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Castro B, Steel JC, Layton CJ. AAV-mediated gene therapies for glaucoma and uveitis: are we there yet? Expert Rev Mol Med 2024; 26:e9. [PMID: 38618935 PMCID: PMC11062146 DOI: 10.1017/erm.2024.4] [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: 08/30/2023] [Revised: 01/03/2024] [Accepted: 02/01/2024] [Indexed: 04/16/2024]
Abstract
Glaucoma and uveitis are non-vascular ocular diseases which are among the leading causes of blindness and visual loss. These conditions have distinct characteristics and mechanisms but share a multifactorial and complex nature, making their management challenging and burdensome for patients and clinicians. Furthermore, the lack of symptoms in the early stages of glaucoma and the diverse aetiology of uveitis hinder timely and accurate diagnoses, which are a cause of poor visual outcomes under both conditions. Although current treatment is effective in most cases, it is often associated with low patient adherence and adverse events, which directly impact the overall therapeutic success. Therefore, long-lasting alternatives with improved safety and efficacy are needed. Gene therapy, particularly utilising adeno-associated virus (AAV) vectors, has emerged as a promising approach to address unmet needs in these diseases. Engineered capsids with enhanced tropism and lower immunogenicity have been proposed, along with constructs designed for targeted and controlled expression. Additionally, several pathways implicated in the pathogenesis of these conditions have been targeted with single or multigene expression cassettes, gene editing and silencing approaches. This review discusses strategies employed in AAV-based gene therapies for glaucoma and non-infectious uveitis and provides an overview of current progress and future directions.
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Affiliation(s)
- Brenda Castro
- LVF Ophthalmology Research Centre, Translational Research Institute, Brisbane, Australia
- Faculty of Medicine, Greenslopes Clinical School, The University of Queensland, Brisbane, Australia
| | - Jason C. Steel
- LVF Ophthalmology Research Centre, Translational Research Institute, Brisbane, Australia
- Faculty of Medicine, Greenslopes Clinical School, The University of Queensland, Brisbane, Australia
- School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Australia
| | - Christopher J. Layton
- LVF Ophthalmology Research Centre, Translational Research Institute, Brisbane, Australia
- Faculty of Medicine, Greenslopes Clinical School, The University of Queensland, Brisbane, Australia
- School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Australia
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2
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Evidence of Chronic Complement Activation in Asymptomatic Pediatric Brain Injury Patients: A Pilot Study. CHILDREN (BASEL, SWITZERLAND) 2022; 10:children10010045. [PMID: 36670596 PMCID: PMC9856304 DOI: 10.3390/children10010045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/16/2022] [Accepted: 12/18/2022] [Indexed: 12/28/2022]
Abstract
Physical insult from a mild Traumatic Brain Injury (mTBI) leads to changes in blood flow in the brain and measurable changes in white matter, suggesting a physiological basis for chronic symptom presentation. Post-traumatic headache (PTH) is frequently reported by persons after an mTBI that may persist beyond the acute period (>3 months). It remains unclear whether ongoing inflammation may contribute to the clinical trajectory of PTH. We recruited a cohort of pediatric subjects with PTH who had an acute or a persistent clinical trajectory, each around the 3-month post-injury time point, as well as a group of age and sex-matched healthy controls. We collected salivary markers of mRNA expression as well as brain imaging and psychological testing. The persistent PTH group showed the highest levels of psychological burden and pain symptom reporting. Our data suggest that the acute and persistent PTH cohort had elevated levels of complement factors relative to healthy controls. The greatest change in mRNA expression was found in the acute-PTH cohort wherein the complement cascade and markers of vascular health showed a prominent role for C1Q in PTH pathophysiology. These findings (1) underscore a prolonged engagement of what is normally a healthy response and (2) show that a persistent PTH symptom trajectory may parallel a poorly regulated inflammatory response.
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3
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Soldatov VO, Kukharsky MS, Belykh AE, Sobolev AM, Deykin AV. Retinal Damage in Amyotrophic Lateral Sclerosis: Underlying Mechanisms. Eye Brain 2021; 13:131-146. [PMID: 34012311 PMCID: PMC8128130 DOI: 10.2147/eb.s299423] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 03/04/2021] [Indexed: 01/04/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease resulting in a gradual loss of motor neuron function. Although ophthalmic complaints are not presently considered a classic symptom of ALS, retinal changes such as thinning, axonal degeneration and inclusion bodies have been found in many patients. Retinal abnormalities observed in postmortem human tissues and animal models are similar to spinal cord changes in ALS. These findings are not dramatically unexpected because retina shares an ontogenetic relationship with the brain, and many genes are associated both with neurodegeneration and retinal diseases. Experimental studies have demonstrated that ALS affects many “vulnerable points” of the retina. Aggregate deposition, impaired nuclear protein import, endoplasmic reticulum stress, glutamate excitotoxicity, vascular regression, and mitochondrial dysfunction are factors suspected as being the main cause of motor neuron damage in ALS. Herein, we show that all of these pathways can affect retinal cells in the same way as motor neurons. Furthermore, we suppose that understanding the patterns of neuro-ophthalmic interaction in ALS can help in the diagnosis and treatment of this disease.
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Affiliation(s)
- Vladislav O Soldatov
- Core Facility Centre, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.,Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia
| | - Michail S Kukharsky
- Department of General and Cell Biology, Faculty of Medical Biology, Pirogov Russian National Research Medical University, Moscow, Russia.,Laboratory of Genetic Modelling of Neurodegenerative Processes, Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Russia
| | - Andrey E Belykh
- Department of Pathophysiology, Kursk State Medical University, Kursk, Russia
| | - Andrey M Sobolev
- Laboratory of Genetic Modelling of Neurodegenerative Processes, Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Russia
| | - Alexey V Deykin
- Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
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4
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Rhee J, Shih KC. Use of Gene Therapy in Retinal Ganglion Cell Neuroprotection: Current Concepts and Future Directions. Biomolecules 2021; 11:biom11040581. [PMID: 33920974 PMCID: PMC8071340 DOI: 10.3390/biom11040581] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 12/14/2022] Open
Abstract
We systematically reviewed published translational research on gene-based therapy for retinal ganglion cell (RGC) neuroprotection. A search was conducted on Entrez PubMed on 23 December 2020 using the keywords "gene therapy", "retinal ganglion cell" and "neuroprotection". The initial search yielded 82 relevant articles. After restricting publications to those with full text available and in the English language, and then curating for only original articles on gene-based therapy, the final yield was 18 relevant articles. From the 18 papers, 17 of the papers utilized an adeno-associated viral (AAV) vector for gene therapy encoding specific genes of interest. Specifically, six of the studies utilized an AAV vector encoding brain-derived neurotrophic factor (BDNF), two of the studies utilized an AAV vector encoding erythropoietin (EPO), the remaining 10 papers utilized AAV vectors encoding different genes and one microRNA study. Although the literature shows promising results in both in vivo and in vitro models, there is still a significant way to go before gene-based therapy for RGC neuroprotection can proceed to clinical trials. Namely, the models of injury in many of the studies were more acute in nature, unlike the more progressive and neurodegenerative pathophysiology of diseases, such as glaucoma. The regulation of gene expression is also highly unexplored despite the use of AAV vectors in the majority of the studies reviewed. It is also expected that with the successful launch of messenger ribonucleic acid (mRNA)-based vaccinations in 2020, we will see a shift towards this technology for gene-based therapy in glaucoma neuroprotection.
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Affiliation(s)
- Jess Rhee
- Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON N6A3K7, Canada;
| | - Kendrick Co Shih
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Correspondence:
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5
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Harre J, Heinkele L, Steffens M, Warnecke A, Lenarz T, Just I, Rohrbeck A. Potentiation of Brain-Derived Neurotrophic Factor-Induced Protection of Spiral Ganglion Neurons by C3 Exoenzyme/Rho Inhibitor. Front Cell Neurosci 2021; 15:602897. [PMID: 33776650 PMCID: PMC7991574 DOI: 10.3389/fncel.2021.602897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 02/19/2021] [Indexed: 11/17/2022] Open
Abstract
Preservation of the excitability of spiral ganglion neurons (SGN) may contribute to an improved speech perception after cochlear implantation. Thus, the application of exogenous neurotrophic factors such as the neurotrophin brain-derived neurotrophic factor (BDNF) to increase SGN survival in vitro and in vivo is a promising pharmacological approach in cochlear implant (CI) research. Due to the difficult pharmacokinetic profile of proteins such as BDNF, there is a quest for small molecules to mediate the survival of SGN or to increase the efficacy of BDNF. The C3 exoenzyme from Clostridium botulinum could be a potential new candidate for the protection and regeneration of SGN. Inhibition of the RhoA GTPase pathway which can be mediated by C3 is described as a promising strategy to enhance axonal regeneration and to exert pro-survival signals in neurons. Nanomolar concentrations of C3, its enzymatically inactive form C3E174Q, and a 26mer C-terminal peptide fragment covering amino acid 156–181 (C3156-181) potentiated the neuroprotective effect on SGN mediated by BDNF in vitro. The neuroprotective effect of C3/BDNF was reduced to the neuroprotective effect of BDNF alone after the treatment with wortmannin, an inhibitor of the phosphatidylinositol-3-kinase (PI3K).The exoenzyme C3 (wild-type and enzyme-deficient) and the C3 peptide fragment C3154–181 present novel biologically active compounds for the protection of the SGN. The exact underlying intracellular mechanisms that mediate the neuroprotective effect are not clarified yet, but the combination of BDNF (TrkB stimulation) and C3 exoenzyme (RhoA inhibition) can be used to protect SGN in vitro.
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Affiliation(s)
- Jennifer Harre
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany.,Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 2177/1), Hannover, Germany
| | - Laura Heinkele
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Melanie Steffens
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Athanasia Warnecke
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany.,Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 2177/1), Hannover, Germany
| | - Thomas Lenarz
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany.,Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 2177/1), Hannover, Germany
| | - Ingo Just
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Astrid Rohrbeck
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
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6
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Tan J, Liu G, Lan C, Pang IH, Luo X, Wu S, Fan N, Zhang J, Wang N, Liu X. Lentiviral vector-mediated expression of C3 transferase attenuates retinal ischemia and reperfusion injury in rats. Life Sci 2021; 272:119269. [PMID: 33631175 DOI: 10.1016/j.lfs.2021.119269] [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: 11/27/2020] [Revised: 02/17/2021] [Accepted: 02/17/2021] [Indexed: 10/22/2022]
Abstract
AIMS Our previous study showed that intravitreal delivery of self-complementary AAV2 (scAAV2)-mediated exoenzyme C3 transferase (C3) can attenuate retinal ischemia/reperfusion (I/R) injury. The current study investigated the neuroprotective effects of lentivirus (LV)-mediated C3 transgene expression on rat retinal I/R injury. MAIN METHODS The LV encoding C3 and green fluorescent protein (GFP) together (LV-C3-GFP) or GFP only (LV-GFP) was intravitreally injected to SPRAGUE-DAWLEY rats. On day 5 post-intravitreal injection, eyes were evaluated by slit-lamp examination. The GFP expression on retina was confirmed by in vivo and ex vivo assessments. RhoA GTPase expression in retina was examined by western blot. Retinal I/R injury was generated by transiently increasing intraocular pressure (110 mmHg, 90 min). Eyes were then enucleated, and retinas processed for morphological analysis and TdT-dUTP terminal nick-end labeling (TUNEL) assay. KEY FINDINGS No obvious inflammatory reactions or surgical complications were observed after intravitreal injection of LV vectors. There was a significant decrease of total RhoA GTPase level in the retina treated with LV-C3-GFP. Compared to the blank control group, LV-C3-GFP and LV-GFP did not affect the retinal thickness, cell density in ganglion cell layer (GCL), or numbers of apoptotic cells in retinal flat-mounts. In the LV-GFP-treated retinas, I/R decreased the retinal thickness and GCL cell density and increased apoptotic retinal cell numbers. LV-C3-GFP significantly protected against all these degenerative effects of I/R. SIGNIFICANCE This study indicated that LV-mediated C3 transgene expression exhibits neuroprotective effects on the retinal I/R injury and holds potential as a novel neuroprotective approach targeting certain retinopathies.
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Affiliation(s)
- Junkai Tan
- Xiamen Eye Center, Xiamen University, Xiamen 361006, China
| | - Guo Liu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Chunlin Lan
- The First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, China
| | - Iok-Hou Pang
- Department of Pharmaceutical Sciences and North Texas Eye Research Institute, University of North Texas Health Sciences Center, Fort Worth, TX 76107, United States
| | - Xiaolin Luo
- Department of Ophthalmology, the 2nd Clinical Medical College, Jinan University, Shenzhen 518020, China
| | - Shen Wu
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100005, China
| | - Ning Fan
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, School of Optometry, Shenzhen University, Shenzhen 518000, China
| | - Jingxue Zhang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100005, China
| | - Ningli Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100005, China
| | - Xuyang Liu
- Xiamen Eye Center, Xiamen University, Xiamen 361006, China; Department of Ophthalmology, the 2nd Clinical Medical College, Jinan University, Shenzhen 518020, China.
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7
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Tan J, Zhang X, Li D, Liu G, Wang Y, Zhang D, Wang X, Tian W, Dong X, Zhou L, Zhu X, Liu X, Fan N. scAAV2-Mediated C3 Transferase Gene Therapy in a Rat Model with Retinal Ischemia/Reperfusion Injuries. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 17:894-903. [PMID: 32382585 PMCID: PMC7200613 DOI: 10.1016/j.omtm.2020.04.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Accepted: 04/22/2020] [Indexed: 11/26/2022]
Abstract
Glaucoma is characterized by retinal ganglion cell (RGC) death and axonal loss. Therefore, neuroprotection is important in treating glaucoma. In this study, we explored whether exoenzyme C3 transferase (C3)-based gene therapy could protect retinas in an ischemia/reperfusion (I/R) injury rat model. Self-complementary adeno-associated virus 2 (scAAV2) vectors encoding either C3 protein (scAAV2-C3) or enhanced green fluorescence protein (scAAV2-EGFP) were intravitreally delivered into both eyes of rats, and I/R models (acute ocular hypertension) were made in one eye of each rat at day 7 after the injection. The rats were divided into six groups: scAAV2-C3, scAAV2-C3 with I/R, scAAV2-EGFP, scAAV2-EGFP with I/R, blank control, and blank control with I/R. TUNEL (terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate nick end labeling), immunohistochemistry of cleaved caspase-3, NeuN and Brn-3a, and H&E staining were used to detect apoptotic cells and other changes in the retina. The results showed that scAAV2-C3 significantly reduced the number of apoptotic RGCs and decreased cell loss in the ganglion cell layer after I/R injury, and the I/R-injured retinas treated with scAAV2-C3 were the thickest in all I/R groups. These results suggest that scAAV2-mediated C3 gene therapy is able to protect the rat retina from I/R injury and has potential in the treatment of glaucoma in the future.
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Affiliation(s)
- Junkai Tan
- Xiamen Eye Center, Xiamen University, Xiamen 361006, China
| | - Xiaoguang Zhang
- Department of Medicine, Nanchang University, Nanchang 330006, China.,Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, School of Optometry, Shenzhen University, Shenzhen 518000, China
| | - Danli Li
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, School of Optometry, Shenzhen University, Shenzhen 518000, China
| | - Guo Liu
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, School of Optometry, Shenzhen University, Shenzhen 518000, China
| | - Yun Wang
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, School of Optometry, Shenzhen University, Shenzhen 518000, China
| | - Daren Zhang
- Xiamen Eye Center, Xiamen University, Xiamen 361006, China
| | - Xizhen Wang
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, School of Optometry, Shenzhen University, Shenzhen 518000, China
| | - Wenhong Tian
- Beijing FivePlus Molecular Medicine Institute Co., Ltd., Beijing 102600, China
| | - Xiaoyan Dong
- Beijing FivePlus Molecular Medicine Institute Co., Ltd., Beijing 102600, China
| | - Liang Zhou
- Institute of Laboratory Animal Sciences, Sichuan Academy of Medical Sciences and Sichuan Provincial Hospital, Chengdu, Sichuan 610212, China
| | - Xianjun Zhu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China.,Institute of Laboratory Animal Sciences, Sichuan Academy of Medical Sciences and Sichuan Provincial Hospital, Chengdu, Sichuan 610212, China
| | - Xuyang Liu
- Xiamen Eye Center, Xiamen University, Xiamen 361006, China.,Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, School of Optometry, Shenzhen University, Shenzhen 518000, China
| | - Ning Fan
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, School of Optometry, Shenzhen University, Shenzhen 518000, China
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8
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Tan J, Wang X, Cai S, He F, Zhang D, Li D, Zhu X, Zhou L, Fan N, Liu X. C3 Transferase-Expressing scAAV2 Transduces Ocular Anterior Segment Tissues and Lowers Intraocular Pressure in Mouse and Monkey. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 17:143-155. [PMID: 31909087 PMCID: PMC6938898 DOI: 10.1016/j.omtm.2019.11.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 11/19/2019] [Indexed: 01/08/2023]
Abstract
Glaucoma is a lifelong disease with elevated intraocular pressure (IOP) as the main risk factor, and reduction of IOP remains the major treatment for this disease. However, current IOP-lowering therapies are far from being satisfactory. We have demonstrated that the lentivirus-mediated exoenzyme C3 transferase (C3) expression in rat and monkey eyes induced relatively long-term IOP reduction. We now show that intracameral injection of self-complementary AAV2 containing a C3 gene into mouse and monkey eyes resulted in morphological changes in trabecular meshwork and IOP reduction. The vector-transduced corneal endothelium and the C3 transgene expression, not vector itself, induced corneal edema as a result of actin-associated endothelial barrier disruption. There was a positive (quadratic) correlation between measured IOP and grade of corneal edema. This is the first report of using an AAV to transduce the trabecular meshwork of monkeys with a gene capable of altering cellular structure and physiology, indicating a potential gene therapy for glaucoma.
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Affiliation(s)
- Junkai Tan
- Xiamen Eye Center, Xiamen University, Xiamen, China
| | - Xizhen Wang
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
| | - Suping Cai
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
| | - Fen He
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
| | - Daren Zhang
- Xiamen Eye Center, Xiamen University, Xiamen, China
| | - Dongkan Li
- Xiamen Eye Center, Xiamen University, Xiamen, China
| | - Xianjun Zhu
- Institute of Laboratory Medicine, Sichuan Academy of Medical Sciences & Provincial People's Hospital, Chengdu, Sichuan, China.,Institute of Laboratory Animal Sciences, Sichuan Academy of Medical Sciences & Provincial People's Hospital, Chengdu, Sichuan, China
| | - Liang Zhou
- Institute of Laboratory Animal Sciences, Sichuan Academy of Medical Sciences & Provincial People's Hospital, Chengdu, Sichuan, China
| | - Ning Fan
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
| | - Xuyang Liu
- Xiamen Eye Center, Xiamen University, Xiamen, China.,Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
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9
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Pichavaram P, Palani CD, Patel C, Xu Z, Shosha E, Fouda AY, Caldwell RB, Narayanan SP. Targeting Polyamine Oxidase to Prevent Excitotoxicity-Induced Retinal Neurodegeneration. Front Neurosci 2019; 12:956. [PMID: 30686964 PMCID: PMC6335392 DOI: 10.3389/fnins.2018.00956] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 11/30/2018] [Indexed: 12/21/2022] Open
Abstract
Dysfunction of retinal neurons is a major cause of vision impairment in blinding diseases that affect children and adults worldwide. Cellular damage resulting from polyamine catabolism has been demonstrated to be a major player in many neurodegenerative conditions. We have previously shown that inhibition of polyamine oxidase (PAO) using MDL 72527 significantly reduced retinal neurodegeneration and cell death signaling pathways in hyperoxia-mediated retinopathy. In the present study, we investigated the impact of PAO inhibition in limiting retinal neurodegeneration in a model of NMDA (N-Methyl-D-aspartate)-induced excitotoxicity. Adult mice (8–10 weeks old) were given intravitreal injections (20 nmoles) of NMDA or NMLA (N-Methyl-L-aspartate, control). Intraperitoneal injection of MDL 72527 (40 mg/kg body weight/day) or vehicle (normal saline) was given 24 h before NMDA or NMLA treatment and continued until the animals were sacrificed (varied from 1 to 7 days). Analyses of retinal ganglion cell (RGC) layer cell survival was performed on retinal flatmounts. Retinal cryostat sections were prepared for immunostaining, TUNEL assay and retinal thickness measurements. Fresh frozen retinal samples were used for Western blotting analysis. A marked decrease in the neuronal survival in the RGC layer was observed in NMDA treated retinas compared to their NMLA treated controls, as studied by NeuN immunostaining of retinal flatmounts. Treatment with MDL 72527 significantly improved survival of NeuN positive cells in the NMDA treated retinas. Excitotoxicity induced neurodegeneration was also demonstrated by reduced levels of synaptophysin and degeneration of inner retinal neurons in NMDA treated retinas compared to controls. TUNEL labeling studies showed increased cell death in the NMDA treated retinas. However, treatment with MDL 72527 markedly reduced these changes. Analysis of signaling pathways during excitotoxic injury revealed the downregulation of pro-survival signaling molecules p-ERK and p-Akt, and the upregulation of a pro-apoptotic molecule BID, which were normalized with PAO inhibition. Our data demonstrate that inhibition of polyamine oxidase blocks NMDA-induced retinal neurodegeneration and promotes cell survival, thus offering a new therapeutic target for retinal neurodegenerative disease conditions.
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Affiliation(s)
- Prahalathan Pichavaram
- Vision Discovery Institute, Augusta University, Augusta, GA, United States.,College of Allied Health Sciences, Augusta University, Augusta, GA, United States
| | - Chithra Devi Palani
- Vision Discovery Institute, Augusta University, Augusta, GA, United States.,Vascular Biology Center, Augusta University, Augusta, GA, United States.,Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, United States
| | - Chintan Patel
- Vision Discovery Institute, Augusta University, Augusta, GA, United States.,Vascular Biology Center, Augusta University, Augusta, GA, United States
| | - Zhimin Xu
- Vision Discovery Institute, Augusta University, Augusta, GA, United States.,Vascular Biology Center, Augusta University, Augusta, GA, United States
| | - Esraa Shosha
- Vision Discovery Institute, Augusta University, Augusta, GA, United States.,Vascular Biology Center, Augusta University, Augusta, GA, United States
| | - Abdelrahman Y Fouda
- Vision Discovery Institute, Augusta University, Augusta, GA, United States.,Vascular Biology Center, Augusta University, Augusta, GA, United States
| | - Ruth B Caldwell
- Vision Discovery Institute, Augusta University, Augusta, GA, United States.,Vascular Biology Center, Augusta University, Augusta, GA, United States.,VA Medical Center, Augusta, GA, United States
| | - Subhadra Priya Narayanan
- Vision Discovery Institute, Augusta University, Augusta, GA, United States.,College of Allied Health Sciences, Augusta University, Augusta, GA, United States.,Vascular Biology Center, Augusta University, Augusta, GA, United States.,Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, United States.,VA Medical Center, Augusta, GA, United States
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10
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von Elsner L, Hagemann S, Just I, Rohrbeck A. C3 exoenzyme impairs cell proliferation and apoptosis by altering the activity of transcription factors. Naunyn Schmiedebergs Arch Pharmacol 2016; 389:1021-31. [PMID: 27351882 PMCID: PMC4977334 DOI: 10.1007/s00210-016-1270-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 06/21/2016] [Indexed: 12/13/2022]
Abstract
C3 exoenzyme from C. botulinum is an ADP-ribosyltransferase that inactivates selectively RhoA, B, and C by coupling an ADP-ribose moiety. Rho-GTPases are involved in various cellular processes, such as regulation of actin cytoskeleton, cell proliferation, and apoptosis. Previous studies of our group with the murine hippocampal cell line HT22 revealed a C3-mediated inhibition of cell proliferation after 48 h and a prevention of serum-starved cells from apoptosis. For both effects, alterations of various signaling pathways are already known, including also changes on the transcriptional level. Investigations on the transcriptional activity in HT22 cells treated with C3 for 48 h identified five out of 48 transcription factors namely Sp1, ATF2, E2F-1, CBF, and Stat6 with a significantly regulated activity. For validation of identified transcription factors, studies on the protein level of certain target genes were performed. Western blot analyses exhibited an enhanced abundance of Sp1 target genes p21 and COX-2 as well as an increase in phosphorylation of c-Jun. In contrast, the level of p53 and apoptosis-inducing GADD153, a target gene of ATF2, was decreased. Our results reveal that C3 regulates the transcriptional activity of Sp1 and ATF2 resulting downstream in an altered protein abundance of various target genes. As the affected proteins are involved in the regulation of cell proliferation and apoptosis, thus the C3-mediated anti-proliferative and anti-apoptotic effects are consequences of the Rho-dependent alterations of the activity of certain transcriptional factors.
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Affiliation(s)
- Leonie von Elsner
- Institute of Toxicology, Hannover Medical School, Straße 1, D-30625, Hannover, Germany.
| | - Sandra Hagemann
- Institute of Toxicology, Hannover Medical School, Straße 1, D-30625, Hannover, Germany
| | - Ingo Just
- Institute of Toxicology, Hannover Medical School, Straße 1, D-30625, Hannover, Germany
| | - Astrid Rohrbeck
- Institute of Toxicology, Hannover Medical School, Straße 1, D-30625, Hannover, Germany
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