1
|
Miller AL, James RE, Harvey AR, Trifunović D, Carvalho LS. The role of epigenetic changes in the pathology and treatment of inherited retinal diseases. Front Cell Dev Biol 2023; 11:1224078. [PMID: 37601102 PMCID: PMC10436478 DOI: 10.3389/fcell.2023.1224078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 07/20/2023] [Indexed: 08/22/2023] Open
Abstract
Elucidation of the cellular changes that occur in degenerating photoreceptors of people with inherited retinal diseases (IRDs) has been a focus for many research teams, leading to numerous theories on how these changes affect the cell death process. What is clearly emerging from these studies is that there are common denominators across multiple models of IRD, regardless of the underlying genetic mutation. These common markers could open avenues for broad neuroprotective therapeutics to prevent photoreceptor loss and preserve functional vision. In recent years, the role of epigenetic modifications contributing to the pathology of IRDs has been a particular point of interest, due to many studies noting changes in these epigenetic modifications, which coincide with photoreceptor cell death. This review will discuss the two broad categories of epigenetic changes, DNA methylation and histone modifications, that have received particular attention in IRD models. We will review the altered epigenetic regulatory events that are believed to contribute to cell death in IRDs and discuss the therapeutic potential of targeting these alterations.
Collapse
Affiliation(s)
- Annie L. Miller
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, WA, Australia
- Retinal Genomics and Therapy Laboratory, Lions Eye Institute, Nedlands, WA, Australia
| | - Rebekah E. James
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, WA, Australia
- Retinal Genomics and Therapy Laboratory, Lions Eye Institute, Nedlands, WA, Australia
| | - Alan R. Harvey
- Retinal Genomics and Therapy Laboratory, Lions Eye Institute, Nedlands, WA, Australia
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia
| | - Dragana Trifunović
- Institute for Ophthalmic Research, Tubingen University, Tübingen, Germany
| | - Livia S. Carvalho
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, WA, Australia
- Retinal Genomics and Therapy Laboratory, Lions Eye Institute, Nedlands, WA, Australia
- Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
| |
Collapse
|
2
|
Razzaghi N, Fernandez-Gonzalez P, Mas-Sanchez A, Vila-Julià G, Perez JJ, Garriga P. Effect of Sodium Valproate on the Conformational Stability of the Visual G Protein-Coupled Receptor Rhodopsin. Molecules 2021; 26:molecules26103032. [PMID: 34069614 PMCID: PMC8160834 DOI: 10.3390/molecules26103032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/13/2021] [Accepted: 05/17/2021] [Indexed: 12/29/2022] Open
Abstract
Rhodopsin is the G protein-coupled receptor of rod photoreceptor cells that mediates vertebrate vision at low light intensities. Mutations in rhodopsin cause inherited retinal degenerative diseases such as retinitis pigmentosa. Several therapeutic strategies have attempted to address and counteract the deleterious effect of rhodopsin mutations on the conformation and function of this photoreceptor protein, but none has been successful in efficiently preventing retinal degeneration in humans. These approaches include, among others, the use of small molecules, known as pharmacological chaperones, that bind to the receptor stabilizing its proper folded conformation. Valproic acid, in its sodium valproate form, has been used as an anticonvulsant in epileptic patients and in the treatment of several psychiatric disorders. More recently, this compound has been tested as a potential therapeutic agent for the treatment of retinal degeneration associated with retinitis pigmentosa caused by rhodopsin mutations. We now report on the effect of sodium valproate on the conformational stability of heterologously expressed wild-type rhodopsin and a rhodopsin mutant, I307N, which has been shown to be an appropriate model for studying retinal degeneration in mice. We found no sign of enhanced stability for the dark inactive conformation of the I307N mutant. Furthermore, the photoactivated conformation of the mutant appears to be destabilized by sodium valproate as indicated by a faster decay of its active conformation. Therefore, our results support a destabilizing effect of sodium valproate on rhodopsin I307N mutant associated with retinal degeneration. These findings, at the molecular level, agree with recent clinical studies reporting negative effects of sodium valproate on the visual function of retinitis pigmentosa patients.
Collapse
Affiliation(s)
- Neda Razzaghi
- Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Departament d’Enginyeria Química, Universitat Politècnica de Catalunya-Barcelona Tech, Edifici Gaia, Rambla de Sant Nebridi 22, 08222 Terrassa, Spain; (N.R.); (P.F.-G.); (A.M.-S.)
| | - Pol Fernandez-Gonzalez
- Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Departament d’Enginyeria Química, Universitat Politècnica de Catalunya-Barcelona Tech, Edifici Gaia, Rambla de Sant Nebridi 22, 08222 Terrassa, Spain; (N.R.); (P.F.-G.); (A.M.-S.)
| | - Aina Mas-Sanchez
- Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Departament d’Enginyeria Química, Universitat Politècnica de Catalunya-Barcelona Tech, Edifici Gaia, Rambla de Sant Nebridi 22, 08222 Terrassa, Spain; (N.R.); (P.F.-G.); (A.M.-S.)
| | - Guillem Vila-Julià
- Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Departament d’Enginyeria Química, Universitat Politècnica de Catalunya-Barcelona Tech., Avinguda Diagonal, 647, 08028 Barcelona, Spain; (G.V.-J.); (J.J.P.)
| | - Juan Jesus Perez
- Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Departament d’Enginyeria Química, Universitat Politècnica de Catalunya-Barcelona Tech., Avinguda Diagonal, 647, 08028 Barcelona, Spain; (G.V.-J.); (J.J.P.)
| | - Pere Garriga
- Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Departament d’Enginyeria Química, Universitat Politècnica de Catalunya-Barcelona Tech, Edifici Gaia, Rambla de Sant Nebridi 22, 08222 Terrassa, Spain; (N.R.); (P.F.-G.); (A.M.-S.)
- Correspondence:
| |
Collapse
|
3
|
Zhao M, Tao Y, Peng GH. The Role of Histone Acetyltransferases and Histone Deacetylases in Photoreceptor Differentiation and Degeneration. Int J Med Sci 2020; 17:1307-1314. [PMID: 32624685 PMCID: PMC7330661 DOI: 10.7150/ijms.43140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 05/10/2020] [Indexed: 12/18/2022] Open
Abstract
Photoreceptors are critical components of the retina and play a role in the first step of the conversion of light to electrical signals. The differentiation and degeneration of photoreceptors are regulated by specific genes and proteins. With the development of epigenetic approaches, scientists have discovered that histone modifications, such as acetylation, methylation, ubiquitylation, and phosphorylation, may modulate the processes of photoreceptor differentiation and degeneration. Histone acetylation is regulated by two opposing classes of enzymes, namely, histone acetyltransferases (HATs) and histone deacetylases (HDACs), which add and remove acetyl groups to and from target histones, respectively, causing changes in transcriptional activity. Herein, we review the effects of HATs and HDACs on the differentiation and degeneration of photoreceptors and discuss the underlying mechanisms of these effects.
Collapse
Affiliation(s)
- Meng Zhao
- Laboratory of Visual Cell Differentiation and Regulation, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China.,Department of Pathophysiology, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China
| | - Ye Tao
- Laboratory of Visual Cell Differentiation and Regulation, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China.,Department of Physiology, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China
| | - Guang-Hua Peng
- Laboratory of Visual Cell Differentiation and Regulation, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China.,Department of Pathophysiology, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China
| |
Collapse
|
4
|
Chen WJ, Ma L, Li MS, Ma X. Valproic acid's effects on visual acuity in retinitis pigmentosa: a systemic review and Meta-analysis. Int J Ophthalmol 2019; 12:129-134. [PMID: 30662852 DOI: 10.18240/ijo.2019.01.20] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 09/18/2018] [Indexed: 11/23/2022] Open
Abstract
AIM To gain a better understanding of the overall efficacy of valproic acid (VPA) treatment for retinitis pigmentosa (RP). METHODS Publications in PubMed, EMBASE, Cochrane Library, Web of Science and Clinicaltrials.gov were searched for clinical trials of patients with RP assigned to treatment with VPA. Patients' pre- and post-treatment visual field (VF) and best-corrected visual acuity (BCVA) scores were extracted and compared to assess changes. RESULTS A total of 78 reports were retrieved and 6 studies involving 116 patients were included in the Meta-analysis. The combined results showed a significant decrease in logarithm of minimal angle of resolution (logMAR) scores, calculated using baseline and post-treatment BCVA (P<0.00001, mean difference=-0.05, 95%CI: -0.05, -0.04, I 2=36%) scores, which means there was considerable improvement in visual acuity. Meanwhile, more BCVA changes were observed in short-term (≤6mo) treatment studies (P<0.00001, mean difference=-0.05, 95%CI: -0.05, -0.04, I 2=38%), studies conducted in Asia (P<0.00001, mean difference=-0.05, 95%CI: -0.05, -0.04, I 2=4%), studies with a sample size of 30 or fewer patients (P<0.00001, mean difference=-0.05, 95%CI: -0.05, -0.04, I 2=38%) and prospective studies (P<0.00001, mean difference=-0.05, 95%CI: -0.05, -0.04, I 2=0%). However, VPA's effect on VF was inconsistent across studies (P=0.75, mean difference=-22.76, 95%CI: -160.56, 115.05, I 2=68%). CONCLUSION This Meta-analysis reveals that most RP patients who were treated with VPA showed improvement in BCVA. However, its effect on VF remains inconsistent. VPA may be a promising treatment for RP.
Collapse
Affiliation(s)
- Wen-Jun Chen
- Department of Ophthalmology, the First Affiliated Hospital of Dalian Medical University, Dalian 116011, Liaoning Province, China
| | - Li Ma
- Department of Ophthalmology, the First Affiliated Hospital of Dalian Medical University, Dalian 116011, Liaoning Province, China
| | - Ming-Shu Li
- Department of Ophthalmology, the First Affiliated Hospital of Dalian Medical University, Dalian 116011, Liaoning Province, China
| | - Xiang Ma
- Department of Ophthalmology, the First Affiliated Hospital of Dalian Medical University, Dalian 116011, Liaoning Province, China
| |
Collapse
|
5
|
Wang AL, Knight DK, Vu TTT, Mehta MC. Retinitis Pigmentosa: Review of Current Treatment. Int Ophthalmol Clin 2019; 59:263-280. [PMID: 30585930 DOI: 10.1097/iio.0000000000000256] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
|
6
|
Mahalingam K, Chaurasia AK, Gowtham L, Gupta S, Somarajan BI, Velpandian T, Sihota R, Gupta V. Therapeutic potential of valproic acid in advanced glaucoma: A pilot study. Indian J Ophthalmol 2018; 66:1104-1108. [PMID: 30038151 PMCID: PMC6080453 DOI: 10.4103/ijo.ijo_108_18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 04/23/2018] [Indexed: 11/12/2022] Open
Abstract
Purpose Oral valproic acid (VPA) used as an anticonvulsant has been shown to improve contrast threshold sensitivities in patients receiving it on long-term. This study aimed to evaluate the efficacy of oral VPA in improving visual function in eyes with advanced stage glaucoma. Methods In this prospective randomized study, 31 patients (n = 31 eyes) with advanced stage glaucoma (with an intraocular pressure <16 mmHg) in at least one eye received oral VPA 500 mg once a day for 3 months and 33 patients (n = 33 eyes) continued on glaucoma therapy. Patients were followed up at 3 and 12 months (to evaluate the legacy effect of the drug). Blood VPA concentrations were measured at 3 months. Following parameters were assessed at baseline, 3 months and 12 months: log of the minimum angle of resolution (LogMAR) visual acuity, mean deviation on visual fields, and multifocal electroretinogram (ERG). Results Median LogMar visual acuity in the VPA group improved from 0.3 at baseline to 0.18 and 0.18 at 3 and 12 months, respectively (P < 0.01). In comparison, the median visual acuity in control group at baseline was 0.18 and showed neither worsening nor improvement over 3 and 12 months (P = 0.56). The improvement in VPA group was significant compared to the control group (P < 0.01; Wilcoxon Signed-rank test). An improvement in one line was experienced in 11 out of 31 eyes in the VPA group compared to 1 out of 33 eyes among controls (P = 0.003). No significant improvement was noted in the mean deviation, and the multifocal ERG (Latency and amplitudes) in the VPA-treated patients. The average blood VPA concentration measured at 3 months of therapy was 26 ± 8.9 μg/ml (range 8-55 μg/ml) which is much lower than that achieved during anticonvulsant therapy. None of the patients complained of any adverse effects that required stopping VPA therapy. Conclusion A 3 months oral VPA therapy results in some improvement in visual acuity in a subgroup of eyes with advanced glaucoma and the effect was seen to persist 9 months after the drug was stopped.
Collapse
Affiliation(s)
- Karthikeyan Mahalingam
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Abadh Kumar Chaurasia
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | | | - Shikha Gupta
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Bindu I Somarajan
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Thirumurthy Velpandian
- Department of Ocular Pharmacology, All India Institute of Medical Sciences, New Delhi, India
| | - Ramanjit Sihota
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Viney Gupta
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| |
Collapse
|
7
|
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.
Collapse
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.
| | | |
Collapse
|
8
|
Dias MF, Joo K, Kemp JA, Fialho SL, da Silva Cunha A, Woo SJ, Kwon YJ. Molecular genetics and emerging therapies for retinitis pigmentosa: Basic research and clinical perspectives. Prog Retin Eye Res 2017; 63:107-131. [PMID: 29097191 DOI: 10.1016/j.preteyeres.2017.10.004] [Citation(s) in RCA: 259] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 10/19/2017] [Accepted: 10/25/2017] [Indexed: 02/06/2023]
Abstract
Retinitis Pigmentosa (RP) is a hereditary retinopathy that affects about 2.5 million people worldwide. It is characterized with progressive loss of rods and cones and causes severe visual dysfunction and eventual blindness in bilateral eyes. In addition to more than 3000 genetic mutations from about 70 genes, a wide genetic overlap with other types of retinal dystrophies has been reported with RP. This diversity of genetic pathophysiology makes treatment extremely challenging. Although therapeutic attempts have been made using various pharmacologic agents (neurotrophic factors, antioxidants, and anti-apoptotic agents), most are not targeted to the fundamental cause of RP, and their clinical efficacy has not been clearly proven. Current therapies for RP in ongoing or completed clinical trials include gene therapy, cell therapy, and retinal prostheses. Gene therapy, a strategy to correct the genetic defects using viral or non-viral vectors, has the potential to achieve definitive treatment by replacing or silencing a causative gene. Among many clinical trials of gene therapy for hereditary retinal diseases, a phase 3 clinical trial of voretigene neparvovec (AAV2-hRPE65v2, Luxturna) recently showed significant efficacy for RPE65-mediated inherited retinal dystrophy including Leber congenital amaurosis and RP. It is about to be approved as the first ocular gene therapy biologic product. Despite current limitations such as limited target genes and indicated patients, modest efficacy, and the invasive administration method, development in gene editing technology and novel gene delivery carriers make gene therapy a promising therapeutic modality for RP and other hereditary retinal dystrophies in the future.
Collapse
Affiliation(s)
- Marina França Dias
- School of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil; Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA
| | - Kwangsic Joo
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Jessica A Kemp
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA
| | - Silvia Ligório Fialho
- Pharmaceutical Research and Development, Ezequiel Dias Foundation, Belo Horizonte, Brazil
| | | | - Se Joon Woo
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA; Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
| | - Young Jik Kwon
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA; Department of Chemical Engineering and Materials Sciences, University of California, Irvine, CA, USA; Department of Biomedical Engineering, University of California, Irvine, CA, USA; Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA.
| |
Collapse
|
9
|
Chen Y, Brooks MJ, Gieser L, Swaroop A, Palczewski K. Transcriptome profiling of NIH3T3 cell lines expressing opsin and the P23H opsin mutant identifies candidate drugs for the treatment of retinitis pigmentosa. Pharmacol Res 2016; 115:1-13. [PMID: 27838510 DOI: 10.1016/j.phrs.2016.10.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 10/18/2016] [Accepted: 10/26/2016] [Indexed: 01/01/2023]
Abstract
Mammalian cells are commonly employed in screening assays to identify active compounds that could potentially affect the progression of different human diseases including retinitis pigmentosa (RP), a class of inherited diseases causing retinal degeneration with compromised vision. Using transcriptome analysis, we compared NIH3T3 cells expressing wildtype (WT) rod opsin with a retinal disease-causing single P23H mutation. Surprisingly, heterologous expression of WT opsin in NIH3T3 cells caused more than a 2-fold change in 783 out of 16,888 protein coding transcripts. The perturbed genes encoded extracellular matrix proteins, growth factors, cytoskeleton proteins, glycoproteins and metalloproteases involved in cell adhesion, morphology and migration. A different set of 347 transcripts was either up- or down-regulated when the P23H mutant opsin was expressed suggesting an altered molecular perturbation compared to WT opsin. Transcriptome perturbations elicited by drug candidates aimed at mitigating the effects of the mutant protein revealed that different drugs targeted distinct molecular pathways that resulted in a similar phenotype selected by a cell-based high-throughput screen. Thus, transcriptome profiling can provide essential information about the therapeutic potential of a candidate drug to restore normal gene expression in pathological conditions.
Collapse
Affiliation(s)
- Yuanyuan Chen
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, United States
| | - Matthew J Brooks
- Neurobiology-Neurodegeneration & Repair Laboratory (N-NRL), National Eye Institute (NEI), National Institutes of Health (NIH), Bethesda, MD 20892, United States
| | - Linn Gieser
- Neurobiology-Neurodegeneration & Repair Laboratory (N-NRL), National Eye Institute (NEI), National Institutes of Health (NIH), Bethesda, MD 20892, United States
| | - Anand Swaroop
- Neurobiology-Neurodegeneration & Repair Laboratory (N-NRL), National Eye Institute (NEI), National Institutes of Health (NIH), Bethesda, MD 20892, United States
| | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, United States.
| |
Collapse
|
10
|
Iraha S, Hirami Y, Ota S, Sunagawa GA, Mandai M, Tanihara H, Takahashi M, Kurimoto Y. Efficacy of valproic acid for retinitis pigmentosa patients: a pilot study. Clin Ophthalmol 2016; 10:1375-84. [PMID: 27536054 PMCID: PMC4975153 DOI: 10.2147/opth.s109995] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Purpose The purpose of this study was to examine the efficacy and safety of valproic acid (VPA) use in patients with retinitis pigmentosa (RP). Patients and methods This was a prospective, interventional, noncomparative case study. In total, 29 eyes from 29 patients with RP whose best-corrected visual acuities (BCVAs) in logarithm of the minimum angle of resolution (logMAR) ranged from 1.0 to 0.16 with visual fields (VFs) of ≤10° (measured using Goldmann perimeter with I4) were recruited. The patients received oral supplementation with 400 mg of VPA daily for 6 months and were followed for an additional 6 months. BCVAs, VFs (measured with the Humphrey field analyzer central 10-2 program), and subjective questionnaires were examined before, during, and after the cessation of VPA supplementation. Results The changes in BCVA and VF showed statistically significant differences during the internal use of VPA, compared with after cessation (P=0.001). With VPA intake, BCVA in logMAR significantly improved from baseline to 6 months (P=0.006). The mean deviation value of the VF significantly improved from baseline to 1 month (P=0.001), 3 months (P=0.004), and 6 months (P=0.004). These efficacies, however, were reversed to the baseline levels after the cessation of VPA intake. There were no significant relations between the mean blood VPA concentrations of each patient and the changes in BCVA and VF. During the internal use of VPA, 15 of 29 patients answered “easier to see”, whereas blurred vision was registered in 21 of 29 patients on cessation. No systemic drug-related adverse events were observed. Conclusion While in use, oral intake of VPA indicated a short-term benefit to patients with RP. It is necessary to examine the effect of a longer VPA supplementation in a controlled study design.
Collapse
Affiliation(s)
- Satoshi Iraha
- Department of Ophthalmology, Institute of Biomedical Research and Innovation Hospital; Department of Ophthalmology, Kobe City Medical Center General Hospital; Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe; Application Biology and Regenerative Medicine, Graduate School of Medicine, Kyoto University, Kyoto; Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Yasuhiko Hirami
- Department of Ophthalmology, Institute of Biomedical Research and Innovation Hospital; Department of Ophthalmology, Kobe City Medical Center General Hospital
| | - Sachiko Ota
- Department of Ophthalmology, Institute of Biomedical Research and Innovation Hospital; Department of Ophthalmology, Kobe City Medical Center General Hospital
| | - Genshiro A Sunagawa
- Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe
| | - Michiko Mandai
- Department of Ophthalmology, Institute of Biomedical Research and Innovation Hospital; Department of Ophthalmology, Kobe City Medical Center General Hospital; Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe
| | - Hidenobu Tanihara
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Masayo Takahashi
- Department of Ophthalmology, Institute of Biomedical Research and Innovation Hospital; Department of Ophthalmology, Kobe City Medical Center General Hospital; Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe; Application Biology and Regenerative Medicine, Graduate School of Medicine, Kyoto University, Kyoto
| | - Yasuo Kurimoto
- Department of Ophthalmology, Institute of Biomedical Research and Innovation Hospital; Department of Ophthalmology, Kobe City Medical Center General Hospital
| |
Collapse
|
11
|
Guadagni V, Novelli E, Piano I, Gargini C, Strettoi E. Pharmacological approaches to retinitis pigmentosa: A laboratory perspective. Prog Retin Eye Res 2015; 48:62-81. [PMID: 26113212 DOI: 10.1016/j.preteyeres.2015.06.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 06/05/2015] [Accepted: 06/11/2015] [Indexed: 01/08/2023]
Abstract
Retinal photoreceptors are highly specialized and performing neurons. Their cellular architecture is exquisitely designed to host a high concentration of molecules involved in light capture, phototransduction, electric and chemical signaling, membrane and molecular turnover, light and dark adaption, network activities etc. Such high efficiency and molecular complexity require a great metabolic demand, altogether conferring to photoreceptors particular susceptibility to external and internal insults, whose occurrence usually precipitate into degeneration of these cells and blindness. In Retinitis Pigmentosa, an impressive number of mutations in genes expressed in the retina and coding for a large varieties of proteins leads to the progressive death of photoreceptors and blindness. Recent advances in molecular tools have greatly facilitated the identification of the underlying genetics and molecular bases of RP leading to the successful implementation of gene therapy for some types of mutations, with visual restoration in human patients. Yet, genetic heterogeneity of RP makes mutation-independent approaches highly desirable, although many obstacles pave the way to general strategies for treating this complex disease, which remains orphan. The review will focus on treatments for RP based on pharmacological tools, choosing, among the many ongoing studies, approaches which rely on strong experimental evidence or rationale. For perspective treatments, new concepts are foreseen to emerge from basic studies elucidating the pathways connecting the primary mutations to photoreceptor death, possibly revealing common molecular targets for drug intervention.
Collapse
Affiliation(s)
- Viviana Guadagni
- Neuroscience Institute, Italian National Research Council (CNR), Area della Ricerca, Via Giuseppe Moruzzi 1, 56124 Pisa, Italy
| | - Elena Novelli
- Neuroscience Institute, Italian National Research Council (CNR), Area della Ricerca, Via Giuseppe Moruzzi 1, 56124 Pisa, Italy
| | - Ilaria Piano
- Department of Pharmacy, University of Pisa, Pisa, Italy
| | | | - Enrica Strettoi
- Neuroscience Institute, Italian National Research Council (CNR), Area della Ricerca, Via Giuseppe Moruzzi 1, 56124 Pisa, Italy.
| |
Collapse
|