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Atac D, Maggi K, Feil S, Maggi J, Cuevas E, Sowden JC, Koller S, Berger W. Identification and Characterization of ATOH7-Regulated Target Genes and Pathways in Human Neuroretinal Development. Cells 2024; 13:1142. [PMID: 38994994 PMCID: PMC11240604 DOI: 10.3390/cells13131142] [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: 06/05/2024] [Revised: 06/27/2024] [Accepted: 06/29/2024] [Indexed: 07/13/2024] Open
Abstract
The proneural transcription factor atonal basic helix-loop-helix transcription factor 7 (ATOH7) is expressed in early progenitors in the developing neuroretina. In vertebrates, this is crucial for the development of retinal ganglion cells (RGCs), as mutant animals show an almost complete absence of RGCs, underdeveloped optic nerves, and aberrations in retinal vessel development. Human mutations are rare and result in autosomal recessive optic nerve hypoplasia (ONH) or severe vascular changes, diagnosed as autosomal recessive persistent hyperplasia of the primary vitreous (PHPVAR). To better understand the role of ATOH7 in neuroretinal development, we created ATOH7 knockout and eGFP-expressing ATOH7 reporter human induced pluripotent stem cells (hiPSCs), which were differentiated into early-stage retinal organoids. Target loci regulated by ATOH7 were identified by Cleavage Under Targets and Release Using Nuclease with sequencing (CUT&RUN-seq) and differential expression by RNA sequencing (RNA-seq) of wildtype and mutant organoid-derived reporter cells. Additionally, single-cell RNA sequencing (scRNA-seq) was performed on whole organoids to identify cell type-specific genes. Mutant organoids displayed substantial deficiency in axon sprouting, reduction in RGCs, and an increase in other cell types. We identified 469 differentially expressed target genes, with an overrepresentation of genes belonging to axon development/guidance and Notch signaling. Taken together, we consolidate the function of human ATOH7 in guiding progenitor competence by inducing RGC-specific genes while inhibiting other cell fates. Furthermore, we highlight candidate genes responsible for ATOH7-associated optic nerve and retinovascular anomalies, which sheds light to potential future therapy targets for related disorders.
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Affiliation(s)
- David Atac
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Kevin Maggi
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Silke Feil
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Jordi Maggi
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Elisa Cuevas
- UCL Great Ormond Street Institute of Child Health, University College London and NIHR Great Ormond Street Hospital Biomedical Research Centre, London WC1N 1EH, UK
| | - Jane C Sowden
- UCL Great Ormond Street Institute of Child Health, University College London and NIHR Great Ormond Street Hospital Biomedical Research Centre, London WC1N 1EH, UK
| | - Samuel Koller
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, 8057 Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, 8057 Zurich, Switzerland
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Shastry BS. Genetics of familial exudative vitreoretinopathy and its implications for management. EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/eop.12.40] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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3
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Norrin: molecular and functional properties of an angiogenic and neuroprotective growth factor. Prog Retin Eye Res 2012; 31:243-57. [PMID: 22387751 DOI: 10.1016/j.preteyeres.2012.02.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Revised: 02/08/2012] [Accepted: 02/08/2012] [Indexed: 01/08/2023]
Abstract
Norrin is a secreted signaling molecule with structural and functional characteristics of an autocrine and/or paracrine acting growth factor. In the eye, Norrin is constitutively expressed in Müller cells. Norrin specifically binds to Frizzled-4 receptors and activates the canonical Wnt/β-catenin signaling pathway that is profoundly enhanced when Tspan12 is present at the Norrin/Frizzled-4 receptor complex. In the absence of Norrin or Frizzled-4, intraretinal capillaries are not formed during developmental angiogenesis. As a result there is considerable evidence that Norrin and Frizzled-4 are part of an essential signaling system that controls the formation of the retinal vasculature during eye development. Intriguingly, Norrin promotes vessel regrowth and induces the formation of intraretinal capillaries following oxygen-induced retinopathy in mice, an animal model of retinopathy of prematurity. Moreover, Norrin has pronounced neuroprotective properties on retinal ganglion cells (RGC) with the distinct potential to decrease the damaging effects of excitotoxic NMDA-induced RGC injury. The neuroprotective effects of Norrin similarly involve an activation of Wnt/β-catenin signaling and the subsequent induction of neuroprotective growth factor synthesis in Müller cells, such as that of fibroblast growth factor-2 (FGF2) or ciliary neurotrophic factor (CNTF). Overall, Norrin and the molecules involved in its signaling pathway appear to be promising targets to develop strategies that induce intraretinal vessel formation in patients suffering from ischemic retinopathies, or that increase RGC survival in glaucoma.
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Kaloglu C, Cesur I, Bulut HE. Norrin immunolocalization and its possible functions in rat endometrium during the estrus cycle and early pregnancy. Dev Growth Differ 2011; 53:887-96. [DOI: 10.1111/j.1440-169x.2011.01295.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Ye X, Smallwood P, Nathans J. Expression of the Norrie disease gene (Ndp) in developing and adult mouse eye, ear, and brain. Gene Expr Patterns 2010; 11:151-5. [PMID: 21055480 DOI: 10.1016/j.gep.2010.10.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 10/25/2010] [Accepted: 10/27/2010] [Indexed: 01/24/2023]
Abstract
The Norrie disease gene (Ndp) codes for a secreted protein, Norrin, that activates canonical Wnt signaling by binding to its receptor, Frizzled-4. This signaling system is required for normal vascular development in the retina and for vascular survival in the cochlea. In mammals, the pattern of Ndp expression beyond the retina is poorly defined due to the low abundance of Norrin mRNA and protein. Here, we characterize Ndp expression during mouse development by studying a knock-in mouse that carries the coding sequence of human placental alkaline phosphatase (AP) inserted at the Ndp locus (Ndp(AP)). In the CNS, Ndp(AP) expression is apparent by E10.5 and is dynamic and complex. The anatomically delimited regions of Ndp(AP) expression observed prenatally in the CNS are replaced postnatally by widespread expression in astrocytes in the forebrain and midbrain, Bergman glia in the cerebellum, and Müller glia in the retina. In the developing and adult cochlea, Ndp(AP) expression is closely associated with two densely vascularized regions, the stria vascularis and a capillary plexus between the organ of Corti and the spiral ganglion. These observations suggest the possibility that Norrin may have developmental and/or homeostatic functions beyond the retina and cochlea.
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Affiliation(s)
- Xin Ye
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Norrin mediates neuroprotective effects on retinal ganglion cells via activation of the Wnt/beta-catenin signaling pathway and the induction of neuroprotective growth factors in Muller cells. J Neurosci 2010; 30:5998-6010. [PMID: 20427659 DOI: 10.1523/jneurosci.0730-10.2010] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Norrin is a secreted protein that binds to frizzled 4 and controls development of capillaries in retina and inner ear. We provide evidence that Norrin has distinct neuroprotective properties that are independent from its effects on vascular development. The function of Norrin was investigated in a mouse model of excitotoxic retinal ganglion cell (RGC) damage after intravitreal injection of NMDA, and in cultured Müller glia or immortalized RGC-5 cells. Intravitreal injection of Norrin significantly increased the number of surviving RGC axons in the optic nerve and decreased apoptotic death of retinal neurons following NMDA-mediated damage. This effect could be blocked by adding dickkopf (DKK)-1, an inhibitor of the Wnt/beta-catenin signaling pathway. Treatment of eyes with combined Norrin/NMDA activated Wnt/beta-catenin signaling and increased the retinal expression of leukemia inhibitory factor and endothelin-2, as well as that of neurotrophic growth factors such as fibroblast growth factor-2, brain-derived neurotrophic factor, lens epithelium-derived growth factor, and ciliary neurotrophic factor. A similar activation of Wnt/beta-catenin signaling and an increased expression of neurotrophic factors was observed in cultured Müller cells after treatment with Norrin, effects that again could be blocked by adding DKK-1. In addition, conditioned cell culture medium of Norrin-treated Müller cells increased survival of differentiated RGC-5 cells. We conclude that Norrin has pronounced neuroprotective properties on retinal neurons with the distinct potential to decrease the damaging effects of NMDA-induced RGC loss. The effects of Norrin involve activation of Wnt/beta-catenin signaling and subsequent induction of neurotrophic growth factors in Müller cells.
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Pelcastre EL, Villanueva-Mendoza C, Zenteno JC. Novel and recurrent NDP gene mutations in familial cases of Norrie disease and X-linked exudative vitreoretinopathy. Clin Exp Ophthalmol 2010; 38:367-74. [PMID: 20491809 DOI: 10.1111/j.1442-9071.2010.02245.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To present the results of molecular analysis of the NDP gene in Mexican families with Norrie disease (ND) and X-linked familial exudative vitreoretinopathy (XL-FEVR). METHODS Two unrelated families with ND and two with XL-FEVR were studied. Clinical diagnosis was suspected on the basis of a complete ophthalmologic examination. Molecular methods included DNA isolation from peripheral blood leucocytes, polymerase chain reaction amplification and direct nucleotide sequencing analysis of the complete coding region and exon-intron junctions of NDP. Haplotype analysis using NDP-linked microsatellites markers was performed in both ND families. RESULTS A novel Norrin missense mutation, p.Arg41Thr, was identified in two apparently unrelated families with ND. Haplotype analysis demonstrated that affected males in these two families shared the same ND-linked haplotype, suggesting a common origin for this novel mutation. The previously reported p.Arg121Trp and p.Arg121Gln Norrin mutations were identified in the two families with XL-FEVR. CONCLUSION Our results expand the mutational spectrum in ND. This is the first report of ND resulting from mutation at arginine position 41 of Norrin. Interestingly, mutations at the same residue but resulting in a different missense change were previously described in subjects with XL-FEVR (p.Arg41Lys) or persistent fetal vasculature syndrome (p.Arg41Ser), indicating that the novel p.Arg41Thr change causes a more severe retinal phenotype. Preliminary data suggest a founder effect for the ND p.Arg41Thr mutation in these two Mexican families.
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Affiliation(s)
- Erika L Pelcastre
- Research Unit and Department of Genetics, Institute of Ophthalmology Conde de Valenciana, Chimalpopoca 14, Col. Obrera, Mexico City 06800, Mexico
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TSPAN12 regulates retinal vascular development by promoting Norrin- but not Wnt-induced FZD4/beta-catenin signaling. Cell 2009; 139:299-311. [PMID: 19837033 DOI: 10.1016/j.cell.2009.07.048] [Citation(s) in RCA: 288] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 05/14/2009] [Accepted: 07/30/2009] [Indexed: 11/20/2022]
Abstract
Mutations in the genes encoding the Wnt receptor Frizzled-4 (FZD4), coreceptor LRP5, or the ligand Norrin disrupt retinal vascular development and cause ophthalmic diseases. Although Norrin is structurally unrelated to Wnts, it binds FZD4 and activates the canonical Wnt pathway. Here we show that the tetraspanin Tspan12 is expressed in the retinal vasculature, and loss of Tspan12 phenocopies defects seen in Fzd4, Lrp5, and Norrin mutant mice. In addition, Tspan12 genetically interacts with Norrin or Lrp5. Overexpressed TSPAN12 associates with the Norrin-receptor complex and significantly increases Norrin/beta-catenin but not Wnt/beta-catenin signaling, whereas Tspan12 siRNA abolishes transcriptional responses to Norrin but not Wnt3A in retinal endothelial cells. Signaling defects caused by Norrin or FZD4 mutations that are predicted to impair receptor multimerization are rescued by overexpression of TSPAN12. Our data indicate that Norrin multimers and TSPAN12 cooperatively promote multimerization of FZD4 and its associated proteins to elicit physiological levels of signaling.
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Abstract
Single nucleotide polymorphism (SNP) is the simplest form of DNA variation among individuals. These simple changes can be of transition or transversion type and they occur throughout the genome at a frequency of about one in 1,000 bp. They may be responsible for the diversity among individuals, genome evolution, the most common familial traits such as curly hair, interindividual differences in drug response, and complex and common diseases such as diabetes, obesity, hypertension, and psychiatric disorders. SNPs may change the encoded amino acids (nonsynonymous) or can be silent (synonymous) or simply occur in the noncoding regions. They may influence promoter activity (gene expression), messenger RNA (mRNA) conformation (stability), and subcellular localization of mRNAs and/or proteins and hence may produce disease. Therefore, identification of numerous variations in genes and analysis of their effects may lead to a better understanding of their impact on gene function and health of an individual. This improved knowledge may provide a starting point for the development of new, useful SNP markers for medical testing and a safer individualized medication to treat the most common devastating disorders. This will revolutionize the medical field in the future. To illustrate the effect of SNPs on gene function and phenotype, this minireview focuses on evidences revealing the impact of SNPs on the development and progression of three human eye disorders (Norrie disease, familial exudative vitreoretinopathy, and retinopathy of prematurity) that have overlapping clinical manifestations.
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Affiliation(s)
- Barkur S Shastry
- Department of Biological Sciences, Oakland University, Rochester, MI, USA
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Zinn AR, Kushner H, Ross JL. EFHC2 SNP rs7055196 is not associated with fear recognition in 45,X Turner syndrome. Am J Med Genet B Neuropsychiatr Genet 2008; 147B:507-9. [PMID: 17948898 DOI: 10.1002/ajmg.b.30625] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The neurocognitive phenotype of Turner syndrome (TS) includes deficits in social cognitive skills such as recognition of the facial affect expressing fear. A TS social cognition locus was previously mapped to a 5 megabase interval of Xp11.3-p11.4 by Good et al. 2003. A recent study by these same workers found evidence for association of a SNP in the EFHC2 gene, rs7055196, within this interval with fear recognition in 45,X TS. As EFHC2 was not a biological candidate gene for this phenotype a priori, we sought to replicate their finding in an independent cohort of 45,X TS subjects, using the same instrument to measure facial affect fear recognition. In contrast to the previous results, we find no evidence of an association between rs7055196 genotype and fear recognition. Other variations in EFHC2 and other candidate genes should be tested for association with social cognition in 45,X TS.
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Affiliation(s)
- Andrew R Zinn
- Department of Internal Medicine and McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
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Masckauchán TNH, Kitajewski J. Wnt/Frizzled signaling in the vasculature: new angiogenic factors in sight. Physiology (Bethesda) 2007; 21:181-8. [PMID: 16714476 DOI: 10.1152/physiol.00058.2005] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Wnt growth factors function via Frizzled receptors to affect cellular proliferation, differentiation, apoptosis, and migration. Wnt/Frizzled signaling is now linked to human hereditary disorders with retinal vascular defects, implicating Wnts as angiogenic factors. Here, we discuss Wnts and a novel Frizzled ligand, Norrin, in physiological and pathological angiogenesis.
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Affiliation(s)
- T Néstor H Masckauchán
- Department of Pathology, OB/GYN and Institute of Cancer Genetics, Columbia University Medical Center, New York, New York, USA
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12
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Weiss LA, Purcell S, Waggoner S, Lawrence K, Spektor D, Daly MJ, Sklar P, Skuse D. Identification of EFHC2 as a quantitative trait locus for fear recognition in Turner syndrome. Hum Mol Genet 2006; 16:107-13. [PMID: 17164267 DOI: 10.1093/hmg/ddl445] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
One-third of women with Turner syndrome (45,X) have autism-like social and communication difficulties, despite normal verbal IQ. Deletion mapping of the X-chromosome implicated 5 Mb of Xp11.3-4 as critical for recognition of facial fear, a quantitative measure of social cognition. Variability in fear recognition accuracy in Turner syndrome suggested the existence of a quantitative trait locus (QTL) revealed by X-monosomy. We aimed to identify the gene(s) influencing fear recognition by dense mapping of the 5 Mb region. Initial regression-based association mapping of fear recognition in 93 women with Turner syndrome across the critical region was performed, using genotype data at 242 single nucleotide polymorphisms (SNPs). We identified three regions of interest, in which 52 additional SNPs were genotyped. The third region then contained four SNPs associated with fear recognition (0.0030 > P > 0.00046). We obtained an independent sample of 77 Turner syndrome females that we genotyped for 77 SNPs in the initial regions of interest. Region three showed association in the same direction, maximal at SNPs rs7055196 and rs7887763 (P = 0.022 each). Four SNPs in strong linkage disequilibrium (LD), including this pair, span 40 kb within a novel transcript, EF-hand domain containing 2 (EFHC2). In the combined Turner syndrome samples, the most strongly associated SNP (P = 0.00007) has frequency of 8.8% and an estimated effect size accounting for over 13% of the variance in fear recognition. EFHC2 shows genealogy and extended LD consistent with directional selection. This novel QTL may influence social cognition in the general population and in autism.
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Affiliation(s)
- Lauren A Weiss
- Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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Kolb-Kokocinski A, Mehrle A, Bechtel S, Simpson JC, Kioschis P, Wiemann S, Wellenreuther R, Poustka A. The systematic functional characterisation of Xq28 genes prioritises candidate disease genes. BMC Genomics 2006; 7:29. [PMID: 16503986 PMCID: PMC1431524 DOI: 10.1186/1471-2164-7-29] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2005] [Accepted: 02/17/2006] [Indexed: 12/03/2022] Open
Abstract
Background Well known for its gene density and the large number of mapped diseases, the human sub-chromosomal region Xq28 has long been a focus of genome research. Over 40 of approximately 300 X-linked diseases map to this region, and systematic mapping, transcript identification, and mutation analysis has led to the identification of causative genes for 26 of these diseases, leaving another 17 diseases mapped to Xq28, where the causative gene is still unknown. To expedite disease gene identification, we have initiated the functional characterisation of all known Xq28 genes. Results By using a systematic approach, we describe the Xq28 genes by RNA in situ hybridisation and Northern blotting of the mouse orthologs, as well as subcellular localisation and data mining of the human genes. We have developed a relational web-accessible database with comprehensive query options integrating all experimental data. Using this database, we matched gene expression patterns with affected tissues for 16 of the 17 remaining Xq28 linked diseases, where the causative gene is unknown. Conclusion By using this systematic approach, we have prioritised genes in linkage regions of Xq28-mapped diseases to an amenable number for mutational screens. Our database can be queried by any researcher performing highly specified searches including diseases not listed in OMIM or diseases that might be linked to Xq28 in the future.
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Affiliation(s)
- Anja Kolb-Kokocinski
- Division of Molecular Genome Analysis, German Cancer Research Centre (DKFZ), Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
- Embryo Gene Expression Patterns, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Alexander Mehrle
- Division of Molecular Genome Analysis, German Cancer Research Centre (DKFZ), Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
| | - Stephanie Bechtel
- Division of Molecular Genome Analysis, German Cancer Research Centre (DKFZ), Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
| | - Jeremy C Simpson
- Cell Biology and Biophysics Programme, EMBL Heidelberg, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Petra Kioschis
- Institute of Molecular Biology and Cell Culture Technology, Mannheim University of Applied Sciences, Windeckstrasse 110, 68163 Mannheim, Germany
| | - Stefan Wiemann
- Division of Molecular Genome Analysis, German Cancer Research Centre (DKFZ), Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
| | - Ruth Wellenreuther
- Division of Molecular Genome Analysis, German Cancer Research Centre (DKFZ), Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
| | - Annemarie Poustka
- Division of Molecular Genome Analysis, German Cancer Research Centre (DKFZ), Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
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Allen RC, Russell SR, Streb LM, Alsheikheh A, Stone EM. Phenotypic heterogeneity associated with a novel mutation (Gly112Glu) in the Norrie disease protein. Eye (Lond) 2005; 20:234-41. [PMID: 15776010 DOI: 10.1038/sj.eye.6701840] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To determine the molecular pathology and clinical severity of two pedigrees with a history of early retinal detachment and peripheral retinal vascular abnormalities. DESIGN Longitudinal cohort study. METHODS A longitudinal clinical study and DNA analysis was performed on 49 family members of two pedigrees. RESULTS Nine individuals were found to be hemizygous for a mutation at codon 112 (Gly112Glu) of the Norrie disease protein (NDP) in one pedigree. Significant phenotypic heterogeneity was found. The proband presented with a unilateral subtotal retinal detachment at the age of 3 years, and subsequently developed a slowly progressive tractional retinal detachment involving the macula in the contralateral eye at the age of 4 years. One individual had only mild peripheral retinal pigmentary changes with normal vision at the age of 79 years. The remaining seven individuals had varying degrees of peripheral retinal vascular abnormalities and anterior segment findings. Seven affected members of a second pedigree affected by a previously reported mutation, Arg74Cys, also demonstrated wide ocular phenotypic variation. CONCLUSION A novel mutation (Gly112Glu), which represents the most carboxy located, NDP mutation reported, results in significant phenotypic heterogeneity. These data support the contention that the spectrum of ocular disease severity associated with these NDP mutations is broad. Use of terms that characterize this entity by phenotypic appearance, such as familial exudative vitreoretinopathy, do not adequately communicate the potential spectrum of severity of this disorder to affected or carrier family members.
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Affiliation(s)
- R C Allen
- Molecular Ophthalmology Laboratory, Center for Macular Degeneration, The University of Iowa Carver School of Medicine, Iowa City, IA 52242, USA
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Martin AC, Thornton JD, Liu J, Wang X, Zuo J, Jablonski MM, Chaum E, Zindy F, Skapek SX. Pathogenesis of persistent hyperplastic primary vitreous in mice lacking the arf tumor suppressor gene. Invest Ophthalmol Vis Sci 2004; 45:3387-96. [PMID: 15452040 PMCID: PMC1557705 DOI: 10.1167/iovs.04-0349] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Persistent hyperplastic primary vitreous (PHPV) is an idiopathic developmental eye disease associated with failed involution of the hyaloid vasculature. The present work addressed the pathogenesis of PHPV in a mouse model that replicates many aspects of the human disease. METHODS Ophthalmoscopic and histologic analyses documented pathologic processes in eyes of mice lacking the Arf gene compared with Ink4a-deficient and wild-type control animals. Immunohistochemical staining, in situ hybridization, and RT-PCR demonstrated the expression of relevant gene products. Arf gene expression was determined by in situ hybridization using wholemounts of wild-type mouse eyes and by immunofluorescence staining for green fluorescent protein (GFP) in Arf(+/GFP) heterozygous knock-in mouse eyes. RESULTS Abnormalities in Arf(-/-) mice mimicked those found in patients with severe PHPV. The mice had microphthalmia; fibrovascular, retrolental tissue containing retinal pigment epithelial cells and remnants of the hyaloid vascular system; posterior lens capsule destruction with lens degeneration and opacity; and severe retinal dysplasia and detachment. Eyes of mice lacking the overlapping Ink4a gene were normal. Arf was selectively expressed in perivascular cells within the vitreous of the postnatal eye. Cells composing the retrolental mass in Arf(-/-) mice expressed the Arf promoter. The remnant hyaloid vessels expressed Flk-1. Its ligand, vascular endothelial growth factor (Vegf), was expressed in the retrolental tissue and the adjacent dysplastic neuroretina. CONCLUSIONS Arf(-/-) mice have features that accurately mimic severe PHPV. In the HVS, Arf expression in perivascular cells may block their accumulation or repress Vegf expression to promote HVS involution and prevent PHPV.
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Affiliation(s)
- Amy C. Martin
- From the Departments of Hematology/Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - J. Derek Thornton
- From the Departments of Hematology/Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Jiewiu Liu
- From the Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - XiaoFei Wang
- From the Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee
- The Departments of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
- The Tennessee Mouse Genome Consortium, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Jian Zuo
- From the Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Monica M. Jablonski
- From the Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee
- The Departments of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
- The Tennessee Mouse Genome Consortium, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Edward Chaum
- From the Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Frederique Zindy
- From the Departments of Genetics and Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Stephen X. Skapek
- From the Departments of Hematology/Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee
- From the Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee
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Xu Q, Wang Y, Dabdoub A, Smallwood PM, Williams J, Woods C, Kelley MW, Jiang L, Tasman W, Zhang K, Nathans J. Vascular Development in the Retina and Inner Ear. Cell 2004; 116:883-95. [PMID: 15035989 DOI: 10.1016/s0092-8674(04)00216-8] [Citation(s) in RCA: 645] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2003] [Revised: 01/20/2004] [Accepted: 01/23/2004] [Indexed: 11/28/2022]
Abstract
Incomplete retinal vascularization occurs in both Norrie disease and familial exudative vitreoretinopathy (FEVR). Norrin, the protein product of the Norrie disease gene, is a secreted protein of unknown biochemical function. One form of FEVR is caused by defects in Frizzled-4 (Fz4), a presumptive Wnt receptor. We show here that Norrin and Fz4 function as a ligand-receptor pair based on (1) the similarity in vascular phenotypes caused by Norrin and Fz4 mutations in humans and mice, (2) the specificity and high affinity of Norrin-Fz4 binding, (3) the high efficiency with which Norrin induces Fz4- and Lrp-dependent activation of the classical Wnt pathway, and (4) the signaling defects displayed by disease-associated variants of Norrin and Fz4. These data define a Norrin-Fz4 signaling system that plays a central role in vascular development in the eye and ear, and they indicate that ligands unrelated to Wnts can act through Fz receptors.
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MESH Headings
- Animals
- Binding Sites/genetics
- Cells, Cultured
- Cerebellum/blood supply
- Cerebellum/cytology
- Cerebellum/growth & development
- Ear, Inner/blood supply
- Ear, Inner/cytology
- Ear, Inner/growth & development
- Eye Proteins/genetics
- Eye Proteins/metabolism
- Female
- Frizzled Receptors
- Humans
- LDL-Receptor Related Proteins
- Ligands
- Low Density Lipoprotein Receptor-Related Protein-5
- Male
- Mice
- Mice, Knockout
- Microscopy, Electron
- Mutation/genetics
- Neovascularization, Pathologic/genetics
- Neovascularization, Pathologic/pathology
- Neovascularization, Pathologic/physiopathology
- Nerve Tissue Proteins/deficiency
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Organ Culture Techniques
- Pedigree
- Proteins/genetics
- Proteins/metabolism
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, G-Protein-Coupled
- Receptors, LDL/genetics
- Receptors, LDL/metabolism
- Retinal Diseases/genetics
- Retinal Diseases/pathology
- Retinal Diseases/physiopathology
- Retinal Vessels/growth & development
- Retinal Vessels/metabolism
- Retinal Vessels/pathology
- Signal Transduction/genetics
- Wnt Proteins
- Zebrafish Proteins
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Affiliation(s)
- Qiang Xu
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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17
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Shastry BS, Trese MT. Overproduction and partial purification of the Norrie disease gene product, norrin, from a recombinant baculovirus. Biochem Biophys Res Commun 2004; 312:229-34. [PMID: 14630047 DOI: 10.1016/j.bbrc.2003.09.223] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abnormal vascularization of the peripheral retina and retinal detachment are common clinical characteristics of Norrie disease (ND), familial exudative vitreoretinopathy, Coats' disease, and retinopathy of prematurity. Although little is known about the molecular basis of these diseases, studies have shown that all of these diseases are associated with mutations in the ND gene. In spite of this, little is known about norrin, its molecular mechanism of action, and its functional relationship with the development of abnormal retinal vasculature. To obtain a large quantity of norrin for structural and functional studies, we have overproduced it in insect cells. For this purpose, a cDNA fragment (869 bp) was isolated from a human retinal cDNA library by amplification and was cloned into an expression vector. The purified plasmid was co-transfected with wild-type linearized Bac-N-Blue DNA into S. frugiperda Sf21 insect cells. The recombinant virus plaques were purified and clones were selected based on the level of recombinant protein expressed in Sf21 cells infected with a purified recombinant virus. From these, a high-titer stock was generated and subsequently used to prepare a fused protein on a large scale. The protein was partially purified by the process of immobilized metal affinity chromatography and the use of ion exchange chromatography
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Affiliation(s)
- Barkur S Shastry
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA.
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18
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Juan HF, Lin JYC, Chang WH, Wu CY, Pan TL, Tseng MJ, Khoo KH, Chen ST. Biomic study of human myeloid leukemia cells differentiation to macrophages using DNA array, proteomic, and bioinformatic analytical methods. Electrophoresis 2002; 23:2490-504. [PMID: 12210208 DOI: 10.1002/1522-2683(200208)23:15<2490::aid-elps2490>3.0.co;2-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A biomic approach by integrating three independent methods, DNA microarray, proteomics and bioinformatics, is used to study the differentiation of human myeloid leukemia cell line HL-60 into macrophages when induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Analysis of gene expression changes at the RNA level using cDNA against an array of 6033 human genes showed that 5950 (98.6%) of the genes were expressed in the HL-60 cells. A total of 624 genes (10.5%) were found to be regulated during HL-60 cell differentiation. Most of these genes have not been previously associated with HL-60 cells and include genes encoded for secreted proteins as well as genes involved in cell adhesion, signaling transduction, and metabolism. Protein analysis using two-dimensional gel electrophoresis showed a total of 682 distinct protein spots; 136 spots (19.9%) exhibited quantitative changes between HL-60 control and macrophages. These differentially expressed proteins were identified by mass spectrometry. We developed a bioinformatics program, the Bulk Gene Search System (BGSS, http://www.sinica.edu.tw:8900/perl/genequery.pl) to search for the functions of genes and proteins identified by cDNA microarrays and proteomics. The identified regulated proteins and genes were classified into seven groups according to subcellular locations and functions. This powerful holistic biomic approach using cDNA microarray, proteomics coupled to bioinformatics can provide in-depth information on the impact and importance of the regulated genes and proteins for HL-60 differentiation.
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Affiliation(s)
- Hsueh-Fen Juan
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
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19
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Abstract
Deafness is the most common sensory hereditary disorder. It is a genetically heterogeneous and multifactorial disease affecting approximately 1 infant in 2000. It can be acquired or congenital and can also be syndromic or nonsyndromic. There are approximately 70 genetic loci that have been described for nonsyndromic deafness in humans and 25 auditory-pigmentary diseases in mice. The past 2 years have witnessed remarkable progress in identifying the genes involved in both syndromic and nonsyndromic disorders in humans and mice. Many of these are expressed in the inner ear and are most likely involved in cochlear physiology and development. However, the phenotypic variability in patients carrying the same genetic change, and discrepancies between the phenotypes of mice and humans carrying the same gene defect, emphasize environmental factors and interacting genes in producing the clinical outcome. In the future, molecular understanding of the etiology of the disorder may lead to a cure or delay the onset of the disorder.
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Affiliation(s)
- B S Shastry
- Eye Research Institute, Oakland University, Rochester, Michigan 48309, USA
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