1
|
Zhang D, Jennings L, Chen SC, Zaw K, Lamey TM, Thompson JA, McLaren TL, Chen FK, McLenachan S. Establishment of an induced pluripotent stem cell line LEIi019-A from an early-onset retinal dystrophy patient with the autosomal dominant OTX2 c.259G>A variant. Stem Cell Res 2024; 78:103461. [PMID: 38852423 DOI: 10.1016/j.scr.2024.103461] [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: 05/05/2024] [Revised: 05/24/2024] [Accepted: 06/02/2024] [Indexed: 06/11/2024] Open
Abstract
The human induced pluripotent stem cell (iPSC) line LEIi019-A was generated from a patient with early-onset pattern dystrophy caused by a heterozygous mutation NM_001270525.1:c.259G>A (p.Glu87Lys) in OTX2. Patient-derived dermal fibroblasts were reprogrammed using episomal plasmids containing reprogramming factors OCT4, SOX2, KLF4, MYCL, LIN28, TP53 shRNA and miR-302/367. The iPSC line expressed pluripotency markers, displayed a normal 46,XY karyotype and demonstrated the ability to differentiate into the three primary germ layers, retinal organoids and retinal pigment epithelial cells.
Collapse
Affiliation(s)
- Dan Zhang
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Luke Jennings
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Shang-Chih Chen
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Khine Zaw
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Tina M Lamey
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Jennifer A Thompson
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Terri L McLaren
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia; Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Fred K Chen
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia; Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia; Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia; Department of Ophthalmology, Perth Children's Hospital, Nedlands, Western Australia, Australia.
| | - Samuel McLenachan
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia.
| |
Collapse
|
2
|
Pereira MF, Finazzi V, Rizzuti L, Aprile D, Aiello V, Mollica L, Riva M, Soriani C, Dossena F, Shyti R, Castaldi D, Tenderini E, Carminho-Rodrigues MT, Bally JF, de Vries BBA, Gabriele M, Vitriolo A, Testa G. YY1 mutations disrupt corticogenesis through a cell-type specific rewiring of cell-autonomous and non-cell-autonomous transcriptional programs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.16.580337. [PMID: 38405909 PMCID: PMC10888784 DOI: 10.1101/2024.02.16.580337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Germline mutations of YY1 cause Gabriele-de Vries syndrome (GADEVS), a neurodevelopmental disorder featuring intellectual disability and a wide range of systemic manifestations. To dissect the cellular and molecular mechanisms underlying GADEVS, we combined large-scale imaging, single-cell multiomics and gene regulatory network reconstruction in 2D and 3D patient-derived physiopathologically relevant cell lineages. YY1 haploinsufficiency causes a pervasive alteration of cell type specific transcriptional networks, disrupting corticogenesis at the level of neural progenitors and terminally differentiated neurons, including cytoarchitectural defects reminiscent of GADEVS clinical features. Transcriptional alterations in neurons propagated to neighboring astrocytes through a major non-cell autonomous pro-inflammatory effect that grounds the rationale for modulatory interventions. Together, neurodevelopmental trajectories, synaptic formation and neuronal-astrocyte cross talk emerged as salient domains of YY1 dosage-dependent vulnerability. Mechanistically, cell-type resolved reconstruction of gene regulatory networks uncovered the regulatory interplay between YY1, NEUROG2 and ETV5 and its aberrant rewiring in GADEVS. Our findings underscore the reach of advanced in vitro models in capturing developmental antecedents of clinical features and exposing their underlying mechanisms to guide the search for targeted interventions.
Collapse
Affiliation(s)
- Marlene F Pereira
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Via Adamello 16, 20139, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Via Santa Sofia 9, 20122, Milan, Italy
- Human Technopole, Viale Rita Levi-Montalcini 1, 20157, Milan, Italy
| | - Veronica Finazzi
- Human Technopole, Viale Rita Levi-Montalcini 1, 20157, Milan, Italy
| | - Ludovico Rizzuti
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Via Adamello 16, 20139, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Via Santa Sofia 9, 20122, Milan, Italy
- Human Technopole, Viale Rita Levi-Montalcini 1, 20157, Milan, Italy
| | - Davide Aprile
- Human Technopole, Viale Rita Levi-Montalcini 1, 20157, Milan, Italy
| | - Vittorio Aiello
- Department of Oncology and Hemato-Oncology, University of Milan, Via Santa Sofia 9, 20122, Milan, Italy
- Human Technopole, Viale Rita Levi-Montalcini 1, 20157, Milan, Italy
| | - Luca Mollica
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Italy
| | - Matteo Riva
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Italy
| | - Chiara Soriani
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Via Adamello 16, 20139, Milan, Italy
| | | | - Reinald Shyti
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Via Adamello 16, 20139, Milan, Italy
- Human Technopole, Viale Rita Levi-Montalcini 1, 20157, Milan, Italy
| | - Davide Castaldi
- Department of Oncology and Hemato-Oncology, University of Milan, Via Santa Sofia 9, 20122, Milan, Italy
- Human Technopole, Viale Rita Levi-Montalcini 1, 20157, Milan, Italy
| | - Erika Tenderini
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Via Adamello 16, 20139, Milan, Italy
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | | | - Julien F Bally
- Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital & University of Lausanne, Lausanne, Switzerland
| | | | - Michele Gabriele
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Via Adamello 16, 20139, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Via Santa Sofia 9, 20122, Milan, Italy
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- The Broad Institute of MIT and Harvard; Cambridge, MA 02139, USA
- Koch Institute for Integrative Cancer Research; Cambridge, MA, 02139, USA
| | - Alessandro Vitriolo
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Via Adamello 16, 20139, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Via Santa Sofia 9, 20122, Milan, Italy
- Human Technopole, Viale Rita Levi-Montalcini 1, 20157, Milan, Italy
| | - Giuseppe Testa
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Via Adamello 16, 20139, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Via Santa Sofia 9, 20122, Milan, Italy
- Human Technopole, Viale Rita Levi-Montalcini 1, 20157, Milan, Italy
| |
Collapse
|
3
|
Swarup A, Phansalkar R, Morri M, Agarwal A, Subramaniam V, Li B, Wu AY. Single-cell transcriptomic analysis of corneal organoids during development. Stem Cell Reports 2023; 18:2482-2497. [PMID: 38039970 PMCID: PMC10724212 DOI: 10.1016/j.stemcr.2023.10.022] [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: 04/21/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 12/03/2023] Open
Abstract
Corneal organoids are useful tools for disease modeling and tissue transplantation; however, they have not yet been well studied during maturation. We characterized human iPSC-derived corneal organoids at 1, 2, 3, and 4 months of development using single-cell RNA sequencing to determine the cellular heterogeneity at each stage. We found pluripotent cell clusters committed to epithelial cell lineage at 1 month; early corneal epithelial, endothelial, and stromal cell markers at 2 months; keratocytes as the largest cell population at 3 months; and a large epithelial cell population at 4 months. We compared organoid to fetal corneal development at different stages and found that 4-month organoids closely resemble the corneal cellular complexity of the fetal (16 post conception week) and adult cornea. Using RNA velocity trajectory analysis, we found that less differentiated cells appear to give rise to corneal epithelial cells during development.
Collapse
Affiliation(s)
- Aditi Swarup
- Department of Ophthalmology, Stanford University School of Medicine, Stanford, CA, USA
| | - Ragini Phansalkar
- Department of Ophthalmology, Stanford University School of Medicine, Stanford, CA, USA
| | - Maurizio Morri
- Chan Zuckerberg Biohub, Stanford University, San Francisco, CA, USA
| | - Aditi Agarwal
- Chan Zuckerberg Biohub, Stanford University, San Francisco, CA, USA
| | - Varun Subramaniam
- Department of Ophthalmology, Stanford University School of Medicine, Stanford, CA, USA
| | - BaoXiang Li
- Department of Ophthalmology, Stanford University School of Medicine, Stanford, CA, USA
| | - Albert Y Wu
- Department of Ophthalmology, Stanford University School of Medicine, Stanford, CA, USA; Institute of Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA.
| |
Collapse
|
4
|
Terrinoni A, Micheloni G, Moretti V, Caporali S, Bernardini S, Minieri M, Pieri M, Giaroni C, Acquati F, Costantino L, Ferrara F, Valli R, Porta G. OTX Genes in Adult Tissues. Int J Mol Sci 2023; 24:16962. [PMID: 38069286 PMCID: PMC10707059 DOI: 10.3390/ijms242316962] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/22/2023] [Accepted: 11/25/2023] [Indexed: 12/18/2023] Open
Abstract
OTX homeobox genes have been extensively studied for their role in development, especially in neuroectoderm formation. Recently, their expression has also been reported in adult physiological and pathological tissues, including retina, mammary and pituitary glands, sinonasal mucosa, in several types of cancer, and in response to inflammatory, ischemic, and hypoxic stimuli. Reactivation of OTX genes in adult tissues supports the notion of the evolutionary amplification of functions of genes by varying their temporal expression, with the selection of homeobox genes from the "toolbox" to drive or contribute to different processes at different stages of life. OTX involvement in pathologies points toward these genes as potential diagnostic and/or prognostic markers as well as possible therapeutic targets.
Collapse
Affiliation(s)
- Alessandro Terrinoni
- Department of Experimental Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Giovanni Micheloni
- Genomic Medicine Research Center, Department of Medicine and Surgery, University of Insubria, Via JH Dunant 5, 21100 Varese, Italy
| | - Vittoria Moretti
- Genomic Medicine Research Center, Department of Medicine and Surgery, University of Insubria, Via JH Dunant 5, 21100 Varese, Italy
| | - Sabrina Caporali
- Department of Industrial Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy
| | - Sergio Bernardini
- Department of Experimental Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Marilena Minieri
- Department of Experimental Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Massimo Pieri
- Department of Experimental Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Cristina Giaroni
- Department of Medicina e Innovazione Tecnologica, University of Insubria, Via JH Dunant 5, 21100 Varese, Italy
| | - Francesco Acquati
- Genomic Medicine Research Center, Department of Medicine and Surgery, University of Insubria, Via JH Dunant 5, 21100 Varese, Italy
- Department of Biotechnology and Life Science, University of Insubria, Via JH Dunant 3, 21100 Varese, Italy
| | - Lucy Costantino
- Department of Molecular Genetics, Centro Diagnostico Italiano, Via Saint Bon 20, 20147 Milano, Italy
| | - Fulvio Ferrara
- Department of Molecular Genetics, Centro Diagnostico Italiano, Via Saint Bon 20, 20147 Milano, Italy
| | - Roberto Valli
- Genomic Medicine Research Center, Department of Medicine and Surgery, University of Insubria, Via JH Dunant 5, 21100 Varese, Italy
| | - Giovanni Porta
- Genomic Medicine Research Center, Department of Medicine and Surgery, University of Insubria, Via JH Dunant 5, 21100 Varese, Italy
| |
Collapse
|
5
|
Wulff-Fuentes E, Boakye J, Kroenke K, Berendt RR, Martinez-Morant C, Pereckas M, Hanover JA, Olivier-Van Stichelen S. O-GlcNAcylation regulates OTX2's proteostasis. iScience 2023; 26:108184. [PMID: 38026167 PMCID: PMC10661118 DOI: 10.1016/j.isci.2023.108184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 08/28/2023] [Accepted: 10/09/2023] [Indexed: 12/01/2023] Open
Abstract
O-GlcNAcylation is a key post-translational modification, playing a vital role in cell signaling during development, especially in the brain. In this study, we investigated the role of O-GlcNAcylation in regulating the homeobox protein OTX2, which contributes to various brain disorders, such as combined pituitary hormone deficiency, retinopathy, and medulloblastoma. Our research demonstrated that, under normal physiological conditions, the proteasome plays a pivotal role in breaking down endogenous OTX2. However, when the levels of OTX2 rise, it forms oligomers and/or aggregates that require macroautophagy for clearance. Intriguingly, we demonstrated that O-GlcNAcylation enhances the solubility of OTX2, thereby limiting the formation of these aggregates. Additionally, we unveiled an interaction between OTX2 and the chaperone protein CCT5 at the O-GlcNAc sites, suggesting a potential collaborative role in preventing OTX2 aggregation. Finally, our study demonstrated that while OTX2 physiologically promotes cell proliferation, an O-GlcNAc-depleted OTX2 is detrimental to cancer cells.
Collapse
Affiliation(s)
| | - Jeffrey Boakye
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0851, USA
| | - Kaeley Kroenke
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Rex R. Berendt
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | | | - Michaela Pereckas
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - John A. Hanover
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0851, USA
| | - Stephanie Olivier-Van Stichelen
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Obstetrics and Gynecology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| |
Collapse
|
6
|
Zheng Y, Sun C, Zhang X, Ruzycki PA, Chen S. Missense mutations in CRX homeodomain cause dominant retinopathies through two distinct mechanisms. eLife 2023; 12:RP87147. [PMID: 37963072 PMCID: PMC10645426 DOI: 10.7554/elife.87147] [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] [Indexed: 11/16/2023] Open
Abstract
Homeodomain transcription factors (HD TFs) are instrumental to vertebrate development. Mutations in HD TFs have been linked to human diseases, but their pathogenic mechanisms remain elusive. Here, we use Cone-Rod Homeobox (CRX) as a model to decipher the disease-causing mechanisms of two HD mutations, p.E80A and p.K88N, that produce severe dominant retinopathies. Through integrated analysis of molecular and functional evidence in vitro and in knock-in mouse models, we uncover two novel gain-of-function mechanisms: p.E80A increases CRX-mediated transactivation of canonical CRX target genes in developing photoreceptors; p.K88N alters CRX DNA-binding specificity resulting in binding at ectopic sites and severe perturbation of CRX target gene expression. Both mechanisms produce novel retinal morphological defects and hinder photoreceptor maturation distinct from loss-of-function models. This study reveals the distinct roles of E80 and K88 residues in CRX HD regulatory functions and emphasizes the importance of transcriptional precision in normal development.
Collapse
Affiliation(s)
- Yiqiao Zheng
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
| | - Chi Sun
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
| | - Xiaodong Zhang
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
| | - Philip A Ruzycki
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Genetics, Washington University in St LouisSaint LouisUnited States
| | - Shiming Chen
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Developmental Biology, Washington University in St LouisSaint LouisUnited States
| |
Collapse
|
7
|
Jackson D, Moosajee M. The Genetic Determinants of Axial Length: From Microphthalmia to High Myopia in Childhood. Annu Rev Genomics Hum Genet 2023; 24:177-202. [PMID: 37624667 DOI: 10.1146/annurev-genom-102722-090617] [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] [Indexed: 08/27/2023]
Abstract
The axial length of the eye is critical for normal visual function by enabling light to precisely focus on the retina. The mean axial length of the adult human eye is 23.5 mm, but the molecular mechanisms regulating ocular axial length remain poorly understood. Underdevelopment can lead to microphthalmia (defined as a small eye with an axial length of less than 19 mm at 1 year of age or less than 21 mm in adulthood) within the first trimester of pregnancy. However, continued overgrowth can lead to axial high myopia (an enlarged eye with an axial length of 26.5 mm or more) at any age. Both conditions show high genetic and phenotypic heterogeneity associated with significant visual morbidity worldwide. More than 90 genes can contribute to microphthalmia, and several hundred genes are associated with myopia, yet diagnostic yields are low. Crucially, the genetic pathways underpinning the specification of eye size are only now being discovered, with evidence suggesting that shared molecular pathways regulate under- or overgrowth of the eye. Improving our mechanistic understanding of axial length determination will help better inform us of genotype-phenotype correlations in both microphthalmia and myopia, dissect gene-environment interactions in myopia, and develop postnatal therapies that may influence overall eye growth.
Collapse
Affiliation(s)
- Daniel Jackson
- Institute of Ophthalmology, University College London, London, United Kingdom;
| | - Mariya Moosajee
- Institute of Ophthalmology, University College London, London, United Kingdom;
- The Francis Crick Institute, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| |
Collapse
|
8
|
Zheng Y, Sun C, Zhang X, Ruzycki PA, Chen S. Missense mutations in CRX homeodomain cause dominant retinopathies through two distinct mechanisms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.01.526652. [PMID: 36778408 PMCID: PMC9915647 DOI: 10.1101/2023.02.01.526652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Homeodomain transcription factors (HD TFs) are instrumental to vertebrate development. Mutations in HD TFs have been linked to human diseases, but their pathogenic mechanisms remain elusive. Here we use Cone-Rod Homeobox (CRX) as a model to decipher the disease-causing mechanisms of two HD mutations, p.E80A and p.K88N, that produce severe dominant retinopathies. Through integrated analysis of molecular and functional evidence in vitro and in knock-in mouse models, we uncover two novel gain-of-function mechanisms: p.E80A increases CRX-mediated transactivation of canonical CRX target genes in developing photoreceptors; p.K88N alters CRX DNA-binding specificity resulting in binding at ectopic sites and severe perturbation of CRX target gene expression. Both mechanisms produce novel retinal morphological defects and hinder photoreceptor maturation distinct from loss-of-function models. This study reveals the distinct roles of E80 and K88 residues in CRX HD regulatory functions and emphasizes the importance of transcriptional precision in normal development.
Collapse
Affiliation(s)
- Yiqiao Zheng
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Chi Sun
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Xiaodong Zhang
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Philip A. Ruzycki
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
- Department of Genetics, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Shiming Chen
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
- Department of Developmental Biology, Washington University in St Louis, Saint Louis, Missouri, USA
| |
Collapse
|
9
|
Chesneau B, Ivashchenko V, Habib C, Gaston V, Escudié F, Morel G, Capri Y, Vincent-Delorme C, Calvas P, Chassaing N, Plaisancié J. Evaluation of somatic and/or germline mosaicism in congenital malformation of the eye. Eur J Hum Genet 2023; 31:526-530. [PMID: 36404347 PMCID: PMC10172375 DOI: 10.1038/s41431-022-01234-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/17/2022] [Accepted: 11/01/2022] [Indexed: 11/22/2022] Open
Abstract
Microphthalmia, Anophthalmia and Coloboma (MAC) form a spectrum of congenital eye malformations responsible for severe visual impairment. Despite the exploration of hundreds of genes by High-Throughput Sequencing (HTS), most of the patients remain without genetic diagnosis. One explanation could be the not yet demonstrated involvement of somatic mosaicism (undetected by conventional analysis pipelines) in those patients. Furthermore, the proportion of parental germline mosaicism in presumed de novo variations is still unknown in ocular malformations. Thus, using dedicated bioinformatics pipeline designed to detect mosaic variants, we reanalysed the sequencing data obtained from a 119 ocular development genes panel performed on blood samples of 78 probands with sporadic MAC without genetic diagnosis. Using the same HTS strategy, we sequenced 80 asymptomatic parents of 41 probands carrying a disease-causing variant in an ocular development gene considered de novo after Sanger sequencing of both parents. Reanalysis of the previously sequencing data did not find any mosaic variant in probands without genetic diagnosis. However, HTS of parents revealed undetected SOX2 and PAX6 mosaic variants in two parents. Finally, this work, performed on two large cohorts of patients with MAC spectrum, provides for the first time an overview of the interest of looking for mosaicism in ocular development disorders. Somatic mosaicism does not appear to be frequent in MAC spectrum and might explain only few diagnoses. Thus, other approaches such as whole genome sequencing should be considered in those patients. Parental mosaicism is however not that rare (around 5%) and challenging for genetic counselling.
Collapse
Affiliation(s)
- Bertrand Chesneau
- Service de Génétique Médicale, Hôpital Purpan, CHU de Toulouse, Toulouse, France
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU de Toulouse, Toulouse, France
| | | | - Christophe Habib
- Service de Génétique Médicale, Hôpital Purpan, CHU de Toulouse, Toulouse, France
| | - Véronique Gaston
- Service de Génétique Médicale, Hôpital Purpan, CHU de Toulouse, Toulouse, France
| | - Fréderic Escudié
- Département d'anatomopathologie, IUCT Oncopole, Toulouse, France
| | - Godelieve Morel
- Service de Génétique Médicale, CHU de Rennes, Rennes, France
| | - Yline Capri
- Service de Génétique Médicale, Hôpital Robert Debré, APHP, Paris, France
| | | | - Patrick Calvas
- Service de Génétique Médicale, Hôpital Purpan, CHU de Toulouse, Toulouse, France
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU de Toulouse, Toulouse, France
| | - Nicolas Chassaing
- Service de Génétique Médicale, Hôpital Purpan, CHU de Toulouse, Toulouse, France
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU de Toulouse, Toulouse, France
| | - Julie Plaisancié
- Service de Génétique Médicale, Hôpital Purpan, CHU de Toulouse, Toulouse, France.
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU de Toulouse, Toulouse, France.
- INSERM U1214, ToNIC, Université Toulouse III, Toulouse, France.
| |
Collapse
|
10
|
Sun C, Chen S. Disease-causing mutations in genes encoding transcription factors critical for photoreceptor development. Front Mol Neurosci 2023; 16:1134839. [PMID: 37181651 PMCID: PMC10172487 DOI: 10.3389/fnmol.2023.1134839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 04/04/2023] [Indexed: 05/16/2023] Open
Abstract
Photoreceptor development of the vertebrate visual system is controlled by a complex transcription regulatory network. OTX2 is expressed in the mitotic retinal progenitor cells (RPCs) and controls photoreceptor genesis. CRX that is activated by OTX2 is expressed in photoreceptor precursors after cell cycle exit. NEUROD1 is also present in photoreceptor precursors that are ready to specify into rod and cone photoreceptor subtypes. NRL is required for the rod fate and regulates downstream rod-specific genes including the orphan nuclear receptor NR2E3 which further activates rod-specific genes and simultaneously represses cone-specific genes. Cone subtype specification is also regulated by the interplay of several transcription factors such as THRB and RXRG. Mutations in these key transcription factors are responsible for ocular defects at birth such as microphthalmia and inherited photoreceptor diseases such as Leber congenital amaurosis (LCA), retinitis pigmentosa (RP) and allied dystrophies. In particular, many mutations are inherited in an autosomal dominant fashion, including the majority of missense mutations in CRX and NRL. In this review, we describe the spectrum of photoreceptor defects that are associated with mutations in the above-mentioned transcription factors, and summarize the current knowledge of molecular mechanisms underlying the pathogenic mutations. At last, we deliberate the outstanding gaps in our understanding of the genotype-phenotype correlations and outline avenues for future research of the treatment strategies.
Collapse
Affiliation(s)
- Chi Sun
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, United States
- *Correspondence: Chi Sun,
| | - Shiming Chen
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, United States
- Department of Developmental Biology, Washington University in St. Louis, St. Louis, MO, United States
| |
Collapse
|
11
|
Cvekl A, Camerino MJ. Generation of Lens Progenitor Cells and Lentoid Bodies from Pluripotent Stem Cells: Novel Tools for Human Lens Development and Ocular Disease Etiology. Cells 2022; 11:cells11213516. [PMID: 36359912 PMCID: PMC9658148 DOI: 10.3390/cells11213516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
In vitro differentiation of human pluripotent stem cells (hPSCs) into specialized tissues and organs represents a powerful approach to gain insight into those cellular and molecular mechanisms regulating human development. Although normal embryonic eye development is a complex process, generation of ocular organoids and specific ocular tissues from pluripotent stem cells has provided invaluable insights into the formation of lineage-committed progenitor cell populations, signal transduction pathways, and self-organization principles. This review provides a comprehensive summary of recent advances in generation of adenohypophyseal, olfactory, and lens placodes, lens progenitor cells and three-dimensional (3D) primitive lenses, "lentoid bodies", and "micro-lenses". These cells are produced alone or "community-grown" with other ocular tissues. Lentoid bodies/micro-lenses generated from human patients carrying mutations in crystallin genes demonstrate proof-of-principle that these cells are suitable for mechanistic studies of cataractogenesis. Taken together, current and emerging advanced in vitro differentiation methods pave the road to understand molecular mechanisms of cataract formation caused by the entire spectrum of mutations in DNA-binding regulatory genes, such as PAX6, SOX2, FOXE3, MAF, PITX3, and HSF4, individual crystallins, and other genes such as BFSP1, BFSP2, EPHA2, GJA3, GJA8, LIM2, MIP, and TDRD7 represented in human cataract patients.
Collapse
Affiliation(s)
- Aleš Cvekl
- Departments Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Correspondence: ; Tel.: +1-718-430-3217; Fax: +1-718-430-8778
| | - Michael John Camerino
- Departments Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| |
Collapse
|
12
|
Boobalan E, Thompson AH, Alur RP, McGaughey DM, Dong L, Shih G, Vieta-Ferrer ER, Onojafe IF, Kalaskar VK, Arno G, Lotery AJ, Guan B, Bender C, Memon O, Brinster L, Soleilhavoup C, Panman L, Badea TC, Minella A, Lopez AJ, Thomasy SM, Moshiri A, Blain D, Hufnagel RB, Cogliati T, Bharti K, Brooks BP. Zfp503/Nlz2 Is Required for RPE Differentiation and Optic Fissure Closure. Invest Ophthalmol Vis Sci 2022; 63:5. [PMID: 36326727 PMCID: PMC9645360 DOI: 10.1167/iovs.63.12.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Purpose Uveal coloboma is a congenital eye malformation caused by failure of the optic fissure to close in early human development. Despite significant progress in identifying genes whose regulation is important for executing this closure, mutations are detected in a minority of cases using known gene panels, implying additional genetic complexity. We have previously shown knockdown of znf503 (the ortholog of mouse Zfp503) in zebrafish causes coloboma. Here we characterize Zfp503 knockout (KO) mice and evaluate transcriptomic profiling of mutant versus wild-type (WT) retinal pigment epithelium (RPE)/choroid. Methods Zfp503 KO mice were generated by gene targeting using homologous recombination. Embryos were characterized grossly and histologically. Patterns and level of developmentally relevant proteins/genes were examined with immunostaining/in situ hybridization. The transcriptomic profile of E11.5 KO RPE/choroid was compared to that of WT. Results Zfp503 is dynamically expressed in developing mouse eyes, and loss of its expression results in uveal coloboma. KO embryos exhibit altered mRNA levels and expression patterns of several key transcription factors involved in eye development, including Otx2, Mitf, Pax6, Pax2, Vax1, and Vax2, resulting in a failure to maintain the presumptive RPE, as evidenced by reduced melanin pigmentation and its differentiation into a neural retina-like lineage. Comparison of RNA sequencing data from WT and KO E11.5 embryos demonstrated reduced expression of melanin-related genes and significant overlap with genes known to be dynamically regulated at the optic fissure. Conclusions These results demonstrate a critical role of Zfp503 in maintaining RPE fate and optic fissure closure.
Collapse
Affiliation(s)
- Elangovan Boobalan
- Pediatric, Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Amy H. Thompson
- Pediatric, Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Ramakrishna P. Alur
- Pediatric, Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - David M. McGaughey
- Pediatric, Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Lijin Dong
- Mouse Genetic Engineering Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Grace Shih
- Pediatric, Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Emile R. Vieta-Ferrer
- Pediatric, Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Ighovie F. Onojafe
- Pediatric, Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Vijay K. Kalaskar
- Pediatric, Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Gavin Arno
- University College London Institute of Ophthalmology, London, United Kingdom,Moorfields Eye Hospital, London, United Kingdom
| | - Andrew J. Lotery
- Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Bin Guan
- Ophthalmic Genetics Laboratory, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Chelsea Bender
- Ophthalmic Genetics Laboratory, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Omar Memon
- Ocular and Stem Cell Translational Research Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Lauren Brinster
- Division of Veterinary Resources, Office of Research Services, National Institutes of Health, Bethesda, Maryland, United States
| | | | - Lia Panman
- MRC Toxicology Unit, University of Cambridge, Leicester, United Kingdom
| | - Tudor C. Badea
- Retinal Circuit Development and Genetics Unit, Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States,Research and Development Institute, Transilvania University of Brașov, Brașov, Romania,National Center for Brain Research, ICIA, Romanian Academy, Bucharest, România
| | - Andrea Minella
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California–Davis, Davis, California, United States
| | - Antonio Jacobo Lopez
- Department of Ophthalmology and Vision Science, School of Medicine, University of California–Davis, Davis, California, United States
| | - Sara M. Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California–Davis, Davis, California, United States,Department of Ophthalmology and Vision Science, School of Medicine, University of California–Davis, Davis, California, United States
| | - Ala Moshiri
- Department of Ophthalmology and Vision Science, School of Medicine, University of California–Davis, Davis, California, United States
| | - Delphine Blain
- Pediatric, Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Robert B. Hufnagel
- Ophthalmic Genetics Laboratory, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Tiziana Cogliati
- Pediatric, Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Kapil Bharti
- Ocular and Stem Cell Translational Research Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Brian P. Brooks
- Pediatric, Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics & Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| |
Collapse
|
13
|
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] [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.
Collapse
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.
| |
Collapse
|
14
|
Functions of block of proliferation 1 during anterior development in Xenopus laevis. PLoS One 2022; 17:e0273507. [PMID: 36007075 PMCID: PMC9409556 DOI: 10.1371/journal.pone.0273507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 08/09/2022] [Indexed: 11/19/2022] Open
Abstract
Block of proliferation 1 (Bop1) is a nucleolar protein known to be necessary for the assembly of the 60S subunit of ribosomes. Here, we show a specific bop1 expression in the developing anterior tissue of the South African clawed frog Xenopus laevis. Morpholino oligonucleotide-mediated knockdown approaches demonstrated that Bop1 is required for proper development of the cranial cartilage, brain, and the eyes. Furthermore, we show that bop1 knockdown leads to impaired retinal lamination with disorganized cell layers. Expression of neural crest-, brain-, and eye-specific marker genes was disturbed. Apoptotic and proliferative processes, which are known to be affected during ribosomal biogenesis defects, are not hindered upon bop1 knockdown. Because early Xenopus embryos contain a large store of maternal ribosomes, we considered if Bop1 might have a role independent of de novo ribosomal biogenesis. At early embryonic stages, pax6 expression was strongly reduced in bop1 morphants and synergy experiments indicate a common signaling pathway of the two molecules, Bop1 and Pax6. Our studies imply a novel function of Bop1 independent of ribosomal biogenesis.
Collapse
|
15
|
Griffero M, Benedetti AFF, Pérez M, Carvalho L, Jorge A, Latronico AC, Mendonca B, Arnhold I, Mericq V. Novel OTX2 loss of function variant associated with congenital hypopituitarism without eye abnormalities. J Pediatr Endocrinol Metab 2022; 35:831-835. [PMID: 35320640 DOI: 10.1515/jpem-2021-0719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 02/18/2022] [Indexed: 11/15/2022]
Abstract
OBJECTIVES The normal development of the pituitary gland requires multiple induction signals and transcription factors encoded by more than 30 genes, including OTX2. OTX2 mutations have been described with eye abnormalities and variable congenital hypopituitarism, but rarely with hypopituitarism without ocular manifestations. CASE PRESENTATION We report a girl with hypopituitarism associated with pituitary hypoplasia and pituitary stalk atrophy, without ocular manifestations. NGS revealed a novel heterozygous mutation in OTX2 c.426dupC:p.(Ser143Leufs*2). CONCLUSIONS Mutations in the transcription factor OTX2 have been associated with ocular, craniofacial, and pituitary development anomalies. Here we describe a novel mutation in OTX2 associated with hypopituitarism without an ocular phenotype.
Collapse
Affiliation(s)
- Mariana Griffero
- Institute of Maternal and Child Research (IDIMI), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Anna Flavia Figueredo Benedetti
- Laboratório de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Marcela Pérez
- Department of Ophthalmology, Clínica Las Condes and Hospital Salvador, Santiago, Chile
| | - Luciani Carvalho
- Disciplina de Endocrinologia e Metabologia, Departamento de Clinica Medica, LIM/42, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Alexander Jorge
- Laboratório de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, SP, Brazil.,Disciplina de Endocrinologia e Metabologia, Departamento de Clinica Medica, LIM/42, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Ana Claudia Latronico
- Disciplina de Endocrinologia e Metabologia, Departamento de Clinica Medica, LIM/42, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Berenice Mendonca
- Laboratório de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, SP, Brazil.,Disciplina de Endocrinologia e Metabologia, Departamento de Clinica Medica, LIM/42, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Ivo Arnhold
- Disciplina de Endocrinologia e Metabologia, Departamento de Clinica Medica, LIM/42, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Verónica Mericq
- Institute of Maternal and Child Research (IDIMI), Faculty of Medicine, University of Chile, Santiago, Chile
| |
Collapse
|
16
|
Sambu S, Hemaram U, Murugan R, Alsofi AA. Toxicological and Teratogenic Effect of Various Food Additives: An Updated Review. BIOMED RESEARCH INTERNATIONAL 2022; 2022:6829409. [PMID: 35782077 PMCID: PMC9249520 DOI: 10.1155/2022/6829409] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 05/25/2022] [Indexed: 11/17/2022]
Abstract
Scientific evidence is mounting that synthetic chemicals used as food additives may have harmful impacts on health. Food additives are chemicals that are added to food to keep it from spoiling, as well as to improve its colour and taste. Some are linked to negative health impacts, while others are healthy and can be ingested with little danger. According to several studies, health issues such as asthma, attention deficit hyperactivity disorder (ADHD), heart difficulties, cancer, obesity, and others are caused by harmful additives and preservatives. Some food additives may interfere with hormones and influences growth and development. It is one of the reasons why so many children are overweight. Children are more likely than adults to be exposed to these types of dietary intakes. Several food additives are used by women during pregnancy and breast feeding that are not fully safe. We must take specific precaution to avoid consuming dangerous compounds before they begin to wreak havoc on our health. This study is intended to understand how the preservatives induce different health problem in the body once it is consumed. This review focuses on some specific food additives such as sodium benzoate, aspartame, tartrazine, carrageenan, and potassium benzoate, as well as vitamin A. Long-term use of food treated with the above-mentioned food preservatives resulted in teratogenicity and other allergens, according to the study. Other health issues can be avoided in the future by using natural food additives derived from plants and other natural sources.
Collapse
Affiliation(s)
- Saseendran Sambu
- Department of Food Technology, Faculty of Life and Allied Health Sciences, Ramaiah University of Applied Sciences, Bengaluru, Karnataka, India
| | - Urmila Hemaram
- Department of Food Technology, Faculty of Life and Allied Health Sciences, Ramaiah University of Applied Sciences, Bengaluru, Karnataka, India
| | - Rajadurai Murugan
- Department of Food Technology, Faculty of Life and Allied Health Sciences, Ramaiah University of Applied Sciences, Bengaluru, Karnataka, India
| | - Ahmed A. Alsofi
- Department of Pharmacy, Faculty of Medical Sciences, Aljanad University for Science and Technology, Taiz, Yemen
| |
Collapse
|
17
|
Panagiotou ES, Fernandez-Fuentes N, Farraj LA, McKibbin M, Elçioglu NH, Jafri H, Cerman E, Parry DA, Logan CV, Johnson CA, Inglehearn CF, Toomes C, Ali M. Novel SIX6 mutations cause recessively inherited congenital cataract, microcornea, and corneal opacification with or without coloboma and microphthalmia. Mol Vis 2022; 28:57-69. [PMID: 35693420 PMCID: PMC9122475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 05/15/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose To investigate the molecular basis of recessively inherited congenital cataract, microcornea, and corneal opacification with or without coloboma and microphthalmia in two consanguineous families. Methods Conventional autozygosity mapping was performed using single nucleotide polymorphism (SNP) microarrays. Whole-exome sequencing was completed on genomic DNA from one affected member of each family. Exome sequence data were also used for homozygosity mapping and copy number variation analysis. PCR and Sanger sequencing were used to confirm the identification of mutations and to screen further patients. Evolutionary conservation of protein sequences was assessed using CLUSTALW, and protein structures were modeled using PyMol. Results In family MEP68, a novel homozygous nucleotide substitution in SIX6 was found, c.547G>C, that converts the evolutionarily conserved aspartic acid residue at the 183rd amino acid in the protein to a histidine, p.(Asp183His). This residue mapped to the third helix of the DNA-binding homeobox domain in SIX6, which interacts with the major groove of double-stranded DNA. This interaction is likely to be disrupted by the mutation. In family F1332, a novel homozygous 1034 bp deletion that encompasses the first exon of SIX6 was identified, chr14:g.60975890_60976923del. Both mutations segregated with the disease phenotype as expected for a recessive condition and were absent from publicly available variant databases. Conclusions Our findings expand the mutation spectrum in this form of inherited eye disease and confirm that homozygous human SIX6 mutations cause a developmental spectrum of ocular phenotypes that includes not only the previously described features of microphthalmia, coloboma, and congenital cataract but also corneal abnormalities.
Collapse
Affiliation(s)
- Evangelia S. Panagiotou
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, United Kingdom
| | | | - Layal Abi Farraj
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, United Kingdom
| | - Martin McKibbin
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, United Kingdom,Eye Clinic, St. James's University Hospital, Leeds, United Kingdom
| | - Nursel H. Elçioglu
- Department of Pediatric Genetics, Marmara University Medical School, Istanbul, Turkey,Eastern Mediterrean University of Medical School, Cyprus, Turkey
| | | | - Eren Cerman
- Department of Ophthalmology, Marmara University Medical School, Istanbul, Turkey
| | - David A. Parry
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, United Kingdom
| | - Clare V. Logan
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, United Kingdom
| | - Colin A. Johnson
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, United Kingdom
| | - Chris F. Inglehearn
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, United Kingdom
| | - Carmel Toomes
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, United Kingdom
| | - Manir Ali
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, United Kingdom
| |
Collapse
|
18
|
van Heyningen V. A Journey Through Genetics to Biology. Annu Rev Genomics Hum Genet 2022; 23:1-27. [PMID: 35567277 DOI: 10.1146/annurev-genom-010622-095109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although my engagement with human genetics emerged gradually, and sometimes serendipitously, it has held me spellbound for decades. Without my teachers, students, postdocs, colleagues, and collaborators, I would not be writing this review of my scientific adventures. Early gene and disease mapping was a satisfying puzzle-solving exercise, but building biological insight was my main goal. The project trajectory was hugely influenced by the evolutionarily conserved nature of the implicated genes and by the pace of progress in genetic technologies. The rich detail of clinical observations, particularly in eye disease, makes humans an excellent model, especially when complemented by the use of multiple other animal species for experimental validation. The contributions of collaborators and rivals also influenced our approach. We are very fortunate to work in this era of unprecedented progress in genetics and genomics. Expected final online publication date for the Annual Review of Genomics and Human Genetics, Volume 23 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Collapse
Affiliation(s)
- Veronica van Heyningen
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom;
| |
Collapse
|
19
|
Owen N, Toms M, Young RM, Eintracht J, Sarkar H, Brooks BP, Moosajee M. Identification of 4 novel human ocular coloboma genes ANK3, BMPR1B, PDGFRA, and CDH4 through evolutionary conserved vertebrate gene analysis. Genet Med 2022; 24:1073-1084. [PMID: 35034853 DOI: 10.1016/j.gim.2021.12.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 12/17/2021] [Indexed: 11/15/2022] Open
Abstract
PURPOSE Ocular coloboma arises from genetic or environmental perturbations that inhibit optic fissure (OF) fusion during early eye development. Despite high genetic heterogeneity, 70% to 85% of patients remain molecularly undiagnosed. In this study, we have identified new potential causative genes using cross-species comparative meta-analysis. METHODS Evolutionarily conserved differentially expressed genes were identified through in silico analysis, with in situ hybridization, gene knockdown, and rescue performed to confirm spatiotemporal gene expression and phenotype. Interrogation of the 100,000 Genomes Project for putative pathogenic variants was performed. RESULTS Nine conserved differentially expressed genes between zebrafish and mouse were identified. Expression of zebrafish ank3a, bmpr1ba/b, cdh4, and pdgfaa was localized to the OF, periocular mesenchyme cells, or ciliary marginal zone, regions traversed by the OF. Knockdown of ank3, bmpr1b, and pdgfaa revealed a coloboma and/or microphthalmia phenotype. Novel pathogenic variants in ANK3, BMPR1B, PDGFRA, and CDH4 were identified in 8 unrelated coloboma families. We showed BMPR1B rescued the knockdown phenotype but variant messenger RNAs failed, providing evidence of pathogenicity. CONCLUSION We show the utility of cross-species meta-analysis to identify several novel coloboma disease-causing genes. There is a potential to increase the diagnostic yield for new and unsolved patients while adding to our understanding of the genetic basis of OF morphogenesis.
Collapse
Affiliation(s)
- Nicholas Owen
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, United Kingdom
| | - Maria Toms
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, United Kingdom
| | - Rodrigo M Young
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, United Kingdom
| | - Jonathan Eintracht
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, United Kingdom
| | - Hajrah Sarkar
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, United Kingdom
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Mariya Moosajee
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, United Kingdom; Department of Genetics, Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom; Ocular Genomics and Therapeutics, The Francis Crick Institute, London, United Kingdom.
| |
Collapse
|
20
|
Leung RF, George AM, Roussel EM, Faux MC, Wigle JT, Eisenstat DD. Genetic Regulation of Vertebrate Forebrain Development by Homeobox Genes. Front Neurosci 2022; 16:843794. [PMID: 35546872 PMCID: PMC9081933 DOI: 10.3389/fnins.2022.843794] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 03/14/2022] [Indexed: 01/19/2023] Open
Abstract
Forebrain development in vertebrates is regulated by transcription factors encoded by homeobox, bHLH and forkhead gene families throughout the progressive and overlapping stages of neural induction and patterning, regional specification and generation of neurons and glia from central nervous system (CNS) progenitor cells. Moreover, cell fate decisions, differentiation and migration of these committed CNS progenitors are controlled by the gene regulatory networks that are regulated by various homeodomain-containing transcription factors, including but not limited to those of the Pax (paired), Nkx, Otx (orthodenticle), Gsx/Gsh (genetic screened), and Dlx (distal-less) homeobox gene families. This comprehensive review outlines the integral role of key homeobox transcription factors and their target genes on forebrain development, focused primarily on the telencephalon. Furthermore, links of these transcription factors to human diseases, such as neurodevelopmental disorders and brain tumors are provided.
Collapse
Affiliation(s)
- Ryan F. Leung
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
| | - Ankita M. George
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
| | - Enola M. Roussel
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
| | - Maree C. Faux
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
- Department of Surgery, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
| | - Jeffrey T. Wigle
- Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
| | - David D. Eisenstat
- Murdoch Children’s Research Institute, The Royal Children’s Hospital Melbourne, Parkville, VIC, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
21
|
Saffren BD, Yassin SH, Geddie BE, de Faber JTHN, Blieden LS, Bhate M, Gamio S, Rutar T, Levin AV. Optic Nerve Aplasia. J Neuroophthalmol 2022; 42:e140-e146. [PMID: 33870948 DOI: 10.1097/wno.0000000000001246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Optic nerve aplasia (ONA) is a rare ocular anomaly. We report ophthalmologic, systemic, and genetic findings in ONA. METHODS Patients were identified through an International Pediatric Ophthalmology listserv and from the practice of the senior author. Participating Listserv physicians completed a data collection sheet. Children of all ages were included. Neuroimaging findings were also recorded. RESULTS Nine cases of ONA are reported. Patients' ages ranged from 10 days to 2 years (median 9 months). Seven cases were bilateral. All patients had absence of the optic nerve and retinal vessels in the affected eye or eyes. Ophthalmologic findings included glaucoma, microcornea, persistent pupillary membrane, iris coloboma, aniridia, retinal dysplasia, retinal atrophy, chorioretinal coloboma, and persistent fetal vasculature. Systemic findings included facial dysmorphism, cardiac, genitourinary, skeletal, and developmental defects. A BCOR mutation was found in one patient. One patient had rudimentary optic nerves and chiasm on imaging. CONCLUSION ONA is a unilateral or bilateral condition that may be associated with anomalies of the anterior or posterior segment with or without systemic findings. Rudimentary optic nerve on neuroimaging in one case suggests that ONA is on the continuum of optic nerve hypoplasia.
Collapse
Affiliation(s)
- Brooke D Saffren
- Philadelphia College of Osteopathic Medicine (BDS), Philadelphia, Pennsylvania; Pediatric Ophthalmology and Ocular Genetics (BDS, SHY), Wills Eye Hospital, Philadelphia, Pennsylvania; Pediatric Ophthalmology (BEG), Helen DeVos Children's Hospital, Grand Rapids, Michigan; The Rotterdam Eye Hospital (JTHNF), Rotterdam, the Netherlands ; Cullen Eye Institute (LSB), Baylor College of Medicine, Houston, Texas; Department of Pediatric Ophthalmology (MB), LV Prasad Eye Institute, Hyderabad, India ; Ophthalmology Unit (SG), Ricardo Gutiérrez Children Hospital, Buenos Aires, Argentina ; Cataract and Laser Institute of Southern Oregon PC (TR), Medford, Oregon; Flaum Eye Institute and Golisano Children's Hospital (AVL), University of Rochester, New York, New York
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Tingaud-Sequeira A, Trimouille A, Sagardoy T, Lacombe D, Rooryck-Thambo C. Oculo-auriculo-vertebral spectrum: new genes and literature review on a complex disease. J Med Genet 2022; 59:417-427. [PMID: 35110414 DOI: 10.1136/jmedgenet-2021-108219] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/30/2021] [Indexed: 12/23/2022]
Abstract
Oculo-auriculo-vertebral spectrum (OAVS) or Goldenhar syndrome is due to an abnormal development of first and second branchial arches derivatives during embryogenesis and is characterised by hemifacial microsomia associated with auricular, ocular and vertebral malformations. The clinical and genetic heterogeneity of this spectrum with incomplete penetrance and variable expressivity, render its molecular diagnosis difficult. Only a few recurrent CNVs and genes have been identified as causatives in this complex disorder so far. Prenatal environmental causal factors have also been hypothesised. However, most of the patients remain without aetiology. In this review, we aim at updating clinical diagnostic criteria and describing genetic and non-genetic aetiologies, animal models as well as novel diagnostic tools and surgical management, in order to help and improve clinical care and genetic counselling of these patients and their families.
Collapse
Affiliation(s)
- Angèle Tingaud-Sequeira
- Univ. Bordeaux, Maladies Rares: Génétique et Métabolisme (MRGM), U 1211 INSERM, F-33000 Bordeaux, France
| | - Aurélien Trimouille
- Univ. Bordeaux, Maladies Rares: Génétique et Métabolisme (MRGM), U 1211 INSERM, F-33000 Bordeaux, France.,CHU de Bordeaux, Service de Génétique Médicale, Centre de Référence Anomalies du Développement et Syndromes Malformatifs, F-33076, Bordeaux, France
| | - Thomas Sagardoy
- CHU de Bordeaux, Service d'oto-rhino-laryngologie, de chirurgie cervico-faciale et d'ORL pédiatrique, 33076 Bordeaux, France
| | - Didier Lacombe
- Univ. Bordeaux, Maladies Rares: Génétique et Métabolisme (MRGM), U 1211 INSERM, F-33000 Bordeaux, France.,CHU de Bordeaux, Service de Génétique Médicale, Centre de Référence Anomalies du Développement et Syndromes Malformatifs, F-33076, Bordeaux, France
| | - Caroline Rooryck-Thambo
- Univ. Bordeaux, Maladies Rares: Génétique et Métabolisme (MRGM), U 1211 INSERM, F-33000 Bordeaux, France .,CHU de Bordeaux, Service de Génétique Médicale, Centre de Référence Anomalies du Développement et Syndromes Malformatifs, F-33076, Bordeaux, France
| |
Collapse
|
23
|
Cheng JY, Stern AJ, Racimo F, Nielsen R. Detecting Selection in Multiple Populations by Modeling Ancestral Admixture Components. Mol Biol Evol 2022; 39:msab294. [PMID: 34626111 PMCID: PMC8763095 DOI: 10.1093/molbev/msab294] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
One of the most powerful and commonly used approaches for detecting local adaptation in the genome is the identification of extreme allele frequency differences between populations. In this article, we present a new maximum likelihood method for finding regions under positive selection. It is based on a Gaussian approximation to allele frequency changes and it incorporates admixture between populations. The method can analyze multiple populations simultaneously and retains power to detect selection signatures specific to ancestry components that are not representative of any extant populations. Using simulated data, we compare our method to related approaches, and show that it is orders of magnitude faster than the state-of-the-art, while retaining similar or higher power for most simulation scenarios. We also apply it to human genomic data and identify loci with extreme genetic differentiation between major geographic groups. Many of the genes identified are previously known selected loci relating to hair pigmentation and morphology, skin, and eye pigmentation. We also identify new candidate regions, including various selected loci in the Native American component of admixed Mexican-Americans. These involve diverse biological functions, such as immunity, fat distribution, food intake, vision, and hair development.
Collapse
Affiliation(s)
- Jade Yu Cheng
- Lundbeck GeoGenetics Centre, Globe Institute, University of Copenhagen, Copenhagen, Denmark
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Aaron J Stern
- Graduate Group in Computational Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Fernando Racimo
- Lundbeck GeoGenetics Centre, Globe Institute, University of Copenhagen, Copenhagen, Denmark
| | - Rasmus Nielsen
- Lundbeck GeoGenetics Centre, Globe Institute, University of Copenhagen, Copenhagen, Denmark
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
- Department of Statistics, University of California, Berkeley, Berkeley, CA, USA
| |
Collapse
|
24
|
Wangding S, Colaiacovo S, Makar I, Saleh M. OTX2 mutation associated with severe myopia in a Canadian family. Ophthalmic Genet 2021; 43:389-391. [PMID: 34957897 DOI: 10.1080/13816810.2021.2015791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE To describe a case of high myopia in a pediatric patient with a mutation in the OTX2 gene and further characterize the diverse ocular phenotypes of heterozygous OTX2 mutations. PATIENT AND METHODS We describe a three-year-old girl who presented at two months old with abnormal eye movements and suspected retinal dystrophy. Clinical exam and electroretinography (ERG) were conducted, and molecular next generation sequencing (NGS) with the Inherited Retinal Dystrophies panel was completed in our patient and offered to the family. RESULTS Further examination revealed progressive high myopia in our patient and her mother, alongside diffuse retinal thinning and normal ERG. NGS identified a likely pathogenic variant in the OTX2 gene (c.235 G > A) that was maternal in origin. There were no extra-ocular concerns in our patient, and brain MRI was normal. CONCLUSIONS While OTX2 mutations are known to cause retinopathy, this case presents a unique phenotype through a heterozygous missense variant (c.235 G > A) underlying high myopia in a three-generation family. This case further supports the role of OTX2 in ocular development and demonstrates the variable expressivity of OTX2 mutations. Genetic testing in families with high myopia may be useful in future surveillance and preparation for ocular and extra-ocular complications associated with OTX2-syndrome presentations.
Collapse
Affiliation(s)
- Snow Wangding
- Department of Pediatrics, Schulich School of Medicine and Dentistry, London, Canada
| | - Samantha Colaiacovo
- Division of Medical Genetics, Department of Pediatrics, London Health Sciences Centre, London, Canada
| | - Inas Makar
- Department of Pediatrics, Schulich School of Medicine and Dentistry, London, Canada.,Department of Ophthalmology, St. Joseph's Hospital, London, Canada
| | - Maha Saleh
- Department of Pediatrics, Schulich School of Medicine and Dentistry, London, Canada.,Division of Medical Genetics, Department of Pediatrics, London Health Sciences Centre, London, Canada
| |
Collapse
|
25
|
Rafati M, Mohamadhashem F, Jalilian K, Hoseininasab F, Fakhri L, Hoseini A, Amiri H, Barati Z, Darzi Ramandi S, Mostofinezhad N, Mahmoudi AH, Ghaffari SR. Identification of a novel de novo variant in OTX2 in a patient with congenital microphthalmia using targeted next-generation sequencing followed by prenatal diagnosis. Ophthalmic Genet 2021; 43:262-267. [PMID: 34791963 DOI: 10.1080/13816810.2021.2002915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Next-generation sequencing has been proven to be a reliable method for the detection of genetic causes in heterogeneous ocular disorders. In this report an NGS-based diagnostic approach was taken to uncover the genetic etiology in a patient with coloboma and microphthalmia, a highly heterogeneous disease with intrafamilial phenotypic variability. MATERIALS AND METHODS Next generation sequencing using a targeted panel of 316 genes, was carried out in the proband. Prioritized variants were then identified and confirmed using Sanger sequencing. Prenatal diagnosis of the detected variant was then performed in the family. RESULTS A novel de novo frameshift variant c.157_164delTTCACTCG (p.Phe53fs) in OTX2, leading to a truncated protein, was identified. Prenatal diagnosis identified the same variant in the fetus. CONCLUSIONS This report demonstrates the importance of genetic counseling and underscores the efficiency and effectiveness of targeted NGS as a means of detecting variants in inherited eye disorders.
Collapse
Affiliation(s)
- Maryam Rafati
- Comprehensive Genetic Center, Hope Generation Foundation, Tehran, Iran.,Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.,Department of Genomics Gene Clinic, Tehran, Iran
| | - Faezeh Mohamadhashem
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
| | - Koosha Jalilian
- Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Fatemeh Hoseininasab
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
| | - Laya Fakhri
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
| | - Azadeh Hoseini
- Comprehensive Genetic Center, Hope Generation Foundation, Tehran, Iran
| | - Hosna Amiri
- Comprehensive Genetic Center, Hope Generation Foundation, Tehran, Iran
| | - Zeinab Barati
- Comprehensive Genetic Center, Hope Generation Foundation, Tehran, Iran
| | | | | | | | - Saeed Reza Ghaffari
- Comprehensive Genetic Center, Hope Generation Foundation, Tehran, Iran.,Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.,Department of Genomics Gene Clinic, Tehran, Iran
| |
Collapse
|
26
|
Huang CH, Yang CM, Yang CH, Hou YC, Chen TC. Leber's Congenital Amaurosis: Current Concepts of Genotype-Phenotype Correlations. Genes (Basel) 2021; 12:genes12081261. [PMID: 34440435 PMCID: PMC8392113 DOI: 10.3390/genes12081261] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/15/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Leber’s congenital amaurosis (LCA), one of the most severe inherited retinal dystrophies, is typically associated with extremely early onset of visual loss, nystagmus, and amaurotic pupils, and is responsible for 20% of childhood blindness. With advances in molecular diagnostic technology, the knowledge about the genetic background of LCA has expanded widely, while disease-causing variants have been identified in 38 genes. Different pathogenetic mechanisms have been found among these varieties of genetic mutations, all of which result in the dysfunction or absence of their encoded proteins participating in the visual cycle. Hence, the clinical phenotypes also exhibit extensive heterogenicity, including the course of visual impairment, involvement of the macular area, alteration in retinal structure, and residual function of the diseased photoreceptor. By reviewing the clinical course, fundoscopic images, optical coherent tomography examination, and electroretinogram, genotype-phenotype correlations could be established for common genetic mutations in LCA, which would benefit the timing of the diagnosis and thus promote early intervention. Gene therapy is promising in the management of LCA, while several clinical trials are ongoing and preliminary success has been announced, focusing on RPE65 and other common disease-causing genes. This review provides an update on the genetics, clinical examination findings, and genotype-phenotype correlations in the most well-established causative genetic mutations of LCA.
Collapse
Affiliation(s)
- Chu-Hsuan Huang
- Department of Ophthalmology, Cathay General Hospital, Taipei 106, Taiwan; (C.-H.H.); (Y.-C.H.)
| | - Chung-May Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-M.Y.); (C.-H.Y.)
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Chang-Hao Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-M.Y.); (C.-H.Y.)
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Yu-Chih Hou
- Department of Ophthalmology, Cathay General Hospital, Taipei 106, Taiwan; (C.-H.H.); (Y.-C.H.)
| | - Ta-Ching Chen
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-M.Y.); (C.-H.Y.)
- Correspondence: ; Tel.: +886-2-23123456
| |
Collapse
|
27
|
Bando H, Gergics P, Bohnsack BL, Toolan KP, Richter CE, Shavit JA, Camper SA. Otx2b mutant zebrafish have pituitary, eye and mandible defects that model mammalian disease. Hum Mol Genet 2021; 29:1648-1657. [PMID: 32277752 DOI: 10.1093/hmg/ddaa064] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/29/2020] [Accepted: 03/30/2020] [Indexed: 02/07/2023] Open
Abstract
Combined pituitary hormone deficiency (CPHD) is a genetically heterogeneous disorder caused by mutations in over 30 genes. The loss-of-function mutations in many of these genes, including orthodenticle homeobox 2 (OTX2), can present with a broad range of clinical symptoms, which provides a challenge for predicting phenotype from genotype. Another challenge in human genetics is functional evaluation of rare genetic variants that are predicted to be deleterious. Zebrafish are an excellent vertebrate model for evaluating gene function and disease pathogenesis, especially because large numbers of progeny can be obtained, overcoming the challenge of individual variation. To clarify the utility of zebrafish for the analysis of CPHD-related genes, we analyzed the effect of OTX2 loss of function in zebrafish. The otx2b gene is expressed in the developing hypothalamus, and otx2bhu3625/hu3625 fish exhibit multiple defects in the development of head structures and are not viable past 10 days post fertilization (dpf). Otx2bhu3625/hu3625 fish have a small hypothalamus and low expression of pituitary growth hormone and prolactin (prl). The gills of otx2bhu3625/hu3625 fish have weak sodium influx, consistent with the role of prolactin in osmoregulation. The otx2bhu3625/hu3625 eyes are microphthalmic with colobomas, which may underlie the inability of the mutant fish to find food. The small pituitary and eyes are associated with reduced cell proliferation and increased apoptosis evident at 3 and 5 dpf, respectively. These observations establish the zebrafish as a useful tool for the analysis of CPHD genes with variable and complex phenotypes.
Collapse
Affiliation(s)
- Hironori Bando
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Peter Gergics
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Brenda L Bohnsack
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48109, USA
| | - Kevin P Toolan
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Catherine E Richter
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jordan A Shavit
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sally A Camper
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
| |
Collapse
|
28
|
Gregory LC, Gergics P, Nakaguma M, Bando H, Patti G, McCabe MJ, Fang Q, Ma Q, Ozel AB, Li JZ, Poina MM, Jorge AAL, Benedetti AFF, Lerario AM, Arnhold IJP, Mendonca BB, Maghnie M, Camper SA, Carvalho LRS, Dattani MT. The phenotypic spectrum associated with OTX2 mutations in humans. Eur J Endocrinol 2021; 185:121-135. [PMID: 33950863 PMCID: PMC8437083 DOI: 10.1530/eje-20-1453] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 05/05/2021] [Indexed: 11/25/2022]
Abstract
Objective The transcription factor OTX2 is implicated in ocular, craniofacial, and pituitary development. Design We aimed to establish the contribution of OTX2 mutations in congenital hypopituitarism patients with/without eye abnormalities, study functional consequences, and establish OTX2 expression in the human brain, with a view to investigate the mechanism of action. Methods We screened patients from the UK (n = 103), international centres (n = 24), and Brazil (n = 282); 145 were within the septo-optic dysplasia spectrum, and 264 had no eye phenotype. Transactivation ability of OTX2 variants was analysed in murine hypothalamic GT1-7 neurons. In situ hybridization was performed on human embryonic brain sections. Genetically engineered mice were generated with a series of C-terminal OTX2 variants. Results Two chromosomal deletions and six haploinsufficient mutations were identified in individuals with eye abnormalities; an affected relative of one patient harboured the same mutation without an ocular phenotype. OTX2 truncations led to significant transactivation reduction. A missense variant was identified in another patient without eye abnormalities; however, studies revealed it was most likely not causative. In the mouse, truncations proximal to aa219 caused anophthalmia, while distal truncations and the missense variant were tolerated. During human embryogenesis, OTX2 was expressed in the posterior pituitary, retina, ear, thalamus, choroid plexus, and partially in the hypothalamus, but not in the anterior pituitary. Conclusions OTX2 mutations are rarely associated with hypopituitarism in isolation without eye abnormalities, and may be variably penetrant, even within the same pedigree. Our data suggest that the endocrine phenotypes in patients with OTX2 mutations are of hypothalamic origin.
Collapse
Affiliation(s)
- Louise C Gregory
- Section of Molecular Basis of Rare Disease, Genetics and Genomic Medicine Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Peter Gergics
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Marilena Nakaguma
- Developmental Endocrinology Unit, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Hironori Bando
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Giuseppa Patti
- Section of Molecular Basis of Rare Disease, Genetics and Genomic Medicine Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Pediatrics, IRCCS Istituto Giannina Gaslini
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Mark J McCabe
- Section of Molecular Basis of Rare Disease, Genetics and Genomic Medicine Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Qing Fang
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Qianyi Ma
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Ayse Bilge Ozel
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Jun Z Li
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Michele Moreira Poina
- Developmental Endocrinology Unit, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Alexander A L Jorge
- Developmental Endocrinology Unit, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Anna F Figueredo Benedetti
- Developmental Endocrinology Unit, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Antonio M Lerario
- Developmental Endocrinology Unit, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Ivo J P Arnhold
- Developmental Endocrinology Unit, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Berenice B Mendonca
- Developmental Endocrinology Unit, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Mohamad Maghnie
- Department of Pediatrics, IRCCS Istituto Giannina Gaslini
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Sally A Camper
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Luciani R S Carvalho
- Developmental Endocrinology Unit, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Mehul T Dattani
- Section of Molecular Basis of Rare Disease, Genetics and Genomic Medicine Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
| |
Collapse
|
29
|
Flach H, Basten T, Schreiner C, Dietmann P, Greco S, Nies L, Roßmanith N, Walter S, Kühl M, Kühl SJ. Retinol binding protein 1 affects Xenopus anterior neural development via all-trans retinoic acid signaling. Dev Dyn 2021; 250:1096-1112. [PMID: 33570783 DOI: 10.1002/dvdy.313] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 01/30/2021] [Accepted: 02/03/2021] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Retinol binding protein 1 (Rbp1) acts as an intracellular regulator of vitamin A metabolism and retinoid transport. In mice, Rbp1 deficiency decreases the capacity of hepatic stellate cells to take up all-trans retinol and sustain retinyl ester stores. Furthermore, Rbp1 is crucial for visual capacity. Although the function of Rbp1 has been studied in the mature eye, its role during early anterior neural development has not yet been investigated in detail. RESULTS We showed that rbp1 is expressed in the eye, anterior neural crest cells (NCCs) and prosencephalon of the South African clawed frog Xenopus laevis. Rbp1 knockdown led to defects in eye formation, including microphthalmia and disorganized retinal lamination, and to disturbed induction and differentiation of the eye field, as shown by decreased rax and pax6 expression. Furthermore, it resulted in reduced rax expression in the prosencephalon and affected cranial cartilage. Rbp1 inhibition also interfered with neural crest induction and migration, as shown by twist and slug. Moreover, it led to a significant reduction of the all-trans retinoic acid target gene pitx2 in NCC-derived periocular mesenchyme. The Rbp1 knockdown phenotypes were rescued by pitx2 RNA co-injection. CONCLUSION Rbp1 is crucial for the development of the anterior neural tissue.
Collapse
Affiliation(s)
- Hannah Flach
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Thomas Basten
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Corinna Schreiner
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Petra Dietmann
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Sara Greco
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Lea Nies
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Nathalie Roßmanith
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Svenja Walter
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Michael Kühl
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Susanne J Kühl
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| |
Collapse
|
30
|
Sox2 knockdown in the neonatal retina causes cell fate to switch from amacrine to bipolar. Brain Res 2021; 1752:147265. [PMID: 33422527 DOI: 10.1016/j.brainres.2020.147265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/18/2020] [Accepted: 12/26/2020] [Indexed: 11/20/2022]
Abstract
Transcription factor Sox2 is widely recognized for its critical roles in the nervous system, including the neural retina. Here, we aimed to reveal the function of Sox2 in the process of mouse postnatal development. After the suppression of Sox2 at P0, there was an increase number in bipolar cells but a decrease in amacrine cells. Inhibited Sox2 expression also led to decreased visual function. Furthermore, we found a distinctive type of retinal cells expressing the characteristic proteins of both bipolar cells and amacrine cells at P6, which may be an intermediate state in which amacrine cells were transforming into bipolar cells. Transcription factors associated with the development of bipolar cells and amacrine cells also support those changes. Our work indicated that inhibition of Sox2 could change cell fate by affecting transcription factors in the development of bipolar cells and amacrine cells, may provide new directions for the study and treatment of retinal genetic diseases and retinal dysplasia.
Collapse
|
31
|
Abstract
Septo-optic dysplasia (SOD) or de Morsier's syndrome is a rare congenital disorder characterized by a classic triad of: (a) optic nerve hypoplasia, (b) agenesis of septum pellucidum and corpus callosum, and (c) hypoplasia of the hypothalamic-pituitary axis. This chapter will outline the key information regarding the etiology and epidemiology of this syndrome with a focus on its comprehensive management. Particular attention will be paid to the diagnostic stage and the most relevant differential diagnosis, before moving to the complexities of its treatment. In fact, although SOD is not curable, many aspects of this syndrome can be improved through a tailored multidisciplinary approach consisting in hormonal replacement, corrective ophthalmological surgery, management of epileptic seizures, and active neuropsychological support.
Collapse
Affiliation(s)
- Ieva Sataite
- Department of Neurosurgery, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Simon Cudlip
- Department of Neurosurgery, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Jayaratnam Jayamohan
- Department of Neurosurgery, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Mario Ganau
- Department of Neurosurgery, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.
| |
Collapse
|
32
|
Harding P, Cunha DL, Moosajee M. Animal and cellular models of microphthalmia. THERAPEUTIC ADVANCES IN RARE DISEASE 2021; 2:2633004021997447. [PMID: 37181112 PMCID: PMC10032472 DOI: 10.1177/2633004021997447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/02/2021] [Indexed: 05/16/2023]
Abstract
Microphthalmia is a rare developmental eye disorder affecting 1 in 7000 births. It is defined as a small (axial length ⩾2 standard deviations below the age-adjusted mean) underdeveloped eye, caused by disruption of ocular development through genetic or environmental factors in the first trimester of pregnancy. Clinical phenotypic heterogeneity exists amongst patients with varying levels of severity, and associated ocular and systemic features. Up to 11% of blind children are reported to have microphthalmia, yet currently no treatments are available. By identifying the aetiology of microphthalmia and understanding how the mechanisms of eye development are disrupted, we can gain a better understanding of the pathogenesis. Animal models, mainly mouse, zebrafish and Xenopus, have provided extensive information on the genetic regulation of oculogenesis, and how perturbation of these pathways leads to microphthalmia. However, differences exist between species, hence cellular models, such as patient-derived induced pluripotent stem cell (iPSC) optic vesicles, are now being used to provide greater insights into the human disease process. Progress in 3D cellular modelling techniques has enhanced the ability of researchers to study interactions of different cell types during eye development. Through improved molecular knowledge of microphthalmia, preventative or postnatal therapies may be developed, together with establishing genotype-phenotype correlations in order to provide patients with the appropriate prognosis, multidisciplinary care and informed genetic counselling. This review summarises some key discoveries from animal and cellular models of microphthalmia and discusses how innovative new models can be used to further our understanding in the future. Plain language summary Animal and Cellular Models of the Eye Disorder, Microphthalmia (Small Eye) Microphthalmia, meaning a small, underdeveloped eye, is a rare disorder that children are born with. Genetic changes or variations in the environment during the first 3 months of pregnancy can disrupt early development of the eye, resulting in microphthalmia. Up to 11% of blind children have microphthalmia, yet currently no treatments are available. By understanding the genes necessary for eye development, we can determine how disruption by genetic changes or environmental factors can cause this condition. This helps us understand why microphthalmia occurs, and ensure patients are provided with the appropriate clinical care and genetic counselling advice. Additionally, by understanding the causes of microphthalmia, researchers can develop treatments to prevent or reduce the severity of this condition. Animal models, particularly mice, zebrafish and frogs, which can also develop small eyes due to the same genetic/environmental changes, have helped us understand the genes which are important for eye development and can cause birth eye defects when disrupted. Studying a patient's own cells grown in the laboratory can further help researchers understand how changes in genes affect their function. Both animal and cellular models can be used to develop and test new drugs, which could provide treatment options for patients living with microphthalmia. This review summarises the key discoveries from animal and cellular models of microphthalmia and discusses how innovative new models can be used to further our understanding in the future.
Collapse
Affiliation(s)
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, 11-43 Bath
Street, London, EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust,
London, UK
- Great Ormond Street Hospital for Children NHS
Foundation Trust, London, UK
- The Francis Crick Institute, London, UK
| |
Collapse
|
33
|
Vaisfeld A, Spartano S, Gobbi G, Vezzani A, Neri G. Chromosome 14 deletions, rings, and epilepsy genes: A riddle wrapped in a mystery inside an enigma. Epilepsia 2020; 62:25-40. [PMID: 33205446 DOI: 10.1111/epi.16754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 10/16/2020] [Accepted: 10/16/2020] [Indexed: 11/29/2022]
Abstract
The ring 14 syndrome is a rare condition caused by the rearrangement of one chromosome 14 into a ring-like structure. The formation of the ring requires two breakpoints and loss of material from the short and long arms of the chromosome. Like many other chromosome syndromes, it is characterized by multiple congenital anomalies and developmental delays. Typical of the condition are retinal anomalies and drug-resistant epilepsy. These latter manifestations are not found in individuals who are carriers of comparable 14q deletions without formation of a ring (linear deletions). To find an explanation for this apparent discrepancy and gain insight into the mechanisms leading to seizures, we reviewed and compared literature cases of both ring and linear deletion syndrome with respect to both their clinical manifestations and the role and function of potentially epileptogenic genes. Knowledge of the epilepsy-related genes in chromosome 14 is an important premise for the search of new and effective drugs to combat seizures. Current clinical and molecular evidence is not sufficient to explain the known discrepancies between ring and linear deletions.
Collapse
Affiliation(s)
- Alessandro Vaisfeld
- Institute of Genomic Medicine, Catholic University School of Medicine, Rome, Italy
| | - Serena Spartano
- Institute of Genomic Medicine, Catholic University School of Medicine, Rome, Italy
| | - Giuseppe Gobbi
- Residential Center for Rehabilitation Luce Sul Mare, Rimini, Italy
| | - Annamaria Vezzani
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy
| | - Giovanni Neri
- Institute of Genomic Medicine, Catholic University School of Medicine, Rome, Italy.,J.C. Self Research Institute, Greenwood Genetic Center, Greenwood, SC, USA
| |
Collapse
|
34
|
Gregory LC, Dattani MT. The Molecular Basis of Congenital Hypopituitarism and Related Disorders. J Clin Endocrinol Metab 2020; 105:5614788. [PMID: 31702014 DOI: 10.1210/clinem/dgz184] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 11/07/2019] [Indexed: 12/23/2022]
Abstract
CONTEXT Congenital hypopituitarism (CH) is characterized by the presence of deficiencies in one or more of the 6 anterior pituitary (AP) hormones secreted from the 5 different specialized cell types of the AP. During human embryogenesis, hypothalamo-pituitary (HP) development is controlled by a complex spatio-temporal genetic cascade of transcription factors and signaling molecules within the hypothalamus and Rathke's pouch, the primordium of the AP. EVIDENCE ACQUISITION This mini-review discusses the genes and pathways involved in HP development and how mutations of these give rise to CH. This may present in the neonatal period or later on in childhood and may be associated with craniofacial midline structural abnormalities such as cleft lip/palate, visual impairment due to eye abnormalities such as optic nerve hypoplasia (ONH) and microphthalmia or anophthalmia, or midline forebrain neuroradiological defects including agenesis of the septum pellucidum or corpus callosum or the more severe holoprosencephaly. EVIDENCE SYNTHESIS Mutations give rise to an array of highly variable disorders ranging in severity. There are many known causative genes in HP developmental pathways that are routinely screened in CH patients; however, over the last 5 years this list has rapidly increased due to the identification of variants in new genes and pathways of interest by next-generation sequencing. CONCLUSION The majority of patients with these disorders do not have an identified molecular basis, often making management challenging. This mini-review aims to guide clinicians in making a genetic diagnosis based on patient phenotype, which in turn may impact on clinical management.
Collapse
Affiliation(s)
- Louise Cheryl Gregory
- Genetics and Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Mehul Tulsidas Dattani
- Genetics and Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| |
Collapse
|
35
|
Ghinia Tegla MG, Buenaventura DF, Kim DY, Thakurdin C, Gonzalez KC, Emerson MM. OTX2 represses sister cell fate choices in the developing retina to promote photoreceptor specification. eLife 2020; 9:e54279. [PMID: 32347797 PMCID: PMC7237216 DOI: 10.7554/elife.54279] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 04/28/2020] [Indexed: 12/20/2022] Open
Abstract
During vertebrate retinal development, subsets of progenitor cells generate progeny in a non-stochastic manner, suggesting that these decisions are tightly regulated. However, the gene-regulatory network components that are functionally important in these progenitor cells are largely unknown. Here we identify a functional role for the OTX2 transcription factor in this process. CRISPR/Cas9 gene editing was used to produce somatic mutations of OTX2 in the chick retina and identified similar phenotypes to those observed in human patients. Single cell RNA sequencing was used to determine the functional consequences OTX2 gene editing on the population of cells derived from OTX2-expressing retinal progenitor cells. This confirmed that OTX2 is required for the generation of photoreceptors, but also for repression of specific retinal fates and alternative gene regulatory networks. These include specific subtypes of retinal ganglion and horizontal cells, suggesting that in this context, OTX2 functions to repress sister cell fate choices.
Collapse
Affiliation(s)
| | - Diego F Buenaventura
- Department of Biology, The City College of New York, City University of New York (CUNY)New YorkUnited States
- PhD Program in Biology, The Graduate Center of the City University of New York (CUNY)New YorkUnited States
| | - Diana Y Kim
- Department of Biology, The City College of New York, City University of New York (CUNY)New YorkUnited States
| | - Cassandra Thakurdin
- Department of Biology, The City College of New York, City University of New York (CUNY)New YorkUnited States
| | - Kevin C Gonzalez
- Department of Biology, The City College of New York, City University of New York (CUNY)New YorkUnited States
| | - Mark M Emerson
- Department of Biology, The City College of New York, City University of New York (CUNY)New YorkUnited States
- PhD Program in Biology, The Graduate Center of the City University of New York (CUNY)New YorkUnited States
- PhD Program in Biochemistry, The Graduate Center of the City University of New York (CUNY)New YorkUnited States
| |
Collapse
|
36
|
Abstract
The development of the anterior pituitary gland occurs in distinct sequential developmental steps, leading to the formation of a complex organ containing five different cell types secreting six different hormones. During this process, the temporal and spatial expression of a cascade of signaling molecules and transcription factors plays a crucial role in organ commitment, cell proliferation, patterning, and terminal differentiation. The morphogenesis of the gland and the emergence of distinct cell types from a common primordium are governed by complex regulatory networks involving transcription factors and signaling molecules that may be either intrinsic to the developing pituitary or extrinsic, originating from the ventral diencephalon, the oral ectoderm, and the surrounding mesenchyme. Endocrine cells of the pituitary gland are organized into structural and functional networks that contribute to the coordinated response of endocrine cells to stimuli; these cellular networks are formed during embryonic development and are maintained or may be modified in adulthood, contributing to the plasticity of the gland. Abnormalities in any of the steps of pituitary development may lead to congenital hypopituitarism that includes a spectrum of disorders from isolated to combined hormone deficiencies including syndromic disorders such as septo-optic dysplasia. Over the past decade, the acceleration of next-generation sequencing has allowed for rapid analysis of the patient genome to identify novel mutations and novel candidate genes associated with hypothalmo-pituitary development. Subsequent functional analysis using patient fibroblast cells, and the generation of stem cells derived from patient cells, is fast replacing the need for animal models while providing a more physiologically relevant characterization of novel mutations. Furthermore, CRISPR-Cas9 as the method for gene editing is replacing previous laborious and time-consuming gene editing methods that were commonly used, thus yielding knockout cell lines in a fraction of the time. © 2020 American Physiological Society. Compr Physiol 10:389-413, 2020.
Collapse
Affiliation(s)
- Kyriaki S Alatzoglou
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London (UCL), London, UK
| | - Louise C Gregory
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London (UCL), London, UK
| | - Mehul T Dattani
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London (UCL), London, UK
| |
Collapse
|
37
|
Harding P, Brooks BP, FitzPatrick D, Moosajee M. Anophthalmia including next-generation sequencing-based approaches. Eur J Hum Genet 2020; 28:388-398. [PMID: 31358957 PMCID: PMC7029013 DOI: 10.1038/s41431-019-0479-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 06/06/2019] [Accepted: 07/16/2019] [Indexed: 11/09/2022] Open
Abstract
Name of the disease (synonyms) See Table 1, Column 1-"Name of disease" and Column 2-"Alternative names". OMIM# of the disease See Table 1, Column 3-"OMIM# of the disease". Name of the analysed genes or DNA/chromosome segments and OMIM# of the gene(s) Core genes (irrespective of being tested by Sanger sequencing or next-generation sequencing): See Table 1, Column 4-"Cytogenetic location", Column 5-"Associated gene(s)" and Column 6-"OMIM# of associated gene(s)". Additional genes (if tested by next-generation sequencing, including Whole exome/genome sequencing and panel sequencing): See Table 2, Column 1-"Gene", Column 2-"Alternative names", Column 3-"OMIM# of gene" and Column 4-"Cytogenetic location". Review of the analytical and clinical validity as well as of the clinical utility of DNA-based testing for mutations in the gene(s) in diagnostic, predictive and prenatal settings, and for risk assessment in relatives.
Collapse
Affiliation(s)
| | - Brian P Brooks
- Ophthalmic Genetics & Visual Function Branch, National Eye Institute, Bethesda, MD, USA
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, UK. .,Moorfields Eye Hospital NHS Foundation Trust, London, UK. .,Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
| |
Collapse
|
38
|
Markitantova Y, Simirskii V. Inherited Eye Diseases with Retinal Manifestations through the Eyes of Homeobox Genes. Int J Mol Sci 2020; 21:E1602. [PMID: 32111086 PMCID: PMC7084737 DOI: 10.3390/ijms21051602] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/21/2020] [Accepted: 02/24/2020] [Indexed: 12/14/2022] Open
Abstract
Retinal development is under the coordinated control of overlapping networks of signaling pathways and transcription factors. The paper was conceived as a review of the data and ideas that have been formed to date on homeobox genes mutations that lead to the disruption of eye organogenesis and result in inherited eye/retinal diseases. Many of these diseases are part of the same clinical spectrum and have high genetic heterogeneity with already identified associated genes. We summarize the known key regulators of eye development, with a focus on the homeobox genes associated with monogenic eye diseases showing retinal manifestations. Recent advances in the field of genetics and high-throughput next-generation sequencing technologies, including single-cell transcriptome analysis have allowed for deepening of knowledge of the genetic basis of inherited retinal diseases (IRDs), as well as improve their diagnostics. We highlight some promising avenues of research involving molecular-genetic and cell-technology approaches that can be effective for IRDs therapy. The most promising neuroprotective strategies are aimed at mobilizing the endogenous cellular reserve of the retina.
Collapse
|
39
|
George A, Cogliati T, Brooks BP. Genetics of syndromic ocular coloboma: CHARGE and COACH syndromes. Exp Eye Res 2020; 193:107940. [PMID: 32032630 DOI: 10.1016/j.exer.2020.107940] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 02/07/2023]
Abstract
Optic fissure closure defects result in uveal coloboma, a potentially blinding condition affecting between 0.5 and 2.6 per 10,000 births that may cause up to 10% of childhood blindness. Uveal coloboma is on a phenotypic continuum with microphthalmia (small eye) and anophthalmia (primordial/no ocular tissue), the so-called MAC spectrum. This review gives a brief overview of the developmental biology behind coloboma and its clinical presentation/spectrum. Special attention will be given to two prominent, syndromic forms of coloboma, namely, CHARGE (Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital hypoplasia, and Ear anomalies/deafness) and COACH (Cerebellar vermis hypoplasia, Oligophrenia, Ataxia, Coloboma, and Hepatic fibrosis) syndromes. Approaches employed to identify genes involved in optic fissure closure in animal models and recent advances in live imaging of zebrafish eye development are also discussed.
Collapse
Affiliation(s)
- Aman George
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health. Bethesda, Maryland, 20892, USA
| | - Tiziana Cogliati
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health. Bethesda, Maryland, 20892, USA
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health. Bethesda, Maryland, 20892, USA.
| |
Collapse
|
40
|
Bosch I Ara L, Katugampola H, Dattani MT. Congenital Hypopituitarism During the Neonatal Period: Epidemiology, Pathogenesis, Therapeutic Options, and Outcome. Front Pediatr 2020; 8:600962. [PMID: 33634051 PMCID: PMC7902025 DOI: 10.3389/fped.2020.600962] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/31/2020] [Indexed: 12/13/2022] Open
Abstract
Introduction: Congenital hypopituitarism (CH) is characterized by a deficiency of one or more pituitary hormones. The pituitary gland is a central regulator of growth, metabolism, and reproduction. The anterior pituitary produces and secretes growth hormone (GH), adrenocorticotropic hormone, thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone, and prolactin. The posterior pituitary hormone secretes antidiuretic hormone and oxytocin. Epidemiology: The incidence is 1 in 4,000-1 in 10,000. The majority of CH cases are sporadic; however, a small number of familial cases have been identified. In the latter, a molecular basis has frequently been identified. Between 80-90% of CH cases remain unsolved in terms of molecular genetics. Pathogenesis: Several transcription factors and signaling molecules are involved in the development of the pituitary gland. Mutations in any of these genes may result in CH including HESX1, PROP1, POU1F1, LHX3, LHX4, SOX2, SOX3, OTX2, PAX6, FGFR1, GLI2, and FGF8. Over the last 5 years, several novel genes have been identified in association with CH, but it is likely that many genes remain to be identified, as the majority of patients with CH do not have an identified mutation. Clinical manifestations: Genotype-phenotype correlations are difficult to establish. There is a high phenotypic variability associated with different genetic mutations. The clinical spectrum includes severe midline developmental disorders, hypopituitarism (in isolation or combined with other congenital abnormalities), and isolated hormone deficiencies. Diagnosis and treatment: Key investigations include MRI and baseline and dynamic pituitary function tests. However, dynamic tests of GH secretion cannot be performed in the neonatal period, and a diagnosis of GH deficiency may be based on auxology, MRI findings, and low growth factor concentrations. Once a hormone deficit is confirmed, hormone replacement should be started. If onset is acute with hypoglycaemia, cortisol deficiency should be excluded, and if identified this should be rapidly treated, as should TSH deficiency. This review aims to give an overview of CH including management of this complex condition.
Collapse
Affiliation(s)
- Laura Bosch I Ara
- Department of Paediatric Endocrinology, Great Ormond Street Hospital for Children, London, United Kingdom
| | - Harshini Katugampola
- Department of Paediatric Endocrinology, Great Ormond Street Hospital for Children, London, United Kingdom
| | - Mehul T Dattani
- Department of Paediatric Endocrinology, Great Ormond Street Hospital for Children, London, United Kingdom.,Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| |
Collapse
|
41
|
Kaukonen M, Woods S, Ahonen S, Lemberg S, Hellman M, Hytönen MK, Permi P, Glaser T, Lohi H. Maternal Inheritance of a Recessive RBP4 Defect in Canine Congenital Eye Disease. Cell Rep 2019; 23:2643-2652. [PMID: 29847795 PMCID: PMC6546432 DOI: 10.1016/j.celrep.2018.04.118] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 04/16/2018] [Accepted: 04/26/2018] [Indexed: 01/20/2023] Open
Abstract
Maternally skewed transmission of traits has been associated with genomic imprinting and oocyte-derived mRNA. We report canine congenital eye malformations, caused by an amino acid deletion (K12del) near the N terminus of retinol-binding protein (RBP4). The disease is only expressed when both dam and offspring are deletion homozygotes. RBP carries vitamin A (retinol) from hepatic stores to peripheral tissues, including the placenta and developing eye, where it is required to synthesize retinoic acid. Gestational vitamin A deficiency is a known risk factor for ocular birth defects. The K12del mutation disrupts RBP folding in vivo, decreasing its secretion from hepatocytes to serum. The maternal penetrance effect arises from an impairment in the sequential transfer of retinol across the placenta, via RBP encoded by maternal and fetal genomes. Our results demonstrate a mode of recessive maternal inheritance, with a physiological basis, and they extend previous observations on dominant-negative RBP4 alleles in humans.
Collapse
Affiliation(s)
- Maria Kaukonen
- Department of Veterinary Biosciences, University of Helsinki, 00014 Helsinki, Finland; Research Programs Unit, Molecular Neurology, University of Helsinki, 00014 Helsinki, Finland; The Folkhälsan Institute of Genetics, 00290 Helsinki, Finland
| | - Sean Woods
- Department of Cell Biology and Human Anatomy, University of California, Davis School of Medicine, Davis, CA 95616, USA
| | - Saija Ahonen
- Department of Veterinary Biosciences, University of Helsinki, 00014 Helsinki, Finland; Research Programs Unit, Molecular Neurology, University of Helsinki, 00014 Helsinki, Finland; The Folkhälsan Institute of Genetics, 00290 Helsinki, Finland
| | - Seppo Lemberg
- Department of Eye Diseases, Helsinki University Hospital, 00029 The Hospital District of Helsinki and Uusimaa, Finland
| | - Maarit Hellman
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Marjo K Hytönen
- Department of Veterinary Biosciences, University of Helsinki, 00014 Helsinki, Finland; Research Programs Unit, Molecular Neurology, University of Helsinki, 00014 Helsinki, Finland; The Folkhälsan Institute of Genetics, 00290 Helsinki, Finland
| | - Perttu Permi
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland; Department of Biological and Environmental Science, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Tom Glaser
- Department of Cell Biology and Human Anatomy, University of California, Davis School of Medicine, Davis, CA 95616, USA.
| | - Hannes Lohi
- Department of Veterinary Biosciences, University of Helsinki, 00014 Helsinki, Finland; Research Programs Unit, Molecular Neurology, University of Helsinki, 00014 Helsinki, Finland; The Folkhälsan Institute of Genetics, 00290 Helsinki, Finland.
| |
Collapse
|
42
|
Chelban V, Alsagob M, Kloth K, Chirita-Emandi A, Vandrovcova J, Maroofian R, Davagnanam I, Bakhtiari S, AlSayed MD, Rahbeeni Z, AlZaidan H, Malintan NT, Johannsen J, Efthymiou S, Ghayoor Karimiani E, Mankad K, Al-Shahrani SA, Beiraghi Toosi M, AlShammari M, Groppa S, Haridy NA, AlQuait L, Qari A, Huma R, Salih MA, Almass R, Almutairi FB, Hamad MH, Alorainy IA, Ramzan K, Imtiaz F, Puiu M, Kruer MC, Bierhals T, Wood NW, Colak D, Houlden H, Kaya N. Genetic and phenotypic characterization of NKX6-2-related spastic ataxia and hypomyelination. Eur J Neurol 2019; 27:334-342. [PMID: 31509304 PMCID: PMC6946857 DOI: 10.1111/ene.14082] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 08/21/2019] [Indexed: 12/22/2022]
Abstract
Background and purpose Hypomyelinating leukodystrophies are a heterogeneous group of genetic disorders with a wide spectrum of phenotypes and a high rate of genetically unsolved cases. Bi‐allelic mutations in NKX6‐2 were recently linked to spastic ataxia 8 with hypomyelinating leukodystrophy. Methods Using a combination of homozygosity mapping, exome sequencing, and detailed clinical and neuroimaging assessment a series of new NKX6‐2 mutations in a multicentre setting is described. Then, all reported NKX6‐2 mutations and those identified in this study were combined and an in‐depth analysis of NKX6‐2‐related disease spectrum was provided. Results Eleven new cases from eight families of different ethnic backgrounds carrying compound heterozygous and homozygous pathogenic variants in NKX6‐2 were identified, evidencing a high NKX6‐2 mutation burden in the hypomyelinating leukodystrophy disease spectrum. Our data reveal a phenotype spectrum with neonatal onset, global psychomotor delay and worse prognosis at the severe end and a childhood onset with mainly motor phenotype at the milder end. The phenotypic and neuroimaging expression in NKX6‐2 is described and it is shown that phenotypes with epilepsy in the absence of overt hypomyelination and diffuse hypomyelination without seizures can occur. Conclusions NKX6‐2 mutations should be considered in patients with autosomal recessive, very early onset of nystagmus, cerebellar ataxia with hypotonia that rapidly progresses to spasticity, particularly when associated with neuroimaging signs of hypomyelination. Therefore, it is recommended that NXK6‐2 should be included in hypomyelinating leukodystrophy and spastic ataxia diagnostic panels.
Collapse
Affiliation(s)
- V Chelban
- Department of Neuromuscular Diseases, University College London Institute of Neurology, London, UK.,Department of Neurology and Neurosurgery, Institute of Emergency Medicine, Chisinau, Moldova
| | - M Alsagob
- Department of Genetics, KFSHRC, Riyadh, Saudi Arabia
| | - K Kloth
- Institute of Human Genetics, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - A Chirita-Emandi
- Genetics Department, University 'Victor Babes', Timisoara, Romania
| | - J Vandrovcova
- Department of Neuromuscular Diseases, University College London Institute of Neurology, London, UK
| | - R Maroofian
- Genetics Research Centre, Molecular and Clinical Sciences Institute, St George's University of London, London, UK
| | - I Davagnanam
- Brain Repair and Rehabilitation, University College London Institute of Neurology, London, UK
| | - S Bakhtiari
- Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA.,Department of Child Health, Cellular and Molecular Medicine, Department of Neurology, University of Arizona College of Medicine Phoenix, Phoenix, AZ, USA
| | - M D AlSayed
- Medical Genetics, KFSHRC, Riyadh, Saudi Arabia
| | - Z Rahbeeni
- Medical Genetics, KFSHRC, Riyadh, Saudi Arabia
| | - H AlZaidan
- Medical Genetics, KFSHRC, Riyadh, Saudi Arabia
| | - N T Malintan
- Clinical and Experimental Epilepsy, University College London Institute of Neurology, London, UK
| | - J Johannsen
- Department of Paediatrics, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - S Efthymiou
- Department of Neuromuscular Diseases, University College London Institute of Neurology, London, UK
| | - E Ghayoor Karimiani
- Genetics Research Centre, Molecular and Clinical Sciences Institute, St George's University of London, London, UK
| | - K Mankad
- Great Ormond Street Hospitals, London, UK
| | | | - M Beiraghi Toosi
- Department of Paediatric Diseases, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - M AlShammari
- Department of Genetics, KFSHRC, Riyadh, Saudi Arabia
| | - S Groppa
- Department of Neurology and Neurosurgery, Institute of Emergency Medicine, Chisinau, Moldova
| | - N A Haridy
- Department of Neuromuscular Diseases, University College London Institute of Neurology, London, UK.,Department of Neurology and Psychiatry, Assiut University Hospital, Assiut, Egypt
| | - L AlQuait
- Department of Genetics, KFSHRC, Riyadh, Saudi Arabia
| | - A Qari
- Medical Genetics, KFSHRC, Riyadh, Saudi Arabia
| | - R Huma
- Medical Genetics, KFSHRC, Riyadh, Saudi Arabia
| | - M A Salih
- Neurology Division, Department of Pediatrics, College of Medicine, King Saud University KFSHRC, Riyadh, Saudi Arabia
| | - R Almass
- Department of Genetics, KFSHRC, Riyadh, Saudi Arabia
| | - F B Almutairi
- Department of Genetics, KFSHRC, Riyadh, Saudi Arabia
| | - M H Hamad
- Neurology Division, Department of Pediatrics, College of Medicine, King Saud University KFSHRC, Riyadh, Saudi Arabia
| | - I A Alorainy
- Department of Radiology & Medical Imaging, College of Medicine, King Saud University KFSHRC, Riyadh, Saudi Arabia
| | - K Ramzan
- Department of Genetics, KFSHRC, Riyadh, Saudi Arabia
| | - F Imtiaz
- Department of Genetics, KFSHRC, Riyadh, Saudi Arabia
| | - M Puiu
- Genetics Department, University 'Victor Babes', Timisoara, Romania
| | - M C Kruer
- Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA.,Department of Child Health, Cellular and Molecular Medicine, Department of Neurology, University of Arizona College of Medicine Phoenix, Phoenix, AZ, USA
| | - T Bierhals
- Institute of Human Genetics, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - N W Wood
- Department of Neuromuscular Diseases, University College London Institute of Neurology, London, UK
| | - D Colak
- Department of Biostatistics, Epidemiology and Scientific Computing, KFSHRC, Riyadh, Saudi Arabia
| | - H Houlden
- Department of Neuromuscular Diseases, University College London Institute of Neurology, London, UK
| | - N Kaya
- Department of Genetics, KFSHRC, Riyadh, Saudi Arabia
| |
Collapse
|
43
|
Structural and functional brain reorganisation due to blindness: The special case of bilateral congenital anophthalmia. Neurosci Biobehav Rev 2019; 107:765-774. [PMID: 31626815 DOI: 10.1016/j.neubiorev.2019.10.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/03/2019] [Accepted: 10/08/2019] [Indexed: 12/25/2022]
Abstract
Investigating the changes in the brain that result from a loss of sensory input has provided significant insight into the considerable capacity of the brain to reorganise. One of the difficulties in studying sensory-deprived populations is that the time and extent of sensory loss vary significantly. In this review, we consider the changes in the human brain associated with complete absence of visual input resulting from bilateral congenital anophthalmia, in which the eyes fail to develop. We describe the functional reorganisation and associated structural and connectivity changes that occur in the brain of those affected by the condition. By considering animal models of this condition, we investigate the changes that may be occurring on a scale that is not captured by human in vivo imaging techniques. Finally, we lay out a model pathway for taking auditory information to the occipital cortex that may be specific to anophthalmia.
Collapse
|
44
|
Chen Y, Liu Z, Lin Z, Shi X. Eye Signs in Pituitary Disorders. Neurol India 2019; 67:979-982. [PMID: 31512618 DOI: 10.4103/0028-3886.266265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The eye is a vital sense organ and plays a vital role in conveying the underlying physical and mental state of wellbeing of an individual. A comprehensive examination of the eye is often required in patients presenting with systemic complaints. Many endocrine disorders have characteristic manifestations pertaining to the eye, the classical being the exophthalmos in thyrotoxicosis. However, a cursory eye evaluation may lead to the identification of early features that can help in the diagnosis of other endocrine disorders. This is more common in cases of pituitary mass lesions, who often present with the functional hormonal alterations rather than the visual symptoms. The definitive therapy during the late stages of the disease leads to persisting visual disabilities and affects the quality of life. Hence, the endocrinologists and ophthalmologists need to be aware of various ophthalmic features in the pituitary disorders. In this review, we highlight the eye signs in pituitary disorders, along with a brief description of uncommon ocular-pituitary syndromes.
Collapse
Affiliation(s)
- Yan Chen
- Department of Ophthalmology, The Affiiated Hospital to Changchun University of Chinese Medicine, Changchun, Jilin, China
| | - Zhihong Liu
- Department of Ophthalmology, The Affiiated Hospital to Changchun University of Chinese Medicine, Changchun, Jilin, China
| | - Zhihui Lin
- Department of Ophthalmology, The Affiiated Hospital to Changchun University of Chinese Medicine, Changchun, Jilin, China
| | - Xiaozhe Shi
- Department of Ophthalmology, The Affiiated Hospital to Changchun University of Chinese Medicine, Changchun, Jilin, China
| |
Collapse
|
45
|
Harding P, Moosajee M. The Molecular Basis of Human Anophthalmia and Microphthalmia. J Dev Biol 2019; 7:jdb7030016. [PMID: 31416264 PMCID: PMC6787759 DOI: 10.3390/jdb7030016] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/08/2019] [Accepted: 08/08/2019] [Indexed: 12/16/2022] Open
Abstract
Human eye development is coordinated through an extensive network of genetic signalling pathways. Disruption of key regulatory genes in the early stages of eye development can result in aborted eye formation, resulting in an absent eye (anophthalmia) or a small underdeveloped eye (microphthalmia) phenotype. Anophthalmia and microphthalmia (AM) are part of the same clinical spectrum and have high genetic heterogeneity, with >90 identified associated genes. By understanding the roles of these genes in development, including their temporal expression, the phenotypic variation associated with AM can be better understood, improving diagnosis and management. This review describes the genetic and structural basis of eye development, focusing on the function of key genes known to be associated with AM. In addition, we highlight some promising avenues of research involving multiomic approaches and disease modelling with induced pluripotent stem cell (iPSC) technology, which will aid in developing novel therapies.
Collapse
Affiliation(s)
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, London EC1V 9EL, UK.
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK.
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK.
| |
Collapse
|
46
|
Ohuchi H, Sato K, Habuta M, Fujita H, Bando T. Congenital eye anomalies: More mosaic than thought? Congenit Anom (Kyoto) 2019; 59:56-73. [PMID: 30039880 DOI: 10.1111/cga.12304] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 07/16/2018] [Accepted: 07/17/2018] [Indexed: 12/13/2022]
Abstract
The eye is a sensory organ that primarily captures light and provides the sense of sight, as well as delivering non-visual light information involving biological rhythms and neurophysiological activities to the brain. Since the early 1990s, rapid advances in molecular biology have enabled the identification of developmental genes, genes responsible for human congenital diseases, and relevant genes of mutant animals with various anomalies. In this review, we first look at the development of the eye, and we highlight seminal reports regarding archetypal gene defects underlying three developmental ocular disorders in humans: (1) holoprosencephaly (HPE), with cyclopia being exhibited in the most severe cases; (2) microphthalmia, anophthalmia, and coloboma (MAC) phenotypes; and (3) anterior segment dysgenesis (ASDG), known as Peters anomaly and its related disorders. The recently developed methods, such as next-generation sequencing and genome editing techniques, have aided the discovery of gene mutations in congenital eye diseases and gene functions in normal eye development. Finally, we discuss Pax6-genome edited mosaic eyes and propose that somatic mosaicism in developmental gene mutations should be considered a causal factor for variable phenotypes, sporadic cases, and de novo mutations in human developmental disorders.
Collapse
Affiliation(s)
- Hideyo Ohuchi
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Keita Sato
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Munenori Habuta
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Hirofumi Fujita
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Tetsuya Bando
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| |
Collapse
|
47
|
Denis D, Hugo J, Beylerian M, Ramtohul P, Aziz A, Matonti F, Lebranchu P. [Congenital abnormalities of the optic disc]. J Fr Ophtalmol 2019; 42:778-789. [PMID: 30935696 DOI: 10.1016/j.jfo.2018.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 09/03/2018] [Accepted: 09/10/2018] [Indexed: 10/27/2022]
Abstract
Congenital abnormalities of the optic disc are not uncommon in clinical practice and should be recognized. Size abnormalities of the optic disc include optic disc aplasia, hypoplasia, megalopapilla, and optic disc cupping in prematurity. Among congenital excavations of the optic disc head, morning glory disc anomaly and optic disc pit can be complicated by serous retinal detachment; the papillorenal disc is an association of bilateral optic disc cupping and renal hypoplasia which should be ruled out; optic disc coloboma is caused by an abnormal closure of the embryonic fissure and can be complicated by choroidal neovascularization and retinal detachment. Other abnormalities that will be discussed are congenital tilted disc syndrome, duplicity of the optic disc head, congenital pigmentation of the optic disc head and myelinated retinal nerve fibers. All of these abnormalities can be associated with syndromes and neurological diseases, as well as other potentially blinding ophthalmological defects which can be secondarily complicated by amblyopia, strabismus and nystagmus. Thus, they should be recognized in order to plan for appropriate follow-up.
Collapse
Affiliation(s)
- D Denis
- Service d'ophtalmologie, hôpital Nord, centre hospitalier universitaire de l'hôpital Nord, chemin des Bourrely, 13015 Marseille, France.
| | - J Hugo
- Service d'ophtalmologie, hôpital Nord, centre hospitalier universitaire de l'hôpital Nord, chemin des Bourrely, 13015 Marseille, France
| | - M Beylerian
- Service d'ophtalmologie, hôpital Nord, centre hospitalier universitaire de l'hôpital Nord, chemin des Bourrely, 13015 Marseille, France
| | - P Ramtohul
- Service d'ophtalmologie, hôpital Nord, centre hospitalier universitaire de l'hôpital Nord, chemin des Bourrely, 13015 Marseille, France
| | - A Aziz
- Service d'ophtalmologie, hôpital Nord, centre hospitalier universitaire de l'hôpital Nord, chemin des Bourrely, 13015 Marseille, France
| | - F Matonti
- Service d'ophtalmologie, hôpital Nord, centre hospitalier universitaire de l'hôpital Nord, chemin des Bourrely, 13015 Marseille, France
| | - P Lebranchu
- Hôtel-Dieu, 1 place Alexis-Ricordeau, 44000 Nantes, France
| |
Collapse
|
48
|
Yoshitomi Y, Osada H, Satake H, Kojima M, Saito-Takatsuji H, Ikeda T, Yoshitake Y, Ishigaki Y, Kubo E, Sasaki H, Yonekura H. Ultraviolet B-induced Otx2 expression in lens epithelial cells promotes epithelial-mesenchymal transition. Biol Open 2019; 8:bio.035691. [PMID: 30718229 PMCID: PMC6398467 DOI: 10.1242/bio.035691] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Ultraviolet (UV) radiation of eyes is a major risk factor for cataractogenesis, although the molecular mechanisms underlying this process remain poorly understood and genes that are affected by UV radiation have not been fully identified. In this study, we examined the UV-related gene regulation in lens epithelial cells (LECs) of mouse eyes and investigated the molecular mechanisms of UV-triggered cataractogenesis. Forty-one genes were significantly upregulated in LECs following UVB exposure in vivo in two independent experiments. Among these, Otx2 was strongly upregulated in LECs, suggesting that it may act as an upstream regulator of UVB-induced changes in gene expression. Accordingly, Otx2 overexpression in LECs in vitro induced morphological changes in cell shapes. Epithelial-mesenchymal transition (EMT)-related molecules, such as TGFβ2, αSMA and fibronectin were upregulated in Otx2-overexpressing LECs, concomitant with suppression of lens fiber cell marker genes, such as CRYAA and DNASEIIB. In vitro experiments suggested that UVB upregulated Otx2 through hydrogen peroxide generation. Aberrant upregulation of Otx2 in LECs following UV irradiation induces the EMT and alteration of the lens cell characteristics, likely contributing to cataractogenesis.
Collapse
Affiliation(s)
- Yasuo Yoshitomi
- Department of Biochemistry, Kanazawa Medical University School of Medicine, 1-1 Daigaku, Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan
| | - Hiromi Osada
- Department of Ophthalmology, Kanazawa Medical University School of Medicine, 1-1 Daigaku, Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan
| | - Haruka Satake
- Department of Biochemistry, Kanazawa Medical University School of Medicine, 1-1 Daigaku, Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan
| | - Masami Kojima
- Department of Ophthalmology, Faculty of Medical Science, Kanazawa Medical University School of Nursing, 1-1 Daigaku, Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan
| | - Hidehito Saito-Takatsuji
- Department of Biochemistry, Kanazawa Medical University School of Medicine, 1-1 Daigaku, Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan
| | - Takayuki Ikeda
- Department of Biochemistry, Kanazawa Medical University School of Medicine, 1-1 Daigaku, Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan
| | - Yoshino Yoshitake
- Department of Biochemistry, Kanazawa Medical University School of Medicine, 1-1 Daigaku, Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan
| | - Yasuhito Ishigaki
- Medical Research Institute, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University School of Medicine, 1-1 Daigaku, Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan
| | - Hiroshi Sasaki
- Department of Ophthalmology, Kanazawa Medical University School of Medicine, 1-1 Daigaku, Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan
| | - Hideto Yonekura
- Department of Biochemistry, Kanazawa Medical University School of Medicine, 1-1 Daigaku, Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan
| |
Collapse
|
49
|
Genetics of anophthalmia and microphthalmia. Part 1: Non-syndromic anophthalmia/microphthalmia. Hum Genet 2019; 138:799-830. [PMID: 30762128 DOI: 10.1007/s00439-019-01977-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 01/30/2019] [Indexed: 12/22/2022]
Abstract
Eye formation is the result of coordinated induction and differentiation processes during embryogenesis. Disruption of any one of these events has the potential to cause ocular growth and structural defects, such as anophthalmia and microphthalmia (A/M). A/M can be isolated or occur with systemic anomalies, when they may form part of a recognizable syndrome. Their etiology includes genetic and environmental factors; several hundred genes involved in ocular development have been identified in humans or animal models. In humans, around 30 genes have been repeatedly implicated in A/M families, although many other genes have been described in single cases or families, and some genetic syndromes include eye anomalies occasionally as part of a wider phenotype. As a result of this broad genetic heterogeneity, with one or two notable exceptions, each gene explains only a small percentage of cases. Given the overlapping phenotypes, these genes can be most efficiently tested on panels or by whole exome/genome sequencing for the purposes of molecular diagnosis. However, despite whole exome/genome testing more than half of patients currently remain without a molecular diagnosis. The proportion of undiagnosed cases is even higher in those individuals with unilateral or milder phenotypes. Furthermore, even when a strong gene candidate is available for a patient, issues of incomplete penetrance and germinal mosaicism make diagnosis and genetic counseling challenging. In this review, we present the main genes implicated in non-syndromic human A/M phenotypes and, for practical purposes, classify them according to the most frequent or predominant phenotype each is associated with. Our intention is that this will allow clinicians to rank and prioritize their molecular analyses and interpretations according to the phenotypes of their patients.
Collapse
|
50
|
Di Nardo AA, Fuchs J, Joshi RL, Moya KL, Prochiantz A. The Physiology of Homeoprotein Transduction. Physiol Rev 2019; 98:1943-1982. [PMID: 30067157 DOI: 10.1152/physrev.00018.2017] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The homeoprotein family comprises ~300 transcription factors and was long seen as primarily involved in developmental programs through cell autonomous regulation. However, recent evidence reveals that many of these factors are also expressed in the adult where they exert physiological functions not yet fully deciphered. Furthermore, the DNA-binding domain of most homeoproteins contains two signal sequences allowing their secretion and internalization, thus intercellular transfer. This review focuses on this new-found signaling in cell migration, axon guidance, and cerebral cortex physiological homeostasis and speculates on how it may play important roles in early arealization of the neuroepithelium. It also describes the use of homeoproteins as therapeutic proteins in mouse models of diseases affecting the central nervous system, in particular Parkinson disease and glaucoma.
Collapse
Affiliation(s)
- Ariel A Di Nardo
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University , Paris , France
| | - Julia Fuchs
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University , Paris , France
| | - Rajiv L Joshi
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University , Paris , France
| | - Kenneth L Moya
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University , Paris , France
| | - Alain Prochiantz
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University , Paris , France
| |
Collapse
|