1
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Bhakuni T, Norden PR, Ujiie N, Tan C, Lee SK, Tedeschi T, Hsieh YW, Wang Y, Liu T, Fawzi AA, Kume T. FOXC1 regulates endothelial CD98 (LAT1/4F2hc) expression in retinal angiogenesis and blood-retina barrier formation. Nat Commun 2024; 15:4097. [PMID: 38755144 PMCID: PMC11099035 DOI: 10.1038/s41467-024-48134-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 04/22/2024] [Indexed: 05/18/2024] Open
Abstract
Angiogenesis, the growth of new blood vessels from pre-existing vasculature, is essential for the development of new organ systems, but transcriptional control of angiogenesis remains incompletely understood. Here we show that FOXC1 is essential for retinal angiogenesis. Endothelial cell (EC)-specific loss of Foxc1 impairs retinal vascular growth and expression of Slc3a2 and Slc7a5, which encode the heterodimeric CD98 (LAT1/4F2hc) amino acid transporter and regulate the intracellular transport of essential amino acids and activation of the mammalian target of rapamycin (mTOR). EC-Foxc1 deficiency diminishes mTOR activity, while administration of the mTOR agonist MHY-1485 rescues perturbed retinal angiogenesis. EC-Foxc1 expression is required for retinal revascularization and resolution of neovascular tufts in a model of oxygen-induced retinopathy. Foxc1 is also indispensable for pericytes, a critical component of the blood-retina barrier during retinal angiogenesis. Our findings establish FOXC1 as a crucial regulator of retinal vessels and identify therapeutic targets for treating retinal vascular disease.
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Affiliation(s)
- Teena Bhakuni
- Department of Medicine, Feinberg Cardiovascular and Renal Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Pieter R Norden
- Department of Medicine, Feinberg Cardiovascular and Renal Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Naoto Ujiie
- Department of Medicine, Feinberg Cardiovascular and Renal Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Can Tan
- Department of Medicine, Feinberg Cardiovascular and Renal Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Sun Kyong Lee
- Department of Medicine, Feinberg Cardiovascular and Renal Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Thomas Tedeschi
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Yi-Wen Hsieh
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Ying Wang
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Ting Liu
- Department of Medicine, Feinberg Cardiovascular and Renal Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Amani A Fawzi
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Tsutomu Kume
- Department of Medicine, Feinberg Cardiovascular and Renal Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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2
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Rraku E, Kerstjens-Frederikse WS, Swertz MA, Dijkhuizen T, van Ravenswaaij-Arts CMA, Engwerda A. The phenotypic spectrum of terminal and subterminal 6p deletions based on a social media-derived cohort and literature review. Orphanet J Rare Dis 2023; 18:68. [PMID: 36964621 PMCID: PMC10039519 DOI: 10.1186/s13023-023-02670-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 03/11/2023] [Indexed: 03/26/2023] Open
Abstract
BACKGROUND Terminal 6p deletions are rare, and information on their clinical consequences is scarce, which impedes optimal management and follow-up by clinicians. The parent-driven Chromosome 6 Project collaborates with families of affected children worldwide to better understand the clinical effects of chromosome 6 aberrations and to support clinical guidance. A microarray report is required for participation, and detailed phenotype information is collected directly from parents through a multilingual web-based questionnaire. Information collected from parents is then combined with case data from literature reports. Here, we present our findings on 13 newly identified patients and 46 literature cases with genotypically well-characterised terminal and subterminal 6p deletions. We provide phenotype descriptions for both the whole group and for subgroups based on deletion size and HI gene content. RESULTS The total group shared a common phenotype characterised by ocular anterior segment dysgenesis, vision problems, brain malformations, congenital defects of the cardiac septa and valves, mild to moderate hearing impairment, eye movement abnormalities, hypotonia, mild developmental delay and dysmorphic features. These characteristics were observed in all subgroups where FOXC1 was included in the deletion, confirming a dominant role for this gene. Additional characteristics were seen in individuals with terminal deletions exceeding 4.02 Mb, namely complex heart defects, corpus callosum abnormalities, kidney abnormalities and orofacial clefting. Some of these additional features may be related to the loss of other genes in the terminal 6p region, such as RREB1 for the cardiac phenotypes and TUBB2A and TUBB2B for the cerebral phenotypes. In the newly identified patients, we observed previously unreported features including gastrointestinal problems, neurological abnormalities, balance problems and sleep disturbances. CONCLUSIONS We present an overview of the phenotypic characteristics observed in terminal and subterminal 6p deletions. This reveals a common phenotype that can be highly attributable to haploinsufficiency of FOXC1, with a possible additional effect of other genes in the 6p25 region. We also delineate the developmental abilities of affected individuals and report on previously unrecognised features, showing the added benefit of collecting information directly from parents. Based on our overview, we provide recommendations for clinical surveillance to support clinicians, patients and families.
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Affiliation(s)
- Eleana Rraku
- Department of Genetics, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | | | - Morris A Swertz
- Department of Genetics, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Trijnie Dijkhuizen
- Department of Genetics, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Conny M A van Ravenswaaij-Arts
- Department of Genetics, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.
- ATN/Jonx, Groningen, The Netherlands.
| | - Aafke Engwerda
- Department of Genetics, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
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3
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Le H, Jin E, Jewell A, Jackson-Cook C, Haskell GT, Couser N. Chromosome 6p25 deletion syndrome: A case report and review of ophthalmic features. Am J Med Genet A 2023; 191:1639-1645. [PMID: 36941760 DOI: 10.1002/ajmg.a.63186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 12/30/2022] [Accepted: 03/07/2023] [Indexed: 03/23/2023]
Abstract
The 6p25 deletion syndrome is a rare genetic disorder characterized by a wide spectrum of congenital anomalies. Ophthalmic abnormalities appear to be highly associated with the syndrome, although this relationship has not been well characterized to date. We conducted a systematic literature review to highlight the ocular features in patients with this deletion syndrome and describe a 7-month-old female who has a 6.07 MB 6p25.1p25.3 deletion and a 4.25 MB 17q25.3 duplication. Our patient presented with multiple congenital anomalies, including macrocephaly, frontal bossing, low set ears, tent-shaped mouth, saddle nose, flat midface, and hearing impairment. Her ophthalmic features included proptosis, down-slanting palpebral fissures, hypertelorism, nystagmus, bilateral posterior embryotoxon, and decentered and abnormally shaped pupils. A systematic review of the published cases with sufficient clinical eye descriptions included 63 cases with a confirmed 6p25 deletion. The most common eye findings observed were posterior embryotoxon, iris hypoplasia, corectopia, cornea opacity, and glaucoma.
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Affiliation(s)
- Hong Le
- Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Eva Jin
- Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Ann Jewell
- Department of Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Colleen Jackson-Cook
- Department of Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
- Department of Pathology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Gloria T Haskell
- Labcorp Center for Molecular Biology & Pathology, Durham, North Carolina, USA
| | - Natario Couser
- Department of Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
- Department of Ophthalmology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
- Department of Pediatrics, Children's Hospital of Richmond at Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
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4
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The Axenfeld-Rieger Syndrome Gene FOXC1 Contributes to Left-Right Patterning. Genes (Basel) 2021; 12:genes12020170. [PMID: 33530637 PMCID: PMC7912076 DOI: 10.3390/genes12020170] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/14/2021] [Accepted: 01/21/2021] [Indexed: 02/06/2023] Open
Abstract
Precise spatiotemporal expression of the Nodal-Lefty-Pitx2 cascade in the lateral plate mesoderm establishes the left–right axis, which provides vital cues for correct organ formation and function. Mutations of one cascade constituent PITX2 and, separately, the Forkhead transcription factor FOXC1 independently cause a multi-system disorder known as Axenfeld–Rieger syndrome (ARS). Since cardiac involvement is an established ARS phenotype and because disrupted left–right patterning can cause congenital heart defects, we investigated in zebrafish whether foxc1 contributes to organ laterality or situs. We demonstrate that CRISPR/Cas9-generated foxc1a and foxc1b mutants exhibit abnormal cardiac looping and that the prevalence of cardiac situs defects is increased in foxc1a−/−; foxc1b−/− homozygotes. Similarly, double homozygotes exhibit isomerism of the liver and pancreas, which are key features of abnormal gut situs. Placement of the asymmetric visceral organs relative to the midline was also perturbed by mRNA overexpression of foxc1a and foxc1b. In addition, an analysis of the left–right patterning components, identified in the lateral plate mesoderm of foxc1 mutants, reduced or abolished the expression of the NODAL antagonist lefty2. Together, these data reveal a novel contribution from foxc1 to left–right patterning, demonstrating that this role is sensitive to foxc1 gene dosage, and provide a plausible mechanism for the incidence of congenital heart defects in Axenfeld–Rieger syndrome patients.
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Hosono K, Kawase K, Kurata K, Niimi Y, Saitsu H, Minoshima S, Ohnishi H, Yamamoto T, Hikoya A, Tachibana N, Fukao T, Yamamoto T, Hotta Y. A case of childhood glaucoma with a combined partial monosomy 6p25 and partial trisomy 18p11 due to an unbalanced translocation. Ophthalmic Genet 2020; 41:175-182. [PMID: 32223580 DOI: 10.1080/13816810.2020.1744019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Background: Chromosomal deletion involving the 6p25 region results in a clinically recognizable syndrome characterized by anterior eye chamber anomalies with risk of glaucoma and non-ocular malformations (6p25 deletion syndrome). We report a newborn infant case of childhood glaucoma with a combination of partial monosomy 6p25 and partial trisomy 18p11 due to an unbalanced translocation.Materials and methods: The patient was a 0-year-old girl. Both eyes showed aniridia and left eye Peters anomaly with multiple malformations. To identify the chromosomal aberrations in the patient with clinically suspected 6p25 deletion syndrome, we performed cytogenetic analysis (G-banding and multicolor fluorescent in-situ hybridization) and array-based comparative genomic hybridization (array-CGH) analysis.Results: Cytogenetic analyses revealed a derivative chromosome 6 with its distal short arm replaced by an extra copy of the short arm of chromosome 18. Array-CGH analysis detected a 4.6-Mb deletion at 6pter to 6p25.1 and 8.9-Mb duplication at 18pter to 18p11.22. To determine the breakpoint of the unbalanced rearrangement at the single-base level, we performed a long-range PCR for amplifying the junctional fragment of the translocation breakpoint. By sequencing the junctional fragment, we defined the unbalanced translocation as g.chr6:pter_4594783delinschr18:pter_8911541.Conclusions: A phenotype corresponding to combined monosomy 6p25 and trisomy 18p11 presented as childhood glaucoma associated with non-acquired (congenital) ocular anomalies consist of aniridia and Peters anomaly and other systemic malformations. To the best of our knowledge, this is the first report which demonstrated the breakpoint sequence of an unbalanced translocation in a Japanese infant with childhood glaucoma.
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Affiliation(s)
- Katsuhiro Hosono
- Department of Ophthalmology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Kazuhide Kawase
- Department of Ophthalmology, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Kentaro Kurata
- Department of Ophthalmology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yusuke Niimi
- Department of Ophthalmology, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Hirotomo Saitsu
- Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Shinsei Minoshima
- Department of Photomedical Genomics, Institute for Medical Photonics Research, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Hidenori Ohnishi
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Takahiro Yamamoto
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Akiko Hikoya
- Department of Ophthalmology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Nobutaka Tachibana
- Department of Ophthalmology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Tetsuya Yamamoto
- Department of Ophthalmology, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Yoshihiro Hotta
- Department of Ophthalmology, Hamamatsu University School of Medicine, Hamamatsu, Japan
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6
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Childhood glaucoma genes and phenotypes: Focus on FOXC1 mutations causing anterior segment dysgenesis and hearing loss. Exp Eye Res 2019; 190:107893. [PMID: 31836490 DOI: 10.1016/j.exer.2019.107893] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 10/16/2019] [Accepted: 12/04/2019] [Indexed: 12/27/2022]
Abstract
Childhood glaucoma is an important cause of blindness world-wide. Eleven genes are currently known to cause inherited forms of glaucoma with onset before age 20. While all the early-onset glaucoma genes cause severe disease, considerable phenotypic variability is observed among mutations carriers. In particular, FOXC1 genetic variants are associated with a broad range of phenotypes including multiple forms of glaucoma and also systemic abnormalities, especially hearing loss. FOXC1 is a member of the forkhead family of transcription factors and is involved in neural crest development necessary for formation of anterior eye structures and also pharyngeal arches that form the middle ear bones. In this study we review the clinical phenotypes reported for known FOXC1 mutations and show that mutations in patients with reported ocular anterior segment abnormalities and hearing loss primarily disrupt the critically important forkhead domain. These results suggest that optimal care for patients affected with anterior segment dysgenesis should include screening for FOXC1 mutations and also testing for hearing loss.
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7
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Chrystal PW, Walter MA. Aniridia and Axenfeld-Rieger Syndrome: Clinical presentations, molecular genetics and current/emerging therapies. Exp Eye Res 2019; 189:107815. [PMID: 31560925 DOI: 10.1016/j.exer.2019.107815] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/11/2019] [Accepted: 09/23/2019] [Indexed: 12/20/2022]
Abstract
Aniridia and Axenfeld-Rieger Syndrome are related, human ocular disorders that are typically inherited in an autosomal dominant manner. Both result from incorrect development of the eye and have, as their most serious consequences, elevated risk to develop the blinding condition glaucoma. This review will focus on describing the clinical presentations of Aniridia and Axenfeld-Rieger Syndrome as well as the molecular genetics and current and emerging therapies used to treat patients.
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Affiliation(s)
- Paul W Chrystal
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Michael A Walter
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada.
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8
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Congenital radial head dislocation and low immunoglobulin M levels in 6p25.3 deletion. Clin Dysmorphol 2018; 26:181-184. [PMID: 28277378 DOI: 10.1097/mcd.0000000000000178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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9
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Seifi M, Walter MA. Axenfeld-Rieger syndrome. Clin Genet 2018; 93:1123-1130. [PMID: 28972279 DOI: 10.1111/cge.13148] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 09/23/2017] [Accepted: 09/26/2017] [Indexed: 12/29/2022]
Abstract
Axenfeld-Rieger syndrome (ARS) is a clinically and genetically heterogeneous group of developmental disorders affecting primarily the anterior segment of the eye, often leading to secondary glaucoma. Patients with ARS may also present with systemic changes, including dental defects, mild craniofacial dysmorphism, and umbilical anomalies. ARS is inherited in an autosomal-dominant fashion; the underlying defect in 40% of patients is mutations in PITX2 or FOXC1. Here, an overview of the clinical spectrum of ARS is provided. As well, the known underlying genetic defects, clinical diagnostic possibilities, genetic counseling and treatments of ARS are discussed in detail.
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Affiliation(s)
- M Seifi
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Alberta, Edmonton, Canada
| | - M A Walter
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Alberta, Edmonton, Canada
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10
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Moschos MM, Nitoda E, Fenzel I, Song X, Langenbucher A, Kaesmann B, Seitz B, Gatzioufas Z. Prognostic factors of pediatric glaucoma: a retrospective study. Int Ophthalmol 2018; 39:359-373. [PMID: 29349523 DOI: 10.1007/s10792-018-0819-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 01/04/2018] [Indexed: 12/24/2022]
Abstract
PURPOSE To correlate the features of certain types of infantile glaucoma with the progression and the prognosis of the disease, highlighting probable risk factors. METHODS Seventy-six patients with pediatric glaucoma were recruited in this retrospective study. All patients underwent ophthalmological examination in the Department of Ophthalmology of the Saarland University Medical Center from January 2001 to December 2012. Our pediatric patients were classified into four different categories of glaucoma: (1) primary congenital glaucoma (presenting buphthalmus), (2) aniridia-related glaucoma, (3) Peters/Rieger's anomaly-related glaucoma and (4) congenital cataract-related glaucoma. Personal data comprised age, sex, nationality, systemic diseases and gestational age. The best-corrected visual acuity (BCVA), the cup-disk ratio (CDR), the intraocular pressure (IOP), the corneal diameter and thickness, along with the Haab striae and corneal haze, were recorded. RESULTS The majority of the children were male (58%) and suffered from aniridia-related glaucoma (38%). Children with aniridia exhibited the worst BCVA. The CDR and IOP were significantly higher in children with primary congenital glaucoma, compared to the other groups, at the first visit. Those children also were with the largest corneal diameter and prevalence of Haab striae compared to the rest groups, whereas corneal haze was found more often and was more pronounced in children with Peters/Rieger's syndrome. CONCLUSIONS We concluded that glaucoma was earlier detected in children with primary congenital glaucoma, who exhibited increased corneal diameter and high percentage of Haab striae comparing to the other groups. However, these children responded successfully to any therapeutic intervention, exhibiting better BCVA and IOP values than the rest groups at the second visit.
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Affiliation(s)
- Marilita M Moschos
- First Department of Ophthalmology, General Hospital of Athens G. Gennimatas, Medical School, National and Kapodistrian University of Athens, 6, Ikaria Street, Ekali, 14578, Athens, Greece.
| | - Eirini Nitoda
- First Department of Ophthalmology, General Hospital of Athens G. Gennimatas, Medical School, National and Kapodistrian University of Athens, 6, Ikaria Street, Ekali, 14578, Athens, Greece
| | - Isabelle Fenzel
- Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany
| | - Xuefei Song
- Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany.,Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai, China
| | - Achim Langenbucher
- Institute of Experimental Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany
| | - Barbara Kaesmann
- Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany
| | - Zisis Gatzioufas
- Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany.,Moorfields Eye Hospital, London, UK
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11
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Zhu H. Forkhead box transcription factors in embryonic heart development and congenital heart disease. Life Sci 2015; 144:194-201. [PMID: 26656470 DOI: 10.1016/j.lfs.2015.12.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 11/24/2015] [Accepted: 12/01/2015] [Indexed: 12/31/2022]
Abstract
Embryonic heart development is a very complicated process regulated precisely by a network composed of many genes and signaling pathways in time and space. Forkhead box (Fox, FOX) proteins are a family of transcription factors characterized by the presence of an evolutionary conserved "forkhead"or "winged-helix" DNA-binding domain and able to organize temporal and spatial gene expression during development. They are involved in a wide variety of cellular processes, such as cell cycle progression, proliferation, differentiation, migration, metabolism and DNA damage response. An abundance of studies in model organisms and systems has established that Foxa2, Foxc1/c2, Foxh1 and Foxm1, Foxos and Foxps are important components of the signaling pathways that instruct cardiogenesis and embryonic heart development, playing paramount roles in heart development. The previous studies also have demonstrated that mutations in some of the forkhead box genes and the aberrant expression of forkhead box gene are heavily implicated in the congenital heart disease (CHD) of humans. This review primarily focuses on the current understanding of heart development regulated by forkhead box transcription factors and molecular genetic mechanisms by which forkhead box factors modulate heart development during embryogenesis and organogenesis. This review also summarizes human CHD related mutations in forkhead box genes as well as the abnormal expression of forkhead box gene, and discusses additional possible regulatory mechanisms of the forkhead box genes during embryonic heart development that warrant further investigation.
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Affiliation(s)
- Hong Zhu
- Department of Biomedical Engineering, College of Biology, Hunan University, 1 Denggao Road, Yuelu District, Changsha, Hunan 410082, PR China.
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12
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Titheradge H, Togneri F, McMullan D, Brueton L, Lim D, Williams D. Axenfeld-Rieger syndrome: further clinical and array delineation of four unrelated patients with a 4q25 microdeletion. Am J Med Genet A 2014; 164A:1695-701. [PMID: 24715413 DOI: 10.1002/ajmg.a.36540] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 02/14/2014] [Indexed: 11/06/2022]
Abstract
Axenfeld-Rieger syndrome (ARS) is an autosomal dominant disorder with variable expressivity. It is characterized by dysgenesis of the anterior segment of the eye together with dental, cardiac, and umbilical anomalies. There is a high incidence of secondary high tension glaucoma. It is a genetically heterogeneous condition due to deletion or mutations of FOXC1 (6p25) or PITX2 (4q25). We report on four unrelated patients with overlapping microdeletions encompassing PITX2 at 4q25. We compare the genotypes and phenotypes of these newly described ARS patients and discuss the involvement of contiguous genes. Patients 1, 2, and 3 had mild learning difficulties, not typically seen in patients with ARS. We implicate the adjacent neuronally expressed genes; NEUROG2, UGT8, NDST3, and PRSS12 as potentially causal. Our findings support the use of microarray analysis in ARS patients for full prognostic information in infants presenting with ARS-like phenotypes.
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Affiliation(s)
- Hannah Titheradge
- Department of Clinical Genetics, Birmingham Women's NHS Foundation Trust, Birmingham, United Kingdom
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13
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Ito YA, Goping IS, Berry F, Walter MA. Dysfunction of the stress-responsive FOXC1 transcription factor contributes to the earlier-onset glaucoma observed in Axenfeld-Rieger syndrome patients. Cell Death Dis 2014; 5:e1069. [PMID: 24556684 PMCID: PMC3944279 DOI: 10.1038/cddis.2014.8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 12/19/2013] [Accepted: 01/03/2014] [Indexed: 01/12/2023]
Abstract
Mutations in the Forkhead Box C1 (FOXC1) transcription factor gene are associated with Axenfeld-Rieger syndrome (ARS), a developmental disorder affecting structures in the anterior segment of the eye. Approximately 75% of ARS patients with FOXC1 mutations develop earlier-onset glaucoma. Constant exposure of the trabecular meshwork (TM), located in the anterior segment of the eye, to oxidative stress is predicted to be a risk factor for developing glaucoma. Stress-induced death of TM cells results in dysfunction of the TM, leading to elevated intraocular pressure, which is a major risk factor for developing glaucoma. FOXC1 is predicted to maintain homeostasis in TM cells by regulating genes that are important for stress response. In this study, we show that a member of the heat-shock 70 family of proteins, HSPA6, is a target gene of FOXC1. HSPA6 protein, which is only induced under severe oxidative stress conditions, has a protective function in human trabecular meshwork (HTM) cells. We also show that FOXC1 is anti-apoptotic as knocking down FOXC1 significantly decreases HTM cell viability. In addition, we show that FOXC1 itself responds to stress as exposure of cells to H2O2-induced oxidative stress reduces FOXC1 levels and activity. Conditions that decrease FOXC1 function, such as exposure of cells to oxidative stress and FOXC1 ARS mutations, compromise the ability of TM cells to effectively respond to environmental stresses. Dysfunction of FOXC1 contributes to the death of TM cells, an important step in the development of glaucoma.
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Affiliation(s)
- Y A Ito
- Department of Medical Genetics, University of Alberta, Alberta T6G 2H7, Canada
| | - I S Goping
- Department of Biochemistry, University of Alberta, Alberta T6G 2H7, Canada
| | - F Berry
- 1] Department of Medical Genetics, University of Alberta, Alberta T6G 2H7, Canada [2] Department of Surgery, University of Alberta, Alberta T6G 2H7, Canada
| | - M A Walter
- 1] Department of Medical Genetics, University of Alberta, Alberta T6G 2H7, Canada [2] Department of Ophthalmology, University of Alberta, Alberta T6G 2H7, Canada
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14
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Bozza M, Bernardini L, Novelli A, Brovedani P, Moretti E, Canapicchi R, Doccini V, Filippi T, Battaglia A. 6p25 interstitial deletion in two dizygotic twins with gyral pattern anomaly and speech and language disorder. Eur J Paediatr Neurol 2013; 17:225-31. [PMID: 23069351 DOI: 10.1016/j.ejpn.2012.09.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 09/15/2012] [Indexed: 01/08/2023]
Abstract
Submicroscopic 6p25 deletion is now recognized as a clinically identifiable syndrome, characterized by intellectual disability, language impairment, hearing deficit, craniofacial, ophthalmologic, cardiac, and varying central nervous system anomalies. We report on two dyzogotic twins with a maternal segregating hemizygous interstitial deletion on chromosome 6p25.1, spanning 0.9 kb; the smallest ever reported. Both had dysmorphic features (prominence of the metopic suture, synophrys, hypertelorism, down-slanting palpebral fissures, tented mouth), and a distinct brain MRI, showing a focal significant increase of the right peri-frontal subarachnoid space, with shallow sulci and a mild anomaly of the gyral pattern. Such brain anomaly has never been reported in association with del 6p25. Both propositi had a borderline-mild intellectual disability, speech and language difficulties, and behavior abnormalities. Their mother, formally tested, had a borderline cognitive impairment. Although none of the genes mapping to the deleted region are apparently related to the phenotype, LYRM4 resulted down-regulated in the cerebellar cortex of schizophrenia patients compared with controls, and Lyrm4 was down-regulated in the prefrontal cortex of mice with microdeletions in the locus syntenic to human 22q11.2 patients affected by schizophrenia. These data are in agreement with the emerging concept that similar CNVs are pathogenic in patients affected by distinct neurological diseases, and that these loci are more general risk factors for different disorders. The resemblance of our patients to those with the more extensive 6p25.1p25.3 terminal deletion suggests that the gene/s responsible for the physical phenotype should reside in the 6p25.1 genomic region.
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Affiliation(s)
- Margherita Bozza
- Stella Maris Clinical Research Institute for Child and Adolescent Neuropsychiatry, Via dei Giacinti 2, Calambrone, Pisa, Italy
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