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Yang H, Zhang H, Li X. Navigating the future of retinitis pigmentosa treatments: A comprehensive analysis of therapeutic approaches in rd10 mice. Neurobiol Dis 2024; 193:106436. [PMID: 38341159 DOI: 10.1016/j.nbd.2024.106436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 02/06/2024] [Accepted: 02/07/2024] [Indexed: 02/12/2024] Open
Abstract
Retinitis pigmentosa (RP) is a degenerative disease, caused by genetic mutations that lead to a loss in photoreceptors. For research on RP, rd10 mice, which carry mutations in the phosphodiesterase (PDE) gene, exhibit degenerative patterns comparable to those of patients with RP, making them an ideal model for investigating potential treatments. Although numerous studies have reported the potential of biochemical drugs, gene correction, and stem cell transplantation in decelerating rd10 retinal degeneration, a comprehensive review of these studies has yet to be conducted. Therefore, here, a comparative analysis of rd10 mouse treatment research over the past decade was performed. Our findings suggest that biochemical drugs capable of inhibiting the inflammatory response may be promising therapeutics. Additionally, significant progress has been made in the field of gene therapy; nevertheless, challenges such as strict delivery requirements, bystander editing, and off-target effects still need to be resolved. Nevertheless, secretory function is the only unequivocal protective effect of stem cell transplantation. In summary, this review presents a comprehensive analysis and synthesis of the treatment approaches employing rd10 mice as experimental subjects, describing a clear pathway for future RP treatment research and identifies potential clinical interventions.
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Affiliation(s)
- Hongli Yang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251, Fukang Road, Tianjin 300384, China.
| | - Hui Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251, Fukang Road, Tianjin 300384, China
| | - Xiaorong Li
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251, Fukang Road, Tianjin 300384, China.
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Mokady D, Charish J, Barretto-Burns P, Grisé KN, Coles BLK, Raab S, Ortin-Martinez A, Müller A, Fasching B, Jain P, Drukker M, van der Kooy D, Steger M. Small-Molecule-Directed Endogenous Regeneration of Visual Function in a Mammalian Retinal Degeneration Model. Int J Mol Sci 2024; 25:1521. [PMID: 38338800 PMCID: PMC10855388 DOI: 10.3390/ijms25031521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 12/31/2023] [Accepted: 01/20/2024] [Indexed: 02/12/2024] Open
Abstract
Degenerative retinal diseases associated with photoreceptor loss are a leading cause of visual impairment worldwide, with limited treatment options. Phenotypic profiling coupled with medicinal chemistry were used to develop a small molecule with proliferative effects on retinal stem/progenitor cells, as assessed in vitro in a neurosphere assay and in vivo by measuring Msx1-positive ciliary body cell proliferation. The compound was identified as having kinase inhibitory activity and was subjected to cellular pathway analysis in non-retinal human primary cell systems. When tested in a disease-relevant murine model of adult retinal degeneration (MNU-induced retinal degeneration), we observed that four repeat intravitreal injections of the compound improved the thickness of the outer nuclear layer along with the regeneration of the visual function, as measured with ERG, visual acuity, and contrast sensitivity tests. This serves as a proof of concept for the use of a small molecule to promote endogenous regeneration in the eye.
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Affiliation(s)
- Daphna Mokady
- Endogena Therapeutics, Inc., 661 University Ave, Toronto, ON M5G 0B7, Canada (P.B.-B.)
| | - Jason Charish
- Endogena Therapeutics, Inc., 661 University Ave, Toronto, ON M5G 0B7, Canada (P.B.-B.)
| | | | - Kenneth N. Grisé
- Department of Molecular Genetics, University of Toronto, Donnelly Centre Rm 1110, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Brenda L. K. Coles
- Department of Molecular Genetics, University of Toronto, Donnelly Centre Rm 1110, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Susanne Raab
- Endogena Therapeutics, AG, Binzmuehlestrasse 170 d, CH-8050 Zuerich, Switzerland
| | - Arturo Ortin-Martinez
- Endogena Therapeutics, Inc., 661 University Ave, Toronto, ON M5G 0B7, Canada (P.B.-B.)
| | - Alex Müller
- Endogena Therapeutics, AG, Binzmuehlestrasse 170 d, CH-8050 Zuerich, Switzerland
| | - Bernhard Fasching
- Endogena Therapeutics, AG, Binzmuehlestrasse 170 d, CH-8050 Zuerich, Switzerland
| | - Payal Jain
- Endogena Therapeutics, Inc., 661 University Ave, Toronto, ON M5G 0B7, Canada (P.B.-B.)
| | - Micha Drukker
- Endogena Therapeutics, AG, Binzmuehlestrasse 170 d, CH-8050 Zuerich, Switzerland
| | - Derek van der Kooy
- Department of Molecular Genetics, University of Toronto, Donnelly Centre Rm 1110, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Matthias Steger
- Endogena Therapeutics, AG, Binzmuehlestrasse 170 d, CH-8050 Zuerich, Switzerland
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3
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Neil GJ, Kluttig KH, Allison WT. Determining Photoreceptor Cell Identity: Rod Versus Cone Fate Governed by tbx2b Opposing nrl. Invest Ophthalmol Vis Sci 2024; 65:39. [PMID: 38261312 PMCID: PMC10810017 DOI: 10.1167/iovs.65.1.39] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 12/28/2023] [Indexed: 01/24/2024] Open
Abstract
Purpose NRL is an influential transcription factor and central to animal modeling in ophthalmology. Disrupting NRL abrogates rod development and produces an excess of S-cones (also known as "UV cones" or "short-wavelength-sensitive1 [SWS1] cones"). Strikingly, mutations in zebrafish tbx2b produce the exact opposite phenotypes (excess rods and loss of SWS1 cones). We sought to define what genetic relationship exists, if any, between these transcription factors. We also infer whether these two phenotypes (altered rod abundance and altered SWS1 cone abundance) are independent versus inter-related. Methods Zebrafish mutants were bred to disrupt nrl and tbx2b in concert. Rods and SWS1 cones were quantified and characterized at ultrastructural and transcriptional levels. Results Considering single mutant zebrafish, we confirmed previously established phenotypes and noted that the number of rods lost in nrl-/- mutants is reflected by a concomitant increase in SWS1 cone abundance. The tbx2b-/- mutants present the opposite phenotype(s) but exhibit a similar trade-off in cell abundances, with lots of rods and a concomitant decrease in SWS1 cones. Double mutant nrl-/-;tbx2b-/- zebrafish recapitulate the nrl-/- mutant phenotype(s). Conclusions The tbx2b is thought to be required for producing SWS1 cones in zebrafish, but this can be over-ridden when nrl is absent. Regarding the altered cell abundances observed in either tbx2b-/- or nrl-/- mutants, the alterations in rod and SWS1 cones appear to not be two separate phenotypes but are instead a single intertwined outcome. The tbx2b and nrl are in an epistatic relationship, with nrl phenotypes dominating, implying that tbx2b is upstream of nrl in photoreceptor cell fate determination.
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Affiliation(s)
- Gavin J. Neil
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Kaitlyn H. Kluttig
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - W. Ted Allison
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
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4
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Sun Y, Sun Y, Chen S, Yu Y, Ma Y, Sun F. Hypoxic preconditioned MSCs-derived small extracellular vesicles for photoreceptor protection in retinal degeneration. J Nanobiotechnology 2023; 21:449. [PMID: 38001463 PMCID: PMC10675959 DOI: 10.1186/s12951-023-02225-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 11/19/2023] [Indexed: 11/26/2023] Open
Abstract
Photoreceptor apoptosis is an important pathogenesis of retinal degeneration and a primary cause of vision loss with limited treatment methods. Mesenchymal stem/stromal cells-derived small extracellular vesicles (MSC-sEVs) have shown therapeutic value in various ocular disorders. Recent studies have revealed that hypoxic preconditioning can improve the effectiveness of MSC-sEVs in tissue regeneration. However, whether hypoxic preconditioned MSC-sEVs (Hyp-sEVs) exert superior effects on photoreceptor protection relative to normoxic conditioned MSC-sEVs (Nor-sEVs) remains unclear. Here, we reported that Hyp-sEVs further improved retinal structure, recovered retinal function, and suppressed photoreceptor apoptosis in N-methyl-N-nitrosourea (MNU)-induced mouse model compared with Nor-sEVs. Hyp-sEVs also exhibited enhanced anti-apoptotic roles in MNU-provoked 661 W cell injury in vitro. We then analyzed the protein profiles of Nor-sEVs and Hyp-sEVs by LC-MS/MS and found that growth-associated protein 43 (GAP43) was enriched in Hyp-sEVs. The knockdown of GAP43 abolished the retinal therapeutic effects of Hyp-sEVs. Mechanistically, hypoxic stimulation-induced hypoxia-inducible factor-1α (HIF-1α) activation was responsible for preventing tripartite motif-containing protein 25 (TRIM25)-mediated GAP43 ubiquitination and degradation, leading to the upregulation of GAP43 in Hyp-sEVs. Together, our findings uncover the efficacy and mechanism of Hyp-sEVs-based photoreceptor protection and highlight the potential of Hyp-sEVs as optimized therapeutics for retinal degeneration.
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Affiliation(s)
- Yuntong Sun
- Department of Clinical Laboratory, Affiliated Jinhua Hospital, Zhejiang University School of Medicine, Jinhua, 321000, Zhejiang, China
| | - Yuntao Sun
- Jiangsu Province Key Laboratory of Medical Science and Laboratory Medicine, Department of Laboratory Medicine, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Shenyuan Chen
- Jiangsu Province Key Laboratory of Medical Science and Laboratory Medicine, Department of Laboratory Medicine, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Yifan Yu
- Jiangsu Province Key Laboratory of Medical Science and Laboratory Medicine, Department of Laboratory Medicine, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Yongjun Ma
- Department of Clinical Laboratory, Affiliated Jinhua Hospital, Zhejiang University School of Medicine, Jinhua, 321000, Zhejiang, China.
| | - Fengtian Sun
- Department of Clinical Laboratory, Affiliated Jinhua Hospital, Zhejiang University School of Medicine, Jinhua, 321000, Zhejiang, China.
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5
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Barwick SR, Xiao H, Wolff D, Wang J, Perry E, Marshall B, Smith SB. Sigma 1 receptor activation improves retinal structure and function in the Rho P23H/+ mouse model of autosomal dominant retinitis pigmentosa. Exp Eye Res 2023; 230:109462. [PMID: 37003581 PMCID: PMC10155485 DOI: 10.1016/j.exer.2023.109462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/17/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023]
Abstract
Retinitis pigmentosa (RP) is a group of devastating inherited retinal diseases that leads to visual impairment and oftentimes complete blindness. Currently no cure exists for RP thus research into prolonging vision is imperative. Sigma 1 receptor (Sig1R) is a promising small molecule target that has neuroprotective benefits in retinas of rapidly-degenerating mouse models. It is not clear whether Sig1R activation can provide similar neuroprotective benefits in more slowly-progressing RP models. Here, we examined Sig1R-mediated effects in the slowly-progressing RhoP23H/+ mouse, a model of autosomal dominant RP. We characterized the retinal degeneration of the RhoP23H/+ mouse over a 10 month period using three in vivo methods: Optomotor Response (OMR), Electroretinogram (ERG), and Spectral Domain-Optical Coherence Tomography (SD-OCT). A slow retinal degeneration was observed in both male and female RhoP23H/+ mice when compared to wild type. The OMR, which reflects visual acuity, showed a gradual decline through 10 months. Interestingly, female mice had more reduction in visual acuity than males. ERG assessment showed a gradual decline in scotopic and photopic responses in RhoP23H/+ mice. To investigate the neuroprotective benefits of Sig1R activation in the RhoP23H/+ mouse model, mutant mice were treated with a high-specificity Sig1R ligand (+)-pentazocine ((+)-PTZ) 3x/week at 0.5 mg/kg and examined using OMR, ERG, SD-OCT. A significant retention of visual function was observed in males and females at 10 months of age, with treated females retaining ∼50% greater visual acuity than non-treated mutant females. ERG revealed significant retention of scotopic and photopic b-wave amplitudes at 6 months in male and female RhoP23H/+ mice treated with (+)-PTZ. Further, in vivo analysis by SD-OCT revealed a significant retention of outer nuclear layer (ONL) thickness in male and female treated RhoP23H/+ mice. Histological studies showed significant retention of IS/OS length (∼50%), ONL thickness, and number of rows of photoreceptor cell nuclei at 6 months in (+)-PTZ-treated mutant mice. Interestingly, electron microscopy revealed preservation of OS discs in (+)-PTZ treated mutant mice compared to non-treated. Taken collectively, the in vivo and in vitro data provide the first evidence that targeting Sig1R can rescue visual function and structure in the RhoP23H/+ mouse. These results are promising and provide a framework for future studies to investigate Sig1R as a potential therapeutic target in retinal degenerative disease.
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Affiliation(s)
- Shannon R Barwick
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA.
| | - Haiyan Xiao
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - David Wolff
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Jing Wang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Elizabeth Perry
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Brendan Marshall
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
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6
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Erofeeva N, Meshalkina D, Firsov M. Multiple Roles of cAMP in Vertebrate Retina. Cells 2023; 12:cells12081157. [PMID: 37190066 DOI: 10.3390/cells12081157] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/09/2023] [Accepted: 04/10/2023] [Indexed: 05/17/2023] Open
Abstract
cAMP is a key regulatory molecule that controls many important processes in the retina, including phototransduction, cell development and death, growth of neural processes, intercellular contacts, retinomotor effects, and so forth. The total content of cAMP changes in the retina in a circadian manner following the natural light cycle, but it also shows local and even divergent changes in faster time scales in response to local and transient changes in the light environment. Changes in cAMP might also manifest or cause various pathological processes in virtually all cellular components of the retina. Here we review the current state of knowledge and understanding of the regulatory mechanisms by which cAMP influences the physiological processes that occur in various retinal cells.
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Affiliation(s)
- Natalia Erofeeva
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 St. Petersburg, Russia
| | - Darya Meshalkina
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 St. Petersburg, Russia
| | - Michael Firsov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 St. Petersburg, Russia
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Subramanian R, Sahoo D. Boolean implication analysis of single-cell data predicts retinal cell type markers. BMC Bioinformatics 2022; 23:378. [PMID: 36114457 PMCID: PMC9482279 DOI: 10.1186/s12859-022-04915-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/25/2022] [Indexed: 11/15/2022] Open
Abstract
Background The retina is a complex tissue containing multiple cell types that are essential for vision. Understanding the gene expression patterns of various retinal cell types has potential applications in regenerative medicine. Retinal organoids (optic vesicles) derived from pluripotent stem cells have begun to yield insights into the transcriptomics of developing retinal cell types in humans through single cell RNA-sequencing studies. Previous methods of gene reporting have relied upon techniques in vivo using microarray data, or correlational and dimension reduction methods for analyzing single cell RNA-sequencing data computationally. We aimed to develop a state-of-the-art Boolean method that filtered out noise, could be applied to a wide variety of datasets and lent insight into gene expression over differentiation. Results Here, we present a bioinformatic approach using Boolean implication to discover genes which are retinal cell type-specific or involved in retinal cell fate. We apply this approach to previously published retina and retinal organoid datasets and improve upon previously published correlational methods. Our method improves the prediction accuracy of marker genes of retinal cell types and discovers several new high confidence cone and rod-specific genes. Conclusions The results of this study demonstrate the benefits of a Boolean approach that considers asymmetric relationships. We have shown a statistically significant improvement from correlational, symmetric methods in the prediction accuracy of retinal cell-type specific genes. Furthermore, our method contains no cell or tissue-specific tuning and hence could impact other areas of gene expression analyses in cancer and other human diseases. Supplementary Information The online version contains supplementary material available at 10.1186/s12859-022-04915-4.
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Müller T. View Point: Disease Modification and Cell Secretome Based Approaches in Parkinson's Disease: Are We on the Right Track? Biologics 2021; 15:307-316. [PMID: 34349499 PMCID: PMC8328382 DOI: 10.2147/btt.s267281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 07/19/2021] [Indexed: 11/23/2022]
Abstract
The term idiopathic Parkinson's disease describes an entity of various not well-characterized disorders resembling each other. They are characterized by chronic neuronal dying originating from various disease mechanisms. They result in the onset of motor and related non-motor features, both of which respond to administration of personalized drug combinations and surgical therapies. The unmet need is beneficial disease course modification with repair and neurogenesis. Objectives are to discuss the value of cell secretome based treatments including neuronal graft transplantation and to suggest as an alternative the stimulation of an endogenous available approach for neuronal repair. Chronic neurodegenerative processes result from different heterogeneous, but complementing metabolic, pathological cascade sequences. Accumulated evidence from experimental research suggested neuron transplantation, stem cell application and cell secretome-based therapies as a promising future treatment with cure as an ultimate goal. To date, clinical testing of disease-modifying treatments has focused on substitution or repair of the remaining dopamine synthesizing neurons following diagnosis. At diagnosis, many of the still surviving and functioning, but already affected neurons have lost most of their axons and are primed for cell death. A more promising therapeutic concept may be the stimulation of an existing, endogenous repair system in the peripheral and central nervous systems. The abundant protein repulsive guidance molecule A blocks restoration and neurogenesis, both of which are mediated via the neogenin receptor. Inhibition of the physiological effects of repulsive guidance molecule A is an endogenous available repair pathway in chronic neurodegeneration. Antagonism of this protein with antibodies or stimulation of the neogenin receptor should be considered as an initial repair step. It is an alternative to cell replacement, stem cell or associated cell secretome concepts.
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Affiliation(s)
- Thomas Müller
- Department of Neurology, St. Joseph Hospital Berlin-Weissensee, Berlin, 13088, Germany
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9
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Inhibition of Epigenetic Modifiers LSD1 and HDAC1 Blocks Rod Photoreceptor Death in Mouse Models of Retinitis Pigmentosa. J Neurosci 2021; 41:6775-6792. [PMID: 34193554 DOI: 10.1523/jneurosci.3102-20.2021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 06/11/2021] [Accepted: 06/18/2021] [Indexed: 11/21/2022] Open
Abstract
Epigenetic modifiers are increasingly being investigated as potential therapeutics to modify and overcome disease phenotypes. Diseases of the nervous system present a particular problem as neurons are postmitotic and demonstrate relatively stable gene expression patterns and chromatin organization. We have explored the ability of epigenetic modifiers to prevent degeneration of rod photoreceptors in a mouse model of retinitis pigmentosa (RP), using rd10 mice of both sexes. The histone modification eraser enzymes lysine demethylase 1 (LSD1) and histone deacetylase 1 (HDAC1) are known to have dramatic effects on the development of rod photoreceptors. In the RP mouse model, inhibitors of these enzymes blocked rod degeneration, preserved vision, and affected the expression of multiple genes including maintenance of rod-specific transcripts and downregulation of those involved in inflammation, gliosis, and cell death. The neuroprotective activity of LSD1 inhibitors includes two pathways. First, through targeting histone modifications, they increase accessibility of chromatin and upregulate neuroprotective genes, such as from the Wnt pathway. We propose that this process is going in rod photoreceptors. Second, through nonhistone targets, they inhibit transcription of inflammatory genes and inflammation. This process is going in microglia, and lack of inflammation keeps rod photoreceptors alive.SIGNIFICANCE STATEMENT Retinal degenerations are a leading cause of vision loss. RP is genetically very heterogeneous, and the multiple pathways leading to cell death are one reason for the slow progress in identifying suitable treatments for patients. Here we demonstrate that inhibition of LSD1and HDAC1 in a mouse model of RP leads to preservation of rod photoreceptors and visual function, retaining of expression of rod-specific genes, and with decreased inflammation, cell death, and Müller cell gliosis. We propose that these epigenetic inhibitors cause more open and accessible chromatin, allowing expression of neuroprotective genes. A second mechanism that allows rod photoreceptor survival is suppression of inflammation by epigenetic inhibitors in microglia. Manipulation of epigenetic modifiers is a new strategy to fight neurodegeneration in RP.
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10
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Li J, Du W, Xu N, Tao T, Tang X, Huang L. RNA-seq analysis for exploring the pathogenesis of Retinitis pigmentosa in P23H knock-in mice. Ophthalmic Res 2021; 64:798-810. [PMID: 33971646 DOI: 10.1159/000515727] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 03/05/2021] [Indexed: 11/19/2022]
Affiliation(s)
- Jiarui Li
- Eye diseases and Optometry Institute, Department of Ophthalmology, Peking University People's Hospital, Beijing, China,
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China,
- College of Optometry, Peking University Health Science Center, Beijing, China,
| | - Wei Du
- Eye diseases and Optometry Institute, Department of Ophthalmology, Peking University People's Hospital, Beijing, China
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China
- College of Optometry, Peking University Health Science Center, Beijing, China
| | - Ningda Xu
- Eye diseases and Optometry Institute, Department of Ophthalmology, Peking University People's Hospital, Beijing, China
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China
- College of Optometry, Peking University Health Science Center, Beijing, China
| | - Tianchang Tao
- Eye diseases and Optometry Institute, Department of Ophthalmology, Peking University People's Hospital, Beijing, China
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China
- College of Optometry, Peking University Health Science Center, Beijing, China
| | - Xin Tang
- Eye diseases and Optometry Institute, Department of Ophthalmology, Peking University People's Hospital, Beijing, China
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China
- College of Optometry, Peking University Health Science Center, Beijing, China
| | - Lvzhen Huang
- Eye diseases and Optometry Institute, Department of Ophthalmology, Peking University People's Hospital, Beijing, China
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China
- College of Optometry, Peking University Health Science Center, Beijing, China
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11
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Perspective: Treatment for Disease Modification in Chronic Neurodegeneration. Cells 2021; 10:cells10040873. [PMID: 33921342 PMCID: PMC8069143 DOI: 10.3390/cells10040873] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 03/31/2021] [Accepted: 04/09/2021] [Indexed: 02/07/2023] Open
Abstract
Symptomatic treatments are available for Parkinson's disease and Alzheimer's disease. An unmet need is cure or disease modification. This review discusses possible reasons for negative clinical study outcomes on disease modification following promising positive findings from experimental research. It scrutinizes current research paradigms for disease modification with antibodies against pathological protein enrichment, such as α-synuclein, amyloid or tau, based on post mortem findings. Instead a more uniform regenerative and reparative therapeutic approach for chronic neurodegenerative disease entities is proposed with stimulation of an endogenously existing repair system, which acts independent of specific disease mechanisms. The repulsive guidance molecule A pathway is involved in the regulation of peripheral and central neuronal restoration. Therapeutic antagonism of repulsive guidance molecule A reverses neurodegeneration according to experimental outcomes in numerous disease models in rodents and monkeys. Antibodies against repulsive guidance molecule A exist. First clinical studies in neurological conditions with an acute onset are under way. Future clinical trials with these antibodies should initially focus on well characterized uniform cohorts of patients. The efficiency of repulsive guidance molecule A antagonism and associated stimulation of neurogenesis should be demonstrated with objective assessment tools to counteract dilution of therapeutic effects by subjectivity and heterogeneity of chronic disease entities. Such a research concept will hopefully enhance clinical test strategies and improve the future therapeutic armamentarium for chronic neurodegeneration.
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12
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Shabanzadeh AP, Charish J, Tassew NG, Farhani N, Feng J, Qin X, Sugita S, Mothe AJ, Wälchli T, Koeberle PD, Monnier PP. Cholesterol synthesis inhibition promotes axonal regeneration in the injured central nervous system. Neurobiol Dis 2021; 150:105259. [PMID: 33434618 DOI: 10.1016/j.nbd.2021.105259] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 12/24/2020] [Accepted: 01/07/2021] [Indexed: 12/12/2022] Open
Abstract
Neuronal regeneration in the injured central nervous system is hampered by multiple extracellular proteins. These proteins exert their inhibitory action through interactions with receptors that are located in cholesterol rich compartments of the membrane termed lipid rafts. Here we show that cholesterol-synthesis inhibition prevents the association of the Neogenin receptor with lipid rafts. Furthermore, we show that cholesterol-synthesis inhibition enhances axonal growth both on inhibitory -myelin and -RGMa substrates. Following optic nerve injury, lowering cholesterol synthesis with both drugs and siRNA-strategies allows for robust axonal regeneration and promotes neuronal survival. Cholesterol inhibition also enhanced photoreceptor survival in a model of Retinitis Pigmentosa. Our data reveal that Lovastatin leads to several opposing effects on regenerating axons: cholesterol synthesis inhibition promotes regeneration whereas altered prenylation impairs regeneration. We also show that the lactone prodrug form of lovastatin has differing effects on regeneration when compared to the ring-open hydroxy-acid form. Thus the association of cell surface receptors with lipid rafts contributes to axonal regeneration inhibition, and blocking cholesterol synthesis provides a potential therapeutic approach to promote neuronal regeneration and survival in the diseased Central Nervous System. SIGNIFICANCE STATEMENT: Statins have been intensively used to treat high levels of cholesterol in humans. However, the effect of cholesterol inhibition in both the healthy and the diseased brain remains controversial. In particular, it is unclear whether cholesterol inhibition with statins can promote regeneration and survival following injuries. Here we show that late stage cholesterol inhibition promotes robust axonal regeneration following optic nerve injury. We identified distinct mechanisms of action for activated vs non-activated Lovastatin that may account for discrepancies found in the literature. We show that late stage cholesterol synthesis inhibition alters Neogenin association with lipid rafts, thereby i) neutralizing the inhibitory function of its ligand and ii) offering a novel opportunity to promote CNS regeneration and survival following injuries.
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Affiliation(s)
- Alireza P Shabanzadeh
- Krembil Research Institute, KDT 8-417, 60 Leonard St., Toronto M5T 2S8, Ontario, Canada; Department of Physiology, Donald K. Johnson Research Institute, 60 Leonard St., Toronto M5T 2S8, Ontario, Canada; Department of Anatomy, Faculty of Medicine, University of Toronto, Toronto M5S 1A8, Ontario, Canada
| | - Jason Charish
- Krembil Research Institute, KDT 8-417, 60 Leonard St., Toronto M5T 2S8, Ontario, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto M5S 1A8, Ontario, Canada
| | - Nardos G Tassew
- Krembil Research Institute, KDT 8-417, 60 Leonard St., Toronto M5T 2S8, Ontario, Canada; Department of Physiology, Donald K. Johnson Research Institute, 60 Leonard St., Toronto M5T 2S8, Ontario, Canada
| | - Nahal Farhani
- Krembil Research Institute, KDT 8-417, 60 Leonard St., Toronto M5T 2S8, Ontario, Canada
| | - Jinzhou Feng
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Xinjue Qin
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Shuzo Sugita
- Krembil Research Institute, KDT 8-417, 60 Leonard St., Toronto M5T 2S8, Ontario, Canada
| | - Andrea J Mothe
- Krembil Research Institute, KDT 8-417, 60 Leonard St., Toronto M5T 2S8, Ontario, Canada
| | - Thomas Wälchli
- Krembil Research Institute, KDT 8-417, 60 Leonard St., Toronto M5T 2S8, Ontario, Canada
| | - Paulo D Koeberle
- Department of Anatomy, Faculty of Medicine, University of Toronto, Toronto M5S 1A8, Ontario, Canada
| | - Philippe P Monnier
- Krembil Research Institute, KDT 8-417, 60 Leonard St., Toronto M5T 2S8, Ontario, Canada; Department of Physiology, Donald K. Johnson Research Institute, 60 Leonard St., Toronto M5T 2S8, Ontario, Canada; Department of Ophthalmology, Faculty of Medicine, University of Toronto, Toronto M5S 1A8, Ontario, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto M5S 1A8, Ontario, Canada.
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COG5 variants lead to complex early onset retinal degeneration, upregulation of PERK and DNA damage. Sci Rep 2020; 10:21269. [PMID: 33277529 PMCID: PMC7718911 DOI: 10.1038/s41598-020-77394-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 11/10/2020] [Indexed: 01/04/2023] Open
Abstract
Leber congenital amaurosis (LCA), a form of autosomal recessive severe early-onset retinal degeneration, is an important cause of childhood blindness. This may be associated with systemic features or not. Here we identified COG5 compound-heterozygous variants in patients affected with a complex LCA phenotype associated with microcephaly and skeletal dysplasia. COG5 is a component of the COG complex, which facilitates retrograde Golgi trafficking; if disrupted this can result in protein misfolding. To date, variants in COG5 have been associated with a distinct congenital disorder of glycosylation (type IIi) and with a variant of Friedreich’s ataxia. We show that COG5 variants can also result in fragmentation of the Golgi apparatus and upregulation of the UPR modulator, PKR-like endoplasmic reticulum kinase (PERK). In addition, upregulation of PERK induces DNA damage in cultured cells and in murine retina. This study identifies a novel role for COG5 in maintaining ER protein homeostasis and that disruption of that role results in activation of PERK and early-onset retinal degeneration, microcephaly and skeletal dysplasia. These results also highlight the importance of the UPR pathway in early-onset retinal dystrophy and as potential therapeutic targets for patients.
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