RESUMO
Unlike mammals, some nonmammalian species recruit Müller glia for retinal regeneration after injury. Identifying the underlying mechanisms may help to foresee regenerative medicine strategies. Using a Xenopus model of retinitis pigmentosa, we found that Müller cells actively proliferate upon photoreceptor degeneration in old tadpoles but not in younger ones. Differences in the inflammatory microenvironment emerged as an explanation for such stage dependency. Functional analyses revealed that enhancing neuroinflammation is sufficient to trigger Müller cell proliferation, not only in young tadpoles but also in mice. In addition, we showed that microglia are absolutely required for the response of mouse Müller cells to mitogenic factors while negatively affecting their neurogenic potential. However, both cell cycle reentry and neurogenic gene expression are allowed when applying sequential pro- and anti-inflammatory treatments. This reveals that inflammation benefits Müller glia proliferation in both regenerative and nonregenerative vertebrates and highlights the importance of sequential inflammatory modulation to create a regenerative permissive microenvironment.
Assuntos
Proliferação de Células , Células Ependimogliais , Regeneração , Retina , Animais , Células Ependimogliais/metabolismo , Células Ependimogliais/patologia , Camundongos , Retina/patologia , Retina/metabolismo , Doenças Neuroinflamatórias/metabolismo , Doenças Neuroinflamatórias/patologia , Doenças Neuroinflamatórias/etiologia , Microglia/metabolismo , Microglia/patologia , Modelos Animais de Doenças , Retinose Pigmentar/patologia , Retinose Pigmentar/metabolismo , Inflamação/patologia , Inflamação/metabolismo , LarvaRESUMO
Autosomal dominant retinitis pigmentosa (AD-RP) is caused by several genes, among which RHO is one of the most investigated. This article will be focused on RHO and its role in explaining AD-RP cases in the Italian population, taking advantage of the experience of the Genomic Medicine Laboratory UILDM at the Santa Lucia Foundation IRCCS. The retrospective evaluation of the distribution of RHO variants in the Italian patients with a clinical suspicion of RP pointed out eight variants. Of them, four variants (c.632A>T, c.1040C>T, c.1030C>T, c.383_392del) were pathogenic and made it possible to confirm the diagnosis of AD-RP in nine affected patients, highlighting a lower frequency (17%) of RHO variants compared to previous studies (30-40%). In addition, this study identified four variants classified as Variants of Uncertain Significance (VUS). In conclusion, the experience of the Genomic Medicine Laboratory provides an overview of the distribution of RHO variants in the Italian population, highlighting a slightly lower frequency of these variants in our cases series compared to previous reports. However, further studies on RHO variants are essential to characterize peculiar RP phenotypes and extend the spectrum of disease associated with this gene.
Assuntos
Retinose Pigmentar , Humanos , Retinose Pigmentar/genética , Retinose Pigmentar/patologia , Itália , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Mutação , Estudos Retrospectivos , Genes Dominantes , Idoso , Rodopsina/genética , Linhagem , FenótipoRESUMO
Retinitis pigmentosa (RP) is a progressive and degenerative retinal disease resulting in severe vision loss. RP have been extensively studied for pathogenetic mechanisms and treatments. Yet there is little information about alterations of RP associated proteins in phosphodiesterase 6 beta (Pde6b) mutated model. To explore the roles of RP causing proteins, we performed a label free quantitative mass spectrometry based proteomic analysis in rd10 mouse retinas. 3737 proteins were identified at the degenerative time points in rd10 mice. 222 and 289 differentially expressed proteins (DEPs) (fold change, FC > 2, p < 0.05) were detected at 5 and 8 weeks. Based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, visual perception and phototransduction were severely affected. The downregulated DEPs were significantly enriched in cilium assembly and protein localization. 25 decreased DEPs causing autosomal recessive/dominant retinitis pigmentosa were visualized by heatmaps. Protein-protein interaction network represented 13 DEPs interacted directly with Pde6b protein. 25 DEPs causing RP were involved in phototransduction, visual perception, response to stimulus, protein localization and cilium assembly pathways. The significantly reduced expressions of DEPs were further validated by quantitative reverse transcription polymerase chain reaction (qPCR), Western blots (WB) and immunohistochemistry (IHC). This study revealed the molecular mechanisms underlying early and late stage of RP, as well as changes of RP-causing proteins.
Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 6 , Modelos Animais de Doenças , Mutação , Proteômica , Retinose Pigmentar , Animais , Nucleotídeo Cíclico Fosfodiesterase do Tipo 6/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 6/genética , Retinose Pigmentar/metabolismo , Retinose Pigmentar/genética , Retinose Pigmentar/patologia , Proteômica/métodos , Camundongos , Proteínas do Olho/metabolismo , Proteínas do Olho/genética , Degeneração Retiniana/metabolismo , Degeneração Retiniana/genética , Degeneração Retiniana/patologia , Retina/metabolismo , Retina/patologia , Mapas de Interação de Proteínas , Proteoma/metabolismoRESUMO
Retinitis pigmentosa (RP) is a genetic blinding disease with over 80 causative genes. Disease progression varies between patients with similar genetic backgrounds. We assessed the association between environment, gut microbiota, and retinal degeneration in the RP rat model Royal College of Surgeons (RCS). The rats were born and raised for two generations under specific pathogen-free (SPF, n = 69) or non-SPF conditions (n = 48). At the age of four weeks, SPF rats had significantly shorter dark-adapted a-wave and dark and light-adapted b-wave implicit times by electroretinogram (p = 0.014, p = 9.5*10-6, p = 0.009, respectively). The SPF rats had significantly less photoreceptor apoptosis at ages four, eight, and twelve weeks (all p < 0.022), significantly thicker debris zone at age 14 weeks, and smaller hypofluorescent lesions in SPF rats at ages 10-16 weeks, especially in the inferior retina. The non-SPF rats had significantly higher microbiota alpha diversity (p = 0.037) and failed to present the age-related maturation of Proteobacteria, Spirochaetes, Actinobacteria, and Bacteroidetes seen in SPF conditions. Specific microbial amplicon sequence variants were reduced in rats with more severe retinal degeneration. Our data suggest an environmental effect on retinal deterioration in RCS rats. These findings may lead to the development of novel microbiome-related interventions for retinal degeneration.
Assuntos
Modelos Animais de Doenças , Microbioma Gastrointestinal , Degeneração Retiniana , Animais , Ratos , Degeneração Retiniana/microbiologia , Degeneração Retiniana/patologia , Organismos Livres de Patógenos Específicos , Eletrorretinografia , Retinose Pigmentar/microbiologia , Retinose Pigmentar/patologia , Retina/microbiologia , Retina/patologia , Abrigo para Animais , MasculinoRESUMO
BACKGROUND: A comprehensive understanding of the genetic basis of rare diseases and their regulatory mechanisms is essential for human molecular genetics. However, the genetic mutant spectrum of pathogenic genes within the Chinese population remains underrepresented. Here, we reported previously unreported functional ABHD12 variants in two Chinese families and explored the correlation between genetic polymorphisms and phenotypes linked to PHARC syndrome. METHODS: Participants with biallelic pathogenic ABHD12 variants were recruited from the Chinese Deafness Genetics Cohort. These participants underwent whole-genome sequencing. Subsequently, a comprehensive literature review was conducted. RESULTS: Two Han Chinese families were identified, one with a compound heterozygous variant and the other with a novel homozygous variant in ABHD12. Among 65 PHARC patients, including 62 from the literature and 3 from this study, approximately 90% (57 out of 63) exhibited hearing loss, 82% (50 out of 61) had cataracts, 82% (46 out of 56) presented with retinitis pigmentosa, 79% (42 out of 53) experienced polyneuropathy, and 63% (36 out of 57) displayed ataxia. Seventeen different patterns were observed in the five main phenotypes of PHARC syndrome. A total of 33 pathogenic variants were identified in the ABHD12. Compared with other genotypes, individuals with biallelic truncating variants showed a higher incidence of polyneuropathy (p = 0.006), but no statistically significant differences were observed in the incidence of hearing loss, ataxia, retinitis pigmentosa and cataracts. CONCLUSIONS: The diagnosis of PHARC syndrome is challenging because of its genetic heterogeneity. Therefore, exploring novel variants and establishing genotype-phenotype correlations can significantly enhance gene diagnosis and genetic counseling for this complex disease.
Assuntos
Ataxia , Catarata , Estudos de Associação Genética , Monoacilglicerol Lipases , Linhagem , Fenótipo , Polineuropatias , Retinose Pigmentar , Humanos , Masculino , Feminino , Ataxia/genética , Catarata/genética , Retinose Pigmentar/genética , Retinose Pigmentar/patologia , Polineuropatias/genética , Monoacilglicerol Lipases/genética , Mutação , Adulto , Criança , Adolescente , GenótipoRESUMO
Genome analysis of individuals affected by retinitis pigmentosa (RP) identified two rare nucleotide substitutions at the same genomic location on chromosome 11 (g.61392563 [GRCh38]), 69 base pairs upstream of the start codon of the ciliopathy gene TMEM216 (c.-69G>A, c.-69G>T [GenBank: NM_001173991.3]), in individuals of South Asian and African ancestry, respectively. Genotypes included 71 homozygotes and 3 mixed heterozygotes in trans with a predicted loss-of-function allele. Haplotype analysis showed single-nucleotide variants (SNVs) common across families, suggesting ancestral alleles within the two distinct ethnic populations. Clinical phenotype analysis of 62 available individuals from 49 families indicated a similar clinical presentation with night blindness in the first decade and progressive peripheral field loss thereafter. No evident systemic ciliopathy features were noted. Functional characterization of these variants by luciferase reporter gene assay showed reduced promotor activity. Nanopore sequencing confirmed the lower transcription of the TMEM216 c.-69G>T allele in blood-derived RNA from a heterozygous carrier, and reduced expression was further recapitulated by qPCR, using both leukocytes-derived RNA of c.-69G>T homozygotes and total RNA from genome-edited hTERT-RPE1 cells carrying homozygous TMEM216 c.-69G>A. In conclusion, these variants explain a significant proportion of unsolved cases, specifically in individuals of African ancestry, suggesting that reduced TMEM216 expression might lead to abnormal ciliogenesis and photoreceptor degeneration.
Assuntos
Linhagem , Polimorfismo de Nucleotídeo Único , Retinose Pigmentar , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Adulto Jovem , Alelos , Haplótipos , Heterozigoto , Homozigoto , Proteínas de Membrana/genética , Fenótipo , Retinose Pigmentar/genética , Retinose Pigmentar/patologiaRESUMO
Retinitis pigmentosa (RP), an inherited retinal disease, affects 1,5 million people worldwide. The initial mutation-driven photoreceptor degeneration leads to chronic inflammation, characterized by Müller cell activation and upregulation of CD44. CD44 is a cell surface transmembrane glycoprotein and the primary receptor for hyaluronic acid. It is involved in many pathological processes, but little is known about CD44's retinal functions. CD44 expression is also increased in Müller cells from our Pde6bSTOP/STOP RP mouse model. To gain a more detailed understanding of CD44's role in healthy and diseased retinas, we analyzed Cd44-/- and Cd44-/-Pde6bSTOP/STOP mice, respectively. The loss of CD44 led to enhanced photoreceptor degeneration, reduced retinal function, and increased inflammatory response. To understand the underlying mechanism, we performed proteomic analysis on isolated Müller cells from Cd44-/- and Cd44-/-Pde6bSTOP/STOP retinas and identified a significant downregulation of glutamate transporter 1 (SLC1A2). This downregulation was accompanied by higher glutamate levels, suggesting impaired glutamate homeostasis. These novel findings indicate that CD44 stimulates glutamate uptake via SLC1A2 in Müller cells, which in turn, supports photoreceptor survival and function.
Assuntos
Células Ependimogliais , Receptores de Hialuronatos , Retinose Pigmentar , Transdução de Sinais , Animais , Receptores de Hialuronatos/metabolismo , Receptores de Hialuronatos/genética , Camundongos , Células Ependimogliais/metabolismo , Transdução de Sinais/fisiologia , Retinose Pigmentar/metabolismo , Retinose Pigmentar/patologia , Retinose Pigmentar/genética , Camundongos Knockout , Camundongos Endogâmicos C57BL , Células Fotorreceptoras de Vertebrados/metabolismo , Sobrevivência Celular/fisiologia , Camundongos Transgênicos , Retina/metabolismo , Retina/patologiaRESUMO
Purpose: To examine whether the extension of retinal pigment epithelium (RPE) and outer retinal atrophy (RORA) and various other morphofunctional parameters correlate with the genetic assessment and severity of retinitis pigmentosa (RP). Methods: Thirty-eight patients (76 eyes) with RP were prospectively enrolled and underwent full ophthalmic examination, including visual field testing, full-field electroretinography (ERG), and optical coherence tomography angiography. The severity of the disease was calculated using the RP stage scoring system, and the area of RORA was assessed using the automatically calculated area of sub-RPE illumination. Blood or saliva samples were collected from subjects, and DNA extraction was performed to evaluate genetic mutations and nucleotide and amino acid variations. Results: There was a statistically significant correlation between the extent of RORA and patient age, best-corrected visual acuity, ellipsoid zone extension, and disease severity in both eyes (each, P < 0.05). In contrast, RORA did not correlate with either the visual field or the ERG amplitude. Cumulative score and grade severity were both significantly correlated with superficial and deep capillary plexus density (both, P < 0.001) in both eyes. Evaluating RORA, we found genes with an overall less severe phenotype, such as EYS, PCDH15, and PRPF31, and those with a worse phenotype, such as RPGR. Conclusions: The correlation of RORA with structural, functional, and genetic assessment in RP disease leads us to consider RORA as a potential biomarker for prediction of disease stage. Multicenter studies are needed to confirm our findings. Translational Relevance: The morphofunctional and genetic correlations suggest a role for RORA in RP diagnosis and follow-up.
Assuntos
Eletrorretinografia , Epitélio Pigmentado da Retina , Retinose Pigmentar , Tomografia de Coerência Óptica , Acuidade Visual , Humanos , Retinose Pigmentar/genética , Retinose Pigmentar/patologia , Retinose Pigmentar/fisiopatologia , Retinose Pigmentar/diagnóstico por imagem , Retinose Pigmentar/diagnóstico , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Estudos Prospectivos , Epitélio Pigmentado da Retina/patologia , Epitélio Pigmentado da Retina/diagnóstico por imagem , Adulto Jovem , Idoso , Campos Visuais , Angiofluoresceinografia , Mutação , Proteínas do Olho/genética , Índice de Gravidade de Doença , Testes de Campo VisualRESUMO
Retinitis Pigmentosa is a leading cause of severe vision loss. Retinitis Pigmentosa can present with a broad range of phenotypes impacted by disease age of onset, severity, and progression. This variation is influenced both by different gene mutations as well as unique variants within the same gene. Mutations in the nuclear hormone receptor 2 family e, member 3 are associated with several forms of retinal degeneration, including Retinitis Pigmentosa. In our previous studies we demonstrated that subretinal administration of one Nr2e3 dose attenuated retinal degeneration in rd7 mice for at least 3 months. Here we expand the studies to evaluate the efficacy and longitudinal impact of the NR2E3 therapeutic by examining three different doses administered at early or intermediate stages of retinal degeneration in the rd7 mice. Our study revealed retinal morphology was significantly improved 6 months post for all doses in the early-stage treatment groups and for the low and mid doses in the intermediate stage treatment groups. Similarly, photoreceptor function was significantly improved in the early stage for all doses and intermediate stage low and mid dose groups 6 months post treatment. This study demonstrated efficacy in multiple doses of NR2E3 therapy.
Assuntos
Modelos Animais de Doenças , Receptores Nucleares Órfãos , Degeneração Retiniana , Animais , Camundongos , Degeneração Retiniana/genética , Degeneração Retiniana/patologia , Degeneração Retiniana/tratamento farmacológico , Receptores Nucleares Órfãos/genética , Receptores Nucleares Órfãos/metabolismo , Retinose Pigmentar/genética , Retinose Pigmentar/patologia , Retinose Pigmentar/tratamento farmacológico , Retina/patologia , Retina/metabolismo , Retina/efeitos dos fármacosRESUMO
Inherited retinal diseases, which include retinitis pigmentosa, are a family of genetic disorders characterized by gradual rod-cone degeneration and vision loss, without effective pharmacological treatments. Experimental approaches aim to delay disease progression, supporting cones' survival, crucial for human vision. Histone deacetylases (HDACs) mediate the activation of epigenetic and nonepigenetic pathways that modulate cone degeneration in RP mouse models. We developed new HDAC inhibitors (5a-p), typified by a tetrahydro-γ-carboline scaffold, characterized by high HDAC6 inhibition potency with balanced physicochemical properties for in vivo studies. Compound 5d (repistat, IC50 HDAC6 = 6.32 nM) increased the levels of acetylated α-tubulin compared to histone H3 in ARPE-19 and 661W cells. 5d promoted vision rescue in the atp6v0e1-/- zebrafish model of photoreceptor dysfunction. A single intravitreal injection of 5d in the rd10 mouse model of RP supported morphological and functional preservation of cone cells and maintenance of the retinal pigment epithelium array.
Assuntos
Inibidores de Histona Desacetilases , Células Fotorreceptoras Retinianas Cones , Peixe-Zebra , Animais , Células Fotorreceptoras Retinianas Cones/metabolismo , Células Fotorreceptoras Retinianas Cones/efeitos dos fármacos , Células Fotorreceptoras Retinianas Cones/patologia , Humanos , Camundongos , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/uso terapêutico , Retinose Pigmentar/metabolismo , Retinose Pigmentar/tratamento farmacológico , Retinose Pigmentar/patologia , Histona Desacetilases/metabolismo , Desacetilase 6 de Histona/antagonistas & inibidores , Desacetilase 6 de Histona/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Relação Estrutura-AtividadeRESUMO
Transient receptor potential canonical (TRPC) channels are calcium channels with diverse expression profiles and physiological implications in the retina. Neurons and glial cells of rat retinas with photoreceptor degeneration caused by retinitis pigmentosa (RP) exhibit basal calcium levels that are above those detected in healthy retinas. Inner retinal cells are the last to degenerate and are responsible for maintaining the activity of the visual cortex, even after complete loss of photoreceptors. We considered the possibility that TRPC1 and TRPC5 channels might be associated with both the high calcium levels and the delay in inner retinal degeneration. TRPC1 is known to mediate protective effects in neurodegenerative processes while TRPC5 promotes cell death. In order to comprehend the implications of these channels in RP, the co-localization and subsequent physical interaction between TRPC1 and TRPC5 in healthy retina (Sprague-Dawley rats) and degenerating (P23H-1, a model of RP) retina were detected by immunofluorescence and proximity ligation assays. There was an overlapping signal in the innermost retina of all animals where TRPC1 and TRPC5 physically interacted. This interaction increased significantly as photoreceptor loss progressed. Both channels function as TRPC1/5 heteromers in the healthy and damaged retina, with a marked function of TRPC1 in response to retinal degenerative mechanisms. Furthermore, our findings support that TRPC5 channels also function in partnership with STIM1 in Müller and retinal ganglion cells. These results suggest that an increase in TRPC1/5 heteromers may contribute to the slowing of the degeneration of the inner retina during the outer retinal degeneration.
Assuntos
Ratos Sprague-Dawley , Degeneração Retiniana , Canais de Cátion TRPC , Animais , Canais de Cátion TRPC/metabolismo , Ratos , Degeneração Retiniana/metabolismo , Degeneração Retiniana/patologia , Retina/metabolismo , Retina/patologia , Células Fotorreceptoras de Vertebrados/metabolismo , Células Fotorreceptoras de Vertebrados/patologia , Retinose Pigmentar/metabolismo , Retinose Pigmentar/patologia , Retinose Pigmentar/genética , Modelos Animais de DoençasRESUMO
The retina, a tissue of the central nervous system, is vital for vision as its photoreceptors capture light and transform it into electrical signals, which are further processed before they are sent to the brain to be interpreted as images. The retina is unique in that it is continuously exposed to light and has the highest metabolic rate and demand for energy amongst all the tissues in the body. Consequently, the retina is very susceptible to oxidative stress. VDAC, a pore in the outer membrane of mitochondria, shuttles metabolites between mitochondria and the cytosol and normally protects cells from oxidative damage, but when a cell's integrity is greatly compromised it initiates cell death. There are three isoforms of VDAC, and existing evidence indicates that all three are expressed in the retina. However, their precise localization and function in each cell type is unknown. It appears that most retinal cells express substantial amounts of VDAC2 and VDAC3, presumably to protect them from oxidative stress. Photoreceptors express VDAC2, HK2, and PKM2-key proteins in the Warburg pathway that also protect these cells. Consistent with its role in initiating cell death, VDAC is overexpressed in the retinal degenerative diseases retinitis pigmentosa, age related macular degeneration (AMD), and glaucoma. Treatment with antioxidants or inhibiting VDAC oligomerization reduced its expression and improved cell survival. Thus, VDAC may be a promising therapeutic candidate for the treatment of these diseases.
Assuntos
Retina , Canais de Ânion Dependentes de Voltagem , Humanos , Canais de Ânion Dependentes de Voltagem/metabolismo , Retina/metabolismo , Animais , Estresse Oxidativo , Doenças Retinianas/metabolismo , Doenças Retinianas/patologia , Mitocôndrias/metabolismo , Retinose Pigmentar/metabolismo , Retinose Pigmentar/patologiaRESUMO
Mutations in the gene SCAPER (S phase Cyclin A-Associated Protein residing in the Endoplasmic Reticulum) have recently been associated with retinitis pigmentosa (RP) and intellectual disability (ID). In 2011, a possible involvement of SCAPER in human diseases was discovered for the first time due to the identification of a homozygous mutation causing ID in an Iranian family. Later, five studies were published in 2019 that described patients with autosomal recessive syndromic retinitis pigmentosa (arRP) accompanied by ID and attention-deficit/hyperactivity disorder (ADHD). This present study describes three patients from an Arab consanguineous family in Israel with similar clinical features of the SCAPER syndrome. In addition, new manifestations of ocular symptoms, nystagmus, glaucoma, and elevator palsy, were observed. Genetic testing of the patients and both parents via whole-exome sequencing revealed the homozygous mutation c.2023-2A>G in SCAPER. Phenotypic and genotypic descriptions for all available cases described in the literature including our current three cases (37 cases) were carried out, in addition to a bioinformatics analysis for all the genetic variants that was undertaken. Our study confirms and extends the clinical manifestations of SCAPER-related disorders.
Assuntos
Biologia Computacional , Deficiência Intelectual , Mutação , Linhagem , Fenótipo , Retinose Pigmentar , Adolescente , Adulto , Feminino , Humanos , Proteínas de Transporte/genética , Biologia Computacional/métodos , Consanguinidade , Sequenciamento do Exoma , Genes Recessivos , Homozigoto , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Peptídeos e Proteínas de Sinalização Intercelular , Retinose Pigmentar/genética , Retinose Pigmentar/patologiaRESUMO
Retinitis pigmentosa (RP) is a heterogeneous inherited retinal disorder. Mutations in KIZ cause autosomal recessive (AR) RP. We aimed to characterize the genotype, expression pattern, and phenotype in a large cohort of KIZ cases. Sanger and whole exome sequencing were used to identify the KIZ variants. Medical records were reviewed and analyzed. Thirty-one patients with biallelic KIZ mutations were identified: 28 homozygous for c.226C>T (p.R76*), 2 compound heterozygous for p.R76* and c.3G>A (p.M1?), and one homozygous for c.247C>T (p.R83*). c.226C>T is a founder mutation among patients of Jewish descent. The clinical parameters were less severe in KIZ compared to DHDDS and FAM161A cases. RT-PCR analysis in fibroblast cells revealed the presence of four different transcripts in both WT and mutant samples with a lower percentage of the WT transcript in patients. Sequence analysis identified an exonic sequence enhancer (ESE) that includes the c.226 position which is affected by the mutation. KIZ mutations are an uncommon cause of IRD worldwide but are not rare among Ashkenazi Jews. Our data indicate that p.R76* affect an ESE which in turn results in the pronounced skipping of exon 3. Therefore, RNA-based therapies might show low efficacy since the mutant transcripts are spliced.
Assuntos
Mutação , Retinose Pigmentar , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sequenciamento do Exoma/métodos , Proteínas do Olho/genética , Judeus/genética , Linhagem , Fenótipo , Retinose Pigmentar/genética , Retinose Pigmentar/patologiaRESUMO
Mutations in the eyes shut homolog (EYS) gene are one of the common causes of autosomal recessive retinitis pigmentosa (RP). The lack of suitable animal models hampers progress understanding of the disease mechanism and drug development. This study reported the reprogramming of CD34+ hematopoietic stem/progenitor cells from a patient with compound heterozygous EYS mutations (c.6416 G > A and c.7228 + 1 G > A) into the induced pluripotent stem cell line, MUi038-A, using non-integrating vectors. The MUi038-A demonstrates pluripotency, tri-lineage differentiation potential, and a normal karyotype, offering a valuable model for studying the mechanism of EYS-related RP and new therapeutic development.
Assuntos
Proteínas do Olho , Células-Tronco Pluripotentes Induzidas , Retinose Pigmentar , Humanos , Retinose Pigmentar/patologia , Retinose Pigmentar/genética , Retinose Pigmentar/metabolismo , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Linhagem Celular , Diferenciação Celular , MutaçãoRESUMO
The aim of this paper is to investigate whether a multifractal analysis can be applied to study choroidal blood vessels and help ophthalmologists in the early diagnosis of retinitis pigmentosa (RP). In a case study, we used spectral domain optical coherence tomography (SDOCT), which is a noninvasive and highly sensitive imaging technique of the retina and choroid. The image of a choroidal branching pattern can be regarded as a multifractal. Therefore, we calculated the generalized Renyi point-centered dimensions, which are considered a measure of the inhomogeneity of data, to prove that it increases in patients with RP as compared to those in the control group.
Assuntos
Corioide , Retinose Pigmentar , Tomografia de Coerência Óptica , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Corioide/diagnóstico por imagem , Corioide/patologia , Fractais , Retinose Pigmentar/diagnóstico por imagem , Retinose Pigmentar/patologia , Tomografia de Coerência Óptica/métodosRESUMO
Rhodopsin mislocalization encompasses various blind conditions. Rhodopsin mislocalization is the primary factor leading to rod photoreceptor dysfunction and degeneration in autosomal dominant retinitis pigmentosa (adRP) caused by class I mutations. In this study, we report a new knock-in mouse model that harbors a class I Q344X mutation in the endogenous rhodopsin gene, which causes rod photoreceptor degeneration in an autosomal dominant pattern. In RhoQ344X/+ mice, mRNA transcripts from the wild-type (Rho) and RhoQ344X mutant rhodopsin alleles are expressed at equal levels. However, the amount of RHOQ344X mutant protein is 2.7 times lower than that of wild-type rhodopsin, a finding consistent with the rapid degradation of the mutant protein. Immunofluorescence microscopy indicates that RHOQ344X is mislocalized to the inner segment and outer nuclear layers of rod photoreceptors in both RhoQ344X/+ and RhoQ344X/Q344X mice, confirming the essential role of the C-terminal VxPx motif in promoting OS delivery of rhodopsin. The mislocalization of RHOQ344X is associated with the concurrent mislocalization of wild-type rhodopsin in RhoQ344X/+ mice. To understand the global changes in proteostasis, we conducted quantitative proteomics analysis and found attenuated expression of rod-specific OS membrane proteins accompanying reduced expression of ciliopathy causative gene products, including constituents of BBSome and axonemal dynein subunit. Those studies unveil a novel negative feedback regulation involving ciliopathy-associated proteins. In this process, a defect in the trafficking signal leads to a reduced quantity of the trafficking apparatus, culminating in a widespread reduction in the transport of ciliary proteins.
Assuntos
Modelos Animais de Doenças , Técnicas de Introdução de Genes , Células Fotorreceptoras Retinianas Bastonetes , Retinose Pigmentar , Rodopsina , Animais , Rodopsina/metabolismo , Rodopsina/genética , Retinose Pigmentar/metabolismo , Retinose Pigmentar/genética , Retinose Pigmentar/patologia , Camundongos , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Células Fotorreceptoras Retinianas Bastonetes/patologia , Cílios/metabolismo , Cílios/patologiaRESUMO
In this study, N-Methyl-N-nitrosourea (MNU) was intraperitoneally injected to construct a mouse retinitis pigmentosa (RP) model to evaluate the protective effect of chitosan and ß-carotene on RP. The results demonstrated that chitosan synergized with ß-carotene significantly reduced retinal histopathological structural damage in RP mice. The co-treatment group of ß-carotene and chitosan restored the retinal thickness and outer nuclear layer thickness better than the group treated with the two alone, and the thickness reached the normal level. The content of ß-carotene and retinoids in the liver of chitosan and ß-carotene co-treated group increased by 46.75 % and 20.69 %, respectively, compared to the ß-carotene group. Chitosan and ß-carotene supplement suppressed the expressions of Bax, Calpain2, Caspase3, NF-κB, TNF-α, IL-6, and IL-1ß, and promoted the up-regulation of Bcl2. Chitosan and ß-carotene interventions remarkably contributed to the content of SCFAs and enhanced the abundance of Ruminococcaceae, Rikenellaceae, Odoribacteraceae and Helicobacteraceae. Correlation analysis demonstrated a strong association between gut microbiota and improvement in retinitis pigmentosa. This study will provide a reference for the study of the gut-eye axis.
Assuntos
Quitosana , Metilnitrosoureia , Retinose Pigmentar , beta Caroteno , Animais , beta Caroteno/farmacologia , Quitosana/farmacologia , Quitosana/química , Retinose Pigmentar/tratamento farmacológico , Retinose Pigmentar/metabolismo , Retinose Pigmentar/patologia , Camundongos , Sinergismo Farmacológico , Retina/efeitos dos fármacos , Retina/metabolismo , Retina/patologia , Modelos Animais de Doenças , Microbioma Gastrointestinal/efeitos dos fármacos , Masculino , Retinoides/farmacologia , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/metabolismoRESUMO
Retinitis pigmentosa is a group of genetically determined retinal dystrophies characterized by primary photoreceptor apoptosis and can occur in isolated or syndromic conditions. This study reviewed the clinical data of 15 patients with syndromic retinitis pigmentosa from a Rare Disease Reference Center in Brazil and the results of their next-generation sequencing tests. Five males and ten females participated, with the mean ages for ocular disease onset, fundoscopic diagnosis, and molecular evaluation being 9, 19, and 29 years, respectively. Bardet-Biedl syndrome (n = 5) and Usher syndrome (n = 3) were the most frequent diagnoses, followed by other rare conditions. Among the patients, fourteen completed molecular studies, with three negative results and eleven revealing findings in known genes, including novel variants in MKKS (c.432_435del, p.Phe144Leufs*14), USH2A (c.(7301+1_7302-1)_(9369+1_9370-1)del), and CEP250 (c.5383dup, p.Glu1795Glyfs*13, and c.5050del, p.Asp1684Thrfs*9). Except for Kearn-Sayre, all presented an autosomal recessive inheritance pattern with 64% homozygosity results. The long gap between symptom onset and diagnosis highlights the diagnostic challenges faced by the patients. This study reaffirms the clinical heterogeneity of syndromic retinitis pigmentosa and underscores the pivotal role of molecular analysis in advancing our understanding of these diseases.
Assuntos
Retinose Pigmentar , Humanos , Retinose Pigmentar/genética , Retinose Pigmentar/patologia , Retinose Pigmentar/diagnóstico , Masculino , Feminino , Adulto , Adolescente , Criança , Adulto Jovem , Síndromes de Usher/genética , Síndromes de Usher/patologia , Síndromes de Usher/diagnóstico , Brasil/epidemiologia , Pessoa de Meia-Idade , Sequenciamento de Nucleotídeos em Larga Escala , Síndrome de Bardet-Biedl/genética , MutaçãoRESUMO
The endoplasmic reticulum (ER) plays an indispensable role in cellular processes, including maintenance of calcium homeostasis, and protein folding, synthesized and processing. Disruptions in these processes leading to ER stress and the accumulation of misfolded proteins can instigate the unfolded protein response (UPR), culminating in either restoration of balanced proteostasis or apoptosis. A key player in this intricate balance is CLCC1, an ER-resident chloride channel, whose essential role extends to retinal development, regulation of ER stress, and UPR. The importance of CLCC1 is further underscored by its interaction with proteins localized to mitochondria-associated endoplasmic reticulum membranes (MAMs), where it participates in UPR induction by MAM proteins. In previous research, we identified a p.(Asp25Glu) pathogenic CLCC1 variant associated with retinitis pigmentosa (RP) (CLCC1 hg38 NC_000001.11; NM_001048210.3, c.75C > A; UniprotKB Q96S66). In attempt to decipher the impact of this variant function, we leveraged liquid chromatography-mass spectrometry (LC-MS) to identify likely CLCC1-interacting proteins. We discovered that the CLCC1 interactome is substantially composed of proteins that localize to ER compartments and that the Asp25Glu variant results in noticeable loss and gain of specific protein interactors. Intriguingly, the analysis suggests that the CLCC1Asp25Glu mutant protein exhibits a propensity for increased interactions with cytoplasmic proteins compared to its wild-type counterpart. To corroborate our LC-MS data, we further scrutinized two novel CLCC1 interactors, Calnexin and SigmaR1, chaperone proteins that localize to the ER and MAMs. Through microscopy, we demonstrate that CLCC1 co-localizes with both proteins, thereby validating our initial findings. Moreover, our results reveal that CLCC1 co-localizes with SigmaR1 not merely at the ER, but also at MAMs. These findings reinforce the notion of CLCC1 interacting with MAM proteins at the ER-mitochondria interface, setting the stage for further exploration into how these interactions impact ER or mitochondria function and lead to retinal degenerative disease when impaired.