1
|
De Angeli P, Flores-Tufiño A, Stingl K, Kühlewein L, Roschi E, Wissinger B, Kohl S. Splicing defects and CRISPR-Cas9 correction in isogenic homozygous photoreceptor precursors harboring clustered deep-intronic ABCA4 variants. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102113. [PMID: 38274366 PMCID: PMC10809099 DOI: 10.1016/j.omtn.2023.102113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 12/21/2023] [Indexed: 01/27/2024]
Abstract
Splicing defects from deep-intronic variants significantly contribute to the mutational spectrum in ABCA4-associated inherited retinal diseases, necessitating functional validation for their pathological classification. Typically, minigene assays in HEK293(T) can qualitatively assess splicing defects, yet they often fail to quantitatively reproduce the resulting mis-splicing patterns, leaving uncertainty on severity and pathogenicity. As a potential cellular model derived from patient cells, photoreceptor precursor cells (PPCs) play a pivotal role in assessing the severity of specific splicing mutations. Nevertheless, the accessibility of biosamples is commonly constrained, and their establishment is costly and laborious. In this study, we combined and investigated the use of a minigene assay and isogenic PPCs, as superior qualitative and more accessible cellular models for the assessment of splicing defects. Specifically, we focused on the clustered c.5196+1013A>G, c.5196+1056A>G, and c.5196+1216C>A deep-intronic variants in intron 36 of ABCA4, comparing their resulting (mis)splicing patterns in minigene-transfected cells and isogenic CRISPR-Cas9-knocked-in PPCs harboring these pathogenic variants in homozygous state. Moreover, we demonstrate the successful correction of these three splicing defects in homozygous mutant PPCs using a single pair of guide RNAs to target Cas9 cleavage, thereby identifying an efficient gene editing strategy for therapeutic applications.
Collapse
Affiliation(s)
- Pietro De Angeli
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Clinics Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany
| | - Arturo Flores-Tufiño
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Clinics Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany
| | - Katarina Stingl
- University Eye Hospital, Centre for Ophthalmology, University Clinics Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany
| | - Laura Kühlewein
- University Eye Hospital, Centre for Ophthalmology, University Clinics Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany
| | - Eleonora Roschi
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Clinics Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany
- Wellcome Sanger Institute, Hinxton CB10 1RQ, Saffron Walden, UK
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Clinics Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Clinics Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany
| |
Collapse
|
2
|
Whelan L, Dockery A, Stephenson KAJ, Zhu J, Kopčić E, Post IJM, Khan M, Corradi Z, Wynne N, O' Byrne JJ, Duignan E, Silvestri G, Roosing S, Cremers FPM, Keegan DJ, Kenna PF, Farrar GJ. Detailed analysis of an enriched deep intronic ABCA4 variant in Irish Stargardt disease patients. Sci Rep 2023; 13:9380. [PMID: 37296172 PMCID: PMC10256698 DOI: 10.1038/s41598-023-35889-9] [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: 05/17/2022] [Accepted: 05/25/2023] [Indexed: 06/12/2023] Open
Abstract
Over 15% of probands in a large cohort of more than 1500 inherited retinal degeneration patients present with a clinical diagnosis of Stargardt disease (STGD1), a recessive form of macular dystrophy caused by biallelic variants in the ABCA4 gene. Participants were clinically examined and underwent either target capture sequencing of the exons and some pathogenic intronic regions of ABCA4, sequencing of the entire ABCA4 gene or whole genome sequencing. ABCA4 c.4539 + 2028C > T, p.[= ,Arg1514Leufs*36] is a pathogenic deep intronic variant that results in a retina-specific 345-nucleotide pseudoexon inclusion. Through analysis of the Irish STGD1 cohort, 25 individuals across 18 pedigrees harbour ABCA4 c.4539 + 2028C > T and another pathogenic variant. This includes, to the best of our knowledge, the only two homozygous patients identified to date. This provides important evidence of variant pathogenicity for this deep intronic variant, highlighting the value of homozygotes for variant interpretation. 15 other heterozygous incidents of this variant in patients have been reported globally, indicating significant enrichment in the Irish population. We provide detailed genetic and clinical characterization of these patients, illustrating that ABCA4 c.4539 + 2028C > T is a variant of mild to intermediate severity. These results have important implications for unresolved STGD1 patients globally with approximately 10% of the population in some western countries claiming Irish heritage. This study exemplifies that detection and characterization of founder variants is a diagnostic imperative.
Collapse
Affiliation(s)
- Laura Whelan
- The School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland.
| | - Adrian Dockery
- The School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
- Next Generation Sequencing Laboratory, Pathology Department, The Mater Misericordiae University Hospital, Dublin 7, Ireland
| | - Kirk A J Stephenson
- Department of Ophthalmology, Royal Victoria Eye and Ear Hospital, Dublin 2, Ireland
- Mater Clinical Ophthalmic Genetics Unit, The Mater Misericordiae University Hospital, Dublin 7, Ireland
| | - Julia Zhu
- Mater Clinical Ophthalmic Genetics Unit, The Mater Misericordiae University Hospital, Dublin 7, Ireland
| | - Ella Kopčić
- The School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Iris J M Post
- The School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Mubeen Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
- International Max Planck Research School for Language Sciences, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
| | - Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Academic Alliance Genetics, Radboud University Medical Center, Nijmegen, and Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Niamh Wynne
- Department of Ophthalmology, Royal Victoria Eye and Ear Hospital, Dublin 2, Ireland
| | - James J O' Byrne
- Mater Clinical Ophthalmic Genetics Unit, The Mater Misericordiae University Hospital, Dublin 7, Ireland
- International Max Planck Research School for Language Sciences, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
- National Centre for Inherited Metabolic Disorders, The Mater Misericordiae University Hospital, Dublin 7, Ireland
- School of Medicine, Trinity College Dublin, Dublin 2, Ireland
| | - Emma Duignan
- Department of Ophthalmology, Royal Victoria Eye and Ear Hospital, Dublin 2, Ireland
| | - Giuliana Silvestri
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, Northern Ireland, UK
- School of Medicine, University College Dublin, Dublin 4, Ireland
- Department of Ophthalmology, The Royal Victoria Hospital, Belfast, Northern Ireland, UK
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Academic Alliance Genetics, Radboud University Medical Center, Nijmegen, and Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Academic Alliance Genetics, Radboud University Medical Center, Nijmegen, and Maastricht University Medical Center+, Maastricht, The Netherlands
| | - David J Keegan
- Mater Clinical Ophthalmic Genetics Unit, The Mater Misericordiae University Hospital, Dublin 7, Ireland
| | - Paul F Kenna
- The School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
- Department of Ophthalmology, Royal Victoria Eye and Ear Hospital, Dublin 2, Ireland
| | - G Jane Farrar
- The School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| |
Collapse
|
3
|
Corral-Serrano JC, Sladen PE, Ottaviani D, Rezek FO, Jovanovic K, Athanasiou D, van der Spuy J, Mansfield BC, Cheetham ME. Eupatilin improves cilia defects in human CEP290 ciliopathy models. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.12.536565. [PMID: 37205323 PMCID: PMC10187159 DOI: 10.1101/2023.04.12.536565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The photoreceptor outer segment is a highly specialized primary cilium essential for phototransduction and vision. Biallelic pathogenic variants in the cilia-associated gene CEP290 cause non-syndromic Leber congenital amaurosis 10 (LCA10) and syndromic diseases, where the retina is also affected. While RNA antisense oligonucleotides and gene editing are potential treatment options for the common deep intronic variant c.2991+1655A>G in CEP290 , there is a need for variant-independent approaches that could be applied to a broader spectrum of ciliopathies. Here, we generated several distinct human models of CEP290 -related retinal disease and investigated the effects of the flavonoid eupatilin as a potential treatment. Eupatilin improved cilium formation and length in CEP290 LCA10 patient-derived fibroblasts, in gene-edited CEP290 knockout (CEP290 KO) RPE1 cells, and in both CEP290 LCA10 and CEP290 KO iPSCs-derived retinal organoids. Furthermore, eupatilin reduced rhodopsin retention in the outer nuclear layer of CEP290 LCA10 retinal organoids. Eupatilin altered gene transcription in retinal organoids, by modulating the expression of rhodopsin, and by targeting cilia and synaptic plasticity pathways. This work sheds light into the mechanism of action of eupatilin, and supports its potential as a variant-independent approach for CEP290 -associated ciliopathies. Abstract Figure
Collapse
Affiliation(s)
- JC Corral-Serrano
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL UK
| | - PE Sladen
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL UK
| | - D Ottaviani
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL UK
- Department of Biology, University of Padova, Padova, Italy
| | - FO Rezek
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL UK
| | - K Jovanovic
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL UK
| | - D Athanasiou
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL UK
| | - J van der Spuy
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL UK
| | - BC Mansfield
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
| | - ME Cheetham
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL UK
| |
Collapse
|
4
|
Minella AL, Narfström Wiechel K, Petersen-Jones SM. Alternative splicing in CEP290 mutant cats results in a milder phenotype than LCA CEP290 patients. Vet Ophthalmol 2023; 26:4-11. [PMID: 36495011 PMCID: PMC10107307 DOI: 10.1111/vop.13052] [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: 07/13/2022] [Revised: 10/28/2022] [Accepted: 12/02/2022] [Indexed: 12/14/2022]
Abstract
PURPOSE The rdAc cat has an intronic mutation in the centrosomal 290 kDa (CEP290) gene resulting in a frameshift and a premature stop codon (c.6960 + 9 T > G, p.Ile2321AlafsTer3) predicted to truncate the protein by 157 amino acids. CEP290 mutations in human patients cause a range or phenotypes including syndromic conditions and severe childhood loss of vision while the rdAc cat has a milder phenotype. We sought to further characterize the effect of rdAc mutation on CEP290 expression. METHODS TaqMan quantitative real-time polymerase chain reaction assays were used to compare wildtype and truncated transcript levels. Relative protein abundance was analyzed by Western blot. Immunohistochemistry (IHC) was performed to detect CEP290 protein. RESULTS CEP290 mutant cats show low-level (17.4% of wildtype cats) use of the wildtype splice site and usage of the mutant splice site. Western analysis shows retina from cats homozygous for the mutation has CEP290 protein that likely comprises a combination of both wildtype and truncated protein. IHC detects CEP290 in affected and control retina labeling the region of the interconnecting cilium. CONCLUSIONS The comparably milder phenotype of CEP290 mutant cats is likely due to the retained production of some full-length CEP290 protein with possible functional contributions from presence of truncated protein.
Collapse
Affiliation(s)
- Andrea L Minella
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Kristina Narfström Wiechel
- Department of Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, Mssouri, USA
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| |
Collapse
|
5
|
Aleman TS, O'Neil EC, Uyhazi KE, Parchinski KM, Santos AJ, Weber ML, Colclough SP, Billek AS, Zhu X, Leroy BP, Bedoukian EC. Fleck-like lesions in CEP290-associated leber congenital amaurosis: a case series. Ophthalmic Genet 2022; 43:824-833. [PMID: 36469661 DOI: 10.1080/13816810.2022.2147960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE To provide a detailed ophthalmic phenotype of a small cohort of patients with Leber Congenital Amaurosis (LCA) caused by mutations in CEP290 (CEP290-LCA) with a focus on elucidating the origin of yellow-white lesions observed in 30% of patients with this condition. METHODS This is a retrospective review of records of five patients with CEP290-LCA. Patients had comprehensive ophthalmic evaluations. Visual function was assessed with full-field electroretinograms (ffERGs) and full-field sensitivity testing (FST). Multimodal imaging was performed with spectral domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF) with short- (SW) and near-infrared (NIR) excitation wavelengths. RESULTS All patients showed relative structural preservation of the foveal and near midperipheral retina separated by a pericentral area of photoreceptor loss. Yellow-white, fleck-like lesions in an annular distribution around the near midperiphery co-localized with hyperreflective lesions on SD-OCT. The lesions located between the inner segment ellipsoid signal and the apical retinal pigment epithelium (RPE). The inner retina was normal. Longitudinal observations in one of the patients indicates the abnormalities may represent an intermediate stage in the degenerative process between the near normal appearing retina previously documented in young CEP290-LCA patients and the pigmentary retinopathy observed along the same region in older individuals. CONCLUSIONS We speculate that fleck-like lesions in CEP290-LCA correspond to malformed, rudimentary or degenerated, including shed, photoreceptor outer segments. The topography and possible origin of the abnormalities may inform the planning of evolving genetic therapies for this disease.
Collapse
Affiliation(s)
- Tomas S Aleman
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Erin C O'Neil
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Katherine E Uyhazi
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kelsey M Parchinski
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Arlene J Santos
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mariejel L Weber
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sherice P Colclough
- The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrew S Billek
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Xiaosong Zhu
- The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bart P Leroy
- The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Head & Skin, Ghent University, Ghent, Belgium.,Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium.,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Emma C Bedoukian
- The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,The Individualized Medical Genetics Center of the Children's Hospital of Philadelphia, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
6
|
The Predicted Splicing Variant c.11+5G>A in RPE65 Leads to a Reduction in mRNA Expression in a Cell-Specific Manner. Cells 2022; 11:cells11223640. [PMID: 36429068 PMCID: PMC9688607 DOI: 10.3390/cells11223640] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/01/2022] [Accepted: 11/15/2022] [Indexed: 11/18/2022] Open
Abstract
Pathogenic variants in RPE65 lead to retinal diseases, causing a vision impairment. In this work, we investigated the pathomechanism behind the frequent RPE65 variant, c.11+5G>A. Previous in silico predictions classified this change as a splice variant. Our prediction using novel software's suggested a 124-nt exon elongation containing a premature stop codon. This elongation was validated using midigenes-based approaches. Similar results were observed in patient-derived induced pluripotent stem cells (iPSC) and photoreceptor precursor cells. However, the splicing defect in all cases was detected at low levels and thereby does not fully explain the recessive condition of the resulting disease. Long-read sequencing discarded other rearrangements or variants that could explain the diseases. Subsequently, a more relevant model was employed: iPSC-derived retinal pigment epithelium (RPE) cells. In patient-derived iPSC-RPE cells, the expression of RPE65 was strongly reduced even after inhibiting a nonsense-mediated decay, contradicting the predicted splicing defect. Additional experiments demonstrated a cell-specific gene expression reduction due to the presence of the c.11+5G>A variant. This decrease also leads to the lack of the RPE65 protein, and differences in size and pigmentation between the patient and control iPSC-RPE. Altogether, our data suggest that the c.11+5G>A variant causes a cell-specific defect in the expression of RPE65 rather than the anticipated splicing defect which was predicted in silico.
Collapse
|
7
|
Antisense RNA Therapeutics: A Brief Overview. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2434:33-49. [PMID: 35213008 DOI: 10.1007/978-1-0716-2010-6_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Nucleic acid therapeutics is a growing field aiming to treat human conditions that has gained special attention due to the successful development of mRNA vaccines against SARS-CoV-2. Another type of nucleic acid therapeutics is antisense oligonucleotides, versatile tools that can be used in multiple ways to target pre-mRNA and mRNA. While some years ago these molecules were just considered a useful research tool and a curiosity in the clinical market, this has rapidly changed. These molecules are promising strategies for personalized treatments for rare genetic diseases and they are in development for very common disorders too. In this chapter, we provide a brief description of the different mechanisms of action of these RNA therapeutic molecules, with clear examples at preclinical and clinical stages.
Collapse
|
8
|
Vázquez-Domínguez I, Garanto A. Considerations for Generating Humanized Mouse Models to Test Efficacy of Antisense Oligonucleotides. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2434:267-279. [PMID: 35213024 DOI: 10.1007/978-1-0716-2010-6_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Over the last decades, animal models have become increasingly important in therapeutic drug development and assessment. The use of these models, mainly mice and rats, allow evaluating drugs in the real-organism environment and context. However, several molecular therapeutic approaches are sequence-dependent, and therefore, the humanization of such models is required to assess the efficacy. The generation of genetically modified humanized mouse models is often an expensive and laborious process that may not always recapitulate the human molecular and/or physiological phenotype. In this chapter, we summarize basic aspects to consider before designing and generating humanized models, especially when they are aimed to test antisense-based therapies.
Collapse
Affiliation(s)
- Irene Vázquez-Domínguez
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Alejandro Garanto
- Department of Pediatrics, Amalia Children's Hospital, Radboud Institute of Molecular Life Sciences (RIMLS), Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
9
|
Garanto A. Delivery of Antisense Oligonucleotides to the Mouse Retina. Methods Mol Biol 2022; 2434:321-332. [PMID: 35213028 PMCID: PMC9703207 DOI: 10.1007/978-1-0716-2010-6_22] [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] [Indexed: 06/14/2023]
Abstract
The eye is the organ in charge of vision and, given its properties, has become an excellent organ to test genetic therapies, including antisense oligonucleotide (AON) technology. In fact, the first AON receiving FDA and EMA approval was meant to treat an eye condition. Currently, dozens of clinical trials are being conducted for a variety of subtypes of inherited retinal disease. Although most of them are based on gene augmentation therapies, a phase 3 and two phase 1/2 clinical trials using AONs are ongoing. Since the retina is a layered structure of nondividing cells, obtaining human retinal tissue and expanding it in the lab is not possible, unless induced pluripotent stem cell technology is used. Mouse models have helped to elucidate the function of many genes, and the retinal structure is quite similar to that of humans. Thus, drug delivery to the mouse eye can provide valuable information for further optimization of therapies. In this chapter, the protocol for intravitreal injections of AONs is described in detail.
Collapse
Affiliation(s)
- Alejandro Garanto
- Department of Pediatrics, Amalia Children's Hospital, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center, Nijmegen, The Netherlands.
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.
| |
Collapse
|
10
|
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
|
11
|
Suárez-Herrera N, Tomkiewicz TZ, Garanto A, Collin RWJ. Development and Use of Cellular Systems to Assess and Correct Splicing Defects. Methods Mol Biol 2022; 2434:145-165. [PMID: 35213015 PMCID: PMC9703848 DOI: 10.1007/978-1-0716-2010-6_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A significant proportion of mutations underlying genetic disorders affect pre-mRNA splicing, generally causing partial or total skipping of exons, and/or inclusion of pseudoexons. These changes often lead to the formation of aberrant transcripts that can induce nonsense-mediated decay, and a subsequent lack of functional protein. For some genetic disorders, including inherited retinal diseases (IRDs), reproducing splicing dynamics in vitro is a challenge due to the specific environment provided by, e.g. the retinal tissue, cells of which cannot be easily obtained and/or cultured. Here, we describe how to engineer splicing vectors, validate the reliability and reproducibility of alternative cellular systems, assess pre-mRNA splicing defects involved in IRD, and finally correct those by using antisense oligonucleotide-based strategies.
Collapse
Affiliation(s)
- Nuria Suárez-Herrera
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tomasz Z Tomkiewicz
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alejandro Garanto
- Department of Pediatrics, Amalia Children's Hospital, Nijmegen, The Netherlands
- Department of Human Genetics and Radboud Institute of Molecular Life Sciences (RIMLS), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rob W J Collin
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
| |
Collapse
|
12
|
Amato A, Arrigo A, Aragona E, Manitto MP, Saladino A, Bandello F, Battaglia Parodi M. Gene Therapy in Inherited Retinal Diseases: An Update on Current State of the Art. Front Med (Lausanne) 2021; 8:750586. [PMID: 34722588 PMCID: PMC8553993 DOI: 10.3389/fmed.2021.750586] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/20/2021] [Indexed: 12/11/2022] Open
Abstract
Background: Gene therapy cannot be yet considered a far perspective, but a tangible therapeutic option in the field of retinal diseases. Although still confined in experimental settings, the preliminary results are promising and provide an overall scenario suggesting that we are not so far from the application of gene therapy in clinical settings. The main aim of this review is to provide a complete and updated overview of the current state of the art and of the future perspectives of gene therapy applied on retinal diseases. Methods: We carefully revised the entire literature to report all the relevant findings related to the experimental procedures and the future scenarios of gene therapy applied in retinal diseases. A clinical background and a detailed description of the genetic features of each retinal disease included are also reported. Results: The current literature strongly support the hope of gene therapy options developed for retinal diseases. Although being considered in advanced stages of investigation for some retinal diseases, such as choroideremia (CHM), retinitis pigmentosa (RP), and Leber's congenital amaurosis (LCA), gene therapy is still quite far from a tangible application in clinical practice for other retinal diseases. Conclusions: Gene therapy is an extremely promising therapeutic tool for retinal diseases. The experimental data reported in this review offer a strong hope that gene therapy will be effectively available in clinical practice in the next years.
Collapse
Affiliation(s)
- Alessia Amato
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Alessandro Arrigo
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Emanuela Aragona
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Maria Pia Manitto
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Andrea Saladino
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Francesco Bandello
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | | |
Collapse
|
13
|
Koschak A, Fernandez-Quintero ML, Heigl T, Ruzza M, Seitter H, Zanetti L. Cav1.4 dysfunction and congenital stationary night blindness type 2. Pflugers Arch 2021; 473:1437-1454. [PMID: 34212239 PMCID: PMC8370969 DOI: 10.1007/s00424-021-02570-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 04/14/2021] [Accepted: 04/18/2021] [Indexed: 12/04/2022]
Abstract
Cav1.4 L-type Ca2+ channels are predominantly expressed in retinal neurons, particularly at the photoreceptor terminals where they mediate sustained Ca2+ entry needed for continuous neurotransmitter release at their ribbon synapses. Cav1.4 channel gating properties are controlled by accessory subunits, associated regulatory proteins, and also alternative splicing. In humans, mutations in the CACNA1F gene encoding for Cav1.4 channels are associated with X-linked retinal disorders such as congenital stationary night blindness type 2. Mutations in the Cav1.4 protein result in a spectrum of altered functional channel activity. Several mouse models broadened our understanding of the role of Cav1.4 channels not only as Ca2+ source at retinal synapses but also as synaptic organizers. In this review, we highlight different structural and functional phenotypes of Cav1.4 mutations that might also occur in patients with congenital stationary night blindness type 2. A further important yet mostly neglected aspect that we discuss is the influence of alternative splicing on channel dysfunction. We conclude that currently available functional phenotyping strategies should be refined and summarize potential specific therapeutic options for patients carrying Cav1.4 mutations. Importantly, the development of new therapeutic approaches will permit a deeper understanding of not only the disease pathophysiology but also the physiological function of Cav1.4 channels in the retina.
Collapse
MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Animals
- Calcium Channel Agonists/pharmacology
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Eye Diseases, Hereditary/genetics
- Eye Diseases, Hereditary/metabolism
- Genetic Diseases, X-Linked/genetics
- Genetic Diseases, X-Linked/metabolism
- Humans
- Mutation/physiology
- Myopia/genetics
- Myopia/metabolism
- Night Blindness/genetics
- Night Blindness/metabolism
- Retina/drug effects
- Retina/metabolism
- Synapses/drug effects
- Synapses/genetics
- Synapses/metabolism
Collapse
Affiliation(s)
- Alexandra Koschak
- Institute of Pharmacy, Pharmacology and Toxicology, Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82/III, 6020, Innsbruck, Austria.
| | - Monica L Fernandez-Quintero
- Institute of General, Inorganic and Theoretical Chemistry, Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82/III, 6020, Innsbruck, Austria
| | - Thomas Heigl
- Institute of Pharmacy, Pharmacology and Toxicology, Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82/III, 6020, Innsbruck, Austria
| | - Marco Ruzza
- Institute of Pharmacy, Pharmacology and Toxicology, Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82/III, 6020, Innsbruck, Austria
| | - Hartwig Seitter
- Institute of Pharmacy, Pharmacology and Toxicology, Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82/III, 6020, Innsbruck, Austria
| | - Lucia Zanetti
- Institute of Pharmacy, Pharmacology and Toxicology, Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82/III, 6020, Innsbruck, Austria
| |
Collapse
|
14
|
Piotter E, McClements ME, MacLaren RE. Therapy Approaches for Stargardt Disease. Biomolecules 2021; 11:1179. [PMID: 34439845 PMCID: PMC8393614 DOI: 10.3390/biom11081179] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/27/2021] [Accepted: 08/05/2021] [Indexed: 12/14/2022] Open
Abstract
Despite being the most prevalent cause of inherited blindness in children, Stargardt disease is yet to achieve the same clinical trial success as has been achieved for other inherited retinal diseases. With an early age of onset and continual progression of disease over the life course of an individual, Stargardt disease appears to lend itself to therapeutic intervention. However, the aetiology provides issues not encountered with the likes of choroideremia and X-linked retinitis pigmentosa and this has led to a spectrum of treatment strategies that approach the problem from different aspects. These include therapeutics ranging from small molecules and anti-sense oligonucleotides to viral gene supplementation and cell replacement. The advancing development of CRISPR-based molecular tools is also likely to contribute to future therapies by way of genome editing. In this we review, we consider the most recent pre-clinical and clinical trial data relating to the different strategies being applied to the problem of generating a treatment for the large cohort of Stargardt disease patients worldwide.
Collapse
Affiliation(s)
- Elena Piotter
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; (E.P.); (M.E.M.)
- Oxford University Hospitals NHS Foundation Trust NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
| | - Michelle E McClements
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; (E.P.); (M.E.M.)
- Oxford University Hospitals NHS Foundation Trust NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; (E.P.); (M.E.M.)
- Oxford University Hospitals NHS Foundation Trust NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
| |
Collapse
|
15
|
Testa F, Sodi A, Signorini S, Di Iorio V, Murro V, Brunetti-Pierri R, Valente EM, Karali M, Melillo P, Banfi S, Simonelli F. Spectrum of Disease Severity in Nonsyndromic Patients With Mutations in the CEP290 Gene: A Multicentric Longitudinal Study. Invest Ophthalmol Vis Sci 2021; 62:1. [PMID: 34196655 PMCID: PMC8267213 DOI: 10.1167/iovs.62.9.1] [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] [Indexed: 11/29/2022] Open
Abstract
Purpose The purpose of this study was to perform a detailed longitudinal phenotyping and genetic characterization of 32 Italian patients with a nonsyndromic retinal dystrophy and mutations in the CEP290 gene. Methods We reviewed the clinical history and examinations of 32 patients with a nonsyndromic retinal dystrophy due to mutations in the CEP290 gene, followed up (mean follow-up: 5.9 years) at 3 Italian centers. The clinical examinations included: best corrected visual acuity (BCVA), optical coherence tomography (OCT), and full-field electroretinogram (ERG). Results Patients (mean age = 19.0 ± 3.4 years) had a mean BCVA of 1.73 ± 0.20 logMAR. Longitudinal analysis of BCVA showed a nonsignificant decline. Central retinal thickness (CRT) declined significantly with age at an exponential rate of 1.0%/year (P = 0.001). At disease onset, most patients (19/32; 49.4%) had nystagmus. The absence of nystagmus was significantly associated with better BCVA and more preserved CRT (P < 0.05). ERG showed undetectable responses in most patients (64.0%), whereas reduced scotopic and photopic responses were observed in four patients (16.0%) who had no nystagmus. We identified 35 different variants, among which 12 were novel. Our genotype-phenotype correlation analysis shows a significantly worse BCVA in patients harboring a loss-of-function mutation and the deep-intronic variant c.2991+1655A>G. Conclusions Our study highlights a mild phenotype of the disease, characterized by absence of nystagmus, good visual acuity, considerably preserved retinal morphology, and recordable ERG, confirming the wide spectrum of CEP290-related retinal dystrophies. Finally, in our cohort, the deep intronic variant c.2991+1655A>G was associated with a more severe phenotype.
Collapse
Affiliation(s)
- Francesco Testa
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli", Naples, Italy
| | - Andrea Sodi
- Eye Clinic, Neuromuscolar and Sense Organs Department, Careggi University Hospital, Florence, Italy
| | - Sabrina Signorini
- Unit of Child Neurology and Psychiatry, IRCCS C. Mondino Foundation, Pavia, Italy
| | - Valentina Di Iorio
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli", Naples, Italy
| | - Vittoria Murro
- Eye Clinic, Neuromuscolar and Sense Organs Department, Careggi University Hospital, Florence, Italy
| | - Raffaella Brunetti-Pierri
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli", Naples, Italy
| | - Enza Maria Valente
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Neurogenetics Unit, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Marianthi Karali
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli", Naples, Italy.,Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | - Paolo Melillo
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli", Naples, Italy
| | - Sandro Banfi
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Medical Genetics, Department of Precision Medicine, Università degli Studi della Campania "Luigi Vanvitelli", Naples, Italy
| | - Francesca Simonelli
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli", Naples, Italy
| |
Collapse
|
16
|
Abstract
Antisense oligonucleotides (AON) are synthetic single-stranded fragments of nucleic acids that bind to a specific complementary messenger RNA (mRNA) sequence and change the final gene product. AON were initially approved for treating cytomegalovirus retinitis and have shown promise in treating Mendelian systemic disease. AON are currently being investigated as a treatment modality for many ophthalmic diseases, including inherited retinal disorders (IRD), inflammatory response and wound healing after glaucoma surgery, and macular degeneration. They provide a possible solution to gene therapy for IRD that are not candidates for adeno-associated virus (AAV) delivery. This chapter outlines the historical background of AON and reviews clinical applications and ongoing clinical trials.
Collapse
Affiliation(s)
- Kevin Ferenchak
- Inherited Retinal Disorders Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Iris Deitch
- Inherited Retinal Disorders Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Rachel Huckfeldt
- Inherited Retinal Disorders Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| |
Collapse
|
17
|
Tomkiewicz TZ, Suárez-Herrera N, Cremers FPM, Collin RWJ, Garanto A. Antisense Oligonucleotide-Based Rescue of Aberrant Splicing Defects Caused by 15 Pathogenic Variants in ABCA4. Int J Mol Sci 2021; 22:ijms22094621. [PMID: 33924840 PMCID: PMC8124656 DOI: 10.3390/ijms22094621] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 12/16/2022] Open
Abstract
The discovery of novel intronic variants in the ABCA4 locus has contributed significantly to solving the missing heritability in Stargardt disease (STGD1). The increasing number of variants affecting pre-mRNA splicing makes ABCA4 a suitable candidate for antisense oligonucleotide (AON)-based splicing modulation therapies. In this study, AON-based splicing modulation was assessed for 15 recently described intronic variants (three near-exon and 12 deep-intronic variants). In total, 26 AONs were designed and tested in vitro using a midigene-based splice system. Overall, partial or complete splicing correction was observed for two variants causing exon elongation and all variants causing pseudoexon inclusion. Together, our results confirm the high potential of AONs for the development of future RNA therapies to correct splicing defects causing STGD1.
Collapse
Affiliation(s)
- Tomasz Z. Tomkiewicz
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands; (T.Z.T.); (N.S.-H.); (F.P.M.C.); (R.W.J.C.)
| | - Nuria Suárez-Herrera
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands; (T.Z.T.); (N.S.-H.); (F.P.M.C.); (R.W.J.C.)
| | - Frans P. M. Cremers
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands; (T.Z.T.); (N.S.-H.); (F.P.M.C.); (R.W.J.C.)
| | - Rob W. J. Collin
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands; (T.Z.T.); (N.S.-H.); (F.P.M.C.); (R.W.J.C.)
| | - Alejandro Garanto
- Departments of Pediatrics and Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands
- Correspondence:
| |
Collapse
|
18
|
Das S, Chen Y, Yan J, Christensen G, Belhadj S, Tolone A, Paquet-Durand F. The role of cGMP-signalling and calcium-signalling in photoreceptor cell death: perspectives for therapy development. Pflugers Arch 2021; 473:1411-1421. [PMID: 33864120 PMCID: PMC8370896 DOI: 10.1007/s00424-021-02556-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/04/2021] [Accepted: 03/10/2021] [Indexed: 12/12/2022]
Abstract
The second messengers, cGMP and Ca2+, have both been implicated in retinal degeneration; however, it is still unclear which of the two is most relevant for photoreceptor cell death. This problem is exacerbated by the close connections and crosstalk between cGMP-signalling and calcium (Ca2+)-signalling in photoreceptors. In this review, we summarize key aspects of cGMP-signalling and Ca2+-signalling relevant for hereditary photoreceptor degeneration. The topics covered include cGMP-signalling targets, the role of Ca2+ permeable channels, relation to energy metabolism, calpain-type proteases, and how the related metabolic processes may trigger and execute photoreceptor cell death. A focus is then put on cGMP-dependent mechanisms and how exceedingly high photoreceptor cGMP levels set in motion cascades of Ca2+-dependent and independent processes that eventually bring about photoreceptor cell death. Finally, an outlook is given into mutation-independent therapeutic approaches that exploit specific features of cGMP-signalling. Such approaches might be combined with suitable drug delivery systems for translation into clinical applications.
Collapse
Affiliation(s)
- Soumyaparna Das
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany
| | - Yiyi Chen
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany
| | - Jie Yan
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany
| | - Gustav Christensen
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany
| | - Soumaya Belhadj
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany
| | - Arianna Tolone
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany
| | - François Paquet-Durand
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany.
| |
Collapse
|
19
|
Hammond SM, Aartsma‐Rus A, Alves S, Borgos SE, Buijsen RAM, Collin RWJ, Covello G, Denti MA, Desviat LR, Echevarría L, Foged C, Gaina G, Garanto A, Goyenvalle AT, Guzowska M, Holodnuka I, Jones DR, Krause S, Lehto T, Montolio M, Van Roon‐Mom W, Arechavala‐Gomeza V. Delivery of oligonucleotide-based therapeutics: challenges and opportunities. EMBO Mol Med 2021; 13:e13243. [PMID: 33821570 PMCID: PMC8033518 DOI: 10.15252/emmm.202013243] [Citation(s) in RCA: 161] [Impact Index Per Article: 53.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 11/27/2020] [Accepted: 11/30/2020] [Indexed: 12/12/2022] Open
Abstract
Nucleic acid-based therapeutics that regulate gene expression have been developed towards clinical use at a steady pace for several decades, but in recent years the field has been accelerating. To date, there are 11 marketed products based on antisense oligonucleotides, aptamers and small interfering RNAs, and many others are in the pipeline for both academia and industry. A major technology trigger for this development has been progress in oligonucleotide chemistry to improve the drug properties and reduce cost of goods, but the main hurdle for the application to a wider range of disorders is delivery to target tissues. The adoption of delivery technologies, such as conjugates or nanoparticles, has been a game changer for many therapeutic indications, but many others are still awaiting their eureka moment. Here, we cover the variety of methods developed to deliver nucleic acid-based therapeutics across biological barriers and the model systems used to test them. We discuss important safety considerations and regulatory requirements for synthetic oligonucleotide chemistries and the hurdles for translating laboratory breakthroughs to the clinic. Recent advances in the delivery of nucleic acid-based therapeutics and in the development of model systems, as well as safety considerations and regulatory requirements for synthetic oligonucleotide chemistries are discussed in this review on oligonucleotide-based therapeutics.
Collapse
Affiliation(s)
| | | | - Sandra Alves
- Department of Human Genetics, Research and Development UnitNational Health Institute Doutor Ricardo JorgePortoPortugal
| | - Sven E Borgos
- Department of Biotechnology and NanomedicineSINTEF ASTrondheimNorway
| | - Ronald A M Buijsen
- Department of Human GeneticsLeiden University Medical CenterLeidenThe Netherlands
| | - Rob W J Collin
- Department of Human Genetics and Donders Institute for Brain, Cognition and BehaviourRadboud University Medical CenterNijmegenThe Netherlands
| | - Giuseppina Covello
- Department of BiologyUniversity of PadovaPadovaItaly
- Department of Cellular, Computational and Integrative Biology ‐ CIBIOUniversity of TrentoTrentoItaly
| | - Michela A Denti
- Department of Cellular, Computational and Integrative Biology ‐ CIBIOUniversity of TrentoTrentoItaly
| | - Lourdes R Desviat
- Centro de Biología Molecular Severo Ochoa UAM‐CSICCIBERER, IdiPazUniversidad Autónoma de MadridMadridSpain
| | | | - Camilla Foged
- Department of PharmacyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagen ØDenmark
| | - Gisela Gaina
- Victor Babes National Institute of PathologyBucharestRomania
- Department of Biochemistry and Molecular BiologyUniversity of BucharestBucharestRomania
| | - Alejandro Garanto
- Department of Human Genetics and Donders Institute for Brain, Cognition and BehaviourRadboud University Medical CenterNijmegenThe Netherlands
- Department of PediatricsRadboud University Medical CenterNijmegenThe Netherlands
| | | | - Magdalena Guzowska
- Department of Physiological SciencesFaculty of Veterinary MedicineWarsaw University of Life Sciences – SGGWWarsawPoland
| | - Irina Holodnuka
- Institute of Microbiology and VirologyRiga Stradins UniversityRigaLatvia
| | | | - Sabine Krause
- Department of NeurologyFriedrich‐Baur‐InstituteLudwig‐Maximilians‐University of MunichMunichGermany
| | - Taavi Lehto
- Institute of TechnologyUniversity of TartuTartuEstonia
- Division of Biomolecular and Cellular MedicineDepartment of Laboratory MedicineKarolinska InstitutetHuddingeSweden
| | - Marisol Montolio
- Duchenne Parent Project EspañaMadridSpain
- Department of Cell Biology, Fisiology and ImmunologyFaculty of BiologyUniversity of BarcelonaBarcelonaSpain
| | - Willeke Van Roon‐Mom
- Department of Human GeneticsLeiden University Medical CenterLeidenThe Netherlands
| | - Virginia Arechavala‐Gomeza
- Neuromuscular Disorders GroupBiocruces Bizkaia Health Research InstituteBarakaldoSpain
- Ikerbasque, Basque Foundation for ScienceBilbaoSpain
| |
Collapse
|
20
|
Perrault I, Hanein S, Gérard X, Mounguengue N, Bouyakoub R, Zarhrate M, Fourrage C, Jabot-Hanin F, Bocquet B, Meunier I, Zanlonghi X, Kaplan J, Rozet JM. Whole Locus Sequencing Identifies a Prevalent Founder Deep Intronic RPGRIP1 Pathologic Variant in the French Leber Congenital Amaurosis Cohort. Genes (Basel) 2021; 12:genes12020287. [PMID: 33670832 PMCID: PMC7922592 DOI: 10.3390/genes12020287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/10/2021] [Accepted: 02/16/2021] [Indexed: 01/04/2023] Open
Abstract
Leber congenital amaurosis (LCA) encompasses the earliest and most severe retinal dystrophies and can occur as a non-syndromic or a syndromic disease. Molecular diagnosis in LCA is of particular importance in clinical decision-making and patient care since it can provide ocular and extraocular prognostics and identify patients eligible to develop gene-specific therapies. Routine high-throughput molecular testing in LCA yields 70%–80% of genetic diagnosis. In this study, we aimed to investigate the non-coding regions of one non-syndromic LCA gene, RPGRIP1, in a series of six families displaying one single disease allele after a gene-panel screening of 722 LCA families which identified 26 biallelic RPGRIP1 families. Using trio-based high-throughput whole locus sequencing (WLS) for second disease alleles, we identified a founder deep intronic mutation (NM_020366.3:c.1468-128T>G) in 3/6 families. We employed Sanger sequencing to search for the pathologic variant in unresolved LCA cases (106/722) and identified three additional families (two homozygous and one compound heterozygous with the NM_020366.3:c.930+77A>G deep intronic change). This makes the c.1468-128T>G the most frequent RPGRIP1 disease allele (8/60, 13%) in our cohort. Studying patient lymphoblasts, we show that the pathologic variant creates a donor splice-site and leads to the insertion of the pseudo-exon in the mRNA, which we were able to hamper using splice-switching antisense oligonucleotides (AONs), paving the way to therapies.
Collapse
Affiliation(s)
- Isabelle Perrault
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
- Correspondence:
| | - Sylvain Hanein
- Translational Genetics, Institute of Genetic Diseases, INSERM UMR1163, Imagine and Paris Descartes University, 75015 Paris, France;
| | - Xavier Gérard
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
| | - Nelson Mounguengue
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
| | - Ryme Bouyakoub
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
| | - Mohammed Zarhrate
- Genomics Platform, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France;
| | - Cécile Fourrage
- Bioinformatic Platform, Institute of Genetic Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (C.F.); (F.J.-H.)
| | - Fabienne Jabot-Hanin
- Bioinformatic Platform, Institute of Genetic Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (C.F.); (F.J.-H.)
- Bioinformatics Core Facility, Université Paris Descartes-Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, 75015 Paris, France
| | - Béatrice Bocquet
- Centre de Référence des Affections Sensorielles Génétiques, Institut des Neurosciences de Montpellier, CHU-Saint Eloi Montpellier, 34091 Montpellier, France; (B.B.); (I.M.)
| | - Isabelle Meunier
- Centre de Référence des Affections Sensorielles Génétiques, Institut des Neurosciences de Montpellier, CHU-Saint Eloi Montpellier, 34091 Montpellier, France; (B.B.); (I.M.)
- National Reference Centre for Inherited Sensory Diseases, Univ Montpellier, CHU, 34091 Montpellier, France
| | - Xavier Zanlonghi
- Eye Clinic Jules Verne, 44300 Nantes, France;
- CHU, 35000 Rennes, France
| | - Josseline Kaplan
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
- Ophthalmology Department, University Hospital Henri Mondor, APHP, 94000 Créteil, France
| | - Jean-Michel Rozet
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
| |
Collapse
|
21
|
Khan M, Arno G, Fakin A, Parfitt DA, Dhooge PPA, Albert S, Bax NM, Duijkers L, Niblock M, Hau KL, Bloch E, Schiff ER, Piccolo D, Hogden MC, Hoyng CB, Webster AR, Cremers FPM, Cheetham ME, Garanto A, Collin RWJ. Detailed Phenotyping and Therapeutic Strategies for Intronic ABCA4 Variants in Stargardt Disease. MOLECULAR THERAPY. NUCLEIC ACIDS 2020; 21:412-427. [PMID: 32653833 PMCID: PMC7352060 DOI: 10.1016/j.omtn.2020.06.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/15/2020] [Accepted: 06/09/2020] [Indexed: 01/17/2023]
Abstract
Stargardt disease is a progressive retinal disorder caused by bi-allelic mutations in the ABCA4 gene that encodes the ATP-binding cassette, subfamily A, member 4 transporter protein. Over the past few years, we and others have identified several pathogenic variants that reside within the introns of ABCA4, including a recurrent variant in intron 36 (c.5196+1137G>A) of which the pathogenicity so far remained controversial. Detailed clinical characterization of this variant confirmed its pathogenic nature, and classified it as an allele of intermediate severity. Moreover, we discovered several additional ABCA4 variants clustering in intron 36. Several of these variants resulted in aberrant splicing of ABCA4, i.e., the inclusion of pseudoexons, while the splicing defects caused by the recurrent c.5196+1137G>A variant strongly increased upon differentiation of patient-derived induced pluripotent stem cells into retina-like cells. Finally, all splicing defects could be rescued by the administration of antisense oligonucleotides that were designed to specifically block the pseudoexon insertion, including rescue in 3D retinal organoids harboring the c.5196+1137G>A variant. Our data illustrate the importance of intronic variants in ABCA4 and expand the therapeutic possibilities for overcoming splicing defects in Stargardt disease.
Collapse
Affiliation(s)
- Mubeen Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Gavin Arno
- UCL Institute for Ophthalmology, London, UK; Moorfields Eye Hospital, London, UK; Great Ormond Street Hospital for Children, London, UK
| | - Ana Fakin
- UCL Institute for Ophthalmology, London, UK; Moorfields Eye Hospital, London, UK; Eye Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | | | - Patty P A Dhooge
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Silvia Albert
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Nathalie M Bax
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Lonneke Duijkers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | | | - Kwan L Hau
- UCL Institute for Ophthalmology, London, UK
| | - Edward Bloch
- UCL Institute for Ophthalmology, London, UK; Moorfields Eye Hospital, London, UK
| | | | | | | | - Carel B Hoyng
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Andrew R Webster
- UCL Institute for Ophthalmology, London, UK; Moorfields Eye Hospital, London, UK
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | | | - Alejandro Garanto
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands.
| |
Collapse
|
22
|
Chen W, Hu Y, Ju D. Gene therapy for neurodegenerative disorders: advances, insights and prospects. Acta Pharm Sin B 2020; 10:1347-1359. [PMID: 32963936 PMCID: PMC7488363 DOI: 10.1016/j.apsb.2020.01.015] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/09/2019] [Accepted: 12/06/2019] [Indexed: 02/07/2023] Open
Abstract
Gene therapy is rapidly emerging as a powerful therapeutic strategy for a wide range of neurodegenerative disorders, including Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD). Some early clinical trials have failed to achieve satisfactory therapeutic effects. Efforts to enhance effectiveness are now concentrating on three major fields: identification of new vectors, novel therapeutic targets, and reliable of delivery routes for transgenes. These approaches are being assessed closely in preclinical and clinical trials, which may ultimately provide powerful treatments for patients. Here, we discuss advances and challenges of gene therapy for neurodegenerative disorders, highlighting promising technologies, targets, and future prospects.
Collapse
Key Words
- AADC, aromatic-l-amino-acid
- AAVs, adeno-associated viruses
- AD, Alzheimer's disease
- ARSA, arylsulfatase A
- ASOs, antisense oligonucleotides
- ASPA, aspartoacylase
- Adeno-associated viruses
- Adv, adenovirus
- BBB, blood–brain barrier
- BCSFB, blood–cerebrospinal fluid barrier
- BRB, blood–retina barrier
- Bip, glucose regulated protein 78
- CHOP, CCAAT/enhancer binding homologous protein
- CLN6, ceroidlipofuscinosis neuronal protein 6
- CNS, central nervous system
- CSF, cerebrospinal fluid
- Central nervous system
- Delivery routes
- ER, endoplasmic reticulum
- FDA, U.S. Food and Drug Administration
- GAA, lysosomal acid α-glucosidase
- GAD, glutamic acid decarboxylase
- GDNF, glial derived neurotrophic factor
- Gene therapy
- HD, Huntington's disease
- HSPGs, heparin sulfate proteoglycans
- HTT, mutant huntingtin
- IDS, iduronate 2-sulfatase
- LVs, retrovirus/lentivirus
- Lamp2a, lysosomal-associated membrane protein 2a
- NGF, nerve growth factor
- Neurodegenerative disorders
- PD, Parkinson's disease
- PGRN, Progranulin
- PINK1, putative kinase 1
- PTEN, phosphatase and tensin homolog
- RGCs, retinal ganglion cells
- RNAi, RNA interference
- RPE, retinal pigmented epithelial
- SGSH, lysosomal heparan-N-sulfamidase gene
- SMN, survival motor neuron
- SOD, superoxide dismutase
- SUMF, sulfatase-modifying factor
- TFEB, transcription factor EB
- TPP1, tripeptidyl peptidase 1
- TREM2, triggering receptor expressed on myeloid cells 2
- UPR, unfolded protein response
- ZFPs, zinc finger proteins
- mTOR, mammalian target of rapamycin
- siRNA, small interfering RNA
Collapse
Affiliation(s)
- Wei Chen
- Department of Biological Medicines, Fudan University School of Pharmacy, Shanghai 201203, China
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Dianwen Ju
- Department of Biological Medicines, Fudan University School of Pharmacy, Shanghai 201203, China
| |
Collapse
|
23
|
Cremers FPM, Lee W, Collin RWJ, Allikmets R. Clinical spectrum, genetic complexity and therapeutic approaches for retinal disease caused by ABCA4 mutations. Prog Retin Eye Res 2020; 79:100861. [PMID: 32278709 PMCID: PMC7544654 DOI: 10.1016/j.preteyeres.2020.100861] [Citation(s) in RCA: 159] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 03/13/2020] [Accepted: 03/18/2020] [Indexed: 12/18/2022]
Abstract
The ABCA4 protein (then called a “rim protein”) was first
identified in 1978 in the rims and incisures of rod photoreceptors. The
corresponding gene, ABCA4, was cloned in 1997, and variants
were identified as the cause of autosomal recessive Stargardt disease (STGD1).
Over the next two decades, variation in ABCA4 has been
attributed to phenotypes other than the classically defined STGD1 or fundus
flavimaculatus, ranging from early onset and fast progressing cone-rod dystrophy
and retinitis pigmentosa-like phenotypes to very late onset cases of mostly mild
disease sometimes resembling, and confused with, age-related macular
degeneration. Similarly, analysis of the ABCA4 locus uncovered
a trove of genetic information, including >1200 disease-causing mutations
of varying severity, and of all types – missense, nonsense, small
deletions/insertions, and splicing affecting variants, of which many are located
deep-intronic. Altogether, this has greatly expanded our understanding of
complexity not only of the diseases caused by ABCA4 mutations,
but of all Mendelian diseases in general. This review provides an in depth
assessment of the cumulative knowledge of ABCA4-associated retinopathy –
clinical manifestations, genetic complexity, pathophysiology as well as current
and proposed therapeutic approaches.
Collapse
Affiliation(s)
- Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, PO Box 9104, 6500 HE, Nijmegen, the Netherlands.
| | - Winston Lee
- Department of Ophthalmology, Columbia University, New York, NY, 10032, USA; Department of Genetics & Development, Columbia University, New York, NY, 10032, USA
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, PO Box 9104, 6500 HE, Nijmegen, the Netherlands
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York, NY, 10032, USA; Department of Pathology & Cell Biology, Columbia University, New York, NY, 10032, USA.
| |
Collapse
|
24
|
Fadaie Z, Khan M, Del Pozo‐Valero M, Cornelis SS, Ayuso C, Cremers FPM, Roosing S, The ABCA4 study group. Identification of splice defects due to noncanonical splice site or deep-intronic variants in ABCA4. Hum Mutat 2019; 40:2365-2376. [PMID: 31397521 PMCID: PMC6899986 DOI: 10.1002/humu.23890] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/30/2019] [Accepted: 08/04/2019] [Indexed: 12/25/2022]
Abstract
Pathogenic variants in the ATP-binding cassette transporter A4 (ABCA4) gene cause a continuum of retinal disease phenotypes, including Stargardt disease. Noncanonical splice site (NCSS) and deep-intronic variants constitute a large fraction of disease-causing alleles, defining the functional consequences of which remains a challenge. We aimed to determine the effect on splicing of nine previously reported or unpublished NCSS variants, one near exon splice variant and nine deep-intronic variants in ABCA4, using in vitro splice assays in human embryonic kidney 293T cells. Reverse transcription-polymerase chain reaction and Sanger sequence analysis revealed splicing defects for 12 out of 19 variants. Four deep-intronic variants create pseudoexons or elongate the upstream exon. Furthermore, eight NCSS variants cause a partial deletion or skipping of one or more exons in messenger RNAs. Among the 12 variants, nine lead to premature stop codons and predicted truncated ABCA4 proteins. At least two deep-intronic variants affect splice enhancer and silencer motifs and, therefore, these conserved sequences should be carefully evaluated when predicting the outcome of NCSS and deep-intronic variants.
Collapse
Affiliation(s)
- Zeinab Fadaie
- Department of Human Genetics, Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Mubeen Khan
- Department of Human Genetics, Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Marta Del Pozo‐Valero
- Department of Human Genetics, Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
- Department of Genetics, Instituto de Investigación Sanitaria–Fundación Jiménez Díaz University HospitalUniversidad Autónoma de Madrid (IIS‐FJD, UAM)MadridSpain
| | - Stéphanie S. Cornelis
- Department of Human Genetics, Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Carmen Ayuso
- Department of Genetics, Instituto de Investigación Sanitaria–Fundación Jiménez Díaz University HospitalUniversidad Autónoma de Madrid (IIS‐FJD, UAM)MadridSpain
| | - Frans P. M. Cremers
- Department of Human Genetics, Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Susanne Roosing
- Department of Human Genetics, Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | | |
Collapse
|
25
|
Gene Therapy in Retinal Dystrophies. Int J Mol Sci 2019; 20:ijms20225722. [PMID: 31739639 PMCID: PMC6888000 DOI: 10.3390/ijms20225722] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/13/2019] [Accepted: 11/13/2019] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal dystrophies (IRDs) are a group of clinically and genetically heterogeneous degenerative disorders. To date, mutations have been associated with IRDs in over 270 disease genes, but molecular diagnosis still remains elusive in about a third of cases. The methodologic developments in genome sequencing techniques that we have witnessed in this last decade have represented a turning point not only in diagnosis and prognosis but, above all, in the identification of new therapeutic perspectives. The discovery of new disease genes and pathogenetic mechanisms underlying IRDs has laid the groundwork for gene therapy approaches. Several clinical trials are ongoing, and the recent approval of Luxturna, the first gene therapy product for Leber congenital amaurosis, marks the beginning of a new era. Due to its anatomical and functional characteristics, the retina is the organ of choice for gene therapy, although there are quite a few difficulties in the translational approaches from preclinical models to humans. In the first part of this review, an overview of the current knowledge on methodological issues and future perspectives of gene therapy applied to IRDs is discussed; in the second part, the state of the art of clinical trials on the gene therapy approach in IRDs is illustrated.
Collapse
|
26
|
Molecular Approaches for the Treatment of Pompe Disease. Mol Neurobiol 2019; 57:1259-1280. [PMID: 31713816 DOI: 10.1007/s12035-019-01820-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 10/23/2019] [Indexed: 12/14/2022]
Abstract
Glycogen storage disease type II (GSDII, Pompe disease) is a rare metabolic disorder caused by a deficiency of acid alpha-glucosidase (GAA), an enzyme localized within lysosomes that is solely responsible for glycogen degradation in this compartment. The manifestations of GSDII are heterogeneous but are classified as early or late onset. The natural course of early-onset Pompe disease (EOPD) is severe and rapidly fatal if left untreated. Currently, one therapeutic approach, namely, enzyme replacement therapy, is available, but advances in molecular medicine approaches hold promise for even more effective therapeutic strategies. These approaches, which we review here, comprise splicing modification by antisense oligonucleotides, chaperone therapy, stop codon readthrough therapy, and the use of viral vectors to introduce wild-type genes. Considering the high rate at which innovations are translated from bench to bedside, it is reasonable to expect substantial improvements in the treatment of this illness in the foreseeable future.
Collapse
|
27
|
Shivanna M, Anand M, Chakrabarti S, Khanna H. Ocular Ciliopathies: Genetic and Mechanistic Insights into Developing Therapies. Curr Med Chem 2019; 26:3120-3131. [PMID: 30221600 DOI: 10.2174/0929867325666180917102557] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/21/2018] [Accepted: 09/05/2018] [Indexed: 12/12/2022]
Abstract
Developing suitable medicines for genetic diseases requires a detailed understanding of not only the pathways that cause the disease, but also the identification of the genetic components involved in disease manifestation. This article focuses on the complexities associated with ocular ciliopathies - a class of debilitating disorders of the eye caused by ciliary dysfunction. Ciliated cell types have been identified in both the anterior and posterior segments of the eye. Photoreceptors (rods and cones) are the most studied ciliated neurons in the retina, which is located in the posterior eye. The photoreceptors contain a specialized lightsensing outer segment, or cilium. Any defects in the development or maintenance of the outer segment can result in severe retinal ciliopathies, such as retinitis pigmentosa and Leber congenital amaurosis. A role of cilia in the cell types involved in regulating aqueous fluid outflow in the anterior segment of the eye has also been recognized. Defects in these cell types are frequently associated with some forms of glaucoma. Here, we will discuss the significance of understanding the genetic heterogeneity and the pathogenesis of ocular ciliopathies to develop suitable treatment strategies for these blinding disorders.
Collapse
Affiliation(s)
- Mahesh Shivanna
- School of Optometry, Massachusetts College of Pharmacy and Health Sciences University, Worcester, MA, United States
| | - Manisha Anand
- UMASS Medical School, Worcester, MA 01605, United States
| | | | - Hemant Khanna
- UMASS Medical School, Worcester, MA 01605, United States
| |
Collapse
|
28
|
Prevalence of ABCA4 Deep-Intronic Variants and Related Phenotype in An Unsolved "One-Hit" Cohort with Stargardt Disease. Int J Mol Sci 2019; 20:ijms20205053. [PMID: 31614660 PMCID: PMC6829239 DOI: 10.3390/ijms20205053] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/24/2019] [Accepted: 10/09/2019] [Indexed: 02/06/2023] Open
Abstract
We investigated the prevalence of reported deep-intronic variants in a French cohort of 70 patients with Stargardt disease harboring a monoallelic pathogenic variant on the exonic regions of ABCA4. Direct Sanger sequencing of selected intronic regions of ABCA4 was conducted. Complete phenotypic analysis and correlation with the genotype was performed in case a known intronic pathogenic variant was identified. All other variants found on the analyzed sequences were queried for minor allele frequency and possible pathogenicity by in silico predictions. The second mutated allele was found in 14 (20%) subjects. The three known deep-intronic variants found were c.5196+1137G>A in intron 36 (6 subjects), c.4539+2064C>T in intron 30 (4 subjects) and c.4253+43G>A in intron 28 (4 subjects). Even though the phenotype depends on the compound effect of the biallelic variants, a genotype-phenotype correlation suggests that the c.5196+1137G>A was mostly associated with a mild phenotype and the c.4539+2064C>T with a more severe one. A variable effect was instead associated with the variant c.4253+43G>A. In addition, two novel variants, c.768+508A>G and c.859-245_859-243delinsTGA never associated with Stargardt disease before, were identified and a possible splice defect was predicted in silico. Our study calls for a larger cohort analysis including targeted locus sequencing and 3D protein modeling to better understand phenotype-genotype correlations associated with deep-intronic changes and patients’ selection for clinical trials.
Collapse
|
29
|
Vázquez-Domínguez I, Garanto A, Collin RWJ. Molecular Therapies for Inherited Retinal Diseases-Current Standing, Opportunities and Challenges. Genes (Basel) 2019; 10:genes10090654. [PMID: 31466352 PMCID: PMC6770110 DOI: 10.3390/genes10090654] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/23/2019] [Accepted: 08/26/2019] [Indexed: 12/15/2022] Open
Abstract
Inherited retinal diseases (IRDs) are both genetically and clinically highly heterogeneous and have long been considered incurable. Following the successful development of a gene augmentation therapy for biallelic RPE65-associated IRD, this view has changed. As a result, many different therapeutic approaches are currently being developed, in particular a large variety of molecular therapies. These are depending on the severity of the retinal degeneration, knowledge of the pathophysiological mechanism underlying each subtype of IRD, and the therapeutic target molecule. DNA therapies include approaches such as gene augmentation therapy, genome editing and optogenetics. For some genetic subtypes of IRD, RNA therapies and compound therapies have also shown considerable therapeutic potential. In this review, we summarize the current state-of-the-art of various therapeutic approaches, including the pros and cons of each strategy, and outline the future challenges that lie ahead in the combat against IRDs.
Collapse
Affiliation(s)
- Irene Vázquez-Domínguez
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands
| | - Alejandro Garanto
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands.
| | - Rob W J Collin
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands.
| |
Collapse
|
30
|
Breuel S, Vorm M, Bräuer AU, Owczarek-Lipska M, Neidhardt J. Combining Engineered U1 snRNA and Antisense Oligonucleotides to Improve the Treatment of a BBS1 Splice Site Mutation. MOLECULAR THERAPY. NUCLEIC ACIDS 2019; 18:123-130. [PMID: 31541798 PMCID: PMC6796732 DOI: 10.1016/j.omtn.2019.08.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 06/14/2019] [Accepted: 08/01/2019] [Indexed: 12/23/2022]
Abstract
Manipulation of pre-mRNA processing is a promising approach toward overcoming disease-causing mutations and treating human diseases. We show that a combined treatment applying two splice-manipulating technologies improves therapeutic efficacies to correct mutation-induced splice defects. Previously, we identified a family affected by retinitis pigmentosa caused by the homozygous BBS1 splice donor site mutation c.479G > A. The mutation leads to both exon 5 skipping and intron 5 retention. We developed a therapeutic approach applying lentivirus-mediated gene delivery of engineered U1 small nuclear RNA (U1), which resulted in increased levels of correctly spliced BBS1. Herein, we show that the therapeutic effect of the engineered U1 efficiently reverted exon skipping but failed to reduce the intron retention. To complement the engineered U1 treatment, we identified four different antisense oligonucleotides (AONs) that block intron 5 retention in BBS1 transcripts. A treatment using engineered U1 in combination with AONs showed the highest therapeutic efficacy and increased the amount of correctly spliced BBS1 transcripts. We did not detect elevated levels of apoptotic cell death in AON-treated cell lines. In conclusion, engineered U1 or AONs provide efficient therapies with complementary effects and can be combined to increase efficacy of therapeutic approaches to correct splice defects.
Collapse
Affiliation(s)
- Saskia Breuel
- Human Genetics, Faculty of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Mariann Vorm
- Human Genetics, Faculty of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Anja U Bräuer
- Anatomy, Faculty of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany; Research Center Neurosensory Science, University of Oldenburg, Germany
| | - Marta Owczarek-Lipska
- Human Genetics, Faculty of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - John Neidhardt
- Human Genetics, Faculty of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany; Research Center Neurosensory Science, University of Oldenburg, Germany; Joint research training group of the Faculty of Medicine and Health Sciences, University of Oldenburg, Germany and the University Medical Center Groningen, Groningen, Netherlands.
| |
Collapse
|
31
|
Targeted exon skipping rescues ciliary protein composition defects in Joubert syndrome patient fibroblasts. Sci Rep 2019; 9:10828. [PMID: 31346239 PMCID: PMC6658666 DOI: 10.1038/s41598-019-47243-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 07/12/2019] [Indexed: 12/19/2022] Open
Abstract
Joubert syndrome (JBTS) is an incurable multisystem ciliopathy syndrome. The most commonly mutated gene in JBTS patients with a cerebello-retinal-renal phenotype is CEP290 (alias JBTS5). The encoded CEP290 protein localises to the proximal end of the primary cilium, in the transition zone, where it controls ciliary protein composition and signalling. We examined primary cilium structure and composition in fibroblast cells derived from homozygous and compound heterozygous JBTS5 patients with nonsense mutations in CEP290 and show that elongation of cilia, impaired ciliogenesis and ciliary composition defects are typical features in JBTS5 cells. Targeted skipping of the mutated exon c.5668 G > T using antisense oligonucleotide (ASO) therapy leads to restoration of CEP290 protein expression and functions at the transition zone in homozygous and compound heterozygous JBTS5 cells, allowing a rescue of both cilia morphology and ciliary composition. This study, by demonstrating that targeted exon skipping is able to rescue ciliary protein composition defects, provides functional evidence for the efficacy of this approach in the treatment of JBTS.
Collapse
|
32
|
Balancing the Photoreceptor Proteome: Proteostasis Network Therapeutics for Inherited Retinal Disease. Genes (Basel) 2019; 10:genes10080557. [PMID: 31344897 PMCID: PMC6722924 DOI: 10.3390/genes10080557] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/09/2019] [Accepted: 07/16/2019] [Indexed: 12/17/2022] Open
Abstract
The light sensing outer segments of photoreceptors (PRs) are renewed every ten days due to their high photoactivity, especially of the cones during daytime vision. This demands a tremendous amount of energy, as well as a high turnover of their main biosynthetic compounds, membranes, and proteins. Therefore, a refined proteostasis network (PN), regulating the protein balance, is crucial for PR viability. In many inherited retinal diseases (IRDs) this balance is disrupted leading to protein accumulation in the inner segment and eventually the death of PRs. Various studies have been focusing on therapeutically targeting the different branches of the PR PN to restore the protein balance and ultimately to treat inherited blindness. This review first describes the different branches of the PN in detail. Subsequently, insights are provided on how therapeutic compounds directed against the different PN branches might slow down or even arrest the appalling, progressive blinding conditions. These insights are supported by findings of PN modulators in other research disciplines.
Collapse
|
33
|
Garanto A, Duijkers L, Tomkiewicz TZ, Collin RWJ. Antisense Oligonucleotide Screening to Optimize the Rescue of the Splicing Defect Caused by the Recurrent Deep-Intronic ABCA4 Variant c.4539+2001G>A in Stargardt Disease. Genes (Basel) 2019; 10:genes10060452. [PMID: 31197102 PMCID: PMC6628380 DOI: 10.3390/genes10060452] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/04/2019] [Accepted: 06/11/2019] [Indexed: 12/17/2022] Open
Abstract
Deep-sequencing of the ABCA4 locus has revealed that ~10% of autosomal recessive Stargardt disease (STGD1) cases are caused by deep-intronic mutations. One of the most recurrent deep-intronic variants in the Belgian and Dutch STGD1 population is the c.4539+2001G>A mutation. This variant introduces a 345-nt pseudoexon to the ABCA4 mRNA transcript in a retina-specific manner. Antisense oligonucleotides (AONs) are short sequences of RNA that can modulate splicing. In this work, we designed 26 different AONs to perform a thorough screening to identify the most effective AONs to correct splicing defects associated with c.4539+2001G>A. All AONs were tested in patient-derived induced pluripotent stem cells (iPSCs) that were differentiated to photoreceptor precursor cells (PPCs). AON efficacy was assessed through RNA analysis and was based on correction efficacy, and AONs were grouped and their properties assessed. We (a) identified nine AONs with significant correction efficacies (>50%), (b) confirmed that a single nucleotide mismatch was sufficient to significantly decrease AON efficacy, and (c) found potential correlations between efficacy and some of the parameters analyzed. Overall, our results show that AON-based splicing modulation holds great potential for treating Stargardt disease caused by splicing defects in ABCA4.
Collapse
Affiliation(s)
- Alejandro Garanto
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands.
| | - Lonneke Duijkers
- Department of Human Genetics, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands.
| | - Tomasz Z Tomkiewicz
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands.
| | - Rob W J Collin
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands.
| |
Collapse
|
34
|
Pitout I, Flynn LL, Wilton SD, Fletcher S. Antisense-mediated splice intervention to treat human disease: the odyssey continues. F1000Res 2019; 8. [PMID: 31164976 PMCID: PMC6534073 DOI: 10.12688/f1000research.18466.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/15/2019] [Indexed: 12/24/2022] Open
Abstract
Recent approvals of oligonucleotide analogue drugs to alter gene expression have been welcomed by patient communities but not universally supported. These compounds represent a class of drugs that are designed to target a specific gene transcript, and they include a number of chemical entities to evoke different antisense mechanisms, depending upon the disease aetiology. To date, oligonucleotide therapeutics that are in the clinic or at advanced stages of translation target rare diseases, posing challenges to clinical trial design, recruitment and evaluation and requiring new evaluation paradigms. This review discusses the currently available and emerging therapeutics that alter exon selection through an effect on pre-mRNA splicing and explores emerging concerns over safety and efficacy. Although modification of synthetic nucleic acids destined for therapeutic application is common practice to protect against nuclease degradation and to influence drug function, such modifications may also confer unexpected physicochemical and biological properties. Negatively charged oligonucleotides have a strong propensity to bind extra- and intra-cellular proteins, whereas those analogues with a neutral backbone show inefficient cellular uptake but excellent safety profiles. In addition, the potential for incorporation of chemically modified nucleic acid monomers, yielded by nuclease degradation of exogenous oligonucleotides, into biomolecules has been raised and the possibility not entirely discounted. We conclude with a commentary on the ongoing efforts to develop novel antisense compounds and enhance oligonucleotide delivery in order to further improve efficacy and accelerate implementation of antisense therapeutics for human disease.
Collapse
Affiliation(s)
| | - Loren L Flynn
- Murdoch University, Murdoch, WA, 6150, Australia.,The University of Western Australia, Nedlands, WA, 6009, Australia.,Perron Institute, Nedlands, WA, 6009, Australia
| | - Steve D Wilton
- Murdoch University, Murdoch, WA, 6150, Australia.,The University of Western Australia, Nedlands, WA, 6009, Australia.,Perron Institute, Nedlands, WA, 6009, Australia
| | - Sue Fletcher
- Murdoch University, Murdoch, WA, 6150, Australia.,The University of Western Australia, Nedlands, WA, 6009, Australia.,Perron Institute, Nedlands, WA, 6009, Australia
| |
Collapse
|
35
|
Barny I, Perrault I, Michel C, Goudin N, Defoort-Dhellemmes S, Ghazi I, Kaplan J, Rozet JM, Gerard X. AON-Mediated Exon Skipping to Bypass Protein Truncation in Retinal Dystrophies Due to the Recurrent CEP290 c.4723A > T Mutation. Fact or Fiction? Genes (Basel) 2019; 10:E368. [PMID: 31091803 PMCID: PMC6562928 DOI: 10.3390/genes10050368] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/09/2019] [Accepted: 05/09/2019] [Indexed: 01/09/2023] Open
Abstract
Mutations in CEP290 encoding a centrosomal protein important to cilia formation cause a spectrum of diseases, from isolated retinal dystrophies to multivisceral and sometimes embryo-lethal ciliopathies. In recent years, endogenous and/or selective non-canonical exon skipping of mutant exons have been documented in attenuated retinal disease cases. This observation led us to consider targeted exon skipping to bypass protein truncation resulting from a recurrent mutation in exon 36 (c.4723A > T, p.Lys1575*) causing isolated retinal ciliopathy. Here, we report two unrelated individuals (P1 and P2), carrying the mutation in homozygosity but affected with early-onset severe retinal dystrophy and congenital blindness, respectively. Studying skin-derived fibroblasts, we observed basal skipping and nonsense associated-altered splicing of exon 36, producing low (P1) and very low (P2) levels of CEP290 products. Consistent with a more severe disease, fibroblasts from P2 exhibited reduced ciliation compared to P1 cells displaying normally abundant cilia; both lines presented however significantly elongated cilia, suggesting altered axonemal trafficking. Antisense oligonucleotides (AONs)-mediated skipping of exon 36 increased the abundance of the premature termination codon (PTC)-free mRNA and protein, reduced axonemal length and improved cilia formation in P2 but not in P1 expressing higher levels of skipped mRNA, questioning AON-mediated exon skipping to treat patients carrying the recurrent c.4723A > T mutation.
Collapse
Affiliation(s)
- Iris Barny
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France.
| | - Isabelle Perrault
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France.
| | - Christel Michel
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France.
| | - Nicolas Goudin
- Cell Imaging Core Facility of the Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, Imagine and Paris Descartes University, 75015 Paris, France.
| | - Sabine Defoort-Dhellemmes
- Service D'exploration de la Vision et Neuro-Ophtalmologie, Pôle D'imagerie et Explorations Fonctionnelles, CHRU de Lille, 59037 Lille, France.
| | - Imad Ghazi
- Department of Ophthalmology, IHU Necker-Enfants Malades, 75015 Paris, France.
| | - Josseline Kaplan
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France.
| | - Jean-Michel Rozet
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France.
| | - Xavier Gerard
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France.
- Unit of Retinal Degeneration and Regeneration, Department of Ophthalmology, University of Lausanne, Hôpital Ophtalmique Jules Gonin, Fondation Asile des Aveugles, 1004 Lausanne, Switzerland.
| |
Collapse
|
36
|
Verbakel SK, Fadaie Z, Klevering BJ, van Genderen MM, Feenstra I, Cremers FPM, Hoyng CB, Roosing S. The identification of a RNA splice variant in TULP1 in two siblings with early-onset photoreceptor dystrophy. Mol Genet Genomic Med 2019; 7:e660. [PMID: 30950243 PMCID: PMC6565574 DOI: 10.1002/mgg3.660] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 02/21/2019] [Accepted: 03/04/2019] [Indexed: 12/23/2022] Open
Abstract
Background Early‐onset photoreceptor dystrophies are a major cause of irreversible visual impairment in children and young adults. This clinically heterogeneous group of disorders can be caused by mutations in many genes. Nevertheless, to date, 30%–40% of cases remain genetically unexplained. In view of expanding therapeutic options, it is essential to obtain a molecular diagnosis in these patients as well. In this study, we aimed to identify the genetic cause in two siblings with genetically unexplained retinal disease. Methods Whole exome sequencing was performed to identify the causative variants in two siblings in whom a single pathogenic variant in TULP1 was found previously. Patients were clinically evaluated, including assessment of the medical history, slit‐lamp biomicroscopy, and ophthalmoscopy. In addition, a functional analysis of the putative splice variant in TULP1 was performed using a midigene assay. Results Clinical assessment showed a typical early‐onset photoreceptor dystrophy in both the patients. Whole exome sequencing identified two pathogenic variants in TULP1, a c.1445G>A (p.(Arg482Gln)) missense mutation and an intronic c.718+23G>A variant. Segregation analysis confirmed that both siblings were compound heterozygous for the TULP1 c.718+23G>A and c.1445G>A variants, while the unaffected parents were heterozygous. The midigene assay for the c.718+23G>A variant confirmed an elongation of exon 7 leading to a frameshift. Conclusion Here, we report the first near‐exon RNA splice variant that is not present in a consensus splice site sequence in TULP1, which was found in a compound heterozygous manner with a previously described pathogenic TULP1 variant in two patients with an early‐onset photoreceptor dystrophy. We provide proof of pathogenicity for this splice variant by performing an in vitro midigene splice assay, and highlight the importance of analysis of noncoding regions beyond the noncanonical splice sites in patients with inherited retinal diseases.
Collapse
Affiliation(s)
- Sanne K Verbakel
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Zeinab Fadaie
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - B Jeroen Klevering
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maria M van Genderen
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands.,Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Ilse Feenstra
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Carel B Hoyng
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Susanne Roosing
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
37
|
Bolduc V, Foley AR, Solomon-Degefa H, Sarathy A, Donkervoort S, Hu Y, Chen GS, Sizov K, Nalls M, Zhou H, Aguti S, Cummings BB, Lek M, Tukiainen T, Marshall JL, Regev O, Marek-Yagel D, Sarkozy A, Butterfield RJ, Jou C, Jimenez-Mallebrera C, Li Y, Gartioux C, Mamchaoui K, Allamand V, Gualandi F, Ferlini A, Hanssen E, Wilton SD, Lamandé SR, MacArthur DG, Wagener R, Muntoni F, Bönnemann CG. A recurrent COL6A1 pseudoexon insertion causes muscular dystrophy and is effectively targeted by splice-correction therapies. JCI Insight 2019; 4:124403. [PMID: 30895940 DOI: 10.1172/jci.insight.124403] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 02/12/2019] [Indexed: 12/27/2022] Open
Abstract
The clinical application of advanced next-generation sequencing technologies is increasingly uncovering novel classes of mutations that may serve as potential targets for precision medicine therapeutics. Here, we show that a deep intronic splice defect in the COL6A1 gene, originally discovered by applying muscle RNA sequencing in patients with clinical findings of collagen VI-related dystrophy (COL6-RD), inserts an in-frame pseudoexon into COL6A1 mRNA, encodes a mutant collagen α1(VI) protein that exerts a dominant-negative effect on collagen VI matrix assembly, and provides a unique opportunity for splice-correction approaches aimed at restoring normal gene expression. Using splice-modulating antisense oligomers, we efficiently skipped the pseudoexon in patient-derived fibroblast cultures and restored a wild-type matrix. Similarly, we used CRISPR/Cas9 to precisely delete an intronic sequence containing the pseudoexon and efficiently abolish its inclusion while preserving wild-type splicing. Considering that this splice defect is emerging as one of the single most frequent mutations in COL6-RD, the design of specific and effective splice-correction therapies offers a promising path for clinical translation.
Collapse
Affiliation(s)
- Véronique Bolduc
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - A Reghan Foley
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Herimela Solomon-Degefa
- Center for Biochemistry, Faculty of Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Apurva Sarathy
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Sandra Donkervoort
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Ying Hu
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Grace S Chen
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Katherine Sizov
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Matthew Nalls
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Haiyan Zhou
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health & Great Ormond Street Hospital for Children, London, United Kingdom.,Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Sara Aguti
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health & Great Ormond Street Hospital for Children, London, United Kingdom
| | - Beryl B Cummings
- Analytical and Translation Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts, USA.,Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Monkol Lek
- Analytical and Translation Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Taru Tukiainen
- Analytical and Translation Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts, USA.,Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Jamie L Marshall
- Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Oded Regev
- Courant Institute of Mathematical Sciences, New York University, New York, USA
| | - Dina Marek-Yagel
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Anna Sarkozy
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health & Great Ormond Street Hospital for Children, London, United Kingdom
| | - Russell J Butterfield
- Department of Neurology and Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Cristina Jou
- Pathology Department and Biobanc de l'Hospital Infantil Sant Joan de Déu per a la Investigació, Hospital Sant Joan de Déu, Barcelona, Spain.,Neuromuscular Unit, Neuropediatrics Department, Hospital Sant Joan de Déu, Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Barcelona, Spain.,CIBERER (ISCIII), Madrid, Spain
| | - Cecilia Jimenez-Mallebrera
- Neuromuscular Unit, Neuropediatrics Department, Hospital Sant Joan de Déu, Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Barcelona, Spain.,CIBERER (ISCIII), Madrid, Spain
| | - Yan Li
- Peptide/Protein Sequencing Facility, National Institute of Neurological Disorder and Stroke, NIH, Bethesda, Maryland, USA
| | - Corine Gartioux
- Sorbonne Université, Inserm, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris, France
| | - Kamel Mamchaoui
- Sorbonne Université, Inserm, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris, France
| | - Valérie Allamand
- Sorbonne Université, Inserm, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris, France
| | - Francesca Gualandi
- Medical Genetics Unit, Department of Medical Science, University of Ferrara, Ferrara, Italy
| | - Alessandra Ferlini
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health & Great Ormond Street Hospital for Children, London, United Kingdom.,Medical Genetics Unit, Department of Medical Science, University of Ferrara, Ferrara, Italy
| | - Eric Hanssen
- Bio21 Advanced Microscopy Facility, The University of Melbourne, Melbourne, Australia
| | | | - Steve D Wilton
- Centre for Molecular Medicine and Therapeutics, Murdoch University, Perth, Australia.,Perron Institute for Neurological and Translational Science, University of Western Australia, Perth, Australia
| | - Shireen R Lamandé
- Murdoch Children's Research Institute, Parkville, Australia.,Department of Paediatrics, University of Melbourne, Parkville, Australia
| | - Daniel G MacArthur
- Analytical and Translation Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts, USA.,Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Raimund Wagener
- Center for Biochemistry, Faculty of Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health & Great Ormond Street Hospital for Children, London, United Kingdom.,NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| |
Collapse
|
38
|
Montes M, Sanford BL, Comiskey DF, Chandler DS. RNA Splicing and Disease: Animal Models to Therapies. Trends Genet 2019; 35:68-87. [PMID: 30466729 PMCID: PMC6339821 DOI: 10.1016/j.tig.2018.10.002] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 10/01/2018] [Accepted: 10/16/2018] [Indexed: 02/07/2023]
Abstract
Alternative splicing of pre-mRNA increases genetic diversity, and recent studies estimate that most human multiexon genes are alternatively spliced. If this process is not highly regulated and accurate, it leads to mis-splicing events, which may result in proteins with altered function. A growing body of work has implicated mis-splicing events in a range of diseases, including cancer, neurodegenerative diseases, and muscular dystrophies. Understanding the mechanisms that cause aberrant splicing events and how this leads to disease is vital for designing effective therapeutic strategies. In this review, we focus on advances in therapies targeting splicing, and highlight the animal models developed to recapitulate disease phenotypes as a model for testing these therapies.
Collapse
Affiliation(s)
- Matías Montes
- Molecular, Cellular, and Developmental Biology Graduate Program and The Center for RNA Biology, The Ohio State University, Columbus, OH, USA; Center for Childhood Cancer and Blood Diseases, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Brianne L Sanford
- Center for Childhood Cancer and Blood Diseases, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Daniel F Comiskey
- Molecular, Cellular, and Developmental Biology Graduate Program and The Center for RNA Biology, The Ohio State University, Columbus, OH, USA; Center for Childhood Cancer and Blood Diseases, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Dawn S Chandler
- Molecular, Cellular, and Developmental Biology Graduate Program and The Center for RNA Biology, The Ohio State University, Columbus, OH, USA; Center for Childhood Cancer and Blood Diseases, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA; Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA.
| |
Collapse
|
39
|
Baehr W, Hanke-Gogokhia C, Sharif A, Reed M, Dahl T, Frederick JM, Ying G. Insights into photoreceptor ciliogenesis revealed by animal models. Prog Retin Eye Res 2018; 71:26-56. [PMID: 30590118 DOI: 10.1016/j.preteyeres.2018.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 12/10/2018] [Accepted: 12/18/2018] [Indexed: 12/11/2022]
Abstract
Photoreceptors are polarized neurons, with very specific subcellular compartmentalization and unique requirements for protein expression and trafficking. Each photoreceptor contains an outer segment, the site of photon capture that initiates vision, an inner segment that houses the biosynthetic machinery and a synaptic terminal for signal transmission to downstream neurons. Outer segments and inner segments are connected by a connecting cilium (CC), the equivalent of a transition zone (TZ) of primary cilia. The connecting cilium is part of the basal body/axoneme backbone that stabilizes the outer segment. This report will update the reader on late developments in photoreceptor ciliogenesis and transition zone formation, specifically in mouse photoreceptors, focusing on early events in photoreceptor ciliogenesis. The connecting cilium, an elongated and narrow structure through which all outer segment proteins and membrane components must traffic, functions as a gate that controls access to the outer segment. Here we will review genes and their protein products essential for basal body maturation and for CC/TZ genesis, sorted by phenotype. Emphasis is given to naturally occurring mouse mutants and gene knockouts that interfere with CC/TZ formation and ciliogenesis.
Collapse
Affiliation(s)
- Wolfgang Baehr
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA.
| | - Christin Hanke-Gogokhia
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Ali Sharif
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Michelle Reed
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Tiffanie Dahl
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Jeanne M Frederick
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Guoxin Ying
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| |
Collapse
|
40
|
Jensen VL, Lambacher NJ, Li C, Mohan S, Williams CL, Inglis PN, Yoder BK, Blacque OE, Leroux MR. Role for intraflagellar transport in building a functional transition zone. EMBO Rep 2018; 19:e45862. [PMID: 30429209 PMCID: PMC6280794 DOI: 10.15252/embr.201845862] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 10/22/2018] [Accepted: 10/26/2018] [Indexed: 12/21/2022] Open
Abstract
Genetic disorders caused by cilia dysfunction, termed ciliopathies, frequently involve the intraflagellar transport (IFT) system. Mutations in IFT subunits-including IFT-dynein motor DYNC2H1-impair ciliary structures and Hedgehog signalling, typically leading to "skeletal" ciliopathies such as Jeune asphyxiating thoracic dystrophy. Intriguingly, IFT gene mutations also cause eye, kidney and brain ciliopathies often linked to defects in the transition zone (TZ), a ciliary gate implicated in Hedgehog signalling. Here, we identify a C. elegans temperature-sensitive (ts) IFT-dynein mutant (che-3; human DYNC2H1) and use it to show a role for retrograde IFT in anterograde transport and ciliary maintenance. Unexpectedly, correct TZ assembly and gating function for periciliary proteins also require IFT-dynein. Using the reversibility of the novel ts-IFT-dynein, we show that restoring IFT in adults (post-developmentally) reverses defects in ciliary structure, TZ protein localisation and ciliary gating. Notably, this ability to reverse TZ defects declines as animals age. Together, our findings reveal a previously unknown role for IFT in TZ assembly in metazoans, providing new insights into the pathomechanism and potential phenotypic overlap between IFT- and TZ-associated ciliopathies.
Collapse
Affiliation(s)
- Victor L Jensen
- Department of Molecular Biology and Biochemistry, and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Nils J Lambacher
- Department of Molecular Biology and Biochemistry, and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Chunmei Li
- Department of Molecular Biology and Biochemistry, and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Swetha Mohan
- Department of Molecular Biology and Biochemistry, and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Corey L Williams
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, AL, USA
| | - Peter N Inglis
- Department of Biology, Kwantlen Polytechnic University, Surrey, BC, Canada
| | - Bradley K Yoder
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, AL, USA
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Michel R Leroux
- Department of Molecular Biology and Biochemistry, and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| |
Collapse
|
41
|
Targeted exon skipping of a CEP290 mutation rescues Joubert syndrome phenotypes in vitro and in a murine model. Proc Natl Acad Sci U S A 2018; 115:12489-12494. [PMID: 30446612 PMCID: PMC6298104 DOI: 10.1073/pnas.1809432115] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Genetic treatments of renal ciliopathies leading to cystic kidney disease would provide a real advance in current therapies. Mutations in CEP290 underlie a ciliopathy called Joubert syndrome (JBTS). Human disease phenotypes include cerebral, retinal, and renal disease, which typically progresses to end stage renal failure (ESRF) within the first two decades of life. While currently incurable, there is often a period of years between diagnosis and ESRF that provides a potential window for therapeutic intervention. By studying patient biopsies, patient-derived kidney cells, and a mouse model, we identify abnormal elongation of primary cilia as a key pathophysiological feature of CEP290-associated JBTS and show that antisense oligonucleotide (ASO)-induced splicing of the mutated exon (41, G1890*) restores protein expression in patient cells. We demonstrate that ASO-induced splicing leading to exon skipping is tolerated, resulting in correct localization of CEP290 protein to the ciliary transition zone, and restoration of normal cilia length in patient kidney cells. Using a gene trap Cep290 mouse model of JBTS, we show that systemic ASO treatment can reduce the cystic burden of diseased kidneys in vivo. These findings indicate that ASO treatment may represent a promising therapeutic approach for kidney disease in CEP290-associated ciliopathy syndromes.
Collapse
|
42
|
Mookherjee S, Chen HY, Isgrig K, Yu W, Hiriyanna S, Levron R, Li T, Colosi P, Chien W, Swaroop A, Wu Z. A CEP290 C-Terminal Domain Complements the Mutant CEP290 of Rd16 Mice In Trans and Rescues Retinal Degeneration. Cell Rep 2018; 25:611-623.e6. [PMID: 30332642 PMCID: PMC6245950 DOI: 10.1016/j.celrep.2018.09.043] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 08/09/2018] [Accepted: 09/13/2018] [Indexed: 12/27/2022] Open
Abstract
Mutations in CEP290 cause ciliogenesis defects, leading to diverse clinical phenotypes, including Leber congenital amaurosis (LCA). Gene therapy for CEP290-associated diseases is hindered by the 7.4 kb CEP290 coding sequence, which is difficult to deliver in vivo. The multi-domain structure of the CEP290 protein suggests that a specific CEP290 domain may complement disease phenotypes. Thus, we constructed AAV vectors with overlapping CEP290 regions and evaluated their impact on photoreceptor degeneration in Cep290rd16/rd16 and Cep290rd16/rd16;Nrl-/- mice, two models of CEP290-LCA. One CEP290 fragment (the C-terminal 989 residues, including the domain deleted in mutant mice) reconstituted CEP290 function and resulted in cone preservation and delayed rod death. The CEP290 C-terminal domain also improved cilia phenotypes in mouse embryonic fibroblasts and iPSC-derived retinal organoids carrying the Cep290rd16 mutation. Our study strongly argues for in trans complementation of CEP290 mutations by a cognate fragment and suggests therapeutic avenues.
Collapse
Affiliation(s)
| | - Holly Yu Chen
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, NIH, Bethesda, MD 20892, USA
| | - Kevin Isgrig
- Neurotology Program, National Institute on Deafness and Communication Disorders, NIH, Bethesda, MD 20892, USA
| | - Wenhan Yu
- Ocular Gene Therapy Core, National Eye Institute, NIH, Bethesda, MD 20892, USA
| | - Suja Hiriyanna
- Ocular Gene Therapy Core, National Eye Institute, NIH, Bethesda, MD 20892, USA
| | - Rivka Levron
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, NIH, Bethesda, MD 20892, USA
| | - Tiansen Li
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, NIH, Bethesda, MD 20892, USA
| | - Peter Colosi
- Ocular Gene Therapy Core, National Eye Institute, NIH, Bethesda, MD 20892, USA
| | - Wade Chien
- Neurotology Program, National Institute on Deafness and Communication Disorders, NIH, Bethesda, MD 20892, USA
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, NIH, Bethesda, MD 20892, USA
| | - Zhijian Wu
- Ocular Gene Therapy Core, National Eye Institute, NIH, Bethesda, MD 20892, USA.
| |
Collapse
|
43
|
Dulla K, Aguila M, Lane A, Jovanovic K, Parfitt DA, Schulkens I, Chan HL, Schmidt I, Beumer W, Vorthoren L, Collin RWJ, Garanto A, Duijkers L, Brugulat-Panes A, Semo M, Vugler AA, Biasutto P, Adamson P, Cheetham ME. Splice-Modulating Oligonucleotide QR-110 Restores CEP290 mRNA and Function in Human c.2991+1655A>G LCA10 Models. MOLECULAR THERAPY. NUCLEIC ACIDS 2018; 12:730-740. [PMID: 30114557 PMCID: PMC6092551 DOI: 10.1016/j.omtn.2018.07.010] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 07/18/2018] [Accepted: 07/18/2018] [Indexed: 12/11/2022]
Abstract
Leber congenital amaurosis type 10 (LCA10) is a severe inherited retinal dystrophy associated with mutations in CEP290. The deep intronic c.2991+1655A>G mutation in CEP290 is the most common mutation in LCA10 individuals and represents an ideal target for oligonucleotide therapeutics. Here, a panel of antisense oligonucleotides was designed to correct the splicing defect associated with the mutation and screened for efficacy and safety. This identified QR-110 as the best-performing molecule. QR-110 restored wild-type CEP290 mRNA and protein expression levels in CEP290 c.2991+1655A>G homozygous and compound heterozygous LCA10 primary fibroblasts. Furthermore, in homozygous three-dimensional iPSC-derived retinal organoids, QR-110 showed a dose-dependent restoration of mRNA and protein function, as measured by percentage and length of photoreceptor cilia, without off-target effects. Localization studies in wild-type mice and rabbits showed that QR-110 readily reached all retinal layers, with an estimated half-life of 58 days. It was well tolerated following intravitreal injection in monkeys. In conclusion, the pharmacodynamic, pharmacokinetic, and safety properties make QR-110 a promising candidate for treating LCA10, and clinical development is currently ongoing.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Rob W J Collin
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Alejandro Garanto
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Lonneke Duijkers
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | | | | | | | | | - Peter Adamson
- ProQR Therapeutics, Leiden, the Netherlands; UCL Institute of Ophthalmology, London, UK.
| | | |
Collapse
|
44
|
Duncan JL, Pierce EA, Laster AM, Daiger SP, Birch DG, Ash JD, Iannaccone A, Flannery JG, Sahel JA, Zack DJ, Zarbin MA. Inherited Retinal Degenerations: Current Landscape and Knowledge Gaps. Transl Vis Sci Technol 2018; 7:6. [PMID: 30034950 PMCID: PMC6052953 DOI: 10.1167/tvst.7.4.6] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 05/28/2018] [Indexed: 12/11/2022] Open
Affiliation(s)
- Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA
| | - Eric A Pierce
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - Amy M Laster
- Foundation Fighting Blindness, Columbia, MD, USA
| | - Stephen P Daiger
- Human Genetics Center, School of Public Health, and Ruiz Department of Ophthalmology and Visual Science, The University of Texas Health Science Center, Houston, TX, USA
| | - David G Birch
- Rose-Silverthorne Retinal Degenerations Laboratory, Retina Foundation of the Southwest, Dallas, TX, USA
| | - John D Ash
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Alessandro Iannaccone
- Center for Retinal Degenerations and Ophthalmic Genetic Diseases, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - John G Flannery
- Vision Science, the Helen Wills Neuroscience Institute, the Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - José A Sahel
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Institut de la Vision-Sorbonne Université, Inserm, CNRS-Paris, France
| | - Donald J Zack
- Departments of Ophthalmology, Neuroscience, Molecular Biology and Genetics, and Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Marco A Zarbin
- Institute of Ophthalmology and Visual Science, Rutgers-New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | | |
Collapse
|
45
|
Garanto A, Collin RWJ. Design and In Vitro Use of Antisense Oligonucleotides to Correct Pre-mRNA Splicing Defects in Inherited Retinal Dystrophies. Methods Mol Biol 2018; 1715:61-78. [PMID: 29188506 DOI: 10.1007/978-1-4939-7522-8_5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Antisense oligonucleotides (AONs) are small molecules able to bind to the pre-mRNA and modulate splicing. The increasing amount of intronic mutations leading to pseudoexon insertion in genes underlying inherited retinal dystrophies (IRDs) has highlighted the potential of AONs as a therapeutic tool for these disorders. Here we describe how to design and test AON molecules in vitro in order to correct pre-mRNA splicing defects involved in IRDs.
Collapse
Affiliation(s)
- Alejandro Garanto
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Rob W J Collin
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
46
|
DiCarlo JE, Mahajan VB, Tsang SH. Gene therapy and genome surgery in the retina. J Clin Invest 2018; 128:2177-2188. [PMID: 29856367 DOI: 10.1172/jci120429] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Precision medicine seeks to treat disease with molecular specificity. Advances in genome sequence analysis, gene delivery, and genome surgery have allowed clinician-scientists to treat genetic conditions at the level of their pathology. As a result, progress in treating retinal disease using genetic tools has advanced tremendously over the past several decades. Breakthroughs in gene delivery vectors, both viral and nonviral, have allowed the delivery of genetic payloads in preclinical models of retinal disorders and have paved the way for numerous successful clinical trials. Moreover, the adaptation of CRISPR-Cas systems for genome engineering have enabled the correction of both recessive and dominant pathogenic alleles, expanding the disease-modifying power of gene therapies. Here, we highlight the translational progress of gene therapy and genome editing of several retinal disorders, including RPE65-, CEP290-, and GUY2D-associated Leber congenital amaurosis, as well as choroideremia, achromatopsia, Mer tyrosine kinase- (MERTK-) and RPGR X-linked retinitis pigmentosa, Usher syndrome, neovascular age-related macular degeneration, X-linked retinoschisis, Stargardt disease, and Leber hereditary optic neuropathy.
Collapse
Affiliation(s)
- James E DiCarlo
- Jonas Children's Vision Care and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA
| | - Vinit B Mahajan
- Omics Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, California, USA.,Veterans Affairs Palo Alto Health Care System, Palo Alto, California, USA
| | - Stephen H Tsang
- Jonas Children's Vision Care and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA
| |
Collapse
|
47
|
Zarouchlioti C, Sanchez-Pintado B, Hafford Tear NJ, Klein P, Liskova P, Dulla K, Semo M, Vugler AA, Muthusamy K, Dudakova L, Levis HJ, Skalicka P, Hysi P, Cheetham ME, Tuft SJ, Adamson P, Hardcastle AJ, Davidson AE. Antisense Therapy for a Common Corneal Dystrophy Ameliorates TCF4 Repeat Expansion-Mediated Toxicity. Am J Hum Genet 2018; 102:528-539. [PMID: 29526280 PMCID: PMC5985359 DOI: 10.1016/j.ajhg.2018.02.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 02/14/2018] [Indexed: 12/12/2022] Open
Abstract
Fuchs endothelial corneal dystrophy (FECD) is a common disease for which corneal transplantation is the only treatment option in advanced stages, and alternative treatment strategies are urgently required. Expansion (≥50 copies) of a non-coding trinucleotide repeat in TCF4 confers >76-fold risk for FECD in our large cohort of affected individuals. An FECD subject-derived corneal endothelial cell (CEC) model was developed to probe disease mechanism and investigate therapeutic approaches. The CEC model demonstrated that the repeat expansion leads to nuclear RNA foci, with the sequestration of splicing factor proteins (MBNL1 and MBNL2) to the foci and altered mRNA processing. Antisense oligonucleotide (ASO) treatment led to a significant reduction in the incidence of nuclear foci, MBNL1 recruitment to the foci, and downstream aberrant splicing events, suggesting functional rescue. This proof-of-concept study highlights the potential of a targeted ASO therapy to treat the accessible and tractable corneal tissue affected by this repeat expansion-mediated disease.
Collapse
Affiliation(s)
| | | | | | - Pontus Klein
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Petra Liskova
- Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, Prague 128 08, Czech Republic; Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, U nemocnice 2, Prague, Czech Republic
| | - Kalyan Dulla
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Ma'ayan Semo
- UCL Institute of Ophthalmology, London ECIV 9EL, UK
| | | | - Kirithika Muthusamy
- UCL Institute of Ophthalmology, London ECIV 9EL, UK; Moorfields Eye Hospital, London EC1V 2PD, UK
| | - Lubica Dudakova
- Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, Prague 128 08, Czech Republic
| | - Hannah J Levis
- Institute of Aging and Chronic Disease, University of Liverpool, Liverpool L7 8TX, UK
| | - Pavlina Skalicka
- Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, Prague 128 08, Czech Republic; Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, U nemocnice 2, Prague, Czech Republic
| | - Pirro Hysi
- Department of Ophthalmology and Twin Research, King's College London, London SE1 7EH, UK
| | | | - Stephen J Tuft
- UCL Institute of Ophthalmology, London ECIV 9EL, UK; Moorfields Eye Hospital, London EC1V 2PD, UK
| | - Peter Adamson
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | | | | |
Collapse
|
48
|
Albert S, Garanto A, Sangermano R, Khan M, Bax NM, Hoyng CB, Zernant J, Lee W, Allikmets R, Collin RW, Cremers FP. Identification and Rescue of Splice Defects Caused by Two Neighboring Deep-Intronic ABCA4 Mutations Underlying Stargardt Disease. Am J Hum Genet 2018. [PMID: 29526278 DOI: 10.1016/j.ajhg.2018.02.008] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Sequence analysis of the coding regions and splice site sequences in inherited retinal diseases is not able to uncover ∼40% of the causal variants. Whole-genome sequencing can identify most of the non-coding variants, but their interpretation is still very challenging, in particular when the relevant gene is expressed in a tissue-specific manner. Deep-intronic variants in ABCA4 have been associated with autosomal-recessive Stargardt disease (STGD1), but the exact pathogenic mechanism is unknown. By generating photoreceptor precursor cells (PPCs) from fibroblasts obtained from individuals with STGD1, we demonstrated that two neighboring deep-intronic ABCA4 variants (c.4539+2001G>A and c.4539+2028C>T) result in a retina-specific 345-nt pseudoexon insertion (predicted protein change: p.Arg1514Leufs∗36), likely due to the creation of exonic enhancers. Administration of antisense oligonucleotides (AONs) targeting the 345-nt pseudoexon can significantly rescue the splicing defect observed in PPCs of two individuals with these mutations. Intriguingly, an AON that is complementary to c.4539+2001G>A rescued the splicing defect only in PPCs derived from an individual with STGD1 with this but not the other mutation, demonstrating the high specificity of AONs. In addition, a single AON molecule rescued splicing defects associated with different neighboring mutations, thereby providing new strategies for the treatment of persons with STGD1. As many genes associated with human genetic conditions are expressed in specific tissues and pre-mRNA splicing may also rely on organ-specific factors, our approach to investigate and treat splicing variants using differentiated cells derived from individuals with STGD1 can be applied to any tissue of interest.
Collapse
|
49
|
Antisense Oligonucleotide-Based Splicing Correction in Individuals with Leber Congenital Amaurosis due to Compound Heterozygosity for the c.2991+1655A>G Mutation in CEP290. Int J Mol Sci 2018. [PMID: 29518907 PMCID: PMC5877614 DOI: 10.3390/ijms19030753] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Leber congenital amaurosis (LCA) is a rare inherited retinal disorder affecting approximately 1:50,000 people worldwide. So far, mutations in 25 genes have been associated with LCA, with CEP290 (encoding the Centrosomal protein of 290 kDa) being the most frequently mutated gene. The most recurrent LCA-causing CEP290 mutation, c.2991+1655A>G, causes the insertion of a pseudoexon into a variable proportion of CEP290 transcripts. We previously demonstrated that antisense oligonucleotides (AONs) have a high therapeutic potential for patients homozygously harbouring this mutation, although to date, it is unclear whether rescuing one single allele is enough to restore CEP290 function. Here, we assessed the AON efficacy at RNA, protein and cellular levels in samples that are compound heterozygous for this mutation, together with a protein-truncating mutation in CEP290. We demonstrate that AONs can efficiently restore splicing and increase protein levels. However, due to a high variability in ciliation among the patient-derived cell lines, the efficacy of the AONs was more difficult to assess at the cellular level. This observation points towards the importance of the severity of the second allele and possibly other genetic variants present in each individual. Overall, AONs seem to be a promising tool to treat CEP290-associated LCA, not only in homozygous but also in compound heterozygous carriers of the c.2991+1655A>G variant.
Collapse
|
50
|
Zelinger L, Swaroop A. RNA Biology in Retinal Development and Disease. Trends Genet 2018; 34:341-351. [PMID: 29395379 DOI: 10.1016/j.tig.2018.01.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/28/2017] [Accepted: 01/03/2018] [Indexed: 02/06/2023]
Abstract
For decades, RNA has served in a supporting role between the genetic carrier (DNA) and the functional molecules (proteins). It is finally time for RNA to take center stage in all aspects of biology. The retina provides a unique opportunity to dissect the molecular underpinnings of neuronal diversity and disease. Transcriptome profiles of the retina and its resident cell types have unraveled unique features of the RNA landscape. The discovery of distinct RNA molecules and the recognition that RNA processing is a major cause of retinal neurodegeneration have prompted the design of biomarkers and novel therapeutic paradigms. We review here RNA biology as it pertains to the retina, emphasizing new avenues for investigations in development and disease.
Collapse
Affiliation(s)
- Lina Zelinger
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|