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Shinsato RN, Correa CG, Herai RH. Genetic network analysis indicate that individuals affected by neurodevelopmental conditions have genetic variations associated with ophthalmologic alterations: A critical review of literature. Gene 2024; 908:148246. [PMID: 38325665 DOI: 10.1016/j.gene.2024.148246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 01/19/2024] [Accepted: 02/02/2024] [Indexed: 02/09/2024]
Abstract
Changes in the nervous system are related to a wide range of mental disorders, which include neurodevelopmental disorders (NDD) that are characterized by early onset mental conditions, such as schizophrenia and autism spectrum disorders and correlated conditions (ASD). Previous studies have shown distinct genetic components associated with diverse schizophrenia and ASD phenotypes, with mostly focused on rescuing neural phenotypes and brain activity, but alterations related to vision are overlooked. Thus, as the vision is composed by the eyes that itself represents a part of the brain, with the retina being formed by neurons and cells originating from the glia, genetic variations affecting the brain can also affect the vision. Here, we performed a critical systematic literature review to screen for all genetic variations in individuals presenting NDD with reported alterations in vision. Using these restricting criteria, we found 20 genes with distinct types of genetic variations, inherited or de novo, that includes SNP, SNV, deletion, insertion, duplication or indel. The variations occurring within protein coding regions have different impact on protein formation, such as missense, nonsense or frameshift. Moreover, a molecular analysis of the 20 genes found revealed that 17 shared a common protein-protein or genetic interaction network. Moreover, gene expression analysis in samples from the brain and other tissues indicates that 18 of the genes found are highly expressed in the brain and retina, indicating their potential role in adult vision phenotype. Finally, we only found 3 genes from our study described in standard public databanks of ophthalmogenetics, suggesting that the other 17 genes could be novel target for vision diseases.
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Affiliation(s)
- Rogério N Shinsato
- Unisalesiano, Araçatuba, São Paulo, Brazil; Laboratory of Bioinformatics and Neurogenetics (LaBiN/LEM), Graduate Program in Health Sciences, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná, 80215-901, Brazil.
| | - Camila Graczyk Correa
- Laboratory of Bioinformatics and Neurogenetics (LaBiN/LEM), Graduate Program in Health Sciences, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná, 80215-901, Brazil
| | - Roberto H Herai
- Laboratory of Bioinformatics and Neurogenetics (LaBiN/LEM), Graduate Program in Health Sciences, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná, 80215-901, Brazil; Research Division, Buko Kaesemodel Institute (IBK), Curitiba, Paraná 80240-000, Brazil; Research Division, 9p Brazil Association (A9pB), Santa Maria, Rio Grande do Sul 97060-580, Brazil.
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Page ML, Heberle BA, Brandon JA, Wadsworth ME, Gordon LA, Nations KA, Ebbert MTW. Surveying the landscape of RNA isoform diversity and expression across 9 GTEx tissues using long-read sequencing data. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.13.579945. [PMID: 38405825 PMCID: PMC10888753 DOI: 10.1101/2024.02.13.579945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Even though alternative RNA splicing was discovered in 1977 (nearly 50 years ago), we still understand very little about most isoforms arising from a single gene, including in which tissues they are expressed and if their functions differ. Human gene annotations suggest remarkable transcriptional complexity, with approximately 252,798 distinct RNA isoform annotations from 62,710 gene bodies (Ensembl v109; 2023), emphasizing the need to understand their biological effects. For example, 256 gene bodies have ≥50 annotated isoforms and 30 have ≥100, where one protein-coding gene (MAPK10) even has 192 distinct RNA isoform annotations. Whether such isoform diversity results from biological noise (i.e., spurious alternative splicing) or whether it represents biological intent and specialized functions (even if subtle) remains a mystery. Recent studies by Aguzzoli-Heberle et al., Leung et al., and Glinos et al. demonstrate long-read RNAseq enables improved RNA isoform quantification for essentially any tissue, cell type, or biological condition (e.g., disease, development, aging, etc.) making it possible to better assess individual isoform expression and function. While each study provided important discoveries related to RNA isoform diversity, deeper exploration is needed. We sought, in part, to quantify real isoform usage across tissues (compared to annotations) and explore whether observed diversity is biological noise or intent. We used long-read RNAseq data from 58 GTEx samples across nine tissues (three brain, two heart, muscle, lung, liver, and cultured fibroblasts) generated by Glinos et al. and found considerable isoform diversity within and across tissues. Cerebellar hemisphere was the most transcriptionally complex tissue (22,522 distinct isoforms; 3,726 unique); liver was least diverse (12,435 isoforms; 1,039 unique). We highlight gene clusters exhibiting high tissue-specific isoform diversity per tissue (e.g., TPM1 expresses 19 in heart's atrial appendage), and specific genes (PAX6 and TPM1) that counterintuitively exhibit evidence that their expressed isoform diversity results from both biological noise and intent. We also validated 447 of the 700 new isoforms discovered by Aguzzoli-Heberle et al. and found that 88 were expressed in all nine tissues, while 58 were specific to a single tissue. This study represents a broad survey of the RNA isoform landscape, demonstrating isoform diversity across nine tissues and emphasizes the need to better understand how individual isoforms from a single gene body contribute to human health and disease.
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Affiliation(s)
- Madeline L. Page
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
| | - Bernardo Aguzzoli Heberle
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
| | - J. Anthony Brandon
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
| | - Mark E. Wadsworth
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
| | - Lacey A. Gordon
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
| | - Kayla A. Nations
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
| | - Mark T. W. Ebbert
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY
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3
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Daruich A, Duncan M, Robert MP, Lagali N, Semina EV, Aberdam D, Ferrari S, Romano V, des Roziers CB, Benkortebi R, De Vergnes N, Polak M, Chiambaretta F, Nischal KK, Behar-Cohen F, Valleix S, Bremond-Gignac D. Congenital aniridia beyond black eyes: From phenotype and novel genetic mechanisms to innovative therapeutic approaches. Prog Retin Eye Res 2023; 95:101133. [PMID: 36280537 PMCID: PMC11062406 DOI: 10.1016/j.preteyeres.2022.101133] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 09/27/2022] [Accepted: 10/03/2022] [Indexed: 11/05/2022]
Abstract
Congenital PAX6-aniridia, initially characterized by the absence of the iris, has progressively been shown to be associated with other developmental ocular abnormalities and systemic features making congenital aniridia a complex syndromic disorder rather than a simple isolated disease of the iris. Moreover, foveal hypoplasia is now recognized as a more frequent feature than complete iris hypoplasia and a major visual prognosis determinant, reversing the classical clinical picture of this disease. Conversely, iris malformation is also a feature of various anterior segment dysgenesis disorders caused by PAX6-related developmental genes, adding a level of genetic complexity for accurate molecular diagnosis of aniridia. Therefore, the clinical recognition and differential genetic diagnosis of PAX6-related aniridia has been revealed to be much more challenging than initially thought, and still remains under-investigated. Here, we update specific clinical features of aniridia, with emphasis on their genotype correlations, as well as provide new knowledge regarding the PAX6 gene and its mutational spectrum, and highlight the beneficial utility of clinically implementing targeted Next-Generation Sequencing combined with Whole-Genome Sequencing to increase the genetic diagnostic yield of aniridia. We also present new molecular mechanisms underlying aniridia and aniridia-like phenotypes. Finally, we discuss the appropriate medical and surgical management of aniridic eyes, as well as innovative therapeutic options. Altogether, these combined clinical-genetic approaches will help to accelerate time to diagnosis, provide better determination of the disease prognosis and management, and confirm eligibility for future clinical trials or genetic-specific therapies.
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Affiliation(s)
- Alejandra Daruich
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France; INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France
| | - Melinda Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Matthieu P Robert
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France; Borelli Centre, UMR 9010, CNRS-SSA-ENS Paris Saclay-Paris Cité University, Paris, France
| | - Neil Lagali
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Faculty of Medicine, Linköping University, 581 83, Linköping, Sweden; Department of Ophthalmology, Sørlandet Hospital Arendal, Arendal, Norway
| | - Elena V Semina
- Department of Pediatrics, Children's Research Institute at the Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI, 53226, USA
| | - Daniel Aberdam
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France
| | - Stefano Ferrari
- Fondazione Banca degli Occhi del Veneto, Via Paccagnella 11, Venice, Italy
| | - Vito Romano
- Department of Medical and Surgical Specialties, Radiolological Sciences, and Public Health, Ophthalmology Clinic, University of Brescia, Italy
| | - Cyril Burin des Roziers
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France; Service de Médecine Génomique des Maladies de Système et d'Organe, APHP. Centre Université de Paris, Fédération de Génétique et de Médecine Génomique Hôpital Cochin, 27 rue du Fbg St-Jacques, 75679, Paris Cedex 14, France
| | - Rabia Benkortebi
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France
| | - Nathalie De Vergnes
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France
| | - Michel Polak
- Pediatric Endocrinology, Gynecology and Diabetology, Hôpital Universitaire Necker Enfants Malades, AP-HP, Paris Cité University, INSERM U1016, Institut IMAGINE, France
| | | | - Ken K Nischal
- Division of Pediatric Ophthalmology, Strabismus, and Adult Motility, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA; UPMC Eye Center, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Francine Behar-Cohen
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France
| | - Sophie Valleix
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France; Service de Médecine Génomique des Maladies de Système et d'Organe, APHP. Centre Université de Paris, Fédération de Génétique et de Médecine Génomique Hôpital Cochin, 27 rue du Fbg St-Jacques, 75679, Paris Cedex 14, France
| | - Dominique Bremond-Gignac
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France; INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France.
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4
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Tamayo A, Núñez-Moreno G, Ruiz C, Plaisancie J, Damian A, Moya J, Chassaing N, Calvas P, Ayuso C, Minguez P, Corton M. Minigene Splicing Assays and Long-Read Sequencing to Unravel Pathogenic Deep-Intronic Variants in PAX6 in Congenital Aniridia. Int J Mol Sci 2023; 24:ijms24021562. [PMID: 36675087 PMCID: PMC9863980 DOI: 10.3390/ijms24021562] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/05/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
PAX6 haploinsufficiency causes aniridia, a congenital eye disorder that involves the iris, and foveal hypoplasia. Comprehensive screening of the PAX6 locus, including the non-coding regions, by next-generation sequencing revealed four deep-intronic variants with potential effects on pre-RNA splicing. Nevertheless, without a functional analysis, their pathogenicity could not be established. We aimed to decipher their impact on the canonical PAX6 splicing using in vitro minigene splicing assays and nanopore-based long-read sequencing. Two multi-exonic PAX6 constructs were generated, and minigene assays were carried out. An aberrant splicing pattern was observed for two variants in intron 6, c.357+136G>A and c.357+334G>A. In both cases, several exonization events, such as pseudoexon inclusions and partial intronic retention, were observed due to the creation or activation of new/cryptic non-canonical splicing sites, including a shared intronic donor site. In contrast, two variants identified in intron 11, c.1032+170A>T and c.1033-275A>C, seemed not to affect splicing processes. We confirmed the high complexity of alternative splicing of PAX6 exon 6, which also involves unreported cryptic intronic sites. Our study highlights the importance of integrating functional studies into diagnostic algorithms to decipher the potential implication of non-coding variants, usually classified as variants of unknown significance, thus allowing variant reclassification to achieve a conclusive genetic diagnosis.
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Affiliation(s)
- Alejandra Tamayo
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Department of Surgery, Medical and Social Sciences, Faculty of Medicine and Health Sciences, Science and Technology Campus, University of Alcalá, 28871 Alcalá de Henares, Spain
| | - Gonzalo Núñez-Moreno
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28240 Madrid, Spain
| | - Carolina Ruiz
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
| | - Julie Plaisancie
- Centre de Référence des Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Purpan, CHU Toulouse, 31000 Toulouse, France
- INSERM U1214, Université Toulouse III, 31000 Toulouse, France
| | - Alejandra Damian
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Jennifer Moya
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
| | - Nicolas Chassaing
- Centre de Référence des Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Purpan, CHU Toulouse, 31000 Toulouse, France
- INSERM U1214, Université Toulouse III, 31000 Toulouse, France
| | - Patrick Calvas
- Centre de Référence des Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Purpan, CHU Toulouse, 31000 Toulouse, France
- INSERM U1214, Université Toulouse III, 31000 Toulouse, France
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Pablo Minguez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28240 Madrid, Spain
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence:
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Boehm BO, Kratzer W, Bansal V. Whole-genome sequencing of multiple related individuals with type 2 diabetes reveals an atypical likely pathogenic mutation in the PAX6 gene. Eur J Hum Genet 2023; 31:89-96. [PMID: 36202929 PMCID: PMC9823100 DOI: 10.1038/s41431-022-01182-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 06/21/2022] [Accepted: 08/18/2022] [Indexed: 02/08/2023] Open
Abstract
Pathogenic variants in more than 14 genes have been implicated in monogenic diabetes; however, a significant fraction of individuals with young-onset diabetes and a strong family history of diabetes have unknown genetic etiology. To identify novel pathogenic alleles for monogenic diabetes, we performed whole-genome sequencing (WGS) on four related individuals with type 2 diabetes - including one individual diagnosed at the age of 31 years - that were negative for mutations in known monogenic diabetes genes. The individuals were ascertained from a large case-control study and had a multi-generation family history of diabetes. Identity-by-descent (IBD) analysis revealed that the four individuals represent two sib-pairs that are third-degree relatives. A novel missense mutation (p.P81S) in the PAX6 gene was one of eight rare coding variants across the genome shared IBD by all individuals and was inherited from affected mothers in both sib-pairs. The mutation affects a highly conserved amino acid located in the paired-domain of PAX6 - a hotspot for missense mutations that cause aniridia and other eye abnormalities. However, no eye-related phenotype was observed in any individual. The well-established functional role of PAX6 in glucose-induced insulin secretion and the co-segregation of diabetes in families with aniridia provide compelling support for the pathogenicity of this mutation for diabetes. The mutation could be classified as "likely pathogenic" with a posterior probability of 0.975 according to the ACMG/AMP guidelines. This is the first PAX6 missense mutation that is likely pathogenic for autosomal-dominant adult-onset diabetes without eye abnormalities.
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Affiliation(s)
- Bernhard O. Boehm
- grid.59025.3b0000 0001 2224 0361Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Singapore, Singapore
| | - Wolfgang Kratzer
- grid.6582.90000 0004 1936 9748Department of Internal Medicine I, Ulm University Medical Centre, Ulm, Germany
| | - Vikas Bansal
- grid.266100.30000 0001 2107 4242Department of Pediatrics, University of California San Diego, La Jolla, CA USA
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Qian T, Chen C, Li C, Gong Q, Liu K, Wang G, Schrauwen I, Xu X. A novel 4.25 kb heterozygous deletion in PAX6 in a Chinese Han family with congenital aniridia combined with cataract and nystagmus. BMC Ophthalmol 2021; 21:353. [PMID: 34610801 PMCID: PMC8491394 DOI: 10.1186/s12886-021-02120-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 09/28/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this study is to identify the genetic defect in a Chinese family with congenital aniridia combined with cataract and nystagmus. METHODS Complete ophthalmic examinations, including slit-lamp biomicroscopy, dilated indirect ophthalmoscopy, anterior segment photography, and anterior segment optical coherence tomography (OCT) were performed. Blood samples were collected from all family members and genomic DNA was extracted. Genome sequencing was performed in all family members and Sanger sequencing was used to verify variant breakpoints. RESULTS All the thirteen members in this Chinese family, including seven patients and six normal people, were recruited in this study. The ophthalmic examination of affected patients in this family was consistent with congenital aniridia combined with cataract and nystagmus. A novel heterozygous deletion (NC_000011.10:g.31802307_31806556del) containing the 5' region of PAX6 gene was detected that segregated with the disease. CONCLUSION We detected a novel deletion in PAX6 responsible for congenital aniridia in the affected individuals of this Chinese family. The novel 4.25 kb deletion in PAX6 gene of our study would further broaden the genetic defects of PAX6 associated with congenital aniridia.
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Affiliation(s)
- Tianwei Qian
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Rd., Shanghai, 200080, China.,National Clinical Research Center for Eye Diseases, Shanghai, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Disease, Shanghai, China.,Department of Neurology, Columbia University Medical Center, 630W 168th St, New York, NY, 10032, USA.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Chong Chen
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Rd., Shanghai, 200080, China.,National Clinical Research Center for Eye Diseases, Shanghai, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Disease, Shanghai, China
| | - Caihua Li
- Genesky Biotechnologies Inc, Shanghai, China
| | - Qiaoyun Gong
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Rd., Shanghai, 200080, China.,National Clinical Research Center for Eye Diseases, Shanghai, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Disease, Shanghai, China
| | - Kun Liu
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Rd., Shanghai, 200080, China.,National Clinical Research Center for Eye Diseases, Shanghai, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Disease, Shanghai, China
| | - Gao Wang
- Department of Neurology, Columbia University Medical Center, 630W 168th St, New York, NY, 10032, USA
| | - Isabelle Schrauwen
- Department of Neurology, Columbia University Medical Center, 630W 168th St, New York, NY, 10032, USA.
| | - Xun Xu
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Rd., Shanghai, 200080, China. .,National Clinical Research Center for Eye Diseases, Shanghai, China. .,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China. .,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China. .,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Disease, Shanghai, China.
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7
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Shen T, Qiu X, Lin X, Lin J, Li X, Chen Q, Pan L, Wang Z, Shen H, Zhang Q, Yan J. Missense mutation in the PAX6 gene can cause a complex mild variable phenotype predominated by concomitant strabismus. Ophthalmic Genet 2021; 43:88-96. [PMID: 34344282 DOI: 10.1080/13816810.2021.1961283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE We aimed to reveal the underlying genetic defect in a multigenerational Chinese family with autosomal dominant concomitant strabismus complicated by multiple ocular developmental abnormalities. METHODS Comprehensive ophthalmic examinations were performed in 14 patients and 24 healthy family members. Whole exome sequencing was performed, and Sanger sequencing was used to confirm the probable mutation in all the family members. RESULTS Concomitant strabismus was the predominant phenotype in the affected family members, although the patients also exhibited variable phenotypes, including nystagmus, mild iris abnormalities, myopia, cataract, and coloboma. An R208W mutation in PAX6 was identified as the pathogenic mutation in the affected family members. CONCLUSIONS We recommend considering PAX6 as a candidate gene in the diagnostic screen for familial concomitant strabismus in order to avoid missed diagnosis of the mild ocular abnormalities. Careful examinations of mild ocular phenotypes are necessary for an accurate diagnosis of varied ocular abnormalities in the families with the PAX6 mutation, and proper diagnosis can facilitate genetic and clinical counseling for affected patients.
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Affiliation(s)
- Tao Shen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xuan Qiu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiaoming Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jing Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiuling Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qiwen Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Liuqing Pan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Zhonghao Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Huangxuan Shen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jianhua Yan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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8
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Jiang Y, Li S, Xiao X, Sun W, Zhang Q. Genotype-Phenotype of Isolated Foveal Hypoplasia in a Large Cohort: Minor Iris Changes as an Indicator of PAX6 Involvement. Invest Ophthalmol Vis Sci 2021; 62:23. [PMID: 34415986 PMCID: PMC8383911 DOI: 10.1167/iovs.62.10.23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Foveal hypoplasia (FVH) is defined as the lack of fovea with a relatively preserved neuroretina, occurring either as an isolated FVH (IFVH) condition or associated with other diseases. This study aimed to systemically molecularly characterize IFVH. Methods Genetic defects in 33 families with IFVH were analyzed by exome sequencing. Variants in three genes (PAX6, SLC38A8, and AHR) were selected and evaluated with multistep bioinformatic tools. Results Mutations in the three genes were identified in 69.7% (23/33) of families with IFVH and infantile nystagmus, including 18 families with PAX6 mutations, 5 with SLC38A8 mutations, but none with AHR mutations. Clinical data from 32 patients in the 23 families showed FVH, infantile nystagmus, and full iris. Careful follow-up visits revealed subtle changes in iris in 9 of 14 patients with PAX6 variants. The PAX6 variants of the 18 families (15 missense and one stop-loss) were mostly located in the C-terminal region of the paired box domain. Variants in AHR, SLC38A8, and PAX6 contributed to IFVH in one (2%), 25 (45%), and 30 (53%) families with identified genetic defects (23 families in this study and 33 reported previously), respectively. Conclusions PAX6 and SLC38A8 mutations are the main cause of IFVH based on our data and a systematic review. IFVH-associated PAX6 variants are mostly missense with a specific location, indicating a specific correlation of these variants with IFVH but not with typical aniridia. Full iris with subtle structural abnormalities is more common in patients with PAX6-associated IFVH, suggesting a potential diagnostic indicator.
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Affiliation(s)
- Yi Jiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xueshan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Wenmin Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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9
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Tarilonte M, Ramos P, Moya J, Fernandez-Sanz G, Blanco-Kelly F, Swafiri ST, Villaverde C, Romero R, Tamayo A, Gener B, Calvas P, Ayuso C, Corton M. Activation of cryptic donor splice sites by non-coding and coding PAX6 variants contributes to congenital aniridia. J Med Genet 2021; 59:428-437. [PMID: 33782094 DOI: 10.1136/jmedgenet-2020-106932] [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] [Received: 02/20/2020] [Revised: 01/22/2021] [Accepted: 02/14/2021] [Indexed: 12/17/2022]
Abstract
BACKGROUND The paired-domain transcription factor paired box gene 6 (PAX6) causes a wide spectrum of ocular developmental anomalies, including congenital aniridia, Peters anomaly and microphthalmia. Here, we aimed to functionally assess the involvement of seven potentially non-canonical splicing variants on missplicing of exon 6, which represents the main hotspot region for loss-of-function PAX6 variants. METHODS By locus-specific analysis of PAX6 using Sanger and/or targeted next-generation sequencing, we screened a Spanish cohort of 106 patients with PAX6-related diseases. Functional splicing assays were performed by in vitro minigene approaches or directly in RNA from patient-derived lymphocytes cell line, when available. RESULTS Five out seven variants, including three synonymous changes, one small exonic deletion and one non-canonical splice variant, showed anomalous splicing patterns yielding partial exon skipping and/or elongation. CONCLUSION We describe new spliceogenic mechanisms for PAX6 variants mediated by creating or strengthening five different cryptic donor sites at exon 6. Our work revealed that the activation of cryptic PAX6 splicing sites seems to be a recurrent and underestimated cause of aniridia. Our findings pointed out the importance of functional assessment of apparently silent PAX6 variants to uncover hidden genetic alterations and to improve variant interpretation for genetic counselling in aniridia.
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Affiliation(s)
- Maria Tarilonte
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Patricia Ramos
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain
| | - Jennifer Moya
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain
| | - Guilermo Fernandez-Sanz
- Department of Ophthalmology, Fundación Jiménez Díaz University Hospital, Madrid, Spain.,Department of Ophthalmology, Clínica Universidad de Navarra, Madrid, Spain
| | - Fiona Blanco-Kelly
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Saoud Tahsin Swafiri
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Cristina Villaverde
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Raquel Romero
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain
| | - Alejandra Tamayo
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Blanca Gener
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain.,Department of Genetics, Cruces University Hospital, BioCruces Health Research Institute, Barakaldo, Spain
| | - Patrick Calvas
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, Toulouse, France.,INSERM U1056, Université Toulouse III, Toulouse, France
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain .,Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
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10
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Grant MK, Bobilev AM, Branch A, Lauderdale JD. Structural and functional consequences of PAX6 mutations in the brain: Implications for aniridia. Brain Res 2021; 1756:147283. [PMID: 33515537 DOI: 10.1016/j.brainres.2021.147283] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 12/15/2020] [Accepted: 01/05/2021] [Indexed: 12/27/2022]
Abstract
The paired-box 6 (PAX6) gene encodes a highly conserved transcription factor essential for the proper development of the eye and brain. Heterozygous loss-of-function mutations in PAX6 are causal for a condition known as aniridia in humans and the Small eye phenotype in mice. Aniridia is characterized by iris hypoplasia and other ocular abnormalities, but recent evidence of neuroanatomical, sensory, and cognitive impairments in this population has emerged, indicating brain-related phenotypes as a prevalent feature of the disorder. Determining the neurophysiological origins of brain-related phenotypes in this disorder presents a substantial challenge, as the majority of extra-ocular traits in aniridia demonstrate a high degree of heterogeneity. Here, we summarize and integrate findings from human and rodent model studies, which have focused on neuroanatomical and functional consequences of PAX6 mutations. We highlight novel findings from PAX6 central nervous system studies in adult mammals, and integrate these findings into what we know about PAX6's role in development of the central nervous system. This review presents the current literature in the field in order to inform clinical application, discusses what is needed in future studies, and highlights PAX6 as a lens through which to understand genetic disorders affecting the human nervous system.
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Affiliation(s)
- Madison K Grant
- Department of Cellular Biology, The University of Georgia, Athens, GA 30602, USA.
| | - Anastasia M Bobilev
- Neuroscience Division of the Biomedical and Health Sciences Institute, The University of Georgia, Athens, GA 30602, USA; Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Audrey Branch
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA.
| | - James D Lauderdale
- Department of Cellular Biology, The University of Georgia, Athens, GA 30602, USA; Neuroscience Division of the Biomedical and Health Sciences Institute, The University of Georgia, Athens, GA 30602, USA.
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11
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Yoon KH, Fox SC, Dicipulo R, Lehmann OJ, Waskiewicz AJ. Ocular coloboma: Genetic variants reveal a dynamic model of eye development. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2020; 184:590-610. [PMID: 32852110 DOI: 10.1002/ajmg.c.31831] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 12/21/2022]
Abstract
Ocular coloboma is a congenital disorder of the eye where a gap exists in the inferior retina, lens, iris, or optic nerve tissue. With a prevalence of 2-19 per 100,000 live births, coloboma, and microphthalmia, an associated ocular disorder, represent up to 10% of childhood blindness. It manifests due to the failure of choroid fissure closure during eye development, and it is a part of a spectrum of ocular disorders that include microphthalmia and anophthalmia. Use of genetic approaches from classical pedigree analyses to next generation sequencing has identified more than 40 loci that are associated with the causality of ocular coloboma. As we have expanded studies to include singleton cases, hereditability has been very challenging to prove. As such, researchers over the past 20 years, have unraveled the complex interrelationship amongst these 40 genes using vertebrate model organisms. Such research has greatly increased our understanding of eye development. These genes function to regulate initial specification of the eye field, migration of retinal precursors, patterning of the retina, neural crest cell biology, and activity of head mesoderm. This review will discuss the discovery of loci using patient data, their investigations in animal models, and the recent advances stemming from animal models that shed new light in patient diagnosis.
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Affiliation(s)
- Kevin H Yoon
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.,Women & Children's Health Research Institute, University of Alberta, Edmonton, Canada
| | - Sabrina C Fox
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.,Women & Children's Health Research Institute, University of Alberta, Edmonton, Canada
| | - Renée Dicipulo
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.,Women & Children's Health Research Institute, University of Alberta, Edmonton, Canada
| | - Ordan J Lehmann
- Women & Children's Health Research Institute, University of Alberta, Edmonton, Canada.,Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada.,Department of Ophthalmology, University of Alberta, Edmonton, Alberta, Canada
| | - Andrew J Waskiewicz
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.,Women & Children's Health Research Institute, University of Alberta, Edmonton, Canada
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12
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Cross E, Duncan-Flavell PJ, Howarth RJ, Crooks RO, Thomas NS, Bunyan DJ. Screening of a large PAX6 cohort identified many novel variants and emphasises the importance of the paired and homeobox domains. Eur J Med Genet 2020; 63:103940. [DOI: 10.1016/j.ejmg.2020.103940] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/20/2019] [Accepted: 04/23/2020] [Indexed: 12/21/2022]
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13
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The Genetic and Endoplasmic Reticulum-Mediated Molecular Mechanisms of Primary Open-Angle Glaucoma. Int J Mol Sci 2020; 21:ijms21114171. [PMID: 32545285 PMCID: PMC7312987 DOI: 10.3390/ijms21114171] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/04/2020] [Accepted: 06/09/2020] [Indexed: 12/14/2022] Open
Abstract
Glaucoma is a heterogenous, chronic, progressive group of eye diseases, which results in irreversible loss of vision. There are several types of glaucoma, whereas the primary open-angle glaucoma (POAG) constitutes the most common type of glaucoma, accounting for three-quarters of all glaucoma cases. The pathological mechanisms leading to POAG pathogenesis are multifactorial and still poorly understood, but it is commonly known that significantly elevated intraocular pressure (IOP) plays a crucial role in POAG pathogenesis. Besides, genetic predisposition and aggregation of abrogated proteins within the endoplasmic reticulum (ER) lumen and subsequent activation of the protein kinase RNA-like endoplasmic reticulum kinase (PERK)-dependent unfolded protein response (UPR) signaling pathway may also constitute important factors for POAG pathogenesis at the molecular level. Glaucoma is commonly known as a ‘silent thief of sight’, as it remains asymptomatic until later stages, and thus its diagnosis is frequently delayed. Thereby, detailed knowledge about the glaucoma pathophysiology is necessary to develop both biochemical and genetic tests to improve its early diagnosis as well as develop a novel, ground-breaking treatment strategy, as currently used medical therapies against glaucoma are limited and may evoke numerous adverse side-effects in patients.
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14
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Boese EA, Tollefson MR, Schnieders MJ, Darbro BW, Alward WLM, Fingert JH. Novel Intragenic PAX6 Deletion in a Pedigree with Aniridia, Morbid Obesity, and Diabetes. Curr Eye Res 2020; 45:91-96. [PMID: 31361967 PMCID: PMC10413309 DOI: 10.1080/02713683.2019.1649704] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 07/18/2019] [Accepted: 07/20/2019] [Indexed: 10/26/2022]
Abstract
Purpose: Aniridia is a rare congenital eye disease, characterized by a constellation of symptoms including hypoplastic irides, foveal hypoplasia, early cataract, corneal stem cell deficiency, and glaucoma. Large chromosomal deletions spanning the PAX6 gene cause WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies, and intellectual disability [formerly called mental retardation]). We describe clinical and genetic studies of a three-generation pedigree with aniridia along with additional systemic conditions (morbid obesity, diabetes) suggesting the possibility of a contiguous-gene syndrome like WAGR.Methods: Clinical records were obtained and DNA was prepared from blood samples from three of the four patients and tested for mutations in the coding sequences of the PAX6 gene. The index patient also had cardiomyopathy and was tested for known cardiomyopathy genetic mutations using a next-generation DNA sequencing assay.Results: We discovered a novel intragenic PAX6 mutation, a 16 bp heterozygous deletion c.203delCCAGGGCAATCGGTGG, with Sanger sequencing that is the likely cause of autosomal dominant aniridia in this pedigree. This PAX6 deletion causes a frameshift in predicted protein translation and a subsequent premature termination, p.Pro68Leufs*6. The PAX6 deletion was detected in all three available family members with aniridia, the index patient, his mother, and his maternal aunt but was not observed in the Exome Aggregation Consortium (ExAC) database. Targeted sequencing of known cardiomyopathy genes in the index patient identified a second mutation, a 1.7 Mp deletion that spans the MYBPC3 gene.Conclusions: We report a pedigree with aniridia and other systemic abnormalities that were initially suspicious for a contiguous-gene syndrome like WAGR. However, genetic analysis of the pedigree revealed two independent genetic abnormalities on chromosome 11p: 1) a novel PAX6 mutation, and 2) a large chromosome deletion spanning MYBPC3, a known cardiomyopathy gene. It is unclear if morbid obesity and type II diabetes mellitus have a related genetic cause.
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Affiliation(s)
- Erin A Boese
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Mallory R Tollefson
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Michael J Schnieders
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Benjamin W Darbro
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Wallace L M Alward
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - John H Fingert
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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15
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Williams C, Suderman M, Guggenheim JA, Ellis G, Gregory S, Iles-Caven Y, Northstone K, Golding J, Pembrey M. Grandmothers' smoking in pregnancy is associated with a reduced prevalence of early-onset myopia. Sci Rep 2019; 9:15413. [PMID: 31659193 PMCID: PMC6817861 DOI: 10.1038/s41598-019-51678-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 10/02/2019] [Indexed: 12/30/2022] Open
Abstract
Myopia (near sightedness) is the most common vision disorder resulting in visual impairment worldwide. We tested the hypothesis that intergenerational, non-genetic heritable effects influence refractive development, using grandparental prenatal smoking as a candidate exposure. Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC), we found that the prevalence of myopia at age 7 was lower if the paternal grandmother had smoked in pregnancy, an association primarily found among grandsons compared to granddaughters. There was a weaker, non-sex-specific, reduction in the prevalence of myopia at age 7 if the maternal grandmother had smoked in pregnancy. For children who became myopic later (between 7 and 15 years of age) there were no associations with either grandmother smoking. Differences between early and late-onset myopia were confirmed with DNA methylation patterns: there were very distinct and strong associations with methylation for early-onset but not later-onset myopia.
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Affiliation(s)
- Cathy Williams
- Centre for Academic Child Health, Population Health Sciences, Bristol Medical School, Oakfield House, Oakfield Grove, University of Bristol, Bristol, BS8 2BN, UK.
| | - Matthew Suderman
- MRC Integrative Epidemiology Unit, Bristol Medical School, Oakfield House, Oakfield Grove, University of Bristol, Bristol, BS8 2BN, UK
| | - Jeremy A Guggenheim
- School of Optometry & Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Genette Ellis
- Centre for Academic Child Health, Population Health Sciences, Bristol Medical School, Oakfield House, Oakfield Grove, University of Bristol, Bristol, BS8 2BN, UK
| | - Steve Gregory
- Centre for Academic Child Health, Population Health Sciences, Bristol Medical School, Oakfield House, Oakfield Grove, University of Bristol, Bristol, BS8 2BN, UK
| | - Yasmin Iles-Caven
- Centre for Academic Child Health, Population Health Sciences, Bristol Medical School, Oakfield House, Oakfield Grove, University of Bristol, Bristol, BS8 2BN, UK
| | - Kate Northstone
- ALSPAC, Oakfield House, Oakfield Grove, University of Bristol, Bristol, BS8 2BN, UK
| | - Jean Golding
- Centre for Academic Child Health, Population Health Sciences, Bristol Medical School, Oakfield House, Oakfield Grove, University of Bristol, Bristol, BS8 2BN, UK.
| | - Marcus Pembrey
- Centre for Academic Child Health, Population Health Sciences, Bristol Medical School, Oakfield House, Oakfield Grove, University of Bristol, Bristol, BS8 2BN, UK
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16
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Bobilev AM, Hudgens-Haney ME, Hamm JP, Oliver WT, McDowell JE, Lauderdale JD, Clementz BA. Early and late auditory information processing show opposing deviations in aniridia. Brain Res 2019; 1720:146307. [PMID: 31247203 DOI: 10.1016/j.brainres.2019.146307] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 06/12/2019] [Accepted: 06/23/2019] [Indexed: 01/29/2023]
Abstract
Aniridia is a congenital disorder, predominantly caused by heterozygous mutations of the PAX6 gene. While ocular defects have been extensively characterized in this population, brain-related anatomical and functional abnormalities are emerging as a prominent feature of the disorder. Individuals with aniridia frequently exhibit auditory processing deficits despite normal audiograms. While previous studies have reported hypoplasia of the anterior commissure and corpus callosum in some of these individuals, the neurophysiological basis of these impairments remains unexplored. This study provides direct assessment of neural activity related to auditory processing in aniridia. Participants were presented with tones designed to elicit an auditory steady-state response (ASSR) at 22 Hz, 40 Hz, and 84 Hz, and infrequent broadband target tones to maintain attention during electroencephalography (EEG) recording. Persons with aniridia showed increased early cortical responses (P50 AEP) in response to all tones, and increased high-frequency oscillatory entrainment (84 Hz ASSR). In contrast, this group showed a decreased cortical integration response (P300 AEP to target tones) and reduced neural entrainment to cortical beta-band stimuli (22 Hz ASSR). Collectively, our results suggest that subcortical and early cortical auditory processing is augmented in aniridia, while functional cortical integration of auditory information is deficient in this population.
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Affiliation(s)
- Anastasia M Bobilev
- Department of Cellular Biology, Bio-Imaging Research Center, University of Georgia, Athens, GA, United States; Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, United States.
| | - Matthew E Hudgens-Haney
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, United States; Departments of Psychology and Neuroscience, Bio-Imaging Research Center, University of Georgia, Athens, GA, United States
| | - Jordan P Hamm
- Departments of Psychology and Neuroscience, Bio-Imaging Research Center, University of Georgia, Athens, GA, United States; Neuroscience Institute, Georgia State University, Petit Science Center, Atlanta, GA, United States; Center for Neuroinflammation and Cardiometabolic Diseases, Georgia State University, Petit Science Center, Atlanta, GA, United States
| | - William T Oliver
- Departments of Psychology and Neuroscience, Bio-Imaging Research Center, University of Georgia, Athens, GA, United States
| | - Jennifer E McDowell
- Departments of Psychology and Neuroscience, Bio-Imaging Research Center, University of Georgia, Athens, GA, United States
| | - James D Lauderdale
- Department of Cellular Biology, Bio-Imaging Research Center, University of Georgia, Athens, GA, United States
| | - Brett A Clementz
- Departments of Psychology and Neuroscience, Bio-Imaging Research Center, University of Georgia, Athens, GA, United States
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17
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Sarkar A, Gogia N, Glenn N, Singh A, Jones G, Powers N, Srivastava A, Kango-Singh M, Singh A. A soy protein Lunasin can ameliorate amyloid-beta 42 mediated neurodegeneration in Drosophila eye. Sci Rep 2018; 8:13545. [PMID: 30202077 PMCID: PMC6131139 DOI: 10.1038/s41598-018-31787-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 08/24/2018] [Indexed: 01/30/2023] Open
Abstract
Alzheimer's disease (AD), a fatal progressive neurodegenerative disorder, also results from accumulation of amyloid-beta 42 (Aβ42) plaques. These Aβ42 plaques trigger oxidative stress, abnormal signaling, which results in neuronal death by unknown mechanism(s). We misexpress high levels of human Aβ42 in the differentiating retinal neurons of the Drosophila eye, which results in the Alzheimer's like neuropathology. Using our transgenic model, we tested a soy-derived protein Lunasin (Lun) for a possible role in rescuing neurodegeneration in retinal neurons. Lunasin is known to have anti-cancer effect and reduces stress and inflammation. We show that misexpression of Lunasin by transgenic approach can rescue Aβ42 mediated neurodegeneration by blocking cell death in retinal neurons, and results in restoration of axonal targeting from retina to brain. Misexpression of Lunasin downregulates the highly conserved cJun-N-terminal Kinase (JNK) signaling pathway. Activation of JNK signaling can prevent neuroprotective role of Lunasin in Aβ42 mediated neurodegeneration. This neuroprotective function of Lunasin is not dependent on retinal determination gene cascade in the Drosophila eye, and is independent of Wingless (Wg) and Decapentaplegic (Dpp) signaling pathways. Furthermore, Lunasin can significantly reduce mortality rate caused by misexpression of human Aβ42 in flies. Our studies identified the novel neuroprotective role of Lunasin peptide, a potential therapeutic agent that can ameliorate Aβ42 mediated neurodegeneration by downregulating JNK signaling.
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Affiliation(s)
- Ankita Sarkar
- Department of Biology, University of Dayton, Dayton, OH, 45469, USA
| | - Neha Gogia
- Department of Biology, University of Dayton, Dayton, OH, 45469, USA
| | - Neil Glenn
- Premedical Program, University of Dayton, Dayton, OH, 45469, USA
| | - Aditi Singh
- Department of Biology, University of Dayton, Dayton, OH, 45469, USA
| | - Gillian Jones
- Department of Biology and Biotechnology Center, Western Kentucky University, 1906 College Heights Boulevard, TCCW 351, Bowling Green, KY, 42101, USA
| | - Nathan Powers
- Department of Biology and Biotechnology Center, Western Kentucky University, 1906 College Heights Boulevard, TCCW 351, Bowling Green, KY, 42101, USA
| | - Ajay Srivastava
- Department of Biology and Biotechnology Center, Western Kentucky University, 1906 College Heights Boulevard, TCCW 351, Bowling Green, KY, 42101, USA
| | - Madhuri Kango-Singh
- Department of Biology, University of Dayton, Dayton, OH, 45469, USA
- Premedical Program, University of Dayton, Dayton, OH, 45469, USA
- Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, OH, 45469, USA
- The Integrative Science and Engineering Center, University of Dayton, Dayton, OH, 45469, USA
| | - Amit Singh
- Department of Biology, University of Dayton, Dayton, OH, 45469, USA.
- Premedical Program, University of Dayton, Dayton, OH, 45469, USA.
- Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, OH, 45469, USA.
- The Integrative Science and Engineering Center, University of Dayton, Dayton, OH, 45469, USA.
- Center for Genomic Advocacy (TCGA), Indiana State University, Terre Haute, IN, USA.
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18
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Lin Y, Gao H, Zhu Y, Chen C, Li T, Liu B, Lyu C, Huang Y, Li H, Wu Q, Jin C, Liang X, Huang X, Lu L. Two Paired Box 6 mutations identified in Chinese patients with classic congenital aniridia and cataract. Mol Med Rep 2018; 18:4439-4445. [PMID: 30221735 PMCID: PMC6172400 DOI: 10.3892/mmr.2018.9469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 08/02/2018] [Indexed: 02/02/2023] Open
Abstract
Congenital aniridia is a rare genetic disorder characterized by a variable degree of hypoplasia or absence of iris. It is frequently associated with keratopathy, cataract, juvenile-onset glaucoma and foveal and optic nerve hypoplasia. Mutations in the Paired Box 6 (PAX6) gene on chromosome 11p13 have been demonstrated to cause aniridia. The aim of the present study was to investigate the genetic variations of PAX6 in two sporadic patients from southern China with classic congenital aniridia and cataract. Complete ophthalmic and physical examinations were performed, including best-corrected visual acuity, intraocular pressure, slit-lamp examination, fundus examination, optical coherence tomography, ultrasound biomicroscopy, and Pentacam scanning. Genomic DNA was extracted from leukocytes of peripheral blood collected from the two patients, their unaffected parents and 200 unrelated control subjects from the same population. Exons 4–13 of the PAX6 gene were amplified by polymerase chain reaction and sequenced directly. Patient 1 was affected with aniridia accompanied by congenital cataract and nystagmus. A novel heterozygous PAX6 frameshift mutation c.277delG (p.Glu93SerfsX31) in exon 6 was identified in this patient. Patient 2 was presented with aniridia, congenital cataract, lens subluxation and glaucoma. A recurrent nonsense mutation c.718C>T (p.Arg240X) in exon 9 was identified in this patient. The present results expand the mutation spectrum of PAX6 and will be valuable for genetic counseling in the affected families. Additionally, the identification of these mutations reiterates the importance of PAX6 in ocular development and sheds light on the pathogenesis of congenital aniridia.
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Affiliation(s)
- Ying Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Hongbin Gao
- Department of Toxicology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Yi Zhu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Chuan Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Tao Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Bingqian Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Cancan Lyu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Ying Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Haichun Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Qingxiu Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Chenjin Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Xiaoling Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Xinhua Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Lin Lu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
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Nguyen KN, Bobba S, Richardson A, Park M, Watson SL, Wakefield D, Di Girolamo N. Native and synthetic scaffolds for limbal epithelial stem cell transplantation. Acta Biomater 2018; 65:21-35. [PMID: 29107055 DOI: 10.1016/j.actbio.2017.10.037] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 10/22/2017] [Accepted: 10/25/2017] [Indexed: 12/13/2022]
Abstract
UNLABELLED Limbal stem cell deficiency (LSCD) is a complex blinding disease of the cornea, which cannot be treated with conventional corneal transplants. Instead, a stem cell (SC) graft is required to replenish the limbal epithelial stem cell (LESC) reservoir, which is ultimately responsible for regenerating the corneal epithelium. Current therapies utilize limbal tissue biopsies that harbor LESCs as well as tissue culture expanded cells. Typically, this tissue is placed on a scaffold that supports the formation of corneal epithelial cell sheets, which are then transferred to diseased eyes. A wide range of biological and synthetic materials have been identified as carrier substrates for LESC, some of which have been used in the clinic, including amniotic membrane, fibrin, and silicon hydrogel contact lenses, each with their own advantages and limitations. This review will provide a brief background of LSCD, focusing on bio-scaffolds that have been utilized in limbal stem cell transplantation (LSCT) and materials that are being developed as potentially novel therapeutics for patients with this disease. STATEMENT OF SIGNIFICANCE The outcome of patients with corneal blindness that receive stem cell grafts to restore eye health and correct vision varies considerably and may be due to the different biological and synthetic scaffolds used to deliver these cells to the ocular surface. This review will highlight the positive attributes and limitations of the myriad of carriers developed for clinical use as well as those that are being trialled in pre-clinical models. The overall focus is on developing a standardized therapy for patients, however due to the multiple causes of corneal blindness, a personal regenerative medicine approach may be the best option.
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Affiliation(s)
- Kim N Nguyen
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Samantha Bobba
- Prince of Wales Hospital Clinical School, Sydney, Australia
| | | | - Mijeong Park
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | | | - Denis Wakefield
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Nick Di Girolamo
- School of Medical Sciences, University of New South Wales, Sydney, Australia.
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20
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Rim JH, Lee ST, Gee HY, Lee BJ, Choi JR, Park HW, Han SH, Han J. Accuracy of Next-Generation Sequencing for Molecular Diagnosis in Patients With Infantile Nystagmus Syndrome. JAMA Ophthalmol 2017; 135:1376-1385. [PMID: 29145603 PMCID: PMC6583550 DOI: 10.1001/jamaophthalmol.2017.4859] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 09/23/2017] [Indexed: 01/10/2023]
Abstract
Importance Infantile nystagmus syndrome (INS) is a group of disorders presenting with genetic and clinical heterogeneities that have challenged the genetic and clinical diagnoses of INS. Precise molecular diagnosis in early infancy may result in more accurate genetic counseling and improved patient management. Objective To assess the accuracy of genomic data from next-generation sequencing (NGS) and phenotypic data to enhance the definitive diagnosis of INS. Design, Setting, and Participants A single-center retrospective case series was conducted in 48 unrelated, consecutive patients with INS, with or without associated ocular or systemic conditions, who underwent genetic testing between June 1, 2015, and January 31, 2017. Next-generation sequencing analysis was performed using a target panel that included 113 genes associated with INS (n = 47) or a TruSight One sequencing panel that included 4813 genes associated with known human phenotypes (n = 1). Variants were filtered and prioritized by in-depth clinical review, and finally classified according to the American College of Medical Genetics and Genomics guidelines. Patients underwent a detailed ophthalmic examination, including electroretinography and optical coherence tomography, if feasible. Main Outcomes and Measures Diagnostic yield of targeted NGS testing. Results Among the 48 patients (21 female and 27 male; mean [SD] age at genetic testing, 9.2 [10.3] years), 8 had a family history of nystagmus and 40 were simplex. All patients were of a single ethnicity (Korean). Genetic variants that were highly likely to be causative were identified in 28 of the 48 patients, corresponding to a molecular diagnostic yield of 58.3% (95% CI, 44.4%-72.2%). FRMD7, GPR143, and PAX6 mutations appeared to be the major genetic causes of familial INS. A total of 10 patients (21%) were reclassified to a different diagnosis based on results of NGS testing, enabling accurate clinical management. Conclusions and Relevance These findings suggest that NGS is an accurate diagnostic tool to differentiate causes of INS because diagnostic tests, such as electroretinography and optical coherence tomography, are not easily applicable in young infants. Accurate application of NGS using a standardized, stepwise, team-based approach in early childhood not only facilitated early molecular diagnosis but also led to improved personalized management in patients with INS.
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Affiliation(s)
- John Hoon Rim
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
- Department of Medicine, Yonsei University Graduate School of Medicine, Seoul, Korea
- Department of Pharmacology, Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Heon Yung Gee
- Department of Medicine, Yonsei University Graduate School of Medicine, Seoul, Korea
- Department of Pharmacology, Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Byung Joo Lee
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hye Won Park
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
| | - Sueng-Han Han
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
| | - Jinu Han
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
- Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
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21
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Miao Q, Ping X, Tang X, Zhang L, Zhang X, Cheng Y, Shentu X. Experimental assessment of novel PAX6 splicing mutations in two Chinese families with aniridia. Gene 2017; 630:44-48. [DOI: 10.1016/j.gene.2017.07.073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 07/07/2017] [Accepted: 07/27/2017] [Indexed: 01/13/2023]
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22
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Grant MK, Bobilev AM, Pierce JE, DeWitte J, Lauderdale JD. Structural brain abnormalities in 12 persons with aniridia. F1000Res 2017; 6:255. [PMID: 29034075 PMCID: PMC5615777 DOI: 10.12688/f1000research.11063.2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/27/2017] [Indexed: 02/04/2023] Open
Abstract
Background: Aniridia is a disorder predominately caused by heterozygous loss-of-function mutations of the
PAX6 gene, which is a transcriptional regulator necessary for normal eye and brain development. The ocular abnormalities of aniridia have been well characterized, but mounting evidence has implicated brain-related phenotypes as a prominent feature of this disorder as well. Investigations using neuroimaging in aniridia patients have shown reductions in discrete brain structures and changes in global grey and white matter. However, limited sample sizes and substantive heterogeneity of structural phenotypes in the brain remain a challenge.
Methods: Here, we examined brain structure in a new population sample in an effort to add to the collective understanding of anatomical abnormalities in aniridia. The current study used 3T magnetic resonance imaging to acquire high-resolution structural data in 12 persons with aniridia and 12 healthy demographically matched comparison subjects.
Results: We examined five major structures: the anterior commissure, the posterior commissure, the pineal gland, the corpus callosum, and the optic chiasm. The most consistent reductions were found in the anterior commissure and the pineal gland; however, abnormalities in all of the other structures examined were present in at least one individual.
Conclusions: Our results indicate that the anatomical abnormalities in aniridia are variable and largely individual-specific. These findings suggest that future studies investigate this heterogeneity further, and that normal population variation should be considered when evaluating structural abnormalities.
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Affiliation(s)
- Madison K Grant
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Anastasia M Bobilev
- Neuroscience Division of the Biomedical and Health Sciences Institute, University of Georgia, Athens, GA, 30602, USA
| | - Jordan E Pierce
- Department of Psychology, University of Georgia, Athens, GA, 30602, USA
| | - Jon DeWitte
- Athens Radiology Associates, Athens, GA, 30604, USA
| | - James D Lauderdale
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA.,Neuroscience Division of the Biomedical and Health Sciences Institute, University of Georgia, Athens, GA, 30602, USA
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23
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Pibiri V, Ravarino A, Gerosa C, Pintus MC, Fanos V, Faa G. Stem/progenitor cells in the developing human cerebellum: an immunohistochemical study. Eur J Histochem 2016; 60:2686. [PMID: 27734996 PMCID: PMC5062635 DOI: 10.4081/ejh.2016.2686] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/28/2016] [Accepted: 07/30/2016] [Indexed: 11/25/2022] Open
Abstract
The aim of this study was to analyze, by immunohistochemistry, the occurrence of stem/progenitor cells localized in the different niches of the developing human cerebellum. To this end, cerebellar samples were obtained from 3 fetuses and 3 newborns ranging, respectively, from 11 to 24 and from 30 to 38 weeks of gestation. Specimens were 10% formalin-fixed, routinely processed and paraffin-embedded; 3 μm-tick sections were immunostained with anti-SOX2 and PAX6 antibodies. Our study evidenced SOX2 and PAX6 immunoreactivity in precursors cells in all six developing human cerebella. SOX2 was expressed in precursors of different neural cell types, including Purkinje neurons, stellate cells, basket cells and Golgi cells. In the cerebellar cortex, SOX2 expression changed during gestation, being highly expressed from the 20th up to the 24th week, whereas at the 30th and at the 34th week SOX2 immunoreactivity was restricted to the Purkinje cell layer and the inner zone. Cerebellar human cortex was negative at the 38th week of gestation. PAX6 immunoreactivity was restricted to granule cell precursors in the external granule layer (EGL), being detected at all gestational ages. Our study indicates SOX2 and PAX6 as two useful markers of stem/progenitor cells that highlight the different germinative zones in the developing human cerebellum.
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24
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Bobilev AM, McDougal ME, Taylor WL, Geisert EE, Netland PA, Lauderdale JD. Assessment of PAX6 alleles in 66 families with aniridia. Clin Genet 2016; 89:669-77. [PMID: 26661695 DOI: 10.1111/cge.12708] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 12/03/2015] [Accepted: 12/04/2015] [Indexed: 12/18/2022]
Abstract
We report on PAX6 alleles associated with a clinical diagnosis of classical aniridia in 81 affected individuals representing 66 families. Allelic variants expected to affect PAX6 function were identified in 61 families (76 individuals). Ten cases of sporadic aniridia (10 families) had complete (8 cases) or partial (2 cases) deletion of the PAX6 gene. Sequence changes that introduced a premature termination codon into the open reading frame of PAX6 occurred in 47 families (62 individuals). Three individuals with sporadic aniridia (three families) had sequence changes (one deletion, two run-on mutations) expected to result in a C-terminal extension. An intronic deletion of unknown functional significance was detected in one case of sporadic aniridia (one family), but not in unaffected relatives. Within these 61 families, single nucleotide substitutions accounted for 30/61 (49%), indels for 23/61 (38%), and complete deletion of the PAX6 locus for 8/61 (13%). In five cases of sporadic aniridia (five families), no disease-causing mutation in the coding region was detected. In total, 23 unique variants were identified that have not been reported in the Leiden Open Variation Database (LOVD) database. Within the group assessed, 92% had sequence changes expected to reduce PAX6 function, confirming the primacy of PAX6 haploinsufficiency as causal for aniridia.
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Affiliation(s)
- A M Bobilev
- Neuroscience Division of the Biomedical and Health Sciences Institute, The University of Georgia, Athens, GA, USA
| | - M E McDougal
- Department of Cellular Biology, The University of Georgia, Athens, GA, USA
| | - W L Taylor
- Molecular Resource Center, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - E E Geisert
- Department of Ophthalmology in the Hamilton Eye Institute, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - P A Netland
- Molecular Resource Center, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - J D Lauderdale
- Neuroscience Division of the Biomedical and Health Sciences Institute, The University of Georgia, Athens, GA, USA.,Department of Cellular Biology, The University of Georgia, Athens, GA, USA
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25
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Sartaj R, Chee RI, Yang J, Wan P, Liu A, Guaiquil V, Fuchs E, Rosenblatt MI. LIM Homeobox Domain 2 Is Required for Corneal Epithelial Homeostasis. Stem Cells 2016; 34:493-503. [PMID: 26661907 PMCID: PMC4834794 DOI: 10.1002/stem.2257] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 07/15/2015] [Accepted: 08/06/2015] [Indexed: 11/09/2022]
Abstract
The cornea requires constant epithelial renewal to maintain clarity for appropriate vision. A subset of stem cells residing at the limbus is primarily responsible for maintaining corneal epithelium homeostasis. Trauma and disease may lead to stem cell deficiency and therapeutic targeting to replenish the stemness capacity has been stalled by the lack of reliable corneal epithelial stem cell markers. Here we identified the location of Lhx2 in mice (mLhx2) cornea and conjunctival tissue using an Lhx2eGFP reporter model and in human tissues (hLHX2). Lhx2 localized to the basal cells of central cornea, the conjunctiva and the entire limbal epithelium in humans and mice. To ascribe a functional role we generated Lhx2 conditional knockout (cKO) mice and the phenotypic effects in corneas were analyzed by slit lamp microscopy, in cell‐based assays and in a model of corneal epithelium debridement. Immunodetection on corneal sections were used to visualize conjunctivalization, a sign of limbal barrier failure. Lhx2cKO mice produced reduced body hair and spontaneous epithelial defects in the cornea that included neovascularization, perforation with formation of scar tissue and opacification. Cell based assays showed that Lhx2cKO derived corneal epithelial cells have a significantly lower capacity to form colonies over time and delayed wound‐healing recovery when compared to wildtype cells. Repeated corneal epithelial wounding resulted in decreased re‐epithelialization and multiple cornea lesions in Lhx2cKO mice compared to normal recovery seen in wildtype mice. We conclude that Lhx2 is required for maintenance of the corneal epithelial cell compartment and the limbal barrier. Stem Cells2016;34:493–503
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Affiliation(s)
- Rachel Sartaj
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Ru-ik Chee
- Margaret Dyson Vision Research Institute, Weill Cornell Medical College, New York, New York, USA
| | - Jing Yang
- Margaret Dyson Vision Research Institute, Weill Cornell Medical College, New York, New York, USA
| | - Pengxia Wan
- Margaret Dyson Vision Research Institute, Weill Cornell Medical College, New York, New York, USA
| | - Aihong Liu
- Margaret Dyson Vision Research Institute, Weill Cornell Medical College, New York, New York, USA
| | - Victor Guaiquil
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Elaine Fuchs
- Howard Hughes Medical Institute, Laboratory of Mammalian Cell Biology Development, The Rockefeller University, New York, New York, USA
| | - Mark I Rosenblatt
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
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26
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Hahn IK, Kim DH, Lim HT. Clinical Features and Molecular Characteristics of Korean Patients with Congenital Aniridia. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2016. [DOI: 10.3341/jkos.2016.57.9.1441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- In Kyun Hahn
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Dae Hee Kim
- Department of Ophthalmology, Myongji Hospital, Seonam University College of Medicine, Goyang, Korea
| | - Hyun Taek Lim
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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27
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Wittkorn E, Sarkar A, Garcia K, Kango-Singh M, Singh A. The Hippo pathway effector Yki downregulates Wg signaling to promote retinal differentiation in the Drosophila eye. Development 2015; 142:2002-13. [PMID: 25977365 DOI: 10.1242/dev.117358] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 04/16/2015] [Indexed: 01/22/2023]
Abstract
The evolutionarily conserved Hippo signaling pathway is known to regulate cell proliferation and maintain tissue homeostasis during development. We found that activation of Yorkie (Yki), the effector of the Hippo signaling pathway, causes separable effects on growth and differentiation of the Drosophila eye. We present evidence supporting a role for Yki in suppressing eye fate by downregulation of the core retinal determination genes. Other upstream regulators of the Hippo pathway mediate this effect of Yki on retinal differentiation. Here, we show that, in the developing eye, Yki can prevent retinal differentiation by blocking morphogenetic furrow (MF) progression and R8 specification. The inhibition of MF progression is due to ectopic induction of Wingless (Wg) signaling and Homothorax (Hth), the negative regulators of eye development. Modulating Wg signaling can modify Yki-mediated suppression of eye fate. Furthermore, ectopic Hth induction due to Yki activation in the eye is dependent on Wg. Last, using Cut (Ct), a marker for the antennal fate, we show that suppression of eye fate by hyperactivation of yki does not change the cell fate (from eye to antenna-specific fate). In summary, we provide the genetic mechanism by which yki plays a role in cell fate specification and differentiation - a novel aspect of Yki function that is emerging from multiple model organisms.
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Affiliation(s)
- Erika Wittkorn
- Department of Biology, University of Dayton, Dayton, OH 45469, USA
| | - Ankita Sarkar
- Department of Biology, University of Dayton, Dayton, OH 45469, USA
| | - Kristine Garcia
- Department of Biology, University of Dayton, Dayton, OH 45469, USA
| | - Madhuri Kango-Singh
- Department of Biology, University of Dayton, Dayton, OH 45469, USA Premedical Program, University of Dayton, Dayton, OH 45469, USA Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, OH 45469, USA
| | - Amit Singh
- Department of Biology, University of Dayton, Dayton, OH 45469, USA Premedical Program, University of Dayton, Dayton, OH 45469, USA Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, OH 45469, USA
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28
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Panova IG, Markitantova YV, Smirnova YA, Zinovieva RD. Molecular-genetic mechanisms of cornea morphogenesis. BIOL BULL+ 2015. [DOI: 10.1134/s1062359015020077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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29
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Gharahkhani P, Burdon KP, Fogarty R, Sharma S, Hewitt AW, Martin S, Law MH, Cremin K, Bailey JNC, Loomis SJ, Pasquale LR, Haines JL, Hauser MA, Viswanathan AC, McGuffin P, Topouzis F, Foster PJ, Graham SL, Casson RJ, Chehade M, White AJ, Zhou T, Souzeau E, Landers J, Fitzgerald JT, Klebe S, Ruddle JB, Goldberg I, Healey PR, Mills RA, Wang JJ, Montgomery GW, Martin NG, RadfordSmith G, Whiteman DC, Brown MA, Wiggs JL, Mackey DA, Mitchell P, MacGregor S, Craig JE. Common variants near ABCA1, AFAP1 and GMDS confer risk of primary open-angle glaucoma. Nat Genet 2014; 46:1120-1125. [PMID: 25173105 PMCID: PMC4177327 DOI: 10.1038/ng.3079] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 08/04/2014] [Indexed: 12/13/2022]
Abstract
Primary open-angle glaucoma (POAG) is a major cause of irreversible blindness worldwide. We performed a genome-wide association study in an Australian discovery cohort comprising 1,155 advanced POAG cases and 1,992 controls. Association of the top SNPs from the discovery stage was investigated in two Australian replication cohorts (total 932 cases, 6,862 controls) and two US replication cohorts (total 2,616 cases, 2,634 controls). Meta-analysis of all cohorts revealed three novel loci associated with development of POAG. These loci are located upstream of ABCA1 (rs2472493 [G] OR=1.31, P= 2.1 × 10−19), within AFAP1 (rs4619890 [G] OR=1.20, P= 7.0 × 10−10) and within GMDS (rs11969985 [G] OR=1.31, and P= 7.7 × 10−10). Using RT-PCR and immunolabelling, we also showed that these genes are expressed within human retina, optic nerve and trabecular meshwork and that ABCA1 and AFAP1 are also expressed in retinal ganglion cells.
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Affiliation(s)
- Puya Gharahkhani
- QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
| | - Kathryn P Burdon
- Department of Ophthalmology, Flinders University, Adelaide, SA 5042, Australia.,Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS, 7000, Australia
| | - Rhys Fogarty
- Department of Ophthalmology, Flinders University, Adelaide, SA 5042, Australia
| | - Shiwani Sharma
- Department of Ophthalmology, Flinders University, Adelaide, SA 5042, Australia
| | - Alex W Hewitt
- Centre for Eye Research Australia (CERA), University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
| | - Sarah Martin
- Department of Ophthalmology, Flinders University, Adelaide, SA 5042, Australia
| | - Matthew H Law
- QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
| | - Katie Cremin
- University of Queensland Diamantina Institute, Brisbane, QLD 4102, Australia
| | - Jessica N Cooke Bailey
- Center for Human Genetics Research, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio, USA
| | - Stephanie J Loomis
- Department of Ophthalmology, Harvard Medical School and Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Louis R Pasquale
- Department of Ophthalmology, Harvard Medical School and Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.,Channing Division of Network Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Jonathan L Haines
- Center for Human Genetics Research, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio, USA
| | - Michael A Hauser
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Ananth C Viswanathan
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Peter McGuffin
- MRC Social Genetic and Developmental Psychiatry Research Centre, Institute of Psychiatry, King's College, De Crespigny Park, London, UK
| | - Fotis Topouzis
- Department of Ophthalmology, School of Medicine, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece
| | - Paul J Foster
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Stuart L Graham
- Ophthalmology and Vision Science, Macquarie University, Sydney, New South Wales, Australia
| | - Robert J Casson
- South Australian Institute of Ophthalmology, University of Adelaide, Adelaide, South Australia, Australia
| | - Mark Chehade
- South Australian Institute of Ophthalmology, University of Adelaide, Adelaide, South Australia, Australia
| | - Andrew J White
- Centre for Vision Research, Westmead Millennium Institute, University of Sydney, Westmead, NSW 2145, Australia
| | - Tiger Zhou
- Department of Ophthalmology, Flinders University, Adelaide, SA 5042, Australia
| | - Emmanuelle Souzeau
- Department of Ophthalmology, Flinders University, Adelaide, SA 5042, Australia
| | - John Landers
- Department of Ophthalmology, Flinders University, Adelaide, SA 5042, Australia
| | - Jude T Fitzgerald
- Department of Ophthalmology, Flinders University, Adelaide, SA 5042, Australia
| | - Sonja Klebe
- Department of Anatomical Pathology, Flinders University, Flinders Medical Centre, South Australia
| | - Jonathan B Ruddle
- Centre for Eye Research Australia (CERA), University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
| | - Ivan Goldberg
- Department of Ophthalmology, University of Sydney, Sydney Eye Hospital, Sydney, Australia
| | - Paul R Healey
- Centre for Vision Research, Westmead Millennium Institute, University of Sydney, Westmead, NSW 2145, Australia
| | | | - Richard A Mills
- Department of Ophthalmology, Flinders University, Adelaide, SA 5042, Australia
| | - Jie Jin Wang
- Centre for Vision Research, Westmead Millennium Institute, University of Sydney, Westmead, NSW 2145, Australia
| | - Grant W Montgomery
- QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
| | - Nicholas G Martin
- QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
| | - Graham RadfordSmith
- QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia.,School of Medicine, University of Queensland, Herston Campus, Brisbane, QLD, Australia
| | - David C Whiteman
- QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
| | - Matthew A Brown
- University of Queensland Diamantina Institute, Brisbane, QLD 4102, Australia
| | - Janey L Wiggs
- Department of Ophthalmology, Harvard Medical School and Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - David A Mackey
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS, 7000, Australia.,Centre for Ophthalmology and Visual Science, Lions Eye Institute, University of Western Australia, Perth, Australia
| | - Paul Mitchell
- Centre for Vision Research, Westmead Millennium Institute, University of Sydney, Westmead, NSW 2145, Australia
| | - Stuart MacGregor
- QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
| | - Jamie E Craig
- Department of Ophthalmology, Flinders University, Adelaide, SA 5042, Australia.,South Australian Health and Medical Research Institute, Adelaide, South Australia
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Chen Y, Cao W, Zhou S, Shen L, Wen J. Mutant PAX6 downregulates prohormone convertase 2 expression in mouse islets. Exp Biol Med (Maywood) 2013; 238:1259-64. [PMID: 24047795 DOI: 10.1177/1535370213502627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Transcriptional factor paired box 6 (PAX6) is very important for the development of the eyes, central nervous system, and pancreas. PAX6 mutations are associated with a diabetic phenotype and abnormal glucose metabolism. Our previous study showed that PAX6 directly bound to and activated the prohormone convertase 1/3 (Pc1/3) gene promoter and subsequently regulated proinsulin processing. Prohormone convertase 2 (PC2) is the essential enzyme for pancreatic proinsulin processing. To study the regulation of PAX6 in Pc2 expression, we did research on the pancreas of Pax6 R266Stop mutant mice, where truncated mutations happened in the C-terminal of the PAX6 protein. Our studies showed that the mutant PAX6 protein was stable and regulated the activity of Pc2 promoter as shown by luciferase activity assays. We found that the wild-type PAX6 protein imparts a transcriptional effect, and the mutant PAX6 can also regulate the downstream molecules. The results provide new insights into the mechanism of truncated PAX6 in regulating the functions of the pancreas and endocrine system.
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Affiliation(s)
- Yuanyuan Chen
- Peking University Stem Cell Research Center, and Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
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Douvaras P, Mort RL, Edwards D, Ramaesh K, Dhillon B, Morley SD, Hill RE, West JD. Increased corneal epithelial turnover contributes to abnormal homeostasis in the Pax6(+/-) mouse model of aniridia. PLoS One 2013; 8:e71117. [PMID: 23967157 PMCID: PMC3742784 DOI: 10.1371/journal.pone.0071117] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 06/24/2013] [Indexed: 01/09/2023] Open
Abstract
We aimed to test previous predictions that limbal epithelial stem cells (LESCs) are quantitatively deficient or qualitatively defective in Pax6+/− mice and decline with age in wild-type (WT) mice. Consistent with previous studies, corneal epithelial stripe patterns coarsened with age in WT mosaics. Mosaic patterns were also coarser in Pax6+/− mosaics than WT at 15 weeks but not at 3 weeks, which excludes a developmental explanation and strengthens the prediction that Pax6+/− mice have a LESC-deficiency. To investigate how Pax6 genotype and age affected corneal homeostasis, we compared corneal epithelial cell turnover and label-retaining cells (LRCs; putative LESCs) in Pax6+/− and WT mice at 15 and 30 weeks. Limbal BrdU-LRC numbers were not reduced in the older WT mice, so this analysis failed to support the predicted age-related decline in slow-cycling LESC numbers in WT corneas. Similarly, limbal BrdU-LRC numbers were not reduced in Pax6+/− heterozygotes but BrdU-LRCs were also present in Pax6+/− corneas. It seems likely that Pax6+/− LRCs are not exclusively stem cells and some may be terminally differentiated CD31-positive blood vessel cells, which invade the Pax6+/− cornea. It was not, therefore, possible to use this approach to test the prediction that Pax6+/− corneas had fewer LESCs than WT. However, short-term BrdU labelling showed that basal to suprabasal movement (leading to cell loss) occurred more rapidly in Pax6+/− than WT mice. This implies that epithelial cell loss is higher in Pax6+/− mice. If increased corneal epithelial cell loss exceeds the cell production capacity it could cause corneal homeostasis to become unstable, resulting in progressive corneal deterioration. Although it remains unclear whether Pax6+/− mice have LESC-deficiency, we suggest that features of corneal deterioration, that are often taken as evidence of LESC-deficiency, might occur in the absence of stem cell deficiency if corneal homeostasis is destabilised by excessive cell loss.
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Affiliation(s)
- Panagiotis Douvaras
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Richard L. Mort
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Dominic Edwards
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Kanna Ramaesh
- Tennent Institute of Ophthalmology, Gartnaval General Hospital, Glasgow, United Kingdom
| | - Baljean Dhillon
- School of Clinical Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Steven D. Morley
- Division of Health Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Robert E. Hill
- Medical Research Council Human Genetics Unit, Medical Research Council Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - John D. West
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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Li Y, Jiang Y, Chen Y, Karandikar U, Hoffman K, Chattopadhyay A, Mardon G, Chen R. optix functions as a link between the retinal determination network and the dpp pathway to control morphogenetic furrow progression in Drosophila. Dev Biol 2013; 381:50-61. [PMID: 23792115 DOI: 10.1016/j.ydbio.2013.06.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 10/26/2022]
Abstract
optix, the Drosophila ortholog of the SIX3/6 gene family in vertebrate, encodes a homeodomain protein with a SIX protein-protein interaction domain. In vertebrates, Six3/6 genes are required for normal eye as well as brain development. However, the normal function of optix in Drosophila remains unknown due to lack of loss-of-function mutation. Previous studies suggest that optix is likely to play an important role as part of the retinal determination (RD) network. To elucidate normal optix function during retinal development, multiple null alleles for optix have been generated. Loss-of-function mutations in optix result in lethality at the pupae stage. Surprisingly, close examination of its function during eye development reveals that, unlike other members of the RD network, optix is required only for morphogenetic furrow (MF) progression, but not initiation. The mechanisms by which optix regulates MF progression is likely through regulation of signaling molecules in the furrow. Specifically, although unaffected during MF initiation, expression of dpp in the MF is dramatically reduced in optix mutant clones. In parallel, we find that optix is regulated by sine oculis and eyes absent, key members of the RD network. Furthermore, positive feedback between optix and sine oculis and eyes absent is observed, which is likely mediated through dpp signaling pathway. Together with the observation that optix expression does not depend on hh or dpp, we propose that optix functions together with hh to regulate dpp in the MF, serving as a link between the RD network and the patterning pathways controlling normal retinal development.
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Affiliation(s)
- Yumei Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77303, USA
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Thomas MG, Gottlob I. Optical Coherence Tomography Studies Provides New Insights into Diagnosis and Prognosis of Infantile Nystagmus: A Review. Strabismus 2012; 20:175-80. [DOI: 10.3109/09273972.2012.735336] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Mervyn G. Thomas
- Ophthalmology Group, School of Medicine, University of Leicester,
Leicester, UK
| | - Irene Gottlob
- Ophthalmology Group, School of Medicine, University of Leicester,
Leicester, UK
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Abstract
Three embryonic tissue sources-the neural ectoderm, the surface ectoderm, and the periocular mesenchyme-contribute to the formation of the mammalian eye. For this reason, the developing eye has presented an invaluable system for studying the interactions among cells and, more recently, genes, in specifying cell fate. This article describes how the eye primordium is specified in the anterior neural plate by four eye field transcription factors and how the optic vesicle becomes regionalized into three distinct tissue types. Specific attention is given to how cross talk between the optic vesicle and surface ectoderm contributes to lens and optic cup formation. This article also describes how signaling networks and cell movements set up axes in the optic cup and establish the multiple cell fates important for vision. How multipotent retinal progenitor cells give rise to the six neuronal and one glial cell type in the mature retina is also explained. Finally, the history and progress of cellular therapeutics for the treatment of degenerative eye disease is outlined. Throughout this article, special attention is given to how disruption of gene function causes ocular malformation in humans. Indeed, the accessibility of the eye has contributed much to our understanding of the basic processes involved in mammalian development.
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Affiliation(s)
- Whitney Heavner
- UNC Neuroscience Center, Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
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Lim HT, Seo EJ, Kim GH, Ahn H, Lee HJ, Shin KH, Lee JK, Yoo HW. Comparison between aniridia with and without PAX6 mutations: clinical and molecular analysis in 14 Korean patients with aniridia. Ophthalmology 2012; 119:1258-64. [PMID: 22361317 DOI: 10.1016/j.ophtha.2011.12.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 10/25/2011] [Accepted: 12/06/2011] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To describe clinical and molecular characteristics of Korean patients with aniridia and to compare the clinical phenotype between those having an identifiable PAX6 mutation and those not. DESIGN Comparative case series. PARTICIPANTS A total of 14 Korean patients from 10 families with aniridia. METHODS Complete ophthalmologic examinations were performed for all patients. PAX6 analysis included direct sequencing of all coding regions and multiplex ligation-dependent probe amplification (MLPA) to detect large deletions when the sequencing was negative. If the PAX6 analysis failed to reveal any identifiable mutations, genomic copy number variation analysis via array comparative genomic hybridization (CGH) and candidate gene PITX3 and FOXE3 sequencing were then performed. MAIN OUTCOME MEASURES Severity of ocular abnormalities and genetic findings. RESULTS Sequencing of PAX6 exhibited 5 different heterozygous mutations in 8 patients from 5 families; 2 (p.Ser43Phe, IVS8-9C>G) were novel, and 3 (p.Arg208Trp, p.Arg317X, and p.X423L) have been previously reported. Among the remaining 6 patients in whom the PAX6 sequencing was negative, MLPA identified large deletions in 2 sporadic patients. However, the array CGH and candidate gene sequencing found no genomic or genetic abnormalities. The mutation detection rate was therefore 70%. Patients harboring an identifiable mutation in PAX6 had either a severe or a mild variant phenotype depending on the type of mutations. Likewise, among patients without an identifiable PAX6 mutation, their phenotypes varied widely from severe to very mild. CONCLUSIONS This study adds 2 novel PAX6 mutations to those previously reported, providing further evidence for genetic and phenotypic heterogeneity in aniridic ocular malformation. There was no difference in the clinical phenotype between patients with and without detectable mutations in the PAX6 gene. The wide variability of ocular phenotype regardless of the presence or absence of PAX6 mutations calls for a further appreciation of the complexity in the molecular diagnosis of aniridia and suggests that this ocular malformation may be better regarded as a group of heterogeneous disorders, rather than a single disease entity, associated with mutations in PAX6 and/or other genes located elsewhere in the human genome. FINANCIAL DISCLOSURE(S) The authors have no proprietary or commercial interest in any of the materials discussed in this article.
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Affiliation(s)
- Hyun Taek Lim
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
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Ng WY, Pasutto F, Bardakjian TM, Wilson MJ, Watson G, Schneider A, Mackey DA, Grigg JR, Zenker M, Jamieson RV. A puzzle over several decades: eye anomalies with FRAS1 and STRA6 mutations in the same family. Clin Genet 2012; 83:162-8. [PMID: 22283518 DOI: 10.1111/j.1399-0004.2012.01851.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Fraser syndrome (FS) and microphthalmia syndromic 9 (MCOPS9) are autosomal recessive conditions with distinct, and some overlapping features affecting the ocular, respiratory and cardiac systems. Mutations in FRAS1 and FREM2 occur in FS, and mutations in STRA6 occur in MCOPS9. We report two sibships, in the same family, where four deceased offspring had ocular, respiratory and cardiac abnormalities. Two sibs with microphthalmia had syndactyly and laryngeal stenosis, suggesting a clinical diagnosis of FS. Our results indicate that they were compound heterozygotes for novel FRAS1 mutations, p.Cys729Phe and p.Leu3813Pro. The other two sibs, first cousins to the first sib pair, had anophthalmia, lung hypoplasia and cardiac anomalies, suggesting a retrospective diagnosis of MCOPS9. Our results indicate compound heterozygous STRA6 mutations, a novel frameshift leading to p.Tyr18* and a p.Thr644Met mutation. The one surviving individual from these sibships is heterozygous for the p.Tyr18*STRA6 mutation and has bilateral ocular colobomata and microphthalmia. This work emphasises the need for careful phenotypic characterisation to determine genes for assessment in ocular syndromic conditions. It also indicates that heterozygous STRA6 mutations may rarely contribute to microphthalmia and coloboma.
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Affiliation(s)
- W Y Ng
- Eye Genetics Research Group, Children's Medical Research Institute, The Children's Hospital at Westmead, Save Sight Institute, Sydney, Australia
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Zaghloul NA, Yan B, Moody SA. Step-wise specification of retinal stem cells during normal embryogenesis. Biol Cell 2012; 97:321-37. [PMID: 15836431 DOI: 10.1042/bc20040521] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The specification of embryonic cells to produce the retina begins at early embryonic stages as a multi-step process that gradually restricts fate potentials. First, a subset of embryonic cells becomes competent to form retina by their lack of expression of endo-mesoderm-specifying genes. From these cells, a more restricted subset is biased to form retina by virtue of their close proximity to sources of bone morphogenetic protein antagonists during neural induction. During gastrulation, the definitive RSCs (retinal stem cells) are specified as the eye field by interactions with underlying mesoderm and the expression of a network of retina-specifying genes. As the eye field is transformed into the optic vesicle and optic cup, a heterogeneous population of RPCs (retinal progenitor cells) forms to give rise to the different domains of the retina: the optic stalk, retinal pigmented epithelium and neural retina. Further diversity of RPCs appears to occur under the influences of cell-cell interactions, cytokines and combinations of regulatory genes, leading to the differentiation of a multitude of different retinal cell types. This review examines what is known about each sequential step in retinal specification during normal vertebrate development, and how that knowledge will be important to understand how RSCs might be manipulated for regenerative therapies to treat retinal diseases.
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Affiliation(s)
- Norann A Zaghloul
- Department of Anatomy and Cell Biology, The George Washington University, 2300 Eye Street, NW, Washington, DC 20037, USA
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38
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Khan K, Logan CV, McKibbin M, Sheridan E, Elçioglu NH, Yenice O, Parry DA, Fernandez-Fuentes N, Abdelhamed ZIA, Al-Maskari A, Poulter JA, Mohamed MD, Carr IM, Morgan JE, Jafri H, Raashid Y, Taylor GR, Johnson CA, Inglehearn CF, Toomes C, Ali M. Next generation sequencing identifies mutations in Atonal homolog 7 (ATOH7) in families with global eye developmental defects. Hum Mol Genet 2011; 21:776-83. [PMID: 22068589 PMCID: PMC3263993 DOI: 10.1093/hmg/ddr509] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The atonal homolog 7 (ATOH7) gene encodes a transcription factor involved in determining the fate of retinal progenitor cells and is particularly required for optic nerve and ganglion cell development. Using a combination of autozygosity mapping and next generation sequencing, we have identified homozygous mutations in this gene, p.E49V and p.P18RfsX69, in two consanguineous families diagnosed with multiple ocular developmental defects, including severe vitreoretinal dysplasia, optic nerve hypoplasia, persistent fetal vasculature, microphthalmia, congenital cataracts, microcornea, corneal opacity and nystagmus. Most of these clinical features overlap with defects in the Norrin/β-catenin signalling pathway that is characterized by dysgenesis of the retinal and hyaloid vasculature. Our findings document Mendelian mutations within ATOH7 and imply a role for this molecule in the development of structures at the front as well as the back of the eye. This work also provides further insights into the function of ATOH7, especially its importance in retinal vascular development and hyaloid regression.
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Affiliation(s)
- Kamron Khan
- Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK
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Two novel mutations of the PAX6 gene causing different phenotype in a cohort of Chinese patients. Eye (Lond) 2011; 25:1581-9. [PMID: 21904390 DOI: 10.1038/eye.2011.215] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Aniridia (AN) is a rare congenital panocular disorder caused by the mutations of the paired box homeotic gene 6(PAX6) gene. The PAX6gene is also involved in other anterior segment malformations including Peters anomaly. We studied the PAX6gene mutations in a cohort of affected individuals with different clinical phenotype including AN, coloboma of iris and choroid, or anterior segment malformations. PATIENTS AND METHODS Six unrelated families and 10 sporadic patients were examined clinically. After informed consent was obtained, genomic DNA was extracted from the venous blood of all participants. Mutation screening of all exons of the PAX6gene was performed by direct sequencing of PCR-amplified DNA fragments. Multiplex ligation-dependent probe amplification (MLPA) was performed to detect large deletions. RESULTS By clinical examination, the patients and the pedigrees were divided into the following three groups: AN, coloboma of iris and choroids, and the anterior segment malformations including peters anomaly. Sequencing of the PAX6gene, three intragenic mutations including a novel heterozygous splicing-site mutations c.357-3C>G (p.Ser119fsX) were identified in the patients of the AN group. A novel missense mutation c.643T>C (p.S216P) was detected in the anterior segment malformation group. The mutation p.S216P located in the homeodomain region of the PAX6 caused the phenotype of Peters anomaly in family A6 with different expressing. Through MLPA analysis, a large deletion including the whole PAX6gene and DKFZ p686k1684gene was detected in one sporadic patient from the AN group. Neither intragenic mutation nor large deletion was identified in the group with coloboma of iris and choroid. CONCLUSION Our findings further confirmed that different kind of mutations might cause different ocular phenotype, and clearly clinical phenotype classification might increase the mutation detection rate of the PAX6gene.
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40
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Immunohistological markers for proliferative events, gliogenesis, and neurogenesis within the adult hippocampus. Cell Tissue Res 2011; 345:1-19. [PMID: 21647561 DOI: 10.1007/s00441-011-1196-4] [Citation(s) in RCA: 232] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Accepted: 05/13/2011] [Indexed: 12/29/2022]
Abstract
Biologists long believed that, once development is completed, no new neurons are produced in the forebrain. However, as is now firmly established, new neurons can be produced at least in two specific forebrain areas: the subventricular zone (SVZ) and the dentate gyrus (DG) of the hippocampal formation. Neurogenesis within the adult DG occurs constitutively throughout postnatal life, and the rate of neurogenesis within the DG can be altered under various physiological and pathophysiological conditions. The process of adult neurogenesis within the DG is a multi-step process (proliferation, differentiation, migration, targeting, and synaptic integration) that ends with the formation of a post-mitotic functionally integrated new neuron. Various markers are expressed during specific stages of adult neurogenesis. The availability of such markers allows the time-course and fate of newly born cells to be followed within the DG in a detailed and precise fashion. Several of the available markers (e.g., PCNA, Ki-67, PH3, MCM2) are markers for proliferative events, whereas others are more specific for early phases of neurogenesis and gliogenesis within the adult DG (e.g., nestin, GFAP, Sox2, Pax6). In addition, markers are available allowing events to be distinguished that are related to later steps of gliogenesis (e.g., vimentin, BLBP, S100beta) or neurogenesis (e.g., NeuroD, PSA-NCAM, DCX).
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42
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Chung SH, Kim CT, Jung YH, Lee NS, Jeong YG. Early cerebellar granule cell migration in the mouse embryonic development. Anat Cell Biol 2010; 43:86-95. [PMID: 21190009 PMCID: PMC2998778 DOI: 10.5115/acb.2010.43.1.86] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 02/19/2010] [Accepted: 03/04/2010] [Indexed: 11/27/2022] Open
Abstract
Pax6, a paired homeobox DNA binding protein, has been found to be expressed in the cerebellum in both granule cells and their precursors in the external granular layer (EGL). In this study we have traced Pax6 expression through embryonic development in mice by using a polyclonal antibody against Pax6 and used it to study the cellular dispersal pattern of the EGL. During dispersal the EGL was thicker and Pax6 expression was more intense on the rostral side of the lateral corners of the cerebellum. Pax6 immunoreactive cells were found to be migrating from the EGL during the early stage of EGL dispersal, which suggested the early inward migration of granule cells. Double staining with various markers confirmed that the early-migrating cells are not Purkinje cells, interneurons or glia. Although the Pax6 immunoreactive cells within the cerebellum were not apparently proliferating, NeuN, a marker for postmitotic granule cells, was not expressed in these cells until E16. Furthermore, granule cells were observed migrating inwards from the EGL both during and after EGL dispersal. These early migrating granule cells populated the whole cerebellum. These findings offer novel views on specific stages of granule cell dispersal and migration.
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Affiliation(s)
- Seung-Hyuk Chung
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, Sacramento, California 95817, USA
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Zhang W, Mulieri PJ, Gaio U, Bae GU, Krauss RS, Kang JS. Ocular abnormalities in mice lacking the immunoglobulin superfamily member Cdo. FEBS J 2009; 276:5998-6010. [PMID: 19754878 DOI: 10.1111/j.1742-4658.2009.07310.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Vertebrate eye development requires a series of complex morphogenetic and inductive events to produce a lens vesicle centered within the bilayered optic cup and a posteriorly positioned optic stalk. Multiple congenital eye defects, including microphthalmia and coloboma, result from defects in early eye morphogenesis. Cdo is a multifunctional cell surface immunoglobulin superfamily member that interacts with and mediates signaling by cadherins and netrins to regulate myogenesis. In addition, Cdo plays an essential role in early forebrain development by functioning as coreceptor for sonic hedgehog. It is reported here that Cdo is expressed in a dynamic, but dorsally restricted, fashion during early eye development, and that mice lacking Cdo display multiple eye defects. Anomalies seen in Cdo(-/-) mice include coloboma (failure to close the optic fissure); failure to form a proper boundary between the retinal pigmented epithelium and optic stalk; defective lens formation, including failure to separate from the surface ectoderm; and microphthalmia. Consistent with this wide array of defects, developing eyes of Cdo(-/-) mice show altered expression of several regulators of dorsoventral eye patterning, including Pax6, Pax2, and Tbx5. Taken together, these findings show that Cdo is required for normal eye development and is required for normal expression of patterning genes in both the ventral and dorsal domains. The multiple eye development defects seen in Cdo(-/-) mice suggest that mutations in human Cdo could contribute to congenital eye anomalies, such as Jacobsen syndrome, which is frequently associated with ocular defects, including coloboma and Peters' anomaly.
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Affiliation(s)
- Wei Zhang
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY, USA
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44
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Mutational analysis of the eyeless gene and phenotypic rescue reveal that an intact Eyeless protein is necessary for normal eye and brain development in Drosophila. Dev Biol 2009; 334:503-12. [PMID: 19666017 DOI: 10.1016/j.ydbio.2009.08.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 07/28/2009] [Accepted: 08/03/2009] [Indexed: 11/20/2022]
Abstract
Pax6 genes encode evolutionarily highly conserved transcription factors that are required for eye and brain development. Despite the characterization of mutations in Pax6 homologs in a range of organisms, and despite functional studies, it remains unclear what the relative importance is of the various parts of the Pax6 protein. To address this, we have studied the Drosophila Pax6 homolog eyeless. Specifically, we have generated new eyeless alleles, each with single missense mutations in one of the four domains of the protein. We show that these alleles result in abnormal eye and brain development while maintaining the OK107 eyeless GAL4 activity from which they were derived. We performed in vivo functional rescue experiments by expressing in an eyeless-specific pattern Eyeless proteins in which either the paired domain, the homeodomain, or the C-terminal domain was deleted. Rescue of the eye and brain phenotypes was only observed when full-length Eyeless was expressed, while all deletion constructs failed to rescue. These data, along with the phenotypes observed in the four newly characterized eyeless alleles, demonstrate the requirement for an intact Eyeless protein for normal Drosophila eye and brain development. They also suggest that some endogenous functions may be obscured in ectopic expression experiments.
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Neethirajan G, Solomon A, Krishnadas SR, Vijayalakshmi P, Sundaresan P. Genotype/phenotype association in Indian congenital aniridia. Indian J Pediatr 2009; 76:513-7. [PMID: 19390808 DOI: 10.1007/s12098-009-0075-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Accepted: 08/20/2008] [Indexed: 10/20/2022]
Abstract
The developmental birth eye disorder of iris is known as aniridia. Heterozygous PAX6 gene, which causes human aniridia and small eye in mice, is located on chromosome 11p13. The variability had been documented between the affected individuals within the families, is due to genotypic variation. Haploinsufficiency renders PAX6 allele non-functional or amorphic, however it presents hypomorphic or neomorphic alleles. India is not a well-studied ethnic group, hence the focus on congenital aniridia gene analysis supports the literature and the phenotypic association were analysed both in sporadic as well as familial. The consistent association of truncating PAX6 mutations with the phenotype is owing to non-sense-mediated decay (NMD). It is presumed that the genetic impact of increased homozygosity and heterozygocity in Indian counter part arises as the consequence of consanguineous marriages. The real fact involved in congenital aniridia with other related phenotypes with PAX6 mutations are still controversial.
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Affiliation(s)
- Guruswamy Neethirajan
- Department of Ophthalmology, Hebrew University Medical Center Jerusalem, Jerusalem, Israel
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Kumar JP. The molecular circuitry governing retinal determination. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1789:306-14. [PMID: 19013263 PMCID: PMC2700058 DOI: 10.1016/j.bbagrm.2008.10.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 10/06/2008] [Accepted: 10/14/2008] [Indexed: 10/21/2022]
Abstract
The developing eye of the fruit fly, Drosophila melanogaster, has become a premier model system for studying the genetic and molecular mechanisms that govern tissue determination. Over the last fifteen years a regulatory circuit consisting of the members of the Pax, Six, Eya and Dach gene families has been identified and shown to govern the specification of a wide range of tissues including the retina of both insects and mammals. These genes are not organized in a simple developmental pathway or cascade in which there is a unidirectional flow of information. Rather, there are multiple feedback loops built into the system rendering its appearance and functionality more in line with the workings of a network. In this review I will attempt to describe the genetic, molecular and biochemical interactions that govern the specification of the Drosophila compound eye. In particular, the primary focus will be on the interactions that have been experimentally verified at the molecular and biochemical levels. During the course of this description I will also attempt to place each discovery in its own historical context. While a number of signaling pathways play significant roles in early eye development this review will focus on the network of nuclear factors that promote retinal determination.
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Affiliation(s)
- Justin P Kumar
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
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Mihelec M, St Heaps L, Flaherty M, Billson F, Rudduck C, Tam PPL, Grigg JR, Peters GB, Jamieson RV. Chromosomal rearrangements and novel genes in disorders of eye development, cataract and glaucoma. Twin Res Hum Genet 2009; 11:412-21. [PMID: 18637741 DOI: 10.1375/twin.11.4.412] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Disorders of eye development such as microphthalmia and anophthalmia (small and absent eyes respectively), anterior segment dysgenesis where there may be pupillary and iris anomalies, and associated cataract and glaucoma, often lead to visual impairment or blindness. Currently treatment options are limited, as much is unknown about the molecular pathways that control normal eye development and induce the aberrant processes that lead to ocular defects. Mutation detection rates in most of the known genes are generally low, emphasizing the genetic heterogeneity of developmental ocular defects. Identification of the disease genes in these conditions improves the clinical information available for affected individuals and families, and provides new insights into the underlying biological processes for facilitation of better treatment options. Investigation of chromosomal rearrangements associated with an ocular phenotype has been especially powerful for disease gene identification. Molecular characterization of such rearrangements, which pinpoints the region by physically disrupting the causative gene or its regulatory sequences, allows for rapid elucidation of underlying genetic factors that contribute to the phenotype. Genes including PAX6, PITX2, FOXC1, MAF, TMEM114, SOX2, OTX2 and BMP4 have been identified in this way to be associated with developmental eye disorders. More recently, new methods in chromosomal analysis such as comparative genomic hybridization (CGH) microarray, have also enhanced our ability in disease gene identification.
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Affiliation(s)
- Marija Mihelec
- Eye Genetics Research Group, Children's Medical Research Institute, The Children's Hospital at Westmead and Save Sight Institute, Sydney, Australia
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SUN DG. A novel PAX6 mutation (c.1286delC) in the patients with hereditary congenital aniridia. YI CHUAN = HEREDITAS 2008; 30:1301-6. [DOI: 10.3724/sp.j.1005.2008.01301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Mossböck G, Faschinger C, Weger M, Renner W. Die Rolle genetischer Faktoren bei den Glaukomen. SPEKTRUM DER AUGENHEILKUNDE 2008. [DOI: 10.1007/s00717-008-0269-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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The Evolution of Alternative Splicing in the Pax Family: The View from the Basal Chordate Amphioxus. J Mol Evol 2008; 66:605-20. [DOI: 10.1007/s00239-008-9113-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Revised: 04/16/2008] [Accepted: 04/22/2008] [Indexed: 10/22/2022]
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