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Updated: May 15, 2026
Limbal Approach-Subretinal Injection of Viral Vectors for Gene Therapy in Mice Retinal Pigment Epithelium
Published on: August 7, 2015
Synergistic antioxidant and gene supplementation for high-efficacy retinitis pigmentosa therapy
Fuhua Wu1, Haiping Wu1, Jialiang Yang1
1Genetic diseases Key Laboratory of Sichuan Province and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of medicine, University of Electronic Science and Technology of China, Chengdu 610072, P.R. China.
Abstract:
Retinitis pigmentosa (RP) is a leading cause of inherited blindness, yet current gene supplementation strategies are limited by heterogeneous responses, with more than 40% of patients showing insufficient rescue. Moreover, oxidative stress constitutes a defining pathological feature of RP and critically impairs the efficacy of gene therapy. Consistently, transcriptomic and ultrastructural analyses of Pde6brd10/rd10 (rd10) retinas revealed early and progressive dysregulation of oxidative stress-related pathways and photoreceptor degeneration. To overcome this barrier, we engineered an adeno-associated virus (AAV) vector covalently conjugated with a catalytic G-quadruplex-hemin DNAzyme (CoG4) via genetic code expansion and click chemistry. This design enables synchronized delivery of CoG4 and therapeutic Pde6b into photoreceptors, where CoG4 directly scavenges excess ROS and restores mitochondrial homeostasis, thereby creating a favorable microenvironment for gene supplementation. In rd10 mice, AAV-CoG4 treatment resulted in sustained expression of Pde6b, preservation of photoreceptor morphology, restoration of rod and cone function as evidenced by electroretinogram, and improved visual behavior, outperforming AAV or CoG4 monotherapies. Our findings establish oxidative stress as a major barrier to retinal gene therapy and demonstrate a dual-function platform that couples microenvironment modulation with genetic correction, offering a broadly applicable strategy for treating degenerative retinal diseases.
Insights
This study presents a novel gene therapy for retinitis pigmentosa (RP) that combines gene delivery with oxidative stress reduction. The dual-action approach improves photoreceptor survival and vision in mouse models, offering new hope for inherited blindness.
Area of Science:
- Ophthalmology
- Molecular Biology
- Biotechnology
Background:
- Retinitis pigmentosa (RP) is a leading cause of inherited blindness.
- Gene therapy for RP faces challenges due to heterogeneous patient responses and oxidative stress.
- Oxidative stress exacerbates photoreceptor degeneration and limits gene therapy efficacy in RP.
Purpose of the Study:
- To engineer a dual-function adeno-associated virus (AAV) vector for treating RP.
- To overcome oxidative stress barriers in retinal gene therapy.
- To improve the efficacy of gene supplementation for Pde6b deficiency.
Main Methods:
- Developed an AAV vector conjugated with a catalytic G-quadruplex-hemin DNAzyme (CoG4) using genetic code expansion and click chemistry.
- Delivered CoG4 and therapeutic Pde6b simultaneously to photoreceptors in rd10 mice.
- Assessed photoreceptor morphology, function (electroretinogram), and visual behavior.
Main Results:
- AAV-CoG4 treatment led to sustained Pde6b expression and photoreceptor preservation.
- Restored rod and cone function and improved visual behavior in rd10 mice.
- Outperformed AAV or CoG4 monotherapies, demonstrating synergistic effects.
Conclusions:
- Oxidative stress is a significant impediment to effective retinal gene therapy.
- The dual-function AAV-CoG4 platform successfully modulates the retinal microenvironment and provides genetic correction.
- This strategy offers a broadly applicable approach for treating degenerative retinal diseases.
