1
|
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.
Collapse
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
| |
Collapse
|
2
|
Anderson BD, Lee TT, Bell BA, Wang T, Dunaief JL. Optimizing the sodium iodate model: Effects of dose, gender, and age. Exp Eye Res 2024; 239:109772. [PMID: 38158173 PMCID: PMC10922497 DOI: 10.1016/j.exer.2023.109772] [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: 10/24/2023] [Revised: 12/26/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
Sodium iodate (NaIO3) is a commonly used model for age-related macular degeneration (AMD), but its rapid and severe induction of retinal pigment epithelial (RPE) and photoreceptor degeneration can lead to the premature dismissal of potentially effective therapeutics. Additionally, little is known about how sex and age affect the retinal response to NaIO3. This study aims to establish a less severe yet reproducible regimen by testing low doses of NaIO3 while considering age- and sex-related effects, enabling a broader range of therapeutic evaluations. In this study, young (3-5 months) and old (18-24 months) male and female C57Bl/6J mice were given an intraperitoneal (IP) injection of 15, 20, or 25 mg/kg NaIO3. Damage assessment one week post-injection included in vivo imaging, histological examination, and qRT-PCR analysis. The results revealed that young mice showed no damage at 15 mg/kg IP NaIO3, with varying degrees of damage observed at 20 mg/kg. At 25 mg/kg, most young mice displayed widespread retinal damage, with females exhibiting less retinal thinning than males. In contrast, older mice at 20 and 25 mg/kg displayed a more patchy degeneration pattern, outer retinal undulations, and greater variability in degeneration than the young mice. The most effective model for minimizing damage while maintaining consistency utilizes young female mice injected with 25 mg/kg NaIO3. The observed sex- and age-related differences underscore the importance of considering these variables in research, aligning with the National Institutes of Health's guidance. While the model does not fully replicate the complexity of AMD, these findings enhance its utility as a valuable tool for testing RPE/photoreceptor protective or replacement therapies.
Collapse
Affiliation(s)
- Brandon D Anderson
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Timothy T Lee
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Brent A Bell
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Tan Wang
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA; Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Joshua L Dunaief
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
| |
Collapse
|
3
|
Ahmed CM, Patel AP, Johnson HM, Ildefonso CJ, Lewin AS. Suppressor of cytokine signaling 3-derived peptide as a therapeutic for inflammatory and oxidative stress-induced damage to the retina. Mol Vis 2023; 29:338-356. [PMID: 38264613 PMCID: PMC10805335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 12/15/2023] [Indexed: 01/25/2024] Open
Abstract
Purpose Inflammation and oxidative stress contribute to age-related macular degeneration (AMD) and other retinal diseases. We tested a cell-penetrating peptide from the kinase inhibitory region of an intracellular checkpoint inhibitor suppressor of cytokine signaling 3 (R9-SOCS3-KIR) peptide for its ability to blunt the inflammatory or oxidative pathways leading to AMD. Methods We used anaphylatoxin C5a to mimic the effect of activated complement, lipopolysaccharide (LPS), and tumor necrosis factor alpha (TNFα) to stimulate inflammation and paraquat to induce mitochondrial oxidative stress. We used a human retinal pigment epithelium (RPE) cell line (ARPE-19) as proliferating cells and a mouse macrophage cell line (J774A.1) to follow cell propagation using microscopy or cell titer assays. We evaluated inflammatory pathways by monitoring the nuclear translocation of NF-κB p65 and mitogen-activated protein kinase p38. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot were used to evaluate the induction of inflammatory markers. In differentiated ARPE-19 monolayers, we evaluated the integrity of tight junction proteins through microscopy and the measurement of transepithelial electrical resistance (TEER). We used intraperitoneal injection of sodium iodate in mice to test the ability of R9-SOC3-KIR to prevent RPE and retinal injury, as assessed by fundoscopy, optical coherence tomography, and histology. Results R9-SOCS3-KIR treatment suppressed C5a-induced nuclear translocation of the NF-kB activation domain p65 in undifferentiated ARPE-19 cells. TNF-mediated damage to tight junction proteins in RPE, and the loss of TEER was prevented in the presence of R9-SOCS3-KIR. Treatment with the R9-SOCS3-KIR peptide blocked the C5a-induced expression of inflammatory genes. The R9-SOCS3-KIR treatment also blocked the LPS-induced expression of interleukin-6, MCP1, cyclooxygenase 2, and interleukin-1 beta. R9-SOCS3-KIR prevented paraquat-mediated cell death and enhanced the levels of antioxidant effectors. Daily eye drop treatment with R9-SOCS3-KIR protected against retinal injury caused by i.p. administration of sodium iodate. Conclusions R9-SOCS3-KIR blocks the induction of inflammatory signaling in cell culture and reduces retinal damage in a widely used RPE/retinal oxidative injury model. As this peptide can be administered through corneal instillation, this treatment may offer a convenient way to slow down the progression of ocular diseases arising from inflammation and chronic oxidative stress.
Collapse
Affiliation(s)
- Chulbul M Ahmed
- Department of Molecular Genetics and Microbiology, University of Florida Gainesville, FL
| | - Anil P Patel
- Department of Molecular Genetics and Microbiology, University of Florida Gainesville, FL
| | - Howard M Johnson
- Department of Microbiology and Cell Science, University of Florida Gainesville, FL
| | | | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, University of Florida Gainesville, FL
| |
Collapse
|
4
|
Du Y, Zhou L, Wen Z, Feng L, Zhang S, Zhang T. Slit2 suppresses endotoxin-induced uveitis by inhibiting the PI3K/Akt/IKK/NF-κB pathway. Scand J Immunol 2023; 98:e13319. [PMID: 38441217 DOI: 10.1111/sji.13319] [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: 03/08/2023] [Revised: 06/17/2023] [Accepted: 07/18/2023] [Indexed: 03/07/2024]
Abstract
Uveitis is a devastating intraocular inflammatory disease. The secreted leucine-rich repeat protein slit homologue 2 (Slit2) has been found to be an essential regulator of inflammation. This study aimed to analyse the anti-inflammatory effects and the underlying mechanisms of Slit2 in an endotoxin-induced uveitis (EIU) rat model. In this study, rats with EIU pretreated recombinant human Slit2 (rhSlit2) or a control vehicle by intravitreal injection. The clinical scores were graded under a slit lamp. The protein concentrations and total number of cells in the aqueous humour (AqH) were examined, and the retinal expression of various inflammatory mediators was detected. The levels of nuclear factor-kappa B (NF-κB), phosphorylated NF-κB, IkappaB-a (IκB-a), phosphorylated IκB-a, IKK, phosphorylated IKK, PI3Kp85, phosphorylated PI3Kp85, Akt and phosphorylated Akt were evaluated by western blotting. Treatment with rhSlit2 dramatically diminished the clinical scores of EIU, with significant decreases in inflammatory cell infiltration, protein concentrations, cellulose-like exudates, the production of ICAM-1, MCP-1, TNF-α and IL-6 in the AqH; and adhesion of leucocytes. The PI3K/Akt/IKK/NF-κB pathway was found to be activated in EIU. However, the pre-treatment of rhSlit2 significantly inhibited the production of ICAM-1, MCP-1, TNF-α, and IL-6, and inhibited leucocyte adhesion by modulating the PI3K/Akt/IKK/NF-κB pathway. In conclusion, the intravitreal injection of rhSlit2 alleviated EIU-related inflammation in Sprague-Dawley rats by reducing the proinflammatory cytokines and leucocyte adhesion; in particular, rhSlit2 may inhibit LPS-induced inflammation by inhibiting the activation of PI3K/Akt/IKK/NF-κB signalling pathway. Therefore, rhSlit2 shows significant potential for effectively alleviating immune inflammatory responses in vivo.
Collapse
Affiliation(s)
- Yong Du
- Chongqing Key Lab of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, China
| | - Linbin Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Zijun Wen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Lujia Feng
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, China
| | - Shaochong Zhang
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, China
| | - Ting Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| |
Collapse
|
5
|
Giunta S, D'Amico AG, Maugeri G, Bucolo C, Romano GL, Rossi S, Eandi CM, Pricoco E, D'Agata V. Drug-Repurposing Strategy for Dimethyl Fumarate. Pharmaceuticals (Basel) 2023; 16:974. [PMID: 37513886 PMCID: PMC10386358 DOI: 10.3390/ph16070974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/26/2023] [Accepted: 06/29/2023] [Indexed: 07/30/2023] Open
Abstract
In the area of drug discovery, repurposing strategies represent an approach to discover new uses of approved drugs besides their original indications. We used this approach to investigate the effects of dimethyl fumarate (DMF), a drug approved for relapsing-remitting multiple sclerosis and psoriasis treatment, on early injury associated with diabetic retinopathy (DR). We used an in vivo streptozotocin (STZ)-induced diabetic rat model. Diabetes was induced by a single injection of STZ in rats, and after 1 week, a group of animals was treated with a daily intraperitoneal injection of DMF or a vehicle. Three weeks after diabetes induction, the retinal expression levels of key enzymes involved in DR were evaluated. In particular, the biomarkers COX-2, iNOS, and HO-1 were assessed via Western blot and immunohistochemistry analysis. Diabetic rats showed a significant retinal upregulation of COX-2 and iNOS compared to the retina of normal rats (non-diabetic), and an increase in HO-1 was also observed in the STZ group. This latter result was due to a mechanism of protection elicited by the pathological condition. DMF treatment significantly induced the retinal expression of HO-1 in STZ-induced diabetic animals with a reduction in iNOS and COX-2 retinal levels. Taken together, these results suggested that DMF might be useful to counteract the inflammatory process and the oxidative response in DR. In conclusion, we believe that DMF represents a potential candidate to treat diabetic retinopathy and warrants further in vivo and clinical evaluation.
Collapse
Affiliation(s)
- Salvatore Giunta
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Agata Grazia D'Amico
- Department of Drug and Health Sciences, University of Catania, 95123 Catania, Italy
| | - Grazia Maugeri
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
- Center for Research in Ocular Pharmacology (CERFO), University of Catania, 95123 Catania, Italy
| | - Giovanni Luca Romano
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
- Center for Research in Ocular Pharmacology (CERFO), University of Catania, 95123 Catania, Italy
| | - Settimio Rossi
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, University of Campania "Luigi Vanvitelli", 80131 Napoli, Italy
| | - Chiara M Eandi
- Department of Ophthalmology, University of Lausanne, Fondation Asile des Aveugles, Jules Gonin Eye Hospital, 1004 Lausanne, Switzerland
| | - Elisabetta Pricoco
- Department of Medical and Surgical Sciences and Advanced Technologies "G. F. Ingrassia", University of Catania, 95123 Catania, Italy
| | - Velia D'Agata
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
- Center for Research in Ocular Pharmacology (CERFO), University of Catania, 95123 Catania, Italy
| |
Collapse
|
6
|
Chew LA, Iannaccone A. Gene-agnostic approaches to treating inherited retinal degenerations. Front Cell Dev Biol 2023; 11:1177838. [PMID: 37123404 PMCID: PMC10133473 DOI: 10.3389/fcell.2023.1177838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 03/31/2023] [Indexed: 05/02/2023] Open
Abstract
Most patients with inherited retinal degenerations (IRDs) have been waiting for treatments that are "just around the corner" for decades, with only a handful of seminal breakthroughs happening in recent years. Highlighting the difficulties in the quest for curative therapeutics, Luxturna required 16 years of development before finally obtaining United States Food and Drug Administration (FDA) approval and its international equivalents. IRDs are both genetically and phenotypically heterogeneous. While this diversity offers many opportunities for gene-by-gene precision medicine-based approaches, it also poses a significant challenge. For this reason, alternative (or parallel) strategies to identify more comprehensive, across-the-board therapeutics for the genetically and phenotypically diverse IRD patient population are very appealing. Even when gene-specific approaches may be available and become approved for use, many patients may have reached a disease stage whereby these approaches may no longer be viable. Thus, alternate visual preservation or restoration therapeutic approaches are needed at these stages. In this review, we underscore several gene-agnostic approaches that are being developed as therapeutics for IRDs. From retinal supplementation to stem cell transplantation, optogenetic therapy and retinal prosthetics, these strategies would bypass at least in part the need for treating every individual gene or mutation or provide an invaluable complement to them. By considering the diverse patient population and treatment strategies suited for different stages and patterns of retinal degeneration, gene agnostic approaches are very well poised to impact favorably outcomes and prognosis for IRD patients.
Collapse
Affiliation(s)
- Lindsey A. Chew
- Duke Center for Retinal Degenerations and Ophthalmic Genetic Diseases, Department of Ophthalmology, Duke Eye Center, Duke University School of Medicine, Durham, NC, United States
- Department of Cell Biology, Duke University School of Medicine, Durham, NC, United States
| | - Alessandro Iannaccone
- Duke Center for Retinal Degenerations and Ophthalmic Genetic Diseases, Department of Ophthalmology, Duke Eye Center, Duke University School of Medicine, Durham, NC, United States
| |
Collapse
|
7
|
Tong S, An K, Zhou W, Chen W, Sun Y, Wang Q, Li D. Establishment of High-Efficiency Screening System for Gene Deletion in Fusarium venenatum TB01. J Fungi (Basel) 2022; 8:jof8020169. [PMID: 35205923 PMCID: PMC8878023 DOI: 10.3390/jof8020169] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/04/2022] [Accepted: 02/05/2022] [Indexed: 02/04/2023] Open
Abstract
Genetic engineering is one of the most effective methods to obtain fungus strains with desirable traits. However, in some filamentous fungi, targeted gene deletion transformant screening on primary transformation plates is time-consuming and laborious due to a relatively low rate of homologous recombination. A strategy that compensates for the low recombination rate by improving screening efficiency was performed in F. venenatum TB01. In this study, the visualized gene deletion system that could easily distinguish the fluorescent randomly inserted and nonfluorescent putative deletion transformants using green fluorescence protein (GFP) as the marker and a hand-held lamp as the tool was developed. Compared to direct polymerase chain reaction (PCR) screening, the screening efficiency of gene deletion transformants in this system was increased approximately fourfold. The visualized gene deletion system developed here provides a viable method with convenience, high efficiency, and low cost for reaping gene deletion transformants from species with low recombination rates.
Collapse
Affiliation(s)
- Sheng Tong
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (S.T.); (K.A.); (W.Z.); (W.C.); (Y.S.); (Q.W.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
| | - Kexin An
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (S.T.); (K.A.); (W.Z.); (W.C.); (Y.S.); (Q.W.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
| | - Wenyuan Zhou
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (S.T.); (K.A.); (W.Z.); (W.C.); (Y.S.); (Q.W.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
| | - Wuxi Chen
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (S.T.); (K.A.); (W.Z.); (W.C.); (Y.S.); (Q.W.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
| | - Yuanxia Sun
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (S.T.); (K.A.); (W.Z.); (W.C.); (Y.S.); (Q.W.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
| | - Qinhong Wang
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (S.T.); (K.A.); (W.Z.); (W.C.); (Y.S.); (Q.W.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
| | - Demao Li
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (S.T.); (K.A.); (W.Z.); (W.C.); (Y.S.); (Q.W.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
- Correspondence:
| |
Collapse
|
8
|
Zhou Y, Tian W, Jiang X, Yang H, Jiang Z, Li X, Jiang D, Sun K, Yang Y, Liu W, Zhu X. Deletion of Asrgl1 Leads to Photoreceptor Degeneration in Mice. Front Cell Dev Biol 2022; 9:783547. [PMID: 35118070 PMCID: PMC8805730 DOI: 10.3389/fcell.2021.783547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 11/23/2021] [Indexed: 01/01/2023] Open
Abstract
The asparaginase and isoaspartyl peptidase 1 (ASRGL1) is an L-asparaginase and beta-aspartyl peptidase enzyme that may be involved in the formation of L-aspartate, a neurotransmitter that can operate as an excitatory neurotransmitter in some brain regions. Although variants in ASRGL1 have been reported in retinitis pigmentosa (RP) patients, the in vivo functions and mechanisms of ASRGL in RP remains unknown due to the lack of suitable disease models. To explore the role of ASRGL in RP, we generated an Asrgl1 knockout mouse model (Asrgl1 KO) using the CRISPR/Cas9 technique. Asrgl1 ablation in mice led to an attenuated electroretinogram (ERG) response around 8 months. The thickness of the outer nuclei layer (ONL) started to decrease around 9 months in Asrgl1 KO mice and gradually intensified at 12 and 15 months. Immunostaining revealed thinner inner segment (IS) and thinner outer segment (OS) as well as the progressive degeneration of rod and cone cells in Asrgl1 KO mice. One hundred forty-nine transcriptional differentially expressed genes (DEGs) were found by RNA-seq in Asrgl1 KO retina. These DEGs were linked to a number of biological processes that were considerably enriched, including gastrointestinal disease and organismal injury and abnormalities. By analysis of canonical pathways, glucocorticoid receptor signaling was the most significant canonical pathway altered in Asrgl1 KO retina. Several molecules, including NFE2L2, IL-4, Foxp3, and Fos, were in the central nodes of the interaction network in Asrgl1 KO retina. In summary, our study provided a knockout mouse model for a better understanding of the molecular mechanism for ASRGL1-related RP.
Collapse
Affiliation(s)
- Yu Zhou
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
- *Correspondence: Yu Zhou, ; Wenjing Liu, ; Xianjun Zhu,
| | - Wanli Tian
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
| | - Xiaoyan Jiang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
| | - Huining Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
| | - Zhilin Jiang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
| | - Xiao Li
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
| | - Dan Jiang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
| | - Kuanxiang Sun
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
| | - Yeming Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
| | - Wenjing Liu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
- *Correspondence: Yu Zhou, ; Wenjing Liu, ; Xianjun Zhu,
| | - Xianjun Zhu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
- Department of Ophthalmology, First People’s Hospital of Shangqiu, Shangqiu, China
- *Correspondence: Yu Zhou, ; Wenjing Liu, ; Xianjun Zhu,
| |
Collapse
|
9
|
Xu Q, Zhang J, Qin T, Bao J, Dong H, Zhou X, Hou S, Mao L. The role of the inflammasomes in the pathogenesis of uveitis. Exp Eye Res 2021; 208:108618. [PMID: 33989670 DOI: 10.1016/j.exer.2021.108618] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 04/05/2021] [Accepted: 05/05/2021] [Indexed: 01/01/2023]
Abstract
Uveitis is a diverse group of sight-threatening intraocular inflammatory diseases usually causing eye redness, pain, blurred vision, and sometimes blindness. Although the exact pathogenesis of uveitis is not yet clear, accumulating evidences have shown that an imbalanced regulation of immune responses caused by a combination of genetic and environmental factors are implicated in the pathogenesis of this disease. As critical regulators of inflammation, inflammasomes have been assumed to play a role in the pathogenesis of uveitis. Recent studies have reported the association between a number of genetic variants in inflammasome related genes (such as NLRP3, NLRP1, NLRC4 and AIM2) with increased risk to uveitis. Mounting evidence have shown an aberrant activation of the NLRP3 inflammasome in both uveitis patients and murine models of uveitis. Some studies explored the intervention of uveitis via modulating inflammasome activity in the eye. This review aims at summarizing the main findings of these studies, proposing the possible mechanism whereby inflammasomes affect the susceptibility to develop uveitis, and giving a perspective for future studies, which may further improve our understanding about the role of inflammasomes and related cytokines in the pathogenesis of uveitis, and may hopefully lead to new therapeutics by targeting inflammasomes.
Collapse
Affiliation(s)
- Qiuyun Xu
- Department of Immunology, School of Medicine, Nantong University, 19 Qixiu Road, Nantong, Jiangsu, 226001, China
| | - Jie Zhang
- Department of Immunology, School of Medicine, Nantong University, 19 Qixiu Road, Nantong, Jiangsu, 226001, China
| | - Tingyu Qin
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, 1 East Jianshe Road, Zhengzhou, 450052, China
| | - Jingyin Bao
- Basic Medical Research Center, School of Medicine, Nantong University, Nantong, 226001, China
| | - Hongtao Dong
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, 1 East Jianshe Road, Zhengzhou, 450052, China
| | - Xiaorong Zhou
- Department of Immunology, School of Medicine, Nantong University, 19 Qixiu Road, Nantong, Jiangsu, 226001, China.
| | - Shengping Hou
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Eye Institute, Chongqing Key Laboratory of Ophthalmology, Chongqing, 400016, China; Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, 400016, China.
| | - Liming Mao
- Department of Immunology, School of Medicine, Nantong University, 19 Qixiu Road, Nantong, Jiangsu, 226001, China; Basic Medical Research Center, School of Medicine, Nantong University, Nantong, 226001, China.
| |
Collapse
|
10
|
Potilinski MC, Tate PS, Lorenc VE, Gallo JE. New insights into oxidative stress and immune mechanisms involved in age-related macular degeneration tackled by novel therapies. Neuropharmacology 2021; 188:108513. [PMID: 33662390 DOI: 10.1016/j.neuropharm.2021.108513] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 02/14/2021] [Accepted: 02/22/2021] [Indexed: 12/20/2022]
Abstract
The prevalence of age-related macular degeneration (AMD) has increased in the last years. Although anti-VEGF agents have improved the prognosis of exudative AMD, dry AMD has still devastating effects on elderly people vision. Oxidative stress and inflammation are mechanisms involved in AMD pathogenesis and its progression. Molecular pathways involving epidermal growth factor receptor (EGFR), bone morphogenetic protein (BMP4) and the nuclear erythroid related factor 2 (Nrf2) are behind oxidative stress in AMD due to their participation in antioxidant cellular pathways. As a consequence of the disbalance produced in the antioxidant mechanisms, there is an activation of innate and adaptative immune response with cell recruitment, changes in complement factors expression, and modification of cellular milieu. Different therapies are being studied to treat dry AMD based on the possible effects on antioxidant molecular pathways or their action on the immune response. There is a wide range of treatments presented in this review, from natural antioxidant compounds to cell and gene therapy, based on their mechanisms. Finally, we hypothesize that alpha-1-antitrypsin (AAT), an anti-inflammatory and immunomodulatory molecule that can also modulate antioxidant cellular defenses, could be a good candidate for testing in AMD. This article is part of the special ssue on 'The Quest for Disease-Modifying Therapies for Neurodegenerative Disorders'.
Collapse
Affiliation(s)
- María Constanza Potilinski
- Nanomedicine & Vision Lab, Instituto de Investigaciones en Medicina Translacional, Universidad Austral, CONICET, Pilar, Buenos Aires, Argentina
| | - Pablo S Tate
- Laboratorio de Enfermedades Neurodegenerativas, Instituto de Investigaciones en Medicina Translacional, Universidad Austral, CONICET, Pilar, Buenos Aires, Argentina
| | - Valeria E Lorenc
- Nanomedicine & Vision Lab, Instituto de Investigaciones en Medicina Translacional, Universidad Austral, CONICET, Pilar, Buenos Aires, Argentina
| | - Juan E Gallo
- Nanomedicine & Vision Lab, Instituto de Investigaciones en Medicina Translacional, Universidad Austral, CONICET, Pilar, Buenos Aires, Argentina; Departamento de Oftalmología, Hospital Universitario Austral, Pilar, Buenos Aires, Argentina.
| |
Collapse
|
11
|
Fu Z, Kern TS, Hellström A, Smith LEH. Fatty acid oxidation and photoreceptor metabolic needs. J Lipid Res 2021; 62:100035. [PMID: 32094231 PMCID: PMC7905050 DOI: 10.1194/jlr.tr120000618] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/14/2020] [Indexed: 01/31/2023] Open
Abstract
Photoreceptors have high energy demands and a high density of mitochondria that produce ATP through oxidative phosphorylation (OXPHOS) of fuel substrates. Although glucose is the major fuel for CNS brain neurons, in photoreceptors (also CNS), most glucose is not metabolized through OXPHOS but is instead metabolized into lactate by aerobic glycolysis. The major fuel sources for photoreceptor mitochondria remained unclear for almost six decades. Similar to other tissues (like heart and skeletal muscle) with high metabolic rates, photoreceptors were recently found to metabolize fatty acids (palmitate) through OXPHOS. Disruption of lipid entry into photoreceptors leads to extracellular lipid accumulation, suppressed glucose transporter expression, and a duel lipid/glucose fuel shortage. Modulation of lipid metabolism helps restore photoreceptor function. However, further elucidation of the types of lipids used as retinal energy sources, the metabolic interaction with other fuel pathways, as well as the cross-talk among retinal cells to provide energy to photoreceptors is not fully understood. In this review, we will focus on the current understanding of photoreceptor energy demand and sources, and potential future investigations of photoreceptor metabolism.
Collapse
Affiliation(s)
- Zhongjie Fu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Manton Center for Orphan Disease, Boston Children's Hospital, Boston, MA, USA.
| | - Timothy S Kern
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Irvine, CA, USA
| | - Ann Hellström
- Section for Ophthalmology, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Lois E H Smith
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
12
|
Wu DM, Ji X, Ivanchenko MV, Chung M, Piper M, Rana P, Wang SK, Xue Y, West E, Zhao SR, Xu H, Cicconet M, Xiong W, Cepko CL. Nrf2 overexpression rescues the RPE in mouse models of retinitis pigmentosa. JCI Insight 2021; 6:145029. [PMID: 33491671 PMCID: PMC7934854 DOI: 10.1172/jci.insight.145029] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/02/2020] [Indexed: 12/11/2022] Open
Abstract
Nrf2, a transcription factor that regulates the response to oxidative stress, has been shown to rescue cone photoreceptors and slow vision loss in mouse models of retinal degeneration (rd). The retinal pigment epithelium (RPE) is damaged in these models, but whether it also could be rescued by Nrf2 has not been previously examined. We used an adeno-associated virus (AAV) with an RPE-specific (Best1) promoter to overexpress Nrf2 in the RPE of rd mice. Control rd mice showed disruption of the regular array of the RPE, as well as loss of RPE cells. Cones were lost in circumscribed regions within the cone photoreceptor layer. Overexpression of Nrf2 specifically in the RPE was sufficient to rescue the RPE, as well as the disruptions in the cone photoreceptor layer. Electron microscopy showed compromised apical microvilli in control rd mice but showed preserved microvilli in Best1-Nrf2–treated mice. The rd mice treated with Best1-Nrf2 had slightly better visual acuity. Transcriptome profiling showed that Nrf2 upregulates multiple oxidative defense pathways, reversing declines seen in the glutathione pathway in control rd mice. In summary, Nrf2 overexpression in the RPE preserves RPE morphology and survival in rd mice, and it is a potential therapeutic for diseases involving RPE degeneration, including age-related macular degeneration (AMD).
Collapse
Affiliation(s)
- David M Wu
- Massachusetts Eye and Ear Infirmary Retina Service, Department of Ophthalmology.,Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Xuke Ji
- Massachusetts Eye and Ear Infirmary Retina Service, Department of Ophthalmology.,Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Maryna V Ivanchenko
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Michelle Chung
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and.,Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
| | - Mary Piper
- Department of Bioinformatics, T.H. Chan Harvard School of Public Health, Boston, Massachusetts, USA
| | - Parimal Rana
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Sean K Wang
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Yunlu Xue
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Emma West
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Sophia R Zhao
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Hongbin Xu
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and.,Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
| | - Marcelo Cicconet
- Image and Data Analysis Core, Harvard Medical School, Boston, Massachusetts, USA
| | - Wenjun Xiong
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Constance L Cepko
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA.,Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
| |
Collapse
|
13
|
Mitochondria: The Retina's Achilles' Heel in AMD. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1256:237-264. [PMID: 33848005 DOI: 10.1007/978-3-030-66014-7_10] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Strong experimental evidence from studies in human donor retinas and animal models supports the idea that the retinal pathology associated with age-related macular degeneration (AMD) involves mitochondrial dysfunction and consequent altered retinal metabolism. This chapter provides a brief overview of mitochondrial structure and function, summarizes evidence for mitochondrial defects in AMD, and highlights the potential ramifications of these defects on retinal health and function. Discussion of mitochondrial haplogroups and their association with AMD brings to light how mitochondrial genetics can influence disease outcome. As one of the most metabolically active tissues in the human body, there is strong evidence that disruption in key metabolic pathways contributes to AMD pathology. The section on retinal metabolism reviews cell-specific metabolic differences and how the metabolic interdependence of each retinal cell type creates a unique ecosystem that is disrupted in the diseased retina. The final discussion includes strategies for therapeutic interventions that target key mitochondrial pathways as a treatment for AMD.
Collapse
|
14
|
Taylor RE, Zahid M. Cell Penetrating Peptides, Novel Vectors for Gene Therapy. Pharmaceutics 2020; 12:E225. [PMID: 32138146 PMCID: PMC7150854 DOI: 10.3390/pharmaceutics12030225] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 02/27/2020] [Accepted: 03/01/2020] [Indexed: 12/31/2022] Open
Abstract
Cell penetrating peptides (CPPs), also known as protein transduction domains (PTDs), first identified ~25 years ago, are small, 6-30 amino acid long, synthetic, or naturally occurring peptides, able to carry variety of cargoes across the cellular membranes in an intact, functional form. Since their initial description and characterization, the field of cell penetrating peptides as vectors has exploded. The cargoes they can deliver range from other small peptides, full-length proteins, nucleic acids including RNA and DNA, liposomes, nanoparticles, and viral particles as well as radioisotopes and other fluorescent probes for imaging purposes. In this review, we will focus briefly on their history, classification system, and mechanism of transduction followed by a summary of the existing literature on use of CPPs as gene delivery vectors either in the form of modified viruses, plasmid DNA, small interfering RNA, oligonucleotides, full-length genes, DNA origami or peptide nucleic acids.
Collapse
Affiliation(s)
- Rebecca E. Taylor
- Mechanical Engineering, Biomedical Engineering and Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA;
| | - Maliha Zahid
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15201, USA
| |
Collapse
|
15
|
Hu X, Calton MA, Tang S, Vollrath D. Depletion of Mitochondrial DNA in Differentiated Retinal Pigment Epithelial Cells. Sci Rep 2019; 9:15355. [PMID: 31653972 PMCID: PMC6814719 DOI: 10.1038/s41598-019-51761-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 09/26/2019] [Indexed: 11/17/2022] Open
Abstract
We investigated the effects of treating differentiated retinal pigment epithelial (RPE) cells with didanosine (ddI), which is associated with retinopathy in individuals with HIV/AIDS. We hypothesized that such treatment would cause depletion of mitochondrial DNA and provide insight into the consequences of degradation of RPE mitochondrial function in aging and disease. Treatment of differentiated ARPE-19 or human primary RPE cells with 200 µM ddI for 6–24 days was not cytotoxic but caused up to 60% depletion of mitochondrial DNA, and a similar reduction in mitochondrial membrane potential and NDUFA9 protein abundance. Mitochondrial DNA-depleted RPE cells demonstrated enhanced aerobic glycolysis by extracellular flux analysis, increased AMP kinase activation, reduced mTOR activity, and increased resistance to cell death in response to treatment with the oxidant, sodium iodate. We conclude that ddI-mediated mitochondrial DNA depletion promotes a glycolytic shift in differentiated RPE cells and enhances resistance to oxidative damage. Our use of ddI treatment to induce progressive depletion of mitochondrial DNA in differentiated human RPE cells should be widely applicable for other studies aimed at understanding RPE mitochondrial dysfunction in aging and disease.
Collapse
Affiliation(s)
- Xinqian Hu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China. .,Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Melissa A Calton
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Shibo Tang
- AIER School of Ophthalmology, Central South University, Changsha, China.,AIER Eye Institute, Changsha, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Douglas Vollrath
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| |
Collapse
|
16
|
Comitato A, Schiroli D, Montanari M, Marigo V. Calpain Activation Is the Major Cause of Cell Death in Photoreceptors Expressing a Rhodopsin Misfolding Mutation. Mol Neurobiol 2019; 57:589-599. [PMID: 31401765 DOI: 10.1007/s12035-019-01723-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 07/26/2019] [Indexed: 10/26/2022]
Abstract
The majority of mutations in rhodopsin (RHO) cause misfolding of the protein and has been linked to degeneration of photoreceptor cells in the retina. A lot of attention has been set on targeting ER stress for the development of new therapies for inherited retinal degeneration caused by mutations in the RHO gene. Nevertheless, the cell death pathway activated by RHO misfolded protein is still debated. In this study, we analyzed the retina of the knock-in mouse expressing the P23H misfolded mutant RHO. We found persistent unfolded protein response (UPR) during degeneration. Interestingly, long-term stimulation of the PERK branch of ER stress had a protective effect by phosphorylating nuclear factor erythroid 2-related factor 2 (NRF2) transcription factor, associated with antioxidant responses. Otherwise, we provide evidence that increased intracellular calcium and activation of calpains strongly correlated with rod photoreceptor cell death. By blocking calpain activity, we significantly decreased the activation of caspase-7 and apoptosis-inducing factor (AIF), two cell death effectors, and cell demise, and effectively protected the retina from degeneration caused by the P23H dominant mutation in RHO.
Collapse
Affiliation(s)
- Antonella Comitato
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi, 287, 41125, Modena, Italy
| | - Davide Schiroli
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi, 287, 41125, Modena, Italy
| | - Monica Montanari
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi, 287, 41125, Modena, Italy
| | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi, 287, 41125, Modena, Italy.
| |
Collapse
|
17
|
Massengill MT, Young B, Patel D, Jafri F, Sabogal E, Ash N, Li H, Ildefonso CJ, Lewin AS. Clinically Relevant Outcome Measures for the I307N Rhodopsin Mouse: A Model of Inducible Autosomal Dominant Retinitis Pigmentosa. Invest Ophthalmol Vis Sci 2019; 59:5417-5430. [PMID: 30452595 PMCID: PMC6237214 DOI: 10.1167/iovs.18-25345] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Purpose The I307N rhodopsin (Rho) mouse is a light-inducible model of autosomal dominant retinitis pigmentosa (adRP) that may be useful in testing therapies. We investigated the time-course of retinal changes of the I307N Rho mouse with spectral-domain optical coherence tomography (SD-OCT). Methods SD-OCT was performed up to day 30 after light damage; electroretinography (ERG) was employed to evaluate photoreceptor function. We utilized ImageJ to analyze reflectivity of the retina. We used light and electron microscopy to assess retinal organization. We stained synaptophysin and zonula occludins-1 with immunohistochemistry to determine injury to the plexiform layers and retinal pigment epithelium (RPE). We performed lectin staining to evaluate retinal blood vessels. Results Retinal degeneration increased with longer exposures to light. An increase in retinal thickness was detected by SD-OCT on day 1 after light challenge followed by loss of the outer nuclear layer (ONL) by day 8. Degeneration was most severe in the nasal and inferior retina. Hyper-reflectivity on SD-OCT developed as early as 1 day after light exposure. Disorganization of the ONL, condensation of photoreceptor chromatin, disruption of the outer limiting membrane, and disarray of outer segments were associated with the hyper-reflectivity. Retraction of the outer plexiform synapses and resorption of the subretinal detachment contributed to retinal thinning. The RPE remained intact, whereas atrophied major retinal vessels were evident after light damage. Conclusions Our time-course analysis of retinal degeneration in the I307N Rho mouse with SD-OCT and other outcome measures should enable the use of the mouse model in preclinical efficacy studies and mechanistic studies.
Collapse
Affiliation(s)
- Michael T Massengill
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Brianna Young
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Deep Patel
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Farwa Jafri
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Ernesto Sabogal
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Neil Ash
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Hong Li
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Cristhian J Ildefonso
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| |
Collapse
|
18
|
Ji S, Xiong Y, Zhao X, Liu Y, Yu LQ. Effect of the Nrf2-ARE signaling pathway on biological characteristics and sensitivity to sunitinib in renal cell carcinoma. Oncol Lett 2019; 17:5175-5186. [PMID: 31186733 DOI: 10.3892/ol.2019.10156] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 01/17/2019] [Indexed: 12/30/2022] Open
Abstract
The aim of the present study was to examine the effects of the nuclear factor erythroid-2 related factor 2-antioxidant-responsive element (Nrf2-ARE) signaling pathway on the biological characteristics and sensitivity to targeted therapy in human renal cell carcinoma (RCC) cells. RCC tissues and adjacent tissues were collected and assessed by immunohistochemistry to determine the expression of Nrf2, NAD(P)H dehydrogenase [quinone] 1 (NQO1) and heme oxygenase-1 (HO-1) to analyze the clinicopathological features of RCC. A series of in vitro experiments were conducted to analyze the biological characteristics of Nrf2-ARE signaling in RCC. The renal cancer cell line, 786-0 was used, and cells was divided into a mock group, negative control group and small hairpin (sh)RNA-Nrf2 group. A Cell Counting Kit-8 assay was performed alongside flow cytometry to detect cell viability, cell cycle stage and apoptosis following treatment with sunitinib. The results demonstrated that Nrf2, NQO1 and HO-1 were significantly upregulated in RCC tissues compared with adjacent tissues and were associated with tumor node metastasis stage, Fuhrman classification and lymph node metastasis. Following shRNA-Nrf2 transfection, the 786-0 cells demonstrated a significant decrease in viability, cell invasion and scratch healing rate, and the mRNA and protein expression levels of Nrf2, NQO1, HO-1 and glutathione transferase were significantly decreased, which enhanced the sensitivity to sunitinib, arrested cells in the G0/G1 phase and increased apoptosis. In conclusion, Nrf2-ARE signaling is important for RCC progression, and its inhibition may increase sensitivity to targeted drugs to provide novel developments for RCC treatment.
Collapse
Affiliation(s)
- Shiliang Ji
- Department of Pharmacy, Suzhou Science and Technology Town Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215153, P.R. China
| | - Yufeng Xiong
- Department of Clinical Laboratory, Guangdong Women and Children Health Hospital, Guangzhou, Guangdong 510000, P.R. China
| | - Xingxing Zhao
- Department of Neonatology, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, P.R. China
| | - Yanli Liu
- College of Pharmaceutical Science, Soochow University, Suzhou, Jiangsu 215123, P.R. China
| | - Li Qiang Yu
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China
| |
Collapse
|
19
|
Santiago CP, Keuthan CJ, Boye SL, Boye SE, Imam AA, Ash JD. A Drug-Tunable Gene Therapy for Broad-Spectrum Protection against Retinal Degeneration. Mol Ther 2018; 26:2407-2417. [PMID: 30078764 PMCID: PMC6171322 DOI: 10.1016/j.ymthe.2018.07.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 07/10/2018] [Accepted: 07/16/2018] [Indexed: 12/27/2022] Open
Abstract
Retinal degenerations are a large cluster of diseases characterized by the irreversible loss of light-sensitive photoreceptors that impairs the vision of 9.1 million people in the US. An attractive treatment option is to use gene therapy to deliver broad-spectrum neuroprotective factors. However, this approach has had limited clinical translation because of the inability to control transgene expression. To address this problem, we generated an adeno-associated virus vector named RPF2 that was engineered to express domains of leukemia inhibitory factor fused to the destabilization domain of bacterial dihydrofolate reductase. Fusion proteins containing the destabilization domain are degraded in mammalian cells but can be stabilized with the binding of the drug trimethoprim. Our data show that expression levels of RPF2 are tightly regulated by the dose of trimethoprim and can be reversed by trimethoprim withdrawal. We further show that stabilized RPF2 can protect photoreceptors and prevent blindness in treated mice.
Collapse
Affiliation(s)
- Clayton P Santiago
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Casey J Keuthan
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Sanford L Boye
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Shannon E Boye
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Aisha A Imam
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - John D Ash
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA.
| |
Collapse
|
20
|
Kapupara K, Wen YT, Tsai RK, Huang SP. Soluble P-selectin promotes retinal ganglion cell survival through activation of Nrf2 signaling after ischemia injury. Cell Death Dis 2017; 8:e3172. [PMID: 29144506 PMCID: PMC5775414 DOI: 10.1038/cddis.2017.566] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 09/17/2017] [Accepted: 09/20/2017] [Indexed: 12/21/2022]
Abstract
Retinal ischemic injuries play an important role in the pathogenesis of several eye disorders. Inflammation and oxidative stress are key players in ischemic injuries. Following retinal ischemia, vascular endothelial cells and leukocytes express several inflammatory adhesion receptors, such as selectins and cell adhesion molecules. P-selectin stimulates leukocyte recruitment to platelet aggregates and has an important role in vascular homeostasis and inflammatory leukocyte extravasation. Soluble P-selectin can be neuroprotective through competitive binding to the receptors of endogenous P-selectin molecules. Here, we demonstrate the neuroprotective effect of a recombinant P-selectin immunoglobin G (P-sel-IgG) chimeric fusion protein in a rat anterior ischemic optic neuropathy (rAION) model. rAION was induced by photodynamic therapy. P-sel-IgG treatment reduced optic nerve edema and stabilized the blood-optic nerve barrier (BONB) in the acute phase of rAION. Further, P-sel-IgG increased the retinal ganglion cell (RGC) survival rate, reduced RGC apoptosis, preserved visual function, maintained retinal nerve fiber layer thickness, and reduced macrophage infiltration in optic nerve tissue in the chronic phase (day 28). Increased NAD(P)H quinone dehydrogenase 1 (NQO1) and heme oxygenase 1(HO-1) expression levels, along with increased transcription factor Nrf2, suggesting an antioxidant role of P-sel-IgG via the Nrf2 signaling pathway. In conclusion, this study is the first to demonstrate that P-sel-IgG treatment promotes RGC survival by stabilizing the BONB and activating the Nrf2 signaling pathway in a rAION model.
Collapse
Affiliation(s)
- Kishan Kapupara
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan
| | - Yao-Tseng Wen
- Institute of Eye Research, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - Rong-Kung Tsai
- Institute of Eye Research, Buddhist Tzu Chi General Hospital, Hualien, Taiwan.,Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan
| | - Shun-Ping Huang
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan
| |
Collapse
|
21
|
Ulasov AV, Rosenkranz AA, Sobolev AS. Transcription factors: Time to deliver. J Control Release 2017; 269:24-35. [PMID: 29113792 DOI: 10.1016/j.jconrel.2017.11.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 11/02/2017] [Accepted: 11/03/2017] [Indexed: 12/17/2022]
Abstract
Transcription factors (TFs) are at the center of the broad regulatory network orchestrating gene expression programs that elicit different biological responses. For a long time, TFs have been considered as potent drug targets due to their implications in the pathogenesis of a variety of diseases. At the same time, TFs, located at convergence points of cellular regulatory pathways, are powerful tools providing opportunities both for cell type change and for managing the state of cells. This task formulation requires the TF modulation problem to come to the fore. We review several ways to manage TF activity (small molecules, transfection, nanocarriers, protein-based approaches), analyzing their limitations and the possibilities to overcome them. Delivery of TFs could revolutionize the biomedical field. Whether this forecast comes true will depend on the ability to develop convenient technologies for targeted delivery of TFs.
Collapse
Affiliation(s)
- Alexey V Ulasov
- Department of Molecular Genetics of Intracellular Transport, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
| | - Andrey A Rosenkranz
- Department of Molecular Genetics of Intracellular Transport, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia; Faculty of Biology, Moscow State University, 1-12 Leninskiye Gory St., 119234 Moscow, Russia
| | - Alexander S Sobolev
- Department of Molecular Genetics of Intracellular Transport, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia; Faculty of Biology, Moscow State University, 1-12 Leninskiye Gory St., 119234 Moscow, Russia.
| |
Collapse
|
22
|
An inducible form of Nrf2 confers enhanced protection against acute oxidative stresses in RPE cells. Exp Eye Res 2017; 164:31-36. [PMID: 28782506 DOI: 10.1016/j.exer.2017.08.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 07/05/2017] [Accepted: 08/01/2017] [Indexed: 01/02/2023]
Abstract
Increasing evidence suggests that overt oxidative stress within the retina plays an important role in the progression of age-related retinal decline, and in particular, in the disease age-related macular degeneration (AMD). Nuclear factor erythroid 2-like 2 (Nrf2) is a master transcription factor that upregulates numerous of antioxidant/detoxification genes. Nrf2-/- mice develop progressive retinal degeneration that includes the formation of drusen-like deposits, lipofuscin, and sub-retinal pigment epithelium (RPE) deposition of inflammatory proteins. Furthermore, strategies that promote Nrf2 activation have shown promise for the treatment of cone/rod dystrophies and other forms of retinal degeneration. Herein we explored whether utilizing a small molecule-inducible version of Nrf2 confers additional protection against oxidative stresses when compared to a constitutively expressed version of Nrf2. Stable populations of human ARPE-19 cells were generated that express either constitutive FLAG-tagged (FT) Nrf2 (FT cNrf2) or doxycycline (dox)-inducible FT Nrf2 (FT iNrf2) at low levels (∼4.5 fold vs. endogenous). Expression of either FT cNRF2 or FT iNrf2 upregulated canonical antioxidant genes (e.g., NQO1, GCLC). Both FT cNrf2 and FT iNrf2 ARPE-19 cells were protected from cigarette smoke extract-induced nitric oxide generation to similar extents. However, only FT iNrf2 cells demonstrated enhanced resistance to doxorubicin and cumene hydroperoxide-mediated increases in mitochondrial superoxide and lipid peroxidation, respectively, and did so in a dox-dependent manner. These results suggest that therapeutic approaches which conditionally control Nrf2 activity may provide additional protection against acute oxidative stresses when compared to constitutively expressed Nrf2 strategies.
Collapse
|
23
|
Lajko M, Cardona HJ, Taylor JM, Farrow KN, Fawzi AA. Photoreceptor oxidative stress in hyperoxia-induced proliferative retinopathy accelerates rd8 degeneration. PLoS One 2017; 12:e0180384. [PMID: 28671996 PMCID: PMC5495396 DOI: 10.1371/journal.pone.0180384] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 06/14/2017] [Indexed: 12/13/2022] Open
Abstract
To investigate the impact of photoreceptor oxidative stress on photoreceptor degeneration in mice carrying the rd8 mutation (C57BL/6N). We compared the hyperoxia-induced proliferative retinopathy (HIPR) model in two mouse strains (C57BL/6J and C57BL/6N). Pups were exposed to 75% oxygen, starting at birth and continuing for 14 days (P14). Mice were euthanized at P14, or allowed to recover in room air for one day (P15), seven days (P21), or 14 days (P28). We quantified retinal thickness and the length of residual photoreceptors not affected by rosette formation. In addition we explored differences in retinal immunostaining for NADPH oxidase 4 (NOX4), Rac1, vascular endothelium, and activated Mϋller cells. We analyzed photoreceptor oxidative stress using DCF staining in cross sections and quantified NOX4 protein levels using western blotting. C57BL/6N mice in HIPR showed increased oxidative stress, NOX4, and Rac1 in the photoreceptors at P14 and P15 compared to C57BL/6J. In addition, we observed significant progression of photoreceptor degeneration, with significantly accelerated rosette formation in C57BL/6N under HIPR, compared to their room air counterparts. Furthermore, C57BL/6N under HIPR had significantly thinner central retinas than C57BL/6J in HIPR. We did not find a difference in vascular disruption or Mϋller cell activation comparing the two strains in hyperoxia. In HIPR, the C57BL/6N strain carrying the rd8 mutation showed significantly accelerated photoreceptor degeneration, mediated via exacerbated photoreceptor oxidative stress, which we believe relates to Rac1-NOX dysregulation in the setting of Crb1 loss-of-function.
Collapse
Affiliation(s)
- Michelle Lajko
- Department of Ophthalmology, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
| | - Herminio J. Cardona
- Department of Pediatrics, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
| | - Joann M. Taylor
- Department of Pediatrics, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
| | - Kathryn N. Farrow
- Department of Pediatrics, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
| | - Amani A. Fawzi
- Department of Ophthalmology, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
- * E-mail:
| |
Collapse
|
24
|
Involvement of Nrf2 in Ocular Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:1703810. [PMID: 28473877 PMCID: PMC5394909 DOI: 10.1155/2017/1703810] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 03/14/2017] [Indexed: 12/15/2022]
Abstract
The human body harbors within it an intricate and delicate balance between oxidants and antioxidants. Any disruption in this checks-and-balances system can lead to harmful consequences in various organs and tissues, such as the eye. This review focuses on the effects of oxidative stress and the role of a particular antioxidant system—the Keap1-Nrf2-ARE pathway—on ocular diseases, specifically age-related macular degeneration, cataracts, diabetic retinopathy, and glaucoma. Together, they are the major causes of blindness in the world.
Collapse
|
25
|
Tan HY, Agarwal A, Lee CS, Chhablani J, Gupta V, Khatri M, Nirmal J, Pavesio C, Agrawal R. Management of noninfectious posterior uveitis with intravitreal drug therapy. Clin Ophthalmol 2016; 10:1983-2020. [PMID: 27789936 PMCID: PMC5068474 DOI: 10.2147/opth.s89341] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Uveitis is an important cause of vision loss worldwide due to its sight-threatening complications, especially cystoid macular edema, as well as choroidal neovascularization, macular ischemia, cataract, and glaucoma. Systemic corticosteroids are the mainstay of therapy for noninfectious posterior uveitis; however, various systemic side effects can occur. Intravitreal medication achieves a therapeutic level in the vitreous while minimizing systemic complications and is thus used as an exciting alternative. Corticosteroids, antivascular endothelial growth factors, immunomodulators such as methotrexate and sirolimus, and nonsteroidal anti-inflammatory drugs are currently available for intravitreal therapy. This article reviews the existing literature for efficacy and safety of these various options for intravitreal drug therapy for the management of noninfectious uveitis (mainly intermediate, posterior, and panuveitis).
Collapse
Affiliation(s)
- Hui Yi Tan
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Aniruddha Agarwal
- Department of Vitreoretina, Stanley M Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE
| | - Cecilia S Lee
- Department of Ophthalmology, University of Washington, Seattle, WA, USA
| | - Jay Chhablani
- Department of Vitreoretina, L V Prasad Eye Institute, Hyderabad, Telangana
| | - Vishali Gupta
- Department of Retina and Uvea, Post Graduate Institute of Medical Education and Research, Chandigarh
| | - Manoj Khatri
- Department of Retina, Rajan Eye Care Hospital, Chennai, Tamil Nadu, India
| | - Jayabalan Nirmal
- School of Material Science and Engineering, Nanyang Technological University, Singapore
| | - Carlos Pavesio
- Department of Medical Retina, Moorfields Eye Hospital, NHS Foundation Trust, London, UK
| | - Rupesh Agrawal
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore; School of Material Science and Engineering, Nanyang Technological University, Singapore; Department of Medical Retina, Moorfields Eye Hospital, NHS Foundation Trust, London, UK; Department of Ophthalmology, National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore
| |
Collapse
|
26
|
Tyrosinase-Cre-Mediated Deletion of the Autophagy Gene Atg7 Leads to Accumulation of the RPE65 Variant M450 in the Retinal Pigment Epithelium of C57BL/6 Mice. PLoS One 2016; 11:e0161640. [PMID: 27537685 PMCID: PMC4990303 DOI: 10.1371/journal.pone.0161640] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 08/09/2016] [Indexed: 12/26/2022] Open
Abstract
Targeted gene knockout mouse models have helped to identify roles of autophagy in many tissues. Here, we investigated the retinal pigment epithelium (RPE) of Atg7f/f Tyr-Cre mice (on a C57BL/6 background), in which Cre recombinase is expressed under the control of the tyrosinase promoter to delete the autophagy gene Atg7. In line with pigment cell-directed blockade of autophagy, the RPE and the melanocytes of the choroid showed strong accumulation of the autophagy adaptor and substrate, sequestosome 1 (Sqstm1)/p62, relative to the levels in control mice. Immunofluorescence and Western blot analysis demonstrated that the RPE, but not the choroid melanocytes, of Atg7f/f Tyr-Cre mice also had strongly increased levels of retinoid isomerohydrolase RPE65, a pivotal enzyme for the maintenance of visual perception. In contrast to Sqstm1, genes involved in retinal regeneration, i.e. Lrat, Rdh5, Rgr, and Rpe65, were expressed at higher mRNA levels. Sequencing of the Rpe65 gene showed that Atg7f/f and Atg7f/f Tyr-Cre mice carry a point mutation (L450M) that is characteristic for the C57BL/6 mouse strain and reportedly causes enhanced degradation of the RPE65 protein by an as-yet unknown mechanism. These results suggest that the increased abundance of RPE65 M450 in the RPE of Atg7f/f Tyr-Cre mice is, at least partly, mediated by upregulation of Rpe65 transcription; however, our data are also compatible with the hypothesis that the RPE65 M450 protein is degraded by Atg7-dependent autophagy in Atg7f/f mice. Further studies in mice of different genetic backgrounds are necessary to determine the relative contributions of these mechanisms.
Collapse
|