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International Journal of Molecular... Apr 2022Retinitis pigmentosa (RP) is genetically heterogeneous retinopathy caused by photoreceptor cell death and retinal pigment epithelial atrophy that eventually results in... (Review)
Review
Retinitis pigmentosa (RP) is genetically heterogeneous retinopathy caused by photoreceptor cell death and retinal pigment epithelial atrophy that eventually results in blindness in bilateral eyes. Various photoreceptor cell death types and pathological phenotypic changes that have been disclosed in RP demand in-depth research of its pathogenic mechanism that may account for inter-patient heterogeneous responses to mainstream drug treatment. As the primary method for studying the genetic characteristics of RP, molecular biology has been widely used in disease diagnosis and clinical trials. Current technology iterations, such as gene therapy, stem cell therapy, and optogenetics, are advancing towards precise diagnosis and clinical applications. Specifically, technologies, such as effective delivery vectors, CRISPR/Cas9 technology, and iPSC-based cell transplantation, hasten the pace of personalized precision medicine in RP. The combination of conventional therapy and state-of-the-art medication is promising in revolutionizing RP treatment strategies. This article provides an overview of the latest research on the pathogenesis, diagnosis, and treatment of retinitis pigmentosa, aiming for a convenient reference of what has been achieved so far.
Topics: Genetic Therapy; Humans; Induced Pluripotent Stem Cells; Pathology, Molecular; Photoreceptor Cells; Retinitis Pigmentosa
PubMed: 35563274
DOI: 10.3390/ijms23094883 -
Medecine Sciences : M/S 2020Retinitis pigmentosa is the most common blinding inherited retinal dystrophy. Gene therapy is a burgeoning revolutionary approach that paves the way to treatment of... (Review)
Review
Retinitis pigmentosa is the most common blinding inherited retinal dystrophy. Gene therapy is a burgeoning revolutionary approach that paves the way to treatment of previously incurable diseases. At the end of 2017 and 2018, a gene therapy, Luxturna, obtained a marketing authorization by respectively the FDA (Food and Drug Administration) and the EMA (European Medicines Agency). This treatment, with proven efficacy, is available to patients with Leber congenital amaurosis and retinitis pigmentosa associated with bi-allelic mutations of the RPE 65 gene. In this paper, we present the current advances in gene therapy for retinitis pigmentosa and discuss the technological, economic and ethical challenges to overcome for gene therapy to improve medical practices.
Topics: Genetic Association Studies; Genetic Therapy; Humans; Mutation; Practice Patterns, Physicians'; Quality Improvement; Retinitis Pigmentosa
PubMed: 32614312
DOI: 10.1051/medsci/2020095 -
Progress in Retinal and Eye Research Sep 2018Retinitis pigmentosa (RP) encompasses a group of inherited retinal dystrophies characterized by the primary degeneration of rod and cone photoreceptors. RP is a leading... (Review)
Review
Retinitis pigmentosa (RP) encompasses a group of inherited retinal dystrophies characterized by the primary degeneration of rod and cone photoreceptors. RP is a leading cause of visual disability, with a worldwide prevalence of 1:4000. Although the majority of RP cases are non-syndromic, 20-30% of patients with RP also have an associated non-ocular condition. RP typically manifests with night blindness in adolescence, followed by concentric visual field loss, reflecting the principal dysfunction of rod photoreceptors; central vision loss occurs later in life due to cone dysfunction. Photoreceptor function measured with an electroretinogram is markedly reduced or even absent. Optical coherence tomography (OCT) and fundus autofluorescence (FAF) imaging show a progressive loss of outer retinal layers and altered lipofuscin distribution in a characteristic pattern. Over the past three decades, a vast number of disease-causing variants in more than 80 genes have been associated with non-syndromic RP. The wide heterogeneity of RP makes it challenging to describe the clinical findings and pathogenesis. In this review, we provide a comprehensive overview of the clinical characteristics of RP specific to genetically defined patient subsets. We supply a unique atlas with color fundus photographs of most RP subtypes, and we discuss the relevant considerations with respect to differential diagnoses. In addition, we discuss the genes involved in the pathogenesis of RP, as well as the retinal processes that are affected by pathogenic mutations in these genes. Finally, we review management strategies for patients with RP, including counseling, visual rehabilitation, and current and emerging therapeutic options.
Topics: Diagnosis, Differential; Diagnostic Techniques, Ophthalmological; Electroretinography; Eye Proteins; Genotype; Humans; Mutation; Night Blindness; Phenotype; Retinal Cone Photoreceptor Cells; Retinal Rod Photoreceptor Cells; Retinitis Pigmentosa; Tomography, Optical Coherence; Vision Disorders
PubMed: 29597005
DOI: 10.1016/j.preteyeres.2018.03.005 -
Revue Medicale de Liege Feb 2020Retinitis pigmentosa is the most frequent hereditary dystrophy of the retina, with a global prevalence of 1/4.000. The underlying mechanism involves progressive loss,...
Retinitis pigmentosa is the most frequent hereditary dystrophy of the retina, with a global prevalence of 1/4.000. The underlying mechanism involves progressive loss, first of the rod photoreceptor cells, followed by the cone photoreceptor cells. Finally, complete blindness may occur. Genetic transmission is known but most cases are sporadic. Few effective treatments exist nowadays and hence regular follow-up is required in a revalidation center.
Topics: Humans; Retina; Retinal Cone Photoreceptor Cells; Retinal Rod Photoreceptor Cells; Retinitis Pigmentosa
PubMed: 32030928
DOI: No ID Found -
Investigative Ophthalmology & Visual... Feb 2021To describe the molecular epidemiology of nonsyndromic retinitis pigmentosa (RP) and Usher syndrome (US) in Italian patients.
PURPOSE
To describe the molecular epidemiology of nonsyndromic retinitis pigmentosa (RP) and Usher syndrome (US) in Italian patients.
METHODS
A total of 591 probands (315 with family history and 276 sporadics) were analyzed. For 155 of them, we performed a family segregation study, considering a total of 382 relatives. Probands were analyzed by a customized multigene panel approach. Sanger sequencing was used to validate all genetic variants and to perform family segregation studies. Copy number variants of selected genes were analyzed by multiplex ligation-dependent probe amplification. Four patients who tested negative to targeted next-generation sequencing analysis underwent clinical exome sequencing.
RESULTS
The mean diagnostic yield of molecular testing among patients with a family history of retinal disorders was 55.2% while the diagnostic yield including sporadic cases was 37.4%. We found 468 potentially pathogenic variants, 147 of which were unpublished, in 308 probands and 66 relatives. Mean ages of onset of the different classes of RP were autosomal dominant RP, 19.3 ± 12.6 years; autosomal recessive RP, 23.2 ± 16.6 years; X-linked RP, 13.9 ± 9.9 years; and Usher syndrome, 18.9 ± 9.5 years. We reported potential new genotype-phenotype correlations in three probands, two revealed by TruSight One testing. All three probands showed isolated RP caused by biallelic variants in genes usually associated with syndromes such as PERCHING and Senior-Loken or with retinal dystrophy, iris coloboma, and comedogenic acne syndrome.
CONCLUSIONS
This is the largest molecular study of Italian patients with RP in the literature, thus reflecting the epidemiology of the disease in Italy with reasonable accuracy.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; DNA Mutational Analysis; Extracellular Matrix Proteins; Female; Follow-Up Studies; Genetic Association Studies; Genetic Testing; Humans; Incidence; Italy; Male; Middle Aged; Molecular Epidemiology; Mutation; Pedigree; Phenotype; Retinitis Pigmentosa; Retrospective Studies; Usher Syndromes; Exome Sequencing; Young Adult
PubMed: 33576794
DOI: 10.1167/iovs.62.2.13 -
Nature Medicine Mar 2020Retinal gene therapy has shown great promise in treating retinitis pigmentosa (RP), a primary photoreceptor degeneration that leads to severe sight loss in young people....
Retinal gene therapy has shown great promise in treating retinitis pigmentosa (RP), a primary photoreceptor degeneration that leads to severe sight loss in young people. In the present study, we report the first-in-human phase 1/2, dose-escalation clinical trial for X-linked RP caused by mutations in the RP GTPase regulator (RPGR) gene in 18 patients over up to 6 months of follow-up (https://clinicaltrials.gov/: NCT03116113). The primary outcome of the study was safety, and secondary outcomes included visual acuity, microperimetry and central retinal thickness. Apart from steroid-responsive subretinal inflammation in patients at the higher doses, there were no notable safety concerns after subretinal delivery of an adeno-associated viral vector encoding codon-optimized human RPGR (AAV8-coRPGR), meeting the pre-specified primary endpoint. Visual field improvements beginning at 1 month and maintained to the last point of follow-up were observed in six patients.
Topics: Adult; Eye Proteins; Genetic Diseases, X-Linked; Genetic Therapy; Humans; Middle Aged; Mutation; Retina; Retinitis Pigmentosa; Young Adult
PubMed: 32094925
DOI: 10.1038/s41591-020-0763-1 -
Genes Apr 2021We conducted targeted next-generation sequencing (TGS) and/or whole exome sequencing (WES) to assess the genetic profiles of clinically suspected retinitis pigmentosa... (Observational Study)
Observational Study
We conducted targeted next-generation sequencing (TGS) and/or whole exome sequencing (WES) to assess the genetic profiles of clinically suspected retinitis pigmentosa (RP) in the Korean population. A cohort of 279 unrelated Korean patients with clinically diagnosed RP and available family members underwent molecular analyses using TGS consisting of 88 RP-causing genes and/or WES with clinical variant interpretation. The combined genetic tests (TGS and/or WES) found a mutation in the 44 RP-causing genes and seven inherited retinal disease (IRD)-causing genes, and the total mutation detection rate was 57%. The mutation detection rate was higher in patients who experienced visual deterioration at a younger age (75.4%, age of symptom onset under 10 years) and who had a family history of RP (70.7%). The most common causative genes were (8.2%), (6.8%), and (4.7%), but mutations were dispersed among the 51 RP/IRD genes generally. Meanwhile, the mutation was the most common in patients experiencing initial symptoms in their first decade, in their second to third decades, and in their fifth decades and older. Of note, WES revealed some unexpected genotypes: , , , , , , and , which were verified by ophthalmological re-phenotyping.
Topics: Adult; Aged; Cyclic Nucleotide Phosphodiesterases, Type 6; Extracellular Matrix Proteins; Eye Proteins; Female; Gene Frequency; Genotype; Humans; Male; Middle Aged; Republic of Korea; Retinitis Pigmentosa
PubMed: 33946315
DOI: 10.3390/genes12050675 -
Developmental Dynamics : An Official... Sep 2020The spliceosome is a complex of RNA and proteins that function together to identify intron-exon junctions in precursor messenger-RNAs, splice out the introns, and join... (Review)
Review
The spliceosome is a complex of RNA and proteins that function together to identify intron-exon junctions in precursor messenger-RNAs, splice out the introns, and join the flanking exons. Mutations in any one of the genes encoding the proteins that make up the spliceosome may result in diseases known as spliceosomopathies. While the spliceosome is active in all cell types, with the majority of the proteins presumably expressed ubiquitously, spliceosomopathies tend to be tissue-specific as a result of germ line or somatic mutations, with phenotypes affecting primarily the retina in retinitis pigmentosa, hematopoietic lineages in myelodysplastic syndromes, or the craniofacial skeleton in mandibulofacial dysostosis. Here we describe the major spliceosomopathies, review the proposed mechanisms underlying retinitis pigmentosa and myelodysplastic syndromes, and discuss how this knowledge may inform our understanding of craniofacial spliceosomopathies.
Topics: Animals; Humans; Mandibulofacial Dysostosis; Mutation; Myelodysplastic Syndromes; Retinitis Pigmentosa; Spliceosomes
PubMed: 32506634
DOI: 10.1002/dvdy.214 -
Molecular Genetics & Genomic Medicine Mar 2020This study aimed to identify the gene variants and molecular etiologies in 76 unrelated Chinese families with retinitis pigmentosa (RP).
BACKGROUND
This study aimed to identify the gene variants and molecular etiologies in 76 unrelated Chinese families with retinitis pigmentosa (RP).
METHODS
In total, 76 families with syndromic or nonsyndromic RP, diagnosed on the basis of clinical manifestations, were recruited for this study. Genomic DNA samples from probands were analyzed by targeted panels or whole exome sequencing. Bioinformatics analysis, Sanger sequencing, and available family member segregation were used to validate sequencing data and confirm the identities of disease-causing genes.
RESULTS
The participants enrolled in the study included 62 families that exhibited nonsyndromic RP, 13 that exhibited Usher syndrome, and one that exhibited Bardet-Biedl syndrome. We found that 43 families (56.6%) had disease-causing variants in 15 genes, including RHO, PRPF31, USH2A, CLRN1, BBS2, CYP4V2, EYS, RPE65, CNGA1, CNGB1, PDE6B, MERTK, RP1, RP2, and RPGR; moreover, 12 families (15.8%) had only one heterozygous variant in seven autosomal recessive RP genes, including USH2A, EYS, CLRN1, CERKL, RP1, CRB1, and SLC7A14. We did not detect any variants in the remaining 21 families (27.6%). We also identified 67 potential pathogenic gene variants, of which 24 were novel.
CONCLUSION
The gene variants identified in this study expand the variant frequency and spectrum of RP genes; moreover, the identification of these variants supplies foundational clues for future RP diagnosis and therapy.
Topics: Adolescent; Adult; Child; Child, Preschool; Female; Genetic Testing; Humans; Male; Middle Aged; Retinitis Pigmentosa; Exome Sequencing
PubMed: 31960602
DOI: 10.1002/mgg3.1131 -
Stem Cell Research & Therapy Aug 2022Retinitis pigmentosa is a rod-cone degenerative disease that induces irreversible vision loss. This study probed the protective capacity of mesenchymal stem cell-derived...
BACKGROUND
Retinitis pigmentosa is a rod-cone degenerative disease that induces irreversible vision loss. This study probed the protective capacity of mesenchymal stem cell-derived small EVs (MSC-EVs) on the retinas of rd10 mice and the underlying mechanism.
METHODS
MSC-EVs were injected into the vitreous of rd10 mice at postnatal day 14 and P21; morphology and function were examined at P28. The mechanism of action was explored by using co-culture of photoreceptor cell line 661 W and microglia cell line BV2.
RESULTS
Treatment with MSC-EVs increased the survival of photoreceptors and preserved their structure. Visual function, as reflected by optomotor and electroretinogram responses, was significantly enhanced in MSC-EVs-treated rd10 mice. Mechanistically, staining for Iba1, GFAP, F4/80, CD68 and CD206 showed that MSC-EVs suppressed the activation of microglial, Müller glial and macrophages. Furthermore, western blotting showed that the treatment inhibited the NF-κB pathway. RNA-seq and qPCR showed that MSC-EVs upregulated anti-inflammatory cytokines while downregulating pro-inflammatory cytokines. MSC-EVs application in vitro decreased the number of TUNEL-positive 661 W cells co-cultured with LPS-stimulated BV2, with similar impact on the cytokine expression as in vivo study. Genetic screening predicted miR-146a to be the downstream target of MSC-EVs, which was detected in MSC-EVs and upregulated in co-cultured 661 W cells and BV2 cells after MSC-EVs treatment. Upregulation of miR-146a by using its mimic decreased the expression of the transcription factor Nr4a3, and its downregulation inhibition promoted Nr4a3 expression in both 661 W and BV2 cells. Nr4a3 was further identified as the target gene of miR-146a by dual-luciferase assay. Furthermore, overexpressing miR-146a significantly decreased the expression of LPS-induced pro-inflammatory cytokines in BV2 cells.
CONCLUSIONS
MSC-EVs delays retinal degeneration in rd10 mice mainly by its anti-inflammatory effect via the miR-146a-Nr4a3axis. Hence, MSC-EVs may be used in the treatment of neurodegenerative diseases.
Topics: Animals; Anti-Inflammatory Agents; Cytokines; DNA-Binding Proteins; Disease Models, Animal; Extracellular Vesicles; Lipopolysaccharides; Mesenchymal Stem Cells; Mice; MicroRNAs; Nerve Tissue Proteins; Receptors, Steroid; Receptors, Thyroid Hormone; Retina; Retinitis Pigmentosa
PubMed: 35922863
DOI: 10.1186/s13287-022-03100-x