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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 PMCID: PMC11238277 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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Csaky KG, Miller JML, Martin DF, Johnson MW. Drug Approval for the Treatment of Geographic Atrophy: How We Got Here and Where We Need to Go. Am J Ophthalmol 2024; 263:231-239. [PMID: 38387826 PMCID: PMC11162935 DOI: 10.1016/j.ajo.2024.02.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 01/22/2024] [Accepted: 02/12/2024] [Indexed: 02/24/2024]
Abstract
PURPOSE To discuss the clinical trial results leading to the US Food and Drug Administration (FDA) approval of anti-complement therapies for geographic atrophy (GA), perspectives on functional data from the GA clinical trials, and how lessons from the FDA approval may guide future directions for basic and clinical research in AMD. DESIGN Selected literature review with analysis and perspective METHODS: We performed a targeted review of publicly available data from the clinical trials of pegcetacoplan and avacincaptad for the treatment of GA, as well as scientific literature on the natural history of GA and the genetics and basic science of complement in AMD. RESULTS The approval of pegcetacoplan and avacincaptad was based on an anatomic endpoint of a reduction in the rate of GA expansion over time. However, functional data from 2 phase 3 clinical trials for each drug demonstrated no visual benefit to patients in the treatment groups. Review of the genetics of AMD and the basic science of the role for complement in AMD provides only modest support for targeting complement as treatment for GA expansion, and alternative molecular targets for GA treatment are therefore discussed. Reasons for the disconnect between anatomic and functional outcomes in the clinical trials of anti-complement therapies are discussed, providing insight to guide the configuration of future clinical studies for GA. CONCLUSION Although avacincaptad and pegcetacoplan are our first FDA-approved treatments for GA, results from the clinical trials failed to show any functional improvement after 1 and 2 years, respectively, calling into question whether the drugs represent a "clinically relevant outcome." To improve the chances of more impactful therapies in the future, we provide basic-science rationale for pursuing non-complement targets; emphasize the importance of ongoing clinical research that more closely pins anatomic features of GA to functional outcomes; and provide suggestions for clinical endpoints for future clinical trials on GA.
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Affiliation(s)
- Karl G Csaky
- From the Retina Foundation of the Southwest (K.G.C.), Dallas, Texas, USA.
| | - Jason M L Miller
- Kellogg Eye Center (J.M.L.M., M.W.J.), University of Michigan, Ann Arbor, Michigan, USA; Cellular and Molecular Biology Program (J.M.L.M.), University of Michigan, Ann Arbor, Michigan, USA
| | - Daniel F Martin
- Cole Eye Institute (D.F.M.), Cleveland Clinic, Cleveland Ohio, USA
| | - Mark W Johnson
- Kellogg Eye Center (J.M.L.M., M.W.J.), University of Michigan, Ann Arbor, Michigan, USA
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3
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Pfau K, Lengyel I, Ossewaarde-van Norel J, van Leeuwen R, Risseeuw S, Leftheriotis G, Scholl HPN, Feltgen N, Holz FG, Pfau M. Pseudoxanthoma elasticum - Genetics, pathophysiology, and clinical presentation. Prog Retin Eye Res 2024; 102:101274. [PMID: 38815804 DOI: 10.1016/j.preteyeres.2024.101274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 05/17/2024] [Accepted: 05/20/2024] [Indexed: 06/01/2024]
Abstract
Pseudoxanthoma elasticum (PXE) is an autosomal-recessively inherited multisystem disease. Mutations in the ABCC6-gene are causative, coding for a transmembrane transporter mainly expressed in hepatocytes, which promotes the efflux of adenosine triphosphate (ATP). This results in low levels of plasma inorganic pyrophosphate (PPi), a critical anti-mineralization factor. The clinical phenotype of PXE is characterized by the effects of elastic fiber calcification in the skin, the cardiovascular system, and the eyes. In the eyes, calcification of Bruch's membrane results in clinically visible lesions, including peau d'orange, angioid streaks, and comet tail lesions. Frequently, patients must be treated for secondary macular neovascularization. No effective therapy is available for treating the cause of PXE, but several promising approaches are emerging. Finding appropriate outcome measures remains a significant challenge for clinical trials in this slowly progressive disease. This review article provides an in-depth summary of the current understanding of PXE and its multi-systemic manifestations. The article offers a detailed overview of the ocular manifestations, including their morphological and functional consequences, as well as potential complications. Lastly, previous and future clinical trials of causative treatments for PXE are discussed.
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Affiliation(s)
- Kristina Pfau
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland; Department of Ophthalmology, University Hospital Bonn, Bonn, Germany.
| | - Imre Lengyel
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom; Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | | | - Redmer van Leeuwen
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Sara Risseeuw
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Georges Leftheriotis
- University Hospital Nice, Vascular Physiology and Medicine Unit, 06000, Nice, France
| | | | - Nicolas Feltgen
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | - Frank G Holz
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany
| | - Maximilian Pfau
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland; Institute of Molecular and Clinical Ophthalmology Basel, Basel, Basel-Stadt, Switzerland
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Motipally SI, Kolson DR, Guan T, Kolandaivelu S. Aberrant lipid accumulation and retinal pigmental epithelium dysfunction in PRCD-deficient mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.08.584131. [PMID: 38558979 PMCID: PMC10979840 DOI: 10.1101/2024.03.08.584131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Progressive Rod-Cone Degeneration (PRCD) is an integral membrane protein found in photoreceptor outer segment (OS) disc membranes and its function remains unknown. Mutations in Prcd are implicated in Retinitis pigmentosa (RP) in humans and multiple dog breeds. PRCD-deficient models exhibit decreased levels of cholesterol in the plasma. However, potential changes in the retinal cholesterol remain unexplored. In addition, impaired phagocytosis observed in these animal models points to potential deficits in the retinal pigment epithelium (RPE). Here, using a Prcd -/- murine model we investigated the alterations in the retinal cholesterol levels and impairments in the structural and functional integrity of the RPE. Lipidomic and immunohistochemical analyses show a 5-fold increase in the levels of cholesteryl esters (C.Es) and accumulation of neutral lipids in the PRCD-deficient retina, respectively, indicating alterations in total retinal cholesterol. Longitudinal fundus and spectral domain optical coherence tomography (SD-OCT) examinations showed focal lesions and RPE hyperreflectivity. Strikingly, the RPE of Prcd -/- mice exhibited age-related pathological features such as neutral lipid deposits, lipofuscin accumulation, Bruch's membrane (BrM) thickening and drusenoid focal deposits, mirroring an Age-related Macular Degeneration (AMD)-like phenotype. We propose that the extensive lipofuscin accumulation likely impairs lysosomal function, leading to the defective phagocytosis observed in Prcd -/- mice. Our findings support the dysregulation of retinal cholesterol homeostasis in the absence of PRCD. Further, we demonstrate that progressive photoreceptor degeneration in Prcd -/- mice is accompanied by progressive structural and functional deficits in the RPE, which likely exacerbates vision loss over time.
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Becker S, L'Ecuyer Z, Jones BW, Zouache MA, McDonnell FS, Vinberg F. Modeling complex age-related eye disease. Prog Retin Eye Res 2024; 100:101247. [PMID: 38365085 DOI: 10.1016/j.preteyeres.2024.101247] [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: 08/15/2023] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 02/18/2024]
Abstract
Modeling complex eye diseases like age-related macular degeneration (AMD) and glaucoma poses significant challenges, since these conditions depend highly on age-related changes that occur over several decades, with many contributing factors remaining unknown. Although both diseases exhibit a relatively high heritability of >50%, a large proportion of individuals carrying AMD- or glaucoma-associated genetic risk variants will never develop these diseases. Furthermore, several environmental and lifestyle factors contribute to and modulate the pathogenesis and progression of AMD and glaucoma. Several strategies replicate the impact of genetic risk variants, pathobiological pathways and environmental and lifestyle factors in AMD and glaucoma in mice and other species. In this review we will primarily discuss the most commonly available mouse models, which have and will likely continue to improve our understanding of the pathobiology of age-related eye diseases. Uncertainties persist whether small animal models can truly recapitulate disease progression and vision loss in patients, raising doubts regarding their usefulness when testing novel gene or drug therapies. We will elaborate on concerns that relate to shorter lifespan, body size and allometries, lack of macula and a true lamina cribrosa, as well as absence and sequence disparities of certain genes and differences in their chromosomal location in mice. Since biological, rather than chronological, age likely predisposes an organism for both glaucoma and AMD, more rapidly aging organisms like small rodents may open up possibilities that will make research of these diseases more timely and financially feasible. On the other hand, due to the above-mentioned anatomical and physiological features, as well as pharmacokinetic and -dynamic differences small animal models are not ideal to study the natural progression of vision loss or the efficacy and safety of novel therapies. In this context, we will also discuss the advantages and pitfalls of alternative models that include larger species, such as non-human primates and rabbits, patient-derived retinal organoids, and human organ donor eyes.
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Affiliation(s)
- Silke Becker
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Zia L'Ecuyer
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Bryan W Jones
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Moussa A Zouache
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Fiona S McDonnell
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
| | - Frans Vinberg
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Biomedical Engineering, University of Utah, Salt Lake City, UT, USA.
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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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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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11
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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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12
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Cellular and Molecular Mechanisms of Pathogenesis Underlying Inherited Retinal Dystrophies. Biomolecules 2023; 13:biom13020271. [PMID: 36830640 PMCID: PMC9953031 DOI: 10.3390/biom13020271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/23/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
Inherited retinal dystrophies (IRDs) are congenital retinal degenerative diseases that have various inheritance patterns, including dominant, recessive, X-linked, and mitochondrial. These diseases are most often the result of defects in rod and/or cone photoreceptor and retinal pigment epithelium function, development, or both. The genes associated with these diseases, when mutated, produce altered protein products that have downstream effects in pathways critical to vision, including phototransduction, the visual cycle, photoreceptor development, cellular respiration, and retinal homeostasis. The aim of this manuscript is to provide a comprehensive review of the underlying molecular mechanisms of pathogenesis of IRDs by delving into many of the genes associated with IRD development, their protein products, and the pathways interrupted by genetic mutation.
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13
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Garland D, Harnly J, Ayyagari R. Mouse Choroid Proteome Revisited: Focus on Aging. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:359-363. [PMID: 37440057 DOI: 10.1007/978-3-031-27681-1_52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Age is a major risk factor for age-related macular degeneration (AMD), and age has a role in the disease phenotypes of heritable macular dystrophies. The proteomes of C57Bl6/J mouse choroids at 2 ages were analyzed to identify biochemical processes affected by aging. Proteins of interest were identified as those contributing most to the variance in principal component analysis and those showing the largest significant differences between ages. These proteins implicated altered ECM composition, immune system function, and lipid metabolism.
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Affiliation(s)
| | - James Harnly
- Human Nutrition Center, US Department of Agriculture, Beltsville, MD, USA
| | - Radha Ayyagari
- Departments of Ophthalmology and Pathology, Shiley Eye Institute, University of California, San Diego, CA, USA
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14
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Biasella F, Plössl K, Baird PN, Weber BHF. The extracellular microenvironment in immune dysregulation and inflammation in retinal disorders. Front Immunol 2023; 14:1147037. [PMID: 36936905 PMCID: PMC10014728 DOI: 10.3389/fimmu.2023.1147037] [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: 01/18/2023] [Accepted: 02/15/2023] [Indexed: 03/05/2023] Open
Abstract
Inherited retinal dystrophies (IRDs) as well as genetically complex retinal phenotypes represent a heterogenous group of ocular diseases, both on account of their phenotypic and genotypic characteristics. Therefore, overlaps in clinical features often complicate or even impede their correct clinical diagnosis. Deciphering the molecular basis of retinal diseases has not only aided in their disease classification but also helped in our understanding of how different molecular pathologies may share common pathomechanisms. In particular, these relate to dysregulation of two key processes that contribute to cellular integrity, namely extracellular matrix (ECM) homeostasis and inflammation. Pathological changes in the ECM of Bruch's membrane have been described in both monogenic IRDs, such as Sorsby fundus dystrophy (SFD) and Doyne honeycomb retinal dystrophy (DHRD), as well as in the genetically complex age-related macular degeneration (AMD) or diabetic retinopathy (DR). Additionally, complement system dysfunction and distorted immune regulation may also represent a common connection between some IRDs and complex retinal degenerations. Through highlighting such overlaps in molecular pathology, this review aims to illuminate how inflammatory processes and ECM homeostasis are linked in the healthy retina and how their interplay may be disturbed in aging as well as in disease.
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Affiliation(s)
- Fabiola Biasella
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
| | - Karolina Plössl
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
| | - Paul N. Baird
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
- Department of Surgery, Ophthalmology, University of Melbourne, Melbourne, VIC, Australia
- *Correspondence: Paul N. Baird, ; Bernhard H. F. Weber,
| | - Bernhard H. F. Weber
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
- Institute of Clinical Human Genetics, University Hospital Regensburg, Regensburg, Germany
- *Correspondence: Paul N. Baird, ; Bernhard H. F. Weber,
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15
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Gogna N, Hyde LF, Collin GB, Stone L, Naggert JK, Nishina PM. Current Views on Chr10q26 Contribution to Age-Related Macular Degeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:27-36. [PMID: 37440010 DOI: 10.1007/978-3-031-27681-1_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in the global aging population. Familial aggregation and genome-wide association (GWA) studies have identified gene variants associated with AMD, implying a strong genetic contribution to AMD development. Two loci, on human Chr 1q31 and 10q26, respectively, represent the most influential of all genetic factors. While the role of CFH at Chr 1q31 is well established, uncertainty remains about the genes ARMS2 and HTRA1, at the Chr 10q26 locus. Since both genes are in strong linkage disequilibrium, assigning individual gene effects is difficult. In this chapter, we review current literature about ARMS2 and HTRA1 and their relevance to AMD risk. Future studies will be necessary to unravel the mechanisms by which they contribute to AMD.
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Affiliation(s)
| | | | | | - Lisa Stone
- The Jackson Laboratory, Bar Harbor, ME, USA
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16
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Navneet S, Rohrer B. Elastin turnover in ocular diseases: A special focus on age-related macular degeneration. Exp Eye Res 2022; 222:109164. [PMID: 35798060 PMCID: PMC9795808 DOI: 10.1016/j.exer.2022.109164] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/08/2022] [Accepted: 06/20/2022] [Indexed: 12/30/2022]
Abstract
The extracellular matrix (ECM) and its turnover play a crucial role in the pathogenesis of several inflammatory diseases, including age-related macular degeneration (AMD). Elastin, a critical protein component of the ECM, not only provides structural and mechanical support to tissues, but also mediates several intracellular and extracellular molecular signaling pathways. Abnormal turnover of elastin has pathological implications. In the eye elastin is a major structural component of Bruch's membrane (BrM), a critical ECM structure separating the retinal pigment epithelium (RPE) from the choriocapillaris. Reduced integrity of macular BrM elastin, increased serum levels of elastin-derived peptides (EDPs), and elevated elastin antibodies have been reported in AMD. Existing reports suggest that elastases, the elastin-degrading enzymes secreted by RPE, infiltrating macrophages or neutrophils could be involved in BrM elastin degradation, thus contributing to AMD pathogenesis. EDPs derived from elastin degradation can increase inflammatory and angiogenic responses in tissues, and the elastin antibodies are shown to play roles in immune cell activity and complement activation. This review summarizes our current understanding on the elastases/elastin fragments-mediated mechanisms of AMD pathogenesis.
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Affiliation(s)
- Soumya Navneet
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, USA.
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA; Ralph H. Johnson VA Medical Center, Division of Research, Charleston, SC, USA.
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17
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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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18
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CLEC3B is a novel causative gene for macular-retinal dystrophy. Genet Med 2022; 24:1249-1260. [PMID: 35331648 DOI: 10.1016/j.gim.2022.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 11/22/2022] Open
Abstract
PURPOSE Macular degeneration is the leading cause of blindness worldwide. In this study, we aimed to define a new subtype of macular-retinal dystrophy and its genetic predisposition in 5 families. METHODS Exome sequencing was performed to determine the putative disease-causing genes in patients with inherited macular disorders confirmed through comprehensive ophthalmic examinations. To validate its functional consequence, adeno-associated virus-mediated mutant gene was delivered into the murine retina, and both structural and functional tests were performed to investigate its pathological effects in vivo. RESULTS In total, 5 multigenerational families diagnosed with autosomal dominant maculoretinopathy were found to carry a pathogenic variant in a new gene, CLEC3B, which encodes tetranectin, a plasminogen kringle-4 binding protein. Consistent with the disease phenotypes of patients, mice that received subretinal injections with the CLEC3B variant displayed multiple subretinal hyperreflective deposits, reduced retinal thickness, and decreased electroretinographic responses. Moreover, the optokinetic tracking response indicated that spatial frequency was significantly lower (P < .05), implying impaired visual function in these mice. CONCLUSION We have presented a new subtype of macular-retinal dystrophy in 5 families as well as a new pathogenic gene, CLEC3B, providing new insights into maculoretinopathy etiology.
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19
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Collantes ERA, Delfin MS, Fan B, Torregosa JMR, Siguan-Bell C, de Guzman Florcruz NV, Martinez JMD, Masna-Hidalgo BJ, Guzman VPT, Anotado-Flores JF, Levina FD, Hernandez SRC, Collantes AA, Sibulo MC, Rong S, Wiggs JL. EFEMP1 rare variants cause familial juvenile-onset open-angle glaucoma. Hum Mutat 2022; 43:240-252. [PMID: 34923728 PMCID: PMC8972201 DOI: 10.1002/humu.24320] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 12/02/2021] [Accepted: 12/15/2021] [Indexed: 02/03/2023]
Abstract
Juvenile open-angle glaucoma (JOAG) is a severe type of glaucoma with onset before age 40 and dominant inheritance. Using exome sequencing we identified 3 independent families from the Philippines with novel EFEMP1 variants (c.238A>T, p.Asn80Tyr; c.1480T>C, p.Ter494Glnext*29; and c.1429C>T, p.Arg477Cys) co-segregating with disease. Affected variant carriers (N = 34) exhibited severe disease with average age of onset of 16 years and with 76% developing blindness. To investigate functional effects, we transfected COS7 cells with vectors expressing the three novel EFEMP1 variants and showed that all three variants found in JOAG patients caused significant intracellular protein aggregation and retention compared to wild type and also compared to EFEMP1 variants associated with other ocular phenotypes including an early-onset form of macular degeneration, Malattia Leventinese/Doyne's Honeycomb retinal dystrophy. These results suggest that rare EFEMP1 coding variants can cause JOAG through a mechanism involving protein aggregation and retention, and that the extent of intracellular retention correlates with disease phenotype. This is the first report of EFEMP1 variants causing JOAG, expanding the EFEMP1 disease spectrum. Our results suggest that EFEMP1 mutations appear to be a relatively common cause of JOAG in Filipino families, an ethnically diverse population.
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Affiliation(s)
- Edward Ryan A. Collantes
- Harvard Medical School Department of Ophthalmology, Massachusetts Eye and Ear, Boston, USA
- Department of Ophthalmology, Manila Doctors Hospital, Manila, Philippines
| | - Manuel S. Delfin
- Department of Ophthalmology, Manila Doctors Hospital, Manila, Philippines
| | - Baojian Fan
- Harvard Medical School Department of Ophthalmology, Massachusetts Eye and Ear, Boston, USA
| | - Justine May R. Torregosa
- Department of Ophthalmology, Cebu Institute of Medicine, Cebu Velez General Hospital, Cebu City, Philippines
| | - Christine Siguan-Bell
- Department of Ophthalmology, Cebu Institute of Medicine, Cebu Velez General Hospital, Cebu City, Philippines
| | - Nilo Vincent de Guzman Florcruz
- Department of Ophthalmology and Visual Sciences, University of the Philippines-Philippine General Hospital, Manila, Philippines
- Glaucoma Service, Department of Ophthalmology, East Avenue Medical Center, Quezon City, Philippines
| | - Jose Maria D. Martinez
- Glaucoma Service, Department of Ophthalmology, East Avenue Medical Center, Quezon City, Philippines
| | | | | | | | - Faye D. Levina
- Department of Ophthalmology, Jose R. Reyes Memorial Medical Center, Manila, Philippines
| | | | | | | | - Shisong Rong
- Harvard Medical School Department of Ophthalmology, Massachusetts Eye and Ear, Boston, USA
| | - Janey L. Wiggs
- Harvard Medical School Department of Ophthalmology, Massachusetts Eye and Ear, Boston, USA
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20
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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: 16] [Impact Index Per Article: 5.3] [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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21
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Chinchilla B, Foltopoulou P, Fernandez-Godino R. Tick-over-mediated complement activation is sufficient to cause basal deposit formation in cell-based models of macular degeneration. J Pathol 2021; 255:120-131. [PMID: 34155630 DOI: 10.1002/path.5747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/08/2021] [Accepted: 06/15/2021] [Indexed: 12/17/2022]
Abstract
Despite numerous unsuccessful clinical trials for anti-complement drugs to treat age-related macular degeneration (AMD), the complement system has not been fully explored as a target to stop drusen growth in patients with dry AMD. We propose that the resilient autoactivation of C3 by hydrolysis of its internal thioester (tick-over), which cannot be prevented by existing drugs, plays a critical role in the formation of drusenoid deposits underneath the retinal pigment epithelium (RPE). We have combined gene editing tools with stem cell technology to generate cell-based models that allow the role of the tick-over in sub-RPE deposit formation to be studied. The results demonstrate that structurally or genetically driven pathological events affecting the RPE and Bruch's membrane can lead to dysregulation of the tick-over, which is sufficient to stimulate the formation of sub-RPE deposits. This can be prevented with therapies that downregulate C3 expression. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Blanca Chinchilla
- The Ocular Genomics Institute at Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Parthena Foltopoulou
- The Ocular Genomics Institute at Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Rosario Fernandez-Godino
- The Ocular Genomics Institute at Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
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22
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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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23
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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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24
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Du J, Zhu S, Lim RR, Chao JR. Proline metabolism and transport in retinal health and disease. Amino Acids 2021; 53:1789-1806. [PMID: 33871679 PMCID: PMC8054134 DOI: 10.1007/s00726-021-02981-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/10/2021] [Indexed: 12/11/2022]
Abstract
The retina is one of the most energy-demanding tissues in the human body. Photoreceptors in the outer retina rely on nutrient support from the neighboring retinal pigment epithelium (RPE), a monolayer of epithelial cells that separate the retina and choroidal blood supply. RPE dysfunction or cell death can result in photoreceptor degeneration, leading to blindness in retinal degenerative diseases including some inherited retinal degenerations and age-related macular degeneration (AMD). In addition to having ready access to rich nutrients from blood, the RPE is also supplied with lactate from adjacent photoreceptors. Moreover, RPE can phagocytose lipid-rich outer segments for degradation and recycling on a daily basis. Recent studies show RPE cells prefer proline as a major metabolic substrate, and they are highly enriched for the proline transporter, SLC6A20. In contrast, dysfunctional or poorly differentiated RPE fails to utilize proline. RPE uses proline to fuel mitochondrial metabolism, synthesize amino acids, build the extracellular matrix, fight against oxidative stress, and sustain differentiation. Remarkably, the neural retina rarely imports proline directly, but it uptakes and utilizes intermediates and amino acids derived from proline catabolism in the RPE. Mutations of genes in proline metabolism are associated with retinal degenerative diseases, and proline supplementation is reported to improve RPE-initiated vision loss. This review will cover proline metabolism in RPE and highlight the importance of proline transport and utilization in maintaining retinal metabolism and health.
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Affiliation(s)
- Jianhai Du
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV, 26506, USA. .,Department of Biochemistry, West Virginia University, Morgantown, WV, 26506, USA. .,One Medical Center Dr, WVU Eye Institute, PO Box 9193, Morgantown, WV, 26505, USA.
| | - Siyan Zhu
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV, 26506, USA.,Department of Biochemistry, West Virginia University, Morgantown, WV, 26506, USA
| | - Rayne R Lim
- Department of Ophthalmology, University of Washington, Seattle, WA, 98109, USA
| | - Jennifer R Chao
- Department of Ophthalmology, University of Washington, Seattle, WA, 98109, USA
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25
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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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26
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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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27
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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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28
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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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29
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Hongisto H, Dewing JM, Christensen DR, Scott J, Cree AJ, Nättinen J, Määttä J, Jylhä A, Aapola U, Uusitalo H, Kaarniranta K, Ratnayaka JA, Skottman H, Lotery AJ. In vitro stem cell modelling demonstrates a proof-of-concept for excess functional mutant TIMP3 as the cause of Sorsby fundus dystrophy. J Pathol 2020; 252:138-150. [PMID: 32666594 DOI: 10.1002/path.5506] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 06/06/2020] [Accepted: 06/29/2020] [Indexed: 12/28/2022]
Abstract
Sorsby fundus dystrophy (SFD) is a rare autosomal dominant disease of the macula that leads to bilateral loss of central vision and is caused by mutations in the TIMP3 gene. However, the mechanisms by which TIMP3 mutations cause SFD are poorly understood. Here, we generated human induced pluripotent stem cell-derived retinal pigmented epithelial (hiPSC-RPE) cells from three SFD patients carrying TIMP3 p.(Ser204Cys) and three non-affected controls to study disease-related structural and functional differences in the RPE. SFD-hiPSC-RPE exhibited characteristic RPE structure and physiology but showed significantly reduced transepithelial electrical resistance associated with enriched expression of cytoskeletal remodelling proteins. SFD-hiPSC-RPE exhibited basolateral accumulation of TIMP3 monomers, despite no change in TIMP3 gene expression. TIMP3 dimers were observed in both SFD and control hiPSC-RPE, suggesting that mutant TIMP3 dimerisation does not drive SFD pathology. Furthermore, mutant TIMP3 retained matrix metalloproteinase activity. Proteomic profiling showed increased expression of ECM proteins, endothelial cell interactions and angiogenesis-related pathways in SFD-hiPSC-RPE. By contrast, there were no changes in VEGF secretion. However, SFD-hiPSC-RPE secreted higher levels of monocyte chemoattractant protein 1, PDGF and angiogenin. Our findings provide a proof-of-concept that SFD patient-derived hiPSC-RPE mimic mature RPE cells and support the hypothesis that excess accumulation of mutant TIMP3, rather than an absence or deficiency of functional TIMP3, drives ECM and angiogenesis-related changes in SFD. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Heidi Hongisto
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Faculty of Medicine and Health Technology, BioMediTech, Tampere University, Tampere, Finland
| | - Jennifer M Dewing
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - David Rg Christensen
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Jennifer Scott
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Angela J Cree
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Janika Nättinen
- SILK, Department of Ophthalmology, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Juha Määttä
- SILK, Department of Ophthalmology, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Antti Jylhä
- SILK, Department of Ophthalmology, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Ulla Aapola
- SILK, Department of Ophthalmology, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Hannu Uusitalo
- SILK, Department of Ophthalmology, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Tays Eye Centre, Tampere University Hospital, Tampere, Finland
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland
| | - J Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Heli Skottman
- Faculty of Medicine and Health Technology, BioMediTech, Tampere University, Tampere, Finland
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
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30
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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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31
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Chekuri A, Zientara‐Rytter K, Soto‐Hermida A, Borooah S, Voronchikhina M, Biswas P, Kumar V, Goodsell D, Hayward C, Shaw P, Stanton C, Garland D, Subramani S, Ayyagari R. Late-onset retinal degeneration pathology due to mutations in CTRP5 is mediated through HTRA1. Aging Cell 2019; 18:e13011. [PMID: 31385385 PMCID: PMC6826137 DOI: 10.1111/acel.13011] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/13/2019] [Accepted: 06/16/2019] [Indexed: 12/22/2022] Open
Abstract
Late-onset retinal degeneration (L-ORD) is an autosomal dominant macular degeneration characterized by the formation of sub-retinal pigment epithelium (RPE) deposits and neuroretinal atrophy. L-ORD results from mutations in the C1q-tumor necrosis factor-5 protein (CTRP5), encoded by the CTRP5/C1QTNF5 gene. To understand the mechanism underlying L-ORD pathology, we used a human cDNA library yeast two-hybrid screen to identify interacting partners of CTRP5. Additionally, we analyzed the Bruch's membrane/choroid (BM-Ch) from wild-type (Wt), heterozygous S163R Ctrp5 mutation knock-in (Ctrp5S163R/wt ), and homozygous knock-in (Ctrp5S163R/S163R ) mice using mass spectrometry. Both approaches showed an association between CTRP5 and HTRA1 via its C-terminal PDZ-binding motif, stimulation of the HTRA1 protease activity by CTRP5, and CTRP5 serving as an HTRA1 substrate. The S163R-CTRP5 protein also binds to HTRA1 but is resistant to HTRA1-mediated cleavage. Immunohistochemistry and proteomic analysis showed significant accumulation of CTRP5 and HTRA1 in BM-Ch of Ctrp5S163R/S163R and Ctrp5S163R/wt mice compared with Wt. Additional extracellular matrix (ECM) components that are HTRA1 substrates also accumulated in these mice. These results implicate HTRA1 and its interaction with CTRP5 in L-ORD pathology.
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Affiliation(s)
- Anil Chekuri
- Shiley Eye InstituteUniversity of California San DiegoSan DiegoCAUSA
| | | | | | - Shyamanga Borooah
- Shiley Eye InstituteUniversity of California San DiegoSan DiegoCAUSA
| | | | - Pooja Biswas
- Shiley Eye InstituteUniversity of California San DiegoSan DiegoCAUSA
| | - Virender Kumar
- Shiley Eye InstituteUniversity of California San DiegoSan DiegoCAUSA
| | - David Goodsell
- Integrative Structural and Computational Biology (ISCB)Scripps Research InstituteSan DiegoCAUSA
| | - Caroline Hayward
- Medical Research Council Human Genetics Unit, Medical Research Council Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Peter Shaw
- Shiley Eye InstituteUniversity of California San DiegoSan DiegoCAUSA
| | - Chloe Stanton
- Medical Research Council Human Genetics Unit, Medical Research Council Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Donita Garland
- Massachusetts Eye and Ear Infirmary, Department of OphthalmologyHarvard Medical SchoolBostonMAUSA
| | - Suresh Subramani
- Division of Biological SciencesUniversity of California San DiegoSan DiegoCAUSA
| | - Radha Ayyagari
- Shiley Eye InstituteUniversity of California San DiegoSan DiegoCAUSA
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32
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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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Fields MA, Del Priore LV, Adelman RA, Rizzolo LJ. Interactions of the choroid, Bruch's membrane, retinal pigment epithelium, and neurosensory retina collaborate to form the outer blood-retinal-barrier. Prog Retin Eye Res 2019; 76:100803. [PMID: 31704339 DOI: 10.1016/j.preteyeres.2019.100803] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 10/26/2019] [Accepted: 10/28/2019] [Indexed: 01/10/2023]
Abstract
The three interacting components of the outer blood-retinal barrier are the retinal pigment epithelium (RPE), choriocapillaris, and Bruch's membrane, the extracellular matrix that lies between them. Although previously reviewed independently, this review integrates these components into a more wholistic view of the barrier and discusses reconstitution models to explore the interactions among them. After updating our understanding of each component's contribution to barrier function, we discuss recent efforts to examine how the components interact. Recent studies demonstrate that claudin-19 regulates multiple aspects of RPE's barrier function and identifies a barrier function whereby mutations of claudin-19 affect retinal development. Co-culture approaches to reconstitute components of the outer blood-retinal barrier are beginning to reveal two-way interactions between the RPE and choriocapillaris. These interactions affect barrier function and the composition of the intervening Bruch's membrane. Normal or disease models of Bruch's membrane, reconstituted with healthy or diseased RPE, demonstrate adverse effects of diseased matrix on RPE metabolism. A stumbling block for reconstitution studies is the substrates typically used to culture cells are inadequate substitutes for Bruch's membrane. Together with human stem cells, the alternative substrates that have been designed offer an opportunity to engineer second-generation culture models of the outer blood-retinal barrier.
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Affiliation(s)
- Mark A Fields
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, PO Box 208061, New Haven, CT, 06520-8061, USA
| | - Lucian V Del Priore
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, PO Box 208061, New Haven, CT, 06520-8061, USA
| | - Ron A Adelman
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, PO Box 208061, New Haven, CT, 06520-8061, USA
| | - Lawrence J Rizzolo
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, PO Box 208061, New Haven, CT, 06520-8061, USA; Department of Surgery, Yale University School of Medicine, PO Box 208062, New Haven, CT, 06520-8062, USA.
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Thompson S, Blodi FR, Larson DR, Anderson MG, Stasheff SF. The Efemp1R345W Macular Dystrophy Mutation Causes Amplified Circadian and Photophobic Responses to Light in Mice. Invest Ophthalmol Vis Sci 2019; 60:2110-2117. [PMID: 31095679 PMCID: PMC6735810 DOI: 10.1167/iovs.19-26881] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Purpose The R345W mutation in EFEMP1 causes malattia leventinese, an autosomal dominant eye disease with pathogenesis similar to an early-onset age-related macular degeneration. In mice, Efemp1R345W does not cause detectable degeneration but small subretinal deposits do accumulate. The purpose of this study was to determine whether there were abnormal responses to light at this presymptomatic stage in Efemp1R345W mice. Methods Responses to light were assessed by visual water task, circadian phase shifting, and negative masking behavior. The mechanism of abnormal responses was investigated by anterior eye exam, electroretinogram, melanopsin cell quantification, and multielectrode recording of retinal ganglion cell activity. Results Visual acuity was not different in Efemp1R345W mice. However, amplitudes of circadian phase shifting (P = 0.016) and negative masking (P < 0.0001) were increased in Efemp1R345W mice. This phenotype was not explained by anterior eye defects or amplified outer retina responses. Instead, we identified increased melanopsin-generated responses to light in the ganglion cell layer of the retina (P < 0.01). Conclusions Efemp1R345W increases the sensitivity to light of behavioral responses driven by detection of irradiance. An amplified response to light in melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) is consistent with this phenotype. The major concern with this effect of the malattia leventinese mutation is the potential for abnormal regulation of physiology by light to negatively affect health.
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Affiliation(s)
- Stewart Thompson
- Department of Psychology, New Mexico Tech, Socorro, New Mexico, United States.,Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States.,Institute for Vision Research, University of Iowa, Iowa City, Iowa, United States
| | - Frederick R Blodi
- Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States.,Institute for Vision Research, University of Iowa, Iowa City, Iowa, United States.,Pediatrics, University of Iowa, Iowa City, Iowa, United States.,Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, United States
| | - Demelza R Larson
- Institute for Vision Research, University of Iowa, Iowa City, Iowa, United States.,Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa, United States.,Biology Department, College of St. Benedict & St. John's University, Collegeville, Minnesota, United States
| | - Michael G Anderson
- Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States.,Institute for Vision Research, University of Iowa, Iowa City, Iowa, United States.,Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa, United States.,VA Center for Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States
| | - Steven F Stasheff
- Institute for Vision Research, University of Iowa, Iowa City, Iowa, United States.,Pediatrics, University of Iowa, Iowa City, Iowa, United States.,Unit on Retinal Neurophysiology, National Eye Institute, Bethesda, Maryland, United States.,Center for Neurosciences and Behavioral Medicine, Children's National Medical Center, Washington, DC, United States.,George Washington University School of Medicine and Health Sciences, Washington, DC, United States
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CFH exerts anti-oxidant effects on retinal pigment epithelial cells independently from protecting against membrane attack complex. Sci Rep 2019; 9:13873. [PMID: 31554875 PMCID: PMC6761137 DOI: 10.1038/s41598-019-50420-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/20/2019] [Indexed: 12/03/2022] Open
Abstract
Age Related Macular Degeneration (AMD) is the first cause of social blindness in people aged over 65 leading to atrophy of retinal pigment epithelial cells (RPE), photoreceptors and choroids, eventually associated with choroidal neovascularization. Accumulation of undigested cellular debris within RPE cells or under the RPE (Drusen), oxidative stress and inflammatory mediators contribute to the RPE cell death. The major risk to develop AMD is the Y402H polymorphism of complement factor H (CFH). CFH interacting with oxidized phospholipids on the RPE membrane modulates the functions of these cells, but the exact role of CFH in RPE cell death and survival remain poorly understood. The aim of this study was to analyze the potential protective mechanism of CFH on RPE cells submitted to oxidative stress. Upon exposure to oxidized lipids 4-HNE (4-hydroxy-2-nonenal) derived from photoreceptors, both the human RPE cell line ARPE-19 and RPE cells derived from human induced pluripotent stem cells were protected from death only in the presence of the full length human recombinant CFH in the culture medium. This protective effect was independent from the membrane attack complex (MAC) formation. CFH maintained RPE cells tight junctions’ structure and regulated the caspase dependent apoptosis process. These results demonstrated the CFH anti-oxidative stress functions independently of its capacity to inhibit MAC formation.
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Fernandez-Godino R, Bujakowska KM, Pierce EA. Changes in extracellular matrix cause RPE cells to make basal deposits and activate the alternative complement pathway. Hum Mol Genet 2019; 27:147-159. [PMID: 29095988 DOI: 10.1093/hmg/ddx392] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/25/2017] [Indexed: 01/13/2023] Open
Abstract
The design of efficient therapies for age-related macular degeneration (AMD) is limited by our understanding of the pathogenesis of basal deposits, which form between retinal pigment epithelium (RPE) and Bruch's membrane (BrM) early in disease, and involve activation of the complement system. To investigate the roles of BrM, RPE and complement in an AMD, we generated abnormal extracellular matrix (ECM) using CRISPR-edited ARPE-19 cells. We introduced to these cells the p.R345W mutation in EFEMP1, which causes early-onset macular degeneration. The abnormal ECM binds active complement C3 and causes the formation of basal deposits by normal human fetal (hf)RPE cells. Human fetal RPE (hfRPE) cells grown on abnormal ECM or BrM explants from AMD donors show chronic activation of the alternative complement pathway by excessive deposition of C3b. This process is exacerbated by impaired ECM turnover via increased matrix metalloproteinase-2 activity. The local cleavage of C3 via convertase-independent mechanisms can be a new therapeutic target for early AMD.
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Affiliation(s)
- Rosario Fernandez-Godino
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Ocular Genomics Institute, Boston, MA 02114, USA.,Harvard Medical School, Boston, MA 02114, USA
| | - Kinga M Bujakowska
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Ocular Genomics Institute, Boston, MA 02114, USA.,Harvard Medical School, Boston, MA 02114, USA
| | - Eric A Pierce
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Ocular Genomics Institute, Boston, MA 02114, USA.,Harvard Medical School, Boston, MA 02114, USA
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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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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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Chen Y, Gilbert MA, Grochowski CM, McEldrew D, Llewellyn J, Waisbourd-Zinman O, Hakonarson H, Bailey-Wilson JE, Russo P, Wells RG, Loomes KM, Spinner NB, Devoto M. A genome-wide association study identifies a susceptibility locus for biliary atresia on 2p16.1 within the gene EFEMP1. PLoS Genet 2018; 14:e1007532. [PMID: 30102696 PMCID: PMC6107291 DOI: 10.1371/journal.pgen.1007532] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 08/23/2018] [Accepted: 07/04/2018] [Indexed: 02/06/2023] Open
Abstract
Biliary atresia (BA) is a rare pediatric cholangiopathy characterized by fibrosclerosing obliteration of the extrahepatic bile ducts, leading to cholestasis, fibrosis, cirrhosis, and eventual liver failure. The etiology of BA remains unknown, although environmental, inflammatory, infectious, and genetic risk factors have been proposed. We performed a genome-wide association study (GWAS) in a European-American cohort of 343 isolated BA patients and 1716 controls to identify genetic loci associated with BA. A second GWAS was performed in an independent European-American cohort of 156 patients with BA and other extrahepatic anomalies and 212 controls to confirm the identified candidate BA-associated SNPs. Meta-analysis revealed three genome-wide significant BA-associated SNPs on 2p16.1 (rs10865291, rs6761893, and rs727878; P < 5 ×10-8), located within the fifth intron of the EFEMP1 gene, which encodes a secreted extracellular protein implicated in extracellular matrix remodeling, cell proliferation, and organogenesis. RNA expression analysis showed an increase in EFEMP1 transcripts from human liver specimens isolated from patients with either BA or other cholestatic diseases when compared to normal control liver samples. Immunohistochemistry demonstrated that EFEMP1 is expressed in cholangiocytes and vascular smooth muscle cells in liver specimens from patients with BA and other cholestatic diseases, but it is absent from cholangiocytes in normal control liver samples. Efemp1 transcripts had higher expression in cholangiocytes and portal fibroblasts as compared with other cell types in normal rat liver. The identification of a novel BA-associated locus, and implication of EFEMP1 as a new BA candidate susceptibility gene, could provide new insights to understanding the mechanisms underlying this severe pediatric disorder.
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Affiliation(s)
- Ying Chen
- Genomics and Computational Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Division of Human Genetics, Department of Pediatrics, at The Children's Hospital of Philadelphia, and The Perelman School of Medicine at The University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Melissa A. Gilbert
- Division of Genomic Diagnostics, Department of Pathology and Laboratory Medicine, The Children’s Hospital of Philadelphia, and The Perelman School of Medicine at The University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Christopher M. Grochowski
- Division of Genomic Diagnostics, Department of Pathology and Laboratory Medicine, The Children’s Hospital of Philadelphia, and The Perelman School of Medicine at The University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Deborah McEldrew
- Division of Genomic Diagnostics, Department of Pathology and Laboratory Medicine, The Children’s Hospital of Philadelphia, and The Perelman School of Medicine at The University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jessica Llewellyn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Orith Waisbourd-Zinman
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics at The Children's Hospital of Philadelphia, and The Perelman School of Medicine at The University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Schneider Children's Medical Center of Israel, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Hakon Hakonarson
- Division of Human Genetics, Department of Pediatrics, at The Children's Hospital of Philadelphia, and The Perelman School of Medicine at The University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Joan E. Bailey-Wilson
- Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Pierre Russo
- Division of Anatomic Pathology, Department of Pathology and Laboratory Medicine, Children’s Hospital of Philadelphia and Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Rebecca G. Wells
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kathleen M. Loomes
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics at The Children's Hospital of Philadelphia, and The Perelman School of Medicine at The University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Nancy B. Spinner
- Division of Genomic Diagnostics, Department of Pathology and Laboratory Medicine, The Children’s Hospital of Philadelphia, and The Perelman School of Medicine at The University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Marcella Devoto
- Division of Human Genetics, Department of Pediatrics, at The Children's Hospital of Philadelphia, and The Perelman School of Medicine at The University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Molecular Medicine, Sapienza University, Rome, Italy
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Fernandez-Godino R, Pierce EA. C3a triggers formation of sub-retinal pigment epithelium deposits via the ubiquitin proteasome pathway. Sci Rep 2018; 8:9679. [PMID: 29946065 PMCID: PMC6018664 DOI: 10.1038/s41598-018-28143-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 06/15/2018] [Indexed: 01/25/2023] Open
Abstract
The mechanisms that connect complement system activation and basal deposit formation in early stages of age-related macular degeneration (AMD) are insufficiently understood, which complicates the design of efficient therapies to prevent disease progression. Using human fetal (hf) retinal pigment epithelial (RPE) cells, we have established an in vitro model to investigate the effect of complement C3a on RPE cells and its role in the formation of sub-RPE deposits. The results of these studies revealed that C3a produced after C3 activation is sufficient to induce the formation of sub-RPE deposits via complement-driven proteasome inhibition. C3a binds the C3a receptor (C3aR), stimulates deposition of collagens IV and VI underneath the RPE, and impairs the extracellular matrix (ECM) turnover by increased MMP-2 activity, all mediated by downregulation of the ubiquitin proteasome pathway (UPP). The formation of basal deposits can be prevented by the addition of a C3aR antagonist, which restores the UPP activity and ECM turnover. These findings indicate that the cell-based model can be used to test potential therapeutic agents in vitro. The data suggest that modulation of C3aR-mediated events could be a therapeutic approach for treatment of early AMD.
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Affiliation(s)
- Rosario Fernandez-Godino
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, 02114, USA.
| | - Eric A Pierce
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, 02114, USA
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Ayana R, Singh S, Pati S. Deconvolution of Human Brain Cell Type Transcriptomes Unraveled Microglia-Specific Potential Biomarkers. Front Neurol 2018; 9:266. [PMID: 29755398 PMCID: PMC5932158 DOI: 10.3389/fneur.2018.00266] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 04/05/2018] [Indexed: 12/19/2022] Open
Abstract
Microglial cells form a context-dependent network of brain immunoeffector cells. Despite their indispensable roles, unresolved questions exist around biomarker discovery relevant to their cellular localization, self-renewing potential, and brain developmental dynamics. To resolve the existent gap in the annotation of candidate biomarkers, we conducted a meta-analysis of brain cells using available high-throughput data sets for deciphering microglia-specific expression profiles. We have identified 3,290 significant genes specific to microglia and further selected the top 20 dysregulated genes on the basis of p-value and log2FC. To this list, we added 7 known microglia-specific markers making the candidate list comprising 27 genes for further downstream analyses. Next, we established a connectome of these potential markers with their putative protein partners, which demonstrated strong associations of upregulated genes like Dedicator of cytokinesis 2 (DOCK2) with early/mature microglial markers such as Sphingosine kinase 1 (SPHK1), CD68, and CD45. To elucidate their respective brain anatomical location, we deconvoluted the BrainSpan Atlas expression data. This analysis showed high expression of the majority of candidate genes in microglia-dense regions (Amygdala, Hippocampus, Striatum) in the postnatal brain. Furthermore, to decipher their localized expression across brain ages, we constructed a developmental dynamics map (DDM) comprising extensive gene expression profiles throughout prenatal to postnatal stages, which resulted in the discovery of novel microglia-specific gene signatures. One of the interesting readout from DDM is that all the microglia-dense regions exhibit dynamic regulation of few genes at 37 post conception week (pcw), the transition period between pre- and postnatal stages. To validate these findings and correlate them as potential biomarkers, we analyzed the expression of corresponding proteins in hESC-derived human microglia precursors. The cultured microglial precursors showed expression of Pentraxin 3 (PTX3) and SPHK1 as well as several known markers like CD68, Allograft inflammatory factor 1 (AIF1/IBA1). In summary, this study has furnished critical insights into microglia dynamics across human brain ages and cataloged potential transcriptomic fingerprints that can be further exploited for designing novel neurotherapeutics.
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Affiliation(s)
- R Ayana
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Lucknow, India
| | - Shailja Singh
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Lucknow, India.,Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Soumya Pati
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Lucknow, India
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Fernandez-Godino R. Alterations in Extracellular Matrix/Bruch’s Membrane Can Cause the Activation of the Alternative Complement Pathway via Tick-Over. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1074:29-35. [DOI: 10.1007/978-3-319-75402-4_4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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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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Broadgate S, Yu J, Downes SM, Halford S. Unravelling the genetics of inherited retinal dystrophies: Past, present and future. Prog Retin Eye Res 2017; 59:53-96. [PMID: 28363849 DOI: 10.1016/j.preteyeres.2017.03.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 03/21/2017] [Accepted: 03/23/2017] [Indexed: 02/07/2023]
Abstract
The identification of the genes underlying monogenic diseases has been of interest to clinicians and scientists for many years. Using inherited retinal dystrophies as an example of monogenic disease we describe the history of molecular genetic techniques that have been pivotal in the discovery of disease causing genes. The methods that were developed in the 1970's and 80's are still in use today but have been refined and improved. These techniques enabled the concept of the Human Genome Project to be envisaged and ultimately realised. When the successful conclusion of the project was announced in 2003 many new tools and, as importantly, many collaborations had been developed that facilitated a rapid identification of disease genes. In the post-human genome project era advances in computing power and the clever use of the properties of DNA replication has allowed the development of next-generation sequencing technologies. These methods have revolutionised the identification of disease genes because for the first time there is no need to define the position of the gene in the genome. The use of next generation sequencing in a diagnostic setting has allowed many more patients with an inherited retinal dystrophy to obtain a molecular diagnosis for their disease. The identification of novel genes that have a role in the development or maintenance of retinal function is opening up avenues of research which will lead to the development of new pharmacological and gene therapy approaches. Neither of which can be used unless the defective gene and protein is known. The continued development of sequencing technologies also holds great promise for the advent of truly personalised medicine.
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Affiliation(s)
- Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Jing Yu
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Susan M Downes
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, OX3 9DU, UK
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK.
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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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Hunt NC, Hallam D, Karimi A, Mellough CB, Chen J, Steel DHW, Lako M. 3D culture of human pluripotent stem cells in RGD-alginate hydrogel improves retinal tissue development. Acta Biomater 2017; 49:329-343. [PMID: 27826002 DOI: 10.1016/j.actbio.2016.11.016] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 11/01/2016] [Accepted: 11/03/2016] [Indexed: 12/22/2022]
Abstract
No treatments exist to effectively treat many retinal diseases. Retinal pigmented epithelium (RPE) and neural retina can be generated from human embryonic stem cells/induced pluripotent stem cells (hESCs/hiPSCs). The efficacy of current protocols is, however, limited. It was hypothesised that generation of laminated neural retina and/or RPE from hiPSCs/hESCs could be enhanced by three dimensional (3D) culture in hydrogels. hiPSC- and hESC-derived embryoid bodies (EBs) were encapsulated in 0.5% RGD-alginate; 1% RGD-alginate; hyaluronic acid (HA) or HA/gelatin hydrogels and maintained until day 45. Compared with controls (no gel), 0.5% RGD-alginate increased: the percentage of EBs with pigmented RPE foci; the percentage EBs with optic vesicles (OVs) and pigmented RPE simultaneously; the area covered by RPE; frequency of RPE cells (CRALBP+); expression of RPE markers (TYR and RPE65) and the retinal ganglion cell marker, MATH5. Furthermore, 0.5% RGD-alginate hydrogel encapsulation did not adversely affect the expression of other neural retina markers (PROX1, CRX, RCVRN, AP2α or VSX2) as determined by qRT-PCR, or the percentage of VSX2 positive cells as determined by flow cytometry. 1% RGD-alginate increased the percentage of EBs with OVs and/or RPE, but did not significantly influence any other measures of retinal differentiation. HA-based hydrogels had no significant effect on retinal tissue development. The results indicated that derivation of retinal tissue from hESCs/hiPSCs can be enhanced by culture in 0.5% RGD-alginate hydrogel. This RGD-alginate scaffold may be useful for derivation, transport and transplantation of neural retina and RPE, and may also enhance formation of other pigmented, neural or epithelial tissue. STATEMENT OF SIGNIFICANCE The burden of retinal disease is ever growing with the increasing age of the world-wide population. Transplantation of retinal tissue derived from human pluripotent stem cells (PSCs) is considered a promising treatment. However, derivation of retinal tissue from PSCs using defined media is a lengthy process and often variable between different cell lines. This study indicated that alginate hydrogels enhanced retinal tissue development from PSCs, whereas hyaluronic acid-based hydrogels did not. This is the first study to show that 3D culture with a biomaterial scaffold can improve retinal tissue derivation from PSCs. These findings indicate potential for the clinical application of alginate hydrogels for the derivation and subsequent transplantation retinal tissue. This work may also have implications for the derivation of other pigmented, neural or epithelial tissue.
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Affiliation(s)
- Nicola C Hunt
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle NE1 3BZ, UK.
| | - Dean Hallam
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle NE1 3BZ, UK.
| | - Ayesha Karimi
- Cumberland Infirmary, North Cumbria University Hospitals NHS Trust, Carlisle CA2 7HY, UK
| | - Carla B Mellough
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle NE1 3BZ, UK.
| | - Jinju Chen
- School of Mechanical & Systems Engineering, Stephenson Building, Newcastle University, Newcastle upon Tyne, UK.
| | - David H W Steel
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle NE1 3BZ, UK; Sunderland Eye Infirmary, Queen Alexandra Road, Sunderland SR2 9HP, UK.
| | - Majlinda Lako
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle NE1 3BZ, UK.
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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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