurons called photoreceptors. At the onset of degeneration, stressed photoreceptors cause retinal glial cells to secrete neuroprotective factors that slow the pace of degeneration. Leukemia inhibitory factor (LIF) is one such factor that is required for endogenous neuroprotection. Photoreceptors are known to release signals of cellular stress, called damage-associated molecular patterns (DAMPs) early in degeneration, and we hypothesized that receptors for DAMPs or pattern recognition receptors (PRRs) play a key role in the induction of LIF and neuroprotective stress responses in retinal glial cells. Toll-like receptor 2 (TLR2) is a well-established DAMP receptor. In our experiments, activation of TLR2 protected both male and female mice from light damage, while the loss of TLR2 in female mice did not impact photoreceptor survival. In contrast, induction of protective stress responses, microglial phenotype and photoreceptor survival were strongly impacted in male TLR2−/− mice. Lastly, using publicly available gene expression data, we show that TLR2 is expressed highly in resting microglia prior to injury, but is also induced in Müller cells in inherited retinal degeneration.
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12
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Ma M, Xu Y, Xiong S, Zhang J, Gu Q, Ke B, Xu X. Involvement of ciliary neurotrophic factor in early diabetic retinal neuropathy in streptozotocin-induced diabetic rats. Eye (Lond) 2018; 32:1463-1471. [PMID: 29795129 PMCID: PMC6137181 DOI: 10.1038/s41433-018-0110-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 03/06/2018] [Accepted: 03/18/2018] [Indexed: 12/24/2022] Open
Abstract
Objective Ciliary neurotrophic factor (CNTF) has been evaluated as a candidate therapeutic agent for diabetes and its neural complications. However, its role in diabetic retinopathy has not been fully elucidated. Methods This is a randomized unblinded animal experiment. Wistar rats with streptozocin (STZ)-induced diabetes were regularly injected with CNTF or vehicle control in their vitreous bodies beginning at 2 weeks after STZ injection. A total of five injections were used. In diabetic rats, the levels of CNTF and neurotrophin-3 (NT-3) were evaluated by enzyme-linked immunosorbent assays (ELISA) and real-time PCR. The abundance of tyrosine hydroxylase (TH) and β-III tubulin was detected by western blot. Transferase-mediated dUTP nick-end labeling staining (TUNEL) was used to detect cell apoptosis in the retinal tissue. The activation of caspase-3 was also measured. Results The protein and mRNA levels of CNTF in diabetic rat retinas were reduced compared to control rats. In addition, retinal ganglion cells (RGCs) and dopaminergic amacrine cells appeared to undergo degeneration in diabetic rat retinas, as revealed by transferase-mediated dUTP nick-end labeling staining (TUNEL). Tyrosine hydroxylase (TH) and β-III tubulin protein levels also decreased significantly. Intraocular administration of CNTF rescued RGCs and dopaminergic amacrine cells from neurodegeneration and counteracted the downregulation of β-III tubulin and TH expression, thus demonstrating its therapeutic potential. Conclusion Our study suggests that early diabetic retinal neuropathy involves the reduced expression of CNTF and can be ameliorated by an exogenous supply of this neurotrophin.
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Affiliation(s)
- Mingming Ma
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai General Hospital, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Yupeng Xu
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai General Hospital, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Shuyu Xiong
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai General Hospital, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Jian Zhang
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai General Hospital, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Qing Gu
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai General Hospital, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Bilian Ke
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai General Hospital, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Xun Xu
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China. .,Department of Ophthalmology, Shanghai General Hospital, Shanghai, China. .,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China.
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TLR4 modulates inflammatory gene targets in the retina during Bacillus cereus endophthalmitis. BMC Ophthalmol 2018; 18:96. [PMID: 29661181 PMCID: PMC5902844 DOI: 10.1186/s12886-018-0764-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 04/03/2018] [Indexed: 02/07/2023] Open
Abstract
Background Endophthalmitis is a serious intraocular infection that frequently results in significant inflammation and vision loss. Because current therapeutics are often unsuccessful in mitigating damaging inflammation during endophthalmitis, more rational targets are needed. Toll-like receptors (TLRs) recognize specific motifs on invading pathogens and initiate the innate inflammatory response. We reported that TLR4 contributes to the robust inflammation which is a hallmark of Bacillus cereus endophthalmitis. To identify novel, targetable host inflammatory factors in this disease, we performed microarray analysis to detect TLR4-dependent changes to the retinal transcriptome during B. cereus endophthalmitis. Results C57BL/6 J and TLR4−/− mouse eyes were infected with B. cereus and retinas were harvested at 4 h postinfection, a time representing the earliest onset of neutrophil infiltration. Genes related to acute inflammation and inflammatory cell recruitment including CXCL1 (KC), CXCL2 (MIP2-α), CXCL10 (IP-10), CCL2 (MCP1), and CCL3 (MIP1-α)) were significantly upregulated 5-fold or greater in C57BL/6 J retinas. The immune modulator IL-6, intercellular adhesion molecule ICAM1, and the inhibitor of cytokine signal transduction SOCS3 were upregulated 25-, 11-, and 10-fold, respectively, in these retinas. LIF, which is crucial for photoreceptor cell survival, was increased 6-fold. PTGS2/COX-2, which converts arachidonic acid to prostaglandin endoperoxide H2, was upregulated 9-fold. PTX3, typically produced in response to TLR engagement, was induced 15-fold. None of the aforementioned genes were upregulated in TLR4−/− retinas following B. cereus infection. Conclusions Our results have identified a cohort of mediators driven by TLR4 that may be important in regulating pro-inflammatory and protective pathways in the retina in response to B. cereus intraocular infection. This supports the prospect that blocking the activation of TLR-based pathways might serve as alternative targets for Gram-positive and Gram-negative endophthalmitis therapies in general. Electronic supplementary material The online version of this article (10.1186/s12886-018-0764-8) contains supplementary material, which is available to authorized users.
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Chitranshi N, Dheer Y, Abbasi M, You Y, Graham SL, Gupta V. Glaucoma Pathogenesis and Neurotrophins: Focus on the Molecular and Genetic Basis for Therapeutic Prospects. Curr Neuropharmacol 2018; 16:1018-1035. [PMID: 29676228 PMCID: PMC6120108 DOI: 10.2174/1570159x16666180419121247] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 04/10/2018] [Accepted: 04/18/2018] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Retinal ganglion cell (RGC) degeneration is a major feature of glaucoma pathology. Neuroprotective approaches that delay or halt the progression of RGC loss are needed to prevent vision loss which can occur even after conventional medical or surgical treatments to lower intraocular pressure. OBJECTIVE The aim of this review was to examine the progress in genetics and cellular mechanisms associated with endoplasmic reticulum (ER) stress, RGC dysfunction and cell death pathways in glaucoma. MATERIALS AND METHODS Here, we review the involvement of neurotrophins like brain derived neurotrophic factor (BDNF) and its high affinity receptor tropomyosin receptor kinase (TrkB) in glaucoma. The role of ER stress markers in human and animal retinas in health and disease conditions is also discussed. Further, we analysed the literature highlighting genetic linkage in the context of primary open angle glaucoma and suggested mechanistic insights into potential therapeutic options relevant to glaucoma management. RESULTS The literature review of the neurobiology underlying neurotrophin pathways, ER stress and gene associations provide critical insights into association of RGCs death in glaucoma. Alteration in signalling pathway is associated with increased risk of misfolded protein aggregation in ER promoting RGC apoptosis. Several genes that are linked with neurotrophin signalling pathways have been reported to be associated with glaucoma pathology. CONCLUSION Understanding genetic heterogeneity and involvement of neurotrophin biology in glaucoma could help to understand the complex pathophysiology of glaucoma. Identification of novel molecular targets will be critical for drug development and provide neuroprotection to the RGCs and optic nerve.
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Affiliation(s)
- Nitin Chitranshi
- Address correspondence to this author at the Faculty of Medicine and Health Sciences, 75, Talavera Road, Macquarie University, Sydney, NSW 2109, Australia; Tel: +61-298502760; E-mail:
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Szabó K, Énzsöly A, Dékány B, Szabó A, Hajdú RI, Radovits T, Mátyás C, Oláh A, Laurik LK, Somfai GM, Merkely B, Szél Á, Lukáts Á. Histological Evaluation of Diabetic Neurodegeneration in the Retina of Zucker Diabetic Fatty (ZDF) Rats. Sci Rep 2017; 7:8891. [PMID: 28827737 PMCID: PMC5566374 DOI: 10.1038/s41598-017-09068-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 07/21/2017] [Indexed: 01/24/2023] Open
Abstract
In diabetes, retinal dysfunctions exist prior to clinically detectable vasculopathy, however the pathology behind these functional deficits is still not fully established. Previously, our group published a detailed study on the retinal histopathology of type 1 diabetic (T1D) rat model, where specific alterations were detected. Although the majority of human diabetic patients have type 2 diabetes (T2D), similar studies on T2D models are practically absent. To fill this gap, we examined Zucker Diabetic Fatty (ZDF) rats - a model for T2D - by immunohistochemistry at the age of 32 weeks. Glial reactivity was observed in all diabetic specimens, accompanied by an increase in the number of microglia cells. Prominent outer segment degeneration was detectable with changes in cone opsin expression pattern, without a decrease in the number of labelled elements. The immunoreactivity of AII amacrine cells was markedly decreased and changes were detectable in the number and staining of some other amacrine cell subtypes, while most other cells examined did not show any major alterations. Overall, the retinal histology of ZDF rats shows a surprising similarity to T1D rats indicating that despite the different evolution of the disease, the neuroretinal cells affected are the same in both subtypes of diabetes.
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Affiliation(s)
- Klaudia Szabó
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary
| | - Anna Énzsöly
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary
- Department of Ophthalmology, Semmelweis University, Budapest, H-1085, Hungary
| | - Bulcsú Dékány
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary
| | - Arnold Szabó
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary
| | - Rozina I Hajdú
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary
| | - Tamás Radovits
- Heart and Vascular Center, Semmelweis University, Budapest, H-1085, Hungary
| | - Csaba Mátyás
- Heart and Vascular Center, Semmelweis University, Budapest, H-1085, Hungary
| | - Attila Oláh
- Heart and Vascular Center, Semmelweis University, Budapest, H-1085, Hungary
| | - Lenke K Laurik
- Department of Ophthalmology, Semmelweis University, Budapest, H-1085, Hungary
| | - Gábor M Somfai
- Department of Ophthalmology, Semmelweis University, Budapest, H-1085, Hungary
| | - Béla Merkely
- Heart and Vascular Center, Semmelweis University, Budapest, H-1085, Hungary
| | - Ágoston Szél
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary
| | - Ákos Lukáts
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary.
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Rapid monocyte infiltration following retinal detachment is dependent on non-canonical IL6 signaling through gp130. J Neuroinflammation 2017. [PMID: 28645275 PMCID: PMC5481880 DOI: 10.1186/s12974-017-0886-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Retinal detachment (RD) can lead to proliferative vitreoretinopathy (PVR), a leading cause of intractable vision loss. PVR is associated with a cytokine storm involving common proinflammatory molecules like IL6, but little is known about the source and downstream signaling of IL6 and the consequences for the retina. Here, we investigated the early immune response and resultant cytokine signaling following RD in mice. METHODS RD was induced in C57BL/6 J and IL6 knockout mice, and the resulting inflammatory response was examined using immunohistochemistry and flow cytometry. Cytokines and signaling proteins of vitreous and retinas were quantified by multiple cytokine arrays and Western blotting. To attempt to block IL6 signaling, a neutralizing antibody of IL6 receptor α (IL6Rα) or IL6 receptor β (gp-130) was injected intravitreally immediately after RD. RESULTS Within one day of RD, bone marrow-derived Cd11b + monocytes had extravasated from the vasculature and lined the vitreal surface of the retina, while the microglia, the resident macrophages of the retina, were relatively unperturbed. Cytokine arrays and Western blot analysis revealed that this sterile inflammation did not cause activation of IL6 signaling in the neurosensory retina, but rather only in the vitreous and aqueous humor. Monocyte infiltration was inhibited by blocking gp130, but not by IL6 knockout or IL6Rα blockade. CONCLUSIONS Together, our results demonstrate that monocytes are the primary immune cell mediating the cytokine storm following RD, and that any resulting retinal damage is unlikely to be a direct result of retinal IL6 signaling, but rather gp130-mediated signaling in the monocytes themselves. These results suggest that RD should be treated immediately, and that gp130-directed therapies may prevent PVR and promote retinal healing.
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Differentiation/Purification Protocol for Retinal Pigment Epithelium from Mouse Induced Pluripotent Stem Cells as a Research Tool. PLoS One 2016; 11:e0158282. [PMID: 27385038 PMCID: PMC4934919 DOI: 10.1371/journal.pone.0158282] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/13/2016] [Indexed: 01/12/2023] Open
Abstract
Purpose To establish a novel protocol for differentiation of retinal pigment epithelium (RPE) with high purity from mouse induced pluripotent stem cells (iPSC). Methods Retinal progenitor cells were differentiated from mouse iPSC, and RPE differentiation was then enhanced by activation of the Wnt signaling pathway, inhibition of the fibroblast growth factor signaling pathway, and inhibition of the Rho-associated, coiled-coil containing protein kinase signaling pathway. Expanded pigmented cells were purified by plate adhesion after Accutase® treatment. Enriched cells were cultured until they developed a cobblestone appearance with cuboidal shape. The characteristics of iPS-RPE were confirmed by gene expression, immunocytochemistry, and electron microscopy. Functions and immunologic features of the iPS-RPE were also evaluated. Results We obtained iPS-RPE at high purity (approximately 98%). The iPS-RPE showed apical-basal polarity and cellular structure characteristic of RPE. Expression levels of several RPE markers were lower than those of freshly isolated mouse RPE but comparable to those of primary cultured RPE. The iPS-RPE could form tight junctions, phagocytose photoreceptor outer segments, express immune antigens, and suppress lymphocyte proliferation. Conclusion We successfully developed a differentiation/purification protocol to obtain mouse iPS-RPE. The mouse iPS-RPE can serve as an attractive tool for functional and morphological studies of RPE.
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Sethna S, Chamakkala T, Gu X, Thompson TC, Cao G, Elliott MH, Finnemann SC. Regulation of Phagolysosomal Digestion by Caveolin-1 of the Retinal Pigment Epithelium Is Essential for Vision. J Biol Chem 2016; 291:6494-506. [PMID: 26814131 DOI: 10.1074/jbc.m115.687004] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Indexed: 01/09/2023] Open
Abstract
Caveolin-1 associates with the endo/lysosomal machinery of cells in culture, suggesting that it functions at these organelles independently of its contribution to cell surface caveolae. Here we explored mice lacking caveolin-1 specifically in the retinal pigment epithelium (RPE). The RPE supports neighboring photoreceptors via diurnal phagocytosis of spent photoreceptor outer segment fragments. Like mice lacking caveolin-1 globally, (RPE)CAV1(-/-) mice developed a normal RPE and neural retina but showed reduced rod photoreceptor light responses, indicating that lack of caveolin-1 affects photoreceptor function in a non-cell-autonomous manner. (RPE)CAV1(-/-) RPE in situ showed normal particle engulfment but delayed phagosome clearance and reversed diurnal profiles of levels and activities of lysosomal enzymes. Therefore, eliminating caveolin-1 specifically impairs phagolysosomal degradation by the RPE in vivo. Endogenous caveolin-1 was recruited to maturing phagolysosomes in RPE cells in culture. Consistent with these in vivo data, a moderate increase (to ∼ 2.5-fold) or decrease (by half) of caveolin-1 protein levels in RPE cells in culture was sufficient to accelerate or impair phagolysosomal digestion, respectively. A mutant form of caveolin-1 that fails to reach the cell surface augmented degradation like wild-type caveolin-1. Acidic lysosomal pH and increased protease activity are essential for digestion. We show that halving caveolin-1 protein levels significantly alkalinized lysosomal pH and decreased lysosomal enzyme activities. Taken together, our results reveal a novel role for intracellular caveolin-1 in modulating phagolysosomal function. Moreover, they show, for the first time, that organellar caveolin-1 significantly affects tissue functionality in vivo.
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Affiliation(s)
- Saumil Sethna
- From the Department of Biological Sciences, Center for Cancer Genetic Diseases and Gene Regulation, Fordham University, Bronx, New York 10458
| | - Tess Chamakkala
- From the Department of Biological Sciences, Center for Cancer Genetic Diseases and Gene Regulation, Fordham University, Bronx, New York 10458
| | - Xiaowu Gu
- the Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, and
| | - Timothy C Thompson
- the Department of Genitourinary Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030
| | - Guangwen Cao
- the Department of Genitourinary Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030
| | - Michael H Elliott
- the Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, and
| | - Silvia C Finnemann
- From the Department of Biological Sciences, Center for Cancer Genetic Diseases and Gene Regulation, Fordham University, Bronx, New York 10458,
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Song D, Wilson B, Zhao L, Bhuyan R, Bandyopadhyay M, Lyubarsky A, Yu C, Li Y, Kanu L, Miwa T, Song WC, Finnemann SC, Rohrer B, Dunaief JL. Retinal Pre-Conditioning by CD59a Knockout Protects against Light-Induced Photoreceptor Degeneration. PLoS One 2016; 11:e0166348. [PMID: 27893831 PMCID: PMC5125596 DOI: 10.1371/journal.pone.0166348] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 10/27/2016] [Indexed: 11/25/2022] Open
Abstract
Complement dysregulation plays a key role in the pathogenesis of age-related macular degeneration (AMD), but the specific mechanisms are incompletely understood. Complement also potentiates retinal degeneration in the murine light damage model. To test the retinal function of CD59a, a complement inhibitor, CD59a knockout (KO) mice were used for light damage (LD) experiments. Retinal degeneration and function were compared in WT versus KO mice following light damage. Gene expression changes, endoplasmic reticulum (ER) stress, and glial cell activation were also compared. At baseline, the ERG responses and rhodopsin levels were lower in CD59aKO compared to wild-type (WT) mice. Following LD, the ERG responses were better preserved in CD59aKO compared to WT mice. Correspondingly, the number of photoreceptors was higher in CD59aKO retinas than WT controls after LD. Under normal light conditions, CD59aKO mice had higher levels than WT for GFAP immunostaining in Müller cells, mRNA and protein levels of two ER-stress markers, and neurotrophic factors. The reduction in photon capture, together with the neurotrophic factor upregulation, may explain the structural and functional protection against LD in the CD59aKO.
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Affiliation(s)
- Delu Song
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
| | - Brooks Wilson
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC
| | - Liangliang Zhao
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
- Department of Ophthalmology, The Second Hospital of Jilin University, Jilin, China
| | - Rupak Bhuyan
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
| | | | - Arkady Lyubarsky
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
| | - Chen Yu
- Center for Cancer, Genetic Diseases, and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY
| | - Yafeng Li
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
| | - Levi Kanu
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
| | - Takashi Miwa
- Department of Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Wen-Chao Song
- Department of Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Silvia C. Finnemann
- Center for Cancer, Genetic Diseases, and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC
- Research Service, Ralph H. Johnson VA Medical Center, Charleston, SC
- * E-mail: (JLD); (BR)
| | - Joshua L. Dunaief
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
- * E-mail: (JLD); (BR)
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Retinal Caveolin-1 Modulates Neuroprotective Signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 854:411-8. [DOI: 10.1007/978-3-319-17121-0_54] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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Agca C, Boldt K, Gubler A, Meneau I, Corpet A, Samardzija M, Stucki M, Ueffing M, Grimm C. Expression of leukemia inhibitory factor in Müller glia cells is regulated by a redox-dependent mRNA stability mechanism. BMC Biol 2015; 13:30. [PMID: 25907681 PMCID: PMC4462110 DOI: 10.1186/s12915-015-0137-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 04/08/2015] [Indexed: 12/15/2022] Open
Abstract
Background Photoreceptor degeneration is a main hallmark of many blinding diseases making protection of photoreceptors crucial to prevent vision loss. Thus, regulation of endogenous neuroprotective factors may be key for cell survival and attenuation of disease progression. Important neuroprotective factors in the retina include H2O2 generated by injured photoreceptors, and leukemia inhibitory factor (LIF) expressed in Müller glia cells in response to photoreceptor damage. Results We present evidence that H2O2 connects to the LIF response by inducing stabilization of Lif transcripts in Müller cells. This process was independent of active gene transcription and p38 MAPK, but relied on AU-rich elements (AREs), which we identified within the highly conserved Lif 3′UTR. Affinity purification combined with quantitative mass spectrometry identified several proteins that bound to these AREs. Among those, interleukin enhancer binding factor 3 (ILF3) was confirmed to participate in the redox-dependent Lif mRNA stabilization. Additionally we show that KH-type splicing regulatory protein (KHSRP) was crucial for maintaining basal Lif expression levels in non-stressed Müller cells. Conclusions Our results suggest that H2O2-induced redox signaling increases Lif transcript levels through ILF3 mediated mRNA stabilization. Generation of H2O2 by injured photoreceptors may thus enhance stability of Lif mRNA and therefore augment neuroprotective LIF signaling during degenerative conditions in vivo. Electronic supplementary material The online version of this article (doi:10.1186/s12915-015-0137-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cavit Agca
- Department of Ophthalmology, Lab for Retinal Cell Biology, University of Zurich, Wagistrasse 14, Zurich, 8091, Switzerland. .,Present address: Department of Biomedicine, University Hospital Basel, Basel, 4031, Switzerland.
| | - Karsten Boldt
- Division of Experimental Ophthalmology and Medical Proteome Center, Centre for Ophthalmology, University of Tübingen, 72076, Tübingen, Germany.
| | - Andrea Gubler
- Department of Ophthalmology, Lab for Retinal Cell Biology, University of Zurich, Wagistrasse 14, Zurich, 8091, Switzerland.
| | - Isabelle Meneau
- Department of Ophthalmology, Lab for Retinal Cell Biology, University of Zurich, Wagistrasse 14, Zurich, 8091, Switzerland.
| | - Armelle Corpet
- Department of Gynecology, University of Zurich, Zurich, 8091, Switzerland. .,Present address: Center for Molecular and Cellular Physiology and Genetics, University Lyon I, Villeurbanne, France.
| | - Marijana Samardzija
- Department of Ophthalmology, Lab for Retinal Cell Biology, University of Zurich, Wagistrasse 14, Zurich, 8091, Switzerland.
| | - Manuel Stucki
- Department of Gynecology, University of Zurich, Zurich, 8091, Switzerland.
| | - Marius Ueffing
- Division of Experimental Ophthalmology and Medical Proteome Center, Centre for Ophthalmology, University of Tübingen, 72076, Tübingen, Germany.
| | - Christian Grimm
- Department of Ophthalmology, Lab for Retinal Cell Biology, University of Zurich, Wagistrasse 14, Zurich, 8091, Switzerland. .,Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, 8091, Switzerland. .,Neuroscience Center (ZNZ), University of Zurich, Zurich, 8091, Switzerland.
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Chucair-Elliott AJ, Zheng M, Carr DJJ. Degeneration and regeneration of corneal nerves in response to HSV-1 infection. Invest Ophthalmol Vis Sci 2015; 56:1097-107. [PMID: 25587055 DOI: 10.1167/iovs.14-15596] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
PURPOSE Herpes simplex virus type 1 (HSV-1) infection is one cause of neurotrophic keratitis, characterized by decreases in corneal sensation, blink reflex, and tear secretion as consequence of damage to the sensory fibers innervating the cornea. Our aim was to characterize changes in the corneal nerve network and its function in response to HSV-1 infection. METHODS C57BL/6J mice were infected with HSV-1 or left uninfected. Corneas were harvested at predetermined times post infection (pi) and assessed for β III tubulin, substance P, calcitonin gene-related peptide, and neurofilament H staining by immunohistochemistry (IHC). Corneal sensitivity was evaluated using a Cochet-Bonnet esthesiometer. Expression of genes associated with nerve repair was determined in corneas by real time RT-PCR, Western blotting, and IHC. Semaphorin 7A (SEMA 7A) neutralizing antibody or isotype control was subconjunctivally administered to infected mice. RESULTS The area of cornea occupied by β III tubulin immunoreactivity and sensitivity significantly decreased by day 8 pi. Modified reinnervation was observed by day 30 pi without recovery of corneal sensation. Sensory fibers were lost by day 8 pi and were still absent or abnormal at day 30 pi. Expression of SEMA 7A increased at day 8 pi, localizing to corneal epithelial cells. Neutralization of SEMA 7A resulted in defective reinnervation and lower corneal sensitivity. CONCLUSIONS Corneal sensory nerves were lost, consistent with loss of corneal sensation at day 8 pi. At day 30 pi, the cornea reinnervated but without recovering the normal arrangement of its fibers or function. SEMA 7A expression was increased at day 8pi, likely as part of a nerve regeneration mechanism.
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Affiliation(s)
- Ana J Chucair-Elliott
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Min Zheng
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Daniel J J Carr
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
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Patil H, Saha A, Senda E, Cho KI, Haque M, Yu M, Qiu S, Yoon D, Hao Y, Peachey NS, Ferreira PA. Selective impairment of a subset of Ran-GTP-binding domains of ran-binding protein 2 (Ranbp2) suffices to recapitulate the degeneration of the retinal pigment epithelium (RPE) triggered by Ranbp2 ablation. J Biol Chem 2014; 289:29767-89. [PMID: 25187515 DOI: 10.1074/jbc.m114.586834] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Retinal pigment epithelium (RPE) degeneration underpins diseases triggered by disparate genetic lesions, noxious insults, or both. The pleiotropic Ranbp2 controls the expression of intrinsic and extrinsic pathological stressors impinging on cellular viability. However, the physiological targets and mechanisms controlled by Ranbp2 in tissue homeostasis, such as RPE, are ill defined. We show that mice, RPE-cre::Ranbp2(-/-), with selective Ranbp2 ablation in RPE develop pigmentary changes, syncytia, hypoplasia, age-dependent centrifugal and non-apoptotic degeneration of the RPE, and secondary leakage of choriocapillaris. These manifestations are accompanied by the development of F-actin clouds, metalloproteinase-11 activation, deregulation of expression or subcellular localization of critical RPE proteins, atrophic cell extrusions into the subretinal space, and compensatory proliferation of peripheral RPE. To gain mechanistic insights into what Ranbp2 activities are vital to the RPE, we performed genetic complementation analyses of transgenic lines of bacterial artificial chromosomes of Ranbp2 harboring loss of function of selective Ranbp2 domains expressed in a Ranbp2(-/-) background. Among the transgenic lines produced, only Tg(RBD2/3*-HA)::RPE-cre::Ranbp2(-/-)-expressing mutations, which selectively impair binding of RBD2/3 (Ran-binding domains 2 and 3) of Ranbp2 to Ran-GTP, recapitulate RPE degeneration, as observed with RPE-cre::Ranbp2(-/-). By contrast, Tg(RBD2/3*-HA) expression rescues the degeneration of cone photoreceptors lacking Ranbp2. The RPE of RPE-cre::Ranbp2(-/-) and Tg(RBD2/3*-HA)::RPE-cre::Ranbp2(-/-) share proteostatic deregulation of Ran GTPase, serotransferrin, and γ-tubulin and suppression of light-evoked electrophysiological responses. These studies unravel selective roles of Ranbp2 and its RBD2 and RBD3 in RPE survival and functions. We posit that the control of Ran GTPase by Ranbp2 emerges as a novel therapeutic target in diseases promoting RPE degeneration.
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Affiliation(s)
| | - Arjun Saha
- From the Departments of Ophthalmology and
| | | | | | | | - Minzhong Yu
- the Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195
| | - Sunny Qiu
- From the Departments of Ophthalmology and
| | - Dosuk Yoon
- From the Departments of Ophthalmology and
| | - Ying Hao
- From the Departments of Ophthalmology and
| | - Neal S Peachey
- the Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, the Research Service, Cleveland Veterans Affairs Medical Center, Cleveland, Ohio 44106, and the Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio 44195
| | - Paulo A Ferreira
- From the Departments of Ophthalmology and Pathology, Duke University Medical Center, Durham, North Carolina 27710,
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von Toerne C, Menzler J, Ly A, Senninger N, Ueffing M, Hauck SM. Identification of a novel neurotrophic factor from primary retinal Müller cells using stable isotope labeling by amino acids in cell culture (SILAC). Mol Cell Proteomics 2014; 13:2371-81. [PMID: 24925906 DOI: 10.1074/mcp.m113.033613] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Retinal Müller glial cells (RMGs) have a primary role in maintaining the homeostasis of the retina. In pathological situations, RMGs execute protective and regenerative effects, but they can also contribute to neurodegeneration. It has recently been recognized that cultured primary RMGs secrete pro-survival factors for retinal neurons for up to 2 weeks in culture, but this ability is lost when RMGs are cultivated for longer durations. In our study, we investigated RMG supernatants for novel neuroprotective factors using a quantitative proteomic approach. Stable isotope labeling by amino acids in cell culture (SILAC) was used on primary porcine RMGs. Supernatants of RMGs cultivated for 2 weeks were compared with supernatants from cells that had already lost their protective capacity. Using this approach, we detected established neurotrophic factors such as transferrin, osteopontin, and leukemia inhibitory factor and identified C-X-C motif chemokine 10 (CXCL10) as a novel candidate neuroprotective factor. All factors prolonged photoreceptor survival in vitro. Ex vivo treatment of retinal explants with leukemia inhibitory factor or CXCL10 demonstrated a neuroprotective effect on photoreceptors. Western blots on CXCL10- and leukemia inhibitory factor-stimulated explanted retina and photoreceptor lysates indicated activation of pro-survival signal transducer and activator of transcription signaling and B-cell lymphoma pathways. These findings suggest that CXCL10 contributes to the supportive potential of RMGs toward retinal neurons.
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Affiliation(s)
- Christine von Toerne
- From the ‡Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany
| | - Jacob Menzler
- From the ‡Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany
| | - Alice Ly
- From the ‡Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany
| | - Nicole Senninger
- From the ‡Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany
| | - Marius Ueffing
- From the ‡Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; §Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, 72076 Tübingen, Germany
| | - Stefanie M Hauck
- From the ‡Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany;
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Narimatsu T, Ozawa Y, Miyake S, Nagai N, Tsubota K. Angiotensin II type 1 receptor blockade suppresses light-induced neural damage in the mouse retina. Free Radic Biol Med 2014; 71:176-185. [PMID: 24662196 DOI: 10.1016/j.freeradbiomed.2014.03.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 03/06/2014] [Accepted: 03/16/2014] [Indexed: 12/26/2022]
Abstract
Exposure to light contributes to the development and progression of retinal degenerative diseases. However, the mechanisms underlying light-induced tissue damage are not fully understood. Here, we examined the role of angiotensin II type 1 receptor (AT1R) signaling, which is part of the renin-angiotensin system, in light-induced retinal damage. Light-exposed Balb/c mice that were treated with the AT1R blockers (angiotensin II receptor blockers; ARBs) valsartan, losartan, and candesartan before and after the light exposure exhibited attenuated visual function impairment, compared to vehicle-treated mice. This effect was dose-dependent and observed across the ARB class of inhibitors. Further evaluation of valsartan showed that it suppressed a number of light-induced retinal effects, including thinning of the photoreceptor cell layer caused by apoptosis, shortening of the photoreceptor cell outer segment, and increased levels of reactive oxygen species (ROS). The role of ROS in retinal pathogenesis was investigated further using the antioxidant N-acetyl-l-cysteine (NAC). Treatment of light-exposed mice with NAC before the light exposure suppressed the visual function impairment and photoreceptor cell histological changes due to apoptosis. Moreover, treatment with valsartan or NAC suppressed the induction of c-fos (a component of the AP-1 transcription factor) and the upregulation of fasl (a proapoptotic molecule whose transcript is regulated downstream of AP-1). Our results suggest that AT1R signaling mediates light-induced apoptosis, by increasing the levels of ROS and proapoptotic molecules in the retina. Thus, AT1R blockade may represent a new therapeutic approach for preventing light-induced retinal neural tissue damage.
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Affiliation(s)
- Toshio Narimatsu
- Laboratory of Retinal Cell Biology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan; Department of Ophthalmology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Yoko Ozawa
- Laboratory of Retinal Cell Biology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan; Department of Ophthalmology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan.
| | - Seiji Miyake
- Laboratory of Retinal Cell Biology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Norihiro Nagai
- Laboratory of Retinal Cell Biology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan; Department of Ophthalmology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
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26
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Masuda T, Wahlin K, Wan J, Hu J, Maruotti J, Yang X, Iacovelli J, Wolkow N, Kist R, Dunaief JL, Qian J, Zack DJ, Esumi N. Transcription factor SOX9 plays a key role in the regulation of visual cycle gene expression in the retinal pigment epithelium. J Biol Chem 2014; 289:12908-21. [PMID: 24634209 DOI: 10.1074/jbc.m114.556738] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The retinal pigment epithelium (RPE) performs specialized functions to support retinal photoreceptors, including regeneration of the visual chromophore. Enzymes and carrier proteins in the visual cycle function sequentially to regenerate and continuously supply 11-cis-retinal to retinal photoreceptor cells. However, it is unknown how the expression of the visual cycle genes is coordinated at the transcriptional level. Here, we show that the proximal upstream regions of six visual cycle genes contain chromatin-accessible sex-determining region Y box (SOX) binding sites, that SOX9 and LIM homeobox 2 (LHX2) are coexpressed in the nuclei of mature RPE cells, and that SOX9 acts synergistically with orthodenticle homeobox 2 (OTX2) to activate the RPE65 and retinaldehyde binding protein 1 (RLBP1) promoters and acts synergistically with LHX2 to activate the retinal G protein-coupled receptor (RGR) promoter. ChIP reveals that SOX9 and OTX2 bind to the promoter regions of RPE65, RLBP1, and RGR and that LHX2 binds to those of RPE65 and RGR in bovine RPE. ChIP with human fetal RPE cells shows that SOX9 and OTX2 also bind to the human RPE65, RLBP1, and RGR promoters. Conditional inactivation of Sox9 in mouse RPE results in reduced expression of several visual cycle genes, most dramatically Rpe65 and Rgr. Furthermore, bioinformatic analysis predicts that multiple common microRNAs (miRNAs) regulate visual cycle genes, and cotransfection of miRNA mimics with luciferase reporter constructs validated some of the predicted miRNAs. These results implicate SOX9 as a key regulator of visual cycle genes, reveal for the first time the functional role of LHX2 in the RPE, and suggest the possible regulation of visual cycle genes by common miRNAs.
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Affiliation(s)
- Tomohiro Masuda
- From the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231
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27
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Immunocytochemical analysis of misplaced rhodopsin-positive cells in the developing rodent retina. Cell Tissue Res 2014; 356:49-63. [PMID: 24496510 DOI: 10.1007/s00441-013-1788-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 12/19/2013] [Indexed: 10/25/2022]
Abstract
During the first postnatal weeks of the developing rodent retina, rhodopsin can be detected in a number of neuron-like cells in the inner retina. In the present study, we aim to characterize the morphology, number and staining characteristics of this peculiar population. Misplaced rhodopsin-positive cells (MRCs) were analyzed on retinas of four rodent species, labeled with various rhodopsin-specific antibodies. To investigate their possible relation with non-photoreceptor cells, sections were double-stained against distinct retinal cell types and proteins of the phototransduction cascade. The possibility of synapse formation and apoptosis were also investigated. In all species studied, misplaced cells comprised a few percent of all rhodopsin-positive elements. This ratio declined from the end of the second week and MRCs disappeared nearly completely from the retina by P24. MRCs resembled resident neurons of the inner retina, while outer segment-like processes were seen only rarely. MRCs expressed no other photopigment types and showed no colocalization with any of the bipolar, horizontal, amacrine and ganglion cell markers used. While all MRCs colabeled for arrestin and recoverin, other proteins of the phototransduction cascade were only detectable in a minority of the population. Only a few MRCs were shown to form synaptic-like endings. Our results showed that, during development, some rhodopsin-expressing cells are displaced to the inner retinal layers. Although most MRCs lack morphological features of photoreceptors, they contain some but not all, elements of the phototransduction cascade, indicating that they are most probably misplaced rods that failed to complete differentiation and integrate into the photoreceptor mosaic.
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28
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Gu X, Fliesler SJ, Zhao YY, Stallcup WB, Cohen AW, Elliott MH. Loss of caveolin-1 causes blood-retinal barrier breakdown, venous enlargement, and mural cell alteration. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 184:541-55. [PMID: 24326256 DOI: 10.1016/j.ajpath.2013.10.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 09/13/2013] [Accepted: 10/28/2013] [Indexed: 12/20/2022]
Abstract
Blood-retinal barrier (BRB) breakdown and related vascular changes are implicated in several ocular diseases. The molecules and mechanisms regulating BRB integrity and pathophysiology are not fully elucidated. Caveolin-1 (Cav-1) ablation results in loss of caveolae and microvascular pathologies, but the role of Cav-1 in the retina is largely unknown. We examined BRB integrity and vasculature in Cav-1 knockout mice and found a significant increase in BRB permeability, compared with wild-type controls, with branch veins being frequent sites of breakdown. Vascular hyperpermeability occurred without apparent alteration in junctional proteins. Such hyperpermeability was not rescued by inhibiting eNOS activity. Veins of Cav-1 knockout retinas exhibited additional pathological features, including i) eNOS-independent enlargement, ii) altered expression of mural cell markers (eg, down-regulation of NG2 and up-regulation of αSMA), and iii) dramatic alterations in mural cell phenotype near the optic nerve head. We observed a significant NO-dependent increase in retinal artery diameter in Cav-1 knockout mice, suggesting that Cav-1 plays a role in autoregulation of resistance vessels in the retina. These findings implicate Cav-1 in maintaining BRB integrity in retinal vasculature and suggest a previously undefined role in the retinal venous system and associated mural cells. Our results are relevant to clinically significant retinal disorders with vascular pathologies, including diabetic retinopathy, uveoretinitis, and primary open-angle glaucoma.
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Affiliation(s)
- Xiaowu Gu
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Steven J Fliesler
- Research Service, Veterans Affairs Western New York Healthcare System, Buffalo, New York; Department of Ophthalmology, University at Buffalo, State University of New York, Buffalo, New York; Department of Biochemistry, University at Buffalo, State University of New York, Buffalo, New York; SUNY Eye Institute, University at Buffalo, State University of New York, Buffalo, New York
| | - You-Yang Zhao
- Department of Pharmacology, University of Illinois College of Medicine, Chicago, Illinois; Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, Illinois
| | - William B Stallcup
- Tumor Microenvironment Program, Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, California
| | - Alex W Cohen
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Michael H Elliott
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
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29
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CNTF-mediated protection of photoreceptors requires initial activation of the cytokine receptor gp130 in Müller glial cells. Proc Natl Acad Sci U S A 2013; 110:E4520-9. [PMID: 24191003 DOI: 10.1073/pnas.1303604110] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Ciliary neurotrophic factor (CNTF) acts as a potent neuroprotective agent in multiple retinal degeneration animal models. Recently, CNTF has been evaluated in clinical trials for the inherited degenerative disease retinitis pigmentosa (RP) and for dry age-related macular degeneration (AMD). Despite its potential as a broad-spectrum therapeutic treatment for blinding diseases, the target cells of exogenous CNTF and its mechanism of action remain poorly understood. We have shown previously that constitutive expression of CNTF prevents photoreceptor death but alters the retinal transcriptome and suppresses visual function. Here, we use a lentivirus to deliver the same secreted human CNTF used in clinical trials to a mouse model of RP. We found that low levels of CNTF halt photoreceptor death, improve photoreceptor morphology, and correct opsin mislocalization. However, we did not detect corresponding improvement of retinal function as measured by the electroretinogram. Disruption of the cytokine receptor gp130 gene in Müller glia reduces CNTF-dependent photoreceptor survival and prevents phosphorylation of STAT3 and ERK in Müller glia and the rest of the retina. Targeted deletion of gp130 in rods also demolishes neuroprotection by CNTF and prevents further activation of Müller glia. Moreover, CNTF elevates the expression of LIF and endothelin 2, thus positively promoting Müller and photoreceptor interactions. We propose that exogenous CNTF initially targets Müller glia, and subsequently induces cytokines acting through gp130 in photoreceptors to promote neuronal survival. These results elucidate a cellular mechanism for exogenous CNTF-triggered neuroprotection and provide insight into the complex cellular responses induced by CNTF in diseased retinas.
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30
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Maeda T, Lee MJ, Palczewska G, Marsili S, Tesar PJ, Palczewski K, Takahashi M, Maeda A. Retinal pigmented epithelial cells obtained from human induced pluripotent stem cells possess functional visual cycle enzymes in vitro and in vivo. J Biol Chem 2013; 288:34484-93. [PMID: 24129572 DOI: 10.1074/jbc.m113.518571] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Differentiated retinal pigmented epithelial (RPE) cells have been obtained from human induced pluripotent stem (hiPS) cells. However, the visual (retinoid) cycle in hiPS-RPE cells has not been adequately examined. Here we determined the expression of functional visual cycle enzymes in hiPS-RPE cells compared with that of isolated wild-type mouse primary RPE (mpRPE) cells in vitro and in vivo. hiPS-RPE cells appeared morphologically similar to mpRPE cells. Notably, expression of certain visual cycle proteins was maintained during cell culture of hiPS-RPE cells, whereas expression of these same molecules rapidly decreased in mpRPE cells. Production of the visual chromophore, 11-cis-retinal, and retinosome formation also were documented in hiPS-RPE cells in vitro. When mpRPE cells with luciferase activity were transplanted into the subretinal space of mice, bioluminance intensity was preserved for >3 months. Additionally, transplantation of mpRPE into blind Lrat(-/-) and Rpe65(-/-) mice resulted in the recovery of visual function, including increased electrographic signaling and endogenous 11-cis-retinal production. Finally, when hiPS-RPE cells were transplanted into the subretinal space of Lrat(-/-) and Rpe65(-/-) mice, their vision improved as well. Moreover, histological analyses of these eyes displayed replacement of dysfunctional RPE cells by hiPS-RPE cells. Together, our results show that hiPS-RPE cells can exhibit a functional visual cycle in vitro and in vivo. These cells could provide potential treatment options for certain blinding retinal degenerative diseases.
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Affiliation(s)
- Tadao Maeda
- From the Departments of Ophthalmology and Visual Sciences
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31
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Patel AK, Syeda S, Hackam AS. Signal transducer and activator of transcription 3 (STAT3) signaling in retinal pigment epithelium cells. JAKSTAT 2013; 2:e25434. [PMID: 24416648 PMCID: PMC3876436 DOI: 10.4161/jkst.25434] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 06/14/2013] [Accepted: 06/17/2013] [Indexed: 11/19/2022] Open
Abstract
The retinal pigmented epithelium (RPE) is a monolayer of specialized epithelial cells located between the photoreceptors of the retina and the choroidal blood supply. The RPE is essential for maintaining retinal health and vision. Recent findings identified STAT3 as a newly recognized regulator of RPE survival, inflammatory response, visual cycle maintenance, and cytokine release. Additionally, STAT3 is implicated in retinal diseases that affect the RPE, including the common blinding disease age-related macular degeneration. Determining how STAT3 influences RPE functions ultimately may lead to novel therapeutics for retinal disease. In this review, we summarize the roles of JAK-STAT3 signaling in the RPE, and its potential contribution to retinal degenerations.
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Affiliation(s)
- Amit K Patel
- Bascom Palmer Eye Institute; University of Miami Miller School of Medicine; Miami, FL USA
| | - Sarah Syeda
- Bascom Palmer Eye Institute; University of Miami Miller School of Medicine; Miami, FL USA
| | - Abigail S Hackam
- Bascom Palmer Eye Institute; University of Miami Miller School of Medicine; Miami, FL USA
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