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Nguyen Y, Rudd Zhong Manis J, Ronczkowski NM, Bui T, Oxenrider A, Jadeja RN, Thounaojam MC. Unveiling the gut-eye axis: how microbial metabolites influence ocular health and disease. Front Med (Lausanne) 2024; 11:1377186. [PMID: 38799150 PMCID: PMC11122920 DOI: 10.3389/fmed.2024.1377186] [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: 01/26/2024] [Accepted: 04/19/2024] [Indexed: 05/29/2024] Open
Abstract
The intricate interplay between the gut microbiota and ocular health has surpassed conventional medical beliefs, fundamentally reshaping our understanding of organ interconnectivity. This review investigates into the intricate relationship between gut microbiota-derived metabolites and their consequential impact on ocular health and disease pathogenesis. By examining the role of specific metabolites, such as short-chain fatty acids (SCFAs) like butyrate and bile acids (BAs), herein we elucidate their significant contributions to ocular pathologies, thought-provoking the traditional belief of organ sterility, particularly in the field of ophthalmology. Highlighting the dynamic nature of the gut microbiota and its profound influence on ocular health, this review underlines the necessity of comprehending the complex workings of the gut-eye axis, an emerging field of science ready for further exploration and scrutiny. While acknowledging the therapeutic promise in manipulating the gut microbiome and its metabolites, the available literature advocates for a targeted, precise approach. Instead of broad interventions, it emphasizes the potential of exploiting specific microbiome-related metabolites as a focused strategy. This targeted approach compared to a precision tool rather than a broad-spectrum solution, aims to explore the therapeutic applications of microbiome-related metabolites in the context of various retinal diseases. By proposing a nuanced strategy targeted at specific microbial metabolites, this review suggests that addressing specific deficiencies or imbalances through microbiome-related metabolites might yield expedited and pronounced outcomes in systemic health, extending to the eye. This focused strategy holds the potential in bypassing the irregularity associated with manipulating microbes themselves, paving a more efficient pathway toward desired outcomes in optimizing gut health and its implications for retinal diseases.
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Affiliation(s)
- Yvonne Nguyen
- Mercer University School of Medicine, Macon, GA, United States
| | | | | | - Tommy Bui
- Departments of Cellular Biology and Anatomy, Augusta University, Augusta, GA, United States
| | - Allston Oxenrider
- Departments of Cellular Biology and Anatomy, Augusta University, Augusta, GA, United States
| | - Ravirajsinh N. Jadeja
- Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Menaka C. Thounaojam
- Departments of Cellular Biology and Anatomy, Augusta University, Augusta, GA, United States
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2
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Yang P, Mustafi D, Pepple KL. Immunology of Retinitis Pigmentosa and Gene Therapy-Associated Uveitis. Cold Spring Harb Perspect Med 2024; 14:a041305. [PMID: 37037600 PMCID: PMC10562523 DOI: 10.1101/cshperspect.a041305] [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] [Indexed: 04/12/2023]
Abstract
The underlying immune state of inherited retinal degenerations (IRDs) and retinitis pigmentosa (RP) has been an emerging area of interest, wherein the consequences have never been greater given the widespread recognition of gene therapy-associated uveitis (GTU) in gene therapy clinical trials. Whereas some evidence suggests that the adaptive immune system may play a role, the majority of studies indicate that the innate immune system is likely the primary driver of neuroinflammation in RP. During retinal degeneration, discrete mechanisms activate resident microglia and promote infiltrating macrophages that can either be protective or detrimental to photoreceptor cell death. This persistent stimulation of innate immunity, overlaid by the introduction of viral antigens as part of gene therapy, has the potential to trigger a complex microglia/macrophage-driven proinflammatory state. A better understanding of the immune pathophysiology in IRD and GTU will be necessary to improve the success of developing novel treatments for IRDs.
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Affiliation(s)
- Paul Yang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregan 97239, USA
| | - Debarshi Mustafi
- Department of Ophthalmology, Roger and Karalis Johnson Retina Center, University of Washington, Seattle, Washington 98109, USA
- Brotman Baty Institute for Precision Medicine, Seattle, Washington 98109, USA
- Department of Ophthalmology, Seattle Children's Hospital, Seattle, Washington 98109, USA
| | - Kathryn L Pepple
- Department of Ophthalmology, Roger and Karalis Johnson Retina Center, University of Washington, Seattle, Washington 98109, USA
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Li J, Huang Z, Jin Y, Liang L, Li Y, Xu K, Zhou W, Li X. Neuroprotective Effect of Tauroursodeoxycholic Acid (TUDCA) on In Vitro and In Vivo Models of Retinal Disorders: A Systematic Review. Curr Neuropharmacol 2024; 22:1374-1390. [PMID: 37691227 PMCID: PMC11092919 DOI: 10.2174/1570159x21666230907152207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 02/15/2023] [Accepted: 03/07/2023] [Indexed: 09/12/2023] Open
Abstract
BACKGROUND Tauroursodeoxycholic acid (TUDCA) is a naturally produced hydrophilic bile acid that has been used for centuries in Chinese medicine. Numerous recent in vitro and in vivo studies have shown that TUDCA has neuroprotective action in various models of retinal disorders. OBJECTIVE To systematically review the scientific literature and provide a comprehensive summary on the neuroprotective action and the mechanisms involved in the cytoprotective effects of TUDCA. METHODS A systematic review was conducted in accordance with the PRISMA (The Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Systematic literature search of United States National Library of Medicine (PubMed), Web of Science, Embase, Scopus and Cochrane Library was performed, which covered all original articles published up to July 2022. The terms, "TUDCA" in combination with "retina", "retinal protection", "neuroprotection" were searched. Possible biases were identified with the adopted SYRCLE's tool. RESULTS Of the 423 initially gathered studies, 24 articles met inclusion/exclusion criteria for full-text review. Six of them were in vitro experiments, 17 studies reported in vivo data and one study described both in vitro and in vivo data. The results revealed the effect of TUDCA on different retinal diseases, such as retinitis pigmentosa (RP), diabetic retinopathy (DR), retinal degeneration (RD), retinal ganglion cell (RGC) injury, Leber's hereditary optic neuropathy (LHON), choroidal neovascularization (CNV), and retinal detachment (RDT). The quality scores of the in vivo studies were ranged from 5 to 7 points (total 10 points), according to SYRCLE's risk of bias tool. Both in vitro and in vivo data suggested that TUDCA could effectively delay degeneration and apoptosis of retinal neurons, preserve retinal structure and function, and its mechanism of actions might be related with inhibiting apoptosis, decreasing inflammation, attenuating oxidative stress, suppressing endoplasmic reticulum (ER) stress, and reducing angiogenesis. CONCLUSION This systematic review demonstrated that TUDCA has neuroprotective effect on in vivo and in vitro models of retinal disorders, reinforcing the currently available evidence that TUDCA could be a promising therapeutic agent in retinal diseases treatment. However, well designed clinical trials are necessary to appraise the efficacy of TUDCA in clinical setting.
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Affiliation(s)
- Jiaxian Li
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing 100040, China
| | - Ziyang Huang
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing 100040, China
| | - Yu Jin
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing 100040, China
| | - Lina Liang
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing 100040, China
| | - Yamin Li
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing 100040, China
| | - Kai Xu
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing 100040, China
| | - Wei Zhou
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing 100040, China
| | - Xiaoyu Li
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing 100040, China
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Sarkar H, Lahne M, Nair N, Moosajee M. Oxidative and Endoplasmic Reticulum Stress Represent Novel Therapeutic Targets for Choroideremia. Antioxidants (Basel) 2023; 12:1694. [PMID: 37759997 PMCID: PMC10525549 DOI: 10.3390/antiox12091694] [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: 07/24/2023] [Revised: 08/09/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023] Open
Abstract
Choroideremia (CHM) is a rare X-linked chorioretinal dystrophy, affecting the photoreceptors, retinal pigment epithelium (RPE) and choroid, with no approved therapy. CHM is caused by mutations in the CHM gene, which encodes the ubiquitously expressed Rab escort protein 1 (REP1). REP1 is involved in prenylation, a post-translational modification of Rab proteins, and plays an essential role in intracellular trafficking. In this study, we examined oxidative and endoplasmic reticulum (ER) stress pathways in chmru848 zebrafish and CHMY42X patient fibroblasts, and screened a number of neuroprotectants for their ability to reduce stress. The expression of the oxidative stress markers txn, cat and sod3a, and the ER stress markers bip, atf4 and atf6, were dysregulated in chmru848 fish. The expression of SOD2 was also reduced in CHMY42X fibroblasts, along with reduced BIP and increased CHOP expression. The lack of REP1 is associated with defects in vesicular trafficking, photoreceptor outer segment phagocytosis and melanosome transport, leading to increased levels of stress within the retina and RPE. Drugs targeting oxidative and ER stress pathways represent novel therapeutic avenues.
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Affiliation(s)
- Hajrah Sarkar
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Francis Crick Institute, London NW1 1AT, UK
| | | | - Neelima Nair
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Francis Crick Institute, London NW1 1AT, UK
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5
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Wu KY, Kulbay M, Toameh D, Xu AQ, Kalevar A, Tran SD. Retinitis Pigmentosa: Novel Therapeutic Targets and Drug Development. Pharmaceutics 2023; 15:685. [PMID: 36840007 PMCID: PMC9963330 DOI: 10.3390/pharmaceutics15020685] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/12/2023] [Accepted: 02/16/2023] [Indexed: 02/19/2023] Open
Abstract
Retinitis pigmentosa (RP) is a heterogeneous group of hereditary diseases characterized by progressive degeneration of retinal photoreceptors leading to progressive visual decline. It is the most common type of inherited retinal dystrophy and has a high burden on both patients and society. This condition causes gradual loss of vision, with its typical manifestations including nyctalopia, concentric visual field loss, and ultimately bilateral central vision loss. It is one of the leading causes of visual disability and blindness in people under 60 years old and affects over 1.5 million people worldwide. There is currently no curative treatment for people with RP, and only a small group of patients with confirmed RPE65 mutations are eligible to receive the only gene therapy on the market: voretigene neparvovec. The current therapeutic armamentarium is limited to retinoids, vitamin A supplements, protection from sunlight, visual aids, and medical and surgical interventions to treat ophthalmic comorbidities, which only aim to slow down the progression of the disease. Considering such a limited therapeutic landscape, there is an urgent need for developing new and individualized therapeutic modalities targeting retinal degeneration. Although the heterogeneity of gene mutations involved in RP makes its target treatment development difficult, recent fundamental studies showed promising progress in elucidation of the photoreceptor degeneration mechanism. The discovery of novel molecule therapeutics that can selectively target specific receptors or specific pathways will serve as a solid foundation for advanced drug development. This article is a review of recent progress in novel treatment of RP focusing on preclinical stage fundamental research on molecular targets, which will serve as a starting point for advanced drug development. We will review the alterations in the molecular pathways involved in the development of RP, mainly those regarding endoplasmic reticulum (ER) stress and apoptotic pathways, maintenance of the redox balance, and genomic stability. We will then discuss the therapeutic approaches under development, such as gene and cell therapy, as well as the recent literature identifying novel potential drug targets for RP.
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Affiliation(s)
- Kevin Y. Wu
- Division of Ophthalmology, Department of Surgery, University of Sherbrooke, Sherbrooke, QC J1G 2E8, Canada
| | - Merve Kulbay
- Faculty of Medicine, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Dana Toameh
- Faculty of Medicine, McGill University, Montreal, QC H3G 2M1, Canada
| | - An Qi Xu
- Faculty of Medicine, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Ananda Kalevar
- Division of Ophthalmology, Department of Surgery, University of Sherbrooke, Sherbrooke, QC J1G 2E8, Canada
| | - Simon D. Tran
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, QC H3A 1G1, Canada
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Pinilla I, Maneu V, Campello L, Fernández-Sánchez L, Martínez-Gil N, Kutsyr O, Sánchez-Sáez X, Sánchez-Castillo C, Lax P, Cuenca N. Inherited Retinal Dystrophies: Role of Oxidative Stress and Inflammation in Their Physiopathology and Therapeutic Implications. Antioxidants (Basel) 2022; 11:antiox11061086. [PMID: 35739983 PMCID: PMC9219848 DOI: 10.3390/antiox11061086] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/24/2022] [Accepted: 05/26/2022] [Indexed: 12/13/2022] Open
Abstract
Inherited retinal dystrophies (IRDs) are a large group of genetically and clinically heterogeneous diseases characterized by the progressive degeneration of the retina, ultimately leading to loss of visual function. Oxidative stress and inflammation play fundamental roles in the physiopathology of these diseases. Photoreceptor cell death induces an inflammatory state in the retina. The activation of several molecular pathways triggers different cellular responses to injury, including the activation of microglia to eliminate debris and recruit inflammatory cells from circulation. Therapeutical options for IRDs are currently limited, although a small number of patients have been successfully treated by gene therapy. Many other therapeutic strategies are being pursued to mitigate the deleterious effects of IRDs associated with oxidative metabolism and/or inflammation, including inhibiting reactive oxygen species’ accumulation and inflammatory responses, and blocking autophagy. Several compounds are being tested in clinical trials, generating great expectations for their implementation. The present review discusses the main death mechanisms that occur in IRDs and the latest therapies that are under investigation.
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Affiliation(s)
- Isabel Pinilla
- Aragón Health Research Institute (IIS Aragón), 50009 Zaragoza, Spain
- Department of Ophthalmology, Lozano Blesa, University Hospital, 50009 Zaragoza, Spain
- Department of Surgery, University of Zaragoza, 50009 Zaragoza, Spain
- Correspondence: (I.P.); (V.M.)
| | - Victoria Maneu
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain;
- Alicante Institute for Health and Biomedical Research (ISABIAL), 03010 Alicante, Spain; (P.L.); (N.C.)
- Correspondence: (I.P.); (V.M.)
| | - Laura Campello
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
| | - Laura Fernández-Sánchez
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain;
| | - Natalia Martínez-Gil
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
| | - Oksana Kutsyr
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
| | - Xavier Sánchez-Sáez
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
| | - Carla Sánchez-Castillo
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
| | - Pedro Lax
- Alicante Institute for Health and Biomedical Research (ISABIAL), 03010 Alicante, Spain; (P.L.); (N.C.)
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
| | - Nicolás Cuenca
- Alicante Institute for Health and Biomedical Research (ISABIAL), 03010 Alicante, Spain; (P.L.); (N.C.)
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
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7
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Fernández-Sánchez L, Albertos-Arranz H, Ortuño-Lizarán I, Lax P, Cuenca N. Neuroprotective Effects of Tauroursodeoxicholic Acid Involves Vascular and Glial Changes in Retinitis Pigmentosa Model. Front Neuroanat 2022; 16:858073. [PMID: 35493706 PMCID: PMC9039202 DOI: 10.3389/fnana.2022.858073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 03/10/2022] [Indexed: 11/17/2022] Open
Abstract
Purpose Retinitis pigmentosa is primarily characterized by a massive photoreceptor loss. But a global retinal remodeling occurs in later stages of the disease. At that phase, glial cells and retinal vasculature are also strongly affected. The main aim of the present work is to assess if the bile acid Tauroursodeoxicholic acid (TUDCA), which has a demonstrated neuroprotective effect in numerous neurodegenerative diseases, is able to prevent glial and vascular degeneration in the P23H rat retina. Methods Homozygous P23H (line 3) animals were injected weekly with a TUDCA (500 mg/kg, i.p.) or vehicle solution, from the postnatal day (P) 21 to P120. Sprague-Dawley rats (SD) were used as control. Retinal cross-sections and wholemounts were immunostained using different glial and vascular markers and visualized with confocal microscopy. Retinal blood vessels were stained with nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry and retinal vascular networks were drawn by hand using a camera lucida. Results At P120, the photoreceptor degeneration observed in P23H rats was accompanied by a reduction in the vascular network density and complexity at the deep capillary plexus. In addition, astrocytes showed gliotic features and the outer processes of Müller cells displayed an aberrant distribution in ring-shaped structures. When treated with TUDCA, P23H rats displayed better-preserved vessels and capillary loops in the deep capillary plexus which are associated with the partial preservation of photoreceptors. TUDCA treatment also increased the number of astrocytes and reduced the presence of Müller cell process clusters in the outer retina. Conclusion This work suggests that, besides its neuroprotective effect on photoreceptor cells, TUDCA treatment also protects from vascular and glial degeneration, a fact that encourages the use of TUDCA as a powerful therapy for neurodegenerative diseases.
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Affiliation(s)
| | - Henar Albertos-Arranz
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Isabel Ortuño-Lizarán
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Pedro Lax
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
- Alicante Institute for Health and Biomedical Research (ISABIAL-FISABIO Foundation), Alicante, Spain
| | - Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
- Alicante Institute for Health and Biomedical Research (ISABIAL-FISABIO Foundation), Alicante, Spain
- Institute Ramón Margalef, University of Alicante, Alicante, Spain
- *Correspondence: Nicolás Cuenca,
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Daruich A, Picard E, Guégan J, Jaworski T, Parenti L, Delaunay K, Naud MC, Berdugo M, Boatright JH, Behar-Cohen F. Comparative Analysis of Urso- and Tauroursodeoxycholic Acid Neuroprotective Effects on Retinal Degeneration Models. Pharmaceuticals (Basel) 2022; 15:334. [PMID: 35337132 PMCID: PMC8955596 DOI: 10.3390/ph15030334] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/24/2022] [Accepted: 03/01/2022] [Indexed: 02/01/2023] Open
Abstract
Ursodeoxycholic (UDCA) and tauroursodeoxycholic (TUDCA) acids have shown neuroprotective properties in neurodegenerative diseases, but differential effects of the two bile acids have been poorly explored. The aim of this study was to evaluate the neuroprotective effects of UDCA versus TUDCA in a neuroretinal degeneration model and to compare transcriptionally regulated pathways. The WERI-Rb-1 human cone-like cell line and retinal explants were exposed to albumin and TUDCA or UDCA. Viability, cell death, and microglial activation were quantified. Transcriptionally regulated pathways were analyzed after RNA sequencing using the edgeR bioconductor package. Pre-treatment of cone-like cells with UDCA or TUDCA significantly protected cells from albumin toxicity. On retinal explants, either bile acid reduced apoptosis, necroptosis, and microglia activation at 6 h. TUDCA induced the regulation of 463 genes, whilst 31 genes were regulated by UDCA. Only nineteen common genes were regulated by both bile acids, mainly involved in iron control, cell death, oxidative stress, and cell metabolism. As compared to UDCA, TUDCA up-regulated genes involved in endoplasmic reticulum stress pathways and down-regulated genes involved in axonal and neuronal development. Either bile acid protected against albumin-induced cell loss. However, TUDCA regulated substantially more neuroprotective genes than UDCA.
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Affiliation(s)
- Alejandra Daruich
- From Physiopathology of Ocular Diseases to Clinical Development, Centre de Recherche des Cordeliers, Sorbonne University, Paris University, Inserm, F-75006 Paris, France; (E.P.); (T.J.); (L.P.); (K.D.); (M.-C.N.); (M.B.); (F.B.-C.)
- Ophthalmology Department, Necker-Enfants Malades University Hospital, Assistance Publique Hôpitaux de Paris, Paris University, F-75015 Paris, France
| | - Emilie Picard
- From Physiopathology of Ocular Diseases to Clinical Development, Centre de Recherche des Cordeliers, Sorbonne University, Paris University, Inserm, F-75006 Paris, France; (E.P.); (T.J.); (L.P.); (K.D.); (M.-C.N.); (M.B.); (F.B.-C.)
| | - Justine Guégan
- Institut du Cerveau (ICM), INSERM, CNRS, AP-HP, Sorbonne University, Pitié-Salpêtrière University Hospital, F-75013 Paris, France;
| | - Thara Jaworski
- From Physiopathology of Ocular Diseases to Clinical Development, Centre de Recherche des Cordeliers, Sorbonne University, Paris University, Inserm, F-75006 Paris, France; (E.P.); (T.J.); (L.P.); (K.D.); (M.-C.N.); (M.B.); (F.B.-C.)
| | - Léa Parenti
- From Physiopathology of Ocular Diseases to Clinical Development, Centre de Recherche des Cordeliers, Sorbonne University, Paris University, Inserm, F-75006 Paris, France; (E.P.); (T.J.); (L.P.); (K.D.); (M.-C.N.); (M.B.); (F.B.-C.)
| | - Kimberley Delaunay
- From Physiopathology of Ocular Diseases to Clinical Development, Centre de Recherche des Cordeliers, Sorbonne University, Paris University, Inserm, F-75006 Paris, France; (E.P.); (T.J.); (L.P.); (K.D.); (M.-C.N.); (M.B.); (F.B.-C.)
| | - Marie-Christine Naud
- From Physiopathology of Ocular Diseases to Clinical Development, Centre de Recherche des Cordeliers, Sorbonne University, Paris University, Inserm, F-75006 Paris, France; (E.P.); (T.J.); (L.P.); (K.D.); (M.-C.N.); (M.B.); (F.B.-C.)
| | - Marianne Berdugo
- From Physiopathology of Ocular Diseases to Clinical Development, Centre de Recherche des Cordeliers, Sorbonne University, Paris University, Inserm, F-75006 Paris, France; (E.P.); (T.J.); (L.P.); (K.D.); (M.-C.N.); (M.B.); (F.B.-C.)
| | - Jeffrey H. Boatright
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA 30322, USA;
- Center of Excellence, Atlanta Veterans Administration Medical Center, Decatur, GA 30033, USA
| | - Francine Behar-Cohen
- From Physiopathology of Ocular Diseases to Clinical Development, Centre de Recherche des Cordeliers, Sorbonne University, Paris University, Inserm, F-75006 Paris, France; (E.P.); (T.J.); (L.P.); (K.D.); (M.-C.N.); (M.B.); (F.B.-C.)
- Ophtalmopole, Cochin Hospital, Assistance Publique Hôpitaux de Paris, Paris University, F-75015 Paris, France
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Brunet AA, Harvey AR, Carvalho LS. Primary and Secondary Cone Cell Death Mechanisms in Inherited Retinal Diseases and Potential Treatment Options. Int J Mol Sci 2022; 23:ijms23020726. [PMID: 35054919 PMCID: PMC8775779 DOI: 10.3390/ijms23020726] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/05/2022] [Accepted: 01/05/2022] [Indexed: 12/13/2022] Open
Abstract
Inherited retinal diseases (IRDs) are a leading cause of blindness. To date, 260 disease-causing genes have been identified, but there is currently a lack of available and effective treatment options. Cone photoreceptors are responsible for daylight vision but are highly susceptible to disease progression, the loss of cone-mediated vision having the highest impact on the quality of life of IRD patients. Cone degeneration can occur either directly via mutations in cone-specific genes (primary cone death), or indirectly via the primary degeneration of rods followed by subsequent degeneration of cones (secondary cone death). How cones degenerate as a result of pathological mutations remains unclear, hindering the development of effective therapies for IRDs. This review aims to highlight similarities and differences between primary and secondary cone cell death in inherited retinal diseases in order to better define cone death mechanisms and further identify potential treatment options.
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Affiliation(s)
- Alicia A. Brunet
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia;
- Lions Eye Institute Ltd., 2 Verdun St, Nedlands, WA 6009, Australia
- Correspondence: ; Tel.: +61-423-359-714
| | - Alan R. Harvey
- School of Human Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia;
- Perron Institute for Neurological and Translational Science, 8 Verdun St, Nedlands, WA 6009, Australia
| | - Livia S. Carvalho
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia;
- Lions Eye Institute Ltd., 2 Verdun St, Nedlands, WA 6009, Australia
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10
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Wagner JE, Zobel L, Gerhardt MJ, O'Riordan CR, Frederick A, Petersen-Jones SM, Biel M, Michalakis S. In vivo potency testing of subretinal rAAV5.hCNGB1 gene therapy in the Cngb1 knockout mouse model of retinitis pigmentosa. Hum Gene Ther 2021; 32:1158-1170. [PMID: 34376057 DOI: 10.1089/hum.2021.121] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Retinitis pigmentosa type 45 (RP45) is an autosomal-recessively inherited blinding disease caused by mutations in the cyclic nucleotide gated channel subunit beta 1 (CNGB1) gene. In this study, we developed and tested a novel gene supplementation therapy suitable for clinical translation. To this end, we designed a recombinant adeno-associated virus (rAAV) vector carrying a genome that features a novel human rhodopsin promoter (hRHO194) driving rod-specific expression of full-length human CNGB1 (rAAV5.hCNGB1). rAAV5.hCNGB1 was evaluated for efficacy in the Cngb1 knockout (Cngb1-/-) mouse model of RP45. In particular, increasing doses of rAAV5.hCNGB1 were delivered via single subretinal injection in 4-week-old Cngb1-/- mice and the treatment effect was assessed over a follow-up period of 9 months at the level of (i) retinal morphology, (ii) retinal function, (iii) vision-guided behavior, and (iv) transgene expression. We found that subretinal treatment with rAAV5.hCNGB1 resulted in efficient expression of the human CNGB1 protein in mouse rods and was able to normalize the expression of the endogenous mouse CNGA1 subunit, which together with CNGB1 forms the native heterotetrameric cGMP-gated cation channel in rod photoreceptors. The treatment led to a dose-dependent recovery of rod photoreceptor-driven function and preservation of retinal morphology in Cngb1-/- mice. In summary, these results demonstrate the efficacy of hCNGB1 gene supplementation therapy in the Cngb1-/- mouse model of RP45 and support the translation of this approach towards future clinical application.
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Affiliation(s)
- Johanna E Wagner
- Ludwig-Maximilians-Universität München, 9183, Department of Pharmacy - Center for Drug Research, Munich, Bayern, Germany;
| | - Lena Zobel
- Ludwig-Maximilians-Universität München, 9183, Department of Pharmacy - Center for Drug Research, Munich, Bayern, Germany.,Ludwig-Maximilians-Universität München, 9183, University Hospital - Department of Ophthalmology, Munich, Bayern, Germany;
| | - Maximilian Joachim Gerhardt
- Ludwig-Maximilians-Universität München, 9183, University Hospital - Department of Ophthalmology, Munich, Bayern, Germany;
| | - Catherine R O'Riordan
- Sanofi Genzyme, 2194, Gene Therapy, Rare Diseases, Framingham, Massachusetts, United States; Catherine.O'
| | - Amy Frederick
- Sanofi Genzyme, 2194, Gene Therapy, Rare Diseases, Framingham, Massachusetts, United States;
| | - Simon M Petersen-Jones
- Michigan State University, Veterinary Medical Center, East Lansing, Michigan, United States;
| | - Martin Biel
- Ludwig-Maximilians-Universität München, 9183, Department of Pharmacy - Center for Drug Research, Munich, Bayern, Germany;
| | - Stylianos Michalakis
- Ludwig-Maximilians-Universität München, 9183, Department of Pharmacy - Center for Drug Research, Munich, Bayern, Germany.,Ludwig-Maximilians-Universität München, 9183, University Hospital - Department of Ophthalmology, Munich, Bayern, Germany;
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11
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Fu J, Aung MH, Prunty MC, Hanif AM, Hutson LM, Boatright JH, Pardue MT. Tauroursodeoxycholic Acid Protects Retinal and Visual Function in a Mouse Model of Type 1 Diabetes. Pharmaceutics 2021; 13:1154. [PMID: 34452115 PMCID: PMC8400977 DOI: 10.3390/pharmaceutics13081154] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/20/2021] [Accepted: 07/20/2021] [Indexed: 01/14/2023] Open
Abstract
PURPOSE Previous studies demonstrated that systemic treatment with tauroursodeoxycholic acid (TUDCA) is protective in in vivo mouse models of retinal degeneration and in culture models of hyperglycemia. This study tested the hypothesis that TUDCA will preserve visual and retinal function in a mouse model of early diabetic retinopathy (DR). METHODS Adult C57BL/6J mice were treated with streptozotocin (STZ) and made diabetic at 8-10 weeks of age. Control and diabetic mice were treated with vehicle or TUDCA starting 1 or 3 weeks after induction of diabetes, and were assessed bimonthly for visual function via an optomotor response and monthly for retinal function via scotopic electroretinograms. RESULTS Diabetic mice showed significantly reduced spatial frequency and contrast sensitivity thresholds compared to control mice, while diabetic mice treated early with TUDCA showed preservation at all timepoints. A-wave, b-wave, and oscillatory potential 2 (OP2) amplitudes decreased in diabetic mice. Diabetic mice also exhibited delays in a-wave and OP2-implicit times. Early TUDCA treatment ameliorated a-wave, b-wave, and OP2 deficits. Late TUDCA treatment showed reduced preservation effects compared to early treatment. CONCLUSIONS Early TUDCA treatment preserved visual function in an STZ-mouse model of Type I diabetes. These data add to a growing body of preclinical research that may support testing whether TUDCA may be an effective early clinical intervention against declining visual function caused by diabetic retinopathy.
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Affiliation(s)
- Jieming Fu
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA 30033, USA; (J.F.); (M.H.A.); (M.C.P.); (A.M.H.); (L.M.H.)
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA 22904, USA
| | - Moe H. Aung
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA 30033, USA; (J.F.); (M.H.A.); (M.C.P.); (A.M.H.); (L.M.H.)
- Neuroscience, Emory University, Atlanta, GA 30322, USA
- Department of Ophthalmology, Dell Medical School, The University of Texas at Austin, Austin, TX 78712, USA
| | - Megan C. Prunty
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA 30033, USA; (J.F.); (M.H.A.); (M.C.P.); (A.M.H.); (L.M.H.)
- Case Western Reserve University School of Medicine, Urology Institute of University Hospitals, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Adam M. Hanif
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA 30033, USA; (J.F.); (M.H.A.); (M.C.P.); (A.M.H.); (L.M.H.)
- Casey Eye Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Lauren M. Hutson
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA 30033, USA; (J.F.); (M.H.A.); (M.C.P.); (A.M.H.); (L.M.H.)
- Department of Psychology and Neuroscience, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27514, USA
| | - Jeffrey H. Boatright
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA 30033, USA; (J.F.); (M.H.A.); (M.C.P.); (A.M.H.); (L.M.H.)
- Neuroscience, Emory University, Atlanta, GA 30322, USA
- Ophthalmology, Emory University, Atlanta, GA 30322, USA
| | - Machelle T. Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA 30033, USA; (J.F.); (M.H.A.); (M.C.P.); (A.M.H.); (L.M.H.)
- Neuroscience, Emory University, Atlanta, GA 30322, USA
- Ophthalmology, Emory University, Atlanta, GA 30322, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory School of Medicine, Atlanta, GA 30332, USA
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12
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Bilbao-Malavé V, González-Zamora J, de la Puente M, Recalde S, Fernandez-Robredo P, Hernandez M, Layana AG, Saenz de Viteri M. Mitochondrial Dysfunction and Endoplasmic Reticulum Stress in Age Related Macular Degeneration, Role in Pathophysiology, and Possible New Therapeutic Strategies. Antioxidants (Basel) 2021; 10:1170. [PMID: 34439418 PMCID: PMC8388889 DOI: 10.3390/antiox10081170] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/14/2021] [Accepted: 07/20/2021] [Indexed: 02/07/2023] Open
Abstract
Age related macular degeneration (AMD) is the main cause of legal blindness in developed countries. It is a multifactorial disease in which a combination of genetic and environmental factors contributes to increased risk of developing this vision-incapacitating condition. Oxidative stress plays a central role in the pathophysiology of AMD and recent publications have highlighted the importance of mitochondrial dysfunction and endoplasmic reticulum stress in this disease. Although treatment with vascular endothelium growth factor inhibitors have decreased the risk of blindness in patients with the exudative form of AMD, the search for new therapeutic options continues to prevent the loss of photoreceptors and retinal pigment epithelium cells, characteristic of late stage AMD. In this review, we explain how mitochondrial dysfunction and endoplasmic reticulum stress participate in AMD pathogenesis. We also discuss a role of several antioxidants (bile acids, resveratrol, melatonin, humanin, and coenzyme Q10) in amelioration of AMD pathology.
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Affiliation(s)
- Valentina Bilbao-Malavé
- Department of Opthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (V.B.-M.); (J.G.-Z.); (M.d.l.P.); (A.G.L.)
| | - Jorge González-Zamora
- Department of Opthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (V.B.-M.); (J.G.-Z.); (M.d.l.P.); (A.G.L.)
| | - Miriam de la Puente
- Department of Opthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (V.B.-M.); (J.G.-Z.); (M.d.l.P.); (A.G.L.)
| | - Sergio Recalde
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Universidad de Navarra, 31008 Pamplona, Spain; (S.R.); (P.F.-R.); (M.H.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa en Salud: ‘Prevention, Early Detection, and Treatment of the Prevalent Degenerative and Chronic Ocular Pathology’ from (RD16/0008/0011), Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Patricia Fernandez-Robredo
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Universidad de Navarra, 31008 Pamplona, Spain; (S.R.); (P.F.-R.); (M.H.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa en Salud: ‘Prevention, Early Detection, and Treatment of the Prevalent Degenerative and Chronic Ocular Pathology’ from (RD16/0008/0011), Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - María Hernandez
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Universidad de Navarra, 31008 Pamplona, Spain; (S.R.); (P.F.-R.); (M.H.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa en Salud: ‘Prevention, Early Detection, and Treatment of the Prevalent Degenerative and Chronic Ocular Pathology’ from (RD16/0008/0011), Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Alfredo Garcia Layana
- Department of Opthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (V.B.-M.); (J.G.-Z.); (M.d.l.P.); (A.G.L.)
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Universidad de Navarra, 31008 Pamplona, Spain; (S.R.); (P.F.-R.); (M.H.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa en Salud: ‘Prevention, Early Detection, and Treatment of the Prevalent Degenerative and Chronic Ocular Pathology’ from (RD16/0008/0011), Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Manuel Saenz de Viteri
- Department of Opthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (V.B.-M.); (J.G.-Z.); (M.d.l.P.); (A.G.L.)
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Universidad de Navarra, 31008 Pamplona, Spain; (S.R.); (P.F.-R.); (M.H.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa en Salud: ‘Prevention, Early Detection, and Treatment of the Prevalent Degenerative and Chronic Ocular Pathology’ from (RD16/0008/0011), Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, 28029 Madrid, Spain
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13
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Yang F, Ma H, Butler MR, Ding XQ. Preservation of endoplasmic reticulum (ER) Ca 2+ stores by deletion of inositol-1,4,5-trisphosphate receptor type 1 promotes ER retrotranslocation, proteostasis, and protein outer segment localization in cyclic nucleotide-gated channel-deficient cone photoreceptors. FASEB J 2021; 35:e21579. [PMID: 33960001 DOI: 10.1096/fj.202002711r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/03/2021] [Accepted: 03/25/2021] [Indexed: 11/11/2022]
Abstract
Endoplasmic reticulum (ER) Ca2+ homeostasis relies on an appropriate balance between efflux- and influx-channel activity responding to dynamic changes of intracellular Ca2+ levels. Dysregulation of this complex signaling network has been shown to contribute to neuronal and photoreceptor death in neuro- and retinal degenerative diseases, respectively. In mice with cone cyclic nucleotide-gated (CNG) channel deficiency, a model of achromatopsia/cone dystrophy, cones display early-onset ER stress-associated apoptosis and protein mislocalization. Cones in these mice also show reduced cytosolic Ca2+ level and subsequent elevation in the ER Ca2+ -efflux-channel activity, specifically the inositol-1,4,5-trisphosphate receptor type 1 (IP3 R1), and deletion of IP3 R1 results in preservation of cones. This work investigated how preservation of ER Ca2+ stores leads to cone protection. We examined the effects of cone specific deletion of IP3 R1 on ER stress responses/cone death, protein localization, and ER proteostasis/ER-associated degradation. We demonstrated that deletion of IP3 R1 improves trafficking of cone-specific proteins M-/S-opsin and phosphodiesterase 6C to cone outer segments and reduces localization to cone inner segments. Consistent with the improved protein localization, deletion of IP3 R1 results in increased ER retrotranslocation protein expression, reduced proteasome subunit expression, reduced ER stress/cone death, and reduced retinal remodeling. We also observed the enhanced ER retrotranslocation in mice that have been treated with a chemical chaperone, supporting the connection between improved ER retrotranslocation/proteostasis and alleviation of ER stress. Findings from this work demonstrate the importance of ER Ca2+ stores in ER proteostasis and protein trafficking/localization in photoreceptors, strengthen the link between dysregulation of ER Ca2+ homeostasis and ER stress/cone degeneration, and support an involvement of improved ER proteostasis in ER Ca2+ preservation-induced cone protection; thereby identifying IP3 R1 as a critical mediator of ER stress and protein mislocalization and as a potential target to preserve cones in CNG channel deficiency.
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Affiliation(s)
- Fan Yang
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Hongwei Ma
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Michael R Butler
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Xi-Qin Ding
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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14
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Sabat MJ, Wiśniewska-Becker AM, Markiewicz M, Marzec KM, Dybas J, Furso J, Pabisz P, Duda M, Pawlak AM. Tauroursodeoxycholic Acid (TUDCA)-Lipid Interactions and Antioxidant Properties of TUDCA Studied in Model of Photoreceptor Membranes. MEMBRANES 2021; 11:327. [PMID: 33946822 PMCID: PMC8146903 DOI: 10.3390/membranes11050327] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/25/2021] [Accepted: 04/27/2021] [Indexed: 12/16/2022]
Abstract
Tauroursodeoxycholic acid (TUDCA), a hydrophilic bile acid containing taurine conjugated with the ursodeoxycholic acid (UDCA), has been known and used from ancient times as a therapeutic compound in traditional Chinese medicine. TUDCA has recently been gaining significant interest as a neuroprotective agent, also exploited in the visual disorders. Among several mechanisms of TUDCA's protective action, its antioxidant activity and stabilizing effect on mitochondrial and plasma membranes are considered. In this work we investigated antioxidant activity of TUDCA and its impact on structural properties of model membranes of different composition using electron paramagnetic resonance spectroscopy and the spin labeling technique. Localization of TUDCA molecules in a pure POPC bilayer has been studied using a molecular dynamics simulation (MD). The obtained results indicate that TUDCA is not an efficient singlet oxygen (1O2 (1Δg)) quencher, and the determined rate constant of its interaction with 1O2 (1Δg) is only 1.9 × 105 M-1s-1. However, in lipid oxidation process induced by a Fenton reaction, TUDCA reveals substantial antioxidant activity significantly decreasing the rate of oxygen consumption in the system studied. In addition, TUDCA induces slight, but noticeable changes in the polarity and fluidity of the investigated model membranes. The results of performed MD simulation correspond very well with the experimental results.
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Affiliation(s)
- Michał J. Sabat
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (M.J.S.); (A.M.W.-B.); (J.F.); (P.P.); (M.D.)
| | - Anna M. Wiśniewska-Becker
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (M.J.S.); (A.M.W.-B.); (J.F.); (P.P.); (M.D.)
| | - Michał Markiewicz
- Department of Computational Biophysics and Bioinformatics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland;
| | - Katarzyna M. Marzec
- Jagiellonian Centre for Experimental Therapeutics, Jagiellonian University, 30-348 Krakow, Poland; (K.M.M.); (J.D.)
| | - Jakub Dybas
- Jagiellonian Centre for Experimental Therapeutics, Jagiellonian University, 30-348 Krakow, Poland; (K.M.M.); (J.D.)
| | - Justyna Furso
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (M.J.S.); (A.M.W.-B.); (J.F.); (P.P.); (M.D.)
| | - Paweł Pabisz
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (M.J.S.); (A.M.W.-B.); (J.F.); (P.P.); (M.D.)
| | - Mariusz Duda
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (M.J.S.); (A.M.W.-B.); (J.F.); (P.P.); (M.D.)
| | - Anna M. Pawlak
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (M.J.S.); (A.M.W.-B.); (J.F.); (P.P.); (M.D.)
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15
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Co-delivery of glial cell-derived neurotrophic factor (GDNF) and tauroursodeoxycholic acid (TUDCA) from PLGA microspheres: potential combination therapy for retinal diseases. Drug Deliv Transl Res 2021; 11:566-580. [PMID: 33641047 DOI: 10.1007/s13346-021-00930-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/26/2021] [Indexed: 01/21/2023]
Abstract
Retinitis pigmentosa (RP) is a group of genetically diverse inherited disorders characterised by the progressive photoreceptors and pigment epithelial cell dysfunction leading to central vision impairment. Although important advances in the understanding of the pathophysiologic pathways involved in RP have been made, drug delivery for the treatment of ocular disorders affecting the posterior segment of the eye is still an unmet clinical need. In the present study, we describe the development of multi-loaded PLGA-microspheres (MSs) incorporating two neuroprotectants agents (glial cell-line-derived neurotrophic factor-GDNF and Tauroursodeoxycholic acid-TUDCA) as a potential therapeutic tool for the treatment of RP. A solid-in-oil-in-water (S/O/W) emulsion solvent extraction-evaporation technique was employed for MS preparation. A combination of PLGA and vitamin E was used to create the microcarriers. The morphology, particle size, encapsulation efficiency and in vitro release profile of the MSs were studied. Encapsulation efficiencies of GDNF and TUDCA for the initial multiloaded MSs, prepared with methylene chloride (MC) as organic solvent and polyvinyl alcohol (PVA) solution in the external phase, were 28.53±0.36% and 45.65±8.01% respectively. Different technological parameters to optimise the formulation such as the incorporation of a water-soluble co-solvent ethanol (EtOH) in the internal organic phase, as well as NaCl concentration, and viscosity using a viscosizing agent (hydroxypropyl methylcellulose-HPMC) in the external aqueous phase were considered. EtOH incorporation and external phase viscosity of the emulsion were critical attributes for improving drug loading of both compounds. In such a way, when using a methylene chloride/EtOH ratio 75:25 into the inner organic phase and the viscosity agent HPMC (1% w/v) in the external aqueous phase, GDNF and TUDCA payloads resulted 48.86±1.49% and 78.58±10.40% respectively, and a decrease in the initial release of GDNF was observed (22.03±1.41% compared with 40.86±6.66% of the initial multi-loaded formulation). These optimised microparticles exhibited sustained in vitro releases over 91 days. These results suggest that the microencapsulation procedure optimised in this work presents a promising technological strategy for the development of multi-loaded intraocular drug delivery systems (IODDS).
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Win A, Delgado A, Jadeja RN, Martin PM, Bartoli M, Thounaojam MC. Pharmacological and Metabolic Significance of Bile Acids in Retinal Diseases. Biomolecules 2021; 11:biom11020292. [PMID: 33669313 PMCID: PMC7920062 DOI: 10.3390/biom11020292] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/10/2021] [Accepted: 02/13/2021] [Indexed: 12/21/2022] Open
Abstract
Bile acids (BAs) are amphipathic sterols primarily synthesized from cholesterol in the liver and released in the intestinal lumen upon food intake. BAs play important roles in micellination of dietary lipids, stimulating bile flow, promoting biliary phospholipid secretion, and regulating cholesterol synthesis and elimination. Emerging evidence, however, suggests that, aside from their conventional biological function, BAs are also important signaling molecules and therapeutic tools. In the last decade, the therapeutic applications of BAs in the treatment of ocular diseases have gained great interest. Despite the identification of BA synthesis, metabolism, and recycling in ocular tissues, much remains unknown with regards to their biological significance in the eye. Additionally, as gut microbiota directly affects the quality of circulating BAs, their analysis could derive important information on changes occurring in this microenvironment. This review aims at providing an overview of BA metabolism and biological function with a focus on their potential therapeutic and diagnostic use for retinal diseases.
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Affiliation(s)
- Alice Win
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; (A.W.); (A.D.); (P.M.M.); (M.B.)
| | - Amanda Delgado
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; (A.W.); (A.D.); (P.M.M.); (M.B.)
| | - Ravirajsinh N. Jadeja
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA;
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Pamela M. Martin
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; (A.W.); (A.D.); (P.M.M.); (M.B.)
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA;
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Manuela Bartoli
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; (A.W.); (A.D.); (P.M.M.); (M.B.)
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Menaka C. Thounaojam
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; (A.W.); (A.D.); (P.M.M.); (M.B.)
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Correspondence: ; Tel.: +706-721-9163 or +706-721-7910; Fax: +706-721-9799
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Tauroursodeoxycholic Acid Protects Retinal Pigment Epithelial Cells from Oxidative Injury and Endoplasmic Reticulum Stress In Vitro. Biomedicines 2020; 8:biomedicines8090367. [PMID: 32967221 PMCID: PMC7555559 DOI: 10.3390/biomedicines8090367] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/10/2020] [Accepted: 09/15/2020] [Indexed: 12/12/2022] Open
Abstract
Retinal degeneration is characterized by the dysfunction of retinal cells. Oxidative and endoplasmic reticulum (ER) stress play an important role in the pathogenesis and progression of retinal degeneration. Tauroursodeoxycholic acid (TUDCA) has been demonstrated to have protective effects in in vitro and in vivo retinal degeneration models. To fully understand the molecular mechanisms of TUDCA’s protection, we first treated human retinal pigment epithelial (RPE) cells, ARPE-19, with H2O2 or H2O2 plus TUDCA for 24 h. RPE cells co-exposed to TUDCA had higher cell viability and lower cell death rate compared to cells exposed to H2O2 alone. TUDCA significantly increased antioxidant capacity in H2O2-treated RPE cells by decreasing the generation of reactive oxygen species (ROS) and Malondialdehyde (MDA), upregulating the expression of antioxidant genes, and increasing the generation of glutathione (GSH). TUDCA also inhibited inflammation in H2O2-challenged RPE cells by decreasing the expression of proinflammatory cytokines. Furthermore, TUDCA suppressed thapsigargin-induced ER stress in RPE cells, as demonstrated by decreased the expression of CCAAT-enhancer-binding protein homologous protein (CHOP) and apoptosis. Our present study suggests that TUDCA can protect RPE cells against oxidative damage, inflammation, and ER stress and may benefit patients with retinal degeneration.
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Olsen TW, Dyer RB, Mano F, Boatright JH, Chrenek MA, Paley D, Wabner K, Schmit J, Chae JB, Sellers JT, Singh RJ, Wiedmann TS. Drug Tissue Distribution of TUDCA From a Biodegradable Suprachoroidal Implant versus Intravitreal or Systemic Delivery in the Pig Model. Transl Vis Sci Technol 2020; 9:11. [PMID: 32821508 PMCID: PMC7408862 DOI: 10.1167/tvst.9.6.11] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 03/10/2020] [Indexed: 12/14/2022] Open
Abstract
Purpose To determine local ocular tissue levels of the bile acid, tauroursodeoxycholic acid (TUDCA), in the pig model using oral, intravenous (IV), intravitreal injection (IVitI) and low- and high-dose suprachoroidal, sustained-release implants (SCI-L or SCI-H). Methods Forty-six pigs (92 globes) were included in the study. TUDCA was delivered orally in 5 pigs, IV in 4, IVitI in 6, SCI-L in 17, and SCI-H in 14. Testing timeframes varied from the same day (within minutes) for IV; 1 to 6 days, oral; and 1 to 4 weeks, IVitI and SCI. Enucleated globes were dissected, specimens from specific tissues were separated, and TUDCA was extracted and quantified using mass spectrometry. Results The highest TUDCA tissue levels occurred after IV delivery in the macula (252 ± 238 nM) and peripheral retina (196 ± 171 nM). Macular choroid and peripheral choroid levels were also high (1032 ± 1269 and 1219 ± 1486 nM, respectively). For IVitI delivery, macular levels at day 6 were low (0.5 ± 0.5 nM), whereas peripheral choroid was higher (15.3 ± 16.7 nM). Neither the SCI-L nor SCI-H implants delivered meaningful macular doses (≤1 nM); however, peripheral retina and choroid levels were significantly higher. Bile acid isoforms were found in the serum specimens. Conclusions The highest TUDCA tissue levels in the pig model were obtained using IV delivery. Oral delivery was associated with reasonable tissue levels. Local delivery (IVitI and SCI) was able to achieve measurable local ocular tissue levels. Translational Relevance Diffusional kinetics from the suprachoroidal space follow the choroidal blood flow, away from the macula and toward the periphery.
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Affiliation(s)
- Timothy W Olsen
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, USA.,Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA
| | - Roy B Dyer
- Division of Clinical Biochemistry and Immunology, Mayo Clinic, Rochester, MN, USA
| | - Fukutaro Mano
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, USA
| | - Jeffrey H Boatright
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA
| | - Micah A Chrenek
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA
| | - Daniel Paley
- Department of Civil Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Kathy Wabner
- Department of Pharmaceutics, University of Minnesota, Minneapolis, MN, USA
| | - Jenn Schmit
- Department of Pharmaceutics, University of Minnesota, Minneapolis, MN, USA
| | - Ju Byung Chae
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA.,Department of Ophthalmology, Chungbuk National University, Chungbuk, South Korea
| | - Jana T Sellers
- Department of Pharmaceutics, University of Minnesota, Minneapolis, MN, USA
| | - Ravinder J Singh
- Division of Clinical Biochemistry and Immunology, Mayo Clinic, Rochester, MN, USA.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Timothy S Wiedmann
- Department of Civil Engineering, University of Minnesota, Minneapolis, MN, USA
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19
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Kusaczuk M. Tauroursodeoxycholate-Bile Acid with Chaperoning Activity: Molecular and Cellular Effects and Therapeutic Perspectives. Cells 2019; 8:E1471. [PMID: 31757001 PMCID: PMC6952947 DOI: 10.3390/cells8121471] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/15/2019] [Accepted: 11/19/2019] [Indexed: 12/11/2022] Open
Abstract
Tauroursodeoxycholic acid (TUDCA) is a naturally occurring hydrophilic bile acid that has been used for centuries in Chinese medicine. Chemically, TUDCA is a taurine conjugate of ursodeoxycholic acid (UDCA), which in contemporary pharmacology is approved by Food and Drug Administration (FDA) for treatment of primary biliary cholangitis. Interestingly, numerous recent studies demonstrate that mechanisms of TUDCA functioning extend beyond hepatobiliary disorders. Thus, TUDCA has been demonstrated to display potential therapeutic benefits in various models of many diseases such as diabetes, obesity, and neurodegenerative diseases, mostly due to its cytoprotective effect. The mechanisms underlying this cytoprotective activity have been mainly attributed to alleviation of endoplasmic reticulum (ER) stress and stabilization of the unfolded protein response (UPR), which contributed to naming TUDCA as a chemical chaperone. Apart from that, TUDCA has also been found to reduce oxidative stress, suppress apoptosis, and decrease inflammation in many in-vitro and in-vivo models of various diseases. The latest research suggests that TUDCA can also play a role as an epigenetic modulator and act as therapeutic agent in certain types of cancer. Nevertheless, despite the massive amount of evidence demonstrating positive effects of TUDCA in pre-clinical studies, there are certain limitations restraining its wide use in patients. Here, molecular and cellular modes of action of TUDCA are described and therapeutic opportunities and limitations of this bile acid are discussed.
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Affiliation(s)
- Magdalena Kusaczuk
- Department of Pharmaceutical Biochemistry, Medical University of Białystok, Mickiewicza 2A, 15-222 Białystok, Poland
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20
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Daruich A, Picard E, Boatright JH, Behar-Cohen F. Review: The bile acids urso- and tauroursodeoxycholic acid as neuroprotective therapies in retinal disease. Mol Vis 2019; 25:610-624. [PMID: 31700226 PMCID: PMC6817734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 10/12/2019] [Indexed: 10/28/2022] Open
Abstract
Bile acids are produced in the liver and excreted into the intestine, where their main function is to participate in lipid digestion. Ursodeoxycholic acid (UDCA) and tauroursodeoxycholic acid (TUDCA) have shown antiapoptotic, anti-inflammatory, and antioxidant effects in various models of neurodegenerative diseases. However, little is known about signaling pathways and molecular mechanisms through which these bile acids act as neuroprotectors, delaying translation to the clinical setting. We review evidence supporting a potentially therapeutic role for bile acids in retinal disorders, and the mechanisms and pathways involved in the cytoprotective effects of bile acids from the liver and the enterohepatic circulation to the central nervous system and the retina. As secondary bile acids are generated by the microbiota metabolism, bile acids might be a link between neurodegenerative retinal diseases and microbiota.
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Affiliation(s)
- Alejandra Daruich
- INSERM, UMRS1138, Team 17, From physiopathology of ocular diseases to clinical development, Université Sorbonne Paris Cité, Centre de Recherche des Cordeliers, Paris, France,Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris, France
| | - Emilie Picard
- INSERM, UMRS1138, Team 17, From physiopathology of ocular diseases to clinical development, Université Sorbonne Paris Cité, Centre de Recherche des Cordeliers, Paris, France
| | - Jeffrey H. Boatright
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA,Center of Excellence, Atlanta Veterans Administration Medical Center, Decatur, GA
| | - Francine Behar-Cohen
- INSERM, UMRS1138, Team 17, From physiopathology of ocular diseases to clinical development, Université Sorbonne Paris Cité, Centre de Recherche des Cordeliers, Paris, France,Ophtalmopole, Cochin Hospital, AP-HP, Assistance Publique Hôpitaux de Paris, Paris, France
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21
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Schisa JA. Germ Cell Responses to Stress: The Role of RNP Granules. Front Cell Dev Biol 2019; 7:220. [PMID: 31632971 PMCID: PMC6780003 DOI: 10.3389/fcell.2019.00220] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 09/18/2019] [Indexed: 11/13/2022] Open
Abstract
The ability to respond to stress is critical to survival for animals. While stress responses have been studied at both organismal and cellular levels, less attention has been given to the effect of stress on the germ line. Effective germ line adaptations to stress are essential to the propagation of a species. Recent studies suggest that germ cells share some cellular responses to stress with somatic cells, including the assembly of RNP granules, but may also have unique requirements. One fundamental difference between oocytes and sperm, as well as most somatic cells, is the long lifespan of oocytes. Since women are born with all of their eggs, oocytes must maintain their cellular quality over decades prior to fertilization. This prolonged meiotic arrest is one type of stress that eventually contributes to decreased fertility in older women. Germ cell responses to nutritional stress and heat stress have also been well-characterized using model systems. Here we review our current understanding of how germ cells respond to stress, with an emphasis on the dynamic assembly of RNP granules that may be adaptive. We compare and contrast stress responses of male gametes with those of female gametes, and discuss how the dynamic cellular remodeling of the germ line can impact the regulation of gene expression. We also discuss the implications of recent in vitro studies of ribonucleoprotein granule assembly on our understanding of germ line responses to stress, and the gaps that remain in our understanding of the function of RNP granules during stress.
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Affiliation(s)
- Jennifer A Schisa
- Department of Biology, Central Michigan University, Mount Pleasant, MI, United States
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22
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Balancing the Photoreceptor Proteome: Proteostasis Network Therapeutics for Inherited Retinal Disease. Genes (Basel) 2019; 10:genes10080557. [PMID: 31344897 PMCID: PMC6722924 DOI: 10.3390/genes10080557] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/09/2019] [Accepted: 07/16/2019] [Indexed: 12/17/2022] Open
Abstract
The light sensing outer segments of photoreceptors (PRs) are renewed every ten days due to their high photoactivity, especially of the cones during daytime vision. This demands a tremendous amount of energy, as well as a high turnover of their main biosynthetic compounds, membranes, and proteins. Therefore, a refined proteostasis network (PN), regulating the protein balance, is crucial for PR viability. In many inherited retinal diseases (IRDs) this balance is disrupted leading to protein accumulation in the inner segment and eventually the death of PRs. Various studies have been focusing on therapeutically targeting the different branches of the PR PN to restore the protein balance and ultimately to treat inherited blindness. This review first describes the different branches of the PN in detail. Subsequently, insights are provided on how therapeutic compounds directed against the different PN branches might slow down or even arrest the appalling, progressive blinding conditions. These insights are supported by findings of PN modulators in other research disciplines.
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23
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Tao Y, Dong X, Lu X, Qu Y, Wang C, Peng G, Zhang J. Subcutaneous delivery of tauroursodeoxycholic acid rescues the cone photoreceptors in degenerative retina: A promising therapeutic molecule for retinopathy. Biomed Pharmacother 2019; 117:109021. [PMID: 31387173 DOI: 10.1016/j.biopha.2019.109021] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 05/16/2019] [Accepted: 05/21/2019] [Indexed: 12/11/2022] Open
Abstract
Inherited retinal degeneration (RD) comprises a heterogeneous group of retinopathies that rank among the main causes of blindness. Tauroursodeoxycholic acid (TUDCA) is taurine conjugate hydrophilic bile acid that demonstrates profound protective effects against a series of neurodegenerative diseases related to oxidative stress. This study sought to evaluate the TUDCA induced effects of on a pharmacologically induced RD animal model by electroretinogram (ERG) examination, behavior tests, morphological analysis and immunochemistry assay. Massive photoreceptor degeneration in mice retina was induced by an intraperitoneal administration of N-methyl-N-nitrosourea(MNU). Subcutaneous delivery of TUDCA inhibits effectively the photoreceptor loss and visual impairments in the MNU administered mice. In the retinal flat-mounts of TUDCA treated mice, the cone photoreceptors were efficiently preserved. Furthermore, the multi-electrodes array (MEA) was used to detect the firing activities of retinal ganglion cells within the inner retinal circuits. TUDCA therapy could restrain the spontaneous firing response, enhance the light induced firing response, and preserve the basic configurations of ON-OFF signal pathway in degenerative retinas. Our MEA assay provided an example to evaluate the potency of pharmacological compounds on retinal plasticity. TUDCA affords these protective effects by modulating apoptosis and alleviating oxidative stress in the degenerative retina. In conclusion, TUDCA therapy can ameliorate the photoreceptor degeneration and rectify the abnormities in visual signal transmission. These findings suggest that TUDCA might act as a potential medication for these retinopathies with progressive photoreceptor degeneration.
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Affiliation(s)
- Ye Tao
- Department of Physiology, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China; Lab of Visual Cell Differentiation, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China
| | - Xin Dong
- Department of Orthopedic Surgery, Orthopedics Oncology Institute of Chinese PLA, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, China
| | - Xin Lu
- Department of Physiology, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China; Lab of Visual Cell Differentiation, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China
| | - Yingxin Qu
- Department of Physiology, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China
| | - Chunhui Wang
- Department of Pediatric, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, China.
| | - Guanghua Peng
- Department of Physiology, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China; Lab of Visual Cell Differentiation, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China.
| | - Jianbin Zhang
- Department of Occupational & Environmental Health, Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, Shaanxi Key Laboratory of Free Radical Biology and Medicine, Fourth Military Medical University, Xi'an, 710032, China.
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24
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Zhang X, Shahani U, Reilly J, Shu X. Disease mechanisms and neuroprotection by tauroursodeoxycholic acid in Rpgr knockout mice. J Cell Physiol 2019; 234:18801-18812. [PMID: 30924157 DOI: 10.1002/jcp.28519] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 02/22/2019] [Accepted: 03/06/2019] [Indexed: 12/16/2022]
Abstract
Mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene are the predominant cause of retinitis pigmentosa. RPGR plays a critical role as a scaffold protein in the regulation of protein trafficking from the basal body to the axoneme, where the cargoes are transported to the outer segments (OSs) of photoreceptors. This trafficking process is controlled directly by intraflagellar transport complexes and regulated by the RPGR protein complex, although the precise mechanisms have yet to be defined. We used an Rpgr conditional knockout (cko) mouse model to investigate the disease mechanisms during retinal degeneration and to evaluate the protective effects of tauroursodeoxycholic acid (TUDCA). Rhodopsin, cone opsins and transducin were mislocalized in Rpgr cko photoreceptors, while localization of NPHP4 to connecting cilia was absent, suggesting that RPGR is required for ciliary protein trafficking. Microglia were activated in advance of retinal degeneration in Rpgr cko mouse retinas. TUDCA treatment suppressed microglial activation and inflammation and prevented photoreceptor degeneration in Rpgr cko mice. Our data demonstrated that TUDCA has therapeutic potential for RPGR-associated RP patients.
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Affiliation(s)
- Xun Zhang
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, Scotland
| | - Uma Shahani
- Department of Vision Science, Glasgow Caledonian University, Glasgow, Scotland
| | - James Reilly
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, Scotland
| | - Xinhua Shu
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, Scotland.,Department of Vision Science, Glasgow Caledonian University, Glasgow, Scotland
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25
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Burkard M, Kohl S, Krätzig T, Tanimoto N, Brennenstuhl C, Bausch AE, Junger K, Reuter P, Sothilingam V, Beck SC, Huber G, Ding XQ, Mayer AK, Baumann B, Weisschuh N, Zobor D, Hahn GA, Kellner U, Venturelli S, Becirovic E, Charbel Issa P, Koenekoop RK, Rudolph G, Heckenlively J, Sieving P, Weleber RG, Hamel C, Zong X, Biel M, Lukowski R, Seeliger MW, Michalakis S, Wissinger B, Ruth P. Accessory heterozygous mutations in cone photoreceptor CNGA3 exacerbate CNG channel-associated retinopathy. J Clin Invest 2018; 128:5663-5675. [PMID: 30418171 PMCID: PMC6264655 DOI: 10.1172/jci96098] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 10/02/2018] [Indexed: 01/01/2023] Open
Abstract
Mutations in CNGA3 and CNGB3, the genes encoding the subunits of the tetrameric cone photoreceptor cyclic nucleotide-gated ion channel, cause achromatopsia, a congenital retinal disorder characterized by loss of cone function. However, a small number of patients carrying the CNGB3/c.1208G>A;p.R403Q mutation present with a variable retinal phenotype ranging from complete and incomplete achromatopsia to moderate cone dysfunction or progressive cone dystrophy. By exploring a large patient cohort and published cases, we identified 16 unrelated individuals who were homozygous or (compound-)heterozygous for the CNGB3/c.1208G>A;p.R403Q mutation. In-depth genetic and clinical analysis revealed a co-occurrence of a mutant CNGA3 allele in a high proportion of these patients (10 of 16), likely contributing to the disease phenotype. To verify these findings, we generated a Cngb3R403Q/R403Q mouse model, which was crossbred with Cnga3-deficient (Cnga3-/-) mice to obtain triallelic Cnga3+/- Cngb3R403Q/R403Q mutants. As in human subjects, there was a striking genotype-phenotype correlation, since the presence of 1 Cnga3-null allele exacerbated the cone dystrophy phenotype in Cngb3R403Q/R403Q mice. These findings strongly suggest a digenic and triallelic inheritance pattern in a subset of patients with achromatopsia/severe cone dystrophy linked to the CNGB3/p.R403Q mutation, with important implications for diagnosis, prognosis, and genetic counseling.
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Affiliation(s)
- Markus Burkard
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy
- Department of Vegetative and Clinical Physiology
| | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, and
| | - Timm Krätzig
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy
| | - Naoyuki Tanimoto
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | | | - Anne E. Bausch
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy
| | - Katrin Junger
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy
| | - Peggy Reuter
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, and
| | - Vithiyanjali Sothilingam
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Susanne C. Beck
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Gesine Huber
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Xi-Qin Ding
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Anja K. Mayer
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, and
| | - Britta Baumann
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, and
| | - Nicole Weisschuh
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, and
| | - Ditta Zobor
- Institute of Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Gesa-Astrid Hahn
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, and
| | - Ulrich Kellner
- Rare Retinal Disease Center, Augenzentrum Siegburg, MVZ ADTC Siegburg GmbH, Siegburg, Germany
| | | | - Elvir Becirovic
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy–Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Peter Charbel Issa
- Oxford Eye Hospital, OUH NHS Foundation Trust and the Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Robert K. Koenekoop
- McGill Ocular Genetics Centre, McGill University Health Centre, Montreal, Quebec, Canada
| | | | | | - Paul Sieving
- The National Eye Institute, Bethesda, Maryland, USA
| | - Richard G. Weleber
- Casey Eye Institute, Department of Ophthalmogenetics, Portland, Oregon, USA
| | - Christian Hamel
- INSERM U583, Institut des Neurosciences, Montpellier, France
| | - Xiangang Zong
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy–Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy–Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Robert Lukowski
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy
| | - Matthias W. Seeliger
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy–Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, and
| | - Peter Ruth
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy
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26
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Pardue MT, Allen RS. Neuroprotective strategies for retinal disease. Prog Retin Eye Res 2018; 65:50-76. [PMID: 29481975 PMCID: PMC6081194 DOI: 10.1016/j.preteyeres.2018.02.002] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/14/2018] [Accepted: 02/20/2018] [Indexed: 12/20/2022]
Abstract
Diseases that affect the eye, including photoreceptor degeneration, diabetic retinopathy, and glaucoma, affect 11.8 million people in the US, resulting in vision loss and blindness. Loss of sight affects patient quality of life and puts an economic burden both on individuals and the greater healthcare system. Despite the urgent need for treatments, few effective options currently exist in the clinic. Here, we review research on promising neuroprotective strategies that promote neuronal survival with the potential to protect against vision loss and retinal cell death. Due to the large number of neuroprotective strategies, we restricted our review to approaches that we had direct experience with in the laboratory. We focus on drugs that target survival pathways, including bile acids like UDCA and TUDCA, steroid hormones like progesterone, therapies that target retinal dopamine, and neurotrophic factors. In addition, we review rehabilitative methods that increase endogenous repair mechanisms, including exercise and electrical stimulation therapies. For each approach, we provide background on the neuroprotective strategy, including history of use in other diseases; describe potential mechanisms of action; review the body of research performed in the retina thus far, both in animals and in humans; and discuss considerations when translating each treatment to the clinic and to the retina, including which therapies show the most promise for each retinal disease. Despite the high incidence of retinal diseases and the complexity of mechanisms involved, several promising neuroprotective treatments provide hope to prevent blindness. We discuss attractive candidates here with the goal of furthering retinal research in critical areas to rapidly translate neuroprotective strategies into the clinic.
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Affiliation(s)
- Machelle T Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA; Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Drive, Atlanta, GA, 30332, USA.
| | - Rachael S Allen
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA
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27
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A Docosahexaenoic Acid-Derived Pro-resolving Agent, Maresin 1, Protects Motor Neuron Cells Death. Neurochem Res 2018; 43:1413-1423. [DOI: 10.1007/s11064-018-2556-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 05/10/2018] [Accepted: 05/17/2018] [Indexed: 12/19/2022]
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28
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Abstract
Retinal blindness is an important cause of pediatric visual loss. Leber's congenital amaurosis (LCA) is one of these causes, often wrongly included in the spectrum of retinitis pigmentosa. The disease has become the center of research after initial reports of success in management with gene therapy. This review discusses in brief the clinical presentation and investigative modalities used in LCA. Further, the road to gene discovery and details of currently applied gene therapy are presented. LCA is one of the first successfully managed human diseases and offers an entirely new dimension in ocular therapeutics.
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29
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Athanasiou D, Aguila M, Bellingham J, Li W, McCulley C, Reeves PJ, Cheetham ME. The molecular and cellular basis of rhodopsin retinitis pigmentosa reveals potential strategies for therapy. Prog Retin Eye Res 2018; 62:1-23. [PMID: 29042326 PMCID: PMC5779616 DOI: 10.1016/j.preteyeres.2017.10.002] [Citation(s) in RCA: 217] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/03/2017] [Accepted: 10/13/2017] [Indexed: 12/12/2022]
Abstract
Inherited mutations in the rod visual pigment, rhodopsin, cause the degenerative blinding condition, retinitis pigmentosa (RP). Over 150 different mutations in rhodopsin have been identified and, collectively, they are the most common cause of autosomal dominant RP (adRP). Mutations in rhodopsin are also associated with dominant congenital stationary night blindness (adCSNB) and, less frequently, recessive RP (arRP). Recessive RP is usually associated with loss of rhodopsin function, whereas the dominant conditions are a consequence of gain of function and/or dominant negative activity. The in-depth characterisation of many rhodopsin mutations has revealed that there are distinct consequences on the protein structure and function associated with different mutations. Here we categorise rhodopsin mutations into seven discrete classes; with defects ranging from misfolding and disruption of proteostasis, through mislocalisation and disrupted intracellular traffic to instability and altered function. Rhodopsin adRP offers a unique paradigm to understand how disturbances in photoreceptor homeostasis can lead to neuronal cell death. Furthermore, a wide range of therapies have been tested in rhodopsin RP, from gene therapy and gene editing to pharmacological interventions. The understanding of the disease mechanisms associated with rhodopsin RP and the development of targeted therapies offer the potential of treatment for this currently untreatable neurodegeneration.
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Affiliation(s)
| | - Monica Aguila
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - James Bellingham
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Wenwen Li
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Caroline McCulley
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Philip J Reeves
- School of Biological Sciences, University of Essex, Wivenhoe Park, Essex CO4 3SQ, UK.
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30
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Schön C, Sothilingam V, Mühlfriedel R, Garcia Garrido M, Beck SC, Tanimoto N, Wissinger B, Paquet-Durand F, Biel M, Michalakis S, Seeliger MW. Gene Therapy Successfully Delays Degeneration in a Mouse Model of PDE6A-Linked Retinitis Pigmentosa (RP43). Hum Gene Ther 2017; 28:1180-1188. [PMID: 29212391 DOI: 10.1089/hum.2017.156] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Retinitis pigmentosa type 43 (RP43) is a blinding disease caused by mutations in the gene for rod phosphodiesterase 6 alpha (PDE6A). The disease process begins with a dysfunction of rod photoreceptors, subsequently followed by a currently untreatable progressive degeneration of the entire outer retina. Aiming at a curative approach via PDE6A gene supplementation, a novel adeno-associated viral (AAV) vector was developed for expression of the human PDE6A cDNA under control of the human rhodopsin promotor (rAAV8.PDE6A). This study assessed the therapeutic efficacy of rAAV8.PDE6A in the Pde6anmf363/nmf363-mutant mouse model of RP43. All mice included in this study were treated with sub-retinal injections of the vector at 2 weeks after birth. The therapeutic effect was monitored at 1 month and 6 months post injection. Biological function of the transgene was assessed in vivo by means of electroretinography. The degree of morphological rescue was investigated both in vivo using optical coherence tomography and ex vivo by immunohistological staining. It was found that the novel rAAV8.PDE6A vector resulted in a stable and efficient expression of PDE6A protein in rod photoreceptors of Pde6anmf363/nmf363 mice following treatment at both the short- and long-term time points. The treatment led to a substantial morphological preservation of outer nuclear layer thickness, rod outer segment structure, and prolonged survival of cone photoreceptors for at least 6 months. Additionally, the ERG analysis confirmed a restoration of retinal function in a group of treated mice. Taken together, this study provides successful proof-of-concept for the cross-species efficacy of the rAAV8.PDE6A vector developed for use in human patients. Importantly, the data show stable expression and rescue effects for a prolonged period of time, raising hope for future translational studies based on this approach.
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Affiliation(s)
- Christian Schön
- Center for Integrated Protein Science Munich CiPSM at the Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | | | - Regine Mühlfriedel
- Divisions of Ocular Neurodegeneration, Eberhard Karls University, Tuebingen, Germany
| | - Marina Garcia Garrido
- Divisions of Ocular Neurodegeneration, Eberhard Karls University, Tuebingen, Germany
| | - Susanne C Beck
- Divisions of Ocular Neurodegeneration, Eberhard Karls University, Tuebingen, Germany
| | - Naoyuki Tanimoto
- Divisions of Ocular Neurodegeneration, Eberhard Karls University, Tuebingen, Germany
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Eberhard Karls University, Tuebingen, Germany
| | - François Paquet-Durand
- Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University, Tuebingen, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich CiPSM at the Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich CiPSM at the Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Mathias W Seeliger
- Divisions of Ocular Neurodegeneration, Eberhard Karls University, Tuebingen, Germany
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31
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Petersen-Jones SM, Occelli LM, Winkler PA, Lee W, Sparrow JR, Tsukikawa M, Boye SL, Chiodo V, Capasso JE, Becirovic E, Schön C, Seeliger MW, Levin AV, Michalakis S, Hauswirth WW, Tsang SH. Patients and animal models of CNGβ1-deficient retinitis pigmentosa support gene augmentation approach. J Clin Invest 2017; 128:190-206. [PMID: 29202463 PMCID: PMC5749539 DOI: 10.1172/jci95161] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 10/10/2017] [Indexed: 01/07/2023] Open
Abstract
Retinitis pigmentosa (RP) is a major cause of blindness that affects 1.5 million people worldwide. Mutations in cyclic nucleotide-gated channel β 1 (CNGB1) cause approximately 4% of autosomal recessive RP. Gene augmentation therapy shows promise for treating inherited retinal degenerations; however, relevant animal models and biomarkers of progression in patients with RP are needed to assess therapeutic outcomes. Here, we evaluated RP patients with CNGB1 mutations for potential biomarkers of progression and compared human phenotypes with those of mouse and dog models of the disease. Additionally, we used gene augmentation therapy in a CNGβ1-deficient dog model to evaluate potential translation to patients. CNGB1-deficient RP patients and mouse and dog models had a similar phenotype characterized by early loss of rod function and slow rod photoreceptor loss with a secondary decline in cone function. Advanced imaging showed promise for evaluating RP progression in human patients, and gene augmentation using adeno-associated virus vectors robustly sustained the rescue of rod function and preserved retinal structure in the dog model. Together, our results reveal an early loss of rod function in CNGB1-deficient patients and a wide window for therapeutic intervention. Moreover, the identification of potential biomarkers of outcome measures, availability of relevant animal models, and robust functional rescue from gene augmentation therapy support future work to move CNGB1-RP therapies toward clinical trials.
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Affiliation(s)
- Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, Michigan, USA
| | - Laurence M Occelli
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, Michigan, USA
| | - Paige A Winkler
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, Michigan, USA
| | - Winston Lee
- Department of Ophthalmology Pathology & Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Janet R Sparrow
- Department of Ophthalmology Pathology & Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Mai Tsukikawa
- Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Sanford L Boye
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Vince Chiodo
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Jenina E Capasso
- Ocular Genetics, Wills Eye Hospital (WEH), Philadelphia, Pennsylvania, USA
| | - Elvir Becirovic
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Christian Schön
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Mathias W Seeliger
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Alex V Levin
- Thomas Jefferson University, Philadelphia, Pennsylvania, USA.,Ocular Genetics, Wills Eye Hospital (WEH), Philadelphia, Pennsylvania, USA
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - William W Hauswirth
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Stephen H Tsang
- Department of Ophthalmology Pathology & Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA.,Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center (CUMC), Edward S. Harkness Eye Institute, New York, New York, USA
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32
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Pharmacological Amelioration of Cone Survival and Vision in a Mouse Model for Leber Congenital Amaurosis. J Neurosci 2017; 36:5808-19. [PMID: 27225770 DOI: 10.1523/jneurosci.3857-15.2016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 04/20/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED RPE65, an abundant membrane-associate protein in the retinal pigment epithelium (RPE), is a key retinoid isomerase of the visual cycle necessary for generating 11-cis-retinal that functions not only as a molecular switch for activating cone and rod visual pigments in response to light stimulation, but also as a chaperone for normal trafficking of cone opsins to the outer segments. Many mutations in RPE65 are associated with Leber congenital amaurosis (LCA). A R91W substitution, the most frequent LCA-associated mutation, results in a severe decrease in protein level and enzymatic activity of RPE65, causing cone opsin mislocalization and early cone degeneration in the mutation knock-in mouse model of LCA. Here we show that R91W RPE65 undergoes ubiquitination-dependent proteasomal degradation in the knock-in mouse RPE due to misfolding. The 26S proteasome non-ATPase regulatory subunit 13 mediated degradation specifically of misfolded R91W RPE65. The mutation disrupted membrane-association and colocalization of RPE65 with lecithin:retinol acyltransferase (LRAT) that provides the hydrophobic substrate for RPE65. Systemic administration of sodium 4-phenylbutyrate (PBA), a chemical chaperone, increased protein stability, enzymatic activity, membrane-association, and colocalization of R91W RPE65 with LRAT. This rescue effect increased synthesis of 11-cis-retinal and 9-cis-retinal, a functional iso-chromophore of the visual pigments, led to alleviation of S-opsin mislocalization and cone degeneration in the knock-in mice. Importantly, PBA-treatment also improved cone-mediated vision in the mutant mice. These results indicate that PBA, a U.S. Food and Drug Administration-approved safe oral medication, may provide a noninvasive therapeutic intervention that delays daylight vision loss in patients with RPE65 mutations. SIGNIFICANCE STATEMENT LCA is a severe early onset retinal dystrophy. Recent clinical trials of gene therapy have implicated the need of an alternative or combination therapy to improve cone survival and function in patients with LCA caused by RPE65 mutations. Using a mouse model carrying the most frequent LCA-associated mutation (R91W), we found that the mutant RPE65 underwent ubiquitination-dependent proteasomal degradation due to misfolding. Treatment of the mice with a chemical chaperone partially corrected stability, enzymatic activity, and subcellular localization of R91W RPE65, which was also accompanied by improvement of cone survival and vision. These findings identify an in vivo molecular pathogenic mechanism for R91W mutation and provide a feasible pharmacological approach that can delay vision loss in patients with RPE65 mutations.
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Fernández-Sánchez L, Bravo-Osuna I, Lax P, Arranz-Romera A, Maneu V, Esteban-Pérez S, Pinilla I, Puebla-González MDM, Herrero-Vanrell R, Cuenca N. Controlled delivery of tauroursodeoxycholic acid from biodegradable microspheres slows retinal degeneration and vision loss in P23H rats. PLoS One 2017; 12:e0177998. [PMID: 28542454 PMCID: PMC5444790 DOI: 10.1371/journal.pone.0177998] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/05/2017] [Indexed: 12/14/2022] Open
Abstract
Successful drug therapies for treating ocular diseases require effective concentrations of neuroprotective compounds maintained over time at the site of action. The purpose of this work was to assess the efficacy of intravitreal controlled delivery of tauroursodeoxycholic acid (TUDCA) encapsulated in poly(D,L-lactic-co-glycolic acid) (PLGA) microspheres for the treatment of the retina in a rat model of retinitis pigmentosa. PLGA microspheres (MSs) containing TUDCA were produced by the O/W emulsion-solvent evaporation technique. Particle size and morphology were assessed by light scattering and scanning electronic microscopy, respectively. Homozygous P23H line 3 rats received a treatment of intravitreal injections of TUDCA-PLGA MSs. Retinal function was assessed by electroretinography at P30, P60, P90 and P120. The density, structure and synaptic contacts of retinal neurons were analyzed using immunofluorescence and confocal microscopy at P90 and P120. TUDCA-loaded PLGA MSs were spherical, with a smooth surface. The production yield was 78%, the MSs mean particle size was 23 μm and the drug loading resulted 12.5 ± 0.8 μg TUDCA/mg MSs. MSs were able to deliver the loaded active compound in a gradual and progressive manner over the 28-day in vitro release study. Scotopic electroretinografic responses showed increased ERG a- and b-wave amplitudes in TUDCA-PLGA-MSs-treated eyes as compared to those injected with unloaded PLGA particles. TUDCA-PLGA-MSs-treated eyes showed more photoreceptor rows than controls. The synaptic contacts of photoreceptors with bipolar and horizontal cells were also preserved in P23H rats treated with TUDCA-PLGA MSs. This work indicates that the slow and continuous delivery of TUDCA from PLGA-MSs has potential neuroprotective effects that could constitute a suitable therapy to prevent neurodegeneration and visual loss in retinitis pigmentosa.
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Affiliation(s)
- Laura Fernández-Sánchez
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Irene Bravo-Osuna
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain
| | - Pedro Lax
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Alicia Arranz-Romera
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain
| | - Victoria Maneu
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Sergio Esteban-Pérez
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain
| | - Isabel Pinilla
- Department of Ophthalmology, Lozano Blesa University Hospital, Zaragoza, Spain
- Aragon Institute for Health Research (IIS Aragon), Zaragoza, Spain
| | - María del Mar Puebla-González
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain
| | - Rocío Herrero-Vanrell
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain
- Sanitary Research Institute of the San Carlos Clinical Hospital (IdISSC), Madrid, Spain
- Industrial Pharmacy Institute, Complutense University of Madrid, Madrid, Spain
- * E-mail: (NS); (RHV)
| | - Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
- Institute Ramón Margalef, University of Alicante, Alicante, Spain
- * E-mail: (NS); (RHV)
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34
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Butler MR, Ma H, Yang F, Belcher J, Le YZ, Mikoshiba K, Biel M, Michalakis S, Iuso A, Križaj D, Ding XQ. Endoplasmic reticulum (ER) Ca 2+-channel activity contributes to ER stress and cone death in cyclic nucleotide-gated channel deficiency. J Biol Chem 2017; 292:11189-11205. [PMID: 28495882 DOI: 10.1074/jbc.m117.782326] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/01/2017] [Indexed: 02/05/2023] Open
Abstract
Endoplasmic reticulum (ER) stress and mislocalization of improperly folded proteins have been shown to contribute to photoreceptor death in models of inherited retinal degenerative diseases. In particular, mice with cone cyclic nucleotide-gated (CNG) channel deficiency, a model for achromatopsia, display both early-onset ER stress and opsin mistrafficking. By 2 weeks of age, these mice show elevated signaling from all three arms of the ER-stress pathway, and by 1 month, cone opsin is improperly distributed away from its normal outer segment location to other retinal layers. This work investigated the role of Ca2+-release channels in ER stress, protein mislocalization, and cone death in a mouse model of CNG-channel deficiency. We examined whether preservation of luminal Ca2+ stores through pharmacological and genetic suppression of ER Ca2+ efflux protects cones by attenuating ER stress. We demonstrated that the inhibition of ER Ca2+-efflux channels reduced all three arms of ER-stress signaling while improving opsin trafficking to cone outer segments and decreasing cone death by 20-35%. Cone-specific gene deletion of the inositol-1,4,5-trisphosphate receptor type I (IP3R1) also significantly increased cone density in the CNG-channel-deficient mice, suggesting that IP3R1 signaling contributes to Ca2+ homeostasis and cone survival. Consistent with the important contribution of organellar Ca2+ signaling in this achromatopsia mouse model, significant differences in dynamic intraorganellar Ca2+ levels were detected in CNG-channel-deficient cones. These results thus identify a novel molecular link between Ca2+ homeostasis and cone degeneration, thereby revealing novel therapeutic targets to preserve cones in inherited retinal degenerative diseases.
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Affiliation(s)
| | | | - Fan Yang
- From the Departments of Cell Biology
| | | | - Yun-Zheng Le
- From the Departments of Cell Biology.,Internal Medicine, and.,Ophthalmology and.,the Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Katsuhiko Mikoshiba
- the Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Hirosawa Wako-shi, Saitama 351-0198, Japan
| | - Martin Biel
- the Center for Integrated Protein Science Munich (CIPSM) and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany, and
| | - Stylianos Michalakis
- the Center for Integrated Protein Science Munich (CIPSM) and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany, and
| | - Anthony Iuso
- the John A. Moran Eye Center, University of Utah, Salt Lake City, Utah 84132
| | - David Križaj
- the John A. Moran Eye Center, University of Utah, Salt Lake City, Utah 84132
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35
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Ackerman HD, Gerhard GS. Bile Acids in Neurodegenerative Disorders. Front Aging Neurosci 2016; 8:263. [PMID: 27920719 PMCID: PMC5118426 DOI: 10.3389/fnagi.2016.00263] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 10/21/2016] [Indexed: 12/13/2022] Open
Abstract
Bile acids, a structurally related group of molecules derived from cholesterol, have a long history as therapeutic agents in medicine, from treatment for primarily ocular diseases in ancient Chinese medicine to modern day use as approved drugs for certain liver diseases. Despite evidence supporting a neuroprotective role in a diverse spectrum of age-related neurodegenerative disorders, including several small pilot clinical trials, little is known about their molecular mechanisms or their physiological roles in the nervous system. We review the data reported for their use as treatments for neurodegenerative diseases and their underlying molecular basis. While data from cellular and animal models and clinical trials support potential efficacy to treat a variety of neurodegenerative disorders, the relevant bile acids, their origin, and the precise molecular mechanism(s) by which they confer neuroprotection are not known delaying translation to the clinical setting.
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Affiliation(s)
- Hayley D Ackerman
- Department of Medical Genetics and Molecular Biochemistry, The Lewis Katz School of Medicine at Temple University Philadelphia, PA, USA
| | - Glenn S Gerhard
- Department of Medical Genetics and Molecular Biochemistry, The Lewis Katz School of Medicine at Temple University Philadelphia, PA, USA
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36
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Uggenti C, Briant K, Streit AK, Thomson S, Koay YH, Baines RA, Swanton E, Manson FD. Restoration of mutant bestrophin-1 expression, localisation and function in a polarised epithelial cell model. Dis Model Mech 2016; 9:1317-1328. [PMID: 27519691 PMCID: PMC5117222 DOI: 10.1242/dmm.024216] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 07/21/2016] [Indexed: 01/13/2023] Open
Abstract
Autosomal recessive bestrophinopathy (ARB) is a retinopathy caused by mutations in the bestrophin-1 protein, which is thought to function as a Ca2+-gated Cl− channel in the basolateral surface of the retinal pigment epithelium (RPE). Using a stably transfected polarised epithelial cell model, we show that four ARB mutant bestrophin-1 proteins were mislocalised and subjected to proteasomal degradation. In contrast to the wild-type bestrophin-1, each of the four mutant proteins also failed to conduct Cl− ions in transiently transfected cells as determined by whole-cell patch clamp. We demonstrate that a combination of two clinically approved drugs, bortezomib and 4-phenylbutyrate (4PBA), successfully restored the expression and localisation of all four ARB mutant bestrophin-1 proteins. Importantly, the Cl− conductance function of each of the mutant bestrophin-1 proteins was fully restored to that of wild-type bestrophin-1 by treatment of cells with 4PBA alone. The functional rescue achieved with 4PBA is significant because it suggests that this drug, which is already approved for long-term use in infants and adults, might represent a promising therapy for the treatment of ARB and other bestrophinopathies resulting from missense mutations in BEST1. Summary: Chemical chaperone 4PBA fully restores Cl− conductance activity for mutant bestrophin-1 proteins associated with inherited retinal dystrophy, autosomal recessive bestrophinopathy.
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Affiliation(s)
- Carolina Uggenti
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Kit Briant
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Anne-Kathrin Streit
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Steven Thomson
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Yee Hui Koay
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Richard A Baines
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Eileithyia Swanton
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Forbes D Manson
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
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37
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Shinde V, Pitale PM, Howse W, Gorbatyuk O, Gorbatyuk M. Neuronatin is a stress-responsive protein of rod photoreceptors. Neuroscience 2016; 328:1-8. [PMID: 27109921 DOI: 10.1016/j.neuroscience.2016.04.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/12/2016] [Accepted: 04/14/2016] [Indexed: 11/20/2022]
Abstract
Neuronatin (NNAT) is a small transmembrane proteolipid that is highly expressed in the embryonic developing brain and several other peripheral tissues. This study is the first to provide evidence that NNAT is detected in the adult retina of various adult rod-dominant mammals, including wild-type (WT) rodents, transgenic rodents expressing mutant S334ter, P23H, or T17M rhodopsin, non-human primates, humans, and cone-dominant tree shrews. Immunohistochemical and quantitative real time polymerase chain reaction (qRT-PCR) analyses were applied to detect NNAT. Confocal microscopy analysis revealed that NNAT immunofluorescence is restricted to the outer segments (OSs) of photoreceptors without evidence of staining in other retinal cell types across all mammalian species. Moreover, in tree shrew retinas, we found NNAT to be co-localized with rhodopsin, indicating its predominant expression in rods. The rod-derived expression of NNAT was further confirmed by qRT-PCR in isolated rod photoreceptor cells. We also used these cells to mimic cellular stress in transgenic retinas by treating them with the endoplasmic reticulum stress inducer, tunicamycin. Thus, our data revealed accumulation of NNAT around the nucleus as compared to dispersed localization of NNAT within control cells. This distribution coincided with the partial intracellular mislocalization of NNAT to the outer nuclear layer observed in transgenic retinas. In addition, stressed retinas demonstrated an increase of NNAT mRNA and protein levels. Therefore, our study demonstrated that NNAT is a novel stress-responsive protein with a potential structural and/or functional role in adult mammalian retinas.
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Affiliation(s)
- Vishal Shinde
- University of Alabama at Birmingham, Department of Optometry, United States; University of Alabama at Birmingham, Department of Vision Science, School of Optometry, United States
| | - Priyamvada M Pitale
- University of Alabama at Birmingham, Department of Optometry, United States; University of Alabama at Birmingham, Department of Vision Science, School of Optometry, United States
| | - Wayne Howse
- University of Alabama at Birmingham, Department of Optometry, United States; University of Alabama at Birmingham, Department of Vision Science, School of Optometry, United States
| | - Oleg Gorbatyuk
- University of Alabama at Birmingham, Department of Optometry, United States; University of Alabama at Birmingham, Department of Vision Science, School of Optometry, United States
| | - Marina Gorbatyuk
- University of Alabama at Birmingham, Department of Optometry, United States; University of Alabama at Birmingham, Department of Vision Science, School of Optometry, United States.
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38
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Gómez-Vicente V, Lax P, Fernández-Sánchez L, Rondón N, Esquiva G, Germain F, de la Villa P, Cuenca N. Neuroprotective Effect of Tauroursodeoxycholic Acid on N-Methyl-D-Aspartate-Induced Retinal Ganglion Cell Degeneration. PLoS One 2015; 10:e0137826. [PMID: 26379056 PMCID: PMC4574963 DOI: 10.1371/journal.pone.0137826] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 08/24/2015] [Indexed: 01/01/2023] Open
Abstract
Retinal ganglion cell degeneration underlies the pathophysiology of diseases affecting the retina and optic nerve. Several studies have previously evidenced the anti-apoptotic properties of the bile constituent, tauroursodeoxycholic acid, in diverse models of photoreceptor degeneration. The aim of this study was to investigate the effects of systemic administration of tauroursodeoxycholic acid on N-methyl-D-aspartate (NMDA)-induced damage in the rat retina using a functional and morphological approach. Tauroursodeoxycholic acid was administered intraperitoneally before and after intravitreal injection of NMDA. Three days after insult, full-field electroretinograms showed reductions in the amplitudes of the positive and negative-scotopic threshold responses, scotopic a- and b-waves and oscillatory potentials. Quantitative morphological evaluation of whole-mount retinas demonstrated a reduction in the density of retinal ganglion cells. Systemic administration of tauroursodeoxycholic acid attenuated the functional impairment induced by NMDA, which correlated with a higher retinal ganglion cell density. Our findings sustain the efficacy of tauroursodeoxycholic acid administration in vivo, suggesting it would be a good candidate for the pharmacological treatment of degenerative diseases coursing with retinal ganglion cell loss.
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Affiliation(s)
- Violeta Gómez-Vicente
- Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Alicante, Spain
| | - Pedro Lax
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Laura Fernández-Sánchez
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Netxibeth Rondón
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Gema Esquiva
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Francisco Germain
- Departamento de Biología de Sistemas, Universidad de Alcalá, Alcalá de Henares, Spain
| | - Pedro de la Villa
- Departamento de Biología de Sistemas, Universidad de Alcalá, Alcalá de Henares, Spain
| | - Nicolás Cuenca
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
- * E-mail:
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39
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Fernández-Sánchez L, Lax P, Noailles A, Angulo A, Maneu V, Cuenca N. Natural Compounds from Saffron and Bear Bile Prevent Vision Loss and Retinal Degeneration. Molecules 2015; 20:13875-93. [PMID: 26263962 PMCID: PMC6332441 DOI: 10.3390/molecules200813875] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 07/23/2015] [Accepted: 07/28/2015] [Indexed: 12/13/2022] Open
Abstract
All retinal disorders, regardless of their aetiology, involve the activation of oxidative stress and apoptosis pathways. The administration of neuroprotective factors is crucial in all phases of the pathology, even when vision has been completely lost. The retina is one of the most susceptible tissues to reactive oxygen species damage. On the other hand, proper development and functioning of the retina requires a precise balance between the processes of proliferation, differentiation and programmed cell death. The life-or-death decision seems to be the result of a complex balance between pro- and anti-apoptotic signals. It has been recently shown the efficacy of natural products to slow retinal degenerative process through different pathways. In this review, we assess the neuroprotective effect of two compounds used in the ancient pharmacopoeia. On one hand, it has been demonstrated that administration of the saffron constituent safranal to P23H rats, an animal model of retinitis pigmentosa, preserves photoreceptor morphology and number, the capillary network and the visual response. On the other hand, it has been shown that systemic administration of tauroursodeoxycholic acid (TUDCA), the major component of bear bile, to P23H rats preserves cone and rod structure and function, together with their contact with postsynaptic neurons. The neuroprotective effects of safranal and TUDCA make these compounds potentially useful for therapeutic applications in retinal degenerative diseases.
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Affiliation(s)
- Laura Fernández-Sánchez
- Departament of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain.
| | - Pedro Lax
- Departament of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain.
| | - Agustina Noailles
- Departament of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain.
| | - Antonia Angulo
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain.
| | - Victoria Maneu
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain.
| | - Nicolás Cuenca
- Departament of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain.
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Abstract
Cones are photoreceptor cells used for bright light and color vision. Retinoids are vitamin A derivatives, one of which is the 11-cis aldehyde form that serves as the chromophore for both cone and rod visual pigments. In the visual disease, Type 2 Leber congenital amaurosis (LCA2), 11-cis-retinal generation is inhibited or abolished. Work by others has shown that patients with LCA2 have symptoms consistent with degenerating cones. In mouse models for LCA2, early cone degeneration is readily apparent: cone opsins and other proteins associated with the outer segment are delocalized and cell numbers decline rapidly within the first month. Rods would appear normal morphologically and functionally, if not for the absence of chromophore. Supplementation of mouse models of LCA2 with cis-retinoids has been shown to slow loss of cone photoreceptor cells if mice were maintained in darkness. Thus, 11-cis-retinal appears not only to have a role in the light response reaction but also to promote proper trafficking of the cone opsins and maintain viable cones.
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Affiliation(s)
- Masahiro Kono
- Department of Ophthalmology, Albert Florens Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.
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Retinal cone photoreceptors require phosducin-like protein 1 for G protein complex assembly and signaling. PLoS One 2015; 10:e0117129. [PMID: 25659125 PMCID: PMC4319785 DOI: 10.1371/journal.pone.0117129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 12/19/2014] [Indexed: 12/24/2022] Open
Abstract
G protein β subunits (Gβ) play essential roles in phototransduction as part of G protein βγ (Gβγ) and regulator of G protein signaling 9 (RGS9)-Gβ5 heterodimers. Both are obligate dimers that rely on the cytosolic chaperone CCT and its co-chaperone PhLP1 to form complexes from their nascent polypeptides. The importance of PhLP1 in the assembly process was recently demonstrated in vivo in a retinal rod-specific deletion of the Phlp1 gene. To test whether this is a general mechanism that also applies to other cell types, we disrupted the Phlp1 gene specifically in mouse cones and measured the effects on G protein expression and cone visual signal transduction. In PhLP1-deficient cones, expression of cone transducin (Gt2) and RGS9-Gβ5 subunits was dramatically reduced, resulting in a 27-fold decrease in sensitivity and a 38-fold delay in cone photoresponse recovery. These results demonstrate the essential role of PhLP1 in cone G protein complex formation. Our findings reveal a common mechanism of Gβγ and RGS9-Gβ5 assembly in rods and cones, highlighting the importance of PhLP1 and CCT-mediated Gβ complex formation in G protein signaling.
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Zhang T, Enemchukwu NO, Jones A, Wang S, Dennis E, Watt CB, Pugh EN, Fu Y. Genetic deletion of S-opsin prevents rapid cone degeneration in a mouse model of Leber congenital amaurosis. Hum Mol Genet 2014; 24:1755-63. [PMID: 25416279 DOI: 10.1093/hmg/ddu588] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mutations in RPE65 or lecithin-retinol acyltransferase (LRAT) disrupt 11-cis-retinal synthesis and cause Leber congenital amaurosis (LCA), a severe hereditary blindness occurring in early childhood. The pathology is attributed to a combination of 11-cis-retinal deficiency and photoreceptor degeneration. The mistrafficking of cone membrane-associated proteins including cone opsins (M- and S-opsins), cone transducin (Gαt2), G-protein-coupled receptor kinase 1 (GRK1) and guanylate cyclase 1 (GC1) has been suggested to play a role in cone degeneration. However, their precise role in cone degeneration is unclear. Here we investigated the role of S-opsin (Opn1sw) in cone degeneration in Lrat(-) (/-), a murine model for LCA, by genetic ablation of S-opsin. We show that deletion of just one allele of S-opsin from Lrat(-) (/-) mice is sufficient to prevent the rapid cone degeneration for at least 1 month. Deletion of both alleles of S-opsin prevents cone degeneration for an extended period (at least 12 months). This genetic prevention is accompanied by a reduction of endoplasmic reticulum (ER) stress in Lrat(-) (/-) photoreceptors. Despite cone survival in Opn1sw(-/-)Lrat(-) (/-) mice, cone membrane-associated proteins (e.g. Gαt2, GRK1 and GC1) continue to have trafficking problems. Our results suggest that cone opsins are the 'culprit' linking 11-cis-retinal deficiency to cone degeneration in LCA. This result has important implications for the current gene therapy strategy that emphasizes the need for a combinatorial therapy to both improve vision and slow photoreceptor degeneration.
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Affiliation(s)
- Tao Zhang
- Department of Ophthalmology and Visual Sciences
| | | | - Alex Jones
- Department of Ophthalmology and Visual Sciences
| | | | | | - Carl B Watt
- Department of Ophthalmology and Visual Sciences
| | - Edward N Pugh
- Physiology and Membrane Biology, University of California, Davis, 3301 Tupper Hall, 1 Shields Avenue, Davis, CA 95616, USA
| | - Yingbin Fu
- Department of Ophthalmology and Visual Sciences, Department of Neurobiology and Anatomy, University of Utah Health Sciences Center, 65 Mario Capecchi Drive, Salt Lake City, UT 84132, USA
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Prukova D, Ileninova Z, Antosova B, Kasparek P, Gregor M, Sedlacek R. Transgenic reporter mice with promoter region of murine LRAT specifically marks lens and meiosis spermatocytes. Physiol Res 2014; 64:247-54. [PMID: 25317684 DOI: 10.33549/physiolres.932733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Lecithin:retinol acyltransferase (LRAT) is the major enzyme responsible for retinol esterification in the mammalian body. LRAT exhibits specific activity in the cells with active retinol metabolism where it converts retinols into retinyl esters, which represents the major storage form of retinol. Besides hepatic stellate cells in the liver, LRAT appears to have a key physiologic role in several other tissues. In this study, we generated a transgenic reporter mouse expressing green fluorescence protein (EGFP) under the control of region containing -1166 bps from promoter upstream from the putative transcriptional start site and 262 bps downstream of this start. Transgenic reporter mice exhibited specific expression in eyes and testes. In eyes, expression of EGFP-reporter is found in lens and lens epithelium and fibers from embryo to adulthood. In testes, LRAT-EGFP reporter is expressed both in Sertoli and in spermatocytes marking initiation of spermatogenesis in prepubertal mice. Our data show that the examined LRAT regulatory region is sufficient to achieve strong and selective expression in the eye and testes but not in liver and other organs.
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Affiliation(s)
- D Prukova
- Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the CAS, Prague, Czech Republic. ;
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Cuenca N, Fernández-Sánchez L, Campello L, Maneu V, De la Villa P, Lax P, Pinilla I. Cellular responses following retinal injuries and therapeutic approaches for neurodegenerative diseases. Prog Retin Eye Res 2014; 43:17-75. [PMID: 25038518 DOI: 10.1016/j.preteyeres.2014.07.001] [Citation(s) in RCA: 296] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/03/2014] [Accepted: 07/07/2014] [Indexed: 01/17/2023]
Abstract
Retinal neurodegenerative diseases like age-related macular degeneration, glaucoma, diabetic retinopathy and retinitis pigmentosa each have a different etiology and pathogenesis. However, at the cellular and molecular level, the response to retinal injury is similar in all of them, and results in morphological and functional impairment of retinal cells. This retinal degeneration may be triggered by gene defects, increased intraocular pressure, high levels of blood glucose, other types of stress or aging, but they all frequently induce a set of cell signals that lead to well-established and similar morphological and functional changes, including controlled cell death and retinal remodeling. Interestingly, an inflammatory response, oxidative stress and activation of apoptotic pathways are common features in all these diseases. Furthermore, it is important to note the relevant role of glial cells, including astrocytes, Müller cells and microglia, because their response to injury is decisive for maintaining the health of the retina or its degeneration. Several therapeutic approaches have been developed to preserve retinal function or restore eyesight in pathological conditions. In this context, neuroprotective compounds, gene therapy, cell transplantation or artificial devices should be applied at the appropriate stage of retinal degeneration to obtain successful results. This review provides an overview of the common and distinctive features of retinal neurodegenerative diseases, including the molecular, anatomical and functional changes caused by the cellular response to damage, in order to establish appropriate treatments for these pathologies.
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Affiliation(s)
- Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain; Multidisciplinary Institute for Environmental Studies "Ramon Margalef", University of Alicante, Alicante, Spain.
| | - Laura Fernández-Sánchez
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Laura Campello
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Victoria Maneu
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Pedro De la Villa
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Spain
| | - Pedro Lax
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Isabel Pinilla
- Department of Ophthalmology, Lozano Blesa University Hospital, Aragon Institute of Health Sciences, Zaragoza, Spain
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Vang S, Longley K, Steer CJ, Low WC. The Unexpected Uses of Urso- and Tauroursodeoxycholic Acid in the Treatment of Non-liver Diseases. Glob Adv Health Med 2014; 3:58-69. [PMID: 24891994 PMCID: PMC4030606 DOI: 10.7453/gahmj.2014.017] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Tauroursodeoxycholic acid (TUDCA) is the taurine conjugate of ursodeoxycholic acid (UDCA), a US Food and Drug Administration–approved hydrophilic bile acid for the treatment of certain cholestatic liver diseases. There is a growing body of research on the mechanism(s) of TUDCA and its potential therapeutic effect on a wide variety of non-liver diseases. Both UDCA and TUDCA are potent inhibitors of apoptosis, in part by interfering with the upstream mitochondrial pathway of cell death, inhibiting oxygen-radical production, reducing endoplasmic reticulum (ER) stress, and stabilizing the unfolded protein response (UPR). Several studies have demonstrated that TUDCA serves as an anti-apoptotic agent for a number of neurodegenerative diseases, including amyotrophic lateral sclerosis, Alzheimer's disease, Parkinson's disease, and Huntington's disease. In addition, TUDCA plays an important role in protecting against cell death in certain retinal disorders, such as retinitis pigmentosa. It has been shown to reduce ER stress associated with elevated glucose levels in diabetes by inhibiting caspase activation, up-regulating the UPR, and inhibiting reactive oxygen species. Obesity, stroke, acute myocardial infarction, spinal cord injury, and a long list of acute and chronic non-liver diseases associated with apoptosis are all potential therapeutic targets for T/UDCA. A growing number of pre-clinical and clinical studies underscore the potential benefit of this simple, naturally occurring bile acid, which has been used in Chinese medicine for more than 3000 years.
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Affiliation(s)
- Sheila Vang
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis (Ms Vang), United States
| | - Katie Longley
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis (Ms Longley), United States
| | - Clifford J Steer
- Department of Medicine, University of Minnesota Medical School, Minneapolis, and Department of Genetics, Cell Biology and Development, University of Minnesota (Dr Steer), United States
| | - Walter C Low
- Department of Neurosurgery, University of Minnesota Medical School and Department of Integrative Biology and Physiology, University of Minnesota (Dr Low), United States
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Zhang SX, Sanders E, Fliesler SJ, Wang JJ. Endoplasmic reticulum stress and the unfolded protein responses in retinal degeneration. Exp Eye Res 2014; 125:30-40. [PMID: 24792589 DOI: 10.1016/j.exer.2014.04.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 04/02/2014] [Accepted: 04/18/2014] [Indexed: 02/06/2023]
Abstract
The endoplasmic reticulum (ER) is the primary intracellular organelle responsible for protein and lipid biosynthesis, protein folding and trafficking, calcium homeostasis, and several other vital processes in cell physiology. Disturbance in ER function results in ER stress and subsequent activation of the unfolded protein response (UPR). The UPR up-regulates ER chaperones, reduces protein translation, and promotes clearance of cytotoxic misfolded proteins to restore ER homeostasis. If this vital process fails, the cell will be signaled to enter apoptosis, resulting in cell death. Sustained ER stress also can trigger an inflammatory response and exacerbate oxidative stress, both of which contribute synergistically to tissue damage. Studies performed over the past decade have implicated ER stress in a broad range of human diseases, including neurodegenerative diseases, cancer, diabetes, and vascular disorders. Several of these diseases also entail retinal dysfunction and degeneration caused by injury to retinal neurons and/or to the blood vessels that supply retinal cells with nutrients, trophic and homeostatic factors, oxygen, and other essential molecules, as well as serving as a conduit for removal of waste products and potentially toxic substances from the retina. Collectively, such injuries represent the leading cause of blindness world-wide in all age groups. Herein, we summarize recent progress on the study of ER stress and UPR signaling in retinal biology and discuss the molecular mechanisms and the potential clinical applications of targeting ER stress as a new therapeutic approach to prevent and treat neuronal degeneration in the retina.
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Affiliation(s)
- Sarah X Zhang
- Departments of Ophthalmology and Biochemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA; SUNY Eye Institute, Buffalo, NY, USA.
| | - Emily Sanders
- Department of Medicine, Endocrinology and Diabetes, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Steven J Fliesler
- Departments of Ophthalmology and Biochemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA; SUNY Eye Institute, Buffalo, NY, USA; Research Service, Veterans Administration Western New York Healthcare System, Buffalo, NY, USA
| | - Joshua J Wang
- Departments of Ophthalmology and Biochemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA; SUNY Eye Institute, Buffalo, NY, USA
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Fu Y, Zhang T. Pathophysilogical mechanism and treatment strategies for Leber congenital amaurosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 801:791-6. [PMID: 24664772 PMCID: PMC4080891 DOI: 10.1007/978-1-4614-3209-8_99] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Mutations in retinoid isomerase, RPE65, or lecithin-retinol acyltransferase (LRAT) disrupt 11-cis-retinal recycling and cause Leber congenital amaurosis (LCA), the most severe retinal dystrophy in early childhood. We used Lrat (-/-), a murine model for LCA, to investigate the mechanism of rapid cone degeneration. We found that mislocalized M-opsin was degraded whereas mislocalized S-opsin accumulated in Lrat (-/-) cones before the onset of massive ventral/central cone degeneration. Since the ventral and central retina expresses higher levels of S-opsin than the dorsal retina in mice, our results may explain why ventral and central cones degenerate more rapidly than dorsal cones in Rpe65 (-/-) and Lrat (-/-) LCA models. In addition, human blue opsin and mouse S-opsin, but not mouse M-opsin or human red/green opsins, aggregated to form cytoplasmic inclusions in transfected cells, which may explain why blue cone function is lost earlier than red/green-cone function in LCA patients. The aggregation of short-wavelength opsins likely caused rapid cone degenerations through an ER stress pathway as demonstrated in both the Lrat (-/-) retina and transfected cells. Based on this mechanism, we designed a new therapy of LCA by reducing ER stress. We found that systemic injection of an ER chemical chaperone, tauroursodeoxycholic acid (TUDCA), is effective in reducing ER stress, preventing apoptosis, and preserving cones in Lrat (-/-) mice.
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Michalakis S, Shaltiel L, Sothilingam V, Koch S, Schludi V, Krause S, Zeitz C, Audo I, Lancelot ME, Hamel C, Meunier I, Preising MN, Friedburg C, Lorenz B, Zabouri N, Haverkamp S, Garcia Garrido M, Tanimoto N, Seeliger MW, Biel M, Wahl-Schott CA. Mosaic synaptopathy and functional defects in Cav1.4 heterozygous mice and human carriers of CSNB2. Hum Mol Genet 2013; 23:1538-50. [PMID: 24163243 DOI: 10.1093/hmg/ddt541] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mutations in CACNA1F encoding the α1-subunit of the retinal Cav1.4 L-type calcium channel have been linked to Cav1.4 channelopathies including incomplete congenital stationary night blindness type 2A (CSNB2), Åland Island eye disease (AIED) and cone-rod dystrophy type 3 (CORDX3). Since CACNA1F is located on the X chromosome, Cav1.4 channelopathies are typically affecting male patients via X-chromosomal recessive inheritance. Occasionally, clinical symptoms have been observed in female carriers, too. It is currently unknown how these mutations lead to symptoms in carriers and how the retinal network in these females is affected. To investigate these clinically important issues, we compared retinal phenotypes in Cav1.4-deficient and Cav1.4 heterozygous mice and in human female carrier patients. Heterozygous Cacna1f carrier mice have a retinal mosaic consistent with differential X-chromosomal inactivation, characterized by adjacent vertical columns of affected and non-affected wild-type-like retinal network. Vertical columns in heterozygous mice are well comparable to either the wild-type retinal network of normal mice or to the retina of homozygous mice. Affected retinal columns display pronounced rod and cone photoreceptor synaptopathy and cone degeneration. These changes lead to vastly impaired vision-guided navigation under dark and normal light conditions and reduced retinal electroretinography (ERG) responses in Cacna1f carrier mice. Similar abnormal ERG responses were found in five human CACNA1F carriers, four of which had novel mutations. In conclusion, our data on Cav1.4 deficient mice and human female carriers of mutations in CACNA1F are consistent with a phenotype of mosaic CSNB2.
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Affiliation(s)
- Stylianos Michalakis
- Center for Integrated Protein Science Munich (CIPSM) and Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
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Vitamin A derivatives as treatment options for retinal degenerative diseases. Nutrients 2013; 5:2646-66. [PMID: 23857173 PMCID: PMC3738993 DOI: 10.3390/nu5072646] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 06/05/2013] [Accepted: 06/13/2013] [Indexed: 11/17/2022] Open
Abstract
The visual cycle is a sequential enzymatic reaction for vitamin A, all-trans-retinol, occurring in the outer layer of the human retina and is essential for the maintenance of vision. The central source of retinol is derived from dietary intake of both retinol and pro-vitamin A carotenoids. A series of enzymatic reactions, located in both the photoreceptor outer segment and the retinal pigment epithelium, transform retinol into the visual chromophore 11-cis-retinal, regenerating visual pigments. Retina specific proteins carry out the majority of the visual cycle, and any significant interruption in this sequence of reactions is capable of causing varying degrees of blindness. Among these important proteins are Lecithin:retinol acyltransferase (LRAT) and retinal pigment epithelium-specific 65-kDa protein (RPE65) known to be responsible for esterification of retinol to all-trans-retinyl esters and isomerization of these esters to 11-cis-retinal, respectively. Deleterious mutations in these genes are identified in human retinal diseases that cause blindness, such as Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP). Herein, we discuss the pathology of 11-cis-retinal deficiency caused by these mutations in both animal disease models and human patients. We also review novel therapeutic strategies employing artificial visual chromophore 9-cis-retinoids which have been employed in clinical trials involving LCA patients.
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50
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Koirala A, Conley SM, Naash MI. A review of therapeutic prospects of non-viral gene therapy in the retinal pigment epithelium. Biomaterials 2013; 34:7158-67. [PMID: 23796578 DOI: 10.1016/j.biomaterials.2013.06.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 06/02/2013] [Indexed: 10/26/2022]
Abstract
Ocular gene therapy has been extensively explored in recent years as a therapeutic avenue to target diseases of the cornea, retina and retinal pigment epithelium (RPE). Adeno-associated virus (AAV)-mediated gene therapy has shown promise in several RPE clinical trials but AAVs have limited payload capacity and potential immunogenicity. Traditionally however, non-viral alternatives have been plagued by low transfection efficiency, short-term expression and low expression levels. Recently, these drawbacks have begun to be overcome by the use of specialty carriers such as polylysine, liposomes, or polyethyleneimines, and by inclusion of suitable DNA elements to enhance gene expression and longevity. Recent advancements in the field have yielded non-viral vectors that have favorable safety profiles, lack immunogenicity, exhibit long-term elevated gene expression, and show efficient transfection in the retina and RPE, making them poised to transition to clinical applications. Here we discuss the advancements in nanotechnology and vector engineering that have improved the prospects for clinical application of non-viral gene therapy in the RPE.
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Affiliation(s)
- Adarsha Koirala
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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