RESUMO
Within the last decade, a wide variety of protocols have emerged for the generation of retinal organoids. A subset of studies have compared protocols based on stem cell source, the physical features of the microenvironment, and both internal and external signals, all features that influence embryoid body and retinal organoid formation. Most of these comparisons have focused on the effect of signaling pathways on retinal organoid development. In this study, our aim is to understand whether starting cell conditions, specifically those involved in embryoid body formation, affect the development of retinal organoids in terms of differentiation capacity and reproducibility. To investigate this, we used the popular 3D floating culture method to generate retinal organoids from stem cells. This method starts with either small clumps of stem cells generated from larger clones (clumps protocol, CP) or with an aggregation of single cells (single cells protocol, SCP). Using histological analysis and gene-expression comparison, we found a retention of the pluripotency capacity on embryoid bodies generated through the SCP compared to the CP. Nonetheless, these early developmental differences seem not to impact the final retinal organoid formation, suggesting a potential compensatory mechanism during the neurosphere stage. This study not only facilitates an in-depth exploration of embryoid body development but also provides valuable insights for the selection of the most suitable protocol in order to study retinal development and to model inherited retinal disorders in vitro.
Assuntos
Corpos Embrioides , Retina , Reprodutibilidade dos Testes , Retina/metabolismo , Organoides , Diferenciação CelularRESUMO
PURPOSE: To describe the natural course, phenotype, and genotype of patients with X-linked retinoschisis (XLRS). DESIGN: Retrospective cohort study. PARTICIPANTS: Three hundred forty patients with XLRS from 178 presumably unrelated families. METHODS: This multicenter, retrospective cohort study reviewed medical records of patients with XLRS for medical history, symptoms, visual acuity (VA), ophthalmoscopy, full-field electroretinography, and retinal imaging (fundus photography, spectral-domain [SD] OCT, fundus autofluorescence). MAIN OUTCOME MEASURES: Age at onset, age at diagnosis, severity of visual impairment, annual visual decline, and electroretinography and imaging findings. RESULTS: Three hundred forty patients were included with a mean follow-up time of 13.2 years (range, 0.1-50.1 years). The median ages to reach mild visual impairment and low vision were 12 and 25 years, respectively. Severe visual impairment and blindness were observed predominantly in patients older than 40 years, with a predicted prevalence of 35% and 25%, respectively, at 60 years of age. The VA increased slightly during the first 2 decades of life and subsequently transitioned into an average annual decline of 0.44% (P < 0.001). No significant difference was found in decline of VA between variants that were predicted to be severe and mild (P = 0.239). The integrity of the ellipsoid zone (EZ) as well as the photoreceptor outer segment (PROS) length in the fovea on SD OCT correlated significantly with VA (Spearman's ρ = -0.759 [P < 0.001] and -0.592 [P = 0.012], respectively). Fifty-three different RS1 variants were found. The most common variants were the founder variant c.214GâA (p.(Glu72Lys)) (101 patients [38.7%]) and a deletion of exon 3 (38 patients [14.6%]). CONCLUSIONS: Large variabilities in phenotype and natural course of XLRS were seen in this study. In most patients, XLRS showed a slow deterioration starting in the second decade of life, suggesting an optimal window of opportunity for treatment within the first 3 decades of life. The integrity of EZ as well as the PROS length on SD OCT may be important in choosing optimal candidates for treatment and as potential structural end points in future therapeutic studies. No clear genotype-phenotype correlation was found.
Assuntos
Proteínas do Olho/genética , Retinosquise/diagnóstico , Retinosquise/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cegueira/diagnóstico , Cegueira/fisiopatologia , Criança , Pré-Escolar , Eletrorretinografia , Feminino , Seguimentos , Estudos de Associação Genética , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Oftalmoscopia , Imagem Óptica , Retina/diagnóstico por imagem , Retina/fisiopatologia , Segmento Externo das Células Fotorreceptoras da Retina/patologia , Retinosquise/fisiopatologia , Estudos Retrospectivos , Tomografia de Coerência Óptica , Baixa Visão/diagnóstico , Baixa Visão/fisiopatologia , Acuidade Visual/fisiologiaRESUMO
Retinal photoreceptors undergo daily renewal of their distal outer segments, a process indispensable for maintaining retinal health. Photoreceptor outer segment (POS) phagocytosis occurs as a daily peak, roughly about 1 hour after light onset. However, the underlying cellular and molecular mechanisms which initiate this process are still unknown. Here we show that, under constant darkness, mice deficient for core circadian clock genes (Per1 and Per2) lack a daily peak in POS phagocytosis. By qPCR analysis, we found that core clock genes were rhythmic over 24 hours in both WT and Per1, Per2 double mutant whole retinas. More precise transcriptomics analysis of laser capture microdissected WT photoreceptors revealed no differentially expressed genes between time points preceding and during the peak of POS phagocytosis. In contrast, we found that microdissected WT retinal pigment epithelium (RPE) had a number of genes that were differentially expressed at the peak phagocytic time point compared to adjacent ones. We also found a number of differentially expressed genes in Per1, Per2 double mutant RPE compared to WT ones at the peak phagocytic time point. Finally, based on STRING analysis, we found a group of interacting genes that potentially drive POS phagocytosis in the RPE. This potential pathway consists of genes such as: Pacsin1, Syp, Camk2b, and Camk2d among others. Our findings indicate that Per1 and Per2 are necessary clock components for driving POS phagocytosis and suggest that this process is transcriptionally driven by the RPE.
Assuntos
Relógios Circadianos/genética , Ritmo Circadiano/genética , Proteínas Circadianas Period/genética , Fagocitose/genética , Células Fotorreceptoras de Vertebrados/fisiologia , Retina/fisiologia , Animais , Relógios Circadianos/fisiologia , Ritmo Circadiano/fisiologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fagocitose/fisiologia , Células Fotorreceptoras/fisiologia , Epitélio Pigmentado da Retina/fisiologia , Transcrição Gênica/genética , Transcrição Gênica/fisiologiaRESUMO
PURPOSE: The lack of suitable animal models for (dry) age-related macular degeneration (AMD) has hampered therapeutic research into the disease, so far. In this study, pigmented rats and mice were systematically injected with various doses of sodium iodate (SI). After injection, the retinal structure and visual function were non-invasively characterized over time to obtain in-depth data on the suitability of these models for studying experimental therapies for retinal degenerative diseases, such as dry AMD. METHODS: SI was injected into the tail vein (i.v.) using a series of doses (0-70 mg/kg) in adolescent C57BL/6J mice and Brown Norway rats. The retinal structure and function were assessed non-invasively at baseline (day 1) and at several time points (1-3, 5, and 10-weeks) post-injection by scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), and electroretinography (ERG). RESULTS: After the SI injection, retinal degeneration in mice and rats yielded similar results. The lowest dose (10 mg/kg) resulted in non-detectable structural or functional effects. An injection with 20 mg/kg SI did not result in an evident retinal degeneration as judged from the OCT data. In contrast, the ERG responses were temporarily decreased but returned to baseline within two-weeks. Higher doses (30, 40, 50, and 70 mg/kg) resulted in moderate to severe structural RPE and retinal injury and decreased the ERG amplitudes, indicating visual impairment in both mice and rat strains. CONCLUSIONS: After the SI injections, we observed dose-dependent structural and functional pathological effects on the retinal pigment epithelium (RPE) and retina in the pigmented mouse and rat strains that were used in this study. Similar effects were observed in both species. In particular, a dose of 30 mg/kg seems to be suitable for future studies on developing experimental therapies. These relatively easily induced non-inherited models may serve as useful tools for evaluating novel therapies for RPE-related retinal degenerations, such as AMD.
Assuntos
Degeneração Macular , Degeneração Retiniana , Animais , Modelos Animais de Doenças , Eletrorretinografia , Seguimentos , Iodatos , Degeneração Macular/diagnóstico por imagem , Degeneração Macular/tratamento farmacológico , Degeneração Macular/patologia , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Retina/patologia , Degeneração Retiniana/diagnóstico por imagem , Degeneração Retiniana/tratamento farmacológico , Degeneração Retiniana/patologia , Epitélio Pigmentado da Retina/patologia , Sódio/farmacologia , Tomografia de Coerência ÓpticaRESUMO
BACKGROUND: To investigate whether copy number variations (CNVs) are implicated in molecular mechanisms underlying primary open-angle glaucoma (POAG), we used genotype data of POAG individuals and healthy controls from two case-control studies, AGS (n = 278) and GLGS-UGLI (n = 1292). PennCNV, QuantiSNP, and cnvPartition programs were used to detect CNV. Stringent quality controls at both sample and marker levels were applied. The identified CNVs were intersected in CNV region (CNVR). After, we performed burden analysis, CNV-genome-wide association analysis, gene set overrepresentation and pathway analysis. In addition, in human eye tissues we assessed the expression of the genes lying within significant CNVRs. RESULTS: We reported a statistically significant greater burden of CNVs in POAG cases compared to controls (p-value = 0,007). In common between the two cohorts, CNV-association analysis identified statistically significant CNVRs associated with POAG that span 11 genes (APC, BRCA2, COL3A1, HLA-DRB1, HLA-DRB5, HLA-DRB6, MFSD8, NIPBL, SCN1A, SDHB, and ZDHHC11). Functional annotation and pathway analysis suggested the involvement of cadherin, Wnt signalling, and p53 pathways. CONCLUSIONS: Our data suggest that CNVs may have a role in the susceptibility of POAG and they can reveal more information on the mechanism behind this disease. Additional genetic and functional studies are warranted to ascertain the contribution of CNVs in POAG.
Assuntos
Variações do Número de Cópias de DNA , Glaucoma de Ângulo Aberto , Caderinas/genética , Proteínas de Ciclo Celular , Estudo de Associação Genômica Ampla , Glaucoma de Ângulo Aberto/genética , Humanos , Proteínas de Membrana Transportadoras , Polimorfismo de Nucleotídeo Único , Proteína Supressora de Tumor p53/genéticaRESUMO
PURPOSE: To investigate the natural history of RHO-associated retinitis pigmentosa (RP). METHODS: A multicenter, medical chart review of 100 patients with autosomal dominant RHO-associated RP. RESULTS: Based on visual fields, time-to-event analysis revealed median ages of 52 and 79 years to reach low vision (central visual field <20°) and blindness (central visual field <10°), respectively. For the best-corrected visual acuity (BCVA), the median age to reach mild impairment (20/67 ≤ BCVA < 20/40) was 72 years, whereas this could not be computed for lower acuities. Disease progression was significantly faster in patients with a generalized RP phenotype (n = 75; 75%) than that in patients with a sector RP phenotype (n = 25; 25%), in terms of decline rates of the BCVA (P < 0.001) and V4e retinal seeing areas (P < 0.005). The foveal thickness of the photoreceptor-retinal pigment epithelium (PR + RPE) complex correlated significantly with BCVA (Spearman's ρ = 0.733; P < 0.001). CONCLUSION: Based on central visual fields, the optimal window of intervention for RHO-associated RP is before the 5th decade of life. Significant differences in disease progression are present between generalized and sector RP phenotypes. Our findings suggest that the PR + RPE complex is a potential surrogate endpoint for the BCVA in future studies.
Assuntos
Proteínas de Fase Aguda/genética , Previsões , Epitélio Pigmentado da Retina/patologia , Retinose Pigmentar/diagnóstico , Acuidade Visual , Campos Visuais/fisiologia , Proteínas de Fase Aguda/metabolismo , Idoso , Eletrorretinografia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Retinose Pigmentar/sangue , Retinose Pigmentar/genética , Estudos Retrospectivos , Tomografia de Coerência Óptica/métodosRESUMO
PURPOSE: We developed and phenotyped a pigmented knockout rat model for lecithin retinol acyltransferase (LRAT) using CRISPR/Cas9. The introduced mutation (c.12delA) is based on a patient group harboring a homologous homozygous frameshift mutation in the LRAT gene (c.12delC), causing a dysfunctional visual (retinoid) cycle. METHODS: The introduced mutation was confirmed by DNA and RNA sequencing. The expression of Lrat was determined on both the RNA and protein level in wildtype and knockout animals using RT-PCR and immunohistochemistry. The retinal structure and function, as well as the visual behavior of the Lrat-/- and control rats, were characterized using scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), electroretinography (ERG) and vision-based behavioral assays. RESULTS: Wildtype animals had high Lrat mRNA expression in multiple tissues, including the eye and liver. In contrast, hardly any expression was detected in Lrat-/- animals. LRAT protein was abundantly present in wildtype animals and absent in Lrat-/- animals. Lrat-/- animals showed progressively reduced ERG potentials compared to wildtype controls from two weeks of age onwards. Vison-based behavioral assays confirmed reduced vision. Structural abnormalities, such as overall retinal thinning, were observed in Lrat-/- animals. The retinal thickness in knockout rats was decreased to roughly 80% by four months of age. No functional or structural differences were observed between wildtype and heterozygote animals. CONCLUSIONS: Our Lrat-/- rat is a new animal model for retinal dystrophy, especially for the LRAT-subtype of early-onset retinal dystrophies. This model has advantages over the existing mouse models and the RCS rat strain and can be used for translational studies of retinal dystrophies.
Assuntos
Aciltransferases/deficiência , Aciltransferases/genética , Retinose Pigmentar/genética , Animais , Comportamento Animal , Sistemas CRISPR-Cas , Modelos Animais de Doenças , Eletrorretinografia , Feminino , Técnicas de Inativação de Genes , Humanos , Masculino , Camundongos , Oftalmoscopia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Transgênicos , Retinose Pigmentar/diagnóstico por imagem , Retinose Pigmentar/fisiopatologia , Deleção de Sequência , Tomografia de Coerência Óptica , Visão OcularRESUMO
A substantial proportion of subjects with autosomal recessive retinitis pigmentosa (arRP) or Usher syndrome type II (USH2) lacks a genetic diagnosis due to incomplete USH2A screening in the early days of genetic testing. These cases lack eligibility for optimal genetic counseling and future therapy. USH2A defects are the most frequent cause of USH2 and are also causative in individuals with arRP. Therefore, USH2A is an important target for genetic screening. The aim of this study was to assess unscreened or incompletely screened and unexplained USH2 and arRP cases for (likely) pathogenic USH2A variants. Molecular inversion probe (MIP)-based sequencing was performed for the USH2A exons and their flanking regions, as well as published deep-intronic variants. This was done to identify single nucleotide variants (SNVs) and copy number variants (CNVs) in 29 unscreened or partially pre-screened USH2 and 11 partially pre-screened arRP subjects. In 29 out of these 40 cases, two (likely) pathogenic variants were successfully identified. Four of the identified SNVs and one CNV were novel. One previously identified synonymous variant was demonstrated to affect pre-mRNA splicing. In conclusion, genetic diagnoses were obtained for a majority of cases, which confirms that MIP-based sequencing is an effective screening tool for USH2A. Seven unexplained cases were selected for future analysis with whole genome sequencing.
Assuntos
Análise Custo-Benefício , Éxons/genética , Proteínas da Matriz Extracelular/genética , Sondas Moleculares/metabolismo , Sítios de Splice de RNA/genética , Retinose Pigmentar/genética , Análise de Sequência de DNA , Síndromes de Usher/genética , Sequência de Bases , Variações do Número de Cópias de DNA/genética , Deleção de Genes , Humanos , Polimorfismo de Nucleotídeo Único/genética , Retinose Pigmentar/economia , Síndromes de Usher/economiaRESUMO
Multiple retinal cells harbor a circadian oscillator, including retinal pigment epithelial cells (RPE). However, little is known about the functions that are regulated by the RPE clock. The aim of this study was to investigate whether the circadian clock in the RPE regulates the transport of glucose and its glycolytic metabolic by-product - lactate. To that end, we first characterized the mRNA expression profile of glucose and monocarboxylate transporters in ARPE-19â¯cells. We found that SLC2A1 and SLC16A1 were, respectively, the most abundantly expressed glucose and lactate (monocarboxylate) transporters. We further observed that the protein products of SLC2A1 (encoding GLUT1) and SLC16A1 (encoding MCT1) localize on the apical membrane of ARPE-19 monolayers. In a subsequent time-course experiment, we found that SLC2A1 and SLC16A1 mRNA oscillated in ARPE-19 monolayers, but not in dispersed cells, suggesting that monolayer cellular organization is necessary for rhythmic regulation of these transporters. In these monolayers, we found that MCT1 proteins varied over time, in contrast to GLUT1 proteins which did not vary over time. Spectrophotometric measurements of supernatants sampled from ARPE-19 monolayer cultures revealed that glucose concentrations did not significantly differ between apical (Api) supernatants and basolateral (BL) ones. In addition, we did not find rhythms in Api or BL glucose concentrations. Conversely, we found higher lactate concentrations in Api supernatants than BL ones. Further, we found that Api lactate concentrations were rhythmic. Pearson's r revealed that the concentration gradients (Api - BL) of glucose and lactate correlated with the gene expression of respective SLC2A1 and SLC16A1 transporters. Incubation with photoreceptor outer segments (POS) affected the mRNA expression of SLC16A1 and SLC2A1 in ARPE-19 monolayers in a time-dependent manner, thus suggesting that the retina might modulate the RPE clock-controlled expression of transporters via interactions with POS. In conclusion, this work provides evidence that the transport of lactate is regulated by the circadian clock in the RPE.
Assuntos
Relógios Circadianos/fisiologia , Transportador de Glucose Tipo 1/genética , Glucose/metabolismo , Ácido Láctico/metabolismo , Transportadores de Ácidos Monocarboxílicos/genética , Epitélio Pigmentado da Retina/metabolismo , Simportadores/genética , Transcriptoma/fisiologia , Animais , Western Blotting , Bovinos , Linhagem Celular , Membrana Celular/metabolismo , Impedância Elétrica , Humanos , Imuno-Histoquímica , Microscopia Confocal , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Segmento Externo das Células Fotorreceptoras da Retina/metabolismoRESUMO
This study describes the clinical, genetic, and histopathological features in patients with RPGR-associated retinal dystrophies. Nine male patients from eight unrelated families underwent a comprehensive ophthalmic examination. Additionally, the histopathology of the right eye from a patient with an end-stage cone-rod-dystrophy (CRD)/sector retinitis pigmentosa (RP) phenotype was examined. All RPGR mutations causing a CRD phenotype were situated in exon ORF15. The mean best-corrected visual acuity (BCVA, decimals) was 0.58 (standard deviation (SD)): 0.34; range: 0.05-1.13); and the mean spherical refractive error was -4.1 D (SD: 2.11; range: -1.38 to -8.19). Hyperautofluorescent rings were observed in six patients. Full-field electroretinography responses were absent in all patients. The visual field defects ranged from peripheral constriction to central islands. The mean macular sensitivity on microperimetry was 11.6 dB (SD: 7.8; range: 1.6-24.4) and correlated significantly with BCVA (r = 0.907; p = 0.001). A histological examination of the donor eye showed disruption of retinal topology and stratification, with a more severe loss found in the peripheral regions. Reactive gliosis was seen in the inner layers of all regions. Our study demonstrates the highly variable phenotype found in RPGR-associated retinal dystrophies. Therapies should be applied at the earliest signs of photoreceptor degeneration, prior to the remodeling of the inner retina.
Assuntos
Distrofias de Cones e Bastonetes/diagnóstico , Proteínas do Olho/genética , Mutação , Retinose Pigmentar/diagnóstico , Adolescente , Adulto , Idade de Início , Distrofias de Cones e Bastonetes/genética , Eletrorretinografia , Éxons , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Retinose Pigmentar/genética , Acuidade Visual , Testes de Campo Visual , Adulto JovemRESUMO
PURPOSE: To describe the phenotype and clinical course of patients with RPGR-associated retinal dystrophies, and to identify genotype-phenotype correlations. METHODS: A multicenter medical records review of 74 male patients with RPGR-associated retinal dystrophies. RESULTS: Patients had retinitis pigmentosa (RP; n = 52; 70%), cone dystrophy (COD; n = 5; 7%), or cone-rod dystrophy (CORD; n = 17; 23%). The median follow-up time was 11.6 years (range 0-57.1). The median age at symptom onset was 5.0 years (range 0-14 years) for patients with RP and 23.0 years (range 0-60 years) for patients with COD/CORD. The probability of being blind (best-corrected visual acuity <0.05) at the age of 40 was 20% and 55% in patients with RP and COD/CORD, respectively. RPGR-ORF15 mutations were associated with high myopia (P = 0.01), which led to a faster best-corrected visual acuity decline in patients with RP (P < 0.001) and COD/CORD (P = 0.03). Patients with RP with RPGR-ORF15 mutations had a faster visual field decline (P = 0.01) and thinner central retina (P = 0.03) than patients with mutations in exon 1 to 14. CONCLUSION: Based on best-corrected visual acuity survival probabilities, the intervention window for gene therapy for RPGR-associated retinal dystrophies is relatively broad in patients with RP. RPGR-ORF15 mutations were associated with COD/CORD and with a more severe phenotype in RP. High myopia is a risk factor for faster best-corrected visual acuity decline.
Assuntos
DNA/genética , Proteínas do Olho/genética , Previsões , Mutação , Distrofias Retinianas/genética , Acuidade Visual , Campos Visuais , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Análise Mutacional de DNA , Progressão da Doença , Eletrorretinografia , Proteínas do Olho/metabolismo , Seguimentos , Estudos de Associação Genética , Fatores de Troca do Nucleotídeo Guanina , Humanos , Masculino , Pessoa de Meia-Idade , Distrofias Retinianas/diagnóstico , Tomografia de Coerência Óptica , Adulto JovemRESUMO
PURPOSE: To evaluate the long-term clinical course and visual outcome of patients with choroideremia. METHODS: Clinical examination, a social questionnaire, and medical records review of 21 patients with choroideremia from 14 families. RESULTS: The mean follow-up time was 25.2 years (SD: 13.3; range 2-57 years). The mean age at symptom onset was 15.1 years (SD: 10.1; range 5-40 years). Best-corrected visual acuity was stable until the age of 35 (P = 0.96), but declined significantly faster after the age of 35 (11%/year, P = 0.001), with a high variability between individual patients. The mean age at which patients discontinued working was 48.1 years (SD: 11.7, range 25-65 years). The reason for work discontinuation was vision related in 60% of cases. Most patients (70%) reported visual field constriction as the most debilitating symptom. The authors report scleral pits and tunnels as a novel finding visible on spectral domain optical coherence tomography and ophthalmoscopy. CONCLUSION: Choroideremia is a severely debilitating disease showing a rapid decline of visual acuity generally after the age of 35, but a more gradual decline for other abnormalities.
Assuntos
Anormalidades Múltiplas/diagnóstico , Coroideremia/diagnóstico , Fenda Labial/diagnóstico , Fissura Palatina/diagnóstico , Cistos/diagnóstico , Angiofluoresceinografia/métodos , Previsões , Lábio/anormalidades , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Corioide/patologia , Progressão da Doença , Feminino , Seguimentos , Fundo de Olho , Humanos , Masculino , Pessoa de Meia-Idade , Oftalmoscopia , Retina/patologia , Estudos Retrospectivos , Campos Visuais , Adulto JovemRESUMO
PURPOSE: To describe the phenotype, long-term clinical course, clinical variability, and genotype of patients with CRB1-associated retinal dystrophies. DESIGN: Retrospective cohort study. PARTICIPANTS: Fifty-five patients with CRB1-associated retinal dystrophies from 16 families. METHODS: A medical record review of 55 patients for age at onset, medical history, initial symptoms, best-corrected visual acuity, ophthalmoscopy, fundus photography, full-field electroretinography (ffERG), Goldmann visual fields (VFs), and spectral-domain optical coherence tomography. MAIN OUTCOME MEASURES: Age at onset, visual acuity survival time, visual acuity decline rate, and electroretinography and imaging findings. RESULTS: A retinitis pigmentosa (RP) phenotype was present in 50 patients, 34 of whom were from a Dutch genetic isolate (GI), and 5 patients had a Leber congenital amaurosis phenotype. The mean follow-up time was 15.4 years (range, 0-55.5 years). For the RP patients, the median age at symptom onset was 4.0 years. In the RP group, median ages for reaching low vision, severe visual impairment, and blindness were 18, 32, and 44 years, respectively, with a visual acuity decline rate of 0.03 logarithm of the minimum angle of resolution per year. The presence of a truncating mutation did not alter the annual decline rate significantly (P = 0.75). Asymmetry in visual acuity was found in 31% of patients. The annual VF decline rate was 5% in patients from the genetic isolate, which was significantly faster than in non-GI patients (P < 0.05). Full-field electroretinography responses were extinguished in 50% of patients, were pathologically attenuated without a documented rod or cone predominance in 30% of patients, and showed a rod-cone dysfunction pattern in 20% of RP patients. Cystoid fluid collections in the macula were found in 50% of RP patients. CONCLUSIONS: Mutations in the CRB1 gene are associated with a spectrum of progressive retinal degeneration. Visual acuity survival analyses indicate that the optimal intervention window for subretinal gene therapy is within the first 2 to 3 decades of life.
Assuntos
Proteínas do Olho/genética , Estudos de Associação Genética , Amaurose Congênita de Leber/genética , Proteínas de Membrana/genética , Mutação de Sentido Incorreto , Proteínas do Tecido Nervoso/genética , Retinose Pigmentar/genética , Adolescente , Adulto , Idade de Início , Idoso , Criança , Pré-Escolar , Estudos de Coortes , Eletrorretinografia , Feminino , Seguimentos , Genótipo , Humanos , Amaurose Congênita de Leber/diagnóstico , Amaurose Congênita de Leber/fisiopatologia , Masculino , Pessoa de Meia-Idade , Oftalmoscopia , Fenótipo , Retina/fisiopatologia , Retinose Pigmentar/diagnóstico , Retinose Pigmentar/fisiopatologia , Estudos Retrospectivos , Tomografia de Coerência Óptica , Acuidade Visual/fisiologia , Campos Visuais/fisiologiaRESUMO
PURPOSE: To examine the long-term clinical course and variability in a large pedigree segregating CRB1 type autosomal recessive retinitis pigmentosa. METHODS: An observational case study of 30 patients with CRB1 type autosomal recessive retinitis pigmentosa, homozygous for the CRB1 c.3122T > C; p.(Met1041Thr) mutation from a Dutch genetically isolated population in which the CRB1 gene was originally identified. The authors evaluated medical records, analyzed a questionnaire, and performed a comprehensive ophthalmic examination, including optical coherence tomography. RESULTS: Mean follow-up was 19 years (range 0-45 years, SD 15 years). With aging, patients showed progressive visual decline, deterioration of visual fields, increasing narrowing of the anterior chamber, increased prevalence of cataract, and an increase in the amount of intraretinal pigmentations. Fifty percent of patients had a visual acuity of ≤0.3 at Age 18 and of ≤0.1 at Age 35. Electroretinogram responses were severely reduced or absent already at a young age and optical coherence tomography showed increased retinal thickness with often cystoid maculopathy at young age, and thinning of the retina and disorientation of the photoreceptor layer in the late stages. The clinical course showed considerable interindividual variability, but intraindividual similarity between both eyes was the rule. CONCLUSION: The wide and variable clinical spectrum in patients with the same CRB1 mutation supports the hypothesis that the CRB1 type autosomal recessive retinitis pigmentosa-phenotype is modulated by other factors. The clinical variability will make it harder to evaluate the effect of (upcoming) therapies for retinitis pigmentosa, although because of the intraindividual similarity between both eyes, the contralateral eye can be used as an excellent internal control.
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Proteínas do Olho/genética , Proteínas de Membrana/genética , Mutação , Proteínas do Tecido Nervoso/genética , Adolescente , Adulto , Idoso , Eletrorretinografia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Retinose Pigmentar/genética , Retinose Pigmentar/patologia , Retinose Pigmentar/fisiopatologia , Tomografia de Coerência Óptica , Transtornos da Visão/etiologia , Transtornos da Visão/fisiopatologia , Acuidade Visual/fisiologia , Campos Visuais/fisiologia , Adulto JovemRESUMO
BACKGROUND: Alzheimer's disease (AD) is the most common form of dementia. AD has a multifactorial disease etiology and is currently untreatable. Multiple genes and molecular mechanisms have been implicated in AD, including ß-amyloid deposition in the brain, neurofibrillary tangle accumulation of hyper-phosphorylated Tau, synaptic failure, oxidative stress and inflammation. Relatively little is known about the role of the blood-brain barriers, especially the blood-cerebrospinal fluid barrier (BCSFB), in AD. The BCSFB is involved in cerebrospinal fluid (CSF) production, maintenance of brain homeostasis and neurodegenerative disorders. RESULTS: Using an Agilent platform with common reference design, we performed a large scale gene expression analysis and functional annotation of the Choroid Plexus Epithelium (CPE), which forms the BCSFB. We obtained 2 groups of freshly frozen Choroid Plexus (CP) of 7 human donor brains each, with and without AD: Braak stages (0-1) and (5-6). We cut CP cryo-sections and isolated RNA from cresyl-violet stained, laser dissected CPE cells. Gene expression results were analysed with T-tests (R) and the knowledge-database Ingenuity. We found statistically significantly altered gene expression data sets, biological functions, canonical pathways, molecular networks and functionalities in AD-affected CPE. We observed specific cellular changes due to increased oxidative stress, such as the unfolded protein response, E1F2 and NRF2 signalling and the protein ubiquitin pathway. Most likely, the AD-affected BCSFB barrier becomes more permeable due to downregulation of CLDN5. Finally, our data also predicted down regulation of the glutathione mediated detoxification pathway and the urea cycle in the AD CPE, which suggest that the CPE sink action may be impaired. Remarkably, the expression of a number of genes known to be involved in AD, such as APP, PSEN1, PSEN2, TTR and CLU is moderate to high and remains stable in both healthy and affected CPE. Literature labelling of our new functional molecular networks confirmed multiple previous (molecular) observations in the AD literature and revealed many new ones. CONCLUSIONS: We conclude that CPE failure in AD exists. Combining our data with those of the literature, we propose the following chronological and overlapping chain of events: increased Aß burden on CPE; increased oxidative stress in CPE; despite continuous high expression of TTR: decreased capability of CPE to process amyloid; (pro-) inflammatory and growth factor signalling by CPE; intracellular ubiquitin involvement, remodelling of CPE tight junctions and, finally, cellular atrophy. Our data corroborates the hypothesis that increased BCSFB permeability, especially loss of selective CLDN5-mediated paracellular transport, altered CSF production and CPE sink action, as well as loss of CPE mediated macrophage recruitment contribute to the pathogenesis of AD.
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Doença de Alzheimer/genética , Plexo Corióideo/metabolismo , Perfilação da Expressão Gênica , Anotação de Sequência Molecular , Idoso , Doença de Alzheimer/patologia , Estudos de Casos e Controles , Epitélio/metabolismo , Humanos , Pessoa de Meia-IdadeRESUMO
Intraocular pressure (IOP) is a highly heritable risk factor for primary open-angle glaucoma and is the only target for current glaucoma therapy. The genetic factors which determine IOP are largely unknown. We performed a genome-wide association study for IOP in 11,972 participants from 4 independent population-based studies in The Netherlands. We replicated our findings in 7,482 participants from 4 additional cohorts from the UK, Australia, Canada, and the Wellcome Trust Case-Control Consortium 2/Blue Mountains Eye Study. IOP was significantly associated with rs11656696, located in GAS7 at 17p13.1 (p=1.4×10(-8)), and with rs7555523, located in TMCO1 at 1q24.1 (p=1.6×10(-8)). In a meta-analysis of 4 case-control studies (total Nâ=â1,432 glaucoma cases), both variants also showed evidence for association with glaucoma (p=2.4×10(-2) for rs11656696 and p=9.1×10(-4) for rs7555523). GAS7 and TMCO1 are highly expressed in the ciliary body and trabecular meshwork as well as in the lamina cribrosa, optic nerve, and retina. Both genes functionally interact with known glaucoma disease genes. These data suggest that we have identified two clinically relevant genes involved in IOP regulation.
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Estudo de Associação Genômica Ampla , Glaucoma de Ângulo Aberto/genética , Pressão Intraocular/genética , Proteínas do Tecido Nervoso/genética , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Corpo Ciliar/metabolismo , Corpo Ciliar/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nervo Óptico/metabolismo , Nervo Óptico/patologia , Polimorfismo de Nucleotídeo Único , Malha Trabecular/metabolismo , Malha Trabecular/patologiaRESUMO
PURPOSE: To describe phenotypic, genotypic, and histopathological features of inherited retinal dystrophies associated with the CRX gene (CRX-RDs). DESIGN: Retrospective multicenter cohort study including histopathology. SUBJECTS: Thirty-nine patients from 31 families with pathogenic variants in the CRX gene. METHODS: Clinical data of 152 visits were collected from medical records with a median follow-up time of 9.1 years (IQR, 3.3-15.3 years; range, 0.0-48.8 years). Histopathologic examination of the eye of a 17-year-old patient with advanced early-onset CRX-RD was performed. MAIN OUTCOME MEASURES: Visual acuity, retinal imaging, electroretinography (ERG), genotype-phenotype correlation, and histopathological examination were evaluated. RESULTS: The age at onset ranged from birth to the 8th decade of life. Median visual acuity was 1.00 logMAR (IQR, 0.69-1.48 logMAR; range, 0.06-3.00 logMAR) at a mean age of 52.0 ± 19.9 years (range, 4.6-81.9 years). Sufficient imaging was available for 36 out of 39 patients (92.3%), and all showed degeneration of at least the macula. Out of these 36 patients, 22 (61.1%) had only macular dystrophy. Another 10 patients (27.8%) had additional degeneration beyond the vascular arcades, and 4 patients (11.1%) panretinal degeneration. Two patients (5.1%) had Leber congenital amaurosis (LCA). In total, 21 different disease-associated heterozygous CRX variants were identified (10 missense, 8 frameshift, 2 deletion, 1 deletion-insertion variants). Missense variants in the CRX homeodomain and two variants deleting all functional domains, thus causing haploinsufficiency, generally tended to cause milder late-onset phenotypes. Histopathologic examination of the eye of a 17-year-old patient with advanced early-onset retinal dystrophy due to a heterozygous deletion of exons 3 and 4 of the CRX gene revealed loss of laminar integrity and widespread photoreceptor degeneration especially in the central retina, with extensive loss of photoreceptor nuclei and outer segments. CONCLUSION: This study illustrates the large clinical and genetic heterogenic spectrum of CRX-RDs, ranging from LCA to mild late-onset maculopathy resembling occult macular dystrophy. Haploinsufficiency and missense variants tended to be associated with milder phenotypes. Patients showed degeneration predominantly affecting the central retina on imaging. The histopathological findings also mirror these clinical findings and features similar to previously reported animal models of CRX-RDs.
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Purpose: To investigate the histology of Bruch's membrane (BM) calcification in pseudoxanthoma elasticum (PXE) and correlate this to clinical retinal imaging. Design: Experimental study with clinicopathological correlation. Subjects and Controls: Six postmortem eyes from 4 PXE patients and 1 comparison eye from an anonymous donor without PXE. One of the eyes had a multimodal clinical image set for comparison. Methods: Calcification was labeled with OsteSense 680RD, a fluorescent dye specific for hydroxyapatite, and visualized with confocal microscopy. Scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy (SEM-EDX) and time-of-flight secondary ion mass spectrometry (TOF-SIMs) were used to analyze the elemental and ionic composition of different anatomical locations. Findings on cadaver tissues were compared with clinical imaging of 1 PXE patient. Main Outcome Measures: The characteristics and topographical distribution of hydroxyapatite in BM in eyes with PXE were compared with the clinical manifestations of the disease. Results: Analyses of whole-mount and sectioned PXE eyes revealed an extensive, confluent OsteoSense labeling in the central and midperipheral BM, transitioning to a speckled labeling in the midperiphery. These areas corresponded to hyperreflective and isoreflective zones on clinical imaging. Scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy and TOF-SIMs analyses identified these calcifications as hydroxyapatite in BM of PXE eyes. The confluent fluorescent appearance originates from heavily calcified fibrous structures of both the collagen and the elastic layers of BM. Calcification was also detected in an aged comparison eye, but this was markedly different from PXE eyes and presented as small snowflake-like deposits in the posterior pole. Conclusions: Pseudoxanthoma elasticum eyes show extensive hydroxyapatite deposition in the inner and outer collagenous and elastic BM layers in the macula with a gradual change toward the midperiphery, which seems to correlate with the clinical phenotype. The snowflake-like calcification in BM of an aged comparison eye differed markedly from the extensive calcification in PXE. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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PURPOSE: To date, there is no standard treatment regimen for carbonic anhydrase inhibitors (CAIs) in X-linked retinoschisis (XLRS) patients. This retrospective study aims to evaluate the efficacy of CAIs on visual acuity and cystoid fluid collections (CFC) in XRLS patients in Dutch and Belgian tertiary referral centers. DESIGN: Retrospective cohort study. PARTICIPANTS: Forty-two patients with XLRS. METHODS: In total, 42 patients were enrolled. To be included, patients had to have previous treatment with an oral CAI (acetazolamide), a topical CAI (brinzolamide/dorzolamide), or a combination of an oral and a topical CAI for at least 4 consecutive weeks. We evaluated the effect of the CAI on best-corrected visual acuity (BCVA) and central foveal thickness (CFT) on OCT. MAIN OUTCOME MEASURES: Central foveal thickness and BCVA. RESULTS: The median age at the baseline visit of the patients in this cohort study was 14.7 (range, 43.6) years, with a median (interquartile range [IQR]) follow-up period of 4.0 (2.2-5.2) years. During the follow-up period, 25 patients were treated once with an oral CAI (60%), 24 patients were treated once with a topical CAI (57%), and 11 patients were treated once with a combination of both topical and oral CAI (26%). We observed a significant reduction of CFT for oral CAI by 14.37 µm per 100 mg per day (P < 0.001; 95% confidence interval [CI], -19.62 to -9.10 µm) and for topical CAI by 7.52 µm per drop per day (P = 0.017; 95% CI, -13.67 to -1.32 µm). The visual acuity changed significantly while on treatment with oral CAI by -0.0059 logMAR per 100 mg (P = 0.008; 95% CI, -0.010 to -0.0013 logMAR). Seven patients (17%) had side effects leading to treatment discontinuation. CONCLUSIONS: Our data indicate that treatment with (oral) CAI may be beneficial for short-term management of CFC in patients with XLRS. Despite a significant reduction in CFT, the change in visual acuity was modest and not of clinical significance. Nonetheless, the anatomic improvement of the central retina in these patients may be of value to create an optimal retinal condition for future potential treatment options such as gene therapy. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.
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Inibidores da Anidrase Carbônica , Retinosquise , Tomografia de Coerência Óptica , Acuidade Visual , Humanos , Inibidores da Anidrase Carbônica/administração & dosagem , Retinosquise/tratamento farmacológico , Retinosquise/diagnóstico , Retinosquise/fisiopatologia , Estudos Retrospectivos , Masculino , Tomografia de Coerência Óptica/métodos , Adulto , Adolescente , Feminino , Seguimentos , Adulto Jovem , Resultado do Tratamento , Criança , Líquido Sub-Retiniano , Pessoa de Meia-Idade , Sulfonamidas/administração & dosagem , Administração OralRESUMO
A significant number of individuals with a rare disorder such as Usher syndrome (USH) and (non-)syndromic autosomal recessive retinitis pigmentosa (arRP) remain genetically unexplained. Therefore, we assessed subjects suspected of USH2A-associated disease and no or mono-allelic USH2A variants using whole genome sequencing (WGS) followed by an improved pipeline for variant interpretation to provide a conclusive diagnosis. One hundred subjects were screened using WGS to identify causative variants in USH2A or other USH/arRP-associated genes. In addition to the existing variant interpretation pipeline, a particular focus was put on assessing splice-affecting properties of variants, both in silico and in vitro. Also structural variants were extensively addressed. For variants resulting in pseudoexon inclusion, we designed and evaluated antisense oligonucleotides (AONs) using minigene splice assays and patient-derived photoreceptor precursor cells. Biallelic variants were identified in 49 of 100 subjects, including novel splice-affecting variants and structural variants, in USH2A or arRP/USH-associated genes. Thirteen variants were shown to affect USH2A pre-mRNA splicing, including four deep-intronic USH2A variants resulting in pseudoexon inclusion, which could be corrected upon AON treatment. We have shown that WGS, combined with a thorough variant interpretation pipeline focused on assessing pre-mRNA splicing defects and structural variants, is a powerful method to provide subjects with a rare genetic condition, a (likely) conclusive genetic diagnosis. This is essential for the development of future personalized treatments and for patients to be eligible for such treatments.