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Yuan H, Chen S, Duncan MR, de Rivero Vaccari JP, Keane RW, Dalton Dietrich W, Chou TH, Benny M, Schmidt AF, Young K, Park KK, Porciatti V, Elizabeth Hartnett M, Wu S. IC100, a humanized therapeutic monoclonal anti-ASC antibody alleviates oxygen-induced retinopathy in mice. Angiogenesis 2024; 27:423-440. [PMID: 38709389 PMCID: PMC11303442 DOI: 10.1007/s10456-024-09917-9] [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: 10/12/2023] [Accepted: 03/28/2024] [Indexed: 05/07/2024]
Abstract
BACKGROUND Retinopathy of prematurity (ROP), which often presents with bronchopulmonary dysplasia (BPD), is among the most common morbidities affecting extremely premature infants and is a leading cause of severe vision impairment in children worldwide. Activations of the inflammasome cascade and microglia have been implicated in playing a role in the development of both ROP and BPD. Apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) is pivotal in inflammasome assembly. Utilizing mouse models of both oxygen-induced retinopathy (OIR) and BPD, this study was designed to test the hypothesis that hyperoxia induces ASC speck formation, which leads to microglial activation and retinopathy, and that inhibition of ASC speck formation by a humanized monoclonal antibody, IC100, directed against ASC, will ameliorate microglial activation and abnormal retinal vascular formation. METHODS We first tested ASC speck formation in the retina of ASC-citrine reporter mice expressing ASC fusion protein with a C-terminal citrine (fluorescent GFP isoform) using a BPD model that causes both lung and eye injury by exposing newborn mice to room air (RA) or 85% O2 from postnatal day (P) 1 to P14. The retinas were dissected on P14 and retinal flat mounts were used to detect vascular endothelium with AF-594-conjugated isolectin B4 (IB4) and citrine-tagged ASC specks. To assess the effects of IC100 on an OIR model, newborn ASC citrine reporter mice and wildtype mice (C57BL/6 J) were exposed to RA from P1 to P6, then 75% O2 from P7 to P11, and then to RA from P12 to P18. At P12 mice were randomized to the following groups: RA with placebo PBS (RA-PBS), O2 with PBS (O2-PBS), O2 + IC100 intravitreal injection (O2-IC100-IVT), and O2 + IC100 intraperitoneal injection (O2-IC100-IP). Retinal vascularization was evaluated by flat mount staining with IB4. Microglial activation was detected by immunofluorescence staining for allograft inflammatory factor 1 (AIF-1) and CD206. Retinal structure was analyzed on H&E-stained sections, and function was analyzed by pattern electroretinography (PERG). RNA-sequencing (RNA-seq) of the retinas was performed to determine the transcriptional effects of IC100 treatment in OIR. RESULTS ASC specks were significantly increased in the retinas by hyperoxia exposure and colocalized with the abnormal vasculature in both BPD and OIR models, and this was associated with increased microglial activation. Treatment with IC100-IVT or IC100-IP significantly reduced vaso-obliteration and intravitreal neovascularization. IC100-IVT treatment also reduced retinal microglial activation, restored retinal structure, and improved retinal function. RNA-seq showed that IC100 treatment corrected the induction of genes associated with angiogenesis, leukocyte migration, and VEGF signaling caused by O2. IC100 also corrected the suppression of genes associated with cell junction assembly, neuron projection, and neuron recognition caused by O2. CONCLUSION These data demonstrate the crucial role of ASC in the pathogenesis of OIR and the efficacy of a humanized therapeutic anti-ASC antibody in treating OIR mice. Thus, this anti-ASC antibody may potentially be considered in diseases associated with oxygen stresses and retinopathy, such as ROP.
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Affiliation(s)
- Huijun Yuan
- Department of Pediatrics/Division of Neonatology, Batchelor Children's Research Institute and Holtz Children's Hospital, University of Miami Miller School of Medicine, P. O. Box 016960, Miami, FL, 33101, USA
| | - Shaoyi Chen
- Department of Pediatrics/Division of Neonatology, Batchelor Children's Research Institute and Holtz Children's Hospital, University of Miami Miller School of Medicine, P. O. Box 016960, Miami, FL, 33101, USA
| | - Matthew R Duncan
- Department of Pediatrics/Division of Neonatology, Batchelor Children's Research Institute and Holtz Children's Hospital, University of Miami Miller School of Medicine, P. O. Box 016960, Miami, FL, 33101, USA
| | - Juan Pablo de Rivero Vaccari
- The Miami Project to Cure Paralysis and Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Robert W Keane
- The Miami Project to Cure Paralysis and Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - W Dalton Dietrich
- The Miami Project to Cure Paralysis and Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Tsung-Han Chou
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Merline Benny
- Department of Pediatrics/Division of Neonatology, Batchelor Children's Research Institute and Holtz Children's Hospital, University of Miami Miller School of Medicine, P. O. Box 016960, Miami, FL, 33101, USA
| | - Augusto F Schmidt
- Department of Pediatrics/Division of Neonatology, Batchelor Children's Research Institute and Holtz Children's Hospital, University of Miami Miller School of Medicine, P. O. Box 016960, Miami, FL, 33101, USA
| | - Karen Young
- Department of Pediatrics/Division of Neonatology, Batchelor Children's Research Institute and Holtz Children's Hospital, University of Miami Miller School of Medicine, P. O. Box 016960, Miami, FL, 33101, USA
| | - Kevin K Park
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Vittorio Porciatti
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | | | - Shu Wu
- Department of Pediatrics/Division of Neonatology, Batchelor Children's Research Institute and Holtz Children's Hospital, University of Miami Miller School of Medicine, P. O. Box 016960, Miami, FL, 33101, USA.
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Neuroprotective effect of the calcium channel blocker nilvadipine on retinal ganglion cell death in a mouse ocular hypertension model. Heliyon 2023; 9:e13812. [PMID: 36879972 PMCID: PMC9984798 DOI: 10.1016/j.heliyon.2023.e13812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 02/05/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023] Open
Abstract
We investigated whether nilvadipine has a neuroprotective effect on retinal ganglion cells (RGCs) in a mouse model of ocular hypertension (OH) that expresses cyan fluorescein protein (CFP) in RGCs. OH was induced in the right eyes of Thy1-CFP transgenic mice using a laser. Nilvadipine or vehicle treatment began simultaneously with OH modeling and was administered intraperitoneally once daily for 8 weeks. Intraocular pressure (IOP) in both the laser- and non-treated eyes was measured weekly with the microneedle method, and calculations were performed to estimate the pressure insult in each eye. Using a retinal whole mount, the number of RGCs was counted at week 9. Laser-treated eyes showed a significant increase in IOP (p < 0.01), and the pressure insult did not differ between the drug-treated groups. Over time, laser treatment produced a significant decrease in the number of RGCs in the vehicle-treated groups, but this effect was attenuated by nilvadipine treatment. The pressure insult and RGC survival rate were significantly negatively correlated in the vehicle-treated group (y = -0.078 x + 107.8, r = 0.76, p < 0.001), but not in the nilvadipine-treated group (y = -0.015 x + 99.9, r = 0.43, p = 0.128). Nilvadipine was a potent neuroprotective agent for RGCs in our mouse model of OH and may have potential for protection against glaucoma. This model is useful as a screening tool for drugs with retinal protective effects.
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Peeters MHCA, Khan M, Rooijakkers AAMB, Mulders T, Haer-Wigman L, Boon CJF, Klaver CCW, van den Born LI, Hoyng CB, Cremers FPM, den Hollander AI, Dhaenens CM, Collin RWJ. PRPH2 mutation update: In silico assessment of 245 reported and 7 novel variants in patients with retinal disease. Hum Mutat 2021; 42:1521-1547. [PMID: 34411390 PMCID: PMC9290825 DOI: 10.1002/humu.24275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/22/2021] [Accepted: 08/16/2021] [Indexed: 01/31/2023]
Abstract
Mutations in PRPH2, encoding peripherin-2, are associated with the development of a wide variety of inherited retinal diseases (IRDs). To determine the causality of the many PRPH2 variants that have been discovered over the last decades, we surveyed all published PRPH2 variants up to July 2020, describing 720 index patients that in total carried 245 unique variants. In addition, we identified seven novel PRPH2 variants in eight additional index patients. The pathogenicity of all variants was determined using the ACMG guidelines. With this, 107 variants were classified as pathogenic, 92 as likely pathogenic, one as benign, and two as likely benign. The remaining 50 variants were classified as variants of uncertain significance. Interestingly, of the total 252 PRPH2 variants, more than half (n = 137) were missense variants. All variants were uploaded into the Leiden Open source Variation and ClinVar databases. Our study underscores the need for experimental assays for variants of unknown significance to improve pathogenicity classification, which would allow us to better understand genotype-phenotype correlations, and in the long-term, hopefully also support the development of therapeutic strategies for patients with PRPH2-associated IRD.
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Affiliation(s)
- Manon H C A Peeters
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Human Genetics and Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Mubeen Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Human Genetics and Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | | | - Timo Mulders
- Department of Human Genetics and Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.,Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lonneke Haer-Wigman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands.,Department of Ophthalmology, Amsterdam UMC, Academic Medical Center, Amsterdam, The Netherlands
| | - Caroline C W Klaver
- Department of Human Genetics and Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.,Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Ophthalmology, Erasmus University Medical Centre, Rotterdam, The Netherlands.,Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| | - L Ingeborgh van den Born
- The Rotterdam Eye Hospital, Rotterdam, The Netherlands.,Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands
| | - Carel B Hoyng
- Department of Human Genetics and Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.,Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Human Genetics and Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Anneke I den Hollander
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Human Genetics and Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.,Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Claire-Marie Dhaenens
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Biochemistry and Molecular Biology, Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, Lille, France
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Human Genetics and Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
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Function of cone and cone-related pathways in Ca V1.4 IT mice. Sci Rep 2021; 11:2732. [PMID: 33526839 PMCID: PMC7851161 DOI: 10.1038/s41598-021-82210-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 01/11/2021] [Indexed: 11/09/2022] Open
Abstract
CaV1.4 L-type calcium channels are predominantly expressed in photoreceptor terminals playing a crucial role for synaptic transmission and, consequently, for vision. Human mutations in the encoding gene are associated with congenital stationary night blindness type-2. Besides rod-driven scotopic vision also cone-driven photopic responses are severely affected in patients. The present study therefore examined functional and morphological changes in cones and cone-related pathways in mice carrying the CaV1.4 gain-of function mutation I756T (CaV1.4-IT) using multielectrode array, patch-clamp and immunohistochemical analyses. CaV1.4-IT ganglion cell responses to photopic stimuli were seen only in a small fraction of cells indicative of a major impairment in the cone pathway. Though cone photoreceptors underwent morphological rearrangements, they retained their ability to release glutamate. Our functional data suggested a postsynaptic cone bipolar cell defect, supported by the fact that the majority of cone bipolar cells showed sprouting, while horizontal cells maintained contacts with cones and cone-to-horizontal cell input was preserved. Furthermore a reduction of basal Ca2+ influx by a calcium channel blocker was not sufficient to rescue synaptic transmission deficits caused by the CaV1.4-IT mutation. Long term treatments with low-dose Ca2+ channel blockers might however be beneficial reducing Ca2+ toxicity without major effects on ganglion cells responses.
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Newton F, Megaw R. Mechanisms of Photoreceptor Death in Retinitis Pigmentosa. Genes (Basel) 2020; 11:genes11101120. [PMID: 32987769 PMCID: PMC7598671 DOI: 10.3390/genes11101120] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/15/2020] [Accepted: 09/22/2020] [Indexed: 02/08/2023] Open
Abstract
Retinitis pigmentosa (RP) is the most common cause of inherited blindness and is characterised by the progressive loss of retinal photoreceptors. However, RP is a highly heterogeneous disease and, while much progress has been made in developing gene replacement and gene editing treatments for RP, it is also necessary to develop treatments that are applicable to all causative mutations. Further understanding of the mechanisms leading to photoreceptor death is essential for the development of these treatments. Recent work has therefore focused on the role of apoptotic and non-apoptotic cell death pathways in RP and the various mechanisms that trigger these pathways in degenerating photoreceptors. In particular, several recent studies have begun to elucidate the role of microglia and innate immune response in the progression of RP. Here, we discuss some of the recent progress in understanding mechanisms of rod and cone photoreceptor death in RP and summarise recent clinical trials targeting these pathways.
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Affiliation(s)
- Fay Newton
- MRC Human Genetics Unit, University of Edinburgh, South Bridge, Edinburgh EH8 9YL, UK;
- Correspondence:
| | - Roly Megaw
- MRC Human Genetics Unit, University of Edinburgh, South Bridge, Edinburgh EH8 9YL, UK;
- Princess Alexandra Eye Pavilion, NHS Lothian, Edinburgh EH3 9HA, UK
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Tolone A, Belhadj S, Rentsch A, Schwede F, Paquet-Durand F. The cGMP Pathway and Inherited Photoreceptor Degeneration: Targets, Compounds, and Biomarkers. Genes (Basel) 2019; 10:genes10060453. [PMID: 31207907 PMCID: PMC6627777 DOI: 10.3390/genes10060453] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/05/2019] [Accepted: 06/11/2019] [Indexed: 12/17/2022] Open
Abstract
Photoreceptor physiology and pathophysiology is intricately linked to guanosine-3’,5’-cyclic monophosphate (cGMP)-signaling. Here, we discuss the importance of cGMP-signaling for the pathogenesis of hereditary retinal degeneration. Excessive accumulation of cGMP in photoreceptors is a common denominator in cell death caused by a variety of different gene mutations. The cGMP-dependent cell death pathway may be targeted for the treatment of inherited photoreceptor degeneration, using specifically designed and formulated inhibitory cGMP analogues. Moreover, cGMP-signaling and its down-stream targets may be exploited for the development of novel biomarkers that could facilitate monitoring of disease progression and reveal the response to treatment in future clinical trials. We then briefly present the importance of appropriate formulations for delivery to the retina, both for drug and biomarker applications. Finally, the review touches on important aspects of future clinical translation, highlighting the need for interdisciplinary cooperation of researchers from a diverse range of fields.
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Affiliation(s)
- Arianna Tolone
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 5-7, 72076 Tübingen, Germany.
| | - Soumaya Belhadj
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 5-7, 72076 Tübingen, Germany.
| | | | - Frank Schwede
- Biolog Life Science Institute, 28199 Bremen, Germany.
| | - François Paquet-Durand
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 5-7, 72076 Tübingen, Germany.
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Getter T, Suh S, Hoang T, Handa JT, Dong Z, Ma X, Chen Y, Blackshaw S, Palczewski K. The selective estrogen receptor modulator raloxifene mitigates the effect of all- trans-retinal toxicity in photoreceptor degeneration. J Biol Chem 2019; 294:9461-9475. [PMID: 31073029 DOI: 10.1074/jbc.ra119.008697] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/08/2019] [Indexed: 12/19/2022] Open
Abstract
The retinoid cycle is a metabolic process in the vertebrate retina that continuously regenerates 11-cis-retinal (11-cisRAL) from the all-trans-retinal (atRAL) isomer. atRAL accumulation can cause photoreceptor degeneration and irreversible visual dysfunction associated with incurable blinding retinal diseases, such as Stargardt disease, retinitis pigmentosa (RP), and atrophic age-related macular degeneration (AMD). The underlying cellular mechanisms leading to retinal degeneration remain uncertain, although previous studies have shown that atRAL promotes calcium influx associated with cell apoptosis. To identify compounds that mitigate the effects of atRAL toxicity, here we developed an unbiased and robust image-based assay that can detect changes in intracellular calcium levels in U2OS cells. Using our assay in a high-throughput screen of 2,400 compounds, we noted that selective estrogen receptor modulators (SERMs) potently stabilize intracellular calcium and thereby counteract atRAL-induced toxicity. In a light-induced retinal degeneration mouse model (Abca4 -/- Rdh8 -/-), raloxifene (a benzothiophene-type scaffold SERM) prevented the onset of photoreceptor apoptosis and thus protected the retina from degeneration. The minor structural differences between raloxifene and one of its derivatives (Y 134) had a major impact on calcium homeostasis after atRAL exposure in vitro, and we verified this differential impact in vivo In summary, the SERM raloxifene has structural and functional neuroprotective effects in the retina. We propose that the highly sensitive image-based assay developed here could be applied for the discovery of additional drug candidates preventing photoreceptor degeneration.
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Affiliation(s)
- Tamar Getter
- From the Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697, .,the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Susie Suh
- From the Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697.,the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Thanh Hoang
- the Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - James T Handa
- the Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | | | - Xiuli Ma
- Polgenix Inc., Irvine, California 92617
| | - Yuanyuan Chen
- the Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, and.,the McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Seth Blackshaw
- the Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Krzysztof Palczewski
- From the Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697, .,the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
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Conley SM, Naash MI. Gene therapy for PRPH2-associated ocular disease: challenges and prospects. Cold Spring Harb Perspect Med 2014; 4:a017376. [PMID: 25167981 DOI: 10.1101/cshperspect.a017376] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The peripherin-2 (PRPH2) gene encodes a photoreceptor-specific tetraspanin protein called peripherin-2/retinal degeneration slow (RDS), which is critical for the formation and maintenance of rod and cone outer segments. Over 90 different disease-causing mutations in PRPH2 have been identified, which cause a variety of forms of retinitis pigmentosa and macular degeneration. Given the disease burden associated with PRPH2 mutations, the gene has long been a focus for preclinical gene therapy studies. Adeno-associated viruses and compacted DNA nanoparticles carrying PRPH2 have been successfully used to mediate improvement in the rds(-/-) and rds(+/-) mouse models. However, complexities in the pathogenic mechanism for PRPH2-associated macular disease coupled with the need for a precise dose of peripherin-2 to combat a severe haploinsufficiency phenotype have delayed the development of clinically viable genetic treatments. Here we discuss the progress and prospects for PRPH2-associated gene therapy.
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Affiliation(s)
- Shannon M Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Muna I Naash
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
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Wang D, Wang Z, Li Y, Chen X, Sun GY. Nimodipine inhibits N-methyl-N-nitrosourea-induced retinal photoreceptor apoptosis in vivo. Indian J Pharmacol 2014; 45:149-54. [PMID: 23716891 PMCID: PMC3660927 DOI: 10.4103/0253-7613.108297] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 09/09/2012] [Accepted: 01/12/2012] [Indexed: 11/17/2022] Open
Abstract
Purpose: The purpose of the present study was to investigate the effect of nimodipine (NMD), a calcium channel blocker, on N-methyl-N-nitrosourea (MNU)-induced retinal degeneration. Materials and Methods: 60 mg/kg MNU was given intraperitoneally to 6-week-old female Sprague-Dawley rats, and NMD was injected intraperitoneally for up to 5 days after MNU. The effect of NMD was evaluated by electron microscopy and electroretinography (ERG). Proteins of Bax, Bcl-2, Caspase-3, and mitochondrial membrane potential (MMP) were analyzed with flow cytometry. The expressions of phosphodiesterase (PDE) and Caspase-3 were detected by reverse transcriptase polymerase chain reaction (RT-PCR). Results: The apparent preservation of NMD to the photoreceptor cell was demonstrated by electron microscopy. After NMD treatment, both a- and b-waves of ERG were significantly higher compared with the control group, and had a protective effect on MNU-damaged retinal ERG. Flow cytometric assays showed that NMD decreased the level of Bax and Caspase-3 and increased the activity of Bcl-2 in retina. NMD significantly restored the mitochondrial membrane potential (MMP). RT-PCR analysis demonstrated that NMD treatment significantly decreased mRNA level of Caspase-3, and mRNA level of PDE was clearly upregulated. Conclusions: These data suggest that NMD may regulate the expressions of Bax, Bcl-2, Caspases-3, and PDE, and protection on the functions of retinal cell mitochondria inhibit MNU-induced photoreceptor cell apoptosis and protect retinal function in rats.
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Affiliation(s)
- Dan Wang
- Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang- 110 001, People's Republic of China
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Trophic factors in the pathogenesis and therapy for retinal degenerative diseases. Surv Ophthalmol 2014; 59:134-65. [PMID: 24417953 DOI: 10.1016/j.survophthal.2013.09.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 09/11/2013] [Accepted: 09/17/2013] [Indexed: 12/27/2022]
Abstract
Trophic factors are endogenously secreted proteins that act in an autocrine and/or paracrine fashion to affect vital cellular processes such as proliferation, differentiation, and regeneration, thereby maintaining overall cell homeostasis. In the eye, the major contributors of these molecules are the retinal pigment epithelial (RPE) and Müller cells. The primary paracrine targets of these secreted proteins include the photoreceptors and choriocapillaris. Retinal degenerative diseases such as age-related macular degeneration and retinitis pigmentosa are characterized by aberrant function and/or eventual death of RPE cells, photoreceptors, choriocapillaris, and other retinal cells. We discuss results of in vitro and in vivo animal studies in which candidate trophic factors, either singly or in combination, were used in an attempt to ameliorate photoreceptor and/or retinal degeneration. We also examine current trophic factor therapies as they relate to the treatment of retinal degenerative diseases in clinical studies.
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Long-term effects of nilvadipine against progression of the central visual field defect in retinitis pigmentosa: an extended study. BIOMED RESEARCH INTERNATIONAL 2013; 2013:585729. [PMID: 24319686 PMCID: PMC3844269 DOI: 10.1155/2013/585729] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 09/24/2013] [Accepted: 09/27/2013] [Indexed: 12/03/2022]
Abstract
Purpose. To assess the long-term effects of nilvadipine on the progression of central visual field defect in retinitis pigmentosa (RP). Methods. Patients with RP were randomly divided into a treated group receiving oral nilvadipine and a control group. Progression of RP was evaluated with MD slope and the average sensitivity of the central 2° (ΔCENT4). Results. The mean MD slopes were −0.55/−0.39 (right/left eyes, n = 19) dB/year in the treated group and −1.37/−1.15 (right/left eyes, n = 22) dB/year in the control group (P = 0.016/0.050, resp.). In both eyes, however, no statistical difference was observed between the two groups for the ΔCENT4 values. Conclusion. Although we confirmed that nilvadipine significantly retarded the progression of the average of MD value defects in the central 10°, it was not specific for the central 2° of the visual field in RP.
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Cho KI, Haque M, Wang J, Yu M, Hao Y, Qiu S, Pillai ICL, Peachey NS, Ferreira PA. Distinct and atypical intrinsic and extrinsic cell death pathways between photoreceptor cell types upon specific ablation of Ranbp2 in cone photoreceptors. PLoS Genet 2013; 9:e1003555. [PMID: 23818861 PMCID: PMC3688534 DOI: 10.1371/journal.pgen.1003555] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 04/23/2013] [Indexed: 12/26/2022] Open
Abstract
Non-autonomous cell-death is a cardinal feature of the disintegration of neural networks in neurodegenerative diseases, but the molecular bases of this process are poorly understood. The neural retina comprises a mosaic of rod and cone photoreceptors. Cone and rod photoreceptors degenerate upon rod-specific expression of heterogeneous mutations in functionally distinct genes, whereas cone-specific mutations are thought to cause only cone demise. Here we show that conditional ablation in cone photoreceptors of Ran-binding protein-2 (Ranbp2), a cell context-dependent pleiotropic protein linked to neuroprotection, familial necrotic encephalopathies, acute transverse myelitis and tumor-suppression, promotes early electrophysiological deficits, subcellular erosive destruction and non-apoptotic death of cones, whereas rod photoreceptors undergo cone-dependent non-autonomous apoptosis. Cone-specific Ranbp2 ablation causes the temporal activation of a cone-intrinsic molecular cascade highlighted by the early activation of metalloproteinase 11/stromelysin-3 and up-regulation of Crx and CoREST, followed by the down-modulation of cone-specific phototransduction genes, transient up-regulation of regulatory/survival genes and activation of caspase-7 without apoptosis. Conversely, PARP1+-apoptotic rods develop upon sequential activation of caspase-9 and caspase-3 and loss of membrane permeability. Rod photoreceptor demise ceases upon cone degeneration. These findings reveal novel roles of Ranbp2 in the modulation of intrinsic and extrinsic cell death mechanisms and pathways. They also unveil a novel spatiotemporal paradigm of progression of neurodegeneration upon cell-specific genetic damage whereby a cone to rod non-autonomous death pathway with intrinsically distinct cell-type death manifestations is triggered by cell-specific loss of Ranbp2. Finally, this study casts new light onto cell-death mechanisms that may be shared by human dystrophies with distinct retinal spatial signatures as well as with other etiologically distinct neurodegenerative disorders. The secondary demise of healthy neurons upon the degeneration of neurons harboring primary genetic defect(s) is hallmark to neurodegenerative diseases. However, the factors and mechanisms driving these cell-death processes are not understood, a severe limitation which has hampered the therapeutic development of neuroprotective approaches. The neuroretina is comprised of two main types of photoreceptor neurons, rods and cones. These undergo degeneration upon heterogeneous mutations or environmental stressors and the underlying diseases present conspicuous spatiotemporal pathological signatures whose molecular bases are not understood. We employed the multifunctional protein, Ran-binding protein-2 (Ranbp2), which is implicated in cell-type and stress-dependent clinical manifestations, to examine its role(s) in primary and secondary photoreceptor death mechanisms upon its specific loss in cones. Contrary to prior findings, we found that dying cones can trigger the loss of healthy rods. This process arises by the immediate activation of novel Ranbp2-responsive factors and downstream cascade events in cones that promote extrinsically the demise of rods. The mechanisms of rod and cone demise are molecularly distinct. Collectively, the data uncover distinct Ranbp2 roles in intrinsic and extrinsic cell-death and will likely contribute to our understanding of the spatiotemporal onset and progression of diseases affecting photoreceptor mosaics and other neural networks.
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Affiliation(s)
- Kyoung-in Cho
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - MdEmdadul Haque
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Jessica Wang
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Minzhong Yu
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America
| | - Ying Hao
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Sunny Qiu
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Indulekha C. L. Pillai
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Neal S. Peachey
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America
- Research Service, Cleveland Veterans Affairs Medical Center, Cleveland, Ohio, United States of America
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Paulo A. Ferreira
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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Wang D, Li Y, Wang Z, Sun GY, Zhang QH. Nimodipine rescues N-methyl-N-nitrosourea-induced retinal degeneration in rats. Pharmacogn Mag 2013; 9:149-54. [PMID: 23772111 PMCID: PMC3680855 DOI: 10.4103/0973-1296.111276] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 02/29/2012] [Accepted: 04/30/2013] [Indexed: 11/09/2022] Open
Abstract
Background: That nimodipine (NMD) is potentially useful for ophthalmic treatment. However, the effect of NMD is unknown on retinal degenerative diseases. Objective: The purpose of the present study was to investigate the effect of NMD on N-methyl-N-nitrosourea (MNU)-induced retinal degeneration (RD) and elucidate its possible mechanisms. Materials and Methods: Morphological observation of NMD on MNU-induced RD was evaluated by light microscopy and electron microscopy. Nonenzymatic antioxidant glutathione (GSH) was measured by a colorimetric method. Transforming growth factor-beta (TGF-β) was measured by enzyme-linked immunosorbent assay (ELISA). Telomerase was detected by reverse transcriptase polymerase chain reaction (RT-PCR). Results: The significantly protective effect of NMD on MNU-induced RD was demonstrated morphologically. NMD increased the content of GSH and decreased the level of TGF-β in rat retina. RT-PCR analysis demonstrated that NMD treatment significantly decreased mRNA level of telomerase. Conclusion: These data suggest that NMD inhibit MNU-induced RD in rats. The expressions of TGF-β, telomerase and GSH contents might partially contribute to its protective effects on MNU-induced RD.
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Affiliation(s)
- Dan Wang
- Department of Histology and Embryology, College of Basic Medical Science, China Medical University, P. R. China ; Department of Pharmacology, HE's University, P. R. China
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15
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Long-term in vivo impedance changes of subretinal microelectrodes implanted in dystrophic P23H rats. Int J Artif Organs 2013; 36:612-9. [PMID: 23918262 DOI: 10.5301/ijao.5000213] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2013] [Indexed: 11/20/2022]
Abstract
Retinal prostheses are being developed to restore vision in blind patients with photoreceptor degeneration. Electrodes arrays were subretinally implanted in transgenic P23H rats with their photoreceptors degenerated. Electrical stability of the implants was evaluated by long-term monitoring of their impedance changes. Electrode impedances were found to increase by two log units over a three weeks period whereas no impedance increase was noted when the implants were located in the vitreous. In case of hemorrhage or major fibrous reactions, the impedance continued to increase steadily. After explantation, it recovered its initial value indicating no deterioration of the implant. Although the glial cell layer at the surface of the subretinal space was slightly larger, no major glial reaction was seen in direct contact to the implant. These results indicate that no functional testing should be considered before at least three weeks post implantation.
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16
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Falsini B, Bush RA, Sieving PA. Neuroprotection. Retina 2013. [DOI: 10.1016/b978-1-4557-0737-9.00037-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Intravitreal injection or topical eye-drop application of a μ-calpain C2L domain peptide protects against photoreceptor cell death in Royal College of Surgeons' rats, a model of retinitis pigmentosa. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1783-95. [DOI: 10.1016/j.bbadis.2012.07.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 07/25/2012] [Accepted: 07/30/2012] [Indexed: 11/20/2022]
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18
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Djilas M, Olès C, Lorach H, Bendali A, Dégardin J, Dubus E, Lissorgues-Bazin G, Rousseau L, Benosman R, Ieng SH, Joucla S, Yvert B, Bergonzo P, Sahel J, Picaud S. Three-dimensional electrode arrays for retinal prostheses: modeling, geometry optimization and experimental validation. J Neural Eng 2011; 8:046020. [DOI: 10.1088/1741-2560/8/4/046020] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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19
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Sakamoto K, Mori A, Nakahara T, Ishii K. [Cause of retinitis pigmentosa and new therapeutics under development]. Nihon Yakurigaku Zasshi 2011; 137:22-26. [PMID: 21233585 DOI: 10.1254/fpj.137.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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20
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Effects of calcium ion, calpains, and calcium channel blockers on retinitis pigmentosa. J Ophthalmol 2010; 2011:292040. [PMID: 21253505 PMCID: PMC3021879 DOI: 10.1155/2011/292040] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Revised: 09/13/2010] [Accepted: 11/15/2010] [Indexed: 11/19/2022] Open
Abstract
Recent advances in molecular genetic studies have revealed many of the causative genes of retinitis pigmentosa (RP). These achievements have provided clues to the mechanisms of photoreceptor degeneration in RP. Apoptosis is known to be a final common pathway in RP and, therefore, a possible therapeutic target for photoreceptor rescue. However, apoptosis is not a single molecular cascade, but consists of many different reactions such as caspase-dependent and caspase-independent pathways commonly leading to DNA fractionation and cell death. The intracellular concentration of calcium ions is also known to increase in apoptosis. These findings suggest that calpains, one of the calcium-dependent proteinases, play some roles in the process of photoreceptor apoptosis and that calcium channel antagonists may potentially inhibit photoreceptor apoptosis. Herein, the effects of calpains and calcium channel antagonists on photoreceptor degeneration are reviewed.
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Mizukoshi S, Nakazawa M, Sato K, Ozaki T, Metoki T, Ishiguro SI. Activation of mitochondrial calpain and release of apoptosis-inducing factor from mitochondria in RCS rat retinal degeneration. Exp Eye Res 2010; 91:353-61. [DOI: 10.1016/j.exer.2010.06.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Revised: 06/05/2010] [Accepted: 06/07/2010] [Indexed: 02/05/2023]
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22
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Samuels IS, Sturgill GM, Grossman GH, Rayborn ME, Hollyfield JG, Peachey NS. Light-evoked responses of the retinal pigment epithelium: changes accompanying photoreceptor loss in the mouse. J Neurophysiol 2010; 104:391-402. [PMID: 20484527 DOI: 10.1152/jn.00088.2010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Mutations in genes expressed in the retinal pigment epithelium (RPE) underlie a number of human inherited retinal disorders that manifest with photoreceptor degeneration. Because light-evoked responses of the RPE are generated secondary to rod photoreceptor activity, RPE response reductions observed in human patients or animal models may simply reflect decreased photoreceptor input. The purpose of this study was to define how the electrophysiological characteristics of the RPE change when the complement of rod photoreceptors is decreased. To measure RPE function, we used an electroretinogram (dc-ERG)-based technique. We studied a slowly progressive mouse model of photoreceptor degeneration (Prph(Rd2/+)), which was crossed onto a Nyx(nob) background to eliminate the b-wave and most other postreceptoral ERG components. On this background, Prph(Rd2/+) mice display characteristic reductions in a-wave amplitude, which parallel those in slow PIII amplitude and the loss of rod photoreceptors. At 2 and 4 mo of age, the amplitude of each dc-ERG component (c-wave, fast oscillation, light peak, and off response) was larger in Prph(Rd2/+) mice than predicted by rod photoreceptor activity (Rm(P3)) or anatomical analysis. At 4 mo of age, the RPE in Prph(Rd2/+) mice showed several structural abnormalities including vacuoles and swollen, hypertrophic cells. These data demonstrate that insights into RPE function can be gained despite a loss of photoreceptors and structural changes in RPE cells and, moreover, that RPE function can be evaluated in a broader range of mouse models of human retinal disease.
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Affiliation(s)
- Ivy S Samuels
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio 44106, USA.
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23
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Do calcium channel blockers rescue dying photoreceptors in the Pde6b ( rd1 ) mouse? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 664:491-9. [PMID: 20238051 DOI: 10.1007/978-1-4419-1399-9_56] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Retinitis pigmentosa (RP) is a genetically heterogeneous set of blinding diseases that affects more than a million people worldwide. In humans, ~5-8% of recessive and dominant RP cases are caused by nonsense mutations in the Pde6b gene coding for the ss-subunit of the rod photoreceptor cGMP phosphodiesterase 6 (PDE6-ss). The study of the disease has been greatly aided by the Pde6b ( rd1 ) (rd1) mouse model of RP carrying a null PDE6ss allele. Degenerating rd1 rods were found to experience a pathological increase in intracellular calcium concentration ('Ca overload') when they enter the apoptotic process at postnatal day 10. A 1999 study suggested that the Ca(2+) channel antagonist D-cis diltiazem delays the kinetics of rd1 rod degeneration, conferring partial rescue of scotopic vision. Subsequent reports were mixed: whereas several studies failed to replicate the original results, others appeared to confirm the neuroprotective effects of Ca(2+) channel antagonists such as diltiazem, nilvadipine and verapamil. We discuss the discrepancies between the results of different groups and suggest plausible causes for the discordant results. We also discuss potential involvement of recently identified Ca(2+)-dependent mechanisms that include protective calcium ATPase mechanisms, ryanodine and IP3 calcium stores, and store operated channels in Pde6b ( rd1 ) neurodegeneration.
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Paquet-Durand F, Hauck SM, van Veen T, Ueffing M, Ekström P. PKG activity causes photoreceptor cell death in two retinitis pigmentosa models. J Neurochem 2009; 108:796-810. [PMID: 19187097 DOI: 10.1111/j.1471-4159.2008.05822.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Photoreceptor degeneration in retinitis pigmentosa is one of the leading causes of hereditary blindness in the developed world. Although causative genetic mutations have been elucidated in many cases, the underlying neuronal degeneration mechanisms are still unknown. Here, we show that activation of cGMP-dependent protein kinase (PKG) hallmarks photoreceptor degeneration in rd1 and rd2 human homologous mouse models. When induced in wild-type retinae, PKG activity was both necessary and sufficient to trigger cGMP-mediated photoreceptor cell death. Target-specific, pharmacological inhibition of PKG activity in both rd1 and rd2 retinae strongly reduced photoreceptor cell death in organotypic retinal explants. Likewise, inhibition of PKG in vivo, using three different application paradigms, resulted in robust photoreceptor protection in the rd1 retina. These findings suggest a pivotal role for PKG activity in cGMP-mediated photoreceptor degeneration mechanisms and highlight the importance of PKG as a novel target for the pharmacological intervention in RP.
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Affiliation(s)
- François Paquet-Durand
- University of Tübingen, Centre for Ophthalmology, Institute for Ophthalmic Research, Division of Experimental Ophthalmology, Röntgenweg 11, Tübingen, Germany.
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25
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Sancho-Pelluz J, Arango-Gonzalez B, Kustermann S, Romero FJ, van Veen T, Zrenner E, Ekström P, Paquet-Durand F. Photoreceptor cell death mechanisms in inherited retinal degeneration. Mol Neurobiol 2008; 38:253-69. [PMID: 18982459 DOI: 10.1007/s12035-008-8045-9] [Citation(s) in RCA: 212] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Accepted: 10/16/2008] [Indexed: 02/24/2023]
Abstract
Photoreceptor cell death is the major hallmark of a group of human inherited retinal degenerations commonly referred to as retinitis pigmentosa (RP). Although the causative genetic mutations are often known, the mechanisms leading to photoreceptor degeneration remain poorly defined. Previous research work has focused on apoptosis, but recent evidence suggests that photoreceptor cell death may result primarily from non-apoptotic mechanisms independently of AP1 or p53 transcription factor activity, Bcl proteins, caspases, or cytochrome c release. This review briefly describes some animal models used for studies of retinal degeneration, with particular focus on the rd1 mouse. After outlining the major features of different cell death mechanisms in general, we then compare them with results obtained in retinal degeneration models, where photoreceptor cell death appears to be governed by, among other things, changes in cyclic nucleotide metabolism, downregulation of the transcription factor CREB, and excessive activation of calpain and PARP. Based on recent experimental evidence, we propose a putative non-apoptotic molecular pathway for photoreceptor cell death in the rd1 retina. The notion that inherited photoreceptor cell death is driven by non-apoptotic mechanisms may provide new ideas for future treatment of RP.
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Affiliation(s)
- Javier Sancho-Pelluz
- Institute for Ophthalmic Research, University of Tübingen, Centre for Ophthalmology, Röntgenweg 11, 72076, Tübingen, Germany
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