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WNT7A/B promote choroidal neovascularization. Exp Eye Res 2018; 174:107-112. [PMID: 29864439 DOI: 10.1016/j.exer.2018.05.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 05/28/2018] [Accepted: 05/31/2018] [Indexed: 12/19/2022]
Abstract
Perturbations in WNT signaling are associated with congenital eye disorders, including familial exudative vitreoretinopathy and Norrie disease. More recently, activation of the WNT pathway has also been shown to be associated with age-related macular degeneration (AMD). In this study, we identified that in choroidal neovascular membranes from AMD patients, β-catenin is activated specifically in the vascular endothelium, suggesting that WNT promotes pathologic angiogenesis by directly affecting vascular endothelial cells. WNT7B has been shown to be important during eye development for regression of the fetal hyaloid vasculature. However, it has not yet been established whether WNT7A and/or WNT7B are involved in neovascular AMD pathogenesis. Here, we show that WNT7A and WNT7B increase the proliferation of human dermal microvascular endothelial cells in a dose-dependent manner. Both WNT7A and WNT7B also stimulated vascular sprouting from mouse choroidal explants in vitro. To evaluate in vivo relevance, we generated mice systemically deficient in Wnt7a and/or Wnt7b. Genetic deletion of both Wnt7a and Wnt7b decreased the severity of laser injury-induced choroidal neovascularization (CNV), while individual deletion of either Wnt7a or Wnt7b did not have a significant effect on CNV, suggesting that WNT7A and WNT7B have redundant pro-angiogenic roles in vivo. Cumulatively, these findings identify specific WNT isoforms that may play a pathologic role in CNV as observed in patients with neovascular AMD. Although the source of increased WNT7A and/or WNT7B in CNV requires further investigation, WNT signaling may be a potential target for therapeutic intervention if these results are demonstrated to be relevant in human disease.
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Tauqeer Z, Yonekawa Y. Familial Exudative Vitreoretinopathy: Pathophysiology, Diagnosis, and Management. Asia Pac J Ophthalmol (Phila) 2018; 7:176-182. [PMID: 29633588 DOI: 10.22608/apo.201855] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) is a heritable vitreoretinopathy characterized by anomalous retinal vascular development. The principal feature of the disease is an avascular peripheral retina. This in turn can cause further pathological changes including neovascularization, exudation, hemorrhage, and retinal detachment. The biological basis of the disease is thought to be from defects in the Wnt signaling pathway. Many gene mutations have been implicated, and these can be inherited in an autosomal dominant (most common), autosomal recessive, and X-linked recessive fashion. Examination with wide-field fluorescein angiography is essential and can identify the disease in its earlier stages, enabling timely treatment, in addition to helping identify asymptomatic family members. The current treatment paradigm involves laser photocoagulation of the avascular peripheral retina for neovascular sequelae and vitreoretinal surgery for progressive retinal detachment. Further studies are underway to better characterize this complex vitreoretinopathy.
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Affiliation(s)
- Zujaja Tauqeer
- Retina Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts
| | - Yoshihiro Yonekawa
- Retina Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts
- Pediatric Retina Surgery, Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
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Huang XY, Zhuang H, Wu JH, Li JK, Hu FY, Zheng Y, Tellier LCAM, Zhang SH, Gao FJ, Zhang JG, Xu GZ. Targeted next-generation sequencing analysis identifies novel mutations in families with severe familial exudative vitreoretinopathy. Mol Vis 2017; 23:605-613. [PMID: 28867931 PMCID: PMC5568910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 08/21/2017] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Familial exudative vitreoretinopathy (FEVR) is a genetically and clinically heterogeneous disease, characterized by failure of vascular development of the peripheral retina. The symptoms of FEVR vary widely among patients in the same family, and even between the two eyes of a given patient. This study was designed to identify the genetic defect in a patient cohort of ten Chinese families with a definitive diagnosis of FEVR. METHODS To identify the causative gene, next-generation sequencing (NGS)-based target capture sequencing was performed. Segregation analysis of the candidate variant was performed in additional family members by using Sanger sequencing and quantitative real-time PCR (QPCR). RESULTS Of the cohort of ten FEVR families, six pathogenic variants were identified, including four novel and two known heterozygous mutations. Of the variants identified, four were missense variants, and two were novel heterozygous deletion mutations [LRP5, c.4053 DelC (p.Ile1351IlefsX88); TSPAN12, EX8Del]. The two novel heterozygous deletion mutations were not observed in the control subjects and could give rise to a relatively severe FEVR phenotype, which could be explained by the protein function prediction. CONCLUSIONS We identified two novel heterozygous deletion mutations [LRP5, c.4053 DelC (p.Ile1351IlefsX88); TSPAN12, EX8Del] using targeted NGS as a causative mutation for FEVR. These genetic deletion variations exhibit a severe form of FEVR, with tractional retinal detachments compared with other known point mutations. The data further enrich the mutation spectrum of FEVR and enhance our understanding of genotype-phenotype correlations to provide useful information for disease diagnosis, prognosis, and effective genetic counseling.
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Affiliation(s)
- Xiao-Yan Huang
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China,BGI-Shenzhen, Shenzhen, China,China National GeneBank-Shenzhen, BGI-Shenzhen, Shenzhen, China
| | - Hong Zhuang
- Eye and ENT Hospital, Fudan University, Shanghai, China,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Ji-Hong Wu
- Eye and ENT Hospital, Fudan University, Shanghai, China,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Jian-Kang Li
- BGI-Shenzhen, Shenzhen, China,China National GeneBank-Shenzhen, BGI-Shenzhen, Shenzhen, China
| | - Fang-Yuan Hu
- Eye and ENT Hospital, Fudan University, Shanghai, China,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Yu Zheng
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China,BGI-Shenzhen, Shenzhen, China,China National GeneBank-Shenzhen, BGI-Shenzhen, Shenzhen, China
| | - Laurent Christian Asker M. Tellier
- BGI-Shenzhen, Shenzhen, China,China National GeneBank-Shenzhen, BGI-Shenzhen, Shenzhen, China,Department of Biology, Bioinformatics, University of Copenhagen, Denmark
| | - Sheng-Hai Zhang
- Eye and ENT Hospital, Fudan University, Shanghai, China,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Feng-Juan Gao
- Eye and ENT Hospital, Fudan University, Shanghai, China,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Jian-Guo Zhang
- BGI-Shenzhen, Shenzhen, China,China National GeneBank-Shenzhen, BGI-Shenzhen, Shenzhen, China
| | - Ge-Zhi Xu
- Eye and ENT Hospital, Fudan University, Shanghai, China,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
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54
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Díaz-Coránguez M, Ramos C, Antonetti DA. The inner blood-retinal barrier: Cellular basis and development. Vision Res 2017; 139:123-137. [PMID: 28619516 DOI: 10.1016/j.visres.2017.05.009] [Citation(s) in RCA: 163] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/26/2017] [Accepted: 05/30/2017] [Indexed: 01/01/2023]
Abstract
The blood-retinal barrier (BRB) regulates transport across retinal capillaries maintaining proper neural homeostasis and protecting the neural tissue from potential blood borne toxicity. Loss of the BRB contributes to the pathophysiology of a number of blinding retinal diseases including diabetic retinopathy. In this review, we address the basis of the BRB, including the molecular mechanisms that regulate flux across the retinal vascular bed. The routes of transcellular and paracellular flux are described as well as alterations in these pathways in response to permeabilizing agents in diabetes. Finally, we provide information on exciting new studies that help to elucidate the process of BRB development or barriergenesis and how understanding this process may lead to new opportunities for barrier restoration in diabetic retinopathy.
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Affiliation(s)
- Mónica Díaz-Coránguez
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, United States
| | - Carla Ramos
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, United States
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, United States.
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Keser V, Khan A, Siddiqui S, Lopez I, Ren H, Qamar R, Nadaf J, Majewski J, Chen R, Koenekoop RK. The Genetic Causes of Nonsyndromic Congenital Retinal Detachment: A Genetic and Phenotypic Study of Pakistani Families. Invest Ophthalmol Vis Sci 2017; 58:1028-1036. [PMID: 28192794 PMCID: PMC5308768 DOI: 10.1167/iovs.16-20281] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate consanguineous pedigrees from Pakistan with a clinical diagnosis of nonsyndromic congenital retinal nonattachment (NCRNA) and identify genes responsible for the disease as currently only one NCRNA gene is known (atonal basic helix-loop-helix transcription factor 7: ATOH7). Methods We implemented a three-step genotyping platform: single nucleotide polymorphism genotyping to identify loss of heterozygosity regions in patients, Retinal Information Network panel screening for mutations in currently known retinal genes. Negative patients were then subjected to whole exome sequencing. Results We evaluated 21 consanguineous NCRNA pedigrees and identified the causal mutations in known retinal genes in 13 out of our 21 families. We found mutations in ATOH7 in three families. Surprisingly, we then found mutations in familial exudative vitreoretinopathy (FEVR) genes; low-density lipoprotein receptor-related protein 5 mutations (six families), tetraspanin 12 mutations (two families), and NDP mutations (two families). Thus, 62% of the patients were successfully genotyped in our study with seven novel and six previously reported mutations in known retinal genes. Conclusions Although the clinical diagnosis of all children was NCRNA with severe congenital fibrotic retinal detachments, the molecular diagnosis determined that the disease process was in fact a very severe form of FEVR in 10 families. Because severe congenital retinal detachment has not been previously associated with all the FEVR genes, we have thus expanded the phenotypic spectrum of FEVR, a highly variable retinal detachment phenotype that has clinical overlap with NCRNA. We identified seven novel mutations. We also established for the first time genetic overlap between the Iranian and Pakistani populations. We identified eight NCRNA families that do not harbor mutations in any known retinal genes, suggesting novel causal genes in these families.
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Affiliation(s)
- Vafa Keser
- McGill Ocular Genetics Laboratory, McGill University Health Centre, Montreal, Quebec, Canada
| | - Ayesha Khan
- McGill Ocular Genetics Laboratory, McGill University Health Centre, Montreal, Quebec, Canada
| | - Sorath Siddiqui
- McGill Ocular Genetics Laboratory, McGill University Health Centre, Montreal, Quebec, Canada
| | - Irma Lopez
- McGill Ocular Genetics Laboratory, McGill University Health Centre, Montreal, Quebec, Canada
| | - Huanan Ren
- McGill Ocular Genetics Laboratory, McGill University Health Centre, Montreal, Quebec, Canada
| | - Raheel Qamar
- Department of Pediatric Ophthalmology, Al Shifa Trust Eye Hospital, Rawalpindi, Pakistan
| | - Javad Nadaf
- Quebec Genome Centre, Montreal, Quebec, Canada
| | - Jacek Majewski
- Quebec Genome Centre, Montreal, Quebec, Canada 4Faculty of Medicine, Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Rui Chen
- Department of Molecular and Human Genetics, Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, United States
| | - Robert K Koenekoop
- McGill Ocular Genetics Laboratory, McGill University Health Centre, Montreal, Quebec, Canada
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56
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Chen Q, Ma JX. Canonical Wnt signaling in diabetic retinopathy. Vision Res 2017; 139:47-58. [PMID: 28545982 DOI: 10.1016/j.visres.2017.02.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 02/21/2017] [Accepted: 02/22/2017] [Indexed: 11/16/2022]
Abstract
Diabetic retinopathy (DR) is a common eye complication of diabetes, and the pathogenic mechanism of DR is still under investigation. The canonical Wnt signaling pathway is an evolutionarily conserved pathway that plays fundamental roles in embryogenesis and adult tissue homeostasis. Wnt signaling regulates expression of multiple genes that control retinal development and eye organogenesis, and dysregulated Wnt signaling plays pathophysiological roles in many ocular diseases, including DR. This review highlights recent progress in studies of Wnt signaling in DR. We discuss Wnt signaling regulation in the retina and dysregulation of Wnt signaling associated with ocular diseases with an emphasis on DR. We also discuss the therapeutic potential of modulating Wnt signaling in DR. Continued studies in this field will advance our current understanding on DR and contribute to the development of new treatments.
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Affiliation(s)
- Qian Chen
- Department of Physiology, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States
| | - Jian-Xing Ma
- Department of Physiology, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States.
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Panagiotou ES, Sanjurjo Soriano C, Poulter JA, Lord EC, Dzulova D, Kondo H, Hiyoshi A, Chung BHY, Chu YWY, Lai CH, Tafoya ME, Karjosukarso D, Collin RW, Topping J, Downey LM, Ali M, Inglehearn CF, Toomes C. Defects in the Cell Signaling Mediator β-Catenin Cause the Retinal Vascular Condition FEVR. Am J Hum Genet 2017; 100:960-968. [PMID: 28575650 DOI: 10.1016/j.ajhg.2017.05.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 05/03/2017] [Indexed: 12/30/2022] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) is an inherited blinding disorder characterized by the abnormal development of the retinal vasculature. The majority of mutations identified in FEVR are found within four genes that encode the receptor complex (FZD4, LRP5, and TSPAN12) and ligand (NDP) of a molecular pathway that controls angiogenesis, the Norrin-β-catenin signaling pathway. However, half of all FEVR-affected case subjects do not harbor mutations in these genes, indicating that further mutated genes remain to be identified. Here we report the identification of mutations in CTNNB1, the gene encoding β-catenin, as a cause of FEVR. We describe heterozygous mutations (c.2142_2157dup [p.His720∗] and c.2128C>T [p.Arg710Cys]) in two dominant FEVR-affected families and a de novo mutation (c.1434_1435insC [p.Glu479Argfs∗18]) in a simplex case subject. Previous studies have reported heterozygous de novo CTNNB1 mutations as a cause of syndromic intellectual disability (ID) and autism spectrum disorder, and somatic mutations are linked to many cancers. However, in this study we show that Mendelian inherited CTNNB1 mutations can cause non-syndromic FEVR and that FEVR can be a part of the syndromic ID phenotype, further establishing the role that β-catenin signaling plays in the development of the retinal vasculature.
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58
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Live imaging of primary ocular vasculature formation in zebrafish. PLoS One 2017; 12:e0176456. [PMID: 28445524 PMCID: PMC5405983 DOI: 10.1371/journal.pone.0176456] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 04/11/2017] [Indexed: 12/31/2022] Open
Abstract
Ocular vasculature consists of the central retinal and ciliary vascular systems, which are essential to maintaining visual function. Many researchers have attempted to determine their origins and development; however, the detailed, stepwise process of ocular vasculature formation has not been established. In zebrafish, two angioblast clusters, the rostral and midbrain organizing centers, form almost all of the cranial vasculature, including the ocular vasculature, and these are from where the cerebral arterial and venous angioblast clusters, respectively, differentiate. In this study, we first determined the anatomical architecture of the primary ocular vasculature and then followed its path from the two cerebral angioblast clusters using a time-lapse analysis of living Tg(flk1:EGFP)k7 zebrafish embryos, in which the endothelial cells specifically expressed enhanced green fluorescent protein. We succeeded in capturing images of the primary ocular vasculature formation and were able to determine the origin of each ocular vessel. In zebrafish, the hyaloid and ciliary arterial systems first organized independently, and then anastomosed via the inner optic circle on the surface of the lens by the lateral transfer of the optic vein. Finally, the choroidal vascular plexus formed around the eyeball to complete the primary ocular vasculature formation. To our knowledge, this study is the first to report successful capture of circular integration of the optic artery and vein, lateral transfer of the optic vein to integrate the hyaloidal and superficial ocular vasculatures, and formation of the choroidal vascular plexus. Furthermore, this new morphological information enables us to assess the entire process of the primary ocular vasculature formation, which will be useful for its precise understanding.
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59
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Charette JR, Earp SE, Bell BA, Ackert-Bicknell CL, Godfrey DA, Rao S, Anand-Apte B, Nishina PM, Peachey NS. A mutagenesis-derived Lrp5 mouse mutant with abnormal retinal vasculature and low bone mineral density. Mol Vis 2017; 23:140-148. [PMID: 28356706 PMCID: PMC5360454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 03/16/2017] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Familial exudative vitreoretinopathy (FEVR) is caused by mutations in the genes encoding low-density lipoprotein receptor-related protein (LRP5) or its interacting partners, namely frizzled class receptor 4 (FZD4) and norrin cystine knot growth factor (NDP). Mouse models for Lrp5, Fzd4, and Ndp have proven to be important for understanding the retinal pathophysiology underlying FEVR and systemic abnormalities related to defective Wnt signaling. Here, we report a new mouse mutant, tvrm111B, which was identified by electroretinogram (ERG) screening of mice generated in the Jackson Laboratory Translational Vision Research Models (TVRM) mutagenesis program. METHODS ERGs were used to examine outer retinal physiology. The retinal vasculature was examined by in vivo retinal imaging, as well as by histology and immunohistochemistry. The tvrm111B locus was identified by genetic mapping of mice generated in a cross to DBA/2J, and subsequent sequencing analysis. Gene expression was examined by real-time PCR of retinal RNA. Bone mineral density (BMD) was examined by peripheral dual-energy X-ray absorptiometry. RESULTS The tvrm111B allele is inherited as an autosomal recessive trait. Genetic mapping of the decreased ERG b-wave phenotype of tvrm111B mice localized the mutation to a region on chromosome 19 that included Lrp5. Sequencing of Lrp5 identified the insertion of a cytosine (c.4724_4725insC), which is predicted to cause a frameshift that disrupts the last three of five conserved PPPSPxS motifs in the cytoplasmic domain of LRP5, culminating in a premature termination. In addition to a reduced ERG b-wave, Lrp5tvrm111B homozygotes have low BMD and abnormal features of the retinal vasculature that have been reported previously in Lrp5 mutant mice, including persistent hyaloid vessels, leakage on fluorescein angiography, and an absence of the deep retinal capillary bed. CONCLUSIONS The phenotype of the Lrp5tvrm111B mutant includes abnormalities of the retinal vasculature and of BMD. This model may be a useful resource to further our understanding of the biological role of LRP5 and to evaluate experimental therapies for FEVR or other conditions associated with LRP5 dysfunction.
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Affiliation(s)
| | - Sarah E Earp
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH; Cole Eye Institute, Cleveland Clinic, Cleveland, OH
| | - Brent A Bell
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH
| | - Cheryl L Ackert-Bicknell
- The Jackson Laboratory, Bar Harbor, ME; Center for Musculoskeletal Research, Department of Orthopaedics, University of Rochester, Rochester, NY
| | - Dana A Godfrey
- Center for Musculoskeletal Research, Department of Orthopaedics, University of Rochester, Rochester, NY
| | - Sujata Rao
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH; Cole Eye Institute, Cleveland Clinic, Cleveland, OH
| | - Bela Anand-Apte
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH; Cole Eye Institute, Cleveland Clinic, Cleveland, OH
| | | | - Neal S Peachey
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH; Cole Eye Institute, Cleveland Clinic, Cleveland, OH; Louis Stokes Cleveland VA Medical Center, Cleveland, OH
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Gupta MP, Talcott KE, Kim DY, Agarwal S, Mukai S. Retinal findings and a novel TINF2 mutation in Revesz syndrome: Clinical and molecular correlations with pediatric retinal vasculopathies. Ophthalmic Genet 2017; 38:51-60. [DOI: 10.1080/13816810.2016.1275019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Mrinali P. Gupta
- Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
| | - Katherine E. Talcott
- Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
| | - David Y. Kim
- Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
| | - Suneet Agarwal
- Division of Hematology/Oncology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Shizuo Mukai
- Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
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Alowolodu O, Johnson G, Alashwal L, Addou I, Zhdanova IV, Uversky VN. Intrinsic disorder in spondins and some of their interacting partners. INTRINSICALLY DISORDERED PROTEINS 2016; 4:e1255295. [PMID: 28232900 DOI: 10.1080/21690707.2016.1255295] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 10/22/2016] [Accepted: 10/27/2016] [Indexed: 12/28/2022]
Abstract
Spondins, which are proteins that inhibit and promote adherence of embryonic cells so as to aid axonal growth are part of the thrombospondin-1 family. Spondins function in several important biological processes, such as apoptosis, angiogenesis, etc. Spondins constitute a thrombospondin subfamily that includes F-spondin, a protein that interacts with Aβ precursor protein and inhibits its proteolytic processing; R-spondin, a 4-membered group of proteins that regulates Wnt pathway and have other functions, such as regulation of kidney proliferation, induction of epithelial proliferation, the tumor suppressant action; M-spondin that mediates mechanical linkage between the muscles and apodemes; and the SCO-spondin, a protein important for neuronal development. In this study, we investigated intrinsic disorder status of human spondins and their interacting partners, such as members of the LRP family, LGR family, Frizzled family, and several other binding partners in order to establish the existence and importance of disordered regions in spondins and their interacting partners by conducting a detailed analysis of their sequences, finding disordered regions, and establishing a correlation between their structure and biological functions.
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Affiliation(s)
- Oluwole Alowolodu
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida , Tampa, FL, USA
| | - Gbemisola Johnson
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida , Tampa, FL, USA
| | - Lamis Alashwal
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida , Tampa, FL, USA
| | - Iqbal Addou
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida , Tampa, FL, USA
| | - Irina V Zhdanova
- Department of Anatomy & Neurobiology, Boston University School of Medicine , Boston, MA, USA
| | - Vladimir N Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA; USF Health Byrd Alzheimer Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, USA; Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
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62
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Ngo MH, Borowska-Fielding J, Heathcote G, Nejat S, Kelly ME, McMaster CR, Robitaille JM. Fzd4 Haploinsufficiency Delays Retinal Revascularization in the Mouse Model of Oxygen Induced Retinopathy. PLoS One 2016; 11:e0158320. [PMID: 27489958 PMCID: PMC4973993 DOI: 10.1371/journal.pone.0158320] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 06/14/2016] [Indexed: 12/11/2022] Open
Abstract
Mutations in genes that code for components of the Norrin-FZD4 ligand-receptor complex cause the inherited childhood blinding disorder familial exudative vitreoretinopathy (FEVR). Statistical evidence from studies of patients at risk for the acquired disease retinopathy of prematurity (ROP) suggest that rare polymorphisms in these same genes increase the risk of developing severe ROP, implying that decreased Norrin-FZD4 activity predisposes patients to more severe ROP. To test this hypothesis, we measured the development and recovery of retinopathy in wild type and Fzd4 heterozygous mice in the absence or presence of ocular ischemic retinopathy (OIR) treatment. Avascular and total retinal vascular areas and patterning were determined, and vessel number and caliber were quantified. In room air, there was a small delay in retinal vascularization in Fzd4 heterozygous mice that resolved as mice reached maturity suggestive of a slight defect in retinal vascular development. Subsequent to OIR treatment there was no difference between wild type and Fzd4 heterozygous mice in the vaso-obliterated area following exposure to high oxygen. Importantly, after return of Fzd4 heterozygous mice to room air subsequent to OIR treatment, there was a substantial delay in retinal revascularization of the avascular area surrounding the optic nerve, as well as delayed vascularization toward the periphery of the retina. Our study demonstrates that a small decrease in Norrin-Fzd4 dependent retinal vascular development lengthens the period during which complications from OIR could occur.
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Affiliation(s)
- Michael H. Ngo
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | | | - Godfrey Heathcote
- Department of Pathology, Dalhousie University, Halifax, NS, Canada
- Department of Ophthalmology and Visual Sciences, Dalhousie University and the IWK Health Centre, Halifax, NS, Canada
| | - Sara Nejat
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Melanie E. Kelly
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
- Department of Ophthalmology and Visual Sciences, Dalhousie University and the IWK Health Centre, Halifax, NS, Canada
| | | | - Johane M. Robitaille
- Department of Pathology, Dalhousie University, Halifax, NS, Canada
- Department of Ophthalmology and Visual Sciences, Dalhousie University and the IWK Health Centre, Halifax, NS, Canada
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63
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Pefkianaki M, Hasanreisoglu M, Suchy SF, Shields CL. Familial Exudative Vitreoretinopathy With a Novel LRP5 Mutation. J Pediatr Ophthalmol Strabismus 2016; 53:e39-42. [PMID: 27486893 DOI: 10.3928/01913913-20160719-02] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 03/24/2016] [Indexed: 11/20/2022]
Abstract
This report reviews the genetics of familial exudative vitreoretinopathy (FEVR) and describes the identification of a novel variant in the LRP5 gene. A 20-month-old boy presented with reduced visual acuity in the right eye from exudative retinal detachment with mild retinal traction. Fluorescein angiography in the right eye disclosed extensive peripheral retinal non-perfusion and telangiectatic vessels and the left eye showed minimal peripheral non-perfusion. These features were suggestive of FEVR. Treatment with laser photocoagulation and cryotherapy to the region of non-perfusion was performed with resolution of the exudative retinal detachment. Fundus examination of the father revealed mild signs of FEVR, such as hyperacute retinal vascular branching and slight retinal vascular traction, whereas the mother's fundus examination was unremarkable. Genetic testing revealed that the affected boy was negative for mutations in the FZD4, NDP, and TSPAN12 genes and heterozygous for a previously unreported A745V variant in the LRP5 gene. The father was also heterozygous for the A745V variant in the LRP5 gene and the unaffected mother showed no mutation. A genetic evaluation of the known genes associated with FEVR revealed a novel variant in the LRP5 gene that co-segregated with the phenotype in the family. [J Pediatr Ophthalmol Strabismus. 2016;53:e39-e42.].
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Tang M, Ding X, Li J, Hu A, Yuan M, Yang Y, Zhan Z, Li Z, Lu L. Novel mutations in FZD4 and phenotype-genotype correlation in Chinese patients with familial exudative vitreoretinopathy. Mol Vis 2016; 22:917-32. [PMID: 27555740 PMCID: PMC4968609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 07/28/2016] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To identify novel mutations in the frizzled 4 (FZD4) gene in patients with familial exudative vitreoretinopathy (FEVR) in southern China and to delineate the mutation-associated clinical manifestations. METHODS Clinical data and genomic DNA were collected from 100 probands and their family members. The coding regions of FZD4 were screened for mutations with PCR and Sanger sequencing. Cosegregation analysis was used to verify suspected variants, and clinical symptoms in the probands were analyzed. RESULTS Fourteen causative heterozygous mutations in FZD4 in 21 unrelated probands were noted, in 21.0% of the index patients (21/100). Four novel missense mutations (C45R, C45S, C53S, and C90R) and three novel deletion mutations (T326fsX356, G492fsX512, and S345_A351del) with a high possibility of pathogenicity were detected. None of these mutations were found in current online databases and 150 ethnically matched control subjects without retinopathy. The majority of the mutations in FZD4 were identified in probands with retinal folds (15/21) and ectopic macula (5/21). No mutations in FZD4 were found in probands with complete tractional retinal detachment in infancy or with mild asymptomatic FEVR in adulthood. CONCLUSIONS Seven novel mutations found in this study have broadened the spectrum of mutations in FZD4 known to cause FEVR, providing a deeper understanding of this disease. The results show that mutations in FZD4 are associated with the phenotypes of retinal folds or ectopic macula in FEVR but might not be associated with extreme severe bilateral FEVR during infancy, at least in southern Chinese patients.
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Musada GR, Syed H, Jalali S, Chakrabarti S, Kaur I. Mutation spectrum of the FZD-4, TSPAN12 AND ZNF408 genes in Indian FEVR patients. BMC Ophthalmol 2016; 16:90. [PMID: 27316669 PMCID: PMC4912735 DOI: 10.1186/s12886-016-0236-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 05/10/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mutations in candidate genes that encode for a ligand (NDP) and receptor complex (FZD4, LRP5 and TSPAN12) in the Norrin β-catenin signaling pathway are involved in the pathogenesis of familial exudative vitreoretinopathy (FEVR, MIM # 133780). Recently, a transcription factor (ZNF408) has also been implicated in FEVR. We had earlier characterized the variations in NDP among FEVR patients from India. The present study aimed at understanding the involvement of the remaining genes (FZD4, TSPAN12 and ZNF408) in the same cohort. METHODS The DNA of 110 unrelated FEVR patients and 115 unaffected controls were screened for variations in the entire coding and untranslated regions of these 3 genes by resequencing. Segregation of the disease-associated variants was assessed in the family members of the probands. The effect of the observed missense changes were further analyzed by SIFT and PolyPhen-2 scores. RESULTS The screening of FZD4, TSPAN12 and ZNF408 genes identified 11 different mutations in 15/110 FEVR probands. Of the 11 identified mutations, 6 mutations were novel. The detected missense mutations were mainly located in the domains which are functionally crucial for the formation of ligand-receptor complex and as they replaced evolutionarily highly conserved amino acids with a SIFT score < 0.005, they are predicted to be pathogenic. Additionally 2 novel and 16 reported single nucleotide polymorphisms (SNP) were also detected. CONCLUSIONS Our genetic screening revealed varying mutation frequencies in the FZD4 (8.0 %), TSPAN12 (5.4 %) and ZNF408 (2.7 %) genes among the FEVR patients, indicating their potential role in the disease pathogenesis. The observed mutations segregated with the disease phenotype and exhibited variable expressivity. The mutations in FZD4 and TSPAN12 were involved in autosomal dominant and autosomal recessive families and further validates the involvement of these gene in FEVR development.
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Affiliation(s)
- Ganeswara Rao Musada
- Kallam Anji Reddy Molecular Genetics Laboratory, Brien Holden Eye Research Centre, L V Prasad Eye Institute (KAR Campus), Road#2, Banjara Hills, Hyderabad, 500034, India
| | - Hameed Syed
- Kallam Anji Reddy Molecular Genetics Laboratory, Brien Holden Eye Research Centre, L V Prasad Eye Institute (KAR Campus), Road#2, Banjara Hills, Hyderabad, 500034, India
| | - Subhadra Jalali
- Smt. Kanuri Santhamma Centre for Vitreo Retinal Diseases, LV Prasad Eye Institute, Hyderabad, India
| | - Subhabrata Chakrabarti
- Kallam Anji Reddy Molecular Genetics Laboratory, Brien Holden Eye Research Centre, L V Prasad Eye Institute (KAR Campus), Road#2, Banjara Hills, Hyderabad, 500034, India
| | - Inderjeet Kaur
- Kallam Anji Reddy Molecular Genetics Laboratory, Brien Holden Eye Research Centre, L V Prasad Eye Institute (KAR Campus), Road#2, Banjara Hills, Hyderabad, 500034, India.
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Zhang L, Yang Y, Li S, Tai Z, Huang L, Liu Y, Zhu X, Di Y, Qu C, Jiang Z, Li Y, Zhang G, Kim R, Sundaresan P, Yang Z, Zhu X. Whole Exome Sequencing Analysis Identifies Mutations in LRP5 in Indian Families with Familial Exudative Vitreoretinopathy. Genet Test Mol Biomarkers 2016; 20:346-51. [PMID: 27228167 DOI: 10.1089/gtmb.2015.0322] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Familial exudative vitreoretinopathy (FEVR, OMIM 133780) is a severe inherited retinal disorder characterized by incomplete retinal vascular development and neovascularization. At least five genes have been reported to be associated with FEVR, including NDP, LRP5, FZD4, TSPAN12, and ZNF408. Recently reported data showed that mutations in the KIF11 gene can also lead to FEVR conditions. Previous studies suggested that known mutations only explain approximately 40-60% of FEVR cases in different populations. PURPOSE To investigate the causative genetic mutations in four Indian families with FEVR. METHODS Whole exome sequencing was carried out to analyze the genomic DNA samples from the four FEVR proband patients and Sanger sequencing was utilized to verify all identified polymorphisms. A luciferase assay was used to test the mutant protein activity. RESULTS We identified four novel LRP5 missense mutations in these FEVR families: c.C1042T (p.R348W), c.G1141A (p.D381N), c.C1870T (p.R624W), and c.A4550G (p.Y1517C). The luciferase assay demonstrated that all four of these LRP5 mutations led to significant reduction of enzymatic activity with response to NORRIN, suggesting that they are pathogenic. CONCLUSION Our findings expand the mutational spectrum of FEVR in the Indian population and provide some guidelines in clinical diagnosis.
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Affiliation(s)
- Lin Zhang
- 1 Chengdu Institute of Biology, Chinese Academy of Sciences , Chengdu, China .,2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China
| | - Yeming Yang
- 2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China .,4 Key Laboratory for NeuroInformation of Ministry of Education and Medical Information Center, School of Medicine, University of Electronic Science and Technology of China , Chengdu, Sichuan, China
| | - Shujin Li
- 1 Chengdu Institute of Biology, Chinese Academy of Sciences , Chengdu, China .,2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China
| | - Zhengfu Tai
- 1 Chengdu Institute of Biology, Chinese Academy of Sciences , Chengdu, China .,2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China
| | - Lulin Huang
- 2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China .,4 Key Laboratory for NeuroInformation of Ministry of Education and Medical Information Center, School of Medicine, University of Electronic Science and Technology of China , Chengdu, Sichuan, China
| | - Yuqing Liu
- 2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China .,4 Key Laboratory for NeuroInformation of Ministry of Education and Medical Information Center, School of Medicine, University of Electronic Science and Technology of China , Chengdu, Sichuan, China
| | - Xiong Zhu
- 1 Chengdu Institute of Biology, Chinese Academy of Sciences , Chengdu, China .,2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China .,4 Key Laboratory for NeuroInformation of Ministry of Education and Medical Information Center, School of Medicine, University of Electronic Science and Technology of China , Chengdu, Sichuan, China
| | - Yanan Di
- 2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China
| | - Chao Qu
- 2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China
| | - Zhilin Jiang
- 2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China
| | - Yuanfeng Li
- 2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China
| | - Guolin Zhang
- 1 Chengdu Institute of Biology, Chinese Academy of Sciences , Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China
| | - Ramasamy Kim
- 5 Retina-Vitreous Services, Aravind Eye Hospital , Madurai, Tamil Nadu, India
| | - Periasamy Sundaresan
- 6 Department of Genetics, Aravind Medical Research Foundation, Aravind Eye Hospital , Madurai, Tamil Nadu, India
| | - Zhenglin Yang
- 1 Chengdu Institute of Biology, Chinese Academy of Sciences , Chengdu, China .,2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China .,4 Key Laboratory for NeuroInformation of Ministry of Education and Medical Information Center, School of Medicine, University of Electronic Science and Technology of China , Chengdu, Sichuan, China
| | - Xianjun Zhu
- 2 Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Hospital of the University of Electronic Science and Technology of China , and Sichuan Provincial People's Hospital, Chengdu, China .,3 Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital , Chengdu, Sichuan, China .,4 Key Laboratory for NeuroInformation of Ministry of Education and Medical Information Center, School of Medicine, University of Electronic Science and Technology of China , Chengdu, Sichuan, China .,7 Institute of Laboratory Animal Sciences, Sichuan Academy of Medical Science and Sichuan Provincial People's Hospital , Chengdu, Sichuan, China
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Musada GR, Jalali S, Hussain A, Chururu AR, Gaddam PR, Chakrabarti S, Kaur I. Mutation spectrum of the Norrie disease pseudoglioma (NDP) gene in Indian patients with FEVR. Mol Vis 2016; 22:491-502. [PMID: 27217716 PMCID: PMC4872281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 05/13/2016] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Mutations in the Norrie disease pseudoglioma (NDP; Xp11.3) gene have been involved in retinal blood vessel formation and neural differentiation and are implicated in familial exudative vitreoretinopathy (FEVR) cases. However, the role of the gene has not been explored in the Indian context. Thus, this study was designed to understand the involvement of NDP among Indian patients with FEVR. METHODS The study cohort comprised 225 subjects, including unrelated patients with FEVR (n = 110) and ethnically matched healthy subjects (n = 115) recruited from a tertiary eye care center in India. The entire coding regions, intron-exon boundaries, along with the 5' and 3' untranslated regions of NDP were screened with resequencing following standard protocols. The spectrum of the observed variants was analyzed in conjunction with data available from other populations. RESULTS Eight potentially pathogenic mutations (p.His4ArgfsX21, p.Asp23GlufsX9, p.Ile48ValfsX55, p.His50Asp, p.Ser57*, p.Gly113Asp, p.Arg121Gln, and p.Cys126Arg, including five novel ones), were observed in the coding region of the NDP gene in ten unrelated FEVR probands (9%). The novel changes were not observed in the control subjects and were unavailable in the dbSNP, ESP5400, NIEHS95, and ExAC databases. All probands with NDP mutations exhibited classical features of the disease as observed among patients with FEVR worldwide. CONCLUSIONS This is perhaps the first study to demonstrate the involvement of NDP among patients with Indian FEVR that further expands its mutation spectrum. The data generated could have broad implications in genetic counseling, disease management, and early intervention for a better prognosis in FEVR.
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Affiliation(s)
- Ganeswara Rao Musada
- Kallam Anji Reddy Molecular Genetics Laboratory, Brien Holden Eye Research Centre, BHERC, L V Prasad Eye Institute, Hyderabad, India
| | - Subhadra Jalali
- Smt. Kanuri Santhamma Centre for Vitreo Retinal Diseases, L V Prasad Eye Institute, Hyderabad, India
| | - Anjli Hussain
- Smt. Kanuri Santhamma Centre for Vitreo Retinal Diseases, L V Prasad Eye Institute, Hyderabad, India
| | | | | | - Subhabrata Chakrabarti
- Kallam Anji Reddy Molecular Genetics Laboratory, Brien Holden Eye Research Centre, BHERC, L V Prasad Eye Institute, Hyderabad, India
| | - Inderjeet Kaur
- Kallam Anji Reddy Molecular Genetics Laboratory, Brien Holden Eye Research Centre, BHERC, L V Prasad Eye Institute, Hyderabad, India
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Wu JH, Liu JH, Ko YC, Wang CT, Chung YC, Chu KC, Liu TT, Chao HM, Jiang YJ, Chen SJ, Chung MY. Haploinsufficiency of RCBTB1 is associated with Coats disease and familial exudative vitreoretinopathy. Hum Mol Genet 2016; 25:1637-47. [PMID: 26908610 DOI: 10.1093/hmg/ddw041] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/08/2016] [Indexed: 12/31/2022] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) belongs to a group of genetically and clinically heterogeneous disorders in retinal vascular development. To date, in approximately 50% of patients with FEVR, pathogenic mutations have been detected in FZD4, LRP5, TSPAN12, NDP and ZNF408. In this study, we identified two heterozygous frameshift mutations in RCBTB1 from three Taiwanese cases through exome sequencing. In patient-derived lymphoblastoid cell lines (LCLs), the protein level of RCBTB1 is approximately half that of unaffected control LCLs, which is indicative of a haploinsufficiency mechanism. By employing transient transfection and reporter assays for the transcriptional activity of β-catenin, we demonstrated that RCBTB1 participates in the Norrin/FZD4 signaling pathway and that knockdown of RCBTB1 by shRNA significantly reduced nuclear accumulation of β-catenin under Norrin and Wnt3a treatments. Furthermore, transgenic fli1:EGFP zebrafish with rcbtb1 knockdown exhibited anomalies in intersegmental and intraocular vessels. These results strongly support that reduced RCBTB1 expression may lead to defects in angiogenesis through the Norrin-dependent Wnt pathway, and that RCBTB1 is a putative genetic cause of vitreoretinopathies.
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Affiliation(s)
- Jeng-Hung Wu
- Department of Life Sciences and Institute of Genome Sciences
| | - Jorn-Hon Liu
- Department of Ophthalmology, Cheng-Hsin General Hospital, Taipei, 11220, Taiwan, ROC
| | - Yu-Chieh Ko
- Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan, ROC, Department of Ophthalmology
| | - Chi-Tang Wang
- Department of Life Sciences and Institute of Genome Sciences
| | | | - Kuo-Chang Chu
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli 35053, Taiwan, ROC
| | | | - Hsiao-Ming Chao
- Department of Ophthalmology, Cheng-Hsin General Hospital, Taipei, 11220, Taiwan, ROC
| | - Yun-Jin Jiang
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli 35053, Taiwan, ROC
| | | | - Ming-Yi Chung
- Department of Life Sciences and Institute of Genome Sciences, Department of Medical Research, Taipei Veterans General Hospital, Taipei, 11217, Taiwan, ROC and
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Kramer GD, Say EAT, Shields CL. Simultaneous Novel Mutations of LRP5 and TSPAN12 in a Case of Familial Exudative Vitreoretinopathy. J Pediatr Ophthalmol Strabismus 2016; 53 Online:e1-5. [PMID: 27007396 DOI: 10.3928/01913913-20151215-01] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 12/14/2015] [Indexed: 11/20/2022]
Abstract
Familial exudative vitreoretinopathy and osteoporosis pseudoglioma syndrome are conditions that result from mutations in the LRP5 gene. Persistent fetal vasculature is a rare congenital malformation that can mimic end-stage familial exudative vitreoretinopathy. The authors report a case of familial exudative vitreoretinopathy in the spectrum of osteoporosis pseudoglioma syndrome associated with novel mutations of the LRP5 and TSPAN12 genes that resulted in a phenotype similar to bilateral persistent fetal vasculature. Both conditions can result in bilateral early-onset blindness. A high index of suspicion, dilated fundus examination and angiography of the parents, and genetic testing are necessary to ensure a correct diagnosis.
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Kheir V, Munier FL, Aubry-Rozier B, Schorderet DF. Potential blindness in children of patients with hereditary bone disease. Osteoporos Int 2016; 27:841-4. [PMID: 26243358 DOI: 10.1007/s00198-015-3245-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 07/08/2015] [Indexed: 11/27/2022]
Abstract
Mono- and bi-allelic mutations in the low-density lipoprotein receptor related protein 5 (LRP5) may cause osteopetrosis, autosomal dominant and recessive exudative vitreoretinopathy, juvenile osteoporosis, or persistent hyperplastic primary vitreous (PHPV). We report on a child affected with PHPV and carrying compound mutations. The father carried the splice mutation and suffered from severe bone fragility since childhood. The mother carried the missense mutation without any clinical manifestations. The genetic diagnosis of their child allowed for appropriate treatment in the father and for the detection of osteopenia in the mother. Mono- and bi-allelic mutations in LRP5 may cause osteopetrosis, autosomal dominant and recessive exudative vitreoretinopathy, juvenile osteoporosis, or PHPV. PHPV is a component of persistent fetal vasculature of the eye, characterized by highly variable expressivity and resulting in a wide spectrum of anterior and/or posterior congenital developmental defects, which may lead to blindness. We evaluated a family diagnosed with PHPV in their only child. The child presented photophobia during the first 3 weeks of life, followed by leukocoria at 2 months of age. Molecular resequencing of NDP, FZD4, and LRP5 was performed in the child and segregation of the observed mutations in the parents. At presentation, fundus examination of the child showed a retrolental mass in the right eye. Ultrasonography revealed retinal detachment in both eyes. Thorough familial analysis revealed that the father suffered from many fractures since childhood without specific fragility bone diagnosis, treatment, or management. The mother was asymptomatic. Molecular analysis in the proband identified two mutations: a c.[2091+2T>C] splice mutation and c.[1682C>T] missense mutation. We report the case of a child affected with PHPV and carrying compound heterozygous LRP5 mutations. This genetic diagnosis allowed the clinical diagnosis of the bone problem to be made in the father, resulting in better management of the family. It also enabled preventive treatment to be prescribed for the mother and accurate genetic counseling to be provided.
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Affiliation(s)
- V Kheir
- IRO - Institute for Research in Ophthalmology, Av. du Grand-Champsec 64, 1950, Sion, Switzerland
| | - F L Munier
- IRO - Institute for Research in Ophthalmology, Av. du Grand-Champsec 64, 1950, Sion, Switzerland
- Department of Ophthalmology, Jules-Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland
| | - B Aubry-Rozier
- Bone and Joint Department, Center of Bone Diseases, University of Lausanne, Lausanne, Switzerland
| | - D F Schorderet
- IRO - Institute for Research in Ophthalmology, Av. du Grand-Champsec 64, 1950, Sion, Switzerland.
- Department of Ophthalmology, Jules-Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland.
- Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
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Fei P, Zhu X, Jiang Z, Ma S, Li J, Zhang Q, Zhou Y, Xu Y, Tai Z, Zhang L, Huang L, Yang Z, Zhao P, Zhu X. Identification and functional analysis of novel FZD4 mutations in Han Chinese with familial exudative vitreoretinopathy. Sci Rep 2015; 5:16120. [PMID: 26530129 PMCID: PMC4632081 DOI: 10.1038/srep16120] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/09/2015] [Indexed: 12/19/2022] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) is a hereditary eye disease characterized by defects in the development of retinal vessels. However, known genetic mutations can only explain approximately 50% of FEVR patients. To assess the mutation frequency of Frizzled 4 (FZD4) in Chinese patients, we analysed patients with FEVR from 61 families from China to identify mutations in FZD4 and to study the effects of identified mutations on FZD4 function. All coding exons and adjacent intronic regions of FZD4 were amplified by polymerase chain reaction and subjected to Sanger sequencing analysis. Three mutations in the FZD4 gene were identified in these families. Of these, two were novel mutations: p.E134* and p.T503fs. Both mutations involve highly conserved residues and were not present in 800 normal individuals. Each of these two novel FZD4 mutations was introduced into wild-type FZD4 cDNA by site-directed mutagenesis. Wild-type and mutant FZD4 DNAs were introduced into HEK293 cells to analyse the function of FZD4 in Norrin-dependent activation of the Norrin/β-catenin pathway using luciferase reporter assays. Both the p.E134* and p.T503fs mutants failed to induce luciferase reporter activity in response to Norrin. Our study identified two novel FZD4 mutations in Chinese patients with FEVR.
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Affiliation(s)
- Ping Fei
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Xiong Zhu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Zhilin Jiang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Shi Ma
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Jing Li
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Qi Zhang
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Yu Zhou
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Yu Xu
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Zhengfu Tai
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Lin Zhang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Lulin Huang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Zhenglin Yang
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China.,Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Peiquan Zhao
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Xianjun Zhu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China
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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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Alonso N, Soares DC, V McCloskey E, Summers GD, Ralston SH, Gregson CL. Atypical femoral fracture in osteoporosis pseudoglioma syndrome associated with two novel compound heterozygous mutations in LRP5. J Bone Miner Res 2015; 30:615-20. [PMID: 25384351 DOI: 10.1002/jbmr.2403] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 10/20/2014] [Accepted: 11/05/2014] [Indexed: 12/13/2022]
Abstract
Osteoporosis pseudoglioma syndrome (OPPG) is a rare autosomal recessive condition of congenital blindness and severe childhood osteoporosis with skeletal fragility, caused by loss-of-function mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene. We report the first case of atypical (subtrochanteric) femoral fracture (AFF) in OPPG, occurring in a 38-year-old man within the context of relatively low bone turnover and trabecular osteoporosis on bone histology. We identify two novel LRP5 mutations: R752W is associated with low bone mineral density (BMD), as demonstrated by the heterozygous carriage identified in his 57-year-old mother; however, the combination of this R752W mutation with another novel W79R mutation, causes a severe case of compound heterozygous OPPG. We undertake 3D homology modeling of the four extracellular YWTD β-propeller/EGF-like domains (E1-E4) of LRP5, and show that both novel mutations destabilize the β-propeller domains that are critical for protein and ligand binding to regulate Wnt signaling and osteoblast function. Although AFFs have been reported in other rare bone diseases, this is the first in a genetic condition of primary osteoblast dysfunction. The relatively low bone turnover observed, and knowledge of LRP5 function, implicates impaired bone remodeling in the pathogenesis of AFF.
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Affiliation(s)
- Nerea Alonso
- Rheumatic Diseases Unit, Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
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74
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Familial exudative vitreoretinopathy and related retinopathies. Eye (Lond) 2014; 29:1-14. [PMID: 25323851 DOI: 10.1038/eye.2014.70] [Citation(s) in RCA: 176] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 03/05/2014] [Indexed: 12/24/2022] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) is a rare inherited disorder of retinal angiogenesis. Cases can be autosomal dominant, autosomal recessive, or X-linked. FEVR patients have an avascular peripheral retina which, depending on the degree of ischaemia, causes the secondary complications of the disease. Expressivity may be asymmetric and is highly variable. Five genes have been identified that when mutated, cause FEVR; NDP (X-linked), FZD4 (autosomal dominant and recessive), LRP5 (autosomal dominant and recessive), TSPAN12 (autosomal dominant and recessive), and ZNF408 (autosomal dominant). Four of these genes have been shown to have a central role in Norrin/Frizzled4 signalling, suggesting a critical role for this pathway in retinal angiogenesis. In addition to the ocular features, LRP5 mutations can cause osteopenia and osteoporosis. All FEVR patients in whom molecular testing is not easily accessible should have dual energy X-ray absorptiometry (DEXA) scans to assess bone mineral density, as treatment can be initiated to reduce the risk of bone fractures.
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75
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Gal M, Levanon EY, Hujeirat Y, Khayat M, Pe'er J, Shalev S. Novel mutation in TSPAN12 leads to autosomal recessive inheritance of congenital vitreoretinal disease with intra-familial phenotypic variability. Am J Med Genet A 2014; 164A:2996-3002. [DOI: 10.1002/ajmg.a.36739] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Accepted: 06/23/2014] [Indexed: 11/05/2022]
Affiliation(s)
- Moran Gal
- The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat-Gan Israel
| | - Erez Y. Levanon
- The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat-Gan Israel
| | - Yasir Hujeirat
- The Genetic Institute; Emek Medical Center; Afula Israel
| | - Morad Khayat
- The Genetic Institute; Emek Medical Center; Afula Israel
| | - Jacob Pe'er
- Department of Ophthalmology; Hadassah-Hebrew University Medical Center; Jerusalem Israel
| | - Stavit Shalev
- The Genetic Institute; Emek Medical Center; Afula Israel
- Rappaport Faculty of Medicine; Technion; Haifa Israel
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Cook FJ, Mumm S, Whyte MP, Wenkert D. Pregnancy-associated osteoporosis with a heterozygous deactivating LDL receptor-related protein 5 (LRP5) mutation and a homozygous methylenetetrahydrofolate reductase (MTHFR) polymorphism. J Bone Miner Res 2014; 29:922-8. [PMID: 24014470 DOI: 10.1002/jbmr.2095] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 07/26/2013] [Accepted: 09/05/2013] [Indexed: 11/07/2022]
Abstract
Pregnancy-associated osteoporosis (PAO) is a rare, idiopathic disorder that usually presents with vertebral compression fractures (VCFs) within 6 months of a first pregnancy and delivery. Spontaneous improvement is typical. There is no known genetic basis for PAO. A 26-year-old primagravida with a neonatal history of unilateral blindness attributable to hyperplastic primary vitreous sustained postpartum VCFs consistent with PAO. Her low bone mineral density (BMD) seemed to respond to vitamin D and calcium therapy, with no fractures after her next successful pregnancy. Investigation of subsequent fetal losses revealed homozygosity for the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism associated both with fetal loss and with osteoporosis (OP). Because her neonatal unilateral blindness and OP were suggestive of loss-of-function mutation(s) in the gene that encodes LDL receptor-related protein 5 (LRP5), LRP5 exon and splice site sequencing was also performed. This revealed a unique heterozygous 12-bp deletion in exon 21 (c.4454_4465del, p.1485_1488del SSSS) in the patient, her mother and sons, but not her father or brother. Her mother had a normal BMD, no history of fractures, PAO, ophthalmopathy, or fetal loss. Her two sons had no ophthalmopathy and no skeletal issues. Her osteoporotic father (with a family history of blindness) and brother had low BMDs first documented at ages ∼40 and 32 years, respectively. Serum biochemical and bone turnover studies were unremarkable in all subjects. We postulate that our patient's heterozygous LRP5 mutation together with her homozygous MTHFR polymorphism likely predisposed her to low peak BMD. However, OP did not cosegregate in her family with the LRP5 mutation, the homozygous MTHFR polymorphism, or even the combination of the two, implicating additional genetic or nongenetic factors in her PAO. Nevertheless, exploration for potential genetic contributions to PAO may explain part of the pathogenesis of this enigmatic disorder and identify some at-risk women.
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Affiliation(s)
- Fiona J Cook
- Division of Endocrinology, Brody School of Medicine, Greenville, NC, USA
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Fei P, Zhang Q, Huang L, Xu Y, Zhu X, Tai Z, Gong B, Ma S, Yao Q, Li J, Zhao P, Yang Z. Identification of two novel LRP5 mutations in families with familial exudative vitreoretinopathy. Mol Vis 2014; 20:395-409. [PMID: 24715757 PMCID: PMC3976684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 03/27/2014] [Indexed: 11/16/2022] Open
Abstract
PURPOSE To investigate the clinical features and disease-causing mutations in two Chinese families with familial exudative vitreoretinopathy (FEVR). METHODS Clinical data and genomic DNA were collected for patients with FEVR. The coding exons and adjacent intronic regions of FZD4, LRP5, TSPAN12, and NDP were amplified with PCR, and the resulting amplicons were analyzed with Sanger sequencing. Wild-type and mutant LRP5 proteins were assayed for the Norrin/β-catenin pathway by luciferase reporter assays. RESULTS Two novel heterozygous mutations in the LRP5 gene were identified in two relatives--p.A422T and p.L540P. Typical FEVR fundus change and mild reduced bone mineral density (BMD) was found in the two patients and the affected parent. In the luciferase studies, both p.A422T and p.L540P mutants displayed a significant reduction of the luciferase activity in SuperTopFlash (STF) cells in response to Norrin (87% reduction for p.A422T and 97% reduction for p.L540P). Both patients had an additional LRP5 sequence change (p.Q816P in Patient 1 from the unaffected mother and p.T852M in Patient 2 verified as a new mutation). Luciferase assay showed no reduction for p.Q816P and 94.9% reduction for the new mutation p.T852M, suggesting that p.Q816P may be not pathogenic and p.T852M may be pathogenic. CONCLUSIONS Our findings demonstrated two new novel LRP5 mutations in Chinese patients with FEVR and mild reduced BMD. They emphasize the complexity of FEVR mutations and phenotypes.
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Affiliation(s)
- Ping Fei
- Department of Ophthalmology, Xin Hua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qi Zhang
- Department of Ophthalmology, Xin Hua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Luling Huang
- Sichuan Key Laboratory for Human Disease Gene Study, Institute of Laboratory Medicine, School of Medicine, University of Science and Technology of China & Sichuan Provincial People's Hospital & Sichuan Provincial People’s Hospital, Sichuan, China
| | - Yu Xu
- Department of Ophthalmology, Xin Hua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiong Zhu
- Sichuan Key Laboratory for Human Disease Gene Study, Institute of Laboratory Medicine, School of Medicine, University of Science and Technology of China & Sichuan Provincial People's Hospital & Sichuan Provincial People’s Hospital, Sichuan, China
| | - Zhengfu Tai
- Sichuan Key Laboratory for Human Disease Gene Study, Institute of Laboratory Medicine, School of Medicine, University of Science and Technology of China & Sichuan Provincial People's Hospital & Sichuan Provincial People’s Hospital, Sichuan, China
| | - Bo Gong
- Sichuan Key Laboratory for Human Disease Gene Study, Institute of Laboratory Medicine, School of Medicine, University of Science and Technology of China & Sichuan Provincial People's Hospital & Sichuan Provincial People’s Hospital, Sichuan, China
| | - Shi Ma
- Sichuan Key Laboratory for Human Disease Gene Study, Institute of Laboratory Medicine, School of Medicine, University of Science and Technology of China & Sichuan Provincial People's Hospital & Sichuan Provincial People’s Hospital, Sichuan, China
| | | | - Jing Li
- Department of Ophthalmology, Xin Hua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Peiquan Zhao
- Department of Ophthalmology, Xin Hua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhenglin Yang
- Sichuan Key Laboratory for Human Disease Gene Study, Institute of Laboratory Medicine, School of Medicine, University of Science and Technology of China & Sichuan Provincial People's Hospital & Sichuan Provincial People’s Hospital, Sichuan, China
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78
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Sutherland JE, Day MA. Advantages and disadvantages of molecular testing in ophthalmology. EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/eop.11.2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Kwinta P, Pietrzyk JJ. Retinopathy of prematurity: is genetic predisposition an important risk factor? EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/17469899.2.2.275] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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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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81
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Deletion of LRP5 in VLDLR knockout mice inhibits retinal neovascularization. PLoS One 2013; 8:e75186. [PMID: 24058663 PMCID: PMC3772893 DOI: 10.1371/journal.pone.0075186] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 08/12/2013] [Indexed: 11/19/2022] Open
Abstract
The development and maintenance of retinal vasculature require a precise balance between pro-angiogenic and anti-angiogenic factors. However, mechanisms underlying normal homeostasis of retinal vasculature and pathological changes of disrupted retinal vessel development are not fully understood. Recent studies of the low-density lipoprotein receptor-related protein 5 (LRP5) and the very low-density lipoprotein receptor (VLDLR) mutant mice indicate that LRP5 mediates a pro-angiogenic signal while VLDLR mediates an anti-angiogenic signal in retinal vasculature. Mice with a loss of LRP5 display underdeveloped intraretinal vasculature associated with endothelial cell (EC) clustering and failed EC migration into deep retinal layers. In contrast, VLDLR knockout mice show overgrown intraretinal vasculature and subretinal neovascularization. To understand the mechanisms for the opposite retinal vascular abnormalities between LRP5 and VLDLR mutant mice and to test how a loss of LRP5 perturbs subretinal neovascularization caused by a loss of VLDLR, we have generated and characterized the retinal vasculature in LRP5/VLDLR double knockout (DKO) mice. Our data show that DKO mice develop substantial EC clustering without subretinal neovascularization. The absence of subretinal neovascularization in DKO mice is associated with inhibited migration of ECs into the photoreceptor cell layer. In addition, the transcription level of Slc38a5, which encodes a Müller cell specific glutamine transporter, is significantly reduced in DKO mice, similar to previously reported changes in LRP5 single knockout mice. Thus, LRP5 signaling is a prerequisite for neovascularization in VLDLR knockout mice. LRP5 may be an effective target for inhibiting intraretinal neovascularization.
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Savarese M, Spinelli E, Gandolfo F, Lemma V, Di Fruscio G, Padoan R, Morescalchi F, D'Agostino M, Savoldi G, Semeraro F, Nigro V, Bonatti S. Familial exudative vitreoretinopathy caused by a homozygous mutation in TSPAN12 in a cystic fibrosis infant. Ophthalmic Genet 2013; 35:184-6. [PMID: 23834558 DOI: 10.3109/13816810.2013.811270] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Familial exudative vitreoretinopathy (FEVR) is a genetic disease affecting the vascularization of the peripheral retina. The clinical manifestations are very heterogeneous, ranging from mildly affected patients, who could present no visual defects, to severe conditions which can also cause complete blindness at birth or in the first decade. FEVR can be inherited in all the three genetic forms: dominant, recessive and X-linked. To date, four genes have been associated with the condition: TSPAN12. NDP. FDZ4 and LRP5. Interestingly, mutations in TSPAN12 have been considered causative of both a dominant and recessive inheritance and a FEVR phenotype sensitive to the number of TSPAN12 mutations has been supposed. Here we describe a case of a female infant affected by cystic fibrosis and by a severe form of exudative vitreoretinopathy. In particular, we have detected the homozygous missense mutation c.668 T > C in TSPAN12. Neither of the heterozygous parents has ocular manifestations of the disease, suggesting a classic recessive mendelian pattern of inheritance.
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Affiliation(s)
- Marco Savarese
- Department of Biochemistry, Biophysics and General Pathology, Second University of Naples , Italy
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ZNF408 is mutated in familial exudative vitreoretinopathy and is crucial for the development of zebrafish retinal vasculature. Proc Natl Acad Sci U S A 2013; 110:9856-61. [PMID: 23716654 DOI: 10.1073/pnas.1220864110] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) is a genetically heterogeneous disorder characterized by abnormal vascularization of the peripheral retina, which can result in retinal detachment and severe visual impairment. In a large Dutch FEVR family, we performed linkage analysis, exome sequencing, and segregation analysis of DNA variants. We identified putative disease-causing DNA variants in proline-alanine-rich ste20-related kinase (c.791dup; p.Ser265ValfsX64) and zinc finger protein 408 (ZNF408) (c.1363C>T; p.His455Tyr), the latter of which was also present in an additional Dutch FEVR family that subsequently appeared to share a common ancestor with the original family. Sequence analysis of ZNF408 in 132 additional individuals with FEVR revealed another potentially pathogenic missense variant, p.Ser126Asn, in a Japanese family. Immunolocalization studies in COS-1 cells transfected with constructs encoding the WT and mutant ZNF408 proteins, revealed that the WT and the p.Ser126Asn mutant protein show complete nuclear localization, whereas the p.His455Tyr mutant protein was localized almost exclusively in the cytoplasm. Moreover, in a cotransfection assay, the p.His455Tyr mutant protein retains the WT ZNF408 protein in the cytoplasm, suggesting that this mutation acts in a dominant-negative fashion. Finally, morpholino-induced knockdown of znf408 in zebrafish revealed defects in developing retinal and trunk vasculature, that could be rescued by coinjection of RNA encoding human WT ZNF408 but not p.His455Tyr mutant ZNF408. Together, our data strongly suggest that mutant ZNF408 results in abnormal retinal vasculogenesis in humans and is associated with FEVR.
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Maupin KA, Droscha CJ, Williams BO. A Comprehensive Overview of Skeletal Phenotypes Associated with Alterations in Wnt/β-catenin Signaling in Humans and Mice. Bone Res 2013; 1:27-71. [PMID: 26273492 DOI: 10.4248/br201301004] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 01/20/2013] [Indexed: 12/23/2022] Open
Abstract
The Wnt signaling pathway plays key roles in differentiation and development and alterations in this signaling pathway are causally associated with numerous human diseases. While several laboratories were examining roles for Wnt signaling in skeletal development during the 1990s, interest in the pathway rose exponentially when three key papers were published in 2001-2002. One report found that loss of the Wnt co-receptor, Low-density lipoprotein related protein-5 (LRP5), was the underlying genetic cause of the syndrome Osteoporosis pseudoglioma (OPPG). OPPG is characterized by early-onset osteoporosis causing increased susceptibility to debilitating fractures. Shortly thereafter, two groups reported that individuals carrying a specific point mutation in LRP5 (G171V) develop high-bone mass. Subsequent to this, the causative mechanisms for these observations heightened the need to understand the mechanisms by which Wnt signaling controlled bone development and homeostasis and encouraged significant investment from biotechnology and pharmaceutical companies to develop methods to activate Wnt signaling to increase bone mass to treat osteoporosis and other bone disease. In this review, we will briefly summarize the cellular mechanisms underlying Wnt signaling and discuss the observations related to OPPG and the high-bone mass disorders that heightened the appreciation of the role of Wnt signaling in normal bone development and homeostasis. We will then present a comprehensive overview of the core components of the pathway with an emphasis on the phenotypes associated with mice carrying genetically engineered mutations in these genes and clinical observations that further link alterations in the pathway to changes in human bone.
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Affiliation(s)
- Kevin A Maupin
- Program for Skeletal Pathobiology and Center for Tumor Metastasis, Van Andel Research Institute , 333 Bostwick NE, Grand Rapids, MI 49503, USA
| | - Casey J Droscha
- Program for Skeletal Pathobiology and Center for Tumor Metastasis, Van Andel Research Institute , 333 Bostwick NE, Grand Rapids, MI 49503, USA
| | - Bart O Williams
- Program for Skeletal Pathobiology and Center for Tumor Metastasis, Van Andel Research Institute , 333 Bostwick NE, Grand Rapids, MI 49503, USA
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Gandhi JK, Tollefson TT, Telander DG. Falciform macular folds and chromosome 22q11.2: evidence in support of a locus for familial exudative vitreoretinopathy (FEVR). Ophthalmic Genet 2013; 35:112-6. [PMID: 23521024 DOI: 10.3109/13816810.2013.779382] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Familial exudative vitreoretinopathy (FEVR) is a genetic disease caused by abnormal retinal vascular development. New additional genetic loci for FEVR have recently been identified. Microduplication of 22q11.2 has been reported with a heterogeneous phenotype and microdeletion of 22q11.2 has been associated with FEVR. We describe a case of a girl with microduplication of 22q11.2 and falciform macular folds. MATERIALS AND METHODS The infant and first-degree relatives were examined. A dilated fundus examination was performed. Genetic screening was done by chromosomal microarray analysis and confirmed by fluorescent in situ hybridization (FISH). RESULTS Bilateral macular folds were found with temporal fibrosis in the proband. A chromosomal microarray revealed a 2.21 Mb microduplication of the 22q11.2 region. CONCLUSION This is the first report to associate microduplication of 22q11.2 with macular folds, supporting the potential for a FEVR locus on chromosome 22q11.2. We encourage full ophthalmological examination for patients with microduplication of 22q11.2 to identify ocular associations.
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87
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Stiegel E, Say EAT, Carter BC, Thomas MJ, Shields CL. Simultaneous fzd4 and lrp5 mutation in autosomal dominant familial exudative vitreoretinopathy. Retin Cases Brief Rep 2013; 7:26-28. [PMID: 25390515 DOI: 10.1097/icb.0b013e31827537eb] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
PURPOSE The purpose of this study was to report simultaneous mutations of FZD4 and LRP5 genes associated with autosomal dominant familial exudative vitreoretinopathy in members of one family. METHODS Case report. RESULTS A 16-month-old white boy with a 6-month history of leukocoria was referred for possible retinoblastoma. On examination, the left eye displayed extensive white vitreoretinal fibrosis filling the entire vitreous cavity up to the lens and with additional dystrophic calcification and iris neovascularization. The right eye showed temporal peripheral fibrovascular ridge. Fluorescein angiography showed 360° of peripheral nonperfusion with leakage from the fibrovascular ridge of the right eye and diffuse leakage from the massive vitreoretinal fibrosis and iris neovascularization of the left eye, consistent with familial exudative vitreoretinopathy. Laser photocoagulation of the avascular areas of the right eye was performed with disease stabilization. Clinical examination and genetic testing of the family members demonstrated that the proband and a male sibling had similar clinical findings and simultaneous mutations in the FZD4 and LRP5 genes. Both affected patients had normal bone mineral dual-energy X-ray absorptiometry. CONCLUSION Familial exudative vitreoretinopathy is a retinal vascular disorder usually caused by a single mutation. Rarely, multiple simultaneous mutations can occur and, in this case, result in classic ophthalmic phenotypic and known risk for bone disorders.
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Affiliation(s)
- Evan Stiegel
- *Ocular Oncology Service, Wills Eye Institute, Thomas Jefferson University, Philadelphia, Pennsylvania †Department of Ophthalmology ‡Division of Pediatric Genetics, University of Virginia, Charlottesville, Virginia
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Yang H, Li S, Xiao X, Wang P, Guo X, Zhang Q. Identification of FZD4 and LRP5 mutations in 11 of 49 families with familial exudative vitreoretinopathy. Mol Vis 2012; 18:2438-46. [PMID: 23077402 PMCID: PMC3472927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 10/02/2012] [Indexed: 12/03/2022] Open
Abstract
PURPOSE To identify mutations in FZD4 and LRP5 in 49 Chinese families with familial exudative vitreoretinopathy (FEVR) and to reveal the mutation spectrum and frequency of these genes in the Chinese population. METHODS Clinical data and genomic DNA were collected for patients from 49 families with FEVR. The coding exons and adjacent intronic regions of FZD4 and LRP5 were amplified with polymerase chain reaction, and the resulting amplicons were analyzed with Sanger sequencing. RESULTS Eleven mutations were detected in 11 of the 49 families (22.4%), including five mutations in the FZD4 gene in six families and six mutations in the LRP5 gene in five families. Of the 11 mutations, eight were novel. Two families had the same FZD4 mutation, and one family had compound heterozygous mutations in LRP5. The phenotypes of the patients with the mutations showed great variability. CONCLUSIONS Our findings provide an overview of the mutation spectrum and frequency of FZD4 and LRP5 in Chinese patients with FEVR and emphasize the complexity of FEVR mutations and phenotypes.
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Edwards TL, Burt BO, Black GCM, Perveen R, Kearns LS, Staffieri SE, Toomes C, Buttery RG, Mackey DA. Familial retinal detachment associated with COL2A1 exon 2 and FZD4 mutations. Clin Exp Ophthalmol 2012; 40:476-83. [PMID: 22574936 DOI: 10.1111/j.1442-9071.2012.02804.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND To characterize the clinical and genetic abnormalities within two Australian pedigrees with high incidences of retinal detachment and visual disability. DESIGN Prospective review of two extended Australian pedigrees with high rates of retinal detachment. PARTICIPANTS Twenty-two family members from two extended Australian pedigrees with high rates of retinal detachment were examined. METHODS A full ophthalmic history and examination were performed, and DNA was analysed by linkage analysis and mutation screening. MAIN OUTCOME MEASURES Characterization of a causative hereditary gene mutation in each family. RESULTS All affected family members of one pedigree carried a C192A COL2A1 exon 2 mutation. None of the affected family members had early-onset arthritis, hearing abnormalities, abnormal clefting or facial features characteristic of classical Stickler syndrome. All affected members of the familial exudative vitreoretinopathy pedigree carried a 957delG FZD4 mutation. CONCLUSIONS Patients with retinal detachment and a positive family history should be investigated for heritable conditions associated with retinal detachment such as Stickler syndrome and familial exudative vitreoretinopathy. The absence of non-ocular features of Stickler syndrome should raise the possibility of mutations in exon 2 of COL2A1. Similarly, late-onset familial exudative vitreoretinopathy may appear more like a rhegmatogenous detachment and not be correctly diagnosed. When a causative gene mutation is identified, cascade genetic screening of the family will facilitate genetic counselling and screening of high-risk relatives, allowing targeted management of the pre-detachment changes in affected patients.
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Affiliation(s)
- Thomas L Edwards
- Centre for Eye Research Australia, University of Melbourne, Department of Ophthalmology Vitreo-retinal Unit, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria
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90
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Chen J, Stahl A, Krah NM, Seaward MR, Joyal JS, Juan AM, Hatton CJ, Aderman CM, Dennison RJ, Willett KL, Sapieha P, Smith LEH. Retinal expression of Wnt-pathway mediated genes in low-density lipoprotein receptor-related protein 5 (Lrp5) knockout mice. PLoS One 2012; 7:e30203. [PMID: 22272305 PMCID: PMC3260226 DOI: 10.1371/journal.pone.0030203] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 12/12/2011] [Indexed: 01/13/2023] Open
Abstract
Mutations in low-density lipoprotein receptor-related protein 5 (Lrp5) impair retinal angiogenesis in patients with familial exudative vitreoretinopathy (FEVR), a rare type of blinding vascular eye disease. The defective retinal vasculature phenotype in human FEVR patients is recapitulated in Lrp5 knockout (Lrp5−/−) mouse with delayed and incomplete development of retinal vessels. In this study we examined gene expression changes in the developing Lrp5−/− mouse retina to gain insight into the molecular mechanisms that underlie the pathology of FEVR in humans. Gene expression levels were assessed with an Illumina microarray on total RNA from Lrp5−/− and WT retinas isolated on postnatal day (P) 8. Regulated genes were confirmed using RT-qPCR analysis. Consistent with a role in vascular development, we identified expression changes in genes involved in cell-cell adhesion, blood vessel morphogenesis and membrane transport in Lrp5−/− retina compared to WT retina. In particular, tight junction protein claudin5 and amino acid transporter slc38a5 are both highly down-regulated in Lrp5−/− retina. Similarly, several Wnt ligands including Wnt7b show decreased expression levels. Plasmalemma vesicle associated protein (plvap), an endothelial permeability marker, in contrast, is up-regulated consistent with increased permeability in Lrp5−/− retinas. Together these data suggest that Lrp5 regulates multiple groups of genes that influence retinal angiogenesis and may contribute to the pathogenesis of FEVR.
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Affiliation(s)
- Jing Chen
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, Massachusetts, United States of America
| | - Andreas Stahl
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, Massachusetts, United States of America
- University Eye Hospital Freiburg, Freiburg, Germany
| | - Nathan M. Krah
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, Massachusetts, United States of America
| | - Molly R. Seaward
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, Massachusetts, United States of America
| | - Jean-Sebastian Joyal
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, Massachusetts, United States of America
| | - Aimee M. Juan
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, Massachusetts, United States of America
| | - Colman J. Hatton
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, Massachusetts, United States of America
| | - Christopher M. Aderman
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, Massachusetts, United States of America
| | - Roberta J. Dennison
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, Massachusetts, United States of America
| | - Keirnan L. Willett
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, Massachusetts, United States of America
| | - Przemyslaw Sapieha
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, Massachusetts, United States of America
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Montreal, Canada
| | - Lois E. H. Smith
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, Massachusetts, United States of America
- * E-mail:
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91
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Chen S, Bubeck D, MacDonald BT, Liang WX, Mao JH, Malinauskas T, Llorca O, Aricescu AR, Siebold C, He X, Jones EY. Structural and functional studies of LRP6 ectodomain reveal a platform for Wnt signaling. Dev Cell 2011; 21:848-61. [PMID: 22000855 PMCID: PMC3564486 DOI: 10.1016/j.devcel.2011.09.007] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 08/31/2011] [Accepted: 09/13/2011] [Indexed: 11/17/2022]
Abstract
LDL-receptor-related protein 6 (LRP6), alongside Frizzled receptors, transduces Wnt signaling across the plasma membrane. The LRP6 ectodomain comprises four tandem β-propeller-EGF-like domain (PE) pairs that harbor binding sites for Wnt morphogens and their antagonists including Dickkopf 1 (Dkk1). To understand how these multiple interactions are integrated, we combined crystallographic analysis of the third and fourth PE pairs with electron microscopy (EM) to determine the complete ectodomain structure. An extensive inter-pair interface, conserved for the first-to-second and third-to-fourth PE interactions, contributes to a compact platform-like architecture, which is disrupted by mutations implicated in developmental diseases. EM reconstruction of the LRP6 platform bound to chaperone Mesd exemplifies a binding mode spanning PE pairs. Cellular and binding assays identify overlapping Wnt3a- and Dkk1-binding surfaces on the third PE pair, consistent with steric competition, but also suggest a model in which the platform structure supports an interplay of ligands through multiple interaction sites.
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Affiliation(s)
- Shuo Chen
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Doryen Bubeck
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Bryan T. MacDonald
- F. M. Kirby Neurobiology Center, Children’s Hospital Boston, Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Wen-Xue Liang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Jian-Hua Mao
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Tomas Malinauskas
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Oscar Llorca
- Centro de Investigaciones Biológicas (CIB), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, 28040, Spain
| | - A. Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Christian Siebold
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Xi He
- F. M. Kirby Neurobiology Center, Children’s Hospital Boston, Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - E. Yvonne Jones
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
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92
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Chen J, Stahl A, Krah NM, Seaward MR, Dennison RJ, Sapieha P, Hua J, Hatton CJ, Juan AM, Aderman CM, Willett KL, Guerin KI, Mammoto A, Campbell M, Smith LEH. Wnt signaling mediates pathological vascular growth in proliferative retinopathy. Circulation 2011; 124:1871-81. [PMID: 21969016 PMCID: PMC3326389 DOI: 10.1161/circulationaha.111.040337] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND Ischemic proliferative retinopathy, characterized by pathological retinal neovascularization, is a major cause of blindness in working-age adults and children. Defining the molecular pathways distinguishing pathological neovascularization from normal vessels is critical to controlling these blinding diseases with targeted therapy. Because mutations in Wnt signaling cause defective retinal vasculature in humans with some characteristics of the pathological vessels in retinopathy, we investigated the potential role of Wnt signaling in pathological retinal vascular growth in proliferative retinopathy. METHODS AND RESULTS In this study, we show that Wnt receptors (Frizzled4 and low-density lipoprotein receptor-related protein5 [Lrp5]) and activity are significantly increased in pathological neovascularization in a mouse model of oxygen-induced proliferative retinopathy. Loss of Wnt coreceptor Lrp5 and downstream signaling molecule dishevelled2 significantly decreases the formation of pathological retinal neovascularization in retinopathy. Loss of Lrp5 also affects retinal angiogenesis during development and formation of the blood-retinal barrier, which is linked to significant downregulation of tight junction protein claudin5 in Lrp5(-/-) vessels. Blocking claudin5 significantly suppresses Wnt pathway-driven endothelial cell sprouting in vitro and developmental and pathological vascular growth in retinopathy in vivo. CONCLUSIONS These results demonstrate an important role of Wnt signaling in pathological vascular development in retinopathy and show a novel function of Cln5 in promoting angiogenesis.
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MESH Headings
- Animals
- Cell Proliferation
- Cells, Cultured
- Disease Models, Animal
- Endothelium, Vascular/growth & development
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Frizzled Receptors/biosynthesis
- Frizzled Receptors/physiology
- Humans
- Low Density Lipoprotein Receptor-Related Protein-5/biosynthesis
- Low Density Lipoprotein Receptor-Related Protein-5/physiology
- Lysosomal Membrane Proteins
- Membrane Glycoproteins/biosynthesis
- Mice
- Mice, Knockout
- Neovascularization, Pathologic/metabolism
- Neovascularization, Pathologic/pathology
- Receptors, Wnt/biosynthesis
- Receptors, Wnt/physiology
- Retina/growth & development
- Retina/pathology
- Retina/physiology
- Wnt Signaling Pathway/physiology
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Affiliation(s)
- Jing Chen
- Department of Ophthalmology, Harvard Medical School/Children's Hospital Boston, Boston MA 02115, USA
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93
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Ahn VE, Chu MLH, Choi HJ, Tran D, Abo A, Weis WI. Structural basis of Wnt signaling inhibition by Dickkopf binding to LRP5/6. Dev Cell 2011; 21:862-73. [PMID: 22000856 DOI: 10.1016/j.devcel.2011.09.003] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 08/07/2011] [Accepted: 09/12/2011] [Indexed: 12/17/2022]
Abstract
LDL receptor-related proteins 5 and 6 (LRP5/6) are coreceptors for Wnt growth factors, and also bind Dkk proteins, secreted inhibitors of Wnt signaling. The LRP5/6 ectodomain contains four β-propeller/EGF-like domain repeats. The first two repeats, LRP6(1-2), bind to several Wnt variants, whereas LRP6(3-4) binds other Wnts. We present the crystal structure of the Dkk1 C-terminal domain bound to LRP6(3-4), and show that the Dkk1 N-terminal domain binds to LRP6(1-2), demonstrating that a single Dkk1 molecule can bind to both portions of the LRP6 ectodomain and thereby inhibit different Wnts. Small-angle X-ray scattering analysis of LRP6(1-4) bound to a noninhibitory antibody fragment or to full-length Dkk1 shows that in both cases the ectodomain adopts a curved conformation that places the first three repeats at a similar height relative to the membrane. Thus, Wnts bound to either portion of the LRP6 ectodomain likely bear a similar spatial relationship to Frizzled coreceptors.
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Affiliation(s)
- Victoria E Ahn
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
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94
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Kondo H, Kusaka S, Yoshinaga A, Uchio E, Tawara A, Hayashi K, Tahira T. Mutations in the TSPAN12 gene in Japanese patients with familial exudative vitreoretinopathy. Am J Ophthalmol 2011; 151:1095-1100.e1. [PMID: 21334594 DOI: 10.1016/j.ajo.2010.11.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 11/18/2010] [Accepted: 11/19/2010] [Indexed: 11/19/2022]
Abstract
PURPOSE To search for mutations in the TSPAN12 gene in 90 Japanese probands with familial exudative vitreoretinopathy (FEVR) and their family members and to determine the types and frequencies of the mutations. DESIGN Laboratory investigation and clinical case analyses. METHODS Direct sequencing after polymerase chain reaction of the coding exons of TSPAN12 was performed for 90 probands with FEVR and some of their family members. The clinical signs and symptoms that were characteristic of individuals with TSPAN12 mutations were determined. RESULTS Three families were found to carry 2 mutations in TSPAN12. One of these mutations was a new missense change, L245P, and the other was an already reported nonsense mutation, L140X, in 2 families. Mutations in TSPAN12 accounted for 3% of Japanese FEVR patients and 8% of the FEVR families who did not have mutations in any of the known FEVR genes, FZD4, LRP5, and NDP. The clinical signs and symptoms varied among the patients, but the retinal findings with TSPAN12 mutations were not different from those with mutations in the known FEVR-causing genes. CONCLUSIONS Mutant TSPAN12 is responsible for approximately 3% of FEVR patients in Japan. The results provide further evidence that mutations in TSPAN12 are FEVR causing and that the gene products most likely play a role in the development of retinal vessels.
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Affiliation(s)
- Hiroyuki Kondo
- Department of Ophthalmology, University of Occupational and Environmental Health Japan, Kitakyushu, Japan.
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95
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Yang H, Xiao X, Li S, Mai G, Zhang Q. Novel TSPAN12 mutations in patients with familial exudative vitreoretinopathy and their associated phenotypes. Mol Vis 2011; 17:1128-35. [PMID: 21552475 PMCID: PMC3087453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Accepted: 04/26/2011] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Mutations in tetraspanin 12 (TSPAN12) have recently been identified as a cause of autosomal dominant familial exudative vitreoretinopathy (FEVR). The purpose of this study was to detect TSPAN12 mutations in Chinese patients with FEVR and to describe the associated phenotypes. METHODS Sanger sequencing was used to analyze the seven coding exons and their adjacent regions of TSPAN12 in 49 unrelated FEVR patients. Clinical phenotypes of the patients with TSPAN12 mutations were documented. RESULTS Three novel heterozygous mutations in TSPAN12 were identified in three patients from unrelated families: c.146C>T (p.Thr49Met), c.313T>C (p.Cys105Arg), and c.601delC (p.Leu201PhefsX14). All three mutations involved highly conserved residues and were not present in 180 normal individuals. Ocular phenotypes included retinal folds, inferotemporal dragging of the optic disc and macula, increased vessels in the equatorial region, and a peripheral avascular zone. A father and his daughter had the same mutation but the father only had mild peripheral fundus changes while his daughter had obvious dragged disc and macular ectopia. CONCLUSIONS Our results suggest that TSPAN12 mutations are responsible for FEVR. Similar to patients with mutations in NDP, LRP5, or FZD4, the phenotypes associated with TSPAN12 mutations showed great variations between different individuals within a family and between the two eyes in individual patients.
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96
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Mao W, Wordinger RJ, Clark AF. Functional analysis of disease-associated polymorphism LRP5.Q89R. Mol Vis 2011; 17:894-902. [PMID: 21528003 PMCID: PMC3081804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 03/30/2011] [Indexed: 12/02/2022] Open
Abstract
PURPOSE The canonical wingless and Int1 (Wnt) signaling pathway plays key roles in multiple biologic events. The pathway co-receptor, low density lipoprotein receptor-related protein 5 (LRP5), is involved in the pathogenesis of retinal diseases and has been implicated in glaucoma. We studied whether a disease-associated polymorphism LRP5.Q89R, which is located in the second blade of the first β-propeller domain, directly alters Wnt signaling activity with cell-based assays. METHODS The LRP5.Q89R polymorphism was evaluated by transfection of HEK293T or GTM3 cells with expression vectors. LRP5 expression and interaction with the molecular chaperone mesoderm development (MESD) were determined by western immunoblotting and co-immunoprecipitation analyses. To compare membrane-associated LRP5 proteins, surface proteins were labeled with biotin and pulled down with avidin beads followed by western immunoblotting. TCF-reporter plasmid-based luciferase assays were used to determine whether LRP5.Q89R affects the canonical Wnt signaling, or has altered efficacy to suppression by Dickkopf-1 (DKK-1). RESULTS Cell-based assays showed that this polymorphism did not change protein expression, interaction with the molecular chaperone MESD, protein trafficking, Wnt signaling transduction, or its efficacy in DKK1-mediated inhibition. CONCLUSIONS Our data suggest that this specific polymorphism does not appear to alter the canonical Wnt signaling pathway. Further studies of LRP5 polymorphisms are needed to elucidate their roles in various associated diseases.
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97
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Fitzsimons RB. Retinal vascular disease and the pathogenesis of facioscapulohumeral muscular dystrophy. A signalling message from Wnt? Neuromuscul Disord 2011; 21:263-71. [PMID: 21377364 DOI: 10.1016/j.nmd.2011.02.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The peripheral retinal vascular abnormality which accompanies FSHD belongs morphologically and clinically to a class of developmental 'retinal hypovasculopathies' caused by abnormalities of 'Wnt' signalling, which controls retinal angiogenesis. Wnt signalling is also fundamental to myogenesis. This paper integrates modern concepts of myogenic cell signalling and of transcription factor expression and control with data from the classic early ophthalmic and myology embryology literature. Together, they support an hypothesis that abnormalities of Wnt signalling, which activates myogenic programs and transcription factors in myoblasts and satellite cells, leads to defective muscle regeneration in FSHD. The selective vulnerability of different FSHD muscles (notably facial muscle, from the second branchial arch) might reflect patterns of transcription factor redundancies. This hypothesis has implications for FSHD research through study of transcription factors patterning in normal human muscles, and for autologous cell transplantation.
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98
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Genetic screening of Wnt signaling factors in advanced retinopathy of prematurity. Mol Vis 2010; 16:2572-7. [PMID: 21151595 PMCID: PMC3000231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 11/28/2010] [Indexed: 11/01/2022] Open
Abstract
PURPOSE To evaluate the possibility of genetic involvement in retinopathy of prematurity (ROP). Although ROP is most often associated with low birthweight and low gestational age, these factors do not necessarily predict the severity of ROP. The possible involvement of other factors, including genetic variants, has been considered. Familial exudative vitreoretinopathy (FEVR) is a hereditary vitreoretinal disorder with clinical manifestations similar to those of ROP. Three genes involving the wingless/int1 (Wnt) receptor signaling pathway-FZD4 for frizzled 4, LRP5 for low-density lipoprotein receptor-related protein 5, and ND for Norrie disease protein-are associated with the development of FEVR. METHODS In the present study, 17 Japanese patients with advanced ROP were screened for these three candidate genes of FEVR. Genomic DNA from each patient was subjected to PCR and direct sequencing of the ND, FZD4, and LRP5 genes. RESULTS One patient had a heterozygous mutation in the 5' untranslated region of the ND gene. Another had a leucine insertion in the signal peptide of LRP5. None showed any mutation in FZD4. CONCLUSIONS These findings suggest that genetic changes in the Wnt receptor signaling pathway associate to the development of advanced ROP.
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99
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Ye X, Wang Y, Nathans J. The Norrin/Frizzled4 signaling pathway in retinal vascular development and disease. Trends Mol Med 2010; 16:417-25. [PMID: 20688566 DOI: 10.1016/j.molmed.2010.07.003] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 07/09/2010] [Accepted: 07/09/2010] [Indexed: 01/22/2023]
Abstract
Disorders of retinal vascular growth and function are responsible for vision loss in a variety of diseases, including diabetic retinopathy, age-related macular degeneration, retinopathy of prematurity and retinal artery or vein occlusion. Over the past decade, a new signaling pathway that controls retinal vascular development has emerged from the study of inherited disorders - in both humans and mice - that are characterized by retinal hypovascularization. This pathway utilizes a glial-derived extracellular ligand, Norrin, that acts on a transmembrane receptor, Frizzled4, a coreceptor, Lrp5, and an auxiliary membrane protein, Tspan12, on the surface of developing endothelial cells. The resulting signal controls a transcriptional program that regulates endothelial growth and maturation. It will be of great interest to determine whether modulating this pathway could represent a therapeutic approach to human retinal vascular disease.
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Affiliation(s)
- Xin Ye
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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100
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LRP5 is required for vascular development in deeper layers of the retina. PLoS One 2010; 5:e11676. [PMID: 20652025 PMCID: PMC2907392 DOI: 10.1371/journal.pone.0011676] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 06/28/2010] [Indexed: 11/19/2022] Open
Abstract
Background The low-density lipoprotein receptor-related protein 5 (LRP5) plays an important role in the development of retinal vasculature. LRP5 loss-of-function mutations cause incomplete development of retinal vessel network in humans as well as in mice. To understand the underlying mechanism for how LRP5 mutations lead to retinal vascular abnormalities, we have determined the retinal cell types that express LRP5 and investigated specific molecular and cellular functions that may be regulated by LRP5 signaling in the retina. Methods and Findings We characterized the development of retinal vasculature in LRP5 mutant mice using specific retinal cell makers and a GFP transgene expressed in retinal endothelial cells. Our data revealed that retinal vascular endothelial cells predominantly formed cell clusters in the inner-plexiform layer of LRP5 mutant retina rather than sprouting out or migrating into deeper layers to form normal vascular network in the retina. The IRES-β-galactosidase (LacZ) report gene under the control of the endogenous LRP5 promoter was highly expressed in Müller cells and was also weakly detected in endothelial cells of the retinal surface vasculature. Moreover, the LRP5 mutant mice had a reduction of a Müller cell-specific glutamine transporter, Slc38a5, and showed a decrease in b-wave amplitude of electroretinogram. Conclusions LRP5 is not only essential for vascular endothelial cells to sprout, migrate and/or anastomose in the deeper plexus during retinal vasculature development but is also important for the functions of Müller cells and retinal interneurons. Müller cells may utilize LRP5-mediated signaling pathway to regulate vascular development in deeper layers and to maintain the function of retinal interneurons.
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