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Daniel S, Hulleman JD. Exploring ocular fibulin-3 (EFEMP1): Anatomical, age-related, and species perspectives. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167239. [PMID: 38750770 DOI: 10.1016/j.bbadis.2024.167239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 05/03/2024] [Accepted: 05/10/2024] [Indexed: 05/24/2024]
Abstract
Fibulin-3 (FBLN3, aka EFEMP1) is a secreted extracellular matrix (ECM) glycoprotein implicated in ocular diseases including glaucoma and age-related macular degeneration. Yet surprisingly, little is known about its native biology, expression patterns, and localization in the eye. To overcome these shortcomings, we conducted gene expression analysis and immunohistochemistry for FBLN3 in ocular tissues from mice, pigs, non-human primates, and humans. Moreover, we evaluated age-related changes in FBLN3 and FBLN3-related ECM remodeling enzymes/inhibitors in aging mice. We found that FBLN3 displayed distinct staining patterns consistent across the mouse retina, particularly in the ganglion cell layer and inner nuclear layer (INL). In contrast, human retinas exhibited a unique staining pattern, with enrichment of FBLN3 in the retinal pigment epithelium (RPE), INL, and outer nuclear layer (ONL) in the peripheral retina. This staining transitioned to the outer plexiform layer (OPL) in the central retina/macula, and was accompanied by reduced RPE immunoreactivity approaching the fovea. Surprisingly, we found significant age-related increases in FBLN3 expression and protein abundance in the mouse retina which was paralleled by reduced transcript levels of FBLN3-degrading enzymes (i.e., Mmp2 and Htra1). Our findings highlight important species-dependent, retinal region-specific, and age-related expression and localization patterns of FBLN3 which favor its accumulation during aging. These findings contribute to a better understanding of FBLN3's role in ocular pathology and provide valuable insights for future FBLN3 research.
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Affiliation(s)
- Steffi Daniel
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, 2001 6th St. SE, Minneapolis, MN 55455, United States
| | - John D Hulleman
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, 2001 6th St. SE, Minneapolis, MN 55455, United States.
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2
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Forghani I, Lang SH, Rodier MJ, Bivona SA, Morales AA, Zuchner S, Bademci G, Tekin M. EFEMP1 haploinsufficiency causes a Marfan-like hereditary connective tissue disorder. Am J Med Genet A 2024; 194:e63556. [PMID: 38348595 PMCID: PMC11060917 DOI: 10.1002/ajmg.a.63556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 11/25/2023] [Accepted: 01/20/2024] [Indexed: 02/23/2024]
Abstract
Phenotypic features of a hereditary connective tissue disorder, including craniofacial characteristics, hyperextensible skin, joint laxity, kyphoscoliosis, arachnodactyly, inguinal hernia, and diverticulosis associated with biallelic pathogenic variants in EFEMP1 have been previously described in four patients. Genome sequencing on a proband and her mother with comparable phenotypic features revealed that both patients were heterozygous for a stop-gain variant c.1084C>T (p.Arg362*). Complementary RNA-seq on fibroblasts revealed significantly reduced levels of mutant EFEMP1 transcript. Considering the absence of other molecular explanations, we extrapolated that EFEMP1 could be the cause of the patient's phenotypes. Furthermore, nonsense-mediated decay was demonstrated for the mutant allele as the principal mechanism for decreased levels of EFEMP1 mRNA. We provide strong clinical and genetic evidence for the haploinsufficiency of EFEMP1 due to nonsense-medicated decay to cause severe kyphoscoliosis, generalized hypermobility of joints, high and narrow arched palate, and potentially severe diverticulosis. To the best of our knowledge, this is the first report of an autosomal dominant EFEMP1-associated hereditary connective tissue disorder and therefore expands the phenotypic spectrum of EFEMP1 related disorders.
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Affiliation(s)
- Irman Forghani
- Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL
| | - Steven H. Lang
- Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL
- Baylor College of Medicine, Houston, TX
| | - Matthew J. Rodier
- Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL
| | - Stephanie A. Bivona
- Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL
| | | | - Alejo A. Morales
- Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL
| | - Stephan Zuchner
- Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL
| | - Guney Bademci
- Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL
| | - Mustafa Tekin
- Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL
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3
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Georgiou M, Robson AG, Fujinami K, de Guimarães TAC, Fujinami-Yokokawa Y, Daich Varela M, Pontikos N, Kalitzeos A, Mahroo OA, Webster AR, Michaelides M. Phenotyping and genotyping inherited retinal diseases: Molecular genetics, clinical and imaging features, and therapeutics of macular dystrophies, cone and cone-rod dystrophies, rod-cone dystrophies, Leber congenital amaurosis, and cone dysfunction syndromes. Prog Retin Eye Res 2024; 100:101244. [PMID: 38278208 DOI: 10.1016/j.preteyeres.2024.101244] [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: 10/26/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024]
Abstract
Inherited retinal diseases (IRD) are a leading cause of blindness in the working age population and in children. The scope of this review is to familiarise clinicians and scientists with the current landscape of molecular genetics, clinical phenotype, retinal imaging and therapeutic prospects/completed trials in IRD. Herein we present in a comprehensive and concise manner: (i) macular dystrophies (Stargardt disease (ABCA4), X-linked retinoschisis (RS1), Best disease (BEST1), PRPH2-associated pattern dystrophy, Sorsby fundus dystrophy (TIMP3), and autosomal dominant drusen (EFEMP1)), (ii) cone and cone-rod dystrophies (GUCA1A, PRPH2, ABCA4, KCNV2 and RPGR), (iii) predominant rod or rod-cone dystrophies (retinitis pigmentosa, enhanced S-Cone syndrome (NR2E3), Bietti crystalline corneoretinal dystrophy (CYP4V2)), (iv) Leber congenital amaurosis/early-onset severe retinal dystrophy (GUCY2D, CEP290, CRB1, RDH12, RPE65, TULP1, AIPL1 and NMNAT1), (v) cone dysfunction syndromes (achromatopsia (CNGA3, CNGB3, PDE6C, PDE6H, GNAT2, ATF6), X-linked cone dysfunction with myopia and dichromacy (Bornholm Eye disease; OPN1LW/OPN1MW array), oligocone trichromacy, and blue-cone monochromatism (OPN1LW/OPN1MW array)). Whilst we use the aforementioned classical phenotypic groupings, a key feature of IRD is that it is characterised by tremendous heterogeneity and variable expressivity, with several of the above genes associated with a range of phenotypes.
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Affiliation(s)
- Michalis Georgiou
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - Anthony G Robson
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Kaoru Fujinami
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
| | - Thales A C de Guimarães
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Yu Fujinami-Yokokawa
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Department of Health Policy and Management, Keio University School of Medicine, Tokyo, Japan.
| | - Malena Daich Varela
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Nikolas Pontikos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Angelos Kalitzeos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Omar A Mahroo
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Section of Ophthalmology, King s College London, St Thomas Hospital Campus, London, United Kingdom; Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, United Kingdom; Department of Translational Ophthalmology, Wills Eye Hospital, Philadelphia, PA, USA.
| | - Andrew R Webster
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Michel Michaelides
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
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Tan J, Cai S, Luo X, Li Q, Chen Y, Chen Z, Mao Y, Liu G, Yang M, Liu X. Stop codon variant in EFEMP1 is associated with primary open-angle glaucoma due to impaired regulation of aqueous humor outflow. Exp Eye Res 2024; 241:109859. [PMID: 38467175 DOI: 10.1016/j.exer.2024.109859] [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: 01/01/2024] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 03/13/2024]
Abstract
It is known that the actin cytoskeleton and its associated cellular interactions in the trabecular meshwork (TM) and juxtacanalicular tissues mainly contribute to the formation of resistance to aqueous outflow of the eye. Fibulin-3, encoded by EFEMP1 gene, has a role in extracellular matrix (ECM) modulation, and interacts with enzymatic ECM regulators, but the effects of fibulin-3 on TM cells has not been explored. Here, we report a stop codon variant (c.T1480C, p.X494Q) of EFEMP1 that co-segregates with primary open angle glaucoma (POAG) in a Chinese pedigree. In the human TM cells, overexpression of wild-type fibulin-3 reduced intracellular actin stress fibers formation and the extracellular fibronectin levels by inhibiting Rho/ROCK signaling. TGFβ1 up-regulated fibulin-3 protein levels in human TM cells by activating Rho/ROCK signaling. In rat eyes, overexpression of wild-type fibulin-3 decreased the intraocular pressure and the fibronectin expression of TM, however, overexpression of mutant fibulin-3 (c.T1480C, p.X494Q) showed opposite effects in cells and rat eyes. Taken together, the EFEMP1 variant may impair the regulatory capacity of fibulin-3 which has a role for modulating the cell contractile activity and ECM synthesis in TM cells, and in turn may maintain normal resistance of aqueous humor outflow. This study contributes to the understanding of the important role of fibulin-3 in TM pathophysiology and provides a new possible POAG therapeutic approach.
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Affiliation(s)
- Junkai Tan
- Xiamen Eye Center, Xiamen University, Xiamen Research Center for Eye Diseases and Key Laboratory of Ophthalmology, Xiamen, 361000, Fujian, China
| | - Suping Cai
- Xiamen Eye Center, Xiamen University, Xiamen Research Center for Eye Diseases and Key Laboratory of Ophthalmology, Xiamen, 361000, Fujian, China
| | - Xiaolin Luo
- Department of Ophthalmology, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, 518020, Guangdong, China
| | - Qiang Li
- Department of Ophthalmology, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, 518020, Guangdong, China
| | - Yanbing Chen
- Xiamen Eye Center, Xiamen University, Xiamen Research Center for Eye Diseases and Key Laboratory of Ophthalmology, Xiamen, 361000, Fujian, China
| | - Zijie Chen
- Xiamen Eye Center, Xiamen University, Xiamen Research Center for Eye Diseases and Key Laboratory of Ophthalmology, Xiamen, 361000, Fujian, China
| | - Yukai Mao
- Xiamen Eye Center, Xiamen University, Xiamen Research Center for Eye Diseases and Key Laboratory of Ophthalmology, Xiamen, 361000, Fujian, China
| | - Guo Liu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan Province, China
| | - Mingming Yang
- Department of Ophthalmology, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, 518020, Guangdong, China.
| | - Xuyang Liu
- Xiamen Eye Center, Xiamen University, Xiamen Research Center for Eye Diseases and Key Laboratory of Ophthalmology, Xiamen, 361000, Fujian, China; Department of Ophthalmology, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, 518020, Guangdong, China.
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Heath Jeffery RC, Chen FK. Macular neovascularization in inherited retinal diseases: A review. Surv Ophthalmol 2024; 69:1-23. [PMID: 37544613 DOI: 10.1016/j.survophthal.2023.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 07/25/2023] [Accepted: 07/31/2023] [Indexed: 08/08/2023]
Abstract
Inherited retinal diseases (IRDs) are the most common cause of blindness in working-age adults. Macular neovascularization (MNV) may be a presenting feature or occurs as a late-stage complication in several IRDs. We performed an extensive literature review on MNV associated with IRDs. MNV is a well-known complication of Sorsby fundus dystrophy and pseudoxanthoma elasticum. Those with late-onset Stargardt disease may masquerade as exudative age-related macular degeneration (AMD) when MNV is the presenting feature. Peripherinopathies may develop MNV that responds well to a short course of anti-vascular endothelial growth factor (anti-VEGF) therapy, while bestrophinopathies tend to develop MNV in the early stages of the disease without vision loss. Enhanced S-cone syndrome manifests type 3 MNV that typically regresses into a subfoveal fibrotic nodule. MNV is only a rare complication in choroideraemia and rod-cone dystrophies. Most IRD-related MNVs exhibit a favorable visual prognosis requiring less intensive regimens of anti-vascular endothelial growth factor therapy compared to age-related macular degeneration. We discuss the role of key imaging modalities in the diagnosis of MNV across a wide spectrum of IRDs and highlight the gaps in our knowledge with respect to the natural history and prognosis to pave the way for future directions of research.
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Affiliation(s)
- Rachael C Heath Jeffery
- Centre for Ophthalmology and Visual Science (Lions Eye Institute), The University of Western Australia, Nedlands, WA, Australia; Royal Victorian Eye and Ear Hospital (Centre for Eye Research Australia), East Melbourne, VIC, Australia
| | - Fred K Chen
- Centre for Ophthalmology and Visual Science (Lions Eye Institute), The University of Western Australia, Nedlands, WA, Australia; Royal Victorian Eye and Ear Hospital (Centre for Eye Research Australia), East Melbourne, VIC, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, East Melbourne, VIC, Australia; Department of Ophthalmology, Royal Perth Hospital, Perth, WA, Australia.
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6
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Raman R, Bahri MA, Degueldre C, Caetano da Silva C, Sanchez C, Ostertag A, Collet C, Cohen-Solal M, Plenevaux A, Henrotin Y, Muller M. A Zebrafish Mutant in the Extracellular Matrix Protein Gene efemp1 as a Model for Spinal Osteoarthritis. Animals (Basel) 2023; 14:74. [PMID: 38200805 PMCID: PMC10778253 DOI: 10.3390/ani14010074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 12/17/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024] Open
Abstract
Osteoarthritis is a degenerative articular disease affecting mainly aging animals and people. The extracellular matrix protein Efemp1 was previously shown to have higher turn-over and increased secretion in the blood serum, urine, and subchondral bone of knee joints in osteoarthritic patients. Here, we use the zebrafish as a model system to investigate the function of Efemp1 in vertebrate skeletal development and homeostasis. Using in situ hybridization, we show that the efemp1 gene is expressed in the brain, the pharyngeal arches, and in the chordoblasts surrounding the notochord at 48 hours post-fertilization. We generated an efemp1 mutant line, using the CRISPR/Cas9 method, that produces a severely truncated Efemp1 protein. These mutant larvae presented a medially narrower chondrocranium at 5 days, which normalized later at day 10. At age 1.5 years, µCT analysis revealed an increased tissue mineral density and thickness of the vertebral bodies, as well as a decreased distance between individual vertebrae and ruffled borders of the vertebral centra. This novel defect, which has, to our knowledge, never been described before, suggests that the efemp1 mutant represents the first zebrafish model for spinal osteoarthritis.
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Affiliation(s)
- Ratish Raman
- Laboratory for Organogenesis and Regeneration (LOR), GIGA Institute, University of Liège, 4000 Liège, Belgium;
| | - Mohamed Ali Bahri
- GIGA CRC In Vivo Imaging, University of Liege, Sart Tilman, 4000 Liège, Belgium; (M.A.B.); (C.D.); (A.P.)
| | - Christian Degueldre
- GIGA CRC In Vivo Imaging, University of Liege, Sart Tilman, 4000 Liège, Belgium; (M.A.B.); (C.D.); (A.P.)
| | - Caroline Caetano da Silva
- Hospital Lariboisière, Reference Centre for Rare Bone Diseases, INSERM U1132, Université de Paris-Cité, F-75010 Paris, France; (C.C.d.S.); (A.O.); (C.C.); (M.C.-S.)
| | - Christelle Sanchez
- MusculoSKeletal Innovative Research Lab, Center for Interdisciplinary Research on Medicines, University of Liège, 4000 Liège, Belgium; (C.S.); (Y.H.)
| | - Agnes Ostertag
- Hospital Lariboisière, Reference Centre for Rare Bone Diseases, INSERM U1132, Université de Paris-Cité, F-75010 Paris, France; (C.C.d.S.); (A.O.); (C.C.); (M.C.-S.)
| | - Corinne Collet
- Hospital Lariboisière, Reference Centre for Rare Bone Diseases, INSERM U1132, Université de Paris-Cité, F-75010 Paris, France; (C.C.d.S.); (A.O.); (C.C.); (M.C.-S.)
- UF de Génétique Moléculaire, Hôpital Robert Debré, APHP, F-75019 Paris, France
| | - Martine Cohen-Solal
- Hospital Lariboisière, Reference Centre for Rare Bone Diseases, INSERM U1132, Université de Paris-Cité, F-75010 Paris, France; (C.C.d.S.); (A.O.); (C.C.); (M.C.-S.)
| | - Alain Plenevaux
- GIGA CRC In Vivo Imaging, University of Liege, Sart Tilman, 4000 Liège, Belgium; (M.A.B.); (C.D.); (A.P.)
| | - Yves Henrotin
- MusculoSKeletal Innovative Research Lab, Center for Interdisciplinary Research on Medicines, University of Liège, 4000 Liège, Belgium; (C.S.); (Y.H.)
| | - Marc Muller
- Laboratory for Organogenesis and Regeneration (LOR), GIGA Institute, University of Liège, 4000 Liège, Belgium;
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DiCesare SM, Ortega AJ, Collier GE, Daniel S, Thompson KN, McCoy MK, Posner BA, Hulleman JD. GSK3 inhibition reduces ECM production and prevents age-related macular degeneration-like pathology. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.14.571757. [PMID: 38168310 PMCID: PMC10760106 DOI: 10.1101/2023.12.14.571757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Malattia Leventinese/Doyne Honeycomb Retinal Dystrophy (ML/DHRD) is an age-related macular degeneration (AMD)-like retinal dystrophy caused by an autosomal dominant R345W mutation in the secreted glycoprotein, fibulin-3 (F3). To identify new small molecules that reduce F3 production from retinal pigmented epithelium (RPE) cells, we knocked-in a luminescent peptide tag (HiBiT) into the endogenous F3 locus which enabled simple, sensitive, and high throughput detection of the protein. The GSK3 inhibitor, CHIR99021 (CHIR), significantly reduced F3 burden (expression, secretion, and intracellular levels) in immortalized RPE and non-RPE cells. Low-level, long-term CHIR treatment promoted remodeling of the RPE extracellular matrix (ECM), reducing sub-RPE deposit-associated proteins (e.g., amelotin, complement component 3, collagen IV, and fibronectin), while increasing RPE differentiation factors (e.g., tyrosinase, and pigment epithelium derived factor). In vivo, treatment of 8 mo R345W+/+ knockin mice with CHIR (25 mg/kg i.p., 1 mo) was well tolerated and significantly reduced R345W F3-associated AMD-like basal laminar deposit number and size, thereby preventing the main pathological feature in these mice. This is the first demonstration of small molecule-based prevention of AMD-like pathology in ML/DHRD mice and may herald a rejuvenation of interest in GSK3 inhibition for the treatment of neurodegenerative diseases, including, potentially AMD itself.
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Affiliation(s)
- Sophia M. DiCesare
- Department of Ophthalmology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, Texas, 75390, United States
| | - Antonio J. Ortega
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, 2001 6 St. SE, Minneapolis, Minnesota, 55455, United States
| | - Gracen E. Collier
- Department of Ophthalmology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, Texas, 75390, United States
| | - Steffi Daniel
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, 2001 6 St. SE, Minneapolis, Minnesota, 55455, United States
| | - Krista N. Thompson
- Department of Ophthalmology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, Texas, 75390, United States
| | - Melissa K. McCoy
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, Texas, United States
| | - Bruce A. Posner
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, Texas, United States
| | - John D. Hulleman
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, 2001 6 St. SE, Minneapolis, Minnesota, 55455, United States
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Anderson DM, Kotnala A, Migas LG, Patterson NH, Tideman L, Cao D, Adhikari B, Messinger JD, Ach T, Tortorella S, Van de Plas R, Curcio CA, Schey KL. Lysolipids are prominent in subretinal drusenoid deposits, a high-risk phenotype in age-related macular degeneration. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1258734. [PMID: 38186747 PMCID: PMC10769005 DOI: 10.3389/fopht.2023.1258734] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Introduction Age related macular degeneration (AMD) causes legal blindness worldwide, with few therapeutic targets in early disease and no treatments for 80% of cases. Extracellular deposits, including drusen and subretinal drusenoid deposits (SDD; also called reticular pseudodrusen), disrupt cone and rod photoreceptor functions and strongly confer risk for advanced disease. Due to the differential cholesterol composition of drusen and SDD, lipid transfer and cycling between photoreceptors and support cells are candidate dysregulated pathways leading to deposit formation. The current study explores this hypothesis through a comprehensive lipid compositional analysis of SDD. Methods Histology and transmission electron microscopy were used to characterize the morphology of SDD. Highly sensitive tools of imaging mass spectrometry (IMS) and nano liquid chromatography tandem mass spectrometry (nLC-MS/MS) in positive and negative ion modes were used to spatially map and identify SDD lipids, respectively. An interpretable supervised machine learning approach was utilized to compare the lipid composition of SDD to regions of uninvolved retina across 1873 IMS features and to automatically discern candidate markers for SDD. Immunohistochemistry (IHC) was used to localize secretory phospholipase A2 group 5 (PLA2G5). Results Among the 1873 detected features in IMS data, three lipid classes, including lysophosphatidylcholine (LysoPC), lysophosphatidylethanolamine (LysoPE) and lysophosphatidic acid (LysoPA) were observed nearly exclusively in SDD while presumed precursors, including phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidic acid (PA) lipids were detected in SDD and adjacent photoreceptor outer segments. Molecular signals specific to SDD were found in central retina and elsewhere. IHC results indicated abundant PLA2G5 in photoreceptors and retinal pigment epithelium (RPE). Discussion The abundance of lysolipids in SDD implicates lipid remodeling or degradation in deposit formation, consistent with ultrastructural evidence of electron dense lipid-containing structures distinct from photoreceptor outer segment disks and immunolocalization of secretory PLA2G5 in photoreceptors and RPE. Further studies are required to understand the role of lipid signals observed in and around SDD.
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Affiliation(s)
| | - Ankita Kotnala
- Department of Biochemistry, Vanderbilt University, Nashville TN
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham AL
| | - Lukasz G. Migas
- Delft Center for Systems and Control (DCSC), Delft University of Technology, Delft, Netherlands
| | | | - Léonore Tideman
- Delft Center for Systems and Control (DCSC), Delft University of Technology, Delft, Netherlands
| | - Dongfeng Cao
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham AL
| | - Bibek Adhikari
- Vision Science Graduate Program, University of Alabama at Birmingham, Birmingham AL
| | - Jeffrey D. Messinger
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham AL
| | - Thomas Ach
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany
| | - Sara Tortorella
- Molecular Horizon Srl, Via Montelino 30, 06084 Bettona, Perugia, Italy
| | - Raf Van de Plas
- Department of Biochemistry, Vanderbilt University, Nashville TN
- Delft Center for Systems and Control (DCSC), Delft University of Technology, Delft, Netherlands
| | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham AL
| | - Kevin L. Schey
- Department of Biochemistry, Vanderbilt University, Nashville TN
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Xu L, Ruddick WN, Bolch SN, Klingeborn M, Dyka FM, Kulkarni MM, Simpson CP, Beltran WA, Bowes Rickman C, Smith WC, Dinculescu A. Distinct Phenotypic Consequences of Pathogenic Mutants Associated with Late-Onset Retinal Degeneration. THE AMERICAN JOURNAL OF PATHOLOGY 2023; 193:1706-1720. [PMID: 36328299 PMCID: PMC10726427 DOI: 10.1016/j.ajpath.2022.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/23/2022] [Accepted: 10/11/2022] [Indexed: 11/09/2022]
Abstract
A pathologic feature of late-onset retinal degeneration caused by the S163R mutation in C1q-tumor necrosis factor-5 (C1QTNF5) is the presence of unusually thick deposits between the retinal pigmented epithelium (RPE) and the vascular choroid, considered a hallmark of this disease. Following its specific expression in mouse RPE, the S163R mutant exhibits a reversed polarized distribution relative to the apically secreted wild-type C1QTNF5, and forms widespread, prominent deposits that gradually increase in size with aging. The current study shows that S163R deposits expand to a considerable thickness through a progressive increase in the basolateral RPE membrane, substantially raising the total RPE height, and enabling their clear imaging as a distinct hyporeflective layer by noninvasive optical coherence tomography in advanced age animals. This phenotype bears a striking resemblance to ocular pathology previously documented in patients harboring the S163R mutation. Therefore, a similar viral vector-based gene delivery approach was used to also investigate the behavior of P188T and G216C, two novel pathogenic C1QTNF5 mutants recently reported in patients for which histopathologic data are lacking. Both mutants primarily impacted the RPE/photoreceptor interface and did not generate basal laminar deposits. Distinct distribution patterns and phenotypic consequences of C1QTNF5 mutants were observed in vivo, which suggested that multiple pathobiological mechanisms contribute to RPE dysfunction and vision loss in this disorder.
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Affiliation(s)
- Lei Xu
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
| | - William N Ruddick
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
| | - Susan N Bolch
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
| | - Mikael Klingeborn
- McLaughlin Research Institute, Great Falls, Montana; Helen Wills Neuroscience Institute, Berkeley, California
| | - Frank M Dyka
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
| | - Manoj M Kulkarni
- Division of Experimental Retinal Therapies, Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Chiab P Simpson
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
| | - William A Beltran
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina
| | - Catherine Bowes Rickman
- Helen Wills Neuroscience Institute, Berkeley, California; Department of Cell Biology, Duke University Medical Center, Durham, North Carolina
| | - W Clay Smith
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
| | - Astra Dinculescu
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida.
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10
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Kamei T, Ooto S, Uji A, Ichioka A, Tsujikawa A. CHORIOCAPILLARIS STRUCTURE IN THE FELLOW EYES OF PATIENTS WITH NEOVASCULAR AGE-RELATED MACULAR DEGENERATION: An OCT Angiography Image Averaging Study. Retina 2023; 43:286-293. [PMID: 36695798 DOI: 10.1097/iae.0000000000003660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PURPOSE Histological choriocapillaris abnormalities have been reported in age-related macular degeneration (AMD). Averaging multiple en face optical coherence tomography angiography improves the quality of imaging of the choriocapillaris. This study used multiple en face swept source optical coherence tomography angiography image averaging to examine the structural changes in the choriocapillaris in the fellow eyes of patients with neovascular AMD. METHODS All patients underwent macular optical coherence tomography angiography imaging. One eye per subject was repeatedly imaged, and nine raster scan sets were obtained. Registered en face images were averaged, and area of flow voids and number of flow voids were measured using ImageJ software. RESULTS Forty-eight patients with neovascular AMD were recruited for analysis. Twenty-seven patients had polypoidal choroidal vasculopathy, and 22 eyes had soft drusen. Twenty-six eyes of 26 healthy individuals were included as age-matched normal controls. The choriocapillaris had a meshwork appearance in all eyes. The mean flow void area of the choriocapillaris was larger in patients with AMD than normal controls (1.14 ± 0.16 mm2 vs. 1.01 ± 0.12 mm2, P = 0.002). The mean size of each flow void was greater in patients with AMD than normal controls (729 ± 210 µm2 vs. 583 ± 120 µm2, P = 0.003). The mean flow void area of the choriocapillaris was larger in eyes with soft drusen than without soft drusen (1.2 ± 0.2 mm2 vs. 1.1 ± 0.1 mm2, P = 0.024). CONCLUSION Multiple en face image averaging revealed precise choriocapillaris structures in the fellow eyes of patients with neovascular AMD.
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Affiliation(s)
- Takuro Kamei
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
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11
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Stradiotto E, Allegrini D, Fossati G, Raimondi R, Sorrentino T, Tripepi D, Barone G, Inforzato A, Romano MR. Genetic Aspects of Age-Related Macular Degeneration and Their Therapeutic Potential. Int J Mol Sci 2022; 23:13280. [PMID: 36362067 PMCID: PMC9653831 DOI: 10.3390/ijms232113280] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/05/2022] [Accepted: 10/28/2022] [Indexed: 08/27/2023] Open
Abstract
Age-related macular degeneration (AMD) is a complex and multifactorial disease, resulting from the interaction of environmental and genetic factors. The continuous discovery of associations between genetic polymorphisms and AMD gives reason for the pivotal role attributed to the genetic component to its development. In that light, genetic tests and polygenic scores have been created to predict the risk of development and response to therapy. Still, none of them have yet been validated. Furthermore, there is no evidence from a clinical trial that the determination of the individual genetic structure can improve treatment outcomes. In this comprehensive review, we summarize the polymorphisms of the main pathogenetic ways involved in AMD development to identify which of them constitutes a potential therapeutic target. As complement overactivation plays a major role, the modulation of targeted complement proteins seems to be a promising therapeutic approach. Herein, we summarize the complement-modulating molecules now undergoing clinical trials, enlightening those in an advanced phase of trial. Gene therapy is a potential innovative one-time treatment, and its relevance is quickly evolving in the field of retinal diseases. We describe the state of the art of gene therapies now undergoing clinical trials both in the field of complement-suppressors and that of anti-VEGF.
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Affiliation(s)
- Elisa Stradiotto
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
- Department of Ophthalmology, Eye Unit Humanitas Gavazzeni-Castelli, Via Mazzini 11, 24128 Bergamo, Italy
| | - Davide Allegrini
- Department of Ophthalmology, Eye Unit Humanitas Gavazzeni-Castelli, Via Mazzini 11, 24128 Bergamo, Italy
| | - Giovanni Fossati
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
- Department of Ophthalmology, Eye Unit Humanitas Gavazzeni-Castelli, Via Mazzini 11, 24128 Bergamo, Italy
| | - Raffaele Raimondi
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
- Department of Ophthalmology, Eye Unit Humanitas Gavazzeni-Castelli, Via Mazzini 11, 24128 Bergamo, Italy
| | - Tania Sorrentino
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
- Department of Ophthalmology, Eye Unit Humanitas Gavazzeni-Castelli, Via Mazzini 11, 24128 Bergamo, Italy
| | - Domenico Tripepi
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
- Department of Ophthalmology, Eye Unit Humanitas Gavazzeni-Castelli, Via Mazzini 11, 24128 Bergamo, Italy
| | - Gianmaria Barone
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
- Department of Ophthalmology, Eye Unit Humanitas Gavazzeni-Castelli, Via Mazzini 11, 24128 Bergamo, Italy
| | - Antonio Inforzato
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
- IRCCS Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano-Milan, Italy
| | - Mario R. Romano
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
- Department of Ophthalmology, Eye Unit Humanitas Gavazzeni-Castelli, Via Mazzini 11, 24128 Bergamo, Italy
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12
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Crowley MA, Garland DL, Sellner H, Banks A, Fan L, Rejtar T, Buchanan N, Delgado O, Xu YY, Jose S, Adams CM, Mogi M, Wang K, Bigelow CE, Poor S, Anderson K, Jaffee BD, Prasanna G, Grosskreutz C, Fernandez-Godino R, Pierce EA, Dryja TP, Liao SM. Complement factor B is critical for sub-RPE deposit accumulation in a model of Doyne honeycomb retinal dystrophy with features of age-related macular degeneration. Hum Mol Genet 2022; 32:204-217. [PMID: 35943778 PMCID: PMC9840207 DOI: 10.1093/hmg/ddac187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 01/19/2023] Open
Abstract
EFEMP1 R345W is a dominant mutation causing Doyne honeycomb retinal dystrophy/malattia leventinese (DHRD/ML), a rare blinding disease with clinical pathology similar to age-related macular degeneration (AMD). Aged Efemp1 R345W/R345W knock-in mice (Efemp1ki/ki) develop microscopic deposits on the basal side of retinal pigment epithelial cells (RPE), an early feature in DHRD/ML and AMD. Here, we assessed the role of alternative complement pathway component factor B (FB) in the formation of these deposits. RNA-seq analysis of the posterior eyecups revealed increased unfolded protein response, decreased mitochondrial function in the neural retina (by 3 months of age) and increased inflammatory pathways in both neural retina and posterior eyecups (at 17 months of age) of Efemp1ki/ki mice compared with wild-type littermate controls. Proteomics analysis of eye lysates confirmed similar dysregulated pathways as detected by RNA-seq. Complement activation was increased in aged Efemp1ki/ki eyes with an approximately 2-fold elevation of complement breakdown products iC3b and Ba (P < 0.05). Deletion of the Cfb gene in female Efemp1ki/ki mice partially normalized the above dysregulated biological pathway changes and oral dosing of a small molecule FB inhibitor from 10 to 12 months of age reduced sub-RPE deposits by 65% (P = 0.029). In contrast, male Efemp1ki/ki mice had fewer sub-RPE deposits than age-matched females, no elevation of ocular complement activation and no effect of FB inhibition on sub-RPE deposits. The effects of FB deletion or inhibition on Efemp1ki/ki mice supports systemic inhibition of the alternative complement pathway as a potential treatment of dry AMD and DHRD/ML.
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Affiliation(s)
- Maura A Crowley
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Donita L Garland
- Ocular Genomics Institute at Massachusetts Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
| | - Holger Sellner
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Angela Banks
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Lin Fan
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Tomas Rejtar
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Natasha Buchanan
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Omar Delgado
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Yong Yao Xu
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Sandra Jose
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Christopher M Adams
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Muneto Mogi
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Karen Wang
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Chad E Bigelow
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Stephen Poor
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | | | - Bruce D Jaffee
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Ganesh Prasanna
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Cynthia Grosskreutz
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA 02319, USA
| | - Rosario Fernandez-Godino
- Ocular Genomics Institute at Massachusetts Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
| | - Eric A Pierce
- Ocular Genomics Institute at Massachusetts Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
| | | | - Sha-Mei Liao
- To whom correspondence should be addressed at: Department of Ophthalmology, Novartis Institutes for BioMedical Research, 22 Windsor Street, Cambridge, MA 02139, USA. Tel: +1-(617)871-4004; Fax: +1-(617)871-5748;
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13
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Epithelial phenotype restoring drugs suppress macular degeneration phenotypes in an iPSC model. Nat Commun 2021; 12:7293. [PMID: 34911940 PMCID: PMC8674335 DOI: 10.1038/s41467-021-27488-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 11/16/2021] [Indexed: 01/14/2023] Open
Abstract
Age-related Macular Degeneration (AMD), a blinding eye disease, is characterized by pathological protein- and lipid-rich drusen deposits underneath the retinal pigment epithelium (RPE) and atrophy of the RPE monolayer in advanced disease stages - leading to photoreceptor cell death and vision loss. Currently, there are no drugs that stop drusen formation or RPE atrophy in AMD. Here we provide an iPSC-RPE AMD model that recapitulates drusen and RPE atrophy. Drusen deposition is dependent on AMD-risk-allele CFH(H/H) and anaphylatoxin triggered alternate complement signaling via the activation of NF-κB and downregulation of autophagy pathways. Through high-throughput screening we identify two drugs, L-745,870, a dopamine receptor antagonist, and aminocaproic acid, a protease inhibitor that reduce drusen deposits and restore RPE epithelial phenotype in anaphylatoxin challenged iPSC-RPE with or without the CFH(H/H) genotype. This comprehensive iPSC-RPE model replicates key AMD phenotypes, provides molecular insight into the role of CFH(H/H) risk-allele in AMD, and discovers two candidate drugs to treat AMD.
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14
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Landowski M, Bowes Rickman C. Targeting Lipid Metabolism for the Treatment of Age-Related Macular Degeneration: Insights from Preclinical Mouse Models. J Ocul Pharmacol Ther 2021; 38:3-32. [PMID: 34788573 PMCID: PMC8817708 DOI: 10.1089/jop.2021.0067] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Age-related macular degeneration (AMD) is a major leading cause of irreversible visual impairment in the world with limited therapeutic interventions. Histological, biochemical, genetic, and epidemiological studies strongly implicate dysregulated lipid metabolism in the retinal pigmented epithelium (RPE) in AMD pathobiology. However, effective therapies targeting lipid metabolism still need to be identified and developed for this blinding disease. To test lipid metabolism-targeting therapies, preclinical AMD mouse models are needed to establish therapeutic efficacy and the role of lipid metabolism in the development of AMD-like pathology. In this review, we provide a comprehensive overview of current AMD mouse models available to researchers that could be used to provide preclinical evidence supporting therapies targeting lipid metabolism for AMD. Based on previous studies of AMD mouse models, we discuss strategies to modulate lipid metabolism as well as examples of studies evaluating lipid-targeting therapeutics to restore lipid processing in the RPE. The use of AMD mouse models may lead to worthy lipid-targeting candidate therapies for clinical trials to prevent the blindness caused by AMD.
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Affiliation(s)
- Michael Landowski
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA.,McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Catherine Bowes Rickman
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA
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15
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Niewiadomska-Cimicka A, Doussau F, Perot JB, Roux MJ, Keime C, Hache A, Piguet F, Novati A, Weber C, Yalcin B, Meziane H, Champy MF, Grandgirard E, Karam A, Messaddeq N, Eisenmann A, Brouillet E, Nguyen HHP, Flament J, Isope P, Trottier Y. SCA7 Mouse Cerebellar Pathology Reveals Preferential Downregulation of Key Purkinje Cell-Identity Genes and Shared Disease Signature with SCA1 and SCA2. J Neurosci 2021; 41:4910-4936. [PMID: 33888607 PMCID: PMC8260160 DOI: 10.1523/jneurosci.1882-20.2021] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 03/03/2021] [Accepted: 03/05/2021] [Indexed: 12/11/2022] Open
Abstract
Spinocerebellar ataxia type 7 (SCA7) is an inherited neurodegenerative disease mainly characterized by motor incoordination because of progressive cerebellar degeneration. SCA7 is caused by polyglutamine expansion in ATXN7, a subunit of the transcriptional coactivator SAGA, which harbors histone modification activities. Polyglutamine expansions in specific proteins are also responsible for SCA1-SCA3, SCA6, and SCA17; however, the converging and diverging pathomechanisms remain poorly understood. Using a new SCA7 knock-in mouse, SCA7140Q/5Q, we analyzed gene expression in the cerebellum and assigned gene deregulation to specific cell types using published datasets. Gene deregulation affects all cerebellar cell types, although at variable degree, and correlates with alterations of SAGA-dependent epigenetic marks. Purkinje cells (PCs) are by far the most affected neurons and show reduced expression of 83 cell-type identity genes, including these critical for their spontaneous firing activity and synaptic functions. PC gene downregulation precedes morphologic alterations, pacemaker dysfunction, and motor incoordination. Strikingly, most PC genes downregulated in SCA7 have also decreased expression in SCA1 and SCA2 mice, revealing converging pathomechanisms and a common disease signature involving cGMP-PKG and phosphatidylinositol signaling pathways and LTD. Our study thus points out molecular targets for therapeutic development, which may prove beneficial for several SCAs. Furthermore, we show that SCA7140Q/5Q males and females exhibit the major disease features observed in patients, including cerebellar damage, cerebral atrophy, peripheral nerves pathology, and photoreceptor dystrophy, which account for progressive impairment of behavior, motor, and visual functions. SCA7140Q/5Q mice represent an accurate model for the investigation of different aspects of SCA7 pathogenesis.SIGNIFICANCE STATEMENT Spinocerebellar ataxia 7 (SCA7) is one of the several forms of inherited SCAs characterized by cerebellar degeneration because of polyglutamine expansion in specific proteins. The ATXN7 involved in SCA7 is a subunit of SAGA transcriptional coactivator complex. To understand the pathomechanisms of SCA7, we determined the cell type-specific gene deregulation in SCA7 mouse cerebellum. We found that the Purkinje cells are the most affected cerebellar cell type and show downregulation of a large subset of neuronal identity genes, critical for their spontaneous firing and synaptic functions. Strikingly, the same Purkinje cell genes are downregulated in mouse models of two other SCAs. Thus, our work reveals a disease signature shared among several SCAs and uncovers potential molecular targets for their treatment.
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Affiliation(s)
- Anna Niewiadomska-Cimicka
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
| | - Frédéric Doussau
- Université de Strasbourg, Illkirch 67404, France
- Centre National de la Recherche Scientifique UPR3212, Strasbourg 67000, France
| | - Jean-Baptiste Perot
- Université Paris-Saclay, Centre National de la Recherche Scientifique, Commissariat à l'Energie Atomique, Direction de la Recherche Fondamentale, Institut de biologie François Jacob, Molecular Imaging Research Center, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses 92260, France
| | - Michel J Roux
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
| | - Celine Keime
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
| | - Antoine Hache
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
| | - Françoise Piguet
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
| | - Ariana Novati
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen 72076, Germany
- Department of Human Genetics, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Chantal Weber
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
| | - Binnaz Yalcin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
| | - Hamid Meziane
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
- Celphedia, Phenomin, Institut Clinique de la Souris, Illkirch 67404, France
| | - Marie-France Champy
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
- Celphedia, Phenomin, Institut Clinique de la Souris, Illkirch 67404, France
| | - Erwan Grandgirard
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
| | - Alice Karam
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
| | - Nadia Messaddeq
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
| | - Aurélie Eisenmann
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
| | - Emmanuel Brouillet
- Université Paris-Saclay, Centre National de la Recherche Scientifique, Commissariat à l'Energie Atomique, Direction de la Recherche Fondamentale, Institut de biologie François Jacob, Molecular Imaging Research Center, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses 92260, France
| | - Hoa Huu Phuc Nguyen
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen 72076, Germany
- Department of Human Genetics, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Julien Flament
- Université Paris-Saclay, Centre National de la Recherche Scientifique, Commissariat à l'Energie Atomique, Direction de la Recherche Fondamentale, Institut de biologie François Jacob, Molecular Imaging Research Center, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses 92260, France
| | - Philippe Isope
- Université de Strasbourg, Illkirch 67404, France
- Centre National de la Recherche Scientifique UPR3212, Strasbourg 67000, France
| | - Yvon Trottier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch 67404, France
- Institut National de la Santé et de la Recherche Médicale, Illkirch 67404, U964, France
- Université de Strasbourg, Illkirch 67404, France
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16
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Bao X, Zhang Z, Guo Y, Buser C, Kochounian H, Wu N, Li X, He S, Sun B, Ross-Cisneros FN, Sadun AA, Huang L, Zhao M, Fong HKW. Human RGR Gene and Associated Features of Age-Related Macular Degeneration in Models of Retina-Choriocapillaris Atrophy. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:1454-1473. [PMID: 34022179 DOI: 10.1016/j.ajpath.2021.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 04/16/2021] [Accepted: 05/05/2021] [Indexed: 01/28/2023]
Abstract
Age-related macular degeneration (AMD) is a progressive eye disease and the most common cause of blindness among the elderly. AMD is characterized by early atrophy of the choriocapillaris and retinal pigment epithelium (RPE). Although AMD is a multifactorial disease with many environmental and genetic risk factors, a hallmark of the disease is the origination of extracellular deposits, or drusen, between the RPE and Bruch membrane. Human retinal G-protein-coupled receptor (RGR) gene generates an exon-skipping splice variant of RGR-opsin (RGR-d; NP_001012740) that is a persistent component of small and large drusen. Herein, the findings show that abnormal RGR proteins, including RGR-d, are pathogenic in an animal retina with degeneration of the choriocapillaris, RPE, and photoreceptors. A frameshift truncating mutation resulted in severe retinal degeneration with a continuous band of basal deposits along the Bruch membrane. RGR-d produced less severe disease with choriocapillaris and RPE atrophy, including focal accumulation of abnormal RGR-d protein at the basal boundary of the RPE. Degeneration of the choriocapillaris was marked by a decrease in endothelial CD31 protein and choriocapillaris breakdown at the ultrastructural level. Fundus lesions with patchy depigmentation were characteristic of old RGR-d mice. RGR-d was mislocalized in cultured cells and caused a strong cell growth defect. These results uphold the notion of a potential hidden link between AMD and a high-frequency RGR allele.
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Affiliation(s)
- Xuan Bao
- Department of Ophthalmology, Beijing Key Laboratory for the Diagnosis and Treatment of Retinal and Choroid Diseases, Peking University People's Hospital, Beijing, China; Department of Ophthalmology, Keck School of Medicine of USC, Los Angeles, California
| | - Zhaoxia Zhang
- Department of Ophthalmology, Keck School of Medicine of USC, Los Angeles, California; Shanxi Eye Hospital, Taiyuan, China
| | - Yanjiang Guo
- Department of Ophthalmology, Beijing Key Laboratory for the Diagnosis and Treatment of Retinal and Choroid Diseases, Peking University People's Hospital, Beijing, China
| | | | | | - Nancy Wu
- Norris Cancer Center, Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Xiaohua Li
- Henan Eye Institute, Henan Provincial People's Hospital, Henan, China
| | - Shikun He
- Department of Pathology, Keck School of Medicine of USC, Los Angeles, California
| | - Bin Sun
- Shanxi Eye Hospital, Taiyuan, China
| | | | - Alfredo A Sadun
- Doheny Eye Institute, Los Angeles, California; Department of Ophthalmology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Lvzhen Huang
- Department of Ophthalmology, Beijing Key Laboratory for the Diagnosis and Treatment of Retinal and Choroid Diseases, Peking University People's Hospital, Beijing, China
| | - Mingwei Zhao
- Department of Ophthalmology, Beijing Key Laboratory for the Diagnosis and Treatment of Retinal and Choroid Diseases, Peking University People's Hospital, Beijing, China.
| | - Henry K W Fong
- Department of Ophthalmology, Keck School of Medicine of USC, Los Angeles, California; University of Southern California Roski Eye Institute, Los Angeles, California; Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, California.
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17
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Garland DL, Pierce EA, Fernandez-Godino R. Complement C5 is not critical for the formation of sub-RPE deposits in Efemp1 mutant mice. Sci Rep 2021; 11:10416. [PMID: 34001980 PMCID: PMC8128922 DOI: 10.1038/s41598-021-89978-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 05/05/2021] [Indexed: 12/27/2022] Open
Abstract
The complement system plays a role in the formation of sub-retinal pigment epithelial (RPE) deposits in early stages of age-related macular degeneration (AMD). But the specific mechanisms that connect complement activation and deposit formation in AMD patients are unknown, which limits the development of efficient therapies to reduce or stop disease progression. We have previously demonstrated that C3 blockage prevents the formation of sub-RPE deposits in a mouse model of EFEMP1-associated macular degeneration. In this study, we have used double mutant Efemp1R345W/R345W:C5-/- mice to investigate the role of C5 in the formation of sub-RPE deposits in vivo and in vitro. The data revealed that the genetic ablation of C5 does not eliminate the formation of sub-RPE deposits. Contrarily, the absence of C5 in RPE cultures promotes complement dysregulation that results in increased activation of C3, which likely contributes to deposit formation even in the absence of EFEMP1-R345W mutant protein. The results also suggest that genetic ablation of C5 alters the extracellular matrix turnover through an effect on matrix metalloproteinases in RPE cell cultures. These results confirm that C3 rather than C5 could be an effective therapeutic target to treat early AMD.
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Affiliation(s)
- Donita L Garland
- Ocular Genomics Institute at Massachusetts Eye and Ear, Harvard Medical School, Boston, USA
| | - Eric A Pierce
- Ocular Genomics Institute at Massachusetts Eye and Ear, Harvard Medical School, Boston, USA
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Tsai YT, Li Y, Ryu J, Su PY, Cheng CH, Wu WH, Li YS, Quinn PMJ, Leong KW, Tsang SH. Impaired cholesterol efflux in retinal pigment epithelium of individuals with juvenile macular degeneration. Am J Hum Genet 2021; 108:903-918. [PMID: 33909993 PMCID: PMC8206198 DOI: 10.1016/j.ajhg.2021.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 03/30/2021] [Indexed: 12/12/2022] Open
Abstract
Macular degeneration (MD) is characterized by the progressive deterioration of the macula and represents one of the most prevalent causes of blindness worldwide. Abnormal intracellular accumulation of lipid droplets and pericellular deposits of lipid-rich material in the retinal pigment epithelium (RPE) called drusen are clinical hallmarks of different forms of MD including Doyne honeycomb retinal dystrophy (DHRD) and age-related MD (AMD). However, the appropriate molecular therapeutic target underlying these disorder phenotypes remains elusive. Here, we address this knowledge gap by comparing the proteomic profiles of induced pluripotent stem cell (iPSC)-derived RPEs (iRPE) from individuals with DHRD and their isogenic controls. Our analysis and follow-up studies elucidated the mechanism of lipid accumulation in DHRD iRPE cells. Specifically, we detected significant downregulation of carboxylesterase 1 (CES1), an enzyme that converts cholesteryl ester to free cholesterol, an indispensable process in cholesterol export. CES1 knockdown or overexpression of EFEMP1R345W, a variant of EGF-containing fibulin extracellular matrix protein 1 that is associated with DHRD and attenuated cholesterol efflux and led to lipid droplet accumulation. In iRPE cells, we also found that EFEMP1R345W has a hyper-inhibitory effect on epidermal growth factor receptor (EGFR) signaling when compared to EFEMP1WT and may suppress CES1 expression via the downregulation of transcription factor SP1. Taken together, these results highlight the homeostatic role of cholesterol efflux in iRPE cells and identify CES1 as a mediator of cholesterol efflux in MD.
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Key Words
- age-related macular degeneration, Doyne honeycomb destrophy, DHRD, cholesterol efflux, drusen, RPE, CRISPR, isogenic, EGFR signaling, unfolded protein response, lipid accumulation
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Affiliation(s)
- Yi-Ting Tsai
- Department of Biomedical Engineering, Columbia University, New York, NY 10032, USA
| | - Yao Li
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Joseph Ryu
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Pei-Yin Su
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Chia-Hua Cheng
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Wen-Hsuan Wu
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Yong-Shi Li
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Peter M J Quinn
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Kam W Leong
- Department of Biomedical Engineering, Columbia University, New York, NY 10032, USA
| | - Stephen H Tsang
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA; Department of Pathology & Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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19
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Role of Fibulins in Embryonic Stage Development and Their Involvement in Various Diseases. Biomolecules 2021; 11:biom11050685. [PMID: 34063320 PMCID: PMC8147605 DOI: 10.3390/biom11050685] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/29/2021] [Accepted: 04/30/2021] [Indexed: 12/24/2022] Open
Abstract
The extracellular matrix (ECM) plays an important role in the evolution of early metazoans, as it provides structural and biochemical support to the surrounding cells through the cell–cell and cell–matrix interactions. In multi-cellular organisms, ECM plays a pivotal role in the differentiation of tissues and in the development of organs. Fibulins are ECM glycoproteins, found in a variety of tissues associated with basement membranes, elastic fibers, proteoglycan aggregates, and fibronectin microfibrils. The expression profile of fibulins reveals their role in various developmental processes such as elastogenesis, development of organs during the embryonic stage, tissue remodeling, maintenance of the structural integrity of basement membrane, and elastic fibers, as well as other cellular processes. Apart from this, fibulins are also involved in the progression of human diseases such as cancer, cardiac diseases, congenital disorders, and chronic fibrotic disorders. Different isoforms of fibulins show a dual role of tumor-suppressive and tumor-promoting activities, depending on the cell type and cellular microenvironment in the body. Knockout animal models have provided deep insight into their role in development and diseases. The present review covers details of the structural and expression patterns, along with the role of fibulins in embryonic development and disease progression, with more emphasis on their involvement in the modulation of cancer diseases.
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Sheyanth IN, Lolas IB, Okkels H, Kiruparajan LP, Abildgaard SK, Petersen MB. First reported case of Doyne honeycomb retinal dystrophy (Malattia Leventinese/autosomal dominant drusen) in Scandinavia. Mol Genet Genomic Med 2021; 9:e1652. [PMID: 33689237 PMCID: PMC8123724 DOI: 10.1002/mgg3.1652] [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: 08/25/2020] [Revised: 11/11/2020] [Accepted: 02/19/2021] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Doyne honeycomb retinal dystrophy (DHRD)/malattia leventinese (ML) is an autosomal dominant, progressive retinal disorder characterized by massive central retinal drusen often partly coalescent forming a characteristic honeycomb-like pattern. Debut of vision loss often occurs in early to mid-adulthood, and the degree varies. A single variant in EFEMP1: c.1033C>T (R345W) has been identified as the cause in all cases. METHODS Following DNA isolation, exome sequencing was performed in seven genes associated with flecked retina. Direct sequencing was used for variant verification. RESULTS We report the first Scandinavian case of molecular genetically verified DHRD/ML: a 57-year-old woman debuting with vision loss and metamorphopsia. On both eyes, ophthalmological findings included massive hard drusen in the macular region and nasal to the optic disc as well as macular hyperpigmentation. Secondary choroidal neovascularizations were identified on both eyes, and anti-vascular endothelial growth factor was administered, without effect. CONCLUSION Molecular genetic investigation revealed heterozygosity for the known pathogenic missense variant in EFEMP1: c.1033C>T (R345W) previously reported in relation to DHRD/ML. Family history revealed no other cases of similar visual impairment suggesting a de novo mutation. Furthermore, there was no correlation between the unique DHRD/ML haplotypes reported in the literature and our patient.
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Affiliation(s)
- Inger Norlyk Sheyanth
- Research and Knowledge Center in Sensory Genetics, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Genetics, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - Ihab Bishara Lolas
- Research and Knowledge Center in Sensory Genetics, Aalborg University Hospital, Aalborg, Denmark.,Department of Molecular Diagnostics, Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark
| | - Henrik Okkels
- Research and Knowledge Center in Sensory Genetics, Aalborg University Hospital, Aalborg, Denmark.,Department of Molecular Diagnostics, Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark
| | - Ligor Pradeep Kiruparajan
- Research and Knowledge Center in Sensory Genetics, Aalborg University Hospital, Aalborg, Denmark.,Department of Ophthalmology, Aalborg University Hospital, Aalborg, Denmark
| | - Søren Kromann Abildgaard
- Research and Knowledge Center in Sensory Genetics, Aalborg University Hospital, Aalborg, Denmark.,Department of Ophthalmology, Aalborg University Hospital, Aalborg, Denmark
| | - Michael Bjørn Petersen
- Research and Knowledge Center in Sensory Genetics, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Genetics, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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21
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Clinically-identified C-terminal mutations in fibulin-3 are prone to misfolding and destabilization. Sci Rep 2021; 11:2998. [PMID: 33542268 PMCID: PMC7862258 DOI: 10.1038/s41598-020-79570-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 12/09/2020] [Indexed: 11/24/2022] Open
Abstract
Distinct mutations in the secreted extracellular matrix protein, fibulin-3 (F3), have been associated with a number of ocular diseases ranging from primary open angle glaucoma to cuticular age-related macular degeneration to a rare macular dystrophy, Malattia Leventinese (ML). The R345W F3 mutation that causes ML leads to F3 misfolding, inefficient secretion and accumulation at higher intracellular steady state levels in cultured cells. Herein, we determined whether fifteen other clinically-identified F3 mutations also led to similar levels of misfolding and secretion defects, which might provide insight into their potential pathogenicity. Surprisingly, we found that only a single F3 variant, L451F, presented with a significant secretion defect (69.5 ± 2.4% of wild-type (WT) F3 levels) and a corresponding increase in intracellular levels (226.8 ± 25.4% of WT F3 levels). Upon follow-up studies, when this conserved residue (L451) was mutated to a charged (Asp or Arg) or bulky (Pro, Trp, Tyr) residue, F3 secretion was also compromised, indicating the importance of small side chains (Leu, Ala, or Gly) at this residue. To uncover potential inherent F3 instability not easily observed under typical culture conditions, we genetically eliminated the sole stabilizing N-linked glycosylation site (N249) from select clinically-identified F3 mutants. This removal exacerbated R345W and L451F secretion defects (19.8 ± 3.0% and 12.4 ± 1.2% of WT F3 levels, respectively), but also revealed a previously undiscovered secretion defect in another C-terminal variant, Y397H (42.0 ± 10.1% of WT F3 levels). Yet, glycan removal did not change the relative secretion of the N-terminal mutants tested (D49A, R140W, I220F). These results highlight the uniqueness and molecular similarities between the R345W and L451F variants and also suggest that previously identified disease-associated mutations (e.g., R140W) are indistinguishable from WT with respect to secretion, hinting that they may lead to disease by an alternative mechanism.
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22
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Chen L, Messinger JD, Kar D, Duncan JL, Curcio CA. Biometrics, Impact, and Significance of Basal Linear Deposit and Subretinal Drusenoid Deposit in Age-Related Macular Degeneration. Invest Ophthalmol Vis Sci 2021; 62:33. [PMID: 33512402 PMCID: PMC7846955 DOI: 10.1167/iovs.62.1.33] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 01/04/2021] [Indexed: 02/07/2023] Open
Abstract
Purpose Basal linear deposit (BLinD) is a thin layer of soft drusen material. To elucidate the biology of extracellular deposits conferring age-related macular degeneration (AMD) progression risk and inform multimodal clinical imaging based on optical coherence tomography (OCT), we examined lipid content and regional prevalence of BLinD, soft drusen, pre-BLinD, and subretinal drusenoid deposit (SDD) in AMD and non-AMD aged eyes. We estimated BLinD volume and illustrated its relation to type 1 macular neovascularization (MNV). Methods Donor eyes were classified as early to intermediate AMD (n = 25) and age-matched controls (n = 54). In high-resolution histology, we assessed BLinD/soft drusen thickness at 836 and 1716 locations in AMD and control eyes, respectively. BLinD volume was estimated using solid geometry in donor eyes, one clinically characterized. Results BLinD, drusen, type 1 MNV, and fluid occupy the sub-RPE-basal laminar space. BLinD volume in a 3-mm diameter circle may be as much as 0.0315 mm3. Osmophilic lipid was more concentrated in BLinD/drusen than SDD. In the fovea, BLinD/drusen was prevalent in AMD eyes; pre-BLinD was prevalent in control eyes. SDD was low in the fovea and high in perifovea, especially in AMD eyes. Conclusions Although invisible, BLinD may presage type 1 MNV. BLinD volume approaches the criterion OCT drusen volume of 0.03 mm3 for AMD progression risk. BLinD culminates years of subfoveal lipid accumulation. SDD is detected relatively late in life, with currently unknown precursors. Deposit topography suggests one outer retinal lipid recycling system serving specialized cone and rod physiology, and its dysregulation in AMD is due to impaired transfer to the circulation.
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Affiliation(s)
- Ling Chen
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, and Chongqing Eye Institute, Chongqing, China
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Jeffrey D. Messinger
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Deepayan Kar
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Jacque L. Duncan
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States
| | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
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Grillo SL, Etzel JD, Weber SR, Ondeck C, Wang W, Zhao Y, Barber AJ, Sundstrom JM. Descriptive analysis of Fibulin-3 and the extracellular vesicle marker, Alix, in drusen from a small cohort of postmortem human eyes. Exp Eye Res 2020; 203:108422. [PMID: 33387484 DOI: 10.1016/j.exer.2020.108422] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 12/04/2020] [Accepted: 12/21/2020] [Indexed: 01/08/2023]
Abstract
Fibulin-3 (Fib3) is a secreted glycoprotein that is expressed in the retina and has been associated with drusen formation in age-related macular degeneration (AMD). The purpose of this study was to assess whether Fib3 is associated with extracellular vesicles (EVs) in drusen from non-diseased and AMD human donors. De-identified sections of human eyes were received from the National Disease Research Institute (NDRI, Philadelphia). Donor eyes were either non-diseased (no known ocular pathology) or had been diagnosed with AMD. Retinal cryostat sections were labeled with primary antibodies targeted to Fib3, Apolipoprotein E (ApoE; a drusen marker), and ALG-2 interacting protein X (Alix, an EV marker) for confocal imaging (Leica TCS SP8). Fib3-positive (Fib3+) puncta were detected on the apical region of the RPE layer and within large AMD drusen. Alix-positive (Alix+) puncta were also detected in a single AMD druse, where a number were Fib3+ and the remaining were Fib3-negative. Similarly, there were Fib3+ puncta that were Alix-negative. Fib3 and Alix also showed a degree of colocalization in the photoreceptor outer segments of the neural retina. Our data suggest that the Alix+ puncta are EV-rich populations that accumulate, together with Fib3, within the drusen matrix during AMD. The EV population is likely heterogeneous, such that there are sub-populations with different cargo content.
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Affiliation(s)
- Stephanie L Grillo
- Department of Ophthalmology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
| | - Justin D Etzel
- Department of Ophthalmology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
| | - Sarah R Weber
- Department of Ophthalmology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
| | - Cassandra Ondeck
- Department of Ophthalmology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
| | - Weiwei Wang
- Department of Ophthalmology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
| | - Yuanjun Zhao
- Department of Ophthalmology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
| | - Alistair J Barber
- Department of Ophthalmology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
| | - Jeffrey M Sundstrom
- Department of Ophthalmology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
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Fibulin-3 knockout mice demonstrate corneal dysfunction but maintain normal retinal integrity. J Mol Med (Berl) 2020; 98:1639-1656. [PMID: 32964303 DOI: 10.1007/s00109-020-01974-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/16/2020] [Accepted: 09/01/2020] [Indexed: 12/17/2022]
Abstract
Fibulin-3 (F3) is an extracellular matrix glycoprotein found in basement membranes across the body. An autosomal dominant R345W mutation in F3 causes a macular dystrophy resembling dry age-related macular degeneration (AMD), whereas genetic removal of wild-type (WT) F3 protects mice from sub-retinal pigment epithelium (RPE) deposit formation. These observations suggest that F3 is a protein which can regulate pathogenic sub-RPE deposit formation in the eye. Yet the precise role of WT F3 within the eye is still largely unknown. We found that F3 is expressed throughout the mouse eye (cornea, trabecular meshwork (TM) ring, neural retina, RPE/choroid, and optic nerve). We next performed a thorough structural and functional characterization of each of these tissues in WT and homozygous (F3-/-) knockout mice. The corneal stroma in F3-/- mice progressively thins beginning at 2 months, and the development of corneal opacity and vascularization starts at 9 months, which worsens with age. However, in all other tissues (TM, neural retina, RPE, and optic nerve), gross structural anatomy and functionality were similar across WT and F3-/- mice when evaluated using SD-OCT, histological analyses, electron microscopy, scotopic electroretinogram, optokinetic response, and axonal anterograde transport. The lack of noticeable retinal abnormalities in F3-/- mice was confirmed in a human patient with biallelic loss-of-function mutations in F3. These data suggest that (i) F3 is important for maintaining the structural integrity of the cornea, (ii) absence of F3 does not affect the structure or function of any other ocular tissue in which it is expressed, and (iii) targeted silencing of F3 in the retina and/or RPE will likely be well-tolerated, serving as a safe therapeutic strategy for reducing sub-RPE deposit formation in disease. KEY MESSAGES: • Fibulins are expressed throughout the body at varying levels. • Fibulin-3 has a tissue-specific pattern of expression within the eye. • Lack of fibulin-3 leads to structural deformities in the cornea. • The retina and RPE remain structurally and functionally healthy in the absence of fibulin-3 in both mice and humans.
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25
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Bizzari S, El-Bazzal L, Nair P, Younan A, Stora S, Mehawej C, El-Hayek S, Delague V, Mégarbané A. Recessive marfanoid syndrome with herniation associated with a homozygous mutation in Fibulin-3. Eur J Med Genet 2020; 63:103869. [PMID: 32006683 DOI: 10.1016/j.ejmg.2020.103869] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 01/26/2020] [Accepted: 01/27/2020] [Indexed: 01/10/2023]
Abstract
We have previously reported on a consanguineous family where 2 siblings, a girl and a boy, presented with tall stature, long and triangular faces, prominent forehead, telecanthus, ptosis, everted lower eyelids, downslanting palpebral fissures, large ears, high arched palate, long arm span, arachnodactyly, advanced bone age, joint laxity, pectus excavatum, inguinal hernia, and myopia, suggestive of a new subtype of connective tissue disorder (Megarbane et al. AJMG, 2012; 158(A)5: 1185-1189). On clinical follow-up, both patients had multiple inguinal, crural, and abdominal herniae, intestinal occlusions, several huge diverticula throughout the gut and the bladder, and rectal prolapse. In addition, the girl had a mild hearing impairment, and the boy a left diaphragmatic hernia. Here we describe the molecular characterization of this disorder using Whole Exome Sequencing, revealing, in both siblings, a novel homozygous missense variant in the EFEMP1 gene, c.163T > C; p.(Cys55Arg) whose homozygous by descent, autosomal recessive transmission was confirmed through segregation analysis by Sanger sequencing. In addition, the girl exhibited a homozygous mutation in the MYO3A gene, c.1370_1371delGA; p.(Arg457Asnfs*25), associated with non-syndromic deafness. The siblings were also found to harbor a homozygous nonsense variant in the VCPKMT gene. We review the literature and discuss our updated clinical and molecular findings that suggest EFEMP1 to be the probable candidate gene implicated in this novel connective tissue disease.
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Affiliation(s)
- Sami Bizzari
- Centre for Arab Genomic Studies, Dubai, United Arab Emirates
| | - Lara El-Bazzal
- Aix Marseille Univ, Inserm, MMG, U 1251, Marseille, France
| | - Pratibha Nair
- Centre for Arab Genomic Studies, Dubai, United Arab Emirates
| | | | | | | | | | | | - André Mégarbané
- Institut Jérôme Lejeune, CRB BioJeL, Paris, France; INOVIE-MENA, Beirut, Lebanon.
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Rahman N, Georgiou M, Khan KN, Michaelides M. Macular dystrophies: clinical and imaging features, molecular genetics and therapeutic options. Br J Ophthalmol 2019; 104:451-460. [PMID: 31704701 PMCID: PMC7147237 DOI: 10.1136/bjophthalmol-2019-315086] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/24/2019] [Accepted: 10/21/2019] [Indexed: 11/03/2022]
Abstract
Macular dystrophies (MDs) consist of a heterogeneous group of disorders that are characterised by bilateral symmetrical central visual loss. Advances in genetic testing over the last decade have led to improved knowledge of the underlying molecular basis. The developments in high-resolution multimodal retinal imaging have also transformed our ability to make accurate and more timely diagnoses and more sensitive quantitative assessment of disease progression, and allowed the design of optimised clinical trial endpoints for novel therapeutic interventions. The aim of this review was to provide an update on MDs, including Stargardt disease, Best disease, X-linked r etinoschisis, pattern dystrophy, Sorsby fundus dystrophy and autosomal dominant drusen. It highlights the range of innovations in retinal imaging, genotype-phenotype and structure-function associations, animal models of disease and the multiple treatment strategies that are currently in clinical trial or planned in the near future, which are anticipated to lead to significant changes in the management of patients with MDs.
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Affiliation(s)
| | - Michalis Georgiou
- Moorfields Eye Hospital, London, UK.,Institute of Ophthalmology, UCL, London, UK
| | - Kamron N Khan
- Ophthalmology Department, St James's University Hospital, Leeds, UK
| | - Michel Michaelides
- Moorfields Eye Hospital, London, UK .,Institute of Ophthalmology, UCL, London, UK
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Genetic LAMP2 deficiency accelerates the age-associated formation of basal laminar deposits in the retina. Proc Natl Acad Sci U S A 2019; 116:23724-23734. [PMID: 31699817 PMCID: PMC6876195 DOI: 10.1073/pnas.1906643116] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Extracellular tissue debris accumulates with aging and in the most prevalent central-vision-threatening eye disorder, age-related macular degeneration (AMD). In this work, we discovered that lysosome-associated membrane protein-2 (LAMP2), a glycoprotein that plays a critical role in lysosomal biogenesis and maturation of autophagosomes/phagosomes, is preferentially expressed in the outermost, neuroepithelial layer of the retina, the retinal pigment epithelium (RPE), and contributes to the prevention of ultrastructural changes in extracellular basolaminar deposits including lipids and apolipoproteins. LAMP2 thus appears to play an important role in RPE biology, and its apparent decrease with aging and in AMD specimens suggests that its deficiency may accelerate the basolaminar deposit formation and RPE dysfunction seen in these conditions. The early stages of age-related macular degeneration (AMD) are characterized by the accumulation of basal laminar deposits (BLamDs). The mechanism for BLamDs accumulating between the retinal pigment epithelium (RPE) and its basal lamina remains elusive. Here we examined the role in AMD of lysosome-associated membrane protein-2 (LAMP2), a glycoprotein that plays a critical role in lysosomal biogenesis and maturation of autophagosomes/phagosomes. LAMP2 was preferentially expressed by RPE cells, and its expression declined with age. Deletion of the Lamp2 gene in mice resulted in age-dependent autofluorescence abnormalities of the fundus, thickening of Bruch’s membrane, and the formation of BLamDs, resembling histopathological changes occurring in AMD. Moreover, LAMP2-deficient mice developed molecular signatures similar to those found in human AMD—namely, the accumulation of APOE, APOA1, clusterin, and vitronectin—adjacent to BLamDs. In contrast, collagen 4, laminin, and fibronectin, which are extracellular matrix proteins constituting RPE basal lamina and Bruch’s membrane were reduced in Lamp2 knockout (KO) mice. Mechanistically, retarded phagocytic degradation of photoreceptor outer segments compromised lysosomal degradation and increased exocytosis in LAMP2-deficient RPE cells. The accumulation of BLamDs observed in LAMP2-deficient mice was eventually followed by loss of the RPE and photoreceptors. Finally, we observed loss of LAMP2 expression along with ultramicroscopic features of abnormal phagocytosis and exocytosis in eyes from AMD patients but not from control individuals. Taken together, these results indicate an important role for LAMP2 in RPE function in health and disease, suggesting that LAMP2 reduction may contribute to the formation of BLamDs in AMD.
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Milenkovic A, Schmied D, Tanimoto N, Seeliger MW, Sparrow JR, Weber BHF. The Y227N mutation affects bestrophin-1 protein stability and impairs sperm function in a mouse model of Best vitelliform macular dystrophy. Biol Open 2019; 8:bio.041335. [PMID: 31201163 PMCID: PMC6679414 DOI: 10.1242/bio.041335] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Human bestrophin-1 (BEST1) is an integral membrane protein known to function as a Ca2+-activated and volume-regulated chloride channel. The majority of disease-associated mutations in BEST1 constitute missense mutations and were shown in vitro to lead to a reduction in mutant protein half-life causing Best disease (BD), a rare autosomal dominant macular dystrophy. To further delineate BEST1-associated pathology in vivo and to provide an animal model useful to explore experimental treatment efficacies, we have generated a knock-in mouse line (Best1Y227N). Heterozygous and homozygous mutants revealed no significant ocular abnormalities up to 2 years of age. In contrast, knock-in animals demonstrated a severe phenotype in the male reproductive tract. In heterozygous Best1Y227N males, Best1 protein was significantly reduced in testis and almost absent in homozygous mutant mice, although mRNA transcription of wild-type and knock-in allele is present and similar in quantity. Degradation of mutant Best1 protein in testis was associated with adverse effects on sperm motility and the capability to fertilize eggs. Based on these results, we conclude that mice carrying the Best1 Y227N mutation reveal a reproducible pathologic phenotype and thus provide a valuable in vivo tool to evaluate efficacy of drug therapies aimed at restoring Best1 protein stability and function.
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Affiliation(s)
- Andrea Milenkovic
- Institute of Human Genetics, University of Regensburg, 93053 Regensburg, Germany
| | - Denise Schmied
- Institute of Human Genetics, University of Regensburg, 93053 Regensburg, Germany
| | - Naoyuki Tanimoto
- Division of Ocular Neurodegeneration, Centre for Ophthalmology, Institute for Ophthalmic Research, 72076 Tübingen, Germany.,Department of Ophthalmology, University of Kiel, 24105 Kiel, Germany
| | - Mathias W Seeliger
- Division of Ocular Neurodegeneration, Centre for Ophthalmology, Institute for Ophthalmic Research, 72076 Tübingen, Germany
| | - Janet R Sparrow
- Department of Ophthalmology, Harkness Eye Institute, Columbia University Medical Center, 10032 New York, USA
| | - Bernhard H F Weber
- Institute of Human Genetics, University of Regensburg, 93053 Regensburg, Germany
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29
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Yam M, Engel AL, Wang Y, Zhu S, Hauer A, Zhang R, Lohner D, Huang J, Dinterman M, Zhao C, Chao JR, Du J. Proline mediates metabolic communication between retinal pigment epithelial cells and the retina. J Biol Chem 2019; 294:10278-10289. [PMID: 31110046 PMCID: PMC6664195 DOI: 10.1074/jbc.ra119.007983] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/16/2019] [Indexed: 01/16/2023] Open
Abstract
The retinal pigment epithelium (RPE) is a monolayer of pigmented cells between the choroid and the retina. RPE dysfunction underlies many retinal degenerative diseases, including age-related macular degeneration, the leading cause of age-related blindness. To perform its various functions in nutrient transport, phagocytosis of the outer segment, and cytokine secretion, the RPE relies on an active energy metabolism. We previously reported that human RPE cells prefer proline as a nutrient and transport proline-derived metabolites to the apical, or retinal, side. In this study, we investigated how RPE utilizes proline in vivo and why proline is a preferred substrate. By using [13C]proline labeling both ex vivo and in vivo, we found that the retina rarely uses proline directly, whereas the RPE utilizes it at a high rate, exporting proline-derived mitochondrial intermediates for use by the retina. We observed that in primary human RPE cell culture, proline is the only amino acid whose uptake increases with cellular maturity. In human RPE, proline was sufficient to stimulate de novo serine synthesis, increase reductive carboxylation, and protect against oxidative damage. Blocking proline catabolism in RPE impaired glucose metabolism and GSH production. Notably, in an acute model of RPE-induced retinal degeneration, dietary proline improved visual function. In conclusion, proline is an important nutrient that supports RPE metabolism and the metabolic demand of the retina.
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Affiliation(s)
- Michelle Yam
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Abbi L Engel
- the Department of Ophthalmology, University of Washington, Seattle, Washington 98109
| | - Yekai Wang
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Siyan Zhu
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Allison Hauer
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Rui Zhang
- From the Departments of Ophthalmology and
- the Save Sight Institute, University of Sydney, 8 Macquarie Street, Sydney, New South Wales 2000, Australia
| | - Daniel Lohner
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Jiancheng Huang
- From the Departments of Ophthalmology and
- the Eye Institute, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China, and
- the Department of Ophthalmology, State Key Laboratory of Reproductive Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Marlee Dinterman
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Chen Zhao
- the Eye Institute, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China, and
| | - Jennifer R Chao
- the Department of Ophthalmology, University of Washington, Seattle, Washington 98109,
| | - Jianhai Du
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
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30
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Song D, Mohammed I, Bhuyan R, Miwa T, Williams AL, Gullipalli D, Sato S, Song Y, Dunaief JL, Song WC. Retinal Basal Laminar Deposits in Complement fH/fP Mouse Model of Dense Deposit Disease. Invest Ophthalmol Vis Sci 2019; 59:3405-3415. [PMID: 30025090 PMCID: PMC6040236 DOI: 10.1167/iovs.18-24133] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Purpose Dense deposit disease (DDD) is caused by dysregulation of the alternative pathway of the complement cascade and characterized by electron-dense deposits in the kidney glomerular basement membrane (GBM) and drusen in Bruch's membrane (BrM). Complement factor H (fH) and factor properdin (fP) regulate complement activation; fH inhibits alternative pathway (AP) activation, whereas fP promotes it. We report pathologic changes in eyes of an fH and fP double-mutant mouse, which we previously showed have dense deposits in the GBM and early mortality from nephropathy. Methods fHm/m, fP−/−, and fHm/m/fP−/− mice were generated on a C57BL/6–129J background. Fundus imaging at 8 weeks of age was followed by analysis via light and electron microscopy. Retinal function was assessed by electroretinography (ERG). Complement levels and localization were tested by immunohistochemistry and ELISA. Retinas of fHm/m/fP−/− mice treated with intraperitoneal injections of an anti-C5 antibody were compared to those of age- and genotype-matched mice injected with an isotype control antibody. Results fHm/m/fP−/− mice suffered early-onset retinal hypopigmented spots detected using in vivo retinal photography, and histologic examination showed basal laminar deposits (BLamD), degeneration of the photoreceptors, and RPE vacuolization. ERG showed diminished retinal function. The anti-C5 antibody was retina-protective. Conclusions This unique mouse represents a new model of complement-mediated rapid-onset DDD, and could be useful in exploring the pathologic changes associated with BLamD in age-related macular degeneration.
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Affiliation(s)
- Delu Song
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Imran Mohammed
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Rupak Bhuyan
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Takashi Miwa
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Allison Lesher Williams
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Damodar Gullipalli
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Sayaka Sato
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Ying Song
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Joshua L Dunaief
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Wen-Chao Song
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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31
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Dalvi S, Galloway CA, Singh R. Pluripotent Stem Cells to Model Degenerative Retinal Diseases: The RPE Perspective. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1186:1-31. [PMID: 31654384 DOI: 10.1007/978-3-030-28471-8_1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Pluripotent stem cell technology, including human-induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs), has provided a suitable platform to investigate molecular and pathological alterations in an individual cell type using patient's own cells. Importantly, hiPSCs/hESCs are amenable to genome editing providing unique access to isogenic controls. Specifically, the ability to introduce disease-causing mutations in control (unaffected) and conversely correct disease-causing mutations in patient-derived hiPSCs has provided a powerful approach to clearly link the disease phenotype with a specific gene mutation. In fact, utilizing hiPSC/hESC and CRISPR technology has provided significant insight into the pathomechanism of several diseases. With regard to the eye, the use of hiPSCs/hESCs to study human retinal diseases is especially relevant to retinal pigment epithelium (RPE)-based disorders. This is because several studies have now consistently shown that hiPSC-RPE in culture displays key physical, gene expression and functional attributes of human RPE in vivo. In this book chapter, we will discuss the current utility, limitations, and plausible future approaches of pluripotent stem cell technology for the study of retinal degenerative diseases. Of note, although we will broadly summarize the significant advances made in modeling and studying several retinal diseases utilizing hiPSCs/hESCs, our specific focus will be on the utility of patient-derived hiPSCs for (1) establishment of human cell models and (2) molecular and pharmacological studies on patient-derived cell models of retinal degenerative diseases where RPE cellular defects play a major pathogenic role in disease development and progression.
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Affiliation(s)
- Sonal Dalvi
- Department of Ophthalmology, Flaum Eye Institute, University of Rochester, Rochester, NY, USA.,Department of Biomedical Genetics, University of Rochester, Rochester, NY, USA
| | - Chad A Galloway
- Department of Ophthalmology, Flaum Eye Institute, University of Rochester, Rochester, NY, USA.,Department of Biomedical Genetics, University of Rochester, Rochester, NY, USA
| | - Ruchira Singh
- Department of Ophthalmology, Flaum Eye Institute, University of Rochester, Rochester, NY, USA. .,Department of Biomedical Genetics, University of Rochester, Rochester, NY, USA. .,UR Stem Cell and Regenerative Medicine Institute, Rochester, NY, USA. .,Center for Visual Science, University of Rochester, Rochester, NY, USA.
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Curcio CA. Soft Drusen in Age-Related Macular Degeneration: Biology and Targeting Via the Oil Spill Strategies. Invest Ophthalmol Vis Sci 2018; 59:AMD160-AMD181. [PMID: 30357336 PMCID: PMC6733535 DOI: 10.1167/iovs.18-24882] [Citation(s) in RCA: 173] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
AMD is a major cause of legal blindness in older adults approachable through multidisciplinary research involving human tissues and patients. AMD is a vascular-metabolic-inflammatory disease, in which two sets of extracellular deposits, soft drusen/basal linear deposit (BLinD) and subretinal drusenoid deposit (SDD), confer risk for end-stages of atrophy and neovascularization. Understanding how deposits form can lead to insights for new preventions and therapy. The topographic correspondence of BLinD and SDD with cones and rods, respectively, suggest newly realized exchange pathways among outer retinal cells and across Bruch's membrane and the subretinal space, in service of highly evolved, eye-specific physiology. This review focuses on soft drusen/BLinD, summarizing evidence that a major ultrastructural component is large apolipoprotein B,E-containing, cholesterol-rich lipoproteins secreted by the retinal pigment epithelium (RPE) that offload unneeded lipids of dietary and outer segment origin to create an atherosclerosis-like progression in the subRPE-basal lamina space. Clinical observations and an RPE cell culture system combine to suggest that soft drusen/BLinD form when secretions of functional RPE back up in the subRPE-basal lamina space by impaired egress across aged Bruch's membrane-choriocapillary endothelium. The soft drusen lifecycle includes growth, anterior migration of RPE atop drusen, then collapse, and atrophy. Proof-of-concept studies in humans and animal models suggest that targeting the “Oil Spill in Bruch's membrane” offers promise of treating a process in early AMD that underlies progression to both end-stages. A companion article addresses the antecedents of soft drusen within the biology of the macula.
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Affiliation(s)
- Christine A Curcio
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
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33
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Roles of short fibulins, a family of matricellular proteins, in lung matrix assembly and disease. Matrix Biol 2018; 73:21-33. [DOI: 10.1016/j.matbio.2018.02.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/26/2017] [Accepted: 02/01/2018] [Indexed: 12/19/2022]
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34
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Lin MK, Yang J, Hsu CW, Gore A, Bassuk AG, Brown LM, Colligan R, Sengillo JD, Mahajan VB, Tsang SH. HTRA1, an age-related macular degeneration protease, processes extracellular matrix proteins EFEMP1 and TSP1. Aging Cell 2018; 17:e12710. [PMID: 29730901 PMCID: PMC6052470 DOI: 10.1111/acel.12710] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2017] [Indexed: 01/12/2023] Open
Abstract
High-temperature requirement protein A1 (HTRA1) is a serine protease secreted by a number of tissues including retinal pigment epithelium (RPE). A promoter variant of the gene encoding HTRA1 is part of a mutant allele that causes increased HTRA1 expression and contributed to age-related macular degeneration (AMD) in genomewide association studies. AMD is characterized by pathological development of drusen, extracellular deposits of proteins and lipids on the basal side of RPE. The molecular pathogenesis of AMD is not well understood, and understanding dysregulation of the extracellular matrix may be key. We assess the high-risk genotype at 10q26 by proteomic comparison of protein levels of RPE cells with and without the mutation. We show HTRA1 protein level is increased in high-risk RPE cells along with several extracellular matrix proteins, including known HTRA1 cleavage targets LTBP-1 and clusterin. In addition, two novel targets of HTRA1 have been identified: EFEMP1, an extracellular matrix protein mutated in Doyne honeycomb retinal dystrophy, a genetic eye disease similar to AMD, and thrombospondin 1 (TSP1), an inhibitor of angiogenesis. Our data support the role of RPE extracellular deposition with potential effects in compromised barrier to neovascularization in exudative AMD.
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Affiliation(s)
- Michael K. Lin
- College of Physicians & SurgeonsColumbia UniversityNew YorkNYUSA
- Edward S. Harkness Eye InstituteNew York‐Presbyterian HospitalNew YorkNYUSA
- Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma LaboratoryColumbia Stem Cell InitiativeDepartments of Ophthalmology, Pathology & Cell BiologyInstitute of Human NutritionHerbert Irving Comprehensive Cancer CenterColumbia UniversityNew YorkNYUSA
| | - Jin Yang
- Edward S. Harkness Eye InstituteNew York‐Presbyterian HospitalNew YorkNYUSA
- Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma LaboratoryColumbia Stem Cell InitiativeDepartments of Ophthalmology, Pathology & Cell BiologyInstitute of Human NutritionHerbert Irving Comprehensive Cancer CenterColumbia UniversityNew YorkNYUSA
- Tianjin Medical University Eye HospitalTianjinChina
| | - Chun Wei Hsu
- Edward S. Harkness Eye InstituteNew York‐Presbyterian HospitalNew YorkNYUSA
- Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma LaboratoryColumbia Stem Cell InitiativeDepartments of Ophthalmology, Pathology & Cell BiologyInstitute of Human NutritionHerbert Irving Comprehensive Cancer CenterColumbia UniversityNew YorkNYUSA
| | - Anuradha Gore
- Omics LaboratoryDepartment of OphthalmologyByers Eye InstituteStanford UniversityPalo AltoCAUSA
| | | | - Lewis M. Brown
- Quantitative Proteomics and Metabolomics CenterDepartment of Biological SciencesColumbia UniversityNew YorkNYUSA
| | - Ryan Colligan
- Quantitative Proteomics and Metabolomics CenterDepartment of Biological SciencesColumbia UniversityNew YorkNYUSA
| | - Jesse D. Sengillo
- Edward S. Harkness Eye InstituteNew York‐Presbyterian HospitalNew YorkNYUSA
- Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma LaboratoryColumbia Stem Cell InitiativeDepartments of Ophthalmology, Pathology & Cell BiologyInstitute of Human NutritionHerbert Irving Comprehensive Cancer CenterColumbia UniversityNew YorkNYUSA
| | - Vinit B. Mahajan
- Omics LaboratoryDepartment of OphthalmologyByers Eye InstituteStanford UniversityPalo AltoCAUSA
- Palo Alto Veterans AdministrationPalo AltoCAUSA
| | - Stephen H. Tsang
- Edward S. Harkness Eye InstituteNew York‐Presbyterian HospitalNew YorkNYUSA
- Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma LaboratoryColumbia Stem Cell InitiativeDepartments of Ophthalmology, Pathology & Cell BiologyInstitute of Human NutritionHerbert Irving Comprehensive Cancer CenterColumbia UniversityNew YorkNYUSA
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35
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Velez G, Tsang SH, Tsai YT, Hsu CW, Gore A, Abdelhakim AH, Mahajan M, Silverman RH, Sparrow JR, Bassuk AG, Mahajan VB. Gene Therapy Restores Mfrp and Corrects Axial Eye Length. Sci Rep 2017; 7:16151. [PMID: 29170418 PMCID: PMC5701072 DOI: 10.1038/s41598-017-16275-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 11/09/2017] [Indexed: 01/07/2023] Open
Abstract
Hyperopia (farsightedness) is a common and significant cause of visual impairment, and extreme hyperopia (nanophthalmos) is a consequence of loss-of-function MFRP mutations. MFRP deficiency causes abnormal eye growth along the visual axis and significant visual comorbidities, such as angle closure glaucoma, cystic macular edema, and exudative retinal detachment. The Mfrp rd6 /Mfrp rd6 mouse is used as a pre-clinical animal model of retinal degeneration, and we found it was also hyperopic. To test the effect of restoring Mfrp expression, we delivered a wild-type Mfrp to the retinal pigmented epithelium (RPE) of Mfrp rd6 /Mfrp rd6 mice via adeno-associated viral (AAV) gene therapy. Phenotypic rescue was evaluated using non-invasive, human clinical testing, including fundus auto-fluorescence, optical coherence tomography, electroretinography, and ultrasound. These analyses showed gene therapy restored retinal function and normalized axial length. Proteomic analysis of RPE tissue revealed rescue of specific proteins associated with eye growth and normal retinal and RPE function. The favorable response to gene therapy in Mfrp rd6 /Mfrp rd6 mice suggests hyperopia and associated refractive errors may be amenable to AAV gene therapy.
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Affiliation(s)
- Gabriel Velez
- Omics Laboratory, Stanford University, Palo Alto, CA, USA
- Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, CA, USA
- Medical Scientist Training Program, University of Iowa, Iowa City, IA, USA
| | - Stephen H Tsang
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia University, New York, NY, USA.
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA.
| | - Yi-Ting Tsai
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia University, New York, NY, USA
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Chun-Wei Hsu
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia University, New York, NY, USA
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Anuradha Gore
- Omics Laboratory, Stanford University, Palo Alto, CA, USA
| | - Aliaa H Abdelhakim
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia University, New York, NY, USA
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | | | - Ronald H Silverman
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia University, New York, NY, USA
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Janet R Sparrow
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia University, New York, NY, USA
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Alexander G Bassuk
- Department of Pediatrics, University of Iowa, Iowa City, IA, USA.
- Department of Neurology, University of Iowa, Iowa City, IA, USA.
- Palo Alto Veterans Administration, Palo Alto, CA, USA.
| | - Vinit B Mahajan
- Omics Laboratory, Stanford University, Palo Alto, CA, USA.
- Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, CA, USA.
- Department of Neurology, University of Iowa, Iowa City, IA, USA.
- Palo Alto Veterans Administration, Palo Alto, CA, USA.
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Abstract
Age-related macular degeneration (AMD) and related macular dystrophies (MDs) are a major cause of vision loss. However, the mechanisms underlying their progression remain ill-defined. This is partly due to the lack of disease models recapitulating the human pathology. Furthermore, in vivo studies have yielded limited understanding of the role of specific cell types in the eye vs. systemic influences (e.g., serum) on the disease pathology. Here, we use human induced pluripotent stem cell-retinal pigment epithelium (hiPSC-RPE) derived from patients with three dominant MDs, Sorsby's fundus dystrophy (SFD), Doyne honeycomb retinal dystrophy/malattia Leventinese (DHRD), and autosomal dominant radial drusen (ADRD), and demonstrate that dysfunction of RPE cells alone is sufficient for the initiation of sub-RPE lipoproteinaceous deposit (drusen) formation and extracellular matrix (ECM) alteration in these diseases. Consistent with clinical studies, sub-RPE basal deposits were present beneath both control (unaffected) and patient hiPSC-RPE cells. Importantly basal deposits in patient hiPSC-RPE cultures were more abundant and displayed a lipid- and protein-rich "drusen-like" composition. Furthermore, increased accumulation of COL4 was observed in ECM isolated from control vs. patient hiPSC-RPE cultures. Interestingly, RPE-specific up-regulation in the expression of several complement genes was also seen in patient hiPSC-RPE cultures of all three MDs (SFD, DHRD, and ADRD). Finally, although serum exposure was not necessary for drusen formation, COL4 accumulation in ECM, and complement pathway gene alteration, it impacted the composition of drusen-like deposits in patient hiPSC-RPE cultures. Together, the drusen model(s) of MDs described here provide fundamental insights into the unique biology of maculopathies affecting the RPE-ECM interface.
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Zayas-Santiago A, Cross SD, Stanton JB, Marmorstein AD, Marmorstein LY. Mutant Fibulin-3 Causes Proteoglycan Accumulation and Impaired Diffusion Across Bruch's Membrane. Invest Ophthalmol Vis Sci 2017. [PMID: 28622396 PMCID: PMC5477800 DOI: 10.1167/iovs.17-21720] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Purpose The mutation R345W in EFEMP1 (fibulin-3) causes macular degeneration. This study sought to determine whether proteoglycan content and diffusion across Bruch's membrane are altered in Efemp1ki/ki mice carrying this mutation or in Efemp1−/− mice. Methods Proteoglycans in mouse Bruch's membranes were stained with Cupromeronic Blue (CB). Heparan sulfated proteoglycan (HSPG) and chondroitin/dermatan sulfate proteoglycan (C/DSPG) distributions were visualized following treatments with chondroitinase ABC (C-ABC) or nitrous acid. Total sulfated glycosaminoglycans (sGAGs) in Bruch's membrane/choroid (BrM/Ch) were measured with dimethylmethylene blue (DMMB). Matrix metalloprotease (MMP)-2, MMP-9, and tissue inhibitor of metalloproteinase (TIMP)-3 were examined by immunofluorescence and quantified using Image J. Molecules with different Stokes radius (Rs) were allowed simultaneously to diffuse through mouse BrM/Ch mounted in a modified Ussing chamber. Samples were quantified using gel exclusion chromatography. Results HSPGs and C/DSPGs were markedly increased in Efemp1ki/ki Bruch's membrane, and MMP-2 and MMP-9 were decreased, but TIMP-3 was increased. Diffusion across Efemp1ki/ki Bruch's membrane was impaired. In contrast, the proteoglycan amount in Efemp1−/− Bruch's membrane was not significantly different, but the size of proteoglycans was much larger. MMP-2, MMP-3, and TIMP-3 levels were similar to that of Efemp1+/+ mice, but they were localized diffusely in retinal pigment epithelium (RPE) cells instead of Bruch's membrane. Diffusion across Efemp1−/− Bruch's membrane was enhanced. Conclusions Mutant fibulin-3 causes proteoglycan accumulation, reduction of MMP-2 and MMP-9, but increase of TIMP-3, and impairs diffusion across Bruch's membrane. Fibulin-3 ablation results in altered sizes of proteoglycans, altered distributions of MMP-2, MMP-9, and TIMP-3, and enhances diffusion across Bruch's membrane.
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Affiliation(s)
- Astrid Zayas-Santiago
- Department of Pathology & Laboratory Medicine, Universidad Central del Caribe, Bayamón, Puerto Rico
| | - Samuel D Cross
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - James B Stanton
- Department of Ophthalmology & Vision Science, University of Arizona, Tucson, Arizona, United States
| | - Alan D Marmorstein
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - Lihua Y Marmorstein
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
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Stanton JB, Marmorstein AD, Zhang Y, Marmorstein LY. Deletion of Efemp1 Is Protective Against the Development of Sub-RPE Deposits in Mouse Eyes. Invest Ophthalmol Vis Sci 2017; 58:1455-1461. [PMID: 28264101 PMCID: PMC5361459 DOI: 10.1167/iovs.16-20955] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Purpose EFEMP1 (fibulin-3) is mutated in Malattia Leventinese/Doyne's honeycomb retinal dystrophy (ML/DHRD), an inherited macular dystrophy similar to AMD. Both ML/DHRD and AMD are characterized by the presence of sub-RPE deposits. Efemp1 knockout mice do not develop sub-RPE deposits. This study was to test whether sub-RPE deposits can be induced in Efemp1 knockout mice by experimentally applied stress conditions that cause wild-type mice to develop sub-RPE deposits. Methods Efemp1 knockout and control mice at 6, 18, or 24 months old were fed with a synthetic high-fat diet (HFD). Beginning 1 month after starting the HFD, one group of mice was exposed to cigarette smoke daily for 1 month, and another group of mice was subjected to photochemical injury every other day for 2 weeks from a 488-nm argon laser. After the treatments, histologic analysis was performed to assess whether sub-RPE deposits were induced. Results Basal laminar deposits (BLamDs), a form of sub-RPE deposits, were observed in the 18- and 24-month-old wild-type mice but not in Efemp1 knockout mice in any age groups after exposure to HFD and cigarette smoke or laser injury. Conclusions Mice lacking fibulin-3 do not develop sub-RPE deposits. Environmental oxidative stressors (HFD/cigarette smoke or HFD/laser) known to cause BLamD formation in wild-type mice failed to induce BLamD formation in Efemp1 knockout mice. These results suggest that fibulin-3 is a central player in the development of BLamD, and deletion of fibulin-3 is protective against the development of BLamD.
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Affiliation(s)
- James B Stanton
- Department of Ophthalmology & Vision Science, University of Arizona, Tucson, Arizona, United States
| | - Alan D Marmorstein
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - Youwen Zhang
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - Lihua Y Marmorstein
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
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Vessey KA, Gu BJ, Jobling AI, Phipps JA, Greferath U, Tran MX, Dixon MA, Baird PN, Guymer RH, Wiley JS, Fletcher EL. Loss of Function of P2X7 Receptor Scavenger Activity in Aging Mice: A Novel Model for Investigating the Early Pathogenesis of Age-Related Macular Degeneration. THE AMERICAN JOURNAL OF PATHOLOGY 2017. [PMID: 28628761 DOI: 10.1016/j.ajpath.2017.04.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Age-related macular degeneration (AMD) is a leading cause of irreversible, severe vision loss in Western countries. Recently, we identified a novel pathway involving P2X7 receptor scavenger function expressed on ocular immune cells as a risk factor for advanced AMD. In this study, we investigate the effect of loss of P2X7 receptor function on retinal structure and function during aging. P2X7-null and wild-type C57bl6J mice were investigated at 4, 12, and 18 months of age for macrophage phagocytosis activity, ocular histological changes, and retinal function. Phagocytosis activity of blood-borne macrophages decreased with age at 18 months in the wild-type mouse. Lack of P2X7 receptor function reduced phagocytosis at all ages compared to wild-type mice. At 12 months of age, P2X7-null mice had thickening of Bruchs membrane and retinal pigment epithelium dysfunction. By 18 months of age, P2X7-null mice displayed phenotypic characteristics consistent with early AMD, including Bruchs membrane thickening, retinal pigment epithelium cell loss, retinal functional deficits, and signs of subretinal inflammation. Our present study shows that loss of function of the P2X7 receptor in mice induces retinal changes representing characteristics of early AMD, providing a valuable model for investigating the role of scavenger receptor function and the immune system in the development of this age-related disease.
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Affiliation(s)
- Kirstan A Vessey
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria, Australia
| | - Ben J Gu
- Florey Institute of Neuroscience, Melbourne, Victoria, Australia
| | - Andrew I Jobling
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria, Australia
| | - Joanna A Phipps
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria, Australia
| | - Ursula Greferath
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria, Australia
| | - Mai X Tran
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria, Australia
| | - Michael A Dixon
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria, Australia
| | - Paul N Baird
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia; Division of Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia
| | - Robyn H Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia; Division of Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia
| | - James S Wiley
- Florey Institute of Neuroscience, Melbourne, Victoria, Australia
| | - Erica L Fletcher
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria, Australia.
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Bonilha VL, Bell BA, Rayborn ME, Samuels IS, King A, Hollyfield JG, Xie C, Cai H. Absence of DJ-1 causes age-related retinal abnormalities in association with increased oxidative stress. Free Radic Biol Med 2017; 104:226-237. [PMID: 28088625 PMCID: PMC5328840 DOI: 10.1016/j.freeradbiomed.2017.01.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 01/09/2017] [Accepted: 01/10/2017] [Indexed: 01/05/2023]
Abstract
Oxidative stress alters physiological function in most biological tissues and can lead to cell death. In the retina, oxidative stress initiates a cascade of events leading to focal loss of RPE and photoreceptors, which is thought to be a major contributing factor to geographic atrophy. Despite these implications, the molecular regulation of RPE oxidative stress under normal and pathological conditions remains largely unknown. A better understanding of the mechanisms involved in regulating RPE and photoreceptors oxidative stress response is greatly needed. To this end we evaluated photoreceptor and RPE changes in mice deficient in DJ-1, a protein that is thought to be important in protecting cells from oxidative stress. Young (3 months) and aged (18 months) DJ-1 knockout (DJ-1 KO) and age-matched wild-type mice were examined. In both group of aged mice, scanning laser ophthalmoscopy (SLO) showed the presence of a few autofluorescent foci. The 18 month-old DJ-1 KO retinas were also characterized by a noticeable increase in RPE fluorescence to wild-type. Optical coherence tomography (OCT) imaging demonstrated that all retinal layers were present in the eyes of both DJ-1 KO groups. ERG comparisons showed that older DJ-1 KO mice had reduced sensitivity under dark- and light-adapted conditions compared to age-matched control. Histologically, the RPE contained prominent vacuoles in young DJ-1 KO group with the appearance of enlarged irregularly shaped RPE cells in the older group. These were also evident in OCT and in whole mount RPE/choroid preparations labeled with phalloidin. Photoreceptors in the older DJ-1 KO mice displayed decreased immunoreactivity to rhodopsin and localized reduction in cone markers compared to the wild-type control group. Lower levels of activated Nrf2 were evident in retina/RPE lysates in both young and old DJ-1 KO mouse groups compared to wild-type control levels. Conversely, higher levels of protein carbonyl derivatives and iNOS immunoreactivity were detected in retina/RPE lysates from both young and old DJ-1 KO mice. These results demonstrate that DJ-1 KO mice display progressive signs of retinal/RPE degeneration in association with higher levels of oxidative stress markers. Collectively this analysis indicates that DJ-1 plays an important role in protecting photoreceptors and RPE from oxidative damage during aging.
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Affiliation(s)
- Vera L Bonilha
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH 44195, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
| | - Brent A Bell
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Mary E Rayborn
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Ivy S Samuels
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Anna King
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Joe G Hollyfield
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH 44195, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Chengsong Xie
- Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD, USA
| | - Huaibin Cai
- Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD, USA
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Mapping wild-type and R345W fibulin-3 intracellular interactomes. Exp Eye Res 2016; 153:165-169. [PMID: 27777122 DOI: 10.1016/j.exer.2016.10.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 10/17/2016] [Accepted: 10/20/2016] [Indexed: 12/17/2022]
Abstract
Fibulin-3 (F3) is an important, disulfide-rich, extracellular matrix glycoprotein that has been associated with a number of diseases ranging from cancer to retinal degeneration. An Arg345Trp (R345W) mutation in F3 causes the rare, autosomal dominant macular dystrophy, Malattia Leventinese. The purpose of this study was to identify and validate novel intracellular interacting partners of wild-type (WT) and R345W F3 in retinal pigment epithelium cells. We used stable isotope labeling by amino acids in cell culture (SILAC) to generate 'heavy' and 'light' isotopically labeled ARPE-19 cell populations which were subsequently infected with adenovirus encoding for FLAG-tagged WT or R345W F3. After immunoprecipitation, interacting proteins were identified by multidimensional protein identification technology (MudPIT). We identified sixteen new intracellular F3 interacting partners, the vast majority of which are involved in protein folding and/or degradation in the endoplasmic reticulum (ER). Eight of these interactions (ANXA5, ERdj5, PDIA4, P4HB, PDIA6, RCN1, SDF2L1, and TXNDC5) were verified at the western blotting level. These F3 interactome results can serve as the basis for pursuing targeted genetic or pharmacologic approaches in an effort to alter the fate of either WT or mutant F3.
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Abstract
Age-related macular degeneration (AMD), widely prevalent across the globe, is a major stakeholder among adult visual morbidity and blindness, not only in the Western world but also in Asia. Several risk factors have been identified, including critical genetic factors, which were never imagined 2 decades ago. The etiopathogenesis is emerging to demonstrate that immune and complement-related inflammation pathway members chronically exposed to environmental insults could justifiably influence disease morbidity and treatment outcomes. Approximately half a dozen physiological and biochemical cascades are disrupted in the AMD disease genesis, eventually leading to the distortion and disruption of the subretinal space, subretinal pigment epithelium, and Bruch membrane, thus setting off chaos and disorder for signs and symptoms to manifest. Approximately 3 dozen genetic factors have so far been identified, including the recent ones, through powerful genomic technologies and large robust sample sizes. The noteworthy genetic variants (common and rare) are complement factor H, complement factor H-related genes 1 to 5, C3, C9, ARMS2/HTRA1, vascular endothelial growth factor A, vascular endothelial growth factor receptor 2/KDR, and rare variants (show causal link) such as TIMP3, fibrillin, COL4A3, MMP19, and MMP9. Despite the enormous amount of scientific information generated over the years, diagnostic genetic or biomarker tests are still not available for clinicians to understand the natural course of the disease and its management in a patient. However, further research in the field should reduce this gap not only by aiding the clinician but also through the possibilities of clinical intervention with complement pathway-related inhibitors entering preclinical and clinical trials in the near future.
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Lambert NG, ElShelmani H, Singh MK, Mansergh FC, Wride MA, Padilla M, Keegan D, Hogg RE, Ambati BK. Risk factors and biomarkers of age-related macular degeneration. Prog Retin Eye Res 2016; 54:64-102. [PMID: 27156982 DOI: 10.1016/j.preteyeres.2016.04.003] [Citation(s) in RCA: 225] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 04/01/2016] [Accepted: 04/12/2016] [Indexed: 02/03/2023]
Abstract
A biomarker can be a substance or structure measured in body parts, fluids or products that can affect or predict disease incidence. As age-related macular degeneration (AMD) is the leading cause of blindness in the developed world, much research and effort has been invested in the identification of different biomarkers to predict disease incidence, identify at risk individuals, elucidate causative pathophysiological etiologies, guide screening, monitoring and treatment parameters, and predict disease outcomes. To date, a host of genetic, environmental, proteomic, and cellular targets have been identified as both risk factors and potential biomarkers for AMD. Despite this, their use has been confined to research settings and has not yet crossed into the clinical arena. A greater understanding of these factors and their use as potential biomarkers for AMD can guide future research and clinical practice. This article will discuss known risk factors and novel, potential biomarkers of AMD in addition to their application in both academic and clinical settings.
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Affiliation(s)
- Nathan G Lambert
- Ambati Lab, John A. Moran Eye Center, 65 Mario Capecchi Drive, Salt Lake City, UT, USA; Department of Ophthalmology & Visual Sciences, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, USA.
| | - Hanan ElShelmani
- Ocular Development and Neurobiology Research Group, Zoology Department, School of Natural Sciences, University of Dublin, Trinity College, Dublin 2, Ireland.
| | - Malkit K Singh
- Ambati Lab, John A. Moran Eye Center, 65 Mario Capecchi Drive, Salt Lake City, UT, USA; Department of Ophthalmology & Visual Sciences, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, USA.
| | - Fiona C Mansergh
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland.
| | - Michael A Wride
- Ocular Development and Neurobiology Research Group, Zoology Department, School of Natural Sciences, University of Dublin, Trinity College, Dublin 2, Ireland.
| | - Maximilian Padilla
- Ambati Lab, John A. Moran Eye Center, 65 Mario Capecchi Drive, Salt Lake City, UT, USA; Department of Ophthalmology & Visual Sciences, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, USA.
| | - David Keegan
- Mater Misericordia Hospital, Eccles St, Dublin 7, Ireland.
| | - Ruth E Hogg
- Centre for Experimental Medicine, Institute of Clinical Science Block A, Grosvenor Road, Belfast, Co.Antrim, Northern Ireland, UK.
| | - Balamurali K Ambati
- Ambati Lab, John A. Moran Eye Center, 65 Mario Capecchi Drive, Salt Lake City, UT, USA; Department of Ophthalmology & Visual Sciences, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, USA.
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Dinculescu A, Min SH, Dyka FM, Deng WT, Stupay RM, Chiodo V, Smith WC, Hauswirth WW. Pathological Effects of Mutant C1QTNF5 (S163R) Expression in Murine Retinal Pigment Epithelium. Invest Ophthalmol Vis Sci 2016; 56:6971-80. [PMID: 26513502 DOI: 10.1167/iovs.15-17166] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The mutation S163R in complement C1q tumor necrosis factor-related protein-5 (C1QTNF5) causes an autosomal dominant disorder known as late-onset retinal degeneration (L-ORD). In this study, our goal is to evaluate the consequences of mutant S163R C1QTNF5 expression in mouse RPE following its delivery using an adeno-associated viral (AAV) vector. METHODS We generated AAV vectors containing either human wild-type C1QTNF5 or mutant S163R C1QTNF5 driven by an RPE-specific BEST1 promoter, and delivered them subretinally into one eye of adult C57BL/6 mice. Transgene expression was detected by immunohistochemistry. Retinal function was assessed by full-field ERG. Pathological changes were further examined by digital fundus imaging and spectral-domain optical coherence tomography (SD-OCT). RESULTS We show that the AAV-expressed mutant S163R leads to pathological effects similar to some of those found in patients with advanced L-ORD, including RPE thinning, RPE cell loss, and retinal degeneration. In addition, we provide in vivo evidence that mutant S163R C1QTNF5 can form large, transparent, spherical intracellular aggregates throughout the RPE, which are detectable by light microscopy. In contrast to AAV-expressed wild-type C1QTNF5, which is secreted apically from the RPE toward the photoreceptor cells and the outer limiting membrane, the S163R mutant is primarily routed toward the basal side of RPE, where it forms thick, extracellular deposits over time. CONCLUSIONS Adeno-associated viral-targeted expression of mutant S163R in the RPE represents a useful approach for quickly generating animal models that mimic pathological features of L-ORD and offers the potential to understand disease mechanisms and develop therapeutic strategies.
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Malattia Leventinese/Doyne Honeycomb Retinal Dystrophy: Similarities to Age-Related Macular Degeneration and Potential Therapies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:153-8. [PMID: 26427406 DOI: 10.1007/978-3-319-17121-0_21] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Fibulin-3 (F3) is a secreted, disulfide-rich glycoprotein which is expressed in a variety of tissues within the body, including the retina. An Arg345Trp (R345W) mutation in F3 was identified as the cause of a rare retinal dystrophy, Malattia Leventinese/Doyne Honeycomb Retinal Dystrophy (ML/DHRD). ML/DHRD shares many phenotypic similarities with age-related macular degeneration (AMD). The most prominent feature of ML/DHRD is the development of radial or honeycomb patterns of drusen which can develop as early as adolescence. Two independent mouse models of ML/DHRD show evidence of complement activation as well as retinal pigment epithelium (RPE) atrophy, strengthening the phenotypic connection with AMD. Because of its similarities with AMD, ML/DHRD is receiving increasing interest as a potential surrogate disease to study the underpinnings of AMD. This mini-review summarizes the current knowledge of F3 and points toward potential therapeutic strategies which directly or indirectly target cellular dysfunction associated with R345W F3.
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Collin GB, Hubmacher D, Charette JR, Hicks WL, Stone L, Yu M, Naggert JK, Krebs MP, Peachey NS, Apte SS, Nishina PM. Disruption of murine Adamtsl4 results in zonular fiber detachment from the lens and in retinal pigment epithelium dedifferentiation. Hum Mol Genet 2015; 24:6958-74. [PMID: 26405179 DOI: 10.1093/hmg/ddv399] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 09/21/2015] [Indexed: 12/16/2022] Open
Abstract
Human gene mutations have revealed that a significant number of ADAMTS (a disintegrin-like and metalloproteinase (reprolysin type) with thrombospondin type 1 motifs) proteins are necessary for normal ocular development and eye function. Mutations in human ADAMTSL4, encoding an ADAMTS-like protein which has been implicated in fibrillin microfibril biogenesis, cause ectopia lentis (EL) and EL et pupillae. Here, we report the first ADAMTSL4 mouse model, tvrm267, bearing a nonsense mutation in Adamtsl4. Homozygous Adamtsl4(tvrm267) mice recapitulate the EL phenotype observed in humans, and our analysis strongly suggests that ADAMTSL4 is required for stable anchorage of zonule fibers to the lens capsule. Unexpectedly, homozygous Adamtsl4(tvrm267) mice exhibit focal retinal pigment epithelium (RPE) defects primarily in the inferior eye. RPE dedifferentiation was indicated by reduced pigmentation, altered cellular morphology and a reduction in RPE-specific transcripts. Finally, as with a subset of patients with ADAMTSL4 mutations, increased axial length, relative to age-matched controls, was observed and was associated with the severity of the RPE phenotype. In summary, the Adamtsl4(tvrm267) model provides a valuable tool to further elucidate the molecular basis of zonule formation, the pathophysiology of EL and ADAMTSL4 function in the maintenance of the RPE.
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Affiliation(s)
| | - Dirk Hubmacher
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA
| | | | | | - Lisa Stone
- The Jackson Laboratory, Bar Harbor, ME, USA
| | - Minzhong Yu
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA, Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA and
| | | | | | - Neal S Peachey
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA, Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA and Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Suneel S Apte
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA
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Zanzottera EC, Messinger JD, Ach T, Smith RT, Freund KB, Curcio CA. The Project MACULA Retinal Pigment Epithelium Grading System for Histology and Optical Coherence Tomography in Age-Related Macular Degeneration. Invest Ophthalmol Vis Sci 2015; 56:3253-68. [PMID: 25813989 DOI: 10.1167/iovs.15-16431] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
PURPOSE To seek pathways of retinal pigment epithelium (RPE) fate in age-related macular degeneration via a morphology grading system; provide nomenclature, visualization targets, and metrics for clinical imaging and model systems. METHODS Donor eyes with geographic atrophy (GA) or choroidal neovascularization (CNV) and one GA eye with previous clinical spectral-domain optical coherence tomography (SDOCT) imaging were processed for histology, photodocumented, and annotated at predefined locations. Retinal pigment epithelial cells contained spindle-shaped melanosomes, apposed a basal lamina or basal laminar deposit (BLamD), and exhibited recognizable morphologies. Thicknesses and unbiased estimates of frequencies were obtained. RESULTS In 13 GA eyes (449 locations), 'Shedding,' 'Sloughed,' and 'Dissociated' morphologies were abundant; 22.2% of atrophic locations had 'Dissociated' RPE. In 39 CNV eyes (1363 locations), 37.3% of locations with fibrovascular/fibrocellular scar had 'Entombed' RPE; 'Sloughed,' 'Dissociated,' and 'Bilaminar' morphologies were abundant. Of abnormal RPE, CNV and GA both had ~35% 'Sloughed'/'Intraretinal,' with more Intraretinal in CNV (9.5% vs. 1.8%). 'Shedding' cells associated with granule aggregations in BLamD. The RPE layer did not thin, and BLamD remained thick, with progression. Granule-containing material consistent with three morphologies correlated to SDOCT hyperreflective foci in the previously examined GA patient. CONCLUSIONS Retinal pigment epithelium morphology indicates multiple pathways in GA and CNV. Atrophic/scarred areas have numerous cells capable of transcribing genes and generating imaging signals. Shed granule aggregates, possibly apoptotic, are visible in SDOCT, as are 'Dissociated' and 'Sloughed' cells. The significance of RPE phenotypes is addressable in longitudinal, high-resolution imaging in clinic populations. Data can motivate future molecular phenotyping studies.
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Affiliation(s)
- Emma C Zanzottera
- Department of Ophthalmology University of Alabama School of Medicine, Birmingham, Alabama, United States 2Eye Clinic, Department of Clinical Science "Luigi Sacco," Sacco Hospital, University of Milan, Milan, Italy
| | - Jeffrey D Messinger
- Department of Ophthalmology University of Alabama School of Medicine, Birmingham, Alabama, United States
| | - Thomas Ach
- Department of Ophthalmology University of Alabama School of Medicine, Birmingham, Alabama, United States 3University Hospital Würzburg, Department of Ophthalmology, Würzburg, Germany
| | - R Theodore Smith
- Department of Ophthalmology, New York University School of Medicine, New York City, New York, United States
| | - K Bailey Freund
- Department of Ophthalmology, New York University School of Medicine, New York City, New York, United States 5Vitreous Retina Macula Consultants of New York, New York, New York, United States 6LuEsther T. Mertz Retinal Research Center, Manhattan Eye, Ear
| | - Christine A Curcio
- Department of Ophthalmology University of Alabama School of Medicine, Birmingham, Alabama, United States
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Aredo B, Li T, Chen X, Zhang K, Wang CXZ, Gou D, Zhao B, He Y, Ufret-Vincenty RL. A chimeric Cfh transgene leads to increased retinal oxidative stress, inflammation, and accumulation of activated subretinal microglia in mice. Invest Ophthalmol Vis Sci 2015; 56:3427-40. [PMID: 26030099 DOI: 10.1167/iovs.14-16089] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
PURPOSE Variants of complement factor H (Cfh) affecting short consensus repeats (SCRs) 6 to 8 increase the risk of age-related macular degeneration. Our aim was to explore the effect of expressing a Cfh variant on the in vivo susceptibility of the retina and RPE to oxidative stress and inflammation, using chimeric Cfh transgenic mice (chCfhTg). METHODS The chCfhTg and age-matched C57BL/6J (B6) mice were subjected to oxidative stress by either normal aging, or by exposure to a combination of oral hydroquinone (0.8% HQ) and increased light. Eyes were collected for immunohistochemistry of RPE-choroid flat mounts and of retinal sections, ELISA, electron microscopy, and RPE/microglia gene expression analysis. RESULTS Aging mice to 2 years led to an increased accumulation of basal laminar deposits, subretinal microglia/macrophages (MG/MΦ) staining for CD16 and for malondialdehyde (MDA), and MDA-modified proteins in the retina in chCfhTg compared to B6 mice. The chCfhTg mice maintained on HQ diet and increased light showed greater deposition of basal laminar deposits, more accumulation of fundus spots suggestive of MG/MΦ, and increased deposition of C3d in the sub-RPE space, compared to controls. In addition, chCfhTg mice demonstrated upregulation of NLRP3, IP-10, CD68, and TREM-2 in the RNA isolates from RPE/MG/MΦ. CONCLUSIONS Expression of a Cfh transgene introducing a variant in SCRs 6 to 8 was sufficient to lead to increased retinal/RPE susceptibility to oxidative stress, a proinflammatory MG/MΦ phenotype, and a proinflammatory RPE/MG/MΦ gene expression profile in a transgenic mouse model. Our data suggest that altered interactions of Cfh with MDA-modified proteins may be relevant in explaining the effects of the Cfh variant.
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Affiliation(s)
- Bogale Aredo
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | - Tao Li
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States 2Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Xiao Chen
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | - Kaiyan Zhang
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | - Cynthia Xin-Zhao Wang
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | - Darlene Gou
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | - Biren Zhao
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | - Yuguang He
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
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Fernandez-Godino R, Garland DL, Pierce EA. A local complement response by RPE causes early-stage macular degeneration. Hum Mol Genet 2015. [PMID: 26199322 DOI: 10.1093/hmg/ddv287] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Inherited and age-related macular degenerations (AMDs) are important causes of vision loss. An early hallmark of these disorders is the formation of sub-retinal pigment epithelium (RPE) basal deposits. A role for the complement system in MDs was suggested by genetic association studies, but direct functional connections between alterations in the complement system and the pathogenesis of MD remain to be defined. We used primary RPE cells from a mouse model of inherited MD due to a p.R345W mutation in EGF-containing fibulin-like extracellular matrix protein 1 (EFEMP1) to investigate the role of the RPE in early MD pathogenesis. Efemp1(R345W) RPE cells recapitulate the basal deposit formation observed in vivo by producing sub-RPE deposits in vitro. The deposits share features with basal deposits, and their formation was mediated by EFEMP1(R345W) or complement component 3a (C3a), but not by complement component 5a (C5a). Increased activation of complement appears to occur in response to an abnormal extracellular matrix (ECM), generated by the mutant EFEMP1(R345W) protein and reduced ECM turnover due to inhibition of matrix metalloproteinase 2 by EFEMP1(R345W) and C3a. Increased production of C3a also stimulated the release of cytokines such as interleukin (IL)-6 and IL-1B, which appear to have a role in deposit formation, albeit downstream of C3a. These studies provide the first direct indication that complement components produced locally by the RPE are involved in the formation of basal deposits. Furthermore, these results suggest that C3a generated by RPE is a potential therapeutic target for the treatment of EFEMP1-associated MD as well as AMD.
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Affiliation(s)
| | | | - Eric A Pierce
- Ocular Genomics Institute, Department of Ophthalmology and Berman-Gund Laboratory for the Study of Retinal Degenerations, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
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Mackay DS, Bennett TM, Shiels A. Exome Sequencing Identifies a Missense Variant in EFEMP1 Co-Segregating in a Family with Autosomal Dominant Primary Open-Angle Glaucoma. PLoS One 2015; 10:e0132529. [PMID: 26162006 PMCID: PMC4498621 DOI: 10.1371/journal.pone.0132529] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 06/15/2015] [Indexed: 11/18/2022] Open
Abstract
Primary open-angle glaucoma (POAG) is a clinically important and genetically heterogeneous cause of progressive vision loss as a result of retinal ganglion cell death. Here we have utilized trio-based, whole-exome sequencing to identify the genetic defect underlying an autosomal dominant form of adult-onset POAG segregating in an African-American family. Exome sequencing identified a novel missense variant (c.418C>T, p.Arg140Trp) in exon-5 of the gene coding for epidermal growth factor (EGF) containing fibulin-like extracellular matrix protein 1 (EFEMP1) that co-segregated with disease in the family. Linkage and haplotype analyses with microsatellite markers indicated that the disease interval overlapped a known POAG locus (GLC1H) on chromosome 2p. The p.Arg140Trp substitution was predicted in silico to have damaging effects on protein function and transient expression studies in cultured cells revealed that the Trp140-mutant protein exhibited increased intracellular accumulation compared with wild-type EFEMP1. In situ hybridization of the mouse eye with oligonucleotide probes detected the highest levels of EFEMP1 transcripts in the ciliary body, cornea, inner nuclear layer of the retina, and the optic nerve head. The recent finding that a common variant near EFEMP1 was associated with optic nerve-head morphology supports the possibility that the EFEMP1 variant identified in this POAG family may be pathogenic.
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Affiliation(s)
- Donna S. Mackay
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Thomas M. Bennett
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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