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Abokyi S, Tse DYY. Age-related driving mechanisms of retinal diseases and neuroprotection by transcription factor EB-targeted therapy. Neural Regen Res 2025; 20:366-377. [PMID: 38819040 PMCID: PMC11317960 DOI: 10.4103/nrr.nrr-d-23-02033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 02/08/2024] [Accepted: 03/07/2024] [Indexed: 06/01/2024] Open
Abstract
Retinal aging has been recognized as a significant risk factor for various retinal disorders, including diabetic retinopathy, age-related macular degeneration, and glaucoma, following a growing understanding of the molecular underpinnings of their development. This comprehensive review explores the mechanisms of retinal aging and investigates potential neuroprotective approaches, focusing on the activation of transcription factor EB. Recent meta-analyses have demonstrated promising outcomes of transcription factor EB-targeted strategies, such as exercise, calorie restriction, rapamycin, and metformin, in patients and animal models of these common retinal diseases. The review critically assesses the role of transcription factor EB in retinal biology during aging, its neuroprotective effects, and its therapeutic potential for retinal disorders. The impact of transcription factor EB on retinal aging is cell-specific, influencing metabolic reprogramming and energy homeostasis in retinal neurons through the regulation of mitochondrial quality control and nutrient-sensing pathways. In vascular endothelial cells, transcription factor EB controls important processes, including endothelial cell proliferation, endothelial tube formation, and nitric oxide levels, thereby influencing the inner blood-retinal barrier, angiogenesis, and retinal microvasculature. Additionally, transcription factor EB affects vascular smooth muscle cells, inhibiting vascular calcification and atherogenesis. In retinal pigment epithelial cells, transcription factor EB modulates functions such as autophagy, lysosomal dynamics, and clearance of the aging pigment lipofuscin, thereby promoting photoreceptor survival and regulating vascular endothelial growth factor A expression involved in neovascularization. These cell-specific functions of transcription factor EB significantly impact retinal aging mechanisms encompassing proteostasis, neuronal synapse plasticity, energy metabolism, microvasculature, and inflammation, ultimately offering protection against retinal aging and diseases. The review emphasizes transcription factor EB as a potential therapeutic target for retinal diseases. Therefore, it is imperative to obtain well-controlled direct experimental evidence to confirm the efficacy of transcription factor EB modulation in retinal diseases while minimizing its risk of adverse effects.
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Affiliation(s)
- Samuel Abokyi
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region, China
- Research Center for SHARP Vision, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region, China
| | - Dennis Yan-yin Tse
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region, China
- Research Center for SHARP Vision, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region, China
- Center for Eye and Vision Research, Sha Tin, Hong Kong Special Administrative Region, China
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2
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Sorrentino FS, Di Terlizzi P, De Rosa F, Salati C, Spadea L, Gagliano C, Musa M, Zeppieri M. New frontiers in retinal transplantation. World J Transplant 2024; 14:97690. [DOI: 10.5500/wjt.v14.i4.97690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/22/2024] [Accepted: 07/24/2024] [Indexed: 09/20/2024] Open
Abstract
New frontiers about retinal cell transplantation for retinal degenerative diseases start from the idea that acting on stem cells can help regenerate retinal layers and establish new synapses among retinal cells. Deficiency or alterations of synaptic input and neurotrophic factors result in trans-neuronal degeneration of the inner retinal cells. Thus, the disruption of photoreceptors takes place. However, even in advanced forms of retinal degeneration, a good percentage of the ganglion cells and the inner nuclear layer neurons remain intact. This phenomenon provides evidence for obtaining retinal circuitry through the transplantation of photoreceptors into the subretinal region. The eye is regarded as an optimal organ for cell transplantation because of its immunological privilege and the relatively small number of cells collaborating to carry out visual activities. The eyeball's immunological privilege, characterized by the suppression of delayed-type hypersensitivity responses in ocular tissues, is responsible for the low rate of graft rejection in transplant patients. The main discoveries highlight the capacity of embryonic stem cells (ESCs) and induced pluripotent stem cells to regenerate damaged retinal regions. Recent progress has shown significant enhancements in transplant procedures and results. The research also explores the ethical ramifications linked to the utilization of stem cells, emphasizing the ongoing issue surrounding ESCs. The analysis centers on recent breakthroughs, including the fabrication of three-dimensional retinal organoids and the innovation of scaffolding for cell transportation. Moreover, researchers are currently assessing the possibility of CRISPR and other advanced gene editing technologies to enhance the outcomes of retinal transplantation. The widespread use of universally recognized safe surgical and imaging methods enables retinal transplantation and monitoring of transplanted cell growth toward the correct location. Currently, most therapy approaches are in the first phases of development and necessitate further research, including both pre-clinical and clinical trials, to attain favorable visual results for individuals suffering from retinal degenerative illnesses.
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Affiliation(s)
| | - Patrick Di Terlizzi
- Department of Surgical Sciences, Unit of Ophthalmology, Ospedale Maggiore, Bologna 40100, Italy
| | - Francesco De Rosa
- Department of Oncology, IRCCS Istituto Romagnolo per lo Studio dei Tumori “Dino Amadori”, Meldola 47014, Italy
| | - Carlo Salati
- Department of Ophthalmology, University Hospital of Udine, Udine 33100, Italy
| | - Leopoldo Spadea
- Eye Clinic, Policlinico Umberto I, "Sapienza" University of Rome, Rome 00142, Italy
| | - Caterina Gagliano
- Department of Medicine and Surgery, University of Enna "Kore", Enna 94100, Italy
- Eye Clinic, Catania University San Marco Hospital, Catania 95121, Italy
| | - Mutali Musa
- Department of Optometry, University of Benin, Benin 300283, Nigeria
- Department of Ophthalmology, Centre for Sight Africa, Nkpor, Onitsha 434112, Nigeria
| | - Marco Zeppieri
- Department of Ophthalmology, University Hospital of Udine, Udine 33100, Italy
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Schloesser L, Klose SM, Mauschitz MM, Abdullah Z, Finger RP. The role of immune modulators in age-related macular degeneration. Surv Ophthalmol 2024; 69:851-869. [PMID: 39097172 DOI: 10.1016/j.survophthal.2024.07.009] [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: 03/25/2024] [Revised: 07/27/2024] [Accepted: 07/29/2024] [Indexed: 08/05/2024]
Abstract
We provide an overview of the expanding literature on the role of cytokines and immune mediators in pathophysiology of age-related macular degeneration (AMD). Although many immunological mediators have been linked to AMD pathophysiology, the broader mechanistic picture remains unclear with substantial variations in the levels of evidence supporting these mediators. Therefore, we reviewed the literature considering the varying levels of supporting evidence. A Medical Subject Headings (MeSH) term-based literature research was conducted in September, 2023, consisting of the MeSH terms "cytokine" and "Age-related macular degeneration" connected by the operator "AND". After screening the publications by title, abstract, and full text, a total of 146 publications were included. The proinflammatory cytokines IL-1β (especially in basic research studies), IL-6, IL-8, IL-18, TNF-α, and MCP-1 are the most extensively characterised cytokines/chemokines, highlighting the role of local inflammasome activation and altered macrophage function in the AMD pathophysiology. Among the antiinflammatory mediators IL-4, IL-10, and TGF-β were found to be the most extensively characterised, with IL-4 driving and IL-10 and TGF-β suppressing disease progression. Despite the extensive literature on this topic, a profound understanding of AMD pathophysiology has not yet been achieved. Therefore, further studies are needed to identify potential therapeutic targets, followed by clinical studies.
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Affiliation(s)
- Lukas Schloesser
- Department of Ophthalmology, University of Bonn, Bonn, Germany; Department of Ophthalmology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
| | - Sara M Klose
- Institute of Molecular Medicine and Experimental Immunology, University of Bonn, Bonn, Germany; Asia-Pacific Centre for Animal Health, Faculty of Science, University of Melbourne, Melbourne, Australia
| | | | - Zeinab Abdullah
- Institute of Molecular Medicine and Experimental Immunology, University of Bonn, Bonn, Germany
| | - Robert P Finger
- Department of Ophthalmology, University of Bonn, Bonn, Germany; Department of Ophthalmology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Abbasi N, O'Neill H. Cytocompatibility of electrospun poly-L-lactic acid membranes for Bruch's membrane regeneration using human embryonic stem cell-derived retinal pigment epithelial cells. J Biomed Mater Res A 2024; 112:1902-1920. [PMID: 38726752 DOI: 10.1002/jbm.a.37736] [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: 11/30/2023] [Revised: 04/11/2024] [Accepted: 04/30/2024] [Indexed: 09/03/2024]
Abstract
Cell replacement therapy is under development for dry age-related macular degeneration (AMD). A thin membrane resembling the Bruch's membrane is required to form a cell-on-membrane construct with retinal pigment epithelial (RPE) cells. These cells have been differentiated from human embryonic stem cells (hESCs) in vitro. A carrier membrane is required for cell implantation, which is biocompatible for cell growth and has dimensions and physical properties resembling the Bruch's membrane. Here a nanofiber electrospun poly-L-lactic acid (PLLA) membrane is tested for capacity to support cell growth and maturation. The requirements for laminin coating of the membrane are identified here. A porous electrospun nanofibrous PLLA membrane of ∼50 nm fiber diameter was developed as a prototype support for functional RPE cells grown as a monolayer. The need for laminin coating applied to the membrane following treatment with poly-L-ornithine (PLO), was identified in terms of cell growth and survival. Test membranes were compared in terms of hydrophilicity after laminin coating, mechanical properties of surface roughness and Young's modulus, porosity and ability to promote the attachment and proliferation of hESC-RPE cells in culture for up to 8 weeks. Over this time, RPE cell proliferation, morphology, and marker and gene expression, were monitored. The functional capacity of cell monolayers was identified in terms of transepithelial electrical resistance (TEER), phagocytosis of cells, as well as expression of the cytokines, vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF). PLLA polymer fibers are naturally hydrophobic, so their hydrophilicity was improved by pretreatment with PLO for subsequent coating with the bioactive protein laminin. They were then assessed for amount of laminin adsorbed, contact angle and uniformity of coating using scanning electron microscopy (SEM). Pretreatment with 100% PLO gave the best result over 10% PLO treatment or no treatment prior to laminin adsorption with significantly greater surface stiffness and modulus. By 6 weeks after cell plating, the coated membranes could support a mature RPE monolayer showing a dense apical microvillus structure and pigmented 3D polygonal cell morphology. After 8 weeks, PLO (100%)-Lam coated membranes exhibited the highest cell number, cell proliferation, and RPE barrier function measured as TEER. RPE cells showed the higher levels of specific surface marker and gene expression. Microphthalmia-associated transcription factor expression was highly upregulated indicating maturation of cells. Functionality of cells was indicated by expression of VEGF and PEDF genes as well as phagocytic capacity. In conclusion, electrospun PLLA membranes coated with PLO-Lam have the physical and biological properties to support the distribution and migration of hESC-RPE cells throughout the whole structure. They represent a good membrane candidate for preparation of hESC-RPE cells as a monolayer for implantation into the subretinal space of AMD patients.
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Affiliation(s)
- Naghmeh Abbasi
- Clem Jones Centre for Regenerative Medicine, Faculty of Health Sciences & Medicine, Bond University, Gold Coast, Queensland, Australia
| | - Helen O'Neill
- Clem Jones Centre for Regenerative Medicine, Faculty of Health Sciences & Medicine, Bond University, Gold Coast, Queensland, Australia
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Ji Z, Lin S, Gui S, Gao J, Cao F, Guan Y, Ni Q, Chen K, Tao L, Zhengxuan J. Overexpressed Poldip2 Incurs Retinal Fibrosis via the TGF-β1/SMAD3 Signaling Pathway in Diabetic Retinopathy. Diabetes 2024; 73:1742-1755. [PMID: 38968428 DOI: 10.2337/db23-1036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 06/19/2024] [Indexed: 07/07/2024]
Abstract
Retinal fibrosis is one of the major features of diabetic retinopathy (DR). Our recent research has shown that Poldip2 can affect early DR through oxidative stress, but whether Poldip2 would regulate retinal fibrosis during DR development is still enigmatic. Here, diabetic Sprague-Dawley (SD) rats were induced with streptozotocin (STZ) and treated with adeno-associated virus serotype 9-polymerase-δ interacting protein 2 (Poldip2) shRNA, while human adult retinal pigment epithelial (ARPE-19) cells were treated with high glucose or Poldip2 siRNA. We identified that in STZ-induced DR rats and ARPE-19 cells treated with high glucose, the expression of Poldip2, transforming growth factor-β1 (TGF-β1), phosphorylated-SMAD3/SMAD3, MMP9, COL-1, FN, and CTGF increased while the expression of cadherin decreased. However, deleting Poldip2 inhibited the TGF-β1/SMAD3 signaling pathway and attenuated the above protein expression in vivo and in vitro. Mechanistically, we found that Poldip2 promotes the activation of SMAD3, facilitates its nuclear translocation through interacting with it, and significantly enhances the expression of fibrosis makers. Collectively, Poldip2 was identified is a novel regulator of DR fibrosis and is expected to become a therapeutic target for PDR. ARTICLE HIGHLIGHTS
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Affiliation(s)
- Zhiyu Ji
- Department of Ophthalmology, The Second Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - Siyu Lin
- Department of Ophthalmology, The Second Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - Siyu Gui
- Department of Ophthalmology, The Second Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - Jie Gao
- Department of Ophthalmology, The Second Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - Fan Cao
- Department of Ophthalmology, The Second Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - Yiming Guan
- Department of Ophthalmology, The Second Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - Qinyu Ni
- Department of Ophthalmology, The Second Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - Keyang Chen
- Department of Nutrition and Food Hygiene, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Liming Tao
- Department of Ophthalmology, The Second Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - Jiang Zhengxuan
- Department of Ophthalmology, The Second Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
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Bernd J, Plastino F, Karayannis JJ, Kvanta A, Locri F, André H. Accelerated maturation of ARPE-19 cells for the translational assessment of gene therapy. FASEB J 2024; 38:e70020. [PMID: 39222301 DOI: 10.1096/fj.202301707rr] [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: 08/24/2023] [Revised: 07/16/2024] [Accepted: 08/19/2024] [Indexed: 09/04/2024]
Abstract
The human retinal pigment epithelium (RPE) cell line ARPE-19 is widely used as an alternative to primary RPE despite losing many features of primary RPE. We aimed to determine whether a combination of RPE-specific laminin (LN) and nicotinamide (NAM) could improve ARPE-19 redifferentiation to resemble mature RPE and improve the assessment of RPE-specific gene therapy strategies. ARPE-19 cells were propagated on tissue culture plastic supplemented with NAM and human recombinant LN521-coating. RPE maturation was performed by immunocytochemistry and gene expression by qPCR. Viral transduction experiments with adeno-associated virus (AAV)1 or AAV2, carrying a VMD2-driven GFP, were assessed at 2- and 4-weeks post-plating in the different culturing conditions with a low multiplicity of infection. The combination of LN521 coating with NAM supplementation promoted cytoskeletal and tight junction protein reorganization. The expression of maturation markers bestrophin-1 and RPE 65 was promoted concomitantly with a reduction of several epithelial-mesenchymal transition markers, such as TNF-α, TGF-β, CDH2, and vimentin. Redifferentiated ARPE-19 transduced at low multiplicity of infection of both AAV1- and AAV2-VMD2-GFP. Expression of GFP was detected at 2 weeks and increased at 4 weeks post-plating. AAV1 exhibited a greater expression efficacy compared to AAV2 in maturated ARPE-19 cells already after 2 weeks with increased efficiency after 4 weeks. Our study demonstrates an improved maturation protocol for ARPE-19 cells in vitro, mimicking an in vivo phenotype with the expression of signature genes and improved morphology. Viral-mediated RPE-specific gene expression demonstrates that the combination cultures mimic in vivo AAV tropism essential to test new gene therapies for RPE-centered diseases.
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Affiliation(s)
- Jonathan Bernd
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Flavia Plastino
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Joanna Jackelin Karayannis
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Anders Kvanta
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Filippo Locri
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Helder André
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
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Shi W, Dong Y, Liu S, Li F, Zhu C. Corilagin alleviates ferroptosis in diabetic retinopathy by activating the Nrf2 signaling pathway. Biomed Pharmacother 2024; 179:117409. [PMID: 39243434 DOI: 10.1016/j.biopha.2024.117409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 08/16/2024] [Accepted: 09/02/2024] [Indexed: 09/09/2024] Open
Abstract
BACKGROUND AND PURPOSE Diabetic retinopathy (DR) is a prevalent complication of diabetes, with a rising global incidence, and can result in significant vision impairment and potential blindness in adults. Corilagin (COR) has been shown to regulate several pathological processes. However, the specific protective role and mechanism of action of COR in DR remain unknown. EXPERIMENTAL APPROACH The protective effects and mechanisms of COR in DR were examined using the ARPE-19 cell line and C57BL/6 mice. Intraretinal tissue damage and molecular markers were evaluated to investigate the impact of COR on oxidative stress and cell death pathways. KEY RESULTS In vitro, COR significantly reduced the cytotoxic effects of high glucose (HG) on ARPE-19 cells. Furthermore, COR also effectively decreased HG-induced lipid peroxidation, iron deposition, and ferroptosis and reduced damage to retinal tight junction proteins. Similarly, an in vivo study of streptozotocin (STZ)-induced DM mice showed that the daily gavage of COR for eight weeks notably alleviated DR. Mechanistically, COR activated the Nrf2 antioxidant signaling pathway both in vivo and in vitro, preventing HG-induced alterations in morphological and biochemical parameters. Notably, our study demonstrated that compared with controls, Nrf2 knockout mice and siNrf2-treated cells were more vulnerable to ferroptosis under HG conditions, and the protective effect of COR on DR was substantially diminished in these models. CONCLUSION AND IMPLICATIONS These data indicate that COR has a protective effect against HG-induced retinal injury via a mechanism associated with the Nrf2-dependent antioxidant pathway and ferroptosis regulation.
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Affiliation(s)
- Wenxin Shi
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, China
| | - Yuchen Dong
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, China
| | - Shuyan Liu
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, China
| | - Fengji Li
- The Second Hospital of Jilin University, Changchun, China
| | - Chao Zhu
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, China.
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Rizwan S, Toothman B, Li B, Engel AL, Lim RR, Niernberger S, Lu J, Ratliff C, Xiang Y, Eminhizer M, Chao JR, Du J. Metabolic Phenotyping of Healthy and Diseased Human RPE Cells. Invest Ophthalmol Vis Sci 2024; 65:5. [PMID: 39230994 PMCID: PMC11379083 DOI: 10.1167/iovs.65.11.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2024] Open
Abstract
Purpose Metabolic defects in the retinal pigment epithelium (RPE) underlie many retinal degenerative diseases. This study aims to identify the nutrient requirements of healthy and diseased human RPE cells. Methods We profiled nutrient use of various human RPE cells, including differentiated and dedifferentiated fetal RPE (fRPE), induced pluripotent stem cell-derived RPE (iPSC RPE), Sorsby fundus dystrophy (SFD) patient-derived iPSC RPE, CRISPR-corrected isogenic SFD (cSFD) iPSC RPE, and ARPE-19 cell lines using Biolog Phenotype MicroArray Assays. Results Differentiated fRPE cells and healthy iPSC RPE cells can use 51 and 48 nutrients respectively, including sugars, intermediates from glycolysis and tricarboxylic acid (TCA) cycle, fatty acids, ketone bodies, amino acids, and dipeptides. However, when fRPE cells lose their epithelial phenotype through dedifferentiation, nutrient use becomes restricted to 17 nutrients, primarily sugar and glutamine-related amino acids. SFD RPE cells can use 37 nutrients; however, compared to cSFD RPE and healthy iPSC RPE, they are unable to use lactate, some TCA cycle intermediates, and short-chain fatty acids. Nonetheless, they show increased use of branch-chain amino acids (BCAAs) and BCAA-containing dipeptides. Dedifferentiated ARPE-19 cells grown in traditional culture media cannot use lactate and ketone bodies. In contrast, nicotinamide supplementation promotes differentiation toward an epithelial phenotype, restoring the ability to use these nutrients. Conclusions Epithelial phenotype confers metabolic flexibility to healthy RPE for using various nutrients. SFD RPE cells have reduced metabolic flexibility, relying on the oxidation of BCAAs. Our findings highlight the potentially important roles of nutrient availability and use in RPE differentiation and diseases.
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Affiliation(s)
- Saira Rizwan
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, United States
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, United States
| | - Beverly Toothman
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, United States
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, United States
| | - Bo Li
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, United States
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, United States
- Department of Ophthalmology, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, Jiangsu Province, China
| | - Abbi L Engel
- Department of Ophthalmology, University of Washington, Seattle, Washington, United States
| | - Rayne R Lim
- Department of Ophthalmology, University of Washington, Seattle, Washington, United States
| | - Sheldon Niernberger
- Department of Ophthalmology, University of Washington, Seattle, Washington, United States
| | - Jinyu Lu
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, United States
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, United States
| | - Cloe Ratliff
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, United States
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, United States
| | - Yinxiao Xiang
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, United States
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, United States
| | - Mark Eminhizer
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, United States
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, United States
| | - Jennifer R Chao
- Department of Ophthalmology, University of Washington, Seattle, Washington, United States
| | - Jianhai Du
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, United States
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, West Virginia, United States
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Kong I, Ka-Wing Yuen G, Wu QY, Sui-Sui Guo M, Gao J, Ting-Xia Dong T, Wah-Keung Tsim K. Acetylcholine regulates the melanogenesis of retinal pigment epithelia cells via a cAMP-dependent pathway: A non-neuronal function of cholinergic system in retina. Heliyon 2024; 10:e36207. [PMID: 39253121 PMCID: PMC11382043 DOI: 10.1016/j.heliyon.2024.e36207] [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: 01/09/2024] [Revised: 08/11/2024] [Accepted: 08/12/2024] [Indexed: 09/11/2024] Open
Abstract
The turnover rate of melanogenesis in retinal pigment epithelium (RPE) and its molecular signaling remain unclear. This study aimed to investigate the role of cholinergic signaling in the process of melanogenesis of cultured RPE cells. Here, a human retinal pigment epithelia cell line, ARPE-19 cell, was used to study the process of melanogenesis. The mRNA and protein expressions of cholinergic molecules, e.g., acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and melanogenic molecules i.e., tyrosinase (TYR), microphthalmia-associated transcription factor (MITF), and melanin pigment were measured during melanogenesis of cultured ARPE-19 cells. Forskolin (a cAMP inducing agent), acetylcholine (ACh) and bethanechol (Bch; a muscarinic AChR agonist) were used to induce melanogenesis in the cultures. Muscarinic acetylcholine receptor (mAChR) antagonists were employed to identify the receptor subtype. During melanogenesis of ARPE-19 cells, the mRNA and protein expressions of cholinergic molecules, e.g., AChE and BChE, were increased along with melanogenic molecules, i.e., TYR, MITF and melanin pigment. Forskolin, ACh, and Bch induced an upregulation of melanogenesis in cultured ARPE-19 cultures: the induction was parallel to an increase of AChE expression. The Bch-induced enzymatic activities and mRNA levels of AChE and TYR were fully blocked by the treatments of gallamine (a M2 specific antagonist), tropicamide (a M4 specific antagonist) and atropine (non-specific antagonist for mAChRs). Cholinergic signaling via M2/M4 mAChRs regulates melanogenesis in cultured ARPE-19 cells through a cAMP-dependent pathway. This study provides insights into the regulation of RPE cell melanogenesis via a non-neuronal function of cholinergic system.
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Affiliation(s)
- Ivan Kong
- Division of Life Science and Centre for Chinese Medicine, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, HKUST Shenzhen Research Institute, Shenzhen 518057, China
| | - Gary Ka-Wing Yuen
- Division of Life Science and Centre for Chinese Medicine, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, HKUST Shenzhen Research Institute, Shenzhen 518057, China
| | - Qi-Yun Wu
- Division of Life Science and Centre for Chinese Medicine, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, HKUST Shenzhen Research Institute, Shenzhen 518057, China
| | - Maggie Sui-Sui Guo
- Division of Life Science and Centre for Chinese Medicine, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, HKUST Shenzhen Research Institute, Shenzhen 518057, China
| | - Jin Gao
- Division of Life Science and Centre for Chinese Medicine, The Hong Kong University of Science and Technology, Hong Kong, China
- Department of Neurobiology and Cellular Biology, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China
| | - Tina Ting-Xia Dong
- Division of Life Science and Centre for Chinese Medicine, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, HKUST Shenzhen Research Institute, Shenzhen 518057, China
| | - Karl Wah-Keung Tsim
- Division of Life Science and Centre for Chinese Medicine, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, HKUST Shenzhen Research Institute, Shenzhen 518057, China
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Wen C, Yu X, Zhu J, Zeng J, Kuang X, Zhang Y, Tang S, Zhang Q, Yan J, Shen H. Gastrodin ameliorates oxidative stress-induced RPE damage by facilitating autophagy and phagocytosis through PPARα-TFEB/CD36 signal pathway. Free Radic Biol Med 2024; 224:103-116. [PMID: 39173893 DOI: 10.1016/j.freeradbiomed.2024.08.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2024] [Revised: 08/19/2024] [Accepted: 08/20/2024] [Indexed: 08/24/2024]
Abstract
Age-related macular degeneration (AMD), the leading cause of irreversible blindness in the elderly, is primarily characterized by the degeneration of the retinal pigment epithelium (RPE). However, effective therapeutic options for dry AMD are currently lacking, necessitating further exploration into preventive and pharmaceutical interventions. This study aimed to investigate the protective effects of gastrodin on RPE cells exposed to oxidative stress. We constructed an in vitro oxidative stress model of 4-hydroxynonenal (4-HNE) and performed RNA-seq, and demonstrated the protective effect of gastrodin through mouse experiments. Our findings reveal that gastrodin can inhibit 4-HNE-induced oxidative stress, effectively improving the mitochondrial and lysosomal dysfunction of RPE cells. We further elucidated that gastrodin promotes autophagy and phagocytosis through activating the PPARα-TFEB/CD36 signaling pathway. Interestingly, these outcomes were corroborated in a mouse model, in which gastrodin maintained retinal integrity and reduced RPE disorganization and degeneration under oxidative stress. The accumulation of LC3B and SQSTM1 in mouse RPE-choroid was also reduced. Moreover, activating PPARα and downstream pathways to restore autophagy and phagocytosis, thereby countering RPE injury from oxidative stress. In conclusion, this study demonstrated that gastrodin maintains the normal function of RPE cells by reducing oxidative stress, enhancing their phagocytic function, and restoring the level of autophagic flow. These findings suggest that gastrodin is a novel formulation with potential applications in the development of AMD disease.
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Affiliation(s)
- Chaojuan Wen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Xinyue Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Jingya Zhu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Jingshu Zeng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Xielan Kuang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
- Eye Biobank, State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Youao Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Shiyu Tang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Jianhua Yan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Huangxuan Shen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
- Eye Biobank, State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
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11
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Fonseca AF, Coelho R, da-Silva ML, Lemos L, Hall MJ, Oliveira D, Falcão AS, Tenreiro S, Seabra MC, Antas P. Modeling Choroideremia Disease with Isogenic Induced Pluripotent Stem Cells. Stem Cells Dev 2024. [PMID: 39078329 DOI: 10.1089/scd.2024.0105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2024] Open
Abstract
Choroideremia (CHM) is a rare X-linked chorioretinal dystrophy causing progressive vision loss due to mutations in the CHM gene, leading to Rab escort protein 1 loss of function. CHM disease is characterized by a progressive degeneration of the choroid, the retinal pigment epithelium (RPE), and the retina. The RPE is a monolayer of polarized cells that supports photoreceptors, providing nutrients, growth factors, and ions, and removes retinal metabolism waste products, having a central role in CHM pathogenesis. Commonly used models such as ARPE-19 cells do not reproduce accurately the nature of RPE cells. Human induced pluripotent stem cells (hiPSCs) can be differentiated into RPE cells (hiPSC-RPE), which mimic key features of native RPE, being more suited to study retinal diseases. Therefore, we took advantage of hiPSCs to generate new human-based CHM models. Two isogenic hiPSC lines were generated through CRISPR/Cas9: a CHM knock-out line from a healthy donor and a corrected CHM patient line using a knock-in approach. The differentiated hiPSC-RPE lines exhibited critical morphological and physiological characteristics of native RPE, including the presence of the tight junction markers Claudin-19 and Zonula Occludens-1, phagocytosis of photoreceptor outer segments, pigmentation, a postmitotic state, and the characteristic polygonal shape. In addition, all the studied cells were able to form retinal organoids. This work resulted in the establishment of isogenic hiPSC lines, representing a new and important CHM cellular model. To our knowledge, this is the first time that isogenic cell lines have been developed to model CHM disease, providing a valuable tool for studying the mechanisms at the onset of RPE degeneration.
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Affiliation(s)
- Ana Fragoso Fonseca
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS | FCM, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Rita Coelho
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS | FCM, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Mafalda Lopes- da-Silva
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS | FCM, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Luísa Lemos
- Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal
| | - Michael J Hall
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS | FCM, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Daniela Oliveira
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS | FCM, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Ana Sofia Falcão
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS | FCM, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Sandra Tenreiro
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS | FCM, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Miguel C Seabra
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS | FCM, Universidade Nova de Lisboa, Lisboa, Portugal
- Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal
| | - Pedro Antas
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS | FCM, Universidade Nova de Lisboa, Lisboa, Portugal
- Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal
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12
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Xu J, Zhao C, Kang Y. The Formation and Renewal of Photoreceptor Outer Segments. Cells 2024; 13:1357. [PMID: 39195247 DOI: 10.3390/cells13161357] [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: 06/30/2024] [Revised: 08/12/2024] [Accepted: 08/13/2024] [Indexed: 08/29/2024] Open
Abstract
The visual system is essential for humans to perceive the environment. In the retina, rod and cone photoreceptor neurons are the initial sites where vision forms. The apical region of both cone and rod photoreceptors contains a light-sensing organelle known as the outer segment (OS), which houses tens of thousands of light-sensitive opsins. The OSs of photoreceptors are not static; they require rhythmic renewal to maintain normal physiological functions. Disruptions in OS renewal can lead to various genetic disorders, such as retinitis pigmentosa (RP). Understanding the patterns and molecular mechanisms of photoreceptor OS renewal remains one of the most intriguing topics in visual biology. This review aims to elucidate the structure of photoreceptor OSs, the molecular mechanisms underlying photoreceptor OS renewal, and the retinal diseases resulting from defects in this renewal process. Additionally, we will explore retinal diseases related to photoreceptor OS renewal and potential therapeutic strategies, concluding with a discussion on future research directions for OS renewal.
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Affiliation(s)
- Jingjin Xu
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
- MoE Key Laboratory of Evolution and Marine Biodiversity, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Chengtian Zhao
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
- MoE Key Laboratory of Evolution and Marine Biodiversity, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Yunsi Kang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
- MoE Key Laboratory of Evolution and Marine Biodiversity, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
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13
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Hyttinen JMT, Koskela A, Blasiak J, Kaarniranta K. Autophagy in drusen biogenesis secondary to age-related macular degeneration. Acta Ophthalmol 2024. [PMID: 39087629 DOI: 10.1111/aos.16744] [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: 03/25/2024] [Accepted: 07/11/2024] [Indexed: 08/02/2024]
Abstract
Age-related macular degeneration (AMD) is an emerging cause of blindness in aged people worldwide. One of the key signs of AMD is the degeneration of the retinal pigment epithelium (RPE), which is indispensable for the maintenance of the adjacent photoreceptors. Because of impaired energy metabolism resulting from constant light exposure, hypoxia, and oxidative stress, accumulation of drusen in AMD-affected eyes is observed. Drusen contain damaged cellular proteins, lipoprotein particles, lipids and carbohydrates and they are related to impaired protein clearance, inflammation, and extracellular matrix modification. When autophagy, a major cellular proteostasis pathway, is impaired, the accumulations of intracellular lipofuscin and extracellular drusen are detected. As these aggregates grow over time, they finally cause the disorganisation and destruction of the RPE and photoreceptors leading to visual loss. In this review, the role of autophagy in drusen biogenesis is discussed since impairment in removing cellular waste in RPE cells plays a key role in AMD progression. In the future, means which improve intracellular clearance might be of use in AMD therapy to slow the progression of drusen formation.
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Affiliation(s)
- Juha M T Hyttinen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Ali Koskela
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Janusz Blasiak
- Faculty of Medicine, Collegium Medicum, Mazovian Academy in Plock, Plock, Poland
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
- Department of Molecular Genetics, University of Lodz, Lodz, Poland
- Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland
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14
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Liu X, Pacwa A, Bresciani G, Swierczynska M, Dorecka M, Smedowski A. Retinal primary cilia and their dysfunction in retinal neurodegenerative diseases: beyond ciliopathies. Mol Med 2024; 30:109. [PMID: 39060957 PMCID: PMC11282803 DOI: 10.1186/s10020-024-00875-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 07/13/2024] [Indexed: 07/28/2024] Open
Abstract
Primary cilia are sensory organelles that extend from the cellular membrane and are found in a wide range of cell types. Cilia possess a plethora of vital components that enable the detection and transmission of several signaling pathways, including Wnt and Shh. In turn, the regulation of ciliogenesis and cilium length is influenced by various factors, including autophagy, organization of the actin cytoskeleton, and signaling inside the cilium. Irregularities in the development, maintenance, and function of this cellular component lead to a range of clinical manifestations known as ciliopathies. The majority of people with ciliopathies have a high prevalence of retinal degeneration. The most common theory is that retinal degeneration is primarily caused by functional and developmental problems within retinal photoreceptors. The contribution of other ciliated retinal cell types to retinal degeneration has not been explored to date. In this review, we examine the occurrence of primary cilia in various retinal cell types and their significance in pathology. Additionally, we explore potential therapeutic approaches targeting ciliopathies. By engaging in this endeavor, we present new ideas that elucidate innovative concepts for the future investigation and treatment of retinal ciliopathies.
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Affiliation(s)
- Xiaonan Liu
- Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Ceglana 35, 40-514, Katowice, Poland.
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland.
| | - Anna Pacwa
- GlaucoTech Co, Katowice, Poland
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medykow 18, 40-752, Katowice, Poland
| | | | - Marta Swierczynska
- Department of Ophthalmology, Professor K. Gibinski University Clinical Center, Medical University of Silesia, Katowice, Poland
- Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Ceglana 35, 40-514, Katowice, Poland
| | - Mariola Dorecka
- Department of Ophthalmology, Professor K. Gibinski University Clinical Center, Medical University of Silesia, Katowice, Poland
- Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Ceglana 35, 40-514, Katowice, Poland
| | - Adrian Smedowski
- GlaucoTech Co, Katowice, Poland.
- Department of Ophthalmology, Professor K. Gibinski University Clinical Center, Medical University of Silesia, Katowice, Poland.
- Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Ceglana 35, 40-514, Katowice, Poland.
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15
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Erguven P, Sevgin K, Kotil T, Kaleci B, Caglar HG, Ozer OF. Continuous Thymoquinone Administration Mitigates Sodium Iodate-Induced Retinal Degeneration in Rats. Curr Eye Res 2024:1-9. [PMID: 39039707 DOI: 10.1080/02713683.2024.2381203] [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: 01/24/2024] [Accepted: 07/12/2024] [Indexed: 07/24/2024]
Abstract
PURPOSE This study aimed to investigate the protective or therapeutic effect of thymoquinone (TQ) in a retinal degeneration rat model and its relationships with the retina ultrastructure, heme oxygenase 1 (HO-1), caspase-3, and RPE65 expressions and to determine whether TQ has a therapeutic effect at the biochemical level. METHODS A total of 25 adult Wistar albino rats were divided into the following treatment groups: saline (control: CONT), CO (corn oil), sodium iodate (SI), TQ + SI, and SI + TQ injection groups. Retina morphology, RPE65, HO-1, and caspase-3 expression levels were evaluated using immunohistochemistry, and optical density was determined using ImageJ. Ultrastructural evaluations were performed with electron microscopy. Thiol-disulfide homeostatic parameters were examined in serum samples. RESULTS Outer nuclear layer (ONL) thickness was significantly higher in the SI + TQ group compared to the SI group. The RPE65 expression significantly decreased in the SI group compared with the CONT and CO groups. A significant increase in RPE65 expression level and a significant decrease in caspase-3 expression level were found in the SI + TQ group compared with the SI group. The increase in HO-1 expression level was significantly higher in the TQ treatment groups, particularly in the SI + TQ group. In the SI and TQ + SI groups, the ONL thickness significantly decreased with a significant increase in caspase-3 expression compared to the CONT and CO groups. In the treatment groups, decreased organelle damage was observed on electron microscopy. In the SI + TQ group, the disulfide/native thiol and disulfide/total thiol ratios were significantly lower than all other groups, while the native/total thiol ratio was significantly higher than the other experimental groups. CONCLUSIONS The present study provides evidence that continuous TQ treatment can increase HO-1 and RPE65 expression and decrease apoptosis (caspase-3 levels), thereby preserving the retina at the ultrastructural level. Moreover, TQ administration can maintain thiol/disulfide homeostasis in SI-induced retinal degeneration-modelled rats.
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Affiliation(s)
- Pelin Erguven
- Department of Histology and Embryology, International Faculty of Medicine, University of Health Sciences, Istanbul, Turkey
| | - Kubra Sevgin
- Department of Histology and Embryology, International Faculty of Medicine, University of Health Sciences, Istanbul, Turkey
| | - Tugba Kotil
- Department of Histology and Embryology, Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Belisa Kaleci
- Department of Nursing and Physiotherapy, Faculty of Medical Sciences, Albanian University, Tirana, Albania
| | | | - Omer Faruk Ozer
- Department of Medical Biochemistry, Faculty of Medicine, Bezmialem University, Istanbul, Turkey
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16
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Jones RM, Ruiz JH, Scaramuzza S, Nath S, Liu C, Henklewska M, Natsume T, Bristow RG, Romero F, Kanemaki MT, Gambus A. Characterizing replisome disassembly in human cells. iScience 2024; 27:110260. [PMID: 39055910 PMCID: PMC11269944 DOI: 10.1016/j.isci.2024.110260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 03/22/2024] [Accepted: 06/10/2024] [Indexed: 07/28/2024] Open
Abstract
To ensure timely duplication of the entire eukaryotic genome, thousands of replication machineries (replisomes) act on genomic DNA at any time during S phase. In the final stages of this process, replisomes are unloaded from chromatin. Unloading is driven by polyubiquitylation of MCM7, a subunit of the terminated replicative helicase, and processed by p97/VCP segregase. Most of our knowledge of replication termination comes from model organisms, and little is known about how this process is executed and regulated in human somatic cells. Here we show that replisome disassembly in this system requires CUL2LRR1-driven MCM7 ubiquitylation, p97, and UBXN7 for unloading and provide evidence for "backup" mitotic replisome disassembly, demonstrating conservation of such mechanisms. Finally, we find that small-molecule inhibitors against Cullin ubiquitin ligases (CULi) and p97 (p97i) affect replisome unloading but also lead to induction of replication stress in cells, which limits their usefulness to specifically target replisome disassembly processes.
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Affiliation(s)
- Rebecca M. Jones
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
| | - Joaquin Herrero Ruiz
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka, Japan
| | - Shaun Scaramuzza
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
| | - Sarmi Nath
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
| | - Chaoyu Liu
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
| | - Marta Henklewska
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
| | - Toyoaki Natsume
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems, Mishima, Shizuoka, Japan
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka, Japan
| | - Robert G. Bristow
- Cancer Research UK – Manchester Institute, Manchester Cancer Research Center, Manchester, UK
| | - Francisco Romero
- Department of Microbiology, University of Seville, Seville, Spain
| | - Masato T. Kanemaki
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems, Mishima, Shizuoka, Japan
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka, Japan
- Department of Biological Science, The University of Tokyo, Tokyo, Japan
| | - Agnieszka Gambus
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
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17
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Rizwan S, Toothman B, Li B, Engel AJ, Lim RR, Niernberger S, Lu J, Ratliff C, Xiang Y, Eminhizer M, Chao JR, Du J. Metabolic phenotyping of healthy and diseased human RPE cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.28.582405. [PMID: 38464098 PMCID: PMC10925320 DOI: 10.1101/2024.02.28.582405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Purpose Metabolic defects in the retinal pigment epithelium (RPE) underlie many retinal degenerative diseases. This study aims to identify the nutrient requirements of healthy and diseased human RPE cells. Methods We profiled nutrient utilization of various human RPE cells, including differentiated and dedifferentiated fetal RPE (fRPE), induced pluripotent stem cell derived-RPE (iPSC RPE), Sorsby fundus dystrophy (SFD) patient-derived iPSC RPE, CRISPR-corrected isogenic SFD (cSFD) iPSC RPE, and ARPE-19 cell lines using Biolog Phenotype MicroArray Assays. Results Differentiated fRPE cells and healthy iPSC RPE cells can utilize 51 and 48 nutrients respectively, including sugars, intermediates from glycolysis and tricarboxylic acid (TCA) cycle, fatty acids, ketone bodies, amino acids, and dipeptides. However, when fRPE cells lose their epithelial phenotype through dedifferentiation, nutrient utilization becomes restricted to 17 nutrients, primarily sugar and glutamine-related amino acids. SFD RPE cells can utilize 37 nutrients; however, compared to cSFD RPE and healthy iPSC RPE, they are unable to utilize lactate, some TCA cycle intermediates, and short-chain fatty acids. Nonetheless, they show increased utilization of branch-chain amino acids (BCAAs) and BCAA-containing dipeptides. Dedifferentiated ARPE-19 cells grown in traditional culture media cannot utilize lactate and ketone bodies. In contrast, nicotinamide supplementation promotes differentiation towards an epithelial phenotype, restoring the ability to use these nutrients. Conclusions Epithelial phenotype confers metabolic flexibility to healthy RPE for utilizing various nutrients. SFD RPE cells have reduced metabolic flexibility, relying on the oxidation of BCAAs. Our findings highlight the potentially important roles of nutrient availability and utilization in RPE differentiation and diseases.
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18
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He J, Xiong S, Zhou W, Qiu H, Rao Y, Liu Y, Shen G, Zhao P, Chen G, Li J. Long-term polystyrene nanoparticles exposure reduces electroretinal responses and exacerbates retinal degeneration induced by light exposure. JOURNAL OF HAZARDOUS MATERIALS 2024; 473:134586. [PMID: 38776811 DOI: 10.1016/j.jhazmat.2024.134586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/25/2024]
Abstract
The impact of plastic pollution on living organisms have gained significant research attention. However, the effects of nanoplastics (NPs) on retina remain unclear. This study aimed to investigate the effect of long-term polystyrene nanoparticles (PS-NPs) exposure on mouse retina. Eight weeks old C57BL/6 J mice were exposed to PS-NPs at the diameter of 100 nm and concentration of 10 mg/L in drinking water for 3 months. PS-NPs were able to penetrate the blood-retina barrier, accumulated at retinal tissue, caused increased oxidative stress level and reduced scotopic electroretinal responses without remarkable structural damage. PS-NPs exposure caused cytotoxicity and reactive oxygen species accumulation in cultured photoreceptor cell. PS-NPs exposure increased oxidative stress level in retinal pigment epithelial (RPE) cells, leading to changes of gene and protein expression indicative of compromised phagocytic activity and cell junction formation. Long-term PS-NPs exposure also aggravated light-induced photoreceptor cell degeneration and retinal inflammation. The transcriptomic profile of PS-NPs-exposed, light-challenged retinal tissue shared similar features with those of age-related macular degeneration (AMD) patients in the activation of complement-mediated phagocytic and proinflammatory responses. Collectively, these findings demonstrated the oxidative stress- and inflammation-mediated detrimental effect of PS-NPs on retinal function, suggested that long-term PS-NPs exposure could be an environmental risk factor contributing to retinal degeneration.
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Affiliation(s)
- Jincan He
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092 China
| | - Shiyi Xiong
- Shanghai Key Laboratory of Maternal Fetal Medicine, Department of Fetal Medicine and Prenatal Diagnosis Center, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai 201204, China
| | - Wenchuan Zhou
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092 China
| | - Hao Qiu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yuqing Rao
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092 China
| | - Ya Liu
- Institute of Traditional Chinese Medicine and Stem Cell Research, College of Basic Medical Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Guiyan Shen
- Institute of Traditional Chinese Medicine and Stem Cell Research, College of Basic Medical Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Peiquan Zhao
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092 China
| | - Guangquan Chen
- Department of Obstetrics and Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai 201204, China.
| | - Jing Li
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092 China.
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19
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Ohguro H, Watanabe M, Hikage F, Sato T, Nishikiori N, Umetsu A, Higashide M, Ogawa T, Furuhashi M. Fatty Acid-Binding Protein 4-Mediated Regulation Is Pivotally Involved in Retinal Pathophysiology: A Review. Int J Mol Sci 2024; 25:7717. [PMID: 39062961 PMCID: PMC11277531 DOI: 10.3390/ijms25147717] [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: 06/01/2024] [Revised: 07/09/2024] [Accepted: 07/11/2024] [Indexed: 07/28/2024] Open
Abstract
Fatty acid-binding proteins (FABPs), a family of lipid chaperone molecules that are involved in intracellular lipid transportation to specific cellular compartments, stimulate lipid-associated responses such as biological signaling, membrane synthesis, transcriptional regulation, and lipid synthesis. Previous studies have shown that FABP4, a member of this family of proteins that are expressed in adipocytes and macrophages, plays pivotal roles in the pathogenesis of various cardiovascular and metabolic diseases, including diabetes mellitus (DM) and hypertension (HT). Since significant increases in the serum levels of FABP4 were detected in those patients, FABP4 has been identified as a crucial biomarker for these systemic diseases. In addition, in the field of ophthalmology, our group found that intraocular levels of FABP4 (ioFABP4) and free fatty acids (ioFFA) were substantially elevated in patients with retinal vascular diseases (RVDs) including proliferative diabetic retinopathy (PDR) and retinal vein occlusion (RVO), for which DM and HT are also recognized as significant risk factors. Recent studies have also revealed that ioFABP4 plays important roles in both retinal physiology and pathogenesis, and the results of these studies have suggested potential molecular targets for retinal diseases that might lead to future new therapeutic strategies.
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Affiliation(s)
- Hiroshi Ohguro
- Departments of Ophthalmology, School of Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (M.W.); (F.H.); (N.N.); (A.U.); (M.H.)
| | - Megumi Watanabe
- Departments of Ophthalmology, School of Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (M.W.); (F.H.); (N.N.); (A.U.); (M.H.)
| | - Fumihito Hikage
- Departments of Ophthalmology, School of Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (M.W.); (F.H.); (N.N.); (A.U.); (M.H.)
| | - Tatsuya Sato
- Departments of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (T.S.); (T.O.)
- Departments of Cellular Physiology and Signal Transduction, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan
| | - Nami Nishikiori
- Departments of Ophthalmology, School of Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (M.W.); (F.H.); (N.N.); (A.U.); (M.H.)
| | - Araya Umetsu
- Departments of Ophthalmology, School of Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (M.W.); (F.H.); (N.N.); (A.U.); (M.H.)
| | - Megumi Higashide
- Departments of Ophthalmology, School of Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (M.W.); (F.H.); (N.N.); (A.U.); (M.H.)
| | - Toshifumi Ogawa
- Departments of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (T.S.); (T.O.)
- Departments of Cellular Physiology and Signal Transduction, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan
| | - Masato Furuhashi
- Departments of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (T.S.); (T.O.)
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20
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Zhou L, Mo Y, Zhang H, Zhang M, Xu J, Liang S. Role of AMPK-regulated autophagy in retinal pigment epithelial cell homeostasis: A review. Medicine (Baltimore) 2024; 103:e38908. [PMID: 38996139 PMCID: PMC11245211 DOI: 10.1097/md.0000000000038908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/14/2024] Open
Abstract
The retinal pigment epithelium (RPE) is a regularly arranged monolayer of cells in the outermost layer of the retina. It is crucial for transporting nutrients and metabolic substances in the retina and maintaining the retinal barrier. RPE dysfunction causes diseases related to vision loss. Thus, understanding the mechanisms involved in normal RPE function is vital. Adenosine monophosphate-activated protein kinase (AMPK) is an RPE energy sensor regulating various signaling and metabolic pathways to maintain cellular energetic homeostasis. AMPK activation is involved in multiple signaling pathways regulated by autophagy in the RPE, thereby protecting the cells from oxidative stress and slowing RPE degeneration. In this review, we attempt to broaden the understanding of the pathogenesis of RPE dysfunction by focusing on the role and mechanism of AMPK regulation of autophagy in the RPE. The correlation between RPE cellular homeostasis and role of AMPK was determined by analyzing the structure and mechanism of AMPK and its signaling pathway in autophagy. The protective effect of AMPK-regulated autophagy on the RPE for gaining insights into the regulatory pathways of RPE dysfunction has been discussed.
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Affiliation(s)
- Liangliang Zhou
- Department of Opthalmology, Chengdu University of Traditional Chinese Medicine, Chengdu, People's Republic of China
- Department of Opthalmology, People's Hospital of Dayi County, Chengdu, People's Republic of China
| | - Ya Mo
- Department of Opthalmology, Chengdu University of Traditional Chinese Medicine, Chengdu, People's Republic of China
- Department of Opthalmology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, People's Republic of China
| | - Haiyan Zhang
- Department of Opthalmology, Chengdu University of Traditional Chinese Medicine, Chengdu, People's Republic of China
| | - Mengdi Zhang
- Department of Opthalmology, Chengdu University of Traditional Chinese Medicine, Chengdu, People's Republic of China
| | - Jiayu Xu
- Department of Opthalmology, Chengdu University of Traditional Chinese Medicine, Chengdu, People's Republic of China
| | - Sumin Liang
- Department of Opthalmology, Chengdu University of Traditional Chinese Medicine, Chengdu, People's Republic of China
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21
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Martin CG, Bent JS, Hill T, Topalidou I, Singhvi A. Epithelial UNC-23 limits mechanical stress to maintain glia-neuron architecture in C. elegans. Dev Cell 2024; 59:1668-1688.e7. [PMID: 38670103 PMCID: PMC11233253 DOI: 10.1016/j.devcel.2024.04.005] [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: 11/23/2022] [Revised: 12/23/2023] [Accepted: 04/03/2024] [Indexed: 04/28/2024]
Abstract
For an organ to maintain correct architecture and function, its diverse cellular components must coordinate their size and shape. Although cell-intrinsic mechanisms driving homotypic cell-cell coordination are known, it is unclear how cell shape is regulated across heterotypic cells. We find that epithelial cells maintain the shape of neighboring sense-organ glia-neuron units in adult Caenorhabditis elegans (C. elegans). Hsp co-chaperone UNC-23/BAG2 prevents epithelial cell shape from deforming, and its loss causes head epithelia to stretch aberrantly during animal movement. In the sense-organ glia, amphid sheath (AMsh), this causes progressive fibroblast growth factor receptor (FGFR)-dependent disruption of the glial apical cytoskeleton. Resultant glial cell shape alteration causes concomitant shape change in glia-associated neuron endings. Epithelial UNC-23 maintenance of glia-neuron shape is specific both spatially, within a defined anatomical zone, and temporally, in a developmentally critical period. As all molecular components uncovered are broadly conserved across central and peripheral nervous systems, we posit that epithelia may similarly regulate glia-neuron architecture cross-species.
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Affiliation(s)
- Cecilia G Martin
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - James S Bent
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Tyler Hill
- Department of Biology, Brandeis University, Waltham, MA 02454, USA
| | - Irini Topalidou
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98195, USA.
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22
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Ashok S, Ramachandra Rao S. Updates on protein-prenylation and associated inherited retinopathies. FRONTIERS IN OPHTHALMOLOGY 2024; 4:1410874. [PMID: 39026984 PMCID: PMC11254824 DOI: 10.3389/fopht.2024.1410874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 06/13/2024] [Indexed: 07/20/2024]
Abstract
Membrane-anchored proteins play critical roles in cell signaling, cellular architecture, and membrane biology. Hydrophilic proteins are post-translationally modified by a diverse range of lipid molecules such as phospholipids, glycosylphosphatidylinositol, and isoprenes, which allows their partition and anchorage to the cell membrane. In this review article, we discuss the biochemical basis of isoprenoid synthesis, the mechanisms of isoprene conjugation to proteins, and the functions of prenylated proteins in the neural retina. Recent discovery of novel prenyltransferases, prenylated protein chaperones, non-canonical prenylation-target motifs, and reversible prenylation is expected to increase the number of inherited systemic and blinding diseases with aberrant protein prenylation. Recent important investigations have also demonstrated the role of several unexpected regulators (such as protein charge, sequence/protein-chaperone interaction, light exposure history) in the photoreceptor trafficking of prenylated proteins. Technical advances in the investigation of the prenylated proteome and its application in vision research are discussed. Clinical updates and technical insights into known and putative prenylation-associated retinopathies are provided herein. Characterization of non-canonical prenylation mechanisms in the retina and retina-specific prenylated proteome is fundamental to the understanding of the pathogenesis of protein prenylation-associated inherited blinding disorders.
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Affiliation(s)
- Sudhat Ashok
- Department of Ophthalmology, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY, United States
| | - Sriganesh Ramachandra Rao
- Department of Ophthalmology, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY, United States
- Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY, United States
- Research Service, VA Western New York Healthcare System, Buffalo, NY, United States
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23
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Wu L, Foo LL, Hu Z, Pan W, Jiang Y, Saw SM, Hoang QV, Lan W. Bruch's Membrane Opening Changes in Eyes With Myopic Macular Degeneration: AIER-SERI Adult High Myopia Study. Invest Ophthalmol Vis Sci 2024; 65:36. [PMID: 39028975 PMCID: PMC11262543 DOI: 10.1167/iovs.65.8.36] [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: 01/10/2024] [Accepted: 05/31/2024] [Indexed: 07/21/2024] Open
Abstract
Purpose The purpose of this study was to assess the choroidal thickness and the Bruch's membrane opening size and their relationship to visual acuity in eyes with myopic macular degeneration (MMD). Methods This was a population-based, cross-sectional study. Patients over the age of 30 years with high myopia (spherical equivalent ≤-5 diopters [D]) were recruited. The eyes were grouped according to the International Meta-Analysis for Pathologic Myopia (META-PM) classification based on fundus photographs and diffuse atrophy was subdivided into peripapillary diffuse choroidal atrophy (PDCA) or macular diffuse choroidal atrophy (MDCA). Swept-source optical coherence tomography imaging was performed and then the subfoveal choroidal thickness (SFCT) and Bruch's membrane opening diameter (BMOD) were measured. Results Of the 470 study participants recruited, 373 patients (691 eyes), with a mean age of 42.8 ± 7.2 years, were eligible for the study and included in the analysis. There was no significant difference in SFCT between MDCA and patchy atrophy (M3) groups (P = 1.000), and the BMOD enlarged significantly from no myopic macular lesions to M3 (the P values of multiple comparison tests were all <0.005). Simple linear regression analysis showed that BMOD correlated positively with age (P < 0.001) and axial length (P < 0.001). Multiple linear regression analysis showed that best corrected visual acuity (BCVA) was significantly correlated with age (P = 0.041), axial length (P = 0.001), and BMOD (P = 0.017), but not with SFCT (P = 0.231). Conclusions The significant variation of BMOD among MMD groups and the correlation between BMOD and BCVA in MMD eyes suggest that BMOD may be an imaging biomarker for monitoring MMD.
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Affiliation(s)
- Linli Wu
- Aier Academy of Ophthalmology, Central South University, Changsha, Hunan, China
| | - Li-Lian Foo
- Singapore Eye Research Institute, Singapore National Eye Centre, Duke-NUS Medical School, Singapore
| | - Ziqi Hu
- Aier Eye Hospital Group, Changsha, China
| | - Wei Pan
- Aier Academy of Ophthalmology, Central South University, Changsha, Hunan, China
| | - Yanfeng Jiang
- Aier Academy of Ophthalmology, Central South University, Changsha, Hunan, China
| | - Seang-Mei Saw
- Singapore Eye Research Institute, Singapore National Eye Centre, Duke-NUS Medical School, Singapore
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Quan V. Hoang
- Singapore Eye Research Institute, Singapore National Eye Centre, Duke-NUS Medical School, Singapore
- Department of Ophthalmology, Columbia University, New York, New York, United States
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Weizhong Lan
- Aier Academy of Ophthalmology, Central South University, Changsha, Hunan, China
- Hunan Province Optometry Engineering and Technology Research Center, Changsha, Hunan, China
- Hunan Province International Cooperation Base for Optometry Science and Technology, Changsha, Hunan, China
- Guangzhou Aier Eye Hospital, Jinan University, Guangzhou, China
- Aier School of Optometry and Vision Science, Hubei University of Science and Technology, Xianning, Hubei, China
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24
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Tan B, Li H, Zhuo Y, Han L, Mupparapu R, Nanni D, Barathi VA, Palanker D, Schmetterer L, Ling T. Light-evoked deformations in rod photoreceptors, pigment epithelium and subretinal space revealed by prolonged and multilayered optoretinography. Nat Commun 2024; 15:5156. [PMID: 38898002 PMCID: PMC11186825 DOI: 10.1038/s41467-024-49014-5] [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: 11/21/2023] [Accepted: 05/21/2024] [Indexed: 06/21/2024] Open
Abstract
Phototransduction involves changes in concentration of ions and other solutes within photoreceptors and in subretinal space, which affect osmotic pressure and the associated water flow. Corresponding expansion and contraction of cellular layers can be imaged using optoretinography (ORG), based on phase-resolved optical coherence tomography (OCT). Until now, ORG could reliably detect only photoisomerization and phototransduction in photoreceptors, primarily in cones under bright stimuli. Here, by employing a phase-restoring subpixel motion correction algorithm, which enables imaging of the nanometer-scale tissue dynamics during minute-long recordings, and unsupervised learning of spatiotemporal patterns, we discover optical signatures of the other retinal structures' response to visual stimuli. These include inner and outer segments of rod photoreceptors, retinal pigment epithelium, and subretinal space in general. The high sensitivity of our technique enables detection of the retinal responses to dim stimuli: down to 0.01% bleach level, corresponding to natural levels of scotopic illumination. We also demonstrate that with a single flash, the optoretinogram can map retinal responses across a 12° field of view, potentially replacing multifocal electroretinography. This technique expands the diagnostic capabilities and practical applicability of optoretinography, providing an alternative to electroretinography, while combining structural and functional retinal imaging in the same OCT machine.
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Affiliation(s)
- Bingyao Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE) Program, Singapore, Singapore
| | - Huakun Li
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
| | - Yueming Zhuo
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, 94305, USA
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Le Han
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE) Program, Singapore, Singapore
| | - Rajeshkumar Mupparapu
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE) Program, Singapore, Singapore
| | - Davide Nanni
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
| | - Veluchamy Amutha Barathi
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore, Singapore
| | - Daniel Palanker
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, 94305, USA.
- Department of Ophthalmology, Stanford University, Stanford, CA, 94305, USA.
| | - Leopold Schmetterer
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.
- SERI-NTU Advanced Ocular Engineering (STANCE) Program, Singapore, Singapore.
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore.
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore.
- Ophthalmology and Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore, Singapore.
- Department of Ophthalmology, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
- Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland.
| | - Tong Ling
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.
- SERI-NTU Advanced Ocular Engineering (STANCE) Program, Singapore, Singapore.
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore.
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, Singapore.
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25
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Jiménez-Loygorri JI, Viedma-Poyatos Á, Gómez-Sintes R, Boya P. Urolithin A promotes p62-dependent lysophagy to prevent acute retinal neurodegeneration. Mol Neurodegener 2024; 19:49. [PMID: 38890703 PMCID: PMC11186080 DOI: 10.1186/s13024-024-00739-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 06/07/2024] [Indexed: 06/20/2024] Open
Abstract
BACKGROUND Age-related macular degeneration (AMD) is the leading cause of blindness in elderly people in the developed world, and the number of people affected is expected to almost double by 2040. The retina presents one of the highest metabolic demands in our bodies that is partially or fully fulfilled by mitochondria in the neuroretina and retinal pigment epithelium (RPE), respectively. Together with its post-mitotic status and constant photooxidative damage from incoming light, the retina requires a tightly-regulated housekeeping system that involves autophagy. The natural polyphenol Urolithin A (UA) has shown neuroprotective benefits in several models of aging and age-associated disorders, mostly attributed to its ability to induce mitophagy and mitochondrial biogenesis. Sodium iodate (SI) administration recapitulates the late stages of AMD, including geographic atrophy and photoreceptor cell death. METHODS A combination of in vitro, ex vivo and in vivo models were used to test the neuroprotective potential of UA in the SI model. Functional assays (OCT, ERGs), cellular analysis (flow cytometry, qPCR) and fine confocal microscopy (immunohistochemistry, tandem selective autophagy reporters) helped address this question. RESULTS UA alleviated neurodegeneration and preserved visual function in SI-treated mice. Simultaneously, we observed severe proteostasis defects upon SI damage induction, including autophagosome accumulation, that were resolved in animals that received UA. Treatment with UA restored autophagic flux and triggered PINK1/Parkin-dependent mitophagy, as previously reported in the literature. Autophagy blockage caused by SI was caused by severe lysosomal membrane permeabilization. While UA did not induce lysosomal biogenesis, it did restore upcycling of permeabilized lysosomes through lysophagy. Knockdown of the lysophagy adaptor SQSTM1/p62 abrogated viability rescue by UA in SI-treated cells, exacerbated lysosomal defects and inhibited lysophagy. CONCLUSIONS Collectively, these data highlight a novel putative application of UA in the treatment of AMD whereby it bypasses lysosomal defects by promoting p62-dependent lysophagy to sustain proteostasis.
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Affiliation(s)
- Juan Ignacio Jiménez-Loygorri
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain.
| | - Álvaro Viedma-Poyatos
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
| | - Raquel Gómez-Sintes
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
| | - Patricia Boya
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain.
- Department of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
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Chen M, Wang Y, Dalal R, Du J, Vollrath D. Alternative oxidase blunts pseudohypoxia and photoreceptor degeneration due to RPE mitochondrial dysfunction. Proc Natl Acad Sci U S A 2024; 121:e2402384121. [PMID: 38865272 PMCID: PMC11194566 DOI: 10.1073/pnas.2402384121] [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: 02/05/2024] [Accepted: 05/15/2024] [Indexed: 06/14/2024] Open
Abstract
Loss of mitochondrial electron transport complex (ETC) function in the retinal pigment epithelium (RPE) in vivo results in RPE dedifferentiation and progressive photoreceptor degeneration, and has been implicated in the pathogenesis of age-related macular degeneration. Xenogenic expression of alternative oxidases in mammalian cells and tissues mitigates phenotypes arising from some mitochondrial electron transport defects, but can exacerbate others. We expressed an alternative oxidase from Ciona intestinalis (AOX) in ETC-deficient murine RPE in vivo to assess the retinal consequences of stimulating coenzyme Q oxidation and respiration without ATP generation. RPE-restricted expression of AOX in this context is surprisingly beneficial. This focused intervention mitigates RPE mTORC1 activation, dedifferentiation, hypertrophy, stress marker expression, pseudohypoxia, and aerobic glycolysis. These RPE cell autonomous changes are accompanied by increased glucose delivery to photoreceptors with attendant improvements in photoreceptor structure and function. RPE-restricted AOX expression normalizes accumulated levels of succinate and 2-hydroxyglutarate in ETC-deficient RPE, and counteracts deficiencies in numerous neural retinal metabolites. These features can be attributed to the activation of mitochondrial inner membrane flavoproteins such as succinate dehydrogenase and proline dehydrogenase, and alleviation of inhibition of 2-oxyglutarate-dependent dioxygenases such as prolyl hydroxylases and epigenetic modifiers. Our work underscores the importance to outer retinal health of coenzyme Q oxidation in the RPE and identifies a metabolic network critical for photoreceptor survival in the context of RPE mitochondrial dysfunction.
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Affiliation(s)
- Ming Chen
- Department of Genetics, Stanford University School of Medicine, Palo Alto, CA94305
| | - Yekai Wang
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV26506
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV26506
| | - Roopa Dalal
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA94305
| | - Jianhai Du
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV26506
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV26506
| | - Douglas Vollrath
- Department of Genetics, Stanford University School of Medicine, Palo Alto, CA94305
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA94305
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27
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Wendland RJ, Tucker BA, Worthington KS. Influence of Substrate Stiffness on iPSC-Derived Retinal Pigmented Epithelial Cells. Stem Cells Transl Med 2024; 13:582-592. [PMID: 38560893 PMCID: PMC11165161 DOI: 10.1093/stcltm/szae022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 03/03/2024] [Indexed: 04/04/2024] Open
Abstract
Retinal degenerative diseases are a major cause of blindness involving the dysfunction of photoreceptors, retinal pigmented epithelium (RPE), or both. A promising treatment approach involves replacing these cells via surgical transplantation, and previous work has shown that cell delivery scaffolds are vital to ensure sufficient cell survival. Thus, identifying scaffold properties that are conducive to cell viability and maturation (such as suitable material and mechanical properties) is critical to ensuring a successful treatment approach. In this study, we investigated the effect of scaffold stiffness on human RPE attachment, survival, and differentiation, comparing immortalized (ARPE-19) and stem cell-derived RPE (iRPE) cells. Polydimethylsiloxane was used as a model polymer substrate, and varying stiffness (~12 to 800 kPa) was achieved by modulating the cross-link-to-base ratio. Post-attachment changes in gene and protein expression were assessed using qPCR and immunocytochemistry. We found that while ARPE-19 and iRPE exhibited significant differences in morphology and expression of RPE markers, substrate stiffness did not have a substantial impact on cell growth or maturation for either cell type. These results highlight the differences in expression between immortalized and iPSC-derived RPE cells, and also suggest that stiffnesses in this range (~12-800 kPa) may not result in significant differences in RPE growth and maturation, an important consideration in scaffold design.
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Affiliation(s)
- Rion J Wendland
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, USA
- Institute for Vision Research, Department of Ophthalmology and Visual Science, University of Iowa, Iowa City, IA, USA
| | - Budd A Tucker
- Institute for Vision Research, Department of Ophthalmology and Visual Science, University of Iowa, Iowa City, IA, USA
| | - Kristan S Worthington
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, USA
- Institute for Vision Research, Department of Ophthalmology and Visual Science, University of Iowa, Iowa City, IA, USA
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28
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Lulli M, Tartaro R, Papucci L, Magnelli L, Kaur IP, Caporossi T, Rizzo S, Mannini A, Giansanti F, Schiavone N. Effects of a human amniotic membrane extract on ARPE-19 cells. Mol Biol Rep 2024; 51:746. [PMID: 38874663 PMCID: PMC11178654 DOI: 10.1007/s11033-024-09647-7] [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: 08/10/2023] [Accepted: 05/16/2024] [Indexed: 06/15/2024]
Abstract
BACKGROUND Human Amniotic Membrane (hAM) is endowed with several biological activities and might be considered an optimal tool in surgical treatment for different ophthalmic pathologies. We pioneered the surgical use of hAM to treat retinal pathologies such as macular holes, tears, and retinal detachments, and to overcome photoreceptor damage in age-related macular degeneration. Although hAM contributed to improved outcomes, the mechanisms of its effects are not yet fully understood. The characterization and explanation of the effects of hAM would allow the adoption of this new natural product in different retinal pathologies, operative contexts, and hAM formulations. At this end, we studied the properties of a hAM extract (hAME) on the ARPE-19 cells. METHODS AND RESULTS A non-denaturing sonication-based technique was developed to obtain a suitable hAME. Viability, proliferation, apoptosis, oxidative stress, and epithelial-mesenchymal transition (EMT) were studied in hAME-treated ARPE-19 cells. The hAME was able to increase ARPE-19 cell viability even in the presence of oxidative stress (H2O2, TBHP). Moreover, hAME prevented the expression of EMT features, such as EMT-related proteins, fibrotic foci formation, and migration induced by different cytokines. CONCLUSIONS Our results demonstrate that the hAME retains most of the properties observed in the whole tissue by others. The hAME, other than providing a manageable research tool, could represent a cost-effective and abundant drug to treat retinal pathologies in the future.
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Affiliation(s)
- Matteo Lulli
- Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, Florence, Italy
| | - Ruggero Tartaro
- Department of NEUROFARBA, Ophthalmology, University of Florence, Careggi, Florence, Italy
| | - Laura Papucci
- Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, Florence, Italy
| | - Lucia Magnelli
- Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, Florence, Italy
| | - Indu Pal Kaur
- UGC-Centre of Advanced Study, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
| | - Tomaso Caporossi
- Vitreoretinal Surgery Unit, Isola Tiberina Gemelli Isola Hospital, Rome, Italy
- Catholic University Sacro Cuore, Rome, Italy
| | - Stanislao Rizzo
- Department of Ophthalmology, Catholic University of Sacred-Heart Foundation "Policlinico Universitario A. Gemelli" IRCCS, Rome, Italy
| | - Antonella Mannini
- Department of Experimental and Clinical Medicine - Internal Medicine Section, University of Florence, Florence, Italy.
| | - Fabrizio Giansanti
- Department of NEUROFARBA, Ophthalmology, University of Florence, Careggi, Florence, Italy
| | - Nicola Schiavone
- Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, Florence, Italy
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Ohguro H, Watanabe M, Sato T, Nishikiori N, Umetsu A, Higashide M, Ogawa T, Furuhashi M. FABP4 Is an Indispensable Factor for Regulating Cellular Metabolic Functions of the Human Retinal Choroid. Bioengineering (Basel) 2024; 11:584. [PMID: 38927820 PMCID: PMC11200562 DOI: 10.3390/bioengineering11060584] [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: 05/09/2024] [Revised: 06/02/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
The purpose of the current study was to elucidate the physiological roles of intraocularly present fatty acid-binding protein 4 (FABP4). Using four representative intraocular tissue-derived cell types, including human non-pigmented ciliary epithelium (HNPCE) cells, retinoblastoma (RB) cells, adult retinal pigment epithelial19 (ARPE19) cells and human ocular choroidal fibroblast (HOCF) cells, the intraocular origins of FABP4 were determined by qPCR analysis, and the intracellular functions of FABP4 were investigated by seahorse cellular metabolic measurements and RNA sequencing analysis using a specific inhibitor for FABP4, BMS309403. Among these four different cell types, FABP4 was exclusively expressed in HOCF cells. In HOCF cells, both mitochondrial and glycolytic functions were significantly decreased to trace levels by BMS309403 in a dose-dependent manner. In the RNA sequencing analysis, 67 substantially up-regulated and 94 significantly down-regulated differentially expressed genes (DEGs) were identified in HOCF cells treated with BMS309403 and those not treated with BMS309403. The results of Gene Ontology enrichment analysis and ingenuity pathway analysis (IPA) revealed that the DEGs were most likely involved in G-alpha (i) signaling, cAMP-response element-binding protein (CREB) signaling in neurons, the S100 family signaling pathway, visual phototransduction and adrenergic receptor signaling. Furthermore, upstream analysis using IPA suggested that NKX2-1 (thyroid transcription factor1), HOXA10 (homeobox A10), GATA2 (gata2 protein), and CCAAT enhancer-binding protein A (CEBPA) were upstream regulators and that NKX homeobox-1 (NKX2-1), SFRP1 (Secreted frizzled-related protein 1) and TREM2 (triggering receptor expressed on myeloid cells 2) were causal network master regulators. The findings in this study suggest that intraocularly present FABP4 originates from the ocular choroid and may be a critical regulator for the cellular homeostasis of non-adipocyte HOCF cells.
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Affiliation(s)
- Hiroshi Ohguro
- Departments of Ophthalmology, School of Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (H.O.); (M.W.); (N.N.); (A.U.); (M.H.)
| | - Megumi Watanabe
- Departments of Ophthalmology, School of Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (H.O.); (M.W.); (N.N.); (A.U.); (M.H.)
| | - Tatsuya Sato
- Departments of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (T.O.); (M.F.)
- Departments of Cellular Physiology and Signal Transduction, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan
| | - Nami Nishikiori
- Departments of Ophthalmology, School of Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (H.O.); (M.W.); (N.N.); (A.U.); (M.H.)
| | - Araya Umetsu
- Departments of Ophthalmology, School of Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (H.O.); (M.W.); (N.N.); (A.U.); (M.H.)
| | - Megumi Higashide
- Departments of Ophthalmology, School of Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (H.O.); (M.W.); (N.N.); (A.U.); (M.H.)
| | - Toshifumi Ogawa
- Departments of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (T.O.); (M.F.)
- Departments of Cellular Physiology and Signal Transduction, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan
| | - Masato Furuhashi
- Departments of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University, S1W17, Chuo-ku, Sapporo 060-8556, Japan; (T.O.); (M.F.)
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Xu Y, Tummala SR, Chen X, Vardi N. VDAC in Retinal Health and Disease. Biomolecules 2024; 14:654. [PMID: 38927058 PMCID: PMC11201675 DOI: 10.3390/biom14060654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/22/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024] Open
Abstract
The retina, a tissue of the central nervous system, is vital for vision as its photoreceptors capture light and transform it into electrical signals, which are further processed before they are sent to the brain to be interpreted as images. The retina is unique in that it is continuously exposed to light and has the highest metabolic rate and demand for energy amongst all the tissues in the body. Consequently, the retina is very susceptible to oxidative stress. VDAC, a pore in the outer membrane of mitochondria, shuttles metabolites between mitochondria and the cytosol and normally protects cells from oxidative damage, but when a cell's integrity is greatly compromised it initiates cell death. There are three isoforms of VDAC, and existing evidence indicates that all three are expressed in the retina. However, their precise localization and function in each cell type is unknown. It appears that most retinal cells express substantial amounts of VDAC2 and VDAC3, presumably to protect them from oxidative stress. Photoreceptors express VDAC2, HK2, and PKM2-key proteins in the Warburg pathway that also protect these cells. Consistent with its role in initiating cell death, VDAC is overexpressed in the retinal degenerative diseases retinitis pigmentosa, age related macular degeneration (AMD), and glaucoma. Treatment with antioxidants or inhibiting VDAC oligomerization reduced its expression and improved cell survival. Thus, VDAC may be a promising therapeutic candidate for the treatment of these diseases.
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Affiliation(s)
- Ying Xu
- Guangdong Key Laboratory of Non-Human Primate Research, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China; (Y.X.); (X.C.)
| | - Shanti R. Tummala
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104, USA;
| | - Xiongmin Chen
- Guangdong Key Laboratory of Non-Human Primate Research, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China; (Y.X.); (X.C.)
| | - Noga Vardi
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA 19104, USA
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Wu S, Li F, Mo K, Huang H, Yu Y, Huang Y, Liu J, Li M, Tan J, Lin Z, Han Z, Wang L, Ouyang H. IGF2BP2 Maintains Retinal Pigment Epithelium Homeostasis by Stabilizing PAX6 and OTX2. Invest Ophthalmol Vis Sci 2024; 65:17. [PMID: 38861275 PMCID: PMC11174093 DOI: 10.1167/iovs.65.6.17] [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: 02/19/2024] [Accepted: 05/15/2024] [Indexed: 06/12/2024] Open
Abstract
Purpose N6-methyladenosine (m6A) methylation is a chemical modification that occurs on RNA molecules, where the hydrogen atom of adenine (A) nucleotides is replaced by a methyl group, forming N6-methyladenosine. This modification is a dynamic and reversible process that plays a crucial role in regulating various biological processes, including RNA stability, transport, translation, and degradation. Currently, there is a lack of research on the role of m6A modifications in maintaining the characteristics of RPE cells. m6A readers play a crucial role in executing the functions of m6A modifications, which prompted our investigation into their regulatory roles in the RPE. Methods Phagocytosis assays, immunofluorescence staining, flow cytometry experiments, β-galactosidase staining, and RNA sequencing (RNA-seq) were conducted to assess the functional and cellular characteristics changes in retinal pigment epithelium (RPE) cells following short-hairpin RNA-mediated knockdown of insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2). RNA-seq and ultraviolet crosslinking immunoprecipitation with high-throughput sequencing (HITS-CLIP) were employed to identify the target genes regulated by IGF2BP2. adeno-associated virus (AAV) subretinal injection was performed in 6- to 8-week-old C57 mice to reduce IGF2BP2 expression in the RPE, and the impact of IGF2BP2 knockdown on mouse visual function was assessed using immunofluorescence, quantitative real-time PCR, optical coherence tomography, and electroretinography. Results IGF2BP2 was found to have a pronounced effect on RPE phagocytosis. Subsequent in-depth exploration revealed that IGF2BP2 modulates the mRNA stability of PAX6 and OTX2, and the loss of IGF2BP2 induces inflammatory and aging phenotypes in RPE cells. IGF2BP2 knockdown impaired RPE function, leading to retinal dysfunction in vivo. Conclusions Our data suggest a crucial role of IGF2BP2 as an m6A reader in maintaining RPE homeostasis by regulating the stability of PAX6 and OTX2, making it a potential target for preventing the occurrence of retinal diseases related to RPE malfunction.
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Affiliation(s)
- Siqi Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Fuxi Li
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Kunlun Mo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Huaxing Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Yankun Yu
- Department of Pathology, The First Affiliated Hospital of Shihezi University, Shihezi, Xinjiang, China
| | - Ying Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Jiafeng Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Mingsen Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Jieying Tan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Zesong Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Zhuo Han
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Li Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Hong Ouyang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
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Babcock SJ, Curtis AG, Gaston G, Elizondo G, Gillingham MB, Ryals RC. The LCHADD Mouse Model Recapitulates Early-Stage Chorioretinopathy in LCHADD Patients. Invest Ophthalmol Vis Sci 2024; 65:33. [PMID: 38904639 PMCID: PMC11193142 DOI: 10.1167/iovs.65.6.33] [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: 03/19/2024] [Accepted: 05/27/2024] [Indexed: 06/22/2024] Open
Abstract
Purpose Recent studies have shown that the retinal pigment epithelium (RPE) relies on fatty acid oxidation (FAO) for energy, however, its role in overall retinal health is unknown. The only FAO disorder that presents with chorioretinopathy is long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD). Studying the molecular mechanisms can lead to new treatments for patients and elucidate the role of FAO in the RPE. This paper characterizes the chorioretinopathy progression in a recently reported LCHADD mouse model. Methods Visual assessments, such as optokinetic tracking and fundus imaging, were performed in wildtype (WT) and LCHADD mice at 3, 6, 10, and 12 months of age. Retinal morphology was analyzed in 12-month retinal cross-sections using hematoxylin and eosin (H&E), RPE65, CD68, and TUNEL staining, whereas RPE structure was assessed using transmission electron microscopy (TEM). Acylcarnitine profiles were measured in isolated RPE/sclera samples to determine if FAO was blocked. Bulk RNA-sequencing of 12 month old male WT mice and LCHADD RPE/sclera samples assessed gene expression changes. Results LCHADD RPE/sclera samples had a 5- to 7-fold increase in long-chain hydroxyacylcarnitines compared to WT, suggesting an impaired LCHAD step in long-chain FAO. LCHADD mice have progressively decreased visual performance and increased RPE degeneration starting at 6 months. LCHADD RPE have an altered structure and a two-fold increase in macrophages in the subretinal space. Finally, LCHADD RPE/sclera have differentially expressed genes compared to WT, including downregulation of genes important for RPE function and angiogenesis. Conclusions Overall, this LCHADD mouse model recapitulates early-stage chorioretinopathy seen in patients with LCHADD and is a useful model for studying LCHADD chorioretinopathy.
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Affiliation(s)
- Shannon J. Babcock
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States
| | - Allison G. Curtis
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Garen Gaston
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States
| | - Gabriela Elizondo
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States
| | - Melanie B. Gillingham
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States
| | - Renee C. Ryals
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
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Du SW, Komirisetty R, Lewandowski D, Choi EH, Panas D, Suh S, Tabaka M, Radu RA, Palczewski K. Conditional deletion of miR-204 and miR-211 in murine retinal pigment epithelium results in retinal degeneration. J Biol Chem 2024; 300:107344. [PMID: 38705389 PMCID: PMC11140208 DOI: 10.1016/j.jbc.2024.107344] [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: 03/15/2024] [Revised: 04/18/2024] [Accepted: 04/27/2024] [Indexed: 05/07/2024] Open
Abstract
MicroRNAs (miRs) are short, evolutionarily conserved noncoding RNAs that canonically downregulate expression of target genes. The miR family composed of miR-204 and miR-211 is among the most highly expressed miRs in the retinal pigment epithelium (RPE) in both mouse and human and also retains high sequence identity. To assess the role of this miR family in the developed mouse eye, we generated two floxed conditional KO mouse lines crossed to the RPE65-ERT2-Cre driver mouse line to perform an RPE-specific conditional KO of this miR family in adult mice. After Cre-mediated deletion, we observed retinal structural changes by optical coherence tomography; dysfunction and loss of photoreceptors by retinal imaging; and retinal inflammation marked by subretinal infiltration of immune cells by imaging and immunostaining. Single-cell RNA sequencing of diseased RPE and retinas showed potential miR-regulated target genes, as well as changes in noncoding RNAs in the RPE, rod photoreceptors, and Müller glia. This work thus highlights the role of miR-204 and miR-211 in maintaining RPE function and how the loss of miRs in the RPE exerts effects on the neural retina, leading to inflammation and retinal degeneration.
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Affiliation(s)
- Samuel W Du
- Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, University of California, Irvine, California, USA; Department of Physiology and Biophysics, University of California, Irvine, California, USA.
| | - Ravikiran Komirisetty
- Department of Ophthalmology and UCLA Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Dominik Lewandowski
- Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, University of California, Irvine, California, USA
| | - Elliot H Choi
- Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, University of California, Irvine, California, USA
| | - Damian Panas
- International Centre for Translational Eye Research, Warsaw, Poland; Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Susie Suh
- Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, University of California, Irvine, California, USA
| | - Marcin Tabaka
- International Centre for Translational Eye Research, Warsaw, Poland; Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Roxana A Radu
- Department of Ophthalmology and UCLA Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, University of California, Irvine, California, USA; Department of Physiology and Biophysics, University of California, Irvine, California, USA; Department of Chemistry, University of California, Irvine, Irvine, California, USA; Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, California, USA.
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Tan LX, Oertel FC, Cheng A, Cobigo Y, Keihani A, Bennett DJ, Abdelhak A, Montes SC, Chapman M, Chen RY, Cordano C, Ward ME, Casaletto K, Kramer JH, Rosen HJ, Boxer A, Miller BL, Green AJ, Elahi FM, Lakkaraju A. Targeting complement C3a receptor resolves mitochondrial hyperfusion and subretinal microglial activation in progranulin-deficient frontotemporal dementia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.29.595206. [PMID: 38854134 PMCID: PMC11160746 DOI: 10.1101/2024.05.29.595206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Mutations in progranulin ( GRN ) cause frontotemporal dementia ( GRN -FTD) due to deficiency of the pleiotropic protein progranulin. GRN -FTD exhibits diverse pathologies including lysosome dysfunction, lipofuscinosis, microgliosis, and neuroinflammation. Yet, how progranulin loss causes disease remains unresolved. Here, we report that non-invasive retinal imaging of GRN -FTD patients revealed deficits in photoreceptors and the retinal pigment epithelium (RPE) that correlate with cognitive decline. Likewise, Grn -/- mice exhibit early RPE dysfunction, microglial activation, and subsequent photoreceptor loss. Super-resolution live imaging and transcriptomic analyses identified RPE mitochondria as an early driver of retinal dysfunction. Loss of mitochondrial fission protein 1 (MTFP1) in Grn -/- RPE causes mitochondrial hyperfusion and bioenergetic defects, leading to NF-kB-mediated activation of complement C3a-C3a receptor signaling, which drives further mitochondrial hyperfusion and retinal inflammation. C3aR antagonism restores RPE mitochondrial integrity and limits subretinal microglial activation. Our study identifies a previously unrecognized mechanism by which progranulin modulates mitochondrial integrity and complement-mediated neuroinflammation.
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Seidemann S, Salomon F, Hoffmann KB, Kurth T, Sbalzarini IF, Haase R, Ader M. Automated quantification of photoreceptor outer segments in developing and degenerating retinas on microscopy images across scales. Front Mol Neurosci 2024; 17:1398447. [PMID: 38854587 PMCID: PMC11157083 DOI: 10.3389/fnmol.2024.1398447] [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: 03/09/2024] [Accepted: 04/17/2024] [Indexed: 06/11/2024] Open
Abstract
The functionality of photoreceptors, rods, and cones is highly dependent on their outer segments (POS), a cellular compartment containing highly organized membranous structures that generate biochemical signals from incident light. While POS formation and degeneration are qualitatively assessed on microscopy images, reliable methodology for quantitative analyses is still limited. Here, we developed methods to quantify POS (QuaPOS) maturation and quality on retinal sections using automated image analyses. POS formation was examined during the development and in adulthood of wild-type mice via light microscopy (LM) and transmission electron microscopy (TEM). To quantify the number, size, shape, and fluorescence intensity of POS, retinal cryosections were immunostained for the cone POS marker S-opsin. Fluorescence images were used to train the robust classifier QuaPOS-LM based on supervised machine learning for automated image segmentation. Characteristic features of segmentation results were extracted to quantify the maturation of cone POS. Subsequently, this quantification method was applied to characterize POS degeneration in "cone photoreceptor function loss 1" mice. TEM images were used to establish the ultrastructural quantification method QuaPOS-TEM for the alignment of POS membranes. Images were analyzed using a custom-written MATLAB code to extract the orientation of membranes from the image gradient and their alignment (coherency). This analysis was used to quantify the POS morphology of wild-type and two inherited retinal degeneration ("retinal degeneration 19" and "rhodopsin knock-out") mouse lines. Both automated analysis technologies provided robust characterization and quantification of POS based on LM or TEM images. Automated image segmentation by the classifier QuaPOS-LM and analysis of the orientation of membrane stacks by QuaPOS-TEM using fluorescent or TEM images allowed quantitative evaluation of POS formation and quality. The assessments showed an increase in POS number, volume, and membrane coherency during wild-type postnatal development, while a decrease in all three observables was detected in different retinal degeneration mouse models. All the code used for the presented analysis is open source, including example datasets to reproduce the findings. Hence, the QuaPOS quantification methods are useful for in-depth characterization of POS on retinal sections in developmental studies, for disease modeling, or after therapeutic interventions affecting photoreceptors.
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Affiliation(s)
- Suse Seidemann
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany
- Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Dresden, Germany
| | - Florian Salomon
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany
- Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Dresden, Germany
| | - Karl B. Hoffmann
- Faculty of Computer Science, Technische Universität Dresden, Dresden, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- Center for Systems Biology Dresden, Dresden, Germany
| | - Thomas Kurth
- Core Facility Electron Microscopy and Histology, Technology Platform, Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Dresden, Germany
| | - Ivo F. Sbalzarini
- Faculty of Computer Science, Technische Universität Dresden, Dresden, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- Center for Systems Biology Dresden, Dresden, Germany
- DFG Cluster of Excellence “Physics of Life”, Technische Universität Dresden, Dresden, Germany
- Center for Scalable Data Analytics and Artificial Intelligence (ScaDS.AI), Leipzig University, Leipzig, Germany
| | - Robert Haase
- DFG Cluster of Excellence “Physics of Life”, Technische Universität Dresden, Dresden, Germany
- Center for Scalable Data Analytics and Artificial Intelligence (ScaDS.AI), Leipzig University, Leipzig, Germany
| | - Marius Ader
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany
- Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Dresden, Germany
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Tebbe L, Kakakhel M, Al-Ubaidi MR, Naash MI. The role of syntaxins in retinal function and health. Front Cell Neurosci 2024; 18:1380064. [PMID: 38799985 PMCID: PMC11119284 DOI: 10.3389/fncel.2024.1380064] [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: 01/31/2024] [Accepted: 04/16/2024] [Indexed: 05/29/2024] Open
Abstract
The soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (SNAP) receptor (SNARE) superfamily plays a pivotal role in cellular trafficking by facilitating membrane fusion events. These SNARE proteins, including syntaxins, assemble into complexes that actively facilitate specific membrane fusion events. Syntaxins, as integral components of the SNARE complex, play a crucial role in initiating and regulating these fusion activities. While specific syntaxins have been extensively studied in various cellular processes, including neurotransmitter release, autophagy and endoplasmic reticulum (ER)-to-Golgi protein transport, their roles in the retina remain less explored. This review aims to enhance our understanding of syntaxins' functions in the retina by shedding light on how syntaxins mediate membrane fusion events unique to the retina. Additionally, we seek to establish a connection between syntaxin mutations and retinal diseases. By exploring the intricate interplay of syntaxins in retinal function and health, we aim to contribute to the broader comprehension of cellular trafficking in the context of retinal physiology and pathology.
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Affiliation(s)
| | | | | | - Muna I. Naash
- *Correspondence: Muna I. Naash, ; Muayyad R. Al-Ubaidi,
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Basyal D, Lee S, Kim HJ. Antioxidants and Mechanistic Insights for Managing Dry Age-Related Macular Degeneration. Antioxidants (Basel) 2024; 13:568. [PMID: 38790673 PMCID: PMC11117704 DOI: 10.3390/antiox13050568] [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: 03/18/2024] [Revised: 04/26/2024] [Accepted: 05/02/2024] [Indexed: 05/26/2024] Open
Abstract
Age-related macular degeneration (AMD) severely affects central vision due to progressive macular degeneration and its staggering prevalence is rising globally, especially in the elderly population above 55 years. Increased oxidative stress with aging is considered an important contributor to AMD pathogenesis despite multifaceted risk factors including genetic predisposition and environmental agents. Wet AMD can be managed with routine intra-vitreal injection of angiogenesis inhibitors, but no satisfactory medicine has been approved for the successful management of the dry form. The toxic carbonyls due to photo-oxidative degradation of accumulated bisretinoids within lysosomes initiate a series of events including protein adduct formation, impaired autophagy flux, complement activation, and chronic inflammation, which is implicated in dry AMD. Therapy based on antioxidants has been extensively studied for its promising effect in reducing the impact of oxidative stress. This paper reviews the dry AMD pathogenesis, delineates the effectiveness of dietary and nutrition supplements in clinical studies, and explores pre-clinical studies of antioxidant molecules, extracts, and formulations with their mechanistic insights.
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Affiliation(s)
| | | | - Hye Jin Kim
- College of Pharmacy, Keimyung University, Dauge 42601, Republic of Korea
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Carozza G, Zerti D, Tisi A, Ciancaglini M, Maccarrone M, Maccarone R. An overview of retinal light damage models for preclinical studies on age-related macular degeneration: identifying molecular hallmarks and therapeutic targets. Rev Neurosci 2024; 35:303-330. [PMID: 38153807 DOI: 10.1515/revneuro-2023-0130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 11/19/2023] [Indexed: 12/30/2023]
Abstract
Age-related macular degeneration (AMD) is a complex, multifactorial disease leading to progressive and irreversible retinal degeneration, whose pathogenesis has not been fully elucidated yet. Due to the complexity and to the multiple features of the disease, many efforts have been made to develop animal models which faithfully reproduce the overall AMD hallmarks or that are able to mimic the different AMD stages. In this context, light damage (LD) rodent models of AMD represent a suitable and reliable approach to mimic the different AMD forms (dry, wet and geographic atrophy) while maintaining the time-dependent progression of the disease. In this review, we comprehensively reported how the LD paradigms reproduce the main features of human AMD. We discuss the capability of these models to broaden the knowledge in AMD research, with a focus on the mechanisms and the molecular hallmarks underlying the pathogenesis of the disease. We also critically revise the remaining challenges and future directions for the use of LD models.
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Affiliation(s)
- Giulia Carozza
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Darin Zerti
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Annamaria Tisi
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Marco Ciancaglini
- Department of Life, Health & Environmental Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Mauro Maccarrone
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
- European Center for Brain Research (CERC)/Santa Lucia Foundation IRCCS, 00143 Rome, Italy
| | - Rita Maccarone
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
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Hansman D, Ma Y, Thomas D, Smith J, Casson R, Peet D. Metabolic reprogramming of the retinal pigment epithelium by cytokines associated with age-related macular degeneration. Biosci Rep 2024; 44:BSR20231904. [PMID: 38567515 PMCID: PMC11043024 DOI: 10.1042/bsr20231904] [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: 11/22/2023] [Revised: 03/17/2024] [Accepted: 04/02/2024] [Indexed: 04/04/2024] Open
Abstract
The complex metabolic relationship between the retinal pigment epithelium (RPE) and photoreceptors is essential for maintaining retinal health. Recent evidence indicates the RPE acts as an adjacent lactate sink, suppressing glycolysis in the epithelium in order to maximize glycolysis in the photoreceptors. Dysregulated metabolism within the RPE has been implicated in the pathogenesis of age-related macular degeneration (AMD), a leading cause of vision loss. In the present study, we investigate the effects of four cytokines associated with AMD, TNFα, TGF-β2, IL-6, and IL-1β, as well as a cocktail containing all four cytokines, on RPE metabolism using ARPE-19 cells, primary human RPE cells, and ex vivo rat eyecups. Strikingly, we found cytokine-specific changes in numerous metabolic markers including lactate production, glucose consumption, extracellular acidification rate, and oxygen consumption rate accompanied by increases in total mitochondrial volume and ATP production. Together, all four cytokines could potently override the constitutive suppression of glycolysis in the RPE, through a mechanism independent of PI3K/AKT, MEK/ERK, or NF-κB. Finally, we observed changes in glycolytic gene expression with cytokine treatment, including in lactate dehydrogenase subunit and glucose transporter expression. Our findings provide new insights into the metabolic changes in the RPE under inflammatory conditions and highlight potential therapeutic targets for AMD.
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Affiliation(s)
- David S. Hansman
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Yuefang Ma
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Daniel Thomas
- South Australian Health and Medical Research Institute (SAHMRI), Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Justine R. Smith
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Robert J. Casson
- Discipline of Ophthalmology and Visual Science, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Daniel J. Peet
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
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Ashimori A, Higashijima F, Ogata T, Sakuma A, Hamada W, Sunada J, Aoki R, Mikuni M, Hayashi K, Wakuta M, Yoshimoto T, Minamoto A, Ko JA, Kimura K. HIF-1α-dependent upregulation of angiogenic factors by mechanical stimulation in retinal pigment epithelial cells. Dis Model Mech 2024; 17:dmm050640. [PMID: 38691000 PMCID: PMC11095633 DOI: 10.1242/dmm.050640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 03/22/2024] [Indexed: 05/03/2024] Open
Abstract
Mechanical stimulation as a mimic of drusen formation in the eye increases the expression of angiogenic factors in retinal pigment epithelial (RPE) cells, but the underlying molecular mechanisms remain unclear. We investigated and characterized the effects of mechanical stimulation on the expression of angiogenic factors in RPE cells both in vitro and in a mouse model. Mechanical stimulation increased the expression of vascular endothelial growth factor (VEGF, encoded by VEGFA) and other angiogenesis-related genes in cultured RPE1 cells. The presence of hypoxia-inducible factor 1α (HIF-1α, encoded by HIF1A) was also increased, and both knockdown of HIF-1α and treatment with the HIF-1α inhibitor CAY10585 attenuated the effect of mechanical stimulation on angiogenesis factor gene expression. Signaling by the tyrosine kinase SRC and p38 mitogen-activated protein kinase was involved in HIF-1α activation and consequent angiogenesis-related gene expression induced by mechanical stimulation. Our results suggest that SRC-p38 and HIF-1α signaling are involved in the upregulation of angiogenic factors in RPE cells by mechanical stimulation. Such in vivo suppression of upregulated expression of angiogenesis-related genes by pharmacological inhibitors of HIF-1α suggests a new potential approach to the treatment of age-related macular degeneration.
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Affiliation(s)
- Atsushige Ashimori
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan
| | - Fumiaki Higashijima
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan
| | - Tadahiko Ogata
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan
| | - Ayano Sakuma
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan
| | - Waka Hamada
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan
| | - Junki Sunada
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan
| | - Ren Aoki
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan
| | - Masanori Mikuni
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan
| | - Ken'ichiro Hayashi
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan
| | - Makiko Wakuta
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan
| | - Takuya Yoshimoto
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan
| | - Akira Minamoto
- Department of Ophthalmology and Visual Science, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Ji-Ae Ko
- Department of Ophthalmology and Visual Science, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Kazuhiro Kimura
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan
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41
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Abcouwer SF, Miglioranza Scavuzzi B, Kish PE, Kong D, Shanmugam S, Le XA, Yao J, Hager H, Zacks DN. The mouse retinal pigment epithelium mounts an innate immune defense response following retinal detachment. J Neuroinflammation 2024; 21:74. [PMID: 38528525 PMCID: PMC10964713 DOI: 10.1186/s12974-024-03062-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 03/11/2024] [Indexed: 03/27/2024] Open
Abstract
The retinal pigment epithelium (RPE) maintains photoreceptor viability and function, completes the visual cycle, and forms the outer blood-retinal barrier (oBRB). Loss of RPE function gives rise to several monogenic retinal dystrophies and contributes to age-related macular degeneration. Retinal detachment (RD) causes separation of the neurosensory retina from the underlying RPE, disrupting the functional and metabolic relationships between these layers. Although the retinal response to RD is highly studied, little is known about how the RPE responds to loss of this interaction. RNA sequencing (RNA-Seq) was used to compare normal and detached RPE in the C57BL6/J mouse. The naïve mouse RPE transcriptome was compared to previously published RPE signature gene lists and from the union of these 14 genes (Bmp4, Crim1, Degs1, Gja1, Itgav, Mfap3l, Pdpn, Ptgds, Rbp1, Rnf13, Rpe65, Slc4a2, Sulf1 and Ttr) representing a core signature gene set applicable across rodent and human RPE was derived. Gene ontology enrichment analysis (GOEA) of the mouse RPE transcriptome identified expected RPE features and functions, such as pigmentation, phagocytosis, lysosomal and proteasomal degradation of proteins, and barrier function. Differentially expressed genes (DEG) at 1 and 7 days post retinal detachment (dprd) were defined as mRNA with a significant (padj≤0.05) fold change (FC) of 0.67 ≥ FC ≥ 1.5 in detached versus naïve RPE. The RPE transcriptome exhibited dramatic changes at 1 dprd, with 2297 DEG identified. The KEGG pathways and biological process GO groups related to innate immune responses were significantly enriched. Lipocalin 2 (Lcn2) and several chemokines were upregulated, while numerous genes related to RPE functions, such as pigment synthesis, visual cycle, phagocytosis, and tight junctions were downregulated at 1 dprd. The response was largely transient, with only 18 significant DEG identified at 7 dprd, including upregulation of complement gene C4b. Validation studies confirmed RNA-Seq results. Thus, the RPE quickly downregulates cell-specific functions and mounts an innate immune defense response following RD. Our data demonstrate that the RPE contributes to the inflammatory response to RD and may play a role in attraction of immune cells to the subretinal space.
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Affiliation(s)
- Steven F Abcouwer
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, 1000 Wall Street, Ann Arbor, MI, 48105, USA.
| | - Bruna Miglioranza Scavuzzi
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Phillip E Kish
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Dejuan Kong
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Sumathi Shanmugam
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Xuan An Le
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Jingyu Yao
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Heather Hager
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - David N Zacks
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medicine, 1000 Wall Street, Ann Arbor, MI, 48105, USA
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Grubaugh CR, Dhingra A, Prakash B, Montenegro D, Sparrow JR, Daniele LL, Curcio CA, Bell BA, Hussain MM, Boesze-Battaglia K. Microsomal triglyceride transfer protein is necessary to maintain lipid homeostasis and retinal function. FASEB J 2024; 38:e23522. [PMID: 38445789 PMCID: PMC10949407 DOI: 10.1096/fj.202302491r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 02/07/2024] [Accepted: 02/16/2024] [Indexed: 03/07/2024]
Abstract
Lipid processing by the retinal pigment epithelium (RPE) is necessary to maintain retinal health and function. Dysregulation of retinal lipid homeostasis due to normal aging or age-related disease triggers lipid accumulation within the RPE, on Bruch's membrane (BrM), and in the subretinal space. In its role as a hub for lipid trafficking into and out of the neural retina, the RPE packages a significant amount of lipid into lipid droplets for storage and into apolipoprotein B (APOB)-containing lipoproteins (Blps) for export. Microsomal triglyceride transfer protein (MTP), encoded by the MTTP gene, is essential for Blp assembly. Herein we test the hypothesis that MTP expression in the RPE is essential to maintain lipid balance and retinal function using the newly generated RPEΔMttp mouse model. Using non-invasive ocular imaging, electroretinography, and histochemical and biochemical analyses we show that genetic depletion of Mttp from the RPE results in intracellular lipid accumulation, increased photoreceptor-associated cholesterol deposits, and photoreceptor cell death, and loss of rod but not cone function. RPE-specific reduction in Mttp had no significant effect on plasma lipids and lipoproteins. While APOB was decreased in the RPE, most ocular retinoids remained unchanged, with the exception of the storage form of retinoid, retinyl ester. Thus suggesting that RPE MTP is critical for Blp synthesis and assembly but is not directly involved in plasma lipoprotein metabolism. These studies demonstrate that RPE-specific MTP expression is necessary to establish and maintain retinal lipid homeostasis and visual function.
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Affiliation(s)
- Catharina R. Grubaugh
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Anuradha Dhingra
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Binu Prakash
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY, 11501 USA
| | - Diego Montenegro
- Department of Ophthalmology and Department of Pathology and Cell Biology, Columbia University, New York, NY, 10027 USA
| | - Janet R. Sparrow
- Department of Ophthalmology and Department of Pathology and Cell Biology, Columbia University, New York, NY, 10027 USA
| | - Lauren L. Daniele
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brent A. Bell
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104 USA
| | - M. Mahmood Hussain
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY, 11501 USA
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
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Fontaine V, Boumedine T, Monteiro E, Fournié M, Gersende G, Sahel JA, Picaud S, Veillet S, Lafont R, Latil M, Dilda PJ, Camelo S. RAR Inhibitors Display Photo-Protective and Anti-Inflammatory Effects in A2E Stimulated RPE Cells In Vitro through Non-Specific Modulation of PPAR or RXR Transactivation. Int J Mol Sci 2024; 25:3037. [PMID: 38474284 PMCID: PMC10932305 DOI: 10.3390/ijms25053037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/23/2024] [Accepted: 03/02/2024] [Indexed: 03/14/2024] Open
Abstract
N-retinylidene-N-retinylethanolamine (A2E) has been associated with age-related macular degeneration (AMD) physiopathology by inducing cell death, angiogenesis and inflammation in retinal pigmented epithelial (RPE) cells. It was previously thought that the A2E effects were solely mediated via the retinoic acid receptor (RAR)-α activation. However, this conclusion was based on experiments using the RAR "specific" antagonist RO-41-5253, which was found to also be a ligand and partial agonist of the peroxisome proliferator-activated receptor (PPAR)-γ. Moreover, we previously reported that inhibiting PPAR and retinoid X receptor (RXR) transactivation with norbixin also modulated inflammation and angiogenesis in RPE cells challenged in the presence of A2E. Here, using several RAR inhibitors, we deciphered the respective roles of RAR, PPAR and RXR transactivations in an in vitro model of AMD. We showed that BMS 195614 (a selective RAR-α antagonist) displayed photoprotective properties against toxic blue light exposure in the presence of A2E. BMS 195614 also significantly reduced the AP-1 transactivation and mRNA expression of the inflammatory interleukin (IL)-6 and vascular endothelial growth factor (VEGF) induced by A2E in RPE cells in vitro, suggesting a major role of RAR in these processes. Surprisingly, however, we showed that (1) Norbixin increased the RAR transactivation and (2) AGN 193109 (a high affinity pan-RAR antagonist) and BMS 493 (a pan-RAR inverse agonist), which are photoprotective against toxic blue light exposure in the presence of A2E, also inhibited PPARs transactivation and RXR transactivation, respectively. Therefore, in our in vitro model of AMD, several commercialized RAR inhibitors appear to be non-specific, and we propose that the phototoxicity and expression of IL-6 and VEGF induced by A2E in RPE cells operates through the activation of PPAR or RXR rather than by RAR transactivation.
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Affiliation(s)
- Valérie Fontaine
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
| | - Thinhinane Boumedine
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
| | - Elodie Monteiro
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
| | - Mylène Fournié
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
| | - Gendre Gersende
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
| | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
- Fondation Ophtalmologique Rothschild, 29 rue Manin, 75019 Paris, France
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Serge Picaud
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
| | - Stanislas Veillet
- Biophytis, Sorbonne Université, BC9, 4 place Jussieu, 75005 Paris, France (M.L.); (P.J.D.)
| | - René Lafont
- Biophytis, Sorbonne Université, BC9, 4 place Jussieu, 75005 Paris, France (M.L.); (P.J.D.)
| | - Mathilde Latil
- Biophytis, Sorbonne Université, BC9, 4 place Jussieu, 75005 Paris, France (M.L.); (P.J.D.)
| | - Pierre J. Dilda
- Biophytis, Sorbonne Université, BC9, 4 place Jussieu, 75005 Paris, France (M.L.); (P.J.D.)
| | - Serge Camelo
- Biophytis, Sorbonne Université, BC9, 4 place Jussieu, 75005 Paris, France (M.L.); (P.J.D.)
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Du X, Butler AG, Chen HY. Cell-cell interaction in the pathogenesis of inherited retinal diseases. Front Cell Dev Biol 2024; 12:1332944. [PMID: 38500685 PMCID: PMC10944940 DOI: 10.3389/fcell.2024.1332944] [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: 11/03/2023] [Accepted: 02/06/2024] [Indexed: 03/20/2024] Open
Abstract
The retina is part of the central nervous system specialized for vision. Inherited retinal diseases (IRD) are a group of clinically and genetically heterogenous disorders that lead to progressive vision impairment or blindness. Although each disorder is rare, IRD accumulatively cause blindness in up to 5.5 million individuals worldwide. Currently, the pathophysiological mechanisms of IRD are not fully understood and there are limited treatment options available. Most IRD are caused by degeneration of light-sensitive photoreceptors. Genetic mutations that abrogate the structure and/or function of photoreceptors lead to visual impairment followed by blindness caused by loss of photoreceptors. In healthy retina, photoreceptors structurally and functionally interact with retinal pigment epithelium (RPE) and Müller glia (MG) to maintain retinal homeostasis. Multiple IRD with photoreceptor degeneration as a major phenotype are caused by mutations of RPE- and/or MG-associated genes. Recent studies also reveal compromised MG and RPE caused by mutations in ubiquitously expressed ciliary genes. Therefore, photoreceptor degeneration could be a direct consequence of gene mutations and/or could be secondary to the dysfunction of their interaction partners in the retina. This review summarizes the mechanisms of photoreceptor-RPE/MG interaction in supporting retinal functions and discusses how the disruption of these processes could lead to photoreceptor degeneration, with an aim to provide a unique perspective of IRD pathogenesis and treatment paradigm. We will first describe the biology of retina and IRD and then discuss the interaction between photoreceptors and MG/RPE as well as their implications in disease pathogenesis. Finally, we will summarize the recent advances in IRD therapeutics targeting MG and/or RPE.
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Affiliation(s)
| | | | - Holly Y. Chen
- Department of Cell, Developmental and Integrative Biology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
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Liu Z, Huang J, Li D, Zhang C, Wan H, Zeng B, Tan Y, Zhong F, Liao H, Liu M, Chen ZS, Zou C, Liu D, Qin B. Targeting ZIP8 mediated ferroptosis as a novel strategy to protect against the retinal pigment epithelial degeneration. Free Radic Biol Med 2024; 214:42-53. [PMID: 38309537 DOI: 10.1016/j.freeradbiomed.2024.01.053] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/10/2024] [Accepted: 01/31/2024] [Indexed: 02/05/2024]
Abstract
The degeneration of retinal pigment epithelium (RPE) plays an important role in the development of age-related macular degeneration (AMD). However, the underlying mechanism remains elusive. In this study, we identified that ZIP8, a metal-ion transporter, plays a crucial role in the degeneration of RPE cells mediated by ferroptosis. ZIP8 was found to be upregulated in patients with AMD through transcriptome analysis. Upregulated ZIP8 was also observed in both oxidative-stressed RPE cells and AMD mouse model. Importantly, knockdown of ZIP8 significantly inhibited ferroptosis in RPE cells induced by sodium iodate-induced oxidative stress. Blocking ZIP8 with specific antibodies reversed RPE degeneration and restored retinal function, improving visual loss in a mouse model of NaIO3-induced. Interestingly, the modification of the N-glycosylation sites N40, N72 and N88, but not N273, was essential for the intracellular iron accumulation mediated by ZIP8, which further led to increased lipid peroxidation and RPE death. These findings highlight the critical role of ZIP8 in RPE ferroptosis and provide a potential target for the treatment of diseases associated with retinal degeneration, including AMD.
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Affiliation(s)
- Ziling Liu
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China; Institute of Biopharmaceutics and Health Engineering, Tsinghua Shenzhen International Graduate School, Shenzhen, China; Shenzhen Aier Ophthalmic Technology Institute, Shenzhen, China
| | - Jianguo Huang
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China
| | - Deshuang Li
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China
| | - Chuanhe Zhang
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China
| | - Huan Wan
- The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Bing Zeng
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China
| | - Yao Tan
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China
| | - Fuhua Zhong
- Department of Clinical Medical Research Center, The Second Clinical Medical College, Jinan University (Shenzhen People's Hospital), Shenzhen, China
| | - Hongxia Liao
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China
| | - MuYun Liu
- National Engineering Research Center of Foundational Technologies for CGT Industry, Shenzhen Kenuo Medical Laboratory, China
| | - Zhe-Sheng Chen
- College of Pharmacy and Health Sciences, St. John's University, Queens, New York, USA
| | - Chang Zou
- Department of Clinical Medical Research Center, The Second Clinical Medical College, Jinan University (Shenzhen People's Hospital), Shenzhen, China.
| | - Dongcheng Liu
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China; Shenzhen Aier Ophthalmic Technology Institute, Shenzhen, China.
| | - Bo Qin
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China; Shenzhen Aier Ophthalmic Technology Institute, Shenzhen, China.
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Bose D, Ortolan D, Farnoodian M, Sharma R, Bharti K. Considerations for Developing an Autologous Induced Pluripotent Stem Cell (iPSC)-Derived Retinal Pigment Epithelium (RPE) Replacement Therapy. Cold Spring Harb Perspect Med 2024; 14:a041295. [PMID: 37487631 PMCID: PMC10910357 DOI: 10.1101/cshperspect.a041295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
Cell-replacement therapies are a new class of treatments, which include induced pluripotent stem cell (iPSC)-derived tissues that aim to replace degenerated cells. iPSCs can potentially be used to generate any cell type of the body, making them a powerful tool for treating degenerative diseases. Cell replacement for retinal degenerative diseases is at the forefront of cell therapies, given the accessibility of the eye for surgical procedures and a huge unmet medical need for retinal degenerative diseases with no current treatment options. Clinical trials are ongoing in different parts of the world using stem cell-derived retinal pigment epithelium (RPE). This review focuses on scientific and regulatory considerations when developing an iPSC-derived RPE cell therapy from the development of a robust and efficient differentiation protocol to critical quality control assays for cell validation, the choice of an appropriate animal model for preclinical testing, and the regulatory aspects that dictate the final approval for proceeding to a first-in-human clinical trial.
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Affiliation(s)
- Devika Bose
- Ocular and Stem Cell Translational Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Davide Ortolan
- Ocular and Stem Cell Translational Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Mitra Farnoodian
- Ocular and Stem Cell Translational Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Ruchi Sharma
- Ocular and Stem Cell Translational Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Kapil Bharti
- Ocular and Stem Cell Translational Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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Gurubaran IS. Mitochondrial damage and clearance in retinal pigment epithelial cells. Acta Ophthalmol 2024; 102 Suppl 282:3-53. [PMID: 38467968 DOI: 10.1111/aos.16661] [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: 01/24/2024] [Accepted: 01/31/2024] [Indexed: 03/13/2024]
Abstract
Age-related macular degeneration (AMD) is a devastating eye disease that causes permanent vision loss in the central part of the retina, known as the macula. Patients with such severe visual loss face a reduced quality of life and are at a 1.5 times greater risk of death compared to the general population. Currently, there is no cure for or effective treatment for dry AMD. There are several mechanisms thought to underlie the disease, for example, ageing-associated chronic oxidative stress, mitochondrial damage, harmful protein aggregation and inflammation. As a way of gaining a better understanding of the molecular mechanisms behind AMD and thus developing new therapies, we have created a peroxisome proliferator-activated receptor gamma coactivator 1-alpha and nuclear factor erythroid 2-related factor 2 (PGC1α/NFE2L2) double-knockout (dKO) mouse model that mimics many of the clinical features of dry AMD, including elevated levels of oxidative stress markers, damaged mitochondria, accumulating lysosomal lipofuscin and extracellular drusen-like structures in retinal pigment epithelial cells (RPE). In addition, a human RPE cell-based model was established to examine the impact of non-functional intracellular clearance systems on inflammasome activation. In this study, we found that there was a disturbance in the autolysosomal machinery responsible for clearing mitochondria in the RPE cells of one-year-old PGC1α/NFE2L2-deficient mice. The confocal immunohistochemical analysis revealed an increase in autophagosome marker microtubule-associated proteins 1A/1B light chain 3B (LC3B) as well as multiple mitophagy markers such as PTE-induced putative kinase 1 (PINK1) and E3 ubiquitin ligase (PARKIN), along with signs of damaged mitochondria. However, no increase in autolysosome formation was detected, nor was there a colocalization of the lysosomal marker LAMP2 or the mitochondrial marker, ATP synthase β. There was an upregulation of late autolysosomal fusion Ras-related protein (Rab7) in the perinuclear space of RPE cells, together with autofluorescent aggregates. Additionally, we observed an increase in the numbers of Toll-like receptors 3 and 9, while those of NOD-like receptor 3 were decreased in PGC1α/NFE2L2 dKO retinal specimens compared to wild-type animals. There was a trend towards increased complement component C5a and increased involvement of the serine protease enzyme, thrombin, in enhancing the terminal pathway producing C5a, independent of C3. The levels of primary acute phase C-reactive protein and receptor for advanced glycation end products were also increased in the PGC1α/NFE2L2 dKO retina. Furthermore, selective proteasome inhibition with epoxomicin promoted both nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and mitochondrial-mediated oxidative stress, leading to the release of mitochondrial DNA to the cytosol, resulting in potassium efflux-dependent activation of the absent in melanoma 2 (AIM2) inflammasome and the subsequent secretion of interleukin-1β in ARPE-19 cells. In conclusion, the data suggest that there is at least a relative decrease in mitophagy, increases in the amounts of C5 and thrombin and decreased C3 levels in this dry AMD-like model. Moreover, selective proteasome inhibition evoked mitochondrial damage and AIM2 inflammasome activation in ARPE-19 cells.
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Affiliation(s)
- Iswariyaraja Sridevi Gurubaran
- Department of Medicine, Clinical Medicine Unit, University of Eastern Finland Institute of Clinical Medicine, Kuopio, Northern Savonia, Finland
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Lee D, Tomita Y, Shinojima A, Ban N, Yamaguchi S, Nishioka K, Negishi K, Yoshino J, Kurihara T. Nicotinamide mononucleotide, a potential future treatment in ocular diseases. Graefes Arch Clin Exp Ophthalmol 2024; 262:689-700. [PMID: 37335334 DOI: 10.1007/s00417-023-06118-w] [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: 02/06/2023] [Revised: 05/10/2023] [Accepted: 05/12/2023] [Indexed: 06/21/2023] Open
Abstract
PURPOSE The burden of ocular diseases has been gradually increasing worldwide. Various factors are suggested for the development and progression of ocular diseases, such as ocular inflammation, oxidative stress, and complex metabolic dysregulation. Thus, managing ocular diseases requires the modulation of pathologic signaling pathways through many mechanisms. Nicotinamide mononucleotide (NMN) is a bioactive molecule naturally found in life forms. NMN is a direct precursor of the important molecule nicotinamide adenine dinucleotide (NAD+), an essential co-enzyme required for enormous cellular functions in most life forms. While the recent experimental evidence of NMN treatment in various metabolic diseases has been well-reviewed, NMN treatment in ocular diseases has not been comprehensively summarized yet. In this regard, we aimed to focus on the therapeutic roles of NMN treatment in various ocular diseases with recent advances. METHODS How we came to our current opinion with a recent summary was described based on our own recent reports as well as a search of the related literature. RESULTS We found that NMN treatment might be available for the prevention of and protection from various experimental ocular diseases, as NMN treatment modulated ocular inflammation, oxidative stress, and complex metabolic dysregulation in murine models for eye diseases such as ischemic retinopathy, corneal defect, glaucoma, and age-related macular degeneration. CONCLUSION Our current review suggests and discusses new modes of actions of NMN for the prevention of and protection from various ocular diseases and can urge future research to obtain more solid evidence on a potential future NMN treatment in ocular diseases at the preclinical stages.
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Affiliation(s)
- Deokho Lee
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo, 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Yohei Tomita
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo, 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Ari Shinojima
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo, 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Norimitsu Ban
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Shintaro Yamaguchi
- Department of Internal Medicine, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Ken Nishioka
- Department of Internal Medicine, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Kazuno Negishi
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Jun Yoshino
- Department of Internal Medicine, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Toshihide Kurihara
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo, 160-8582, Japan.
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, 160-8582, Japan.
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Rzhanova LA, Markitantova YV, Aleksandrova MA. Recent Achievements in the Heterogeneity of Mammalian and Human Retinal Pigment Epithelium: In Search of a Stem Cell. Cells 2024; 13:281. [PMID: 38334673 PMCID: PMC10854871 DOI: 10.3390/cells13030281] [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: 11/30/2023] [Revised: 01/23/2024] [Accepted: 02/01/2024] [Indexed: 02/10/2024] Open
Abstract
Retinal pigment epithelium (RPE) cells are important fundamentally for the development and function of the retina. In this regard, the study of the morphological and molecular properties of RPE cells, as well as their regenerative capabilities, is of particular importance for biomedicine. However, these studies are complicated by the fact that, despite the external morphological similarity of RPE cells, the RPE is a population of heterogeneous cells, the molecular genetic properties of which have begun to be revealed by sequencing methods only in recent years. This review carries out an analysis of the data from morphological and molecular genetic studies of the heterogeneity of RPE cells in mammals and humans, which reveals the individual differences in the subpopulations of RPE cells and the possible specificity of their functions. Particular attention is paid to discussing the properties of "stemness," proliferation, and plasticity in the RPE, which may be useful for uncovering the mechanisms of retinal diseases associated with pathologies of the RPE and finding new ways of treating them.
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Affiliation(s)
| | - Yuliya V. Markitantova
- Koltzov Institute of Developmental Biology of the Russian Academy of Sciences, 26 Vavilov Street, 119334 Moscow, Russia; (L.A.R.); (M.A.A.)
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Kocherlakota S, Baes M. Benefits and Caveats in the Use of Retinal Pigment Epithelium-Specific Cre Mice. Int J Mol Sci 2024; 25:1293. [PMID: 38279294 PMCID: PMC10816505 DOI: 10.3390/ijms25021293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/16/2024] [Accepted: 01/18/2024] [Indexed: 01/28/2024] Open
Abstract
The retinal pigment epithelium (RPE) is an important monolayer of cells present in the outer retina, forming a major part of the blood-retina barrier (BRB). It performs many tasks essential for the maintenance of retinal integrity and function. With increasing knowledge of the retina, it is becoming clear that both common retinal disorders, like age-related macular degeneration, and rare genetic disorders originate in the RPE. This calls for a better understanding of the functions of various proteins within the RPE. In this regard, mice enabling an RPE-specific gene deletion are a powerful tool to study the role of a particular protein within the RPE cells in their native environment, simultaneously negating any potential influences of systemic changes. Moreover, since RPE cells interact closely with adjacent photoreceptors, these mice also provide an excellent avenue to study the importance of a particular gene function within the RPE to the retina as a whole. In this review, we outline and compare the features of various Cre mice created for this purpose, which allow for inducible or non-inducible RPE-specific knockout of a gene of interest. We summarize the various benefits and caveats involved in the use of such mouse lines, allowing researchers to make a well-informed decision on the choice of Cre mouse to use in relation to their research needs.
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Affiliation(s)
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
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