1
|
Wifvat K, Camacho ET, Kawski M, Léveillard T, Wirkus S. Optimal Control with RdCVFL for Degenerating Photoreceptors. Bull Math Biol 2024; 86:29. [PMID: 38345678 PMCID: PMC10861398 DOI: 10.1007/s11538-024-01256-6] [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: 01/03/2023] [Accepted: 01/03/2024] [Indexed: 02/15/2024]
Abstract
Both the rod and cone photoreceptors, along with the retinal pigment epithelium have been experimentally and mathematically shown to work interdependently to maintain vision. Further, the theoredoxin-like rod-derived cone viability factor (RdCVF) and its long form (RdCVFL) have proven to increase photoreceptor survival in experimental results. Aerobic glycolysis is the primary source of energy production for photoreceptors and RdCVF accelerates the intake of glucose into the cones. RdCVFL helps mitigate the negative effects of reactive oxidative species and has shown promise in slowing the death of cones in mouse studies. However, this potential treatment and its effects have never been studied in mathematical models. In this work, we examine an optimal control with the treatment of RdCVFL. We mathematically illustrate the potential this treatment might have for treating degenerative retinal diseases such as retinitis pigmentosa, as well as compare this to the results of an updated control model with RdCVF.
Collapse
Affiliation(s)
- Kathryn Wifvat
- School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Erika T Camacho
- School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, 85287, USA
- Department of Mathematics, The University of Texas at San Antonio, San Antonio, TX, 78249, USA
- INSERM, U968, 75012, Paris, France
- UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Sorbonne Universités, 75012, Paris, France
- CNRS, UMR_7210, 75012, Paris, France
| | - Matthias Kawski
- School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Thierry Léveillard
- INSERM, U968, 75012, Paris, France
- UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Sorbonne Universités, 75012, Paris, France
- CNRS, UMR_7210, 75012, Paris, France
| | - Stephen Wirkus
- Department of Mathematics, The University of Texas at San Antonio, San Antonio, TX, 78249, USA.
- School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ, 85306, USA.
| |
Collapse
|
2
|
Metabolic and Redox Signaling of the Nucleoredoxin-Like-1 Gene for the Treatment of Genetic Retinal Diseases. Int J Mol Sci 2020; 21:ijms21051625. [PMID: 32120883 PMCID: PMC7084304 DOI: 10.3390/ijms21051625] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/24/2020] [Accepted: 02/26/2020] [Indexed: 02/06/2023] Open
Abstract
The loss of cone photoreceptor function in retinitis pigmentosa (RP) severely impacts the central and daily vision and quality of life of patients affected by this disease. The loss of cones follows the degeneration of rods, in a manner independent of the causing mutations in numerous genes associated with RP. We have explored this phenomenon and proposed that the loss of rods triggers a reduction in the expression of rod-derived cone viability factor (RdCVF) encoded by the nucleoredoxin-like 1 (NXNL1) gene which interrupts the metabolic and redox signaling between rods and cones. After providing scientific evidence supporting this mechanism, we propose a way to restore this lost signaling and prevent the cone vision loss in animal models of RP. We also explain how we could restore this signaling to prevent cone vision loss in animal models of the disease and how we plan to apply this therapeutic strategy by the administration of both products of NXNL1 encoding the trophic factor RdCVF and the thioredoxin enzyme RdCVFL using an adeno-associated viral vector. We describe in detail all the steps of this translational program, from the design of the drug, its production, biological validation, and analytical and preclinical qualification required for a future clinical trial that would, if successful, provide a treatment for this incurable disease.
Collapse
|
3
|
Narayan DS, Ao J, Wood JPM, Casson RJ, Chidlow G. Spatio-temporal characterization of S- and M/L-cone degeneration in the Rd1 mouse model of retinitis pigmentosa. BMC Neurosci 2019; 20:46. [PMID: 31481030 PMCID: PMC6720080 DOI: 10.1186/s12868-019-0528-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 08/24/2019] [Indexed: 03/30/2023] Open
Abstract
Background The Pde6brd1 (Rd1) mouse is widely used as a murine model for human retinitis pigmentosa. Understanding the spatio-temporal patterns of cone degeneration is important for evaluating potential treatments. In the present study we performed a systematic characterization of the spatio-temporal patterns of S- and M/L-opsin+ cone outer segment and cell body degeneration in Rd1 mice, described the distribution and proportion of dual cones in Rd1 retinas, and examined the kinetics of microglial activation during the period of cone degeneration. Results Outer segments of S- and M/L-cones degenerated far more rapidly than their somas. Loss of both S- and M/L-opsin+ outer segments was fundamentally complete by P21 in the central retina, and 90% complete by P45 in the peripheral retina. In comparison, degeneration of S- and M/L-opsin+ cell bodies proceeded at a slower rate. There was a marked hemispheric asymmetry in the rate of S-opsin+ and M/L-opsin+ cell body degeneration. M/L-opsin+ cones were more resilient to degeneration in the superior retina, whilst S-opsin+ cones were relatively preserved in the inferior retina. In addition, cone outer segment and cell body degeneration occurred far more rapidly in the central than the peripheral retina. At P14, the superior retina comprised a minority of genuine S-cones with a much greater complement of genuine M/L-opsin cones and dual cones, whilst the other three retinal quadrants had broadly similar numbers of genuine S-cones, genuine M/L-cones and dual cones. At P60, approximately 50% of surviving cones in the superior, nasal and temporal quadrants were dual cones. In contrast, the inferior peripheral retina at P60 contained almost exclusively genuine S-cones with a tiny minority of dual cones. Microglial number and activity were stimulated during rod breakdown, remained relatively high during cone outer segment degeneration and loss of cone somas in the central retina, and decreased thereafter in the period coincident with slow degeneration of cone cell bodies in the peripheral retina. Conclusion The results of the present study provide valuable insights into cone degeneration in the Rd1 mouse, substantiating and extending conclusions drawn from earlier studies.
Collapse
Affiliation(s)
- Daniel S Narayan
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Level 7 Adelaide Health and Medical Sciences Building, North Terrace, Adelaide, SA, 5000, Australia
| | - Jack Ao
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Level 7 Adelaide Health and Medical Sciences Building, North Terrace, Adelaide, SA, 5000, Australia
| | - John P M Wood
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Level 7 Adelaide Health and Medical Sciences Building, North Terrace, Adelaide, SA, 5000, Australia
| | - Robert J Casson
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Level 7 Adelaide Health and Medical Sciences Building, North Terrace, Adelaide, SA, 5000, Australia
| | - Glyn Chidlow
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Level 7 Adelaide Health and Medical Sciences Building, North Terrace, Adelaide, SA, 5000, Australia.
| |
Collapse
|
4
|
A Mathematical Analysis of Aerobic Glycolysis Triggered by Glucose Uptake in Cones. Sci Rep 2019; 9:4162. [PMID: 30858444 PMCID: PMC6411757 DOI: 10.1038/s41598-019-39901-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 01/31/2019] [Indexed: 11/08/2022] Open
Abstract
Patients affected by retinitis pigmentosa, an inherited retinal disease, experience a decline in vision due to photoreceptor degeneration leading to irreversible blindness. Rod-derived cone viability factor (RdCVF) is the most promising mutation-independent treatment today. To identify pathologic processes leading to secondary cone photoreceptor dysfunction triggering central vision loss of these patients, we model the stimulation by RdCVF of glucose uptake in cones and glucose metabolism by aerobic glycolysis. We develop a nonlinear system of enzymatic functions and differential equations to mathematically model molecular and cellular interactions in a cone. We use uncertainty and sensitivity analysis to identify processes that have the largest effect on the system and their timeframes. We consider the case of a healthy cone, a cone with low levels of glucose, and a cone with low and no RdCVF. The three key processes identified are metabolism of fructose-1,6-bisphosphate, production of glycerol-3-phosphate and competition that rods exert on cone resources. The first two processes are proportional to the partition of the carbon flux between glycolysis and the pentose phosphate pathway or the Kennedy pathway, respectively. The last process is the rods' competition for glucose, which may explain why rods also provide the RdCVF signal to compensate.
Collapse
|
5
|
Metabolic and redox signaling in the retina. Cell Mol Life Sci 2016; 74:3649-3665. [PMID: 27543457 PMCID: PMC5597695 DOI: 10.1007/s00018-016-2318-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 07/21/2016] [Accepted: 07/22/2016] [Indexed: 01/04/2023]
Abstract
Visual perception by photoreceptors relies on the interaction of incident photons from light with a derivative of vitamin A that is covalently linked to an opsin molecule located in a special subcellular structure, the photoreceptor outer segment. The photochemical reaction produced by the photon is optimal when the opsin molecule, a seven-transmembrane protein, is embedded in a lipid bilayer of optimal fluidity. This is achieved in vertebrate photoreceptors by a high proportion of lipids made with polyunsaturated fatty acids, which have the detrimental property of being oxidized and damaged by light. Photoreceptors cannot divide, but regenerate their outer segments. This is an enormous energetic challenge that explains why photoreceptors metabolize glucose through aerobic glycolysis, as cancer cells do. Uptaken glucose produces metabolites to renew that outer segment as well as reducing power through the pentose phosphate pathway to protect photoreceptors against oxidative damage.
Collapse
|
6
|
Mei X, Chaffiol A, Kole C, Yang Y, Millet-Puel G, Clérin E, Aït-Ali N, Bennett J, Dalkara D, Sahel JA, Duebel J, Léveillard T. The Thioredoxin Encoded by the Rod-Derived Cone Viability Factor Gene Protects Cone Photoreceptors Against Oxidative Stress. Antioxid Redox Signal 2016; 24:909-23. [PMID: 27025156 DOI: 10.1089/ars.2015.6509] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
AIMS Rod-derived cone viability factor long (RdCVFL) is an enzymatically active thioredoxin encoded by the nucleoredoxin-like-1 (Nxnl1) gene. The second product of the gene, RdCVF, made by alternative splicing is a novel trophic factor secreted by rods that protects cones in rodent models of retinitis pigmentosa, the most prevalent inherited retinal disease. It acts on cones by stimulating aerobic glycolysis through its interaction with a complex containing basigin-1 and the glucose transporter GLUT1. We studied the role of Nxnl1 in cones after its homologous recombination using a transgenic line expressing Cre recombinase under the control of a cone opsin promoter. RESULTS We show that the cones of these mice are dysfunctional and degenerate by 8 months of age. The age-related deficit in cones is exacerbated in young animals by exposure to high level of oxygen. In agreement with this phenotype, we found that the cones express only one of the two Nxnl1 gene products, the thioredoxin RdCVFL. Administration of RdCVFL to the mouse carrying a deletion of the Nxnl1 gene in cones reduces the damage produced by oxidative stress. Silencing the expression of RdCVFL in cone-enriched culture reduces cell viability, showing that RdCVFL is a cell-autonomous mechanism of protection. INNOVATION This novel mode of action is certainly relevant for the therapy of retinitis pigmentosa since the delivery into cones of the rd10 mouse, a recessive model of the disease, rescues cones. CONCLUSION Our work highlights the duality of the Nxnl1 gene, which protects the cones by two distinct mechanisms. Antioxid. Redox Signal. 24, 909-923.
Collapse
Affiliation(s)
- Xin Mei
- 1 INSERM , U968, Paris, France .,2 Department of Genetics, UMR_S 968, Institut de la Vision, Sorbonne Universités , Paris, France .,3 CNRS , UMR_7210, Paris, France
| | - Antoine Chaffiol
- 1 INSERM , U968, Paris, France .,2 Department of Genetics, UMR_S 968, Institut de la Vision, Sorbonne Universités , Paris, France .,3 CNRS , UMR_7210, Paris, France
| | - Christo Kole
- 1 INSERM , U968, Paris, France .,2 Department of Genetics, UMR_S 968, Institut de la Vision, Sorbonne Universités , Paris, France .,3 CNRS , UMR_7210, Paris, France
| | - Ying Yang
- 1 INSERM , U968, Paris, France .,2 Department of Genetics, UMR_S 968, Institut de la Vision, Sorbonne Universités , Paris, France .,3 CNRS , UMR_7210, Paris, France
| | - Géraldine Millet-Puel
- 1 INSERM , U968, Paris, France .,2 Department of Genetics, UMR_S 968, Institut de la Vision, Sorbonne Universités , Paris, France .,3 CNRS , UMR_7210, Paris, France
| | - Emmanuelle Clérin
- 1 INSERM , U968, Paris, France .,2 Department of Genetics, UMR_S 968, Institut de la Vision, Sorbonne Universités , Paris, France .,3 CNRS , UMR_7210, Paris, France
| | - Najate Aït-Ali
- 1 INSERM , U968, Paris, France .,2 Department of Genetics, UMR_S 968, Institut de la Vision, Sorbonne Universités , Paris, France .,3 CNRS , UMR_7210, Paris, France
| | - Jean Bennett
- 4 Scheie Eye Institute, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Deniz Dalkara
- 1 INSERM , U968, Paris, France .,2 Department of Genetics, UMR_S 968, Institut de la Vision, Sorbonne Universités , Paris, France .,3 CNRS , UMR_7210, Paris, France
| | - José-Alain Sahel
- 1 INSERM , U968, Paris, France .,2 Department of Genetics, UMR_S 968, Institut de la Vision, Sorbonne Universités , Paris, France .,3 CNRS , UMR_7210, Paris, France
| | - Jens Duebel
- 1 INSERM , U968, Paris, France .,2 Department of Genetics, UMR_S 968, Institut de la Vision, Sorbonne Universités , Paris, France .,3 CNRS , UMR_7210, Paris, France
| | - Thierry Léveillard
- 1 INSERM , U968, Paris, France .,2 Department of Genetics, UMR_S 968, Institut de la Vision, Sorbonne Universités , Paris, France .,3 CNRS , UMR_7210, Paris, France
| |
Collapse
|
7
|
Aït-Ali N, Fridlich R, Millet-Puel G, Clérin E, Delalande F, Jaillard C, Blond F, Perrocheau L, Reichman S, Byrne LC, Olivier-Bandini A, Bellalou J, Moyse E, Bouillaud F, Nicol X, Dalkara D, van Dorsselaer A, Sahel JA, Léveillard T. Rod-derived cone viability factor promotes cone survival by stimulating aerobic glycolysis. Cell 2016; 161:817-32. [PMID: 25957687 DOI: 10.1016/j.cell.2015.03.023] [Citation(s) in RCA: 263] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 01/21/2015] [Accepted: 03/05/2015] [Indexed: 12/31/2022]
Abstract
Rod-derived cone viability factor (RdCVF) is an inactive thioredoxin secreted by rod photoreceptors that protects cones from degeneration. Because the secondary loss of cones in retinitis pigmentosa (RP) leads to blindness, the administration of RdCVF is a promising therapy for this untreatable neurodegenerative disease. Here, we investigated the mechanism underlying the protective role of RdCVF in RP. We show that RdCVF acts through binding to Basigin-1 (BSG1), a transmembrane protein expressed specifically by photoreceptors. BSG1 binds to the glucose transporter GLUT1, resulting in increased glucose entry into cones. Increased glucose promotes cone survival by stimulation of aerobic glycolysis. Moreover, a missense mutation of RdCVF results in its inability to bind to BSG1, stimulate glucose uptake, and prevent secondary cone death in a model of RP. Our data uncover an entirely novel mechanism of neuroprotection through the stimulation of glucose metabolism.
Collapse
Affiliation(s)
- Najate Aït-Ali
- INSERM, U968, 75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, 75012 Paris, France; CNRS, UMR_7210, 75012 Paris, France
| | - Ram Fridlich
- INSERM, U968, 75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, 75012 Paris, France; CNRS, UMR_7210, 75012 Paris, France
| | - Géraldine Millet-Puel
- INSERM, U968, 75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, 75012 Paris, France; CNRS, UMR_7210, 75012 Paris, France
| | - Emmanuelle Clérin
- INSERM, U968, 75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, 75012 Paris, France; CNRS, UMR_7210, 75012 Paris, France
| | - François Delalande
- BioOrganic Mass Spectrometry Laboratory (LSMBO), IPHC, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg, France; IPHC, CNRS, UMR7178, 67087 Strasbourg, France
| | - Céline Jaillard
- INSERM, U968, 75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, 75012 Paris, France; CNRS, UMR_7210, 75012 Paris, France
| | - Frédéric Blond
- INSERM, U968, 75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, 75012 Paris, France; CNRS, UMR_7210, 75012 Paris, France
| | - Ludivine Perrocheau
- INSERM, U968, 75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, 75012 Paris, France; CNRS, UMR_7210, 75012 Paris, France
| | - Sacha Reichman
- INSERM, U968, 75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, 75012 Paris, France; CNRS, UMR_7210, 75012 Paris, France
| | - Leah C Byrne
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720, USA
| | | | - Jacques Bellalou
- Institut Pasteur, Platform 5 Production of Recombinant Proteins and Antibodies, 75724 Paris Cedex 15, France
| | - Emmanuel Moyse
- Unité de Physiologie de la Reproduction et des Comportements (PRC), UMR-85 INRA, Centre INRA de Tours, Université François Rabelais de Tours, 37380 Nouzilly, France
| | - Frédéric Bouillaud
- Inserm, U1016, Institut Cochin, 75014 Paris, France; Cnrs, UMR8104, 75014 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Xavier Nicol
- INSERM, U968, 75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, 75012 Paris, France; CNRS, UMR_7210, 75012 Paris, France
| | - Deniz Dalkara
- INSERM, U968, 75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, 75012 Paris, France; CNRS, UMR_7210, 75012 Paris, France
| | - Alain van Dorsselaer
- BioOrganic Mass Spectrometry Laboratory (LSMBO), IPHC, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg, France; IPHC, CNRS, UMR7178, 67087 Strasbourg, France
| | - José-Alain Sahel
- INSERM, U968, 75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, 75012 Paris, France; CNRS, UMR_7210, 75012 Paris, France
| | - Thierry Léveillard
- INSERM, U968, 75012 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, 75012 Paris, France; CNRS, UMR_7210, 75012 Paris, France.
| |
Collapse
|
8
|
Computer-assisted counting of retinal cells by automatic segmentation after TV denoising. BMC Ophthalmol 2013; 13:59. [PMID: 24138794 PMCID: PMC3835550 DOI: 10.1186/1471-2415-13-59] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 08/23/2013] [Indexed: 12/02/2022] Open
Abstract
Background Quantitative evaluation of mosaics of photoreceptors and neurons is essential in studies on development, aging and degeneration of the retina. Manual counting of samples is a time consuming procedure while attempts to automatization are subject to various restrictions from biological and preparation variability leading to both over- and underestimation of cell numbers. Here we present an adaptive algorithm to overcome many of these problems. Digital micrographs were obtained from cone photoreceptor mosaics visualized by anti-opsin immuno-cytochemistry in retinal wholemounts from a variety of mammalian species including primates. Segmentation of photoreceptors (from background, debris, blood vessels, other cell types) was performed by a procedure based on Rudin-Osher-Fatemi total variation (TV) denoising. Once 3 parameters are manually adjusted based on a sample, similarly structured images can be batch processed. The module is implemented in MATLAB and fully documented online. Results The object recognition procedure was tested on samples with a typical range of signal and background variations. We obtained results with error ratios of less than 10% in 16 of 18 samples and a mean error of less than 6% compared to manual counts. Conclusions The presented method provides a traceable module for automated acquisition of retinal cell density data. Remaining errors, including addition of background items, splitting or merging of objects might be further reduced by introduction of additional parameters. The module may be integrated into extended environments with features such as 3D-acquisition and recognition.
Collapse
|
9
|
Jaillard C, Mouret A, Niepon ML, Clérin E, Yang Y, Lee-Rivera I, Aït-Ali N, Millet-Puel G, Cronin T, Sedmak T, Raffelsberger W, Kinzel B, Trembleau A, Poch O, Bennett J, Wolfrum U, Lledo PM, Sahel JA, Léveillard T. Nxnl2 splicing results in dual functions in neuronal cell survival and maintenance of cell integrity. Hum Mol Genet 2012; 21:2298-311. [PMID: 22343139 DOI: 10.1093/hmg/dds050] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The rod-derived cone viability factors, RdCVF and RdCVF2, have potential therapeutical interests for the treatment of inherited photoreceptor degenerations. In the mouse lacking Nxnl2, the gene encoding RdCVF2, the progressive decline of the visual performance of the cones in parallel with their degeneration, arises due to the loss of trophic support from RdCVF2. In contrary, the progressive loss of rod visual function of the Nxnl2-/- mouse results from a decrease in outer segment length, mediated by a cell autonomous mechanism involving the putative thioredoxin protein RdCVF2L, the second spliced product of the Nxnl2 gene. This novel signaling mechanism extends to olfaction as shown by the progressive impairment of olfaction in aged Nxnl2-/- mice and the protection of olfactory neurons by RdCVF2. This study shows that Nxnl2 is a bi-functional gene involved in the maintenance of both the function and the viability of sensory neurons.
Collapse
|