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Ovadia S, Cui G, Elkon R, Cohen-Gulkar M, Zuk-Bar N, Tuoc T, Jing N, Ashery-Padan R. SWI/SNF complexes are required for retinal pigmented epithelium differentiation and for the inhibition of cell proliferation and neural differentiation programs. Development 2023; 150:dev201488. [PMID: 37522516 PMCID: PMC10482007 DOI: 10.1242/dev.201488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 07/14/2023] [Indexed: 08/01/2023]
Abstract
During embryonic development, tissue-specific transcription factors and chromatin remodelers function together to ensure gradual, coordinated differentiation of multiple lineages. Here, we define this regulatory interplay in the developing retinal pigmented epithelium (RPE), a neuroectodermal lineage essential for the development, function and maintenance of the adjacent retina. We present a high-resolution spatial transcriptomic atlas of the developing mouse RPE and the adjacent ocular mesenchyme obtained by geographical position sequencing (Geo-seq) of a single developmental stage of the eye that encompasses young and more mature ocular progenitors. These transcriptomic data, available online, reveal the key transcription factors and their gene regulatory networks during RPE and ocular mesenchyme differentiation. Moreover, conditional inactivation followed by Geo-seq revealed that this differentiation program is dependent on the activity of SWI/SNF complexes, shown here to control the expression and activity of RPE transcription factors and, at the same time, inhibit neural progenitor and cell proliferation genes. The findings reveal the roles of the SWI/SNF complexes in controlling the intersection between RPE and neural cell fates and the coupling of cell-cycle exit and differentiation.
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Affiliation(s)
- Shai Ovadia
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Guizhong Cui
- Guangzhou National Laboratory, Department of Basic Research, Guangzhou 510005, China
| | - Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Mazal Cohen-Gulkar
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nitay Zuk-Bar
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Tran Tuoc
- Department of Human Genetics, Ruhr University of Bochum, 44791 Bochum, Germany
| | - Naihe Jing
- Guangzhou National Laboratory, Department of Basic Research, Guangzhou 510005, China
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
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2
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Cohen-Gulkar M, David A, Messika-Gold N, Eshel M, Ovadia S, Zuk-Bar N, Idelson M, Cohen-Tayar Y, Reubinoff B, Ziv T, Shamay M, Elkon R, Ashery-Padan R. The LHX2-OTX2 transcriptional regulatory module controls retinal pigmented epithelium differentiation and underlies genetic risk for age-related macular degeneration. PLoS Biol 2023; 21:e3001924. [PMID: 36649236 PMCID: PMC9844853 DOI: 10.1371/journal.pbio.3001924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 11/16/2022] [Indexed: 01/18/2023] Open
Abstract
Tissue-specific transcription factors (TFs) control the transcriptome through an association with noncoding regulatory regions (cistromes). Identifying the combination of TFs that dictate specific cell fate, their specific cistromes and examining their involvement in complex human traits remain a major challenge. Here, we focus on the retinal pigmented epithelium (RPE), an essential lineage for retinal development and function and the primary tissue affected in age-related macular degeneration (AMD), a leading cause of blindness. By combining mechanistic findings in stem-cell-derived human RPE, in vivo functional studies in mice and global transcriptomic and proteomic analyses, we revealed that the key developmental TFs LHX2 and OTX2 function together in transcriptional module containing LDB1 and SWI/SNF (BAF) to regulate the RPE transcriptome. Importantly, the intersection between the identified LHX2-OTX2 cistrome with published expression quantitative trait loci, ATAC-seq data from human RPE, and AMD genome-wide association study (GWAS) data, followed by functional validation using a reporter assay, revealed a causal genetic variant that affects AMD risk by altering TRPM1 expression in the RPE through modulation of LHX2 transcriptional activity on its promoter. Taken together, the reported cistrome of LHX2 and OTX2, the identified downstream genes and interacting co-factors reveal the RPE transcription module and uncover a causal regulatory risk single-nucleotide polymorphism (SNP) in the multifactorial common blinding disease AMD.
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Affiliation(s)
- Mazal Cohen-Gulkar
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Ahuvit David
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Naama Messika-Gold
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Mai Eshel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Shai Ovadia
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Nitay Zuk-Bar
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Maria Idelson
- The Hadassah Human Embryonic Stem Cell Research Center, The Goldyne Savad Institute of Gene Therapy and Department of Gynecology, Jerusalem, Israel
| | - Yamit Cohen-Tayar
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Benjamin Reubinoff
- The Hadassah Human Embryonic Stem Cell Research Center, The Goldyne Savad Institute of Gene Therapy and Department of Gynecology, Jerusalem, Israel
| | - Tamar Ziv
- Smoler Proteomics Center, Lorry I. Lokey Interdisciplinary Center for Life Sciences and Engineering, Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Meir Shamay
- Daniella Lee Casper Laboratory in Viral Oncology, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
- * E-mail: (RE); (RAP)
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
- * E-mail: (RE); (RAP)
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3
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Diacou R, Nandigrami P, Fiser A, Liu W, Ashery-Padan R, Cvekl A. Cell fate decisions, transcription factors and signaling during early retinal development. Prog Retin Eye Res 2022; 91:101093. [PMID: 35817658 PMCID: PMC9669153 DOI: 10.1016/j.preteyeres.2022.101093] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 06/02/2022] [Accepted: 06/03/2022] [Indexed: 12/30/2022]
Abstract
The development of the vertebrate eyes is a complex process starting from anterior-posterior and dorso-ventral patterning of the anterior neural tube, resulting in the formation of the eye field. Symmetrical separation of the eye field at the anterior neural plate is followed by two symmetrical evaginations to generate a pair of optic vesicles. Next, reciprocal invagination of the optic vesicles with surface ectoderm-derived lens placodes generates double-layered optic cups. The inner and outer layers of the optic cups develop into the neural retina and retinal pigment epithelium (RPE), respectively. In vitro produced retinal tissues, called retinal organoids, are formed from human pluripotent stem cells, mimicking major steps of retinal differentiation in vivo. This review article summarizes recent progress in our understanding of early eye development, focusing on the formation the eye field, optic vesicles, and early optic cups. Recent single-cell transcriptomic studies are integrated with classical in vivo genetic and functional studies to uncover a range of cellular mechanisms underlying early eye development. The functions of signal transduction pathways and lineage-specific DNA-binding transcription factors are dissected to explain cell-specific regulatory mechanisms underlying cell fate determination during early eye development. The functions of homeodomain (HD) transcription factors Otx2, Pax6, Lhx2, Six3 and Six6, which are required for early eye development, are discussed in detail. Comprehensive understanding of the mechanisms of early eye development provides insight into the molecular and cellular basis of developmental ocular anomalies, such as optic cup coloboma. Lastly, modeling human development and inherited retinal diseases using stem cell-derived retinal organoids generates opportunities to discover novel therapies for retinal diseases.
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Affiliation(s)
- Raven Diacou
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Prithviraj Nandigrami
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Andras Fiser
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Wei Liu
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Ruth Ashery-Padan
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Ales Cvekl
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
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4
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Latta L, Figueiredo FC, Ashery-Padan R, Collinson JM, Daniels J, Ferrari S, Szentmáry N, Solá S, Shalom-Feuerstein R, Lako M, Xapelli S, Aberdam D, Lagali N. Pathophysiology of aniridia-associated keratopathy: Developmental aspects and unanswered questions. Ocul Surf 2021; 22:245-266. [PMID: 34520870 DOI: 10.1016/j.jtos.2021.09.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 07/19/2021] [Accepted: 09/08/2021] [Indexed: 12/13/2022]
Abstract
Aniridia, a rare congenital disease, is often characterized by a progressive, pronounced limbal insufficiency and ocular surface pathology termed aniridia-associated keratopathy (AAK). Due to the characteristics of AAK and its bilateral nature, clinical management is challenging and complicated by the multiple coexisting ocular and systemic morbidities in aniridia. Although it is primarily assumed that AAK originates from a congenital limbal stem cell deficiency, in recent years AAK and its pathogenesis has been questioned in the light of new evidence and a refined understanding of ocular development and the biology of limbal stem cells (LSCs) and their niche. Here, by consolidating and comparing the latest clinical and preclinical evidence, we discuss key unanswered questions regarding ocular developmental aspects crucial to AAK. We also highlight hypotheses on the potential role of LSCs and the ocular surface microenvironment in AAK. The insights thus gained lead to a greater appreciation for the role of developmental and cellular processes in the emergence of AAK. They also highlight areas for future research to enable a deeper understanding of aniridia, and thereby the potential to develop new treatments for this rare but blinding ocular surface disease.
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Affiliation(s)
- L Latta
- Dr. Rolf. M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany; Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany.
| | - F C Figueiredo
- Department of Ophthalmology, Royal Victoria Infirmary, Newcastle Upon Tyne, United Kingdom
| | - R Ashery-Padan
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - J M Collinson
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen, AB25 2ZD, United Kingdom
| | - J Daniels
- Cells for Sight, UCL Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
| | - S Ferrari
- The Veneto Eye Bank Foundation, Venice, Italy
| | - N Szentmáry
- Dr. Rolf. M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany
| | - S Solá
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - R Shalom-Feuerstein
- Department of Genetics and Developmental Biology, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel
| | - M Lako
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - S Xapelli
- Instituto Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - D Aberdam
- Centre de Recherche des Cordeliers, INSERM U1138, Team 17, France; Université de Paris, 75006, Paris, France.
| | - N Lagali
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Ophthalmology, Sørlandet Hospital Arendal, Arendal, Norway.
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5
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Ashery-Padan R, Perkins BD, Conte I. Editorial: With the Eyes on Non-coding RNAs. Front Cell Dev Biol 2021; 9:737703. [PMID: 34395454 PMCID: PMC8358668 DOI: 10.3389/fcell.2021.737703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel
| | - Brian D Perkins
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Ivan Conte
- Department of Biology, University of Naples Federico II, Naples, Italy.,Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
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6
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Pang J, Le L, Zhou Y, Tu R, Hou Q, Tsuchiya D, Thomas N, Wang Y, Yu Z, Alexander R, Thexton M, Lewis B, Corbin T, Durnin M, Li H, Ashery-Padan R, Yan D, Xie T. NOTCH Signaling Controls Ciliary Body Morphogenesis and Secretion by Directly Regulating Nectin Protein Expression. Cell Rep 2021; 34:108603. [PMID: 33440163 DOI: 10.1016/j.celrep.2020.108603] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 11/20/2020] [Accepted: 12/14/2020] [Indexed: 11/29/2022] Open
Abstract
Anterior segment dysgenesis is often associated with cornea diseases, cataracts, and glaucoma. In the anterior segment, the ciliary body (CB) containing inner and outer ciliary epithelia (ICE and OCE) secretes aqueous humor that maintains intraocular pressure (IOP). However, CB development and function remain poorly understood. Here, this study shows that NOTCH signaling in the CB maintains the vitreous, IOP, and eye structures by regulating CB morphogenesis, aqueous humor secretion, and vitreous protein expression. Notch2 and Notch3 function via RBPJ in the CB to control ICE-OCE adhesion, CB morphogenesis, aqueous humor secretion, and protein expression, thus maintaining IOP and eye structures. Mechanistically, NOTCH signaling transcriptionally controls Nectin1 expression in the OCE to promote cell adhesion for driving CB morphogenesis and to directly stabilize Cx43 for controlling aqueous humor secretion. Finally, NOTCH signaling directly controls vitreous protein secretion in the ICE. Therefore, this study provides important insight into CB functions and involvement in eye diseases.
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Affiliation(s)
- Ji Pang
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA; School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Liang Le
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Yi Zhou
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA; Department of Anatomy and Cell Biology, University of Kansas School of Medicine, 3901 Rainbow Blvd, Kansas City, KS 66160, USA
| | - Renjun Tu
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Qiang Hou
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA; State Key Laboratory and Key Laboratory of Vision Science, School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Dai Tsuchiya
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Nancy Thomas
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Yongfu Wang
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Zulin Yu
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Richard Alexander
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Marina Thexton
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Brandy Lewis
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Timothy Corbin
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Michael Durnin
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Hua Li
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Deyue Yan
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Ting Xie
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA; Department of Anatomy and Cell Biology, University of Kansas School of Medicine, 3901 Rainbow Blvd, Kansas City, KS 66160, USA.
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7
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Menuchin-Lasowski Y, Dagan B, Conidi A, Cohen-Gulkar M, David A, Ehrlich M, Giladi PO, Clark BS, Blackshaw S, Shapira K, Huylebroeck D, Henis YI, Ashery-Padan R. Zeb2 regulates the balance between retinal interneurons and Müller glia by inhibition of BMP-Smad signaling. Dev Biol 2020; 468:80-92. [PMID: 32950463 DOI: 10.1016/j.ydbio.2020.09.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 08/24/2020] [Accepted: 09/10/2020] [Indexed: 12/27/2022]
Abstract
The interplay between signaling molecules and transcription factors during retinal development is key to controlling the correct number of retinal cell types. Zeb2 (Sip1) is a zinc-finger multidomain transcription factor that plays multiple roles in central and peripheral nervous system development. Haploinsufficiency of ZEB2 causes Mowat-Wilson syndrome, a congenital disease characterized by intellectual disability, epilepsy and Hirschsprung disease. In the developing retina, Zeb2 is required for generation of horizontal cells and the correct number of interneurons; however, its potential function in controlling gliogenic versus neurogenic decisions remains unresolved. Here we present cellular and molecular evidence of the inhibition of Müller glia cell fate by Zeb2 in late stages of retinogenesis. Unbiased transcriptomic profiling of control and Zeb2-deficient early-postnatal retina revealed that Zeb2 functions in inhibiting Id1/2/4 and Hes1 gene expression. These neural progenitor factors normally inhibit neural differentiation and promote Müller glia cell fate. Chromatin immunoprecipitation (ChIP) supported direct regulation of Id1 by Zeb2 in the postnatal retina. Reporter assays and ChIP analyses in differentiating neural progenitors provided further evidence that Zeb2 inhibits Id1 through inhibition of Smad-mediated activation of Id1 transcription. Together, the results suggest that Zeb2 promotes the timely differentiation of retinal interneurons at least in part by repressing BMP-Smad/Notch target genes that inhibit neurogenesis. These findings show that Zeb2 integrates extrinsic cues to regulate the balance between neuronal and glial cell types in the developing murine retina.
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Affiliation(s)
- Yotam Menuchin-Lasowski
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Bar Dagan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Andrea Conidi
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, the Netherlands
| | - Mazal Cohen-Gulkar
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ahuvit David
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Marcelo Ehrlich
- Shumins School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Pazit Oren Giladi
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Brian S Clark
- John F Hardesty, MD Department of Ophthalmology and Visual Sciences and Department of Developmental Biology, Washington University, St. Louis, MO 63110, USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Baltimore, MD 21205, USA; Department of Ophthalmology, Baltimore, MD 21205, USA; Department of Neurology, Baltimore, MD 21205, USA; Center for Human Systems Biology, Baltimore, MD 21205, USA; Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Keren Shapira
- Shumins School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Danny Huylebroeck
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, the Netherlands; Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
| | - Yoav I Henis
- Shumins School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel.
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8
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Lam PT, Padula SL, Hoang TV, Poth JE, Liu L, Liang C, LeFever AS, Wallace LM, Ashery-Padan R, Riggs PK, Shields JE, Shaham O, Rowan S, Brown NL, Glaser T, Robinson ML. Considerations for the use of Cre recombinase for conditional gene deletion in the mouse lens. Hum Genomics 2019; 13:10. [PMID: 30770771 PMCID: PMC6377743 DOI: 10.1186/s40246-019-0192-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 01/22/2019] [Indexed: 12/03/2022] Open
Abstract
Background Despite a number of different transgenes that can mediate DNA deletion in the developing lens, each has unique features that can make a given transgenic line more or less appropriate for particular studies. The purpose of this work encompasses both a review of transgenes that lead to the expression of Cre recombinase in the lens and a comparative analysis of currently available transgenic lines with a particular emphasis on the Le-Cre and P0-3.9GFPCre lines that can mediate DNA deletion in the lens placode. Although both of these transgenes are driven by elements of the Pax6 P0 promoter, the Le-Cre transgene consistently leads to ocular abnormalities in homozygous state and can lead to ocular defects on some genetic backgrounds when hemizygous. Result Although both P0-3.9GFPCre and Le-Cre hemizygous transgenic mice undergo normal eye development on an FVB/N genetic background, Le-Cre homozygotes uniquely exhibit microphthalmia. Examination of the expression patterns of these two transgenes revealed similar expression in the developing eye and pancreas. However, lineage tracing revealed widespread non-ocular CRE reporter gene expression in the P0-3.9GFPCre transgenic mice that results from stochastic CRE expression in the P0-3.9GFPCre embryos prior to lens placode formation. Postnatal hemizygous Le-Cre transgenic lenses express higher levels of CRE transcript and protein than the hemizygous lenses of P0-3.9GFPCre mice. Transcriptome analysis revealed that Le-Cre hemizygous lenses deregulated the expression of 15 murine genes, several of which are associated with apoptosis. In contrast, P0-3.9GFPCre hemizygous lenses only deregulated two murine genes. No known PAX6-responsive genes or genes directly associated with lens differentiation were deregulated in the hemizygous Le-Cre lenses. Conclusions Although P0-3.9GFPCre transgenic mice appear free from ocular abnormalities, extensive non-ocular CRE expression represents a potential problem for conditional gene deletion studies using this transgene. The higher level of CRE expression in Le-Cre lenses versus P0-3.9GFPCre lenses may explain abnormal lens development in homozygous Le-Cre mice. Given the lack of deregulation of PAX6-responsive transcripts, we suggest that abnormal eye development in Le-Cre transgenic mice stems from CRE toxicity. Our studies reinforce the requirement for appropriate CRE-only expressing controls when using CRE as a driver of conditional gene targeting strategies. Electronic supplementary material The online version of this article (10.1186/s40246-019-0192-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Phuong T Lam
- Department of Biology, Miami University, Oxford, OH, 45056, USA
| | | | - Thanh V Hoang
- Department of Biology, Miami University, Oxford, OH, 45056, USA.,Present Address: Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Justin E Poth
- Department of Biology, Miami University, Oxford, OH, 45056, USA
| | - Lin Liu
- Department of Biology, Miami University, Oxford, OH, 45056, USA
| | - Chun Liang
- Department of Biology, Miami University, Oxford, OH, 45056, USA
| | - Adam S LeFever
- Nuclear Medicine Department, University of Cincinnati Medical Center, 234 Goodman Street, Cincinnati, OH, 45219, USA
| | - Lindsay M Wallace
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, OH, 43205, USA
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neurosciences, Tel Aviv University, 69978, Tel Aviv, Israel
| | - Penny K Riggs
- Department of Animal Sciences, Texas A&M University, College Station, TX, 77843-2471, USA
| | - Jordan E Shields
- Department of Animal Sciences, Texas A&M University, College Station, TX, 77843-2471, USA.,Present Address: Emory Children's Center, Room 410, 2015 Uppergate Drive, Atlanta, GA, 30322, USA
| | - Ohad Shaham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neurosciences, Tel Aviv University, 69978, Tel Aviv, Israel
| | - Sheldon Rowan
- Department of Ophthalmology, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Nadean L Brown
- Department of Cell Biology and Human Anatomy, University of California, Davis One Shields Avenue, Davis, CA, 95616, USA
| | - Tom Glaser
- Department of Cell Biology and Human Anatomy, University of California, Davis One Shields Avenue, Davis, CA, 95616, USA
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9
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Cohen-Tayar Y, Cohen H, Mitiagin Y, Abravanel Z, Levy C, Idelson M, Reubinoff B, Itzkovitz S, Raviv S, Kaestner KH, Blinder P, Elkon R, Ashery-Padan R. Pax6 regulation of Sox9 in the mouse retinal pigmented epithelium controls its timely differentiation and choroid vasculature development. Development 2018; 145:dev.163691. [PMID: 29986868 DOI: 10.1242/dev.163691] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 07/02/2018] [Indexed: 01/08/2023]
Abstract
The synchronized differentiation of neuronal and vascular tissues is crucial for normal organ development and function, although there is limited information about the mechanisms regulating the coordinated development of these tissues. The choroid vasculature of the eye serves as the main blood supply to the metabolically active photoreceptors, and develops together with the retinal pigmented epithelium (RPE). Here, we describe a novel regulatory relationship between the RPE transcription factors Pax6 and Sox9 that controls the timing of RPE differentiation and the adjacent choroid maturation. We used a novel machine learning algorithm tool to analyze high resolution imaging of the choroid in Pax6 and Sox9 conditional mutant mice. Additional unbiased transcriptomic analyses in mutant mice and RPE cells generated from human embryonic stem cells, as well as chromatin immunoprecipitation and high-throughput analyses, revealed secreted factors that are regulated by Pax6 and Sox9. These factors might be involved in choroid development and in the pathogenesis of the common blinding disease: age-related macular degeneration (AMD).
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Affiliation(s)
- Yamit Cohen-Tayar
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Hadar Cohen
- Department of Particle Physics, Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Yulia Mitiagin
- Department of Neurobiology, Biochemistry and Biophysics school, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Zohar Abravanel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Carmit Levy
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Masha Idelson
- The Hadassah Human Embryonic Stem Cell Research Center, The Goldyne Savad Institute of Gene Therapy and The Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, 9112001 Jerusalem, Israel
| | - Benjamin Reubinoff
- The Hadassah Human Embryonic Stem Cell Research Center, The Goldyne Savad Institute of Gene Therapy and The Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, 9112001 Jerusalem, Israel
| | - Shalev Itzkovitz
- Department of Molecular Cell Biology, Weizmann Institute of Science 76100, Rehovot, Israel
| | - Shaul Raviv
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Klaus H Kaestner
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, 12-126 Smilow Center for Translational Research, 3400 Civic Center Blvd, Philadelphia, PA 19104-6145, USA
| | - Pablo Blinder
- Department of Neurobiology, Biochemistry and Biophysics school, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 69978, Israel.,Sagol School for Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv 69978, Israel .,Sagol School for Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv 69978, Israel .,Sagol School for Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
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10
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Amram B, Cohen-Tayar Y, David A, Ashery-Padan R. The retinal pigmented epithelium - from basic developmental biology research to translational approaches. Int J Dev Biol 2018. [PMID: 28621420 DOI: 10.1387/ijdb.160393ra] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The development of the eye has been a topic of extensive investigation, from the early studies on tissue induction to more recent breakthroughs in resolving the mechanism regulating progenitor patterning and their gradual and coordinated differentiation into diverse tissue types that function together throughout life. Among the ocular tissue types, the retinal pigmented epithelium (RPE) is at the forefront of developmental biology and stem cell research. The growing interest in this lineage stems from its importance for photoreceptor function as well as from its requirement during embryogenesis for the development of the photoreceptors and the choroid. Indeed mutations in RPE genes and epigenetic changes that occur during aging are the cause of monogenic as well as multifactorial retinal diseases. Importantly, the RPE is readily generated from stem cells, and these stem cell-derived RPE cells are currently being tested in clinical trials for transplantation in cases of retinal dystrophies; they also constitute an important model to study developmental processes in vitro. This review summarizes recent advances in our understanding of RPE development and its requirement for the development of photoreceptors and choroidal vasculature. We discuss the contribution of basic findings to therapeutic applications and the future challenges in uncovering developmental processes and mimicking them ex vivo to further advance research and therapy of retinal disorders.
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Affiliation(s)
- Benjamin Amram
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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11
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Remez LA, Onishi A, Menuchin-Lasowski Y, Biran A, Blackshaw S, Wahlin KJ, Zack DJ, Ashery-Padan R. Pax6 is essential for the generation of late-born retinal neurons and for inhibition of photoreceptor-fate during late stages of retinogenesis. Dev Biol 2017; 432:140-150. [PMID: 28993200 DOI: 10.1016/j.ydbio.2017.09.030] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/08/2016] [Accepted: 09/23/2017] [Indexed: 12/16/2022]
Abstract
In the developing retina, as in other regions of the CNS, neural progenitors give rise to individual cell types during discrete temporal windows. Pax6 is expressed in retinal progenitor cells (RPCs) throughout the course of retinogenesis, and has been shown to be required during early retinogenesis for generation of most early-born cell types. In this study, we examined the function of Pax6 in postnatal mouse retinal development. We found that Pax6 is essential for the generation of late-born interneurons, while inhibiting photoreceptor differentiation. Generation of bipolar interneurons requires Pax6 expression in RPCs, while Pax6 is required for the generation of glycinergic, but not for GABAergic or non-GABAergic-non-glycinergic (nGnG) amacrine cell subtypes. In contrast, overexpression of either full-length Pax6 or its 5a isoform in RPCs induces formation of cells with nGnG amacrine features, and suppresses generation of other inner retinal cell types. Moreover, overexpression of both Pax6 variants prevents photoreceptor differentiation, most likely by inhibiting Crx expression. Taken together, these data show that Pax6 acts in RPCs to control differentiation of multiple late-born neuronal cell types.
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Affiliation(s)
- Liv Aleen Remez
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv, Israel
| | - Akishi Onishi
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
| | - Yotam Menuchin-Lasowski
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv, Israel
| | - Assaf Biran
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv, Israel
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
| | - Karl J Wahlin
- Shiley Eye Institute, University of California San Diego, La Jolla, CA, United States
| | - Donlad J Zack
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States; Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv, Israel.
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12
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Naftelberg S, Abramovitch Z, Gluska S, Yannai S, Joshi Y, Donyo M, Ben-Yaakov K, Gradus T, Zonszain J, Farhy C, Ashery-Padan R, Perlson E, Ast G. Phosphatidylserine Ameliorates Neurodegenerative Symptoms and Enhances Axonal Transport in a Mouse Model of Familial Dysautonomia. PLoS Genet 2016; 12:e1006486. [PMID: 27997532 PMCID: PMC5172536 DOI: 10.1371/journal.pgen.1006486] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 11/15/2016] [Indexed: 12/03/2022] Open
Abstract
Familial Dysautonomia (FD) is a neurodegenerative disease in which aberrant tissue-specific splicing of IKBKAP exon 20 leads to reduction of IKAP protein levels in neuronal tissues. Here we generated a conditional knockout (CKO) mouse in which exon 20 of IKBKAP is deleted in the nervous system. The CKO FD mice exhibit developmental delays, sensory abnormalities, and less organized dorsal root ganglia (DRGs) with attenuated axons compared to wild-type mice. Furthermore, the CKO FD DRGs show elevated HDAC6 levels, reduced acetylated α-tubulin, unstable microtubules, and impairment of axonal retrograde transport of nerve growth factor (NGF). These abnormalities in DRG properties underlie neuronal degeneration and FD symptoms. Phosphatidylserine treatment decreased HDAC6 levels and thus increased acetylation of α-tubulin. Further PS treatment resulted in recovery of axonal outgrowth and enhanced retrograde axonal transport by decreasing histone deacetylase 6 (HDAC6) levels and thus increasing acetylation of α-tubulin levels. Thus, we have identified the molecular pathway that leads to neurodegeneration in FD and have demonstrated that phosphatidylserine treatment has the potential to slow progression of neurodegeneration. We create a novel FD mouse model, in which exon 20 of IKBKAP was deleted in the nervous system, to study the role of IKAP in the neurodegeneration process. The lack of IKBKAP exon 20 impaired retrograde nerve growth factor (NGF) transport and axonal outgrowth. Reduction of IKAP levels resulted in elevated HDAC6 levels and thus reduced acetylated α-tubulin levels. Phosphatidylserine down-regulated HDAC6 levels, furthermore phosphatidylserine treatment facilitated axonal transport and stabilized microtubules. In brief: Naftelberg et al. identify the molecular pathway leading to neurodegeneration using a mouse model of familial dysautonomia and suggest that phosphatidylserine acts as an HDAC6 inhibitor to improve neurologic function.
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Affiliation(s)
- Shiran Naftelberg
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ziv Abramovitch
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shani Gluska
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Sivan Yannai
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yuvraj Joshi
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Maya Donyo
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Keren Ben-Yaakov
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tal Gradus
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jonathan Zonszain
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Chen Farhy
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Eran Perlson
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- * E-mail: (EP); (GA)
| | - Gil Ast
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- * E-mail: (EP); (GA)
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13
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Swisa A, Avrahami D, Eden N, Zhang J, Feleke E, Dahan T, Cohen-Tayar Y, Stolovich-Rain M, Kaestner KH, Glaser B, Ashery-Padan R, Dor Y. PAX6 maintains β cell identity by repressing genes of alternative islet cell types. J Clin Invest 2016; 127:230-243. [PMID: 27941241 DOI: 10.1172/jci88015] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 10/13/2016] [Indexed: 12/19/2022] Open
Abstract
Type 2 diabetes is thought to involve a compromised β cell differentiation state, but the mechanisms underlying this dysfunction remain unclear. Here, we report a key role for the TF PAX6 in the maintenance of adult β cell identity and function. PAX6 was downregulated in β cells of diabetic db/db mice and in WT mice treated with an insulin receptor antagonist, revealing metabolic control of expression. Deletion of Pax6 in β cells of adult mice led to lethal hyperglycemia and ketosis that were attributed to loss of β cell function and expansion of α cells. Lineage-tracing, transcriptome, and chromatin analyses showed that PAX6 is a direct activator of β cell genes, thus maintaining mature β cell function and identity. In parallel, we found that PAX6 binds promoters and enhancers to repress alternative islet cell genes including ghrelin, glucagon, and somatostatin. Chromatin analysis and shRNA-mediated gene suppression experiments indicated a similar function of PAX6 in human β cells. We conclude that reduced expression of PAX6 in metabolically stressed β cells may contribute to β cell failure and α cell dysfunction in diabetes.
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14
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Gueta K, David A, Cohen T, Menuchin-Lasowski Y, Nobel H, Narkis G, Li L, Love P, de Melo J, Blackshaw S, Westphal H, Ashery-Padan R. The stage-dependent roles of Ldb1 and functional redundancy with Ldb2 in mammalian retinogenesis. Development 2016; 143:4182-4192. [PMID: 27697904 DOI: 10.1242/dev.129734] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 09/20/2016] [Indexed: 12/26/2022]
Abstract
The Lim domain-binding proteins are key co-factor proteins that assemble with LIM domains of the LMO/LIM-HD family to form functional complexes that regulate cell proliferation and differentiation. Using conditional mutagenesis and comparative phenotypic analysis, we analyze the function of Ldb1 and Ldb2 in mouse retinal development, and demonstrate overlapping and specific functions of both proteins. Ldb1 interacts with Lhx2 in the embryonic retina and both Ldb1 and Ldb2 play a key role in maintaining the pool of retinal progenitor cells. This is accomplished by controlling the expression of the Vsx2 and Rax, and components of the Notch and Hedgehog signaling pathways. Furthermore, the Ldb1/Ldb2-mediated complex is essential for generation of early-born photoreceptors through the regulation of Rax and Crx. Finally, we demonstrate functional redundancy between Ldb1 and Ldb2. Ldb1 can fully compensate the loss of Ldb2 during all phases of retinal development, whereas Ldb2 alone is sufficient to sustain activity of Lhx2 in both early- and late-stage RPCs and in Müller glia. By contrast, loss of Ldb1 disrupts activity of the LIM domain factors in neuronal precursors. An intricate regulatory network exists that is mediated by Ldb1 and Ldb2, and promotes RPC proliferation and multipotency; it also controls specification of mammalian retina cells.
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Affiliation(s)
- Keren Gueta
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ahuvit David
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Tsadok Cohen
- Mammalian Genes and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yotam Menuchin-Lasowski
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Hila Nobel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ginat Narkis
- Mammalian Genes and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - LiQi Li
- Program on Genomics of Differentiation, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Paul Love
- Program on Genomics of Differentiation, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jimmy de Melo
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Heiner Westphal
- Mammalian Genes and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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15
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Sun J, Zhao Y, McGreal R, Cohen-Tayar Y, Rockowitz S, Wilczek C, Ashery-Padan R, Shechter D, Zheng D, Cvekl A. Pax6 associates with H3K4-specific histone methyltransferases Mll1, Mll2, and Set1a and regulates H3K4 methylation at promoters and enhancers. Epigenetics Chromatin 2016; 9:37. [PMID: 27617035 PMCID: PMC5018195 DOI: 10.1186/s13072-016-0087-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 08/31/2016] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Pax6 is a key regulator of the entire cascade of ocular lens formation through specific binding to promoters and enhancers of batteries of target genes. The promoters and enhancers communicate with each other through DNA looping mediated by multiple protein-DNA and protein-protein interactions and are marked by specific combinations of histone posttranslational modifications (PTMs). Enhancers are distinguished from bulk chromatin by specific modifications of core histone H3, including H3K4me1 and H3K27ac, while promoters show increased H3K4me3 PTM. Previous studies have shown the presence of Pax6 in as much as 1/8 of lens-specific enhancers but a much smaller fraction of tissue-specific promoters. Although Pax6 is known to interact with EP300/p300 histone acetyltransferase responsible for generation of H3K27ac, a potential link between Pax6 and histone H3K4 methylation remains to be established. RESULTS Here we show that Pax6 co-purifies with H3K4 methyltransferase activity in lens cell nuclear extracts. Proteomic studies show that Pax6 immunoprecipitates with Set1a, Mll1, and Mll2 enzymes, and their associated proteins, i.e., Wdr5, Rbbp5, Ash2l, and Dpy30. ChIP-seq studies using chromatin prepared from mouse lens and cultured lens cells demonstrate that Pax6-bound regions are mostly enriched with H3K4me2 and H3K4me1 in enhancers and promoters, though H3K4me3 marks only Pax6-containing promoters. The shRNA-mediated knockdown of Pax6 revealed down-regulation of a set of direct target genes, including Cap2, Farp1, Pax6, Plekha1, Prox1, Tshz2, and Zfp536. Pax6 knockdown was accompanied by reduced H3K4me1 at enhancers and H3K4me3 at promoters, with little or no changes of the H3K4me2 modifications. These changes were prominent in Plekha1, a gene regulated by Pax6 in both lens and retinal pigmented epithelium. CONCLUSIONS Our study supports a general model of Pax6-mediated recruitment of histone methyltransferases Mll1 and Mll2 to lens chromatin, especially at distal enhancers. Genome-wide data in lens show that Pax6 binding correlates with H3K4me2, consistent with the idea that H3K4me2 PTMs correlate with the binding of transcription factors. Importantly, partial reduction of Pax6 induces prominent changes in local H3K4me1 and H3K4me3 modification. Together, these data open the field to mechanistic studies of Pax6, Mll1, Mll2, and H3K4me1/2/3 dynamics at distal enhancers and promoters of developmentally controlled genes.
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Affiliation(s)
- Jian Sun
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Yilin Zhao
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Rebecca McGreal
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461 USA ; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Yamit Cohen-Tayar
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Sagol school of Neuroscience, Tel-Aviv University, Tel Aviv, 69978 Israel
| | - Shira Rockowitz
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Carola Wilczek
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Sagol school of Neuroscience, Tel-Aviv University, Tel Aviv, 69978 Israel
| | - David Shechter
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Deyou Zheng
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461 USA ; Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461 USA ; Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Ales Cvekl
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461 USA ; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461 USA
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16
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Bachmann C, Nguyen H, Rosenbusch J, Pham L, Rabe T, Patwa M, Sokpor G, Seong RH, Ashery-Padan R, Mansouri A, Stoykova A, Staiger JF, Tuoc T. mSWI/SNF (BAF) Complexes Are Indispensable for the Neurogenesis and Development of Embryonic Olfactory Epithelium. PLoS Genet 2016; 12:e1006274. [PMID: 27611684 PMCID: PMC5017785 DOI: 10.1371/journal.pgen.1006274] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 08/03/2016] [Indexed: 01/06/2023] Open
Abstract
Neurogenesis is a key developmental event through which neurons are generated from neural stem/progenitor cells. Chromatin remodeling BAF (mSWI/SNF) complexes have been reported to play essential roles in the neurogenesis of the central nervous system. However, whether BAF complexes are required for neuron generation in the olfactory system is unknown. Here, we identified onscBAF and ornBAF complexes, which are specifically present in olfactory neural stem cells (oNSCs) and olfactory receptor neurons (ORNs), respectively. We demonstrated that BAF155 subunit is highly expressed in both oNSCs and ORNs, whereas high expression of BAF170 subunit is observed only in ORNs. We report that conditional deletion of BAF155, a core subunit in both onscBAF and ornBAF complexes, causes impaired proliferation of oNSCs as well as defective maturation and axonogenesis of ORNs in the developing olfactory epithelium (OE), while the high expression of BAF170 is important for maturation of ORNs. Interestingly, in the absence of BAF complexes in BAF155/BAF170 double-conditional knockout mice (dcKO), OE is not specified. Mechanistically, BAF complex is required for normal activation of Pax6-dependent transcriptional activity in stem cells/progenitors of the OE. Our findings unveil a novel mechanism mediated by the mSWI/SNF complex in OE neurogenesis and development.
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Affiliation(s)
| | - Huong Nguyen
- University Medical Center, Georg-August-University, Goettingen, Germany
| | | | - Linh Pham
- University Medical Center, Georg-August-University, Goettingen, Germany
| | - Tamara Rabe
- Max-Planck-Institute for Biophysical Chemistry, Goettingen, Germany
| | - Megha Patwa
- University Medical Center, Georg-August-University, Goettingen, Germany
| | - Godwin Sokpor
- University Medical Center, Georg-August-University, Goettingen, Germany
| | - Rho H. Seong
- Department of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea
| | - Ruth Ashery-Padan
- Sackler Faculty of Medicine, Department of Human Molecular Genetics and Biochemistry, Tel Aviv University, Tel Aviv, Israel
| | - Ahmed Mansouri
- Max-Planck-Institute for Biophysical Chemistry, Goettingen, Germany
- DFG Center for Nanoscale Microscopy & Molecular Physiology of the Brain (CNMPB), Goettingen, Germany
| | - Anastassia Stoykova
- Max-Planck-Institute for Biophysical Chemistry, Goettingen, Germany
- DFG Center for Nanoscale Microscopy & Molecular Physiology of the Brain (CNMPB), Goettingen, Germany
| | - Jochen F. Staiger
- University Medical Center, Georg-August-University, Goettingen, Germany
- DFG Center for Nanoscale Microscopy & Molecular Physiology of the Brain (CNMPB), Goettingen, Germany
| | - Tran Tuoc
- University Medical Center, Georg-August-University, Goettingen, Germany
- DFG Center for Nanoscale Microscopy & Molecular Physiology of the Brain (CNMPB), Goettingen, Germany
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17
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Menuchin-Lasowski Y, Oren-Giladi P, Xie Q, Ezra-Elia R, Ofri R, Peled-Hajaj S, Farhy C, Higashi Y, Van de Putte T, Kondoh H, Huylebroeck D, Cvekl A, Ashery-Padan R. Sip1 regulates the generation of the inner nuclear layer retinal cell lineages in mammals. Development 2016; 143:2829-41. [PMID: 27385012 DOI: 10.1242/dev.136101] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 06/15/2016] [Indexed: 01/11/2023]
Abstract
The transcription factor Sip1 (Zeb2) plays multiple roles during CNS development from early acquisition of neural fate to cortical neurogenesis and gliogenesis. In humans, SIP1 (ZEB2) haploinsufficiency leads to Mowat-Wilson syndrome, a complex congenital anomaly including intellectual disability, epilepsy and Hirschsprung disease. Here we uncover the role of Sip1 in retinogenesis. Somatic deletion of Sip1 from mouse retinal progenitors primarily affects the generation of inner nuclear layer cell types, resulting in complete loss of horizontal cells and reduced numbers of amacrine and bipolar cells, while the number of Muller glia is increased. Molecular analysis places Sip1 downstream of the eye field transcription factor Pax6 and upstream of Ptf1a in the gene network required for generating the horizontal and amacrine lineages. Intriguingly, characterization of differentiation dynamics reveals that Sip1 has a role in promoting the timely differentiation of retinal interneurons, assuring generation of the proper number of the diverse neuronal and glial cell subtypes that constitute the functional retina in mammals.
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Affiliation(s)
- Yotam Menuchin-Lasowski
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Pazit Oren-Giladi
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Qing Xie
- Department of Ophthalmology & Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Raaya Ezra-Elia
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Ron Ofri
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Shany Peled-Hajaj
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Chen Farhy
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Yujiro Higashi
- Department of Perinatology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi 480-0392, Japan
| | - Tom Van de Putte
- Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
| | - Hisato Kondoh
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo Motoyama, Kita-ku, Kyoto 603-8555, Japan
| | - Danny Huylebroeck
- Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium Department of Cell Biology, Erasmus University Medical Center, 3015 CN Rotterdam, The Netherlands
| | - Ales Cvekl
- Department of Ophthalmology & Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
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18
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He S, Limi S, McGreal RS, Xie Q, Brennan LA, Kantorow WL, Kokavec J, Majumdar R, Hou H, Edelmann W, Liu W, Ashery-Padan R, Zavadil J, Kantorow M, Skoultchi AI, Stopka T, Cvekl A. Chromatin remodeling enzyme Snf2h regulates embryonic lens differentiation and denucleation. Development 2016; 143:1937-47. [PMID: 27246713 PMCID: PMC4920164 DOI: 10.1242/dev.135285] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/21/2016] [Indexed: 12/30/2022]
Abstract
Ocular lens morphogenesis is a model for investigating mechanisms of cellular differentiation, spatial and temporal gene expression control, and chromatin regulation. Brg1 (Smarca4) and Snf2h (Smarca5) are catalytic subunits of distinct ATP-dependent chromatin remodeling complexes implicated in transcriptional regulation. Previous studies have shown that Brg1 regulates both lens fiber cell differentiation and organized degradation of their nuclei (denucleation). Here, we employed a conditional Snf2h(flox) mouse model to probe the cellular and molecular mechanisms of lens formation. Depletion of Snf2h induces premature and expanded differentiation of lens precursor cells forming the lens vesicle, implicating Snf2h as a key regulator of lens vesicle polarity through spatial control of Prox1, Jag1, p27(Kip1) (Cdkn1b) and p57(Kip2) (Cdkn1c) gene expression. The abnormal Snf2h(-/-) fiber cells also retain their nuclei. RNA profiling of Snf2h(-/) (-) and Brg1(-/-) eyes revealed differences in multiple transcripts, including prominent downregulation of those encoding Hsf4 and DNase IIβ, which are implicated in the denucleation process. In summary, our data suggest that Snf2h is essential for the establishment of lens vesicle polarity, partitioning of prospective lens epithelial and fiber cell compartments, lens fiber cell differentiation, and lens fiber cell nuclear degradation.
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Grants
- R01 EY012200 NEI NIH HHS
- R01 CA079057 NCI NIH HHS
- R01 DK096266 NIDDK NIH HHS
- R01 GM116143 NIGMS NIH HHS
- R01 EY013022 NEI NIH HHS
- R01 CA076329 NCI NIH HHS
- T32 GM007491 NIGMS NIH HHS
- R56 CA079057 NCI NIH HHS
- R01 EY014237 NEI NIH HHS
- 001 World Health Organization
- R01 EY022645 NEI NIH HHS
- Grant support: R01 EY012200 (AC), EY014237 (AC), EY014237-7S1 (AC), EY013022 (MK), CA079057 (AIS), EY022645 (WL), T32 GM007491 (SL), GACR: P305/12/1033 (TS, JK), UNCE: 204021 (TS, JK), and an unrestricted grant from Research to Prevent Blindness to the Department of Ophthalmology and Visual Sciences. TS is member of the BIOCEV ? Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (CZ.1.05/1.1.00/02.0109) supported by the European Regional Development Fund. The Israel Science Foundation 610/10, the Israel Ministry of Science 36494, the Ziegler Foundation and the Binational Science Foundation (2013016) to RAP.
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Affiliation(s)
- Shuying He
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Saima Limi
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rebecca S McGreal
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Qing Xie
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Lisa A Brennan
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Wanda Lee Kantorow
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Juraj Kokavec
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA First Faculty of Medicine, Charles University, 121 08 Prague, Czech Republic
| | - Romit Majumdar
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Harry Hou
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Winfried Edelmann
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Wei Liu
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine Tel-Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Jiri Zavadil
- Department of Pathology and NYU Center for Health Informatics and Bioinformatics, New York University Langone Medical Center, New York, NY 10016, USA Mechanisms of Carcinogenesis Section, International Agency for Research on Cancer, Lyon Cedex 08 69372, France
| | - Marc Kantorow
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Tomas Stopka
- First Faculty of Medicine, Charles University, 121 08 Prague, Czech Republic
| | - Ales Cvekl
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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19
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David A, Liu F, Tibelius A, Vulprecht J, Wald D, Rothermel U, Ohana R, Seitel A, Metzger J, Ashery-Padan R, Meinzer HP, Gröne HJ, Izraeli S, Krämer A. Lack of centrioles and primary cilia in STIL(-/-) mouse embryos. Cell Cycle 2015; 13:2859-68. [PMID: 25486474 DOI: 10.4161/15384101.2014.946830] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Although most animal cells contain centrosomes, consisting of a pair of centrioles, their precise contribution to cell division and embryonic development is unclear. Genetic ablation of STIL, an essential component of the centriole replication machinery in mammalian cells, causes embryonic lethality in mice around mid gestation associated with defective Hedgehog signaling. Here, we describe, by focused ion beam scanning electron microscopy, that STIL(-/-) mouse embryos do not contain centrioles or primary cilia, suggesting that these organelles are not essential for mammalian development until mid gestation. We further show that the lack of primary cilia explains the absence of Hedgehog signaling in STIL(-/-) cells. Exogenous re-expression of STIL or STIL microcephaly mutants compatible with human survival, induced non-templated, de novo generation of centrioles in STIL(-/-) cells. Thus, while the abscence of centrioles is compatible with mammalian gastrulation, lack of centrioles and primary cilia impairs Hedgehog signaling and further embryonic development.
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Key Words
- CDK6, cyclin-dependent kinase 6
- CEP, centrosomal protein
- COILEDX, coiled-coil domain deletion
- E, embryonic day
- FIB/SEM, focused ion beam scanning electron microscopy
- MCPH, autosomal recessive primary microcephaly
- MEFs, mouse embryonic fibroblasts
- MTOC, microtubule organizing center
- PLK4, polo kinase 4
- SHH, sonic hedgehog
- STAN, STIL/ANA2
- STANX, STAN domain deletion
- STIL
- STIL, SCL/TAL1 interrupting locus
- centriole
- centrosome
- electron microscopy
- embryo
- microcephaly
- nm, nanometer
- siRNA, small interfering RNA
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Affiliation(s)
- Ahuvit David
- a Sheba Cancer Research Center and the Edmond and Lily Safra Children's Hospital; Sheba Medical Center ; Tel-Hashomer, Ramat Gan , Israel
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20
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Ohana R, Weiman-Kelman B, Raviv S, Tamm ER, Pasmanik-Chor M, Rinon A, Netanely D, Shamir R, Solomon AS, Ashery-Padan R. MicroRNAs are essential for differentiation of the retinal pigmented epithelium and maturation of adjacent photoreceptors. J Cell Sci 2015. [DOI: 10.1242/jcs.177584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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21
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Benavente CA, Finkelstein D, Johnson DA, Marine JC, Ashery-Padan R, Dyer MA. Chromatin remodelers HELLS and UHRF1 mediate the epigenetic deregulation of genes that drive retinoblastoma tumor progression. Oncotarget 2015; 5:9594-608. [PMID: 25338120 PMCID: PMC4259422 DOI: 10.18632/oncotarget.2468] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 09/06/2014] [Indexed: 12/14/2022] Open
Abstract
The retinoblastoma (Rb) family of proteins are key regulators of cell cycle exit during development and their deregulation is associated with cancer. Rb is critical for normal retinal development and germline mutations lead to retinoblastoma making retinae an attractive system to study Rb family signaling. Rb coordinates proliferation and differentiation through the E2f family of transcription factors, a critical interaction for the role of Rb in retinal development and tumorigenesis. However, whether the roles of the different E2fs are interchangeable in controlling development and tumorigenesis in the retina or if they have selective functions remains unknown. In this study, we found that E2f family members play distinct roles in the development and tumorigenesis. In Rb;p107-deficient retinae, E2f1 and E2f3 inactivation rescued tumor formation but only E2f1 rescued the retinal development phenotype. This allowed the identification of key target genes for Rb/E2f family signaling contributing to tumorigenesis and those contributing to developmental defects. We found that Sox4 and Sox11 genes contribute to the developmental phenotype and Hells and Uhrf1 contribute to tumorigenesis. Using orthotopic human xenografts, we validated that upregulation of HELLS and UHRF1 is essential for the tumor phenotype. Also, these epigenetic regulators are important for the regulation of SYK.
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Affiliation(s)
- Claudia A Benavente
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - David Finkelstein
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Dianna A Johnson
- Department of Ophtalmology, The University of Tennessee Health Science Center, Memphis, TN, USA. Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jean-Christophe Marine
- Laboratory for Molecular Cancer Biology, Center for the Biology of Disease, VIB, Leuven, Belgium
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Tel-Aviv University, Tel Aviv, Israel
| | - Michael A Dyer
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA. Department of Human Molecular Genetics and Biochemistry, Tel-Aviv University, Tel Aviv, Israel. Howard Hughes Medical Institute, Chevy Chase, MD, USA
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22
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Sun J, Rockowitz S, Xie Q, Ashery-Padan R, Zheng D, Cvekl A. Identification of in vivo DNA-binding mechanisms of Pax6 and reconstruction of Pax6-dependent gene regulatory networks during forebrain and lens development. Nucleic Acids Res 2015; 43:6827-46. [PMID: 26138486 PMCID: PMC4538810 DOI: 10.1093/nar/gkv589] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 05/23/2015] [Indexed: 01/18/2023] Open
Abstract
The transcription factor Pax6 is comprised of the paired domain (PD) and homeodomain (HD). In the developing forebrain, Pax6 is expressed in ventricular zone precursor cells and in specific subpopulations of neurons; absence of Pax6 results in disrupted cell proliferation and cell fate specification. Pax6 also regulates the entire lens developmental program. To reconstruct Pax6-dependent gene regulatory networks (GRNs), ChIP-seq studies were performed using forebrain and lens chromatin from mice. A total of 3514 (forebrain) and 3723 (lens) Pax6-containing peaks were identified, with ∼70% of them found in both tissues and thereafter called 'common' peaks. Analysis of Pax6-bound peaks identified motifs that closely resemble Pax6-PD, Pax6-PD/HD and Pax6-HD established binding sequences. Mapping of H3K4me1, H3K4me3, H3K27ac, H3K27me3 and RNA polymerase II revealed distinct types of tissue-specific enhancers bound by Pax6. Pax6 directly regulates cortical neurogenesis through activation (e.g. Dmrta1 and Ngn2) and repression (e.g. Ascl1, Fezf2, and Gsx2) of transcription factors. In lens, Pax6 directly regulates cell cycle exit via components of FGF (Fgfr2, Prox1 and Ccnd1) and Wnt (Dkk3, Wnt7a, Lrp6, Bcl9l, and Ccnd1) signaling pathways. Collectively, these studies provide genome-wide analysis of Pax6-dependent GRNs in lens and forebrain and establish novel roles of Pax6 in organogenesis.
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Affiliation(s)
- Jian Sun
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Shira Rockowitz
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Qing Xie
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ruth Ashery-Padan
- Sackler School of Medicine and Sagol School of Neuroscience, Tel-Aviv University, 69978 Ramat Aviv, Tel Aviv, Israel
| | - Deyou Zheng
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ales Cvekl
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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23
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Ohana R, Weiman-Kelman B, Raviv S, Tamm ER, Pasmanik-Chor M, Rinon A, Netanely D, Shamir R, Solomon AS, Ashery-Padan R. MicroRNAs are essential for differentiation of the retinal pigmented epithelium and maturation of adjacent photoreceptors. Development 2015; 142:2487-98. [PMID: 26062936 DOI: 10.1242/dev.121533] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 06/03/2015] [Indexed: 12/21/2022]
Abstract
Dysfunction of the retinal pigmented epithelium (RPE) results in degeneration of photoreceptors and vision loss and is correlated with common blinding disorders in humans. Although many protein-coding genes are known to be expressed in RPE and are important for its development and maintenance, virtually nothing is known about the in vivo roles of non-coding transcripts. The expression patterns of microRNAs (miRNAs) have been analyzed in a variety of ocular tissues, and a few were implicated to play role in RPE based on studies in cell lines. Here, through RPE-specific conditional mutagenesis of Dicer1 or Dgcr8 in mice, the importance of miRNAs for RPE differentiation was uncovered. miRNAs were found to be dispensable for maintaining RPE fate and survival, and yet they are essential for the acquisition of important RPE properties such as the expression of genes involved in the visual cycle pathway, pigmentation and cell adhesion. Importantly, miRNAs of the RPE are required for maturation of adjacent photoreceptors, specifically for the morphogenesis of the outer segments. The alterations in the miRNA and mRNA profiles in the Dicer1-deficient RPE point to a key role of miR-204 in regulation of the RPE differentiation program in vivo and uncover the importance of additional novel RPE miRNAs. This study reveals the combined regulatory activity of miRNAs that is required for RPE differentiation and for the development of the adjacent neuroretina.
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Affiliation(s)
- Reut Ohana
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Benjamin Weiman-Kelman
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Shaul Raviv
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ernst R Tamm
- Institute of Human Anatomy and Embryology, University of Regensburg, D-93053 Regensburg, Germany
| | - Metsada Pasmanik-Chor
- Bioinformatics Unit, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ariel Rinon
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Dvir Netanely
- Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ron Shamir
- Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv 69978, Israel
| | - Arie S Solomon
- The Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
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24
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Carpenter AC, Smith AN, Wagner H, Cohen-Tayar Y, Rao S, Wallace V, Ashery-Padan R, Lang RA. Wnt ligands from the embryonic surface ectoderm regulate 'bimetallic strip' optic cup morphogenesis in mouse. Development 2015; 142:972-82. [PMID: 25715397 PMCID: PMC4352985 DOI: 10.1242/dev.120022] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The Wnt/β-catenin response pathway is central to many developmental processes. Here, we assessed the role of Wnt signaling in early eye development using the mouse as a model system. We showed that the surface ectoderm region that includes the lens placode expressed 12 out of 19 possible Wnt ligands. When these activities were suppressed by conditional deletion of wntless (Le-cre; Wlsfl/fl) there were dramatic consequences that included a saucer-shaped optic cup, ventral coloboma, and a deficiency of periocular mesenchyme. This phenotype shared features with that produced when the Wnt/β-catenin pathway co-receptor Lrp6 is mutated or when retinoic acid (RA) signaling in the eye is compromised. Consistent with this, microarray and cell fate marker analysis identified a series of expression changes in genes known to be regulated by RA or by the Wnt/β-catenin pathway. Using pathway reporters, we showed that Wnt ligands from the surface ectoderm directly or indirectly elicit a Wnt/β-catenin response in retinal pigment epithelium (RPE) progenitors near the optic cup rim. In Le-cre; Wlsfl/fl mice, the numbers of RPE cells are reduced and this can explain, using the principle of the bimetallic strip, the curvature of the optic cup. These data thus establish a novel hypothesis to explain how differential cell numbers in a bilayered epithelium can lead to shape change. Summary: During optic cup morphogenesis, Wnt ligands expressed in the surface ectoderm control cell proliferation in the retinal pigmented epithelium, and thus influence bending of the neural retina.
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Affiliation(s)
- April C Carpenter
- Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - April N Smith
- Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Heidi Wagner
- Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Yamit Cohen-Tayar
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel
| | - Sujata Rao
- Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Valerie Wallace
- Vision Science Research Program, Toronto Western Research Institute, University Health Network, Toronto, Ontario M5T 2S8, Canada Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario M5T 2S8, Canada
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel
| | - Richard A Lang
- Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Department of Ophthalmology, College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA
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25
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Abstract
The ocular lens is a model system for understanding important aspects of embryonic development, such as cell specification and the spatiotemporally controlled formation of a three-dimensional structure. The lens, which is characterized by transparency, refraction and elasticity, is composed of a bulk mass of fiber cells attached to a sheet of lens epithelium. Although lens induction has been studied for over 100 years, recent findings have revealed a myriad of extracellular signaling pathways and gene regulatory networks, integrated and executed by the transcription factor Pax6, that are required for lens formation in vertebrates. This Review summarizes recent progress in the field, emphasizing the interplay between the diverse regulatory mechanisms employed to form lens progenitor and precursor cells and highlighting novel opportunities to fill gaps in our understanding of lens tissue morphogenesis.
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Affiliation(s)
- Aleš Cvekl
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ruth Ashery-Padan
- Sackler School of Medicine and Sagol School of Neuroscience, Tel-Aviv University, 69978 Ramat Aviv, Tel Aviv, Israel
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26
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Raviv S, Bharti K, Rencus-Lazar S, Cohen-Tayar Y, Schyr R, Evantal N, Meshorer E, Zilberberg A, Idelson M, Reubinoff B, Grebe R, Rosin-Arbesfeld R, Lauderdale J, Lutty G, Arnheiter H, Ashery-Padan R. PAX6 regulates melanogenesis in the retinal pigmented epithelium through feed-forward regulatory interactions with MITF. PLoS Genet 2014; 10:e1004360. [PMID: 24875170 PMCID: PMC4038462 DOI: 10.1371/journal.pgen.1004360] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 03/24/2014] [Indexed: 12/19/2022] Open
Abstract
During organogenesis, PAX6 is required for establishment of various progenitor subtypes within the central nervous system, eye and pancreas. PAX6 expression is maintained in a variety of cell types within each organ, although its role in each lineage and how it acquires cell-specific activity remain elusive. Herein, we aimed to determine the roles and the hierarchical organization of the PAX6-dependent gene regulatory network during the differentiation of the retinal pigmented epithelium (RPE). Somatic mutagenesis of Pax6 in the differentiating RPE revealed that PAX6 functions in a feed-forward regulatory loop with MITF during onset of melanogenesis. PAX6 both controls the expression of an RPE isoform of Mitf and synergizes with MITF to activate expression of genes involved in pigment biogenesis. This study exemplifies how one kernel gene pivotal in organ formation accomplishes a lineage-specific role during terminal differentiation of a single lineage. It is currently poorly understood how a single developmental transcription regulator controls early specification as well as a broad range of highly specialized differentiation schemes. PAX6 is one of the most extensively investigated factors in central nervous system development, yet its role in execution of lineage-specific programs remains mostly elusive. Here, we directly investigated the involvement of PAX6 in the differentiation of one lineage, the retinal pigmented epithelium (RPE), a neuroectodermal-derived tissue that is essential for retinal development and function. We revealed that PAX6 accomplishes its role through a unique regulatory interaction with the transcription factor MITF, a master regulator of the pigmentation program. During the differentiation of the RPE, PAX6 regulates the expression of an RPE-specific isoform of Mitf and importantly, at the same time, PAX6 functions together with MITF to directly activate the expression of downstream genes required for pigment biogenesis. These findings provide comprehensive insight into the gene hierarchy that controls RPE development: from a kernel gene (a term referring to the upper-most gene in the gene regulatory network) that is broadly expressed during CNS development through a lineage-specific transcription factor that together with the kernel gene creates cis-regulatory input that contributes to transcriptionally activate a battery of terminal differentiation genes.
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Affiliation(s)
- Shaul Raviv
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Kapil Bharti
- Unit on Ocular and Stem Cell Translational Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sigal Rencus-Lazar
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yamit Cohen-Tayar
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Rachel Schyr
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Naveh Evantal
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eran Meshorer
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Alona Zilberberg
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Maria Idelson
- The Hadassah Human Embryonic Stem Cell Research Center, The Goldyne Savad Institute of Gene Therapy & Department of Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Benjamin Reubinoff
- The Hadassah Human Embryonic Stem Cell Research Center, The Goldyne Savad Institute of Gene Therapy & Department of Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Rhonda Grebe
- Wilmer Ophthalmological Institute, The Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Rina Rosin-Arbesfeld
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - James Lauderdale
- Department of Cellular Biology, The University of Georgia, Athens, Georgia, United States of America
| | - Gerard Lutty
- Wilmer Ophthalmological Institute, The Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Heinz Arnheiter
- Mammalian Development Section, National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, Maryland, United States of America
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- * E-mail:
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Farhy C, Elgart M, Shapira Z, Oron-Karni V, Yaron O, Menuchin Y, Rechavi G, Ashery-Padan R. Pax6 is required for normal cell-cycle exit and the differentiation kinetics of retinal progenitor cells. PLoS One 2013; 8:e76489. [PMID: 24073291 PMCID: PMC3779171 DOI: 10.1371/journal.pone.0076489] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 08/27/2013] [Indexed: 11/19/2022] Open
Abstract
The coupling between cell-cycle exit and onset of differentiation is a common feature throughout the developing nervous system, but the mechanisms that link these processes are mostly unknown. Although the transcription factor Pax6 has been implicated in both proliferation and differentiation of multiple regions within the central nervous system (CNS), its contribution to the transition between these successive states remains elusive. To gain insight into the role of Pax6 during the transition from proliferating progenitors to differentiating precursors, we investigated cell-cycle and transcriptomic changes occurring in Pax6 (-) retinal progenitor cells (RPCs). Our analyses revealed a unique cell-cycle phenotype of the Pax6-deficient RPCs, which included a reduced number of cells in the S phase, an increased number of cells exiting the cell cycle, and delayed differentiation kinetics of Pax6 (-) precursors. These alterations were accompanied by coexpression of factors that promote (Ccnd1, Ccnd2, Ccnd3) and inhibit (P27 (kip1) and P27 (kip2) ) the cell cycle. Further characterization of the changes in transcription profile of the Pax6-deficient RPCs revealed abrogated expression of multiple factors which are known to be involved in regulating proliferation of RPCs, including the transcription factors Vsx2, Nr2e1, Plagl1 and Hedgehog signaling. These findings provide novel insight into the molecular mechanism mediating the pleiotropic activity of Pax6 in RPCs. The results further suggest that rather than conveying a linear effect on RPCs, such as promoting their proliferation and inhibiting their differentiation, Pax6 regulates multiple transcriptional networks that function simultaneously, thereby conferring the capacity to proliferate, assume multiple cell fates and execute the differentiation program into retinal lineages.
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Affiliation(s)
- Chen Farhy
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Michael Elgart
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Zehavit Shapira
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Varda Oron-Karni
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Orly Yaron
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Yotam Menuchin
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Gideon Rechavi
- Cancer Research Center, Chaim Sheba Medical Center, Tel Hashomer and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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Wolf L, Harrison W, Huang J, Xie Q, Xiao N, Sun J, Kong L, Lachke SA, Kuracha MR, Govindarajan V, Brindle PK, Ashery-Padan R, Beebe DC, Overbeek PA, Cvekl A. Histone posttranslational modifications and cell fate determination: lens induction requires the lysine acetyltransferases CBP and p300. Nucleic Acids Res 2013; 41:10199-214. [PMID: 24038357 PMCID: PMC3905850 DOI: 10.1093/nar/gkt824] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Lens induction is a classical embryologic model to study cell fate determination. It has been proposed earlier that specific changes in core histone modifications accompany the process of cell fate specification and determination. The lysine acetyltransferases CBP and p300 function as principal enzymes that modify core histones to facilitate specific gene expression. Herein, we performed conditional inactivation of both CBP and p300 in the ectodermal cells that give rise to the lens placode. Inactivation of both CBP and p300 resulted in the dramatic discontinuation of all aspects of lens specification and organogenesis, resulting in aphakia. The CBP/p300−/− ectodermal cells are viable and not prone to apoptosis. These cells showed reduced expression of Six3 and Sox2, while expression of Pax6 was not upregulated, indicating discontinuation of lens induction. Consequently, expression of αB- and αA-crystallins was not initiated. Mutant ectoderm exhibited markedly reduced levels of histone H3 K18 and K27 acetylation, subtly increased H3 K27me3 and unaltered overall levels of H3 K9ac and H3 K4me3. Our data demonstrate that CBP and p300 are required to establish lens cell-type identity during lens induction, and suggest that posttranslational histone modifications are integral to normal cell fate determination in the mammalian lens.
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Affiliation(s)
- Louise Wolf
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY10461, USA, Department of Genetics, Albert Einstein College of Medicine, Bronx, NY10461, USA, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA, Departments of Ophthalmology and Visual Sciences, Washington University Saint Louis, Saint Louis, MO 63110, USA, Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA, Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19716, USA, Department of Surgery, Creighton University, Omaha, NE 68178, USA, Department of Biochemistry, St. Jude Children's Research Hospital, Memphis, TN 38105, USA and Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine and Sagol School of Neuroscience, Tel Aviv University, Israel 69978
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Bochner R, Ziv Y, Zeevi D, Donyo M, Abraham L, Ashery-Padan R, Ast G. Phosphatidylserine increases IKBKAP levels in a humanized knock-in IKBKAP mouse model. Hum Mol Genet 2013; 22:2785-94. [PMID: 23515154 DOI: 10.1093/hmg/ddt126] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Familial dysautonomia (FD) is a severe neurodegenerative genetic disorder restricted to the Ashkenazi Jewish population. The most common mutation in FD patients is a T-to-C transition at position 6 of intron 20 of the IKBKAP gene. This mutation causes aberrant skipping of exon 20 in a tissue-specific manner, leading to reduction of the IκB kinase complex-associated protein (IKAP) protein in the nervous system. We established a homozygous humanized mouse strain carrying human exon 20 and its two flanking introns; the 3' intron has the transition observed in the IKBKAP gene of FD patients. Although our FD humanized mouse does not display FD symptoms, the unique, tissue-specific splicing pattern of the IKBKAP in these mice allowed us to evaluate the effect of therapies on gene expression and exon 20 splicing. The FD mice were supplemented with phosphatidylserine (PS), a safe food supplement that increases mRNA and protein levels of IKBKAP in cell lines generated from FD patients. Here we demonstrated that PS treatment increases IKBAKP mRNA and IKAP protein levels in various tissues of FD mice without affecting exon 20 inclusion levels. We also observed that genes associated with transcription regulation and developmental processes were up-regulated in the cerebrum of PS-treated mice. Thus, PS holds promise for the treatment of FD.
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Affiliation(s)
- Ron Bochner
- Department of Human Molecular Genetics and Biochemistry
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Shaham O, Gueta K, Mor E, Oren-Giladi P, Grinberg D, Xie Q, Cvekl A, Shomron N, Davis N, Keydar-Prizant M, Raviv S, Pasmanik-Chor M, Bell RE, Levy C, Avellino R, Banfi S, Conte I, Ashery-Padan R. Pax6 regulates gene expression in the vertebrate lens through miR-204. PLoS Genet 2013; 9:e1003357. [PMID: 23516376 PMCID: PMC3597499 DOI: 10.1371/journal.pgen.1003357] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 01/17/2013] [Indexed: 12/22/2022] Open
Abstract
During development, tissue-specific transcription factors regulate both protein-coding and non-coding genes to control differentiation. Recent studies have established a dual role for the transcription factor Pax6 as both an activator and repressor of gene expression in the eye, central nervous system, and pancreas. However, the molecular mechanism underlying the inhibitory activity of Pax6 is not fully understood. Here, we reveal that Trpm3 and the intronic microRNA gene miR-204 are co-regulated by Pax6 during eye development. miR-204 is probably the best known microRNA to function as a negative modulator of gene expression during eye development in vertebrates. Analysis of genes altered in mouse Pax6 mutants during lens development revealed significant over-representation of miR-204 targets among the genes up-regulated in the Pax6 mutant lens. A number of new targets of miR-204 were revealed, among them Sox11, a member of the SoxC family of pro-neuronal transcription factors, and an important regulator of eye development. Expression of Trpm/miR-204 and a few of its targets are also Pax6-dependent in medaka fish eyes. Collectively, this study identifies a novel evolutionarily conserved mechanism by which Pax6 controls the down-regulation of multiple genes through direct up-regulation of miR-204. The transcription factor Pax6 is reiteratively employed in space and time for the establishment of progenitor pools and the differentiation of neuronal and non-neuronal lineages of the CNS, pancreas, and eye. Execution of these diverse developmental programs depends on simultaneous activation and repression of gene networks functioning downstream of Pax6. MicroRNAs function as inhibitors of gene expression. Many microRNA genes are transcribed through common promoters of host genes. In this study, using wide-scale analysis of changes in gene expression following Pax6 deletion in the lens, we discover that Pax6 regulates the gene Trpm3 and its hosted microRNA, miR-204. We then show that miR-204 suppresses several target genes in the lens, notably the neuronal gene Sox11. Lastly, by conducting parallel experiments in the medaka fish, we show that Pax6 control of miR-204 and its target genes is evolutionarily conserved between mammals and fish, stressing the biological importance of this pathway. Pax6 regulation of miR-204 explains part of the complex, divergent inhibitory activity of Pax6 in ocular progenitor cells, which is required to establish and maintain the identity and function of ocular tissues.
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Affiliation(s)
- Ohad Shaham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Karen Gueta
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Eyal Mor
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Pazit Oren-Giladi
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Dina Grinberg
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Qing Xie
- Department of Genetics and Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Ales Cvekl
- Department of Genetics and Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Noam Shomron
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Noa Davis
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Maya Keydar-Prizant
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shaul Raviv
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Metsada Pasmanik-Chor
- Bioinformatics Unit, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Rachel E. Bell
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Carmit Levy
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | - Sandro Banfi
- Telethon Institute of Genetics and Medicine, Naples, Italy
- Medical Genetics, Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Naples, Italy
| | - Ivan Conte
- Telethon Institute of Genetics and Medicine, Naples, Italy
- * E-mail: (IC); (RA-P)
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- * E-mail: (IC); (RA-P)
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Shaham O, Menuchin Y, Farhy C, Ashery-Padan R. Pax6: a multi-level regulator of ocular development. Prog Retin Eye Res 2012; 31:351-76. [PMID: 22561546 DOI: 10.1016/j.preteyeres.2012.04.002] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 04/19/2012] [Accepted: 04/24/2012] [Indexed: 02/08/2023]
Abstract
Eye development has been a paradigm for the study of organogenesis, from the demonstration of lens induction through epithelial tissue morphogenesis, to neuronal specification and differentiation. The transcription factor Pax6 has been shown to play a key role in each of these processes. Pax6 is required for initiation of developmental pathways, patterning of epithelial tissues, activation of tissue-specific genes and interaction with other regulatory pathways. Herein we examine the data accumulated over the last few decades from extensive analyses of biochemical modules and genetic manipulation of the Pax6 gene. Specifically, we describe the regulation of Pax6's expression pattern, the protein's DNA-binding properties, and its specific roles and mechanisms of action at all stages of lens and retinal development. Pax6 functions at multiple levels to integrate extracellular information and execute cell-intrinsic differentiation programs that culminate in the specification and differentiation of a distinct ocular lineage.
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Affiliation(s)
- Ohad Shaham
- Sackler Faculty of Medicine, Department of Human Molecular Genetics and Biochemistry, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
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Magenheim J, Klein AM, Stanger BZ, Ashery-Padan R, Sosa-Pineda B, Gu G, Dor Y. Ngn3(+) endocrine progenitor cells control the fate and morphogenesis of pancreatic ductal epithelium. Dev Biol 2011; 359:26-36. [PMID: 21888903 DOI: 10.1016/j.ydbio.2011.08.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 08/09/2011] [Accepted: 08/10/2011] [Indexed: 02/06/2023]
Abstract
During pancreas development, endocrine and exocrine cells arise from a common multipotent progenitor pool. How these cell fate decisions are coordinated with tissue morphogenesis is poorly understood. Here we have examined ductal morphology, endocrine progenitor cell fate and Notch signaling in Ngn3(-/-) mice, which do not produce islet cells. Ngn3 deficiency results in reduced branching and enlarged pancreatic duct-like structures, concomitant with Ngn3 promoter activation throughout the ductal epithelium and reduced Notch signaling. Conversely, forced generation of surplus endocrine progenitor cells causes reduced duct caliber and an excessive number of tip cells. Thus, endocrine progenitor cells normally provide a feedback signal to adjacent multipotent ductal progenitor cells that activates Notch signaling, inhibits further endocrine differentiation and promotes proper morphogenesis. These results uncover a novel layer of regulation coordinating pancreas morphogenesis and endocrine/exocrine differentiation, and suggest ways to enhance the yield of beta cells from stem cells.
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Affiliation(s)
- Judith Magenheim
- Department of Developmental Biology and Cancer Research, The institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Allon M Klein
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Ben Z Stanger
- Abramson Family Cancer Research Institute, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, 69978 Ramat Aviv, Tel Aviv, Israel
| | - Beatriz Sosa-Pineda
- Department of Genetics and Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Guoqiang Gu
- Program in Developmental Biology and Department of Cell and Developmental Biology, Center for Stem Cell Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, The institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
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Huang J, Rajagopal R, Liu Y, Dattilo LK, Shaham O, Ashery-Padan R, Beebe DC. The mechanism of lens placode formation: a case of matrix-mediated morphogenesis. Dev Biol 2011; 355:32-42. [PMID: 21540023 DOI: 10.1016/j.ydbio.2011.04.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 03/30/2011] [Accepted: 04/13/2011] [Indexed: 11/29/2022]
Abstract
Although placodes are ubiquitous precursors of tissue invagination, the mechanism of placode formation has not been established and the requirement of placode formation for subsequent invagination has not been tested. Earlier measurements in chicken embryos supported the view that lens placode formation occurs because the extracellular matrix (ECM) between the optic vesicle and the surface ectoderm prevents the prospective lens cells from spreading. Continued cell proliferation within this restricted area was proposed to cause cell crowding, leading to cell elongation (placode formation). This view suggested that continued cell proliferation and adhesion to the ECM between the optic vesicle and the surface ectoderm was sufficient to explain lens placode formation. To test the predictions of this "restricted expansion hypothesis," we first confirmed that the cellular events that accompany lens placode formation in chicken embryos also occur in mouse embryos. We then showed that the failure of lens placode formation when the transcription factor, Pax6 was conditionally deleted in the surface ectoderm was associated with greatly diminished accumulation of ECM between the optic vesicle and ectoderm and reduced levels of transcripts encoding components of the ECM. In accord with the "restricted expansion hypothesis," the Pax6-deleted ectoderm expanded, rather than being constrained to a constant area. As a further test, we disrupted the ECM by deleting Fn1, which is required for matrix assembly and cell-matrix adhesion. As in Pax6(CKO) embryos, the Fn1(CKO) lens ectoderm expanded, rather than being constrained to a fixed area and the lens placode did not form. Ectoderm cells in Fn1(CKO) embryos expressed markers of lens induction and reorganized their cytoskeleton as in wild type ectoderm, but did not invaginate, suggesting that placode formation establishes the minimal mechanical requirements for invagination.
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Affiliation(s)
- Jie Huang
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA
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Abstract
The embryonic ocular neuroepithilium generates a myriad of cell types, including the neuroretina, the pigmented epithelium, the ciliary and iris epithelia, and the iris smooth muscles. As in other regions of the developing nervous system, the generation of these various cell types requires a coordinated sequence of patterning, specification and differentiation events. We investigated the roles of microRNAs (miRNAs) in the development of optic cup (OC)-derived structures. We inactivated Dicer1, a key mediator of miRNA biosynthesis, within the OC in overlapping yet distinct spatiotemporal patterns. Ablation of Dicer1 in the inner layer of the OC resulted in patterning alteration, particularly at the most distal margins. Following loss of Dicer1, this region generated a cryptic population of cells with a mixed phenotype of neuronal and ciliary body (CB) progenitors. Notably, inactivation of Dicer1 in the retinal progenitors further resulted in abrogated neurogenesis, with prolongation of ganglion cell birth and arrested differentiation of other neuronal subtypes, including amacrine and photoreceptor cells. These alterations were accompanied by changes in the expression of Notch and Hedgehog signaling components, indicating the sensitivity of the pathways to miRNA activity. Moreover, this study revealed the requirement of miRNAs for morphogenesis of the iris and for the regulation of CB cell type proliferation and differentiation. Together, analysis of the three genetic models revealed novel, stage-dependent roles for miRNAs in the development of the ocular sub-organs, which are all essential for normal vision.
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Affiliation(s)
- Noa Davis
- Sackler Faculty of Medicine, Department of Human Molecular Genetics and Biochemistry, Tel Aviv University, Tel Aviv 69978, Israel
| | - Eyal Mor
- Sackler Faculty of Medicine, Department of Human Molecular Genetics and Biochemistry, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ruth Ashery-Padan
- Sackler Faculty of Medicine, Department of Human Molecular Genetics and Biochemistry, Tel Aviv University, Tel Aviv 69978, Israel
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He S, Pirity MK, Wang WL, Wolf L, Chauhan BK, Cveklova K, Tamm ER, Ashery-Padan R, Metzger D, Nakai A, Chambon P, Zavadil J, Cvekl A. Chromatin remodeling enzyme Brg1 is required for mouse lens fiber cell terminal differentiation and its denucleation. Epigenetics Chromatin 2010; 3:21. [PMID: 21118511 PMCID: PMC3003251 DOI: 10.1186/1756-8935-3-21] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 11/30/2010] [Indexed: 12/18/2022] Open
Abstract
Background Brahma-related gene 1 (Brg1, also known as Smarca4 and Snf2β) encodes an adenosine-5'-triphosphate (ATP)-dependent catalytical subunit of the (switch/sucrose nonfermentable) (SWI/SNF) chromatin remodeling complexes. SWI/SNF complexes are recruited to chromatin through multiple mechanisms, including specific DNA-binding factors (for example, heat shock transcription factor 4 (Hsf4) and paired box gene 6 (Pax6)), chromatin structural proteins (for example, high-mobility group A1 (HMGA1)) and/or acetylated core histones. Previous studies have shown that a single amino acid substitution (K798R) in the Brg1 ATPase domain acts via a dominant-negative (dn) mechanism. Genetic studies have demonstrated that Brg1 is an essential gene for early (that is, prior implantation) mouse embryonic development. Brg1 also controls neural stem cell maintenance, terminal differentiation of multiple cell lineages and organs including the T-cells, glial cells and limbs. Results To examine the roles of Brg1 in mouse lens development, a dnBrg1 transgenic construct was expressed using the lens-specific αA-crystallin promoter in postmitotic lens fiber cells. Morphological studies revealed abnormal lens fiber cell differentiation in transgenic lenses resulting in cataract. Electron microscopic studies showed abnormal lens suture formation and incomplete karyolysis (that is, denucleation) of lens fiber cells. To identify genes regulated by Brg1, RNA expression profiling was performed in embryonic day 15.5 (E15.5) wild-type and dnBrg1 transgenic lenses. In addition, comparisons between differentially expressed genes in dnBrg1 transgenic, Pax6 heterozygous and Hsf4 homozygous lenses identified multiple genes coregulated by Brg1, Hsf4 and Pax6. DNase IIβ, a key enzyme required for lens fiber cell denucleation, was found to be downregulated in each of the Pax6, Brg1 and Hsf4 model systems. Lens-specific deletion of Brg1 using conditional gene targeting demonstrated that Brg1 was required for lens fiber cell differentiation, for expression of DNase IIβ, for lens fiber cell denucleation and indirectly for retinal development. Conclusions These studies demonstrate a cell-autonomous role for Brg1 in lens fiber cell terminal differentiation and identified DNase IIβ as a potential direct target of SWI/SNF complexes. Brg1 is directly or indirectly involved in processes that degrade lens fiber cell chromatin. The presence of nuclei and other organelles generates scattered light incompatible with the optical requirements for the lens.
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Affiliation(s)
- Shuying He
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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36
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Bandah-Rozenfeld D, Mizrahi-Meissonnier L, Farhy C, Obolensky A, Chowers I, Pe'er J, Merin S, Ben-Yosef T, Ashery-Padan R, Banin E, Sharon D. Homozygosity mapping reveals null mutations in FAM161A as a cause of autosomal-recessive retinitis pigmentosa. Am J Hum Genet 2010; 87:382-91. [PMID: 20705279 DOI: 10.1016/j.ajhg.2010.07.022] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 07/22/2010] [Accepted: 07/29/2010] [Indexed: 01/19/2023] Open
Abstract
Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal degenerations caused by mutations in at least 45 genes. Using homozygosity mapping, we identified a ∼4 Mb homozygous region on chromosome 2p15 in patients with autosomal-recessive RP (arRP). This region partially overlaps with RP28, a previously identified arRP locus. Sequence analysis of 12 candidate genes revealed three null mutations in FAM161A in 20 families. RT-PCR analysis in 21 human tissues revealed high levels of FAM161A expression in the retina and lower levels in the brain and testis. In the human retina, we identified two alternatively spliced transcripts with an intact open reading frame, the major one lacking a highly conserved exon. During mouse embryonic development, low levels of Fam161a transcripts were detected throughout the optic cup. After birth, Fam161a expression was elevated and confined to the photoreceptor layer. FAM161A encodes a protein of unknown function that is moderately conserved in mammals. Clinical manifestations of patients with FAM161A mutations varied but were largely within the spectrum associated with arRP. On funduscopy, pallor of the optic discs and attenuation of blood vessels were common, but bone-spicule-like pigmentation was often mild or lacking. Most patients had nonrecordable electroretinographic responses and constriction of visual fields upon diagnosis. Our data suggest a pivotal role for FAM161A in photoreceptors and reveal that FAM161A loss-of-function mutations are a major cause of arRP, accounting for ∼12% of arRP families in our cohort of patients from Israel and the Palestinian territories.
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Affiliation(s)
- Dikla Bandah-Rozenfeld
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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37
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Kroeber M, Davis N, Holzmann S, Kritzenberger M, Shelah-Goraly M, Ofri R, Ashery-Padan R, Tamm ER. Reduced expression of Pax6 in lens and cornea of mutant mice leads to failure of chamber angle development and juvenile glaucoma. Hum Mol Genet 2010; 19:3332-42. [PMID: 20538882 DOI: 10.1093/hmg/ddq237] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Heterozygous mutations in PAX6 are causative for aniridia, a condition that is frequently associated with juvenile glaucoma. Defects in morphogenesis of the iridocorneal angle, such as lack of trabecular meshwork differentiation, absence of Schlemm's canal and blockage of the angle by iris tissue, have been described as likely causes for glaucoma, and comparable defects have been observed in heterozygous Pax6-deficient mice. Here, we employed Cre/loxP-mediated inactivation of a single Pax6 allele in either the lens/cornea or the distal optic cup to dissect in which tissues both alleles of Pax6 need to be expressed to control the development of the tissues in the iridocorneal angle. Somatic inactivation of one allele of Pax6 exclusively from epithelial cells of lens and cornea resulted in the disruption of trabecular meshwork and Schlemm's canal development as well as in an adhesion between iris periphery and cornea in juvenile eyes, which resulted in the complete closure of the iridocorneal angle in the adult eye. Structural changes in the iridocorneal angle presumably caused a continuous increase in intraocular pressure leading to degenerative changes in optic nerve axons and to glaucoma. In contrast, the inactivation of a single Pax6 allele in the distal optic cup did not cause obvious changes in iridocorneal angle formation. We conclude that the defects in iridocorneal angle formation are caused by non-autonomous mechanisms due to Pax6 haploinsufficiency in lens or corneal epithelial cells. Pax6 probably controls the expression of signaling molecules in lens cells that regulate the morphogenetic processes during iridocorneal angle formation.
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Affiliation(s)
- Markus Kroeber
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
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Ashery-Padan R, Farhy C. The multiple roles of Pax6 in mammalian retinogenesis. Neurosci Res 2010. [DOI: 10.1016/j.neures.2010.07.339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Smith AN, Miller LA, Radice G, Ashery-Padan R, Lang RA. Stage-dependent modes of Pax6-Sox2 epistasis regulate lens development and eye morphogenesis. Development 2009; 136:2977-85. [PMID: 19666824 DOI: 10.1242/dev.037341] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The transcription factors Pax6 and Sox2 have been implicated in early events in lens induction and have been proposed to cooperate functionally. Here, we investigated the activity of Sox2 in lens induction and its genetic relationship to Pax6 in the mouse. Conditional deletion of Sox2 in the lens placode arrests lens development at the pit stage. As previously shown, conditional deletion of Pax6 in the placode eliminates placodal thickening and lens pit invagination. The cooperative activity of Sox2 and Pax6 is illustrated by the dramatic failure of lens and eye development in presumptive lens conditional, compound Sox2, Pax6 heterozygotes. The resulting phenotype resembles that of germ line Pax6 inactivation, and the failure of optic cup morphogenesis indicates the importance of ectoderm-derived signals for all aspects of eye development. We further assessed whether Sox2 and Pax6 were required for N-cadherin expression at different stages of lens development. N-cadherin was lost in Sox2-deficient but not Pax6-deficient pre-placodal ectoderm. By contrast, after the lens pit has formed, N-cadherin expression is dependent on Pax6. These data support a model in which the mode of Pax6-Sox2 inter-regulation is stage-dependent and suggest an underlying mechanism in which DNA binding site availability is regulated.
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Affiliation(s)
- April N Smith
- Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229, USA
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Smith AN, Miller LA, Radice G, Ashery-Padan R, Lang RA. Stage-dependent modes of Pax6-Sox2 epistasis regulate lens development and eye morphogenesis. Development 2009. [DOI: 10.1242/dev.043802] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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41
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Davis N, Yoffe C, Raviv S, Antes R, Berger J, Holzmann S, Stoykova A, Overbeek PA, Tamm ER, Ashery-Padan R. Pax6 dosage requirements in iris and ciliary body differentiation. Dev Biol 2009; 333:132-42. [DOI: 10.1016/j.ydbio.2009.06.023] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 06/18/2009] [Accepted: 06/22/2009] [Indexed: 11/15/2022]
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Abstract
The developing ocular lens provides an excellent model system with which to study the intrinsic and extrinsic cues governing cell differentiation. Although the transcription factors Pax6 and Sox2 have been shown to be essential for lens induction, their later roles during lens fiber differentiation remain largely unknown. Using Cre/loxP mutagenesis, we somatically inactivated Pax6 and Sox2 in the developing mouse lens during differentiation of the secondary lens fibers and explored the regulatory interactions of these two intrinsic factors with the canonical Wnt pathway. Analysis of the Pax6-deficient lenses revealed a requirement for Pax6 in cell cycle exit and differentiation into lens fiber cells. In addition, Pax6 disruption led to apoptosis of lens epithelial cells. We show that Pax6 regulates the Wnt antagonist Sfrp2 in the lens, and that Sox2 expression is upregulated in the Pax6-deficient lenses. However, our study demonstrates that the failure of differentiation following loss of Pax6 is independent of beta-catenin signaling or Sox2 activity. This study reveals that Pax6 is pivotal for initiation of the lens fiber differentiation program in the mammalian eye.
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Affiliation(s)
- Ohad Shaham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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43
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Baranes K, Raz-Prag D, Nitzan A, Galron R, Ashery-Padan R, Rotenstreich Y, Assaf Y, Shiloh Y, Wang ZQ, Barzilai A, Solomon AS. Conditional inactivation of the NBS1 gene in the mouse central nervous system leads to neurodegeneration and disorganization of the visual system. Exp Neurol 2009; 218:24-32. [PMID: 19345213 DOI: 10.1016/j.expneurol.2009.03.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Revised: 02/15/2009] [Accepted: 03/19/2009] [Indexed: 01/10/2023]
Abstract
Nijmegen breakage syndrome (NBS) is a genomic instability disease caused by hypomorphic mutations in the NBS1 gene encoding the Nbs1 (nibrin) protein. Nbs1 is a component of the Mre11/Rad50/Nbs1 (MRN) complex that acts as a sensor of double strand breaks (DSBs) in the DNA and is critical for proper activation of the broad cellular response to DSBs. Conditional disruption of the murine ortholog of the human NBS1, Nbs1, in the CNS of mice was previously reported to cause microcephaly, severe cerebellar atrophy and ataxia. Here we report that conditional targeted disruption of the murine NBS1 gene in the CNS results in mal-development, degeneration, disorganization and dysfunction of the murine visual system, especially in the optic nerve. Nbs1 deletion resulted in reduced diameters of Nbs1-CNS-Delta eye and optic nerve. MRI analysis revealed defective white matter development and organization. Nbs1 inactivation altered the morphology and organization of the glial cells. Interestingly, at the age of two-month-old the levels of the axonal guidance molecule semaphorin-3A and its receptor neuropilin-1 were up-regulated in the retina of the mutant mice, a typical injury response. Electroretinogram analysis revealed marked reduction in a- and b-waves, indicative of decreased retinal function. Our study points to a novel role for Nbs1 in the development, organization and function of the visual system.
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Affiliation(s)
- Koby Baranes
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978 Israel
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Boretius S, Michaelis T, Tammer R, Ashery-Padan R, Frahm J, Stoykova A. In vivo MRI of altered brain anatomy and fiber connectivity in adult pax6 deficient mice. ACTA ACUST UNITED AC 2009; 19:2838-47. [PMID: 19329571 DOI: 10.1093/cercor/bhp057] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The impact of developmental ablation of Pax6 function on morphology and functional connectivity of the adult cerebrum was studied in cortex-specific Pax6 knockout mice (Pax6cKO) using structural magnetic resonance imaging (MRI), manganese-enhanced MRI, and diffusion tensor MRI in conjunction with fiber tractography. Mutants presented with decreased volumes of total brain and olfactory bulb, reduced cortical thickness, and altered layering of the piriform cortex. Tracking of major neuronal fiber bundles revealed a disorganization of callosal fibers with an almost complete lack of interhemispheric connectivity. In Pax6cKO mice intrahemispheric callosal fibers as well as intracortical fibers were predominantly directed along a rostrocaudal orientation instead of a left-right and dorsoventral orientation found in controls. Fiber disorganization also involved the septohippocampal connection targeting mostly the lateral septal nucleus. The hippocampus was rostrally extended and its volume was increased relative to that of the forebrain and midbrain. Manganese-induced MRI signal enhancement in the CA3 region suggested a normal function of hippocampal pyramidal cells. Noteworthy, several morphologic disturbances in gray and white matter of Pax6cKO mice were similar to observations in human aniridia patients. The present findings indicate an important role of Pax6 in the development of both the cortex and cerebral fiber connectivity.
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Affiliation(s)
- Susann Boretius
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, 37070 Göttingen, Germany.
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Oron-Karni V, Farhy C, Elgart M, Marquardt T, Remizova L, Yaron O, Xie Q, Cvekl A, Ashery-Padan R. Dual requirement for Pax6 in retinal progenitor cells. Development 2008; 135:4037-4047. [PMID: 19004853 DOI: 10.1242/dev.028308] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Throughout the developing central nervous system, pre-patterning of the ventricular zone into discrete neural progenitor domains is one of the predominant strategies used to produce neuronal diversity in a spatially coordinated manner. In the retina, neurogenesis proceeds in an intricate chronological and spatial sequence, yet it remains unclear whether retinal progenitor cells (RPCs) display intrinsic heterogeneity at any given time point. Here, we performed a detailed study of RPC fate upon temporally and spatially confined inactivation of Pax6. Timed genetic removal of Pax6 appeared to unmask a cryptic divergence of RPCs into qualitatively divergent progenitor pools. In the more peripheral RPCs under normal circumstances, Pax6 seemed to prevent premature activation of a photoreceptor-differentiation pathway by suppressing expression of the transcription factor Crx. More centrally, Pax6 contributed to the execution of the comprehensive potential of RPCs: Pax6 ablation resulted in the exclusive generation of amacrine interneurons. Together, these data suggest an intricate dual role for Pax6 in retinal neurogenesis, while pointing to the cryptic divergence of RPCs into distinct progenitor pools.
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Affiliation(s)
- Varda Oron-Karni
- Sackler Faculty of Medicine, Human Molecular Genetics and Biochemistry, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
| | - Chen Farhy
- Sackler Faculty of Medicine, Human Molecular Genetics and Biochemistry, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
| | - Michael Elgart
- Sackler Faculty of Medicine, Human Molecular Genetics and Biochemistry, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
| | - Till Marquardt
- European Neuroscience Institute, Developmental Neurobiology Laboratory, University of Göttingen Medical School/Max Planck Society, Grisebachstrasse 5, 37077 Göttingen, Germany
| | - Lena Remizova
- Sackler Faculty of Medicine, Human Molecular Genetics and Biochemistry, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
| | - Orly Yaron
- Sackler Faculty of Medicine, Human Molecular Genetics and Biochemistry, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
| | - Qing Xie
- Albert Einstein College of Medicine, Departments of Ophthalmology and Visual Sciences and Genetics, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Ales Cvekl
- Albert Einstein College of Medicine, Departments of Ophthalmology and Visual Sciences and Genetics, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Ruth Ashery-Padan
- Sackler Faculty of Medicine, Human Molecular Genetics and Biochemistry, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
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Pontoriero GF, Deschamps P, Ashery-Padan R, Wong R, Yang Y, Zavadil J, Cvekl A, Sullivan S, Williams T, West-Mays JA. Cell autonomous roles for AP-2alpha in lens vesicle separation and maintenance of the lens epithelial cell phenotype. Dev Dyn 2008; 237:602-17. [PMID: 18224708 DOI: 10.1002/dvdy.21445] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In this study, we have created a conditional deletion of AP-2alpha in the developing mouse lens (Le-AP-2alpha mutants) to determine the cell-autonomous requirement(s) for AP-2alpha in lens development. Embryonic and adult Le-AP-2alpha mutants exhibited defects confined to lens placode derivatives, including a persistent adhesion of the lens to the overlying corneal epithelium (or lens stalk). Expression of known regulators of lens vesicle separation, including Pax6, Pitx3, and Foxe3 was observed in the Le-AP-2alpha mutant lens demonstrating that these genes do not lie directly downstream of AP-2alpha. Unlike germ-line mutants, Le-AP-2alpha mutants did not exhibit defects in the optic cup, further defining the tissue specific role(s) for AP-2alpha in eye development. Finally, comparative microarray analysis of lenses from the Le-AP-2alpha mutants vs. wild-type littermates revealed differential expression of 415 mRNAs, including reduced expression of genes important for maintaining the lens epithelial cell phenotype, such as E-cadherin.
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Affiliation(s)
- Giuseppe F Pontoriero
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
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47
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Davis-Silberman N, Ashery-Padan R. Iris development in vertebrates; genetic and molecular considerations. Brain Res 2008; 1192:17-28. [PMID: 17466284 DOI: 10.1016/j.brainres.2007.03.043] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Revised: 03/11/2007] [Accepted: 03/16/2007] [Indexed: 10/23/2022]
Abstract
The iris plays a key role in visual function. It regulates the amount of light entering the eye and falling on the retina and also operates in focal adjustment of closer objects. The iris is involved in circulation of the aqueous humor and hence functions in regulation of intraocular pressure. Intriguingly, iris pigmented cells possess the ability to transdifferentiate into different ocular cell types of retinal pigmented epithelium, photoreceptors and lens cells. Thus, the iris is considered a potential source for cell-replacement therapies. During embryogenesis, the iris arises from both the optic cup and the periocular mesenchyme. Its interesting mode of development includes specification of the peripheral optic cup to a non-neuronal fate, migration of cells from the surrounding periocular mesenchyme and an atypical formation of smooth muscles from the neuroectoderm. This manner of development raises some interesting general topics concerning the early patterning of the neuroectoderm, the specification and differentiation of diverse cell types and the interactions between intrinsic and extrinsic factors in the process of organogenesis. In this review, we discuss iris anatomy and development, describe major pathologies of the iris and their molecular etiology and finally summarize the recent findings on genes and signaling pathways that are involved in iris development.
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Affiliation(s)
- Noa Davis-Silberman
- Sackler Faculty of Medicine, Department of Human Molecular Genetics and Biochemistry, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
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Bumsted-O'Brien KM, Hendrickson A, Haverkamp S, Ashery-Padan R, Schulte D. Expression of the homeodomain transcription factor Meis2 in the embryonic and postnatal retina. J Comp Neurol 2008; 505:58-72. [PMID: 17729288 DOI: 10.1002/cne.21458] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Members of the Meis subfamily of homeodomain-containing transcription factors play important roles during development and disease. Here we report that the Meis family protein Meis2 is expressed by a subpopulation of gamma-aminobutyric acid (GABA)ergic amacrine (AM) cells in the adult and embryonic retina of different vertebrate species. In mice, Meis2-expressing (Meis2+) AM cells are not cholinergic or dopaminergic, but some are immunoreactive for neuronal nitric oxide synthase (bNOS). About 50% of the mouse Meis2+ AM cell population expresses the calcium-binding protein calretinin, and some Meis2+ AM cells show characteristics of Type II CD-15+ cells. AM cell expression of Meis2 is lost in a conditional knockout mouse model for Pax6, indicating a dependency upon Pax6. Bromodeoxyuridine pulse labeling experiments and immunohistochemical staining for the neuronal marker NeuN in embryonic mouse retinae indicate that Meis2 is an early marker for newly postmitotic AM cells. In addition, taking advantage of the protracted retinal development in humans, we show that newly generated AM cells express Meis2 before adopting the GABAergic or glycinergic neurotransmitter phenotype. As development proceeds, some AM cells lose Meis2 expression concomitantly with the appearance of glycine, while other AM cells retain Meis2 expression after they express GABA. These data identify Meis2 as a suitable marker for the study of AM cell diversity and development in addition to providing evidence for the stepwise specification of the glycinergic and GABAergic neurotransmitter phenotypes during AM cell differentiation.
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Affiliation(s)
- Keely M Bumsted-O'Brien
- Department of Neuroanatomy, Max-Planck-Institute for Brain Research, Deutschordenst. 46, 60218 Frankfurt, Germany
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Alberstein M, Amit M, Vaknin K, O'Donnell A, Farhy C, Lerenthal Y, Shomron N, Shaham O, Sharrocks AD, Ashery-Padan R, Ast G. Regulation of transcription of the RNA splicing factor hSlu7 by Elk-1 and Sp1 affects alternative splicing. RNA 2007; 13:1988-99. [PMID: 17804646 PMCID: PMC2040095 DOI: 10.1261/rna.492907] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Alternative splicing plays a major role in transcriptome diversity and plasticity, but it is largely unknown how tissue-specific and embryogenesis-specific alternative splicing is regulated. The highly conserved splicing factor Slu7 is involved in 3' splice site selection and also regulates alternative splicing. We show that Slu7 has a unique spatial pattern of expression among human and mouse embryonic and adult tissues. We identified several functional Ets binding sites and GC-boxes in the human Slu7 (hSlu7) promoter region. The Ets and GC-box binding transcription factors, Elk-1 and Sp1, respectively, exerted opposite effects on hSlu7 transcription: Sp1 protein enhances and Elk-1 protein represses transcription in a dose-dependent manner. Sp1 protein bound to the hSlu7 promoter in vivo, and depletion of Sp1 by RNA interference (RNAi) repressed hSlu7 expression. Elk-1 protein bound to the hSlu7 promoter in vivo, and depletion of Elk-1 by RNAi caused an increase in the endogenous level of hSlu7 mRNA. Further, depletion of either Sp1 or Elk-1 affected alternative splicing. Our results provide indications of a complex transcription regulation mechanism that controls the spatial and temporal expression of Slu7, presumably allowing regulation of tissue-specific alternative splicing events.
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Affiliation(s)
- Moti Alberstein
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
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50
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Finkler A, Ashery-Padan R, Fromm H. CAMTAs: calmodulin-binding transcription activators from plants to human. FEBS Lett 2007; 581:3893-8. [PMID: 17689537 DOI: 10.1016/j.febslet.2007.07.051] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Revised: 07/18/2007] [Accepted: 07/19/2007] [Indexed: 02/08/2023]
Abstract
Recently, a novel family of calmodulin-binding transcription activators (CAMTAs) was reported in various eukaryotes. All CAMTAs share a similar domain organization, with a novel type of sequence-specific DNA-binding domain (designated CG-1). This domain could bind DNA directly and activate transcription, or interact with other transcription factors, not through DNA binding, thus acting as a co-activator of transcription. Investigations of CAMTAs in various organisms imply a broad range of functions from sensory mechanisms to embryo development and growth control, highlighted by the apparent involvement of mammalian CAMTA2 in cardiac growth, and of CAMTA1 in tumor suppression and memory performance.
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Affiliation(s)
- Aliza Finkler
- Department of Plant Sciences, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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