1
|
Bhattacharyya N, Chai N, Hafford-Tear NJ, Sadan AN, Szabo A, Zarouchlioti C, Jedlickova J, Leung SK, Liao T, Dudakova L, Skalicka P, Parekh M, Moghul I, Jeffries AR, Cheetham ME, Muthusamy K, Hardcastle AJ, Pontikos N, Liskova P, Tuft SJ, Davidson AE. Deciphering novel TCF4-driven mechanisms underlying a common triplet repeat expansion-mediated disease. PLoS Genet 2024; 20:e1011230. [PMID: 38713708 PMCID: PMC11101122 DOI: 10.1371/journal.pgen.1011230] [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: 11/03/2023] [Revised: 05/17/2024] [Accepted: 03/19/2024] [Indexed: 05/09/2024] Open
Abstract
Fuchs endothelial corneal dystrophy (FECD) is an age-related cause of vision loss, and the most common repeat expansion-mediated disease in humans characterised to date. Up to 80% of European FECD cases have been attributed to expansion of a non-coding CTG repeat element (termed CTG18.1) located within the ubiquitously expressed transcription factor encoding gene, TCF4. The non-coding nature of the repeat and the transcriptomic complexity of TCF4 have made it extremely challenging to experimentally decipher the molecular mechanisms underlying this disease. Here we comprehensively describe CTG18.1 expansion-driven molecular components of disease within primary patient-derived corneal endothelial cells (CECs), generated from a large cohort of individuals with CTG18.1-expanded (Exp+) and CTG 18.1-independent (Exp-) FECD. We employ long-read, short-read, and spatial transcriptomic techniques to interrogate expansion-specific transcriptomic biomarkers. Interrogation of long-read sequencing and alternative splicing analysis of short-read transcriptomic data together reveals the global extent of altered splicing occurring within Exp+ FECD, and unique transcripts associated with CTG18.1-expansions. Similarly, differential gene expression analysis highlights the total transcriptomic consequences of Exp+ FECD within CECs. Furthermore, differential exon usage, pathway enrichment and spatial transcriptomics reveal TCF4 isoform ratio skewing solely in Exp+ FECD with potential downstream functional consequences. Lastly, exome data from 134 Exp- FECD cases identified rare (minor allele frequency <0.005) and potentially deleterious (CADD>15) TCF4 variants in 7/134 FECD Exp- cases, suggesting that TCF4 variants independent of CTG18.1 may increase FECD risk. In summary, our study supports the hypothesis that at least two distinct pathogenic mechanisms, RNA toxicity and TCF4 isoform-specific dysregulation, both underpin the pathophysiology of FECD. We anticipate these data will inform and guide the development of translational interventions for this common triplet-repeat mediated disease.
Collapse
Affiliation(s)
- Nihar Bhattacharyya
- University College London Institute of Ophthalmology, London, United Kingdom
| | - Niuzheng Chai
- University College London Institute of Ophthalmology, London, United Kingdom
| | | | - Amanda N. Sadan
- University College London Institute of Ophthalmology, London, United Kingdom
| | - Anita Szabo
- University College London Institute of Ophthalmology, London, United Kingdom
| | | | - Jana Jedlickova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Szi Kay Leung
- Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Tianyi Liao
- University College London Institute of Ophthalmology, London, United Kingdom
| | - Lubica Dudakova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Pavlina Skalicka
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Mohit Parekh
- University College London Institute of Ophthalmology, London, United Kingdom
| | - Ismail Moghul
- University College London Institute of Ophthalmology, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | - Aaron R. Jeffries
- Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Michael E. Cheetham
- University College London Institute of Ophthalmology, London, United Kingdom
| | | | - Alison J. Hardcastle
- University College London Institute of Ophthalmology, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | - Nikolas Pontikos
- University College London Institute of Ophthalmology, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | - Petra Liskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Stephen J. Tuft
- University College London Institute of Ophthalmology, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | - Alice E. Davidson
- University College London Institute of Ophthalmology, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| |
Collapse
|
2
|
Futterknecht S, Chatzimichail E, Gugleta K, Panos GD, Gatzioufas Z. The Role of Rho Kinase Inhibitors in Corneal Diseases. Drug Des Devel Ther 2024; 18:97-108. [PMID: 38264539 PMCID: PMC10804875 DOI: 10.2147/dddt.s435522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 01/10/2024] [Indexed: 01/25/2024] Open
Abstract
The cornea, as the outermost layer of the eye, plays a crucial role in vision by focusing light onto the retina. Various diseases and injuries can compromise its clarity, leading to impaired vision. This review aims to provide a thorough overview of the pharmacological properties, therapeutic potential and associated risks of Rho-associated protein kinase (ROCK) inhibitors in the management of corneal diseases. The article focuses on four key ROCK inhibitors: Y-27632, fasudil, ripasudil, and netarsudil, providing a comparative examination. Studies supporting the use of ROCK inhibitors highlight their efficacy across diverse corneal conditions. In Fuchs' endothelial corneal dystrophy, studies on the application of Y-27632, ripasudil, and netarsudil demonstrated noteworthy enhancements in corneal clarity, endothelial cell density, and visual acuity. In pseudophakic bullous keratopathy, the injection of Y-27632 together with cultured corneal endothelial cells into the anterior chamber lead to enhanced corneal endothelial cell density and improved visual acuity. Animal models simulating chemical injury to the cornea showed a reduction of neovascularization and epithelial defects after application of fasudil and in a case of iridocorneal endothelial syndrome netarsudil improved corneal edema. Addressing safety considerations, netarsudil and ripasudil, both clinically approved, exhibit adverse events such as conjunctival hyperemia, conjunctival hemorrhage, cornea verticillata, conjunctivitis, and blepharitis. Monitoring patients during treatment becomes crucial to balancing the potential therapeutic benefits with these associated risks. In conclusion, ROCK inhibitors, particularly netarsudil and ripasudil, offer promise in managing corneal diseases. The comparative analysis of their pharmacological properties and studies supporting their efficacy underscore their potential therapeutic significance. However, ongoing research is paramount to comprehensively understand their safety profiles and long-term outcomes in diverse corneal conditions, guiding their optimal application in clinical practice.
Collapse
Affiliation(s)
- Stefan Futterknecht
- Department of Ophthalmology, University Hospital of Basel, Basel, Switzerland
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
| | | | - Konstantin Gugleta
- Department of Ophthalmology, University Hospital of Basel, Basel, Switzerland
- Department of Ophthalmology, School of Medicine, University of Basel, Basel, Switzerland
| | - Georgios D Panos
- Department of Ophthalmology, Queen’s Medical Centre, Nottingham University Hospitals, Nottingham, UK
- Division of Ophthalmology and Visual Sciences, School of Medicine, University of Nottingham, Nottingham, UK
| | - Zisis Gatzioufas
- Department of Ophthalmology, University Hospital of Basel, Basel, Switzerland
- Department of Ophthalmology, School of Medicine, University of Basel, Basel, Switzerland
| |
Collapse
|
3
|
Westin IM, Viberg A, Golovleva I, Byström B. CTG18.1 expansion in transcription factor 4 (TCF4) in corneal graft failure: preliminary study. Cell Tissue Bank 2024:10.1007/s10561-023-10123-y. [PMID: 38206443 DOI: 10.1007/s10561-023-10123-y] [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: 12/28/2022] [Accepted: 11/30/2023] [Indexed: 01/12/2024]
Abstract
Fuchs endothelial corneal dystrophy (FECD) is caused by a corneal endothelial cell loss, leading to corneal edema and visual impairment. The most significant genetic risk factor for FECD is an expansion of the CTG18.1 locus in transcription factor 4 (TCF4). The current treatment for severe FECD is corneal transplantation, with Descemet stripping automated keratoplasty (DSAEK) as a common surgical method. Although successful in most cases, the risk for transplant failure due to diverse causes must be considered. In this study, we investigated if presence of TCF4 CTG18.1 expansion with more than 31 (n ≥ 31) repeats in donated corneal grafts could be a reason for corneal transplant failure after DSAEK. For this, nine consecutively failed DSAEK corneal grafts were genotyped for CTG18.1 repeat length. One-sided Mann-Whitney U test was performed to evaluate if failed DSAEK corneal grafts had longer CTG18.1 repeats than healthy controls from the same population. All failed corneal grafts had CTG18.1 n ≤ 27 with a median of 18 (IQR 8.0) repeats for the longest allele. There was no statistical difference in CTG18.1 repeat lengths between failed corneal grafts and the geographically matched healthy control group. In conclusion, none of the nine failed corneal grafts in our material had CTG18.1 repeat lengths ≥ 31, a cut-off known to have a biological relevance in FECD. Thus, our results suggest that the assessment of donors and inspection of the corneal tissue before the decision for procurement is sufficient, in terms of recognizing FECD in the donor.
Collapse
Affiliation(s)
- Ida Maria Westin
- Department of Medical Biosciences, Medical and Clinical Genetics, Umeå University, Umeå, Sweden.
| | - Andreas Viberg
- Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden
| | - Irina Golovleva
- Department of Medical Biosciences, Medical and Clinical Genetics, Umeå University, Umeå, Sweden
| | - Berit Byström
- Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden
| |
Collapse
|
4
|
Oie Y, Yamaguchi T, Nishida N, Okumura N, Maeno S, Kawasaki R, Jhanji V, Shimazaki J, Nishida K. Systematic Review of the Diagnostic Criteria and Severity Classification for Fuchs Endothelial Corneal Dystrophy. Cornea 2023; 42:1590-1600. [PMID: 37603692 DOI: 10.1097/ico.0000000000003343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 05/28/2023] [Indexed: 08/23/2023]
Abstract
PURPOSE There are no defined diagnostic criteria and severity classification for Fuchs endothelial corneal dystrophy (FECD), which are required for objective standardized assessments. Therefore, we performed a systematic literature review of the current diagnosis and severity classification of FECD. METHODS We searched the Ovid MEDLINE and Web of Science databases for studies published until January 13, 2021. We excluded review articles, conference abstracts, editorials, case reports with <5 patients, and letters. RESULTS Among 468 articles identified, we excluded 173 and 165 articles in the first and second screenings, respectively. Among the 130 included articles, 61 (47%) and 99 (76%) mentioned the diagnostic criteria for FECD and described its severity classification, respectively. Regarding diagnosis, slitlamp microscope alone was the most frequently used device in 31 (51%) of 61 articles. Regarding diagnostic findings, corneal guttae alone was the most common parameter [adopted in 23 articles (38%)]. Regarding severity classification, slitlamp microscopes were used in 88 articles (89%). The original or modified Krachmer grading scale was used in 77 articles (78%), followed by Adami's classification in six (6%). Specular microscopes or Scheimpflug tomography were used in four articles (4%) and anterior segment optical coherence tomography in one (1%). CONCLUSIONS FECD is globally diagnosed by the corneal guttae using slitlamp examination, and its severity is predominantly determined by the original or modified Krachmer grading scale. Objective severity grading using Scheimpflug or anterior segment optical coherence tomography can be applied in the future innovative therapies such as cell injection therapy or novel small molecules.
Collapse
Affiliation(s)
- Yoshinori Oie
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Takefumi Yamaguchi
- Department of Ophthalmology, Tokyo Dental College Ichikawa General Hospital, Ichikawa, Japan
| | - Nozomi Nishida
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Naoki Okumura
- Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan; and
| | - Sayo Maeno
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Ryo Kawasaki
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Vishal Jhanji
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Jun Shimazaki
- Department of Ophthalmology, Tokyo Dental College Ichikawa General Hospital, Ichikawa, Japan
| | - Kohji Nishida
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| |
Collapse
|
5
|
Hu J, Gong X, Fan Y, Aguilar S, Rigo F, Prakash TP, Corey DR, Mootha VV. Modulation of Gene Expression in the Eye with Antisense Oligonucleotides. Nucleic Acid Ther 2023; 33:339-347. [PMID: 37917066 PMCID: PMC10698777 DOI: 10.1089/nat.2023.0044] [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: 08/18/2023] [Accepted: 09/16/2023] [Indexed: 11/03/2023] Open
Abstract
One advantage of antisense oligonucleotides (ASOs) for drug development is their long-lasting gene knockdown after administration in vivo. In this study, we examine the effect on gene expression after intraocular injection in target tissues in the eye. We examined expression levels of the Malat1 gene after intracameral or intravitreal (IV) injection of an anti-Malat1 ASO in corneal epithelium/stroma, corneal endothelium, lens capsule epithelium, neurosensory retina, and retinal pigment epithelium/choroid of the mouse eye. We assessed potency of the compound at 7 days as well as duration of the gene knockdown at 14, 28, 60, 90, and 120 days. The ASO was more potent when delivered by IV injection relative to intracameral injection, regardless of whether the tissues analyzed were at the front or back of the eye. For corneal endothelium, inhibition was >50% after 120 days for ASO at 50 μg. At IV dosages of 6 μg, we observed >75% inhibition of gene expression in the retina and lens epithelium for up to 120 days. ASOs have potential as long-lasting gene knockdown agents in the mouse eye, but efficacy varies depending on the specific ocular target tissue and injection protocol.
Collapse
Affiliation(s)
- Jiaxin Hu
- Department of Pharmacology and Biochemistry, University of Texas, Southwestern Medical Center, Dallas, Texas, USA
| | - Xin Gong
- Department of Ophthalmology, and University of Texas, Southwestern Medical Center, Dallas, Texas, USA
| | - Yan Fan
- Department of Ophthalmology, and University of Texas, Southwestern Medical Center, Dallas, Texas, USA
| | - Selina Aguilar
- Department of Pharmacology and Biochemistry, University of Texas, Southwestern Medical Center, Dallas, Texas, USA
- Department of Ophthalmology, and University of Texas, Southwestern Medical Center, Dallas, Texas, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, California, USA
| | | | - David R. Corey
- Department of Pharmacology and Biochemistry, University of Texas, Southwestern Medical Center, Dallas, Texas, USA
| | - V. Vinod Mootha
- Department of Ophthalmology, and University of Texas, Southwestern Medical Center, Dallas, Texas, USA
- Eugene McDermott Center for Human Growth and Development, University of Texas, Southwestern Medical Center, Dallas, Texas, USA
| |
Collapse
|
6
|
Hu J, Shen X, Kheirabadi M, Streeter MD, Qian Z, Mootha VV, Corey DR. Targeting the Expanded TCF4/Fuchs' Endothelial Corneal Dystrophy CUG Repeat with Morpholino Peptide Conjugates. ACS OMEGA 2023; 8:42797-42802. [PMID: 38024683 PMCID: PMC10652360 DOI: 10.1021/acsomega.3c05634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/04/2023] [Accepted: 10/12/2023] [Indexed: 12/01/2023]
Abstract
Fuchs' corneal endothelial dystrophy (FECD) is a major cause of vision loss. Corneal transplantation is the only effective curative treatment, but this surgery has limitations. A pharmacological intervention would complement surgery and be beneficial for many patients. FECD is caused by an expanded CUG repeat within intron 2 of the TCF4 RNA. Agents that recognize the expanded repeat can reverse the splicing defects associated with the disease. Successful drug development will require diverse strategies for optimizing the efficacy of anti-CUG oligomers. In this study, we evaluate anti-CUG morpholinos conjugated to cyclic cell penetrating peptides. The morpholino domain of the conjugate is complementary to the repeat, while the peptide has been optimized for import across cell membranes. We show that morpholino conjugates can enter corneal endothelial cells and block the CUG RNA foci associated with the disease. These experiments support morpholino peptide conjugates as an approach for developing anti-CUG therapies for FECD.
Collapse
Affiliation(s)
- Jiaxin Hu
- Department
of Pharmacology and Biochemistry, UT Southwestern
Medical Center, 6001 Forest Park Road, Dallas, Texas 75390, United States
| | - Xiulong Shen
- Entrada
Therapeutics Inc., Boston, Massachusetts 02210, United States
| | | | | | - Ziqing Qian
- Entrada
Therapeutics Inc., Boston, Massachusetts 02210, United States
| | - V. Vinod Mootha
- Department
of Ophthalmology, UT Southwestern Medical
Center, Dallas, Texas 75390, United States
- McDermott
Center for Human Growth and Development, UT Southwestern Medical Center, Dallas, Texas 75390, United States
| | - David R. Corey
- Department
of Pharmacology and Biochemistry, UT Southwestern
Medical Center, 6001 Forest Park Road, Dallas, Texas 75390, United States
| |
Collapse
|
7
|
Wąsowska A, Sendecki A, Boguszewska-Chachulska A, Teper S. Polygenic Risk Score and Rare Variant Burden Identified by Targeted Sequencing in a Group of Patients with Pigment Epithelial Detachment in Age-Related Macular Degeneration. Genes (Basel) 2023; 14:1707. [PMID: 37761846 PMCID: PMC10531282 DOI: 10.3390/genes14091707] [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: 06/16/2023] [Revised: 08/22/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023] Open
Abstract
A subset of ophthalmic imaging examination results from 334 patients were subjected to reanalysis to identify a specific group of patients with pigment epithelial detachment (PED) in at least one eye. Overall, we found a subgroup of 47 patients manifesting PED and studied their genotypes in comparison to those of patients with age-related macular degeneration without PED and healthy controls. We established a polygenic risk score that allowed the explanation of 16.3% of the variation within the disease. The highest predictive value was achieved for a model consisting of six non-coding variants: rs760306 (BEST1), rs148662546 (BEST1), rs11569560 (C3), rs74600252 (GUCA1B), rs2240688 (PROM1), and rs185507582 (TCF4). The risk of PED occurrence was found to be the highest in the first tercile, showing a 7.89-fold higher risk compared to the third tercile for AMD without PED (95% CI: 2.87; 21.71, p < 0.001) and a 7.22-fold higher risk compared to the healthy controls (95% CI: 2.60; 20.06, p < 0.001). In addition, we focused on rare variants in targeted genes. The rare variants' burden was compared among the groups, but no statistical significance was observed in the number of rare variants, predicted functional effects, or pathogenicity classification.
Collapse
Affiliation(s)
- Anna Wąsowska
- Chair and Clinical Department of Ophthalmology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-055 Katowice, Poland
- Genomed S.A., 02-972 Warszawa, Poland
| | - Adam Sendecki
- Chair and Clinical Department of Ophthalmology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-055 Katowice, Poland
| | | | - Sławomir Teper
- Chair and Clinical Department of Ophthalmology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-055 Katowice, Poland
| |
Collapse
|
8
|
Chan MF, Pan P, Wolfreys FD. Novel Mechanisms Guide Innovative Molecular-Based Therapeutic Strategies for Fuchs Endothelial Corneal Dystrophy. Cornea 2023; 42:929-933. [PMID: 37318135 PMCID: PMC10313750 DOI: 10.1097/ico.0000000000003292] [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: 07/27/2022] [Accepted: 03/13/2023] [Indexed: 06/16/2023]
Abstract
ABSTRACT Major advances in genomics have dramatically increased our understanding of Fuchs endothelial corneal dystrophy (FECD) and identified diverse genetic causes and associations. Biomarkers derived from these studies have the potential to inform both clinical treatment and yield novel therapeutics for this corneal dystrophy.
Collapse
Affiliation(s)
- Matilda F. Chan
- Department of Ophthalmology, University of California, San Francisco, California, USA
- Francis I. Proctor Foundation, University of California, San Francisco, California, USA
| | - Peipei Pan
- Center for Cerebrovascular Research, Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA, USA
| | - Finn D. Wolfreys
- Department of Ophthalmology, University of California, San Francisco, California, USA
| |
Collapse
|
9
|
Kumar R, Sinha NR, Mohan RR. Corneal gene therapy: Structural and mechanistic understanding. Ocul Surf 2023; 29:279-297. [PMID: 37244594 DOI: 10.1016/j.jtos.2023.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/18/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Cornea, a dome-shaped and transparent front part of the eye, affords 2/3rd refraction and barrier functions. Globally, corneal diseases are the leading cause of vision impairment. Loss of corneal function including opacification involve the complex crosstalk and perturbation between a variety of cytokines, chemokines and growth factors generated by corneal keratocytes, epithelial cells, lacrimal tissues, nerves, and immune cells. Conventional small-molecule drugs can treat mild-to-moderate traumatic corneal pathology but requires frequent application and often fails to treat severe pathologies. The corneal transplant surgery is a standard of care to restore vision in patients. However, declining availability and rising demand of donor corneas are major concerns to maintain ophthalmic care. Thus, the development of efficient and safe nonsurgical methods to cure corneal disorders and restore vision in vivo is highly desired. Gene-based therapy has huge potential to cure corneal blindness. To achieve a nonimmunogenic, safe and sustained therapeutic response, the selection of a relevant genes, gene editing methods and suitable delivery vectors are vital. This article describes corneal structural and functional features, mechanistic understanding of gene therapy vectors, gene editing methods, gene delivery tools, and status of gene therapy for treating corneal disorders, diseases, and genetic dystrophies.
Collapse
Affiliation(s)
- Rajnish Kumar
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; One-health One-medicine Vision Research Program, Departments of Veterinary Medicine and Surgery & Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA; Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow campus, UP, 226028, India
| | - Nishant R Sinha
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; One-health One-medicine Vision Research Program, Departments of Veterinary Medicine and Surgery & Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA
| | - Rajiv R Mohan
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; One-health One-medicine Vision Research Program, Departments of Veterinary Medicine and Surgery & Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA; Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, 65212, USA.
| |
Collapse
|
10
|
Tsedilina TR, Sharova E, Iakovets V, Skorodumova LO. Systematic review of SLC4A11, ZEB1, LOXHD1, and AGBL1 variants in the development of Fuchs' endothelial corneal dystrophy. Front Med (Lausanne) 2023; 10:1153122. [PMID: 37441688 PMCID: PMC10333596 DOI: 10.3389/fmed.2023.1153122] [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: 01/28/2023] [Accepted: 03/30/2023] [Indexed: 07/15/2023] Open
Abstract
Introduction The pathogenic role of variants in TCF4 and COL8A2 in causing Fuchs' endothelial corneal dystrophy (FECD) is not controversial and has been confirmed by numerous studies. The causal role of other genes, SLC4A11, ZEB1, LOXHD1, and AGBL1, which have been reported to be associated with FECD, is more complicated and less obvious. We performed a systematic review of the variants in the above-mentioned genes in FECD cases, taking into account the currently available population frequency information, transcriptomic data, and the results of functional studies to assess their pathogenicity. Methods Search for articles published in 2005-2022 was performed manually between July 2022 and February 2023. We searched for original research articles in peer-reviewed journals, written in English. Variants in the genes of interest identified in patients with FECD were extracted for the analysis. We classified each presented variant by pathogenicity status according to the ACMG criteria implemented in the Varsome tool. Diagnosis, segregation data, presence of affected relatives, functional analysis results, and gene expression in the corneal endothelium were taken into account. Data on the expression of genes of interest in the corneal endothelium were extracted from articles in which transcriptome analysis was performed. The identification of at least one variant in a gene classified as pathogenic or significantly associated with FECD was required to confirm the causal role of the gene in FECD. Results The analysis included 34 articles with 102 unique ZEB1 variants, 20 articles with 64 SLC4A11 variants, six articles with 26 LOXHD1 variants, and five articles with four AGBL1 variants. Pathogenic status was confirmed for seven SLC4A11 variants found in FECD. No variants in ZEB1, LOXHD1, and AGBL1 genes were classified as pathogenic for FECD. According to the transcriptome data, AGBL1 and LOXHD1 were not expressed in the corneal endothelium. Functional evidence for the association of LOXHD1, and AGBL1 with FECD was conflicting. Conclusion Our analysis confirmed the causal role of SLC4A11 variants in the development of FECD. The causal role of ZEB1, LOXHD1, and AGBL1 variants in FECD has not been confirmed. Further evidence from familial cases and functional analysis is needed to confirm their causal roles in FECD.
Collapse
Affiliation(s)
- Tatiana Romanovna Tsedilina
- Laboratory of Human Molecular Genetics, Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Elena Sharova
- Laboratory of Human Molecular Genetics, Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Valeriia Iakovets
- Laboratory of Human Molecular Genetics, Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
- I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Liubov Olegovna Skorodumova
- Laboratory of Human Molecular Genetics, Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| |
Collapse
|
11
|
Hu J, Gong X, Johnson ST, Corey DR, Mootha VV. The TCF4 Trinucleotide Repeat Expansion of Fuchs' Endothelial Corneal Dystrophy: Implications for the Anterior Segment of the Eye. Invest Ophthalmol Vis Sci 2023; 64:16. [PMID: 37204786 PMCID: PMC10204776 DOI: 10.1167/iovs.64.5.16] [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: 01/19/2023] [Accepted: 04/24/2023] [Indexed: 05/20/2023] Open
Abstract
Purpose In the United States, 70% of Fuchs' endothelial corneal dystrophy (FECD) cases are caused by an intronic trinucleotide repeat expansion in the TCF4 gene. CUG repeat RNA transcripts from this expansion accumulate as nuclear foci in the corneal endothelium. In this study, we sought to detect foci in other anterior segment cell types and assess their molecular impact. Methods We examined CUG repeat RNA foci appearance, expression of downstream affected genes, gene splicing, and TCF4 RNA expression in corneal endothelium, corneal stromal keratocytes, corneal epithelium, trabecular meshwork cells, and lens epithelium. Results CUG repeat RNA foci, the hallmark of FECD in corneal endothelium (found in 84% of endothelial cells), are less detectable in trabecular meshwork cells (41%), much less prevalent in stromal keratocytes (11%) or corneal epithelium (4%), and absent in lens epithelium. With few exceptions including mis-splicing in the trabecular meshwork, differential gene expression and splicing changes associated with the expanded repeat in corneal endothelial cells are not observed in other cell types. Expression of the TCF4 transcripts including full-length isoforms containing the repeat sequence at the 5' end is much higher in the corneal endothelium or trabecular meshwork than in the corneal stroma or corneal epithelium. Conclusions Expression of the CUG repeat containing TCF4 transcripts is higher in the corneal endothelium, likely contributing to foci formation and the large molecular and pathologic impact on those cells. Further studies are warranted to examine any glaucoma risk and impact of the observed foci in the trabecular meshwork of these patients.
Collapse
Affiliation(s)
- Jiaxin Hu
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Xin Gong
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Samantha T. Johnson
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - David R. Corey
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - V. Vinod Mootha
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| |
Collapse
|
12
|
Liu S, Sadan AN, Muthusamy K, Zarouchlioti C, Jedlickova J, Pontikos N, Thaung C, Hardcastle AJ, Netukova M, Skalicka P, Dudakova L, Bunce C, Tuft SJ, Davidson AE, Liskova P. Phenotype and genotype of concurrent keratoconus and Fuchs endothelial corneal dystrophy. Acta Ophthalmol 2023. [PMID: 36883248 DOI: 10.1111/aos.15654] [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: 08/15/2022] [Revised: 02/12/2023] [Accepted: 02/16/2023] [Indexed: 03/09/2023]
Abstract
PURPOSE To characterise the phenotype and genotype of concurrent keratoconus and Fuchs endothelial corneal dystrophy (KC + FECD). METHODS We recruited 20 patients with concurrent KC + FECD for a retrospective observational case series from the United Kingdom and the Czech Republic. We compared eight parameters of corneal shape (Pentacam, Oculus) with two groups of age-matched controls who had either isolated keratoconus (KC) or isolated FECD. We genotyped probands for an intronic triplet TCF4 repeat expansion (CTG18.1) and the ZEB1 variant c.1920G >T p.(Gln640His). RESULTS The median age at diagnosis of patients with KC + FECD was 54 (interquartile range 46 to 66) years, with no evidence of KC progression (median follow-up 84 months, range 12 to 120 months). The mean (standard deviation (SD)) of the minimum corneal thickness, 493 (62.7) μm, was greater than eyes with KC, 458 (51.1) μm, but less than eyes with FECD, 590 (55.6) μm. Seven other parameters of corneal shape were more like KC than FECD. Seven (35%) probands with KC + FECD had a TCF4 repeat expansion of ≥50 compared to five controls with isolated FECD. The average of the largest TCF4 expansion in cases with KC + FECD (46 repeats, SD 36 repeats) was similar to the age-matched controls with isolated FECD (36 repeats, SD 28 repeats; p = 0.299). No patient with KC + FECD harboured the ZEB1 variant. CONCLUSIONS The KC + FECD phenotype is consistent with KC but with superimposed stromal swelling from endothelial disease. The proportion of cases with a TCF4 expansion is similar in concurrent KC + FECD and age-matched controls with isolated FECD.
Collapse
Affiliation(s)
- Siyin Liu
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK.,UCL Institute of Ophthalmology, London, UK
| | | | - Kirithika Muthusamy
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital, London, UK
| | | | - Jana Jedlickova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | | | - Caroline Thaung
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital, London, UK
| | | | - Magdalena Netukova
- Eye Clinic, Medical Faculty Charles University, Teaching Hospital Kralovske Vinohrady, Prague, Czech Republic
| | - Pavlina Skalicka
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.,Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Lubica Dudakova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Catey Bunce
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital, London, UK
| | - Stephen J Tuft
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital, London, UK
| | | | - Petra Liskova
- UCL Institute of Ophthalmology, London, UK.,Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.,Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| |
Collapse
|
13
|
DNA methylation changes and increased mRNA expression of coagulation proteins, factor V and thrombomodulin in Fuchs endothelial corneal dystrophy. Cell Mol Life Sci 2023; 80:62. [PMID: 36773096 PMCID: PMC9922242 DOI: 10.1007/s00018-023-04714-x] [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: 09/30/2022] [Revised: 01/12/2023] [Accepted: 01/31/2023] [Indexed: 02/12/2023]
Abstract
Late-onset Fuchs endothelial corneal dystrophy (FECD) is a disease affecting the corneal endothelium (CE), associated with a cytosine-thymine-guanine repeat expansion at the CTG18.1 locus in the transcription factor 4 (TCF4) gene. It is unknown whether CTG18.1 expansions affect global methylation including TCF4 gene in CE or whether global CE methylation changes at advanced age. Using genome-wide DNA methylation array, we investigated methylation in CE from FECD patients with CTG18.1 expansions and studied the methylation in healthy CE at different ages. The most revealing DNA methylation findings were analyzed by gene expression and protein analysis. 3488 CpGs had significantly altered methylation pattern in FECD though no substantial changes were found in TCF4. The most hypermethylated site was in a predicted promoter of aquaporin 1 (AQP1) gene, and the most hypomethylated site was in a predicted promoter of coagulation factor V (F5 for gene, FV for protein). In FECD, AQP1 mRNA expression was variable, while F5 gene expression showed a ~ 23-fold increase. FV protein was present in both healthy and affected CE. Further gene expression analysis of coagulation factors interacting with FV revealed a ~ 34-fold increase of thrombomodulin (THBD). THBD protein was detected only in CE from FECD patients. Additionally, we observed an age-dependent hypomethylation in elderly healthy CE.Thus, tissue-specific genome-wide and gene-specific methylation changes associated with altered gene expression were discovered in FECD. TCF4 pathological methylation in FECD because of CTG18.1 expansion was ruled out.
Collapse
|
14
|
Heckenlaible NJ, Dun C, Prescott C, Eghrari AO, Woreta F, Makary MA, Srikumaran D. Predictors of Receiving Keratoplasty for Fuchs' Endothelial Corneal Dystrophy among Medicare Beneficiaries. Ophthalmology 2023; 130:28-38. [PMID: 35932840 DOI: 10.1016/j.ophtha.2022.07.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 01/06/2023] Open
Abstract
PURPOSE To identify factors associated with receipt of endothelial keratoplasty (EK) and penetrating keratoplasty (PK) in patients with Fuchs' endothelial corneal dystrophy (FECD). DESIGN Retrospective cohort study. PARTICIPANTS Medicare beneficiaries 65 years of age or older with a FECD diagnosis between 2011 and 2019. METHODS The 100% Medicare fee-for-service administrative claims database was queried for treatment-naïve FECD patients. A multivariate logistic regression model including age, race and ethnicity, sex, geography, ocular comorbidities and surgeries, Charlson comorbidity index (CCI), and socioeconomic status was used to identify factors associated with receipt of EK and PK. Kaplan-Meier survival analyses were used to determine the rate of EK after cataract or complex or other anterior segment surgery. MAIN OUTCOME MEASURES Factors associated with receipt of an EK or PK, plus rate of EK after cataract or complex or other anterior segment surgery. RESULTS Of 719 066 beneficiaries identified, 31 372 (4.4%) received an EK and 2426 (0.3%) received a PK. In a multivariate analysis, female sex decreased likelihood of both EK and PK (adjusted odds ratio 0.83 [95% confidence interval 0.81-0.85] and 0.84 [0.78-0.92], respectively), while Western residence (1.33 [1.29-1.38]; 1.25 [1.11-1.42]) compared to Southern and history of complex or other anterior segment surgery (1.62 [1.54-1.70]; 5.52 [4.97-6.12]) increased the likelihood of both. Compared to Whites, the likelihood of EK was decreased for Black (0.76 [0.72-0.80]), Asian or Pacific Islander (0.54 [0.48-0.61]), and Hispanic or Latino (0.62 [0.55-0.70]) race and ethnicity, while for the same groups likelihood of PK was increased (for Black 1.32 [1.14-1.53]; Asian/Pacific Islander 1.46 [1.13-1.89]; and Hispanic/Latino 1.62 [1.25-2.11]). Following cataract or complex/other anterior segment surgery, rates of EK were 1.3% and 3.3% at 1 year and 2.3% and 5.6% at 8 years, respectively. CONCLUSIONS In a multivariate analysis, women beneficiaries are less likely to receive EK or PK for FECD compared with men, whereas non-White beneficiaries are less likely to receive EK and more likely to receive PK compared with White beneficiaries.
Collapse
Affiliation(s)
- Nicolas J Heckenlaible
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Chen Dun
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Christina Prescott
- NYU Langone Eye Center, NYU Grossman School of Medicine, New York, New York
| | - Allen O Eghrari
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Fasika Woreta
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Martin A Makary
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland; Johns Hopkins University Carey Business School, Johns Hopkins University, Baltimore, Maryland
| | - Divya Srikumaran
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland.
| |
Collapse
|
15
|
Skalicka P, Jedlickova J, Horinek A, Trkova M, Davidson AE, Tuft SJ, Dudakova L, Liskova P. Snail Track Lesion with Flat Keratometry in Anterior Segment Dysgenesis Caused by a Novel FOXC1 Variant. J Clin Med 2022; 11:jcm11175166. [PMID: 36079096 PMCID: PMC9457150 DOI: 10.3390/jcm11175166] [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: 07/28/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
We report the phenotype of a 15-year-old female patient with anterior segment dysgenesis (ASD) caused by a novel heterozygous loss-of-function FOXC1 variant. The proband underwent an ophthalmic examination as well as a molecular genetic investigation comprising exome sequencing, a single nucleotide polymorphism array to access copy number and Sanger sequencing to exclude non-coding causal variants. There was bilateral mild iris hypoplasia with pupil deformation and iridocorneal adhesions. In addition to these features of ASD, the corneas were flat, with mean keratometry readings of 38.8 diopters in the right eye and 39.5 diopters in the left eye. There was a snail track lesion of the left cornea at the level of the Descemet membrane. The central corneal endothelial cell density was reduced bilaterally at 1964 and 1373 cells/mm2 in the right and left eyes, respectively. Molecular genetic analysis revealed that the proband was a carrier of a novel heterozygous frameshifting variant in FOXC1, c.605del p.(Pro202Argfs*113). Neither parent had this change, suggesting a de novo origin which was supported by paternity testing. We found no possibly pathogenic variants in the other genes associated with posterior corneal dystrophies or ASD. Further studies are warranted to verify whether there is a true association between snail track lesions, corneal flattening, and pathogenic variants in FOXC1.
Collapse
Affiliation(s)
- Pavlina Skalicka
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | - Jana Jedlickova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | - Ales Horinek
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | | | | | - Stephen J. Tuft
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Moorfields Eye Hospital, London EC1V 2PD, UK
| | - Lubica Dudakova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | - Petra Liskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Correspondence: ; Tel.: +420-224-967-139
| |
Collapse
|
16
|
Loss of Corneal Nerves and Corneal Haze in Patients with Fuchs' Endothelial Corneal Dystrophy with the Transcription Factor 4 Gene Trinucleotide Repeat Expansion. OPHTHALMOLOGY SCIENCE 2022; 3:100214. [PMID: 36275201 PMCID: PMC9563205 DOI: 10.1016/j.xops.2022.100214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 07/30/2022] [Accepted: 08/19/2022] [Indexed: 11/22/2022]
Abstract
Objective Seventy percent of Fuchs' endothelial corneal dystrophy (FECD) cases are caused by an intronic trinucleotide repeat expansion in the transcription factor 4 gene (TCF4). The objective of this study was to characterize the corneal subbasal nerve plexus and corneal haze in patients with FECD with (RE+) and without the trinucleotide repeat expansion (RE-) and to assess the correlation of these parameters with disease severity. Design Cross-sectional, single-center study. Participants Fifty-two eyes of 29 subjects with a modified Krachmer grade of FECD severity from 1 to 6 were included in the study. Fifteen of the 29 subjects carried an expanded TCF4 allele length of ≥ 40 cytosine-thymine-guanine repeats (RE+). Main Outcomes Measures In vivo confocal microscopy assessments of corneal nerve fiber length (CNFL), corneal nerve branch density, corneal nerve fiber density (CNFD), and anterior corneal stromal backscatter (haze); Scheimpflug tomography densitometry measurements of haze in anterior, central, and posterior corneal layers. Results Using confocal microscopy, we detected a negative correlation between FECD severity and both CNFL and CNFD in the eyes of RE+ subjects (Spearman ρ = -0.45, P = 0.029 and ρ = -0.62, P = 0.0015, respectively) but not in the eyes of RE- subjects. Additionally, CNFD negatively correlated with the repeat length of the expanded allele in the RE+ subjects (Spearman ρ = -0.42, P = 0.038). We found a positive correlation between anterior stromal backscatter and severity in both the RE+ and RE- groups (ρ = 0.60, P = 0.0023 and ρ = 0.44, P = 0.024, respectively). The anterior, central, and posterior Scheimpflug densitometry measurements also positively correlated with severity in both the RE+ and RE- groups (P = 5.5 × 10-5, 2.5 × 10-4, and 2.9 × 10-4, respectively, after adjusting for the expansion status in a pooled analysis. However, for patients with severe FECD (Krachmer grades 5 and 6), the posterior densitometry measurements were higher in the RE+ group than in the RE- group (P < 0.05). Conclusions Loss of corneal nerves in FECD supports the classification of the TCF4 trinucleotide repeat expansion disorder as a neurodegenerative disease. Haze in the anterior, central, and posterior cornea correlate with severity, irrespective of the genotype. Quantitative assessments of corneal nerves and corneal haze may be useful to gauge and monitor FECD disease severity in RE+ patients.
Collapse
|
17
|
Thaung C, Davidson AE. Fuchs endothelial corneal dystrophy: current perspectives on diagnostic pathology and genetics-Bowman Club Lecture. BMJ Open Ophthalmol 2022; 7:bmjophth-2022-001103. [PMID: 36161831 PMCID: PMC9341215 DOI: 10.1136/bmjophth-2022-001103] [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: 06/28/2022] [Accepted: 07/01/2022] [Indexed: 11/18/2022] Open
Abstract
Fuchs endothelial corneal dystrophy (FECD) was first described over a century ago. Since then, we have learnt much about its clinical manifestations, surgical and non-surgical treatment, microscopic appearance and pathogenesis. Over the past decade, significant advances have been made with respect to our understanding of FECD genetics. This progress now enables us to appreciate that FECD in fact describes multiple entities with distinct underlying genetic causes. For example, an early-onset and rare form of the disease has been attributed to missense mutations in the COL8A2 gene, whereas the vast majority of late-onset cases can be attributed to a non-coding repeat expansion within the TCF4 gene.FECD is one of the most common indications for corneal transplantation. In recent years, attention has turned to alternative treatment techniques that do not depend on donor tissue supply. The design and development of these non-surgical treatment approaches have benefited from increased knowledge of pathogenesis.This review will cover our current knowledge about the histology and genetics of FECD, and how combining these interdisciplinary approaches might may improve diagnostic accuracy and aid the development of therapeutics for this common and visually disabling disease.
Collapse
Affiliation(s)
- Caroline Thaung
- Moorfields Eye Hospital, London, UK .,Department of Eye Pathology, University College London Institute of Ophthalmology, London, UK
| | - Alice E Davidson
- University College London Institute of Ophthalmology, London, UK
| |
Collapse
|
18
|
Kannabiran C, Chaurasia S, Ramappa M, Mootha VV. Update on the genetics of corneal endothelial dystrophies. Indian J Ophthalmol 2022; 70:2239-2248. [PMID: 35791103 PMCID: PMC9426112 DOI: 10.4103/ijo.ijo_992_22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Corneal endothelial dystrophies are a heterogeneous group of diseases with different modes of inheritance and genetic basis for each dystrophy. The genes associated with these diseases encode transcription factors, structural components of the stroma and Descemet membrane, cell transport proteins, and others. Congenital hereditary endothelial dystrophy (CHED) is associated with mutations in two genes, OVOL2 and SLC4A11, for dominant and recessive forms of CHED, respectively. Mutations in three genes are known to cause posterior polymorphous corneal dystrophy (PPCD). They are OVOL2 (PPCD1), ZEB1 (PPCD3), and GRHL1 (PPCD4). The PPCD2 locus involving the collagen gene COL8A2 on chromosome 1 is disputed due to insufficient evidence. Mutations in the COL8A2 gene are associated with early-onset Fuchs’ endothelial corneal dystrophy (FECD). Several genes have been associated with the more common, late-onset FECD. Alterations in each of these genes occur in a fraction of patients, and the most prevalent genetic alteration in FECD patients across the world is a triplet repeat expansion in the TCF4 gene. Knowledge of the genetics of corneal endothelial dystrophies has considerably advanced within the last decade and has contributed to better diagnosis of these dystrophies as well as opened up the possibility of novel therapeutic approaches based on the molecular mechanisms involved. The functions of genes identified to date provide insights into the pathogenic mechanisms involved in each disorder.
Collapse
Affiliation(s)
- Chitra Kannabiran
- Kallam Anji Reddy Molecular Genetics Laboratory, Prof Brien Holden Eye Research Centre, L.V. Prasad Eye Institute, Hyderabad, Telangana, India
| | - Sunita Chaurasia
- Centre for Rare Eye Diseases and Ocular Genetics; The Cornea Institute; Jasti V Ramanamma Children's Eye Care Center, L.V. Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India
| | - Muralidhar Ramappa
- Centre for Rare Eye Diseases and Ocular Genetics; The Cornea Institute; Jasti V Ramanamma Children's Eye Care Center, L.V. Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India
| | | |
Collapse
|
19
|
Wong YL, Liu S, Walkden A. Current Perspectives on Corneal Transplantation (Part 2). Clin Ophthalmol 2022; 16:647-659. [PMID: 35282168 PMCID: PMC8904263 DOI: 10.2147/opth.s349582] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 01/17/2022] [Indexed: 11/23/2022] Open
Abstract
Disease of the cornea is the third leading cause of blindness worldwide. Corneal graft surgery is one of the most successful forms of solid organ transplantations in humans, with ever increasing developments in surgical technique. To date, approximately 4504 corneal transplants are performed in the UK each year. While full thickness transplantation was the most commonly performed keratoplasty over the last few decades, selective lamellar transplantation of the diseased layers of the cornea has been universally adopted. This comprehensive review aims to provide an updated synthesis on different types of corneal transplantations, their treatment outcomes, and the associated complications of each procedure both in adult and pediatric populations. In addition, we also present an up-to-date summary of the emerging therapeutic approaches that have the potential to reduce the demand for donor-dependent keratoplasty.
Collapse
Affiliation(s)
- Yee Ling Wong
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Siyin Liu
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Andrew Walkden
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- Correspondence: Andrew Walkden, Manchester Royal Eye Hospital, Oxford Road, Manchester, M13 9WL, UK, Email
| |
Collapse
|
20
|
Okumura N, Padmanaban V, Balaji JJ, Srinivasan B, Hanada N, Komori Y, Yoshii K, Srinivas SP, Koizumi N, Padmanabhan P. Clinical, Morphological, and Optical Correlates of Visual Function in Patients With Fuchs Endothelial Corneal Dystrophy. Cornea 2022; 41:171-176. [PMID: 34369393 DOI: 10.1097/ico.0000000000002814] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 05/17/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE The purpose of this article was to study the clinical, optical, and morphological correlates of visual function in patients with Fuchs endothelial corneal dystrophy (FECD). METHODS The case records were analyzed for patients diagnosed with FECD between September 2019 and March 2020. The best-corrected visual acuity (BCVA) was recorded as decimal visual acuity and converted to the logarithm of the minimum angle of resolution units. Contrast sensitivity was measured with the Pelli-Robson contrast sensitivity test. Corneal alterations, including central corneal thickness, depression of the posterior cornea, and corneal densitometry values, were evaluated using Scheimpflug images. Corneal epithelial thickness was measured by spectral-domain optical coherence tomography. RESULTS A total of 107 eyes of 61 patients (18 male and 43 female) with FECD were retrospectively investigated. The Spearman rank correlation coefficient showed moderate correlation between BCVA and contrast sensitivity (ρ = -0.66, P < 0.001), with some patients maintaining relatively good BCVA but having reduced contrast sensitivity. Logistic regression analysis demonstrated that age, central corneal thickness, depression of the posterior cornea, and epithelial thickening were negatively associated with contrast sensitivity but not with BCVA. CONCLUSIONS Contrast sensitivity is a useful tool for assessing visual dysfunction and should be incorporated into the assessment protocol of patients with FECD. Alterations in the cornea, including central corneal thickness, depression of the posterior cornea, and epithelial thickening, might be objective parameters that can help the clinician in grading the severity of the disease and tracking its progression.
Collapse
Affiliation(s)
- Naoki Okumura
- Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Vasanthi Padmanaban
- Department of Cornea and Refractive Surgery, Sankara Nethralaya, Chennai, India
| | | | - Bhaskar Srinivasan
- Department of Cornea and Refractive Surgery, Sankara Nethralaya, Chennai, India
| | - Naoya Hanada
- Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Yuya Komori
- Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Kengo Yoshii
- Department of Mathematics and Statistics in Medical Sciences, Kyoto Prefectural University of Medicine, Kyoto, Japan; and
| | | | - Noriko Koizumi
- Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Prema Padmanabhan
- Department of Cornea and Refractive Surgery, Sankara Nethralaya, Chennai, India
| |
Collapse
|
21
|
Girach A, Audo I, Birch DG, Huckfeldt RM, Lam BL, Leroy BP, Michaelides M, Russell SR, Sallum JM, Stingl K, Tsang SH, Yang P. RNA-based therapies in inherited retinal diseases. Ther Adv Ophthalmol 2022; 14:25158414221134602. [PMID: 36388727 PMCID: PMC9643766 DOI: 10.1177/25158414221134602] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 10/05/2022] [Indexed: 11/10/2023] Open
Abstract
Inherited retinal diseases (IRDs) are a genetically and phenotypically heterogeneous group of genetic eye disorders. There are more than 300 disease entities, and together this group of disorders affects millions of people globally and is a frequent cause of blindness or low-vision certification. However, each type is rare or ultra-rare. Characteristically, the impaired vision in IRDs is due to retinal photoreceptor dysfunction and loss resulting from mutation in a gene that codes for a retinal protein. Historically, IRDs have been considered incurable and individuals living with these blinding conditions could be offered only supportive care. However, the treatment landscape for IRDs is beginning to evolve. Progress is being made, driven by improvements in understanding of genotype-phenotype relationships, through advances in molecular genetic testing and retinal imaging. Alongside this expanding knowledge of IRDs, the current era of precision medicine is fueling a growth in targeted therapies. This has resulted in the first treatment for an IRD being approved. Several other therapies are currently in development in the IRD space, including RNA-based therapies, gene-based therapies (such as augmentation therapy and gene editing), cell therapy, visual prosthetics, and optogenetics. RNA-based therapies are a novel approach within precision medicine that have demonstrated success, particularly in rare diseases. Three antisense oligonucleotides (AONs) are currently in development for the treatment of specific IRD subtypes. These RNA-based therapies bring several key advantages in the setting of IRDs, and the potential to bring meaningful vision benefit to individuals living with inherited blinding disorders. This review will examine the increasing breadth and relevance of RNA-based therapies in clinical medicine, explore the key features that make AONs suitable for treating genetic eye diseases, and provide an overview of the three-leading investigational AONs in clinical trials.
Collapse
Affiliation(s)
- Aniz Girach
- ProQR Therapeutics, Zernikedreef 9, 2333 CK
Leiden, the Netherlands
| | - Isabelle Audo
- Centre Hospitalier National d’Ophtalmologie des
Quinze-Vingts, Centre de référence maladies rares REFERET and INSERM-DHOS
CIC 1423, CHNO des Quinze-Vingts, Paris, France
- Institute of Ophthalmology, University College
London, London, UK
- Sorbonne Université, INSERM, CNRS, Institut de
la Vision, Paris, France
| | | | - Rachel M. Huckfeldt
- Department of Ophthalmology, Harvard Medical
School, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Byron L. Lam
- Bascom Palmer Eye Institute, University of
Miami Miller School of Medicine, Miami, FL, USA
| | - Bart P. Leroy
- Department of Ophthalmology & Center for
Medical Genetics, Ghent University Hospital & Ghent University, Ghent,
Belgium
- Division of Ophthalmology & Center for
Cellular & Molecular Therapeutics, The Children’s Hospital of
Philadelphia, Philadelphia, PA, USA
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University
College London and Moorfields Eye Hospital, London, UK
| | - Stephen R. Russell
- The University of Iowa Institute for Vision
Research, University of Iowa, Iowa City, IA, USA
| | - Juliana M.F. Sallum
- Department of Ophthalmology, Universidade
Federal de São Paulo, São Paulo, Brazil
- Instituto de Genética Ocular, São Paulo,
Brazil
| | - Katarina Stingl
- Center for Ophthalmology, University Eye
Hospital, University of Tübingen, Tübingen, Germany
- Center for Rare Eye Diseases, University of
Tübingen, Tübingen, Germany
| | - Stephen H. Tsang
- Jonas Children’s Vision Care and Bernard and
Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Vagelos
College of Physicians and Surgeons, Columbia University, New York, NY,
USA
- Edward S. Harkness Eye Institute, New
York-Presbyterian Hospital, New York, NY, USA
| | - Paul Yang
- Casey Eye Institute, Oregon Health &
Science University, Portland, OR, USA
| |
Collapse
|
22
|
Westin IM, Viberg A, Byström B, Golovleva I. Lower Fractions of TCF4 Transcripts Spanning over the CTG18.1 Trinucleotide Repeat in Human Corneal Endothelium. Genes (Basel) 2021; 12:genes12122006. [PMID: 34946954 PMCID: PMC8702116 DOI: 10.3390/genes12122006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/01/2021] [Accepted: 12/13/2021] [Indexed: 11/16/2022] Open
Abstract
Fuchs' endothelial corneal dystrophy (FECD) is a bilateral disease of the cornea caused by gradual loss of corneal endothelial cells. Late-onset FECD is strongly associated with the CTG18.1 trinucleotide repeat expansion in the Transcription Factor 4 gene (TCF4), which forms RNA nuclear foci in corneal endothelial cells. To date, 46 RefSeq transcripts of TCF4 are annotated by the National Center of Biotechnology information (NCBI), however the effect of the CTG18.1 expansion on expression of alternative TCF4 transcripts is not completely understood. To investigate this, we used droplet digital PCR for quantification of TCF4 transcripts spanning over the CTG18.1 and transcripts with transcription start sites immediately downstream of the CTG18.1. TCF4 expression was analysed in corneal endothelium and in whole blood of FECD patients with and without CTG18.1 expansion, in non-FECD controls without CTG18.1 expansion, and in five additional control tissues. Subtle changes in transcription levels in groups of TCF4 transcripts were detected. In corneal endothelium, we found a lower fraction of transcripts spanning over the CTG18.1 tract compared to all other tissues investigated.
Collapse
Affiliation(s)
- Ida Maria Westin
- Department of Medical Biosciences, Medical and Clinical Genetics, University of Umeå, 901 85 Umeå, Sweden;
| | - Andreas Viberg
- Department of Clinical Sciences, Ophthalmology, University of Umeå, 901 85 Umeå, Sweden; (A.V.); (B.B.)
| | - Berit Byström
- Department of Clinical Sciences, Ophthalmology, University of Umeå, 901 85 Umeå, Sweden; (A.V.); (B.B.)
| | - Irina Golovleva
- Department of Medical Biosciences, Medical and Clinical Genetics, University of Umeå, 901 85 Umeå, Sweden;
- Correspondence: ; Tel.: +46-(90)-7856820
| |
Collapse
|
23
|
Dudakova L, Skalicka P, Davidson AE, Sadan AN, Chylova M, Jahnova H, Anteneova N, Tesarova M, Honzik T, Liskova P. Should Patients with Kearns-Sayre Syndrome and Corneal Endothelial Failure Be Genotyped for a TCF4 Trinucleotide Repeat, Commonly Associated with Fuchs Endothelial Corneal Dystrophy? Genes (Basel) 2021; 12:genes12121918. [PMID: 34946867 PMCID: PMC8702069 DOI: 10.3390/genes12121918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 11/23/2021] [Accepted: 11/28/2021] [Indexed: 11/29/2022] Open
Abstract
The aim of this study was to describe the ocular phenotype in a case with Kearns-Sayre syndrome (KSS) spectrum and to determine if corneal endothelial cell dysfunction could be attributed to other known distinct genetic causes. Herein, genomic DNA was extracted from blood and exome sequencing was performed. Non-coding gene regions implicated in corneal endothelial dystrophies were screened by Sanger sequencing. In addition, a repeat expansion situated within an intron of TCF4 (termed CTG18.1) was genotyped using the short tandem repeat assay. The diagnosis of KSS spectrum was based on the presence of ptosis, chronic progressive external ophthalmoplegia, pigmentary retinopathy, hearing loss, and muscle weakness, which were further supported by the detection of ~6.5 kb mtDNA deletion. At the age of 33 years, the proband’s best corrected visual acuity was reduced to 0.04 in the right eye and 0.2 in the left eye. Rare ocular findings included marked corneal oedema with central corneal thickness of 824 and 844 µm in the right and left eye, respectively. No pathogenic variants in the genes, which are associated with corneal endothelial dystrophies, were identified. Furthermore, the CTG18.1 genotype was 12/33, which exceeds a previously determined critical threshold for toxic RNA foci appearance in corneal endothelial cells.
Collapse
Affiliation(s)
- Lubica Dudakova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
| | - Pavlina Skalicka
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | - Alice E. Davidson
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.E.D.); (A.N.S.)
- Moorfields Eye Hospital, London EC1V 2PD, UK
| | - Amanda N. Sadan
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.E.D.); (A.N.S.)
| | - Monika Chylova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
| | - Helena Jahnova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
| | - Nicole Anteneova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
| | - Marketa Tesarova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
| | - Tomas Honzik
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
| | - Petra Liskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.E.D.); (A.N.S.)
- Correspondence: ; Tel.: +420-224-967-139
| |
Collapse
|
24
|
New Therapies for Corneal Endothelial Diseases: 2020 and Beyond. Cornea 2021; 40:1365-1373. [PMID: 34633355 DOI: 10.1097/ico.0000000000002687] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 01/01/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT Penetrating keratoplasty used to be the only surgical technique for the treatment of end-stage corneal endothelial diseases. Improvements in surgical techniques over the past decade have now firmly established endothelial keratoplasty as a safe and effective modality for the treatment of corneal endothelial diseases. However, there is a worldwide shortage of corneal tissue, with more than 50% of the world having no access to cadaveric tissue. Cell injection therapy and tissue-engineered endothelial keratoplasty may potentially offer comparable results as endothelial keratoplasty while maximizing the use of cadaveric donor corneal tissue. Descemet stripping only, Descemet membrane transplantation, and selective endothelial removal are novel therapeutic modalities that take this a step further by relying on endogenous corneal endothelial cell regeneration, instead of allogenic corneal endothelial cell transfer. Gene therapy modalities, including antisense oligonucleotides and clustered regularly interspaced short palindromic repeats-based gene editing, offer the holy grail of potentially suppressing the phenotypic expression of genetically determined corneal endothelial diseases at the asymptomatic stage. We now stand at the crossroads of exciting developments in medical technologies that will likely revolutionize the way we treat corneal endothelial diseases over the next 2 decades.
Collapse
|
25
|
Impact of TCF4 Repeat Number on Resolution of Corneal Edema after Descemet's Stripping Only in Fuchs Dystrophy: A Pilot Study. Vision (Basel) 2021; 5:vision5040047. [PMID: 34698281 PMCID: PMC8544680 DOI: 10.3390/vision5040047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 09/27/2021] [Accepted: 09/29/2021] [Indexed: 11/30/2022] Open
Abstract
Purpose: To investigate whether Fuchs endothelial corneal dystrophy (FECD) genotype, specifically transcription factor 4 (TCF4) CTG triplet repeat “load” predicts time to clearance following Descemet’s Stripping Only (DSO). Methods: This prospective, interventional trial was conducted on consecutive FECD patients undergoing DSO. Genetic analysis using patients’ saliva was performed to assess the extent of CTG expansion using short tandem repeat analysis, corroborated gel electrophoresis and Sanger sequencing. Polymerase chain reaction and bidirectional Sanger sequencing was undertaken. Partial least square regression and logistic regression modelling was used to evaluate the predictive power of TCF4 repeats on corneal clearance. Results: Of 11 eyes of 11 patients, 8 showed complete corneal clearance. For these 8 patients, mean TCF4 allele repeat was 24.8 (SD: 23.7, range: 11–63) and 63.4 (SD: 30.3; range: 11–97), respectively. In total, 9/11 (81.8%) had expanded CTG repeats (>40) in one allele. In cases with an allele repeat ≥80, there was a significantly increased risk of corneal non-clearance (odds ratio 18.2, p = 0.009). Conclusion: Whilst it was not possible to predict time to corneal clearance based on CTG repeats, there is a significant correlation between allele repeats and achievement of corneal clearance.
Collapse
|
26
|
New Horizons in the Treatment of Corneal Endothelial Dysfunction. J Ophthalmol 2021; 2021:6644114. [PMID: 34306743 PMCID: PMC8285186 DOI: 10.1155/2021/6644114] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 07/01/2021] [Indexed: 01/17/2023] Open
Abstract
The treatment of corneal endothelial dysfunction has experienced a revolutionary change in the past decades with the emergence of endothelial keratoplasty techniques: descemet stripping automated endothelial keratoplasty (DSAEK) and descemet membrane endothelial keratoplasty (DMEK). Recently, new treatments such as cultivated endothelial cell therapy, Rho-kinase inhibitors (ROCK inhibitors), bioengineered grafts, and gene therapy have been described. These techniques represent new lines of treatment for endothelial dysfunction. Their advantages are to help address the shortage of quality endothelial tissue, decrease the complications associated with tissue rejection, and reduce the burden of postoperative care following transplantation. Although further randomized clinical trials are required to validate these findings and prove the long-term efficacy of the treatments, the positive outcomes in preliminary clinical studies are a stepping stone to a promising future. Our aim is to review the latest available alternatives and advancements to endothelial corneal transplant.
Collapse
|
27
|
Català P, Thuret G, Skottman H, Mehta JS, Parekh M, Ní Dhubhghaill S, Collin RWJ, Nuijts RMMA, Ferrari S, LaPointe VLS, Dickman MM. Approaches for corneal endothelium regenerative medicine. Prog Retin Eye Res 2021; 87:100987. [PMID: 34237411 DOI: 10.1016/j.preteyeres.2021.100987] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 12/13/2022]
Abstract
The state of the art therapy for treating corneal endothelial disease is transplantation. Advances in the reproducibility and accessibility of surgical techniques are increasing the number of corneal transplants, thereby causing a global deficit of donor corneas and leaving 12.7 million patients with addressable visual impairment. Approaches to regenerate the corneal endothelium offer a solution to the current tissue scarcity and a treatment to those in need. Methods for generating corneal endothelial cells into numbers that could address the current tissue shortage and the possible strategies used to deliver them have now become a therapeutic reality with clinical trials taking place in Japan, Singapore and Mexico. Nevertheless, there is still a long way before such therapies are approved by regulatory bodies and become clinical practice. Moreover, acellular corneal endothelial graft equivalents and certain drugs could provide a treatment option for specific disease conditions without the need of donor tissue or cells. Finally, with the emergence of gene modulation therapies to treat corneal endothelial disease, it would be possible to treat presymptomatic patients or those presenting early symptoms, drastically reducing the need for donor tissue. It is necessary to understand the most recent developments in this rapidly evolving field to know which conditions could be treated with which approach. This article provides an overview of the current and developing regenerative medicine therapies to treat corneal endothelial disease and provides the necessary guidance and understanding towards the treatment of corneal endothelial disease.
Collapse
Affiliation(s)
- Pere Català
- University Eye Clinic Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands; Department of Cell Biology-Inspired Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, the Netherlands
| | - Gilles Thuret
- Laboratory of Biology, Engineering and Imaging of Corneal Graft, BiiGC, Faculty of Medicine, University of Saint Etienne, Saint Etienne, France; Institut Universitaire de France, Paris, France
| | - Heli Skottman
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Jodhbir S Mehta
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore; Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-National University Singapore Medical School, Singapore; Singapore National Eye Centre, Singapore
| | - Mohit Parekh
- Institute of Ophthalmology, University College London, London, UK; The Veneto Eye Bank Foundation, Venice, Italy; Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Sorcha Ní Dhubhghaill
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium; Ophthalmology, Visual Optics and Visual Rehabilitation, Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Rudy M M A Nuijts
- University Eye Clinic Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands
| | | | - Vanessa L S LaPointe
- Department of Cell Biology-Inspired Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, the Netherlands
| | - Mor M Dickman
- University Eye Clinic Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands; Department of Cell Biology-Inspired Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, the Netherlands.
| |
Collapse
|
28
|
Amador C, Shah R, Ghiam S, Kramerov AA, Ljubimov AV. Gene therapy in the anterior eye segment. Curr Gene Ther 2021; 22:104-131. [PMID: 33902406 DOI: 10.2174/1566523221666210423084233] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/14/2021] [Accepted: 04/04/2021] [Indexed: 11/22/2022]
Abstract
This review provides comprehensive information about the advances in gene therapy in the anterior segment of the eye including cornea, conjunctiva, lacrimal gland, and trabecular meshwork. We discuss gene delivery systems including viral and non-viral vectors as well as gene editing techniques, mainly CRISPR-Cas9, and epigenetic treatments including antisense and siRNA therapeutics. We also provide a detailed analysis of various anterior segment diseases where gene therapy has been tested with corresponding outcomes. Disease conditions include corneal and conjunctival fibrosis and scarring, corneal epithelial wound healing, corneal graft survival, corneal neovascularization, genetic corneal dystrophies, herpetic keratitis, glaucoma, dry eye disease, and other ocular surface diseases. Although most of the analyzed results on the use and validity of gene therapy at the ocular surface have been obtained in vitro or using animal models, we also discuss the available human studies. Gene therapy approaches are currently considered very promising as emerging future treatments of various diseases, and this field is rapidly expanding.
Collapse
Affiliation(s)
- Cynthia Amador
- Eye Program, Board of Governors Regenerative Medicine Institute and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Ruchi Shah
- Eye Program, Board of Governors Regenerative Medicine Institute and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Sean Ghiam
- Sackler School of Medicine, New York State/American Program of Tel Aviv University, Tel Aviv, Israel
| | - Andrei A Kramerov
- Eye Program, Board of Governors Regenerative Medicine Institute and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Alexander V Ljubimov
- Eye Program, Board of Governors Regenerative Medicine Institute and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| |
Collapse
|
29
|
Parekh M, Romano V, Hassanin K, Testa V, Wongvisavavit R, Ferrari S, Haneef A, Willoughby C, Ponzin D, Jhanji V, Sharma N, Daniels J, Kaye SB, Ahmad S, Levis HJ. Biomaterials for corneal endothelial cell culture and tissue engineering. J Tissue Eng 2021; 12:2041731421990536. [PMID: 33643603 PMCID: PMC7894589 DOI: 10.1177/2041731421990536] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 01/08/2021] [Indexed: 12/20/2022] Open
Abstract
The corneal endothelium is the posterior monolayer of cells that are responsible for maintaining overall transparency of the avascular corneal tissue via pump function. These cells are non-regenerative in vivo and therefore, approximately 40% of corneal transplants undertaken worldwide are a result of damage or dysfunction of endothelial cells. The number of available corneal donor tissues is limited worldwide, hence, cultivation of human corneal endothelial cells (hCECs) in vitro has been attempted in order to produce tissue engineered corneal endothelial grafts. Researchers have attempted to recreate the current gold standard treatment of replacing the endothelial layer with accompanying Descemet's membrane or a small portion of stroma as support with tissue engineering strategies using various substrates of both biologically derived and synthetic origin. Here we review the potential biomaterials that are currently in development to support the transplantation of a cultured monolayer of hCECs.
Collapse
Affiliation(s)
- Mohit Parekh
- Faculty of Brain Sciences, Institute of Ophthalmology, University College London, London, UK.,International Center for Ocular Physiopathology, Fondazione Banca degli Occhi del Veneto Onlus, Venice, Italy
| | - Vito Romano
- St. Paul's Eye Unit, Royal Liverpool Broadgreen University Hospital, Liverpool, UK.,Instituto Universitario Fernandez-Vega, Universidad de Oviedo and Fundacion de Investigacion on Oftalmologica, Oviedo, Spain.,Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Kareem Hassanin
- St. Paul's Eye Unit, Royal Liverpool Broadgreen University Hospital, Liverpool, UK
| | - Valeria Testa
- Eye Clinic, Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy.,Ospedale Policlinico San Martino IRCCS, Genoa, Italy
| | - Rintra Wongvisavavit
- Faculty of Brain Sciences, Institute of Ophthalmology, University College London, London, UK.,HRH Princess Chulabhorn College of Medical Sciences, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Stefano Ferrari
- International Center for Ocular Physiopathology, Fondazione Banca degli Occhi del Veneto Onlus, Venice, Italy
| | - Atikah Haneef
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Colin Willoughby
- School of biomedical sciences, University of Ulster, Belfast, UK
| | - Diego Ponzin
- International Center for Ocular Physiopathology, Fondazione Banca degli Occhi del Veneto Onlus, Venice, Italy
| | - Vishal Jhanji
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Namrata Sharma
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Julie Daniels
- Faculty of Brain Sciences, Institute of Ophthalmology, University College London, London, UK
| | - Stephen B Kaye
- St. Paul's Eye Unit, Royal Liverpool Broadgreen University Hospital, Liverpool, UK
| | - Sajjad Ahmad
- Faculty of Brain Sciences, Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Trust Foundation, London, UK
| | - Hannah J Levis
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| |
Collapse
|
30
|
Diseases of the corneal endothelium. Exp Eye Res 2021; 205:108495. [PMID: 33596440 DOI: 10.1016/j.exer.2021.108495] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 02/05/2021] [Accepted: 02/08/2021] [Indexed: 12/17/2022]
Abstract
The corneal endothelial monolayer and associated Descemet's membrane (DM) complex is a unique structure that plays an essential role in corneal function. Endothelial cells are neural crest derived cells that rest on a special extracellular matrix and play a major role in maintaining stromal hydration within a narrow physiologic range necessary for clear vision. A number of diseases affect the endothelial cells and DM complex and can impair corneal function and vision. This review addresses different human corneal endothelial diseases characterized by loss of endothelial function including: Fuchs endothelial corneal dystrophy (FECD), posterior polymorphous corneal dystrophy (PPCD), congenital hereditary endothelial dystrophy (CHED), bullous keratopathy, iridocorneal endothelial (ICE) syndrome, post-traumatic fibrous downgrowth, glaucoma and diabetes mellitus.
Collapse
|
31
|
Xu TT, Li YJ, Afshari NA, Aleff RA, Rinkoski TA, Patel SV, Maguire LJ, Edwards AO, Brown WL, Fautsch MP, Wieben ED, Baratz KH. Disease Expression and Familial Transmission of Fuchs Endothelial Corneal Dystrophy With and Without CTG18.1 Expansion. Invest Ophthalmol Vis Sci 2021; 62:17. [PMID: 33444430 PMCID: PMC7814354 DOI: 10.1167/iovs.62.1.17] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Purpose To characterize inheritance, penetrance, and trinucleotide repeat expansion stability in Fuchs endothelial corneal dystrophy (FECD). Methods One thousand unrelated and related subjects with and without FECD were prospectively recruited. CTG18.1 repeat length (CTG18.1L) was determined via short tandem repeat assay and Southern blotting of leukocyte DNA. Multivariable logistic regression and generalized estimating equation models were employed. Results There were 546 unrelated FECD cases (67.6% female; 70 ± 10 years) and 235 controls (63.8% female; 73 ± 8 years; all ≥ 50 years). CTG18.1 expansion (CTG18.1exp+) was observed in 424 (77.7%) cases and 18 (7.7%) controls (P = 2.48 × 10–44). CTG18.1 expansion was associated with FECD severity (P = 5.62 × 10–7). The family arm of the study included 331 members from 112 FECD-affected families; 87 families were CTG18.1exp+. Autosomal dominant inheritance with variable expression of FECD was observed, regardless of expansion status. FECD penetrance of CTG18.1 expansion increased with age, ranging from 44.4% in the youngest (19–46 years) to 86.2% in the oldest (64–91 years) age quartiles. Among 62 parent–offspring transmissions of CTG18.1exp+, 48 (77.4%) had a change in CTG18.1L ≤ 10 repeats, and eight (12.9%) were ≥50 repeats, including five large expansions (∼1000–2000 repeats) that contracted. Among 44 offspring who did not inherit the CTG18.1exp+ allele, eight (18.2%) exhibited FECD. Conclusions CTG18.1 expansion was highly associated with FECD but demonstrated incomplete penetrance. CTG18.1L instability occurred in a minority of parent–offspring transmissions, with large expansions exhibiting contraction. The observation of FECD without CTG18.1 expansion among family members in CTG18.1exp+ families highlights the complexity of the relationship between the FECD phenotype and CTG18.1 expansion.
Collapse
Affiliation(s)
- Timothy T Xu
- Alix School of Medicine, Mayo Clinic, Rochester, Minnesota, United States
| | - Yi-Ju Li
- Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina, United States.,Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States
| | - Natalie A Afshari
- Shiley Eye Institute, University of California, San Diego, La Jolla, California, United States
| | - Ross A Aleff
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, United States
| | - Tommy A Rinkoski
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - Sanjay V Patel
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - Leo J Maguire
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - Albert O Edwards
- Oregon Retina Division, Sterling Vision, Eugene, Oregon, United States.,Casey Eye Institute, Oregon Health Sciences University, Portland, Oregon, United States
| | - William L Brown
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - Michael P Fautsch
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - Eric D Wieben
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, United States
| | - Keith H Baratz
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| |
Collapse
|
32
|
Ong Tone S, Kocaba V, Böhm M, Wylegala A, White TL, Jurkunas UV. Fuchs endothelial corneal dystrophy: The vicious cycle of Fuchs pathogenesis. Prog Retin Eye Res 2021; 80:100863. [PMID: 32438095 PMCID: PMC7648733 DOI: 10.1016/j.preteyeres.2020.100863] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 04/05/2020] [Accepted: 04/10/2020] [Indexed: 12/13/2022]
Abstract
Fuchs endothelial corneal dystrophy (FECD) is the most common primary corneal endothelial dystrophy and the leading indication for corneal transplantation worldwide. FECD is characterized by the progressive decline of corneal endothelial cells (CECs) and the formation of extracellular matrix (ECM) excrescences in Descemet's membrane (DM), called guttae, that lead to corneal edema and loss of vision. FECD typically manifests in the fifth decades of life and has a greater incidence in women. FECD is a complex and heterogeneous genetic disease where interaction between genetic and environmental factors results in cellular apoptosis and aberrant ECM deposition. In this review, we will discuss a complex interplay of genetic, epigenetic, and exogenous factors in inciting oxidative stress, auto(mito)phagy, unfolded protein response, and mitochondrial dysfunction during CEC degeneration. Specifically, we explore the factors that influence cellular fate to undergo apoptosis, senescence, and endothelial-to-mesenchymal transition. These findings will highlight the importance of abnormal CEC-DM interactions in triggering the vicious cycle of FECD pathogenesis. We will also review clinical characteristics, diagnostic tools, and current medical and surgical management options for FECD patients. These new paradigms in FECD pathogenesis present an opportunity to develop novel therapeutics for the treatment of FECD.
Collapse
Affiliation(s)
- Stephan Ong Tone
- Cornea Center of Excellence, Schepens Eye Research Institute, Harvard Medical School, Boston, MA, United States; Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, United States; Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Viridiana Kocaba
- Cornea Center of Excellence, Schepens Eye Research Institute, Harvard Medical School, Boston, MA, United States; Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, United States; Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Myriam Böhm
- Cornea Center of Excellence, Schepens Eye Research Institute, Harvard Medical School, Boston, MA, United States; Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Adam Wylegala
- Cornea Center of Excellence, Schepens Eye Research Institute, Harvard Medical School, Boston, MA, United States; Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, United States; Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Tomas L White
- Cornea Center of Excellence, Schepens Eye Research Institute, Harvard Medical School, Boston, MA, United States; Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, United States; Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Ula V Jurkunas
- Cornea Center of Excellence, Schepens Eye Research Institute, Harvard Medical School, Boston, MA, United States; Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, United States; Department of Ophthalmology, Harvard Medical School, Boston, MA, United States.
| |
Collapse
|
33
|
Sirp A, Leite K, Tuvikene J, Nurm K, Sepp M, Timmusk T. The Fuchs corneal dystrophy-associated CTG repeat expansion in the TCF4 gene affects transcription from its alternative promoters. Sci Rep 2020; 10:18424. [PMID: 33116252 PMCID: PMC7595208 DOI: 10.1038/s41598-020-75437-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 10/14/2020] [Indexed: 12/14/2022] Open
Abstract
The CTG trinucleotide repeat (TNR) expansion in Transcription factor 4 (TCF4) intron 3 is the main cause of Fuchs’ endothelial corneal dystrophy (FECD) and may confer an increased risk of developing bipolar disorder (BD). Usage of alternative 5′ exons for transcribing the human TCF4 gene results in numerous TCF4 transcripts which encode for at least 18 N-terminally different protein isoforms that vary in their function and transactivation capability. Here we studied the TCF4 region containing the CTG TNR and characterized the transcription initiation sites of the nearby downstream 5′ exons 4a, 4b and 4c. We demonstrate that these exons are linked to alternative promoters and show that the CTG TNR expansion decreases the activity of the nearby downstream TCF4 promoters in primary cultured neurons. We confirm this finding using two RNA sequencing (RNA-seq) datasets of corneal endothelium from FECD patients with expanded CTG TNR in the TCF4 gene. Furthermore, we report an increase in the expression of various other TCF4 transcripts in FECD, possibly indicating a compensatory mechanism. We conclude that the CTG TNR affects TCF4 expression in a transcript-specific manner both in neurons and in the cornea.
Collapse
Affiliation(s)
- Alex Sirp
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia
| | - Kristian Leite
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia.,Department of Neurology, University Medicine Göttingen, Waldweg 33, 37073, Göttingen, Germany
| | - Jürgen Tuvikene
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia.,Protobios LLC, 12618, Tallinn, Estonia
| | - Kaja Nurm
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia
| | - Mari Sepp
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia.,Center for Molecular Biology of Heidelberg University (ZMBH), 69120, Heidelberg, Germany
| | - Tõnis Timmusk
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia. .,Protobios LLC, 12618, Tallinn, Estonia.
| |
Collapse
|
34
|
Price MO, Mehta JS, Jurkunas UV, Price FW. Corneal endothelial dysfunction: Evolving understanding and treatment options. Prog Retin Eye Res 2020; 82:100904. [PMID: 32977001 DOI: 10.1016/j.preteyeres.2020.100904] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/14/2020] [Accepted: 09/19/2020] [Indexed: 12/13/2022]
Abstract
The cornea is exquisitely designed to protect the eye while transmitting and focusing incoming light. Precise control of corneal hydration by the endothelial cell layer that lines the inner surface of the cornea is required for optimal transparency, and endothelial dysfunction or damage can result in corneal edema and visual impairment. Advances in corneal transplantation now allow selective replacement of dysfunctional corneal endothelium, providing rapid visual rehabilitation. A series of technique improvements have minimized complications and various adaptations allow use even in eyes with complicated anatomy. While selective endothelial keratoplasty sets a very high standard for safety and efficacy, a shortage of donor corneas in many parts of the world restricts access, prompting a search for alternatives. Clinical trials are underway to evaluate the potential for self-recovery after removal of dysfunctional central endothelium in patients with healthy peripheral endothelium. Various approaches to using cultured human corneal endothelial cells are also in clinical trials; these aim to multiply cells from a single donor cornea for use in potentially hundreds of patients. Pre-clinical studies are underway with induced pluripotent stem cells, endothelial stem cell regeneration, gene therapy, anti-sense oligonucleotides, and various biologic/pharmacologic approaches designed to treat, prevent, or retard corneal endothelial dysfunction. The availability of more therapeutic options will hopefully expand access around the world while also allowing treatment to be more precisely tailored to each individual patient.
Collapse
Affiliation(s)
- Marianne O Price
- Cornea Research Foundation of America, 9002 N. Meridian St., Suite 212, Indianapolis, IN, USA.
| | - Jodhbir S Mehta
- Singapore National Eye Centre, 11 Third Hospital Ave #08-00, 168751, Singapore
| | - Ula V Jurkunas
- Massachusetts Eye and Ear Infirmary, 243 Charles St., Boston, MA, USA
| | - Francis W Price
- Price Vision Group, 9002 N. Meridian St., Suite 100, Indianapolis, IN, USA
| |
Collapse
|
35
|
Chu Y, Hu J, Liang H, Kanchwala M, Xing C, Beebe W, Bowman CB, Gong X, Corey DR, Mootha VV. Analyzing pre-symptomatic tissue to gain insights into the molecular and mechanistic origins of late-onset degenerative trinucleotide repeat disease. Nucleic Acids Res 2020; 48:6740-6758. [PMID: 32463444 PMCID: PMC7337964 DOI: 10.1093/nar/gkaa422] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 05/02/2020] [Accepted: 05/11/2020] [Indexed: 12/17/2022] Open
Abstract
How genetic defects trigger the molecular changes that cause late-onset disease is important for understanding disease progression and therapeutic development. Fuchs' endothelial corneal dystrophy (FECD) is an RNA-mediated disease caused by a trinucleotide CTG expansion in an intron within the TCF4 gene. The mutant intronic CUG RNA is present at one-two copies per cell, posing a challenge to understand how a rare RNA can cause disease. Late-onset FECD is a uniquely advantageous model for studying how RNA triggers disease because: (i) Affected tissue is routinely removed during surgery; (ii) The expanded CTG mutation is one of the most prevalent disease-causing mutations, making it possible to obtain pre-symptomatic tissue from eye bank donors to probe how gene expression changes precede disease; and (iii) The affected tissue is a homogeneous single cell monolayer, facilitating accurate transcriptome analysis. Here, we use RNA sequencing (RNAseq) to compare tissue from individuals who are pre-symptomatic (Pre_S) to tissue from patients with late stage FECD (FECD_REP). The abundance of mutant repeat intronic RNA in Pre_S and FECD_REP tissue is elevated due to increased half-life in a corneal cells. In Pre_S tissue, changes in splicing and extracellular matrix gene expression foreshadow the changes observed in advanced disease and predict the activation of the fibrosis pathway and immune system seen in late-stage patients. The absolute magnitude of splicing changes is similar in pre-symptomatic and late stage tissue. Our data identify gene candidates for early drivers of disease and biomarkers that may represent diagnostic and therapeutic targets for FECD. We conclude that changes in alternative splicing and gene expression are observable decades prior to the diagnosis of late-onset trinucleotide repeat disease.
Collapse
Affiliation(s)
- Yongjun Chu
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jiaxin Hu
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Hanquan Liang
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Mohammed Kanchwala
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Chao Xing
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Population and Data Sciences, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | | | - Xin Gong
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9057, USA
| | - David R Corey
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - V Vinod Mootha
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9057, USA
| |
Collapse
|
36
|
Rong Z, Gong X, Hulleman JD, Corey DR, Mootha VV. Trinucleotide Repeat-Targeting dCas9 as a Therapeutic Strategy for Fuchs' Endothelial Corneal Dystrophy. Transl Vis Sci Technol 2020; 9:47. [PMID: 32934897 PMCID: PMC7463221 DOI: 10.1167/tvst.9.9.47] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 07/27/2020] [Indexed: 12/12/2022] Open
Abstract
Purpose Fuchs’ endothelial corneal dystrophy (FECD) is the leading indication for corneal transplantation. Seventy percent of cases are caused by an intronic CTG triplet repeat expansion in the TCF4 gene that results in accumulation of pathogenic expanded CUG repeat RNA (CUGexp) as nuclear foci in corneal endothelium. A catalytically dead Cas9 (dCas9) can serve as an effective guide to target genomic DNA or RNA transcripts. Here, we examined the utility of the clustered regularly interspaced short palindromic repeats (CRISPR)-dCas9 system to effectively target and reduce CUGexp. Methods We delivered dCas9 and repeat-targeting single guide RNA (sgRNA) expression plasmids to patient-derived endothelial cells using lipofection or lentiviral transduction. We used fluorescence in situ hybridization (FISH) and RNA dot-blot hybridization to quantify CUGexp foci and repeat RNA levels, respectively. TCF4 expression levels were assessed using quantitative PCR (qPCR). Results Using FISH, we found that expression of both dCas9 and a (CAG)n sgRNA complementary to CUGexp are necessary to reduce foci. We observed a reduction in percentage of cells with foci from 59% to 5.6% and number of foci per 100 cells from 73.4 to 7.45 (P < 0.001) in cells stably expressing dCas9-(CAG)n sgRNA but saw no decrease in cells expressing dCas9-(CUG)n sgRNA or nontargeting control sgRNA. In cells with dCas9-(CAG)n sgRNA, we detected a reduction in CUGexp RNA by dot-blot without any reduction in TCF4 mRNA levels using qPCR. Conclusions Using CRISPR-dCas9 to target the trinucleotide repeat is a promising treatment for FECD contingent on effective in vivo delivery. Translational Relevance This work advances a gene therapy for a common age-related degenerative disorder.
Collapse
Affiliation(s)
- Ziye Rong
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA.,McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas, TX, USA
| | - Xin Gong
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - John D Hulleman
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA.,Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, USA
| | - David R Corey
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, USA.,Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, USA
| | - V Vinod Mootha
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA.,McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas, TX, USA
| |
Collapse
|
37
|
Fautsch MP, Wieben ED, Baratz KH, Bhattacharyya N, Sadan AN, Hafford-Tear NJ, Tuft SJ, Davidson AE. TCF4-mediated Fuchs endothelial corneal dystrophy: Insights into a common trinucleotide repeat-associated disease. Prog Retin Eye Res 2020; 81:100883. [PMID: 32735996 PMCID: PMC7988464 DOI: 10.1016/j.preteyeres.2020.100883] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/24/2020] [Accepted: 07/04/2020] [Indexed: 12/13/2022]
Abstract
Fuchs endothelial corneal dystrophy (FECD) is a common cause for heritable visual loss in the elderly. Since the first description of an association between FECD and common polymorphisms situated within the transcription factor 4 (TCF4) gene, genetic and molecular studies have implicated an intronic CTG trinucleotide repeat (CTG18.1) expansion as a causal variant in the majority of FECD patients. To date, several non-mutually exclusive mechanisms have been proposed that drive and/or exacerbate the onset of disease. These mechanisms include (i) TCF4 dysregulation; (ii) toxic gain-of-function from TCF4 repeat-containing RNA; (iii) toxic gain-of-function from repeat-associated non-AUG dependent (RAN) translation; and (iv) somatic instability of CTG18.1. However, the relative contribution of these proposed mechanisms in disease pathogenesis is currently unknown. In this review, we summarise research implicating the repeat expansion in disease pathogenesis, define the phenotype-genotype correlations between FECD and CTG18.1 expansion, and provide an update on research tools that are available to study FECD as a trinucleotide repeat expansion disease. Furthermore, ongoing international research efforts to develop novel CTG18.1 expansion-mediated FECD therapeutics are highlighted and we provide a forward-thinking perspective on key unanswered questions that remain in the field. FECD is a common, age-related corneal dystrophy. The majority of cases are associated with expansion of a CTG repeat (CTG18.1). FECD is the most common trinucleotide repeat expansion disease in humans. Evidence supports multiple molecular mechanisms underlying the pathophysiology. Novel CTG18.1-targeted therapeutics are in development.
Collapse
Affiliation(s)
- Michael P Fautsch
- Department of Ophthalmology, 200 1st St SW, Mayo Clinic, Rochester, MN, 55905, USA.
| | - Eric D Wieben
- Department of Biochemistry and Molecular Biology, 200 1st St SW, Mayo Clinic, Rochester, MN, USA.
| | - Keith H Baratz
- Department of Ophthalmology, 200 1st St SW, Mayo Clinic, Rochester, MN, 55905, USA.
| | | | - Amanda N Sadan
- University College London Institute of Ophthalmology, London, ECIV 9EL, UK.
| | | | - Stephen J Tuft
- University College London Institute of Ophthalmology, London, ECIV 9EL, UK; Moorfields Eye Hospital, London, EC1V 2PD, UK.
| | - Alice E Davidson
- University College London Institute of Ophthalmology, London, ECIV 9EL, UK.
| |
Collapse
|
38
|
Soh YQ, Kocaba V, Weiss JS, Jurkunas UV, Kinoshita S, Aldave AJ, Mehta JS. Corneal dystrophies. Nat Rev Dis Primers 2020; 6:46. [PMID: 32528047 DOI: 10.1038/s41572-020-0178-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/24/2020] [Indexed: 12/21/2022]
Abstract
Corneal dystrophies are broadly defined as inherited disorders that affect any layer of the cornea and are usually progressive, bilateral conditions that do not have systemic effects. The 2015 International Classification of Corneal Dystrophies classifies corneal dystrophies into four classes: epithelial and subepithelial dystrophies, epithelial-stromal TGFBI dystrophies, stromal dystrophies and endothelial dystrophies. Whereas some corneal dystrophies may result in few or mild symptoms and morbidity throughout a patient's lifetime, others may progress and eventually result in substantial visual and ocular disturbances that require medical or surgical intervention. Corneal transplantation, either with full-thickness or partial-thickness donor tissue, may be indicated for patients with advanced corneal dystrophies. Although corneal transplantation techniques have improved considerably over the past two decades, these surgeries are still associated with postoperative risks of disease recurrence, graft failure and other complications that may result in blindness. In addition, a global shortage of cadaveric corneal graft tissue critically limits accessibility to corneal transplantation in some parts of the world. Ongoing advances in gene therapy, regenerative therapy and cell augmentation therapy may eventually result in the development of alternative, novel treatments for corneal dystrophies, which may substantially improve the quality of life of patients with these disorders.
Collapse
Affiliation(s)
- Yu Qiang Soh
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore.,Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore, Singapore.,Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Viridiana Kocaba
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore.,Netherlands Institute for Innovative Ocular Surgery, Rotterdam, Netherlands
| | - Jayne S Weiss
- Department of Ophthalmology, Pathology and Pharmacology, Louisiana State University, School of Medicine, New Orleans, USA
| | - Ula V Jurkunas
- Cornea and Refractive Surgery Service, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.,Schepens Eye Research Institute, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Shigeru Kinoshita
- Department of Frontier Medical Science and Technology for Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Anthony J Aldave
- Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Jodhbir S Mehta
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore. .,Singapore National Eye Centre, Singapore, Singapore. .,Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore, Singapore. .,Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore.
| |
Collapse
|
39
|
Matthaei M, Hribek A, Clahsen T, Bachmann B, Cursiefen C, Jun AS. Fuchs Endothelial Corneal Dystrophy: Clinical, Genetic, Pathophysiologic, and Therapeutic Aspects. Annu Rev Vis Sci 2020; 5:151-175. [PMID: 31525145 DOI: 10.1146/annurev-vision-091718-014852] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fuchs endothelial corneal dystrophy (FECD) is a bilateral corneal endothelial disorder and the most common cause of corneal transplantation worldwide. Professor Ernst Fuchs described the first 13 cases of FECD more than 100 years ago. Since then, we have seen far-reaching progress in its diagnosis and treatment. In the field of diagnostics, new technologies enable the development of more accurate classification systems and the more detailed breakdown of the genetic basis of FECD. Laboratory studies help in deciphering the molecular pathomechanisms. The development of minimally invasive surgical techniques leads to a continuous improvement of the postoperative result. This review highlights and discusses clinical, genetic, pathophysiologic, and therapeutic aspects of this common and important corneal disorder.
Collapse
Affiliation(s)
- Mario Matthaei
- Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany; , , , ,
| | - Agathe Hribek
- Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany; , , , ,
| | - Thomas Clahsen
- Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany; , , , ,
| | - Björn Bachmann
- Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany; , , , ,
| | - Claus Cursiefen
- Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany; , , , ,
| | - Albert S Jun
- Wilmer Eye Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA;
| |
Collapse
|
40
|
Chau VQ, Hu J, Gong X, Hulleman JD, Ufret-Vincenty RL, Rigo F, Prakash TP, Corey DR, Mootha VV. Delivery of Antisense Oligonucleotides to the Cornea. Nucleic Acid Ther 2020; 30:207-214. [PMID: 32202944 DOI: 10.1089/nat.2019.0838] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Antisense oligonucleotides (ASOs) are synthetic nucleic acids that recognize complementary RNA sequences inside cells and modulate gene expression. In this study, we explore the feasibility of ASO delivery to the cornea. We used quantitative polymerase chain reaction to test the efficacy of a benchmark ASO targeting a noncoding nuclear RNA, Metastasis-Associated Lung Adenocarcinoma Transcript 1 (MALAT1), in a human corneal endothelial cell line, ex vivo human corneas, and in vivo in mice. In vivo delivery was via intravitreal or intracameral injections as well as topical administration. The anti-MALAT1 ASO significantly reduced expression of MALAT1 in a corneal endothelial cell line. We achieved a dose-dependent reduction of target gene expression in endothelial tissue from ex vivo human donor corneas. In vivo mouse experiments confirmed MALAT1 reduction in whole corneal tissue via intravitreal and intracameral routes, 82% and 71% knockdown, respectively (P < 0.001). Effects persisted up to at least 21 days, 32% (P < 0.05) and 43% (P < 0.05) knockdown, respectively. We developed protocols for the isolation and analysis of mouse corneal endothelium and observed reduction in MALAT1 expression upon both intravitreal and intracameral administrations, 64% (P < 0.05) and 63% (P < 0.05) knockdown, respectively. These data open the possibility of using ASOs to treat corneal disease.
Collapse
Affiliation(s)
- Viet Q Chau
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Jiaxin Hu
- Department of Pharmacology and Biochemistry, and UT Southwestern Medical Center, Dallas, Texas, USA
| | - Xin Gong
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - John D Hulleman
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, USA
| | | | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, California, USA
| | | | - David R Corey
- Department of Pharmacology and Biochemistry, and UT Southwestern Medical Center, Dallas, Texas, USA
| | - V Vinod Mootha
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, USA.,McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas, Texas, USA
| |
Collapse
|
41
|
Malhotra D, Casey JR. Molecular Mechanisms of Fuchs and Congenital Hereditary Endothelial Corneal Dystrophies. Rev Physiol Biochem Pharmacol 2020; 178:41-81. [PMID: 32789790 DOI: 10.1007/112_2020_39] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The cornea, the eye's outermost layer, protects the eye from the environment. The cornea's innermost layer is an endothelium separating the stromal layer from the aqueous humor. A central role of the endothelium is to maintain stromal hydration state. Defects in maintaining this hydration can impair corneal clarity and thus visual acuity. Two endothelial corneal dystrophies, Fuchs Endothelial Corneal Dystrophy (FECD) and Congenital Hereditary Endothelial Dystrophy (CHED), are blinding corneal diseases with varied clinical presentation in patients across different age demographics. Recessive CHED with an early onset (typically age: 0-3 years) and dominantly inherited FECD with a late onset (age: 40-50 years) have similar phenotypes, although caused by defects in several different genes. A range of molecular mechanisms have been proposed to explain FECD and CHED pathology given the involvement of multiple causative genes. This critical review provides insight into the proposed molecular mechanisms underlying FECD and CHED pathology along with common pathways that may explain the link between the defective gene products and provide a new perspective to view these genetic blinding diseases.
Collapse
Affiliation(s)
- Darpan Malhotra
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
- Membrane Protein Disease Research Group, University of Alberta, Edmonton, AB, Canada
| | - Joseph R Casey
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.
- Membrane Protein Disease Research Group, University of Alberta, Edmonton, AB, Canada.
- Department of Physiology, University of Alberta, Edmonton, AB, Canada.
- Department of Ophthalmology and Visual Science, University of Alberta, Edmonton, AB, Canada.
| |
Collapse
|
42
|
Brejchova K, Dudakova L, Skalicka P, Dobrovolny R, Masek P, Putzova M, Moosajee M, Tuft SJ, Davidson AE, Liskova P. IPSC-Derived Corneal Endothelial-like Cells Act as an Appropriate Model System to Assess the Impact of SLC4A11 Variants on Pre-mRNA Splicing. Invest Ophthalmol Vis Sci 2019; 60:3084-3090. [PMID: 31323090 PMCID: PMC6645617 DOI: 10.1167/iovs.19-26930] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose To report molecular genetic findings in six probands with congenital hereditary endothelial dystrophy (CHED) variably associated with hearing loss (also known as Harboyan syndrome). Furthermore, we developed a cellular model to determine if disease-associated variants induce aberrant SLC4A11 pre-mRNA splicing. Methods Direct sequencing of the entire SLC4A11 coding region was performed in five probands. In one individual, whole genome sequencing was undertaken. The effect of c.2240+5G>A on pre-mRNA splicing was evaluated in a corneal endothelial-like (CE-like) cell model expressing SLC4A11. CE-like cells were derived from autologous induced pluripotent stem cells (iPSCs) via neural crest cells exposed to B27, PDGF-BB, and DKK-2. Total RNA was extracted, and RT-PCR was performed followed by Sanger and a targeted next generation sequencing (NGS) approach to identify and quantify the relative abundance of alternatively spliced transcripts. Results In total, 11 different mutations in SLC4A11 evaluated as pathogenic were identified; of these, c.1237G>A, c.2003T>C, c.1216+1G>A, and c.2240+5G>A were novel. The c.2240+5G>A variant was demonstrated to result in aberrant pre-mRNA splicing. A targeted NGS approach confirmed that the variant introduces a leaky cryptic splice donor site leading to the production of a transcript containing an insertion of six base pairs with the subsequent introduction of a premature stop codon (p.Thr747*). Furthermore, a subset of transcripts comprising full retention of intron 16 also were observed, leading to the same functionally null allele. Conclusions This proof-of-concept study highlights the potential of using CE-like cells to investigate the pathogenic consequences of SLC4A11 disease–associated variants.
Collapse
Affiliation(s)
- Kristyna Brejchova
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Czech Republic
| | - Lubica Dudakova
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Czech Republic
| | - Pavlina Skalicka
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Czech Republic.,Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Robert Dobrovolny
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Czech Republic
| | - Petr Masek
- Clinic of Ophthalmology, University Hospital Ostrava, Ostrava, Czech Republic.,Department of Craniofacial Surgery, University of Ostrava, Ostrava, Czech Republic
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, United Kingdom.,Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom.,Great Ormond Street Hospital for Children, London, United Kingdom
| | - Stephen J Tuft
- UCL Institute of Ophthalmology, London, United Kingdom.,Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | | | - Petra Liskova
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Czech Republic.,Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.,UCL Institute of Ophthalmology, London, United Kingdom
| |
Collapse
|
43
|
Okumura N, Puangsricharern V, Jindasak R, Koizumi N, Komori Y, Ryousuke H, Nakahara M, Nakano M, Adachi H, Tashiro K, Yoshii K, Chantaren P, Ittiwut R, Shotelersuk V, Suphapeetiporn K. Trinucleotide repeat expansion in the transcription factor 4 (TCF4) gene in Thai patients with Fuchs endothelial corneal dystrophy. Eye (Lond) 2019; 34:880-885. [PMID: 31554942 DOI: 10.1038/s41433-019-0595-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 06/10/2019] [Accepted: 08/22/2019] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To evaluate the association of single nucleotide polymorphisms (SNPs) and the intronic expansion of a trinucleotide repeat (TNR) in the TCF4 gene with Fuchs endothelial corneal dystrophy (FECD) in a Thai population. METHODS In total, 54 Thai FECD patients and 54 controls were recruited for the study. Five SNPs (rs613872, rs2123392, rs17089887, rs1452787, and rs1348047), previously reported to be associated with FECD, were genotyped by direct sequencing. The repeat length was determined by direct sequencing of PCR-amplified DNA (a short tandem repeat; STR assay) and by triplet repeat primed PCR (TP-PCR). RESULTS Only one of the 54 patients with FECD harboured rs613872 (1.9%). Four SNPs (rs2123392, rs17089887, rs1452787, and rs1348047), which are not rare polymorphisms in the Thai population, were found in approximately half of the patients. Of the 54 patients, 21 (1 homozygous and 20 heterozygous patients; 39%) harboured a TNR ≥ 40, while 33 patients (61%) harboured a TNR < 40. CONCLUSIONS The association of TNR expansion in TCF4 with FECD is shown for the first time in the Thai population. The intronic TNR expansion identified in various ethnic groups underlines the importance of expansion as a potent pathophysiological cause of FECD.
Collapse
Affiliation(s)
- Naoki Okumura
- Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Vilavun Puangsricharern
- Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand. .,Excellence Center for Cornea and Limbal Stem Cell Transplantation, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand.
| | - Raina Jindasak
- Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Noriko Koizumi
- Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Yuya Komori
- Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Hayashi Ryousuke
- Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Makiko Nakahara
- Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Masakazu Nakano
- Department of Genomic Medical Sciences, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Hiroko Adachi
- Department of Genomic Medical Sciences, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Kei Tashiro
- Department of Genomic Medical Sciences, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Kengo Yoshii
- Department of Mathematics and Statistics in Medical Sciences, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Patchima Chantaren
- Excellence Center for Cornea and Limbal Stem Cell Transplantation, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Rungnapa Ittiwut
- Center of Excellence for Medical Genomics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand.,Excellence Center for Medical Genetics, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Vorasuk Shotelersuk
- Center of Excellence for Medical Genomics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand.,Excellence Center for Medical Genetics, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Kanya Suphapeetiporn
- Center of Excellence for Medical Genomics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand.,Excellence Center for Medical Genetics, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand
| |
Collapse
|
44
|
Rong Z, Hu J, Corey DR, Mootha VV. Quantitative Studies of Muscleblind Proteins and Their Interaction With TCF4 RNA Foci Support Involvement in the Mechanism of Fuchs' Dystrophy. Invest Ophthalmol Vis Sci 2019; 60:3980-3991. [PMID: 31560764 PMCID: PMC6779288 DOI: 10.1167/iovs.19-27641] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 07/17/2019] [Indexed: 02/07/2023] Open
Abstract
Purpose Fuchs' endothelial corneal dystrophy (FECD) is a major cause of vision loss and the most common nucleotide repeat disorder, affecting 4% of United States population greater than 40 years of age. Seventy percent of FECD cases are due to an intronic CTG expansion within the TCF4 gene, resulting in accumulation of CUG repeat RNA nuclear foci in corneal endothelium. Each endothelial cell has approximately two sense foci, and each focus is a single RNA molecule. This study aimed to obtain a better understanding of how rare repeat RNA species lead to disease. Methods We quantitatively examined muscleblind-like (MBNL) proteins and their interaction with foci in both patient-derived corneal endothelial cell lines and human corneal endothelial tissue. Results Using fluorescent in situ hybridization and immunofluorescence, we found that depletion of both MBNL1 and MBNL2 reduces nuclear RNA foci formed by the repeat, suggesting that both are necessary for foci. Quantitative studies of RNA and protein copy number revealed MBNLs to be abundant in the total cellular pool in endothelial cell lines but are much lower in human corneal endothelial tissue. Studies using human tissue nuclear and cytoplasmic fractions indicate that most MBNL proteins are localized to the cytoplasm. Conclusions The low levels of MBNL1/2 in corneal tissue, in combination with the small fraction of protein in the nucleus, may make corneal endothelial cells especially susceptible to sequestration of MBNL1/2 by CUG repeat RNA. These observations may explain how a limited number of RNA molecules can cause widespread alteration of splicing and late-onset degenerative FECD.
Collapse
Affiliation(s)
- Ziye Rong
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, United States
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Jiaxin Hu
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - David R. Corey
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - V. Vinod Mootha
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, United States
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| |
Collapse
|
45
|
Hafford-Tear NJ, Tsai YC, Sadan AN, Sanchez-Pintado B, Zarouchlioti C, Maher GJ, Liskova P, Tuft SJ, Hardcastle AJ, Clark TA, Davidson AE. CRISPR/Cas9-targeted enrichment and long-read sequencing of the Fuchs endothelial corneal dystrophy-associated TCF4 triplet repeat. Genet Med 2019; 21:2092-2102. [PMID: 30733599 PMCID: PMC6752322 DOI: 10.1038/s41436-019-0453-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/24/2019] [Indexed: 12/15/2022] Open
Abstract
PURPOSE To demonstrate the utility of an amplification-free long-read sequencing method to characterize the Fuchs endothelial corneal dystrophy (FECD)-associated intronic TCF4 triplet repeat (CTG18.1). METHODS We applied an amplification-free method, utilizing the CRISPR/Cas9 system, in combination with PacBio single-molecule real-time (SMRT) long-read sequencing, to study CTG18.1. FECD patient samples displaying a diverse range of CTG18.1 allele lengths and zygosity status (n = 11) were analyzed. A robust data analysis pipeline was developed to effectively filter, align, and interrogate CTG18.1-specific reads. All results were compared with conventional polymerase chain reaction (PCR)-based fragment analysis. RESULTS CRISPR-guided SMRT sequencing of CTG18.1 provided accurate genotyping information for all samples and phasing was possible for 18/22 alleles sequenced. Repeat length instability was observed for all expanded (≥50 repeats) phased CTG18.1 alleles analyzed. Furthermore, higher levels of repeat instability were associated with increased CTG18.1 allele length (mode length ≥91 repeats) indicating that expanded alleles behave dynamically. CONCLUSION CRISPR-guided SMRT sequencing of CTG18.1 has revealed novel insights into CTG18.1 length instability. Furthermore, this study provides a framework to improve the molecular diagnostic accuracy for CTG18.1-mediated FECD, which we anticipate will become increasingly important as gene-directed therapies are developed for this common age-related and sight threatening disease.
Collapse
Affiliation(s)
| | | | | | | | | | - Geoffrey J Maher
- Clinical Genetics Group, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Petra Liskova
- UCL Institute of Ophthalmology, London, UK
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Stephen J Tuft
- UCL Institute of Ophthalmology, London, UK
- Moorfields Eye Hospital, London, UK
| | | | | | | |
Collapse
|
46
|
The future of keratoplasty: cell-based therapy, regenerative medicine, bioengineering keratoplasty, gene therapy. Curr Opin Ophthalmol 2019; 30:286-291. [PMID: 31045881 DOI: 10.1097/icu.0000000000000573] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW To provide an update on the state of development of novel therapeutic modalities for the treatment of corneal diseases. RECENT FINDINGS Novel corneal therapeutics may be broadly classified as cell therapy, regenerative medicine, bioengineered corneal grafts and gene therapy. Cell therapy encompasses cultivation of cells, such as corneal endothelial cells (CECs) and keratocytes to replenish the depleted native cell population. Regenerative medicine is mainly applicable to the corneal endothelium, and is dependent on the ability of native, healthy CECs to restore the corneal endothelium following trauma or descemetorhexis; this approach may be effective for the treatment of Peter's anomaly and Fuchs endothelial corneal dystrophy (FECD). Bioengineered corneal grafts are synthetic constructs designed to replace cadaveric corneal grafts; tissue-engineered endothelial-keratoplasty grafts and bioengineered stromal grafts have been experimented in animal models with favourable results. Gene therapy with antisense oligonucleotide and CRISPR endonucleases, including deactivated Cas9, may potentially be used to treat FECD and TGFBI-related corneal dystrophies. SUMMARY These novel therapeutic modalities may potentially supersede keratoplasty as the standard of care in the future.
Collapse
|
47
|
Patel SV. Towards Clinical Trials in Fuchs Endothelial Corneal Dystrophy: Classification and Outcome Measures-The Bowman Club Lecture 2019. BMJ Open Ophthalmol 2019; 4:e000321. [PMID: 31414054 PMCID: PMC6668606 DOI: 10.1136/bmjophth-2019-000321] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Accepted: 05/12/2019] [Indexed: 12/13/2022] Open
Abstract
The surgical treatment of Fuchs endothelial corneal dystrophy (FECD) has advanced dramatically over the last two decades. Penetrating keratoplasty has been superseded by various iterations of endothelial keratoplasty, and currently, surgical removal of host Descemet membrane without keratoplasty is being investigated. These surgical advances have been accompanied by significant improvement of our understanding of the underlying disease mechanisms, not least the discovery that FECD in western populations is predominantly an intronic trinucleotide repeat expansion disorder in the transcription factor 4 gene that results in RNA toxicity and mis-splicing. Understanding the disease mechanisms augurs well for developing targeted molecular medical therapies, which will require careful clinical investigation through trials to prove their efficacy and safety. As the field advances towards clinical trials, investigators should carefully define the disease state being treated and consider the options for outcome measures relevant to the type of intervention. FECD, and the outcomes of interventions to treat the disease, can be measured in terms of corneal morphology, corneal function and clinical impact. Standardising the approach for defining FECD and careful thought about the outcomes of intervention that are reported will help make the results of future trials for FECD applicable in clinical practice.
Collapse
|
48
|
Abstract
Fuchs' endothelial corneal dystrophy (FECD) is a common disease resulting from corneal endothelial cell dysfunction. It is inherited in an autosomal dominant fashion with incomplete penetrance, and with a female bias. Approximately half of cases occur sporadically, and the remainder are familial. Early and late-onset forms of the disease exist. A review of the literature has revealed more than 15 genes harbouring mutations and/or single nucleotide polymorphisms associated with FECD. The proteins encoded by these genes cover a wide range of endothelial function, including transcription regulation, DNA repair, mitochondrial DNA mutations, targeting of proteins to the cell membrane, deglutamylation of proteins, extracellular matrix secretion, formation of cell-cell and cell-extracellular matrix junctions, water pump, and apoptosis. These genetic variations will form the platform for the further understanding of the pathological basis of the disease, and the development of targeted treatments. This review aims to summarise known genetic variations associated with FECD, discuss any known molecular effects of the variations, how these provide opportunities for targeted therapies, and what therapies are currently in development.
Collapse
|
49
|
Expansion of trinucleotide CTG repeats in the TCF4 gene as a marker of fuchs’ endothelial corneal dystrophy. OPHTHALMOLOGY JOURNAL 2019. [DOI: 10.17816/ov2019211-18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Fuchs’ endothelial corneal dystrophy (FECD) is an inherited severe and progressive disease, characterized by endothelial cell density decrease and increasing corneal edema. FECD development may be linked to expanded trinucleotide repeat, CTG, in the third intron of the TCF4 gene. The study focuses on estimating the prevalence of expanded CTG repeat in TCF4 gene in the Russian population, in patients with normal cornea and in patients with FECD (by applying triplet repeat PCR technique and capillary electrophoresis). 51 patients with FECD and 38 patients with normal cornea were examined. The estimation of the number of CTG triplet repeats in TCF4 gene determination is the veracious laboratory marker of FECD.
Collapse
|
50
|
Nanda GG, Alone DP. REVIEW: Current understanding of the pathogenesis of Fuchs' endothelial corneal dystrophy. Mol Vis 2019; 25:295-310. [PMID: 31263352 PMCID: PMC6571125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 06/03/2019] [Indexed: 11/18/2022] Open
Abstract
Fuchs' endothelial corneal dystrophy (FECD) is the most prominent reason for corneal-endothelial transplantations across the globe. The disease pathophysiology manifests through a combination of various genetic and non-heritable factors. This review provides a comprehensive list of known genetic players that cause FECD, and discusses the prominent pathological features that participate in disease progression, such as channel dysfunction, abnormal extracellular matrix deposition, RNA toxicity, oxidative stress, and apoptosis. Although current practices to correct visual acuity involve surgical intervention, this review also discusses the scope of various non-surgical therapeutics to remedy FECD.
Collapse
|