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van der Veen I, Heredero Berzal A, Koster C, ten Asbroek ALMA, Bergen AA, Boon CJF. The Road towards Gene Therapy for X-Linked Juvenile Retinoschisis: A Systematic Review of Preclinical Gene Therapy in Cell-Based and Rodent Models of XLRS. Int J Mol Sci 2024; 25:1267. [PMID: 38279267 PMCID: PMC10816913 DOI: 10.3390/ijms25021267] [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: 12/22/2023] [Revised: 01/12/2024] [Accepted: 01/17/2024] [Indexed: 01/28/2024] Open
Abstract
X-linked juvenile retinoschisis (XLRS) is an early-onset progressive inherited retinopathy affecting males. It is characterized by abnormalities in the macula, with formation of cystoid retinal cavities, frequently accompanied by splitting of the retinal layers, impaired synaptic transmission of visual signals, and associated loss of visual acuity. XLRS is caused by loss-of-function mutations in the retinoschisin gene located on the X chromosome (RS1, MIM 30083). While proof-of-concept studies for gene augmentation therapy have been promising in in vitro and rodent models, clinical trials in XLRS patients have not been successful thus far. We performed a systematic literature investigation using search strings related to XLRS and gene therapy in in vivo and in vitro models. Three rounds of screening (title/abstract, full text and qualitative) were performed by two independent reviewers until consensus was reached. Characteristics related to study design and intervention were extracted from all studies. Results were divided into studies using (1) viral and (2) non-viral therapies. All in vivo rodent studies that used viral vectors were assessed for quality and risk of bias using the SYRCLE's risk-of-bias tool. Studies using alternative and non-viral delivery techniques, either in vivo or in vitro, were extracted and reviewed qualitatively, given the diverse and dispersed nature of the information. For in-depth analysis of in vivo studies using viral vectors, outcome data for optical coherence tomography (OCT), immunohistopathology and electroretinography (ERG) were extracted. Meta-analyses were performed on the effect of recombinant adeno-associated viral vector (AAV)-mediated gene augmentation therapies on a- and b-wave amplitude as well as the ratio between b- and a-wave amplitudes (b/a-ratio) extracted from ERG data. Subgroup analyses and meta-regression were performed for model, dose, age at injection, follow-up time point and delivery method. Between-study heterogeneity was assessed with a Chi-square test of homogeneity (I2). We identified 25 studies that target RS1 and met our search string. A total of 19 of these studies reported rodent viral methods in vivo. Six of the 25 studies used non-viral or alternative delivery methods, either in vitro or in vivo. Of these, five studies described non-viral methods and one study described an alternative delivery method. The 19 aforementioned in vivo studies were assessed for risk of bias and quality assessments and showed inconsistency in reporting. This resulted in an unclear risk of bias in most included studies. All 19 studies used AAVs to deliver intact human or murine RS1 in rodent models for XLRS. Meta-analyses of a-wave amplitude, b-wave amplitude, and b/a-ratio showed that, overall, AAV-mediated gene augmentation therapy significantly ameliorated the disease phenotype on these parameters. Subgroup analyses and meta-regression showed significant correlations between b-wave amplitude effect size and dose, although between-study heterogeneity was high. This systematic review reiterates the high potential for gene therapy in XLRS, while highlighting the importance of careful preclinical study design and reporting. The establishment of a systematic approach in these studies is essential to effectively translate this knowledge into novel and improved treatment alternatives.
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Affiliation(s)
- Isa van der Veen
- Department of Ophthalmology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (I.v.d.V.); (A.H.B.); (C.K.); (A.A.B.)
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands;
| | - Andrea Heredero Berzal
- Department of Ophthalmology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (I.v.d.V.); (A.H.B.); (C.K.); (A.A.B.)
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands;
| | - Céline Koster
- Department of Ophthalmology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (I.v.d.V.); (A.H.B.); (C.K.); (A.A.B.)
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands;
| | - Anneloor L. M. A. ten Asbroek
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands;
| | - Arthur A. Bergen
- Department of Ophthalmology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (I.v.d.V.); (A.H.B.); (C.K.); (A.A.B.)
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands;
| | - Camiel J. F. Boon
- Department of Ophthalmology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (I.v.d.V.); (A.H.B.); (C.K.); (A.A.B.)
- Department of Ophthalmology, Leiden University Medical Center, Leiden University, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
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Mirjalili Mohanna SZ, Korecki AJ, Simpson EM. rAAV-PHP.B escapes the mouse eye and causes lethality whereas rAAV9 can transduce aniridic corneal limbal stem cells without lethality. Gene Ther 2023; 30:670-684. [PMID: 37072572 PMCID: PMC10506911 DOI: 10.1038/s41434-023-00400-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/28/2023] [Accepted: 04/05/2023] [Indexed: 04/20/2023]
Abstract
Recently safety concerns have been raised in connection with high doses of recombinant adeno-associated viruses (rAAV). Therefore, we undertook a series of experiments to test viral capsid (rAAV9 and rAAV-PHP.B), dose, and route of administration (intrastromal, intravitreal, and intravenous) focused on aniridia, a congenital blindness that currently has no cure. The success of gene therapy for aniridia may depend on the presence of functional limbal stem cells (LSCs) in the damaged aniridic corneas and whether rAAV can transduce them. Both these concerns were unknown, and thus were also addressed by our studies. For the first time, we report ataxia and lethality after intravitreal or intrastromal rAAV-PHP.B virus injections. We demonstrated virus escape from the eye and transduction of non-ocular tissues by rAAV9 and rAAV-PHP.B capsids. We have also shown that intrastromal and intravitreal delivery of rAAV9 can transduce functional LSCs, as well as all four PAX6-expressing retinal cell types in aniridic eye, respectively. Overall, lack of adverse events and successful transduction of LSCs and retinal cells makes it clear that rAAV9 is the capsid of choice for future aniridia gene therapy. Our finding of rAAV lethality after intraocular injections will be impactful for other researchers developing rAAV-based gene therapies.
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Affiliation(s)
- Seyedeh Zeinab Mirjalili Mohanna
- Centre for Molecular Medicine and Therapeutics at British Columbia Children's Hospital, The University of British Columbia, Vancouver, BC, Canada
- Department of Medical Genetics, The University of British Columbia, Vancouver, BC, Canada
| | - Andrea J Korecki
- Centre for Molecular Medicine and Therapeutics at British Columbia Children's Hospital, The University of British Columbia, Vancouver, BC, Canada
| | - Elizabeth M Simpson
- Centre for Molecular Medicine and Therapeutics at British Columbia Children's Hospital, The University of British Columbia, Vancouver, BC, Canada.
- Department of Medical Genetics, The University of British Columbia, Vancouver, BC, Canada.
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Ku CA, Wei LW, Sieving PA. X-Linked Retinoschisis. Cold Spring Harb Perspect Med 2023; 13:a041288. [PMID: 36690462 PMCID: PMC10513161 DOI: 10.1101/cshperspect.a041288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
X-linked retinoschisis (XLRS) is an inherited vitreoretinal dystrophy causing visual impairment in males starting at a young age with an estimated prevalence of 1:5000 to 1:25,000. The condition was first observed in two affected brothers by Josef Haas in 1898 and is clinically diagnosed by characteristic intraretinal cysts arranged in a petaloid "spoke-wheel" pattern centered in the macula. When clinical electroretinogram (ERG) testing began in the 1960s, XLRS was noted to have a characteristic reduction of the dark-adapted b-wave amplitude despite normal or usually nearly normal a-wave amplitudes, which became known as the "electronegative ERG response" of XLRS disease. The causative gene, RS1, was identified on the X-chromosome in 1997 and led to understanding the molecular and cellular basis of the condition, discerning the structure and function of the retinoschisin protein, and generating XLRS murine models. Along with parallel development of gene delivery vectors suitable for targeting retinal diseases, successful gene augmentation therapy was demonstrated by rescuing the XLRS phenotype in mouse. Two human phase I/II therapeutic XLRS gene augmentation studies were initiated; and although these did not yield definitive improvement in visual function, they gave significant new knowledge and experience, which positions the field for further near-term clinical testing with enhanced, next-generation gene therapy for XLRS patients.
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Affiliation(s)
- Cristy A Ku
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, California 95817, USA
| | - Lisa W Wei
- National Institutes of Health, National Institute of Allergy and Infectious Diseases, NIH Office of Biodefense, Research Resources and Translational Research/Vaccine Section, Bethesda, Maryland 20892, USA
| | - Paul A Sieving
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, California 95817, USA
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Pineda-Garrido E, Ruiz-Guijosa A, Valverde-Megías A, Domingo-Gordo B. X-linked retinoschisis: About a case. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2022; 97:705-708. [PMID: 36341910 DOI: 10.1016/j.oftale.2022.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
X-linked retinoschisis (XLR) is a cause of retinal degeneration that affects males at an early age. X-linked disorders classically affect only males. We present the case of a 10-year-old female with the full spectrum of the pathology. BCVA 0.7 OU. Optical coherence tomography (OCT) showed bilateral foveal alteration with cystic appearance. The genetic study identified the variant c.644A>T (p.Glu215Gly) in the RS1 gene in homozygosis, associated with retinoschisis with X-linked recessive mode of inheritance. XLR is a condition that has a great variety in the severity of the disease and there is no correlation between the latter and the progression of the pathology. The disease has been described in a limited number of females mainly in families with high degree of consanguinity.
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Affiliation(s)
- E Pineda-Garrido
- Servicio de Oftalmología, Hospital Clínico San Carlos, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain.
| | - A Ruiz-Guijosa
- Servicio de Oftalmología, Hospital Clínico San Carlos, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain
| | - A Valverde-Megías
- Unidad de Retina, Servicio de Oftalmología, Hospital Clínico San Carlos, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain
| | - B Domingo-Gordo
- Unidad de Motilidad Ocular, Servicio de Oftalmología, Hospital Clínico San Carlos, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain
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Amato A, Arrigo A, Aragona E, Manitto MP, Saladino A, Bandello F, Battaglia Parodi M. Gene Therapy in Inherited Retinal Diseases: An Update on Current State of the Art. Front Med (Lausanne) 2021; 8:750586. [PMID: 34722588 PMCID: PMC8553993 DOI: 10.3389/fmed.2021.750586] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/20/2021] [Indexed: 12/11/2022] Open
Abstract
Background: Gene therapy cannot be yet considered a far perspective, but a tangible therapeutic option in the field of retinal diseases. Although still confined in experimental settings, the preliminary results are promising and provide an overall scenario suggesting that we are not so far from the application of gene therapy in clinical settings. The main aim of this review is to provide a complete and updated overview of the current state of the art and of the future perspectives of gene therapy applied on retinal diseases. Methods: We carefully revised the entire literature to report all the relevant findings related to the experimental procedures and the future scenarios of gene therapy applied in retinal diseases. A clinical background and a detailed description of the genetic features of each retinal disease included are also reported. Results: The current literature strongly support the hope of gene therapy options developed for retinal diseases. Although being considered in advanced stages of investigation for some retinal diseases, such as choroideremia (CHM), retinitis pigmentosa (RP), and Leber's congenital amaurosis (LCA), gene therapy is still quite far from a tangible application in clinical practice for other retinal diseases. Conclusions: Gene therapy is an extremely promising therapeutic tool for retinal diseases. The experimental data reported in this review offer a strong hope that gene therapy will be effectively available in clinical practice in the next years.
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Affiliation(s)
- Alessia Amato
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Alessandro Arrigo
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Emanuela Aragona
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Maria Pia Manitto
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Andrea Saladino
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Francesco Bandello
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
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Zeng Y, Qian H, Campos MM, Li Y, Vijayasarathy C, Sieving PA. Rs1h -/y exon 3-del rat model of X-linked retinoschisis with early onset and rapid phenotype is rescued by RS1 supplementation. Gene Ther 2021; 29:431-440. [PMID: 34548657 PMCID: PMC8938309 DOI: 10.1038/s41434-021-00290-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/03/2021] [Accepted: 08/18/2021] [Indexed: 12/27/2022]
Abstract
Animal models of X-linked juvenile retinoschisis (XLRS) are valuable tools for understanding basic biochemical function of retinoschisin (RS1) protein and to investigate outcomes of preclinical efficacy and toxicity studies. In order to work with an eye larger than mouse, we generated and characterized an Rs1h−/y knockout rat model created by removing exon 3. This rat model expresses no normal RS1 protein. The model shares features of an early onset and more severe phenotype of human XLRS. The morphologic pathology includes schisis cavities at postnatal day 15 (p15), photoreceptors that are misplaced into the subretinal space and OPL, and a reduction of photoreceptor cell numbers by p21. By 6 mo age only 1–3 rows of photoreceptors nuclei remain, and the inner/outer segment layers and the OPL shows major changes. Electroretinogram recordings show functional loss with considerable reduction of both the a-wave and b-wave by p28, indicating early age loss and dysfunction of photoreceptors. The ratio of b-/a-wave amplitudes indicates impaired synaptic transmission to bipolar cells in addition. Supplementing the Rs1h−/y exon3-del retina with normal human RS1 protein using AAV8-RS1 delivery improved the retinal structure. This Rs1h−/y rat model provides a further tool to explore underlying mechanisms of XLRS pathology and to evaluate therapeutic intervention for the XLRS condition.
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Affiliation(s)
- Yong Zeng
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Haohua Qian
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | | | - Yichao Li
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | | | - Paul A Sieving
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA. .,Department of Ophthalmology, University of California Davis, Sacramento, CA, USA. .,Center for Ocular Regenerative Therapy, Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA, USA.
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Vijaysarathy C, Babu Sardar Pasha SP, Sieving PA. Of men and mice: Human X-linked retinoschisis and fidelity in mouse modeling. Prog Retin Eye Res 2021; 87:100999. [PMID: 34390869 DOI: 10.1016/j.preteyeres.2021.100999] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/02/2021] [Accepted: 08/06/2021] [Indexed: 02/07/2023]
Abstract
X-linked Retinoschisis (XLRS) is an early-onset transretinal dystrophy, often with a prominent macular component, that affects males and generally spares heterozygous females because of X-linked recessive inheritance. It results from loss-of-function RS1 gene mutations on the X-chromosome. XLRS causes bilateral reduced acuities from young age, and on clinical exam and by ocular coherence tomography (OCT) the neurosensory retina shows foveo-macular cystic schisis cavities in the outer plexiform (OPL) and inner nuclear layers (INL). XLRS manifests between infancy and school-age with variable phenotypic presentation and without reliable genotype-phenotype correlations. INL disorganization disrupts synaptic signal transmission from photoreceptors to ON-bipolar cells, and this reduces the electroretinogram (ERG) bipolar b-wave disproportionately to photoreceptor a-wave changes. RS1 gene expression is localized mainly to photoreceptors and INL bipolar neurons, and RS1 protein is thought to play a critical cell adhesion role during normal retinal development and later for maintenance of retinal structure. Several independent XLRS mouse models with mutant RS1 were created that recapitulate features of human XLRS disease, with OPL-INL schisis cavities, early onset and variable phenotype across mutant models, and reduced ERG b-wave to a-wave amplitude ratio. The faithful phenotype of the XLRS mouse has assisted in delineating the disease pathophysiology. Delivery to XLRS mouse retina of an AAV8-RS1 construct under control of the RS1 promoter restores the retinal structure and synaptic function (with increase of b-wave amplitude). It also ameliorates the schisis-induced inflammatory microglia phenotype toward a state of immune quiescence. The results imply that XLRS gene therapy could yield therapeutic benefit to preserve morphological and functional retina particularly when intervention is conducted at earlier ages before retinal degeneration becomes irreversible. A phase I/IIa single-center, open-label, three-dose-escalation clinical trial reported a suitable safety and tolerability profile of intravitreally administered AAV8-RS1 gene replacement therapy for XLRS participants. Dose-related ocular inflammation occurred after dosing, but this resolved with topical and oral corticosteroids. Systemic antibodies against AAV8 increased in dose-dependent fashion, but no antibodies were observed against the RS1 protein. Retinal cavities closed transiently in one participant. Technological innovations in methods of gene delivery and strategies to further reduce immune responses are expected to enhance the therapeutic efficacy of the vector and ultimate success of a gene therapy approach.
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Affiliation(s)
| | | | - Paul A Sieving
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, 20892, USA; Department of Ophthalmology, University of California Davis, 95817, USA.
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Wang W, Liu J, Yang M, Qiu R, Li Y, Bian S, Hao B, Lei B. Intravitreal Injection of an Exosome-Associated Adeno-Associated Viral Vector Enhances Retinoschisin 1 Gene Transduction in the Mouse Retina. Hum Gene Ther 2021; 32:707-716. [PMID: 33832349 DOI: 10.1089/hum.2020.328] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
To investigate whether exosome-associated adeno-associated virus (AAV) retinoschisin 1 (RS1) vector improved the transduction efficiency of RS1 in the mouse retina. pAAV2-RS1-ZsGreen plasmid was constructed by homologous recombination. Exosome-associated AAV vectors containing human RS1 gene (exosome-associated AAV [exo-AAV]2-RS1-ZsGreen) were isolated from producer cells' supernatant, and confirmed by transmission electron microscopy, nanoparticle tracking analysis, and western blotting. In vitro, HEK-293T cells were transduced with AAV2-RS1-ZsGreen and exo-AAV2-RS1-ZsGreen. In vivo, 1 μL of AAV2-RS1-ZsGreen or 1 μL exo-AAV2-RS1-ZsGreen (2 × 108 genome copies/μL) was injected intravitreally into the C57BL/6J mouse eyes. Phosphate buffer saline was injected as controls. The mRNA and the protein expression in the retina were detected. Exo-AAV2-RS1-ZsGreen possessed lipid bilayers, a saucer-like structures and an average of 120 nm particle size. The expression of RS1 and ZsGreen in exo-AAV2-RS1-ZsGreen group were 7.6 times and 5.7 times that of AAV2-RS1-ZsGreen group in HEK-293T cells, respectively. Furthermore, RS1 protein expression increased by 11.8 times in HEK-293T cells. Intravitreal injection of exo-AAV significantly increased the transduction efficiency of RS1 than AAV. Exo-AAV may be a powerful gene delivery system for gene therapy of X-link retinoschisis as well as other inherited retina degenerations.
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Affiliation(s)
- Weiping Wang
- Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, China
| | - Jingyang Liu
- Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, China
| | - Mingzhu Yang
- Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, China
| | - Ruiqi Qiu
- Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, China
| | - Ya Li
- Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, China
| | - Shasha Bian
- Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, China
| | - Bingtao Hao
- Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, China
| | - Bo Lei
- Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, China
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Vijayasarathy C, Zeng Y, Brooks MJ, Fariss RN, Sieving PA. Genetic Rescue of X-Linked Retinoschisis Mouse ( Rs1-/y) Retina Induces Quiescence of the Retinal Microglial Inflammatory State Following AAV8- RS1 Gene Transfer and Identifies Gene Networks Underlying Retinal Recovery. Hum Gene Ther 2020; 32:667-681. [PMID: 33019822 PMCID: PMC8312029 DOI: 10.1089/hum.2020.213] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
To understand RS1 gene interaction networks in the X-linked retinoschisis (XLRS) mouse retina (Rs1-/y), we analyzed the transcriptome by RNA sequencing before and after in vivo expression of exogenous retinoschisin (RS1) gene delivered by AAV8. RS1 is a secreted cell adhesion protein that is critical for maintaining structural lamination and synaptic integrity of the neural retina. RS1 loss-of-function mutations cause XLRS disease in young boys and men, with splitting ("schisis") of retinal layers and synaptic dysfunction that cause progressive vision loss with age. Analysis of differential gene expression profiles and pathway enrichment analysis of Rs1-KO (Rs1-/y) retina identified cell surface receptor signaling and positive regulation of cell adhesion as potential RS1 gene interaction networks. Most importantly, it also showed massive dysregulation of immune response genes at early age, with characteristics of a microglia-driven proinflammatory state. Delivery of AAV8-RS1 primed the Rs1-KO retina toward structural and functional recovery. The disease transcriptome transitioned toward a recovery phase with upregulation of genes implicated in wound healing, anatomical structure (camera type eye) development, metabolic pathways, and collagen IV networks that provide mechanical stability to basement membrane. AAV8-RS1 expression also attenuated the microglia gene signatures to low levels toward immune quiescence. This study is among the first to identify RS1 gene interaction networks that underlie retinal structural and functional recovery after RS1 gene therapy. Significantly, it also shows that providing wild-type RS1 gene function caused the retina immune status to transition from a degenerative inflammatory phenotype toward immune quiescence, even though the transgene is not directly linked to microglia function. This study indicates that inhibition of microglial proinflammatory responses is an integral part of therapeutic rescue in XLRS gene therapy, and gene therapy might realize its full potential if delivered before microglia activation and photoreceptor cell death. Clinical Trials. gov Identifier NTC 02317887.
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Affiliation(s)
| | - Yong Zeng
- Section for Translational Research in Retinal and Macular Degeneration
| | | | - Robert N Fariss
- Biological Imaging Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Paul A Sieving
- Department of Ophthalmology, Center for Ocular Regenerative Therapy, School of Medicine, University of California at Davis, Sacramento, CA, USA
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Song H, Zeng Y, Sardar Pasha SPB, Bush RA, Vijayasarathy C, Qian H, Wei L, Wiley HE, Wu Z, Sieving PA. Trans-Ocular Electric Current In Vivo Enhances AAV-Mediated Retinal Transduction in Large Animal Eye After Intravitreal Vector Administration. Transl Vis Sci Technol 2020; 9:28. [PMID: 32844051 PMCID: PMC7416894 DOI: 10.1167/tvst.9.7.28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 05/06/2020] [Indexed: 01/25/2023] Open
Abstract
Purpose Electric micro-current has been shown to enhance penetration and transduction of adeno-associated viral (AAV) vectors in mouse retina after intravitreal administration. We termed this: “electric-current vector mobility (ECVM).” The present study considered whether ECVM could augment retinal transduction efficiency of intravitreal AAV8-CMV-EGFP in normal rabbit and nonhuman primate (NHP) macaque. Potential mechanisms underlying enhanced retinal transduction by ECVM were also studied. Methods We applied an electric micro-current across the intact eye of normal rabbit and monkey in vivo for a brief period immediately after intravitreal injection of AAV8-CMV-EGFP. Retinal GFP expression was evaluated by fundus imaging in vivo. Retinal immunohistochemistry was performed to assess the distribution of retinal cells transduced by the AAV8-EGFP. Basic fibroblast growth factor (bFGF) was analyzed by quantitative RT-polymerase chain reaction (PCR). Müller glial reactivity and inner limiting membrane (ILM) were examined by the glial fibrillary acidic protein (GFAP) and vimentin staining in mouse retina, respectively. Results ECVM significantly increased the efficiency of AAV reaching and transducing the rabbit retina following intravitreal injection, with gene expression in inner nuclear layer, ganglion cells, and Müller cells. Similar trend of improvement was observed in the ECVM-treated monkey eye. The electric micro-current upregulated bFGF expression in Müller cells and vimentin showed ILM structural changes in mouse retina. Conclusions ECVM promotes the transduction efficiency of AAV8-CMV-GFP in normal rabbit and monkey retinas following intravitreal injection. Translational Relevance This work has potential translational relevance to human ocular gene therapy by increasing retinal expression of therapeutic vectors given by intravitreal administration.
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Affiliation(s)
- Hongman Song
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yong Zeng
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | | | - Ronald A Bush
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Camasamudram Vijayasarathy
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Haohua Qian
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Lisa Wei
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Henry E Wiley
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Zhijian Wu
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Paul A Sieving
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA.,Department of Ophthalmology, School of Medicine, University of California at Davis, Sacramento, CA, USA
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12
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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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13
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Huang KC, Wang ML, Chen SJ, Kuo JC, Wang WJ, Nhi Nguyen PN, Wahlin KJ, Lu JF, Tran AA, Shi M, Chien Y, Yarmishyn AA, Tsai PH, Yang TC, Jane WN, Chang CC, Peng CH, Schlaeger TM, Chiou SH. Morphological and Molecular Defects in Human Three-Dimensional Retinal Organoid Model of X-Linked Juvenile Retinoschisis. Stem Cell Reports 2019; 13:906-923. [PMID: 31668851 PMCID: PMC6895767 DOI: 10.1016/j.stemcr.2019.09.010] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/25/2019] [Accepted: 09/26/2019] [Indexed: 12/24/2022] Open
Abstract
X-linked juvenile retinoschisis (XLRS), linked to mutations in the RS1 gene, is a degenerative retinopathy with a retinal splitting phenotype. We generated human induced pluripotent stem cells (hiPSCs) from patients to study XLRS in a 3D retinal organoid in vitro differentiation system. This model recapitulates key features of XLRS including retinal splitting, defective retinoschisin production, outer-segment defects, abnormal paxillin turnover, and impaired ER-Golgi transportation. RS1 mutation also affects the development of photoreceptor sensory cilia and results in altered expression of other retinopathy-associated genes. CRISPR/Cas9 correction of the disease-associated C625T mutation normalizes the splitting phenotype, outer-segment defects, paxillin dynamics, ciliary marker expression, and transcriptome profiles. Likewise, mutating RS1 in control hiPSCs produces the disease-associated phenotypes. Finally, we show that the C625T mutation can be repaired precisely and efficiently using a base-editing approach. Taken together, our data establish 3D organoids as a valid disease model. hiPSC-derived retinal organoid model recapitulates key features of XLRS CRISPR/Cas9 correction normalizes RS1 secretion and retinal development Transcriptome analysis links XLRS to other hereditary retinopathies
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Affiliation(s)
- Kang-Chieh Huang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; Institute of Pharmacology, National Yang-Ming University, Taipei 11221, Taiwan; Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Mong-Lien Wang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; Institute of Pharmacology, National Yang-Ming University, Taipei 11221, Taiwan; School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan; Institute of Food Safety and Health Risk Assessment, National Yang-Ming University, Taipei 11221, Taiwan
| | - Shih-Jen Chen
- School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan; Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Jean-Cheng Kuo
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 11221, Taiwan; Cancer Progression Research Center, National Yang-Ming University, Taipei 11221, Taiwan
| | - Won-Jing Wang
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 11221, Taiwan
| | - Phan Nguyen Nhi Nguyen
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; Institute of Pharmacology, National Yang-Ming University, Taipei 11221, Taiwan
| | - Karl J Wahlin
- Shiley Eye Institute, University of California San Diego, La Jolla, CA 92093, USA
| | - Jyh-Feng Lu
- School of Medicine, Fu-Jen Catholic University, New Taipei City 24205, Taiwan
| | - Audrey A Tran
- Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital and Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Michael Shi
- Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital and Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Yueh Chien
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | | | - Ping-Hsing Tsai
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; Institute of Pharmacology, National Yang-Ming University, Taipei 11221, Taiwan
| | - Tien-Chun Yang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; Institute of Pharmacology, National Yang-Ming University, Taipei 11221, Taiwan
| | - Wann-Neng Jane
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Chia-Ching Chang
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 300, Taiwan
| | - Chi-Hsien Peng
- Department of Ophthalmology, Shin Kong Wu Ho-Su Memorial Hospital & Fu-Jen Catholic University, Taipei 11101, Taiwan
| | - Thorsten M Schlaeger
- Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital and Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA.
| | - Shih-Hwa Chiou
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; Institute of Pharmacology, National Yang-Ming University, Taipei 11221, Taiwan; School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan; Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan; Genomic Research Center, Academia Sinica, Taipei 11529, Taiwan.
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14
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Wide-Field Swept-Source OCT and Angiography in X-Linked Retinoschisis. ACTA ACUST UNITED AC 2019; 3:178-185. [DOI: 10.1016/j.oret.2018.09.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/28/2018] [Accepted: 09/10/2018] [Indexed: 11/17/2022]
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15
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Affiliation(s)
- Joan W Miller
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Grousbeck Gene Therapy Center, Ocular Genomics Institute, Massachusetts Eye and Ear, Boston, MA, USA; Berman-Gund Laboratory for Retinal Degeneration, Massachusetts Eye and Ear, Boston, MA, USA.
| | - Luk H Vandenberghe
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Grousbeck Gene Therapy Center, Ocular Genomics Institute, Massachusetts Eye and Ear, Boston, MA, USA; Berman-Gund Laboratory for Retinal Degeneration, Massachusetts Eye and Ear, Boston, MA, USA; The Broad Institute of Harvard and MIT, Cambridge, MA, USA.
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16
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Retinal AAV8-RS1 Gene Therapy for X-Linked Retinoschisis: Initial Findings from a Phase I/IIa Trial by Intravitreal Delivery. Mol Ther 2018; 26:2282-2294. [PMID: 30196853 DOI: 10.1016/j.ymthe.2018.05.025] [Citation(s) in RCA: 149] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/25/2018] [Accepted: 05/31/2018] [Indexed: 01/15/2023] Open
Abstract
This study evaluated the safety and tolerability of ocular RS1 adeno-associated virus (AAV8-RS1) gene augmentation therapy to the retina of participants with X-linked retinoschisis (XLRS). XLRS is a monogenic trait affecting only males, caused by mutations in the RS1 gene. Retinoschisin protein is secreted principally in the outer retina, and its absence results in retinal cavities, synaptic dysfunction, reduced visual acuity, and susceptibility to retinal detachment. This phase I/IIa single-center, prospective, open-label, three-dose-escalation clinical trial administered vector to nine participants with pathogenic RS1 mutations. The eye of each participant with worse acuity (≤63 letters; Snellen 20/63) received the AAV8-RS1 gene vector by intravitreal injection. Three participants were assigned to each of three dosage groups: 1e9 vector genomes (vg)/eye, 1e10 vg/eye, and 1e11 vg/eye. The investigational product was generally well tolerated in all but one individual. Ocular events included dose-related inflammation that resolved with topical and oral corticosteroids. Systemic antibodies against AAV8 increased in a dose-related fashion, but no antibodies against RS1 were observed. Retinal cavities closed transiently in one participant. Additional doses and immunosuppressive regimens are being explored to pursue evidence of safety and efficacy (ClinicalTrials.gov: NCT02317887).
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17
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Bakall B, Klein KA, Hariprasad SM. Emerging Gene Therapy Treatments for Inherited Retinal Diseases. Ophthalmic Surg Lasers Imaging Retina 2018; 49:472-478. [DOI: 10.3928/23258160-20180628-02] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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18
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Tokuda K, Baron B, Kuramitsu Y, Kitagawa T, Tokuda N, Morishige N, Kobayashi M, Kimura K, Nakamura K, Sonoda KH. Optimization of fixative solution for retinal morphology: a comparison with Davidson's fixative and other fixation solutions. Jpn J Ophthalmol 2018; 62:481-490. [PMID: 29691783 DOI: 10.1007/s10384-018-0592-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 04/02/2018] [Indexed: 11/26/2022]
Abstract
PURPOSE Numerous fixative solutions are available but many are not amenable to the histomorphological preservation of retinae. The investigators specifically focused on retinal histological studies, which rather than 4% formaldehyde (FA), often use Davidson's fixative. However the latter has its limitations. The purpose of this study was to produce a new fixative which maintains retinae closer to the in vivo conditions. STUDY DESIGN Experimental design. METHODS Four fixative formulations (4% paraformaldehyde, Davidson's fixative, modified Davidson's fixative and an in-house fixative - TB-Fix) were tested on retinae and the outcomes on histomorphology and immunohistochemical staining for selected antigenic markers was compared. RESULTS TB-Fix markedly improved morphological detail following hematoxylin and eosin staining, most importantly eliminating the spongiform appearance in the plexiform layer and the swelling of somata (including Müller cells), when compared to FA, Davidson's fixative and its modified version. Retinal samples fixed with TB-Fix or FA showed comparable results in immunohistological staining for neurons and glia in the retina. Importantly, while the whole eye fixed with FA collapsed in shape and induced artificial retinal detachment, the eye fixed with TB-Fix avoided deformation and detachment. Furthermore, we found that TB-Fix also prevented detachment from the culture plate when used to fix HEK293 cells, which are known to detach from the plate easily. CONCLUSION It was demonstrated that TB-Fix provides an overall improvement in the preservation of retinal morphology and chemical composition.
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Affiliation(s)
- Kazuhiro Tokuda
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan.
- Department of Systems Biochemistry in Pathology and Regeneration, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan.
| | - Byron Baron
- Department of Systems Biochemistry in Pathology and Regeneration, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
- Faculty of Medicine and Surgery, Centre for Molecular Medicine and Biobanking, University of Malta, Msida, MSD2080, Malta
| | - Yasuhiro Kuramitsu
- Department of Systems Biochemistry in Pathology and Regeneration, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
- Research Institute of Cancer Prevention, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, 061-0293, Japan
| | - Takao Kitagawa
- Department of Systems Biochemistry in Pathology and Regeneration, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Nobuko Tokuda
- Faculty of Health Sciences, Yamaguchi University Graduate School of Medicine, Ube, 755-8505, Japan
| | - Naoyuki Morishige
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Masaaki Kobayashi
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Kazuhiro Kimura
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Kazuyuki Nakamura
- Department of Systems Biochemistry in Pathology and Regeneration, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Koh-Hei Sonoda
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
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19
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Cernichiaro-Espinosa LA, Tran KD, Berrocal AM. Imaging Modalities in Pediatric Vitreoretinal Disorders. CURRENT OPHTHALMOLOGY REPORTS 2018. [DOI: 10.1007/s40135-018-0159-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Reid CA, Ertel KJ, Lipinski DM. Improvement of Photoreceptor Targeting via Intravitreal Delivery in Mouse and Human Retina Using Combinatory rAAV2 Capsid Mutant Vectors. Invest Ophthalmol Vis Sci 2017; 58:6429-6439. [PMID: 29260200 PMCID: PMC5736327 DOI: 10.1167/iovs.17-22281] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Purpose Effective intravitreal gene delivery to cells of the central retina (i.e., photoreceptors) would be of substantial benefit for treating patients with retinal diseases, such as achromatopsia, where retinal detachment from a subretinal may be harmful. Previous studies demonstrated that mutation of the recombinant adeno-associated virus (rAAV) capsid through introduction of peptide insertions or amino acid substitutions dramatically alters vector tropism. Herein, we evaluate the photoreceptor transduction efficiency of three rAAV2/2-based capsid mutant vectors: rAAV2/2[7m8], rAAV2/2[QuadYF+TV], and a chimeric vector incorporating both mutations (termed rAAV2/2[MAX]) following intravitreal delivery in mice. Furthermore, we evaluate the transduction efficiency of rAAV2/2[MAX] using explanted human central retinal samples to address clinical translatability. Methods Vectors containing a GFP or mCherry reporter gene were intravitreally injected into C57BL/6J or Nrl-EGFP mice, respectively. Transduction was assessed in vivo utilizing a custom multiline confocal scanning laser ophthalmoscope. Injected Nrl-EGFP mouse retinas were used to quantify transduced photoreceptors using flow cytometry. Postmortem human retinal tissue was cultured following administration of rAAV2/2[MAX]. C57BL/6J retinas and human explants were cryosectioned to determine vector tropism. Results The chimeric vector rAAV2/2[MAX] transduced significantly higher proportions of the retina than did either single mutant serotypes following intravitreal delivery in murine retina, including inner retinal cells and photoreceptors. Vector rAAV2[MAX] demonstrated transduction of human photoreceptors and ganglion cells. Conclusions Transduction observed via rAAV2/2[MAX] indicates that combining mutations with complementary mechanisms of action in a single vector results in enhanced transduction. rAAV2/2[MAX] also presented the ability to transduce human photoreceptors and ganglion cells, indicating potential for efficient intravitreal vector delivery.
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Affiliation(s)
- Christopher A Reid
- Department of Ophthalmology, Eye Institute, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Kristina J Ertel
- Department of Ophthalmology, Eye Institute, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Daniel M Lipinski
- Department of Ophthalmology, Eye Institute, Medical College of Wisconsin, Milwaukee, Wisconsin, United States.,Nuffield Laboratory of Ophthalmology, Department of Clinical Neuroscience, University of Oxford, Oxford, United Kingdom
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21
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Piermarocchi S, Miotto S, Colavito D, Del Giudice E, Leon A, Maritan V, Piermarocchi R, Tormene AP. Long-term rearrangement of retinal structures in a novel mutation of X-linked retinoschisis. Biomed Rep 2017; 7:241-246. [PMID: 28811895 DOI: 10.3892/br.2017.954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 06/06/2017] [Indexed: 11/05/2022] Open
Abstract
The aim of the present study was to report a novel mutation in the retinoschisin 1 (RS1) gene in a Caucasian family affected by X-linked juvenile retinoschisis (XLRS) and to describe the long-term modification of retinal structure. Two brothers with an early onset maculopathy were diagnosed with XLRS. Fundus photography, fluorescein angiography, spectral domain optical coherence tomography and electroretinogram analyses were performed. Their sister was also examined. All subjects were screened for mutations in the RS1 gene. XLRS patients demonstrated a marked reduction of best-corrected visual acuity. SD-OCT scans reported a cystic degeneration primarily involving the inner nuclear layer, though some cysts were detected in the outer plexiform layer and in the ganglion cell layer. During the ten-year follow-up, a progressive retinal thickening and coalescence of the cysts was observed. Genetic testing revealed a novel mutation (p.Ile212Asn) in the RS1 gene in both XLRS patients, whereas their sister was not a genetic carrier. Several mutations of the RS1 gene were recognized to be responsible for XLRS. Although the correspondence between genotype and phenotype is still under debate, is reasonable that siblings affected by XLRS could share other genetic and/or epigenetic factors capable to influence clinical course of the disease.
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Affiliation(s)
| | - Stefania Miotto
- Ophthalmic Department, Unità Locale Socio-Sanitaria 6 Euganea, Camposampiero, I-35012 Padua, Italy
| | - Davide Colavito
- Research and Innovation (R&I Genetics) Srl, I-35127 Padua, Italy
| | - Elda Del Giudice
- Research and Innovation (R&I Genetics) Srl, I-35127 Padua, Italy
| | - Alberta Leon
- Research and Innovation (R&I Genetics) Srl, I-35127 Padua, Italy
| | - Veronica Maritan
- Ophthalmic Department, ULSS 6 Euganea, Monselice, I-35043 Padua, Italy
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22
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Hu QR, Huang LZ, Chen XL, Xia HK, Li TQ, Li XX. Genetic analysis and clinical features of X-linked retinoschisis in Chinese patients. Sci Rep 2017; 7:44060. [PMID: 28272453 PMCID: PMC5341047 DOI: 10.1038/srep44060] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 02/03/2017] [Indexed: 11/10/2022] Open
Abstract
Many mutations in the retinoschisis (RS1) gene have been identified, but there are limited clinical data relating to the different genotypes. This study investigated the genotype, clinical phenotype and therapies for X-linked juvenile retinoschisis (XLRS) patients in China to evaluate the effects of gene mutations and therapies on the prognosis of the disease. Thirty patients were recruited in the study. Genetic examination identified 8 novel RS1 gene mutations. Twenty-four patients were identified as missense mutation, which was the most common gene mutation in XLRS patients. Amino acids 102 and 209 were the most common mutation areas, accounting for a total 35.7% of all patients. Mutations affecting amino acid 102 were associated with poor results on the flash electroretinogram (ERG). Sixteen patients had various complications. Anti-vascular endothelial growth factor (VEGF) drugs were given to four patients with hemorrhage or other complications, and serious adverse events did not occur. Our outcome demonstrates that missense mutation was the leading cause of XLRS and more than half of the patients with this missense had various complications. Anti-VEGF drugs may be an effective and safe way to prevent deterioration of XLRS with certain complications. There is wide genotypic and phenotypic variability in Chinese patients with XLRS.
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Affiliation(s)
- Qin-Rui Hu
- Department of Ophthalmology, Peking University People's Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing Key Laboratory for the Diagnosis and Treatment of Retinal and Choroid Diseases, Xizhimen South Street 11, Beijing, China
| | - Lv-Zhen Huang
- Department of Ophthalmology, Peking University People's Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing Key Laboratory for the Diagnosis and Treatment of Retinal and Choroid Diseases, Xizhimen South Street 11, Beijing, China
| | - Xiao-Li Chen
- Department of Ophthalmology, Peking University People's Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing Key Laboratory for the Diagnosis and Treatment of Retinal and Choroid Diseases, Xizhimen South Street 11, Beijing, China
| | - Hui-Ka Xia
- Department of Ophthalmology, Peking University People's Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing Key Laboratory for the Diagnosis and Treatment of Retinal and Choroid Diseases, Xizhimen South Street 11, Beijing, China
| | - Tian-Qi Li
- Department of Ophthalmology, Peking University People's Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing Key Laboratory for the Diagnosis and Treatment of Retinal and Choroid Diseases, Xizhimen South Street 11, Beijing, China
| | - Xiao-Xin Li
- Department of Ophthalmology, Peking University People's Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing Key Laboratory for the Diagnosis and Treatment of Retinal and Choroid Diseases, Xizhimen South Street 11, Beijing, China
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Correction of Monogenic and Common Retinal Disorders with Gene Therapy. Genes (Basel) 2017; 8:genes8020053. [PMID: 28134823 PMCID: PMC5333042 DOI: 10.3390/genes8020053] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/19/2017] [Indexed: 11/16/2022] Open
Abstract
The past decade has seen major advances in gene-based therapies, many of which show promise for translation to human disease. At the forefront of research in this field is ocular disease, as the eye lends itself to gene-based interventions due to its accessibility, relatively immune-privileged status, and ability to be non-invasively monitored. A landmark study in 2001 demonstrating successful gene therapy in a large-animal model for Leber congenital amaurosis set the stage for translation of these strategies from the bench to the bedside. Multiple clinical trials have since initiated for various retinal diseases, and further improvements in gene therapy techniques have engendered optimism for alleviating inherited blinding disorders. This article provides an overview of gene-based strategies for retinal disease, current clinical trials that engage these strategies, and the latest techniques in genome engineering, which could serve as the next frontline of therapeutic interventions.
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