1
|
Knauer C, Haltern H, Schoger E, Kügler S, Roos L, Zelarayán LC, Hasenfuss G, Zimmermann WH, Wollnik B, Cyganek L. Preclinical evaluation of CRISPR-based therapies for Noonan syndrome caused by deep-intronic LZTR1 variants. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102123. [PMID: 38333672 PMCID: PMC10851011 DOI: 10.1016/j.omtn.2024.102123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 01/18/2024] [Indexed: 02/10/2024]
Abstract
Gene variants in LZTR1 are implicated to cause Noonan syndrome associated with a severe and early-onset hypertrophic cardiomyopathy. Mechanistically, LZTR1 deficiency results in accumulation of RAS GTPases and, as a consequence, in RAS-MAPK signaling hyperactivity, thereby causing the Noonan syndrome-associated phenotype. Despite its epidemiological relevance, pharmacological as well as invasive therapies remain limited. Here, personalized CRISPR-Cas9 gene therapies might offer a novel alternative for a curative treatment in this patient cohort. In this study, by utilizing a patient-specific screening platform based on iPSC-derived cardiomyocytes from two Noonan syndrome patients, we evaluated different clinically translatable therapeutic approaches using small Cas9 orthologs targeting a deep-intronic LZTR1 variant to cure the disease-associated molecular pathology. Despite high editing efficiencies in cardiomyocyte cultures transduced with lentivirus or all-in-one adeno-associated viruses, we observed crucial differences in editing outcomes in proliferative iPSCs vs. non-proliferative cardiomyocytes. While editing in iPSCs rescued the phenotype, the same editing approaches did not robustly restore LZTR1 function in cardiomyocytes, indicating critical differences in the activity of DNA double-strand break repair mechanisms between proliferative and non-proliferative cell types and highlighting the importance of cell type-specific screens for testing CRISPR-Cas9 gene therapies.
Collapse
Affiliation(s)
- Carolin Knauer
- Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
| | - Henrike Haltern
- Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
| | - Eric Schoger
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Sebastian Kügler
- Department of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Lennart Roos
- Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
| | - Laura C. Zelarayán
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, 37075 Göttingen, Germany
- Department of Cardiology and Angiology, University of Giessen, 35390 Giessen, Germany
| | - Gerd Hasenfuss
- Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
| | - Wolfram-Hubertus Zimmermann
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, 37075 Göttingen, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, 37075 Göttingen, Germany
- DZNE (German Center for Neurodegenerative Diseases), 37075 Göttingen, Germany
| | - Bernd Wollnik
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Institute of Human Genetics, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Lukas Cyganek
- Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, 37075 Göttingen, Germany
| |
Collapse
|
2
|
Spirig SE, Renner M. Toward Retinal Organoids in High-Throughput. Cold Spring Harb Perspect Med 2024; 14:a041275. [PMID: 37217280 PMCID: PMC10910359 DOI: 10.1101/cshperspect.a041275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Human retinal organoids recapitulate the cellular diversity, arrangement, gene expression, and functional aspects of the human retina. Protocols to generate human retinal organoids from pluripotent stem cells are typically labor intensive, include many manual handling steps, and the organoids need to be maintained for several months until they mature. To generate large numbers of human retinal organoids for therapy development and screening purposes, scaling up retinal organoid production, maintenance, and analysis is of utmost importance. In this review, we discuss strategies to increase the number of high-quality retinal organoids while reducing manual handling steps. We further review different approaches to analyze thousands of retinal organoids with currently available technologies and point to challenges that still await to be overcome both in culture and analysis of retinal organoids.
Collapse
Affiliation(s)
- Stefan Erich Spirig
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Magdalena Renner
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| |
Collapse
|
3
|
Gene-independent therapeutic interventions to maintain and restore light sensitivity in degenerating photoreceptors. Prog Retin Eye Res 2022; 90:101065. [PMID: 35562270 DOI: 10.1016/j.preteyeres.2022.101065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/08/2022] [Accepted: 04/18/2022] [Indexed: 12/14/2022]
Abstract
Neurodegenerative retinal diseases are a prime cause of blindness in industrialized countries. In many cases, there are no therapeutic treatments, although they are essential to improve patients' quality of life. A set of disease-causing genes, which primarily affect photoreceptors, has already been identified and is of major interest for developing gene therapies. Nevertheless, depending on the nature and the state of the disease, gene-independent strategies are needed. Various strategies to halt disease progression or maintain function of the retina are under research. These therapeutic interventions include neuroprotection, direct reprogramming of affected photoreceptors, the application of non-coding RNAs, the generation of artificial photoreceptors by optogenetics and cell replacement strategies. During recent years, major breakthroughs have been made such as the first optogenetic application to a blind patient whose visual function partially recovered by targeting retinal ganglion cells. Also, RPE cell transplantation therapies are under clinical investigation and show great promise to improve visual function in blind patients. These cells are generated from human stem cells. Similar therapies for replacing photoreceptors are extensively tested in pre-clinical models. This marks just the start of promising new cures taking advantage of developments in the areas of genetic engineering, optogenetics, and stem-cell research. In this review, we present the recent therapeutic advances of gene-independent approaches that are currently under clinical evaluation. Our main focus is on photoreceptors as these sensory cells are highly vulnerable to degenerative diseases, and are crucial for light detection.
Collapse
|
4
|
Wimmer T, Bonthu D, Moeschl V, Kleekamp P, Thiel C, Lytvynchuk L, Ellinwood M, Stieger K. A Bioluminescence Resonance Energy Transfer-Based Reporter System: Characterization and Applications. CRISPR J 2021; 4:884-895. [PMID: 34847743 DOI: 10.1089/crispr.2021.0023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Genome editing strategies and DNA repair research need powerful analytical tools. We generated a bioluminescence resonance energy transfer (BRET)-based reporter for the quantification of indel frequencies induced by DNA repair. The BRET reporter, expressed as a single molecule, consists of a mutated Renilla reniformis luciferase domain and a GFP2 domain separated by a shuttle-cloning box for the integration of any given endonuclease target sequence. The luciferase activity acts both as energy donor and as the internal standard, while the loss of GFP2 fluorescence acts as a reporter for the out-of-frame sequence alterations that result from the DNA repair via the non-homologous end joining/microhomology-mediated end joining DNA repair pathways of the endonuclease-mediated DNA double-strand break. This results in a decrease of the fluorescence/luminescence ratio. Employing this reporter in different experimental scenarios, using different cell lines and diseases targeted, we quantified the influence of both protein knockdown of DNA repair pathways as well as guide RNA mismatches on CRISPR-mediated nuclease activity and subsequent repair based on mutagenic repair on the reporter. In conclusion, we demonstrated this BRET-based reporter to be a robust and sensitive analytical tool for assessment of variety of different genome editing-based approaches.
Collapse
Affiliation(s)
- Tobias Wimmer
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Dileep Bonthu
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Vincent Moeschl
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Philip Kleekamp
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Christian Thiel
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Lyubomyr Lytvynchuk
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
| | | | - Knut Stieger
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
| |
Collapse
|
5
|
Afanasyeva TAV, Corral-Serrano JC, Garanto A, Roepman R, Cheetham ME, Collin RWJ. A look into retinal organoids: methods, analytical techniques, and applications. Cell Mol Life Sci 2021; 78:6505-6532. [PMID: 34420069 PMCID: PMC8558279 DOI: 10.1007/s00018-021-03917-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 07/14/2021] [Accepted: 08/09/2021] [Indexed: 12/15/2022]
Abstract
Inherited retinal diseases (IRDs) cause progressive loss of light-sensitive photoreceptors in the eye and can lead to blindness. Gene-based therapies for IRDs have shown remarkable progress in the past decade, but the vast majority of forms remain untreatable. In the era of personalised medicine, induced pluripotent stem cells (iPSCs) emerge as a valuable system for cell replacement and to model IRD because they retain the specific patient genome and can differentiate into any adult cell type. Three-dimensional (3D) iPSCs-derived retina-like tissue called retinal organoid contains all major retina-specific cell types: amacrine, bipolar, horizontal, retinal ganglion cells, Müller glia, as well as rod and cone photoreceptors. Here, we describe the main applications of retinal organoids and provide a comprehensive overview of the state-of-art analysis methods that apply to this model system. Finally, we will discuss the outlook for improvements that would bring the cellular model a step closer to become an established system in research and treatment development of IRDs.
Collapse
Affiliation(s)
- Tess A V Afanasyeva
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands
| | | | - Alejandro Garanto
- Department of Pediatrics, Amalia Children's Hospital and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ronald Roepman
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Michael E Cheetham
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
| | - Rob W J Collin
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands.
| |
Collapse
|
6
|
Wagstaff EL, Heredero Berzal A, Boon CJF, Quinn PMJ, ten Asbroek ALMA, Bergen AA. The Role of Small Molecules and Their Effect on the Molecular Mechanisms of Early Retinal Organoid Development. Int J Mol Sci 2021; 22:7081. [PMID: 34209272 PMCID: PMC8268497 DOI: 10.3390/ijms22137081] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/23/2021] [Accepted: 06/26/2021] [Indexed: 12/12/2022] Open
Abstract
Early in vivo embryonic retinal development is a well-documented and evolutionary conserved process. The specification towards eye development is temporally controlled by consecutive activation or inhibition of multiple key signaling pathways, such as the Wnt and hedgehog signaling pathways. Recently, with the use of retinal organoids, researchers aim to manipulate these pathways to achieve better human representative models for retinal development and disease. To achieve this, a plethora of different small molecules and signaling factors have been used at various time points and concentrations in retinal organoid differentiations, with varying success. Additions differ from protocol to protocol, but their usefulness or efficiency has not yet been systematically reviewed. Interestingly, many of these small molecules affect the same and/or multiple pathways, leading to reduced reproducibility and high variability between studies. In this review, we make an inventory of the key signaling pathways involved in early retinogenesis and their effect on the development of the early retina in vitro. Further, we provide a comprehensive overview of the small molecules and signaling factors that are added to retinal organoid differentiation protocols, documenting the molecular and functional effects of these additions. Lastly, we comparatively evaluate several of these factors using our established retinal organoid methodology.
Collapse
Affiliation(s)
- Ellie L. Wagstaff
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam (UvA), 1105 AZ Amsterdam, The Netherlands;
| | - Andrea Heredero Berzal
- Department of Ophthalmology, Amsterdam UMC, University of Amsterdam (UvA), 1105 AZ Amsterdam, The Netherlands; (A.H.B.); (C.J.F.B.)
| | - Camiel J. F. Boon
- Department of Ophthalmology, Amsterdam UMC, University of Amsterdam (UvA), 1105 AZ Amsterdam, The Netherlands; (A.H.B.); (C.J.F.B.)
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZA Leiden, The Netherlands
| | - Peter M. J. Quinn
- Jonas Children’s Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology & Cell Biology, Institute of Human Nutrition, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA; Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center—New York-Presbyterian Hospital, New York, NY 10032, USA;
| | | | - Arthur A. Bergen
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam (UvA), 1105 AZ Amsterdam, The Netherlands;
- Department of Ophthalmology, Amsterdam UMC, University of Amsterdam (UvA), 1105 AZ Amsterdam, The Netherlands; (A.H.B.); (C.J.F.B.)
- Netherlands Institute for Neuroscience (NIN-KNAW), 1105 BA Amsterdam, The Netherlands
| |
Collapse
|
7
|
Trapani I, Tornabene P, Auricchio A. Large gene delivery to the retina with AAV vectors: are we there yet? Gene Ther 2021; 28:220-222. [PMID: 32661283 DOI: 10.1038/s41434-020-0174-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 06/23/2020] [Accepted: 07/01/2020] [Indexed: 12/26/2022]
Affiliation(s)
- Ivana Trapani
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Medical Genetics, Department of Translational Medicine, Federico II University, Naples, Italy
| | - Patrizia Tornabene
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Medical Genetics, Department of Translational Medicine, Federico II University, Naples, Italy
| | - Alberto Auricchio
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.
- Department of Advanced Biomedicine, Federico II University, Naples, Italy.
| |
Collapse
|
8
|
Pasquini G, Rojo Arias JE, Schäfer P, Busskamp V. Automated methods for cell type annotation on scRNA-seq data. Comput Struct Biotechnol J 2021; 19:961-969. [PMID: 33613863 PMCID: PMC7873570 DOI: 10.1016/j.csbj.2021.01.015] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 01/13/2021] [Accepted: 01/13/2021] [Indexed: 12/22/2022] Open
Abstract
The advent of single-cell sequencing started a new era of transcriptomic and genomic research, advancing our knowledge of the cellular heterogeneity and dynamics. Cell type annotation is a crucial step in analyzing single-cell RNA sequencing data, yet manual annotation is time-consuming and partially subjective. As an alternative, tools have been developed for automatic cell type identification. Different strategies have emerged to ultimately associate gene expression profiles of single cells with a cell type either by using curated marker gene databases, correlating reference expression data, or transferring labels by supervised classification. In this review, we present an overview of the available tools and the underlying approaches to perform automated cell type annotations on scRNA-seq data.
Collapse
Affiliation(s)
- Giovanni Pasquini
- Technische Universität Dresden, Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Dresden 01307, Germany
- Universitäts-Augenklinik Bonn, University of Bonn, Department of Ophthalmology, Bonn 53127, Germany
| | - Jesus Eduardo Rojo Arias
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, UK
| | - Patrick Schäfer
- Technische Universität Dresden, Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Dresden 01307, Germany
| | - Volker Busskamp
- Technische Universität Dresden, Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Dresden 01307, Germany
- Universitäts-Augenklinik Bonn, University of Bonn, Department of Ophthalmology, Bonn 53127, Germany
| |
Collapse
|
9
|
O'Hara-Wright M, Gonzalez-Cordero A. Retinal organoids: a window into human retinal development. Development 2020; 147:147/24/dev189746. [PMID: 33361444 PMCID: PMC7774906 DOI: 10.1242/dev.189746] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Retinal development and maturation are orchestrated by a series of interacting signalling networks that drive the morphogenetic transformation of the anterior developing brain. Studies in model organisms continue to elucidate these complex series of events. However, the human retina shows many differences from that of other organisms and the investigation of human eye development now benefits from stem cell-derived organoids. Retinal differentiation methods have progressed from simple 2D adherent cultures to self-organising micro-physiological systems. As models of development, these have collectively offered new insights into the previously unexplored early development of the human retina and informed our knowledge of the key cell fate decisions that govern the specification of light-sensitive photoreceptors. Although the developmental trajectories of other retinal cell types remain more elusive, the collation of omics datasets, combined with advanced culture methodology, will enable modelling of the intricate process of human retinogenesis and retinal disease in vitro. Summary: Retinal organoid systems derived from human pluripotent stem cells are micro-physiological systems that offer new insights into previously unexplored human retina development.
Collapse
Affiliation(s)
- Michelle O'Hara-Wright
- Stem Cell Medicine Group, Children's Medical Research Institute, University of Sydney, Westmead, 2145, NSW, Australia.,School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, NSW, Australia
| | - Anai Gonzalez-Cordero
- Stem Cell Medicine Group, Children's Medical Research Institute, University of Sydney, Westmead, 2145, NSW, Australia .,School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, NSW, Australia
| |
Collapse
|
10
|
The Rise of Retinal Organoids for Vision Research. Int J Mol Sci 2020; 21:ijms21228484. [PMID: 33187246 PMCID: PMC7697892 DOI: 10.3390/ijms21228484] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/03/2020] [Accepted: 11/07/2020] [Indexed: 02/07/2023] Open
Abstract
Retinal degenerative diseases lead to irreversible blindness. Decades of research into the cellular and molecular mechanisms of retinal diseases, using either animal models or human cell-derived 2D systems, facilitated the development of several therapeutic interventions. Recently, human stem cell-derived 3D retinal organoids have been developed. These self-organizing 3D organ systems have shown to recapitulate the in vivo human retinogenesis resulting in morphological and functionally similar retinal cell types in vitro. In less than a decade, retinal organoids have assisted in modeling several retinal diseases that were rather difficult to mimic in rodent models. Retinal organoids are also considered as a photoreceptor source for cell transplantation therapies to counteract blindness. Here, we highlight the development and field’s improvements of retinal organoids and discuss their application aspects as human disease models, pharmaceutical testbeds, and cell sources for transplantations.
Collapse
|
11
|
Gallego C, Gonçalves MAFV, Wijnholds J. Novel Therapeutic Approaches for the Treatment of Retinal Degenerative Diseases: Focus on CRISPR/Cas-Based Gene Editing. Front Neurosci 2020; 14:838. [PMID: 32973430 PMCID: PMC7468381 DOI: 10.3389/fnins.2020.00838] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 07/20/2020] [Indexed: 12/17/2022] Open
Abstract
Inherited retinal diseases encompass a highly heterogenous group of disorders caused by a wide range of genetic variants and with diverse clinical symptoms that converge in the common trait of retinal degeneration. Indeed, mutations in over 270 genes have been associated with some form of retinal degenerative phenotype. Given the immune privileged status of the eye, cell replacement and gene augmentation therapies have been envisioned. While some of these approaches, such as delivery of genes through recombinant adeno-associated viral vectors, have been successfully tested in clinical trials, not all patients will benefit from current advancements due to their underlying genotype or phenotypic traits. Gene editing arises as an alternative therapeutic strategy seeking to correct mutations at the endogenous locus and rescue normal gene expression. Hence, gene editing technologies can in principle be tailored for treating retinal degeneration. Here we provide an overview of the different gene editing strategies that are being developed to overcome the challenges imposed by the post-mitotic nature of retinal cell types. We further discuss their advantages and drawbacks as well as the hurdles for their implementation in treating retinal diseases, which include the broad range of mutations and, in some instances, the size of the affected genes. Although therapeutic gene editing is at an early stage of development, it has the potential of enriching the portfolio of personalized molecular medicines directed at treating genetic diseases.
Collapse
Affiliation(s)
- Carmen Gallego
- Department of Ophthalmology, Leiden University Medical Center, Leiden, Netherlands
| | - Manuel A F V Gonçalves
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center, Leiden, Netherlands.,Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands
| |
Collapse
|