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Honnell V, Sweeney S, Norrie J, Parks M, Ramirez C, Jannu AJ, Xu B, Teubner B, Lee AY, Bell C, Dyer MA. Evolutionary conservation of VSX2 super-enhancer modules in retinal development. Development 2024; 151:dev202435. [PMID: 38994775 PMCID: PMC11266796 DOI: 10.1242/dev.202435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 06/04/2024] [Indexed: 07/13/2024]
Abstract
Super-enhancers (SEs) are expansive regions of genomic DNA that regulate the expression of genes involved in cell identity and cell fate. We recently identified developmental stage- and cell type-specific modules within the murine Vsx2 SE. Here, we show that the human VSX2 SE modules have similar developmental stage- and cell type-specific activity in reporter gene assays. By inserting the human sequence of one VSX2 SE module into a mouse with microphthalmia, eye size was rescued. To understand the function of these SE modules during human retinal development, we deleted individual modules in human embryonic stem cells and generated retinal organoids. Deleting one module results in small organoids, recapitulating the small-eyed phenotype of mice with microphthalmia, while deletion of the other module led to disruptions in bipolar neuron development. This prototypical SE serves as a model for understanding developmental stage- and cell type-specific effects of neurogenic transcription factors with complex expression patterns. Moreover, by elucidating the gene regulatory mechanisms, we can begin to examine how dysregulation of these mechanisms contributes to phenotypic diversity and disease.
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Affiliation(s)
- Victoria Honnell
- Department of Developmental Neurobiology at St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Shannon Sweeney
- Department of Developmental Neurobiology at St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jackie Norrie
- Department of Developmental Neurobiology at St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Madison Parks
- Department of Developmental Neurobiology at St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Cody Ramirez
- Department of Developmental Neurobiology at St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Asha Jacob Jannu
- Department of Developmental Neurobiology at St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Beisi Xu
- Center for Applied Bioinformatics at St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Brett Teubner
- Department of Developmental Neurobiology at St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Ah Young Lee
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Claire Bell
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Michael A. Dyer
- Department of Developmental Neurobiology at St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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2
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Touahri Y, Hanna J, Tachibana N, Okawa S, Liu H, David LA, Olender T, Vasan L, Pak A, Mehta DN, Chinchalongporn V, Balakrishnan A, Cantrup R, Dixit R, Mattar P, Saleh F, Ilnytskyy Y, Murshed M, Mains PE, Kovalchuk I, Lefebvre JL, Leong HS, Cayouette M, Wang C, Del Sol A, Brand M, Reese BE, Schuurmans C. Pten regulates endocytic trafficking of cell adhesion and Wnt signaling molecules to pattern the retina. Cell Rep 2024; 43:114005. [PMID: 38551961 PMCID: PMC11290456 DOI: 10.1016/j.celrep.2024.114005] [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: 09/08/2022] [Revised: 01/30/2024] [Accepted: 03/11/2024] [Indexed: 04/28/2024] Open
Abstract
The retina is exquisitely patterned, with neuronal somata positioned at regular intervals to completely sample the visual field. Here, we show that phosphatase and tensin homolog (Pten) controls starburst amacrine cell spacing by modulating vesicular trafficking of cell adhesion molecules and Wnt proteins. Single-cell transcriptomics and double-mutant analyses revealed that Pten and Down syndrome cell adhesion molecule Dscam) are co-expressed and function additively to pattern starburst amacrine cell mosaics. Mechanistically, Pten loss accelerates the endocytic trafficking of DSCAM, FAT3, and MEGF10 off the cell membrane and into endocytic vesicles in amacrine cells. Accordingly, the vesicular proteome, a molecular signature of the cell of origin, is enriched in exocytosis, vesicle-mediated transport, and receptor internalization proteins in Pten conditional knockout (PtencKO) retinas. Wnt signaling molecules are also enriched in PtencKO retinal vesicles, and the genetic or pharmacological disruption of Wnt signaling phenocopies amacrine cell patterning defects. Pten thus controls vesicular trafficking of cell adhesion and signaling molecules to establish retinal amacrine cell mosaics.
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Affiliation(s)
- Yacine Touahri
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON M5T 3A9, Canada
| | - Joseph Hanna
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON M5T 3A9, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Nobuhiko Tachibana
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Satoshi Okawa
- Computational Biology Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 4362 Esch-sur-Alzette, Luxembourg; Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Hedy Liu
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Luke Ajay David
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON M5T 3A9, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Thomas Olender
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON K1H 8L6, Canada
| | - Lakshmy Vasan
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Alissa Pak
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Dhruv Nimesh Mehta
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON M5T 3A9, Canada
| | - Vorapin Chinchalongporn
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Anjali Balakrishnan
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Robert Cantrup
- Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Rajiv Dixit
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Pierre Mattar
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, QC H2W 1R7, Canada
| | - Fermisk Saleh
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Yaroslav Ilnytskyy
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Monzur Murshed
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, QC H3G 1A6, Canada
| | - Paul E Mains
- Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Igor Kovalchuk
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Julie L Lefebvre
- Department of Molecular Genetics, University of Toronto, Toronto ON M5S 1A8, Canada; Program for Neuroscience and Mental Health, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Hon S Leong
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Michel Cayouette
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, QC H2W 1R7, Canada
| | - Chao Wang
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Immunology, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Antonio Del Sol
- Computational Biology Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 4362 Esch-sur-Alzette, Luxembourg; CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain; IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Marjorie Brand
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON K1H 8L6, Canada
| | - Benjamin E Reese
- Department of Psychological and Brain Sciences, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106-5060, USA
| | - Carol Schuurmans
- Biological Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON M5T 3A9, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.
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3
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Li Y, Yu S, Jia X, Qiu X, He J. Defining morphologically and genetically distinct GABAergic/cholinergic amacrine cell subtypes in the vertebrate retina. PLoS Biol 2024; 22:e3002506. [PMID: 38363811 PMCID: PMC10914270 DOI: 10.1371/journal.pbio.3002506] [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: 05/06/2023] [Revised: 03/05/2024] [Accepted: 01/18/2024] [Indexed: 02/18/2024] Open
Abstract
In mammals, retinal direction selectivity originates from GABAergic/cholinergic amacrine cells (ACs) specifically expressing the sox2 gene. However, the cellular diversity of GABAergic/cholinergic ACs of other vertebrate species remains largely unexplored. Here, we identified 2 morphologically and genetically distinct GABAergic/cholinergic AC types in zebrafish, a previously undescribed bhlhe22+ type and a mammalian counterpart sox2+ type. Notably, while sole sox2 disruption removed sox2+ type, the codisruption of bhlhe22 and bhlhe23 was required to remove bhlhe22+ type. Also, both types significantly differed in dendritic arbors, lamination, and soma position. Furthermore, in vivo two-photon calcium imaging and the behavior assay suggested the direction selectivity of both AC types. Nevertheless, the 2 types showed preferential responses to moving bars of different sizes. Thus, our findings provide new cellular diversity and functional characteristics of GABAergic/cholinergic ACs in the vertebrate retina.
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Affiliation(s)
- Yan Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shuguang Yu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xinling Jia
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Xiaoying Qiu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Jie He
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
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4
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Kozlowski C, Hadyniak SE, Kay JN. Retinal neurons establish mosaic patterning by excluding homotypic somata from their dendritic territory. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.17.567616. [PMID: 38014021 PMCID: PMC10680827 DOI: 10.1101/2023.11.17.567616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
In vertebrate retina, individual neurons of the same type are distributed regularly across the tissue in a pattern known as a mosaic. Establishment of mosaics during development requires cell-cell repulsion among homotypic neurons, but the mechanisms underlying this repulsion remain unknown. Here we show that two mouse retinal cell types, OFF and ON starburst amacrine cells, establish mosaic spacing by using their dendritic arbors to repel neighboring homotypic somata. Using newly-generated transgenic tools and single cell labeling, we identify a transient developmental period when starburst somata receive extensive contacts from neighboring starburst dendrites; these serve to exclude somata from settling within the neighbor's dendritic territory. Dendrite-soma exclusion is mediated by MEGF10, a cell-surface molecule required for starburst mosaic patterning. Our results implicate dendrite-soma exclusion as a key mechanism underlying starburst mosaic spacing, and suggest that this could be a general mechanism for mosaic patterning across many cell types and species.
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Affiliation(s)
- Christopher Kozlowski
- Departments of Neurobiology, Ophthalmology, and Cell Biology, Duke University School of Medicine, Durham, NC 27710 USA
| | - Sarah E Hadyniak
- Departments of Neurobiology, Ophthalmology, and Cell Biology, Duke University School of Medicine, Durham, NC 27710 USA
| | - Jeremy N Kay
- Departments of Neurobiology, Ophthalmology, and Cell Biology, Duke University School of Medicine, Durham, NC 27710 USA
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5
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Dharmarajan S, Carrillo C, Qi Z, Wilson JM, Baucum AJ, Sorenson CM, Sheibani N, Belecky-Adams TL. Retinal inflammation in murine models of type 1 and type 2 diabetes with diabetic retinopathy. Diabetologia 2023; 66:2170-2185. [PMID: 37670018 PMCID: PMC10541343 DOI: 10.1007/s00125-023-05995-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 06/28/2023] [Indexed: 09/07/2023]
Abstract
AIMS/HYPOTHESIS The loss of pericytes surrounding the retinal vasculature in early diabetic retinopathy underlies changes to the neurovascular unit that lead to more destructive forms of the disease. However, it is unclear which changes lead to loss of retinal pericytes. This study investigated the hypothesis that chronic increases in one or more inflammatory factors mitigate the signalling pathways needed for pericyte survival. METHODS Loss of pericytes and levels of inflammatory markers at the mRNA and protein levels were investigated in two genetic models of diabetes, Ins2Akita/+ (a model of type 1 diabetes) and Leprdb/db (a model of type 2 diabetes), at early stages of diabetic retinopathy. In addition, changes that accompany gliosis and the retinal vasculature were determined. Finally, changes in retinal pericytes chronically incubated with vehicle or increasing amounts of IFNγ were investigated to determine the effects on pericyte survival. The numbers of pericytes, microglia, astrocytes and endothelial cells in retinal flatmounts were determined by immunofluorescence. Protein and mRNA levels of inflammatory factors were determined using multiplex ELISAs and quantitative reverse transcription PCR (qRT-PCR). The effects of IFNγ on the murine retinal pericyte survival-related platelet-derived growth factor receptor β (PDGFRβ) signalling pathway were investigated by western blot analysis. Finally, the levels of cell death-associated protein kinase C isoform delta (PKCδ) and cleaved caspase 3 (CC3) in pericytes were determined by western blot analysis and immunocytochemistry. RESULTS The essential findings of this study were that both type 1 and 2 diabetes were accompanied by a similar progression of retinal pericyte loss, as well as gliosis. However, inflammatory factor expression was dissimilar in the two models of diabetes, with peak expression occurring at different ages for each model. Retinal vascular changes were more severe in the type 2 diabetes model. Chronic incubation of murine retinal pericytes with IFNγ decreased PDGFRβ signalling and increased the levels of active PKCδ and CC3. CONCLUSIONS/INTERPRETATION We conclude that retinal inflammation is involved in and sustains pericyte loss as diabetic retinopathy progresses. Moreover, IFNγ plays a critical role in reducing pericyte survival in the retina by reducing activation of the PDGFRβ signalling pathway and increasing PKCδ levels and pericyte apoptosis.
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Affiliation(s)
- Subramanian Dharmarajan
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Casandra Carrillo
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Zhonghua Qi
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Jonathan M Wilson
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Anthony J Baucum
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Christine M Sorenson
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Nader Sheibani
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Teri L Belecky-Adams
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA.
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6
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Uttley K, Papanastasiou AS, Lahne M, Brisbane JM, MacDonald RB, Bickmore WA, Bhatia S. Unique activities of two overlapping PAX6 retinal enhancers. Life Sci Alliance 2023; 6:e202302126. [PMID: 37643867 PMCID: PMC10465922 DOI: 10.26508/lsa.202302126] [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: 05/01/2023] [Revised: 08/16/2023] [Accepted: 08/17/2023] [Indexed: 08/31/2023] Open
Abstract
Enhancers play a critical role in development by precisely modulating spatial, temporal, and cell type-specific gene expression. Sequence variants in enhancers have been implicated in diseases; however, establishing the functional consequences of these variants is challenging because of a lack of understanding of precise cell types and developmental stages where the enhancers are normally active. PAX6 is the master regulator of eye development, with a regulatory landscape containing multiple enhancers driving the expression in the eye. Whether these enhancers perform additive, redundant or distinct functions is unknown. Here, we describe the precise cell types and regulatory activity of two PAX6 retinal enhancers, HS5 and NRE. Using a unique combination of live imaging and single-cell RNA sequencing in dual enhancer-reporter zebrafish embryos, we uncover differences in the spatiotemporal activity of these enhancers. Our results show that although overlapping, these enhancers have distinct activities in different cell types and therefore likely nonredundant functions. This work demonstrates that unique cell type-specific activities can be uncovered for apparently similar enhancers when investigated at high resolution in vivo.
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Affiliation(s)
- Kirsty Uttley
- https://ror.org/011jsc803 MRC Human Genetics Unithttps://ror.org/01nrxwf90 , Institute of Genetics and Cancer, The University of Edinburgh, Edinburgh, UK
| | - Andrew S Papanastasiou
- https://ror.org/011jsc803 MRC Human Genetics Unithttps://ror.org/01nrxwf90 , Institute of Genetics and Cancer, The University of Edinburgh, Edinburgh, UK
| | - Manuela Lahne
- https://ror.org/02jx3x895 UCL Institute of Ophthalmology, University College London, Greater London, UK
| | - Jennifer M Brisbane
- https://ror.org/011jsc803 MRC Human Genetics Unithttps://ror.org/01nrxwf90 , Institute of Genetics and Cancer, The University of Edinburgh, Edinburgh, UK
| | - Ryan B MacDonald
- https://ror.org/02jx3x895 UCL Institute of Ophthalmology, University College London, Greater London, UK
| | - Wendy A Bickmore
- https://ror.org/011jsc803 MRC Human Genetics Unithttps://ror.org/01nrxwf90 , Institute of Genetics and Cancer, The University of Edinburgh, Edinburgh, UK
| | - Shipra Bhatia
- https://ror.org/011jsc803 MRC Human Genetics Unithttps://ror.org/01nrxwf90 , Institute of Genetics and Cancer, The University of Edinburgh, Edinburgh, UK
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7
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DeOliveira-Mello L, Baronio D, Panula P. Zebrafish embryonically exposed to valproic acid present impaired retinal development and sleep behavior. Autism Res 2023; 16:1877-1890. [PMID: 37638671 DOI: 10.1002/aur.3010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 07/23/2023] [Indexed: 08/29/2023]
Abstract
Prenatal exposure to valproic acid (VPA), a drug widely used to treat epilepsy and bipolar disorder, is an environmental risk factor for autism spectrum disorder (ASD). VPA has been used to reproduce the core symptoms of ASD in animal model organisms, including zebrafish. Visual system functioning is essential in the interpretation of social conditions and plays an important role of several behavioral responses. We hypothesized that behavioral deficits displayed by ASD patients may involve impaired visual processing. We used zebrafish as model organism to investigate the visual system after embryonic exposure to VPA using histological, behavioral and gene expression analysis. We analyzed the pineal gland of zebrafish and sleep-like behavior to study how VPA exposure alters photo-sensibility of zebrafish. VPA-exposed zebrafish showed a delay in the development of the retina and optic nerve, which normalized at five days post fertilization. At larval stage, VPA-exposed zebrafish showed sleep disturbances associated with a reduced number of serotonin-producing cells of the pineal gland. In addition, the number of hypocretin/orexin (hcrt) expressing neurons in the rostral hypothalamus at 6 and 14 days post fertilization was reduced. In conclusion, we demonstrated that although VPA exposure leads to a delay in visual system development, it does not affect larval visual function. The novel finding that VPA alters significantly cells involved in sleep regulation and the sleep-like state itself may be relevant for understanding sleep disturbances in ASD patients.
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Affiliation(s)
| | - Diego Baronio
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Pertti Panula
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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8
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Kerstein PC, Agreda YS, Curran BM, Ma L, Wright KM. Gbx2 controls amacrine cell dendrite stratification through Robo1/2 receptors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.03.551861. [PMID: 37577554 PMCID: PMC10418232 DOI: 10.1101/2023.08.03.551861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Within the neuronal classes of the retina, amacrine cells (ACs) exhibit the greatest neuronal diversity in morphology and function. We show that the selective expression of the transcription factor Gbx2 is required for cell fate specification and dendritic stratification of an individual AC subtype in the mouse retina. We identify Robo1 and Robo2 as downstream effectors that when deleted, phenocopy the dendritic misprojections seen in Gbx2 mutants. Slit1 and Slit2, the ligands of Robo receptors, are localized to the OFF layers of the inner plexiform layer where we observe the dendritic misprojections in both Gbx2 and Robo1/2 mutants. We show that Robo receptors also are required for the proper dendritic stratification of additional AC subtypes, such as Vglut3+ ACs. These results show both that Gbx2 functions as a terminal selector in a single AC subtype and identify Slit-Robo signaling as a developmental mechanism for ON-OFF pathway segregation in the retina.
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9
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Maruyama T, Ishii T, Kaneda M. Starburst amacrine cells form gap junctions in the early postnatal stage of the mouse retina. Front Cell Neurosci 2023; 17:1173579. [PMID: 37293630 PMCID: PMC10244514 DOI: 10.3389/fncel.2023.1173579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 05/03/2023] [Indexed: 06/10/2023] Open
Abstract
Although gap junctional coupling in the developing retina is important for the maturation of neuronal networks, its role in the development of individual neurons remains unclear. Therefore, we herein investigated whether gap junctional coupling by starburst amacrine cells (SACs), a key neuron for the formation of direction selectivity, occurs during the developmental stage in the mouse retina. Neurobiotin-injected SACs coupled with many neighboring cells before eye-opening. The majority of tracer-coupled cells were retinal ganglion cells, and tracer coupling was not detected between SACs. The number of tracer-coupled cells significantly decreased after eye-opening and mostly disappeared by postnatal day 28 (P28). Membrane capacitance (Cm), an indicator of the formation of electrical coupling with gap junctions, was larger in SACs before than after eye-opening. The application of meclofenamic acid, a gap junction blocker, reduced the Cm of SACs. Gap junctional coupling by SACs was regulated by dopamine D1 receptors before eye-opening. In contrast, the reduction in gap junctional coupling after eye-opening was not affected by visual experience. At the mRNA level, 4 subtypes of connexins (23, 36, 43, and 45) were detected in SACs before eye-opening. Connexin 43 expression levels significantly decreased after eye-opening. These results indicate that gap junctional coupling by SACs occurs during the developmental period and suggest that the elimination of gap junctions proceeds with the innate system.
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10
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Development of the vertebrate retinal direction-selective circuit. Dev Biol 2021; 477:273-283. [PMID: 34118273 DOI: 10.1016/j.ydbio.2021.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 05/17/2021] [Accepted: 06/04/2021] [Indexed: 01/13/2023]
Abstract
The vertebrate retina contains an array of neural circuits that detect distinct features in visual space. Direction-selective (DS) circuits are an evolutionarily conserved retinal circuit motif - from zebrafish to rodents to primates - specialized for motion detection. During retinal development, neuronal subtypes that wire DS circuits form exquisitely precise connections with each other to shape the output of retinal ganglion cells tuned for specific speeds and directions of motion. In this review, we follow the chronology of DS circuit development in the vertebrate retina, including the cellular, molecular, and activity-dependent mechanisms that regulate the formation of DS circuits, from cell birth and migration to synapse formation and refinement. We highlight recent findings that identify genetic programs critical for specifying neuronal subtypes within DS circuits and molecular interactions essential for responses along the cardinal axes of motion. Finally, we discuss the roles of DS circuits in visual behavior and in certain human visual disease conditions. As one of the best-characterized circuits in the vertebrate retina, DS circuits represent an ideal model system for studying the development of neural connectivity at the level of individual genes, cells, and behavior.
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11
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Haverkamp S, Albert L, Balaji V, Němec P, Dedek K. Expression of cell markers and transcription factors in the avian retina compared with that in the marmoset retina. J Comp Neurol 2021; 529:3171-3193. [PMID: 33834511 DOI: 10.1002/cne.25154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/27/2021] [Accepted: 03/29/2021] [Indexed: 02/06/2023]
Abstract
In the vertebrate retina, amacrine and ganglion cells represent the most diverse cell classes. They can be classified into different cell types by several features, such as morphology, light responses, and gene expression profile. Although birds possess high visual acuity (similar to primates that we used here for comparison) and tetrachromatic color vision, data on the expression of transcription factors in retinal ganglion cells of birds are largely missing. In this study, we tested various transcription factors, known to label subpopulations of cells in mammalian retinae, in two avian species: the common buzzard (Buteo buteo), a raptor with exceptional acuity, and the domestic pigeon (Columba livia domestica), a good navigator and widely used model for visual cognition. Staining for the transcription factors Foxp2, Satb1 and Satb2 labeled most ganglion cells in the avian ganglion cell layer. CtBP2 was established as marker for displaced amacrine cells, which allowed us to reliably distinguish ganglion cells from displaced amacrine cells and assess their densities in buzzard and pigeon. When we additionally compared the temporal and central fovea of the buzzard with the fovea of primates, we found that the cellular organization in the pits was different in primates and raptors. In summary, we demonstrate that the expression of transcription factors is a defining feature of cell types not only in the retina of mammals but also in the retina of birds. The markers, which we have established, may provide useful tools for more detailed studies on the retinal circuitry of these highly visual animals.
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Affiliation(s)
- Silke Haverkamp
- Department of Computational Neuroethology, Center of Advanced European Studies and Research (caesar), Bonn, Germany
| | - László Albert
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Vaishnavi Balaji
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Pavel Němec
- Department of Zoology, Charles University, Prague, Czech Republic
| | - Karin Dedek
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany.,Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
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12
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Gao H, A L, Huang X, Chen X, Xu H. Müller Glia-Mediated Retinal Regeneration. Mol Neurobiol 2021; 58:2342-2361. [PMID: 33417229 DOI: 10.1007/s12035-020-02274-w] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 12/22/2020] [Indexed: 12/18/2022]
Abstract
Müller glia originate from neuroepithelium and are the principal glial cells in the retina. During retinal development, Müller glia are one of the last cell types to be born. In lower vertebrates, such as zebrafish, Müller glia possess a remarkable capacity for retinal regeneration following various forms of injury through a reprogramming process in which endogenous Müller glia proliferate and differentiate into all types of retinal cells. In mammals, Müller glia become reactive in response to damage to protect or to further impair retinal function. Although mammalian Müller glia have regenerative potential, it is limited as far as repairing damaged retina. Lessons learned from zebrafish will help reveal the critical mechanisms involved in Müller glia reprogramming. Progress has been made in triggering Müller glia to reprogram and generate functional neurons to restore vision in mammals indicating that Müller glia reprogramming may be a promising therapeutic strategy for human retinal diseases. This review comprehensively summarizes the mechanisms related to retinal regeneration in model animals and the critical advanced progress made in Müller glia reprogramming in mammals.
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Affiliation(s)
- Hui Gao
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, 400038, China
| | - Luodan A
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, 400038, China
| | - Xiaona Huang
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, 400038, China
| | - Xi Chen
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
| | - Haiwei Xu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, China.
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, 400038, China.
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13
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Kerstein PC, Leffler J, Sivyer B, Taylor WR, Wright KM. Gbx2 Identifies Two Amacrine Cell Subtypes with Distinct Molecular, Morphological, and Physiological Properties. Cell Rep 2020; 33:108382. [PMID: 33207201 PMCID: PMC7713908 DOI: 10.1016/j.celrep.2020.108382] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/21/2020] [Accepted: 10/22/2020] [Indexed: 01/21/2023] Open
Abstract
Our understanding of nervous system function is limited by our ability to identify and manipulate neuronal subtypes within intact circuits. We show that the Gbx2CreERT2-IRES-EGFP mouse line labels two amacrine cell (AC) subtypes in the mouse retina that have distinct morphological, physiological, and molecular properties. Using a combination of RNA-seq, genetic labeling, and patch clamp recordings, we show that one subtype is GABAergic that receives excitatory input from On bipolar cells. The other population is a non-GABAergic, non-glycinergic (nGnG) AC subtype that lacks the expression of standard neurotransmitter markers. Gbx2+ nGnG ACs have smaller, asymmetric dendritic arbors that receive excitatory input from both On and Off bipolar cells. Gbx2+ nGnG ACs also exhibit spatially restricted tracer coupling to bipolar cells (BCs) through gap junctions. This study identifies a genetic tool for investigating the two distinct AC subtypes, and it provides a model for studying synaptic communication and visual circuit function. Investigations into neural circuit development and function are limited by the lack of genetic tools to label and perturb individual neuronal subtypes. Using the Gbx2CreERT2 mouse line, Kerstein et al. identify two amacrine cell subtypes in the mouse retina and explore their distinct molecular, morphological, and physiological characteristics.
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Affiliation(s)
- Patrick C Kerstein
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Joseph Leffler
- School of Optometry and Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA; Neuroscience Graduate Program, Oregon Health and Science University, Portland, OR 97239, USA
| | - Benjamin Sivyer
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, OR 97239, USA; Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97239, USA
| | - W Rowland Taylor
- School of Optometry and Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Kevin M Wright
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239, USA; Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, OR 97239, USA.
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14
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Abstract
Retinal ganglion cell axons forming the optic nerve (ON) emerge unmyelinated from the eye and become myelinated after passage through the optic nerve lamina region (ONLR), a transitional area containing a vascular plexus. The ONLR has a number of unusual characteristics: it inhibits intraocular myelination, enables postnatal ON myelination of growing axons, modulates the fluid pressure differences between eye and brain, and is the primary lesion site in the age-related disease open angle glaucoma (OAG). We demonstrate that the human and rodent ONLR possesses a mitotically active, age-depletable neural progenitor cell (NPC) niche, with unique characteristics and culture requirements. These NPCs generate both forms of macroglia: astrocytes and oligodendrocytes, and can form neurospheres in culture. Using reporter mice with SOX2-driven, inducible gene expression, we show that ONLR-NPCs generate macroglial cells for the anterior ON. Early ONLR-NPC loss results in regional dysfunction and hypomyelination. In adulthood, ONLR-NPCs may enable glial replacement and remyelination. ONLR-NPC depletion may help explain why ON diseases such as OAG progress in severity during aging.
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15
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Yan W, Laboulaye MA, Tran NM, Whitney IE, Benhar I, Sanes JR. Mouse Retinal Cell Atlas: Molecular Identification of over Sixty Amacrine Cell Types. J Neurosci 2020; 40:5177-5195. [PMID: 32457074 PMCID: PMC7329304 DOI: 10.1523/jneurosci.0471-20.2020] [Citation(s) in RCA: 149] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/07/2020] [Accepted: 05/13/2020] [Indexed: 02/01/2023] Open
Abstract
Amacrine cells (ACs) are a diverse class of interneurons that modulate input from photoreceptors to retinal ganglion cells (RGCs), rendering each RGC type selectively sensitive to particular visual features, which are then relayed to the brain. While many AC types have been identified morphologically and physiologically, they have not been comprehensively classified or molecularly characterized. We used high-throughput single-cell RNA sequencing to profile >32,000 ACs from mice of both sexes and applied computational methods to identify 63 AC types. We identified molecular markers for each type and used them to characterize the morphology of multiple types. We show that they include nearly all previously known AC types as well as many that had not been described. Consistent with previous studies, most of the AC types expressed markers for the canonical inhibitory neurotransmitters GABA or glycine, but several expressed neither or both. In addition, many expressed one or more neuropeptides, and two expressed glutamatergic markers. We also explored transcriptomic relationships among AC types and identified transcription factors expressed by individual or multiple closely related types. Noteworthy among these were Meis2 and Tcf4, expressed by most GABAergic and most glycinergic types, respectively. Together, these results provide a foundation for developmental and functional studies of ACs, as well as means for genetically accessing them. Along with previous molecular, physiological, and morphologic analyses, they establish the existence of at least 130 neuronal types and nearly 140 cell types in the mouse retina.SIGNIFICANCE STATEMENT The mouse retina is a leading model for analyzing the development, structure, function, and pathology of neural circuits. A complete molecular atlas of retinal cell types provides an important foundation for these studies. We used high-throughput single-cell RNA sequencing to characterize the most heterogeneous class of retinal interneurons, amacrine cells, identifying 63 distinct types. The atlas includes types identified previously as well as many novel types. We provide evidence for the use of multiple neurotransmitters and neuropeptides, and identify transcription factors expressed by groups of closely related types. Combining these results with those obtained previously, we proposed that the mouse retina contains ∼130 neuronal types and is therefore comparable in complexity to other regions of the brain.
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Affiliation(s)
- Wenjun Yan
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Mallory A Laboulaye
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Nicholas M Tran
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Irene E Whitney
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Inbal Benhar
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
| | - Joshua R Sanes
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138
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16
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Keeley PW, Eglen SJ, Reese BE. From random to regular: Variation in the patterning of retinal mosaics. J Comp Neurol 2020; 528:2135-2160. [PMID: 32026463 DOI: 10.1002/cne.24880] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/07/2020] [Accepted: 01/31/2020] [Indexed: 12/23/2022]
Abstract
The various types of retinal neurons are each positioned at their respective depths within the retina where they are believed to be assembled as orderly mosaics, in which like-type neurons minimize proximity to one another. Two common statistical analyses for assessing the spatial properties of retinal mosaics include the nearest neighbor analysis, from which an index of their "regularity" is commonly calculated, and the density recovery profile derived from autocorrelation analysis, revealing the presence of an exclusion zone indicative of anti-clustering. While each of the spatial statistics derived from these analyses, the regularity index and the effective radius, can be useful in characterizing such properties of orderly retinal mosaics, they are rarely sufficient for conveying the natural variation in the self-spacing behavior of different types of retinal neurons and the extent to which that behavior generates uniform intercellular spacing across the mosaic. We consider the strengths and limitations of these and other spatial statistical analyses for assessing the patterning in retinal mosaics, highlighting a number of misconceptions and their frequent misuse. Rather than being diagnostic criteria for determining simply whether a population is "regular," they should be treated as descriptive statistics that convey variation in the factors that influence neuronal positioning. We subsequently apply multiple spatial statistics to the analysis of eight different mosaics in the mouse retina, demonstrating conspicuous variability in the degree of patterning present, from essentially random to notably regular. This variability in patterning has both a developmental as well as a functional significance, reflecting the rules governing the positioning of different types of neurons as the architecture of the retina is assembled, and the distinct mechanisms by which they regulate dendritic growth to generate their characteristic coverage and connectivity.
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Affiliation(s)
- Patrick W Keeley
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, California
| | - Stephen J Eglen
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, UK
| | - Benjamin E Reese
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, California.,Department of Psychological and Brain Sciences, University of California at Santa Barbara, Santa Barbara, California
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17
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Shrestha S, Sewell JA, Santoso CS, Forchielli E, Carrasco Pro S, Martinez M, Fuxman Bass JI. Discovering human transcription factor physical interactions with genetic variants, novel DNA motifs, and repetitive elements using enhanced yeast one-hybrid assays. Genome Res 2020; 29:1533-1544. [PMID: 31481462 PMCID: PMC6724672 DOI: 10.1101/gr.248823.119] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 07/23/2019] [Indexed: 12/29/2022]
Abstract
Identifying transcription factor (TF) binding to noncoding variants, uncharacterized DNA motifs, and repetitive genomic elements has been technically and computationally challenging. Current experimental methods, such as chromatin immunoprecipitation, generally test one TF at a time, and computational motif algorithms often lead to false-positive and -negative predictions. To address these limitations, we developed an experimental approach based on enhanced yeast one-hybrid assays. The first variation of this approach interrogates the binding of >1000 human TFs to repetitive DNA elements, while the second evaluates TF binding to single nucleotide variants, short insertions and deletions (indels), and novel DNA motifs. Using this approach, we detected the binding of 75 TFs, including several nuclear hormone receptors and ETS factors, to the highly repetitive Alu elements. Further, we identified cancer-associated changes in TF binding, including gain of interactions involving ETS TFs and loss of interactions involving KLF TFs to different mutations in the TERT promoter, and gain of a MYB interaction with an 18-bp indel in the TAL1 superenhancer. Additionally, we identified TFs that bind to three uncharacterized DNA motifs identified in DNase footprinting assays. We anticipate that these enhanced yeast one-hybrid approaches will expand our capabilities to study genetic variation and undercharacterized genomic regions.
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Affiliation(s)
- Shaleen Shrestha
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA
| | - Jared Allan Sewell
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA
| | | | - Elena Forchielli
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA
| | | | - Melissa Martinez
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA
| | - Juan Ignacio Fuxman Bass
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA.,Bioinformatics Program, Boston University, Boston, Massachusetts 02215, USA
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18
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Peng YR, James RE, Yan W, Kay JN, Kolodkin AL, Sanes JR. Binary Fate Choice between Closely Related Interneuronal Types Is Determined by a Fezf1-Dependent Postmitotic Transcriptional Switch. Neuron 2019; 105:464-474.e6. [PMID: 31812516 DOI: 10.1016/j.neuron.2019.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 10/07/2019] [Accepted: 10/30/2019] [Indexed: 02/08/2023]
Abstract
Many neuronal types occur as pairs that are similar in most respects but differ in a key feature. In some pairs of retinal neurons, called paramorphic, one member responds to increases and the other to decreases in luminance (ON and OFF responses). Here, we focused on one such pair, starburst amacrine cells (SACs), to explore how closely related neuronal types diversify. We find that ON and OFF SACs are transcriptionally distinct prior to their segregation, dendritic outgrowth, and synapse formation. The transcriptional repressor Fezf1 is selectively expressed by postmitotic ON SACs and promotes the ON fate and gene expression program while repressing the OFF fate and program. The atypical Rho GTPase Rnd3 is selectively expressed by OFF SACs and regulates their migration but is repressed by Fezf1 in ON SACs, enabling differential positioning of the two types. These results define a transcriptional program that controls diversification of a paramorphic pair.
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Affiliation(s)
- Yi-Rong Peng
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Rebecca E James
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Wenjun Yan
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Jeremy N Kay
- Departments of Ophthalmology and Neurobiology, Duke University Medical Center, Durham, NC, USA
| | - Alex L Kolodkin
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Joshua R Sanes
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
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19
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DeOliveira-Mello L, Lara JM, Arevalo R, Velasco A, Mack AF. Sox2 expression in the visual system of two teleost species. Brain Res 2019; 1722:146350. [DOI: 10.1016/j.brainres.2019.146350] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 06/20/2019] [Accepted: 07/23/2019] [Indexed: 12/13/2022]
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20
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Mercurio S, Serra L, Nicolis SK. More than just Stem Cells: Functional Roles of the Transcription Factor Sox2 in Differentiated Glia and Neurons. Int J Mol Sci 2019; 20:E4540. [PMID: 31540269 PMCID: PMC6769708 DOI: 10.3390/ijms20184540] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/02/2019] [Accepted: 09/06/2019] [Indexed: 02/06/2023] Open
Abstract
The Sox2 transcription factor, encoded by a gene conserved in animal evolution, has become widely known because of its functional relevance for stem cells. In the developing nervous system, Sox2 is active in neural stem cells, and important for their self-renewal; differentiation to neurons and glia normally involves Sox2 downregulation. Recent evidence, however, identified specific types of fully differentiated neurons and glia that retain high Sox2 expression, and critically require Sox2 function, as revealed by functional studies in mouse and in other animals. Sox2 was found to control fundamental aspects of the biology of these cells, such as the development of correct neuronal connectivity. Sox2 downstream target genes identified within these cell types provide molecular mechanisms for cell-type-specific Sox2 neuronal and glial functions. SOX2 mutations in humans lead to a spectrum of nervous system defects, involving vision, movement control, and cognition; the identification of neurons and glia requiring Sox2 function, and the investigation of Sox2 roles and molecular targets within them, represents a novel perspective for the understanding of the pathogenesis of these defects.
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Affiliation(s)
- Sara Mercurio
- Department of Biotechnology and Biosciences, University Milano-Bicocca, 20126 Milano, Italy.
| | - Linda Serra
- Department of Biotechnology and Biosciences, University Milano-Bicocca, 20126 Milano, Italy
- CNRS, Inserm, iBV, Université Côte d'Azur, 06108 Nice, France
| | - Silvia K Nicolis
- Department of Biotechnology and Biosciences, University Milano-Bicocca, 20126 Milano, Italy.
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21
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Josifovska N, Lumi X, Szatmari-Tóth M, Kristóf E, Russell G, Nagymihály R, Anisimova N, Malyugin B, Kolko M, Ivastinović D, Petrovski G. Clinical and molecular markers in retinal detachment-From hyperreflective points to stem cells and inflammation. PLoS One 2019; 14:e0217548. [PMID: 31185026 PMCID: PMC6559703 DOI: 10.1371/journal.pone.0217548] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 05/14/2019] [Indexed: 12/22/2022] Open
Abstract
PURPOSE Retinal detachment (RD) is one of the most frequently diagnosed ophthalmologic conditions requiring prompt surgical intervention. Combination of proper surgical technique and new diagnostic markers, both clinical and molecular, can help improve the diagnosis and prognosis of RD treatment. METHODS 12 patients with rhegmatogenous RD (rRD) were included into the study after obtaining patient consent and Regional Ethical Approval (average age: 58.1 ± 17.4 years). OCT was performed before and after 23G vitrectomy for RD. Pure subretinal fluid (SRF) was collected during surgery and analyzed by protein array profiling on a panel of 105 inflammatory cytokines (Human XL Cytokine Array), while the effect of SRF upon human macrophages-driven phagocytosis of apoptotic retinal pigment epithelial (RPE) cells ex vivo was quantified by flow cytometry. Immunohistochemistry (IHC) of retinectomized tissue due to PVR caused by RD was performed to determine presence of markers for microglial cells (CD34), macrophages and activated microglia (CD68), regulator of the immune response to infection (NFkB), progenitor and stem cell marker (Sox2), pluripotency marker (Oct4) and intermediate filament markers (GFAP and Nestin). RESULTS OCT of fresh RD patients contained pre-operatively hyper reflective points (HRPs) at the detached neuroretina border and proximal to the RPE layer-their size and number decreased following successful reattachment surgery. IHC of the retinectomized tissue from detached retina due to severe PVR showed presence of cell conglomerates at the detached neuroretina border which were positive for CD68, NFkB, Sox2 and GFAP, less positive for CD47 and Nestin and negative for Oct4 and CD34. The SRF contained at least 37 cytokines with higher, and 4 cytokine with lower concentration compared to that in vitreous from non-RD pathology; when used as conditional medium to human macrophages ex vivo, the SRF doubled their capacity for engulfing dying RPEs. CONCLUSIONS Fresh RD can be hallmarked by presence of HRPs at the detached neuroretina border on OCT; the HRPs decrease in size and number after successful reattachment surgery, and likely resemble the macrophage conglomerates seen by IHC. The neuroretina in RD contains progenitor/stem-like cells and signs of inflammatory reaction, while the SRF contains inflammatory cytokines and other factors which increase the ability of professional phagocytes to engulf dying RPE, or for that matter, other dying cells in the retina.
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Affiliation(s)
- Natasha Josifovska
- Center for Eye Research, Department of Ophthalmology, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Xhevat Lumi
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia
| | - Mária Szatmari-Tóth
- Department of Biochemistry and Molecular Biology and MTA-DE Stem cell, Apoptosis and Genomics Research Group, University of Debrecen, Debrecen, Hungary
| | - Endre Kristóf
- Department of Biochemistry and Molecular Biology and MTA-DE Stem cell, Apoptosis and Genomics Research Group, University of Debrecen, Debrecen, Hungary
| | - Greg Russell
- Department of Ophthalmology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Richárd Nagymihály
- Center for Eye Research, Department of Ophthalmology, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Natalia Anisimova
- S. Fyodorov Eye Microsurgery State Institution, Moscow, Russian Federation
| | - Boris Malyugin
- S. Fyodorov Eye Microsurgery State Institution, Moscow, Russian Federation
| | - Miriam Kolko
- Department of Drug Design and Pharmacology, University of Copenhagen and Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet-Glostrup, Copenhagen, Denmark
| | | | - Goran Petrovski
- Center for Eye Research, Department of Ophthalmology, Oslo University Hospital and University of Oslo, Oslo, Norway
- Department of Ophthalmology, Faculty of Medicine, University of Szeged, Szeged, Hungary
- * E-mail:
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22
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Hicks EA, Zaveri M, Deschamps PA, Noseworthy MD, Ball A, Williams T, West-Mays JA. Conditional Deletion of AP-2α and AP-2β in the Developing Murine Retina Leads to Altered Amacrine Cell Mosaics and Disrupted Visual Function. Invest Ophthalmol Vis Sci 2019; 59:2229-2239. [PMID: 29715367 PMCID: PMC5931233 DOI: 10.1167/iovs.17-23283] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The combined action of the activating protein-2 (AP-2) transcription factors, AP-2α and AP-2β, is important in early retinal development, specifically in the formation of horizontal cells. However, in previous studies, it was not possible to analyze postnatal development and function of additional retinal subtypes. Methods We used a double conditional deletion of AP-2α and AP-2β from the retina to further examine the combinatory role of these genes in retinal cell patterning and function in postnatal adult mice as measured by Voronoi domain area and nearest-neighbor distance spatial analyses and ERGs, respectively. Results Conditional deletion of both AP-2α and AP-2β from the retina resulted in a variety of abnormalities, including the absence of horizontal cells, defects in the photoreceptor ribbons in which synapses failed to form, along with evidence of aberrant amacrine cell arrangement. Although no significant changes in amacrine cell population numbers were observed in the double mutants, significant irregularities in the mosaic patterning of amacrine cells was observed as demonstrated by both Voronoi domain areas and nearest-neighbor distances analyses. These changes were further accompanied by an alteration in the retinal response to light as recorded by ERGs. In particular, in the double-mutant mice lacking AP-2α and AP-2β, the b-wave amplitude, representative of interneuron signal processing, was significantly reduced compared with control littermates. Conclusions Together these findings demonstrate the requirement for both AP-2α and AP-2β in proper amacrine mosaic patterning and a normal functional light response in the retina.
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Affiliation(s)
- Emily Anne Hicks
- McMaster School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Mizna Zaveri
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Paula A Deschamps
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Michael D Noseworthy
- McMaster School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada.,Department of Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada.,Department of Radiology, McMaster University, Hamilton, Ontario, Canada
| | - Alexander Ball
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Trevor Williams
- Department of Craniofacial Biology and Department of Cell and Developmental Biology, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado, United States
| | - Judith A West-Mays
- McMaster School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
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23
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Ghinia MG, Novelli E, Sajgo S, Badea TC, Strettoi E. Brn3a and Brn3b knockout mice display unvaried retinal fine structure despite major morphological and numerical alterations of ganglion cells. J Comp Neurol 2019; 527:187-211. [PMID: 27391320 PMCID: PMC5219957 DOI: 10.1002/cne.24072] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 06/07/2016] [Accepted: 06/30/2016] [Indexed: 01/21/2023]
Abstract
Ganglion cells (GCs), the retinal output neurons, receive synaptic inputs from bipolar and amacrine cells in the inner plexiform layer (IPL) and send information to the brain nuclei via the optic nerve. Although GCs constitute less than 1% of the total retinal cells, they occur in numerous types and are the first neurons formed during retinal development. Using Brn3a and Brn3b mutant mice in which the alkaline phosphatase gene was knocked-in (Badea et al. [Neuron] 2009;61:852-864; Badea and Nathans [Vision Res] 2011;51:269-279), we studied the general effects after gene removal on the retinal neuropil together with the consequences of lack of development of large numbers of GCs onto the remaining retinal neurons of the same class. We analyzed the morphology, number, and general architecture of various neuronal types presynaptic to GCs, searching for changes secondary to the decrement in the number of their postsynaptic partners, as well as the morphology and distribution of retinal astrocytes, for their strong topographical relation to GCs. We found that, despite GC losses, retinal organization in Brn3 null mice is remarkably similar to that of wild-type controls. J. Comp. Neurol. 527:187-211, 2019. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Miruna Georgiana Ghinia
- Neuroscience Institute of the Italian National Research Council, Pisa Research Campus, 56124 Pisa, Italy
- Retinal CIrcuit Development & Genetics Unit, Neurobiology–Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892
- Babeş Bolyai University, 400084 Cluj Napoca, Romania
| | - Elena Novelli
- Neuroscience Institute of the Italian National Research Council, Pisa Research Campus, 56124 Pisa, Italy
| | - Szilard Sajgo
- Retinal CIrcuit Development & Genetics Unit, Neurobiology–Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Tudor Constantin Badea
- Retinal CIrcuit Development & Genetics Unit, Neurobiology–Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Enrica Strettoi
- Neuroscience Institute of the Italian National Research Council, Pisa Research Campus, 56124 Pisa, Italy
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24
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SOX2 haploinsufficiency promotes impaired vision at advanced age. Oncotarget 2018; 9:36684-36692. [PMID: 30613351 PMCID: PMC6291181 DOI: 10.18632/oncotarget.26393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 11/01/2018] [Indexed: 01/05/2023] Open
Abstract
Age-related vision loss has been associated with degeneration of the retina and decline in Müller glia cell activity. Sox2 is a critical transcription factor for the development and maintenance of the mammalian retina. Here we determined the role of Sox2 in retinal aging. We observed a decline in the number of Sox2-positive Müller, amacrine and ganglion cells with age. We also explored the impact of Sox2 haploinsufficiency (Sox2GFP) on the activity of Müller glia cells and vision loss with age. Reduction of Sox2-positive cells promoted impaired Müller glia cell function at advanced age of Sox2GFP. These findings correlated with a significant decline in electroretinographic response in Sox2 haploinsufficient mice. Together, these results indicate that Sox2 is required for the maintenance of the transmission of visual information from cones and rods, and suggest that decline in Sox2 expression is responsible for retinal cell aging and age-related vision loss.
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25
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Sankaran M, Keeley PW, He L, Iuvone PM, Reese BE. Dopaminergic amacrine cell number, plexus density, and dopamine content in the mouse retina: Strain differences and effects of Bax gene disruption. Exp Eye Res 2018; 177:208-212. [PMID: 30240584 DOI: 10.1016/j.exer.2018.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/07/2018] [Accepted: 09/17/2018] [Indexed: 01/01/2023]
Abstract
Many types of retinal neuron modulate the distribution of their processes to ensure a uniform coverage of the retinal surface. Dendritic field area, for instance, is inversely related to the variation in cellular density for many cell types, observed either across retinal eccentricity or between different strains of mice that differ in cell number. Dopaminergic amacrine (DA) cells, by contrast, have dendritic arbors that bear no spatial relationship to the presence of their immediate homotypic neighbors, yet it remains to be determined whether their coverage upon the retina, as a population, is conserved across variation in their total number. The present study assessed the overall density of the dopaminergic plexus in the inner plexiform layer in the presence of large variation in the total number of DA cells, as well as their retinal dopamine content, to determine whether either of these features is conserved. We first compared these traits between two strains of mice (C57BL/6J and A/J) that exhibit a two-fold difference in DA cell number. We subsequently examined these same traits in littermate mice for which the pro-apoptotic Bax gene was either intact or knocked out, yielding a five-fold difference in DA cell number. In both comparisons, we found greater plexus density and DA content in the strain or condition with the greater number of DA cells. The population of DA cells, therefore, does not appear to self-regulate its process coverage to achieve a constant density as the DA mosaic is established during development, nor its functional dopamine content in maturity.
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Affiliation(s)
- Mathangi Sankaran
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA; Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, 93106, USA
| | - Patrick W Keeley
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, 93106, USA
| | - Li He
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, 30322, USA; Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Benjamin E Reese
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA; Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, 93106, USA.
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26
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Stincic TL, Keeley PW, Reese BE, Taylor WR. Bistratified starburst amacrine cells in Sox2 conditional knockout mouse retina display ON and OFF responses. J Neurophysiol 2018; 120:2121-2129. [PMID: 30089022 DOI: 10.1152/jn.00322.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cell-intrinsic factors, in conjunction with environmental signals, guide migration, differentiation, and connectivity during early development of neuronal circuits. Within the retina, inhibitory starburst amacrine cells (SBACs) comprise ON types with somas in the ganglion cell layer (GCL) and dendrites stratifying narrowly in the inner half of the inner plexiform layer (IPL) and OFF types with somas in the inner nuclear layer (INL) and dendrites stratifying narrowly in the outer half of the IPL. The transcription factor Sox2 is crucial to this subtype specification. Without Sox2, many ON-type SBACs destined for the GCL settle in the INL while many that reach the GCL develop bistratified dendritic arbors. This study asked whether ON-type SBACs in Sox2-conditional knockout retinas exhibit selective connectivity only with ON-type bipolar cells or their bistratified morphology allows them to connect to both ON and OFF bipolar cells. Physiological data demonstrate that these cells receive ON and OFF excitatory inputs, indicating that the ectopically stratified dendrites make functional synapses with bipolar cells. The excitatory inputs were smaller and more transient in Sox2-conditional knockout compared with wild type; however, inhibitory inputs appeared largely unchanged. Thus dendritic stratification, rather than cellular identification, may be the major factor that determines ON vs. OFF connectivity. NEW & NOTEWORTHY Conditional knockout of the transcription factor Sox2 during early embryogenesis converts a monostratifying starburst amacrine cell into a bistratifying starburst cell. Here we show that these bistratifying starburst amacrine cells form functional synaptic connections with both ON and OFF bipolar cells. This suggests that normal ON vs. OFF starburst connectivity may not require distinct molecular specification. Proximity alone may be sufficient to allow formation of functional synapses.
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Affiliation(s)
- Todd L Stincic
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University , Portland, Oregon
| | - Patrick W Keeley
- Neuroscience Research Institute, University of California , Santa Barbara, California
| | - Benjamin E Reese
- Neuroscience Research Institute, University of California , Santa Barbara, California.,Department of Psychological and Brain Sciences, University of California , Santa Barbara, California
| | - W Rowland Taylor
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University , Portland, Oregon.,School of Optometry and Helen Wills Neuroscience Institute, University of California , Berkeley, California
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27
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Morrie RD, Feller MB. A Dense Starburst Plexus Is Critical for Generating Direction Selectivity. Curr Biol 2018; 28:1204-1212.e5. [PMID: 29606419 PMCID: PMC5916530 DOI: 10.1016/j.cub.2018.03.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 01/02/2023]
Abstract
Starburst amacrine cell (SAC) morphology is considered central to retinal direction selectivity. In Sema6A-/- mice, SAC dendritic arbors are smaller and no longer radially symmetric, leading to a reduction in SAC dendritic plexus density. Sema6A-/- mice also have a dramatic reduction in the directional tuning of retinal direction-selective ganglion cells (DSGCs). Here we show that the loss of DSGC tuning in Sema6A-/- mice is due to reduced null direction inhibition, even though strong asymmetric SAC-DSGC connectivity and SAC dendritic direction selectivity are maintained. Hence, the reduced coverage factor of SAC dendrites leads specifically to a loss of null direction inhibition. Moreover, SAC dendrites are no longer strictly tuned to centrifugal motion, indicating that SAC morphology is critical in coordinating synaptic connectivity and dendritic integration to generate direction selectivity.
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Affiliation(s)
- Ryan D Morrie
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Marla B Feller
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
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28
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Ray TA, Roy S, Kozlowski C, Wang J, Cafaro J, Hulbert SW, Wright CV, Field GD, Kay JN. Formation of retinal direction-selective circuitry initiated by starburst amacrine cell homotypic contact. eLife 2018; 7:e34241. [PMID: 29611808 PMCID: PMC5931800 DOI: 10.7554/elife.34241] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/29/2018] [Indexed: 12/23/2022] Open
Abstract
A common strategy by which developing neurons locate their synaptic partners is through projections to circuit-specific neuropil sublayers. Once established, sublayers serve as a substrate for selective synapse formation, but how sublayers arise during neurodevelopment remains unknown. Here, we identify the earliest events that initiate formation of the direction-selective circuit in the inner plexiform layer of mouse retina. We demonstrate that radially migrating newborn starburst amacrine cells establish homotypic contacts on arrival at the inner retina. These contacts, mediated by the cell-surface protein MEGF10, trigger neuropil innervation resulting in generation of two sublayers comprising starburst-cell dendrites. This dendritic scaffold then recruits projections from circuit partners. Abolishing MEGF10-mediated contacts profoundly delays and ultimately disrupts sublayer formation, leading to broader direction tuning and weaker direction-selectivity in retinal ganglion cells. Our findings reveal a mechanism by which differentiating neurons transition from migratory to mature morphology, and highlight this mechanism's importance in forming circuit-specific sublayers.
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Affiliation(s)
- Thomas A Ray
- Department of NeurobiologyDuke University School of MedicineDurhamUnited States
- Department of OphthalmologyDuke University School of MedicineDurhamUnited States
| | - Suva Roy
- Department of NeurobiologyDuke University School of MedicineDurhamUnited States
| | - Christopher Kozlowski
- Department of NeurobiologyDuke University School of MedicineDurhamUnited States
- Department of OphthalmologyDuke University School of MedicineDurhamUnited States
| | - Jingjing Wang
- Department of NeurobiologyDuke University School of MedicineDurhamUnited States
- Department of OphthalmologyDuke University School of MedicineDurhamUnited States
| | - Jon Cafaro
- Department of NeurobiologyDuke University School of MedicineDurhamUnited States
| | - Samuel W Hulbert
- Department of NeurobiologyDuke University School of MedicineDurhamUnited States
| | - Christopher V Wright
- Department of Cell and Developmental BiologyVanderbilt University School of MedicineNashvilleUnited States
| | - Greg D Field
- Department of NeurobiologyDuke University School of MedicineDurhamUnited States
| | - Jeremy N Kay
- Department of NeurobiologyDuke University School of MedicineDurhamUnited States
- Department of OphthalmologyDuke University School of MedicineDurhamUnited States
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29
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Zhang C, Yu WQ, Hoshino A, Huang J, Rieke F, Reh TA, Wong ROL. Development of ON and OFF cholinergic amacrine cells in the human fetal retina. J Comp Neurol 2018; 527:174-186. [PMID: 29405294 DOI: 10.1002/cne.24405] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/22/2018] [Accepted: 01/23/2018] [Indexed: 12/13/2022]
Abstract
Choline acetyltransferase (ChAT) expressing retinal amacrine cells are present across vertebrates. These interneurons play important roles in the development of retinal projections to the brain and in motion detection, specifically in generating direction-selective responses to moving stimuli. ChAT amacrine cells typically comprise two spatially segregated populations that form circuits in the 'ON' or 'OFF' synaptic layers of the inner retina. This stereotypic arrangement is also found across the adult human retina, with the notable exception that ChAT expression is evident in the ON but not OFF layer of the fovea, a region specialized for high-acuity vision. We thus investigated whether the human fovea exhibits a developmental path for ON and OFF ChAT cells that is retinal location-specific. Our analysis shows that at each retinal location, human ON and OFF ChAT cells differentiate, form their separate synaptic layers, and establish non-random mosaics at about the same time. However, unlike in the adult fovea, ChAT immunostaining is initially robust in both ON and OFF populations, up until at least mid-gestation. ChAT expression in the OFF layer in the fovea is therefore significantly reduced after mid-gestation. OFF ChAT cells in the human fovea and in the retinal periphery thus follow distinct maturational paths.
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Affiliation(s)
- Chi Zhang
- Department of Biological Structure, University of Washington, Seattle, Washington
| | - Wan-Qing Yu
- Department of Biological Structure, University of Washington, Seattle, Washington
| | - Akina Hoshino
- Department of Biological Structure, University of Washington, Seattle, Washington
| | - Jing Huang
- Department of Ophthalmology, University of Washington, Seattle, Washington
| | - Fred Rieke
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington
| | - Thomas A Reh
- Department of Biological Structure, University of Washington, Seattle, Washington
| | - Rachel O L Wong
- Department of Biological Structure, University of Washington, Seattle, Washington
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30
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Kautzman AG, Keeley PW, Nahmou MM, Luna G, Fisher SK, Reese BE. Sox2 regulates astrocytic and vascular development in the retina. Glia 2017; 66:623-636. [PMID: 29178409 DOI: 10.1002/glia.23269] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 12/13/2022]
Abstract
Sox2 is a transcriptional regulator that is highly expressed in retinal astrocytes, yet its function in these cells has not previously been examined. To understand its role, we conditionally deleted Sox2 from the population of astrocytes and examined the consequences on retinal development. We found that Sox2 deletion does not alter the migration of astrocytes, but it impairs their maturation, evidenced by the delayed upregulation of glial fibrillary acidic protein (GFAP) across the retina. The centro-peripheral gradient of angiogenesis is also delayed in Sox2-CKO retinas. In the mature retina, we observed lasting abnormalities in the astrocytic population evidenced by the sporadic loss of GFAP immunoreactivity in the peripheral retina as well as by the aberrant extension of processes into the inner retina. Blood vessels in the adult retina are also under-developed and show a decrease in the frequency of branch points and in total vessel length. The developmental relationship between maturing astrocytes and angiogenesis suggests a causal relationship between the astrocytic loss of Sox2 and the vascular architecture in maturity. We suggest that the delay in astrocytic maturation and vascular invasion may render the retina hypoxic, thereby causing the abnormalities we observe in adulthood. These studies uncover a novel role for Sox2 in the development of retinal astrocytes and indicate that its removal can lead to lasting changes to retinal homeostasis.
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Affiliation(s)
- Amanda G Kautzman
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA, 93106-5060.,Department of Psychological and Brain Sciences, University of California at Santa Barbara, Santa Barbara, CA, 93106-5060
| | - Patrick W Keeley
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA, 93106-5060
| | - Michael M Nahmou
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA, 93106-5060.,Department of Psychological and Brain Sciences, University of California at Santa Barbara, Santa Barbara, CA, 93106-5060
| | - Gabriel Luna
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA, 93106-5060
| | - Steven K Fisher
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA, 93106-5060
| | - Benjamin E Reese
- Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA, 93106-5060.,Department of Psychological and Brain Sciences, University of California at Santa Barbara, Santa Barbara, CA, 93106-5060
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31
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Abstract
Retinal bipolar cells spread their dendritic arbors to tile the retinal surface, extending them to the tips of the dendritic fields of their homotypic neighbors, minimizing dendritic overlap. Such uniform nonredundant dendritic coverage of these populations would suggest a degree of spatial order in the properties of their somal distributions, yet few studies have examined the patterning in retinal bipolar cell mosaics. The present study examined the organization of two types of cone bipolar cells in the mouse retina, the Type 2 cells and the Type 4 cells, and compared their spatial statistical properties with those of the horizontal cells and the cholinergic amacrine cells, as well as to random simulations of cells matched in density and constrained by soma size. The Delauney tessellation of each field was computed, from which nearest neighbor distances and Voronoi domain areas were extracted, permitting a calculation of their respective regularity indexes (RIs). The spatial autocorrelation of the field was also computed, from which the effective radius and packing factor (PF) were determined. Both cone bipolar cell types were found to be less regular and less efficiently packed than either the horizontal cells or cholinergic amacrine cells. Furthermore, while the latter two cell types had RIs and PFs in excess of those for their matched random simulations, the two types of cone bipolar cells had spatial statistical properties comparable to random distributions. An analysis of single labeled cone bipolar cells revealed dendritic arbors frequently skewed to one side of the soma, as would be expected from a randomly distributed population of cells with dendrites that tile. Taken together, these results suggest that, unlike the horizontal cells or cholinergic amacrine cells which minimize proximity to one another, cone bipolar cell types are constrained only by their physical size.
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32
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Peng YR, Tran NM, Krishnaswamy A, Kostadinov D, Martersteck EM, Sanes JR. Satb1 Regulates Contactin 5 to Pattern Dendrites of a Mammalian Retinal Ganglion Cell. Neuron 2017; 95:869-883.e6. [PMID: 28781169 DOI: 10.1016/j.neuron.2017.07.019] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 06/16/2017] [Accepted: 07/19/2017] [Indexed: 12/13/2022]
Abstract
The size and shape of dendritic arbors are prime determinants of neuronal connectivity and function. We asked how ON-OFF direction-selective ganglion cells (ooDSGCs) in mouse retina acquire their bistratified dendrites, in which responses to light onset and light offset are segregated to distinct strata. We found that the transcriptional regulator Satb1 is selectively expressed by ooDSGCs. In Satb1 mutant mice, ooDSGC dendrites lack ON arbors, and the cells selectively lose ON responses. Satb1 regulates expression of a homophilic adhesion molecule, Contactin 5 (Cntn5). Both Cntn5 and its co-receptor Caspr4 are expressed not only by ooDSGCs, but also by interneurons that form a scaffold on which ooDSGC ON dendrites fasciculate. Removing Cntn5 from either ooDSGCs or interneurons partially phenocopies Satb1 mutants, demonstrating that Satb1-dependent Cntn5 expression in ooDSGCs leads to branch-specific homophilic interactions with interneurons. Thus, Satb1 directs formation of a morphologically and functionally specialized compartment within a complex dendritic arbor.
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Affiliation(s)
- Yi-Rong Peng
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Nicholas M Tran
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Arjun Krishnaswamy
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Dimitar Kostadinov
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Emily M Martersteck
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Joshua R Sanes
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
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33
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de Melo J, Clark BS, Blackshaw S. Multiple intrinsic factors act in concert with Lhx2 to direct retinal gliogenesis. Sci Rep 2016; 6:32757. [PMID: 27605455 PMCID: PMC5015061 DOI: 10.1038/srep32757] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 08/15/2016] [Indexed: 12/14/2022] Open
Abstract
Müller glia (MG) are the principal glial cell type in the vertebrate retina. Recent work has identified the LIM homeodomain factor encoding gene Lhx2 as necessary for both Notch signaling and MG differentiation in late-stage retinal progenitor cells (RPCs). However, the extent to which Lhx2 interacts with other intrinsic regulators of MG differentiation is unclear. We investigated this question by investigating the effects of overexpression of multiple transcriptional regulators that are either known or hypothesized to control MG formation, in both wildtype and Lhx2-deficient RPCs. We observe that constitutively elevated Notch signaling, induced by N1ICD electroporation, inhibited gliogenesis in wildtype animals, but rescued MG development in Lhx2-deficient retinas. Electroporation of Nfia promoted the formation of cells with MG-like radial morphology, but did not drive expression of MG molecular markers. Plagl1 and Sox9 did not induce gliogenesis in wildtype animals, but nonetheless activated expression of the Müller marker P27Kip1 in Lhx2-deficient cells. Finally, Sox2, Sox8, and Sox9 promoted amacrine cell formation in Lhx2-deficient cells, but not in wildtype retinas. These findings demonstrate that overexpression of individual gliogenic factors typically regulates only a subset of characteristic MG markers, and that these effects are differentially modulated by Lhx2.
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Affiliation(s)
- Jimmy de Melo
- Johns Hopkins University School of Medicine, Solomon H. Snyder Department of Neuroscience, Baltimore, 21205, USA
| | - Brian S Clark
- Johns Hopkins University School of Medicine, Solomon H. Snyder Department of Neuroscience, Baltimore, 21205, USA
| | - Seth Blackshaw
- Johns Hopkins University School of Medicine, Solomon H. Snyder Department of Neuroscience, Baltimore, 21205, USA.,Johns Hopkins University School of Medicine, Department of Ophthalmology, Baltimore, 21205, USA.,Johns Hopkins University School of Medicine, Department of Neurology, Baltimore, 21205, USA.,Johns Hopkins University School of Medicine, Center for Human Systems Biology, Baltimore, 21205, USA.,Johns Hopkins University School of Medicine, Institute for Cell Engineering, Baltimore, 21205, USA
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34
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Reese BE, Keeley PW. Genomic control of neuronal demographics in the retina. Prog Retin Eye Res 2016; 55:246-259. [PMID: 27492954 DOI: 10.1016/j.preteyeres.2016.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/21/2016] [Accepted: 07/28/2016] [Indexed: 12/22/2022]
Abstract
The mature retinal architecture is composed of various types of neuron, each population differing in size and constrained to particular layers, wherein the cells achieve a characteristic patterning in their local organization. These demographic features of retinal nerve cell populations are each complex traits controlled by multiple genes affecting different processes during development, and their genetic determinants can be dissected by correlating variation in these traits with their genomic architecture across recombinant-inbred mouse strains. Using such a resource, we consider how the variation in the numbers of twelve different types of retinal neuron are independent of one another, including those sharing transcriptional regulation as well as those that are synaptically-connected, each mapping to distinct genomic loci. Using the populations of two retinal interneurons, the horizontal cells and the cholinergic amacrine cells, we present in further detail examples where the variation in neuronal number, as well as the variation in mosaic patterning or in laminar positioning, each maps to discrete genomic loci where allelic variants modulating these features must be present. At those loci, we identify candidate genes which, when rendered non-functional, alter those very demographic properties, and in turn, we identify candidate coding or regulatory variants that alter protein structure or gene expression, respectively, being prospective contributors to the variation in phenotype. This forward-genetic approach provides an alternative means for dissecting the molecular genetic control of neuronal population dynamics, with each genomic locus serving as a causal anchor from which we may ultimately understand the developmental principles responsible for the control of those traits.
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Affiliation(s)
- Benjamin E Reese
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106-5060, USA; Departments of Psychological & Brain Sciences, University of California, Santa Barbara, CA 93106-9660, USA.
| | - Patrick W Keeley
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106-5060, USA; Departments of Molecular, Cellular & Developmental Biology, University of California, Santa Barbara, CA 93106-9625, USA
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35
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Bachleda AR, Pevny LH, Weiss ER. Sox2-Deficient Müller Glia Disrupt the Structural and Functional Maturation of the Mammalian Retina. Invest Ophthalmol Vis Sci 2016; 57:1488-99. [PMID: 27031842 PMCID: PMC4819558 DOI: 10.1167/iovs.15-17994] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
PURPOSE Müller glia (MG), the principal glial cells of the vertebrate retina, display quiescent progenitor cell characteristics. They express key progenitor markers, including the high mobility group box transcription factor SOX2 and maintain a progenitor-like morphology. In the embryonic and mature central nervous system, SOX2 maintains neural stem cell identity. However, its function in committed Müller glia has yet to be determined. METHODS We use inducible, MG-specific genetic ablation of Sox2 in vivo at the peak of MG genesis to analyze its function in the maturation of murine MG and effects on other cells in the retina. Histologic and functional analysis of the Sox2-deficient retinas is conducted at key points in postnatal development. RESULTS Ablation of Sox2 in the postnatal retina results in disorganization of MG processes in the inner plexiform layer and mislocalized cell bodies in the nuclear layers. This disorganization is concurrent with a thinning of the neural retina and disruption of neuronal processes in the inner and outer plexiform layers. Functional analysis by electroretinography reveals a decrease in the b-wave amplitude. Disruption of MG maturation due to Sox2 ablation therefore negatively affected the function of the retina. CONCLUSIONS These results demonstrate a novel role for SOX2 in glial process outgrowth and adhesion, and provide new insights into the essential role Müller glia play in the development of retinal cytoarchitecture. Prior to this work, SOX2 was known to have a primary role in determining cell fate. Our experiments bypass cell fate conversion to establish a new role for SOX2 in a committed cell lineage.
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Affiliation(s)
- Amelia R Bachleda
- Neuroscience Center, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States 2Curriculum in Neurobiology, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States
| | - Larysa H Pevny
- Neuroscience Center, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States 3Department of Genetics, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States
| | - Ellen R Weiss
- Neuroscience Center, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States 4Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States 5Lineberger Comprehe
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