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Wang X, Tazearslan C, Kim S, Guo Q, Contreras D, Yang J, Hudgins AD, Suh Y. In vitro heterochronic parabiosis identifies pigment epithelium-derived factor as a systemic mediator of rejuvenation by young blood. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.02.592258. [PMID: 38746475 PMCID: PMC11092633 DOI: 10.1101/2024.05.02.592258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Several decades of heterochronic parabiosis (HCPB) studies have demonstrated the restorative impact of young blood, and deleterious influence of aged blood, on physiological function and homeostasis across tissues, although few of the factors responsible for these observations have been identified. Here we develop an in vitro HCPB system to identify these circulating factors, using replicative lifespan (RLS) of primary human fibroblasts as an endpoint of cellular health. We find that RLS is inversely correlated with serum donor age and sensitive to the presence or absence of specific serum components. Through in vitro HCPB, we identify the secreted protein pigment epithelium-derived factor (PEDF) as a circulating factor that extends RLS of primary human fibroblasts and declines with age in mammals. Systemic administration of PEDF to aged mice reverses age-related functional decline and pathology across several tissues, improving cognitive function and reducing hepatic fibrosis and renal lipid accumulation. Together, our data supports PEDF as a systemic mediator of the effect of young blood on organismal health and homeostasis and establishes our in vitro HCPB system as a valuable screening platform for the identification of candidate circulating factors involved in aging and rejuvenation.
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Affiliation(s)
- Xizhe Wang
- Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY
- These authors contributed equally
| | - Cagdas Tazearslan
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY
- These authors contributed equally
| | - Seungsoo Kim
- Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY
| | - Qinghua Guo
- Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY
| | - Daniela Contreras
- Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY
| | - Jiping Yang
- Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY
| | - Adam D. Hudgins
- Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY
| | - Yousin Suh
- Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY
- Department of Genetics and Development, Columbia University Medical Center, New York, NY
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Xu M, Chen X, Yu Z, Li X. Receptors that bind to PEDF and their therapeutic roles in retinal diseases. Front Endocrinol (Lausanne) 2023; 14:1116136. [PMID: 37139333 PMCID: PMC10149954 DOI: 10.3389/fendo.2023.1116136] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 04/04/2023] [Indexed: 05/05/2023] Open
Abstract
Retinal neovascular, neurodegenerative, and inflammatory diseases represented by diabetic retinopathy are the main types of blinding eye disorders that continually cause the increased burden worldwide. Pigment epithelium-derived factor (PEDF) is an endogenous factor with multiple effects including neurotrophic activity, anti-angiogenesis, anti-tumorigenesis, and anti-inflammatory activity. PEDF activity depends on the interaction with the proteins on the cell surface. At present, seven independent receptors, including adipose triglyceride lipase, laminin receptor, lipoprotein receptor-related protein, plexin domain-containing 1, plexin domain-containing 2, F1-ATP synthase, and vascular endothelial growth factor receptor 2, have been demonstrated and confirmed to be high affinity receptors for PEDF. Understanding the interactions between PEDF and PEDF receptors, their roles in normal cellular metabolism and the response the initiate in disease will be accommodating for elucidating the ways in which inflammation, angiogenesis, and neurodegeneration exacerbate disease pathology. In this review, we firstly introduce PEDF receptors comprehensively, focusing particularly on their expression pattern, ligands, related diseases, and signal transduction pathways, respectively. We also discuss the interactive ways of PEDF and receptors to expand the prospective understanding of PEDF receptors in the diagnosis and treatment of retinal diseases.
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Xia YF, Wei J. Study on Factors Associated with High Myopia CNV in Aqueous Humor and Serum. BIOMED RESEARCH INTERNATIONAL 2022; 2022:8592729. [PMID: 35535041 PMCID: PMC9078789 DOI: 10.1155/2022/8592729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 03/16/2022] [Accepted: 04/02/2022] [Indexed: 11/30/2022]
Abstract
Objective The objective is to investigate the relationship and correlation between PEDF and TGF-β in aqueous humor and serum and high myopia CNV lesions. Methods For each group of patients (namely, group A: patients with high myopia CNV (mCNV); group B: patients with high myopia without CNV; group C: patients with CNV caused by other eye diseases; and group D (control group): patients with simple cataract (without CNV and high myopia)), 20 patients were collected. A total of 40 patients have been collected since the beginning of the study in December 2020, including 7 patients in group A, 13 patients in group B, 10 patients in group C, and 10 patients in group D. Serum and aqueous humor samples were collected, and PEDF and TGF-β levels in serum and aqueous humor were detected by enzyme-linked immunosorbent assay (ELISA). SPSS 26.0 statistical software was used to process the data. Independent sample t-test was used to compare the data of the same factor in the same group between serum and aqueous humor. Comparisons of the same factors between different groups were performed using a one-way analysis of variance (ANOVA). Correlation analysis was conducted by the Pearson correlation coefficient test. P < 0.05 indicated that the difference was statistically significant. Results There were no significant differences in age, gender, and course of disease among all groups (P > 0.05). The concentration of PEDF in aqueous humor in group A and group C was higher than that in group B and group D. There was no significant correlation between serum PEDF content and the above-mentioned diseases. The concentration of TGF-β in aqueous humor in groups A, B, and C was significantly higher than that in group D. However, there was no significant correlation between TGF-β content in serum and the above-mentioned diseases. There was no significant correlation between aqueous humor and serum PEDF. There was no significant correlation between the content of TGF-β in aqueous humor and serum. Conclusion TGF-β in aqueous humor may be involved in the development of high myopia and intraocular CNV disease. However, PEDF in aqueous humor may be involved in the development of intraocular CNV disease and has no significant correlation with high myopia. At the same time, TGF-β and PEDF in serum had no significant correlation with high myopia and intraocular CNV disease. There was no significant correlation between the concentrations of TGF-β and PEDF in aqueous humor and serum.
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Affiliation(s)
- Yi Fan Xia
- Henan University of Science and Technology, Luoyang, Henan Province 471000, China
| | - Jing Wei
- Henan University of Science and Technology, Luoyang, Henan Province 471000, China
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Lokman Hakim NYDB, Noble S, Thomas NV, Geegana Gamage BS, Maxwell GK, Govindasamy V, Then KY, Das AK, Cheong SK. Genetic Modification as a New Approach to Ameliorate the Therapeutic Efficacy of Stem Cells in Diabetic Retinopathy. Eur J Ophthalmol 2022; 32:11206721211073430. [PMID: 35037488 DOI: 10.1177/11206721211073430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Over the last decades, the strategy of using stem cells has gained a lot of attention in treating many diseases. Recently, DR was identified as one of the common complications experienced by diabetic patients around the world. The current treatment strategy needs to be addressed since the active progression of DR may lead to permanent blindness. Interestingly, varieties of stem cells have emerged to optimize the therapeutic effects. It is also known that stem cells possess multilineage properties and are capable of differentiating, expanding in vitro and undergoing genetic modification. Moreover, modified stem cells have shown to be an ideal resource to prevent the degenerative disease and exhibit promising effects in conferring the migratory, anti-apoptotic, anti-inflammatory and provide better homing for cells into the damaged tissue or organ as well promoting healing properties. Therefore, the understanding of the functional properties of the stem cells may provide the comprehensive guidance to understand the manipulation of stem cells making them useful for long-term therapeutic applications. Hence in this review the potential use and current challenges of genetically modified stem cells to treat DR will be discussed along with its future perspectives.
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Affiliation(s)
| | - Steven Noble
- CryoCord Sdn Bhd, Bio-X Centre, Cyberjaya, Selangor, Malaysia
| | | | | | | | | | - Kong-Yong Then
- CryoCord Sdn Bhd, Bio-X Centre, Cyberjaya, Selangor, Malaysia
- Brighton Healthcare (Bio-X Healthcare Sdn Bhd), Bio-X Centre, Cyberjaya, Selangor, Malaysia
| | - Anjan Kumar Das
- Department of Surgery, 483702IQ City Medical College, Durgapur, West Bengal, India
| | - Soon-Keng Cheong
- Faculty of Medicine & Health Sciences, 65287Universiti Tunku Abdul Rahman (UTAR), Kajang, Selangor, Malaysia
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Ye Q, Wang J, Liu X, Liu Z, BaZong L, Ma J, Shen R, Ye W, Zhang W, Wang D. The Role of RAD6B and PEDF in Retinal Degeneration. Neuroscience 2021; 480:19-31. [PMID: 34774969 DOI: 10.1016/j.neuroscience.2021.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 12/11/2022]
Abstract
RAD6B is an E2 ubiquitin-conjugating enzyme, playing an important role in DNA damage repair, gene expression, senescence, apoptosis and protein degradation. However, the specific mechanism between ubiquitin and retinal degeneration requires more investigation. Pigment epithelium-derived factor (PEDF) has a potent neurotrophic effect on the retina, protecting retinal neurons and photoreceptors from cell death caused by pathological damage. In this study, we found that loss of RAD6B leads to retinal degeneration in mice, especially in old age. Affymetrix microarray analysis showed that the PEDF signal was changed in RAD6B deficient groups. The expression of γ-H2AX, β-Gal, P53, Caspase-3, P21 and P16 was increased significantly in retinas of RAD6B knockout (KO) mice. Our studies suggest that RAD6B and PEDF play an important role in the health of retina, whereas the absence of RAD6B accelerates the degeneration.
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Affiliation(s)
- Qiang Ye
- Institute of Human Anatomy and Histoembryology, Basic Medical College, Lanzhou University, 199 Donggang West Road, Lanzhou 730000, China; Department of Ophthalmology, The Second Hospital of Lanzhou University, 82 Cuiying Door, Lanzhou 730000, China
| | - Jiaqi Wang
- Institute of Human Anatomy and Histoembryology, Basic Medical College, Lanzhou University, 199 Donggang West Road, Lanzhou 730000, China
| | - Xiangwen Liu
- Institute of Human Anatomy and Histoembryology, Basic Medical College, Lanzhou University, 199 Donggang West Road, Lanzhou 730000, China
| | - Zihua Liu
- Institute of Human Anatomy and Histoembryology, Basic Medical College, Lanzhou University, 199 Donggang West Road, Lanzhou 730000, China
| | - LuoSong BaZong
- Department of Ophthalmology, The Second Hospital of Lanzhou University, 82 Cuiying Door, Lanzhou 730000, China
| | - Jinhai Ma
- Department of Ophthalmology, The Second Hospital of Lanzhou University, 82 Cuiying Door, Lanzhou 730000, China
| | - Rong Shen
- Institute of Human Anatomy and Histoembryology, Basic Medical College, Lanzhou University, 199 Donggang West Road, Lanzhou 730000, China.
| | - Weichun Ye
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou 730000, China.
| | - Wenfang Zhang
- Department of Ophthalmology, The Second Hospital of Lanzhou University, 82 Cuiying Door, Lanzhou 730000, China.
| | - Degui Wang
- Institute of Human Anatomy and Histoembryology, Basic Medical College, Lanzhou University, 199 Donggang West Road, Lanzhou 730000, China.
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6
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Zwanzig A, Meng J, Müller H, Bürger S, Schmidt M, Pankonin M, Wiedemann P, Unterlauft JD, Eichler W. Neuroprotective effects of glial mediators in interactions between retinal neurons and Müller cells. Exp Eye Res 2021; 209:108689. [PMID: 34216615 DOI: 10.1016/j.exer.2021.108689] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 05/31/2021] [Accepted: 06/29/2021] [Indexed: 12/18/2022]
Abstract
Progressive retinal ganglion cell (RGC) loss underlies a number of retinal neurodegenerative disorders, which may lead to permanent vision loss. However, secreted neuroprotective factors, such as PEDF, VEGF and IL-6, which are produced by Müller cells, have been shown to promote RGC survival. Assuming that the communication of RGCs with Müller cells involves a release of glioactive substances we sought to determine whether retinal neurons are able to modulate expression levels of Müller cell-derived PEDF, VEGF and IL-6. We demonstrate elevated mRNA levels of these factors in Müller cells in co-cultures with RGCs or R28 cells when compared to homotypic Müller cell cultures. Furthermore, R28 cells were more protected from apoptosis when co-cultured with Müller cells. IL-6 and VEGF were upregulated in Müller cells under hypoxia. Both cytokines, as well as PEDF, induced an altered neuronal expression of members of the Bcl-2 family, which are central molecules in the regulation of apoptosis. These results suggest that in retinal ischemia, via own secreted mediators, RGCs can resist a potential demise by stimulating Müller cells to increase production of neuroprotective factors, which counteract RGC apoptosis.
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Affiliation(s)
- Annette Zwanzig
- Leipzig University, Department of Ophthalmology and Eye Hospital, Liebigstrasse 10-14, D-04103 Leipzig, Germany
| | - Jie Meng
- Leipzig University, Department of Ophthalmology and Eye Hospital, Liebigstrasse 10-14, D-04103 Leipzig, Germany
| | - Heidi Müller
- Leipzig University, Department of Ophthalmology and Eye Hospital, Liebigstrasse 10-14, D-04103 Leipzig, Germany
| | - Susanne Bürger
- Leipzig University, Department of Ophthalmology and Eye Hospital, Liebigstrasse 10-14, D-04103 Leipzig, Germany
| | - Manuela Schmidt
- Leipzig University, Department of Ophthalmology and Eye Hospital, Liebigstrasse 10-14, D-04103 Leipzig, Germany
| | - Maik Pankonin
- Leipzig University, Department of Ophthalmology and Eye Hospital, Liebigstrasse 10-14, D-04103 Leipzig, Germany
| | - Peter Wiedemann
- Leipzig University, Department of Ophthalmology and Eye Hospital, Liebigstrasse 10-14, D-04103 Leipzig, Germany
| | - Jan Darius Unterlauft
- Leipzig University, Department of Ophthalmology and Eye Hospital, Liebigstrasse 10-14, D-04103 Leipzig, Germany
| | - Wolfram Eichler
- Leipzig University, Department of Ophthalmology and Eye Hospital, Liebigstrasse 10-14, D-04103 Leipzig, Germany.
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Michelis G, German OL, Villasmil R, Soto T, Rotstein NP, Politi L, Becerra SP. Pigment epithelium-derived factor (PEDF) and derived peptides promote survival and differentiation of photoreceptors and induce neurite-outgrowth in amacrine neurons. J Neurochem 2021; 159:840-856. [PMID: 34133756 DOI: 10.1111/jnc.15454] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 12/16/2022]
Abstract
Pigment epithelium-derived factor (PEDF) is a cytoprotective protein for the retina. We hypothesize that this protein acts on neuronal survival and differentiation of photoreceptor cells in culture. The purpose of the present study was to evaluate the neurotrophic effects of PEDF and its fragments in an in vitro model of cultured primary retinal neurons that die spontaneously in the absence of trophic factors. We used Wistar albino rats. Cell death was assayed by immunofluorescence and flow cytometry through TUNEL assay, propidium iodide, mitotracker, and annexin V. Immunofluorescence of cells for visualizing rhodopsin, CRX, and antisyntaxin under confocal microscopy was performed. Neurite outgrowth was also quantified. Results show that PEDF protected photoreceptor precursors from apoptosis, preserved mitochondrial function and promoted polarization of opsin enhancing their developmental process, as well as induced neurite outgrowth in amacrine neurons. These effects were abolished by an inhibitor of the PEDF receptor or receptor-derived peptides that block ligand/receptor interactions. While all the activities were specifically conferred by short peptide fragments (17 amino acid residues) derived from the PEDF neurotrophic domain, no effects were triggered by peptides from the PEDF antiangiogenic region. The observed effects on retinal neurons imply a specific activation of the PEDF receptor by a small neurotrophic region of PEDF. Our findings support the neurotrophic PEDF peptides as neuronal guardians for the retina, highlighting their potential as promoters of retinal differentiation, and inhibitors of retinal cell death and its blinding consequences.
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Affiliation(s)
- Germán Michelis
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute - National Institutes of Health, Bethesda, MD, USA.,Department of Biology, Pharmacy and Biochemistry, Instituto de Investigaciones Bioquímicas (INIBIBB), Universidad Nacional del Sur (UNS)-CONICET, Bahía Blanca, Argentina
| | - Olga Lorena German
- Department of Biology, Pharmacy and Biochemistry, Instituto de Investigaciones Bioquímicas (INIBIBB), Universidad Nacional del Sur (UNS)-CONICET, Bahía Blanca, Argentina
| | - Rafael Villasmil
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute - National Institutes of Health, Bethesda, MD, USA
| | - Tamara Soto
- Department of Biology, Pharmacy and Biochemistry, Instituto de Investigaciones Bioquímicas (INIBIBB), Universidad Nacional del Sur (UNS)-CONICET, Bahía Blanca, Argentina
| | - Nora P Rotstein
- Department of Biology, Pharmacy and Biochemistry, Instituto de Investigaciones Bioquímicas (INIBIBB), Universidad Nacional del Sur (UNS)-CONICET, Bahía Blanca, Argentina
| | - Luis Politi
- Department of Biology, Pharmacy and Biochemistry, Instituto de Investigaciones Bioquímicas (INIBIBB), Universidad Nacional del Sur (UNS)-CONICET, Bahía Blanca, Argentina
| | - S Patricia Becerra
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute - National Institutes of Health, Bethesda, MD, USA
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Delivery Systems of Retinoprotective Proteins in the Retina. Int J Mol Sci 2021; 22:ijms22105344. [PMID: 34069505 PMCID: PMC8160820 DOI: 10.3390/ijms22105344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/12/2021] [Accepted: 05/17/2021] [Indexed: 12/26/2022] Open
Abstract
Retinoprotective proteins play important roles for retinal tissue integrity. They can directly affect the function and the survival of photoreceptors, and/or indirectly target the retinal pigment epithelium (RPE) and endothelial cells that support these tissues. Retinoprotective proteins are used in basic, translational and in clinical studies to prevent and treat human retinal degenerative disorders. In this review, we provide an overview of proteins that protect the retina and focus on pigment epithelium-derived factor (PEDF), and its effects on photoreceptors, RPE cells, and endothelial cells. We also discuss delivery systems such as pharmacologic and genetic administration of proteins to achieve photoreceptor survival and retinal tissue integrity.
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9
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Diabetic retinal neurodegeneration as a form of diabetic retinopathy. Int Ophthalmol 2021; 41:3223-3248. [PMID: 33954860 DOI: 10.1007/s10792-021-01864-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/08/2021] [Indexed: 12/11/2022]
Abstract
PURPOSE To review the evidence supporting diabetic retinal neurodegeneration (DRN) as a form of diabetic retinopathy. METHOD Review of literature. RESULTS DRN is recognized to be a part of retinopathy in patients with diabetes mellitus (DM), in addition to the well-established diabetic retinal vasculopathy (DRV). DRN has been noted in the early stages of DM, before the onset of clinically evident diabetic retinopathy. The occurrence of DRN has been confirmed in animal models of DM, histopathological examination of donor's eyes from diabetic individuals and assessment of neural structure and function in humans. DRN involves alterations in retinal ganglion cells, photoreceptors, amacrine cells and bipolar cells, and is thought to be driven by glutamate, oxidative stress and dysregulation of neuroprotective factors in the retina. Potential therapeutic options for DRN are under evaluation. CONCLUSIONS Literature is divided on the temporal relation between DRN and DRV, with evidence of both precedence and simultaneous occurrence. The relationship between DRN and multi-system neuropathy in DM is yet to be evaluated critically.
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10
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George SM, Lu F, Rao M, Leach LL, Gross JM. The retinal pigment epithelium: Development, injury responses, and regenerative potential in mammalian and non-mammalian systems. Prog Retin Eye Res 2021; 85:100969. [PMID: 33901682 DOI: 10.1016/j.preteyeres.2021.100969] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 03/23/2021] [Accepted: 04/07/2021] [Indexed: 12/13/2022]
Abstract
Diseases that result in retinal pigment epithelium (RPE) degeneration, such as age-related macular degeneration (AMD), are among the leading causes of blindness worldwide. Atrophic (dry) AMD is the most prevalent form of AMD and there are currently no effective therapies to prevent RPE cell death or restore RPE cells lost from AMD. An intriguing approach to treat AMD and other RPE degenerative diseases is to develop therapies focused on stimulating endogenous RPE regeneration. For this to become feasible, a deeper understanding of the mechanisms underlying RPE development, injury responses and regenerative potential is needed. In mammals, RPE regeneration is extremely limited; small lesions can be repaired by the expansion of adjacent RPE cells, but large lesions cannot be repaired as remaining RPE cells are unable to functionally replace lost RPE tissue. In some injury paradigms, RPE cells proliferate but do not regenerate a morphologically normal monolayer, while in others, proliferation is pathogenic and results in further disruption to the retina. This is in contrast to non-mammalian vertebrates, which possess tremendous RPE regenerative potential. Here, we discuss what is known about RPE formation during development in mammalian and non-mammalian vertebrates, we detail the processes by which RPE cells respond to injury, and we describe examples of RPE-to-retina and RPE-to-RPE regeneration in non-mammalian vertebrates. Finally, we outline barriers to RPE-dependent regeneration in mammals that could potentially be overcome to stimulate a regenerative response from the RPE.
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Affiliation(s)
- Stephanie M George
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Fangfang Lu
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA; Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Mishal Rao
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Lyndsay L Leach
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Jeffrey M Gross
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA; Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA.
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11
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Noel NCL, MacDonald IM, Allison WT. Zebrafish Models of Photoreceptor Dysfunction and Degeneration. Biomolecules 2021; 11:78. [PMID: 33435268 PMCID: PMC7828047 DOI: 10.3390/biom11010078] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 12/15/2022] Open
Abstract
Zebrafish are an instrumental system for the generation of photoreceptor degeneration models, which can be utilized to determine underlying causes of photoreceptor dysfunction and death, and for the analysis of potential therapeutic compounds, as well as the characterization of regenerative responses. We review the wealth of information from existing zebrafish models of photoreceptor disease, specifically as they relate to currently accepted taxonomic classes of human rod and cone disease. We also highlight that rich, detailed information can be derived from studying photoreceptor development, structure, and function, including behavioural assessments and in vivo imaging of zebrafish. Zebrafish models are available for a diversity of photoreceptor diseases, including cone dystrophies, which are challenging to recapitulate in nocturnal mammalian systems. Newly discovered models of photoreceptor disease and drusenoid deposit formation may not only provide important insights into pathogenesis of disease, but also potential therapeutic approaches. Zebrafish have already shown their use in providing pre-clinical data prior to testing genetic therapies in clinical trials, such as antisense oligonucleotide therapy for Usher syndrome.
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Affiliation(s)
- Nicole C. L. Noel
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada; (I.M.M.); (W.T.A.)
| | - Ian M. MacDonald
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada; (I.M.M.); (W.T.A.)
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, AB T6G 2R7, Canada
| | - W. Ted Allison
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada; (I.M.M.); (W.T.A.)
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2M8, Canada
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12
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Kim JY, Park S, Park SH, Lee D, Kim GH, Noh JE, Lee KJ, Kim GJ. Overexpression of pigment epithelium-derived factor in placenta-derived mesenchymal stem cells promotes mitochondrial biogenesis in retinal cells. J Transl Med 2021; 101:51-69. [PMID: 32724163 DOI: 10.1038/s41374-020-0470-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 06/05/2020] [Accepted: 07/12/2020] [Indexed: 01/13/2023] Open
Abstract
Pigment epithelium-derived factor (PEDF) plays a role in protecting retinal pigment epithelial (RPE) cells from oxidative stress (OS), a causative factor of RPE cell death. Genetically modified mesenchymal stem cells (MSCs) can be used to treat critical and incurable retinal diseases. Here, we overexpressed PEDF in placenta-derived MSCs (PD-MSCsPEDF, PEDF+) using a nonviral gene delivery system and evaluated the characteristics of PD-MSCsPEDF and their potential regenerative effects on RPE cells damaged by H2O2-induced OS. PD-MSCsPEDF maintained their stemness, cell surface marker, and differentiation potential characteristics. Compared to naive cells, PD-MSCsPEDF promoted mitochondrial respiration by enhancing biogenesis regulators (e.g., NRF1, PPARGC1A, and TFAM) as well as antioxidant enzymes (e.g., HMOXs, SODs, and GPX1). Compared to OS-damaged RPE cells cocultured with naive cells, OS-damaged RPE cells cocultured with PD-MSCsPEDF showed PEDF upregulation and VEGF downregulation. The expression levels of antioxidant genes and RPE-specific genes, such as RPE65, RGR, and RRH, were significantly increased in RPE cells cocultured with PD-MSCsPEDF. Furthermore, OS-damaged RPE cells cocultured with PD-MSCsPEDF had dramatically enhanced mitochondrial functions, and antiapoptotic effects improved due to cell survival signaling pathways. In the H2O2-induced retinal degeneration rat model, compared to administration of the naive counterpart, intravitreal administration of PD-MSCsPEDF alleviated proinflammatory cytokines and restored retinal structure and function by increasing PEDF expression and decreasing VEGF expression. Intravitreal administration of PD-MSCsPEDF also protected retinal degeneration against OS by increasing antioxidant gene expression and regulating the mitochondrial ROS levels and biogenesis. Taken together, PEDF overexpression in PD-MSCs improved the mitochondrial activities and induced OS-damaged RPE cell regeneration by regulating the oxidative status and mitochondrial biogenesis in vitro and in vivo. These data suggest that genetic modification of PEDF in PD-MSCs might be a new cell therapy for the treatment of retinal degenerative diseases.
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Affiliation(s)
- Jae Yeon Kim
- Department of Biomedical Science, CHA University, Seongnam, 13488, Republic of Korea
| | - Sohae Park
- Department of Biomedical Science, CHA University, Seongnam, 13488, Republic of Korea
| | - So Hyun Park
- Paju 365 Veterinary Medical Center, Paju, 10892, Republic of Korea
| | - Dongsook Lee
- Hamchoon Women's clinic, Research Center of Fertility & Genetics, Seoul, 06643, Republic of Korea
| | - Gyu Hyun Kim
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, 41062, Republic of Korea
| | - Jung Eun Noh
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, 41062, Republic of Korea
| | - Kea Joo Lee
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, 41062, Republic of Korea
| | - Gi Jin Kim
- Department of Biomedical Science, CHA University, Seongnam, 13488, Republic of Korea.
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13
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Dixit S, Polato F, Samardzija M, Abu-Asab M, Grimm C, Crawford SE, Becerra SP. PEDF deficiency increases the susceptibility of rd10 mice to retinal degeneration. Exp Eye Res 2020; 198:108121. [PMID: 32721425 DOI: 10.1016/j.exer.2020.108121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/09/2020] [Accepted: 06/15/2020] [Indexed: 12/29/2022]
Abstract
The SERPINF1 gene encodes pigment epithelium-derived factor (PEDF), a member of the serpin superfamily with neurotrophic and antiangiogenic properties in the retina. We hypothesized that absence of PEDF would lead to increased stress-associated retinal degeneration in Serpinf1 null mice. Accordingly, using a Serpinf1 null mouse model, we investigated the impact of PEDF absence on retinal morphology, and susceptibility to induced and inherited retinal degeneration. We studied the pattern of Serpinf1 expression in the mouse retina layers. PEDF protein was detected by western blotting. Transmission electron microscopy was performed on mouse retina. Serpinf1 null mice and wild type littermates were injected with NaIO3 (30 mg/kg body weight) intraperitonially. At post-injection day 1, 3, 4, 6 and 8 mice were euthanized, and eyes were enucleated. Serpinf1 null and rd10 double mutant mice were generated and their eyes enucleated at different time points from post-natal day 15 to post-natal day 28. Enucleated eyes were processed for hematoxylin and eosin staining and histopathological evaluations. We found that Serpinf1 was expressed in the retinal pigment epithelium, in the inner nuclear layer and in the ganglion cell layer, but undetectable in the outer nuclear layer of wild type mice. Plasma PEDF protein levels were undetectable in Serpinf1 null animals. RPE atrophy and retinal thinning were observed in NaIO3-treated wild type mice that progressed with time post-injection. NaIO3-treated Serpinf1 null mice showed comparatively better retinal morphology than wild type mice at day 4 post-injection. However, the absence of PEDF in Serpinf1 null x rd10 mice increased the susceptibility to retinal degeneration relative to that of rd10 mice. We concluded that histopathological evaluation of retinas lacking PEDF showed that removal of the Serpinf1 gene may activate PEDF-independent compensatory mechanisms to protect the retina against oxidative stress, while it increases the susceptibility to degenerate the retina in inherited retinal degeneration models.
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Affiliation(s)
- Shivani Dixit
- Section of Protein Structure and Function, LRCMB-NEI-NIH, Bethesda, MD, USA
| | - Federica Polato
- Section of Protein Structure and Function, LRCMB-NEI-NIH, Bethesda, MD, USA
| | - Marijana Samardzija
- Laboratory of Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Zurich, Switzerland
| | | | - Christian Grimm
- Laboratory of Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Zurich, Switzerland
| | - Susan E Crawford
- Department of Surgery, NorthShore University Health System Research Institute, Evanston, IL, USA
| | - S Patricia Becerra
- Section of Protein Structure and Function, LRCMB-NEI-NIH, Bethesda, MD, USA.
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14
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de Diego-Otero Y, Giráldez-Pérez RM, Lima-Cabello E, Heredia-Farfan R, Calvo Medina R, Sanchez-Salido L, Pérez Costillas L. Pigment epithelium-derived factor (PEDF) and PEDF-receptor in the adult mouse brain: Differential spatial/temporal localization pattern. J Comp Neurol 2020; 529:141-158. [PMID: 32427349 DOI: 10.1002/cne.24940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/20/2020] [Accepted: 04/22/2020] [Indexed: 12/11/2022]
Abstract
Pigment epithelium-derived factor (PEDF) is a multifunctional protein which was initially described in the retina, although it is also present in other tissues. It functions as an antioxidant agent promoting neuronal survival. Recently, a PEDF receptor has shown an elevated binding affinity for PEDF. There are no relevant data regarding the distribution of both proteins in the brain, therefore the main goal of this work was to investigate the spatiotemporal presence of PEDF and PEDFR in the adult mouse brain, and to determine the PEDF blood level in mouse and human. The localization of both proteins was analyzed by different experimental methods such as immunohistochemistry, western-blotting, and also by enzyme-linked immunosorbent assay. Differential expression was found in some telencephalic structures and positive signals for both proteins were detected in the cerebellum. The magnitude of the PEDFR labeling pattern was higher than PEDF and included some cortical and subventricular areas. Age-dependent changes in intensity of both protein immunoreactions were found in the cortical and hippocampal areas with greater reactivity between 4 and 8 months of age, whilst others, like the subventricular zones, these differences were more evident for PEDFR. Although ubiquitous presence was not found in the brain for these two proteins, their relevant functions must not be underestimated. It has been described that PEDF plays an important role in neuroprotection and data provided in the present work represents the first extensive study to understand the relevance of these two proteins in specific brain areas.
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Affiliation(s)
- Yolanda de Diego-Otero
- Research Laboratory, Hospital Civil, Institute of Biomedical Research in Malaga (IBIMA), Málaga, Spain.,Mental Health Clinic Unit, .Regional University Hospital, Hospital Civil, Málaga, Spain.,Research Unit, International Institute of Innovation and Attention to Neurodevelopment and Language, Málaga, Spain
| | - Rosa María Giráldez-Pérez
- Cellular Biology, Physiology and Immunology Department, University of Cordoba, Edificio Charles Darwin, Córdoba, Spain
| | - Elena Lima-Cabello
- Research Laboratory, Hospital Civil, Institute of Biomedical Research in Malaga (IBIMA), Málaga, Spain
| | - Raúl Heredia-Farfan
- Research Laboratory, Hospital Civil, Institute of Biomedical Research in Malaga (IBIMA), Málaga, Spain
| | - Rocío Calvo Medina
- Pediatric Clinic Unit. Regional University Hospital, Hospital Materno-Infantil Avd, Arroyo de los Angeles, Málaga, Spain
| | - Lourdes Sanchez-Salido
- Research Laboratory, Hospital Civil, Institute of Biomedical Research in Malaga (IBIMA), Málaga, Spain
| | - Lucía Pérez Costillas
- Mental Health Clinic Unit, .Regional University Hospital, Hospital Civil, Málaga, Spain.,Psychiatry and Physiotherapy Department, University of Malaga. Medical School, Málaga, Spain
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15
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Araújo RS, Silva GA. PlGF silencing combined with PEDF overexpression: Modeling RPE secretion as potential therapy for retinal neovascularization. Mol Biol Rep 2020; 47:4413-4425. [PMID: 32385771 DOI: 10.1007/s11033-020-05496-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 05/03/2020] [Indexed: 12/21/2022]
Abstract
Ocular neovascularization is a defining feature of several blinding diseases. We have previously described the effectiveness of long-term pigment epithelium-derived factor (PEDF) expression in the retina of diabetic mice in ameliorating some diabetic retinopathy hallmarks. In this study, we aimed to investigate if the antiangiogenic potential of PEDF overexpression was enhanced in combination with placental growth factor (PlGF) silencing. Human RPE cells were transfected with a self-replicating episomal vector (pEPito) for PEDF overexpression and/or a siRNA targeting PlGF gene. Conditioned media from PEDF overexpression, from PlGF inhibition and from their combination thereof were used to culture human umbilical vein endothelial cells, and their proliferation rate, migration capacity, apoptosis and ability to form tube-like structures were analyzed in vitro. We here demonstrate that pEPito-driven PEDF overexpression in combination with PlGF silencing in RPE cells does not affect their viability and results in an enhanced antiangiogenic activity in vitro. We observed a significant decrease in the migration and proliferation of endothelial cells, and an increase in apoptosis induction as well as a significant inhibitory effect on tube formation. Our findings demonstrate that simultaneous PEDF overexpression and PlGF silencing strongly impairs angiogenesis compared with the single approaches, providing a rationale for combining these therapies as a new treatment for retinal neovascularization.
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Affiliation(s)
- Rute S Araújo
- CEDOC - Chronic Diseases Research Center, NOVA Medical School, Universidade Nova de Lisboa, Campo Mártires da Pátria 130, 1169-056, Lisboa, Portugal.,Bioengineering- Cell Therapies and Regenerative Medicine PhD Program, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal
| | - Gabriela A Silva
- CEDOC - Chronic Diseases Research Center, NOVA Medical School, Universidade Nova de Lisboa, Campo Mártires da Pátria 130, 1169-056, Lisboa, Portugal. .,NOVA Medical School, Universidade Nova de Lisboa, Campo Mártires da Pátria 130, 1169-056, Lisboa, Portugal.
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16
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Paraoan L, Sharif U, Carlsson E, Supharattanasitthi W, Mahmud NM, Kamalden TA, Hiscott P, Jackson M, Grierson I. Secretory proteostasis of the retinal pigmented epithelium: Impairment links to age-related macular degeneration. Prog Retin Eye Res 2020; 79:100859. [PMID: 32278708 DOI: 10.1016/j.preteyeres.2020.100859] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/24/2020] [Accepted: 03/26/2020] [Indexed: 12/19/2022]
Abstract
Secretory proteostasis integrates protein synthesis, processing, folding and trafficking pathways that are essential for efficient cellular secretion. For the retinal pigment epithelium (RPE), secretory proteostasis is of vital importance for the maintenance of the structural and functional integrity of apical (photoreceptors) and basal (Bruch's membrane/choroidal blood supply) sides of the environment it resides in. This integrity is achieved through functions governed by RPE secreted proteins, which include extracellular matrix modelling/remodelling, angiogenesis and immune response modulation. Impaired RPE secretory proteostasis affects not only the extracellular environment, but leads to intracellular protein aggregation and ER-stress with subsequent cell death. Ample recent evidence implicates dysregulated proteostasis as a key factor in the development of age-related macular degeneration (AMD), the leading cause of blindness in the developed world, and research aiming to characterise the roles of various proteins implicated in AMD-associated dysregulated proteostasis unveiled unexpected facets of the mechanisms involved in degenerative pathogenesis. This review analyses cellular processes unveiled by the study of the top 200 transcripts most abundantly expressed by the RPE/choroid in the light of the specialised secretory nature of the RPE. Functional roles of these proteins and the mechanisms of their impaired secretion, due to age and genetic-related causes, are analysed in relation to AMD development. Understanding the importance of RPE secretory proteostasis in relation to maintaining retinal health and how it becomes impaired in disease is of paramount importance for the development and assessment of future therapeutic advancements involving gene and cell therapies.
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Affiliation(s)
- Luminita Paraoan
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom.
| | - Umar Sharif
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Emil Carlsson
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Wasu Supharattanasitthi
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom; Department of Physiology, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand
| | - Nur Musfirah Mahmud
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Tengku Ain Kamalden
- Eye Research Centre, Department of Ophthalmology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Paul Hiscott
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Malcolm Jackson
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Ian Grierson
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
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17
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Pigment Epithelium-Derived Factor as a Possible Treatment Agent for Choroidal Neovascularization. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:8941057. [PMID: 32215180 PMCID: PMC7079215 DOI: 10.1155/2020/8941057] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 02/28/2020] [Indexed: 02/06/2023]
Abstract
Choroidal neovascularization (CNV) is a sight-threatening disease and is characterized by the formation of pathological neovascularization in the choroid which extends into the subretinal space. Exudative age-related macular degeneration (AMD) is the formation of CNV in the macular area which leads to irreversible blindness. Continuous leakage and hemorrhage of the CNV lesion may eventually result in scarring or later fibrosis, which could result in photoreceptor cell atrophy. The current strategy for treating CNV is the use of antivascular endothelial growth factor (VEGF) agents. Many studies have demonstrated the efficacy of intravitreal anti-VEGF therapy. Other studies have also reported the side effects of single anti-VEGF treatment. And long-term inhibition of a single system may result in collateral damage to other visual elements. Pigment epithelium-derived factor (PEDF) is a 50 kDa protein that was first isolated from the conditioned medium of human RPE cells. PEDF has both antiangiogenesis and neuroprotective functions for photoreceptor cells. It may be a potential ocular antiangiogenic agent. This review outlines the distribution of PEDF in the eye, the mechanism of antiangiogenesis, the protective effect on the retina, and the relationship between PEDF and VEGF.
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18
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Ma X, Li H, Chen Y, Yang J, Chen H, Arnheiter H, Hou L. The transcription factor MITF in RPE function and dysfunction. Prog Retin Eye Res 2019; 73:100766. [DOI: 10.1016/j.preteyeres.2019.06.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 06/17/2019] [Accepted: 06/21/2019] [Indexed: 12/18/2022]
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19
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PEDF peptides promote photoreceptor survival in rd10 retina models. Exp Eye Res 2019; 184:24-29. [PMID: 30980815 DOI: 10.1016/j.exer.2019.04.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 12/19/2018] [Accepted: 04/05/2019] [Indexed: 12/20/2022]
Abstract
The purpose of the study is to evaluate the protective properties of PEDF peptide fragments on rd10 mouse models of retinal degeneration ex vivo. Human recombinant PEDF and synthetic peptides were used. Rd10 retinal explants as well as wild-type retinal explants treated with zaprinast to mimic the rd10 photoreceptor cell death were employed. PEDF protein was intravitreally administered into rd10 mice. Outer nuclear layer thickness measurements in retinal sections, TUNEL labeling in retinal explants, western blots and immunofluorescence with retinal samples were performed. PEDF protein levels in the RPE of rd10 mice decreased with age (P15 - P25). Levels of PEDF receptor PEDF-R declined in the photoreceptor inner segments from rd10 relative to wild-type mice at P25. PEDF administration increased the outer nuclear layer thickness of rd10 retinas in vivo and decreased the number of TUNEL+ nuclei of photoreceptors in rd10 retinal explant cultures, both relative to untreated controls. Peptides containing the PEDF neurotrophic region decreased the number of TUNEL+ photoreceptors in both rd10 and zaprinast-induced cell death ex vivo models, while peptides without the neurotrophic region and/or lacking affinity for PEDF-R were ineffective in protecting photoreceptors. Thus, retinal explants are a valuable system to evaluate PEDF activity. Short peptides with the photoreceptor-protective property of PEDF may prove useful for the development of therapeutic agents for photoreceptor protection in retinal degenerations.
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20
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Devoldere J, Peynshaert K, De Smedt SC, Remaut K. Müller cells as a target for retinal therapy. Drug Discov Today 2019; 24:1483-1498. [PMID: 30731239 DOI: 10.1016/j.drudis.2019.01.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 12/20/2018] [Accepted: 01/30/2019] [Indexed: 12/28/2022]
Abstract
Müller cells are specialized glial cells that span the entire retina from the vitreous cavity to the subretinal space. Their functional diversity and unique radial morphology render them particularly interesting targets for new therapeutic approaches. In this review, we reflect on various possibilities for selective Müller cell targeting and describe how some of their cellular mechanisms can be used for retinal neuroprotection. Intriguingly, cross-species investigation of their properties has revealed that Müller cells also have an essential role in retinal regeneration. Although many questions regarding this subject remain, it is clear that Müller cells have unique characteristics that make them suitable targets for the prevention and treatment of numerous retinal diseases.
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Affiliation(s)
- Joke Devoldere
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Karen Peynshaert
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Stefaan C De Smedt
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium; Cancer Research Institute Ghent (CRIG), Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Katrien Remaut
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium; Cancer Research Institute Ghent (CRIG), Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
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21
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Chen Y, Yang J, Geng H, Li L, Li J, Cheng B, Ma X, Li H, Hou L. Photoreceptor degeneration in microphthalmia ( Mitf) mice: partial rescue by pigment epithelium-derived factor. Dis Model Mech 2019; 12:12/1/dmm035642. [PMID: 30651300 PMCID: PMC6361154 DOI: 10.1242/dmm.035642] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 12/04/2018] [Indexed: 12/13/2022] Open
Abstract
Dysfunction and loss of the retinal pigment epithelium (RPE) are hallmarks of retinal degeneration, but the underlying pathogenetic processes are only partially understood. Using mice with a null mutation in the transcription factor gene Mitf, in which RPE deficiencies are associated with retinal degeneration, we evaluated the role of trophic factors secreted by the RPE in retinal homeostasis. In such mice, the thickness of the outer nuclear layer (ONL) is as in wild type up to postnatal day 10, but then is progressively reduced, associated with a marked increase in the number of apoptotic cells and a decline in staining for rhodopsin. We show that retinal degeneration and decrease in rhodopsin staining can be prevented partially in three different ways: first, by recombining mutant-derived postnatal retina with postnatal wild-type RPE in tissue explant cultures; second, by adding to cultured mutant retina the trophic factor pigment epithelium-derived factor (PEDF; also known as SERPINF1), which is normally produced in RPE under the control of Mitf; and third, by treating the eyes of Mitf mutant mice in vivo with drops containing a bioactive PEDF 17-mer peptide. This latter treatment also led to marked increases in a number of rod and cone genes. The results indicate that RPE-derived trophic factors, in particular PEDF, are instrumental in retinal homeostasis, and suggest that PEDF or its bioactive fragments may have therapeutic potential in RPE deficiency-associated retinal degeneration.
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Affiliation(s)
- Yu Chen
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Optometry, Ophthalmology, and Vision Science and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou 325003, China
| | - Juan Yang
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Optometry, Ophthalmology, and Vision Science and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou 325003, China
| | - Huiqin Geng
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Optometry, Ophthalmology, and Vision Science and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou 325003, China
| | - Liping Li
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Optometry, Ophthalmology, and Vision Science and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou 325003, China
| | - Jinyang Li
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Optometry, Ophthalmology, and Vision Science and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou 325003, China
| | - Bing Cheng
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Optometry, Ophthalmology, and Vision Science and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou 325003, China
| | - Xiaoyin Ma
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Optometry, Ophthalmology, and Vision Science and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou 325003, China
| | - Huirong Li
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Optometry, Ophthalmology, and Vision Science and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou 325003, China
| | - Ling Hou
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Optometry, Ophthalmology, and Vision Science and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou 325003, China
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22
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Delplace V, Ortin-Martinez A, Tsai ELS, Amin AN, Wallace V, Shoichet MS. Controlled release strategy designed for intravitreal protein delivery to the retina. J Control Release 2019; 293:10-20. [DOI: 10.1016/j.jconrel.2018.11.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/05/2018] [Accepted: 11/09/2018] [Indexed: 12/25/2022]
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23
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Cao L, Liu J, Pu J, Milne G, Chen M, Xu H, Shipley A, Forrester JV, McCaig CD, Lois N. Polarized retinal pigment epithelium generates electrical signals that diminish with age and regulate retinal pathology. J Cell Mol Med 2018; 22:5552-5564. [PMID: 30160348 PMCID: PMC6201363 DOI: 10.1111/jcmm.13829] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 07/06/2018] [Accepted: 07/10/2018] [Indexed: 12/21/2022] Open
Abstract
The transepithelial potential difference (TEP) across the retinal pigment epithelial (RPE) is dependent on ionic pumps and tight junction "seals" between epithelial cells. RPE cells release neurotrophic growth factors such as pigment epithelial derived factor (PEDF), which is reduced in age-related macular degeneration (AMD). The mechanisms that control the secretion of PEDF from RPE cells are not well understood. Using the CCL2/CX3CR1 double knockout mouse model (DKO), which demonstrates RPE damage and retinal degeneration, we uncovered an interaction between PEDF and the TEP which is likely to play an important role in retinal ageing and in the pathogenesis of AMD. We found that: (a) the expression of ATP1B1 (the Na+ /K+ -ATPase β1 subunit) was reduced significantly in RPE from aged mice, in patients with CNV (Choroidal Neovascularization) and in DKO mice; (b) the expression of PEDF also was decreased in aged persons and in DKO mice; (c) the TEP across RPE was reduced markedly in RPE cells from DKO mice and (d) an applied electric field (EF) of 50-100 mV/mm, used to mimic the natural TEP, increased the expression and secretion of PEDF in primary RPE cells. In conclusion, the TEP across the RPE depends on the expression of ATP1B1 and this regulates the secretion of PEDF by RPE cells and so may regulate the onset of retinal disease. Increasing the expression of PEDF using an applied EF to replenish a disease or age-reduced TEP may offer a new way of preventing or reversing retinal dysfunction.
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Affiliation(s)
- Lin Cao
- School of MedicineMedical Sciences and NutritionInstitute of Medical SciencesUniversity of AberdeenAberdeenUK
- Yizhou International Proton Medical Centre and Cancer HospitalHe BeiChina
| | - Jie Liu
- Department of OphthalmologyFrist Hospital Affiliated to the Chinese PLA General HospitalBeijingChina
| | - Jin Pu
- School of MedicineMedical Sciences and NutritionInstitute of Medical SciencesUniversity of AberdeenAberdeenUK
| | - Gillian Milne
- School of MedicineMedical Sciences and NutritionInstitute of Medical SciencesUniversity of AberdeenAberdeenUK
| | - Mei Chen
- Wellcome‐Wolfson Institute for Experimental MedicineQueen's UniversityBelfastUK
| | - Heping Xu
- Wellcome‐Wolfson Institute for Experimental MedicineQueen's UniversityBelfastUK
| | - Alan Shipley
- Biological Research & DevelopmentUniversity of New EnglandBiddefordMaine
| | - John V Forrester
- School of MedicineMedical Sciences and NutritionInstitute of Medical SciencesUniversity of AberdeenAberdeenUK
| | - Colin D McCaig
- School of MedicineMedical Sciences and NutritionInstitute of Medical SciencesUniversity of AberdeenAberdeenUK
| | - Noemi Lois
- Wellcome‐Wolfson Institute for Experimental MedicineQueen's UniversityBelfastUK
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24
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Abstract
Eukaryotic cells depend on precise genome organization within the nucleus to maintain an appropriate gene-expression profile. Critical to this process is the packaging of functional domains of open and closed chromatin to specific regions of the nucleus, but how this is regulated remains unclear. In this study, we show that the zinc finger protein Casz1 regulates higher-order nuclear organization of rod photoreceptors in the mouse retina by repressing nuclear lamina function, which leads to central localization of heterochromatin. Loss of Casz1 in rods leads to an abnormal transcriptional profile followed by degeneration. These results identify Casz1 as a regulator of higher-order genome organization. Genome organization plays a fundamental role in the gene-expression programs of numerous cell types, but determinants of higher-order genome organization are poorly understood. In the developing mouse retina, rod photoreceptors represent a good model to study this question. They undergo a process called “chromatin inversion” during differentiation, in which, as opposed to classic nuclear organization, heterochromatin becomes localized to the center of the nucleus and euchromatin is restricted to the periphery. While previous studies showed that the lamin B receptor participates in this process, the molecular mechanisms regulating lamina function during differentiation remain elusive. Here, using conditional genetics, we show that the zinc finger transcription factor Casz1 is required to establish and maintain the inverted chromatin organization of rod photoreceptors and to safeguard their gene-expression profile and long-term survival. At the mechanistic level, we show that Casz1 interacts with the polycomb repressor complex in a splice variant-specific manner and that both are required to suppress the expression of the nuclear envelope intermediate filament lamin A/C in rods. Lamin A is in turn sufficient to regulate heterochromatin organization and nuclear position. Furthermore, we show that Casz1 is sufficient to expand and centralize the heterochromatin of fibroblasts, suggesting a general role for Casz1 in nuclear organization. Together, these data support a model in which Casz1 cooperates with polycomb to control rod genome organization, in part by silencing lamin A/C.
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25
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Araújo RS, Santos DF, Silva GA. The role of the retinal pigment epithelium and Müller cells secretome in neovascular retinal pathologies. Biochimie 2018; 155:104-108. [PMID: 29960032 DOI: 10.1016/j.biochi.2018.06.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/25/2018] [Indexed: 02/06/2023]
Abstract
Secreted trophic factors are key to maintain the structural and functional integrity of the retina, as they regulate cellular pathways responsible for survival, function, and response to injury. Nevertheless, these same factors can also be involved in retinal pathologies, as a consequence of the impairment of the secretory function of cells. The cells considered as major contributors to the retinal secretome are the retinal pigmented epithelium (RPE) and Müller cells. Their role in the pathophysiology of the most common neovascular pathologies in the retina - Age-related Macular Degeneration (AMD), Diabetic Retinopathy (DR), and Retinopathy of Prematurity (ROP) - is highlighted in this short review, together with current trophic factor-based therapies, which are mainly focused on controlling inflammation, cell survival, and angiogenesis.
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Affiliation(s)
- Rute S Araújo
- CEDOC - Chronic Diseases Center, NOVA Medical School, Universidade Nova de Lisboa, Campo Mártires da Pátria 130, 1169-056 Lisboa, Portugal; Bioengineering-Cell Therapies and Regenerative Medicine PhD Program, NOVA Medical School, Universidade Nova de Lisboa, Campo Mártires da Pátria 130, 1169-056 Lisboa, Portugal
| | - Daniela F Santos
- CEDOC - Chronic Diseases Center, NOVA Medical School, Universidade Nova de Lisboa, Campo Mártires da Pátria 130, 1169-056 Lisboa, Portugal; ProRegeM - PhD Programme Mechanisms of Disease and Regenerative Medicine, NOVA Medical School, Universidade NOVA de Lisboa, Campo Mártires da Pátria 130, 1169-056 Lisboa, Portugal
| | - Gabriela A Silva
- CEDOC - Chronic Diseases Center, NOVA Medical School, Universidade Nova de Lisboa, Campo Mártires da Pátria 130, 1169-056 Lisboa, Portugal.
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Comitato A, Subramanian P, Turchiano G, Montanari M, Becerra SP, Marigo V. Pigment epithelium-derived factor hinders photoreceptor cell death by reducing intracellular calcium in the degenerating retina. Cell Death Dis 2018; 9:560. [PMID: 29752430 PMCID: PMC5948223 DOI: 10.1038/s41419-018-0613-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 04/16/2018] [Accepted: 04/19/2018] [Indexed: 12/21/2022]
Abstract
Calcium ions play a critical role in neuronal cell death. Pigment epithelium-derived factor (PEDF) is a promising neuroprotective protein for photoreceptor cells but the mechanisms mediating its effects against retinal degeneration are still not well characterized. We addressed this question in the rd1 degenerating mouse retina that bears a mutation in the Pde6b gene encoding one subunit of the phosphodiesterase enzyme. Loss of phosphodiesterase activity in rod photoreceptor cells increases cyclic guanosine monophosphate (cGMP) levels leading to a rise in intracellular calcium. Short-term treatments with recombinant human PEDF protein decreased intracellular calcium in photoreceptors in vivo. Taking advantage of calcium pump blockers, we defined that PEDF signaling acts on PMCA calcium pumps to lower intracellular calcium. PEDF restrained cell death pathways activated by high calcium levels and engaging calpains, BAX and AIF. The neurotrophic effects were mediated by the PEDF receptor (PEDF-R), encoded by the PNPLA2 gene. Finally, peptides containing the neurotrophic domain of PEDF targeted these same cell death pathways in vivo. The findings reveal rescue from death of degenerating photoreceptor cells by a PEDF-mediated preservation of intracellular calcium homeostasis.
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Affiliation(s)
- Antonella Comitato
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Preeti Subramanian
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, NEI, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Giandomenico Turchiano
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy.,Institute for Cell and Gene Therapy & Center for Chronic Immunodeficiency - University of Freiburg, Freiburg, Germany
| | - Monica Montanari
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - S Patricia Becerra
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, NEI, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy. .,Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy.
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Negative regulators of angiogenesis: important targets for treatment of exudative AMD. Clin Sci (Lond) 2017; 131:1763-1780. [PMID: 28679845 DOI: 10.1042/cs20170066] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 03/17/2017] [Accepted: 04/03/2017] [Indexed: 12/12/2022]
Abstract
Angiogenesis contributes to the pathogenesis of many diseases including exudative age-related macular degeneration (AMD). It is normally kept in check by a tightly balanced production of pro- and anti-angiogenic factors. The up-regulation of the pro-angiogenic factor, vascular endothelial growth factor (VEGF), is intimately linked to the pathogenesis of exudative AMD, and its antagonism has been effectively targeted for treatment. However, very little is known about potential changes in expression of anti-angiogenic factors and the role they play in choroidal vascular homeostasis and neovascularization associated with AMD. Here, we will discuss the important role of thrombospondins and pigment epithelium-derived factor, two major endogenous inhibitors of angiogenesis, in retinal and choroidal vascular homeostasis and their potential alterations during AMD and choroidal neovascularization (CNV). We will review the cell autonomous function of these proteins in retinal and choroidal vascular cells. We will also discuss the potential targeting of these molecules and use of their mimetic peptides for therapeutic development for exudative AMD.
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Abstract
The idea of treating disease in humans with genetic material was conceived over two decades ago and with that a promising journey involving development and efficacy studies in cells and animals of a large number of novel therapeutic reagents unfolded. In the footsteps of this process, successful gene therapy treatment of genetic conditions in humans has shown clear signs of efficacy. Notably, significant advancements using gene supplementation and silencing strategies have been made in the field of ocular gene therapy, thereby pinpointing ocular gene therapy as one of the compelling "actors" bringing gene therapy to the clinic. Most of all, this success has been facilitated because of (1) the fact that the eye is an effortlessly accessible, exceedingly compartmentalized, and immune-privileged organ offering a unique advantage as a gene therapy target, and (2) significant progress toward efficient, sustained transduction of cells within the retina having been achieved using nonintegrating vectors based on recombinant adeno-associated virus and nonintegrating lentivirus vectors. The results from in vivo experiments and trials suggest that treatment of inherited retinal dystrophies, ocular angiogenesis, and inflammation with gene therapy can be both safe and effective. Here, the progress of ocular gene therapy is examined with special emphasis on the potential use of RNAi- and protein-based antiangiogenic gene therapy to treat exudative age-related macular degeneration.
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Affiliation(s)
- Thomas J Corydon
- Department of Biomedicine, Aarhus University , Aarhus C, Denmark
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29
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Polato F, Becerra SP. Pigment Epithelium-Derived Factor, a Protective Factor for Photoreceptors in Vivo. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:699-706. [PMID: 26427478 DOI: 10.1007/978-3-319-17121-0_93] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Pigment epithelium-derived factor (PEDF) is a natural protein of the retina with demonstrable neurotrophic properties, found in the interphotoreceptor matrix in intimate contact with photoreceptors. This review summarizes the effects of PEDF on photoreceptors in several animal models of retinal degeneration.
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Affiliation(s)
- Federica Polato
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, NEI, National Institutes of Health, NIH-NEI BG.6. Room 134. 6 Center Drive MSC 0608, 20892-0608, Bethesda, MD, USA.
| | - S Patricia Becerra
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, NEI, National Institutes of Health, NIH-NEI BG.6. Room 134. 6 Center Drive MSC 0608, 20892-0608, Bethesda, MD, USA.
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Sun J, Mandai M, Kamao H, Hashiguchi T, Shikamura M, Kawamata S, Sugita S, Takahashi M. Protective Effects of Human iPS-Derived Retinal Pigmented Epithelial Cells in Comparison with Human Mesenchymal Stromal Cells and Human Neural Stem Cells on the Degenerating Retina in rd1 mice. Stem Cells 2016; 33:1543-53. [PMID: 25728228 DOI: 10.1002/stem.1960] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 12/26/2014] [Indexed: 01/03/2023]
Abstract
Retinitis pigmentosa (RP) is a group of visual impairments characterized by progressive rod photoreceptor cell loss due to a genetic background. Pigment epithelium-derived factor (PEDF) predominantly secreted by the retinal pigmented epithelium (RPE) has been reported to protect photoreceptors in retinal degeneration models, including rd1. In addition, clinical trials are currently underway outside Japan using human mesenchymal stromal cells and human neural stem cells to protect photoreceptors in RP and dry age-related macular degeneration, respectively. Thus, this study aimed to investigate the rescue effects of induced pluripotent stem (iPS)-RPE cells in comparison with those types of cells used in clinical trials on photoreceptor degeneration in rd1 mice. Cells were injected into the subretinal space of immune-suppressed 2-week-old rd1 mice. The results demonstrated that human iPS-RPE cells significantly attenuated photoreceptor degeneration on postoperative days (PODs) 14 and 21 and survived longer up to at least 12 weeks after operation than the other two types of graft cells with less immune responses and apoptosis. The mean PEDF concentration in the intraocular fluid in RPE-transplanted eyes was more than 1 µg/ml at PODs 14 and 21, and this may have contributed to the protective effect of RPE transplantation. Our findings suggest that iPS-RPE cells serve as a competent source to delay photoreceptor degeneration through stable survival in degenerating ocular environment and by releasing neuroprotective factors such as PEDF.
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Affiliation(s)
- Jianan Sun
- Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology (CDB), Kobe, Japan; Application Biology and Regenerative Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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Kenealey J, Subramanian P, Comitato A, Bullock J, Keehan L, Polato F, Hoover D, Marigo V, Becerra SP. Small Retinoprotective Peptides Reveal a Receptor-binding Region on Pigment Epithelium-derived Factor. J Biol Chem 2015; 290:25241-53. [PMID: 26304116 DOI: 10.1074/jbc.m115.645846] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Indexed: 11/06/2022] Open
Abstract
The cytoprotective effects of pigment epithelium-derived factor (PEDF) require interactions between an as of a yet undefined region with a distinct ectodomain on the PEDF receptor (PEDF-R). Here we characterized the area in PEDF that interacts with PEDF-R to promote photoreceptor survival. Molecular docking studies suggested that the ligand binding site of PEDF-R interacts with the neurotrophic region of PEDF (44-mer, positions 78-121). Binding assays demonstrated that PEDF-R bound the 44-mer peptide. Moreover, peptide P1 from the PEDF-R ectodomain had affinity for the 44-mer and a shorter fragment within it, 17-mer (positions 98-114). Single residue substitutions to alanine along the 17-mer sequence were designed and tested for binding and biological activity. Altered 17-mer[R99A] did not bind to the P1 peptide, whereas 17-mer[H105A] had higher affinity than the unmodified 17-mer. Peptides 17-mer, 17-mer[H105A], and 44-mer exhibited cytoprotective effects in cultured retina R28 cells. Intravitreal injections of these peptides and PEDF in the rd1 mouse model of retinal degeneration decreased the numbers of dying photoreceptors, 17-mer[H105A] being most effective. The blocking peptide P1 hindered their protective effects both in retina cells and in vivo. Thus, in addition to demonstrating that the region composed of positions 98-114 of PEDF contains critical residues for PEDF-R interaction that mediates survival effects, the findings reveal distinct small PEDF fragments with neurotrophic effects on photoreceptors.
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Affiliation(s)
| | | | - Antonella Comitato
- the Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy, and
| | - Jeanee Bullock
- From the National Eye Institute and the Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, D. C. 20057
| | | | | | - David Hoover
- the Center for Information Technology, National Institutes of Health, Bethesda, Maryland 20892
| | - Valeria Marigo
- the Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy, and
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PEDF and its roles in physiological and pathological conditions: implication in diabetic and hypoxia-induced angiogenic diseases. Clin Sci (Lond) 2015; 128:805-23. [PMID: 25881671 PMCID: PMC4557399 DOI: 10.1042/cs20130463] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Pigment epithelium-derived factor (PEDF) is a broadly expressed multifunctional member of the serine proteinase inhibitor (serpin) family. This widely studied protein plays critical roles in many physiological and pathophysiological processes, including neuroprotection, angiogenesis, fibrogenesis and inflammation. The present review summarizes the temporal and spatial distribution patterns of PEDF in a variety of developing and adult organs, and discusses its functions in maintaining physiological homoeostasis. The major focus of the present review is to discuss the implication of PEDF in diabetic and hypoxia-induced angiogenesis, and the pathways mediating PEDF's effects under these conditions. Furthermore, the regulatory mechanisms of PEDF expression, function and degradation are also reviewed. Finally, the therapeutic potential of PEDF as an anti-angiogenic drug is briefly summarized.
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33
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Attenuation of choroidal neovascularization by histone deacetylase inhibitor. PLoS One 2015; 10:e0120587. [PMID: 25807249 PMCID: PMC4373846 DOI: 10.1371/journal.pone.0120587] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 01/24/2015] [Indexed: 01/13/2023] Open
Abstract
Choroidal neovascularization (CNV) is a blinding complication of age-related macular degeneration that manifests as the growth of immature choroidal blood vessels through Bruch’s membrane, where they can leak fluid or hemorrhage under the retina. Here, we demonstrate that the histone deacetylase inhibitor (HDACi) trichostatin A (TSA) can down-regulate the pro-angiogenic hypoxia-inducible factor-1α and vascular endothelial growth factor (VEGF), and up-regulate the anti-angiogenic and neuro-protective pigment epithelium derived factor in human retinal pigment epithelial (RPE) cells. Most strikingly, TSA markedly down-regulates the expression of VEGF receptor-2 in human vascular endothelial cells and, thus, can knock down pro-angiogenic cell signaling. Additionally, TSA suppresses CNV-associated wound healing response and RPE epithelial-mesenchymal transdifferentiation. In the laser-induced model of CNV using C57Bl/6 mice, systemic administration of TSA significantly reduces fluorescein leakage and the size of CNV lesions at post—laser days 7 and 14 as well as the immunohistochemical expression of VEGF, VEGFR2, and smooth muscle actin in CNV lesions at post-laser day 7. This report suggests that TSA, and possibly HDACi’s in general, should be further evaluated for their therapeutic potential for the treatment of CNV.
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Thangaraj G, Christophel J, Bachmann G, Greif A, Layer PG. PEDF counteracts DL-α-aminoadipate toxicity and rescues gliotoxic damages in RPE-free chicken retinal explants. Exp Eye Res 2015; 134:111-22. [PMID: 25686916 DOI: 10.1016/j.exer.2015.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 01/21/2015] [Accepted: 02/12/2015] [Indexed: 01/03/2023]
Abstract
Gliotoxic responses complicate human eye diseases, the causes of which often remain obscure. Here, we activated Müller cells (MCs) by the gliotoxin DL-α-aminoadipate (AAA) and assayed possible protective effects by pigment epithelium-derived factor (PEDF) in RPE-free retinal explants of the E6 chick embryo. These models are suited to analyze gliotoxic reactions in vitro, since the avian retina contains only Müller cells (MCs) as glial components, and the RPE-free explants are devoid of a major PEDF source. ChAT- and AChE-immunohistochemistry (IHC) revealed that AAA treatment disrupted the differentiation of cholinergic amacrine cells in the inner plexiform layer. At the applied concentration of 1 mM AAA, apoptosis of MCs was slightly increased, as shown by TUNEL and caspase-3 activity assays. Concomitantly, cell-free gaps emerged in the middle of the retina, where MCs were swollen and amassed glutamine synthetase (shown by GS and Vimentin IHC). AAA treatment strongly activated MCs, as shown by GFAP IHC, and by an increase of stress-related catalase activity. Remarkably, nearly all effects of AAA on MCs were effectively counter-balanced by 50 ng/ml PEDF co-treatment, as also shown by RT-PCR. These findings suggest that supplementation with PEDF can protect the retina against gliotoxic attacks. Further studies should establish whether PEDF similarly protects a gliotoxic human retina.
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Affiliation(s)
- Gopenath Thangaraj
- Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany
| | - Jeanette Christophel
- Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany
| | - Gesine Bachmann
- Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany
| | - Alexander Greif
- Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany
| | - Paul G Layer
- Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany.
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36
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Unterlauft JD, Claudepierre T, Schmidt M, Müller K, Yafai Y, Wiedemann P, Reichenbach A, Eichler W. Enhanced survival of retinal ganglion cells is mediated by Müller glial cell-derived PEDF. Exp Eye Res 2014; 127:206-14. [PMID: 25128578 DOI: 10.1016/j.exer.2014.08.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Revised: 08/02/2014] [Accepted: 08/05/2014] [Indexed: 01/01/2023]
Abstract
The death of retinal ganglion cells (RGC) leads to visual impairment and blindness in ocular neurodegenerative diseases, primarily in glaucoma and diabetic retinopathy; hence, mechanisms that contribute to protecting RGC from ischemia/hypoxia are of great interest. We here address the role of retinal glial (Müller) cells and of pigment-epithelium-derived factor (PEDF), one of the main neuroprotectants released from the glial cells. We show that the hypoxia-induced loss in the viability of cultured purified RGC is due to apoptosis, but that the number of viable RGC increases when co-cultured with Müller glial cells suggesting that glial soluble mediators attenuate the death of RGC. When PEDF was ablated from Müller cells a significantly lower number of RGC survived in RGC-Müller cell co-cultures indicating that PEDF is a major survival factor allowing RGC to escape cell death. We further found that RGC express a PEDF receptor known as patatin-like phospholipase domain-containing protein 2 (PNPLA2) and that PEDF exposure, as well as the presence of Müller cells, leads to an activation of nuclear factor (NF)-κB in RGC. Furthermore, adding an NF-κB inhibitor (SN50) to PEDF-treated RGC cultures reduced the survival of RGC. These findings strongly suggest that NF-κB activation in RGC is critically involved in the pro-survival action of Müller-cell derived PEDF and plays an important role in maintaining neuronal survival.
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Affiliation(s)
| | - Thomas Claudepierre
- ENSAIA, UR AFPA, Team BFLA, Université de Lorraine, Vandœuvre-lès-Nancy Cedex, France
| | - Manuela Schmidt
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Germany
| | - Katja Müller
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Germany
| | - Yousef Yafai
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Germany
| | - Peter Wiedemann
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Germany
| | - Andreas Reichenbach
- Paul Flechsig Institute for Brain Research, Pathophysiology of Glia, University of Leipzig, Germany
| | - Wolfram Eichler
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Germany
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Cuenca N, Fernández-Sánchez L, Campello L, Maneu V, De la Villa P, Lax P, Pinilla I. Cellular responses following retinal injuries and therapeutic approaches for neurodegenerative diseases. Prog Retin Eye Res 2014; 43:17-75. [PMID: 25038518 DOI: 10.1016/j.preteyeres.2014.07.001] [Citation(s) in RCA: 296] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/03/2014] [Accepted: 07/07/2014] [Indexed: 01/17/2023]
Abstract
Retinal neurodegenerative diseases like age-related macular degeneration, glaucoma, diabetic retinopathy and retinitis pigmentosa each have a different etiology and pathogenesis. However, at the cellular and molecular level, the response to retinal injury is similar in all of them, and results in morphological and functional impairment of retinal cells. This retinal degeneration may be triggered by gene defects, increased intraocular pressure, high levels of blood glucose, other types of stress or aging, but they all frequently induce a set of cell signals that lead to well-established and similar morphological and functional changes, including controlled cell death and retinal remodeling. Interestingly, an inflammatory response, oxidative stress and activation of apoptotic pathways are common features in all these diseases. Furthermore, it is important to note the relevant role of glial cells, including astrocytes, Müller cells and microglia, because their response to injury is decisive for maintaining the health of the retina or its degeneration. Several therapeutic approaches have been developed to preserve retinal function or restore eyesight in pathological conditions. In this context, neuroprotective compounds, gene therapy, cell transplantation or artificial devices should be applied at the appropriate stage of retinal degeneration to obtain successful results. This review provides an overview of the common and distinctive features of retinal neurodegenerative diseases, including the molecular, anatomical and functional changes caused by the cellular response to damage, in order to establish appropriate treatments for these pathologies.
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Affiliation(s)
- Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain; Multidisciplinary Institute for Environmental Studies "Ramon Margalef", University of Alicante, Alicante, Spain.
| | - Laura Fernández-Sánchez
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Laura Campello
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Victoria Maneu
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Pedro De la Villa
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Spain
| | - Pedro Lax
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Isabel Pinilla
- Department of Ophthalmology, Lozano Blesa University Hospital, Aragon Institute of Health Sciences, Zaragoza, Spain
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Seaborn T, Ravni A, Au R, Chow BKC, Fournier A, Wurtz O, Vaudry H, Eiden LE, Vaudry D. Induction of serpinb1a by PACAP or NGF is required for PC12 cells survival after serum withdrawal. J Neurochem 2014; 131:21-32. [PMID: 24899316 DOI: 10.1111/jnc.12780] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 04/30/2014] [Accepted: 05/13/2014] [Indexed: 01/11/2023]
Abstract
PC12 cells are used to study the signaling mechanisms underlying the neurotrophic and neuroprotective activities of pituitary adenylate cyclase-activating polypeptide (PACAP) and nerve growth factor (NGF). Previous microarray experiments indicated that serpinb1a was the most induced gene after 6 h of treatment with PACAP or NGF. This study confirmed that serpinb1a is strongly activated by PACAP and NGF in a time-dependent manner with a maximum induction (~ 50-fold over control) observed after 6 h of treatment. Co-incubation with PACAP and NGF resulted in a synergistic up-regulation of serpinb1a expression (200-fold over control), suggesting that PACAP and NGF act through complementary mechanisms. Consistently, PACAP-induced serpinb1a expression was not blocked by TrkA receptor inhibition. Nevertheless, the stimulation of serpinb1a expression by PACAP and NGF was significantly reduced in the presence of extracellular signal-regulated kinase, calcineurin, protein kinase A, p38, and PI3K inhibitors, indicating that the two trophic factors share some common pathways in the regulation of serpinb1a. Finally, functional investigations conducted with siRNA revealed that serpinb1a is not involved in the effects of PACAP and NGF on PC12 cell neuritogenesis, proliferation or body cell volume but mediates their ability to block caspases 3/7 activity and to promote PC12 cell survival.
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Affiliation(s)
- Tommy Seaborn
- Neurotrophic Factor and Neuronal Differentiation Team, Inserm U982, DC2N, Mont-Saint-Aignan, France; International Associated Laboratory Samuel de Champlain, Mont-Saint-Aignan, France; Department of Pediatrics, Hôpital St-François d'Assise, Centre de Recherche du Centre Hospitalier Universitaire de Québec (CRCHUQ), Laval University, Québec, Canada
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Askou AL. Development of gene therapy for treatment of age-related macular degeneration. Acta Ophthalmol 2014; 92 Thesis3:1-38. [PMID: 24953666 DOI: 10.1111/aos.12452] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Intraocular neovascular diseases are the leading cause of blindness in the Western world in individuals over the age of 50. Age-related macular degeneration (AMD) is one of these diseases. Exudative AMD, the late-stage form, is characterized by abnormal neovessel development, sprouting from the choroid into the avascular subretinal space, where it can suddenly cause irreversible damage to the vulnerable photoreceptor (PR) cells essential for our high-resolution, central vision. The molecular basis of AMD is not well understood, but several growth factors have been implicated including vascular endothelial growth factor (VEGF), and the advent of anti-VEGF therapy has markedly changed the outcome of treatment. However, common to all current therapies for exudative AMD are the complications of repeated monthly intravitreal injections, which must be continued throughout one's lifetime to maintain visual benefits. Additionally, some patients do not benefit from established treatments. Strategies providing long-term suppression of inappropriate ocular angiogenesis are therefore needed, and gene therapy offers a potential powerful technique. This study aimed to develop a strategy based on RNA interference (RNAi) for the sustained attenuation of VEGF. We designed a panel of anti-VEGF short hairpin RNAs (shRNA), and based on the most potent shRNAs, microRNA (miRNA)-mimicked hairpins were developed. We demonstrated an additive VEGF silencing effect when we combined the miRNAs in a tricistronic miRNA cluster. To meet the requirements for development of medical treatments for AMD with long-term effects, the shRNA/miRNA is expressed from vectors based on adeno-associated virus (AAV) or lentivirus (LV). Both vector systems have been found superior in terms of transduction efficiency and persistence in gene expression in retinal cells. The capacity of AAV-encoded RNAi effector molecules to silence endogenous VEGF gene expression was evaluated in mouse models, including the model of laser-induced choroidal neovascularization (CNV), and we found that subretinal administration of self-complementary (sc)-AAV2/8 encoding anti-VEGF shRNAs can impair vessel formation. In parallel, a significant reduction of endogenous VEGF was demonstrated following injection of scAAV2/8 vectors expressing multiple anti-VEGF miRNAs into murine hind limb muscles. Furthermore, in an ongoing project we have designed versatile, multigenic LV vectors with combined expression of multiple miRNAs and proteins, including pigment epithelium-derived factor (PEDF), a multifunctional, secreted protein that has anti-angiogenic and neurotrophic functions. Co-expression of miRNAs and proteins from a single viral vector increases safety by minimizing the viral load necessary to obtain a therapeutic effect and thereby reduces the risk of insertional mutagenesis as well as the immune response against viral proteins. Our results show co-expression of functional anti-VEGF-miRNAs and PEDF in cell studies, and in vivo studies reveal an efficient retinal pigment epithelium (RPE)-specific gene expression following the incorporation of the vitelliform macular dystrophy 2 (VMD2) promoter, demonstrating the potential applicability of our multigenic LV vectors in ocular anti-VEGF gene therapy, including combination therapy for treatment of exudative AMD. In conclusion, these highly promising data clearly demonstrate that viral-encoded RNAi effector molecules can be used for the inhibition of neovascularization and will, in combination with the growing interest of applying DNA- or RNA-based technologies in the clinic, undoubtedly contribute to the development of efficacious long-term gene therapy treatment of intraocular neovascular diseases.
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Kucharska J, Del Río P, Arango-Gonzalez B, Gorza M, Feuchtinger A, Hauck SM, Ueffing M. Cyr61 activates retinal cells and prolongs photoreceptor survival in rd1 mouse model of retinitis pigmentosa. J Neurochem 2014; 130:227-40. [PMID: 24593181 DOI: 10.1111/jnc.12704] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 02/27/2014] [Accepted: 02/27/2014] [Indexed: 01/08/2023]
Abstract
Subretinal injections with glial cell line-derived neurotrophic factor (GDNF) rescue morphology as well as function of rod cells in mouse and rat animal models of retinitis pigmentosa. At the same time, it is postulated that this effect is indirect, mediated by activation of retinal Müller glial (RMG) cells. Here, we show that Cyr61/CCN1, one of the secreted proteins up-regulated in primary RMG after glial cell line-derived neurotrophic factor stimulation, provides neuroprotective and pro-survival capacities: Recombinant Cyr61 significantly reduced photoreceptor (PR) cells death in organotypic cultures of Pde6b(rd1) retinas. To identify stimulated pathways in the retina, we treated Pde6b(rd1) retinal explants with Cyr61 and observed an overall increase in activated Erk1/2 and Stat3 signalling molecules characterized by activation-site-specific phosphorylation. To identify Cyr61 retinal target cells, we isolated primary porcine PR, RMG and retinal pigment epithelium (RPE) cells and exposed them separately to Cyr61. Here, RMG as well as RPE cells responded with induced phosphorylation of Erk1/2, Stat3 and Akt. In PR, no increase in phosphorylation in any of the studied proteins was detected, suggesting an indirect neuroprotective effect of Cyr61. Cyr61 may thus act as an endogenous pro-survival factor for PR, contributing to the complex repertoire of neuroprotective activities generated by RMG and RPE cells. We propose the following model of Cyr61 neuroprotection within the retina: Cyr61 stimulates retinal Müller glial (RMG) and retinal pigment epithelium (RPE) cells and activates PI3K/Akt, mitogen-activated protein kinase(MAPK)/Erk and Janus kinase(JAK)/Stat-signalling pathways in these cells. Phosphorylated Stat3 and Erk1/2 presumably translocate to the nucleus, induce transcriptional changes, which increase secretion of neuroprotective agents that protect photoreceptors (PR) from mutation-induced death.
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Affiliation(s)
- Joanna Kucharska
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Research Unit Protein Science, Helmholtz Zentrum München, Neuherberg, Germany
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Lax P, Esquiva G, Altavilla C, Cuenca N. Neuroprotective effects of the cannabinoid agonist HU210 on retinal degeneration. Exp Eye Res 2014; 120:175-85. [PMID: 24495949 DOI: 10.1016/j.exer.2014.01.019] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 01/20/2014] [Accepted: 01/24/2014] [Indexed: 11/18/2022]
Abstract
Cannabinoids have been demonstrated to exert neuroprotective effects on different types of neuronal insults. Here we have addressed the therapeutic potential of the synthetic cannabinoid HU210 on photoreceptor degeneration, synaptic connectivity and functional activity of the retina in the transgenic P23H rat, an animal model for autosomal dominant retinitis pigmentosa (RP). In P23H rats administered with HU210 (100 μg/kg, i.p.) from P24 to P90, ERG recordings showed an amelioration of vision loss, as compared to vehicle-administered animals. Under scotopic conditions, the maximum a-wave amplitudes recorded at P60 and P90 were higher in HU210-treated animals, as compared to the values obtained in untreated animals. The scotopic b-waves were significantly higher in treated animals than in untreated rats at P30, P60 and P90. This attenuation of visual deterioration correlated with a delay in photoreceptor degeneration and the preservation of retinal cytoarchitecture. HU210-treated animals had 40% more photoreceptors than untreated animals. Presynaptic and postsynaptic elements, as well as the synaptic contacts between photoreceptors and bipolar or horizontal cells, were also preserved in HU210-treated P23H rats. These results indicate that HU210 preserves cone and rod structure and function, together with their contacts with postsynaptic neurons, in P23H rats. These data suggest that cannabinoids are potentially useful to delay retinal degeneration in RP patients.
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Affiliation(s)
- Pedro Lax
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Gema Esquiva
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Cesare Altavilla
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain; Institute Ramón Margalef, University of Alicante, Alicante, Spain.
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Trophic factors in the pathogenesis and therapy for retinal degenerative diseases. Surv Ophthalmol 2014; 59:134-65. [PMID: 24417953 DOI: 10.1016/j.survophthal.2013.09.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 09/11/2013] [Accepted: 09/17/2013] [Indexed: 12/27/2022]
Abstract
Trophic factors are endogenously secreted proteins that act in an autocrine and/or paracrine fashion to affect vital cellular processes such as proliferation, differentiation, and regeneration, thereby maintaining overall cell homeostasis. In the eye, the major contributors of these molecules are the retinal pigment epithelial (RPE) and Müller cells. The primary paracrine targets of these secreted proteins include the photoreceptors and choriocapillaris. Retinal degenerative diseases such as age-related macular degeneration and retinitis pigmentosa are characterized by aberrant function and/or eventual death of RPE cells, photoreceptors, choriocapillaris, and other retinal cells. We discuss results of in vitro and in vivo animal studies in which candidate trophic factors, either singly or in combination, were used in an attempt to ameliorate photoreceptor and/or retinal degeneration. We also examine current trophic factor therapies as they relate to the treatment of retinal degenerative diseases in clinical studies.
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Rapp M, Woo G, Al-Ubaidi MR, Becerra SP, Subramanian P. Pigment epithelium-derived factor protects cone photoreceptor-derived 661W cells from light damage through Akt activation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 801:813-20. [PMID: 24664775 PMCID: PMC11343582 DOI: 10.1007/978-1-4614-3209-8_102] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Pigment epithelium-derived factor (PEDF) can delay and prevent the death of photoreceptors in vivo. We investigated the survival activity of PEDF on cone photoreceptor-derived 661W cells in culture, the presence of PEDF receptor (PEDF-R) in these cells and the activation of prosurvival Akt. Cell death was induced by light exposure in the presence of 9-cis retinal. Cell viability assays showed that PEDF increased the number of 661W cells exposed to these conditions. Western blots showed that PEDF-treated 661W cells had a higher ratio of phosphorylated Akt to total Akt than untreated cells. The PEDF receptor PEDF-R was immunodetected in the plasma membrane fractions of 661W cells. The results demonstrated that PEDF can protect 661W cells against light-induced cell death and suggest that the binding of PEDF to cell surface PEDF-R triggers a prosurvival signaling pathway.
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Affiliation(s)
- Matthew Rapp
- National Eye Institute, National Institutes of Health, Bldg. 6, Rm. 131F, 6 Center Dr., MSC 0608, 20892-0608, Bethesda, MD, USA,
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Pigment epithelium-derived factor reduces apoptosis and pro-inflammatory cytokine gene expression in a murine model of focal retinal degeneration. ASN Neuro 2013; 5:e00126. [PMID: 24160756 PMCID: PMC3840469 DOI: 10.1042/an20130028] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
AMD (age-related macular degeneration) is a neurodegenerative disease causing irreversible central blindness in the elderly. Apoptosis and inflammation play important roles in AMD pathogenesis. PEDF (pigment epithelium-derived factor) is a potent neurotrophic and anti-inflammatory glycoprotein that protects the retinal neurons and photoreceptors against cell death caused by pathological insults. We studied the effects of PEDF on focal retinal lesions in DKO rd8 (Ccl2−/−/Cx3cr1−/− on C57BL/6N [Crb1rd8]) mice, a model for progressive, focal rd (retinal degeneration). First, we found a significant decrease in PEDF transcript expression in DKO rd8 mouse retina and RPE (retinal pigment epithelium) than WT (wild-type, C57BL/6N). Next, cultured DKO rd8 RPE cells secreted lower levels of PEDF protein in the media than WT. Then the right eyes of DKO rd8 mice were injected intravitreously with recombinant human PEDF protein (1 μg), followed by a subconjunctival injection of PEDF (3 μg) 4 weeks later. The untreated left eyes served as controls. The effect of PEDF was assessed by fundoscopy, ocular histopathology and A2E {[2,6-dimethyl-8-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1E,3E,5E,7E-octatetra-enyl]-1-(2-hydroxyethyl)-4-[4-methyl-6(2,6,6-trimethyl-1-cyclohexen-1-yl) 1E,3E,5E,7E-hexatrienyl]-pyridinium} levels, as well as apoptotic and inflammatory molecules. The PEDF-treated eyes showed slower progression or attenuation of the focal retinal lesions, fewer and/or smaller photoreceptor and RPE degeneration, and significantly lower A2E, relative to the untreated eyes. In addition, lower expression of apoptotic and inflammatory molecules were detected in the PEDF-treated than untreated eyes. Our results establish that PEDF potently stabilizes photoreceptor degeneration via suppression of both apoptotic and inflammatory pathways. The multiple beneficial effects of PEDF represent a novel approach for potential AMD treatment. Apoptosis and inflammation play important roles in age-related macular degeneration. As a potent neurotrophic and anti-inflammatory glycoprotein, PEDF potently stabilizes photoreceptor degeneration via suppression of apoptotic and inflammatory pathways in a mouse model of progressive, focal rd.
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Subramanian P, Locatelli-Hoops S, Kenealey J, DesJardin J, Notari L, Becerra SP. Pigment epithelium-derived factor (PEDF) prevents retinal cell death via PEDF Receptor (PEDF-R): identification of a functional ligand binding site. J Biol Chem 2013; 288:23928-42. [PMID: 23818523 DOI: 10.1074/jbc.m113.487884] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The extracellular pigment epithelium-derived factor (PEDF) displays retina survival activity by interacting with receptor proteins on cell surfaces. We have previously reported that PEDF binds and stimulates PEDF receptor (PEDF-R), a transmembrane phospholipase. However, the PEDF binding site of PEDF-R and its involvement in survival activity have not been identified. The purpose of this work is to identify a biologically relevant ligand-binding site on PEDF-R. PEDF bound the PEDF-R ectodomain L4 (Leu(159)-Met(325)) with affinity similar to the full-length PEDF-R (Met(1)-Leu(504)). Binding assays using synthetic peptides spanning L4 showed that PEDF selectively bound E5b (Ile(193)-Leu(232)) and P1 (Thr(210)-Leu(249)) peptides. Recombinant C-terminal truncated PEDF-R4 (Met(1)-Leu(232)) and internally truncated PEDF-R and PEDF-R4 (ΔHis(203)-Leu(232)) retained phospholipase activity of the full-length PEDF-R. However, PEDF-R polypeptides without the His(203)-Leu(232) region lost the PEDF affinity that stimulated their enzymatic activity. Cell surface labeling showed that PEDF-R is present in the plasma membranes of retina cells. Using siRNA to selectively knock down PEDF-R in retina cells, we demonstrated that PEDF-R is essential for PEDF-mediated cell survival and antiapoptotic activities. Furthermore, preincubation of PEDF with P1 and E5b peptides blocked the PEDF·PEDF-R-mediated retina cell survival activity, implying that peptide binding to PEDF excluded ligand-receptor interactions on the cell surface. Our findings establish that PEDF-R is required for the survival and antiapoptotic effects of PEDF on retina cells and has determinants for PEDF binding within its L4 ectodomain that are critical for enzymatic stimulation.
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Affiliation(s)
- Preeti Subramanian
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, NEI, National Institutes of Health, Bethesda, Maryland 20892, USA
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Kay P, Yang YC, Paraoan L. Directional protein secretion by the retinal pigment epithelium: roles in retinal health and the development of age-related macular degeneration. J Cell Mol Med 2013; 17:833-43. [PMID: 23663427 PMCID: PMC3822888 DOI: 10.1111/jcmm.12070] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 03/24/2013] [Indexed: 11/29/2022] Open
Abstract
The structural and functional integrity of the retinal pigment epithelium (RPE) is fundamental for maintaining the function of the neuroretina. These specialized cells form a polarized monolayer that acts as the retinal–blood barrier, separating two distinct environments with highly specialized functions: photoreceptors of the neuroretina at the apical side and Bruch's membrane/highly vascularized choriocapillaris at the basal side. The polarized nature of the RPE is essential for the health of these two regions, not only in nutrient and waste transport but also in the synthesis and directional secretion of proteins required in maintaining retinal homoeostasis and function. Although multiple malfunctions within the RPE cells have been associated with development of age-related macular degeneration (AMD), the leading cause of legal blindness, clear causative processes have not yet been conclusively characterized at the molecular and cellular level. This article focuses on the involvement of directionally secreted RPE proteins in normal functioning of the retina and on the potential association of incorrect RPE protein secretion with development of AMD. Understanding the importance of RPE polarity and the correct secretion of essential structural and regulatory components emerge as critical factors for the development of novel therapeutic strategies targeting AMD.
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Affiliation(s)
- Paul Kay
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
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Vigneswara V, Berry M, Logan A, Ahmed Z. Pigment epithelium-derived factor is retinal ganglion cell neuroprotective and axogenic after optic nerve crush injury. Invest Ophthalmol Vis Sci 2013; 54:2624-33. [PMID: 23513062 DOI: 10.1167/iovs.13-11803] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To investigate neuroprotective and axogenic properties of pigment epithelium-derived factor (PEDF) in retinal ganglion cells (RGC) in vitro and in vivo. METHODS Adult rat retinal cultures were treated with combinations of PBS and PEDF with or without a cell permeable analogue of cAMP, and RGC survival and neurite lengths quantified. The optic nerves of anesthetised rats were also crushed intraorbitally to transect all RGC axons followed by intravitreal injections of either PBS, PEDF, or cAMP+PEDF every 7 days. RGC were back filled with FluoroGold to quantify RGC survival and longitudinal optic nerve sections were stained with GAP43 antibodies to detect regenerating RGC axons. RESULTS An optimal dose of 2.5 × 10(-5) μg/μL, promoted 65% more RGC survival than controls in vitro, increasing by 4.4- and 5-fold the number of RGC with neurites and the mean neurite length, respectively. Addition of cAMP with or without PEDF did not potentiate RGC survival or the mean number of RGC with neurites, but enhanced RGC neurite length by 1.4-fold, compared with PEDF alone. After optic nerve crush (ONC), PEDF protected RGC from apoptosis and increased the numbers of regenerating RGC axons in the optic nerve by 4.6- and 3.4-fold, respectively when compared with controls. cAMP did not enhance PEDF-induced RGC neuroprotection, but potentiated its neuroregenerative effects by 2- to 3-fold, increasing the number of RGC axons regenerating at 500 and 1000 μm from the lesions site. CONCLUSIONS This study is the first to demonstrate that PEDF enhances both RGC survival and axon regeneration in vitro and in vivo.
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Affiliation(s)
- Vasanthy Vigneswara
- Neurotrauma and Neurodegeneration Section, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
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Characterization of the effects of retinal pigment epithelium-conditioned media on porcine and aged human retina. Graefes Arch Clin Exp Ophthalmol 2013; 251:1515-28. [PMID: 23575949 DOI: 10.1007/s00417-013-2326-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 01/23/2013] [Accepted: 03/13/2013] [Indexed: 10/27/2022] Open
Abstract
BACKGROUND Retinal pigment epithelium (RPE) cells produce neurotrophic factors that rescue photoreceptors from degeneration. Previously, we showed that conditioned medium (CM) from fetal vs adult RPE cells resulted in significantly better porcine retinal preservation, and possessed significantly higher levels of hepatocyte growth factor (HGF) and pigment epithelium-derived factor (PEDF). This study aimed to further describe the effects of human fetal RPE-CM on porcine and aged human retina, and to characterize its effects biochemically. METHODS RPE-CM was harvested from passage-2 fetal RPE, 7 days after passage, 24-hours after exposure to basal medium. After culture in RPE-CM, porcine retinal morphology was assessed with confocal microscopy. The effects of RPE-CM on porcine and aged human retina survival were assessed by cytotoxicity and apoptosis biochemical assays. To characterize RPE-CM biochemically, effects of heating, digesting with proteinase-K, dilution, concentration, and fractionation were tested. Recombinant proteins and neutralizing antibodies were used to identify proteins that might contribute to the salutary effects of RPE-CM on porcine retina. RESULTS Culturing porcine retina in RPE-CM significantly preserved outer nuclear layer width and the number of nuclei in cross-section, and significantly decreased photoreceptor axon retraction. RPE-CM decreased porcine retinal death by 17-34 % (p<0.05) compared to basal medium. Human retina from age-related macular degeneration (AMD) and non-AMD donors responded similarly after culture in RPE-CM. Heating, proteinase-K digestion, and dilution significantly diminished RPE-CM-mediated preservation of porcine retina, whereas concentrating RPE-CM significantly enhanced its preservation of porcine retina. Molecular cut filtration identified retina-preserving activity in the 3-100 kDa filtrate. PEDF or HGF at 90 % receptor occupancy significantly improved retinal preservation over 48 h of culture compared to basal medium. Neutralizing PEDF in RPE-CM decreased its ability to reduce retinal apoptosis by 23-27 % (p<0.05). CONCLUSION RPE-CM reduced biochemically and histologically measured degeneration in porcine retinae. This effect was concentration-dependent, and can be attributed to a protein component(s) in a 3-100 kDa molecular cut fraction. Human retina (including non-AMD and AMD Caucasian and non-AMD African-American) responds to culture in RPE-CM similarly to porcine retina. Receptor occupancy calculations and retinal viability data indicate that PEDF may be one of the components that contribute to retina preservation by RPE-CM.
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Becerra SP, Notario V. The effects of PEDF on cancer biology: mechanisms of action and therapeutic potential. Nat Rev Cancer 2013; 13:258-71. [PMID: 23486238 PMCID: PMC3707632 DOI: 10.1038/nrc3484] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The potent actions of pigment epithelium-derived factor (PEDF) on tumour-associated cells, and its extracellular localization and secretion, stimulated research on this multifunctional serpin. Such studies have identified several PEDF receptors and downstream signalling pathways. Known cellular PEDF responses have expanded from the initial discovery that PEDF induces retinoblastoma cell differentiation to its anti-angiogenic, antitumorigenic and antimetastatic properties. Although the diversity of PEDF activities seems to be complex, they are consistent with the varied mechanisms that regulate this multimodal factor. If PEDF is to be used for cancer management, a deeper appreciation of its many functions and mechanisms of action is needed.
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Affiliation(s)
- S Patricia Becerra
- National Eye Institute, US National Institutes of Health, Bethesda, Maryland, USA.
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