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Hernández-Marrero D, Junaidi RM, Lyons CJ. Unilateral progressive anterior iris adhesions in Mowat-Wilson syndrome: a new ocular finding. J AAPOS 2024; 28:103807. [PMID: 38218547 DOI: 10.1016/j.jaapos.2023.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/03/2023] [Accepted: 11/10/2023] [Indexed: 01/15/2024]
Abstract
Ocular associations in Mowat-Wilson syndrome (MWS) are rare. Those involving the anterior segment are scarce in the literature. We describe a child with genetic confirmation of MWS that presented with acquired onset of unilateral anterior iris adhesions with no known trauma.
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Affiliation(s)
- Dayra Hernández-Marrero
- Department of Ophthalmology, British Columbia Children's Hospital, Vancouver, British Columbia, Canada
| | - Radwan M Junaidi
- Department of Ophthalmology, British Columbia Children's Hospital, Vancouver, British Columbia, Canada
| | - Christopher J Lyons
- Department of Ophthalmology, British Columbia Children's Hospital, Vancouver, British Columbia, Canada.
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2
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Kovács T, Halasy V, Pethő C, Szőcs E, Soós Á, Dóra D, de Santa Barbara P, Faure S, Stavely R, Goldstein AM, Nagy N. Essential Role of BMP4 Signaling in the Avian Ceca in Colorectal Enteric Nervous System Development. Int J Mol Sci 2023; 24:15664. [PMID: 37958648 PMCID: PMC10650322 DOI: 10.3390/ijms242115664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 11/15/2023] Open
Abstract
The enteric nervous system (ENS) is principally derived from vagal neural crest cells that migrate caudally along the entire length of the gastrointestinal tract, giving rise to neurons and glial cells in two ganglionated plexuses. Incomplete migration of enteric neural crest-derived cells (ENCDC) leads to Hirschsprung disease, a congenital disorder characterized by the absence of enteric ganglia along variable lengths of the colorectum. Our previous work strongly supported the essential role of the avian ceca, present at the junction of the midgut and hindgut, in hindgut ENS development, since ablation of the cecal buds led to incomplete ENCDC colonization of the hindgut. In situ hybridization shows bone morphogenetic protein-4 (BMP4) is highly expressed in the cecal mesenchyme, leading us to hypothesize that cecal BMP4 is required for hindgut ENS development. To test this, we modulated BMP4 activity using embryonic intestinal organ culture techniques and retroviral infection. We show that overexpression or inhibition of BMP4 in the ceca disrupts hindgut ENS development, with GDNF playing an important regulatory role. Our results suggest that these two important signaling pathways are required for normal ENCDC migration and enteric ganglion formation in the developing hindgut ENS.
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Affiliation(s)
- Tamás Kovács
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, 1094 Budapest, Hungary; (T.K.); (E.S.); (Á.S.); (D.D.)
| | - Viktória Halasy
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, 1094 Budapest, Hungary; (T.K.); (E.S.); (Á.S.); (D.D.)
| | - Csongor Pethő
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, 1094 Budapest, Hungary; (T.K.); (E.S.); (Á.S.); (D.D.)
| | - Emőke Szőcs
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, 1094 Budapest, Hungary; (T.K.); (E.S.); (Á.S.); (D.D.)
| | - Ádám Soós
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, 1094 Budapest, Hungary; (T.K.); (E.S.); (Á.S.); (D.D.)
| | - Dávid Dóra
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, 1094 Budapest, Hungary; (T.K.); (E.S.); (Á.S.); (D.D.)
| | - Pascal de Santa Barbara
- PhyMedExp, University of Montpellier, INSERM, CNRS, 34295 Montpellier, France; (P.d.S.B.); (S.F.)
| | - Sandrine Faure
- PhyMedExp, University of Montpellier, INSERM, CNRS, 34295 Montpellier, France; (P.d.S.B.); (S.F.)
| | - Rhian Stavely
- Pediatric Surgery Research Laboratories, Department of Pediatric Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; (R.S.); (A.M.G.)
| | - Allan M. Goldstein
- Pediatric Surgery Research Laboratories, Department of Pediatric Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; (R.S.); (A.M.G.)
| | - Nándor Nagy
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, 1094 Budapest, Hungary; (T.K.); (E.S.); (Á.S.); (D.D.)
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3
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A lncRNA-encoded mitochondrial micropeptide exacerbates microglia-mediated neuroinflammation in retinal ischemia/reperfusion injury. Cell Death Dis 2023; 14:126. [PMID: 36792584 PMCID: PMC9932084 DOI: 10.1038/s41419-023-05617-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 01/20/2023] [Accepted: 01/25/2023] [Indexed: 02/17/2023]
Abstract
As a common pathology of many ocular disorders such as diabetic retinopathy and glaucoma, retinal ischemia/reperfusion (IR) triggers inflammation and microglia activation that lead to irreversible retinal damage. The detailed molecular mechanism underlying retinal IR injury, however, remains poorly understood at present. Here we report the bioinformatic identification of a lncRNA 1810058I24Rik (181-Rik) that was shown to encode a mitochondrion-located micropeptide Stmp1. Its deficiency in mice protected retinal ganglion cells from retinal IR injury by attenuating the activation of microglia and the Nlrp3 inflammasome pathway. Moreover, its genetic knockout in mice or knockdown in primary microglia promoted mitochondrial fusion, impaired mitochondrial membrane potential, and reactive oxygen species (ROS) production, diminished aerobic glycolysis, and ameliorated inflammation. It appears that 181-Rik may trigger the Nlrp3 inflammasome activation by controlling mitochondrial functions through inhibiting expression of the metabolic sensor uncoupling protein 2 (Ucp2) and activating expression of the Ca2+ sensors S100a8/a9. Together, our findings shed new light on the molecular pathogenesis of retinal IR injury and may provide a fresh therapeutic target for IR-associated neurodegenerative diseases.
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Zheng X, Guo Y, Zhang R, Chen H, Liu S, Qiu S, Xiang M. The mitochondrial micropeptide Stmp1 promotes retinal cell differentiation. Biochem Biophys Res Commun 2022; 636:79-86. [DOI: 10.1016/j.bbrc.2022.10.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 10/20/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022]
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5
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ZEB2, the Mowat-Wilson Syndrome Transcription Factor: Confirmations, Novel Functions, and Continuing Surprises. Genes (Basel) 2021; 12:genes12071037. [PMID: 34356053 PMCID: PMC8304685 DOI: 10.3390/genes12071037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/30/2021] [Accepted: 07/01/2021] [Indexed: 12/15/2022] Open
Abstract
After its publication in 1999 as a DNA-binding and SMAD-binding transcription factor (TF) that co-determines cell fate in amphibian embryos, ZEB2 was from 2003 studied by embryologists mainly by documenting the consequences of conditional, cell-type specific Zeb2 knockout (cKO) in mice. In between, it was further identified as causal gene causing Mowat-Wilson Syndrome (MOWS) and novel regulator of epithelial–mesenchymal transition (EMT). ZEB2’s functions and action mechanisms in mouse embryos were first addressed in its main sites of expression, with focus on those that helped to explain neurodevelopmental and neural crest defects seen in MOWS patients. By doing so, ZEB2 was identified in the forebrain as the first TF that determined timing of neuro-/gliogenesis, and thereby also the extent of different layers of the cortex, in a cell non-autonomous fashion, i.e., by its cell-intrinsic control within neurons of neuron-to-progenitor paracrine signaling. Transcriptomics-based phenotyping of Zeb2 mutant mouse cells have identified large sets of intact-ZEB2 dependent genes, and the cKO approaches also moved to post-natal brain development and diverse other systems in adult mice, including hematopoiesis and various cell types of the immune system. These new studies start to highlight the important adult roles of ZEB2 in cell–cell communication, including after challenge, e.g., in the infarcted heart and fibrotic liver. Such studies may further evolve towards those documenting the roles of ZEB2 in cell-based repair of injured tissue and organs, downstream of actions of diverse growth factors, which recapitulate developmental signaling principles in the injured sites. Evident questions are about ZEB2’s direct target genes, its various partners, and ZEB2 as a candidate modifier gene, e.g., in other (neuro)developmental disorders, but also the accurate transcriptional and epigenetic regulation of its mRNA expression sites and levels. Other questions start to address ZEB2’s function as a niche-controlling regulatory TF of also other cell types, in part by its modulation of growth factor responses (e.g., TGFβ/BMP, Wnt, Notch). Furthermore, growing numbers of mapped missense as well as protein non-coding mutations in MOWS patients are becoming available and inspire the design of new animal model and pluripotent stem cell-based systems. This review attempts to summarize in detail, albeit without discussing ZEB2’s role in cancer, hematopoiesis, and its emerging roles in the immune system, how intense ZEB2 research has arrived at this exciting intersection.
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Deryckere A, Stappers E, Dries R, Peyre E, van den Berghe V, Conidi A, Zampeta FI, Francis A, Bresseleers M, Stryjewska A, Vanlaer R, Maas E, Smal IV, van IJcken WFJ, Grosveld FG, Nguyen L, Huylebroeck D, Seuntjens E. Multifaceted actions of Zeb2 in postnatal neurogenesis from the ventricular-subventricular zone to the olfactory bulb. Development 2020; 147:dev184861. [PMID: 32253238 DOI: 10.1242/dev.184861] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 03/23/2020] [Indexed: 03/01/2024]
Abstract
The transcription factor Zeb2 controls fate specification and subsequent differentiation and maturation of multiple cell types in various embryonic tissues. It binds many protein partners, including activated Smad proteins and the NuRD co-repressor complex. How Zeb2 subdomains support cell differentiation in various contexts has remained elusive. Here, we studied the role of Zeb2 and its domains in neurogenesis and neural differentiation in the young postnatal ventricular-subventricular zone (V-SVZ), in which neural stem cells generate olfactory bulb-destined interneurons. Conditional Zeb2 knockouts and separate acute loss- and gain-of-function approaches indicated that Zeb2 is essential for controlling apoptosis and neuronal differentiation of V-SVZ progenitors before and after birth, and we identified Sox6 as a potential downstream target gene of Zeb2. Zeb2 genetic inactivation impaired the differentiation potential of the V-SVZ niche in a cell-autonomous fashion. We also provide evidence that its normal function in the V-SVZ also involves non-autonomous mechanisms. Additionally, we demonstrate distinct roles for Zeb2 protein-binding domains, suggesting that Zeb2 partners co-determine neuronal output from the mouse V-SVZ in both quantitative and qualitative ways in early postnatal life.
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Affiliation(s)
- Astrid Deryckere
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven 3000, Belgium
| | - Elke Stappers
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Ruben Dries
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Elise Peyre
- GIGA-Stem Cells and GIGA-Neurosciences, Liège University, Liège 4000, Belgium
| | - Veronique van den Berghe
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
- Department of Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, and MRC Centre for Neurodevelopmental Disorders, King's College London, London SE1 1UL, UK
| | - Andrea Conidi
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - F Isabella Zampeta
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Annick Francis
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
| | - Marjolein Bresseleers
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
| | - Agata Stryjewska
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
| | - Ria Vanlaer
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven 3000, Belgium
| | - Elke Maas
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Leuven 3000, Belgium
| | - Ihor V Smal
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
- Department of Molecular Genetics, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Wilfred F J van IJcken
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
- Center for Biomics-Genomics, Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Frank G Grosveld
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Laurent Nguyen
- GIGA-Stem Cells and GIGA-Neurosciences, Liège University, Liège 4000, Belgium
| | - Danny Huylebroeck
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Eve Seuntjens
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven 3000, Belgium
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
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Jurkute N, Leu C, Pogoda HM, Arno G, Robson AG, Nürnberg G, Altmüller J, Thiele H, Motameny S, Toliat MR, Powell K, Höhne W, Michaelides M, Webster AR, Moore AT, Hammerschmidt M, Nürnberg P, Yu-Wai-Man P, Votruba M. SSBP1 mutations in dominant optic atrophy with variable retinal degeneration. Ann Neurol 2019; 86:368-383. [PMID: 31298765 DOI: 10.1002/ana.25550] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 07/10/2019] [Accepted: 07/10/2019] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Autosomal dominant optic atrophy (ADOA) starts in early childhood with loss of visual acuity and color vision deficits. OPA1 mutations are responsible for the majority of cases, but in a portion of patients with a clinical diagnosis of ADOA, the cause remains unknown. This study aimed to identify novel ADOA-associated genes and explore their causality. METHODS Linkage analysis and sequencing were performed in multigeneration families and unrelated patients to identify disease-causing variants. Functional consequences were investigated in silico and confirmed experimentally using the zebrafish model. RESULTS We defined a new ADOA locus on 7q33-q35 and identified 3 different missense variants in SSBP1 (NM_001256510.1; c.113G>A [p.(Arg38Gln)], c.320G>A [p.(Arg107Gln)] and c.422G>A [p.(Ser141Asn)]) in affected individuals from 2 families and 2 singletons with ADOA and variable retinal degeneration. The mutated arginine residues are part of a basic patch that is essential for single-strand DNA binding. The loss of a positive charge at these positions is very likely to lower the affinity of SSBP1 for single-strand DNA. Antisense-mediated knockdown of endogenous ssbp1 messenger RNA (mRNA) in zebrafish resulted in compromised differentiation of retinal ganglion cells. A similar effect was achieved when mutated mRNAs were administered. These findings point toward an essential role of ssbp1 in retinal development and the dominant-negative nature of the identified human variants, which is consistent with the segregation pattern observed in 2 multigeneration families studied. INTERPRETATION SSBP1 is an essential protein for mitochondrial DNA replication and maintenance. Our data have established pathogenic variants in SSBP1 as a cause of ADOA and variable retinal degeneration. ANN NEUROL 2019;86:368-383.
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Affiliation(s)
- Neringa Jurkute
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom
| | - Costin Leu
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH.,Genomic Medicine Institute, Lerner Research Institute Cleveland Clinic, Cleveland, OH.,Stanley Center for Psychiatric Research, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA
| | - Hans-Martin Pogoda
- Institute for Zoology, Developmental Biology Unit, University of Cologne, Cologne, Germany
| | - Gavin Arno
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom
| | - Anthony G Robson
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom
| | - Gudrun Nürnberg
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Holger Thiele
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Susanne Motameny
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | | | - Kate Powell
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Wolfgang Höhne
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Michel Michaelides
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom
| | - Andrew R Webster
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom
| | - Anthony T Moore
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom.,Department of Ophthalmology, University of California, San Francisco, San Francisco, CA
| | - Matthias Hammerschmidt
- Institute for Zoology, Developmental Biology Unit, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Patrick Yu-Wai-Man
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom.,Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, United Kingdom.,Cambridge Centre for Brain Repair and Medical Research Council Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Marcela Votruba
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom.,Cardiff Eye Unit, University Hospital Wales, Cardiff, United Kingdom
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Jin K, Xiang M. Transcription factor Ptf1a in development, diseases and reprogramming. Cell Mol Life Sci 2019; 76:921-940. [PMID: 30470852 PMCID: PMC11105224 DOI: 10.1007/s00018-018-2972-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 11/13/2018] [Accepted: 11/19/2018] [Indexed: 12/12/2022]
Abstract
The transcription factor Ptf1a is a crucial helix-loop-helix (bHLH) protein selectively expressed in the pancreas, retina, spinal cord, brain, and enteric nervous system. Ptf1a is preferably assembled into a transcription trimeric complex PTF1 with an E protein and Rbpj (or Rbpjl). In pancreatic development, Ptf1a is indispensable in controlling the expansion of multipotent progenitor cells as well as the specification and maintenance of the acinar cells. In neural tissues, Ptf1a is transiently expressed in the post-mitotic cells and specifies the inhibitory neuronal cell fates, mostly mediated by downstream genes such as Tfap2a/b and Prdm13. Mutations in the coding and non-coding regulatory sequences resulting in Ptf1a gain- or loss-of-function are associated with genetic diseases such as pancreatic and cerebellar agenesis in the rodent and human. Surprisingly, Ptf1a alone is sufficient to reprogram mouse or human fibroblasts into tripotential neural stem cells. Its pleiotropic functions in many biological processes remain to be deciphered in the future.
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Affiliation(s)
- Kangxin Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China.
| | - Mengqing Xiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China.
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Xiao D, Jin K, Xiang M. Necessity and Sufficiency of Ldb1 in the Generation, Differentiation and Maintenance of Non-photoreceptor Cell Types During Retinal Development. Front Mol Neurosci 2018; 11:271. [PMID: 30127719 PMCID: PMC6087769 DOI: 10.3389/fnmol.2018.00271] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 07/17/2018] [Indexed: 12/28/2022] Open
Abstract
During mammalian retinal development, the multipotent progenitors differentiate into all classes of retinal cells under the delicate control of transcriptional factors. The deficiency of a transcription cofactor, the LIM-domain binding protein Ldb1, has been shown to cause proliferation and developmental defects in multiple tissues including cardiovascular, hematopoietic, and nervous systems; however, it remains unclear whether and how it regulates retinal development. By expression profiling, RNA in situ hybridization and immunostaining, here we show that Ldb1 is expressed in the progenitors during early retinal development, but later its expression gradually shifts to non-photoreceptor cell types including bipolar, amacrine, horizontal, ganglion, and Müller glial cells. Retina-specific ablation of Ldb1 in mice resulted in microphthalmia, optic nerve hypoplasia, retinal thinning and detachment, and profound vision impairment as determined by electroretinography. In the mutant retina, there was precocious differentiation of amacrine and horizontal cells, indicating a requirement of Ldb1 in maintaining the retinal progenitor pool. Additionally, all non-photoreceptor cell types were greatly reduced which appeared to be caused by a generation defect and/or retinal degeneration via excessive cell apoptosis. Furthermore, we showed that misexpressed Ldb1 was sufficient to promote the generation of bipolar, amacrine, horizontal, ganglion, and Müller glial cells at the expense of photoreceptors. Together, these results demonstrate that Ldb1 is not only necessary but also sufficient for the development and/or maintenance of non-photoreceptor cell types, and implicate that the pleiotropic functions of Ldb1 during retinal development are context-dependent and determined by its interaction with diverse LIM-HD (LIM-homeodomain) and LMO (LIM domain-only) binding protein partners.
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Affiliation(s)
- Dongchang Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Kangxin Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Mengqing Xiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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