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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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Jiang K, Wang S, Sun H, Peng C, Li N, Li S, Gao R, Zhang J. Novel mutation in the NDP gene associated with Norrie disease in a Chinese pedigree. Mol Genet Genomic Med 2024; 12:e2345. [PMID: 38146894 PMCID: PMC10767683 DOI: 10.1002/mgg3.2345] [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: 07/06/2023] [Revised: 11/08/2023] [Accepted: 12/07/2023] [Indexed: 12/27/2023] Open
Abstract
PURPOSE Norrie disease (ND) is a rare X-linked recessive disorder characteristic of early childhood blindness. While several mutations in the NDP gene have been reported as causative for ND, the genetic etiology remains unknown for many patients. This study aims to describe a novel mutation and explore the clinical manifestations in a Chinese family with two affected males. METHODS Exome sequencing (ES) was employed to identify the causative gene in a four-generation pedigree. Sanger sequencing was subsequently utilized to validate the mutation detected by ES in additional family members. Ophthalmologic examination and diagnostic imaging relevant to ND were conducted. RESULTS The proband (IV:2), an 8-month-old male infant, presented with binocular retinal detachment. DNA sequencing revealed a novel heterozygous missense mutation (c.174G>C) within the NDP gene in the proband. This mutation affected highly conserved residues and was predicted to disrupt the normal protein structure. Furthermore, the variant co-segregated with the disease phenotypes within the family. CONCLUSIONS Our findings identified a novel missense mutation in the NDP gene associated with Norrie disease in China, expanding the mutation spectrum associated with ND. This discovery holds diagnostic, prognostic, and genetic counseling implications for affected individuals.
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Affiliation(s)
- Keke Jiang
- Department of Ophthalmology, Zhengda Guangming Ophthalmology GroupWeifang Eye HospitalWeifangChina
| | - Shuying Wang
- Department of OphthalmologyGaomi People's HospitalWeifangChina
| | - Huixin Sun
- Department of OphthalmologyWeifang Medical UniversityWeifangChina
| | - Chuanzhi Peng
- Department of OphthalmologyWeifang Medical UniversityWeifangChina
| | - Nan Li
- Department of Ophthalmology, Zhengda Guangming Ophthalmology GroupWeifang Eye HospitalWeifangChina
| | - Shuchan Li
- Department of Ophthalmology, Zhengda Guangming Ophthalmology GroupWeifang Eye HospitalWeifangChina
| | - Rongyu Gao
- Department of Ophthalmology, Zhengda Guangming Ophthalmology GroupWeifang Eye HospitalWeifangChina
| | - Jie Zhang
- Department of Ophthalmology, Zhengda Guangming Ophthalmology GroupWeifang Eye HospitalWeifangChina
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Miraldi Utz V, Ebert JJ, Brightman DS, Simpson BN, Benoit S, Sisk RA. Dual phenotype: co-occurring Leber congenital amaurosis and familial exudative vitreoretinopathy: a case report. Ophthalmic Genet 2023; 44:89-92. [PMID: 36426739 DOI: 10.1080/13816810.2022.2090011] [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: 11/27/2022]
Abstract
PURPOSE To report the concurrent presentation and management of IQCB1-associated Leber Congenital Amaurosis and NDP-associated Familial Exudative Vitreoretinopathy (FEVR). MATERIALS AND METHODS A 6-month-old Caucasian infant presented with poor visual response, high hypermetropia, and infantile-nystagmus with a provisional diagnosis of Leber Congenital Amaurosis based on clinical findings. Genetic counseling and testing were performed with a 285 gene retinal dystrophy panel (Blueprint Genetics). Clinical characteristics, presentation, ancillary testing results, and management are described. RESULTS Two previously reported heterozygous pathogenic variants in ICQB1 were identified (c.1518_1519del (p.His506Glnfs*13) and c.1381C>T, p.Arg461*) segregating in trans. In addition, a variation of uncertain significance (VUS) was found in NDP (c.280C>T; p.His94Tyr). Fluorescein angiography was performed demonstrating peripheral avascularity and retinal telangiectasia without frank neovascularization. Peripheral ablative laser was applied to the avascular zone. CONCLUSIONS The NDP VUS likely represents a pathogenic variant given the FEVR phenotype in addition to retinal degeneration, creating a rare dual phenotype. The combination of low oxygen demand from the IQCB1-associated retinal degeneration and NDP variant may have led to a more attenuated FEVR presentation with uncertain prognosis. A molecular diagnosis informed ocular and renal surveillance, as well as the recurrence risk for future offspring.
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Affiliation(s)
- Virginia Miraldi Utz
- Abrahamson Pediatric Eye Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Ophthalmology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Jared J Ebert
- Department of Ophthalmology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Diana S Brightman
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Brittany N Simpson
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA
| | - Stefanie Benoit
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA.,Division of Nephrology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Robert A Sisk
- Abrahamson Pediatric Eye Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Ophthalmology, University of Cincinnati, Cincinnati, Ohio, USA.,Cincinnati Eye Institute, Cincinnati, Ohio, USA
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Whole exome sequencing revealed 14 variants in NDP, FZD4, LRP5, and TSPAN12 genes for 20 families with familial exudative vitreoretinopathy. BMC Med Genomics 2022; 15:54. [PMID: 35277167 PMCID: PMC8915523 DOI: 10.1186/s12920-022-01204-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 03/02/2022] [Indexed: 12/13/2022] Open
Abstract
Abstract
Background
Familial exudative vitreoretinopathy (FEVR) is a complex form of blindness-causing retinal degeneration. This study investigated the potential disease-causing variants in 20 Chinese families with FEVR.
Methods
All available family members underwent detailed ophthalmological examinations, including best-corrected visual acuity and fundus examination. All probands and most family members underwent fluorescein fundus angiography. Twenty probands underwent whole exome sequencing; 16 of them also underwent copy number variant and mitochondrial genome analysis. Bioinformatics analysis and Sanger sequencing of available family members were used to confirm the disease-causing gene variant.
Results
Twenty families were diagnosed with FEVR based on clinical symptoms, fundus manifestations, and fundus fluorescein angiography. Whole exome sequencing revealed 14 variants in NDP, FZD4, LRP5, and TSPAN12 genes among the 13 families. These variants were predicted to be damaging or deleterious according to multiple lines of prediction algorithms; they were not frequently found in multiple population databases. Seven variants had not previously been reported to cause FEVR: c.1039T>G p.(Phe347Val) in the FZD4 gene; c.1612C>T p.(Arg538Trp) and c.3237-2A>C in the LRP5 gene; and c.77T>A p.(Ile26Asn), c.170dupT p.(Leu57Phe fsTer60), c.236T>G p.(Met79Arg) and c.550dupA p.(Arg184Lys fsTer16) in the TSPAN12 gene. We did not detect any variants in the remaining seven families.
Conclusions
These results expand the spectrum of variants in the NDP, FZD4, LRP5, and TSPAN12 genes and provide insights regarding accurate diagnosis, family genetic counseling, and future gene therapy for FEVR.
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Canonical Wnt Signaling in the Pathology of Iron Overload-Induced Oxidative Stress and Age-Related Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:7163326. [PMID: 35116092 PMCID: PMC8807048 DOI: 10.1155/2022/7163326] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/04/2022] [Indexed: 12/26/2022]
Abstract
Iron accumulates in the vital organs with aging. This is associated with oxidative stress, inflammation, and mitochondrial dysfunction leading to age-related disorders. Abnormal iron levels are linked to neurodegenerative diseases, liver injury, cancer, and ocular diseases. Canonical Wnt signaling is an evolutionarily conserved signaling pathway that regulates many cellular functions including cell proliferation, apoptosis, cell migration, and stem cell renewal. Recent evidences indicate that iron regulates Wnt signaling, and iron chelators like deferoxamine and deferasirox can inhibit Wnt signaling and cell growth. Canonical Wnt signaling is implicated in the pathogenesis of many diseases, and there are significant efforts ongoing to develop innovative therapies targeting the aberrant Wnt signaling. This review examines how intracellular iron accumulation regulates Wnt signaling in various tissues and their potential contribution in the progression of age-related diseases.
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Peng Y, Zhao R, Dai E, Peng L, He Y, Li S, Yang M. Whole-Exome Sequencing Reveals Novel NDP Variants in X-Linked Familial Exudative Vitreoretinopathy. Eur J Ophthalmol 2022; 32:3220-3226. [PMID: 35037517 DOI: 10.1177/11206721221074209] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
PURPOSE To investigate causative variants in three Chinese families affected with familial exudative vitreoretinopathy (FEVR). METHODS Three unrelated Chinese families were recruited in this study. The three probands and their family members experienced a comprehensive age-appropriate eye examination and genetic analysis. Luciferase assay was performed to evaluate impacts of variants on Norrin/β-catenin signaling activity. RESULTS Here we report two novel NDP variants associated with FEVR in three families, including c.17T>C (p.Leu6Pro) in family 1 and c.58G>A (p.Gly20Arg) in family 2 and 3. These two variants were co-segregated with the disease phenotypes within each family. In addition, both variants resulted in compromised Norrin/β-catenin signaling activity. CONCLUSION Our study identified two FEVR-associated pathogenic variants in NDP, which expanded the variant spectrum and provided information for the genetic diagnosis of FEVR.
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Affiliation(s)
- Yujiao Peng
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, 12599University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & 89669Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
| | - Rulian Zhao
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, 12599University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & 89669Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
| | - Erkuan Dai
- Ophthalmology, 91603Shanghai Jiaotong University School of Medicine Xinhua Hospital, Shanghai, China
| | - Li Peng
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, 12599University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & 89669Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
- Chinese Academy of Sciences Sichuan Translational Medicine Hospital, Chengdu, Sichuan, China
| | - Yunqi He
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, 12599University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & 89669Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
- Chinese Academy of Sciences Sichuan Translational Medicine Hospital, Chengdu, Sichuan, China
| | - Shujin Li
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, 12599University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & 89669Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
- Chinese Academy of Sciences Sichuan Translational Medicine Hospital, Chengdu, Sichuan, China
| | - Mu Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, 12599University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & 89669Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
- Chinese Academy of Sciences Sichuan Translational Medicine Hospital, Chengdu, Sichuan, China
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Chen J, Yang J, Ding J. Rational construction of polycystine-based nanoparticles for biomedical applications. J Mater Chem B 2022; 10:7173-7182. [PMID: 35662309 DOI: 10.1039/d2tb00581f] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polypeptide-based nanoparticles are one of the promising excipients of nanomedicines due to their excellent biosafety and flexible modification. Among all the types of polypeptide nanoparticles, polycystine (PCys2)-based ones draw increasing...
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Affiliation(s)
- Jinjin Chen
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, 107 Yanjiang West Road, Guangzhou 510120, P. R. China
| | - Jiazhen Yang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, P. R. China
| | - Jianxun Ding
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, P. R. China
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8
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Jia LY, Ma K. Novel Norrie disease gene mutations in Chinese patients with familial exudative vitreoretinopathy. BMC Ophthalmol 2021; 21:84. [PMID: 33588793 PMCID: PMC7885586 DOI: 10.1186/s12886-021-01852-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 02/04/2021] [Indexed: 01/22/2023] Open
Abstract
Purpose This study aims to analyze the Norrie disease gene (NDP) variants in patients with familial exudative vitreoretinopathy (FEVR) and their clinical features. Methods Thirty-three Chinese patients (22 familial and 11 simplex) who were diagnosed as FEVR underwent detailed ocular examinations in Beijing Tongren Hospital. Peripheral venous blood was drawn from the patients and their family members for the extraction of genomic DNA. All exons of NDP gene were analyzed by direct sequencing of PCR-amplified DNA fragments. Results Four novel mutations in NDP gene were identified in four X-linked FEVR families: a C → T transversion, c. 625C → T, in exon 3, resulting in a serine-to-proline change in codon 73 (S73P); a C → G transition, c. 751C → G, in exon 3, resulting in an arginine-to-glycine change in codon 115 (R115G); a T → C transversion of nucleotide 331 at 5’UTR in exon 2 (c.331 T → C); and a C → T transversion of the nucleotide 5 in intron 1 (IVS1 + 5C → T). The mutations were not present in the control group (n = 100). Conclusions Our results extend the spectrum of NDP gene mutations. The mutations in the non-coding region of NDP may play a crucial role in the pathogenesis of FEVR.
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Affiliation(s)
- Li-Yun Jia
- Beijing Tongren Hospital, Capital Medical University, Beijing, China.
| | - Kai Ma
- Beijing Tongren Hospital, Capital Medical University, Beijing, China
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Zhu X, Sun K, Huang L, Ma S, Hao F, Yang Z, Sundaresan P, Zhu X. Identification of Novel Mutations in the FZD4 and NDP Genes in Patients with Familial Exudative Vitreoretinopathy in South India. Genet Test Mol Biomarkers 2020; 24:92-98. [PMID: 31999491 DOI: 10.1089/gtmb.2019.0212] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Background: Familial exudative vitreoretinopathy (FEVR) is an inheritable retinal vascular disease, which often leads to severe vision loss and blindness in children. However, reported mutations can only account for 50-60% of patients with FEVR. The purpose of this study was to identify novel frizzled class receptor 4 (FZD4) and Norrin cystine knot growth factor NDP (NDP) mutations in a cohort of Indian patients with FEVR by whole-exome sequencing. Methods: We performed data filtering and bioinformatic analyses. Results: Two novel heterozygous mutations in FZD4 gene were identified, each in two different families: c.1499_1500del [p.500_500del] and c.G296C [p.C99S]. One novel mutation in NDP in another family was identified: c.A256G [p.K86E]. All FZD4 mutations affected conserved amino acid residues and were absent in 1000 control individuals. To assess the effect of these FZD4 mutations on the biological activity of the protein, we introduced each FZD4 mutation into FZD4 cDNA by the site-directed mutagenesis techniques. A Norrin/beta-catenin pathway-based luciferase reporter assay revealed that the c.1499_1500del failed to activate the luciferase reporter; in contrast, compared with the wild-type FZD4 protein, the, c.G296C [p.C99S] mutation exhibited increased luciferase reporter activity. Conclusion: Our study found two novel FZD4 mutations, with opposite effects regarding functional expression levels in Indian patients with FEVR and expands on the mutational spectrum of FZD4 in Indian FEVR patients.
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Affiliation(s)
- Xiong Zhu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Kuanxiang Sun
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Lulin Huang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Shi Ma
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Fang Hao
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Zhenglin Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China.,Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Periasamy Sundaresan
- Department of Genetics, Aravind Medical Research Foundation, Aravind Eye Hospital, Madurai, India
| | - Xianjun Zhu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China.,Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
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Díaz-Coránguez M, Lin CM, Liebner S, Antonetti DA. Norrin restores blood-retinal barrier properties after vascular endothelial growth factor-induced permeability. J Biol Chem 2020; 295:4647-4660. [PMID: 32086377 DOI: 10.1074/jbc.ra119.011273] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 02/11/2020] [Indexed: 12/25/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) contributes to blood-retinal barrier (BRB) dysfunction in several blinding eye diseases, including diabetic retinopathy. Signaling via the secreted protein norrin through the frizzled class receptor 4 (FZD4)/LDL receptor-related protein 5-6 (LRP5-6)/tetraspanin 12 (TSPAN12) receptor complex is required for developmental vascularization and BRB formation. Here, we tested the hypothesis that norrin restores BRB properties after VEGF-induced vascular permeability in diabetic rats or in animals intravitreally injected with cytokines. Intravitreal co-injection of norrin with VEGF completely ablated VEGF-induced BRB permeability to Evans Blue-albumin. Likewise, 5-month diabetic rats exhibited increased permeability of FITC-albumin, and a single norrin injection restored BRB properties. These results were corroborated in vitro, where co-stimulation of norrin with VEGF or stimulation of norrin after VEGF exposure restored barrier properties, indicated by electrical resistance or 70-kDa RITC-dextran permeability in primary endothelial cell culture. Interestingly, VEGF promoted norrin signaling by increasing the FZD4 co-receptor TSPAN12 at cell membranes in an MAPK/ERK kinase (MEK)/ERK-dependent manner. Norrin signaling through β-catenin was required for BRB restoration, but glycogen synthase kinase 3 α/β (GSK-3α/β) inhibition did not restore BRB properties. Moreover, levels of the tight junction protein claudin-5 were increased with norrin and VEGF or with VEGF alone, but both norrin and VEGF were required for enriched claudin-5 localization at the tight junction. These results suggest that VEGF simultaneously induces vascular permeability and promotes responsiveness to norrin. Norrin, in turn, restores tight junction complex organization and BRB properties in a β-catenin-dependent manner.
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Affiliation(s)
- Mónica Díaz-Coránguez
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48105
| | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48105
| | - Stefan Liebner
- Institute of Neurology (Edinger Institute), University Hospital, Goethe University, 60538 Frankfurt, Germany
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48105
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Familial Exudative Vitreoretinopathy-Related Disease-Causing Genes and Norrin/ β-Catenin Signal Pathway: Structure, Function, and Mutation Spectrums. J Ophthalmol 2019; 2019:5782536. [PMID: 31827910 PMCID: PMC6885210 DOI: 10.1155/2019/5782536] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 09/07/2019] [Accepted: 09/26/2019] [Indexed: 02/06/2023] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) is a hereditary ocular disorder characterized by incomplete vascularization/abnormality of peripheral retina. Four of the identified disease-causing genes of FEVR were NDP, FZD4, LRP5, and TSPAN12, the protein coded by which were the components of the Norrin/β-catenin signal pathway. In this review, we summarized and discussed the spectrum of mutations involving these four genes. By the end of 2017, the number of FEVR causing mutations reported for NDP, FZD4, LRP5, and TSPAN12 was, respectively, 26, 121, 58, and 40. Three most frequently reported mutations were c. 362G > A (p.R121Q) of NDP, c. 313A > G (p.M105V), and c.1282_1285delGACA (p.D428SfsX2) of FZD4. Mutations have a tendency to cluster in some “hotspots” domains which may be responsible for protein interactions.
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12
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Wang Z, Liu CH, Huang S, Chen J. Wnt Signaling in vascular eye diseases. Prog Retin Eye Res 2018; 70:110-133. [PMID: 30513356 DOI: 10.1016/j.preteyeres.2018.11.008] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 11/21/2018] [Accepted: 11/28/2018] [Indexed: 12/16/2022]
Abstract
The Wnt signaling pathway plays a pivotal role in vascular morphogenesis in various organs including the eye. Wnt ligands and receptors are key regulators of ocular angiogenesis both during the eye development and in vascular eye diseases. Wnt signaling participates in regulating multiple vascular beds in the eye including regression of the hyaloid vessels, and development of structured layers of vasculature in the retina. Loss-of-function mutations in Wnt signaling components cause rare genetic eye diseases in humans such as Norrie disease, and familial exudative vitreoretinopathy (FEVR) with defective ocular vasculature. On the other hand, experimental studies in more prevalent vascular eye diseases, such as wet age-related macular degeneration (AMD), diabetic retinopathy (DR), retinopathy of prematurity (ROP), and corneal neovascularization, suggest that aberrantly increased Wnt signaling is one of the causations for pathological ocular neovascularization, indicating the potential of modulating Wnt signaling to ameliorate pathological angiogenesis in eye diseases. This review recapitulates the key roles of the Wnt signaling pathway during ocular vascular development and in vascular eye diseases, and pharmaceutical approaches targeting the Wnt signaling as potential treatment options.
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Affiliation(s)
- Zhongxiao Wang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, United States
| | - Chi-Hsiu Liu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, United States
| | - Shuo Huang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, United States
| | - Jing Chen
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, United States.
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Aponte-Santamaría C, Obser T, Grässle S, Oyen F, Budde U, Schneppenheim S, Baldauf C, Gräter F, Schneider SW, Schneppenheim R, Brehm MA, Huck V. von Willebrand disease type 2A phenotypes IIC, IID and IIE: A day in the life of shear-stressed mutant von Willebrand factor. Thromb Haemost 2017; 112:96-108. [DOI: 10.1160/th13-11-0902] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 02/11/2014] [Indexed: 11/05/2022]
Abstract
SummaryThe bleeding disorder von Willebrand disease (VWD) is caused by mutations of von Willebrand factor (VWF), a multimeric glycoprotein essential for platelet-dependent primary haemostasis. VWD type 2A–associated mutations each disrupt VWF biosynthesis and function at different stages, depending on the VWF domain altered by the mutation. These effects cause considerable heterogeneity in phenotypes and symptoms. To characterise the molecular mechanisms underlying the specific VWF deficiencies in VWD 2A/IIC, IID and IIE, we investigated VWF variants with patient-derived mutations either in the VWF pro-peptide or in domains D3 or CK. Additionally to static assays and molecular dynamics (MD) simulations we used microfluidic approaches to perform a detailed investigation of the shear-dependent function of VWD 2A mutants. For each group, we found distinct characteristics in their intracellular localisation visualising specific defects in biosynthesis which are correlated to respective multimer patterns. Using microfluidic assays we further determined shear flow-dependent characteristics in polymer-platelet-aggregate formation, platelet binding and string formation for all mutants. The phenotypes observed under flow conditions were not related to the mutated VWF domain. By MD simulations we further investigated how VWD 2A/IID mutations might alter the ability of VWF to form carboxy-terminal dimers. In conclusion, our study offers a comprehensive picture of shear-dependent and shear-independent dysfunction of VWD type 2A mutants. Furthermore, our microfluidic assay might open new possibilities for diagnosis of new VWD phenotypes and treatment choice for VWD patients with shear-dependent VWF dysfunctions that are currently not detectable by static tests.
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Huang X, Tian M, Li J, Cui L, Li M, Zhang J. Next-generation sequencing reveals a novel NDP gene mutation in a Chinese family with Norrie disease. Indian J Ophthalmol 2017; 65:1161-1165. [PMID: 29133643 PMCID: PMC5700585 DOI: 10.4103/ijo.ijo_442_17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 08/28/2017] [Indexed: 01/08/2023] Open
Abstract
PURPOSE Norrie disease (ND) is a rare X-linked genetic disorder, the main symptoms of which are congenital blindness and white pupils. It has been reported that ND is caused by mutations in the NDP gene. Although many mutations in NDP have been reported, the genetic cause for many patients remains unknown. In this study, the aim is to investigate the genetic defect in a five-generation family with typical symptoms of ND. METHODS To identify the causative gene, next-generation sequencing based target capture sequencing was performed. Segregation analysis of the candidate variant was performed in additional family members using Sanger sequencing. RESULTS We identified a novel missense variant (c.314C>A) located within the NDP gene. The mutation cosegregated within all affected individuals in the family and was not found in unaffected members. By happenstance, in this family, we also detected a known pathogenic variant of retinitis pigmentosa in a healthy individual. CONCLUSION c.314C>A mutation of NDP gene is a novel mutation and broadens the genetic spectrum of ND.
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Affiliation(s)
- Xiaoyan Huang
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China
- BGI-Shenzhen, Shenzhen 518083, China
- Department of Obstetrics, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, China
| | - Mao Tian
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, China
| | - Jiankang Li
- BGI-Shenzhen, Shenzhen 518083, China
- Department of Obstetrics, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, China
| | - Ling Cui
- National GeneBank, BGI-Shenzhen, Shenzhen 518120, China
| | - Min Li
- National GeneBank, BGI-Shenzhen, Shenzhen 518120, China
| | - Jianguo Zhang
- BGI-Shenzhen, Shenzhen 518083, China
- Department of Obstetrics, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, China
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15
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Andarva M, Jamshidi J, Ghaedi H, Daftarian N, Emamalizadeh B, Alehabib E, Taghavi S, Pouriran R, Darvish H. A novel c.240_241insGG mutation in NDP gene in a family with Norrie disease. Clin Exp Optom 2017; 101:255-259. [PMID: 28922694 DOI: 10.1111/cxo.12599] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 03/25/2017] [Accepted: 05/17/2017] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Norrie disease (ND) is a rare, X-linked recessive disorder with the main characteristic of early childhood blindness. The aim of the present study was to identify the genetic cause of the disease and the phenotypic characteristics of the patients in an Iranian family with four affected males with ND. METHODS Norrie disease pseudoglioma (NDP) gene was sequenced and clinical examination was performed on patients. RESULTS A GG dinucleotide insertion in exon 3 (c.240_241insGG) of NDP was detected in all patients. The mutation caused a frameshift and an early stop codon (p.Phe81Glyfs*23). CONCLUSIONS A novel mutation was found in the NDP gene in the affected males of the family. As the mutation was absent in the normal male members of the family, it should be the genetic cause of the disease.
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Affiliation(s)
- Monavvar Andarva
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Javad Jamshidi
- Noncommunicable Diseases Research Center, Fasa University of Medical Sciences, Fasa, Iran
| | - Hamid Ghaedi
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Narsis Daftarian
- Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Babak Emamalizadeh
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Elham Alehabib
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shaghyegh Taghavi
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ramin Pouriran
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Darvish
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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16
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Löf A, Müller JP, Benoit M, Brehm MA. Biophysical approaches promote advances in the understanding of von Willebrand factor processing and function. Adv Biol Regul 2017; 63:81-91. [PMID: 27717713 DOI: 10.1016/j.jbior.2016.09.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 09/19/2016] [Indexed: 06/06/2023]
Abstract
The large multimeric plasma glycoprotein von Willebrand factor (VWF) is essential for primary hemostasis by recruiting platelets to sites of vascular injury. VWF multimers respond to elevated hydrodynamic forces by elongation, thereby increasing their adhesiveness to platelets. Thus, the activation of VWF is force-induced, as is its inactivation. Due to these attributes, VWF is a highly interesting system from a biophysical point of view, and is well suited for investigation using biophysical approaches. Here, we give an overview on recent studies that predominantly employed biophysical methods to gain novel insights into multiple aspects of VWF: Electron microscopy was used to shed light on the domain structure of VWF and the mechanism of VWF secretion. High-resolution stochastic optical reconstruction microscopy, atomic force microscopy (AFM), microscale thermophoresis and fluorescence correlation spectroscopy allowed identification of protein disulfide isomerase isoform A1 as the VWF dimerizing enzyme and, together with molecular dynamics simulations, postulation of the dimerization mechanism. Advanced mass spectrometry led to detailed identification of the glycan structures carried by VWF. Microfluidics was used to illustrate the interplay of force and VWF function. Results from optical tweezers measurements explained mechanisms of the force-dependent functions of VWF's domains A1 and A2 and, together with thermodynamic approaches, increased our understanding of mutation-induced dysfunctions of platelet-binding. AFM-based force measurements and AFM imaging enabled exploration of intermonomer interactions and their dependence on pH and divalent cations. These advances would not have been possible by the use of biochemical methods alone and show the benefit of interdisciplinary research approaches.
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Affiliation(s)
- Achim Löf
- Department of Physics and Center for NanoScience, LMU Munich, Munich, Germany
| | - Jochen P Müller
- Department of Physics and Center for NanoScience, LMU Munich, Munich, Germany
| | - Martin Benoit
- Department of Physics and Center for NanoScience, LMU Munich, Munich, Germany
| | - Maria A Brehm
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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17
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Kondo H. Complex genetics of familial exudative vitreoretinopathy and related pediatric retinal detachments. Taiwan J Ophthalmol 2015; 5:56-62. [PMID: 29018668 PMCID: PMC5602728 DOI: 10.1016/j.tjo.2015.04.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/31/2015] [Accepted: 04/13/2015] [Indexed: 11/19/2022] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) is a hereditary vitreoretinal disorder that can cause various types of retinal detachments. The abnormalities in eyes with FEVR are caused by poor vascularization in the peripheral retina. The genetics of FEVR is highly heterogeneous, and mutations in the genes for Wnt signaling and a transcription factor have been reported to be responsible for FEVR. These factors have been shown to be the regulators of the pathophysiological pathways of retinal vascular development. Studies conducted to identify the causative genes of FEVR have uncovered a diverse and complex relationship between FEVR and other diseases; for example, Norrie disease, a Mendelian-inherited disease; retinopathy of prematurity, a multifactorial genetic disease; and Coats disease, a nongenetic disease, associated with pediatric retinal detachments.
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Affiliation(s)
- Hiroyuki Kondo
- Department of Ophthalmology, University of Occupational and Environmental Health, Kitakyushu, Japan
- Corresponding author. Department of Ophthalmology, University of Occupational and Environmental Health, Number 1-1, Iseigaoka, Yahatanishiku, Kitakyushu 807-8555, Japan. E-mail address:
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18
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Parzefall T, Lucas T, Ritter M, Ludwig M, Ramsebner R, Frohne A, Schöfer C, Hengstschläger M, Frei K. A novel missense NDP mutation [p.(Cys93Arg)] with a manifesting carrier in an austrian family with Norrie disease. Audiol Neurootol 2014; 19:203-9. [PMID: 24801666 DOI: 10.1159/000358866] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 01/17/2014] [Indexed: 11/19/2022] Open
Abstract
Norrie disease is a rare, X-linked genetic syndrome characterized by combined congenital blindness and progressive hearing impairment. Norrie disease is caused by alterations in the NDP gene encoding the growth factor norrin that plays a key role in vascular development and stabilization of the eye, inner ear and brain. We identified a family with 3 affected deafblind males and a single female carrier presenting with a serous retinal detachment but normal hearing. Genetic analysis revealed a novel c.277T>C missense mutation causing the substitution of a hydrophobic cysteine to a hydrophilic arginine [p.(Cys93Arg)] within the highly conserved cysteine knot domain of the norrin protein. These results should expand the scope for amniocentesis and genetic testing for Norrie disease which is gaining in importance due to novel postnatal therapeutic concepts to alleviate the devastating retinal symptoms of Norrie disease.
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Affiliation(s)
- Thomas Parzefall
- Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria
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19
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Mikhail S, Aldin ES, Streiff M, Zeidan A. An update on type 2B von Willebrand disease. Expert Rev Hematol 2014; 7:217-31. [PMID: 24521271 DOI: 10.1586/17474086.2014.868771] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Type 2B von Willebrand disease (VWD) accounts for fewer than 5% of all VWD patients. In this disease, mutations in the A1 domain result in increased von Willebrand factor (VWF) binding to platelet GPIbα receptors, causing increased platelet clearance and preferential loss of high molecular weight VWF multimers. Diagnosis is complicated because of significant clinical variations even among patients with identical mutations. Platelet transfusion often provides suboptimal results since transfused platelets may be aggregated by the patients' abnormal VWF. Desmopressin may cause a transient decrease in platelet count that could lead to an increased risk of bleeding. Replacement therapy with factor VIII/VWF concentrates is the most effective approach to prevention and treatment of bleeding in type 2B VWD.
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Affiliation(s)
- Sameh Mikhail
- Department of Hematology, Ohio State University Medical Center, Columbus, OH, USA
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20
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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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21
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Highly reinforced structure of a C-terminal dimerization domain in von Willebrand factor. Blood 2014; 123:1785-93. [PMID: 24394662 DOI: 10.1182/blood-2013-11-523639] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The C-terminal cystine knot (CK) (CTCK) domain in von Willebrand factor (VWF) mediates dimerization of proVWF in the endoplasmic reticulum and is essential for long multimers required for hemostatic function. The CTCK dimer crystal structure reveals highly elongated monomers with 2 β-ribbons and 4 intra-chain disulfides, including 3 in the CK. Dimerization buries an extensive interface of 1500 Å(2) corresponding to 32% of the surface of each monomer and forms a super β-sheet and 3 inter-chain disulfides. The shape, dimensions, and N-terminal connections of the crystal structure agree perfectly with previous electron microscopic images of VWF dimeric bouquets with the CTCK dimer forming a down-curved base. The dimer interface is suited to resist hydrodynamic force and disulfide reduction. CKs in each monomer flank the 3 inter-chain disulfides, and their presence in β-structures with dense backbone hydrogen bonds creates a rigid, highly crosslinked interface. The structure reveals the basis for von Willebrand disease phenotypes and the fold and disulfide linkages for CTCK domains in diverse protein families involved in barrier function, eye and inner ear development, insect coagulation and innate immunity, axon guidance, and signaling in extracellular matrices.
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22
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Zhang XY, Jiang WY, Chen LM, Chen SQ. A novel Norrie disease pseudoglioma gene mutation, c.-1_2delAAT, responsible for Norrie disease in a Chinese family. Int J Ophthalmol 2013; 6:739-43. [PMID: 24392318 DOI: 10.3980/j.issn.2222-3959.2013.06.01] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 09/26/2013] [Indexed: 11/02/2022] Open
Abstract
AIM To investigate the genetic findings and phenotypic characteristics of a Chinese family with Norrie disease (ND). METHODS Molecular genetic analysis and clinical examinations were performed on a Chinese family with ND. Mutations in the Norrie disease pseudoglioma (NDP) gene were detected by direct sequencing. Haplotypes were constructed and compared with the phenotypes in the family. Evolutionary comparisons and mutant open reading frame (ORF) prediction were also undertaken. RESULTS Two family members with ocular manifestations were diagnosed with ND. No signs of sensorineural hearing loss were observed in either patient, while one of them showed signs of mild mental retardation. A novel heterozygous mutation in the NDP gene, c.-1_2delAAT, was detected in both patients. The mutation and the mutation bearing haplotype co-segregated with the ND phenotype in males and was transmitted from their mothers and/or grandmothers (II:2). The male without ND did not harbor the mutation. The mutation occurred at the highly conserved nucleotides. ORF finder predicted that the mutation would lead to the production of a truncated protein that lacks the first 11 N-terminal amino acids. CONCLUSION A novel mutation, c.-1_2delAAT in the NDP gene, was identified in a Chinese family with ND. This mutation caused ND without obvious sensorineural hearing loss. Mental disorder was found in one but not the other patients. The clinical heterogeneity in the family indicated that other genetic variants and epigenetic factors may also play a role in the disease presentation.
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Affiliation(s)
- Xin-Yu Zhang
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, Guangdong Province, China
| | - Wei-Ying Jiang
- Department of Medical Genetics, Zhongshan Medical College, Sun Yat-sen University, Guangzhou 510080, Guangdong Province, China
| | - Lu-Ming Chen
- Department of Medical Genetics, Zhongshan Medical College, Sun Yat-sen University, Guangzhou 510080, Guangdong Province, China
| | - Su-Qin Chen
- Department of Medical Genetics, Zhongshan Medical College, Sun Yat-sen University, Guangzhou 510080, Guangdong Province, China
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23
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Abstract
Norrin, a protein that acts on Frizzled-4 receptor, participates in angiogenesis in a variety of contexts through the Wnt-signaling pathway. Specifically, Norrin is found to play a crucial role in retinal vascularization. Norrin's pivotal role in angiogenesis led us to investigate its expression and the primary source in the developing retina. In this study we demonstrate, for the first time, that Norrin protein is expressed along the retinal blood vessels. The expression of Norrin coincided with the pattern of vascular growth in the developing mouse retina, and its expression was identified from the endothelial cells of the retinal capillaries. Furthermore, Norrin was also expressed on endothelial cells of the developing human retina. Given that Norrin is crucial in the normal development and maintenance of ocular capillaries, our finding provides a hint of the involvement of Norrin in the self generative and protective mechanism of the endothelial cells in the developing retina.
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Affiliation(s)
- Hanjae Lee
- Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
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24
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Abstract
Weibel-Palade bodies (WPBs) are the storage organelles for von Willebrand factor (VWF) in endothelial cells. VWF forms multimers that assemble into tubular structures in WPBs. Upon demand, VWF is secreted into the blood circulation, where it unfolds into strings that capture platelets during the onset of primary hemostasis. Numerous mutations affecting VWF lead to the bleeding disorder von Willebrand disease. This review reports the recent findings on the effects of VWF mutations on the biosynthetic pathway of VWF and its storage in WPBs. These new findings have deepened our understanding of VWF synthesis, storage, secretion, and function.
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Affiliation(s)
- K M Valentijn
- Department of Molecular Cell Biology, Section Electron Microscopy, Leiden University Medical Center, Leiden, The Netherlands
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25
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Cruciat CM, Niehrs C. Secreted and transmembrane wnt inhibitors and activators. Cold Spring Harb Perspect Biol 2013; 5:a015081. [PMID: 23085770 DOI: 10.1101/cshperspect.a015081] [Citation(s) in RCA: 463] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Signaling by the Wnt family of secreted glycoproteins plays important roles in embryonic development and adult homeostasis. Wnt signaling is modulated by a number of evolutionarily conserved inhibitors and activators. Wnt inhibitors belong to small protein families, including sFRP, Dkk, WIF, Wise/SOST, Cerberus, IGFBP, Shisa, Waif1, APCDD1, and Tiki1. Their common feature is to antagonize Wnt signaling by preventing ligand-receptor interactions or Wnt receptor maturation. Conversely, the Wnt activators, R-spondin and Norrin, promote Wnt signaling by binding to Wnt receptors or releasing a Wnt-inhibitory step. With few exceptions, these antagonists and agonists are not pure Wnt modulators, but also affect additional signaling pathways, such as TGF-β and FGF signaling. Here we discuss their interactions with Wnt ligands and Wnt receptors, their role in developmental processes, as well as their implication in disease.
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Affiliation(s)
- Cristina-Maria Cruciat
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, DKFZ, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
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26
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McNeill B, Mazerolle C, Bassett EA, Mears AJ, Ringuette R, Lagali P, Picketts DJ, Paes K, Rice D, Wallace VA. Hedgehog regulates Norrie disease protein to drive neural progenitor self-renewal. Hum Mol Genet 2012. [PMID: 23201751 DOI: 10.1093/hmg/dds505] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Norrie disease (ND) is a congenital disorder characterized by retinal hypovascularization and cognitive delay. ND has been linked to mutations in 'Norrie Disease Protein' (Ndp), which encodes the secreted protein Norrin. Norrin functions as a secreted angiogenic factor, although its role in neural development has not been assessed. Here, we show that Ndp expression is initiated in retinal progenitors in response to Hedgehog (Hh) signaling, which induces Gli2 binding to the Ndp promoter. Using a combination of genetic epistasis and acute RNAi-knockdown approaches, we show that Ndp is required downstream of Hh activation to induce retinal progenitor proliferation in the retina. Strikingly, Ndp regulates the rate of cell-cycle re-entry and not cell-cycle kinetics, thereby uncoupling the self-renewal and cell-cycle progression functions of Hh. Taken together, we have uncovered a cell autonomous function for Ndp in retinal progenitor proliferation that is independent of its function in the retinal vasculature, which could explain the neural defects associated with ND.
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Affiliation(s)
- Brian McNeill
- Vision Program, Ottawa Hospital Research Institute, Ottawa, Ont. K1H 8L6, Canada
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27
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Choi HJ, Park H, Lee HW, Kwon YG. The Wnt pathway and the roles for its antagonists, DKKS, in angiogenesis. IUBMB Life 2012; 64:724-31. [PMID: 22807036 DOI: 10.1002/iub.1062] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 05/06/2012] [Accepted: 05/24/2012] [Indexed: 11/07/2022]
Abstract
The Wnt signaling pathway is involved in a wide range of developmental and physiological processes, such as cell fate specification, tissue morphogenesis, and homeostasis. Thus, its dysregulation has been found in multiple diseases, including some cardiovascular disorders. The loss or gain of function of Wnt pathway components results in abnormal vascular development and angiogenesis. Further study has revealed that Wnt signaling in endothelial cells appears to contribute to vascular morphogenesis and endothelial cell specification. Owing to the significance of Wnt signaling in angiogenesis, Wnt antagonists have been considered potential treatments for neovascular disorders. In line with this, members of the Dkk protein family (Dkks), well-known Wnt antagonists, have been recently found to regulate angiogenesis. This review summarizes our present knowledge of the roles of Wnt signaling and Wnt antagonists, particularly Dkks, in angiogenic regulation and explores the therapeutic potential of Wnt antagonists.
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Affiliation(s)
- Hyun-Jung Choi
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
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28
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Zhou YF, Eng ET, Zhu J, Lu C, Walz T, Springer TA. Sequence and structure relationships within von Willebrand factor. Blood 2012; 120:449-58. [PMID: 22490677 PMCID: PMC3398765 DOI: 10.1182/blood-2012-01-405134] [Citation(s) in RCA: 205] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 03/24/2012] [Indexed: 11/20/2022] Open
Abstract
In the present study, we re-annotated von Willebrand factor (VWF), assigned its entire sequence to specific modules, and related these modules to structure using electron microscopy (EM). The D domains are assemblies of smaller modules visible as lobes in EM. Modules in the D-domain assemblies include von Willebrand D, 8-cysteine, trypsin inhibitor-like, E or fibronectin type 1-like domains, and a unique D4N module in D4. The D1-D2 prodomain shows 2 large connected assemblies, each containing smaller lobes. The previous B and C regions of VWF are re-annotated as 6 tandem von Willebrand C (VWC) and VWC-like domains. These 6 VWC domains correspond to 6 elongated domains that associate in pairs at acidic pH in the stem region of VWF dimeric bouquets. This correspondence is demonstrated by binding of integrin α(IIb)β(3) to the fourth module seen in EM, VWC4, which bears the VWF Arg-Gly-Asp motif. The C-terminal cystine knot domain dimerizes end-to-end in a manner predicted by homology to TGF-β and orients approximately perpendicular to the VWC domains in dimeric bouquets. Homologies of domains in VWF to domains in other proteins allow many disulfide bonds to be tentatively assigned, which may have functional implications.
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Affiliation(s)
- Yan-Feng Zhou
- Department of Biological Chemistry and Molecular Pharmacology, Immune Disease Institute and Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
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29
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Xu S, Cheng F, Liang J, Wu W, Zhang J. Maternal xNorrin, a canonical Wnt signaling agonist and TGF-β antagonist, controls early neuroectoderm specification in Xenopus. PLoS Biol 2012; 10:e1001286. [PMID: 22448144 PMCID: PMC3308935 DOI: 10.1371/journal.pbio.1001286] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 02/06/2012] [Indexed: 12/28/2022] Open
Abstract
Xenopus maternal Norrin, which activates Wnt signaling but inhibits TGF-β family molecules, is essential for neuroectoderm formation. Loss of TGF-β inhibition in Norrin may contribute to the development of Norrie disease. Dorsal–ventral specification in the amphibian embryo is controlled by β-catenin, whose activation in all dorsal cells is dependent on maternal Wnt11. However, it remains unknown whether other maternally secreted factors contribute to β-catenin activation in the dorsal ectoderm. Here, we show that maternal Xenopus Norrin (xNorrin) promotes anterior neural tissue formation in ventralized embryos. Conversely, when xNorrin function is inhibited, early canonical Wnt signaling in the dorsal ectoderm and the early expression of the zygotic neural inducers Chordin, Noggin, and Xnr3 are severely suppressed, causing the loss of anterior structures. In addition, xNorrin potently inhibits BMP- and Nodal/Activin-related functions through direct binding to the ligands. Moreover, a subset of Norrin mutants identified in humans with Norrie disease retain Wnt activation but show defective inhibition of Nodal/Activin-related signaling in mesoderm induction, suggesting that this disinhibition causes Norrie disease. Thus, xNorrin is an unusual molecule that acts on two major signaling pathways, Wnt and TGF-β, in opposite ways and is essential for early neuroectoderm specification. A key step during early embryogenesis is the generation of neural precursors, which later form the central nervous system. In vertebrates, this process requires proper dorsal–ventral axis specification, and we know that the canonical Wnt and BMP signaling pathways help pattern the dorsal ectoderm. In this study, we examine other factors that are involved in neuroectoderm development in the frog species Xenopus laevis. We find that maternal Xenopus Norrin (xNorrin) is required for canonical Wnt signaling in the dorsal ectoderm, functions upstream of neural inducers, and is required for neural formation. We also find that xNorrin not only activates Wnt signaling, but also inhibits BMP/Nodal-related signaling. In humans, mutations in Norrin cause Norrie disease. Using Norrin mutants identified in patients with Norrie disease, we find that some Norrin mutants fail to inhibit BMP/Nodal-related signaling (specifically, TGF-β) but retain the ability to activate the Wnt pathway, suggesting that loss of TGF-β inhibition may contribute to Norrie disease development.
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Affiliation(s)
- Suhong Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Graduate School of Chinese Academy of Sciences, Beijing, China
| | - Feng Cheng
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Graduate School of Chinese Academy of Sciences, Beijing, China
| | - Juan Liang
- Protein Science Laboratory of the Ministry of Education, School of Life Sciences, Tsinghua University, Beijing, China
| | - Wei Wu
- Protein Science Laboratory of the Ministry of Education, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jian Zhang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- * E-mail:
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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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Sadasivan VD, Narpala SR, Budil DE, Sacco A, Carrier RL. Modeling the human intestinal Mucin (MUC2) C-terminal cystine knot dimer. J Mol Model 2011; 17:2953-63. [DOI: 10.1007/s00894-010-0932-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 12/07/2010] [Indexed: 01/21/2023]
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Chow CC, Kiernan DF, Chau FY, Blair MP, Ticho BH, Galasso JM, Shapiro MJ. Laser Photocoagulation at Birth Prevents Blindness in Norrie's Disease Diagnosed Using Amniocentesis. Ophthalmology 2010; 117:2402-6. [DOI: 10.1016/j.ophtha.2010.03.057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 02/18/2010] [Accepted: 03/25/2010] [Indexed: 12/01/2022] Open
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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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Nikopoulos K, Venselaar H, Collin RW, Riveiro-Alvarez R, Boonstra FN, Hooymans JM, Mukhopadhyay A, Shears D, van Bers M, de Wijs IJ, van Essen AJ, Sijmons RH, Tilanus MA, van Nouhuys CE, Ayuso C, Hoefsloot LH, Cremers FP. Overview of the mutation spectrum in familial exudative vitreoretinopathy and Norrie disease with identification of 21 novel variants in FZD4, LRP5, and NDP. Hum Mutat 2010; 31:656-66. [DOI: 10.1002/humu.21250] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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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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Norrin promotes vascular regrowth after oxygen-induced retinal vessel loss and suppresses retinopathy in mice. J Neurosci 2010; 30:183-93. [PMID: 20053900 DOI: 10.1523/jneurosci.3210-09.2010] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Norrin is a secreted protein that is involved in retinal angiogenesis and activates the Wnt-signaling pathway. We studied the role of Norrin in microvascular endothelial cells in vitro, and in a mouse model of retinopathy characterized by oxygen-induced vascular loss followed by hypoxia-induced pathological neovascularization. Recombinant Norrin significantly increased proliferation, viability, migration, and tube formation in vitro. Two independent transgenic mouse strains with ectopic overexpression of Norrin from the lens (betaB1-Crystallin-Norrin), or the retinal pigment epithelium (Rpe65-Norrin) were generated and exposed to high oxygen. Following oxygen treatment, vascular loss was significantly smaller in retinae of transgenic mice from both strains as compared to wild-type littermates. In addition, the anatomical correct regrowth of vessels was significantly increased, while pathological neovascularization was suppressed. In vitro and in vivo effects of Norrin could be blocked by adding DKK (Dickkopf)-1, an inhibitor of Wnt/beta-catenin signaling. Treatment of microvascular endothelial cells with Norrin caused a substantial increase in the expression of angiopoietin-2 (Ang-2). When inhibitory antibodies against Ang-2 were added to Norrin, the proliferative effects of Norrin were significantly suppressed. We conclude that Norrin is a potent factor to induce angiogenesis in microvascular endothelial cells, which has the distinct potential to suppress the damaging effects of oxygen-induced retinopathy in vivo. The effects of Norrin appear to be mediated, at least partially, via the induction of Ang-2.
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Gal A, Veske A, Jojart G, Grammatico B, Huber B, Gu S, del Porto G, Senyi K. Norrie-Warburg syndrome: two novel mutations in patients with classical clinical phenotype. ACTA OPHTHALMOLOGICA SCANDINAVICA. SUPPLEMENT 2009:13-6. [PMID: 8741107 DOI: 10.1111/j.1600-0420.1996.tb00374.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Norrie-Warburg syndrome (NWS) is a rare X-linked disorder characterized by blindness, which is invariable, deafness and mental disturbances, which are present occasionally. We describe here two novel mutations, a missense mutation (C126S) and a 1-base pair insertion (insT466/T467), together with a recurrent mutation (M1V), found in patients presenting with the classical clinical phenotype of NWS. All three mutations are likely to result in prominent structural changes of the norrin protein.
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Affiliation(s)
- A Gal
- Institut für Humangenetik, Universitäts-Krankenhaus Eppendorf, Hamburg, Germany
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Yu X, He F, Zhang T, Espinoza-Lewis RA, Lin L, Yang J, Chen Y. Cerberus functions as a BMP agonist to synergistically induce nodal expression during left-right axis determination in the chick embryo. Dev Dyn 2009; 237:3613-23. [PMID: 18985739 DOI: 10.1002/dvdy.21769] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Left-sided expression of Nodal in the lateral plate mesoderm (LPM) during early embryogenesis is a crucial step in establishing the left-right (L-R) axis in vertebrates. In the chick, it was suggested that chick Cerberus (cCer), a Cerberus/Dan family member, induces Nodal expression by antagonizing bone morphogenetic protein (BMP) activity in the left LPM. In contrast, it has also been shown that BMPs positively regulate Nodal expression in the left LPM in the chick embryo. Thus, it is still unclear how the bilaterally expressed BMPs induce Nodal expression only in the left LPM. In this study, we demonstrate that BMP signaling is necessary and sufficient for the induction of Nodal expression in the chick LPM where the type I BMP receptor-IB (BMPR-IB) likely mediates this induction. Tissue grafting experiments indicate the existence of a Nodal inductive factor in the left LPM rather than the presence of a Nodal inhibitory factor in the right LPM. We demonstrate that cCer functions as a BMP agonist instead of antagonist, being able to enhance BMP signaling in cell culture. This conclusion is further supported by the immunoprecipitation assays that provide convincing biochemical evidence for a direct interaction between cCer and BMP receptor. Because cCer is expressed restrictedly in the left LPM, BMPs and cCer appear to act synergistically to activate Nodal expression in the left LPM in the chick.
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Affiliation(s)
- Xueyan Yu
- Section of Oral Biology, The Ohio State University College of Dentistry, Columbus, Ohio 43210, USA.
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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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Abstract
The Wnt family of secreted signaling factors plays numerous roles in embryonic development and in stem cell biology. In the adult, Wnt signaling is involved in tissue homeostasis and mutations that lead to the overexpression of Wnt can be linked to cancer. Wnt signaling is transduced intracellularly by the Frizzled (Fzd) family of receptors. In the canonical pathway, accumulation of beta-catenin and the subsequent formation of a complex with T cell factors (TCF) or lymphoid enhancing factors (Lef) lead to target gene activation. The identification of Ryk as an alternative Wnt receptor and the discovery of the novel Fzd ligands Norrie disease protein (NDP) and R-Spondin, changed the traditional view of Wnts binding to Fzd receptors. Mouse R-Spondin cooperates with Wnt signaling and Low density lipoprotein (LDL) receptor related protein (LRP) to activate beta-catenin dependent gene expression and is involved in processes such as limb and placental development in the mouse. NDP is the product of the Norrie disease gene and controls vascular development in the retina, inner ear and in the female reproductive system during pregnancy. In this review a functional overview of the interactions of the different Wnt and non-Wnt ligands with the Fzd receptors is given as well as a survey of Wnts binding to Ryk and we discuss the biological significance of these interactions.
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Affiliation(s)
- Marijke Hendrickx
- Vrije Universiteit Brussel, Lab for Cell Genetics, 2 Pleinlaan, B-1050 Brussels, Belgium
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Khan AO, Aldahmesh MA, Meyer B. Correlation of Ophthalmic Examination with Carrier Status in Females Potentially Harboring a Severe Norrie Disease Gene Mutation. Ophthalmology 2008; 115:730-3. [DOI: 10.1016/j.ophtha.2007.04.064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Revised: 04/22/2007] [Accepted: 04/23/2007] [Indexed: 10/22/2022] Open
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Abstract
The roles of growth factors such as angiopoietin (Ang) and vascular endothelial growth factor (VEGF) in angiogenesis have been known for some time, yet we have just an incipient appreciation for the contribution of Wnts to this process. Cellular proliferation and polarity, apoptosis, branching morphogenesis, inductive processes, and the maintenance of stem cells in an undifferentiated, proliferative state are all regulated by Wnt signaling. The development and maintenance of vascular structures are dependent on all these processes, and their orchestration has, to some extent, been revealed in studies of VEGF and Ang receptors. Recent evidence links the Wnt/Frizzled signaling pathway to proper vascular growth in mammals but our knowledge of Wnt function in the vasculature is rudimentary. Further insight into vascular development and the process of angiogenesis depends on evaluating the function of novel endothelial regulatory pathways such as Wnt/Frizzled signaling.
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Andreoli CM, Warden SM, Mukai S. Inherited proliferative vitreoretinopathies of childhood. Int Ophthalmol Clin 2008; 48:159-174. [PMID: 18427268 DOI: 10.1097/iio.0b013e3181692cd4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Noll H, Alcedo J, Daube M, Frei E, Schiltz E, Hunt J, Humphries T, Matranga V, Hochstrasser M, Aebersold R, Lee H, Noll M. The toposome, essential for sea urchin cell adhesion and development, is a modified iron-less calcium-binding transferrin. Dev Biol 2007; 310:54-70. [PMID: 17707791 DOI: 10.1016/j.ydbio.2007.07.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 07/09/2007] [Accepted: 07/14/2007] [Indexed: 11/21/2022]
Abstract
We describe the structure and function of the toposome, a modified calcium-binding, iron-less transferrin, the first member of a new class of cell adhesion proteins. In addition to the amino acid sequence of the precursor, we determined by Edman degradation the N-terminal amino acid sequences of the mature hexameric glycoprotein present in the egg as well as that of its derived proteolytically modified fragments necessary for development beyond the blastula stage. The approximate C-termini of the fragments were determined by a combination of mass spectrometry and migration in reducing gels before and after deglycosylation. This new member of the transferrin family shows special features which explain its evolutionary adaptation to development and adhesive function in sea urchin embryos: (i) a protease-inhibiting WAP domain, (ii) a 280 amino acid cysteine-less insertion in the C-terminal lobe, and (iii) a 240 residue C-terminal extension with a modified cystine knot motif found in multisubunit external cell surface glycoproteins. Proteolytic removal of the N-terminal WAP domain generates the mature toposome present in the oocyte. The modified cystine knot motif stabilizes cell-bound trimers upon Ca-dependent dissociation of hexamer-linked cells. We determined the positions of the developmentally regulated cuts in the cysteine-less insertion, which produce the fragments observed previously. These fragments remain bound to the hexameric 22S particle in vivo and are released only after treatment of the purified toposome with reducing agents. In addition, some soluble smaller fragments with possible signal function are produced. Sequence comparison of five sea urchin species reveals the location of the cell-cell contact site targeted by the species-specific embryo dissociating antibodies. The evolutionary tree of 2-, 1-, and 0-ferric transferrins implies their evolution from a basic cation-activated allosteric design modified to serve multiple functions.
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Affiliation(s)
- Hans Noll
- Department of Cell and Molecular Biology, University of Hawaii, School of Medicine, 1960 East-West Road, Honolulu, HI 96822, USA.
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Reh TA, McCabe K, Kelley MW, Bermingham-McDonogh O. Growth factors in the treatment of degenerative retinal disorders. CIBA FOUNDATION SYMPOSIUM 2007; 196:120-31; discussion 131-4. [PMID: 8866131 DOI: 10.1002/9780470514863.ch9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
There are currently a number of degenerative conditions, both inherited and acquired, that affect the retina and lead to blindness. Retinal photoreceptors degenerate from inherited conditions, such as retinitis pigmentosa or as a result of light damage or normal ageing; retinal ganglion cells degenerate from optic nerve injury or glaucoma. Current research in this field includes the use of growth factors to: (1) inhibit the degenerative processes; (2) promote regeneration of the retina from the pigmented epithelium; and (3) improve the conditions for transplantation of new cells to the retina by expanding the photoreceptor cell populations in vitro. The results to date have shown that a number of different growth factors promote survival of retinal cells in vitro and in vivo. In addition, some of the same factors can stimulate regeneration in the developing retina and act as mitogens for the retinal progenitor cells. It is likely that a combination of these approaches will ultimately be important for the treatment of the various retinal degenerations.
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Affiliation(s)
- T A Reh
- Department of Biological Structure, University of Washington, Seattle 98195, 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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Lev D, Weigl Y, Hasan M, Gak E, Davidovich M, Vinkler C, Leshinsky-Silver E, Lerman-Sagie T, Watemberg N. A novel missense mutation in theNDP gene in a child with Norrie disease and severe neurological involvement including infantile spasms. Am J Med Genet A 2007; 143A:921-4. [PMID: 17334993 DOI: 10.1002/ajmg.a.31531] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Norrie disease (ND) is a rare X-linked recessive disorder characterized by congenital blindness and in some cases, mental retardation and deafness. Other neurological complications, particularly epilepsy, are rare. We report on a novel mutation identified in a patient with ND and profound mental retardation. The patient was diagnosed at the age of 6 months due to congenital blindness. At the age of 8 months he developed infantile spasms, which were diagnosed at 11 months as his EEG demonstrated hypsarrhythmia. Mutation analysis of the ND gene (NDP) of the affected child and his mother revealed a novel missense mutation at position c.134T > A resulting in amino acid change at codon V45E. To the best of our knowledge, such severe neurological involvement has not been previously reported in ND patients. The severity of the phenotype may suggest the functional importance of this site of the NDP gene.
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Affiliation(s)
- Dorit Lev
- Institute of Medical Genetics, Wolfson Medical Center, Holon, Israel.
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Smallwood PM, Williams J, Xu Q, Leahy DJ, Nathans J. Mutational analysis of Norrin-Frizzled4 recognition. J Biol Chem 2006; 282:4057-68. [PMID: 17158104 DOI: 10.1074/jbc.m609618200] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Norrin and Frizzled4 (Fz4) function as a ligand-receptor pair to control vascular development in the retina and inner ear. In mice and humans, mutations in either of the corresponding genes lead to defects in vascular development. The present work is aimed at defining the sequence determinants of binding specificity between Norrin and the Fz4 amino-terminal ligand-binding domain (the "cysteine-rich domain" (CRD)). The principal conclusions are as follows: 1) Norrin binds to the Fz4 CRD and does not detectably bind to the 14 other mammalian Frizzled and secreted Frizzled-related protein CRDs; 2) Norrin and Xenopus Wnt8 recognize largely overlapping regions of the Fz4 CRD; 3) surface determinants on the Fz4 and Fz8 CRDs that allow Norrin to distinguish between these two CRDs reside within several small regions on one face of the CRD; 4) Norrin function depends critically on three pairs of cysteines that form the highly conserved trio of disulfide bonds shared among all cystine knot proteins, but the remaining two putative disulfide bonds are less important; 5) Norrin-CRD binding depends on a largely contiguous group of amino acids in the extended beta-sheet domain of Norrin that are predicted to face away from the interface between the two monomers in the Norrin homodimer; 6) Norrin-CRD binding is strongly modulated by interactions involving charged amino acid side chains; and 7) Norrin-CRD binding is enhanced approximately 10-fold by the addition of heparin. These observations are discussed in the context of Frizzled signaling and the structure and function of other cystine knot proteins.
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Affiliation(s)
- Philip M Smallwood
- Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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