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Kaufmann M, Han Z. RPE melanin and its influence on the progression of AMD. Ageing Res Rev 2024; 99:102358. [PMID: 38830546 DOI: 10.1016/j.arr.2024.102358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 05/27/2024] [Indexed: 06/05/2024]
Abstract
OBJECTIVE The aim of this review article is to summarize the latest findings and current understanding of the origin of melanin in the retinal pigment epithelium (RPE), its function within the RPE, its role in the pathogenesis of age-related macular degeneration (AMD), its effect on retinal development, and its potential therapeutic benefit in the treatment of AMD. METHODS A comprehensive search of peer-reviewed journals was conducted using various combinations of key terms such as "melanin," "retinal pigment epithelium" or "RPE," "age-related macular degeneration" or AMD," "lipofuscin," "oxidative stress," and "albinism." Databases searched include PubMed, Scopus, Science Direct, and Google Scholar. 147 papers published between the years of 1957 and 2023 were considered with an emphasis on recent findings. SUMMARY OF FINDINGS AMD is thought to result from chronic oxidative stress within the RPE that results in cellular dysfunction, metabolic dysregulation, inflammation, and lipofuscin accumulation. Melanin functions as a photoscreener, free radical scavenger, and metal cation binding reservoir within the RPE. RPE melanin does not regenerate, and it undergoes degradation over time in response to chronic light exposure and oxidative stress. RPE melanin is important for retinal development and RPE function, and in the aging eye, melanin loss is associated with increased lipid peroxidation, inflammation, and the accumulation of toxic oxidized cellular products. Therefore, melanin-based treatments may serve to preserve RPE and retinal function in AMD. CONCLUSIONS The pathogenesis of AMD is not fully understood, but RPE dysfunction and melanin loss in response to chronic oxidative stress and inflammation are thought to be primary drivers of the disease. Due to melanin's antioxidative effects, melanin-based nanotechnology represents a promising avenue for the treatment of AMD.
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Affiliation(s)
- Mary Kaufmann
- University of North Carolina School of Medicine, Chapel Hill, NC, 27599 USA
| | - Zongchao Han
- Department of Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 USA; Division of Pharmacoengineering & Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 USA.
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2
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Kruijt CC, de Wit GC, van Minderhout HM, Schalij-Delfos NE, van Genderen MM. Clinical and mutational characteristics of oculocutaneous albinism type 7. Sci Rep 2024; 14:7572. [PMID: 38555393 PMCID: PMC10981718 DOI: 10.1038/s41598-024-57969-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 03/23/2024] [Indexed: 04/02/2024] Open
Abstract
The purpose of this paper is to expand on the phenotype of oculocutaneous albinism type 7 (OCA7). We described three patients with OCA7: two from a consanguineous family of Kurdish origin and one patient of Dutch origin. We compared them with all patients described to date in the literature. All newly described patients had severely reduced visual acuity (VA), nystagmus, hypopigmentation of the fundus, severe foveal hypoplasia, and chiasmal misrouting. None had iris translucency. All patients had normal pigmentation of skin and hair. We found one novel mutation in the Dutch patient: c.565G > A; p.(Gly189Ser). We compared our patients to the 15 described in the literature to date. All 18 patients had substantially pigmented skin and hair, very poor VA (0.4-1.3 logMAR), nystagmus, (mild) ocular hypopigmentation, foveal hypoplasia, and misrouting. Although pigmentation levels were mildly affected in OCA7, patients had a severe ocular phenotype with VA at the poorer end of the albinism spectrum, severe foveal hypoplasia, and chiasmal misrouting. OCA7 patients had a phenotype restricted to the eyes, and similar to that of X-linked ocular albinism. We therefore propose to rename the disorder in ocular albinism type 2. Unfolding the role of LRMDA in OCA7, may bring us a step closer in identifying the responsible factors for the co-occurrence of foveal hypoplasia and misrouting.
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Affiliation(s)
- C C Kruijt
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands.
- Department of Ophthalmology, Leiden University Medical Center, J3-S, Albinusdreef 2, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
| | - G C de Wit
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
| | - H M van Minderhout
- Department of Ophthalmology, Medical Center Haaglanden, The Hague, The Netherlands
| | - N E Schalij-Delfos
- Department of Ophthalmology, Leiden University Medical Center, J3-S, Albinusdreef 2, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - M M van Genderen
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands
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3
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Ren X, Huang L, Cheng S, Wang J, Li N. Novel pathogenic variants of SLC38A8 gene and literature review. Eur J Ophthalmol 2024:11206721241242155. [PMID: 38515398 DOI: 10.1177/11206721241242155] [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: 03/23/2024]
Abstract
PURPOSE This study aimed to analyze the clinical and genetic characteristics of 6 Chinese patients with foveal hypoplasia (FH) caused by the variants of solute carrier family 38 member 8 (SLC38A8), and to describe the genotype and phenotype of SLC38A8 variants from previous literature. METHODS All subjects underwent comprehensive ophthalmic examinations. Optical coherence tomography (OCT) was performed to evaluate the structural grade of FH. Pathogenic variants of SLC38A8 gene were identified using panel-based next-generation sequencing and direct Sanger sequencing techniques. Further, all previously reported cases of SLC38A8 variants were re-analyzed together with the novel ones identified in this study. RESULTS Nystagmus and FH were present in 6 patients with variants of SLC38A8 gene, accompanied by a normal anterior segment. Grade 4 FH was identified in 4 patients. A total of 12 variants of SLC38A8 gene were identified, including 9 novel variants. Systematical analysis revealed that half of the variants (30/60) were missense, the majority of which (23/30) were distributed in the transmembrane (TM) domains. Grade 4 FH was detected in the majority of patients (66%, 23/35). There was no statistical difference in the clinical features between the subgroups of patients with 0, 1 and 2 missense variants. CONCLUSION Severe arrest of foveal development was identified in patients with variants of SLC38A8. This study provides a brief summary of the clinical and genetic characteristics of the pathogenic SLC38A8 variants, which is helpful in the differentiation diagnosis of FH.
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Affiliation(s)
- Xiaofang Ren
- Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No.56 Nanlishi Road, Xicheng District, Beijing, 100040, China
| | - Lijuan Huang
- Department of Ophthalmology, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, 362000, China
| | - Shan Cheng
- Department of Medical Genetics and Developmental Biology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Jing Wang
- Department of Medical Genetics and Developmental Biology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Ningdong Li
- Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No.56 Nanlishi Road, Xicheng District, Beijing, 100040, China
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, National Clinical Research Center for Eye Diseases, Shanghai, China
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4
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Chang Y, Wu S, Li J, Bao H, Wu C. Identification of Candidate Genes for Red-Eyed (Albinism) Domestic Guppies Using Genomic and Transcriptomic Analyses. Int J Mol Sci 2024; 25:2175. [PMID: 38396851 PMCID: PMC10888696 DOI: 10.3390/ijms25042175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/05/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
Guppies are small tropical fish with brightly colored bodies and variable tail shapes. There are two phenotypes of domestic guppy eye color: red and black. The wild type is black-eyed. The main object of this study was to identify candidate genes for the red-eyed phenotype in domestic guppies. We hope to provide molecular genetic information for the development of new domestic guppy strains. Additionally, the results also contribute to basic research concerning guppies. In this study, 121 domestic guppies were used for genomic analysis (GWAS), and 44 genes were identified. Furthermore, 21 domestic guppies were used for transcriptomic analysis, and 874 differentially expressed genes (DEGs) were identified, including 357 upregulated and 517 downregulated genes. Through GO and KEGG enrichment, we identified some important terms or pathways mainly related to melanin biosynthesis and ion transport. qRT-PCR was also performed to verify the differential expression levels of four important candidate genes (TYR, OCA2, SLC45A2, and SLC24A5) between red-eyed and black-eyed guppies. Based on the results of genomic and transcriptomic analyses, we propose that OCA2 is the most important candidate gene for the red-eyed phenotype in guppies.
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Affiliation(s)
| | | | | | - Haigang Bao
- National Engineering Laboratory for Animal Breeding, Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (Y.C.); (S.W.); (J.L.); (C.W.)
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5
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Chen C, Li J, Wang B, Wang Y, Yu X. TYR mutation in a Chinese population with oculocutaneous albinism: Molecular characteristics and ophthalmic manifestations. Exp Eye Res 2024; 239:109761. [PMID: 38145795 DOI: 10.1016/j.exer.2023.109761] [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: 08/22/2023] [Revised: 12/07/2023] [Accepted: 12/19/2023] [Indexed: 12/27/2023]
Abstract
Oculocutaneous albinism (OCA) is a rare inherited disorder characterized by a partial or complete reduction of melanin biosynthesis that leads to hypopigmentation in the skin, hair and eyes. The OCA1 subtype is caused by mutations in TYR. The purpose of this study was to investigate the genetic and clinical ophthalmic characteristics of TYR mutations in patients with OCA. Herein, 51 probands with a clinical diagnosis of OCA were enrolled. Whole-exome sequencing and comprehensive ophthalmic examinations were performed. Overall, TYR mutations were detected in 37.3% (19/51) in the patients with OCA. Fifteen patients had compound heterozygous variants, and four cases had homozygous variants. Eleven different pathogenic variants in TYR were detected in these 19 patients, with missense, insertion, delins and nonsense in 71.1% (27/38), 15.8% (6/38), 2.6% (1/38), and 10.5% (4/38), respectively. Clinical examinations revealed that 84.2% (16/19) of patients were OCA1A, and 15.8% (3/19) were OCA1B. Most TYR probands (52.6%, 10/19) had moderate vision impairment, 15.8% (3/19) had severe visual impairment, 10.5% (2/19) exhibited blindness, only 5.3% (1/19) had mild visual impairment and 15.8% (3/19) were not available. Photophobia and nystagmus were found in 100% (19/19) of the patients. In addition, grade 4 foveal hypoplasia was detected in 100% (12/12) of the patients. In conclusion: The TYR patients exhibited severe ocular phenotypes: the majority (93.8%, 15/16) of them had a moderate vision impairment or worse, and 100% (12/12) had severe grade 4 foveal hypoplasia. These novel findings could provide insight into the understanding of OCA.
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Affiliation(s)
- Chonglin Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Jun Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Bingqi Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Yinghuan Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Xinping Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China.
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Nagy N, Pal M, Kun J, Galik B, Urban P, Medvecz M, Fabos B, Neller A, Abdolreza A, Danis J, Szabo V, Yang Z, Fenske S, Biel M, Gyenesei A, Adam E, Szell M. Missing Heritability in Albinism: Deep Characterization of a Hungarian Albinism Cohort Raises the Possibility of the Digenic Genetic Background of the Disease. Int J Mol Sci 2024; 25:1271. [PMID: 38279271 PMCID: PMC10817051 DOI: 10.3390/ijms25021271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 01/28/2024] Open
Abstract
Albinism is characterized by a variable degree of hypopigmentation affecting the skin and the hair, and causing ophthalmologic abnormalities. Its oculocutaneous, ocular and syndromic forms follow an autosomal or X-linked recessive mode of inheritance, and 22 disease-causing genes are implicated in their development. Our aim was to clarify the genetic background of a Hungarian albinism cohort. Using a 22-gene albinism panel, the genetic background of 11 of the 17 Hungarian patients was elucidated. In patients with unidentified genetic backgrounds (n = 6), whole exome sequencing was performed. Our investigations revealed a novel, previously unreported rare variant (N687S) of the two-pore channel two gene (TPCN2). The N687S variant of the encoded TPC2 protein is carried by a 15-year-old Hungarian male albinism patient and his clinically unaffected mother. Our segregational analysis and in vitro functional experiments suggest that the detected novel rare TPCN2 variant alone is not a disease-causing variant in albinism. Deep genetic analyses of the family revealed that the patient also carries a phenotype-modifying R305W variant of the OCA2 protein, and he is the only family member harboring this genotype. Our results raise the possibility that this digenic combination might contribute to the observed differences between the patient and the mother, and found the genetic background of the disease in his case.
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Affiliation(s)
- Nikoletta Nagy
- Department of Medical Genetics, University of Szeged, 6720 Szeged, Hungary; (M.P.); (A.N.); (A.A.); (E.A.); (M.S.)
- HUN-REN-SZTE Functional Clinical Genetic Research Group, 6720 Szeged, Hungary
| | - Margit Pal
- Department of Medical Genetics, University of Szeged, 6720 Szeged, Hungary; (M.P.); (A.N.); (A.A.); (E.A.); (M.S.)
- HUN-REN-SZTE Functional Clinical Genetic Research Group, 6720 Szeged, Hungary
| | - Jozsef Kun
- Hungarian Centre for Genomics and Bioinformatics, Szentagothai Research Centre, University of Pecs, 7624 Pecs, Hungary; (J.K.); (B.G.); (P.U.); (A.G.)
| | - Bence Galik
- Hungarian Centre for Genomics and Bioinformatics, Szentagothai Research Centre, University of Pecs, 7624 Pecs, Hungary; (J.K.); (B.G.); (P.U.); (A.G.)
| | - Peter Urban
- Hungarian Centre for Genomics and Bioinformatics, Szentagothai Research Centre, University of Pecs, 7624 Pecs, Hungary; (J.K.); (B.G.); (P.U.); (A.G.)
| | - Marta Medvecz
- Department of Dermatology, Venereology and Dermatooncology, Semmelweis University, 1095 Budapest, Hungary;
- ERN-Skin Reference Centre, Semmelweis University, 1095 Budapest, Hungary
| | - Beata Fabos
- Mor Kaposi Teaching Hospital of Somogy County, 7400 Kaposvar, Hungary;
| | - Alexandra Neller
- Department of Medical Genetics, University of Szeged, 6720 Szeged, Hungary; (M.P.); (A.N.); (A.A.); (E.A.); (M.S.)
| | - Aliasgari Abdolreza
- Department of Medical Genetics, University of Szeged, 6720 Szeged, Hungary; (M.P.); (A.N.); (A.A.); (E.A.); (M.S.)
| | - Judit Danis
- HUN-REN-SZTE Dermatological Research Group, 6720 Szeged, Hungary;
- Department of Immunology, University of Szeged, 6720 Szeged, Hungary
| | - Viktoria Szabo
- Department of Ophthalmology, Semmelweis University, 1085 Budapest, Hungary
| | - Zhuo Yang
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany (M.B.)
| | - Stefanie Fenske
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany (M.B.)
| | - Martin Biel
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany (M.B.)
| | - Attila Gyenesei
- Hungarian Centre for Genomics and Bioinformatics, Szentagothai Research Centre, University of Pecs, 7624 Pecs, Hungary; (J.K.); (B.G.); (P.U.); (A.G.)
| | - Eva Adam
- Department of Medical Genetics, University of Szeged, 6720 Szeged, Hungary; (M.P.); (A.N.); (A.A.); (E.A.); (M.S.)
- HUN-REN-SZTE Functional Clinical Genetic Research Group, 6720 Szeged, Hungary
| | - Marta Szell
- Department of Medical Genetics, University of Szeged, 6720 Szeged, Hungary; (M.P.); (A.N.); (A.A.); (E.A.); (M.S.)
- HUN-REN-SZTE Functional Clinical Genetic Research Group, 6720 Szeged, Hungary
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Talsma HE, Kruijt CC, de Wit GC, Zwerver SHL, van Genderen MM. Nystagmus Characteristics in Albinism: Unveiling the Link to Foveal Hypoplasia and Visual Acuity. Invest Ophthalmol Vis Sci 2023; 64:30. [PMID: 38133506 PMCID: PMC10746925 DOI: 10.1167/iovs.64.15.30] [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: 09/15/2023] [Accepted: 11/21/2023] [Indexed: 12/23/2023] Open
Abstract
Purpose The purpose of this study was to describe the association among nystagmus characteristics, foveal hypoplasia, and visual acuity in patients with albinism. Methods We studied nystagmus recordings of 50 patients with albinism. The nystagmus waveform was decomposed into two types: dominantly pendular and dominantly jerk. We correlated the nystagmus type, amplitude, frequency, and percentage of low velocity (PLOV) to Snellen visual acuity and foveal hypoplasia grades. Results The grade of foveal hypoplasia and visual acuity showed a strong correlation (r = 0.87, P < 0.0001). Nystagmus type and PLOV had the strongest significant (P < 0.0001) correlation with visual acuity (r = 0.70 and r = -0.56, respectively) and with foveal hypoplasia (r = 0.76 and r = -0.60, respectively). Patients with pendular nystagmus type had the lowest PLOV, and the highest grade of foveal hypoplasia (P < 0.0001). Severe foveal hypoplasia (grade 4), was almost invariably associated with pendular nystagmus (86%). Conclusions Foveal hypoplasia grade 4 is associated with pendular nystagmus, lower PLOV, and worse visual acuity. Based on these results, nystagmus recordings at a young age may contribute to predicting visual outcomes.
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Affiliation(s)
- Herman E. Talsma
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
| | - Charlotte C. Kruijt
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Gerard C. de Wit
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
| | - Stefan H. L. Zwerver
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
| | - Maria M. van Genderen
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands
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Sergouniotis PI, Michaud V, Lasseaux E, Campbell C, Plaisant C, Javerzat S, Birney E, Ramsden SC, Black GC, Arveiler B. A multilayered approach to the analysis of genetic data from individuals with suspected albinism. J Med Genet 2023; 60:1245-1249. [PMID: 37460203 DOI: 10.1136/jmg-2022-109088] [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: 12/01/2022] [Accepted: 05/12/2023] [Indexed: 11/29/2023]
Abstract
Albinism is a clinically and genetically heterogeneous group of conditions characterised by visual abnormalities and variable degrees of hypopigmentation. Multiple studies have demonstrated the clinical utility of genetic investigations in individuals with suspected albinism. Despite this, the variation in the provision of genetic testing for albinism remains significant. One key issue is the lack of a standardised approach to the analysis of genomic data from affected individuals. For example, there is variation in how different clinical genetic laboratories approach genotypes that involve incompletely penetrant alleles, including the common, 'hypomorphic' TYR c.1205G>A (p.Arg402Gln) [rs1126809] variant. Here, we discuss the value of genetic testing as a frontline diagnostic tool in individuals with features of albinism and propose a practice pattern for the analysis of genomic data from affected families.
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Affiliation(s)
- Panagiotis I Sergouniotis
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL- EBI), Wellcome Genome Campus, Cambridge, UK
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Vincent Michaud
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
- INSERM U1211, Rare Diseases, Genetics and Metabolism, University of Bordeaux, Bordeaux, France
| | - Eulalie Lasseaux
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
| | - Christopher Campbell
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Claudio Plaisant
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
| | - Sophie Javerzat
- INSERM U1211, Rare Diseases, Genetics and Metabolism, University of Bordeaux, Bordeaux, France
| | - Ewan Birney
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL- EBI), Wellcome Genome Campus, Cambridge, UK
| | - Simon C Ramsden
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Graeme C Black
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Benoit Arveiler
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
- INSERM U1211, Rare Diseases, Genetics and Metabolism, University of Bordeaux, Bordeaux, France
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9
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Al-Nosairy KO, Quanz EV, Eick CM, Hoffmann MB, Kornmeier J. Altered Perception of the Bistable Motion Quartet in Albinism. Invest Ophthalmol Vis Sci 2023; 64:39. [PMID: 38015177 PMCID: PMC10691394 DOI: 10.1167/iovs.64.14.39] [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: 07/31/2023] [Accepted: 10/31/2023] [Indexed: 11/29/2023] Open
Abstract
Purpose Perception of the motion quartet (MQ) alternates between horizontal and vertical motion, with a bias toward vertical motion. This vertical bias has been explained by the dominance of intrahemispheric processing. In albinism, each hemisphere receives input from both visual hemifields owing to enhanced crossing of the optic nerves at the optic chiasm. This might affect the perception of the ambiguous MQ and particularly the vertical bias. Methods The effect of optic nerve misrouting in persons with albinism and nystagmus (PWA, n = 14) on motion perception for MQ was compared with healthy controls (HC; n = 11) and with persons with nystagmus in the absence of optic nerve misrouting (PWN; n = 12). We varied the ratio of horizontal and vertical distances of MQ dots (aspect ratio [AR]) between 0.75 and 1.25 and compared the percentages of horizontal and vertical motion percepts as a function of AR between groups. Results For HC, the probability of vertical motion perception increased as a sigmoid function with increasing AR exhibiting the expected vertical percept bias (mean, 58%; median, 54%; vertical motion percepts). PWA showed a surprisingly strong horizontal bias independent of the AR with a mean of 11% (median, 10%) vertical motion percepts. The PWN was in between PWA and HC, with a mean of 34% (median, 47%) vertical perception. Nystagmus alone is unlikely to explain this pattern of results because PWA and PWN had comparable fixation stabilities. Conclusions The strong horizontal bias observed in PWA and PWN might partly result from the horizontal nystagmus. The even stronger horizontal bias in PWA indicates that the intrahemispherical corepresentation of both visual hemifields may play an additional role. The altered perception of the MQ in PWA opens opportunities to (i) understand the interplay of stability and plasticity in altered visual pathway conditions and (ii) identify visual pathway abnormalities with a perception-based test using the MQ.
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Affiliation(s)
| | - Elisabeth V. Quanz
- Department of Ophthalmology, Otto-von-Guericke University, Magdeburg, Germany
| | - Charlotta M. Eick
- Department of Ophthalmology, Otto-von-Guericke University, Magdeburg, Germany
| | - Michael B. Hoffmann
- Department of Ophthalmology, Otto-von-Guericke University, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg, Germany
| | - Jürgen Kornmeier
- Institute for Frontier Areas of Psychology and Mental Health, Freiburg, Germany
- Department of Psychiatry and Psychotherapy, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
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10
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Guardia A, Fernández A, Seruggia D, Chotard V, Sánchez-Castillo C, Kutsyr O, Sánchez-Sáez X, Zurita E, Cantero M, Rebsam A, Cuenca N, Montoliu L. A Slc38a8 Mouse Model of FHONDA Syndrome Faithfully Recapitulates the Visual Deficits of Albinism Without Pigmentation Defects. Invest Ophthalmol Vis Sci 2023; 64:32. [PMID: 37862028 PMCID: PMC10599165 DOI: 10.1167/iovs.64.13.32] [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: 08/09/2023] [Accepted: 10/02/2023] [Indexed: 10/21/2023] Open
Abstract
Purpose We aimed to generate and phenotype a mouse model of foveal hypoplasia, optic nerve decussation defects, and anterior segment dysgenesis (FHONDA), a rare disease associated with mutations in Slc38a8 that causes severe visual alterations similar to albinism without affecting pigmentation. Methods The FHONDA mouse model was generated with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology using an RNA guide targeting the Scl38a8 murine locus. The resulting mice were backcrossed to C57BL/6J. Melanin content was measured using spectrophotometry. Retinal cell architecture was analyzed through light and electron microscopy. Retinal projections to the brain were evaluated with anterograde labelling in embryos and adults. Visual function was assessed by electroretinography (ERG) and the optomotor test (OT). Results From numerous Slc38a8 mouse mutant alleles generated, we selected one that encodes a truncated protein (p.196Pro*, equivalent to p.199Pro* in the human protein) closely resembling a mutant allele described in patients (p.200Gln*). Slc38a8 mutant mice exhibit wild-type eye and coat pigmentation with comparable melanin content. Subcellular abnormalities were observed in retinal pigment epithelium cells of Slc38a8 mutant mice. Anterograde labeling experiments of retinal projections in embryos and adults showed a reduction of ipsilateral fibers. Functional visual analyses revealed a decreased ERG response in scotopic conditions and a reduction of visual acuity in mutant mice measured by OT. Conclusions Slc38a8 mutant mice recapitulate the phenotype of patients with FHONDA concerning their normal pigmentation and their abnormal visual system, in the latter being a hallmark of all types of albinism. These mice will be helpful in better understanding the pathophysiology of this genetic condition.
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Affiliation(s)
- Ana Guardia
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER-ISCIII), Madrid, Spain
| | - Almudena Fernández
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER-ISCIII), Madrid, Spain
| | - Davide Seruggia
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER-ISCIII), Madrid, Spain
| | - Virginie Chotard
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Carla Sánchez-Castillo
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Oksana Kutsyr
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Xavier Sánchez-Sáez
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Esther Zurita
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER-ISCIII), Madrid, Spain
| | - Marta Cantero
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER-ISCIII), Madrid, Spain
| | - Alexandra Rebsam
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Lluís Montoliu
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER-ISCIII), Madrid, Spain
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11
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Puzniak RJ, Prabhakaran GT, McLean RJ, Stober S, Ather S, Proudlock FA, Gottlob I, Dineen RA, Hoffmann MB. CHIASM-Net: Artificial Intelligence-Based Direct Identification of Chiasmal Abnormalities in Albinism. Invest Ophthalmol Vis Sci 2023; 64:14. [PMID: 37815506 PMCID: PMC10573586 DOI: 10.1167/iovs.64.13.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 09/06/2023] [Indexed: 10/11/2023] Open
Abstract
Purpose Albinism is a congenital disorder affecting pigmentation levels, structure, and function of the visual system. The identification of anatomical changes typical for people with albinism (PWA), such as optic chiasm malformations, could become an important component of diagnostics. Here, we tested an application of convolutional neural networks (CNNs) for this purpose. Methods We established and evaluated a CNN, referred to as CHIASM-Net, for the detection of chiasmal malformations from anatomic magnetic resonance (MR) images of the brain. CHIASM-Net, composed of encoding and classification modules, was developed using MR images of controls (n = 1708) and PWA (n = 32). Evaluation involved 8-fold cross validation involving accuracy, precision, recall, and F1-score metrics and was performed on a subset of controls and PWA samples excluded from the training. In addition to quantitative metrics, we used Explainable AI (XAI) methods that granted insights into factors driving the predictions of CHIASM-Net. Results The results for the scenario indicated an accuracy of 85 ± 14%, precision of 90 ± 14% and recall of 81 ± 18%. XAI methods revealed that the predictions of CHIASM-Net are driven by optic-chiasm white matter and by the optic tracts. Conclusions CHIASM-Net was demonstrated to use relevant regions of the optic chiasm for albinism detection from magnetic resonance imaging (MRI) brain anatomies. This indicates the strong potential of CNN-based approaches for visual pathway analysis and ultimately diagnostics.
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Affiliation(s)
- Robert J Puzniak
- Visual Processing Lab, Department of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
- Department of Neuroscience, Psychology, and Behaviour, University of Leicester, Leicester, United Kingdom
| | - Gokulraj T Prabhakaran
- Visual Processing Lab, Department of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
| | - Rebecca J McLean
- University of Leicester Ulverscroft Eye Unit, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Sebastian Stober
- Artificial Intelligence Lab, Institute for Intelligent Cooperating Systems, Otto-von-Guericke-University, Magdeburg, Germany
| | - Sarim Ather
- Department of Radiology, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Headington, Oxford, United Kingdom
| | - Frank A Proudlock
- University of Leicester Ulverscroft Eye Unit, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Irene Gottlob
- University of Leicester Ulverscroft Eye Unit, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
- Cooper Neurological Institute and Cooper Medical School of Rowan University, Camden, New Jersey, United States
| | - Robert A Dineen
- Mental Health and Clinical Neuroscience, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, United Kingdom
- NIHR Nottingham Biomedical Research Centre, Nottingham, United Kingdom
| | - Michael B Hoffmann
- Visual Processing Lab, Department of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Otto-von-Guericke-Universität, Magdeburg, Germany
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12
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Peterson SM, Watowich MM, Renner LM, Martin S, Offenberg E, Lea A, Montague MJ, Higham JP, Snyder-Mackler N, Neuringer M, Ferguson B. Genetic variants in melanogenesis proteins TYRP1 and TYR are associated with the golden rhesus macaque phenotype. G3 (BETHESDA, MD.) 2023; 13:jkad168. [PMID: 37522525 PMCID: PMC10542561 DOI: 10.1093/g3journal/jkad168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 03/09/2023] [Accepted: 07/12/2023] [Indexed: 08/01/2023]
Abstract
Nonhuman primates (NHPs) are vital translational research models due to their high genetic, physiological, and anatomical homology with humans. The "golden" rhesus macaque (Macaca mulatta) phenotype is a naturally occurring, inherited trait with a visually distinct pigmentation pattern resulting in light blonde colored fur. Retinal imaging also reveals consistent hypopigmentation and occasional foveal hypoplasia. Here, we describe the use of genome-wide association in 2 distinct NHP populations to identify candidate variants in genes linked to the golden phenotype. Two missense variants were identified in the Tyrosinase-related protein 1 gene (Asp343Gly and Leu415Pro) that segregate with the phenotype. An additional and distinct association was also found with a Tyrosinase variant (His256Gln), indicating the light-colored fur phenotype can result from multiple genetic mechanisms. The implicated genes are related through their contribution to the melanogenesis pathway. Variants in these 2 genes are known to cause pigmentation phenotypes in other species and to be associated with oculocutaneous albinism in humans. The novel associations presented in this study will permit further investigations into the role these proteins and variants play in the melanogenesis pathway and model the effects of genetic hypopigmentation and altered melanogenesis in a naturally occurring nonhuman primate model.
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Affiliation(s)
- Samuel M Peterson
- Division of Genetics, Oregon National Primate Research Center, Beaverton, OR 97006, USA
| | - Marina M Watowich
- Department of Biology, University of Washington, Seattle, WA 98195, USA
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ 85281, USA
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
| | - Lauren M Renner
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR 97006, USA
| | - Samantha Martin
- Division of Genetics, Oregon National Primate Research Center, Beaverton, OR 97006, USA
| | - Emma Offenberg
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ 85281, USA
| | - Amanda Lea
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
- Child and Brain Development Program, Canadian Institute for Advanced Research, Toronto, ON M5G 1M1, Canada
| | - Michael J Montague
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - James P Higham
- Department of Anthropology, New York University, New York, NY 10003, USA
| | - Noah Snyder-Mackler
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ 85281, USA
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
- School for Human Evolution & Social Change, Arizona State University, Tempe, AZ 85281, USA
| | - Martha Neuringer
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR 97006, USA
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Betsy Ferguson
- Division of Genetics, Oregon National Primate Research Center, Beaverton, OR 97006, USA
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR 97006, USA
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13
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Emri E, Cappa O, Kelly C, Kortvely E, SanGiovanni JP, McKay BS, Bergen AA, Simpson DA, Lengyel I. Zinc Supplementation Induced Transcriptional Changes in Primary Human Retinal Pigment Epithelium: A Single-Cell RNA Sequencing Study to Understand Age-Related Macular Degeneration. Cells 2023; 12:773. [PMID: 36899910 PMCID: PMC10000409 DOI: 10.3390/cells12050773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/05/2023] Open
Abstract
Zinc supplementation has been shown to be beneficial to slow the progression of age-related macular degeneration (AMD). However, the molecular mechanism underpinning this benefit is not well understood. This study used single-cell RNA sequencing to identify transcriptomic changes induced by zinc supplementation. Human primary retinal pigment epithelial (RPE) cells could mature for up to 19 weeks. After 1 or 18 weeks in culture, we supplemented the culture medium with 125 µM added zinc for one week. RPE cells developed high transepithelial electrical resistance, extensive, but variable pigmentation, and deposited sub-RPE material similar to the hallmark lesions of AMD. Unsupervised cluster analysis of the combined transcriptome of the cells isolated after 2, 9, and 19 weeks in culture showed considerable heterogeneity. Clustering based on 234 pre-selected RPE-specific genes divided the cells into two distinct clusters, we defined as more and less differentiated cells. The proportion of more differentiated cells increased with time in culture, but appreciable numbers of cells remained less differentiated even at 19 weeks. Pseudotemporal ordering identified 537 genes that could be implicated in the dynamics of RPE cell differentiation (FDR < 0.05). Zinc treatment resulted in the differential expression of 281 of these genes (FDR < 0.05). These genes were associated with several biological pathways with modulation of ID1/ID3 transcriptional regulation. Overall, zinc had a multitude of effects on the RPE transcriptome, including several genes involved in pigmentation, complement regulation, mineralization, and cholesterol metabolism processes associated with AMD.
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Affiliation(s)
- Eszter Emri
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, UK
- Section Ophthalmogenetics, Department of Human Genetics, Queen Emma Centre for Precision Medicine, Amsterdam UMC, Location AMC, 1105AZ Amsterdam, The Netherlands
| | - Oisin Cappa
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, UK
| | - Caoimhe Kelly
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, UK
| | - Elod Kortvely
- Immunology, Infectious Diseases and Ophthalmology (I2O) Discovery and Translational Area, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., 4070 Basel, Switzerland
| | - John Paul SanGiovanni
- Biosciences Research Laboratories, BIO5 Institute, University of Arizona, 1230 North Cherry Avenue, Tucson, AZ 85724, USA
| | - Brian S. McKay
- Department of Ophthalmology and Vision Science, University of Arizona, 1656 E. Mabel Street, Tucson, AZ 85724, USA
| | - Arthur A. Bergen
- Section Ophthalmogenetics, Department of Human Genetics, Queen Emma Centre for Precision Medicine, Amsterdam UMC, Location AMC, 1105AZ Amsterdam, The Netherlands
- The Netherlands Institute for Neuroscience (NIN-KNAW), 1105AZ Amsterdam, The Netherlands
| | - David A. Simpson
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, UK
| | - Imre Lengyel
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, UK
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14
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Karkashadze GA, Namazova-Baranova LS, Yatsik LM, Gordeeva OB, Vishneva EA, Efendieva KE, Kaytukova EV, Sukhanova NV, Sergienko NS, Nesterova JV, Kondratova SE, Fatakhova MT, Pashkov AV, Naumova IV, Zelenkova IV, Gankovskiy VA, Gubanova SG, Leonova EV, Pankova AR, Alexeeva AA, Bushueva DA, Gogberashvili TY, Kratko DS, Sadilloeva SH, Sergeeva NE, Kurakina MA, Konstantinidi TA, Povalyaeva IA, Soloshenko MA, Slipka MI, Altunin VV, Rykunova AI, Salimgareeva TA, Prudnikov PA, Ulkina NA, Firumyantc AI, Shilko NS, Kazanceva JE. Levels of Neurospecific Peptides, Neurotransmitters and Neuroreceptor Markers in the Serum of Children with Various Sensory Disorders, Mild Cognitive Impairments and Other Neuropathology. PEDIATRIC PHARMACOLOGY 2023. [DOI: 10.15690/pf.v19i6.2486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Background. The role of recently discovered neurospecific peptides in the pathogenesis of acute and progressive neurologic disorders, their neuroprotective features, and possibilities to use them as markers for the course and prognosis of certain diseases have been actively studied in recent decades. However, neurospecific peptides are almost not studied in chronic residual diseases. In our study we measured the levels of neurospecific peptides and some other markers to achieve understanding of general neurophysiological trends in congenital and acquired chronic non-progressive brain pathology with reference to the selection of relevant groups — study objects. Objective. The aim of the study is to study patterns of neurospecific peptides, neurotransmitters and neuroreceptor markers distribution in the serum of children with various pathogenetic variants of chronic neuropathology. Methods. The study included children from 3 to 16 years old with different pathologies. The sample was divided into groups by pathology type: no sensory and neurological disorders, congenital sensory deficit due to mutation of genes expressed and not expressed in the brain, early acquired sensory deficit of multifactorial nature, congenital mild and severe organic disorders of central nervous system (CNS) in residual stage without baseline sensory deficit, acquired functional CNS disorders without baseline organic defect and sensory deficit. The following laboratory data (neurophysiological components) was studied: nerve growth factor, brain-derived neurotropic factor, neurotrophin-3, neurotrophin-4, neuregulin-1-beta-1, beta-secretase, sirtuin-1, synaptophysin, neuronal nitric oxide synthase, and anti-NR2 glutamate receptor antibodies. The parameters of cognitive activity, sense of vision, sense of smell, and acoustic sense were also evaluated. Results. The study included 274 participants. Neuropeptides and markers have shown a variable degree and range in the group spectrum of differences from normal levels. The most variable in the examined sample was NO-synthase, as well as levels of both neurotrophins, beta-secretase, and glutamate receptor marker. All visual deficits were associated with increased NO-synthase levels (p < 0.001). Neuroplasticity peptides (beta-secretase, neurotrophin-3 and 4) have been activated in all pathological conditions. Nerve growth factor and brain-derived neurotropic factor were specifically activated in mild organic CNS lesions (mild cognitive impairments), while neuregulin — in congenital genetically determined visual deficits. There was no specific activation of neuropeptides and NO-synthase level tended to decrease in cases of severe CNS lesions. Conclusion. The study results suggest that all types of early visual impairment are associated with increased physiological neuronal activity, and non-organic neurological functional disorders — mainly with increased physiological synaptic activity. General neuroplasticity processes were activated in all cases of visual deficits but more specific. However, more specific and well-studied processes were activated in mild organic CNS lesions, and neuroplasticity processes did not activate adequately in severe organic CNS lesions probably due to the limited neuronal and synaptic resources.
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15
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Gray MT, Lefebvre JL. Sticking to your side: A niche for the development of ipsilateral retinal projections. Neuron 2023; 111:5-8. [PMID: 36603550 DOI: 10.1016/j.neuron.2022.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Visual impairments in albinism result from decreased ipsilateral retinal projections. In this issue of Neuron, Slavi, Balasubramanian, and colleagues1 demonstrate how low CyclinD2 in the ciliary marginal zone perturbs generation of ipsilaterally projecting RGCs and that restoring CyclinD2 improves vision in albino mice.
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Affiliation(s)
- Madison T Gray
- Program for Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Julie L Lefebvre
- Program for Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Canada.
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16
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Al-Nosairy KO, Quanz EV, Biermann J, Hoffmann MB. Optical Coherence Tomography as a Biomarker for Differential Diagnostics in Nystagmus: Ganglion Cell Layer Thickness Ratio. J Clin Med 2022; 11:jcm11174941. [PMID: 36078871 PMCID: PMC9456294 DOI: 10.3390/jcm11174941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/12/2022] [Accepted: 08/13/2022] [Indexed: 11/25/2022] Open
Abstract
In albinism, with the use of optical coherence tomography (OCT), a thinning of the macular ganglion cell layer was recently reported. As a consequence, the relevant OCT measure, i.e., a reduction of the temporal/nasal ganglion cell layer thickness quotient (GCLTQ), is a strong candidate for a novel biomarker of albinism. However, nystagmus is a common trait in albinism and is known as a potential confound of imaging techniques. Therefore, there is a need to determine the impact of nystagmus without albinism on the GCLTQ. In this bi-center study, the retinal GCLTQ was determined (OCT Spectralis, Heidelberg Engineering, Heidelberg, Germany) for healthy controls (n = 5, 10 eyes) vs. participants with nystagmus and albinism (Nalbinism, n = 8, 15 eyes), and with nystagmus of other origins (Nother, n = 11, 17 eyes). Macular OCT with 25 horizontal B scans 20 × 20° with 9 automated real time tracking (ART) frames centered on the retina was obtained for each group. From the sectoral GCLTs of the early treatment diabetic retinopathy study (ETDRS) circular thickness maps, i.e., 3 mm and 6 mm ETDRS rings, GCLTQ I and GCLTQ II were determined. Both GCLTQs were reduced in Nalbinism (GCLTQ I and II: 0.78 and 0.77, p < 0.001) compared to Nother (0.91 and 0.93) and healthy controls (0.89 and 0.95). The discrimination of Nalbinism from Nother via GCLTQ I and II had an area under the curve of 80 and 82% with an optimal cutoff point of 0.86 and 0.88, respectively. In conclusion, lower GCLTQ in Nalbinism appears as a distinguished feature in albinism-related nystagmus as opposed to other causes of nystagmus.
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Affiliation(s)
- Khaldoon O. Al-Nosairy
- Department of Ophthalmology, Faculty of Medicine, Otto-von-Guericke University, 39120 Magdeburg, Germany
| | - Elisabeth V. Quanz
- Department of Ophthalmology, Faculty of Medicine, Otto-von-Guericke University, 39120 Magdeburg, Germany
| | - Julia Biermann
- Department of Ophthalmology, University of Muenster Medical Centre, 48149 Muenster, Germany
| | - Michael B. Hoffmann
- Department of Ophthalmology, Faculty of Medicine, Otto-von-Guericke University, 39120 Magdeburg, Germany
- Center for Behavioral Brain Sciences, 39118 Magdeburg, Germany
- Correspondence:
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