scholarly journals Proposed therapy, developed in a Pcdh15-deficient mouse, for progressive loss of vision in human Usher Syndrome

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Saumil Sethna ◽  
Wadih M Zein ◽  
Sehar Riaz ◽  
Arnaud PJ Giese ◽  
Julie M Schultz ◽  
...  
Keyword(s):  
Retinal Degeneration ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Usher Syndrome ◽  
Type I ◽  
Ashkenazi Jews ◽  
Visual Deficits ◽  
Severe Vision Loss ◽  
Protocadherin 15

Usher syndrome type I (USH1) is characterized by deafness, vestibular areflexia and progressive retinal degeneration. The protein-truncating p.Arg245* founder variant of PCDH15 (USH1F) has an ~2% carrier frequency amongst Ashkenazi Jews accountings for ~60% of their USH1 cases. Here, longitudinal phenotyping in thirteen USH1F individuals revealed progressive retinal degeneration, leading to severe vision loss with macular atrophy by the sixth decade. Half of the affected individuals were legally blind by their mid-fifties. The mouse Pcdh15R250X variant is equivalent to human p.Arg245*. Homozygous Pcdh15R250X mice also have visual deficits and aberrant light-dependent translocation of the phototransduction cascade proteins, arrestin and transducin. Retinal pigment epithelium- (RPE) specific retinoid cycle proteins, RPE65 and CRALBP, were also reduced in Pcdh15R250X mice, indicating a dual role for protocadherin-15 in photoreceptors and RPE. Exogenous 9-cis retinal improved ERG amplitudes in Pcdh15R250X mice, suggesting a basis for a clinical trial of FDA approved retinoids to preserve vision in USH1F patients.

scholarly journals Potential therapy for progressive vision loss due to PCDH15-associated Usher syndrome developed in an orthologous Usher mouse

2021 ◽  
Author(s):  
Saumil Sethna ◽  
Wadih M Zein ◽  
Sehar Riaz ◽  
Arnaud P.J. Giese ◽  
Julie M Schultz ◽  
...  
Keyword(s):  
Retinal Degeneration ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Usher Syndrome ◽  
Visual Field Loss ◽  
Type I ◽  
Ashkenazi Jews ◽  
Visual Deficits ◽  
Protocadherin 15

Usher syndrome type I (USH1) is characterized by congenital deafness, vestibular areflexia, and progressive retinal degeneration with age. The protein-truncating p.Arg245* founder variant of PCDH15 has an ~2% carrier frequency among Ashkenazi Jews, accounting for nearly 60% of their USH1 cases. Here, longitudinal ocular phenotyping in thirteen USH1F individuals harboring the p.Arg245* variant revealed progressive retinal degeneration, leading to severe loss of vision with macular atrophy by the sixth decade. Half of the affected individuals met either the visual acuity or visual field loss definition for legal blindness by the middle of their fifth decade of life. Mice homozygous for p.Arg250* (Pcdh15R250X; equivalent to human p.Arg245*) also have early visual deficits evaluated using electroretinography. Light-dependent translocation of phototransduction cascade proteins, arrestin and transducin, was found to be impaired in Pcdh15R250X mice. Retinal pigment epithelium- (RPE) specific visual retinoid cycle proteins, RPE65 which converts all-trans retinoids to 11-cis retinoids and CRALBP that transports retinoids, and key retinoid levels were also reduced in Pcdh15R250X mice, suggesting a dual role for protocadherin-15 in photoreceptors and RPE. Administration of exogenous 9-cis retinal, an analog of the naturally occurring 11-cis retinal, improved ERG amplitudes in these mutant mice, suggesting a basis for a clinical trial of exogenous FDA approved retinoids to preserve vision in USH1F patients.

scholarly journals RNA-Seq reveals differential expression profiles and functional annotation of genes involved in retinal degeneration in Pde6c mutant Danio rerio

2019 ◽  
Author(s):  
Madhu Sudhana Saddala ◽  
Anton Lennikov ◽  
Adam Bouras ◽  
Hu Huang
Keyword(s):  
Gene Expression ◽  
Retinal Degeneration ◽  
Calcium Binding ◽  
Vision Loss ◽  
Gene Annotation ◽  
Expression Profiles ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Tca Cycle ◽  
Kegg Pathways

Abstract Retinal degenerative diseases affect millions of people and represent the leading cause of vision loss around the world. Retinal degeneration has been attributed to a wide variety of causes, such as disruption of genes involved in phototransduction, biosynthesis, folding of the rhodopsin molecule, and the structural support of the retina. The molecular pathogenesis of the biological events in retinal degeneration is unclear; however, the molecular basis of the retinal pathological defect can be potentially determined by gene-expression profiling of the whole retina. In the present study, we analyzed the differential gene expression profile of the retina from a wild-type zebrafish and phosphodiesterase 6C (pde6c) mutant. The datasets were downloaded from the Sequence Read Archive (SRA), and adaptors and unbiased bases were removed, and sequences were checked to ensure the quality. The reads were further aligned to the reference genome of zebrafish, and the gene expression was calculated. The differentially expressed genes (DEGs) were filtered based on the false discovery rate (FDR) (±4) and p-values (p < 0.001). We performed gene annotation (molecular function [MF], biological process [BP], cellular component [CC]) and determined the functional pathways Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway for the DEGs. Our result showed 216 upregulated and 3,527 downregulated genes between normal and pde6c mutant zebrafish. These DEGs are involved in various KEGG pathways, such as the phototransduction (12 genes), mRNA surveillance (17 genes), phagosome (25 genes), glycolysis/gluconeogenesis (15 genes), adrenergic signaling in cardiomyocytes (29 genes), ribosome (20 genes), the citrate cycle (TCA cycle; 8 genes), insulin signaling (24 genes), oxidative phosphorylation (20 genes), and RNA transport (22 genes) pathways. Many more of all the pathway genes were downregulated, while fewer were upregulated in the retina of mutant zebrafish. Our data strongly indicate that, among these genes, the abovementioned pathways’ genes—as well as calcium-binding, neural damage, peptidase, immunological, and apoptosis proteins—are mostly involved in the retinal and neural degeneration that cause abnormalities in photoreceptors or retinal pigment epithelium (RPE) cells.

scholarly journals RNA-Seq reveals differential expression profiles and functional annotation of genes involved in retinal degeneration in Pde6c mutant Danio rerio

2020 ◽  
Author(s):  
Madhu Sudhana Saddala ◽  
Anton Lennikov ◽  
Adam Bouras ◽  
Hu Huang
Keyword(s):  
Gene Expression ◽  
Retinal Degeneration ◽  
Calcium Binding ◽  
Vision Loss ◽  
Gene Annotation ◽  
Expression Profiles ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Tca Cycle ◽  
Kegg Pathways

Abstract Background Retinal degenerative diseases affect millions of people and represent the leading cause of vision loss around the world. Retinal degeneration has been attributed to a wide variety of causes, such as disruption of genes involved in phototransduction, biosynthesis, folding of the rhodopsin molecule, and the structural support of the retina. The molecular pathogenesis of the biological events in retinal degeneration is unclear; however, the molecular basis of the retinal pathological defect can be potentially determined by gene-expression profiling of the whole retina. In the present study, we analyzed the differential gene expression profile of the retina from a wild-type zebrafish and phosphodiesterase 6c (pde6c) mutant. Results The datasets were downloaded from the Sequence Read Archive (SRA), and adaptors and unbiased bases were removed, and sequences were checked to ensure the quality. The reads were further aligned to the reference genome of zebrafish, and the gene expression was calculated. The differentially expressed genes (DEGs) were filtered based on the false discovery rate (FDR) (±4) and p-values (p < 0.001). We performed gene annotation (molecular function [MF], biological process [BP], cellular component [CC]), and determined the functional pathways Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway for the DEGs. Our result showed 216 upregulated and 3,527 downregulated genes between normal and pde6c mutant zebrafish. These DEGs are involved in various KEGG pathways, such as the phototransduction (12 genes), mRNA surveillance (17 genes), phagosome (25 genes), glycolysis/gluconeogenesis (15 genes), adrenergic signaling in cardiomyocytes (29 genes), ribosome (20 genes), the citrate cycle (TCA cycle; 8 genes), insulin signaling (24 genes), oxidative phosphorylation (20 genes), and RNA transport (22 genes) pathways. Many more of all the pathway genes were downregulated, while fewer were upregulated in the retina of mutant zebrafish. Conclusions Our data strongly indicate that, among these genes, the above-mentioned pathways’ genes as well as calcium-binding, neural damage, peptidase, immunological, and apoptosis proteins are mostly involved in the retinal and neural degeneration that cause abnormalities in photoreceptors or retinal pigment epithelium (RPE) cells.

scholarly journals RNA-Seq reveals differential expression profiles and functional annotation of genes involved in retinal degeneration in Pde6c mutant Danio rerio

2020 ◽  
Author(s):  
Madhu Sudhana Saddala ◽  
Anton Lennikov ◽  
Adam Bouras ◽  
Hu Huang
Keyword(s):  
Gene Expression ◽  
Retinal Degeneration ◽  
Calcium Binding ◽  
Vision Loss ◽  
Gene Annotation ◽  
Expression Profiles ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Tca Cycle ◽  
Kegg Pathways

Abstract Background: Retinal degenerative diseases affect millions of people and represent the leading cause of vision loss around the world. Retinal degeneration has been attributed to a wide variety of causes, such as disruption of genes involved in phototransduction, biosynthesis, folding of the rhodopsin molecule, and the structural support of the retina. The molecular pathogenesis of the biological events in retinal degeneration is unclear; however, the molecular basis of the retinal pathological defect can be potentially determined by gene-expression profiling of the whole retina. In the present study, we analyzed the differential gene expression profile of the retina from a wild-type zebrafish and phosphodiesterase 6c (pde6c) mutant. Results: The datasets were downloaded from the Sequence Read Archive (SRA), and adaptors and unbiased bases were removed, and sequences were checked to ensure the quality. The reads were further aligned to the reference genome of zebrafish, and the gene expression was calculated. The differentially expressed genes (DEGs) were filtered based on the false discovery rate (FDR) (±4) and p-values (p < 0.001). We performed gene annotation (molecular function [MF], biological process [BP], cellular component [CC]), and determined the functional pathways Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway for the DEGs. Our result showed 216 upregulated and 3,527 downregulated genes between normal and pde6c mutant zebrafish. These DEGs are involved in various KEGG pathways, such as the phototransduction (12 genes), mRNA surveillance (17 genes), phagosome (25 genes), glycolysis/gluconeogenesis (15 genes), adrenergic signaling in cardiomyocytes (29 genes), ribosome (20 genes), the citrate cycle (TCA cycle; 8 genes), insulin signaling (24 genes), oxidative phosphorylation (20 genes), and RNA transport (22 genes) pathways. Many more of all the pathway genes were downregulated, while fewer were upregulated in the retina of mutant zebrafish. Conclusions: Our data strongly indicate that, among these genes, the above-mentioned pathways’ genes as well as calcium-binding, neural damage, peptidase, immunological, and apoptosis proteins are mostly involved in the retinal and neural degeneration that cause abnormalities in photoreceptors or retinal pigment epithelium (RPE) cells.

scholarly journals Wide-field fundus autofluorescence imaging in patients with hereditary retinal degeneration: a literature review

2019 ◽  
Vol 5 (S1) ◽  
Author(s):  
Akio Oishi ◽  
Manabu Miyata ◽  
Shogo Numa ◽  
Yuki Otsuka ◽  
Maho Oishi ◽  
...  
Keyword(s):  
Retinal Degeneration ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Fundus Autofluorescence ◽  
Retinal Pigment ◽  
Peripheral Retina ◽  
Wide Field ◽  
Characteristic Appearance ◽  
Field Imaging ◽  
Wide Field Imaging

Abstract Background Inherited retinal degeneration (IRD) refers to a heterogenous group of progressive diseases that cause death of photoreceptor cells and subsequent vision loss. These diseases often affect the peripheral retina, objective evaluation of which has been difficult until recently. Fundus autofluorescence (FAF) is a non-invasive retinal imaging technique that depicts the distribution of intrinsic fluorophores in the retina. The primary source of retinal autofluorescence is lipofuscin, which is contained in the retinal pigment epithelium (RPE). Excessive accumulation of lipofuscin and a window defect attributable to loss of photoreceptor pigment result in increased FAF whereas loss of the RPE results in decreased FAF. These changes can be seen during the course of IRD. Mainbody While conventional modalities are limited in their angle of view, recent technologic advances, known as wide-field and ultra-widefield FAF imaging, have enabled visualization of the far peripheral retina. Although clinical application of this technique in patients with IRD is still in its infancy, some studies have already indicated its usefulness. For example, an area with decreased FAF correlates well with a visual field defect in an eye with retinitis pigmentosa (RP) or cone-rod dystrophy. An abnormal FAF pattern may help in the diagnosis of IRD and associated diseases. In addition, female carriers of X-linked RP and female choroideremia show characteristic appearance. Conversely, absence of abnormal FAF despite severe retinal degeneration helps differentiation of cancer-associated retinopathy. Conclusion This paper reviews the principles of FAF, wide-field imaging, and findings in specific diseases. Wide-field imaging, particularly wide-field FAF, will provide further information for the characteristics, prognosis, and pathogenesis of IRD.

scholarly journals RNA-Seq reveals differential expression profiles and functional annotation of genes involved in retinal degeneration in Pde6c mutant Danio rerio

2019 ◽  
Author(s):  
Madhu Sudhana Saddala ◽  
Anton Lennikov(Former Corresponding Author) ◽  
Adam Bouras ◽  
Hu Huang(New Corresponding Author)
Keyword(s):  
Gene Expression ◽  
Retinal Degeneration ◽  
Calcium Binding ◽  
Vision Loss ◽  
Gene Annotation ◽  
Expression Profiles ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Tca Cycle ◽  
Kegg Pathways

Abstract Background Retinal degenerative diseases affect millions of people and represent the leading cause of vision loss around the world. Retinal degeneration has been attributed to a wide variety of causes, such as disruption of genes involved in phototransduction, biosynthesis, folding of the rhodopsin molecule, and the structural support of the retina. The molecular pathogenesis of the biological events in retinal degeneration is unclear; however, the molecular basis of the retinal pathological defect can be potentially determined by gene-expression profiling of the whole retina. In the present study, we analyzed the differential gene expression profile of the retina from a wild-type zebrafish and phosphodiesterase 6C (pde6c) mutant. Results The datasets were downloaded from the Sequence Read Archive (SRA), and adaptors and unbiased bases were removed, and sequences were checked to ensure the quality. The reads were further aligned to the reference genome of zebrafish, and the gene expression was calculated. The differentially expressed genes (DEGs) were filtered based on the false discovery rate (FDR) (±4) and p-values (p < 0.001). We performed gene annotation (molecular function [MF], biological process [BP], cellular component [CC]) and determined the functional pathways Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway for the DEGs. Our result showed 216 upregulated and 3,527 downregulated genes between normal and pde6c mutant zebrafish. These DEGs are involved in various KEGG pathways, such as the phototransduction (12 genes), mRNA surveillance (17 genes), phagosome (25 genes), glycolysis/gluconeogenesis (15 genes), adrenergic signaling in cardiomyocytes (29 genes), ribosome (20 genes), the citrate cycle (TCA cycle; 8 genes), insulin signaling (24 genes), oxidative phosphorylation (20 genes), and RNA transport (22 genes) pathways. Many more of all the pathway genes were downregulated, while fewer were upregulated in the retina of mutant zebrafish. Conclusions Our data strongly indicate that, among these genes, the above-mentioned pathways’ genes as well as calcium-binding, neural damage, peptidase, immunological, and apoptosis proteins are mostly involved in the retinal and neural degeneration that cause abnormalities in photoreceptors or retinal pigment epithelium (RPE) cells.

scholarly journals Localization of Usher 1 proteins to the photoreceptor calyceal processes, which are absent from mice

2012 ◽  
Vol 199 (2) ◽  
pp. 381-399 ◽  
Author(s):  
Iman Sahly ◽  
Eric Dufour ◽  
Cataldo Schietroma ◽  
Vincent Michel ◽  
Amel Bahloul ◽  
...  
Keyword(s):  
Retinal Degeneration ◽  
Outer Segment ◽  
Usher Syndrome ◽  
Retinal Dystrophy ◽  
Photoreceptor Cells ◽  
Type I ◽  
Photoreceptor Outer Segment ◽  
Membrane Interfaces ◽  
Protocadherin 15 ◽  
Cadherin 23

The mechanisms underlying retinal dystrophy in Usher syndrome type I (USH1) remain unknown because mutant mice lacking any of the USH1 proteins—myosin VIIa, harmonin, cadherin-23, protocadherin-15, sans—do not display retinal degeneration. We found here that, in macaque photoreceptor cells, all USH1 proteins colocalized at membrane interfaces (i) between the inner and outer segments in rods and (ii) between the microvillus-like calyceal processes and the outer segment basolateral region in rods and cones. This pattern, conserved in humans and frogs, was mediated by the formation of an USH1 protein network, which was associated with the calyceal processes from the early embryonic stages of outer segment growth onwards. By contrast, mouse photoreceptors lacked calyceal processes and had no USH1 proteins at the inner–outer segment interface. We suggest that USH1 proteins form an adhesion belt around the basolateral region of the photoreceptor outer segment in humans, and that defects in this structure cause the retinal degeneration in USH1 patients.

scholarly journals Role of amyloid β-peptide in the pathogenesis of age-related macular degeneration

2021 ◽  
Vol 6 (1) ◽  
pp. e000774
Author(s):  
Minwei Wang ◽  
Shiqi Su ◽  
Shaoyun Jiang ◽  
Xinghuai Sun ◽  
Jiantao Wang
Keyword(s):  
Mitochondrial Dysfunction ◽  
Macular Degeneration ◽  
Vision Loss ◽  
Cell Structure ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Amyloid Β ◽  
Age Related Macular Degeneration ◽  
Amyloid Β Peptide ◽  
Age Related

Age-related macular degeneration (AMD) is the most common eye disease in elderly patients, which could lead to irreversible vision loss and blindness. Increasing evidence indicates that amyloid β-peptide (Aβ) might be associated with the pathogenesis of AMD. In this review, we would like to summarise the current findings in this field. The literature search was done from 1995 to Feb, 2021 with following keywords, ‘Amyloid β-peptide and age-related macular degeneration’, ‘Inflammation and age-related macular degeneration’, ‘Angiogenesis and age-related macular degeneration’, ‘Actin cytoskeleton and amyloid β-peptide’, ‘Mitochondrial dysfunction and amyloid β-peptide’, ‘Ribosomal dysregulation and amyloid β-peptide’ using search engines Pubmed, Google Scholar and Web of Science. Aβ congregates in subretinal drusen of patients with AMD and participates in the pathogenesis of AMD through enhancing inflammatory activity, inducing mitochondrial dysfunction, altering ribosomal function, regulating the lysosomal pathway, affecting RNA splicing, modulating angiogenesis and modifying cell structure in AMD. The methods targeting Aβ are shown to inhibit inflammatory signalling pathway and restore the function of retinal pigment epithelium cells and photoreceptor cells in the subretinal region. Targeting Aβ may provide a novel therapeutic strategy for AMD.

scholarly journals A human model of Batten disease shows role of CLN3 in phagocytosis at the photoreceptor–RPE interface

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Cynthia Tang ◽  
Jimin Han ◽  
Sonal Dalvi ◽  
Kannan Manian ◽  
Lauren Winschel ◽  
...  
Keyword(s):  
Photoreceptor Cell ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Cell Loss ◽  
Human Model ◽  
Lysosomal Storage ◽  
Rpe Cells ◽  
Cln3 Disease

AbstractMutations in CLN3 lead to photoreceptor cell loss in CLN3 disease, a lysosomal storage disorder characterized by childhood-onset vision loss, neurological impairment, and premature death. However, how CLN3 mutations cause photoreceptor cell death is not known. Here, we show that CLN3 is required for phagocytosis of photoreceptor outer segment (POS) by retinal pigment epithelium (RPE) cells, a cellular process essential for photoreceptor survival. Specifically, a proportion of CLN3 in human, mouse, and iPSC-RPE cells localized to RPE microvilli, the site of POS phagocytosis. Furthermore, patient-derived CLN3 disease iPSC-RPE cells showed decreased RPE microvilli density and reduced POS binding and ingestion. Notably, POS phagocytosis defect in CLN3 disease iPSC-RPE cells could be rescued by wild-type CLN3 gene supplementation. Altogether, these results illustrate a novel role of CLN3 in regulating POS phagocytosis and suggest a contribution of primary RPE dysfunction for photoreceptor cell loss in CLN3 disease that can be targeted by gene therapy.

scholarly journals USH2A-Related Retinitis Pigmentosa: Staging of Disease Severity and Morpho-Functional Studies

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Benedetto Falsini ◽  
Giorgio Placidi ◽  
Elisa De Siena ◽  
Maria Cristina Savastano ◽  
Angelo Maria Minnella ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Usher Syndrome ◽  
Collaborative Study ◽  
Staging System ◽  
International Standards ◽  
Full Field ◽  
Functional Studies ◽  
Cumulative Score

Usher syndrome type 2A (USH2A) is a genetic disease characterized by bilateral neuro-sensory hypoacusia and retinitis pigmentosa (RP). While several methods, including electroretinogram (ERG), describe retinal function in USH2A patients, structural alterations can be assessed by optical coherence tomography (OCT). According to a recent collaborative study, RP can be staged considering visual acuity, visual field area and ellipsoid zone (EZ) width. The aim of this study was to retrospectively determine RP stage in a cohort of patients with USH2A gene variants and to correlate the results with age, as well as additional functional and morphological parameters. In 26 patients with established USH2A genotype, RP was staged according to recent international standards. The cumulative staging score was correlated with patients’ age, amplitude of full-field and focal flicker ERGs, and the OCT-measured area of sub-Retinal Pigment Epithelium (RPE) illumination (SRI). RP cumulative score (CS) was positively correlated (r = 0.6) with age. CS was also negatively correlated (rho = −0.7) with log10 ERG amplitudes and positively correlated (r = 0.5) with SRI. In USH2A patients, RP severity score is correlated with age and additional morpho-functional parameters not included in the international staging system and can reliably predict their abnormality at different stages of disease.

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