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Yan X, Atorf J, Ramos D, Thiele F, Weber S, Dalke C, Sun M, Puk O, Michel D, Fuchs H, Klaften M, Przemeck GKH, Sabrautzki S, Favor J, Ruberte J, Kremers J, de Angelis MH, Graw J. Mutation in Bmpr1b Leads to Optic Disc Coloboma and Ventral Retinal Gliosis in Mice. Invest Ophthalmol Vis Sci 2020; 61:44. [PMID: 32106289 PMCID: PMC7329948 DOI: 10.1167/iovs.61.2.44] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 11/10/2019] [Indexed: 12/14/2022] Open
Abstract
Purpose The clinical phenotype of retinal gliosis occurs in different forms; here, we characterize one novel genetic feature, (i.e., signaling via BMP-receptor 1b). Methods Mouse mutants were generated within a recessive ENU mutagenesis screen; the underlying mutation was identified by linkage analysis and Sanger sequencing. The eye phenotype was characterized by fundoscopy, optical coherence tomography, optokinetic drum, electroretinography, and visual evoked potentials, by histology, immunohistology, and electron-microscopy. Results The mutation affects intron 10 of the Bmpr1b gene, which is causative for skipping of exon 10. The expression levels of pSMAD1/5/8 were reduced in the mutant retina. The loss of BMPR1B-mediated signaling leads to optic nerve coloboma, gliosis in the optic nerve head and ventral retina, defective optic nerve axons, and irregular retinal vessels. The ventral retinal gliosis is proliferative and hypertrophic, which is concomitant with neuronal delamination and the reduction of retinal ganglion cells (RGCs); it is dominated by activated astrocytes overexpressing PAX2 and SOX2 but not PAX6, indicating that they may retain properties of gliogenic precursor cells. The expression pattern of PAX2 in the optic nerve head and ventral retina is altered during embryonic development. These events finally result in reduced electrical transmission of the retina and optic nerve and significantly reduced visual acuity. Conclusions Our study demonstrates that BMPR1B is necessary for the development of the optic nerve and ventral retina. This study could also indicate a new mechanism in the formation of retinal gliosis; it opens new routes for its treatment eventually preventing scar formation in the retina.
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Affiliation(s)
- Xiaohe Yan
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
- School of Optometry, Shenzhen University, Shenzhen, China
| | - Jenny Atorf
- Department of Ophthalmology, University Hospital Erlangen, Erlangen, Germany
| | - David Ramos
- Department of Animal Health and Anatomy, Center of Animal Biotechnology and Gene Therapy, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Frank Thiele
- Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Susanne Weber
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Claudia Dalke
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- The German Mouse Clinic, Helmholtz Zentrum München, Neuherberg, Germany
| | - Minxuan Sun
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- The German Mouse Clinic, Helmholtz Zentrum München, Neuherberg, Germany
| | - Oliver Puk
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- The German Mouse Clinic, Helmholtz Zentrum München, Neuherberg, Germany
| | - Dian Michel
- Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Helmut Fuchs
- Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- The German Mouse Clinic, Helmholtz Zentrum München, Neuherberg, Germany
| | - Matthias Klaften
- Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | | | - Sibylle Sabrautzki
- Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Jack Favor
- The German Mouse Clinic, Helmholtz Zentrum München, Neuherberg, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Jesús Ruberte
- Department of Animal Health and Anatomy, Center of Animal Biotechnology and Gene Therapy, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jan Kremers
- Department of Ophthalmology, University Hospital Erlangen, Erlangen, Germany
| | - Martin Hrabě de Angelis
- Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- The German Mouse Clinic, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Experimental Genetics, Faculty of Life and Food Sciences Weihenstephan, Technische Universität München, Freising-Weihenstephan, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Jochen Graw
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- The German Mouse Clinic, Helmholtz Zentrum München, Neuherberg, Germany
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Gilger BC. The Ophthalmic Examination as It Pertains to General Ocular Toxicology: Basic and Advanced Techniques and Species-Associated Findings. ACTA ACUST UNITED AC 2013. [PMCID: PMC7122657 DOI: 10.1007/7653_2013_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Ocular toxicology pertains to toxicologic effects of drugs administered topically, intraocularly, or systemically. It should also include evaluation of adverse effects of ophthalmic devices such as contact lenses, intraocular lenses, and glaucoma implants. The ophthalmic examination is able to provide detailed in-life information and is used in combination with clinical observations, clinical pathology, and histopathology to assess potential toxicologic effects. The ophthalmologist must be familiar with the wide range of species used in the field of toxicology, be familiar with the anatomic variations associated with these species, be able to determine what is an inherited or a breed-related finding from a study-related effect, be competent with the required ophthalmic equipment, and be capable of examining this wide range of animals.
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Affiliation(s)
- Brian C. Gilger
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina USA
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Weiss O, Kaufman R, Michaeli N, Inbal A. Abnormal vasculature interferes with optic fissure closure in lmo2 mutant zebrafish embryos. Dev Biol 2012; 369:191-8. [PMID: 22819672 DOI: 10.1016/j.ydbio.2012.06.029] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 06/16/2012] [Accepted: 06/19/2012] [Indexed: 01/13/2023]
Abstract
Ocular coloboma is a potentially blinding congenital eye malformation caused by failure of optic fissure closure during early embryogenesis. The optic fissure is a ventral groove that forms during optic cup morphogenesis, and through which hyaloid artery and vein enter and leave the developing eye, respectively. After hyaloid artery and vein formation, the optic fissure closes around them. The mechanisms underlying optic fissure closure are poorly understood, and whether and how this process is influenced by hyaloid vessel development is unknown. Here we show that a loss-of-function mutation in lmo2, a gene specifically required for hematopoiesis and vascular development, results in failure of optic fissure closure in zebrafish. Analysis of ocular blood vessels in lmo2 mutants reveals that some vessels are severely dilated, including the hyaloid vein. Remarkably, reducing vessel size leads to rescue of optic fissure phenotype. Our results reveal a new mechanism leading to coloboma, whereby malformed blood vessels interfere with eye morphogenesis.
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Affiliation(s)
- Omri Weiss
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
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Melis D, Genesio R, Cozzolino M, Del Giudice E, Mormile A, Imperati F, Ronga V, Della Casa R, Nitsch L, Andria G. An emerging phenotype of proximal 11q deletions. Eur J Med Genet 2010; 53:340-3. [PMID: 20688202 DOI: 10.1016/j.ejmg.2010.07.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 07/19/2010] [Indexed: 11/30/2022]
Abstract
Few reports of small interstitial chromosome 11q deletions are reported in the literature and no clear genotype-phenotype correlation has been demonstrated. We describe a five years old boy who was referred to our attention because of the presence of ptosis of the left eyelid, iris coloboma and developmental delay. Clinical examination also revealed the presence of dysmorphic features including: low frontal hairline, flat profile, round face, full cheeks, periorbital fullness, hypertelorism, broad nasal bridge, down-turned corners of the mouth. Cytogenetic analysis, performed by array-CGH (resolution 1 Mb), revealed a deletion of chromosome 11q13.5q14.2. The present case represents a further patient described in the literature with a small interstitial deletion of chromosome 11q. Our patient shares the dysmorphic features and the presence of developmental delay with the previously reported patients with overlapping proximal 11q deletion. Considering these clinical and cytogenetic similarities, we suggest the existence of an emerging syndrome associated to proximal 11q deletions.
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Martín-Suárez EM, Galán A, Galero JMG, Molleda JM. Bilateral typical complete colobomas in a donkey: retinographic and fluorangiographic description. Vet Ophthalmol 2009; 12:338-42. [PMID: 19751496 DOI: 10.1111/j.1463-5224.2009.00720.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An 18-year-old male donkey was referred with a history of blindness. On ocular examination a complete bilateral typical colobomatous defect involving iris, ciliary body, lens, choroid, retina and optic nerve was observed. An optic pit was presented at the temporal side of the right optic head. Ophthalmoscopic and fluorangiographic characteristics are described.
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Affiliation(s)
- Eva María Martín-Suárez
- Department of Animal Medicine and Surgery, University of Cordoba, Crrta Madrid Km 396 Campus Rabanales, 14014 Córdoba, Spain.
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Abstract
PURPOSE OF REVIEW To integrate knowledge on the embryologic and molecular basis of optic fissure closure with clinical observations in patients with uveal coloboma. RECENT FINDINGS Closure of the optic fissure has been well characterized and many genetic alterations have been associated with coloboma; however, molecular mechanisms leading to coloboma remain largely unknown. In the past decade, we have gained better understanding of genes critical to eye development; however, mutations in these genes have been found in few individuals with coloboma. CHD7 mutations have been identified in patients with CHARGE syndrome (coloboma, heart defects, choanal atresia, retarded growth, genital anomalies, and ear anomalies or deafness). Animal models are bringing us closer to a molecular understanding of optic fissure closure. SUMMARY Optic fissure closure requires precise orchestration in timing and apposition of two poles of the optic cup. The relative roles of genetics and environment on this process remain elusive. While most cases of coloboma are sporadic, autosomal dominant, autosomal recessive, and X-linked inheritance patterns have been described. Genetically, colobomata demonstrate pleiotropy, heterogeneity, variable expressivity, and reduced penetrance. Coloboma is a complex disorder with a variable prognosis and requires regular examination to optimize visual acuity and to monitor for potential complications.
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Affiliation(s)
- Lan Chang
- National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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