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Zaydon YA, Tsang SH. The ABCs of Stargardt disease: the latest advances in precision medicine. Cell Biosci 2024; 14:98. [PMID: 39060921 DOI: 10.1186/s13578-024-01272-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 07/01/2024] [Indexed: 07/28/2024] Open
Abstract
Stargardt disease (STGD) is the most common form of inherited juvenile macular dystrophy and is caused by sequence variants in the ABCA4 gene. Due to its genetic complexity and phenotypic variability, STGD poses significant therapeutic challenges. In the past decade, a lot of progress has been made regarding our understanding of the molecular and clinical aspects of STGD, along with its mechanisms. This has led to the development of new therapies, and there are human clinical trials currently ongoing. This paper evaluates the emergence of pharmacological approaches targeting the visual cycle to mitigate retinal damage, the role of gene therapy in correcting specific genetic defects, and the use of stem cell therapies aimed at retinal regeneration by showcasing the latest clinical trials and precision medicine approaches.
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Affiliation(s)
- Yasmine A Zaydon
- Departments of Ophthalmology, Pathology and Cell Biology, Jonas Children's Vision Care, and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Institute of Human Nutrition, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA.
| | - Stephen H Tsang
- Departments of Ophthalmology, Pathology and Cell Biology, Jonas Children's Vision Care, and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Institute of Human Nutrition, 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
- Department of Pathology and Cell Biology, The Herbert Irving Comprehensive Cancer Center, Institute of Human Nutrition, Columbia University, New York, NY, USA
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Poudel BH, Fletcher S, Wilton SD, Aung-Htut M. Limb Girdle Muscular Dystrophy Type 2B (LGMD2B): Diagnosis and Therapeutic Possibilities. Int J Mol Sci 2024; 25:5572. [PMID: 38891760 PMCID: PMC11171558 DOI: 10.3390/ijms25115572] [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: 04/18/2024] [Revised: 05/11/2024] [Accepted: 05/16/2024] [Indexed: 06/21/2024] Open
Abstract
Dysferlin is a large transmembrane protein involved in critical cellular processes including membrane repair and vesicle fusion. Mutations in the dysferlin gene (DYSF) can result in rare forms of muscular dystrophy; Miyoshi myopathy; limb girdle muscular dystrophy type 2B (LGMD2B); and distal myopathy. These conditions are collectively known as dysferlinopathies and are caused by more than 600 mutations that have been identified across the DYSF gene to date. In this review, we discuss the key molecular and clinical features of LGMD2B, the causative gene DYSF, and the associated dysferlin protein structure. We also provide an update on current approaches to LGMD2B diagnosis and advances in drug development, including splice switching antisense oligonucleotides. We give a brief update on clinical trials involving adeno-associated viral gene therapy and the current progress on CRISPR/Cas9 mediated therapy for LGMD2B, and then conclude by discussing the prospects of antisense oligomer-based intervention to treat selected mutations causing dysferlinopathies.
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Affiliation(s)
- Bal Hari Poudel
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA 6150, Australia; (B.H.P.); (S.F.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA 6009, Australia
- Central Department of Biotechnology, Tribhuvan University, Kirtipur, Kathmandu 44618, Nepal
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA 6150, Australia; (B.H.P.); (S.F.); (S.D.W.)
| | - Steve D. Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA 6150, Australia; (B.H.P.); (S.F.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA 6009, Australia
| | - May Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA 6150, Australia; (B.H.P.); (S.F.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA 6009, Australia
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Georgiou M, Robson AG, Fujinami K, de Guimarães TAC, Fujinami-Yokokawa Y, Daich Varela M, Pontikos N, Kalitzeos A, Mahroo OA, Webster AR, Michaelides M. Phenotyping and genotyping inherited retinal diseases: Molecular genetics, clinical and imaging features, and therapeutics of macular dystrophies, cone and cone-rod dystrophies, rod-cone dystrophies, Leber congenital amaurosis, and cone dysfunction syndromes. Prog Retin Eye Res 2024; 100:101244. [PMID: 38278208 DOI: 10.1016/j.preteyeres.2024.101244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024]
Abstract
Inherited retinal diseases (IRD) are a leading cause of blindness in the working age population and in children. The scope of this review is to familiarise clinicians and scientists with the current landscape of molecular genetics, clinical phenotype, retinal imaging and therapeutic prospects/completed trials in IRD. Herein we present in a comprehensive and concise manner: (i) macular dystrophies (Stargardt disease (ABCA4), X-linked retinoschisis (RS1), Best disease (BEST1), PRPH2-associated pattern dystrophy, Sorsby fundus dystrophy (TIMP3), and autosomal dominant drusen (EFEMP1)), (ii) cone and cone-rod dystrophies (GUCA1A, PRPH2, ABCA4, KCNV2 and RPGR), (iii) predominant rod or rod-cone dystrophies (retinitis pigmentosa, enhanced S-Cone syndrome (NR2E3), Bietti crystalline corneoretinal dystrophy (CYP4V2)), (iv) Leber congenital amaurosis/early-onset severe retinal dystrophy (GUCY2D, CEP290, CRB1, RDH12, RPE65, TULP1, AIPL1 and NMNAT1), (v) cone dysfunction syndromes (achromatopsia (CNGA3, CNGB3, PDE6C, PDE6H, GNAT2, ATF6), X-linked cone dysfunction with myopia and dichromacy (Bornholm Eye disease; OPN1LW/OPN1MW array), oligocone trichromacy, and blue-cone monochromatism (OPN1LW/OPN1MW array)). Whilst we use the aforementioned classical phenotypic groupings, a key feature of IRD is that it is characterised by tremendous heterogeneity and variable expressivity, with several of the above genes associated with a range of phenotypes.
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Affiliation(s)
- Michalis Georgiou
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - Anthony G Robson
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Kaoru Fujinami
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
| | - Thales A C de Guimarães
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Yu Fujinami-Yokokawa
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Department of Health Policy and Management, Keio University School of Medicine, Tokyo, Japan.
| | - Malena Daich Varela
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Nikolas Pontikos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Angelos Kalitzeos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Omar A Mahroo
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Section of Ophthalmology, King s College London, St Thomas Hospital Campus, London, United Kingdom; Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, United Kingdom; Department of Translational Ophthalmology, Wills Eye Hospital, Philadelphia, PA, USA.
| | - Andrew R Webster
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Michel Michaelides
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
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Fujinami K, Waheed N, Laich Y, Yang P, Fujinami-Yokokawa Y, Higgins JJ, Lu JT, Curtiss D, Clary C, Michaelides M. Stargardt macular dystrophy and therapeutic approaches. Br J Ophthalmol 2024; 108:495-505. [PMID: 37940365 PMCID: PMC10958310 DOI: 10.1136/bjo-2022-323071] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 10/06/2023] [Indexed: 11/10/2023]
Abstract
Stargardt macular dystrophy (Stargardt disease; STGD1; OMIM 248200) is the most prevalent inherited macular dystrophy. STGD1 is an autosomal recessive disorder caused by multiple pathogenic sequence variants in the large ABCA4 gene (OMIM 601691). Major advances in understanding both the clinical and molecular features, as well as the underlying pathophysiology, have culminated in many completed, ongoing and planned human clinical trials of novel therapies.The aims of this concise review are to describe (1) the detailed phenotypic and genotypic characteristics of the disease, multimodal imaging findings, natural history of the disease, and pathogenesis, (2) the multiple avenues of research and therapeutic intervention, including pharmacological, cellular therapies and diverse types of genetic therapies that have either been investigated or are under investigation and (3) the exciting novel therapeutic approaches on the translational horizon that aim to treat STGD1 by replacing the entire 6.8 kb ABCA4 open reading frame.
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Affiliation(s)
- Kaoru Fujinami
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, NHO Tokyo Medical Center, Meguro-ku, Tokyo, Japan
- Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Nadia Waheed
- Department of Ophthalmology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Yannik Laich
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Eye Center, Medical Center, University of Freiburg Faculty of Medicine, Freiburg, Germany
| | - Paul Yang
- Oregon Health and Science University Casey Eye Institute, Portland, Oregon, USA
| | - Yu Fujinami-Yokokawa
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, NHO Tokyo Medical Center, Meguro-ku, Tokyo, Japan
- Institute of Ophthalmology, University College London, London, UK
- Department of Health Policy and Management, Keio University School of Medicine Graduate School of Medicine, Shinjuku-ku, Tokyo, Japan
| | | | - Jonathan T Lu
- SalioGen Therapeutics Inc, Lexington, Massachusetts, USA
| | - Darin Curtiss
- Applied Genetic Technologies Corporation, Alachua, Florida, USA
| | - Cathryn Clary
- SalioGen Therapeutics Inc, Lexington, Massachusetts, USA
| | - Michel Michaelides
- Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
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Kolesnik VV, Nurtdinov RF, Oloruntimehin ES, Karabelsky AV, Malogolovkin AS. Optimization strategies and advances in the research and development of AAV-based gene therapy to deliver large transgenes. Clin Transl Med 2024; 14:e1607. [PMID: 38488469 PMCID: PMC10941601 DOI: 10.1002/ctm2.1607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 02/07/2024] [Accepted: 02/15/2024] [Indexed: 03/18/2024] Open
Abstract
Adeno-associated virus (AAV)-based therapies are recognized as one of the most potent next-generation treatments for inherited and genetic diseases. However, several biological and technological aspects of AAV vectors remain a critical issue for their widespread clinical application. Among them, the limited capacity of the AAV genome significantly hinders the development of AAV-based gene therapy. In this context, genetically modified transgenes compatible with AAV are opening up new opportunities for unlimited gene therapies for many genetic disorders. Recent advances in de novo protein design and remodelling are paving the way for new, more efficient and targeted gene therapeutics. Using computational and genetic tools, AAV expression cassette and transgenic DNA can be split, miniaturized, shuffled or created from scratch to mediate efficient gene transfer into targeted cells. In this review, we highlight recent advances in AAV-based gene therapy with a focus on its use in translational research. We summarize recent research and development in gene therapy, with an emphasis on large transgenes (>4.8 kb) and optimizing strategies applied by biomedical companies in the research pipeline. We critically discuss the prospects for AAV-based treatment and some emerging challenges. We anticipate that the continued development of novel computational tools will lead to rapid advances in basic gene therapy research and translational studies.
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Affiliation(s)
- Valeria V. Kolesnik
- Martsinovsky Institute of Medical ParasitologyTropical and Vector‐Borne Diseases, Sechenov UniversityMoscowRussia
| | - Ruslan F. Nurtdinov
- Martsinovsky Institute of Medical ParasitologyTropical and Vector‐Borne Diseases, Sechenov UniversityMoscowRussia
| | - Ezekiel Sola Oloruntimehin
- Martsinovsky Institute of Medical ParasitologyTropical and Vector‐Borne Diseases, Sechenov UniversityMoscowRussia
| | | | - Alexander S. Malogolovkin
- Martsinovsky Institute of Medical ParasitologyTropical and Vector‐Borne Diseases, Sechenov UniversityMoscowRussia
- Center for Translational MedicineSirius University of Science and TechnologySochiRussia
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Weller M, Müller B, Stieger K. Long-Term Porcine Retina Explants as an Alternative to In Vivo Experimentation. Transl Vis Sci Technol 2024; 13:9. [PMID: 38477924 PMCID: PMC10941994 DOI: 10.1167/tvst.13.3.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 01/24/2024] [Indexed: 03/14/2024] Open
Abstract
Purpose The porcine retina represents an optimal model system to study treatment approaches for inherited retinal dystrophies owing to close anatomical similarities to the human retina, including a cone enriched visual streak. The aim of this work was to establish a protocol to keep explants in culture for up to 28 days with good morphological preservation. Methods Two to four retina explants per eye were obtained from the central part of the retina and transferred onto a membrane insert with the photoreceptors facing down. Different medium compositions using Neurobasal-A medium containing 100 or 450 mg/dL glucose and combinations of fetal calf serum, B-27 with or without insulin and N-2 were tested. We developed a tissue quality score with robust markers for different retinal cell types (protein kinase C alpha, peanut agglutinin and 4',6-diamidino-2-phenylindol). Results Retinae were kept until 28 days with only little degradation. The best results were attained using Neurobasal-A medium containing 100 mg/dL glucose supplemented with B-27 containing insulin and N-2. For an easy preparation process, it is necessary to minimize transport time and keep the eyes on ice until dissected. Heat-mediated decontamination by the butcher has to be avoided. Conclusions Using a standardized protocol, porcine retina explants represent an easy to handle intermediate model between in vitro and in vivo experimentation. This model system is robustly reproducible and contributes to the implementation of the 3R principle to minimize animal experimentation. Translational Relevance This model can be used to test future therapeutic approaches for inherited retinal dystrophies.
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Affiliation(s)
- Maria Weller
- Department of Ophthalmology, Justus-Liebig-University Giessen, Germany
| | - Brigitte Müller
- Department of Ophthalmology, Justus-Liebig-University Giessen, Germany
| | - Knut Stieger
- Department of Ophthalmology, Justus-Liebig-University Giessen, Germany
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Cuzzuol BR, Apolonio JS, da Silva Júnior RT, de Carvalho LS, Santos LKDS, Malheiro LH, Silva Luz M, Calmon MS, Crivellaro HDL, Lemos FFB, Freire de Melo F. Usher syndrome: Genetic diagnosis and current therapeutic approaches. World J Otorhinolaryngol 2024; 11:1-17. [DOI: 10.5319/wjo.v11.i1.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/21/2023] [Accepted: 01/05/2024] [Indexed: 01/17/2024] Open
Abstract
Usher Syndrome (USH) is the most common deaf-blind syndrome, affecting approximately 1 in 6000 people in the deaf population. This genetic condition is characterized by a combination of hearing loss (HL), retinitis pigmentosa, and, in some cases, vestibular areflexia. Among the subtypes of USH, USH type 1 is considered the most severe form, presenting profound bilateral congenital deafness, vestibular areflexia, and early onset RP. USH type 2 is the most common form, exhibiting congenital moderate to severe HL for low frequencies and severe to profound HL for high frequencies. Conversely, type 3 is the rarest, initially manifesting mild symptoms during childhood that become more prominent in the first decades of life. The dual impact of USH on both visual and auditory senses significantly impairs patients’ quality of life, restricting their daily activities and interactions with society. To date, 9 genes have been confirmed so far for USH: MYO7A, USH1C, CDH23, PCDH15, USH1G, USH2A, ADGRV1, WHRN and CLRN1. These genes are inherited in an autosomal recessive manner and encode proteins expressed in the inner ear and retina, leading to functional loss. Although non-genetic methods can assist in patient triage and disease extension evaluation, genetic and molecular tests play a pivotal role in providing genetic counseling, enabling appropriate gene therapy, and facilitating timely cochlear implantation (CI). The CRISPR/Cas9 system and viral-based gene replacement therapy have recently emerged as highly promising techniques for treating USH. Regarding drug therapy, PTC-124 and Nb54 have been identified as promising drug interventions for genetic HL in USH. Simultaneously, CI has proven to be critical in the restoration of hearing. This review aims to summarize the genetic and molecular diagnosis of USH and highlight the importance of early diagnosis in guiding appropriate treatment strategies and improving patient prognosis.
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Affiliation(s)
- Beatriz Rocha Cuzzuol
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Jonathan Santos Apolonio
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | | | - Lorena Sousa de Carvalho
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Luana Kauany de Sá Santos
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Luciano Hasimoto Malheiro
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Marcel Silva Luz
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Mariana Santos Calmon
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Henrique de Lima Crivellaro
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Fabian Fellipe Bueno Lemos
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Fabrício Freire de Melo
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
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Lye J, Delaney DS, Leith FK, Sardesai VS, McLenachan S, Chen FK, Atlas MD, Wong EYM. Recent Therapeutic Progress and Future Perspectives for the Treatment of Hearing Loss. Biomedicines 2023; 11:3347. [PMID: 38137568 PMCID: PMC10741758 DOI: 10.3390/biomedicines11123347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/06/2023] [Accepted: 12/11/2023] [Indexed: 12/24/2023] Open
Abstract
Up to 1.5 billion people worldwide suffer from various forms of hearing loss, with an additional 1.1 billion people at risk from various insults such as increased consumption of recreational noise-emitting devices and ageing. The most common type of hearing impairment is sensorineural hearing loss caused by the degeneration or malfunction of cochlear hair cells or spiral ganglion nerves in the inner ear. There is currently no cure for hearing loss. However, emerging frontier technologies such as gene, drug or cell-based therapies offer hope for an effective cure. In this review, we discuss the current therapeutic progress for the treatment of hearing loss. We describe and evaluate the major therapeutic approaches being applied to hearing loss and summarize the key trials and studies.
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Affiliation(s)
- Joey Lye
- Hearing Therapeutics, Ear Science Institute Australia, Nedlands, WA 6009, Australia; (J.L.); (D.S.D.); (F.K.L.); (V.S.S.); (M.D.A.)
- Centre for Ear Sciences, Medical School, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Derek S. Delaney
- Hearing Therapeutics, Ear Science Institute Australia, Nedlands, WA 6009, Australia; (J.L.); (D.S.D.); (F.K.L.); (V.S.S.); (M.D.A.)
- Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6102, Australia
| | - Fiona K. Leith
- Hearing Therapeutics, Ear Science Institute Australia, Nedlands, WA 6009, Australia; (J.L.); (D.S.D.); (F.K.L.); (V.S.S.); (M.D.A.)
- Centre for Ear Sciences, Medical School, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Varda S. Sardesai
- Hearing Therapeutics, Ear Science Institute Australia, Nedlands, WA 6009, Australia; (J.L.); (D.S.D.); (F.K.L.); (V.S.S.); (M.D.A.)
| | - Samuel McLenachan
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, WA 6009, Australia; (S.M.); (F.K.C.)
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Fred K. Chen
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, WA 6009, Australia; (S.M.); (F.K.C.)
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, WA 6009, Australia
- Vitroretinal Surgery, Royal Perth Hospital, Perth, WA 6000, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, VIC 3002, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC 3002, Australia
| | - Marcus D. Atlas
- Hearing Therapeutics, Ear Science Institute Australia, Nedlands, WA 6009, Australia; (J.L.); (D.S.D.); (F.K.L.); (V.S.S.); (M.D.A.)
- Centre for Ear Sciences, Medical School, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Elaine Y. M. Wong
- Hearing Therapeutics, Ear Science Institute Australia, Nedlands, WA 6009, Australia; (J.L.); (D.S.D.); (F.K.L.); (V.S.S.); (M.D.A.)
- Centre for Ear Sciences, Medical School, The University of Western Australia, Nedlands, WA 6009, Australia
- Curtin Medical School, Faculty of Health Sciences, Curtin University, Bentley, WA 6102, Australia
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Li L, Vasan L, Kartono B, Clifford K, Attarpour A, Sharma R, Mandrozos M, Kim A, Zhao W, Belotserkovsky A, Verkuyl C, Schmitt-Ulms G. Advances in Recombinant Adeno-Associated Virus Vectors for Neurodegenerative Diseases. Biomedicines 2023; 11:2725. [PMID: 37893099 PMCID: PMC10603849 DOI: 10.3390/biomedicines11102725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 09/29/2023] [Accepted: 10/03/2023] [Indexed: 10/29/2023] Open
Abstract
Recombinant adeno-associated virus (rAAV) vectors are gene therapy delivery tools that offer a promising platform for the treatment of neurodegenerative diseases. Keeping up with developments in this fast-moving area of research is a challenge. This review was thus written with the intention to introduce this field of study to those who are new to it and direct others who are struggling to stay abreast of the literature towards notable recent studies. In ten sections, we briefly highlight early milestones within this field and its first clinical success stories. We showcase current clinical trials, which focus on gene replacement, gene augmentation, or gene suppression strategies. Next, we discuss ongoing efforts to improve the tropism of rAAV vectors for brain applications and introduce pre-clinical research directed toward harnessing rAAV vectors for gene editing applications. Subsequently, we present common genetic elements coded by the single-stranded DNA of rAAV vectors, their so-called payloads. Our focus is on recent advances that are bound to increase treatment efficacies. As needed, we included studies outside the neurodegenerative disease field that showcased improved pre-clinical designs of all-in-one rAAV vectors for gene editing applications. Finally, we discuss risks associated with off-target effects and inadvertent immunogenicity that these technologies harbor as well as the mitigation strategies available to date to make their application safer.
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Affiliation(s)
- Leyao Li
- Department of Biochemistry, University of Toronto, Medical Sciences Building, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, ON M5T 0S8, Canada
| | - Lakshmy Vasan
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
| | - Bryan Kartono
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, ON M5T 0S8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
| | - Kevan Clifford
- Institute of Medical Science, University of Toronto, Medical Sciences Building, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
- Centre for Addiction and Mental Health (CAMH), 250 College St., Toronto, ON M5T 1R8, Canada
| | - Ahmadreza Attarpour
- Department of Medical Biophysics, University of Toronto, 101 College St., Toronto, ON M5G 1L7, Canada
| | - Raghav Sharma
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, ON M5T 0S8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
| | - Matthew Mandrozos
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
| | - Ain Kim
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, ON M5T 0S8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
| | - Wenda Zhao
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, ON M5T 0S8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
| | - Ari Belotserkovsky
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, ON M5T 0S8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
| | - Claire Verkuyl
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, ON M5T 0S8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
| | - Gerold Schmitt-Ulms
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, ON M5T 0S8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
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10
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Wang L, Shah SM, Mangwani-Mordani S, Gregori NZ. Updates on Emerging Interventions for Autosomal Recessive ABCA4-Associated Stargardt Disease. J Clin Med 2023; 12:6229. [PMID: 37834872 PMCID: PMC10573680 DOI: 10.3390/jcm12196229] [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: 09/08/2023] [Revised: 09/25/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023] Open
Abstract
Autosomal recessive Stargardt disease (STGD1) is an inherited retinal degenerative disease associated with a mutated ATP-binding cassette, subfamily A, member 4 (ABCA4) gene. STGD1 is the most common form of juvenile macular degeneration with onset in late childhood to early or middle adulthood and causes progressive, irreversible visual impairment and blindness. No effective treatment is currently available. In the present article, we review the most recent updates in clinical trials targeting the management of STGD1, including gene therapy, small molecule therapy, and stem cell therapy. In gene therapy, dual adeno-associated virus and non-viral vectors have been successful in delivering the human ABCA4 gene in preclinical studies. For pharmaceutical therapies ALK-001, deuterated vitamin A shows promise with preliminary data for phase 2 trial, demonstrating a decreased atrophy growth rate after two years. Stem cell therapy using human pluripotent stem cell-derived retinal pigment epithelium cells demonstrated long-term safety three years after implantation and visual acuity improvements in the first two years after initiation of therapy. Many other treatment options have ongoing investigations and clinical trials. While multiple potential interventions have shown promise in attenuating disease progression, further exploration is necessary to demonstrate treatment safety and efficacy.
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Affiliation(s)
- Liang Wang
- University of Miami Miller School of Medicine, Miami, FL 33136, USA; (L.W.); (S.M.S.)
| | - Serena M. Shah
- University of Miami Miller School of Medicine, Miami, FL 33136, USA; (L.W.); (S.M.S.)
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
| | - Simran Mangwani-Mordani
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
| | - Ninel Z. Gregori
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
- Miami Veterans Administration Medical Center, Miami, FL 33125, USA
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11
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Bućan I, Bućan K. Paramacular Choriocapillaris Atrophy. Biomedicines 2023; 11:2074. [PMID: 37509713 PMCID: PMC10377535 DOI: 10.3390/biomedicines11072074] [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: 06/26/2023] [Revised: 07/21/2023] [Accepted: 07/22/2023] [Indexed: 07/30/2023] Open
Abstract
In this paper, a review of a rare case of paramacular choriocapillaris atrophy with a foveal-sparing phenotype is carried out. The 73-year-old patient stated that they had impaired vision and photophobia in both eyes during a regular ophthalmological examination, denying visual field defects and night blindness. A complete ophthalmological examination (best-corrected visual acuity, applanation tonometry, and biomicroscopy of anterior and posterior segments) and diagnostic tests, including fundus autofluorescence, fluorescein angiography, optical coherence tomography with angiography, computerized perimetry, and electroretinography, were carried out. The underlying genetic pattern is unclear, which points to paramacular choriocapillaris atrophy. According to recent research on histology, pathologies categorized as regional choroidal dystrophies are caused by alterations at the level of the retinal pigment epithelium. Despite the unresolved etiopathogenetic mechanism of foveal sparing in central choroidal and retinal dystrophies, a highly variable disease phenotype with spared fovea and central visual acuity present in a variety of heterogeneous dystrophies supports a disease-independent mechanism that allows the survival of foveal cones. The related preservation of BCVA has implications for individual prognosis and influences how treatment trials for choroidal and retinal dystrophies are designed.
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Affiliation(s)
- Ivona Bućan
- Eye Clinic, University Hospital Centre Split, 21000 Split, Croatia
| | - Kajo Bućan
- Eye Clinic, University Hospital Centre Split, 21000 Split, Croatia
- Department of Opthalmology, School of Medicine, University of Split, 21000 Split, Croatia
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12
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Robbins L, Balaram A, Dejneka S, McMahon M, Najibi Z, Pawlowicz P, Conrad WH. Heterologous production of the D-cycloserine intermediate O-acetyl-L-serine in a human type II pulmonary cell model. Sci Rep 2023; 13:8551. [PMID: 37237156 DOI: 10.1038/s41598-023-35632-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 05/21/2023] [Indexed: 05/28/2023] Open
Abstract
Tuberculosis (TB) is the second leading cause of death by a single infectious disease behind COVID-19. Despite a century of effort, the current TB vaccine does not effectively prevent pulmonary TB, promote herd immunity, or prevent transmission. Therefore, alternative approaches are needed. We seek to develop a cell therapy that produces an effective antibiotic in response to TB infection. D-cycloserine (D-CS) is a second-line antibiotic for TB that inhibits bacterial cell wall synthesis. We have determined D-CS to be the optimal candidate for anti-TB cell therapy due to its effectiveness against TB, relatively short biosynthetic pathway, and its low-resistance incidence. The first committed step towards D-CS synthesis is catalyzed by the L-serine-O-acetyltransferase (DcsE) which converts L-serine and acetyl-CoA to O-acetyl-L-serine (L-OAS). To test if the D-CS pathway could be an effective prophylaxis for TB, we endeavored to express functional DcsE in A549 cells as a human pulmonary model. We observed DcsE-FLAG-GFP expression using fluorescence microscopy. DcsE purified from A549 cells catalyzed the synthesis of L-OAS as observed by HPLC-MS. Therefore, human cells synthesize functional DcsE capable of converting L-serine and acetyl-CoA to L-OAS demonstrating the first step towards D-CS production in human cells.
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Affiliation(s)
- Laurel Robbins
- Department of Chemistry and Biochemistry and Molecular Biology Program, Lake Forest College, Lake Forest, USA
| | - Ariane Balaram
- Department of Chemistry and Biochemistry and Molecular Biology Program, Lake Forest College, Lake Forest, USA
| | - Stefanie Dejneka
- Department of Chemistry and Biochemistry and Molecular Biology Program, Lake Forest College, Lake Forest, USA
| | - Matthew McMahon
- Department of Chemistry and Biochemistry and Molecular Biology Program, Lake Forest College, Lake Forest, USA
| | - Zarina Najibi
- Department of Chemistry and Biochemistry and Molecular Biology Program, Lake Forest College, Lake Forest, USA
| | - Peter Pawlowicz
- Department of Chemistry and Biochemistry and Molecular Biology Program, Lake Forest College, Lake Forest, USA
| | - William H Conrad
- Department of Chemistry and Biochemistry and Molecular Biology Program, Lake Forest College, Lake Forest, USA.
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13
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Karamali F, Behtaj S, Babaei-Abraki S, Hadady H, Atefi A, Savoj S, Soroushzadeh S, Najafian S, Nasr Esfahani MH, Klassen H. Potential therapeutic strategies for photoreceptor degeneration: the path to restore vision. J Transl Med 2022; 20:572. [PMID: 36476500 PMCID: PMC9727916 DOI: 10.1186/s12967-022-03738-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 10/29/2022] [Indexed: 12/12/2022] Open
Abstract
Photoreceptors (PRs), as the most abundant and light-sensing cells of the neuroretina, are responsible for converting light into electrical signals that can be interpreted by the brain. PR degeneration, including morphological and functional impairment of these cells, causes significant diminution of the retina's ability to detect light, with consequent loss of vision. Recent findings in ocular regenerative medicine have opened promising avenues to apply neuroprotective therapy, gene therapy, cell replacement therapy, and visual prostheses to the challenge of restoring vision. However, successful visual restoration in the clinical setting requires application of these therapeutic approaches at the appropriate stage of the retinal degeneration. In this review, firstly, we discuss the mechanisms of PR degeneration by focusing on the molecular mechanisms underlying cell death. Subsequently, innovations, recent developments, and promising treatments based on the stage of disorder progression are further explored. Then, the challenges to be addressed before implementation of these therapies in clinical practice are considered. Finally, potential solutions to overcome the current limitations of this growing research area are suggested. Overall, the majority of current treatment modalities are still at an early stage of development and require extensive additional studies, both pre-clinical and clinical, before full restoration of visual function in PR degeneration diseases can be realized.
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Affiliation(s)
- Fereshteh Karamali
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sanaz Behtaj
- grid.1022.10000 0004 0437 5432Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Queensland, Australia ,grid.1022.10000 0004 0437 5432Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia
| | - Shahnaz Babaei-Abraki
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Hanieh Hadady
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Atefeh Atefi
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Soraya Savoj
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sareh Soroushzadeh
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Samaneh Najafian
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Mohammad Hossein Nasr Esfahani
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Henry Klassen
- grid.266093.80000 0001 0668 7243Gavin Herbert Eye Institute, Irvine, CA USA
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14
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Tawfik M, Chen F, Goldberg JL, Sabel BA. Nanomedicine and drug delivery to the retina: current status and implications for gene therapy. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2022; 395:1477-1507. [PMID: 36107200 PMCID: PMC9630211 DOI: 10.1007/s00210-022-02287-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/31/2022] [Indexed: 10/14/2022]
Abstract
Blindness affects more than 60 million people worldwide. Retinal disorders, including age-related macular degeneration (AMD), diabetic retinopathy (DR), and glaucoma, are the leading causes of blindness. Finding means to optimize local and sustained delivery of drugs or genes to the eye and retina is one goal to advance the development of new therapeutics. Despite the ease of accessibility of delivering drugs via the ocular surface, the delivery of drugs to the retina is still challenging due to anatomic and physiologic barriers. Designing a suitable delivery platform to overcome these barriers should enhance drug bioavailability and provide a safe, controlled, and sustained release. Current inventions for posterior segment treatments include intravitreal implants and subretinal viral gene delivery that satisfy these criteria. Several other novel drug delivery technologies, including nanoparticles, micelles, dendrimers, microneedles, liposomes, and nanowires, are now being widely studied for posterior segment drug delivery, and extensive research on gene delivery using siRNA, mRNA, or aptamers is also on the rise. This review discusses the current state of retinal drug/gene delivery and highlights future therapeutic opportunities.
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Affiliation(s)
- Mohamed Tawfik
- Institute of Medical Psychology, Medical Faculty, Otto-Von-Guericke University, Magdeburg, Germany
| | - Fang Chen
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Jeffrey L Goldberg
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Bernhard A Sabel
- Institute of Medical Psychology, Medical Faculty, Otto-Von-Guericke University, Magdeburg, Germany.
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15
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Marrone L, Marchi PM, Azzouz M. Circumventing the packaging limit of AAV-mediated gene replacement therapy for neurological disorders. Expert Opin Biol Ther 2022; 22:1163-1176. [PMID: 34904932 DOI: 10.1080/14712598.2022.2012148] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 11/25/2021] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Gene therapy provides the exciting opportunity of a curative single treatment for devastating diseases, eradicating the need for chronic medication. Adeno-associated viruses (AAVs) are among the most attractive vector carriers for gene replacement in vivo. Yet, despite the success of recent AAV-based clinical trials, the clinical use of these vectors has been limited. For instance, the AAV packaging capacity is restricted to ~4.7 kb, making it a substantial challenge to deliver large gene products. AREAS COVERED In this review, we explore established and emerging strategies that circumvent the packaging limit of AAVs to make them effective vehicles for gene replacement therapy of monogenic disorders, with a particular focus on diseases affecting the nervous system. We report historical references, design remarks, as well as strengths and weaknesses of these approaches. We additionally discuss examples of neurological disorders for which such strategies have been attempted. EXPERT OPINION The field of AAV-gene therapy has experienced enormous advancements in the last decade. However, there is still ample space for improvement aimed at overcoming existing challenges that are slowing down the progressive trajectory of this field.
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Affiliation(s)
- Lara Marrone
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - Paolo M Marchi
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - Mimoun Azzouz
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
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16
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Molecular analysis of AAV5-hFVIII-SQ vector-genome-processing kinetics in transduced mouse and nonhuman primate livers. Mol Ther Methods Clin Dev 2022; 24:142-153. [PMID: 35036471 PMCID: PMC8749450 DOI: 10.1016/j.omtm.2021.12.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 12/17/2021] [Indexed: 12/18/2022]
Abstract
Valoctocogene roxaparvovec (AAV5-hFVIII-SQ) is an adeno-associated virus serotype 5 (AAV5)-based gene therapy vector containing a B-domain-deleted human coagulation factor VIII (hFVIII) gene controlled by a liver-selective promoter. AAV5-hFVIII-SQ is currently under clinical investigation as a treatment for severe hemophilia A. The full-length AAV5-hFVIII-SQ is >4.9 kb, which is over the optimal packaging limit of AAV5. Following administration, the vector must undergo a number of genome-processing, assembly, and repair steps to form full-length circularized episomes that mediate long-term FVIII expression in target tissues. To understand the processing kinetics of the oversized AAV5-hFVIII-SQ vector genome into circular episomes, we characterized the various molecular forms of the AAV5-hFVIII-SQ genome at multiple time points up to 6 months postdose in the liver of murine and non-human primate models. Full-length circular episomes were detected in liver tissue beginning 1 week postdosing. Over 6 months, quantities of circular episomes (in a predominantly head-to-tail configuration) increased, while DNA species lacking inverted terminal repeats were preferentially degraded. Levels of duplex, circular, full-length genomes significantly correlated with levels of hFVIII-SQ RNA transcripts in mice and non-human primates dosed with AAV5-hFVIII-SQ. Altogether, we show that formation of full-length circular episomes in the liver following AAV5-hFVIII-SQ transduction was associated with long-term FVIII expression.
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17
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Barnes LF, Draper BE, Chen YT, Powers TW, Jarrold MF. Quantitative analysis of genome packaging in recombinant AAV vectors by charge detection mass spectrometry. Mol Ther Methods Clin Dev 2021; 23:87-97. [PMID: 34631929 PMCID: PMC8476707 DOI: 10.1016/j.omtm.2021.08.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 08/16/2021] [Indexed: 12/13/2022]
Abstract
Recombinant adeno-associated virus (rAAV) has emerged as an important gene therapy vector with many clinical trials currently in progress. Analytical characterization and quantitation of particle content remain challenges in both the development and production of rAAV vectors. In this study, charge detection mass spectrometry (CDMS) and gel electrophoresis are used to characterize the DNA content of recombinant AAV8 (rAAV8) vectors with a wide range of target genome sizes. We show that the differences between the masses of empty particles and particles with the genome of interest (GOI) are correlated with the expected genome mass. A small systematic deviation (around 2%) is attributed to the packaging of counterions along with the DNA. In addition to the GOI, a broad distribution of heterogeneous DNA is packaged. The distribution peaks are close to the packaging capacity of the rAAV8 vectors. There is also evidence for the co-packaging of small DNA fragments along with the GOI. Finally, we present evidence that incubation at an elevated temperature can reduce the heterogeneity of the packaged DNA. Taken together, these results show that CDMS is a viable tool for characterization of the packaged genome.
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Affiliation(s)
- Lauren F Barnes
- Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, IN 47405, USA
| | - Benjamin E Draper
- Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, IN 47405, USA
| | - Yu-Ting Chen
- Pfizer, Inc., BioTherapeutics Pharmaceutical Sciences, Analytical R&D, 875 Chesterfield Parkway West, Chesterfield, MO 63017, USA
| | - Thomas W Powers
- Pfizer, Inc., BioTherapeutics Pharmaceutical Sciences, Analytical R&D, 875 Chesterfield Parkway West, Chesterfield, MO 63017, USA
| | - Martin F Jarrold
- Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, IN 47405, USA
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18
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Macdonald J, Marx J, Büning H. Capsid-Engineering for Central Nervous System-Directed Gene Therapy with Adeno-Associated Virus Vectors. Hum Gene Ther 2021; 32:1096-1119. [PMID: 34662226 DOI: 10.1089/hum.2021.169] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Closing the gap in knowledge on the cause of neurodegenerative disorders is paving the way toward innovative treatment strategies, among which gene therapy has emerged as a top candidate. Both conventional gene therapy and genome editing approaches are being developed, and a great number of human clinical trials are ongoing. Already 2 years ago, the first gene therapy for a neurodegenerative disease, spinal muscular atrophy type 1 (SMA1), obtained market approval. To realize such innovative strategies, gene therapy delivery tools are key assets. Here, we focus on recombinant adeno-associated virus (AAV) vectors and report on strategies to improve first-generation vectors. Current efforts focus on the viral capsid to modify the host-vector interaction aiming at increasing the efficacy of target cell transduction, at simplifying vector administration, and at reducing the risk of vector dose-related side effects.
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Affiliation(s)
- Josephine Macdonald
- Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.,REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Jennifer Marx
- Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.,REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Hildegard Büning
- Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.,REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
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19
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Shughoury A, Ciulla TA, Bakall B, Pennesi ME, Kiss S, Cunningham ET. Genes and Gene Therapy in Inherited Retinal Disease. Int Ophthalmol Clin 2021; 61:3-45. [PMID: 34584043 DOI: 10.1097/iio.0000000000000377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20
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Ahmed I, Johnston RJ, Singh MS. Pluripotent stem cell therapy for retinal diseases. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1279. [PMID: 34532416 PMCID: PMC8421932 DOI: 10.21037/atm-20-4747] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 12/04/2020] [Indexed: 12/20/2022]
Abstract
Pluripotent stem cells (PSCs), which include human embryonic stem cells (hESCs) and induced pluripotent stem cell (iPSC), have been used to study development of disease processes, and as potential therapies in multiple organ systems. In recent years, there has been increasing interest in the use of PSC-based transplantation to treat disorders of the retina in which retinal cells have been functionally damaged or lost through degeneration. The retina, which consists of neuronal tissue, provides an excellent system to test the therapeutic utility of PSC-based transplantation due to its accessibility and the availability of high-resolution imaging technology to evaluate effects. Preclinical trials in animal models of retinal diseases have shown improvement in visual outcomes following subretinal transplantation of PSC-derived photoreceptors or retinal pigment epithelium (RPE) cells. This review focuses on preclinical studies and clinical trials exploring the use of PSCs for retinal diseases. To date, several phase I/II clinical trials in patients with age-related macular degeneration (AMD) and Stargardt disease (STGD1) have demonstrated the safety and feasibility of PSC-derived RPE transplantation. Additional phase I/II clinical trials using PSC-derived RPE or photoreceptor cells for the treatment of AMD, STGD1, and also retinitis pigmentosa (RP) are currently in the pipeline. As this field continues to evolve, additional technologies may enhance PSC-derived cell transplantation through gene-editing of autologous cells, transplantation of more complex cellular structures such as organoids, and monitoring of transplanted cells through novel imaging technologies.
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Affiliation(s)
- Ishrat Ahmed
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Mandeep S Singh
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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21
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Huang D, Heath Jeffery RC, Aung-Htut MT, McLenachan S, Fletcher S, Wilton SD, Chen FK. Stargardt disease and progress in therapeutic strategies. Ophthalmic Genet 2021; 43:1-26. [PMID: 34455905 DOI: 10.1080/13816810.2021.1966053] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Background: Stargardt disease (STGD1) is an autosomal recessive retinal dystrophy due to mutations in ABCA4, characterized by subretinal deposition of lipofuscin-like substances and bilateral centrifugal vision loss. Despite the tremendous progress made in the understanding of STGD1, there are no approved treatments to date. This review examines the challenges in the development of an effective STGD1 therapy.Materials and Methods: A literature review was performed through to June 2021 summarizing the spectrum of retinal phenotypes in STGD1, the molecular biology of ABCA4 protein, the in vivo and in vitro models used to investigate the mechanisms of ABCA4 mutations and current clinical trials.Results: STGD1 phenotypic variability remains an challenge for clinical trial design and patient selection. Pre-clinical development of therapeutic options has been limited by the lack of animal models reflecting the diverse phenotypic spectrum of STDG1. Patient-derived cell lines have facilitated the characterization of splice mutations but the clinical presentation is not always predicted by the effect of specific mutations on retinoid metabolism in cellular models. Current therapies primarily aim to delay vision loss whilst strategies to restore vision are less well developed.Conclusions: STGD1 therapy development can be accelerated by a deeper understanding of genotype-phenotype correlations.
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Affiliation(s)
- Di Huang
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Western Australia, Australia.,Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), the University of Western Australia, Nedlands, Western Australia, Australia.,Perron Institute for Neurological and Translational Science & the University of Western Australia, Nedlands, Western Australia, Australia
| | - Rachael C Heath Jeffery
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), the University of Western Australia, Nedlands, Western Australia, Australia
| | - May Thandar Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Western Australia, Australia.,Perron Institute for Neurological and Translational Science & the University of Western Australia, Nedlands, Western Australia, Australia
| | - Samuel McLenachan
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), the University of Western Australia, Nedlands, Western Australia, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Western Australia, Australia.,Perron Institute for Neurological and Translational Science & the University of Western Australia, Nedlands, Western Australia, Australia
| | - Steve D Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Western Australia, Australia.,Perron Institute for Neurological and Translational Science & the University of Western Australia, Nedlands, Western Australia, Australia
| | - Fred K Chen
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), the University of Western Australia, Nedlands, Western Australia, Australia.,Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.,Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia.,Department of Ophthalmology, Perth Children's Hospital, Nedlands, Western Australia, Australia
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22
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Dhurandhar D, Sahoo NK, Mariappan I, Narayanan R. Gene therapy in retinal diseases: A review. Indian J Ophthalmol 2021; 69:2257-2265. [PMID: 34427196 PMCID: PMC8544052 DOI: 10.4103/ijo.ijo_3117_20] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Over 2 million people worldwide are suffering from gene-related retinal diseases, inherited or acquired, and over 270 genes have been identified which are found to be responsible for these conditions. This review article touches upon the mechanisms of gene therapy, various enzymes of the visual cycle responsible for different genetic diseases, Luxturna—the first US Food and Drug Administration (FDA)-approved therapeutic gene product, and several ongoing trials of gene therapy for age-related macular degeneration. Gene therapy has tremendous potential for retinal conditions due to its ease of accessibility, immune-privileged status, and tight blood-retinal barriers, limiting systemic side effects of the drug. In recent years, advances in gene therapy in retinal conditions have increasing significantly, with progress in cell-specific targeting and transduction efficiency of gene products through the use of adeno-associated viral vectors (AAVs), suggesting that even greater success in future clinical trials is possible.
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Affiliation(s)
- Deven Dhurandhar
- Retina and Uveitis Department, GMR Varalakshmi Campus, LV Prasad Eye Institute, Visakhapatnam, Andhra Pradesh, India
| | - Niroj Kumar Sahoo
- Smt. Kanuri Santhamma Centre for Vitreo-Retinal Diseases, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Indumathi Mariappan
- Centre for Ocular Regeneration, Hyderabad Eye Research Foundation, Kallam Anji Reddy Campus, L.V. Prasad Eye Institute, Hyderabad, Telangana, India
| | - Raja Narayanan
- Smt. Kanuri Santhamma Centre for Vitreo-Retinal Diseases, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, Telangana, India
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23
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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.
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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
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24
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Català P, Thuret G, Skottman H, Mehta JS, Parekh M, Ní Dhubhghaill S, Collin RWJ, Nuijts RMMA, Ferrari S, LaPointe VLS, Dickman MM. Approaches for corneal endothelium regenerative medicine. Prog Retin Eye Res 2021; 87:100987. [PMID: 34237411 DOI: 10.1016/j.preteyeres.2021.100987] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 12/13/2022]
Abstract
The state of the art therapy for treating corneal endothelial disease is transplantation. Advances in the reproducibility and accessibility of surgical techniques are increasing the number of corneal transplants, thereby causing a global deficit of donor corneas and leaving 12.7 million patients with addressable visual impairment. Approaches to regenerate the corneal endothelium offer a solution to the current tissue scarcity and a treatment to those in need. Methods for generating corneal endothelial cells into numbers that could address the current tissue shortage and the possible strategies used to deliver them have now become a therapeutic reality with clinical trials taking place in Japan, Singapore and Mexico. Nevertheless, there is still a long way before such therapies are approved by regulatory bodies and become clinical practice. Moreover, acellular corneal endothelial graft equivalents and certain drugs could provide a treatment option for specific disease conditions without the need of donor tissue or cells. Finally, with the emergence of gene modulation therapies to treat corneal endothelial disease, it would be possible to treat presymptomatic patients or those presenting early symptoms, drastically reducing the need for donor tissue. It is necessary to understand the most recent developments in this rapidly evolving field to know which conditions could be treated with which approach. This article provides an overview of the current and developing regenerative medicine therapies to treat corneal endothelial disease and provides the necessary guidance and understanding towards the treatment of corneal endothelial disease.
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Affiliation(s)
- Pere Català
- University Eye Clinic Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands; Department of Cell Biology-Inspired Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, the Netherlands
| | - Gilles Thuret
- Laboratory of Biology, Engineering and Imaging of Corneal Graft, BiiGC, Faculty of Medicine, University of Saint Etienne, Saint Etienne, France; Institut Universitaire de France, Paris, France
| | - Heli Skottman
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Jodhbir S Mehta
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore; Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-National University Singapore Medical School, Singapore; Singapore National Eye Centre, Singapore
| | - Mohit Parekh
- Institute of Ophthalmology, University College London, London, UK; The Veneto Eye Bank Foundation, Venice, Italy; Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Sorcha Ní Dhubhghaill
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium; Ophthalmology, Visual Optics and Visual Rehabilitation, Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Rudy M M A Nuijts
- University Eye Clinic Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands
| | | | - Vanessa L S LaPointe
- Department of Cell Biology-Inspired Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, the Netherlands
| | - Mor M Dickman
- University Eye Clinic Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands; Department of Cell Biology-Inspired Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, the Netherlands.
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25
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Abstract
Inherited retinal diseases (IRDs) are an important cause of blindness worldwide. Over 270 genes have been associated with IRD. Genetic testing can determine the cause of the clinical disease in the majority of patients. However, at least 25-50% of patients with clinical diagnosis of IRD remain unsolved even after whole genome sequencing. Animal models of IRD can be useful for expanding the set of established IRD genes, to gain biological understanding of the function of these genes in the retina, and to test advanced therapeutics prior to human clinical trials. In this chapter some small and large animal models of IRD are discussed including some of the advantages and limitations of each for various forms of retinopathy.
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26
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Chen HY, Lehmann OJ, Swaroop A. Genetics and therapy for pediatric eye diseases. EBioMedicine 2021; 67:103360. [PMID: 33975254 PMCID: PMC8122153 DOI: 10.1016/j.ebiom.2021.103360] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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: 03/29/2021] [Accepted: 04/12/2021] [Indexed: 12/26/2022] Open
Abstract
Ocular morphogenesis in vertebrates is a highly organized process, orchestrated largely by intrinsic genetic programs that exhibit stringent spatiotemporal control. Alternations in these genetic instructions can lead to hereditary or nonhereditary congenital disorders, a major cause of childhood visual impairment, and contribute to common late-onset blinding diseases. Currently, limited treatment options exist for clinical phenotypes involving eye development. This review summarizes recent advances in our understanding of early-onset ocular disorders and highlights genetic complexities in development and diseases, specifically focusing on coloboma, congenital glaucoma and Leber congenital amaurosis. We also discuss innovative paradigms for potential therapeutic modalities.
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Affiliation(s)
- Holly Y Chen
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892 USA.
| | - Ordan J Lehmann
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Canada; Department of Medical Genetics, University of Alberta, Edmonton, Canada.
| | - Anand Swaroop
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892 USA.
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27
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Zhang KY, Johnson TV. The internal limiting membrane: Roles in retinal development and implications for emerging ocular therapies. Exp Eye Res 2021; 206:108545. [PMID: 33753089 DOI: 10.1016/j.exer.2021.108545] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/02/2021] [Accepted: 03/16/2021] [Indexed: 12/17/2022]
Abstract
Basement membranes help to establish, maintain, and separate their associated tissues. They also provide growth and signaling substrates for nearby resident cells. The internal limiting membrane (ILM) is the basement membrane at the ocular vitreoretinal interface. While the ILM is essential for normal retinal development, it is dispensable in adulthood. Moreover, the ILM may constitute a significant barrier to emerging ocular therapeutics, such as viral gene therapy or stem cell transplantation. Here we take a neurodevelopmental perspective in examining how retinal neurons, glia, and vasculature interact with individual extracellular matrix constituents at the ILM. In addition, we review evidence that the ILM may impede novel ocular therapies and discuss approaches for achieving retinal parenchymal targeting of gene vectors and cell transplants delivered into the vitreous cavity by manipulating interactions with the ILM.
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Affiliation(s)
- Kevin Y Zhang
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Maumenee B-110, Baltimore, MD, 21287, USA
| | - Thomas V Johnson
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Maumenee B-110, Baltimore, MD, 21287, USA.
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28
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Georgiou M, Fujinami K, Michaelides M. Inherited retinal diseases: Therapeutics, clinical trials and end points-A review. Clin Exp Ophthalmol 2021; 49:270-288. [PMID: 33686777 DOI: 10.1111/ceo.13917] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/22/2021] [Accepted: 03/01/2021] [Indexed: 12/18/2022]
Abstract
Inherited retinal diseases (IRDs) are a clinically and genetically heterogeneous group of disorders characterised by photoreceptor degeneration or dysfunction. These disorders typically present with severe vision loss that can be progressive, with disease onset ranging from congenital to late adulthood. The advances in genetics, retinal imaging and molecular biology, have conspired to create the ideal environment for establishing treatments for IRDs, with the first approved gene therapy and the commencement of multiple clinical trials. The scope of this review is to familiarise clinicians and scientists with the current management and the prospects for novel therapies for: (1) macular dystrophies, (2) cone and cone-rod dystrophies, (3) cone dysfunction syndromes, (4) Leber congenital amaurosis, (5) rod-cone dystrophies, (6) rod dysfunction syndromes and (7) chorioretinal dystrophies. We also briefly summarise the investigated end points for the ongoing trials.
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Affiliation(s)
- Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Kaoru Fujinami
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
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29
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Rankovic V, Vogl C, Dörje NM, Bahader I, Duque-Afonso CJ, Thirumalai A, Weber T, Kusch K, Strenzke N, Moser T. Overloaded Adeno-Associated Virus as a Novel Gene Therapeutic Tool for Otoferlin-Related Deafness. Front Mol Neurosci 2021; 13:600051. [PMID: 33488357 PMCID: PMC7817888 DOI: 10.3389/fnmol.2020.600051] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/04/2020] [Indexed: 01/19/2023] Open
Abstract
Hearing impairment is the most common sensory disorder in humans. So far, rehabilitation of profoundly deaf subjects relies on direct stimulation of the auditory nerve through cochlear implants. However, in some forms of genetic hearing impairment, the organ of Corti is structurally intact and therapeutic replacement of the mutated gene could potentially restore near natural hearing. In the case of defects of the otoferlin gene (OTOF), such gene therapy is hindered by the size of the coding sequence (~6 kb) exceeding the cargo capacity (<5 kb) of the preferred viral vector, adeno-associated virus (AAV). Recently, a dual-AAV approach was used to partially restore hearing in deaf otoferlin knock-out (Otof-KO) mice. Here, we employed in vitro and in vivo approaches to assess the gene-therapeutic potential of naturally-occurring and newly-developed synthetic AAVs overloaded with the full-length Otof coding sequence. Upon early postnatal injection into the cochlea of Otof-KO mice, overloaded AAVs drove specific expression of otoferlin in ~30% of all IHCs, as demonstrated by immunofluorescence labeling and polymerase chain reaction. Recordings of auditory brainstem responses and a behavioral assay demonstrated partial restoration of hearing. Together, our results suggest that viral gene therapy of DFNB9—using a single overloaded AAV vector—is indeed feasible, reducing the complexity of gene transfer compared to dual-AAV approaches.
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Affiliation(s)
- Vladan Rankovic
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Restorative Cochlear Genomics Group, Auditory Neuroscience and Optogenetics Laboratory, German Primate Center, Göttingen, Germany
| | - Christian Vogl
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Presynaptogenesis and Intracellular Transport in Hair Cells Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
| | - Nele M Dörje
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Presynaptogenesis and Intracellular Transport in Hair Cells Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Iman Bahader
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany.,Auditory Systems Physiology Group, Institute for Auditory Neuroscience and Department of Otolaryngology, University Medical Center Göttingen, Göttingen, Germany
| | - Carlos J Duque-Afonso
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Auditory Neuroscience Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, Göttingen, Germany
| | - Anupriya Thirumalai
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Thomas Weber
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Kathrin Kusch
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Restorative Cochlear Genomics Group, Auditory Neuroscience and Optogenetics Laboratory, German Primate Center, Göttingen, Germany
| | - Nicola Strenzke
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany.,Auditory Systems Physiology Group, Institute for Auditory Neuroscience and Department of Otolaryngology, University Medical Center Göttingen, Göttingen, Germany
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Collaborative Research Center 889, University of Göttingen, Göttingen, Germany.,Auditory Neuroscience Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, Göttingen, Germany.,Synaptic Nanophysiology Group, Max Planck Institute of Biophysical Chemistry, Göttingen, Germany.,Auditory Neuroscience and Optogenetics Laboratory, German Primate Center, Göttingen, Germany
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30
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Whatley M, Francis A, Ng ZY, Khoh XE, Atlas MD, Dilley RJ, Wong EYM. Usher Syndrome: Genetics and Molecular Links of Hearing Loss and Directions for Therapy. Front Genet 2020; 11:565216. [PMID: 33193648 PMCID: PMC7642844 DOI: 10.3389/fgene.2020.565216] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 09/21/2020] [Indexed: 12/19/2022] Open
Abstract
Usher syndrome (USH) is an autosomal recessive (AR) disorder that permanently and severely affects the senses of hearing, vision, and balance. Three clinically distinct types of USH have been identified, decreasing in severity from Type 1 to 3, with symptoms of sensorineural hearing loss (SNHL), retinitis pigmentosa (RP), and vestibular dysfunction. There are currently nine confirmed and two suspected USH-causative genes, and a further three candidate loci have been mapped. The proteins encoded by these genes form complexes that play critical roles in the development and maintenance of cellular structures within the inner ear and retina, which have minimal capacity for repair or regeneration. In the cochlea, stereocilia are located on the apical surface of inner ear hair cells (HC) and are responsible for transducing mechanical stimuli from sound pressure waves into chemical signals. These signals are then detected by the auditory nerve fibers, transmitted to the brain and interpreted as sound. Disease-causing mutations in USH genes can destabilize the tip links that bind the stereocilia to each other, and cause defects in protein trafficking and stereocilia bundle morphology, thereby inhibiting mechanosensory transduction. This review summarizes the current knowledge on Usher syndrome with a particular emphasis on mutations in USH genes, USH protein structures, and functional analyses in animal models. Currently, there is no cure for USH. However, the genetic therapies that are rapidly developing will benefit from this compilation of detailed genetic information to identify the most effective strategies for restoring functional USH proteins.
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Affiliation(s)
- Meg Whatley
- Ear Science Institute Australia, Nedlands, WA, Australia
| | - Abbie Francis
- Ear Science Institute Australia, Nedlands, WA, Australia
- Emergency Medicine, The University of Western Australia, Nedlands, WA, Australia
| | - Zi Ying Ng
- Ear Science Institute Australia, Nedlands, WA, Australia
| | - Xin Ee Khoh
- Ear Science Institute Australia, Nedlands, WA, Australia
- School of Human Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Marcus D. Atlas
- Ear Science Institute Australia, Nedlands, WA, Australia
- Ear Sciences Centre, The University of Western Australia, Nedlands, WA, Australia
| | - Rodney J. Dilley
- Ear Science Institute Australia, Nedlands, WA, Australia
- Ear Sciences Centre, The University of Western Australia, Nedlands, WA, Australia
- Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia, Perth, WA, Australia
| | - Elaine Y. M. Wong
- Ear Science Institute Australia, Nedlands, WA, Australia
- Ear Sciences Centre, The University of Western Australia, Nedlands, WA, Australia
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley, WA, Australia
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31
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Xu Y, Guo P, Zhang J, Chrzanowski M, Chew H, Firrman JA, Sang N, Diao Y, Xiao W. Effects of Thermally Induced Configuration Changes on rAAV Genome's Enzymatic Accessibility. Mol Ther Methods Clin Dev 2020; 18:328-334. [PMID: 32671135 PMCID: PMC7338580 DOI: 10.1016/j.omtm.2020.06.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 06/03/2020] [Indexed: 11/15/2022]
Abstract
Physical titers for recombinant adeno-associated viral (rAAV) vectors are measured by quantifying viral genomes. It is generally perceived that AAV virions disassemble and release DNA upon thermal treatment. Here, we present data on enzymatic accessibility of rAAV genomes when AAV virions were subjected to thermal treatment. For rAAV vectors with a normal genome size (≤4.7 kb), thermal treatment at 75°C-99°C allowed only ∼10% of genomes to be detectable by quantitative real-time PCR. In contrast, greater than 70% of AAV genomes can be detected under similar conditions for AAV vectors with an oversized genome (≥5.0 kb). The permeability of virions, as measured by ethidium bromide (EB) staining, was enhanced by thermal stimulation. These results suggest that in rAAV virions with standard-sized genomes, the capsid and DNA are close enough in proximity for heat-induced "crosslinking," which results in inaccessibility of vector DNA to enzymatic reactions. In contrast, rAAV vectors with oversized genomes release their DNA readily upon thermal treatment. These findings suggested that the spatial arrangement of capsid protein and DNA in AAV virions is genome-size dependent. These results provide a foundation for future improvement of vector assays, design, and applications.
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Affiliation(s)
- Yinxia Xu
- School of Biomedical Science, Huaqiao University, Quanzhou, China
| | - Ping Guo
- School of Biomedical Science, Huaqiao University, Quanzhou, China
| | - Junping Zhang
- Herman B Wells Center for Pediatric Research, Indiana University, Indianapolis, IN 46202, USA
| | | | - Helen Chew
- Temple University Medical School, Philadelphia, PA 19140, USA
| | - Jenni A. Firrman
- United States Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA 19038, USA
| | - Nianli Sang
- Department of Biology, College of Arts and Sciences, Drexel University, Philadelphia, PA 19104, USA
| | - Yong Diao
- School of Biomedical Science, Huaqiao University, Quanzhou, China
| | - Weidong Xiao
- Herman B Wells Center for Pediatric Research, Indiana University, Indianapolis, IN 46202, USA
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32
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Ku CA, Pennesi ME. The new landscape of retinal gene therapy. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2020; 184:846-859. [PMID: 32888388 DOI: 10.1002/ajmg.c.31842] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/07/2020] [Accepted: 08/11/2020] [Indexed: 12/15/2022]
Abstract
Novel therapeutics for inherited retinal dystrophies (IRDs) have rapidly evolved since groundbreaking clinical trials for LCA due to RPE65 mutations led to the first FDA-approved in vivo gene therapy. Since then, advancements in viral vectors have led to more efficient AAV transduction and developed other viral vectors for gene augmentation therapy of large gene targets. Furthermore, significant developments in gene editing and RNA modulation technologies have introduced novel capabilities for treatment of autosomal dominant diseases, intronic mutations, and/or large genes otherwise unable to be treated with current viral vectors. We highlight strategies currently being evaluated in gene therapy clinical trials and promising preclinical developments for IRDs.
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Affiliation(s)
- Cristy A Ku
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Mark E Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
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33
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Reisinger E. Dual-AAV delivery of large gene sequences to the inner ear. Hear Res 2020; 394:107857. [DOI: 10.1016/j.heares.2019.107857] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 11/22/2019] [Indexed: 01/06/2023]
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34
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Akil O. Dual and triple AAV delivery of large therapeutic gene sequences into the inner ear. Hear Res 2020; 394:107912. [DOI: 10.1016/j.heares.2020.107912] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/04/2020] [Accepted: 02/07/2020] [Indexed: 12/17/2022]
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35
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French LS, Mellough CB, Chen FK, Carvalho LS. A Review of Gene, Drug and Cell-Based Therapies for Usher Syndrome. Front Cell Neurosci 2020; 14:183. [PMID: 32733204 PMCID: PMC7363968 DOI: 10.3389/fncel.2020.00183] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 05/28/2020] [Indexed: 12/12/2022] Open
Abstract
Usher syndrome is a genetic disorder causing neurosensory hearing loss and blindness from retinitis pigmentosa (RP). Adaptive techniques such as braille, digital and optical magnifiers, mobility training, cochlear implants, or other assistive listening devices are indispensable for reducing disability. However, there is currently no treatment to reduce or arrest sensory cell degeneration. There are several classes of treatments for Usher syndrome being investigated. The present article reviews the progress this research has made towards delivering commercial options for patients with Usher syndrome.
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Affiliation(s)
- Lucy S French
- Centre for Ophthalmology and Visual Sciences (incorporating Lions Eye Institute), The University of Western Australia, Nedlands, WA, Australia
| | - Carla B Mellough
- Centre for Ophthalmology and Visual Sciences (incorporating Lions Eye Institute), The University of Western Australia, Nedlands, WA, Australia
| | - Fred K Chen
- Centre for Ophthalmology and Visual Sciences (incorporating Lions Eye Institute), The University of Western Australia, Nedlands, WA, Australia.,Department of Ophthalmology, Royal Perth Hospital, Perth, WA, Australia.,Department of Ophthalmology, Perth Children's Hospital, Nedlands, WA, Australia
| | - Livia S Carvalho
- Centre for Ophthalmology and Visual Sciences (incorporating Lions Eye Institute), The University of Western Australia, Nedlands, WA, Australia
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36
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Kleinlogel S, Vogl C, Jeschke M, Neef J, Moser T. Emerging approaches for restoration of hearing and vision. Physiol Rev 2020; 100:1467-1525. [DOI: 10.1152/physrev.00035.2019] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Impairments of vision and hearing are highly prevalent conditions limiting the quality of life and presenting a major socioeconomic burden. For long, retinal and cochlear disorders have remained intractable for causal therapies, with sensory rehabilitation limited to glasses, hearing aids, and electrical cochlear or retinal implants. Recently, the application of gene therapy and optogenetics to eye and ear has generated hope for a fundamental improvement of vision and hearing restoration. To date, one gene therapy for the restoration of vision has been approved and undergoing clinical trials will broaden its application including gene replacement, genome editing, and regenerative approaches. Moreover, optogenetics, i.e. controlling the activity of cells by light, offers a more general alternative strategy. Over little more than a decade, optogenetic approaches have been developed and applied to better understand the function of biological systems, while protein engineers have identified and designed new opsin variants with desired physiological features. Considering potential clinical applications of optogenetics, the spotlight is on the sensory systems. Multiple efforts have been undertaken to restore lost or hampered function in eye and ear. Optogenetic stimulation promises to overcome fundamental shortcomings of electrical stimulation, namely poor spatial resolution and cellular specificity, and accordingly to deliver more detailed sensory information. This review aims at providing a comprehensive reference on current gene therapeutic and optogenetic research relevant to the restoration of hearing and vision. We will introduce gene-therapeutic approaches and discuss the biotechnological and optoelectronic aspects of optogenetic hearing and vision restoration.
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Affiliation(s)
| | | | | | | | - Tobias Moser
- Institute for Auditory Neuroscience, University Medical Center Goettingen, Germany
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37
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Suzuki T, Morimoto N, Akaike A, Osakada F. Multiplex Neural Circuit Tracing With G-Deleted Rabies Viral Vectors. Front Neural Circuits 2020; 13:77. [PMID: 31998081 PMCID: PMC6967742 DOI: 10.3389/fncir.2019.00077] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 11/14/2019] [Indexed: 12/26/2022] Open
Abstract
Neural circuits interconnect to organize large-scale networks that generate perception, cognition, memory, and behavior. Information in the nervous system is processed both through parallel, independent circuits and through intermixing circuits. Analyzing the interaction between circuits is particularly indispensable for elucidating how the brain functions. Monosynaptic circuit tracing with glycoprotein (G) gene-deleted rabies viral vectors (RVΔG) comprises a powerful approach for studying the structure and function of neural circuits. Pseudotyping of RVΔG with the foreign envelope EnvA permits expression of transgenes such as fluorescent proteins, genetically-encoded sensors, or optogenetic tools in cells expressing TVA, a cognate receptor for EnvA. Trans-complementation with rabies virus glycoproteins (RV-G) enables trans-synaptic labeling of input neurons directly connected to the starter neurons expressing both TVA and RV-G. However, it remains challenging to simultaneously map neuronal connections from multiple cell populations and their interactions between intermixing circuits solely with the EnvA/TVA-mediated RV tracing system in a single animal. To overcome this limitation, here, we multiplexed RVΔG circuit tracing by optimizing distinct viral envelopes (oEnvX) and their corresponding receptors (oTVX). Based on the EnvB/TVB and EnvE/DR46-TVB systems derived from the avian sarcoma leukosis virus (ASLV), we developed optimized TVB receptors with lower or higher affinity (oTVB-L or oTVB-H) and the chimeric envelope oEnvB, as well as an optimized TVE receptor with higher affinity (oTVE-H) and its chimeric envelope oEnvE. We demonstrated independence of RVΔG infection between the oEnvA/oTVA, oEnvB/oTVB, and oEnvE/oTVE systems and in vivo proof-of-concept for multiplex circuit tracing from two distinct classes of layer 5 neurons targeting either other cortical or subcortical areas. We also successfully labeled common input of the lateral geniculate nucleus to both cortico-cortical layer 5 neurons and inhibitory neurons of the mouse V1 with multiplex RVΔG tracing. These oEnvA/oTVA, oEnvB/oTVB, and oEnvE/oTVE systems allow for differential labeling of distinct circuits to uncover the mechanisms underlying parallel processing through independent circuits and integrated processing through interaction between circuits in the brain.
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Affiliation(s)
- Toshiaki Suzuki
- Laboratory of Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Nao Morimoto
- Laboratory of Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan.,Laboratory of Neural Information Processing, Institute for Advanced Research, Nagoya University, Nagoya, Japan
| | - Akinori Akaike
- Laboratory of Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Fumitaka Osakada
- Laboratory of Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan.,Laboratory of Neural Information Processing, Institute for Advanced Research, Nagoya University, Nagoya, Japan.,Institute of Nano-Life-Systems, Institutes of Innovation for Future Society, Nagoya University, Nagoya, Japan.,PRESTO/CREST, Japan Science and Technology Agency, Saitama, Japan
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38
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Tornabene P, Trapani I. Can Adeno-Associated Viral Vectors Deliver Effectively Large Genes? Hum Gene Ther 2020; 31:47-56. [DOI: 10.1089/hum.2019.220] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Patrizia Tornabene
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Medical Genetics, Department of Translational Medicine, Federico II University, Naples, Italy
| | - Ivana Trapani
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Medical Genetics, Department of Translational Medicine, Federico II University, Naples, Italy
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39
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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.
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Rahman N, Georgiou M, Khan KN, Michaelides M. Macular dystrophies: clinical and imaging features, molecular genetics and therapeutic options. Br J Ophthalmol 2019; 104:451-460. [PMID: 31704701 PMCID: PMC7147237 DOI: 10.1136/bjophthalmol-2019-315086] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/24/2019] [Accepted: 10/21/2019] [Indexed: 11/03/2022]
Abstract
Macular dystrophies (MDs) consist of a heterogeneous group of disorders that are characterised by bilateral symmetrical central visual loss. Advances in genetic testing over the last decade have led to improved knowledge of the underlying molecular basis. The developments in high-resolution multimodal retinal imaging have also transformed our ability to make accurate and more timely diagnoses and more sensitive quantitative assessment of disease progression, and allowed the design of optimised clinical trial endpoints for novel therapeutic interventions. The aim of this review was to provide an update on MDs, including Stargardt disease, Best disease, X-linked r etinoschisis, pattern dystrophy, Sorsby fundus dystrophy and autosomal dominant drusen. It highlights the range of innovations in retinal imaging, genotype-phenotype and structure-function associations, animal models of disease and the multiple treatment strategies that are currently in clinical trial or planned in the near future, which are anticipated to lead to significant changes in the management of patients with MDs.
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Affiliation(s)
| | - Michalis Georgiou
- Moorfields Eye Hospital, London, UK.,Institute of Ophthalmology, UCL, London, UK
| | - Kamron N Khan
- Ophthalmology Department, St James's University Hospital, Leeds, UK
| | - Michel Michaelides
- Moorfields Eye Hospital, London, UK .,Institute of Ophthalmology, UCL, London, UK
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41
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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.
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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
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42
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Dyka FM, Molday LL, Chiodo VA, Molday RS, Hauswirth WW. Dual ABCA4-AAV Vector Treatment Reduces Pathogenic Retinal A2E Accumulation in a Mouse Model of Autosomal Recessive Stargardt Disease. Hum Gene Ther 2019; 30:1361-1370. [PMID: 31418294 DOI: 10.1089/hum.2019.132] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Autosomal recessive Stargardt disease is the most common inherited macular degeneration in humans. It is caused by mutations in the retina-specific ATP binding cassette transporter A4 (ABCA4) that is essential for the clearance of all-trans-retinal from photoreceptor cells. Loss of this function results in the accumulation of toxic bisretinoids in the outer segment disk membranes and their subsequent transfer into adjacent retinal pigment epithelium (RPE) cells. This ultimately leads to the Stargardt disease phenotype of increased retinal autofluorescence and progressive RPE and photoreceptor cell loss. Adeno-associated virus (AAV) vectors have been widely used in gene therapeutic applications, but their limited cDNA packaging capacity of ∼4.5 kb has impeded their use for transgenes exceeding this limit. AAV dual vectors were developed to overcome this size restriction. In this study, we have evaluated the in vitro expression of ABCA4 using three options: overlap, transplicing, and hybrid ABCA4 dual vector systems. The hybrid system was the most efficient of these dual vector alternatives and used to express the full-length ABCA4 in Abca4-/- mice. The full-length ABCA4 protein correctly localized to photoreceptor outer segments. Moreover, treatment of Abca4-/- mice with this ABCA4 hybrid dual vector system resulted in a reduced accumulation of the lipofuscin/N-retinylidene-N-retinylethanolamine (A2E) autofluorescence in vivo, and retinal A2E quantification supported these findings. These results show that the hybrid AAV dual vector option is both safe and therapeutic in mice, and the delivered ABCA4 transgene is functional and has a significant effect on reducing A2E accumulation in the Abca4-/- mouse model of Stargardt disease.
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Affiliation(s)
- Frank M Dyka
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
| | - Laurie L Molday
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Vince A Chiodo
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
| | - Robert S Molday
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - William W Hauswirth
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
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43
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Keeler AM, Flotte TR. Recombinant Adeno-Associated Virus Gene Therapy in Light of Luxturna (and Zolgensma and Glybera): Where Are We, and How Did We Get Here? Annu Rev Virol 2019; 6:601-621. [PMID: 31283441 PMCID: PMC7123914 DOI: 10.1146/annurev-virology-092818-015530] [Citation(s) in RCA: 195] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The recent market approvals of recombinant adeno-associated virus (rAAV) gene therapies in Europe and the United States are landmark achievements in the history of modern science. These approvals are also anticipated to herald the emergence of a new class of therapies for monogenic disorders, which had hitherto been considered untreatable. These events can be viewed as stemming from the convergence of several important historical trends: the study of basic virology, the development of genomic technologies, the imperative for translational impact of National Institutes of Health-funded research, and the development of economic models for commercialization of rare disease therapies. In this review, these historical trends are described and the key developments that have enabled clinical rAAV gene therapies are discussed, along with an overview of the current state of the field and future directions.
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Affiliation(s)
- Allison M Keeler
- Horae Gene Therapy Center and Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA;
| | - Terence R Flotte
- Horae Gene Therapy Center and Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA;
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44
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Cideciyan AV, Jacobson SG. Leber Congenital Amaurosis (LCA): Potential for Improvement of Vision. Invest Ophthalmol Vis Sci 2019; 60:1680-1695. [PMID: 31009524 PMCID: PMC6892385 DOI: 10.1167/iovs.19-26672] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Samuel G Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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45
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Trapani I. Adeno-Associated Viral Vectors as a Tool for Large Gene Delivery to the Retina. Genes (Basel) 2019; 10:genes10040287. [PMID: 30970639 PMCID: PMC6523333 DOI: 10.3390/genes10040287] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 03/26/2019] [Accepted: 04/05/2019] [Indexed: 12/26/2022] Open
Abstract
Gene therapy using adeno-associated viral (AAV) vectors currently represents the most promising approach for the treatment of many inherited retinal diseases (IRDs), given AAV's ability to efficiently deliver therapeutic genes to both photoreceptors and retinal pigment epithelium, and their excellent safety and efficacy profiles in humans. However, one of the main obstacles to widespread AAV application is their limited packaging capacity, which precludes their use from the treatment of IRDs which are caused by mutations in genes whose coding sequence exceeds 5 kb. Therefore, in recent years, considerable effort has been made to identify strategies to increase the transfer capacity of AAV vectors. This review will discuss these new developed strategies, highlighting the advancements as well as the limitations that the field has still to overcome to finally expand the applicability of AAV vectors to IRDs due to mutations in large genes.
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Affiliation(s)
- Ivana Trapani
- Telethon Institute of Genetics and Medicine (TIGEM), 80078 Pozzuoli, Italy.
- Medical Genetics, Department of Translational Medicine, Federico II University, 80131 Naples, Italy.
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46
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Askou AL, Alsing S, Benckendorff JNE, Holmgaard A, Mikkelsen JG, Aagaard L, Bek T, Corydon TJ. Suppression of Choroidal Neovascularization by AAV-Based Dual-Acting Antiangiogenic Gene Therapy. MOLECULAR THERAPY. NUCLEIC ACIDS 2019; 16:38-50. [PMID: 30825671 PMCID: PMC6393707 DOI: 10.1016/j.omtn.2019.01.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 01/28/2019] [Accepted: 01/28/2019] [Indexed: 01/15/2023]
Abstract
Vascular endothelial growth factor A (VEGFA) is involved in the pathogenesis of vasoproliferative retinal diseases, such as exudative age-related macular degeneration (AMD). The objective of this study was to investigate whether dual-acting therapy based on the simultaneous expression of anti-VEGFA microRNAs (miRNAs) and the secreted, antiangiogenic protein pigment endothelial-derived factor (PEDF) delivered by adeno-associated virus (AAV) vectors provides improved protection against choroidal neovascularization (CNV). To investigate this, a multigenic AAV vector allowing retina pigment epithelium (RPE)-specific expression of anti-VEGFA miRNAs and PEDF was engineered. Robust expression of PEDF, driven by the RPE-specific vitelliform macular dystrophy 2 promoter, was observed in human cells and in mouse retina. A significant reduction in CNV was observed in a laser-induced CNV mouse model 57 days post-injection of the AAV5 particles conveying either anti-VEGFA miRNA and PEDF dual therapy or anti-VEGFA miRNA monotherapy. Overall, CNV reduction was most prominent in animals receiving dual-acting therapy. In both cases, the reduction in CNV was accompanied by a significant attenuation of VEGFA. In conclusion, the presented data reveal that gene therapy targeting VEGFA via multigenic AAV vectors displays combined efficacy, suggesting that dual-acting therapy is an important tool in future eye gene therapy for the treatment of neovascular ocular diseases, including AMD.
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Affiliation(s)
- Anne Louise Askou
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark
| | - Sidsel Alsing
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark
| | | | - Andreas Holmgaard
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark
| | | | - Lars Aagaard
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark
| | - Toke Bek
- Department of Ophthalmology, Aarhus University Hospital, 8000 Aarhus C, Denmark
| | - Thomas J Corydon
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark; Department of Ophthalmology, Aarhus University Hospital, 8000 Aarhus C, Denmark.
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47
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Identification of novel pathogenic ABCA4 variants in a Han Chinese family with Stargardt disease. Biosci Rep 2019; 39:BSR20180872. [PMID: 30563929 PMCID: PMC6331664 DOI: 10.1042/bsr20180872] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 12/05/2018] [Accepted: 12/11/2018] [Indexed: 12/16/2022] Open
Abstract
Stargardt disease (STGD1, OMIM 248200) is a common hereditary juvenile or early adult onset macular degeneration. It ultimately leads to progressive central vision loss. Here, we sought to identify gene mutations associated with STGD1 in a three-generation Han Chinese pedigree by whole exome sequencing and Sanger sequencing. Two novel potentially pathogenic variants in a compound heterozygous state, c.3607G>T (p.(Gly1203Trp)) and c.6722T>C (p.(Leu2241Pro)), in the ATP binding cassette subfamily A member 4 gene (ABCA4) were identified as contributing to the family’s STGD1 phenotype. These variants may impact the ABCA4 protein structure and reduce the retinal-activated ATPase activity, leading to abnormal all-trans retinal accumulation in photoreceptor outer segments and in retinal pigment epithelium cells. The present study broadens the mutational spectrum of the ABCA4 responsible for STGD1. A combination of whole exome sequencing and Sanger sequencing is likely to be a time-saving and cost-efficient approach to screen pathogenic variants in genetic disorders caused by sizable genes, as well as avoiding misdiagnosis. These results perhaps refine genetic counseling and ABCA4-targetted treatments for families affected by STGD1.
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48
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Abstract
Adeno-associated virus (AAV)-mediated gene therapy has evolved from bench to bedside, and now is the therapy of choice for certain inherited diseases. However, the small packaging capacity of AAV vectors prevents this technique from treating genetic diseases with mutations of large genes. Multiple strategies, including split AAV gene delivery and oversized AAV gene delivery, have been explored to deliver large gene expression cassettes. These strategies have gained some success in animal experiments. In this chapter, we review the progress of AAV-mediated delivery of large expression cassettes. We also review using AAV to deliver multiple transgenes.
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Affiliation(s)
- Aman Patel
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Junling Zhao
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, USA
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
- Department of Neurology, School of Medicine, University of Missouri, Columbia, MO, USA
- Department of Bioengineering, University of Missouri, Columbia, MO, USA
| | - Yi Lai
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, USA.
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49
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50
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Mühlfriedel R, Michalakis S, Garrido MG, Sothilingam V, Schön C, Biel M, Seeliger MW. Optimized Subretinal Injection Technique for Gene Therapy Approaches. Methods Mol Biol 2019; 1834:405-412. [PMID: 30324458 DOI: 10.1007/978-1-4939-8669-9_26] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Gene therapy for inherited eye diseases requires local viral vector delivery by intraocular injection. Since large animal models are lacking for most of these diseases, genetically modified mouse models are commonly used in preclinical proof-of-concept studies. However, because of the relatively small mouse eye, adverse effects of the subretinal delivery procedure itself may interfere with the therapeutic outcome. The method described here aims to provide the details relevant to perform a transscleral pars plana virus-mediated gene transfer to achieve an optimized therapeutic effect in the small mouse eye.
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Affiliation(s)
- Regine Mühlfriedel
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls Universität Tübingen, Tübingen, Germany.
| | - Stylianos Michalakis
- Department of Pharmacy-Center for Drug Research, Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Marina Garcia Garrido
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Vithiyanjali Sothilingam
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Christian Schön
- Department of Pharmacy-Center for Drug Research, Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Martin Biel
- Department of Pharmacy-Center for Drug Research, Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Mathias W Seeliger
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls Universität Tübingen, Tübingen, Germany
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