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Bighinati A, Adani E, Stanzani A, D’Alessandro S, Marigo V. Molecular mechanisms underlying inherited photoreceptor degeneration as targets for therapeutic intervention. Front Cell Neurosci 2024; 18:1343544. [PMID: 38370034 PMCID: PMC10869517 DOI: 10.3389/fncel.2024.1343544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 01/16/2024] [Indexed: 02/20/2024] Open
Abstract
Retinitis pigmentosa (RP) is a form of retinal degeneration characterized by primary degeneration of rod photoreceptors followed by a secondary cone loss that leads to vision impairment and finally blindness. This is a rare disease with mutations in several genes and high genetic heterogeneity. A challenging effort has been the characterization of the molecular mechanisms underlying photoreceptor cell death during the progression of the disease. Some of the cell death pathways have been identified and comprise stress events found in several neurodegenerative diseases such as oxidative stress, inflammation, calcium imbalance and endoplasmic reticulum stress. Other cell death mechanisms appear more relevant to photoreceptor cells, such as high levels of cGMP and metabolic changes. Here we review some of the cell death pathways characterized in the RP mutant retina and discuss preclinical studies of therapeutic approaches targeting the molecular outcomes that lead to photoreceptor cell demise.
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Affiliation(s)
- Andrea Bighinati
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Elisa Adani
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Agnese Stanzani
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Sara D’Alessandro
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Center for Neuroscience and Neurotechnology, Modena, Italy
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2
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Bazan HEP, Pham TL. A new R,R-RvD6 isomer with protective actions following corneal nerve injury. Prostaglandins Other Lipid Mediat 2024; 170:106802. [PMID: 38036037 DOI: 10.1016/j.prostaglandins.2023.106802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/05/2023] [Accepted: 11/27/2023] [Indexed: 12/02/2023]
Abstract
The transparent cornea is the most densely innervated tissue in the body, primarily by sensory nerves originating from the trigeminal ganglia (TG). Damage to corneal nerves reduces sensitivity and tear secretion and results in dry eye. Consequently, ocular pain, for which no satisfactory therapies exist, arises in many cases. Treatment of injured corneas with pigment epithelium-derived factor (PEDF) combined with docosahexaenoic acid (DHA) stimulates nerve regeneration in models of refractive surgery, which damages nerves. The mechanism involves the synthesis of a stereoisomer of resolvin D6 (R,R-RvD6) formed after incorporating DHA into membrane lipids. Activation of a PEDF receptor (PEDF-R) with phospholipase activity releases DHA to synthesize the new resolvin isomer, which is secreted via tears. Topical treatment of mice corneas with R,R-RvD6 shows higher bioactivity in regenerating nerves and increasing sensitivity compared to PEDF+DHA. It also stimulates a transcriptome in the TG that modulates genes involved in ocular pain. Our studies suggest an important therapeutic role for R,R-RvD6 in regenerating corneal nerves and decreasing pain resulting from dry eye.
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Affiliation(s)
- Haydee E P Bazan
- Neuroscience Center of Excellence and Department of Ophthalmology, School of Medicine, Louisiana State University Health Sciences Center New Orleans, New Orleans, LA, USA.
| | - Thang L Pham
- Neuroscience Center of Excellence and Department of Ophthalmology, School of Medicine, Louisiana State University Health Sciences Center New Orleans, New Orleans, LA, USA.
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3
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Sun Z, Li X, Li G, Xu Y, Meng J, Meng W, He S. Potential application value of pigment epithelium-derived factor in sensorineural hearing loss. Front Neurosci 2023; 17:1302124. [PMID: 38164244 PMCID: PMC10757943 DOI: 10.3389/fnins.2023.1302124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/17/2023] [Indexed: 01/03/2024] Open
Abstract
The inner ear is a complex and precise auditory perception system responsible for receiving and converting sound signals into neural signals, enabling us to perceive and understand sound. However, the occurrence and development of inner ear diseases and auditory disorders, such as sensorineural hearing loss, remain a global problem. In recent years, there has been increasing research on the treatment of inner ear diseases and auditory regeneration. Among these treatments, pigment epithelium-derived factor (PEDF), as a multifunctional secretory protein, exhibits diverse biological activities and functions through various mechanisms, and has shown potential applications in the inner ear. This minireview comprehensively evaluates the performance of PEDF in sensorineural hearing loss in inner ear and its potential targets and therapeutic prospects.
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Affiliation(s)
- Zihui Sun
- Department of Otolaryngology Head and Neck Surgery, Nanjing Tongren Hospital, School of Medicine, Southeast University, Nanjing, China
- Nanjing Tongren ENT Hospital, Nanjing, China
| | - Xiaoguang Li
- Department of Otolaryngology Head and Neck Surgery, Nanjing Tongren Hospital, School of Medicine, Southeast University, Nanjing, China
- Nanjing Tongren ENT Hospital, Nanjing, China
| | - Guangfei Li
- Department of Otolaryngology Head and Neck Surgery, Nanjing Tongren Hospital, School of Medicine, Southeast University, Nanjing, China
- Nanjing Tongren ENT Hospital, Nanjing, China
| | - Ying Xu
- Department of Stomatology, Nanjing Tongren Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Jie Meng
- Department of Otolaryngology Head and Neck Surgery, Nanjing Tongren Hospital, School of Medicine, Southeast University, Nanjing, China
- Nanjing Tongren ENT Hospital, Nanjing, China
| | - Wei Meng
- Department of Otolaryngology Head and Neck Surgery, Nanjing Tongren Hospital, School of Medicine, Southeast University, Nanjing, China
- Nanjing Tongren ENT Hospital, Nanjing, China
| | - Shuangba He
- Department of Otolaryngology Head and Neck Surgery, Nanjing Tongren Hospital, School of Medicine, Southeast University, Nanjing, China
- Nanjing Tongren ENT Hospital, Nanjing, China
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Bernardo-Colón A, Dong L, Abu-Asab M, Brush RS, Agbaga MP, Becerra SP. Ablation of pigment epithelium-derived factor receptor (PEDF-R/Pnpla2) causes photoreceptor degeneration. J Lipid Res 2023; 64:100358. [PMID: 36934843 PMCID: PMC10233210 DOI: 10.1016/j.jlr.2023.100358] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 03/03/2023] [Accepted: 03/04/2023] [Indexed: 03/19/2023] Open
Abstract
Photoreceptor cells express the patatin-like phospholipase domain-containing 2 (PNPLA2) gene that codes for pigment epithelium-derived factor receptor (PEDF-R) (also known as ATGL). PEDF-R exhibits phospholipase activity that mediates the neurotrophic action of its ligand PEDF. Because phospholipids are the most abundant lipid class in the retina, we investigated the role of PEDF-R in photoreceptors by generating CRISPR Pnpla2 knock-out mouse lines in a retinal degeneration-free background. Pnpla2-/- mice had undetectable retinal Pnpla2 gene expression and PEDF-R protein levels as assayed by RT-PCR and immunofluorescence, respectively. The photoreceptors of mice deficient in PEDF-R had deformities as examined by histology and transmission electron microscopy. Pnpla2 knockdown diminished the PLA2 enzymatic activity of PEDF-R in the retina. Lipidomic analyses revealed the accumulation of lysophosphatidyl choline-DHA and lysophosphatidyl ethanolamine-DHA in PEDF-R-deficient retinas, suggesting a possible causal link to photoreceptor dysfunction. Loss of PEDF-R decreased levels of rhodopsin, opsin, PKCα, and synaptophysin relative to controls. Pnpla2-/- photoreceptors had surface-exposed phosphatidylserine, and their nuclei were TUNEL positive and condensed, revealing an apoptotic onset. Paralleling its structural defects, PEDF-R deficiency compromised photoreceptor function in vivo as indicated by the attenuation of photoreceptor a- and b-waves in Pnpla2-/- and Pnpla2+/- mice relative to controls as determined by electroretinography. In conclusion, ablation of PEDF-R in mice caused alteration in phospholipid composition associated with malformation and malperformance of photoreceptors. These findings identify PEDF-R as an important component for photoreceptor structure and function, highlighting its role in phospholipid metabolism for retinal survival and its consequences.
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Affiliation(s)
- Alexandra Bernardo-Colón
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Lijin Dong
- Genetic Engineering Core, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Mones Abu-Asab
- Histopathology Core Facility, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Richard S Brush
- Department of Ophthalmology(,) and Dean A. McGee Eye Institute, Oklahoma City, OK, USA
| | - Martin-Paul Agbaga
- Department of Ophthalmology(,) and Dean A. McGee Eye Institute, Oklahoma City, OK, USA; Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - 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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Fevereiro-Martins M, Marques-Neves C, Guimarães H, Bicho M. Retinopathy of prematurity: A review of pathophysiology and signaling pathways. Surv Ophthalmol 2023; 68:175-210. [PMID: 36427559 DOI: 10.1016/j.survophthal.2022.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 11/15/2022] [Accepted: 11/18/2022] [Indexed: 11/25/2022]
Abstract
Retinopathy of prematurity (ROP) is a vasoproliferative disorder of the retina and a leading cause of visual impairment and childhood blindness worldwide. The disease is characterized by an early stage of retinal microvascular degeneration, followed by neovascularization that can lead to subsequent retinal detachment and permanent visual loss. Several factors play a key role during the different pathological stages of the disease. Oxidative and nitrosative stress and inflammatory processes are important contributors to the early stage of ROP. Nitric oxide synthase and arginase play important roles in ischemia/reperfusion-induced neurovascular degeneration. Destructive neovascularization is driven by mediators of the hypoxia-inducible factor pathway, such as vascular endothelial growth factor and metabolic factors (succinate). The extracellular matrix is involved in hypoxia-induced retinal neovascularization. Vasorepulsive molecules (semaphorin 3A) intervene preventing the revascularization of the avascular zone. This review focuses on current concepts about signaling pathways and their mediators, involved in the pathogenesis of ROP, highlighting new potentially preventive and therapeutic modalities. A better understanding of the intricate molecular mechanisms underlying the pathogenesis of ROP should allow the development of more effective and targeted therapeutic agents to reduce aberrant vasoproliferation and facilitate physiological retinal vascular development.
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Affiliation(s)
- Mariza Fevereiro-Martins
- Laboratório de Genética and Grupo Ecogenética e Saúde Humana, Instituto de Saúde Ambiental, Faculdade de Medicina, Universidade de Lisboa, Portugal; Instituto de Investigação Científica Bento da Rocha Cabral, Lisboa, Portugal; Departamento de Oftalmologia, Hospital Cuf Descobertas, Lisboa, Portugal.
| | - Carlos Marques-Neves
- Centro de Estudos das Ci.¼ncias da Visão, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Grupo Ecogenética e Saúde Humana, Instituto de Saúde Ambiental, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
| | - Hercília Guimarães
- Departamento de Ginecologia-Obstetrícia e Pediatria, Faculdade de Medicina, Universidade do Porto, Porto, Portugal.
| | - Manuel Bicho
- Laboratório de Genética and Grupo Ecogenética e Saúde Humana, Instituto de Saúde Ambiental, Faculdade de Medicina, Universidade de Lisboa, Portugal; Instituto de Investigação Científica Bento da Rocha Cabral, Lisboa, Portugal.
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Bernardo-Colón A, Lerner M, Becerra SP. Pigment epithelium-derived factor is an interleukin-6 antagonist in the RPE: Insight of structure-function relationships. Front Physiol 2022; 13:1045613. [PMID: 36467689 PMCID: PMC9709256 DOI: 10.3389/fphys.2022.1045613] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/03/2022] [Indexed: 07/04/2024] Open
Abstract
Retinal and choroidal inflammatory lesions increase the levels of the pro-inflammatory cytokine interleukin-6 (IL-6). Pigment epithelium-derived factor (PEDF) has anti-inflammatory properties, but it is not known if it can prevent the production of IL-6 by the retinal pigment epithelium. To investigate the anti-inflammatory effects of PEDF in the RPE, we used human ARPE-19 cells stimulated with human recombinant tumor necrosis factor-alpha (TNF-α) to induce overexpression of the IL6 gene. We found that the viability of ARPE-19 cells decreased by 22% with TNF-α at 10 ng/ml, being drastically decreased at ≥50 ng/ml. TNF-α at 5-100 ng/ml elevated the production and secretion of IL-6 protein, as measured by ELISA. To challenge the TNF-α-mediated stimulation of IL-6, we used recombinant human PEDF protein. PEDF at 100 nM recovered the TNF-α-mediated loss of cell viability and repressed IL-6 gene expression as determined by RT-PCR. PEDF at 10-100 nM attenuated the IL-6 protein secretion in a dose dependent fashion (IC50 = 65 nM), being abolished with 100 nM PEDF. To map the region that confers the IL-6 blocking effect to the PEDF polypeptide, we used chemically synthesized peptides designed from its biologically active domains, pro-death 34-mer, and pro-survival 44-mer and 17-mer (H105A), to challenge the IL-6 overproduction. The pro-survival peptides recovered the TNF-α-mediated cell viability loss, and inhibited IL-6 secretion, while the 34-mer did not have an effect, suggesting a role for the pro-survival domain in blocking TNF-α-mediated cell death and IL-6 stimulation. Our findings position PEDF as a novel antagonistic agent of IL-6 production in RPE cells, underscoring its use for the management of retinal disease-related inflammation.
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Affiliation(s)
| | | | - S. Patricia Becerra
- Laboratory of Retinal Cell and Molecular Biology, Section of Protein Structure and Function, National Eye Institute, National Institutes of Health, Bethesda, MD, United States
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Rebustini IT, Crawford SE, Becerra SP. PEDF Deletion Induces Senescence and Defects in Phagocytosis in the RPE. Int J Mol Sci 2022; 23:7745. [PMID: 35887093 PMCID: PMC9316002 DOI: 10.3390/ijms23147745] [Citation(s) in RCA: 2] [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: 06/15/2022] [Revised: 07/05/2022] [Accepted: 07/09/2022] [Indexed: 02/01/2023] Open
Abstract
The retinal pigment epithelium (RPE) expresses the Serpinf1 gene to produce pigment epithelium-derived factor (PEDF), a retinoprotective protein that is downregulated with cell senescence, aging and retinal degenerations. We determined the expression of senescence-associated genes in the RPE of 3-month-old mice that lack the Serpinf1 gene and found that Serpinf1 deletion induced H2ax for histone H2AX protein, Cdkn1a for p21 protein, and Glb1 gene for β-galactosidase. Senescence-associated β-galactosidase activity increased in the Serpinf1 null RPE when compared with wild-type RPE. We evaluated the subcellular morphology of the RPE and found that ablation of Serpinf1 increased the volume of the nuclei and the nucleoli number of RPE cells, implying chromatin reorganization. Given that the RPE phagocytic function declines with aging, we assessed the expression of the Pnpla2 gene, which is required for the degradation of photoreceptor outer segments by the RPE. We found that both the Pnpla2 gene and its protein PEDF-R declined with the Serpinf1 gene ablation. Moreover, we determined the levels of phagocytosed rhodopsin and lipids in the RPE of the Serpinf1 null mice. The RPE of the Serpinf1 null mice accumulated rhodopsin and lipids compared to littermate controls, implying an association of PEDF deficiency with RPE phagocytosis dysfunction. Our findings establish PEDF loss as a cause of senescence-like changes in the RPE, highlighting PEDF as both a retinoprotective and a regulatory protein of aging-like changes associated with defective degradation of the photoreceptor outer segment in the RPE.
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Affiliation(s)
- Ivan T. Rebustini
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Susan E. Crawford
- Department of Surgery, North Shore University Research Institute, University of Chicago Pritzker School of Medicine, Chicago, IL 60201, USA;
| | - 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 20892, USA;
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Kuriyama S, Tanaka G, Takagane K, Itoh G, Tanaka M. Pigment Epithelium Derived Factor Is Involved in the Late Phase of Osteosarcoma Metastasis by Increasing Extravasation and Cell-Cell Adhesion. Front Oncol 2022; 12:818182. [PMID: 35174090 PMCID: PMC8842676 DOI: 10.3389/fonc.2022.818182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/07/2022] [Indexed: 11/13/2022] Open
Abstract
Organ tropism of metastatic cells is not well understood. To determine the key factors involved in the selection of a specific organ upon metastasis, we established metastatic cell lines and analyzed their homing to specific tissues. Toward this, 143B osteosarcoma cells were injected intracardially until the kidney-metastasizing sub-cell line Bkid was established, which significantly differed from the parental 143B cells. The candidate genes responsible for kidney metastasis were validated, and SerpinF1/Pigment epithelium derived factor (PEDF) was identified as the primary target. Bkid cells with PEDF knockdown injected intracardially did not metastasize to the kidneys. In contrast, PEDF overexpressing 143B cells injected into femur metastasized to the lungs and kidneys. PEDF triggered mesenchymal-to-epithelial transition (MET) in vitro as well as in vivo. Based on these results, we hypothesized that the MET might be a potential barrier to extravasation. PEDF overexpression in various osteosarcoma cell lines increased their extravasation to the kidneys and lungs. Moreover, when cultured close to the renal endothelial cell line TKD2, Bkid cells disturbed the TKD2 layer and hindered wound healing via the PEDF-laminin receptor (lamR) axis. Furthermore, novel interactions were observed among PEDF, lamR, lysyl oxidase-like 1 (Loxl1), and SNAI3 (Snail-like transcription factor) during endothelial-to-mesenchymal transition (EndoMT). Collectively, our results show that PEDF induces cancer cell extravasation by increasing the permeability of kidney and lung vasculature acting via lamR and its downstream genes. We also speculate that PEDF promotes extravasation via inhibiting EndoMT, and this warrants investigation in future studies.
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Affiliation(s)
- Sei Kuriyama
- Department of Molecular Medicine and Biochemistry, Graduate School and Faculty of Medicine, Akita University, Akita City, Japan
| | - Gentaro Tanaka
- Department of Molecular Medicine and Biochemistry, Graduate School and Faculty of Medicine, Akita University, Akita City, Japan.,Department of Lifescience, Faculty and Graduate School of Engineering and Resource Science, Akita University, Akita City, Japan
| | - Kurara Takagane
- Department of Molecular Medicine and Biochemistry, Graduate School and Faculty of Medicine, Akita University, Akita City, Japan
| | - Go Itoh
- Department of Molecular Medicine and Biochemistry, Graduate School and Faculty of Medicine, Akita University, Akita City, Japan
| | - Masamitsu Tanaka
- Department of Molecular Medicine and Biochemistry, Graduate School and Faculty of Medicine, Akita University, Akita City, Japan
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Expression and production of pigment epithelium-derived factor (PEDF) and PEDF receptor variants from mammalian and bacterial cells. Protein Expr Purif 2022; 194:106072. [PMID: 35181508 DOI: 10.1016/j.pep.2022.106072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 11/22/2022]
Abstract
Human SERPINF1 gene codes for pigment epithelium-derived factor (PEDF), a secreted glycoprotein and member of the SERPIN superfamily. To obtain large amounts of recombinant PEDF proteins, we subcloned the coding sequence of human SERPINF1 mutated versions into the pCEP4 vector and generated stably transfected HEK.Ebna cells. The cells produced and secreted recombinant PEDF proteins into the culturing media. The recombinant PEDF proteins were purified by ion-exchange column chromatography and milligram amounts of highly purified protein were recovered. PEDF has affinity for PEDF-receptor (PEDF-R), a membrane-linked lipase encoded by the PNPLA2 gene. Recombinant PEDF-R truncated versions were obtained from Escherichia coli containing expression vectors with human PNPLA2 cDNAs with 3'end deletions and by induction with isopropyl β-d-1-thiogalactopyranoside. The bacterially derived PEDF-R proteins in insoluble inclusion bodies were solubilized with urea and purified by cation-exchange column chromatography. C-terminally truncated PEDF-R versions containing the ligand binding region retained the ability to bind PEDF. The data demonstrate that mammalian-derived recombinant PEDF and bacterially derived recombinant PEDF-R can be produced and purified in large amounts for further use in structural and biological studies.
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Starace V, Battista M, Brambati M, Cavalleri M, Bertuzzi F, Amato A, Lattanzio R, Bandello F, Cicinelli MV. The role of inflammation and neurodegeneration in diabetic macular edema. Ther Adv Ophthalmol 2021; 13:25158414211055963. [PMID: 34901746 PMCID: PMC8652911 DOI: 10.1177/25158414211055963] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 10/08/2021] [Indexed: 12/14/2022] Open
Abstract
The pathogenesis of diabetic macular edema (DME) is complex. Persistently high blood glucose activates multiple cellular pathways and induces inflammation, oxidation stress, and vascular dysfunction. Retinal ganglion cells, macroglial and microglial cells, endothelial cells, pericytes, and retinal pigment epithelium cells are involved. Neurodegeneration, characterized by dysfunction or apoptotic loss of retinal neurons, occurs early and independently from the vascular alterations. Despite the increasing knowledge on the pathways involved in DME, only limited therapeutic strategies are available. Besides antiangiogenic drugs and intravitreal corticosteroids, alternative therapeutic options tackling inflammation, oxidative stress, and neurodegeneration have been considered, but none of them has been currently approved.
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Affiliation(s)
- Vincenzo Starace
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Marco Battista
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Maria Brambati
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Michele Cavalleri
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Federico Bertuzzi
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Alessia Amato
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Rosangela Lattanzio
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Francesco Bandello
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, ItalySchool of Medicine, Vita-Salute San Raffaele University, Milan, Italy
| | - Maria Vittoria Cicinelli
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, via Olgettina 60, 20132 Milan, ItalySchool of Medicine, Vita-Salute San Raffaele University, Milan, Italy
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11
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Miralles de Imperial-Ollero JA, Gallego-Ortega A, Ortín-Martínez A, Villegas-Pérez MP, Valiente-Soriano FJ, Vidal-Sanz M. Animal Models of LED-Induced Phototoxicity. Short- and Long-Term In Vivo and Ex Vivo Retinal Alterations. Life (Basel) 2021; 11:life11111137. [PMID: 34833013 PMCID: PMC8617611 DOI: 10.3390/life11111137] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 12/26/2022] Open
Abstract
Phototoxicity animal models have been largely studied due to their degenerative communalities with human pathologies, e.g., age-related macular degeneration (AMD). Studies have documented not only the effects of white light exposure, but also other wavelengths using LEDs, such as blue or green light. Recently, a blue LED-induced phototoxicity (LIP) model has been developed that causes focal damage in the outer layers of the superior-temporal region of the retina in rodents. In vivo studies described a progressive reduction in retinal thickness that affected the most extensively the photoreceptor layer. Functionally, a transient reduction in a- and b-wave amplitude of the ERG response was observed. Ex vivo studies showed a progressive reduction of cones and an involvement of retinal pigment epithelium cells in the area of the lesion and, in parallel, an activation of microglial cells that perfectly circumscribe the damage in the outer retinal layer. The use of neuroprotective strategies such as intravitreal administration of trophic factors, e.g., basic fibroblast growth factor (bFGF), brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF) or pigment epithelium-derived factor (PEDF) and topical administration of the selective alpha-2 agonist (Brimonidine) have demonstrated to increase the survival of the cone population after LIP.
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Affiliation(s)
- Juan A. Miralles de Imperial-Ollero
- Departamento de Oftalmología, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria (IMIB) Virgen de la Arrixaca, Campus de CC de la Salud, El Palmar, 30120 Murcia, Spain; (J.A.M.d.I.-O.); (A.G.-O.); (M.P.V.-P.)
| | - Alejandro Gallego-Ortega
- Departamento de Oftalmología, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria (IMIB) Virgen de la Arrixaca, Campus de CC de la Salud, El Palmar, 30120 Murcia, Spain; (J.A.M.d.I.-O.); (A.G.-O.); (M.P.V.-P.)
| | - Arturo Ortín-Martínez
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ON M5T 2S8, Canada;
| | - María Paz Villegas-Pérez
- Departamento de Oftalmología, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria (IMIB) Virgen de la Arrixaca, Campus de CC de la Salud, El Palmar, 30120 Murcia, Spain; (J.A.M.d.I.-O.); (A.G.-O.); (M.P.V.-P.)
| | - Francisco J. Valiente-Soriano
- Departamento de Oftalmología, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria (IMIB) Virgen de la Arrixaca, Campus de CC de la Salud, El Palmar, 30120 Murcia, Spain; (J.A.M.d.I.-O.); (A.G.-O.); (M.P.V.-P.)
- Correspondence: (F.J.V.-S.); (M.V.-S.); Tel.: +34-868-88-4503 (F.J.V-S.); +34-868-88-4330 (M.V.-S.)
| | - Manuel Vidal-Sanz
- Departamento de Oftalmología, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria (IMIB) Virgen de la Arrixaca, Campus de CC de la Salud, El Palmar, 30120 Murcia, Spain; (J.A.M.d.I.-O.); (A.G.-O.); (M.P.V.-P.)
- Correspondence: (F.J.V.-S.); (M.V.-S.); Tel.: +34-868-88-4503 (F.J.V-S.); +34-868-88-4330 (M.V.-S.)
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12
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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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13
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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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14
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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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15
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Bullock J, Polato F, Abu-Asab M, Bernardo-Colón A, Aflaki E, Agbaga MP, Becerra SP. Degradation of Photoreceptor Outer Segments by the Retinal Pigment Epithelium Requires Pigment Epithelium-Derived Factor Receptor (PEDF-R). Invest Ophthalmol Vis Sci 2021; 62:30. [PMID: 33605986 PMCID: PMC7900850 DOI: 10.1167/iovs.62.2.30] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 01/19/2021] [Indexed: 12/28/2022] Open
Abstract
Purpose To examine the contribution of pigment epithelium-derived factor receptor (PEDF-R) to the phagocytosis process. Previously, we identified PEDF-R, the protein encoded by the PNPLA2 gene, as a phospholipase A2 in the retinal pigment epithelium (RPE). During phagocytosis, RPE cells ingest abundant phospholipids and protein in the form of photoreceptor outer segment (POS) tips, which are then hydrolyzed. The role of PEDF-R in RPE phagocytosis is not known. Methods Mice in which PNPLA2 was conditionally knocked out (cKO) in the RPE were generated. Mouse RPE/choroid explants were cultured. Human ARPE-19 cells were transfected with siPNPLA2 silencing duplexes. POSs were isolated from bovine retinas. The phospholipase A2 inhibitor bromoenol lactone was used. Transmission electron microscopy, immunofluorescence, lipid labeling, pulse-chase experiments, western blots, and free fatty acid and β-hydroxybutyrate assays were performed. Results The RPE of the cKO mice accumulated lipids, as well as more abundant and larger rhodopsin particles, compared to littermate controls. Upon POS exposure, RPE explants from cKO mice released less β-hydroxybutyrate compared to controls. After POS ingestion during phagocytosis, rhodopsin degradation was stalled both in cells treated with bromoenol lactone and in PNPLA2-knocked-down cells relative to their corresponding controls. Phospholipase A2 inhibition lowered β-hydroxybutyrate release from phagocytic RPE cells. PNPLA2 knockdown also resulted in a decline in fatty acids and β-hydroxybutyrate release from phagocytic RPE cells. Conclusions PEDF-R downregulation delayed POS digestion during phagocytosis. The findings imply that the efficiency of RPE phagocytosis depends on PEDF-R, thus identifying a novel contribution of this protein to POS degradation in the RPE.
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Affiliation(s)
- Jeanee Bullock
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University Medical Center, Washington DC, United States
| | - Federica Polato
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Mones Abu-Asab
- Section of Histopathology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Alexandra Bernardo-Colón
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Elma Aflaki
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Martin-Paul Agbaga
- Departments of Cell Biology and Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - S. Patricia Becerra
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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16
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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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17
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Bürger S, Meng J, Zwanzig A, Beck M, Pankonin M, Wiedemann P, Eichler W, Unterlauft JD. Pigment Epithelium-Derived Factor (PEDF) Receptors Are Involved in Survival of Retinal Neurons. Int J Mol Sci 2020; 22:E369. [PMID: 33396450 PMCID: PMC7795132 DOI: 10.3390/ijms22010369] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 12/25/2020] [Accepted: 12/28/2020] [Indexed: 02/02/2023] Open
Abstract
The demise of retinal ganglion cells (RGCs) is characteristic of diseases of the retina such as glaucoma and diabetic or ischemic retinopathies. Pigment epithelium-derived factor (PEDF) is a multifunctional secreted protein that mediates neuroprotection and inhibition of angiogenesis in the retina. We have studied expression and regulation of two of several receptors for PEDF, patatin-like phospholipase 2 gene product/PEDF-R and laminin receptor (LR), in serum-starved RGC under normoxia and hypoxia and investigated their involvement in the survival of retinal neuronal cells. We show that PEDF-R and LR are co-expressed in RGC and R28 retinal precursor cells. Expression of both receptors was enhanced in the presence of complex secretions from retinal glial (Müller) cells and upregulated by VEGF and under hypoxic conditions. PEDF-R- and LR-knocked-down cells demonstrated a markedly attenuated expression of anti-apoptotic Bcl-2 family members (Bcl-2, Bcl-xL) and neuroprotective mediators (PEDF, VEGF, BDNF) suggesting that both PEDF-R and LR mediate pro-survival effects of PEDF on RGC. While this study does not provide evidence for a differential survival-promoting influence of either PEDF-R or LR, it nevertheless highlights the importance of both PEDF receptors for the viability of retinal neurons.
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Affiliation(s)
| | | | | | | | | | | | - Wolfram Eichler
- Department of Ophthalmology and Eye Hospital, Leipzig University, Liebigstrasse 10-14, D-04103 Leipzig, Germany; (S.B.); (J.M.); (A.Z.); (M.B.); (M.P.); (P.W.); (J.D.U.)
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18
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Pigment Epithelium-Derived Factor (PEDF) Fragments Prevent Mouse Cone Photoreceptor Cell Loss Induced by Focal Phototoxicity In Vivo. Int J Mol Sci 2020; 21:ijms21197242. [PMID: 33008127 PMCID: PMC7582775 DOI: 10.3390/ijms21197242] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 09/21/2020] [Accepted: 09/28/2020] [Indexed: 12/17/2022] Open
Abstract
Here, we evaluated the effects of PEDF (pigment epithelium-derived factor) and PEDF peptides on cone-photoreceptor cell damage in a mouse model of focal LED-induced phototoxicity (LIP) in vivo. Swiss mice were dark-adapted overnight, anesthetized, and their left eyes were exposed to a blue LED placed over the cornea. Immediately after, intravitreal injection of PEDF, PEDF-peptide fragments 17-mer, 17-mer[H105A] or 17-mer[R99A] (all at 10 pmol) were administered into the left eye of each animal. BDNF (92 pmol) and bFGF (27 pmol) injections were positive controls, and vehicle negative control. After 7 days, LIP resulted in a consistent circular lesion located in the supratemporal quadrant and the number of S-cones were counted within an area centered on the lesion. Retinas treated with effectors had significantly greater S-cone numbers (PEDF (60%), 17-mer (56%), 17-mer [H105A] (57%), BDNF (64%) or bFGF (60%)) relative to their corresponding vehicle groups (≈42%). The 17-mer[R99A] with no PEDF receptor binding and no neurotrophic activity, PEDF combined with a molar excess of the PEDF receptor blocker P1 peptide, or with a PEDF-R enzymatic inhibitor had undetectable effects in S-cone survival. The findings demonstrated that the cone survival effects were mediated via interactions between the 17-mer region of the PEDF molecule and its PEDF-R receptor.
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Ethanol-Induced Oxidative Stress Modifies Inflammation and Angiogenesis Biomarkers in Retinal Pigment Epithelial Cells (ARPE-19): Role of CYP2E1 and its Inhibition by Antioxidants. Antioxidants (Basel) 2020; 9:antiox9090776. [PMID: 32825644 PMCID: PMC7555214 DOI: 10.3390/antiox9090776] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/15/2020] [Accepted: 08/19/2020] [Indexed: 12/22/2022] Open
Abstract
The retinal pigment epithelium (RPE) plays a key role in retinal health, being essential for the protection against reactive oxygen species (ROS). Nevertheless, excessive oxidative stress can induce RPE dysfunction, promoting visual loss. Our aim is to clarify the possible implication of CYP2E1 in ethanol (EtOH)-induced oxidative stress in RPE alterations. Despite the increase in the levels of ROS, measured by fluorescence probes, the RPE cells exposed to the lowest EtOH concentrations were able to maintain cell survival, measured by the Cell Proliferation Kit II (XTT). However, EtOH-induced oxidative stress modified inflammation and angiogenesis biomarkers, analyzed by proteome array, ELISA, qPCR and Western blot. The highest EtOH concentration used stimulated a large increase in ROS levels, upregulating the cytochrome P450-2E1 (CYP2E1) and promoting cell death. The use of antioxidants such as N-acetylcysteine (NAC) and diallyl sulfide (DAS), which is also a CYP2E1 inhibitor, reverted cell death and oxidative stress, modulating also the upstream angiogenesis and inflammation regulators. Because oxidative stress plays a central role in most frequent ocular diseases, the results herein support the proposal that CYP2E1 upregulation could aggravate retinal degeneration, especially in those patients with high baseline oxidative stress levels due to their ocular pathology and should be considered as a risk factor.
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20
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Bullock J, Pagan-Mercado G, Becerra SP. Cell-based assays to identify novel retinoprotective agents. MethodsX 2020; 7:101026. [PMID: 32874942 PMCID: PMC7452256 DOI: 10.1016/j.mex.2020.101026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/05/2020] [Indexed: 12/21/2022] Open
Abstract
Degeneration of the retina can lead ultimately to devastating irreversible vision loss, such as in inherited retinitis pigmentosa and age-related macular degeneration. Currently there is no cure to prevent retinal degeneration. Quantitative cell-based assays can be used to test potential drugs that prevent the death of retinal cells. Here, we describe in detail three semi-automated cell-based protocols to identify retinoprotective factors with two retinal cell lines, rat R28 cells and mouse 661W cells. In these protocols, cells are induced to undergo death by photo-oxidation stress, growth factor depletion or cytotoxicity with sodium iodate. Pigment epithelium-derived factor, an established neurotrophic factor for retinal cells, was used as a positive control. We discuss how these protocols will prove useful in high-throughput quantitative screening to identify novel therapeutics for retinal disorders.
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Affiliation(s)
- Jeanee Bullock
- Section on Protein Structure and Function, LRCMB, National Eye Institute, National Institutes of Health, Bethesda, MD, USA.,Department of Biochemistry and Molecular & Cellular Biology, Georgetown University Medical Center, Washington, DC, USA
| | - Glorivee Pagan-Mercado
- Section on Protein Structure and Function, LRCMB, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - S Patricia Becerra
- Section on Protein Structure and Function, LRCMB, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
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21
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Signaling Mechanisms Involved in PEDF-Mediated Retinoprotection. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1185:445-449. [PMID: 31884652 DOI: 10.1007/978-3-030-27378-1_73] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Pigment epithelium-derived factor (PEDF) is involved in signal transduction cascades necessary for protection of the retina. The interaction between PEDF and retinal cells elicits neuroprotective effects in vitro and in vivo. The direct substrates and signaling mechanisms involved in the survival response derived from such interaction are beginning to be revealed. It is of interest to elucidate cell death pathways that are crucial for the retinoprotective response of PEDF for the identification of targets that interfere with retina degeneration with potential therapeutic value. Here we review the molecular pathways triggered by PEDF that are involved in retinal survival activity.
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Kutluer M, Huang L, Marigo V. Targeting molecular pathways for the treatment of inherited retinal degeneration. Neural Regen Res 2020; 15:1784-1791. [PMID: 32246618 PMCID: PMC7513962 DOI: 10.4103/1673-5374.280303] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Inherited retinal degeneration is a major cause of incurable blindness characterized by loss of retinal photoreceptor cells. Inherited retinal degeneration is characterized by high genetic and phenotypic heterogeneity with several genes mutated in patients affected by these genetic diseases. The high genetic heterogeneity of these diseases hampers the development of effective therapeutic interventions for the cure of a large cohort of patients. Common cell demise mechanisms can be envisioned as targets to treat patients regardless the specific mutation. One of these targets is the increase of intracellular calcium ions, that has been detected in several murine models of inherited retinal degeneration. Recently, neurotrophic factors that favor the efflux of calcium ions to concentrations below toxic levels have been identified as promising molecules that should be evaluated as new treatments for retinal degeneration. Here, we discuss therapeutic options for inherited retinal degeneration and we will focus on neuroprotective approaches, such as the neuroprotective activity of the Pigment epithelium-derived factor. The characterization of specific targets for neuroprotection opens new perspectives together with many questions that require deep analyses to take advantage of this knowledge and develop new therapeutic approaches. We believe that minimizing cell demise by neuroprotection may represent a promising treatment strategy for retinal degeneration.
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Affiliation(s)
- Meltem Kutluer
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Li Huang
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
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23
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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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Léveillard T, Klipfel L. Mechanisms Underlying the Visual Benefit of Cell Transplantation for the Treatment of Retinal Degenerations. Int J Mol Sci 2019; 20:ijms20030557. [PMID: 30696106 PMCID: PMC6387096 DOI: 10.3390/ijms20030557] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/23/2019] [Accepted: 01/24/2019] [Indexed: 12/13/2022] Open
Abstract
The transplantation of retinal cells has been studied in animals to establish proof of its potential benefit for the treatment of blinding diseases. Photoreceptor precursors have been grafted in animal models of Mendelian-inherited retinal degenerations, and retinal pigmented epithelial cells have been used to restore visual function in animal models of age-related macular degeneration (AMD) and recently in patients. Cell therapy over corrective gene therapy in inherited retinal degeneration can overcome the genetic heterogeneity by providing one treatment for all genetic forms of the diseases. In AMD, the existence of multiple risk alleles precludes a priori the use of corrective gene therapy. Mechanistically, the experiments of photoreceptor precursor transplantation reveal the importance of cytoplasmic material exchange between the grafted cells and the host cells for functional rescue, an unsuspected mechanism and novel concept. For transplantation of retinal pigmented epithelial cells, the mechanisms behind the therapeutic benefit are only partially understood, and clinical trials are ongoing. The fascinating studies that describe the development of methodologies to produce cells to be grafted and demonstrate the functional benefit for vision are reviewed.
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Affiliation(s)
- Thierry Léveillard
- Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
| | - Laurence Klipfel
- Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
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25
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Small-scale GMP production of plasmid DNA using a simplified and fully disposable production method. J Biotechnol 2019; 306S:100007. [DOI: 10.1016/j.btecx.2019.100007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/18/2019] [Accepted: 05/05/2019] [Indexed: 12/19/2022]
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Wang X, Liu X, Ren Y, Liu Y, Han S, Zhao J, Gou X, He Y. PEDF protects human retinal pigment epithelial cells against oxidative stress via upregulation of UCP2 expression. Mol Med Rep 2018; 19:59-74. [PMID: 30431098 PMCID: PMC6297793 DOI: 10.3892/mmr.2018.9645] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 09/07/2018] [Indexed: 01/23/2023] Open
Abstract
To investigate the protective function of pigment epithelium-derived factor (PEDF) against oxidative stress (OS) in ARPE-19 cells, ARPE-19 cells were divided into different OS groups and treated with various concentrations of H2O2 (0, 75, 150 and 200 µmol/l) for 24 h. To establish the protective group, 200 ng/ml of PEDF was administered to ARPE-19 cells. Cell Counting Kit-8 assays and cell growth curve experiments were performed to determine levels of cell viability; lactate dehydrogenase and propidium iodide (PI) staining assays were also performed. The expression levels of genes associated with apoptosis as well as uncoupling protein 2 (UCP2) were detected by reverse transcription-quantitative, or semi-quantitative polymerase chain reaction. Furthermore, an OS injury animal model was established in both C57BL/6 and BALB/c mice via injection of 5 µg of PEDF in the vitreous cavity and subsequent injection of 150 µM H2O2 following a 24 h time interval. Hematoxylin and eosin (H&E) staining, as well as UCP2 immunofluorescent labeling were also performed. One-way analysis of variance was used to determine statistically significant differences, followed by multiple comparison analysis using the Newman Keuls method. The results of cell viability assays demonstrated that the numbers of apoptotic cells were increased following treatment with H2O2 in a dose-dependent manner; however, this effect was reversed following treatment with PEDF. The expression levels of caspase 3 and B cell lymphoma (Bcl2) associated X genes associated with apoptosis were inhibited, whereas levels of the anti-apoptotic gene Bcl2 were enhanced following treatment with PEDF in different passages of ARPE-19 cells. Significant differences were demonstrated in the levels of UCP2 gene expression between the PEDF+ H2O2 treated group and cells treated with H2O2 alone. Labeling of the UCP2 detector in the confocal images demonstrated decreased UCP2 protein staining in the retinal pigment epithelium (RPE) cells and RPE layers following H2O2 injury; however, this effect was inhibited following treatment with PEDF. H&E staining was performed to investigate the thickness of the RPE layers, and the results revealed that thicknesses were significantly increased in sections treated with PEDF during OS, due to increased numbers of RPE cells. Furthermore, PEDF was demonstrated to increase UCP2 gene expression in ARPE-19 cells and animal RPE layers under OS, which suggested that PEDF may protect RPE cells and tissues during oxidative injury.
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Affiliation(s)
- Xia Wang
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
| | - Xu Liu
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
| | - Yuan Ren
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
| | - Ying Liu
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
| | - Shuangyu Han
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
| | - Jingkang Zhao
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
| | - Xingchun Gou
- Department of Neurobiology, The Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, Shaanxi 710021, P.R. China
| | - Yuan He
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
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Of mice and men: The physiological role of adipose triglyceride lipase (ATGL). Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:880-899. [PMID: 30367950 PMCID: PMC6439276 DOI: 10.1016/j.bbalip.2018.10.008] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 12/12/2022]
Abstract
Adipose triglyceride lipase (ATGL) has been discovered 14 years ago and revised our view on intracellular triglyceride (TG) mobilization – a process termed lipolysis. ATGL initiates the hydrolysis of TGs to release fatty acids (FAs) that are crucial energy substrates, precursors for the synthesis of membrane lipids, and ligands of nuclear receptors. Thus, ATGL is a key enzyme in whole-body energy homeostasis. In this review, we give an update on how ATGL is regulated on the transcriptional and post-transcriptional level and how this affects the enzymes' activity in the context of neutral lipid catabolism. In depth, we highlight and discuss the numerous physiological functions of ATGL in lipid and energy metabolism. Over more than a decade, different genetic mouse models lacking or overexpressing ATGL in a cell- or tissue-specific manner have been generated and characterized. Moreover, pharmacological studies became available due to the development of a specific murine ATGL inhibitor (Atglistatin®). The identification of patients with mutations in the human gene encoding ATGL and their disease spectrum has underpinned the importance of ATGL in humans. Together, mouse models and human data have advanced our understanding of the physiological role of ATGL in lipid and energy metabolism in adipose and non-adipose tissues, and of the pathophysiological consequences of ATGL dysfunction in mice and men. Summary of mouse models with genetic or pharmacological manipulation of ATGL. Summary of patients with mutations in the human gene encoding ATGL. In depth discussion of the role of ATGL in numerous physiological processes in mice and men.
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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: 39] [Impact Index Per Article: 6.5] [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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Zhang Y, Li Y, Liu Z, Zhao Q, Zhang H, Wang X, Lu P, Yu H, Wang M, Dong H, Zhang Z. PEDF regulates lipid metabolism and reduces apoptosis in hypoxic H9c2 cells by inducing autophagy related 5-mediated autophagy via PEDF-R. Mol Med Rep 2018; 17:7170-7176. [PMID: 29568944 PMCID: PMC5928674 DOI: 10.3892/mmr.2018.8733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 11/16/2017] [Indexed: 01/15/2023] Open
Abstract
Pigment epithelial-derived factor (PEDF) is a multifunctional secreted glycoprotein, which exerts a variety of physiological activities. PEDF may protect against hypoxia‑induced cell death associated with its antioxidative effects and p53 mitochondrial translocation in cultured cardiomyocytes and H9c2 cells. Additionally, previous studies have suggested that autophagy is an important cell survival mechanism. However, the effect of PEDF on autophagy and the associated pathway in hypoxic H9c2 cells has not been fully established. Autophagy has been reported to regulate lipid metabolism; however, little is known about whether PEDF is able to regulate lipid metabolism by promoting autophagy. In the present study, western blotting results revealed that PEDF increased the level of microtubule‑associated protein 1A/1B‑light chain 3 (LC3)‑II. Transmission electron microscopy (TEM) and LC3 fluorescence demonstrated that PEDF increased the number of autophagosomes. PEDF also increased the viability of hypoxic H9c2 cells and decreased the level of cleaved caspase‑3 protein, as evidenced by CCK‑8 assays and western blotting, respectively. TEM and a triglyceride assay kit demonstrated that PEDF‑induced autophagy may stimulate lipid degradation. Western blotting results revealed a novel mechanism underlying PEDF‑induced H9c2 cell autophagy via the PEDF‑R‑mediated Atg5 pathway under hypoxic conditions. Furthermore, the results also suggest that PEDF‑induced autophagy may stimulate lipid degradation. The survival function of autophagy suggests that modulation of PEDF‑induced autophagy may be used as a therapeutic strategy to protect cells against lipid-associated metabolic diseases.
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Affiliation(s)
- Yiqian Zhang
- Department of Thoracic and Cardiovascular Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Yufeng Li
- Department of Thoracic Cardiovascular Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Zhiwei Liu
- Research Facility Center for Morphology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Qixiang Zhao
- Department of Thoracic Cardiovascular Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Hao Zhang
- Department of Thoracic Cardiovascular Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Xiaoyu Wang
- Department of Thoracic Cardiovascular Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Peng Lu
- Department of Thoracic Cardiovascular Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Hongli Yu
- Research Facility Center for Morphology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Meng Wang
- Research Facility Center for Morphology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Hongyan Dong
- Research Facility Center for Morphology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Zhongming Zhang
- Department of Thoracic and Cardiovascular Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
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Li Y, Liu Z, Zhang Y, Zhao Q, Wang X, Lu P, Zhang H, Wang Z, Dong H, Zhang Z. PEDF protects cardiomyocytes by promoting FUNDC1‑mediated mitophagy via PEDF-R under hypoxic condition. Int J Mol Med 2018; 41:3394-3404. [PMID: 29512692 PMCID: PMC5881750 DOI: 10.3892/ijmm.2018.3536] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 02/15/2018] [Indexed: 01/15/2023] Open
Abstract
Pigment epithelial-derived factor (PEDF) is known to exert diverse physiological activities. Previous studies suggest that hypoxia could induce mitophagy. Astoundingly, under hypoxic condition, we found that PEDF decreased the mitochondrial density of cardiomyocytes. In this study, we evaluated whether PEDF could decrease the mitochondrial density and play a protective role in hypoxic cardiomyocytes via promoting mitophagy. Immunostaining and western blotting were used to analyze mitochondrial density and mitophagy of hypoxic cardiomyocytes. Gas chromatography-mass spectrometry and ELISA were used to analyze levels of palmitic acid and diacylglycerol. Transmission Electron Microscopy was used to detect mitophagy and the mitochondrial density in adult male Sprague-Dawley rat model of acute myocardial infarction. Compared to the control group, we observed that PEDF decreased mitochondrial density through promoting hypoxic cardiomyocyte mitophagy. PEDF increased the levels of palmitic acid and diacylglycerol, and then upregulated the levels of protein kinase Cα (PKC-α) and its activation. Furthermore, inhibition of PKC-α by Go6976 could effectively suppress PEDF-induced mitophagy. Besides, we found that PEDF promoted FUNDC1-mediated cardiomyocyte mitophagy via ULK1, which depended on the activation of PKC-α. Finally, we discovered that mitophagy was increased and mitochondrial density was reduced in adult male Sprague-Dawley rat model of acute myocardial infarction. We concluded that PEDF promotes mitophagy to protect hypoxic cardiomyocytes, through PEDF/PEDF-R/PA/DAG/PKC-α/ULK1/FUNDC1 pathway.
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Affiliation(s)
- Yufeng Li
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Zhiwei Liu
- Research Facility Center for Morphology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Yiqian Zhang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Qixiang Zhao
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Xiaoyu Wang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Peng Lu
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Hao Zhang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Zhu Wang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Hongyan Dong
- Research Facility Center for Morphology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Zhongming Zhang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
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Peng CH, Chuang JH, Wang ML, Jhan YY, Chien KH, Chung YC, Hung KH, Chang CC, Lee CK, Tseng WL, Hwang DK, Hsu CH, Lin TC, Chiou SH, Chen SJ. Laminin modification subretinal bio-scaffold remodels retinal pigment epithelium-driven microenvironment in vitro and in vivo. Oncotarget 2018; 7:64631-64648. [PMID: 27564261 PMCID: PMC5323104 DOI: 10.18632/oncotarget.11502] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/19/2016] [Indexed: 11/25/2022] Open
Abstract
Advanced age-related macular degeneration (AMD) may lead to geographic atrophy or fibrovascular scar at macular, dysfunctional retinal microenvironment, and cause profound visual loss. Recent clinical trials have implied the potential application of pluripotent cell-differentiated retinal pigment epithelial cells (dRPEs) and membranous scaffolds implantation in repairing the degenerated retina in AMD. However, the efficacy of implanted membrane in immobilization and supporting the viability and functions of dRPEs, as well as maintaining the retinal microenvironment is still unclear. Herein we generated a biomimetic scaffold mimicking subretinal Bruch's basement from plasma modified polydimethylsiloxane (PDMS) sheet with laminin coating (PDMS-PmL), and investigated its potential functions to provide a subretinal environment for dRPE-monolayer grown on it. Firstly, compared to non-modified PDMS, PDMS-PmL enhanced the attachment, proliferation, polarization, and maturation of dRPEs. Second, PDMS-PmL increased the polarized tight junction, PEDF secretion, melanosome pigment deposit, and phagocytotic-ability of dRPEs. Third, PDMS-PmL was able to carry a dRPEs/photoreceptor-precursors multilayer retina tissue. Finally, the in vivo subretinal implantation of PDMS-PmL in porcine eyes showed well-biocompatibility up to 2-year follow-up. Notably, multifocal ERGs at 2-year follow-up revealed well preservation of macular function in PDMS-PmL, but not PDMS, transplanted porcine eyes. Trophic PEDF secretion of macular retina in PDMS-PmL group was also maintained to preserve retinal microenvironment in PDMS-PmL eyes at 2 year. Taken together, these data indicated that PDMS-PmL is able to sustain the physiological morphology and functions of polarized RPE monolayer, suggesting its potential of rescuing macular degeneration in vivo.
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Affiliation(s)
- Chi-Hsien Peng
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Ophthalmology, Shin Kong Wu Ho-Su Memorial Hospital & Fu-Jen Catholic University, Taipei Taiwan.,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Jen-Hua Chuang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
| | - Mong-Lien Wang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yong-Yu Jhan
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
| | - Ke-Hung Chien
- Department of Ophthalmology, Tri-Service General Hospital & National Defense Medical Center, Taipei, Taiwan.,Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
| | - Yu-Chien Chung
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Kuo-Hsuan Hung
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Chia-Ching Chang
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taipei, Taiwan
| | - Chao-Kuei Lee
- Department of Photonics, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Wei-Lien Tseng
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
| | - De-Kuang Hwang
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | | | - Tai-Chi Lin
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Shih-Hwa Chiou
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.,Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Shih-Jen Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan
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32
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Retinal Pigment Epithelium and Photoreceptor Preconditioning Protection Requires Docosanoid Signaling. Cell Mol Neurobiol 2017; 38:901-917. [PMID: 29177613 PMCID: PMC5882642 DOI: 10.1007/s10571-017-0565-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 11/03/2017] [Indexed: 01/10/2023]
Abstract
Omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) are necessary for functional cell integrity. Preconditioning (PC), as we define it, is an acquired protection or resilience by a cell, tissue, or organ to a lethal stimulus enabled by a previous sublethal stressor or stimulus. In this study, we provide evidence that the omega-3 fatty acid docosahexaenoic acid (DHA) and its derivatives, the docosanoids 17-hydroxy docosahexaenoic acid (17-HDHA) and neuroprotectin D1 (NPD1), facilitate cell survival in both in vitro and in vivo models of retinal PC. We also demonstrate that PC requires the enzyme 15-lipoxygenase-1 (15-LOX-1), which synthesizes 17-HDHA and NPD1, and that this is specific to docosanoid signaling despite the concomitant release of the omega-6 arachidonic acid and eicosanoid synthesis. These findings advocate that DHA and docosanoids are protective enablers of PC in photoreceptor and retinal pigment epithelial cells.
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Falero-Perez J, Park S, Sorenson CM, Sheibani N. PEDF expression affects retinal endothelial cell proangiogenic properties through alterations in cell adhesive mechanisms. Am J Physiol Cell Physiol 2017; 313:C405-C420. [PMID: 28747334 PMCID: PMC5668572 DOI: 10.1152/ajpcell.00004.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 07/20/2017] [Accepted: 07/20/2017] [Indexed: 12/17/2022]
Abstract
Pigment epithelium-derived factor (PEDF) is an endogenous inhibitor of angiogenesis. Although various ocular cell types including retinal endothelial cells (EC) produce PEDF, we know very little about cell autonomous effects of PEDF in these cell types. Here we determined how PEDF expression affects retinal EC proangiogenic properties. Retinal EC were prepared from wild-type (PEDF+/+) and PEDF-deficient (PEDF-/-) mice. The identity of EC was confirmed by staining for specific markers including vascular endothelial cadherin, CD31, and B4-lectin. Retinal EC also expressed VEGF receptor 1 and endoglin, as well as ICAM-1, ICAM-2, and VCAM-1. PEDF-/- retinal EC were more proliferative, less apoptotic when challenged with H2O2, less migratory, and less adherent compared with PEDF+/+ EC. These changes could be associated, at least in part, with increased levels of tenascin-C, fibronectin, thrombospondin-1 and collagen IV, and lower amounts of osteopontin. PEDF-/- EC also exhibited alterations in expression of a number of integrins including α2, αv, β1, β8, and αvβ3, and cell-cell adhesion molecules including CD31, zonula occluden-1, and occludin. These observations correlated with attenuation of capillary morphogenesis and increased levels of oxidative stress in PEDF-/- EC. PEDF-/- EC also produced lower levels of VEGF compared with PEDF+/+ cells. Thus, PEDF deficiency has a significant impact on retinal EC adhesion and migration, perhaps through altered production of extracellular matrix and junctional proteins in response to increased oxidative stress affecting their proangiogenic activity.
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Affiliation(s)
- Juliana Falero-Perez
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
- McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - SunYoung Park
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Christine M Sorenson
- McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Nader Sheibani
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin;
- McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
- Department of Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin; and
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
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34
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Pham TL, He J, Kakazu AH, Jun B, Bazan NG, Bazan HEP. Defining a mechanistic link between pigment epithelium-derived factor, docosahexaenoic acid, and corneal nerve regeneration. J Biol Chem 2017; 292:18486-18499. [PMID: 28972155 PMCID: PMC5682960 DOI: 10.1074/jbc.m117.801472] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/22/2017] [Indexed: 12/22/2022] Open
Abstract
The cornea is densely innervated to sustain the integrity of the ocular surface. Corneal nerve damage produced by aging, diabetes, refractive surgeries, and viral or bacterial infections impairs tear production, the blinking reflex, and epithelial wound healing, resulting in loss of transparency and vision. A combination of the known neuroprotective molecule, pigment epithelium–derived factor (PEDF) plus docosahexaenoic acid (DHA), has been shown to stimulate corneal nerve regeneration, but the mechanisms involved are unclear. Here, we sought to define the molecular events of this effect in an in vivo mouse injury model. We first confirmed that PEDF + DHA increased nerve regeneration in the mouse cornea. Treatment with PEDF activates the phospholipase A2 activity of the PEDF-receptor (PEDF-R) leading to the release of DHA; this free DHA led to enhanced docosanoid synthesis and induction of bdnf, ngf, and the axon growth promoter semaphorin 7a (sema7a), and as a consequence, their products appeared in the mouse tears. Surprisingly, corneal injury and treatment with PEDF + DHA induced transcription of neuropeptide y (npy), small proline-rich protein 1a (sprr1a), and vasoactive intestinal peptide (vip) in the trigeminal ganglia (TG). The PEDF-R inhibitor, atglistatin, blocked all of these changes in the cornea and TG. In conclusion, we uncovered here an active cornea–TG axis, driven by PEDF-R activation, that fosters axon outgrowth in the cornea.
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Affiliation(s)
- Thang Luong Pham
- From the Department of Ophthalmology and Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana 70112-2223
| | - Jiucheng He
- From the Department of Ophthalmology and Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana 70112-2223
| | - Azucena H Kakazu
- From the Department of Ophthalmology and Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana 70112-2223
| | - Bokkyoo Jun
- From the Department of Ophthalmology and Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana 70112-2223
| | - Nicolas G Bazan
- From the Department of Ophthalmology and Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana 70112-2223
| | - Haydee E P Bazan
- From the Department of Ophthalmology and Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana 70112-2223
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Pigment epithelium-derived factor promotes tumor metastasis through an interaction with laminin receptor in hepatocellular carcinomas. Cell Death Dis 2017; 8:e2969. [PMID: 28771223 PMCID: PMC5596550 DOI: 10.1038/cddis.2017.359] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/01/2017] [Accepted: 07/03/2017] [Indexed: 02/07/2023]
Abstract
Pigment epithelium-derived factor (PEDF) has complex functions in tumor metastasis, but little is known about the roles of PEDF and its receptors in hepatocellular carcinoma (HCC). Here we found that high expression of PEDF is associated with shorter overall survival in HCC patients. Forced expression of PEDF enhanced HCC cell aggressive behavior in vitro and in vivo, whereas silencing PEDF expression reduced migration and invasion. Furthermore, PEDF expression led to changes in cell morphology and the expression of epithelial-mesenchymal transition (EMT)-related markers via ERK1/2 signaling pathway, including the upregulation of N-cadherin and slug, and the downregulation of E-cadherin in HCC cells. Our results further showed that PEDF could interact with laminin receptor (LR) and LR knockdown attenuated PEDF-induced migration, invasion and the change of EMT-related markers. More importantly, in clinical HCC specimens, we found that PEDF expression was correlated with subcellular localization of LR, and that high expression of PEDF and positive expression of LR predicted a poor prognosis. In conclusion, our results demonstrate a novel functional role of PEDF/LR axis in driving metastasis through ERK1/2-mediated EMT in HCC and provided a promising prognostic marker in HCC.
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Winokur PN, Subramanian P, Bullock JL, Arocas V, Becerra SP. Comparison of two neurotrophic serpins reveals a small fragment with cell survival activity. Mol Vis 2017; 23:372-384. [PMID: 28706437 PMCID: PMC5501690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 06/30/2017] [Indexed: 10/31/2022] Open
Abstract
PURPOSE Protease nexin-1 (PN-1), a serpin encoded by the SERPINE2 gene, has serine protease inhibitory activity and neurotrophic properties in the brain. PN-1 inhibits retinal angiogenesis; however, PN-1's neurotrophic capacities in the retina have not yet been evaluated. Pigment epithelium-derived factor (PEDF) is a serpin that exhibits neurotrophic and antiangiogenic activities but lacks protease inhibitory properties. The aim of this study is to compare PN-1 and PEDF. METHODS Sequence comparisons were performed using computer bioinformatics programs. Mouse and bovine eyes, human retina tissue, and ARPE-19 cells were used to prepare RNA and protein samples. Interphotoreceptor matrix lavage was obtained from bovine eyes. Gene expression and protein levels were evaluated with reverse-transcription PCR (RT-PCR) and western blotting, respectively. Recombinant human PN-1, a version of PN-1 referred to as PN-1[R346A] lacking serine protease inhibitory activity, and PEDF proteins were used, as well as synthetic peptides designed from PEDF and PN-1 sequences. Survival activity in serum-starved, rat-derived retinal precursor (R28) cells was assessed with terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) cell death assays. Bcl2 levels were measured with RT-PCR. RESULTS PN-1 is analogous in primary and tertiary structure to PEDF. A region in PN-1 shares homology with the neurotrophic active region of PEDF, a 17-residue region within alpha helix C. The native human retina, ARPE-19 cells, and murine RPE and retina expressed the gene for PN-1 (SERPINE2 and Serpine2 mRNA). The retina, ARPE-19 cell lysates, and bovine interphotoreceptor matrix contained PN-1 protein. The addition of PN-1, PN-1[R346A], or the 17mer peptide of PN-1 to serum-starved retina cells decreased the number of TUNEL-positive nuclei relative to the untreated cells, such as PEDF. PN-1, PN-1[R346A], and PN-1-17mer treatments increased the Bcl2 transcript levels in serum-starved cells, as seen with PEDF. CONCLUSIONS PN-1 and PEDF share structural and functional features, and expression patterns in the retina. These serpins' mechanisms of action as cell survival factors are independent of serine protease inhibition. We have identified PN-1 as a novel factor for the retina that may play a neuroprotective role in vivo, and small peptides as relevant candidates for preventing retinal degeneration.
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Affiliation(s)
- Paige N. Winokur
- NIH, NEI, Section of Protein Structure and Function, Bethesda, MD
| | | | - Jeanee L. Bullock
- NIH, NEI, Section of Protein Structure and Function, Bethesda, MD,Georgetown University, Department of Biochemistry and Molecular and Cellular Biology, Washington, DC
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Subramanian P, Mendez EF, Becerra SP. A Novel Inhibitor of 5-Lipoxygenase (5-LOX) Prevents Oxidative Stress-Induced Cell Death of Retinal Pigment Epithelium (RPE) Cells. Invest Ophthalmol Vis Sci 2017; 57:4581-8. [PMID: 27635633 PMCID: PMC5033602 DOI: 10.1167/iovs.15-19039] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
PURPOSE 5-Lipoxygenase (5-LOX) oxygenates arachidonic acid to form 5-hydroperoxyeicosatetraenoic acid, which is further converted into biologically detrimental leukotrienes, such as leukotriene B4 (LTB4). The RPE and retina express the PNPLA2 gene for pigment epithelium-derived factor receptor (PEDF-R), a lipase involved in cell survival. The purpose here was to investigate the role of PEDF-R on the 5-LOX pathway in oxidative stress of RPE. METHODS Lipoxygenase activity assays were performed with soybean and potato lipoxygenase. Binding was evaluated by peptide-affinity chromatography and pull-down assays with PEDF-R-derived synthetic peptides or recombinant protein. Oxidative stress was induced in human ARPE-19 and primary pig RPE cells with indicated concentrations of H2O2/TNF-α. Reverse transcription-PCR of ALOX5 and PNPLA2 genes was performed. Cell viability and death rates were determined using respective biomarkers. Leukotriene B4 levels were measured by ELISA. RESULTS Among five peptides spanning between positions Leu159 and Met325 of human PEDF-R polypeptide, only two overlapping peptides, E5b and P1, bound and inhibited lipoxygenase activity. Human recombinant 5-LOX bound specifically to peptide P1 and to His6/Xpress-tagged PEDF-R via ionic interactions. The two inhibitor peptides E5b and P1 promoted cell viability and decreased cell death of RPE cells undergoing oxidative stress. Oxidative stress decreased the levels of PNPLA2 transcripts with no effect on ALOX5 expression. Exogenous additions of P1 peptide or overexpression of the PNPLA2 gene decreased both LTB4 levels and death of RPE cells undergoing oxidative stress. CONCLUSIONS A novel peptide region of PEDF-R inhibits 5-LOX, which intersects with RPE cell death pathways induced by oxidative stress.
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Affiliation(s)
- Preeti Subramanian
- Section of Protein Structure and Function-Laboratory of Retinal Cell and Molecular Biology National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Emily F Mendez
- Section of Protein Structure and Function-Laboratory of Retinal Cell and Molecular Biology National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - S Patricia Becerra
- Section of Protein Structure and Function-Laboratory of Retinal Cell and Molecular Biology National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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PEDF Inhibits the Activation of NLRP3 Inflammasome in Hypoxia Cardiomyocytes through PEDF Receptor/Phospholipase A2. Int J Mol Sci 2016; 17:ijms17122064. [PMID: 27973457 PMCID: PMC5187864 DOI: 10.3390/ijms17122064] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/26/2016] [Accepted: 12/02/2016] [Indexed: 12/23/2022] Open
Abstract
The nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome has been linked to sterile inflammation, which is involved in ischemic injury in myocardial cells. Pigment epithelium-derived factor (PEDF) is a multifunctional secreted glycoprotein with many biological activities, such as anti-inflammatory, antioxidant and anti-angiogenic properties. However, it is not known whether and how PEDF acts to regulate the activation of the NLRP3 inflammasome in cardiomyocytes. In the present study, we used the neonatal cardiomyocytes models of ischemia-like conditions to evaluate the mitochondrial fission and the activation of the NLRP3 inflammasome. We also determined the mechanism by which PEDF inhibits hypoxia-induced activation of the NLRP3 inflammasome. We found that PEDF decreased the activation of the NLRP3 inflammasome in neonatal cardiomyocytes through pigment epithelial-derived factor receptor/calcium-independent phospholipase A2 (PEDFR/iPLA2). Meanwhile, PEDF reduced Drp1-induced mitochondrial fission and mitochondrial fission-induced mitochondrial DNA (mtDNA), as well as mitochondrial reactive oxygen species (mtROS) release into cytosol through PEDFR/iPLA2. We also found that PEDF inhibited mitochondrial fission-induced NLRP3 inflammasome activation. Furthermore, previous research has found that endogenous cytosolic mtDNA and mtROS can serve as activators of NLRP3 inflammasome activity. Therefore, we hypothesized that PEDF can protect against hypoxia-induced activation of the NLRP3 inflammasome by inhibiting mitochondrial fission though PEDFR/iPLA2.
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Shih SC, Ho TC, Chen SL, Tsao YP. Pigment Epithelium Derived Factor Peptide Protects Murine Hepatocytes from Carbon Tetrachloride-Induced Injury. PLoS One 2016; 11:e0157647. [PMID: 27384427 PMCID: PMC4934881 DOI: 10.1371/journal.pone.0157647] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 06/02/2016] [Indexed: 12/31/2022] Open
Abstract
Fibrogenesis is induced by repeated injury to the liver and reactive regeneration and leads eventually to liver cirrhosis. Pigment epithelium derived factor (PEDF) has been shown to prevent liver fibrosis induced by carbon tetrachloride (CCl4). A 44 amino acid domain of PEDF (44-mer) was found to have a protective effect against various insults to several cell types. In this study, we investigated the capability of synthetic 44-mer to protect against liver injury in mice and in primary cultured hepatocytes. Acute liver injury, induced by CCl4, was evident from histological changes, such as cell necrosis, inflammation and apoptosis, and a concomitant reduction of glutathione (GSH) and GSH redox enzyme activities in the liver. Intraperitoneal injection of the 44-mer into CCl4-treated mice abolished the induction of AST and ALT and markedly reduced histological signs of liver injury. The 44-mer treatment can reduce hepatic oxidative stress as evident from lower levels of lipid hydroperoxide, and higher levels of GSH. CCl4 caused a reduction of Bcl-xL, PEDF and PPARγ, which was markedly restored by the 44-mer treatment. Consequently, the 44-mer suppressed liver fibrosis induced by repeated CCl4 injury. Furthermore, our observations in primary culture of rat hepatocytes showed that PEDF and the 44-mer protected primary rat hepatocytes against apoptosis induced by serum deprivation and TGF-β1. PEDF/44-mer induced cell protective STAT3 phosphorylation. Pharmacological STAT3 inhibition prevented the antiapoptotic action of PEDF/44-mer. Among several PEDF receptor candidates that may be responsible for hepatocyte protection, we demonstrated that PNPLA2 was essential for PEDF/44-mer-mediated STAT3 phosphorylation and antiapoptotic activity by using siRNA to selectively knockdown PNPLA2. In conclusion, the PEDF 44-mer protects hepatocytes from single and repeated CCl4 injury. This protective effect may stem from strengthening the counter oxidative stress capacity and induction of hepatoprotective factors.
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Affiliation(s)
- Shou-Chuan Shih
- Mackay Medical College, New Taipei City, Taiwan
- Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan
- * E-mail: (SCS); (YPT)
| | - Tsung-Chuan Ho
- Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan
| | - Show-Li Chen
- Department of Microbiology, School of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yeou-Ping Tsao
- Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan
- Department of Ophthalmology, Mackay Memorial Hospital, Taipei, Taiwan
- * E-mail: (SCS); (YPT)
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Yao S, Zhang Y, Wang X, Zhao F, Sun M, Zheng X, Dong H, Guo K. Pigment Epithelium-Derived Factor (PEDF) Protects Osteoblastic Cell Line from Glucocorticoid-Induced Apoptosis via PEDF-R. Int J Mol Sci 2016; 17:ijms17050730. [PMID: 27187377 PMCID: PMC4881552 DOI: 10.3390/ijms17050730] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/28/2016] [Accepted: 05/06/2016] [Indexed: 01/07/2023] Open
Abstract
Pigment epithelial-derived factor (PEDF) is known as a widely expressed multifunctional secreted glycoprotein whose biological actions are cell-type dependent. Recent studies demonstrated that PEDF displays cytoprotective activity in several cell types. However, it remains unknown whether PEDF is involved in glucocorticoid-induced osteoblast death. The aim of this study was to examine the role of PEDF in osteoblast survival in response to dexamethasone, an active glucocorticoid analogue, and explore the underlying mechanism. In the present study, dexamethasone (DEX) was used to induce MC3T3-E1 pre-osteoblast apoptosis. PEDF mRNA and protein levels and cell apoptosis were determined respectively. Then PEDF receptor (PEDF-R)- and lysophosphatidic acid (LPA)-related signal transductions were assessed. Here we show that DEX down-regulates PEDF expression, which contributes to osteoblast apoptosis. As a result, exogenous recombinant PEDF (rPEDF) inhibited DEX-induced cell apoptosis. We confirmed that PEDF-R was expressed on MC3T3-E1 pre-osteoblast membrane and could bind to PEDF which increased the level of LPA and activated the phosphorylation of Akt. Our results suggest that PEDF attenuated DEX-induced apoptosis in MC3T3-E1 pre-osteoblasts through LPA-dependent Akt activation via PEDF-R.
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Affiliation(s)
- Shengcheng Yao
- Department of Orthopaedic Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221006, China.
| | - Yingnan Zhang
- Department of Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221006, China.
| | - Xiaoyu Wang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221006, China.
| | - Fengchao Zhao
- Department of Orthopaedic Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221006, China.
| | - Maji Sun
- Department of Orthopaedic Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221006, China.
| | - Xin Zheng
- Department of Orthopaedic Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221006, China.
| | - Hongyan Dong
- Research Facility Center for Morphology, Xuzhou Medical University, Xuzhou 221004, China.
| | - Kaijin Guo
- Department of Orthopaedic Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221006, China.
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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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42
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Zhuang W, Zhang H, Pan J, Li Z, Wei T, Cui H, Liu Z, Guan Q, Dong H, Zhang Z. PEDF and PEDF-derived peptide 44mer inhibit oxygen-glucose deprivation-induced oxidative stress through upregulating PPARγ via PEDF-R in H9c2 cells. Biochem Biophys Res Commun 2016; 472:482-8. [PMID: 26966066 DOI: 10.1016/j.bbrc.2016.02.110] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 02/25/2016] [Indexed: 01/30/2023]
Abstract
Pigment epithelial-derived factor (PEDF) is a glycoprotein with broad biological activities including inhibiting oxygen-glucose deprivation(OGD)-induced cardiomyocytes apoptosis through its anti-oxidative properties. PEDF derived peptide-44mer shows similar cytoprotective effect to PEDF. However, the molecular mechanisms mediating cardiomyocytes apoptosis have not been fully established. Here we found that PEDF and 44mer decreased the content of ROS. This content was abolished by either PEDF-R small interfering RNA (siRNA) or PPARγ antagonist. The level of Lysophosphatidic acid (LPA) and phospholipase A2 (PLA2) was observed as drawn from the ELISA assays. PEDF and 44mer sequentially induced PPARγ expression was observed both in qPCR and Western blot assays. The level of LPA and PLA2 and PPARγ expression increased by PEDF and 44mer was significantly attenuated by PEDF-R siRNA. However, PEDF and 44mer inhibited the H9c2 cells and cultured neonatal rat myocardial cells apoptosis rate. On the other hand, TUNEL assay and cleavage of procaspase-3 showed that PEDF-R siRNA or PPARγ antagonist increased the apoptosis again. We conclude that under OGD condition, PEDF and 44mer reduce H9c2 cells apoptosis and inhibit OGD-induced oxidative stress via its receptor PEDF-R and the PPARγ signaling pathway.
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Affiliation(s)
- Wei Zhuang
- Research Facility Center for Morphology, 209 Tong shan Road, Xuzhou Medical College, Xuzhou, Jiangsu, 221004, China
| | - Hao Zhang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical College, 99 West Huaihai Road, Xuzhou, Jiangsu, 221002, China
| | - Jiajun Pan
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical College, 99 West Huaihai Road, Xuzhou, Jiangsu, 221002, China
| | - Zhimin Li
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical College, 99 West Huaihai Road, Xuzhou, Jiangsu, 221002, China
| | - Tengteng Wei
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical College, 99 West Huaihai Road, Xuzhou, Jiangsu, 221002, China
| | - Huazhu Cui
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical College, 99 West Huaihai Road, Xuzhou, Jiangsu, 221002, China
| | - Zhiwei Liu
- Research Facility Center for Morphology, 209 Tong shan Road, Xuzhou Medical College, Xuzhou, Jiangsu, 221004, China
| | - Qiuhua Guan
- Research Center for Biochemistry and Molecular Biology and Provincial Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical College, Xuzhou, Jiangsu, 221004, China
| | - Hongyan Dong
- Research Facility Center for Morphology, 209 Tong shan Road, Xuzhou Medical College, Xuzhou, Jiangsu, 221004, China.
| | - Zhongming Zhang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical College, 99 West Huaihai Road, Xuzhou, Jiangsu, 221002, China.
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Rajagopal A, Homan EP, Joeng KS, Suzuki M, Bertin T, Cela R, Munivez E, Dawson B, Jiang MM, Gannon F, Crawford S, Lee BH. Restoration of the serum level of SERPINF1 does not correct the bone phenotype in Serpinf1 null mice. Mol Genet Metab 2016; 117:378-82. [PMID: 26693895 PMCID: PMC4788589 DOI: 10.1016/j.ymgme.2015.11.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/30/2015] [Accepted: 11/30/2015] [Indexed: 11/16/2022]
Abstract
Osteogenesis imperfecta (OI) is a group of genetic disorders characterized by bone fragility and deformity. OI type VI is unique owing to the mineralization defects observed in patient biopsies. Furthermore, it has been reported to respond less well to standard therapy with bisphosphonates [1]. Others and we have previously identified SERPINF1 mutations in patients with OI type VI. SERPINF1 encodes pigment epithelium derived factor (PEDF), a secreted collagen-binding glycoprotein that is absent in the sera of patients with OI type VI. Serpinf1 null mice show increased osteoid and decreased bone mass, and thus recapitulate the OI type VI phenotype. We tested whether restoration of circulating PEDF in the blood could correct the phenotype of OI type VI in the context of protein replacement. To do so, we utilized a helper-dependent adenoviral vector (HDAd) to express human SERPINF1 in the mouse liver and assessed whether PEDF secreted from the liver was able to rescue the bone phenotype observed in Serpinf1(-/-) mice. We confirmed that expression of SERPINF1 in the liver restored the serum level of PEDF. We also demonstrated that PEDF secreted from the liver was biologically active by showing the expected metabolic effects of increased adiposity and impaired glucose tolerance in Serpinf1(-/-) mice. Interestingly, overexpression of PEDF in vitro increased mineralization with a concomitant increase in the expression of bone gamma-carboxyglutamate protein, alkaline phosphatase and collagen, type I, alpha I, but the increased serum PEDF level did not improve the bone phenotype of Serpinf1(-/-) mice. These results suggest that PEDF may function in a context-dependent and paracrine fashion in bone homeostasis.
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Affiliation(s)
- Abbhirami Rajagopal
- Molecular and Human Genetics Department, Baylor College of Medicine, United States
| | - Erica P Homan
- Molecular and Human Genetics Department, Baylor College of Medicine, United States
| | - Kyu Sang Joeng
- Molecular and Human Genetics Department, Baylor College of Medicine, United States
| | - Masataka Suzuki
- Department of Medicine, Center for Cell and Gene Therapy, Baylor College of Medicine, United States
| | - Terry Bertin
- Molecular and Human Genetics Department, Baylor College of Medicine, United States
| | - Racel Cela
- Molecular and Human Genetics Department, Baylor College of Medicine, United States
| | - Elda Munivez
- Molecular and Human Genetics Department, Baylor College of Medicine, United States
| | - Brian Dawson
- Molecular and Human Genetics Department, Baylor College of Medicine, United States
| | - Ming-Ming Jiang
- Molecular and Human Genetics Department, Baylor College of Medicine, United States
| | - Frank Gannon
- Department of Pathology & Immunology, Baylor College of Medicine, United States
| | - Susan Crawford
- Department of Pathology, Saint Louis University, School of Medicine, United States
| | - Brendan H Lee
- Molecular and Human Genetics Department, Baylor College of Medicine, United States.
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Wang X, Zhang Y, Lu P, Zhang H, Li Y, Dong H, Zhang Z. PEDF attenuates hypoxia-induced apoptosis and necrosis in H9c2 cells by inhibiting p53 mitochondrial translocation via PEDF-R. Biochem Biophys Res Commun 2015; 465:394-401. [PMID: 26277390 DOI: 10.1016/j.bbrc.2015.08.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 08/03/2015] [Indexed: 10/23/2022]
Abstract
Pigment epithelial-derived factor (PEDF) is a multifunctional secreted glycoprotein, which could protect against hypoxia-induced cell death related to its anti-oxidative effect in cultured cardiomyocytes. However, the pathway mediating this cytoprotective process has not been fully established. Here we confirmed that PEDF bound to pigment epithelial-derived factor receptor (PEDF-R) expressed on the membrane of H9c2 cells. Under hypoxic condition, PEDF increased the ratio of MDM2:p53, so as to inhibited p53 mitochondrial translocation via PEDF-R. As a result, mitochondrial outer membrane permeabilization (MOMP) and mitochondrial permeability transition pore (MPTP) opening were inhibited, meanwhile cleaved caspase-3, PARP and the release of HMGB1 were reduced. Accordingly, apoptosis and necrosis were attenuated simultaneously. We conclude that PEDF-R mediates PEDF attenuates hypoxia-induced apoptosis and necrosis in H9c2 cells by inhibiting p53 mitochondrial translocation.
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Affiliation(s)
- Xiaoyu Wang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical College, 99 Huaihai Road, Xuzhou 221006, Jiangsu Province, China
| | - Yiqian Zhang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical College, 99 Huaihai Road, Xuzhou 221006, Jiangsu Province, China
| | - Peng Lu
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical College, 99 Huaihai Road, Xuzhou 221006, Jiangsu Province, China
| | - Hao Zhang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical College, 99 Huaihai Road, Xuzhou 221006, Jiangsu Province, China
| | - Yufeng Li
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical College, 99 Huaihai Road, Xuzhou 221006, Jiangsu Province, China
| | - Hongyan Dong
- Research Facility Center for Morphology, Xuzhou Medical College, 209 Tongshan Road, Xuzhou 221004, Jiangsu Province, China.
| | - Zhongming Zhang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical College, 99 Huaihai Road, Xuzhou 221006, Jiangsu Province, China.
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Franco-Chuaire ML, Ramírez-Clavijo S, Chuaire-Noack L. Pigment epithelium-derived factor: clinical significance in estrogen-dependent tissues and its potential in cancer therapy. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2015; 18:837-55. [PMID: 26523216 PMCID: PMC4620182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pigment epithelium-derived factor (PEDF) is a glycoprotein that belongs to the family of non-inhibitory serpins. The broad spectrum of PEDF biological activity is evident when considering its effects in promoting cell survival and proliferation, as well as its antiangiogenic, antitumor, and anti-metastatic properties. Although the structural domains of the PEDF gene that mediate such diverse effects and their mechanisms of action have not been completely elucidated, there is a large body of evidence describing their diverse range of activities; this evidence combined with the regulation of PEDF expression by sex steroids and their receptors have led to the idea that PEDF is not only a diagnostic and prognostic marker for certain diseases such as cancer, but is also a potential therapeutic target. In this manner, this paper aims to generally review the regulation of PEDF expression and PEDF interactions, as well as the findings that relate PEDF to the role of estrogens and estrogen receptors. In addition, this manuscript will review major advances toward potential therapeutic applications of PEDF.
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Affiliation(s)
| | - Sandra Ramírez-Clavijo
- Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá DC, Colombia
| | - Lilian Chuaire-Noack
- Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá DC, Colombia,Corresponding author: Lilian Chuaire-Noack. Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá DC, Colombia; Tel: 57(1) 2970200; ext 4021;
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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: 26] [Impact Index Per Article: 2.9] [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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48
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Johnston EK, Francis MK, Knepper JE. Recombinant pigment epithelium-derived factor PEDF binds vascular endothelial growth factor receptors 1 and 2. In Vitro Cell Dev Biol Anim 2015; 51:730-8. [PMID: 25948043 DOI: 10.1007/s11626-015-9884-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 02/22/2015] [Indexed: 01/18/2023]
Abstract
Angiogenesis, or the formation of new blood vessels, is stimulated by angiogenic factors such as vascular endothelial growth factor (VEGF). Pigment epithelium-derived factor (PEDF) is a potent inhibitor of angiogenesis. To explore the mechanism by which PEDF acts, recombinant PEDF was expressed with a 6x-His tag (for purification) and a green fluorescent protein (GFP) tag. The PEDF fusion protein was confirmed to be active in inhibition of endothelial cell proliferation and migration. Direct binding of PEDF to both vascular endothelial growth factor receptor-1 (VEGFR-1) and VEGFR-2 was demonstrated in an in vitro assay similar to an enzyme-linked immunosorbent assay (ELISA). PEDF was shown by immune-confocal microscopy to be localized within treated endothelial cells. When VEGF-stimulated endothelial cells were incubated with PEDF the VEGF receptors showed intracellular localization. These data suggest that the interaction between PEDF and VEGFR-1 or VEGFR-2 may be a possible mechanism for inhibiting angiogenesis. PEDF may be binding to the VEGF receptors to promote their internalization and/or degradation to limit VEGF responses in treated cells.
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Affiliation(s)
- Erin K Johnston
- Janssen Research and Development, LLC, Pharma R&D Quality and Compliance, 1400 McKean Road, Building 32-12334, Spring House, PA, 19477, USA,
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Ma L, Tang SM, Rong SS, Chen H, Young AL, Kumaramanickavel G, Pang CP, Chen LJ. Association of PEDF polymorphisms with age-related macular degeneration and polypoidal choroidal vasculopathy: a systematic review and meta-analysis. Sci Rep 2015; 5:9497. [PMID: 25820866 PMCID: PMC4377572 DOI: 10.1038/srep09497] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 03/10/2015] [Indexed: 01/07/2023] Open
Abstract
This study assesses the association of the pigment epithelium-derived factor (PEDF) gene with age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV). Publications in MEDLINE and EMBASE up to 21/08/2014 were searched for case-control association studies of PEDF with AMD and/or PCV. Reported studies giving adequate genotype and/or allele information were included. Pooled odds ratios (OR) and 95% confidence intervals (CI) of each polymorphism were estimated. Our literature search yielded 297 records. After excluding duplicates and reports with incomplete information, 8 studies were eligible for meta-analysis, involving 2284 AMD patients versus 3416 controls, and 317 PCV patients versus 371 controls. Four PEDF polymorphisms were meta-analyzed: rs1136287, rs12150053, rs12948385 and rs9913583, but none was significantly associated with AMD or PCV. The most-investigated polymorphism, rs1136287, had a pooled-OR of 1.02 (95% CI: 0.94-1.11, P = 0.64) for AMD. In subgroup analysis by ethnicity, no significant association was identified. Polymorphisms present in single report showed no association. Therefore, existing data in literature does not support the role of PEDF in the genetic susceptibility of AMD and PCV, although replication in specific populations is warranted. Since the pooled-sample size for PCV was small, there is a need of PEDF genotyping in larger samples of PCV.
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Affiliation(s)
- Li Ma
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Shu Min Tang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Shi Song Rong
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Haoyu Chen
- The Shantou University/Chinese University of Hong Kong Joint Shantou International Eye Center, Shantou, Guangdong Province, China
| | - Alvin L Young
- 1] Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China [2] Department of Ophthalmology and Visual Sciences, Prince of Wales hospital, Hong Kong, China
| | | | - Chi Pui Pang
- 1] Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China [2] Department of Ophthalmology and Visual Sciences, Prince of Wales hospital, Hong Kong, China [3] The Shantou University/Chinese University of Hong Kong Joint Shantou International Eye Center, Shantou, Guangdong Province, China
| | - Li Jia Chen
- 1] Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China [2] Department of Ophthalmology and Visual Sciences, Prince of Wales hospital, Hong Kong, China
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PEDF improves cardiac function in rats with acute myocardial infarction via inhibiting vascular permeability and cardiomyocyte apoptosis. Int J Mol Sci 2015; 16:5618-34. [PMID: 25768344 PMCID: PMC4394496 DOI: 10.3390/ijms16035618] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 02/25/2015] [Accepted: 03/05/2015] [Indexed: 12/23/2022] Open
Abstract
Pigment epithelium-derived factor (PEDF) is a pleiotropic gene with anti-inflammatory, antioxidant and anti-angiogenic properties. However, recent reports about the effects of PEDF on cardiomyocytes are controversial, and it is not known whether and how PEDF acts to inhibit hypoxic or ischemic endothelial injury in the heart. In the present study, adult Sprague-Dawley rat models of acute myocardial infarction (AMI) were surgically established. PEDF-small interfering RNA (siRNA)-lentivirus (PEDF-RNAi-LV) or PEDF-LV was delivered into the myocardium along the infarct border to knockdown or overexpress PEDF, respectively. Vascular permeability, cardiomyocyte apoptosis, myocardial infarct size and animal cardiac function were analyzed. We also evaluated PEDF’s effect on the suppression of the endothelial permeability and cardiomyocyte apoptosis under hypoxia in vitro. The results indicated that PEDF significantly suppressed the vascular permeability and inhibited hypoxia-induced endothelial permeability through PPARγ-dependent tight junction (TJ) production. PEDF protected cardiomyocytes against ischemia or hypoxia-induced cell apoptosis both in vivo and in vitro via preventing the activation of caspase-3. We also found that PEDF significantly reduced myocardial infarct size and enhanced cardiac function in rats with AMI. These data suggest that PEDF could protect cardiac function from ischemic injury, at least by means of reducing vascular permeability, cardiomyocyte apoptosis and myocardial infarct size.
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