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Huang M, Chow CH, Gurdita A, Harada H, Pham Truong VQB, Eide S, Sun HS, Feng ZP, Monnier PP, Wallace VA, Sugita S. SNAP-25, but not SNAP-23, is essential for photoreceptor development, survival, and function in mice. Commun Biol 2024; 7:34. [PMID: 38182732 PMCID: PMC10770054 DOI: 10.1038/s42003-023-05760-8] [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: 09/18/2023] [Accepted: 12/29/2023] [Indexed: 01/07/2024] Open
Abstract
SNARE-mediated vesicular transport is thought to play roles in photoreceptor glutamate exocytosis and photopigment delivery. However, the functions of Synaptosomal-associated protein (SNAP) isoforms in photoreceptors are unknown. Here, we revisit the expression of SNAP-23 and SNAP-25 and generate photoreceptor-specific knockout mice to investigate their roles. Although we find that SNAP-23 shows weak mRNA expression in photoreceptors, SNAP-23 removal does not affect retinal morphology or vision. SNAP-25 mRNA is developmentally regulated and undergoes mRNA trafficking to photoreceptor inner segments at postnatal day 9 (P9). SNAP-25 knockout photoreceptors develop normally until P9 but degenerate by P14 resulting in severe retinal thinning. Photoreceptor loss in SNAP-25 knockout mice is associated with abolished electroretinograms and vision loss. We find mistrafficked photopigments, enlarged synaptic vesicles, and abnormal synaptic ribbons which potentially underlie photoreceptor degeneration. Our results conclude that SNAP-25, but not SNAP-23, mediates photopigment delivery and synaptic functioning required for photoreceptor development, survival, and function.
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Affiliation(s)
- Mengjia Huang
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Chun Hin Chow
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Akshay Gurdita
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Donald K. Johnson Eye Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
| | - Hidekiyo Harada
- Donald K. Johnson Eye Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
| | - Victor Q B Pham Truong
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Donald K. Johnson Eye Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
| | - Sarah Eide
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Hong-Shuo Sun
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Department of Anatomy, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Zhong-Ping Feng
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Philippe P Monnier
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Donald K. Johnson Eye Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
- Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, ON, M5T 3A9, Canada
| | - Valerie A Wallace
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Donald K. Johnson Eye Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
- Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, ON, M5T 3A9, Canada
| | - Shuzo Sugita
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 0S8, Canada.
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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2
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Ramachandra Rao S, Fliesler SJ. A simple, rapid fluorescent reporter-based method for detection of ectopic cre recombinase expression in presumed retinal cell type-targeted mouse lines. Exp Eye Res 2023; 235:109637. [PMID: 37659708 PMCID: PMC10756212 DOI: 10.1016/j.exer.2023.109637] [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: 06/12/2023] [Revised: 08/18/2023] [Accepted: 08/25/2023] [Indexed: 09/04/2023]
Abstract
Although cell type-specific Cre recombinase-expressing mouse lines are commonly used to generate conditional knockout of genes of interest, germline recombination and ectopic "leakiness" in Cre recombinase expression in non-specific cell types has been observed in several neuronal and glial-specific Cre lines. This often leads to inadvertent loss of conditional mouse lines, requiring rederivation. It is therefore imperative to be able to monitor and validate cell type-specific Cre recombinase-mediated gene editing. Herein, we describe a simple, inexpensive, rapid ZsGreen fluor-reporter-based strategy for genotype-free identification of ectopic leakiness using a custom-designed, 3-D blue LED light box. We assessed cell type-specific expression in several allegedly specific Cre recombinase mouse lines commonly used in vision research: retinal pigment epithelium (RPE)-specific (VMD2 (Best1) Cre, RPE65 Cre); astrocyte-specific (GFAP Cre); as well as photoreceptor-bipolar progenitor cell-specific (CRX Cre). Our standardized workflow allows facile, rapid identification of ectopic and non-specific Cre recombinase expression in any presume specific Cre mouse line, without the need for genotyping and without causing animal distress.
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Affiliation(s)
- Sriganesh Ramachandra Rao
- Department of Ophthalmology, Jacobs School of Medicine and Biomedical Sciences, The State University of New York - University at Buffalo, Buffalo, NY, USA; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, The State University of New York - University at Buffalo, Buffalo, NY, USA; Neuroscience Graduate Program, Jacobs School of Medicine and Biomedical Sciences, The State University of New York - University at Buffalo, Buffalo, NY, USA; Research Service, VA Western New York Healthcare System, Buffalo, NY, USA
| | - Steven J Fliesler
- Department of Ophthalmology, Jacobs School of Medicine and Biomedical Sciences, The State University of New York - University at Buffalo, Buffalo, NY, USA; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, The State University of New York - University at Buffalo, Buffalo, NY, USA; Neuroscience Graduate Program, Jacobs School of Medicine and Biomedical Sciences, The State University of New York - University at Buffalo, Buffalo, NY, USA; Research Service, VA Western New York Healthcare System, Buffalo, NY, USA.
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3
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Bosze B, Suarez-Navarro J, Cajias I, Brzezinski IV JA, Brown NL. Notch pathway mutants do not equivalently perturb mouse embryonic retinal development. PLoS Genet 2023; 19:e1010928. [PMID: 37751417 PMCID: PMC10522021 DOI: 10.1371/journal.pgen.1010928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 08/16/2023] [Indexed: 09/28/2023] Open
Abstract
In the vertebrate eye, Notch ligands, receptors, and ternary complex components determine the destiny of retinal progenitor cells in part by regulating Hes effector gene activity. There are multiple paralogues for nearly every node in this pathway, which results in numerous instances of redundancy and compensation during development. To dissect such complexity at the earliest stages of eye development, we used seven germline or conditional mutant mice and two spatiotemporally distinct Cre drivers. We perturbed the Notch ternary complex and multiple Hes genes to understand if Notch regulates optic stalk/nerve head development; and to test intracellular pathway components for their Notch-dependent versus -independent roles during retinal ganglion cell and cone photoreceptor competence and fate acquisition. We confirmed that disrupting Notch signaling universally blocks progenitor cell growth, but delineated specific pathway components that can act independently, such as sustained Hes1 expression in the optic stalk/nerve head. In retinal progenitor cells, we found that among the genes tested, they do not uniformly suppress retinal ganglion cell or cone differentiation; which is not due differences in developmental timing. We discovered that shifts in the earliest cell fates correlate with expression changes for the early photoreceptor factor Otx2, but not with Atoh7, a factor required for retinal ganglion cell formation. During photoreceptor genesis we also better defined multiple and simultaneous activities for Rbpj and Hes1 and identify redundant activities that occur downstream of Notch. Given its unique roles at the retina-optic stalk boundary and cone photoreceptor genesis, our data suggest Hes1 as a hub where Notch-dependent and -independent inputs converge.
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Affiliation(s)
- Bernadett Bosze
- Department of Cell Biology & Human Anatomy, University of California, Davis, California, United States of America
| | - Julissa Suarez-Navarro
- Department of Cell Biology & Human Anatomy, University of California, Davis, California, United States of America
| | - Illiana Cajias
- Department of Cell Biology & Human Anatomy, University of California, Davis, California, United States of America
| | - Joseph A. Brzezinski IV
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Nadean L. Brown
- Department of Cell Biology & Human Anatomy, University of California, Davis, California, United States of America
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4
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Sun C, Chen S. Gene Augmentation for Autosomal Dominant CRX-Associated Retinopathies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:135-141. [PMID: 37440026 PMCID: PMC11010719 DOI: 10.1007/978-3-031-27681-1_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
The cone-rod homeobox (CRX) protein is a key transcription factor essential for photoreceptor function and survival. Mutations in human CRX gene are linked to a wide spectrum of blinding diseases ranging from mild macular dystrophy to severe Leber congenital amaurosis (LCA), cone-rod dystrophy (CRD), and retinitis pigmentosa (RP). These diseases are still incurable and mostly inherited in an autosomal dominant form. Dysfunctional mutant CRX protein interferes with the function of wild-type CRX protein, demonstrating the dominant negative effect. At present, gene augmentation is the most promising treatment strategy for hereditary diseases. This study aims to review the pathogenic mechanisms of various CRX mutations and propose two therapeutic strategies to rescue sick photoreceptors in CRX-associated retinopathies, namely, Tet-On-hCRX system and adeno-associated virus (AAV)-mediated gene augmentation. The outcome of proposed studies will guide future translational research and suggest guidelines for therapy evaluation in terms of treatment safety and efficacy.
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Affiliation(s)
- Chi Sun
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO, USA.
| | - Shiming Chen
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO, USA
- Department of Developmental Biology, Washington University, St. Louis, MO, USA
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5
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Keeley PW, Patel PS, Ryu MS, Reese BE. Neurog2 regulates Isl1 to modulate horizontal cell number. Development 2023; 150:dev201315. [PMID: 36537573 PMCID: PMC10108602 DOI: 10.1242/dev.201315] [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: 09/22/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022]
Abstract
The population sizes of different retinal cell types vary between different strains of mice, and that variation can be mapped to genomic loci in order to identify its polygenic origin. In some cases, controlling genes act independently, whereas in other instances, they exhibit epistasis. Here, we identify an epistatic interaction revealed through the mapping of quantitative trait loci from a panel of recombinant inbred strains of mice. The population of retinal horizontal cells exhibits a twofold variation in number, mapping to quantitative trait loci on chromosomes 3 and 13, where these loci are shown to interact epistatically. We identify a prospective genetic interaction underlying this, mediated by the bHLH transcription factor Neurog2, at the chromosome 3 locus, functioning to repress the LIM homeodomain transcription factor Isl1, at the chromosome 13 locus. Using single and double conditional knockout mice, we confirm the countervailing actions of each gene, and validate in vitro a crucial role for two single nucleotide polymorphisms in the 5'UTR of Isl1, one of which yields a novel E-box, mediating the repressive action of Neurog2.
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Affiliation(s)
- Patrick W. Keeley
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA 93106-5060, USA
| | - Pooja S. Patel
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA 93106-5060, USA
| | - Matthew S. Ryu
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA 93106-5060, USA
| | - Benjamin E. Reese
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA 93106-5060, USA
- Department of Psychological and Brain Sciences, University of California at Santa Barbara, Santa Barbara, CA 93106-5060, USA
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6
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Cell Type-Selective Loss of Peroxisomal β-Oxidation Impairs Bipolar Cell but Not Photoreceptor Survival in the Retina. Cells 2022; 11:cells11010161. [PMID: 35011723 PMCID: PMC8750404 DOI: 10.3390/cells11010161] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/20/2021] [Accepted: 12/29/2021] [Indexed: 12/12/2022] Open
Abstract
Retinal degeneration is a common feature in peroxisomal disorders leading to blindness. Peroxisomes are present in the different cell types of the retina; however, their precise contribution to retinal integrity is still unclear. We previously showed that mice lacking the central peroxisomal β-oxidation enzyme, multifunctional protein 2 (MFP2), develop an early onset retinal decay including photoreceptor cell death. To decipher the function of peroxisomal β-oxidation in photoreceptors, we generated cell type selective Mfp2 knockout mice, using the Crx promotor targeting photoreceptors and bipolar cells. Surprisingly, Crx-Mfp2−/− mice maintained photoreceptor length and number until the age of 1 year. A negative electroretinogram was indicative of preserved photoreceptor phototransduction, but impaired downstream bipolar cell signaling from the age of 6 months. The photoreceptor ribbon synapse was affected, containing free-floating ribbons and vesicles with altered size and density. The bipolar cell interneurons sprouted into the ONL and died. Whereas docosahexaenoic acid levels were normal in the neural retina, levels of lipids containing very long chain polyunsaturated fatty acids were highly increased. Crx-Pex5−/− mice, in which all peroxisomal functions are inactivated in photoreceptors and bipolar cells, developed the same phenotype as Crx-Mfp2−/− mice. In conclusion, the early photoreceptor death in global Mfp2−/− mice is not driven cell autonomously. However, peroxisomal β-oxidation is essential for the integrity of photoreceptor ribbon synapses and of bipolar cells.
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7
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Ortin‐Martinez A, Yan NE, Tsai ELS, Comanita L, Gurdita A, Tachibana N, Liu ZC, Lu S, Dolati P, Pokrajac NT, El‐Sehemy A, Nickerson PEB, Schuurmans C, Bremner R, Wallace VA. Photoreceptor nanotubes mediate the in vivo exchange of intracellular material. EMBO J 2021; 40:e107264. [PMID: 34494680 PMCID: PMC8591540 DOI: 10.15252/embj.2020107264] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 12/17/2022] Open
Abstract
Emerging evidence suggests that intracellular molecules and organelles transfer between cells during embryonic development, tissue homeostasis and disease. We and others recently showed that transplanted and host photoreceptors engage in bidirectional transfer of intracellular material in the recipient retina, a process termed material transfer (MT). We used cell transplantation, advanced tissue imaging approaches, genetic and pharmacologic interventions and primary cell culture to characterize and elucidate the mechanism of MT. We show that MT correlates with donor cell persistence and the accumulation of donor-derived proteins, mitochondria and transcripts in acceptor cells in vivo. MT requires cell contact in vitro and is associated with the formation of stable microtubule-containing protrusions, termed photoreceptor nanotubes (Ph NTs), that connect donor and host cells in vivo and in vitro. Ph NTs mediate GFP transfer between connected cells in vitro. Furthermore, interfering with Ph NT outgrowth by targeting Rho GTPase-dependent actin remodelling inhibits MT in vivo. Collectively, our observations provide evidence for horizontal exchange of intracellular material via nanotube-like connections between neurons in vivo.
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Affiliation(s)
- Arturo Ortin‐Martinez
- Donald K. Johnson Eye InstituteKrembil Research InstituteUniversity Health NetworkTorontoONCanada
| | - Nicole E Yan
- Donald K. Johnson Eye InstituteKrembil Research InstituteUniversity Health NetworkTorontoONCanada
- Department of Laboratory Medicine and PathobiologyUniversity of TorontoTorontoONCanada
| | - En Leh Samuel Tsai
- Donald K. Johnson Eye InstituteKrembil Research InstituteUniversity Health NetworkTorontoONCanada
| | - Lacrimioara Comanita
- Donald K. Johnson Eye InstituteKrembil Research InstituteUniversity Health NetworkTorontoONCanada
| | - Akshay Gurdita
- Donald K. Johnson Eye InstituteKrembil Research InstituteUniversity Health NetworkTorontoONCanada
- Department of Laboratory Medicine and PathobiologyUniversity of TorontoTorontoONCanada
| | - Nobuhiko Tachibana
- Donald K. Johnson Eye InstituteKrembil Research InstituteUniversity Health NetworkTorontoONCanada
| | - Zhongda C Liu
- Donald K. Johnson Eye InstituteKrembil Research InstituteUniversity Health NetworkTorontoONCanada
| | - Suying Lu
- Lunenfeld Tanenbaum Research InstituteMount Sinai HospitalSinai Health SystemsTorontoONCanada
| | - Parnian Dolati
- Donald K. Johnson Eye InstituteKrembil Research InstituteUniversity Health NetworkTorontoONCanada
- Department of Laboratory Medicine and PathobiologyUniversity of TorontoTorontoONCanada
| | - Neno T Pokrajac
- Donald K. Johnson Eye InstituteKrembil Research InstituteUniversity Health NetworkTorontoONCanada
- Department of Laboratory Medicine and PathobiologyUniversity of TorontoTorontoONCanada
| | - Ahmed El‐Sehemy
- Donald K. Johnson Eye InstituteKrembil Research InstituteUniversity Health NetworkTorontoONCanada
- Department of Laboratory Medicine and PathobiologyUniversity of TorontoTorontoONCanada
| | - Philip E B Nickerson
- Donald K. Johnson Eye InstituteKrembil Research InstituteUniversity Health NetworkTorontoONCanada
| | - Carol Schuurmans
- Department of Laboratory Medicine and PathobiologyUniversity of TorontoTorontoONCanada
- Department of BiochemistryUniversity of TorontoTorontoONCanada
- Sunnybrook Research InstituteTorontoONCanada
- Department of Ophthalmology and Vision SciencesUniversity of TorontoTorontoONCanada
| | - Rod Bremner
- Department of Laboratory Medicine and PathobiologyUniversity of TorontoTorontoONCanada
- Lunenfeld Tanenbaum Research InstituteMount Sinai HospitalSinai Health SystemsTorontoONCanada
- Department of Ophthalmology and Vision SciencesUniversity of TorontoTorontoONCanada
| | - Valerie A Wallace
- Donald K. Johnson Eye InstituteKrembil Research InstituteUniversity Health NetworkTorontoONCanada
- Department of Laboratory Medicine and PathobiologyUniversity of TorontoTorontoONCanada
- Department of Ophthalmology and Vision SciencesUniversity of TorontoTorontoONCanada
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8
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Davis ES, Voss G, Miesfeld JB, Zarate-Sanchez J, Voss SR, Glaser T. The rax homeobox gene is mutated in the eyeless axolotl, Ambystoma mexicanum. Dev Dyn 2021; 250:807-821. [PMID: 32864847 PMCID: PMC8907009 DOI: 10.1002/dvdy.246] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 08/11/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Vertebrate eye formation requires coordinated inductive interactions between different embryonic tissue layers, first described in amphibians. A network of transcription factors and signaling molecules controls these steps, with mutations causing severe ocular, neuronal, and craniofacial defects. In eyeless mutant axolotls, eye morphogenesis arrests at the optic vesicle stage, before lens induction, and development of ventral forebrain structures is disrupted. RESULTS We identified a 5-bp deletion in the rax (retina and anterior neural fold homeobox) gene, which was tightly linked to the recessive eyeless (e) axolotl locus in an F2 cross. This frameshift mutation, in exon 2, truncates RAX protein within the homeodomain (P154fs35X). Quantitative RNA analysis shows that mutant and wild-type rax transcripts are equally abundant in E/e embryos. Translation appears to initiate from dual start codons, via leaky ribosome scanning, a conserved feature among gnathostome RAX proteins. Previous data show rax is expressed in the optic vesicle and diencephalon, deeply conserved among metazoans, and required for eye formation in other species. CONCLUSION The eyeless axolotl mutation is a null allele in the rax homeobox gene, with primary defects in neural ectoderm, including the retinal and hypothalamic primordia.
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Affiliation(s)
- Erik S. Davis
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, California
| | - Gareth Voss
- Department of Neuroscience, Spinal Cord and Brain Injury Research Center, and Ambystoma Genetic Stock Center, University of Kentucky, Lexington, Kentucky
| | - Joel B. Miesfeld
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, California
| | - Juan Zarate-Sanchez
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, California
- Davis Senior High School, Davis, California
| | - S. Randal Voss
- Department of Neuroscience, Spinal Cord and Brain Injury Research Center, and Ambystoma Genetic Stock Center, University of Kentucky, Lexington, Kentucky
| | - Tom Glaser
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, California
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9
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Zhang X, Mandric I, Nguyen KH, Nguyen TTT, Pellegrini M, Grove JCR, Barnes S, Yang XJ. Single Cell Transcriptomic Analyses Reveal the Impact of bHLH Factors on Human Retinal Organoid Development. Front Cell Dev Biol 2021; 9:653305. [PMID: 34055784 PMCID: PMC8155690 DOI: 10.3389/fcell.2021.653305] [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: 01/14/2021] [Accepted: 03/22/2021] [Indexed: 11/13/2022] Open
Abstract
The developing retina expresses multiple bHLH transcription factors. Their precise functions and interactions in uncommitted retinal progenitors remain to be fully elucidated. Here, we investigate the roles of bHLH factors ATOH7 and Neurog2 in human ES cell-derived retinal organoids. Single cell transcriptome analyses identify three states of proliferating retinal progenitors: pre-neurogenic, neurogenic, and cell cycle-exiting progenitors. Each shows different expression profile of bHLH factors. The cell cycle-exiting progenitors feed into a postmitotic heterozygous neuroblast pool that gives rise to early born neuronal lineages. Elevating ATOH7 or Neurog2 expression accelerates the transition from the pre-neurogenic to the neurogenic state, and expands the exiting progenitor and neuroblast populations. In addition, ATOH7 and Neurog2 significantly, yet differentially, enhance retinal ganglion cell and cone photoreceptor production. Moreover, single cell transcriptome analyses reveal that ATOH7 and Neurog2 each assert positive autoregulation, and both suppress key bHLH factors associated with the pre-neurogenic and states and elevate bHLH factors expressed by exiting progenitors and differentiating neuroblasts. This study thus provides novel insight regarding how ATOH7 and Neurog2 impact human retinal progenitor behaviors and neuroblast fate choices.
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Affiliation(s)
- Xiangmei Zhang
- Department of Ophthalmology, Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Igor Mandric
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Kevin H Nguyen
- Department of Ophthalmology, Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Thao T T Nguyen
- Department of Ophthalmology, Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Matteo Pellegrini
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States
| | - James C R Grove
- Department of Ophthalmology, Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Steven Barnes
- Department of Ophthalmology, Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States.,Doheny Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Xian-Jie Yang
- Department of Ophthalmology, Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, United States
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10
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Abstract
Cholesterol is a quantitatively and biologically significant constituent of all mammalian cell membrane, including those that comprise the retina. Retinal cholesterol homeostasis entails the interplay between de novo synthesis, uptake, intraretinal sterol transport, metabolism, and efflux. Defects in these complex processes are associated with several congenital and age-related disorders of the visual system. Herein, we provide an overview of the following topics: (a) cholesterol synthesis in the neural retina; (b) lipoprotein uptake and intraretinal sterol transport in the neural retina and the retinal pigment epithelium (RPE); (c) cholesterol efflux from the neural retina and the RPE; and (d) biology and pathobiology of defects in sterol synthesis and sterol oxidation in the neural retina and the RPE. We focus, in particular, on studies involving animal models of monogenic disorders pertinent to the above topics, as well as in vitro models using biochemical, metabolic, and omic approaches. We also identify current knowledge gaps and opportunities in the field that beg further research in this topic area.
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Affiliation(s)
- Sriganesh Ramachandra Rao
- Departments of Ophthalmology and Biochemistry and Neuroscience Graduate Program, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY, USA; Research Service, VA Western NY Healthcare System, Buffalo, NY, USA
| | - Steven J Fliesler
- Departments of Ophthalmology and Biochemistry and Neuroscience Graduate Program, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY, USA; Research Service, VA Western NY Healthcare System, Buffalo, NY, USA.
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11
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Brodie-Kommit J, Clark BS, Shi Q, Shiau F, Kim DW, Langel J, Sheely C, Ruzycki PA, Fries M, Javed A, Cayouette M, Schmidt T, Badea T, Glaser T, Zhao H, Singer J, Blackshaw S, Hattar S. Atoh7-independent specification of retinal ganglion cell identity. SCIENCE ADVANCES 2021; 7:7/11/eabe4983. [PMID: 33712461 PMCID: PMC7954457 DOI: 10.1126/sciadv.abe4983] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 01/29/2021] [Indexed: 06/11/2023]
Abstract
Retinal ganglion cells (RGCs) relay visual information from the eye to the brain. RGCs are the first cell type generated during retinal neurogenesis. Loss of function of the transcription factor Atoh7, expressed in multipotent early neurogenic retinal progenitors leads to a selective and essentially complete loss of RGCs. Therefore, Atoh7 is considered essential for conferring competence on progenitors to generate RGCs. Despite the importance of Atoh7 in RGC specification, we find that inhibiting apoptosis in Atoh7-deficient mice by loss of function of Bax only modestly reduces RGC numbers. Single-cell RNA sequencing of Atoh7;Bax-deficient retinas shows that RGC differentiation is delayed but that the gene expression profile of RGC precursors is grossly normal. Atoh7;Bax-deficient RGCs eventually mature, fire action potentials, and incorporate into retinal circuitry but exhibit severe axonal guidance defects. This study reveals an essential role for Atoh7 in RGC survival and demonstrates Atoh7-dependent and Atoh7-independent mechanisms for RGC specification.
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Affiliation(s)
| | - Brian S Clark
- John F. Hardesty, MD, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Qing Shi
- Department of Biology, University of Maryland, College Park, MD, USA
| | - Fion Shiau
- John F. Hardesty, MD, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Dong Won Kim
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jennifer Langel
- National Institute of Mental Health (NIMH), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Catherine Sheely
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Philip A Ruzycki
- John F. Hardesty, MD, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Michel Fries
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montréal, QC H2W 1R7, Canada
- Molecular Biology Programs, Université de Montréal, QC H3C 3J7, Canada
| | - Awais Javed
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montréal, QC H2W 1R7, Canada
- Molecular Biology Programs, Université de Montréal, QC H3C 3J7, Canada
| | - Michel Cayouette
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montréal, QC H2W 1R7, Canada
- Molecular Biology Programs, Université de Montréal, QC H3C 3J7, Canada
- Department of Anatomy and Cell Biology, McGill University, Montréal, QC H3A 0G4, Canada
- Department of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Tiffany Schmidt
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
| | - Tudor Badea
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
- Research and Development Institute, Transylvania University of Brasov, School of Medicine, Brasov, Romania
| | - Tom Glaser
- Department of Cell Biology and Human Anatomy, University of California, Davis School of Medicine, Davis, CA, USA
| | - Haiqing Zhao
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Joshua Singer
- Department of Biology, University of Maryland, College Park, MD, USA
| | - Seth Blackshaw
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Samer Hattar
- National Institute of Mental Health (NIMH), National Institutes of Health (NIH), Bethesda, MD, USA.
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12
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Brinkmeier ML, Bando H, Camarano AC, Fujio S, Yoshimoto K, de Souza FS, Camper SA. Rathke's cleft-like cysts arise from Isl1 deletion in murine pituitary progenitors. J Clin Invest 2021; 130:4501-4515. [PMID: 32453714 DOI: 10.1172/jci136745] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 05/14/2020] [Indexed: 12/15/2022] Open
Abstract
The transcription factor ISL1 is expressed in pituitary gland stem cells and the thyrotrope and gonadotrope lineages. Pituitary-specific Isl1 deletion causes hypopituitarism with increased stem cell apoptosis, reduced differentiation of thyrotropes and gonadotropes, and reduced body size. Conditional Isl1 deletion causes development of multiple Rathke's cleft-like cysts, with 100% penetrance. Foxa1 and Foxj1 are abnormally expressed in the pituitary gland and associated with a ciliogenic gene-expression program in the cysts. We confirmed expression of FOXA1, FOXJ1, and stem cell markers in human Rathke's cleft cyst tissue, but not craniopharyngiomas, which suggests these transcription factors are useful, pathological markers for diagnosis of Rathke's cleft cysts. These studies support a model whereby expression of ISL1 in pituitary progenitors drives differentiation into thyrotropes and gonadotropes and without it, activation of FOXA1 and FOXJ1 permits development of an oral epithelial cell fate with mucinous cysts. This pituitary-specific Isl1 mouse knockout sheds light on the etiology of Rathke's cleft cysts and the role of ISL1 in normal pituitary development.
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Affiliation(s)
- Michelle L Brinkmeier
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Hironori Bando
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Adriana C Camarano
- Institute of Physiology, Molecular Biology, and Neurosciences-IFIBYNE-CONICET, Pabellon IFIBYNE, Ciudad Universitaria, Buenos Aires, Argentina
| | - Shingo Fujio
- Graduate School of Medical and Dental Sciences, Department of Neurosurgery, Kagoshima University, Kagoshima, Japan
| | - Koji Yoshimoto
- Graduate School of Medical and Dental Sciences, Department of Neurosurgery, Kagoshima University, Kagoshima, Japan
| | - Flávio Sj de Souza
- Institute of Physiology, Molecular Biology, and Neurosciences-IFIBYNE-CONICET, Pabellon IFIBYNE, Ciudad Universitaria, Buenos Aires, Argentina
| | - Sally A Camper
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA
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13
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Xia X, Yu CY, Bian M, Sun CB, Tanasa B, Chang KC, Bruffett DM, Thakur H, Shah SH, Knasel C, Cameron EG, Kapiloff MS, Goldberg JL. MEF2 transcription factors differentially contribute to retinal ganglion cell loss after optic nerve injury. PLoS One 2020; 15:e0242884. [PMID: 33315889 PMCID: PMC7735573 DOI: 10.1371/journal.pone.0242884] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 11/10/2020] [Indexed: 02/07/2023] Open
Abstract
Loss of retinal ganglion cells (RGCs) in optic neuropathies results in permanent partial or complete blindness. Myocyte enhancer factor 2 (MEF2) transcription factors have been shown to play a pivotal role in neuronal systems, and in particular MEF2A knockout was shown to enhance RGC survival after optic nerve crush injury. Here we expanded these prior data to study bi-allelic, tri-allelic and heterozygous allele deletion. We observed that deletion of all MEF2A, MEF2C, and MEF2D alleles had no effect on RGC survival during development. Our extended experiments suggest that the majority of the neuroprotective effect was conferred by complete deletion of MEF2A but that MEF2D knockout, although not sufficient to increase RGC survival on its own, increased the positive effect of MEF2A knockout. Conversely, MEF2A over-expression in wildtype mice worsened RGC survival after optic nerve crush. Interestingly, MEF2 transcription factors are regulated by post-translational modification, including by calcineurin-catalyzed dephosphorylation of MEF2A Ser-408 known to increase MEF2A-dependent transactivation in neurons. However, neither phospho-mimetic nor phospho-ablative mutation of MEF2A Ser-408 affected the ability of MEF2A to promote RGC death in vivo after optic nerve injury. Together these findings demonstrate that MEF2 gene expression opposes RGC survival following axon injury in a complex hierarchy, and further support the hypothesis that loss of or interference with MEF2A expression might be beneficial for RGC neuroprotection in diseases such as glaucoma and other optic neuropathies.
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Affiliation(s)
- Xin Xia
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Caroline Y. Yu
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Minjuan Bian
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Catalina B. Sun
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Bogdan Tanasa
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Kun-Che Chang
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Dawn M. Bruffett
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Hrishikesh Thakur
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Sahil H. Shah
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Cara Knasel
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Evan G. Cameron
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Michael S. Kapiloff
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
- Department of Medicine and Stanford Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
- * E-mail: (MSK); (JLG)
| | - Jeffrey L. Goldberg
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
- * E-mail: (MSK); (JLG)
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14
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Miesfeld JB, Ghiasvand NM, Marsh-Armstrong B, Marsh-Armstrong N, Miller EB, Zhang P, Manna SK, Zawadzki RJ, Brown NL, Glaser T. The Atoh7 remote enhancer provides transcriptional robustness during retinal ganglion cell development. Proc Natl Acad Sci U S A 2020; 117:21690-21700. [PMID: 32817515 PMCID: PMC7474671 DOI: 10.1073/pnas.2006888117] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The retinal ganglion cell (RGC) competence factor ATOH7 is dynamically expressed during retinal histogenesis. ATOH7 transcription is controlled by a promoter-adjacent primary enhancer and a remote shadow enhancer (SE). Deletion of the ATOH7 human SE causes nonsyndromic congenital retinal nonattachment (NCRNA) disease, characterized by optic nerve aplasia and total blindness. We used genome editing to model NCRNA in mice. Deletion of the murine SE reduces Atoh7 messenger RNA (mRNA) fivefold but does not recapitulate optic nerve loss; however, SEdel/knockout (KO) trans heterozygotes have thin optic nerves. By analyzing Atoh7 mRNA and protein levels, RGC development and survival, and chromatin landscape effects, we show that the SE ensures robust Atoh7 transcriptional output. Combining SE deletion and KO and wild-type alleles in a genotypic series, we determined the amount of Atoh7 needed to produce a normal complement of adult RGCs, and the secondary consequences of graded reductions in Atoh7 dosage. Together, these data reveal the workings of an evolutionary fail-safe, a duplicate enhancer mechanism that is hard-wired in the machinery of vertebrate retinal ganglion cell genesis.
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Affiliation(s)
- Joel B Miesfeld
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, CA 95616
| | - Noor M Ghiasvand
- Department of Biology, Grand Valley State University, Allendale, MI 49401
- Functional Neurosurgery Research Center, Shohada Tajrish Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Brennan Marsh-Armstrong
- Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, Sacramento, CA 95817
| | - Nicholas Marsh-Armstrong
- Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, Sacramento, CA 95817
| | - Eric B Miller
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, CA 95616
| | - Pengfei Zhang
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, CA 95616
| | - Suman K Manna
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, CA 95616
| | - Robert J Zawadzki
- Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, Sacramento, CA 95817
| | - Nadean L Brown
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, CA 95616
| | - Tom Glaser
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, CA 95616;
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15
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Syntaxin 3 is essential for photoreceptor outer segment protein trafficking and survival. Proc Natl Acad Sci U S A 2020; 117:20615-20624. [PMID: 32778589 DOI: 10.1073/pnas.2010751117] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Trafficking of photoreceptor membrane proteins from their site of synthesis in the inner segment (IS) to the outer segment (OS) is critical for photoreceptor function and vision. Here we evaluate the role of syntaxin 3 (STX3), in trafficking of OS membrane proteins such as peripherin 2 (PRPH2) and rhodopsin. Photoreceptor-specific Stx3 knockouts [Stx3 f/f(iCre75) and Stx3 f/f(CRX-Cre) ] exhibited rapid, early-onset photoreceptor degeneration and functional decline characterized by structural defects in IS, OS, and synaptic terminals. Critically, in the absence of STX3, OS proteins such as PRPH2, the PRPH2 binding partner, rod outer segment membrane protein 1 (ROM1), and rhodopsin were mislocalized along the microtubules to the IS, cell body, and synaptic region. We find that the PRPH2 C-terminal domain interacts with STX3 as well as other photoreceptor SNAREs, and our findings indicate that STX3 is an essential part of the trafficking pathway for both disc (rhodopsin) and rim (PRPH2/ROM1) components of the OS.
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16
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Rocha-Martins M, de Toledo BC, Santos-França PL, Oliveira-Valença VM, Vieira-Vieira CH, Matos-Rodrigues GE, Linden R, Norden C, Martins RAP, Silveira MS. De novo genesis of retinal ganglion cells by targeted expression of Klf4 in vivo. Development 2019; 146:dev.176586. [PMID: 31405994 DOI: 10.1242/dev.176586] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 07/09/2019] [Indexed: 12/11/2022]
Abstract
Retinal ganglion cell (RGC) degeneration is a hallmark of glaucoma, the most prevalent cause of irreversible blindness. Thus, therapeutic strategies are needed to protect and replace these projection neurons. One innovative approach is to promote de novo genesis of RGCs via manipulation of endogenous cell sources. Here, we demonstrate that the pluripotency regulator gene Krüppel-like factor 4 (Klf4) is sufficient to change the potency of lineage-restricted retinal progenitor cells to generate RGCs in vivo Transcriptome analysis disclosed that the overexpression of Klf4 induces crucial regulators of RGC competence and specification, including Atoh7 and Eya2 In contrast, loss-of-function studies in mice and zebrafish demonstrated that Klf4 is not essential for generation or differentiation of RGCs during retinogenesis. Nevertheless, induced RGCs (iRGCs) generated upon Klf4 overexpression migrate to the proper layer and project axons aligned with endogenous fascicles that reach the optic nerve head. Notably, iRGCs survive for up to 30 days after in vivo generation. We identified Klf4 as a promising candidate for reprogramming retinal cells and regenerating RGCs in the retina.This article has an associated 'The people behind the papers' interview.
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Affiliation(s)
- Maurício Rocha-Martins
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil .,Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Beatriz C de Toledo
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil
| | - Pedro L Santos-França
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil
| | - Viviane M Oliveira-Valença
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil
| | - Carlos H Vieira-Vieira
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil
| | - Gabriel E Matos-Rodrigues
- Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil
| | - Rafael Linden
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil
| | - Caren Norden
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Rodrigo A P Martins
- Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil
| | - Mariana S Silveira
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil
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17
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Kowalchuk AM, Maurer KA, Shoja-Taheri F, Brown NL. Requirements for Neurogenin2 during mouse postnatal retinal neurogenesis. Dev Biol 2018; 442:220-235. [PMID: 30048641 PMCID: PMC6143394 DOI: 10.1016/j.ydbio.2018.07.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 07/22/2018] [Accepted: 07/23/2018] [Indexed: 02/02/2023]
Abstract
During embryonic retinal development, the bHLH factor Neurog2 regulates the temporal progression of neurogenesis, but no role has been assigned for this gene in the postnatal retina. Using Neurog2 conditional mutants, we found that Neurog2 is necessary for the development of an early, embryonic cohort of rod photoreceptors, but also required by both a subset of cone bipolar subtypes, and rod bipolars. Using transcriptomics, we identified a subset of downregulated genes in P2 Neurog2 mutants, which act during rod differentiation, outer segment morphogenesis or visual processing. We also uncovered defects in neuronal cell culling, which suggests that the rod and bipolar cell phenotypes may arise via more complex mechanisms rather than a simple cell fate shift. However, given an overall phenotypic resemblance between Neurog2 and Blimp1 mutants, we explored the relationship between these two factors. We found that Blimp1 is downregulated between E12-birth in Neurog2 mutants, which probably reflects a dependence on Neurog2 in embryonic progenitor cells. Overall, we conclude that the Neurog2 gene is expressed and active prior to birth, but also exerts an influence on postnatal retinal neuron differentiation.
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Affiliation(s)
- Angelica M Kowalchuk
- Department of Cell Biology and Human Anatomy, University of California-Davis, Davis, CA 95616, USA
| | - Kate A Maurer
- Division of Developmental Biology, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229, USA
| | - Farnaz Shoja-Taheri
- Department of Cell Biology and Human Anatomy, University of California-Davis, Davis, CA 95616, USA
| | - Nadean L Brown
- Department of Cell Biology and Human Anatomy, University of California-Davis, Davis, CA 95616, USA; Division of Developmental Biology, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229, USA.
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18
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Chowdhury R, Laboissonniere LA, Wester AK, Muller M, Trimarchi JM. The Trim family of genes and the retina: Expression and functional characterization. PLoS One 2018; 13:e0202867. [PMID: 30208054 PMCID: PMC6135365 DOI: 10.1371/journal.pone.0202867] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 08/10/2018] [Indexed: 11/19/2022] Open
Abstract
To better understand the mechanisms that govern the development of retinal neurons, it is critical to gain additional insight into the specific intrinsic factors that control cell fate decisions and neuronal maturation. In the developing mouse retina, Atoh7, a highly conserved transcription factor, is essential for retinal ganglion cell development. Moreover, Atoh7 expression in the developing retina occurs during a critical time period when progenitor cells are in the process of making cell fate decisions. We performed transcriptome profiling of Atoh7+ individual cells isolated from mouse retina. One of the genes that we found significantly correlated with Atoh7 in our transcriptomic data was the E3 ubiquitin ligase, Trim9. The correlation between Trim9 and Atoh7 coupled with the expression of Trim9 in the early mouse retina led us to hypothesize that this gene may play a role in the process of cell fate determination. To address the role of Trim9 in retinal development, we performed a functional analysis of Trim9 in the mouse and did not detect any morphological changes in the retina in the absence of Trim9. Thus, Trim9 alone does not appear to be involved in cell fate determination or early ganglion cell development in the mouse retina. We further hypothesize that the reason for this lack of phenotype may be compensation by one of the many additional TRIM family members we find expressed in the developing retina.
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Affiliation(s)
- Rebecca Chowdhury
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
| | - Lauren A. Laboissonniere
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
| | - Andrea K. Wester
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
| | - Madison Muller
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
| | - Jeffrey M. Trimarchi
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
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19
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Zhang XM, Hashimoto T, Tang R, Yang XJ. Elevated expression of human bHLH factor ATOH7 accelerates cell cycle progression of progenitors and enhances production of avian retinal ganglion cells. Sci Rep 2018; 8:6823. [PMID: 29717171 PMCID: PMC5931526 DOI: 10.1038/s41598-018-25188-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 04/03/2018] [Indexed: 12/13/2022] Open
Abstract
The production of vertebrate retinal projection neurons, retinal ganglion cells (RGCs), is regulated by cell-intrinsic determinants and cell-to-cell signaling events. The basic-helix-loop-helix (bHLH) protein Atoh7 is a key neurogenic transcription factor required for RGC development. Here, we investigate whether manipulating human ATOH7 expression among uncommitted progenitors can promote RGC fate specification and thus be used as a strategy to enhance RGC genesis. Using the chicken retina as a model, we show that cell autonomous expression of ATOH7 is sufficient to induce precocious RGC formation and expansion of the neurogenic territory. ATOH7 overexpression among neurogenic progenitors significantly enhances RGC production at the expense of reducing the progenitor pool. Furthermore, forced expression of ATOH7 leads to a minor increase of cone photoreceptors. We provide evidence that elevating ATOH7 levels accelerates cell cycle progression from S to M phase and promotes cell cycle exit. We also show that ATOH7-induced ectopic RGCs often exhibit aberrant axonal projection patterns and are correlated with increased cell death during the period of retinotectal connections. These results demonstrate the high potency of human ATOH7 in promoting early retinogenesis and specifying the RGC differentiation program, thus providing insight for manipulating RGC production from stem cell-derived retinal organoids.
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Affiliation(s)
- Xiang-Mei Zhang
- Stein Eye Institute, University of California, Los Angeles, CA, USA
| | - Takao Hashimoto
- Stein Eye Institute, University of California, Los Angeles, CA, USA
| | - Ronald Tang
- Stein Eye Institute, University of California, Los Angeles, CA, USA
| | - Xian-Jie Yang
- Stein Eye Institute, University of California, Los Angeles, CA, USA. .,Molecular Biology Institute, University of California, Los Angeles, CA, USA.
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20
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Cheng L, Wong LJ, Yan N, Han RC, Yu H, Guo C, Batsuuri K, Zinzuwadia A, Guan R, Cho KS, Chen DF. Ezh2 does not mediate retinal ganglion cell homeostasis or their susceptibility to injury. PLoS One 2018; 13:e0191853. [PMID: 29408885 PMCID: PMC5800601 DOI: 10.1371/journal.pone.0191853] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 01/12/2018] [Indexed: 02/05/2023] Open
Abstract
Epigenetic predisposition is thought to critically contribute to adult-onset disorders, such as retinal neurodegeneration. The histone methyltransferase, enhancer of zeste homolog 2 (Ezh2), is transiently expressed in the perinatal retina, particularly enriched in retinal ganglion cells (RGCs). We previously showed that embryonic deletion of Ezh2 from retinal progenitors led to progressive photoreceptor degeneration throughout life, demonstrating a role for embryonic predisposition of Ezh2-mediated repressive mark in maintaining the survival and function of photoreceptors in the adult. Enrichment of Ezh2 in RGCs leads to the question if Ezh2 also mediates gene expression and function in postnatal RGCs, and if its deficiency changes RGC susceptibility to cell death under injury or disease in the adult. To test this, we generated mice carrying targeted deletion of Ezh2 from RGC progenitors driven by Math5-Cre (mKO). mKO mice showed no detectable defect in RGC development, survival, or cell homeostasis as determined by physiological analysis, live imaging, histology, and immunohistochemistry. Moreover, RGCs of Ezh2 deficient mice revealed similar susceptibility against glaucomatous and acute optic nerve trauma-induced neurodegeneration compared to littermate floxed or wild-type control mice. In agreement with the above findings, analysis of RNA sequencing of RGCs purified from Ezh2 deficient mice revealed few gene changes that were related to RGC development, survival and function. These results, together with our previous report, support a cell lineage-specific mechanism of Ezh2-mediated gene repression, especially those critically involved in cellular function and homeostasis.
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Affiliation(s)
- Lin Cheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lucy J. Wong
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
- Eye Center, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Naihong Yan
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Ophthalmology and Ophthalmic Laboratories, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, P. R. China
| | - Richard C. Han
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Honghua Yu
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Chenying Guo
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Khulan Batsuuri
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Aniket Zinzuwadia
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ryan Guan
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kin-Sang Cho
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Dong Feng Chen
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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21
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Fairchild CL, Hino K, Han JS, Miltner AM, Peinado Allina G, Brown CE, Burns ME, La Torre A, Simó S. RBX2 maintains final retinal cell position in a DAB1-dependent and -independent fashion. Development 2018; 145:dev.155283. [PMID: 29361558 DOI: 10.1242/dev.155283] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 12/28/2017] [Indexed: 01/13/2023]
Abstract
The laminated structure of the retina is fundamental for the organization of the synaptic circuitry that translates light input into patterns of action potentials. However, the molecular mechanisms underlying cell migration and layering of the retina are poorly understood. Here, we show that RBX2, a core component of the E3 ubiquitin ligase CRL5, is essential for retinal layering and function. RBX2 regulates the final cell position of rod bipolar cells, cone photoreceptors and Muller glia. Our data indicate that sustained RELN/DAB1 signaling, triggered by depletion of RBX2 or SOCS7 - a CRL5 substrate adaptor known to recruit DAB1 - causes rod bipolar cell misposition. Moreover, whereas SOCS7 also controls Muller glia cell lamination, it is not responsible for cone photoreceptor positioning, suggesting that RBX2, most likely through CRL5 activity, controls other signaling pathways required for proper cone localization. Furthermore, RBX2 depletion reduces the number of ribbon synapses and disrupts cone photoreceptor function. Together, these results uncover RBX2 as a crucial molecular regulator of retina morphogenesis and cone photoreceptor function.
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Affiliation(s)
- Corinne L Fairchild
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Keiko Hino
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Jisoo S Han
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Adam M Miltner
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Gabriel Peinado Allina
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Caileigh E Brown
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Marie E Burns
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA.,Department of Ophthalmology and Vision Science, University of California Davis, CA 95616, USA
| | - Anna La Torre
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Sergi Simó
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
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22
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Miesfeld JB, Glaser T, Brown NL. The dynamics of native Atoh7 protein expression during mouse retinal histogenesis, revealed with a new antibody. Gene Expr Patterns 2018; 27:114-121. [PMID: 29225067 PMCID: PMC5835195 DOI: 10.1016/j.gep.2017.11.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 11/17/2017] [Accepted: 11/28/2017] [Indexed: 12/19/2022]
Abstract
The Atoh7 transcription factor catalyzes the rate-limiting step in the specification of retinal ganglion cells (RGCs). As a tool to study vertebrate retinal development, we validate an antibody that recognizes human and mouse Atoh7 polypeptide, using informative knockout and transgenic mouse tissues and overexpression experiments. The transient features of Atoh7 protein expression during retinal neurogenesis match the expected pattern at the tissue and cellular level. Further, we compare endogenous Atoh7 to established RGC markers, reporter mouse lines and cell cycle markers, demonstrating the utility of the antibody to investigate molecular mechanisms of retinal histogenesis.
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Affiliation(s)
- Joel B Miesfeld
- Department of Cell Biology & Human Anatomy, University of California, Davis School of Medicine, One Shields Avenue, Davis, CA 95616, United States
| | - Tom Glaser
- Department of Cell Biology & Human Anatomy, University of California, Davis School of Medicine, One Shields Avenue, Davis, CA 95616, United States
| | - Nadean L Brown
- Department of Cell Biology & Human Anatomy, University of California, Davis School of Medicine, One Shields Avenue, Davis, CA 95616, United States.
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23
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The effects of C5-substituted 2,4-diaminoquinazolines on selected transcript expression in spinal muscular atrophy cells. PLoS One 2017; 12:e0180657. [PMID: 28662219 PMCID: PMC5491266 DOI: 10.1371/journal.pone.0180657] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/19/2017] [Indexed: 02/03/2023] Open
Abstract
C5-substituted 2,4-diaminoquinazolines (2,4-DAQs) ameliorate disease severity in SMA mice. It is uncertain, however, that these compounds increase SMN protein levels in vivo even though they were identified as activators of the SMN2 promoter. These compounds also regulate the expression of other transcripts in neuroblastoma cells. In this study, we investigate the mechanism by which the 2,4-DAQs regulate the expression of SMN2 as well as other targets. D156844, D158872, D157161 and D157495 (RG3039) increased SMN2 promoter-driven reporter gene activity by at least 3-fold in NSC-34 cells. These compounds, however, did not significantly increase SMN2 mRNA levels in type II SMA fibroblasts nor in NSC-34 cells, although there was a trend for these compounds increasing SMN protein in SMA fibroblasts. The number of SMN-containing gems was increased in SMA fibroblasts in response to 2,4-DAQ treatment in a dose-dependent manner. ATOH7 mRNA levels were significantly lower in type II SMA fibroblasts. 2,4-DAQs significantly increased ATOH7, DRNT1 and DRTN2 transcript levels in type II SMA fibroblasts and restored ATOH7 levels to those observed in healthy fibroblasts. These compounds also increase Atoh7 mRNA expression in NSC-34 cells. In conclusion, 2,4-DAQs regulate SMN2 by increasing protein levels and gem localization. They also increase ATOH7, DRNT1 and DRNT2 transcript levels. This study reveals that the protective effects of 2,4-DAQs in SMA may be independent of SMN2 gene regulation. These compounds could be used in concert with a proven SMN2 inducer to develop a multi-faceted approach to treating SMA.
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24
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Novel Regulatory Mechanisms for the SoxC Transcriptional Network Required for Visual Pathway Development. J Neurosci 2017; 37:4967-4981. [PMID: 28411269 DOI: 10.1523/jneurosci.3430-13.2017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 04/03/2017] [Accepted: 04/06/2017] [Indexed: 01/01/2023] Open
Abstract
What pathways specify retinal ganglion cell (RGC) fate in the developing retina? Here we report on mechanisms by which a molecular pathway involving Sox4/Sox11 is required for RGC differentiation and for optic nerve formation in mice in vivo, and is sufficient to differentiate human induced pluripotent stem cells into electrophysiologically active RGCs. These data place Sox4 downstream of RE1 silencing transcription factor in regulating RGC fate, and further describe a newly identified, Sox4-regulated site for post-translational modification with small ubiquitin-related modifier (SUMOylation) in Sox11, which suppresses Sox11's nuclear localization and its ability to promote RGC differentiation, providing a mechanism for the SoxC familial compensation observed here and elsewhere in the nervous system. These data define novel regulatory mechanisms for this SoxC molecular network, and suggest pro-RGC molecular approaches for cell replacement-based therapies for glaucoma and other optic neuropathies.SIGNIFICANCE STATEMENT Glaucoma is the most common cause of blindness worldwide and, along with other optic neuropathies, is characterized by loss of retinal ganglion cells (RGCs). Unfortunately, vision and RGC loss are irreversible, and lead to bilateral blindness in ∼14% of all diagnosed patients. Differentiated and transplanted RGC-like cells derived from stem cells have the potential to replace neurons that have already been lost and thereby to restore visual function. These data uncover new mechanisms of retinal progenitor cell (RPC)-to-RGC and human stem cell-to-RGC fate specification, and take a significant step toward understanding neuronal and retinal development and ultimately cell-transplant therapy.
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25
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Rodrigues T, Krawczyk M, Skowronska-Krawczyk D, Matter-Sadzinski L, Matter JM. Delayed neurogenesis with respect to eye growth shapes the pigeon retina for high visual acuity. Development 2016; 143:4701-4712. [PMID: 27836962 DOI: 10.1242/dev.138719] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 11/01/2016] [Indexed: 12/31/2022]
Abstract
The macula and fovea located at the optical centre of the retina make primate visual perception unique among mammals. Our current understanding of retina ontogenesis is primarily based on animal models having no macula and no fovea. However, the pigeon retina and the human macula share a number of structural and functional properties that justify introducing the former as a new model system for retina development. Comparative transcriptome analysis of pigeon and chicken retinas at different embryonic stages reveals that the genetic programmes underlying cell differentiation are postponed in the pigeon until the end of the period of cell proliferation. We show that the late onset of neurogenesis has a profound effect on the developmental patterning of the pigeon retina, which is at odds with the current models of retina development. The uncoupling of tissue growth and neurogenesis is shown to result from the fact that the pigeon retinal epithelium is inhibitory to cell differentiation. The sum of these developmental features allows the pigeon to build a retina that displays the structural and functional traits typical of primate macula and fovea.
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Affiliation(s)
- Tania Rodrigues
- Department of Molecular Biology and Department of Biochemistry, Sciences III, University of Geneva, 30 quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Michal Krawczyk
- Shiley Eye Institute, Department of Ophthalmology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Dorota Skowronska-Krawczyk
- Department of Molecular Biology and Department of Biochemistry, Sciences III, University of Geneva, 30 quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Lidia Matter-Sadzinski
- Department of Molecular Biology and Department of Biochemistry, Sciences III, University of Geneva, 30 quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Jean-Marc Matter
- Department of Molecular Biology and Department of Biochemistry, Sciences III, University of Geneva, 30 quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
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26
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The zebrafish homologs of SET/I2PP2A oncoprotein: expression patterns and insights into their physiological roles during development. Biochem J 2016; 473:4609-4627. [PMID: 27754889 DOI: 10.1042/bcj20160523] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 10/13/2016] [Accepted: 10/17/2016] [Indexed: 01/12/2023]
Abstract
The oncoprotein SET/I2PP2A (protein phosphatase 2A inhibitor 2) participates in various cellular mechanisms such as transcription, cell cycle regulation and cell migration. SET is also an inhibitor of the serine/threonine phosphatase PP2A, which is involved in the regulation of cell homeostasis. In zebrafish, there are two paralogous set genes that encode Seta (269 amino acids) and Setb (275 amino acids) proteins which share 94% identity. We show here that seta and setb are similarly expressed in the eye, the otic vesicle, the brain and the lateral line system, as indicated by in situ hybridization labeling. Whole-mount immunofluorescence analysis revealed the expression of Seta/b proteins in the eye retina, the olfactory pit and the lateral line neuromasts. Loss-of-function studies using antisense morpholino oligonucleotides targeting both seta and setb genes (MOab) resulted in increased apoptosis, reduced cell proliferation and morphological defects. The morphant phenotypes were partially rescued when MOab was co-injected with human SET mRNA. Knockdown of setb with a transcription-blocking morpholino oligonucleotide (MOb) resulted in phenotypic defects comparable with those induced by setb gRNA (guide RNA)/Cas9 [CRISPR (clustered regularly interspaced short palindromic repeats)-associated 9] injections. In vivo labeling of hair cells showed a significantly decreased number of neuromasts in MOab-, MOb- and gRNA/Cas9-injected embryos. Microarray analysis of MOab morphant transcriptome revealed differential expression in gene networks controlling transcription in the sensory organs, including the eye retina, the ear and the lateral line. Collectively, our results suggest that seta and setb are required during embryogenesis and play roles in the zebrafish sensory system development.
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27
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Brightman DS, Razafsky D, Potter C, Hodzic D, Chen S. Nrl-Cre transgenic mouse mediates loxP recombination in developing rod photoreceptors. Genesis 2016; 54:129-35. [PMID: 26789558 DOI: 10.1002/dvg.22918] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 01/11/2016] [Accepted: 01/13/2016] [Indexed: 12/15/2022]
Abstract
The developing mouse retina is a tractable model for studying neurogenesis and differentiation. Although transgenic Cre mouse lines exist to mediate conditional genetic manipulations in developing mouse retinas, none of them act specifically in early developing rods. For conditional genetic manipulations of developing retinas, a Nrl-Cre mouse line in which the Nrl promoter drives expression of Cre in rod precursors was created. The results showed that Nrl-Cre expression was specific to the retina where it drives rod-specific recombination with a temporal pattern similar to endogenous Nrl expression during retinal development. This Nrl-Cre transgene does not negatively impact retinal structure and function. Taken together, the data suggested that the Nrl-Cre mouse line was a valuable tool to drive Cre-mediated recombination specifically in developing rods.
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Affiliation(s)
- Diana S Brightman
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, Missouri.,Molecular Cell Biology Graduate Program, Division of Biology & Biomedical Sciences, Washington University School of Medicine, Saint Louis, Missouri
| | - David Razafsky
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, Missouri
| | - Chloe Potter
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, Missouri
| | - Didier Hodzic
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, Missouri
| | - Shiming Chen
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, Missouri.,Department of Developmental Biology, Washington University School of Medicine, Saint Louis, Missouri
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28
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Fritzsch B, Pan N, Jahan I, Elliott KL. Inner ear development: building a spiral ganglion and an organ of Corti out of unspecified ectoderm. Cell Tissue Res 2015; 361:7-24. [PMID: 25381571 PMCID: PMC4426086 DOI: 10.1007/s00441-014-2031-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 10/09/2014] [Indexed: 01/21/2023]
Abstract
The mammalian inner ear develops from a placodal thickening into a complex labyrinth of ducts with five sensory organs specialized to detect position and movement in space. The mammalian ear also develops a spiraled cochlear duct containing the auditory organ, the organ of Corti (OC), specialized to translate sound into hearing. Development of the OC from a uniform sheet of ectoderm requires unparalleled precision in the topological developmental engineering of four different general cell types, namely sensory neurons, hair cells, supporting cells, and general otic epithelium, into a mosaic of ten distinctly recognizable cell types in and around the OC, each with a unique distribution. Moreover, the OC receives unique innervation by ear-derived spiral ganglion afferents and brainstem-derived motor neurons as efferents and requires neural-crest-derived Schwann cells to form myelin and neural-crest-derived cells to induce the stria vascularis. This transformation of a sheet of cells into a complicated interdigitating set of cells necessitates the orchestrated expression of multiple transcription factors that enable the cellular transformation from ectoderm into neurosensory cells forming the spiral ganglion neurons (SGNs), while simultaneously transforming the flat epithelium into a tube, the cochlear duct, housing the OC. In addition to the cellular and conformational changes forming the cochlear duct with the OC, changes in the surrounding periotic mesenchyme form passageways for sound to stimulate the OC. We review molecular developmental data, generated predominantly in mice, in order to integrate the well-described expression changes of transcription factors and their actions, as revealed in mutants, in the formation of SGNs and OC in the correct position and orientation with suitable innervation. Understanding the molecular basis of these developmental changes leading to the formation of the mammalian OC and highlighting the gaps in our knowledge might guide in vivo attempts to regenerate this most complicated cellular mosaic of the mammalian body for the reconstitution of hearing in a rapidly growing population of aging people suffering from hearing loss.
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Affiliation(s)
- Bernd Fritzsch
- College of Liberal Arts and Sciences, Department of Biology, University of Iowa, 143 BB, 123 Jefferson Avenue, Iowa City, IA 52242, USA,
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29
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Takács-Vellai K, Vellai T, Farkas Z, Mehta A. Nucleoside diphosphate kinases (NDPKs) in animal development. Cell Mol Life Sci 2015. [PMID: 25537302 DOI: 10.07/s00018-014-1803-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
In textbooks of biochemistry, nucleoside diphosphate conversion to a triphosphate by nucleoside diphosphate 'kinases' (NDPKs, also named NME or NM23 proteins) merits a few lines of text. Yet this essential metabolic function, mediated by a multimeric phosphotransferase protein, has effects that lie beyond a simple housekeeping role. NDPKs attracted more attention when NM23-H1 was identified as the first metastasis suppressor gene. In this review, we examine these NDPK enzymes from a developmental perspective because of the tractable phenotypes found in simple animal models that point to common themes. The data suggest that NDPK enzymes control the availability of surface receptors to regulate cell-sensing cues during cell migration. NDPKs regulate different forms of membrane enclosure that engulf dying cells during development. We suggest that NDPK enzymes have been essential for the regulated uptake of objects such as bacteria or micronutrients, and this evolutionarily conserved endocytic function contributes to their activity towards the regulation of metastasis.
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Affiliation(s)
- Krisztina Takács-Vellai
- Department of Biological Anthropology, Eötvös Loránd University, Pázmány Péter stny. 1/C, 1117, Budapest, Hungary,
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30
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Takács-Vellai K, Vellai T, Farkas Z, Mehta A. Nucleoside diphosphate kinases (NDPKs) in animal development. Cell Mol Life Sci 2015; 72:1447-62. [PMID: 25537302 PMCID: PMC11113130 DOI: 10.1007/s00018-014-1803-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 12/04/2014] [Accepted: 12/08/2014] [Indexed: 12/25/2022]
Abstract
In textbooks of biochemistry, nucleoside diphosphate conversion to a triphosphate by nucleoside diphosphate 'kinases' (NDPKs, also named NME or NM23 proteins) merits a few lines of text. Yet this essential metabolic function, mediated by a multimeric phosphotransferase protein, has effects that lie beyond a simple housekeeping role. NDPKs attracted more attention when NM23-H1 was identified as the first metastasis suppressor gene. In this review, we examine these NDPK enzymes from a developmental perspective because of the tractable phenotypes found in simple animal models that point to common themes. The data suggest that NDPK enzymes control the availability of surface receptors to regulate cell-sensing cues during cell migration. NDPKs regulate different forms of membrane enclosure that engulf dying cells during development. We suggest that NDPK enzymes have been essential for the regulated uptake of objects such as bacteria or micronutrients, and this evolutionarily conserved endocytic function contributes to their activity towards the regulation of metastasis.
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Affiliation(s)
- Krisztina Takács-Vellai
- Department of Biological Anthropology, Eötvös Loránd University, Pázmány Péter stny. 1/C, 1117, Budapest, Hungary,
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31
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Song WT, Zhang XY, Xia XB. Atoh7 promotes the differentiation of Müller cells-derived retinal stem cells into retinal ganglion cells in a rat model of glaucoma. Exp Biol Med (Maywood) 2015; 240:682-90. [PMID: 25710928 DOI: 10.1177/1535370214560965] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 09/30/2014] [Indexed: 01/10/2023] Open
Abstract
Glaucoma is one of the leading eye diseases resulting in blindness due to the death of retinal ganglion cells. This study aimed to develop novel protocol to promote the differentiation of retinal Müller cells into ganglion cells in vivo in a rat model of glaucoma. The stem cells dedifferentiated from rat retinal Müller cells were randomized to receive transfection with empty lentivirus PGC-FU-GFP or lentivirus PGC-FU-Atoh7-GFP, or no transfection. The stem cells were induced further to differentiate. Ocular hypertension was induced using laser photocoagulation. The eyes were injected with Atoh7 expression vector lentivirus PGC-FU-Atoh7-GFP. Eyeball frozen sections, immunohistochemistry, RT-PCR, Western bolt, and apoptosis assay were performed. We found that the proportion of ganglion cells differentiated from Atoh7-tranfected stem cells was significantly higher than that of the other two groups. The mean intraocular pressure of glaucomatous eyes was elevated significantly compared with those of contralateral eyes. Some retinal Müller cells in the inner nuclear layer entered the mitotic cell cycle in rat chronic ocular hypertension glaucoma model. Atoh7 contributes to the differentiation of retinal Müller cells into retinal ganglion cells in rat model of glaucoma. In conclusion, Atoh7 promotes the differentiation of Müller cells-derived retinal stem cells into retinal ganglion cells in a rat model of glaucoma, thus opening up a new avenue for gene therapy and optic nerve regeneration in glaucoma.
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Affiliation(s)
- Wei-tao Song
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Xue-yong Zhang
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Xiao-bo Xia
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, China
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32
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Sinn R, Peravali R, Heermann S, Wittbrodt J. Differential responsiveness of distinct retinal domains to Atoh7. Mech Dev 2014; 133:218-29. [PMID: 25151399 PMCID: PMC4232737 DOI: 10.1016/j.mod.2014.08.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/24/2014] [Accepted: 08/11/2014] [Indexed: 02/03/2023]
Abstract
During vertebrate eye development retinal progenitor cells (RPCs) differentiate into all neural cell types of the retina. Retinal ganglion cells (RGCs) represent the first cell type to be generated. For their development, Atoh7, a basic Helix Loop Helix (bHLH) transcription factor is crucial. Atoh7 loss of function results in a massive reduction or even a total loss of RGCs. However, inconsistent results have been obtained in atoh7 gain of function experiments with respect to ganglion cell genesis, implying that the effect of Atoh7 is likely to be dependent on the competence state of the RPC. In this study we addressed the differential susceptibilities of early RPCs to Atoh7 in vivo, using medaka. Unexpectedly, we observed a largely normal development of the dorsal retina, although atoh7 was precociously expressed. However, the development of the retina close to the optic nerve head (part of the ventral retina) was disturbed severely. Photoreceptors were largely absent and the Müller glia cell number was reduced significantly. The majority of cells in this domain were ganglion cells and the abnormal development of this area affected the closure of the optic fissure resulting in coloboma.
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Affiliation(s)
- Rebecca Sinn
- Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany; Hartmut Hoffmann-Berling International Graduate School (HBIGS), Heidelberg, Germany
| | - Ravindra Peravali
- Institute of Toxicology and Genetics (ITG), Karlsruhe Institute of Technology, Germany
| | - Stephan Heermann
- Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany; Institute for Anatomy and Cell Biology, Dept. of Molecular Embryology, University Freiburg, Freiburg, Germany
| | - Joachim Wittbrodt
- Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
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33
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Abstract
Proneural genes encode evolutionarily conserved basic-helix-loop-helix transcription factors. In Drosophila, proneural genes are required and sufficient to confer a neural identity onto naïve ectodermal cells, inducing delamination and subsequent neuronal differentiation. In vertebrates, proneural genes are expressed in cells that already have a neural identity, but they are still required and sufficient to initiate neurogenesis. In all organisms, proneural genes control neurogenesis by regulating Notch-mediated lateral inhibition and initiating the expression of downstream differentiation genes. The general mode of proneural gene function has thus been elucidated. However, the regulatory mechanisms that spatially and temporally control proneural gene function are only beginning to be deciphered. Understanding how proneural gene function is regulated is essential, as aberrant proneural gene expression has recently been linked to a variety of human diseases-ranging from cancer to neuropsychiatric illnesses and diabetes. Recent insights into proneural gene function in development and disease are highlighted herein.
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Affiliation(s)
- Carol Huang
- Department of Pediatrics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Jennifer A Chan
- Department of Pathology & Laboratory Medicine, Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada.
| | - Carol Schuurmans
- Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
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34
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Goetz JJ, Farris C, Chowdhury R, Trimarchi JM. Making of a retinal cell: insights into retinal cell-fate determination. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 308:273-321. [PMID: 24411174 DOI: 10.1016/b978-0-12-800097-7.00007-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Understanding the process by which an uncommitted dividing cell produces particular specialized cells within a tissue remains a fundamental question in developmental biology. Many tissues are well suited for cell-fate studies, but perhaps none more so than the developing retina. Traditionally, experiments using the retina have been designed to elucidate the influence that individual environmental signals or transcription factors can have on cell-fate decisions. Despite a substantial amount of information gained through these studies, there is still much that we do not yet understand about how cell fate is controlled on a systems level. In addition, new factors such as noncoding RNAs and regulators of chromatin have been shown to play roles in cell-fate determination and with the advent of "omics" technology more factors will most likely be identified. In this chapter we summarize both the traditional view of retinal cell-fate determination and introduce some new ideas that are providing a challenge to the older way of thinking about the acquisition of cell fates.
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Affiliation(s)
- Jillian J Goetz
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Caitlin Farris
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Rebecca Chowdhury
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Jeffrey M Trimarchi
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, USA.
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35
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Abstract
The basic helix-loop-helix factor Math5 (Atoh7) is critical for the determination of retinal ganglion cell (RGC) fate in mice. Recently, genome-wide association studies have identified the ATOH7 locus as a major determinant of variation in the human optic disc area, which is directly correlated with the RGC number. These studies suggest that the level of Math5 expression may determine the ultimate number of RGCs. To test this hypothesis, we systematically compared optic nerve area and RGC axon number in C57BL/6J congenic Math5+/- and +/+ mice at young adult and neonatal ages by transmission electron microscopy. Optic disc area and RGC abundance were not significantly different in adults, but heterozygotes had thinner optic nerves and 25-30% fewer RGCs at birth than wild-type littermates (P<0.05). Our results suggest that Math5 dosage is important for the genesis, but not the ultimate number, of RGCs. Our findings highlight the importance of ganglion cell culling as a compensatory mechanism for retinal homeostasis, and support a quantitative role for Math5 in RGC specification.
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36
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Hufnagel RB, Riesenberg AN, Quinn M, Brzezinski JA, Glaser T, Brown NL. Heterochronic misexpression of Ascl1 in the Atoh7 retinal cell lineage blocks cell cycle exit. Mol Cell Neurosci 2013; 54:108-20. [PMID: 23481413 DOI: 10.1016/j.mcn.2013.02.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 02/15/2013] [Accepted: 02/18/2013] [Indexed: 12/12/2022] Open
Abstract
Retinal neurons and glia arise from a common progenitor pool in a temporal order, with retinal ganglion cells (RGCs) appearing first, and Müller glia last. The transcription factors Atoh7/Math5 and Ascl1/Mash1 represent divergent bHLH clades, and exhibit distinct spatial and temporal retinal expression patterns, with little overlap during early development. Here, we tested the ability of Ascl1 to change the fate of cells in the Atoh7 lineage when misexpressed from the Atoh7 locus, using an Ascl1-IRES-DsRed2 knock-in allele. In Atoh7(Ascl1KI/+) and Atoh7(Ascl1KI/Ascl1KI) embryos, ectopic Ascl1 delayed cell cycle exit and differentiation, even in cells coexpressing Atoh7. The heterozygous retinas recovered, and eventually produced a normal complement of RGCs, while homozygous substitution of Ascl1 for Atoh7 did not promote postnatal retinal fates precociously, nor rescue Atoh7 mutant phenotypes. However, our analyses revealed two unexpected findings. First, ectopic Ascl1 disrupted cell cycle progression within the marked Atoh7 lineage, but also nonautonomously in other retinal cells. Second, the size of the Atoh7 retinal lineage was unaffected, supporting the idea of a compensatory shift of the non-proliferative cohort to maintain lineage size. Overall, we conclude that Ascl1 acts dominantly to block cell cycle exit, but is incapable of redirecting the fates of early RPCs.
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Affiliation(s)
- Robert B Hufnagel
- Division of Developmental Biology, Cincinnati Children's Hospital Research Foundation, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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Chiodini F, Matter-Sadzinski L, Rodrigues T, Skowronska-Krawczyk D, Brodier L, Schaad O, Bauer C, Ballivet M, Matter JM. A positive feedback loop between ATOH7 and a Notch effector regulates cell-cycle progression and neurogenesis in the retina. Cell Rep 2013; 3:796-807. [PMID: 23434507 DOI: 10.1016/j.celrep.2013.01.035] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 01/02/2013] [Accepted: 01/31/2013] [Indexed: 01/24/2023] Open
Abstract
The HES proteins are known Notch effectors and have long been recognized as important in inhibiting neuronal differentiation. However, the roles that they play in the specification of neuronal fate remain largely unknown. Here, we show that in the differentiating retinal epithelium, the proneural protein ATOH7 (ATH5) is required for the activation of the transcription of the Hes5.3 gene before the penultimate mitosis of progenitor cells. We further show that the HES5.3 protein slows down the cell-cycle progression of Atoh7-expressing cells, thereby establishing conditions for Atoh7 to reach a high level of expression in S phase and induce neuronal differentiation prior to the ultimate mitosis. Our study uncovers how a proneural protein recruits a protein known to be a component of the Notch signaling pathway in order to regulate the transition between an initial phase of selection among uncommitted progenitors and a later phase committing the selected progenitors to neuronal differentiation.
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Affiliation(s)
- Florence Chiodini
- Department of Biochemistry, Sciences II, University of Geneva, 1211 Geneva, Switzerland
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38
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Xiang M. Intrinsic control of mammalian retinogenesis. Cell Mol Life Sci 2012; 70:2519-32. [PMID: 23064704 DOI: 10.1007/s00018-012-1183-2] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 09/25/2012] [Accepted: 09/27/2012] [Indexed: 01/18/2023]
Abstract
The generation of appropriate and diverse neuronal and glial types and subtypes during development constitutes the critical first step toward assembling functional neural circuits. During mammalian retinogenesis, all seven neuronal and glial cell types present in the adult retina are specified from multipotent progenitors by the combined action of various intrinsic and extrinsic factors. Tremendous progress has been made over the past two decades in uncovering the complex molecular mechanisms that control retinal cell diversification. Molecular genetic studies coupled with bioinformatic approaches have identified numerous transcription factors and cofactors as major intrinsic regulators leading to the establishment of progenitor multipotency and eventual differentiation of various retinal cell types and subtypes. More recently, non-coding RNAs have emerged as another class of intrinsic factors involved in generating retinal cell diversity. These intrinsic regulatory factors are found to act in different developmental processes to establish progenitor multipotency, define progenitor competence, determine cell fates, and/or specify cell types and subtypes.
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Affiliation(s)
- Mengqing Xiang
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane West, Piscataway, NJ, 08854, USA.
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