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Purpose. The aim of the study is to describe the genotype and phenotype of a Mexican cohort with PCARE-related retinal disease. Methods. The study included 14 patients from 11 unrelated pedigrees with retinal dystrophies who were demonstrated to carry biallelic pathogenic variants in PCARE. Visual assessment methods included best corrected visual acuity, color fundus photography, Goldmann visual field test, kinetic perimetry, dark/light adapted chromatic perimetry, full-field electroretinography, autofluorescence imaging, and spectral domain-optical coherence tomography imaging. Genetic screening was performed either by gene panel sequencing or by exome sequencing. Results. According to the results of multimodal imaging and functional tests, all 14 patients were diagnosed with cone-rod dystrophy. Six different PCARE pathogenic alleles were identified in our cohort, including three novel mutations: c.3048_3049del (p.Tyr1016 ∗), c.3314_3315del (p.Ser1105 ∗), and c.551A > G (p.His184Arg). Notably, alleles p.His184Arg, p.Arg613 ∗ , and p.Arg984 ∗ were present in 18 of the 22 (82%) PCARE alleles from probands in our cohort. Conclusion. Our work expands the PCARE mutational profile by identifying three novel pathogenic variants causing retinal dystrophy. While phenotypic variations occurred among patients, a cone-rod dystrophy pattern was observed in all affected individuals. [ABSTRACT FROM AUTHOR]

MicroRNAs are a large group of small noncoding RNAs that work in multiple cellular pathways. miR-204, as one of the key axes in the development, maintenance, and pathogenesis of the retina, plays several roles by modulating its target genes. This study was aimed at evaluating the target genes of miR-204 involved in the development and progression of common retinopathies such as glaucoma, retinoblastoma, and age-related macular degeneration. In this study, three datasets related to retinopathies (GSE50195, GSE27276, and GSE97508) were selected from Gene Expression Omnibus. miR-204 target genes were isolated from TargeScan. The shares between retinopathy and miR-204 target genes were then categorized. Using Enrichr and STRING, we highlighted the signaling pathways and the relationships between the proteins. SHC1 events in ERBB2, adherent junction's interactions, NGF signaling via TRKA from the plasma membrane, IRF3-mediated activation of type 1 IFN, pathways in upregulated genes and G0 and early G1, RORA-activated gene expression, PERK-regulated gene expression, adherent junction's interactions, and CREB phosphorylation pathways in downregulated genes were identified in glaucoma, retinoblastoma, and age-related macular degeneration. WEE1, SMC2, HMGB1, RRM2, and POLA1 proteins were also observed to be involved in the progression and invasion of retinoblastoma; SLC24A2 and DTX4 in age-related macular degeneration; and EPHB6, EFNB3, and SHC1 in glaucoma. Continuous bioinformatics analysis has shown that miR-204 has a significant presence and expression in retinal tissue, and approximately 293 genes are controlled and regulated by miR-204 in this tissue; also, target genes of miR-204 have the potential to develop various retinopathies; thus, a study of related target genes can provide appropriate treatment strategies in the future. [ABSTRACT FROM AUTHOR]

Inherited retinal diseases (IRDs), defined by dysfunction or progressive loss of photoreceptors, are disorders characterized by elevated heterogeneity, both at the clinical and genetic levels. Our main goal was to address the genetic landscape of IRD in the largest cohort of Spanish patients reported to date. A retrospective hospital-based cross-sectional study was carried out on 6089 IRD affected individuals (from 4403 unrelated families), referred for genetic testing from all the Spanish autonomous communities. Clinical, demographic and familiar data were collected from each patient, including family pedigree, age of appearance of visual symptoms, presence of any systemic findings and geographical origin. Genetic studies were performed to the 3951 families with available DNA using different molecular techniques. Overall, 53.2% (2100/3951) of the studied families were genetically characterized, and 1549 different likely causative variants in 142 genes were identified. The most common phenotype encountered is retinitis pigmentosa (RP) (55.6% of families, 2447/4403). The most recurrently mutated genes were PRPH2, ABCA4 and RS1 in autosomal dominant (AD), autosomal recessive (AR) and X-linked (XL) NON-RP cases, respectively; RHO, USH2A and RPGR in AD, AR and XL for non-syndromic RP; and USH2A and MYO7A in syndromic IRD. Pathogenic variants c.3386G > T (p.Arg1129Leu) in ABCA4 and c.2276G > T (p.Cys759Phe) in USH2A were the most frequent variants identified. Our study provides the general landscape for IRD in Spain, reporting the largest cohort ever presented. Our results have important implications for genetic diagnosis, counselling and new therapeutic strategies to both the Spanish population and other related populations. [ABSTRACT FROM AUTHOR]

The article discusses the use of head-mounted visual assessment technology in optimizing screening for preventable blindness. Topics include age-related macular degeneration (AMD) as a leading cause of blindness, the challenge in the diagnosis and close monitoring of AMD, and a common method used to detect late AMD.

Leber congenital amaurosis (LCA) is a severe autosomal recessive retinal degenerative disease. The current study describes exome sequencing results for two unrelated Indian LCA patients carrying novel nonsense p.(Glu636*) and frameshift p.(Pro2281Leufs*63) mutations in the ALMS1 gene. Although ALMS1 gene mutations are associated with Alstrom syndrome (AS), the current patients did not exhibit typical syndromic features of AS. These data suggest that ALMS1 should be included in the candidate gene panel for LCA to improve diagnostic efficiency. [ABSTRACT FROM AUTHOR]

Regular drusen, an accumulation of material below the retinal pigment epithelium (RPE), have long been established as a hallmark early feature of nonneovascular age-related macular degeneration (AMD). Advances in imaging have expanded the phenotype of AMD to include another extracellular deposit, reticular pseudodrusen (RPD) (also termed subretinal drusenoid deposits, SDD), which are located above the RPE. We developed an approach to automatically segment retinal layers associated with regular drusen and RPD in spectral domain (SD) optical coherence tomography (OCT) images. More specifically, a shortest-path algorithm enhanced with probability maps generated through a fully convolutional neural network was used to segment drusen and RPD, as well as 11 retinal layers in SD-OCT volumes. This algorithm achieves a mean difference that is within the subpixel accuracy range drusen and RPD, alongside the other 11 retinal layers, highlighting the high robustness of this algorithm for this dataset. To the best of our knowledge, this is the first report of a validated algorithm for the automated segmentation of the retinal layers including early AMD features of RPD and regular drusen separately on SD-OCT images. [ABSTRACT FROM AUTHOR]

Inherited retinal disorder (IRD) is a leading cause of blindness, and CRX is one of a number of genes reported to harbour autosomal dominant (AD) and recessive (AR) causative variants. Eighteen patients from 13 families with CRX-associated retinal disorder (CRX-RD) were identified from 730 Japanese families with IRD. Ophthalmological examinations and phenotype subgroup classification were performed. The median age of onset/latest examination was 45.0/62.5 years (range, 15–77/25–94). The median visual acuity in the right/left eye was 0.52/0.40 (range, −0.08–2.00/−0.18–1.70) logarithm of the minimum angle of resolution (LogMAR) units. There was one family with macular dystrophy, nine with cone-rod dystrophy (CORD), and three with retinitis pigmentosa. In silico analysis of CRX variants was conducted for genotype subgroup classification based on inheritance and the presence of truncating variants. Eight pathogenic CRX variants were identified, including three novel heterozygous variants (p.R43H, p.P145Lfs*42, and p.P197Afs*22). A trend of a genotype-phenotype association was revealed between the phenotype and genotype subgroups. A considerably high proportion of CRX-RD in ADCORD was determined in the Japanese cohort (39.1%), often showing the mild phenotype (CORD) with late-onset disease (sixth decade). Frequently found heterozygous missense variants located within the homeodomain underlie this mild phenotype. This large cohort study delineates the disease spectrum of CRX-RD in the Japanese population. [ABSTRACT FROM AUTHOR]

Mutations in eyes shut homolog (EYS), a secreted extracellular matrix protein containing multiple laminin globular (LG) domains, and in protein O-mannose β1, 2-N-acetylglucosaminyl transferase 1 (POMGnT1), an enzyme involved in O-mannosyl glycosylation, cause retinitis pigmentosa (RP), RP25 and RP76, respectively. How EYS and POMGnT1 regulate photoreceptor survival is poorly understood. Since some LG domain-containing proteins function by binding to the matriglycan moiety of O-mannosyl glycans, we hypothesized that EYS interacted with matriglycans as well. To test this hypothesis, we performed EYS Far-Western blotting assay and generated pomgnt1 mutant zebrafish. The results showed that EYS bound to matriglycans. Pomgnt1 mutation in zebrafish resulted in a loss of matriglycan, retention of synaptotagmin-1-positive EYS secretory vesicles within the outer nuclear layer, and diminished EYS protein near the connecting cilia. Photoreceptor density in 2-month old pomgnt1 mutant retina was similar to the wild-type animals but was significantly reduced at 6-months. These results indicate that EYS protein localization to the connecting cilia requires interaction with the matriglycan and that O-mannosyl glycosylation is required for photoreceptor survival in zebrafish. This study identified a novel interaction between EYS and matriglycan demonstrating that RP25 and RP76 are mechanistically linked in that O-mannosyl glycosylation controls targeting of EYS protein. [ABSTRACT FROM AUTHOR]

Retinitis pigmentosa is a retinal degenerative disease that leads to blindness through photoreceptor loss. Rhodopsin is the most frequently mutated protein in this disease. While many rhodopsin mutations have well-understood consequences that lead to cell death, the disease association of several rhodopsin mutations identified in retinitis pigmentosa patients, including F220C and F45L, has been disputed. In this study, we generated two knockin mouse lines bearing each of these mutations. We did not observe any photoreceptor degeneration in either heterozygous or homozygous animals of either line. F220C mice exhibited minor disruptions of photoreceptor outer segment dimensions without any mislocalization of outer segment proteins, whereas photoreceptors of F45L mice were normal. Suction electrode recordings from individual photoreceptors of both mutant lines showed normal flash sensitivity and photoresponse kinetics. Taken together, these data suggest that neither the F220C nor F45L mutation has pathological consequences in mice and, therefore, may not be causative of retinitis pigmentosa in humans. [ABSTRACT FROM AUTHOR]

As life expectancy increases, the number of people living with age‐related macular degeneration (AMD) is set to rise dramatically, meaning it could become the next public health crisis. Existing treatments are of limited benefit, but researchers are exploring several avenues that could lead to new therapies. [ABSTRACT FROM AUTHOR]

Purpose. To illustrate a data-driven deep learning approach to predicting the gene responsible for the inherited retinal disorder (IRD) in macular dystrophy caused by ABCA4 and RP1L1 gene aberration in comparison with retinitis pigmentosa caused by EYS gene aberration and normal subjects. Methods. Seventy-five subjects with IRD or no ocular diseases have been ascertained from the database of Japan Eye Genetics Consortium; 10 ABCA4 retinopathy, 20 RP1L1 retinopathy, 28 EYS retinopathy, and 17 normal patients/subjects. Horizontal/vertical cross-sectional scans of optical coherence tomography (SD-OCT) at the central fovea were cropped/adjusted to a resolution of 400 pixels/inch with a size of 750 × 500 pix2 for learning. Subjects were randomly split following a 3 : 1 ratio into training and test sets. The commercially available learning tool, Medic mind was applied to this four-class classification program. The classification accuracy, sensitivity, and specificity were calculated during the learning process. This process was repeated four times with random assignment to training and test sets to control for selection bias. For each training/testing process, the classification accuracy was calculated per gene category. Results. A total of 178 images from 75 subjects were included in this study. The mean training accuracy was 98.5%, ranging from 90.6 to 100.0. The mean overall test accuracy was 90.9% (82.0–97.6). The mean test accuracy per gene category was 100% for ABCA4, 78.0% for RP1L1, 89.8% for EYS, and 93.4% for Normal. Test accuracy of RP1L1 and EYS was not high relative to the training accuracy which suggests overfitting. Conclusion. This study highlighted a novel application of deep neural networks in the prediction of the causative gene in IRD retinopathies from SD-OCT, with a high prediction accuracy. It is anticipated that deep neural networks will be integrated into general screening to support clinical/genetic diagnosis, as well as enrich the clinical education. [ABSTRACT FROM AUTHOR]

Highlights • TIMP-3 suppression could alter the macrophage polarization to M2 type in bone marrow-derived macrophages. • siR-TIMP-3 regulates macrophage polarization to a more pro-angiogenic subtype in RPE/Choroidal tissues with CNV animal model. • OCTA is effective to observe the CNV lesion in BN rat eye, indicating the absence of TIMP-3 might accelerate the growth of CNV lesions. Abstract Purpose To investigate the role of tissue inhibitor of metalloproteinases–3 (TIMP-3) as a key moderator of macrophage polarization in choroidal neovascularization (CNV) lesions of model mice and in bone marrow-derived macrophage (BMDM). Method We used siR-TIMP-3 to transfect BMDM and gave an intravitreal injection of siR-TIMP-3 to laser-induced CNV mice model, real time-PCR and western blot were applied for detecting the expressions of TIMP-3 and macrophages' biomarker. Besides, CNV lesions in different treatment groups of animal model were examined by the optical coherence tomography angiography (OCTA). Results Our experimental data showed that lack of TIMP-3 stimulated M2 polarization proved by real time-PCR and western blot in BMDMs and CNV mice model. Moreover, intravitreal injection of siR-TIMP-3 accelerated CNV formation using OCTA, which indicated that TIMP-3 suppression is related to pro-angiogenesis of M2 macrophage. Conclusion We showed that the absence of TIMP-3 leads to a more pro-angiogenic microenvironment, playing a key role in CNV formation by positively modulating M2 polarization. The role of TIMP-3 in the regulating inflammation and novel therapeutic target of nAMD needs to be further studied. [ABSTRACT FROM AUTHOR]

Mutations in the gene BEST1 usually cause bestrophinopathies, such as the rare progressive diseases Best vitelliform macular dystrophy (BVMD) and autosomal recessive bestrophinopathy (ARB). This study aimed to investigate the clinical characteristics of patients with BVMD or ARB carrying BEST1 mutations. A total of 12 probands including 9 patients with a clinical diagnosis of BVMD and 3 patients with a clinical diagnosis of ARB were recruited for genetics analysis. All patients underwent detailed ophthalmic examination. All coding exons of the BEST1 gene were screened by PCR-based DNA sequencing. Programs of PolyPhen-2, SIFT, and MutationTaster were used to analyze the potential pathogenicity of the mutations in BEST1. In the 9 unrelated patients with BVMD, one heterozygous BEST1 mutation was revealed in 8 patients and two compound heterozygous mutations in 1 patient. In the 3 unrelated patients with ARB, two compound heterozygous mutations were revealed in 2 patients and three compound heterozygous mutations in 1 patient. Molecular analyses identified a total of 15 mutations, including 3 novel mutations (c.424A>G p.S142G, c.436G>A p.A146T, and c.155T>C p.L52P). Antivascular endothelial growth factor (VEGF) drugs were given to two affected eyes, especially those also exhibiting choroidal neovascularization (CNV), and no serious adverse events occurred. Our study indicates that there is wide genotypic and phenotypic variability in patients with BVMD or ARB in China. The screening of BEST1 gene is significant for the precise diagnosis of BVMD and ARB. [ABSTRACT FROM AUTHOR]

Background: Several previous studies have assessed the contribution of polymorphisms in genes encoding the complement factors C2/C3/CFB/CFH with the risk of age-related macular degeneration (AMD), however the results have been inconsistent. We conducted a meta-analysis to systematically review the potential association between complement factor polymorphisms and AMD. Methods: Studies that investigated associations between C2 (rs547154 and rs9332739), C3 (rs1047286), CFB (rs4151667 and rs641153), and CFH (rs551397 and rs2274700) polymorphisms and AMD were identified by searching PubMed, EMBASE, Web of Science, and Cochrane Library databases for articles published prior to January 1, 2018. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to evaluate the association between these polymorphisms and AMD using Stata 12.0 software. Q and I2 statistics were used to evaluate between-study heterogeneity. Publication bias analyses were conducted using Begg's test. We also conducted an ethnic subgroup analysis. Results: A total of 53 studies that included data for 53,774 patients and 56,973 healthy controls were evaluated. The pooled ORs for rs551397, rs2274700, rs4151667, rs641153, rs1047286, rs9332739, and rs547154 in the heterozygote model were 0.53 (95% CI: 0.45–0.61), 0.53 (95% CI: 0.40–0.70), 0.54 (95% CI: 0.46–0.63), 0.48 (95% CI: 0.4–0.57), 1.42 (95% CI: 1.22–1.66), 0.5 (95% CI: 0.45–0.56), and 0.52 (95% CI: 0.43–0.62), respectively. Conclusion: Our findings from this analysis confirmed the protective role of C2/CFB/CFH polymorphisms in the development of AMD, but showed that the single nucleotide polymorphism in C3 was a high-risk factor for AMD. The racial analysis results suggested that the effect of variant alleles was stronger in Caucasians than Asians. [ABSTRACT FROM AUTHOR]

Age-related macular degeneration (AMD) is the most common cause of visual loss in developed countries, with a significant economic and social burden on public health. Although genome-wide and gene-candidate studies have been enabled to identify genetic variants in the complement system associated with AMD pathogenesis, the effect of gene-environment interaction is still under debate. In this review we provide an overview of the role of complement system and its genetic variants in AMD, summarizing the consequences of the interaction between genetic and environmental risk factors on AMD onset, progression, and therapeutic response. Finally, we discuss the perspectives of current evidence in the field of genomics driven personalized medicine and public health. [ABSTRACT FROM AUTHOR]

Background: Several studies in various populations have been conducted to determine candidate genes that could contribute to age-related macular degeneration (AMD) pathogenesis. Objective: The present study was undertaken to determine the association of high temperature requirement A-1 (HTRA1), vascular endothelial growth factor (VEGF) and very-low-density receptor (VLDR) genes with wet AMD subjects in Malaysia. Methods: A total of 125 subjects with wet AMD and 120 subjects without AMD from the Malaysian population were selected for this study. Genomic DNA was extracted and copy number variations (CNVs) were determined using quantitative real-time Polymerase Chain Reaction (qPCR) and comparison between the two groups was done. The demographic characteristics were also recorded. Statistical analysis was carried out using software where a level of P < 0.05 was considered to be statistically significant. Result: Statistically significant associations of the VEGF gene were observed in mean copy differences between case and control subjects (P < 0.05). The consistency of both unadjusted and age-adjusted data at Copy Number CN gain (CN = 3 and CN = 4) suggested that VEGF could increase the risk of wet AMD disease (P < 0.05). None of CNVs of HTRA1 and VLDR genes showed associations with the wet AMD disease based on comparisons of the frequencies of mean (P > 0.05). Conclusion: Observations of an association between CNVs of VEGF gene and wet AMD have revealed that the CNVs of VEGF gene appears to be a possible contributor to wet AMD subjects in Malaysia. [ABSTRACT FROM AUTHOR]

Introduction: Adult-onset foveomacular vitelliform dystrophy is a prevalent form of macular degeneration and typically occurs between the fourth and sixth decades of life. Areas covered: A pubmed and medline search was performed using the relevant key words. Several variants of the term ‘adult-onset vitelliform macular dystrophy’ were searched in relation to different terms: ‘diagnosis’, ‘managment’ and ‘treatment’. Expert commentary: Multimodal diagnostic imaging methods such as autofluorescence, fluorescein angiography, indocyanine green angiography, structural spectral domain optical coherence tomography, and optical coherence tomography angiography have led to a better understanding of the pathophysiological features of macular diseases. Gene therapy is a promising future option for treating monogenic forms of adult-onset foveomacular vitelliform dystrophy. [ABSTRACT FROM AUTHOR]

Aim. To evaluate the frequency and pattern of disease-associated mutations of ABCA4 gene among Greek patients with presumed Stargardt disease (STGD1). Materials and Methods. A total of 59 patients were analyzed for ABCA4 mutations using the ABCR400 microarray and PCR-based sequencing of all coding exons and flanking intronic regions. MLPA analysis as well as sequencing of two regions in introns 30 and 36 reported earlier to harbor deep intronic disease-associated variants was used in 4 selected cases. Results. An overall detection rate of at least one mutant allele was achieved in 52 of the 59 patients (88.1%). Direct sequencing improved significantly the complete characterization rate, that is, identification of two mutations compared to the microarray analysis (93.1% versus 50%). In total, 40 distinct potentially disease-causing variants of the ABCA4 gene were detected, including six previously unreported potentially pathogenic variants. Among the disease-causing variants, in this cohort, the most frequent was c.5714+5G>A representing 16.1%, while p.Gly1961Glu and p.Leu541Pro represented 15.2% and 8.5%, respectively. Conclusions. By using a combination of methods, we completely molecularly diagnosed 48 of the 59 patients studied. In addition, we identified six previously unreported, potentially pathogenic ABCA4 mutations. [ABSTRACT FROM AUTHOR]

Background: The role of chemotactic protein CCL2/MCP-1 has been widely explored in age related macular degeneration (AMD) patients as well as animal models through our previous studies. Aim: Aim of the study was to examine the association of another variance of CCL2, rs1024611 in pathophysiology of AMD. Methods: This particular SNP has been found to be involved in inflammatory processes in various diseases. Total 171 subjects were recruited in the study with all demographic details by administering a standard questionnaire. SNP analysis was performed with TaqMan assay. Linear univariate and ANCOVA modeling was performed to show the interaction of rs1024611 with another SNP variant of CCL-2/CCR-2 (rs4586 and rs1799865) and impact of individual genotypes on CCL-2 expression in the context of AMD pathology. Results: Results showed that both heterozygous (AG, p = 0.01) and homozygous (GG, p = 0.0001) genotypes are associated with AMD pathology. Allele frequency analysis showed that ‘G’ allele is frequent in AMD patients as compared to controls (p = 0.0001). Moreover, AMD patients who smoke were found to be associated with ‘AG’ genotype (p = 0.0145). Although, we did not find any significant interaction between the SNP variants by linear univariate analysis but results show the effect of ‘CT’ genotype on ‘TT’ genotype in rs4586 by considering rs1024611 as covariate. Conclusion: Based on these results it is imperative that CCL2 mediated pathology may be associated with AMD. [ABSTRACT FROM AUTHOR]

The article discusses the study which clarifies the role of autophagy in age-related macular degeneration (AMD) pathogenesis. Topics mentioned include the study on cadaver samples of mice and human, the SQSTM1/p62 gene as marker of impaired autophagy, and the use of heat shock protein (hsp)70 in treating retinal pigment epithelium (RPE) degeneration and AMD.

Inherited retinal degeneration (RD) is a devastating and currently untreatable neurodegenerative condition that leads to loss of photoreceptor cells and blindness. The vast genetic heterogeneity of RD' the lack of "druggable" targets, and the access-limiting blood-retinal barrier (BRB) present major hurdles toward effective therapy development. Here, we address these challenges (i) by targeting cGMP (cyclic guanosine- 3',5'-monophosphate) signaling, a disease driver common to different types of RD, and (ii) by combining inhibitory cGMP analogs with a nanosized liposomal drug delivery system designed to facilitate transport across the BRB. Based on a screen of several cGMP analogs we identified an inhibitory cGMP analog that interferes with activation of photoreceptor cell death pathways. Moreover, we found liposomal encapsulation of the analog to achieve efficient drug targeting to the neuroretina. This pharmacological treatment markedly preserved in vivo retinal function and counteracted photoreceptor degeneration in three different in vivo RD models. Taken together, we show that a defined class of compounds for RD treatment in combination with an innovative drug delivery method may enable a single type of treatment to address genetically divergent RD-type diseases. [ABSTRACT FROM AUTHOR]

To assess the progression of Stargardt (STGD) disease over nine years in two branches of a large consanguineous Tunisian family. Initially, different phenotypes were observed with clinical intra- and interfamilial variations. At presentation, four different retinal phenotypes were observed. In phenotype 1, bull’s eye maculopathy and slight alteration of photopic responses in full-field electroretinography were observed in the youngest child. In phenotype 2, macular atrophy and yellow white were observed in two brothers. In phenotype 3, diffuse macular, peripapillary, and peripheral RPE atrophy and hyperfluorescent dots were observed in two sisters. In phenotype 4, Stargardt disease-fundus flavimaculatus phenotype was observed in two cousins with later age of onset. After a progression of 9 years, all seven patients displayed the same phenotype 3 with advanced stage STGD and diffuse atrophy. WES and MLPA identified two ABCA4 mutations M1: c.[(?_4635)_(5714+?)dup; (?_6148)_(6479_+?) del] and M2: c.[2041C>T], p.[R681∗]. In one branch, the three affected patients had M1/M1 causal mutations and in the other branch the two affected patients had M1/M2 causal mutations. After 9-year follow-up, all patients showed the same phenotypic evolution, confirming the progressive nature of the disease. Genetic variations in the two branches made no difference to similar end-stage disease. [ABSTRACT FROM AUTHOR]

Late-stage age-related macular degeneration (AMD) is the leading cause of visual impairment in the elderly with a complex etiology. The most important non-modifiable risk factors for onset and progression of late AMD are age and genetic risk factors, however, little is known about the interplay between genetics and age or sex. Here, we conducted a large-scale age- and sex-stratified genome-wide association study (GWAS) using 1000 Genomes imputed genome-wide and ExomeChip data (>12 million variants). The data were established by the International Age-related Macular Degeneration Genomics Consortium (IAMDGC) from 16,144 late AMD cases and 17,832 controls. Our systematic search for interaction effects yielded significantly stronger effects among younger individuals at two known AMD loci (near CFH and ARMS2/HTRA1). Accounting for age and gene-age interaction using a joint test identified two additional AMD loci compared to the previous main effect scan. One of these two is a novel AMD GWAS locus, near the retinal clusterin-like protein (CLUL1) gene, and the other, near the retinaldehyde binding protein 1 (RLBP1), was recently identified in a joint analysis of nuclear and mitochondrial variants. Despite considerable power in our data, neither sex-dependent effects nor effects with opposite directions between younger and older individuals were observed. This is the first genome-wide interaction study to incorporate age, sex and their interaction with genetic effects for late AMD. Results diminish the potential for a role of sex in the etiology of late AMD yet highlight the importance and existence of age-dependent genetic effects. [ABSTRACT FROM AUTHOR]

Purpose:To evaluate the possible synergistic effect of at risk genotypes ofARMS2/LOC387715(A69S), DNA repairSMUG1rs3087404,CCL2–2518,C3(R102G),CFH Y402H, complement factor B(L9H), andcomplement factor I(CFI) (G119R) in advanced age-related macular degeneration compared to those of healthy controls. Elucidation of synergistic effects between different genetic loci may clarify their pathogenetic pathways. Methods:We calculated relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (S) to estimate the additive or supra-additive effects of the mentioned genotypes. Results:ARMS2-CFH [RERI = 4.78 (95% CI 2.17–10.61), AP = 0.65 (95% CI 0.33–0.83), S = 4.11 (95% CI 1.40–12.06)], and CFH-C3 combinations [RERI = 2.71 (95% CI 0.04–7.01) AP = 0.47 (95% CI −0.03–0.7) S = 2.30 (95%CI 0.97–5.45)] have the most significant levels of synergism and C3-CFI combination [RERI = −1.65 (95%CI −4.34–0.06), AP = −0.92(95%CI −3.09 – −0.09), S = 0.32 (95%CI 0.09 = 1.20)] has the most significant level of antagonism. Conclusion:Among different genotype combinations ARMS2-CFH and CFH-C3 combinations have the most significant levels of synergism and C3-CFI combination has the most significant level of antagonism in AMD patients. [ABSTRACT FROM PUBLISHER]

Retinitis pigmentosa (RP) is a group of inherited retinal degenerative conditions and a leading cause of irreversible blindness. 25%–30% of RP cases are caused by inherited autosomal dominant (ad) mutations in the rhodopsin (Rho) protein of the retina, which impose a barrier for developing therapeutic treatments for this genetically heterogeneous disorder, as simple gene replacement is not sufficient to overcome dominant disease alleles. Previously, we have explored using the genomic short-form of Rho ( sgRho ) for gene augmentation therapy of RP in a Rho knockout mouse model. We have shown improved gene expression and fewer epigenetic modifications compared with the use of a Rho cDNA expression construct. In the current study, we altered our strategy by delivering a codon-optimized genomic form of Rho ( co-sgRho ) (for gene replacement) in combination with an RNAi-based inactivation of endogenous Rho alleles (gene suppression of both mutant Rho alleles, but mismatched with the co-sgRho ) into a homozygous Rho P23H/P23H knock-in (KI) RP mouse model, which has a severe phenotype of adRP. In addition, we have conjugated a cell penetrating TAT peptide sequence to our previously established CK30PEG10 diblock co-polymer. The DNAs were compacted with CK30PEG10-TAT diblock co-polymer to form DNA nanoparticles (NPs). These NPs were injected into the sub-retinal space of the KI mouse eyes. As a proof of concept, we demonstrated the efficiency of this strategy in the partial improvement of visual function in the Rho P23H/P23H KI mouse model. [ABSTRACT FROM AUTHOR]

Abstract: MicroRNAs (miRNAs) are key regulators of gene expression in humans. Overexpression or depletion of individual miRNAs is associated with human disease. Current knowledge suggests that the retina is influenced by miRNAs and that dysregulation of miRNAs as well as alterations in components of the miRNA biogenesis machinery are involved in retinal diseases, including age‐related macular degeneration (AMD). Furthermore, recent studies have indicated that the vitreous has a specific panel of circulating miRNAs and that this panel varies according to the specific pathological stress experienced by the retinal cells. MicroRNA (miRNA) profiling indicates subtype‐specific miRNA profiles for late‐stage AMD highlighting the importance of proper miRNA regulation in AMD. This review will describe the function of important miRNAs involved in inflammation, oxidative stress and pathological neovascularization, the key molecular mechanisms leading to AMD, and focus on dysregulated miRNAs as potential therapeutic targets in AMD. [ABSTRACT FROM AUTHOR]

Neuroinflammation is an early event during diabetic retinopathy (DR) that impacts the dynamics of microglia polarization. Gliosis is a hallmark of DR and we have reported the beneficial effects of 1R-DSO-ONJ, a member of the sp 2 -iminosugar glycolipid (sp 2 -IGL) family, in targeting microglia and reducing gliosis in diabetic db/db mice. Herein, we analyzed the effect of DSO 2 -ONJ, another family compound incorporating a sulfone group that better mimics the phosphate group of phosphatidylinositol ether lipid analogues (PIAs), in Bv.2 microglial cells treated with bacterial lipopolysaccaride (LPS) and in retinal explants from db/db mice. In addition to decreasing iNOS and inflammasome activation, the anti-inflammatory effect of DSO 2 -ONJ was mediated by direct p38α MAPK activation. Computational docking experiments demonstrated that DSO 2 -ONJ binds to p38α MAPK at the same site where PIAs and the alkyl phospholipid perifosine activators do, suggesting similar mechanism of action. Moreover, treatment of microglial cells with DSO 2 -ONJ increased both heme-oxygenase (HO)-1 and Il10 expression regardless the presence of LPS. In retinal explants from db/db mice, DSO 2 -ONJ also induced HO-1 and reduced gliosis. Since IL-10-mediated induction of HO-1 expression is mediated by p38α MAPK activation, our results suggest that this molecular mechanism is involved in the anti-inflammatory effects of DSO 2 -ONJ in microglia. [ABSTRACT FROM AUTHOR]

Background:The clinical phenotype of patients presenting with autosomal recessiveCDHR1-related retinopathy has not been well described. Materials and Methods:This is a retrospective case series of patients presenting to a single institution. Clinical data, including age, visual acuity, dilated fundus exam, fundus photos, fundus autofluorescence (FAF), optical coherence tomography, full-field electroretinograms (ERGs), and results of genetic testing, were collected. Results:Four patients were identified to have biallelic mutations in theCDHR1gene. All four patients were found to have at least one c.783G>A (p.Pro261 = ) mutation. A novel splice site mutation, c.152-2A>G, was identified in two patients. Patients became symptomatic between the fourth and sixth decades of life. Three patients presented initially with nyctalopia and peripheral visual field constriction, and one patient presented with simultaneous onset of photophobia and nyctalopia. The fundus appearance was characterized by macular atrophy with or without peripheral retinal pigment epithelium changes and arteriolar attenuation. FAF showed a hyperautofluorescent ring surrounding a central area of speckled hypoautofluorescence. Full-field electroretinography was available on three patients and showed decreased cone-and-rod responses. Conclusions:CDHR1-related retinal dystrophy should be considered in adult patients with a retinal dystrophy who present with symptoms of cone-and-rod dysfunction and macular atrophy on ophthalmoscopic examination. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the clinical characteristics and genetic basis of inherited retinal degeneration (IRD) in six unrelated pedigrees from Mexico. Methods: A complete ophthalmic evaluation including measurement of visual acuities, Goldman kinetic or Humphrey dynamic perimetry, Amsler test, fundus photography, and color vision testing was performed. Family history and blood samples were collected from available family members. DNA from members of two pedigrees was examined for known mutations using the APEX ARRP genotyping microarray and one pedigree using the APEX LCA genotyping microarray. The remaining three pedigrees were analyzed using a custom-designed targeted capture array covering the exons of 233 known retinal degeneration genes. Sequencing was performed on Illumina HiSeq. Reads were mapped against hg19, and variants were annotated using GATK and filtered by exomeSuite. Segregation and ethnicity-matched control sample analyses were performed by dideoxy sequencing. Results: Six pedigrees with IRD were analyzed. Nine rare or novel, potentially pathogenic variants segregating with the phenotype were detected inIMPDH1, USH2A, RPE65, ABCA4, andFAM161Agenes. Among these, six were known mutations while the remaining three changes inUSH2A, RPE65, andFAM161Agenes have not been previously reported to be associated with IRD. Analysis of 100 ethnicity-matched controls did not detect the presence of these three novel variants indicating, these are rare variants in the Mexican population. Conclusions: Screening patients diagnosed with IRD from Mexico identified six known mutations and three rare or novel potentially damaging variants inIMPDH1, USH2A, RPE65, ABCA4, andFAM161Agenes that segregated with disease. [ABSTRACT FROM PUBLISHER]

Identification of causal genetic defects for human diseases took a significant leap when the first generation DNA sequencing technologies enabled biologists extract sequence-based genetic information from living beings. However, these sequencing methods had unavoidable constraints of throughput, scalability, rapidity, and resolution. In this direction, next-generation sequencing (NGS) since the time of its advent has revolutionized the process of gene discovery for both monogenic and multifactorial genetic diseases. Among several variations of NGS, whole exome sequencing (WES) has emerged as a smart strategy that enables identification of disease causing variants present within the coding region of the human genome. The current review focuses primarily on the application of WES in identification of causal variants for ocular diseases. WES has successfully revealed pathogenic variants in a variety of ocular diseases such as retinal degenerations, refractive errors, lens diseases, corneal dystrophies, and developmental ocular defects. It has demonstrated immense potential for molecular diagnosis of genetic ocular diseases. WES has been extensively used in Mendelian and complex cases, familial and sporadic cases, simplex and multiplex cases, and syndromic and non-syndromic cases of ocular diseases. Although many such ocular diseases have been investigated using WES, reports indicate that it has been employed overwhelmingly for heterogeneous retinal degenerations. WES, within a short period of time, has proved to be a cost-effective and promising approach for understanding the genetic basis of ocular diseases. [ABSTRACT FROM AUTHOR]

We performed a clinical and genetic characterization of a pediatric cohort of patients with inherited retinal dystrophy (IRD) to identify the most suitable cases for gene therapy. The cohort comprised 43 patients, aged between 2 and 18 years, with severe isolated IRD at the time of presentation. The ophthalmological characterization also included assessment of the photoreceptor layer integrity in the macular region (ellipsoid zone (EZ) band). In parallel, we carried out a targeted, next-generation sequencing (NGS)-based analysis using a panel that covers over 150 genes with either an established or a candidate role in IRD pathogenesis. Based on the ophthalmological assessment, the cohort was composed of 24 Leber congenital amaurosis, 14 early onset retinitis pigmentosa, and 5 achromatopsia patients. We identified causative mutations in 58.1% of the cases. We also found novel genotype-phenotype correlations in patients harboring mutations in the CEP290 and CNGB3 genes. The EZ bandwas detectable in 40%of the analyzed cases, also in patientswith genotypes usually associated with severe clinical manifestations. This study provides the first detailed clinical-genetic assessment of severe IRDs with infantile onset and lays the foundation of a standardized protocol for the selection of patients that are more likely to benefit from gene replacement therapeutic approaches. [ABSTRACT FROM AUTHOR]

Background Combined retinal degeneration and sensorineural hearing impairment is mostly due to autosomal recessive Usher syndrome ( USH1: congenital deafness, early retinitis pigmentosa ( RP); USH2: progressive hearing impairment, RP). Methods Sanger sequencing and NGS of 112 genes (Usher syndrome, nonsyndromic deafness, overlapping conditions), MLPA, and array- CGH were conducted in 138 patients clinically diagnosed with Usher syndrome. Results A molecular diagnosis was achieved in 97% of both USH1 and USH2 patients, with biallelic mutations in 97% ( USH1) and 90% ( USH2), respectively. Quantitative readout reliably detected CNVs (confirmed by MLPA or array- CGH), qualifying targeted NGS as one tool for detecting point mutations and CNVs. CNVs accounted for 10% of identified USH2A alleles, often in trans to seemingly monoallelic point mutations. We demonstrate PTC124-induced read-through of the common p.Trp3955* nonsense mutation (13% of detected USH2A alleles), a potential therapy target. Usher gene mutations were found in most patients with atypical Usher syndrome, but the diagnosis was adjusted in case of double homozygosity for mutations in OTOA and NR2E3, genes implicated in isolated deafness and RP. Two patients with additional enamel dysplasia had biallelic PEX26 mutations, for the first time linking this gene to Heimler syndrome. Conclusion Targeted NGS not restricted to Usher genes proved beneficial in uncovering conditions mimicking Usher syndrome. [ABSTRACT FROM AUTHOR]

Background The culture of retinal progenitors from an accessible adult stem cell source such as the limbus could provide a useful autologous source of retinal cell therapies. The human corneoscleral limbus contains multipotent stem cells that can be cultured as floating neurospheres. Previous work in rodents has demonstrated neuronal and photoreceptor differentiation from limbal neurosphere cultures. Here, this study has examined undifferentiated cultured adult human limbal neurospheres as donor cells for retinal cell therapies by transplantation into a rat model of retinal degeneration. Methods Gene expression in limbal neurospheres was examined by immunostaining and western blot. Human limbal neurospheres were transplanted into the subretinal space of Royal College of Surgeon's rats. Rats were monitored by optical coherence tomography for 6 weeks then processed for retinal histology. Results Human limbal neurospheres expressed the neural lineage markers, Nestin, sex determining region box-2 and N-cadherin, and the retinal transcription factors microphthalmia-associated transcription factor, sex determining region box-2 and orthodentical homeobox-2. Human limbal neurospheres could be cultured to express NeuN, neurofilament and rhodopsin. Rats receiving saline or no injection underwent complete degeneration of the retinal outer nuclear layer after 3 weeks. In contrast, rats injected with human limbal neurospheres or retinal pigment epithelial cells maintained the outer nuclear layer for up to 6 weeks. Gene expression in transplanted limbal neurospheres was inconsistent with the production of mature retinal pigment epithelial or photoreceptor cells. Conclusions Human limbal neurospheres represent an accessible source of autologous donor cells for the treatment of retinal diseases. [ABSTRACT FROM AUTHOR]

The identification of the genes underlying monogenic diseases has been of interest to clinicians and scientists for many years. Using inherited retinal dystrophies as an example of monogenic disease we describe the history of molecular genetic techniques that have been pivotal in the discovery of disease causing genes. The methods that were developed in the 1970's and 80's are still in use today but have been refined and improved. These techniques enabled the concept of the Human Genome Project to be envisaged and ultimately realised. When the successful conclusion of the project was announced in 2003 many new tools and, as importantly, many collaborations had been developed that facilitated a rapid identification of disease genes. In the post-human genome project era advances in computing power and the clever use of the properties of DNA replication has allowed the development of next-generation sequencing technologies. These methods have revolutionised the identification of disease genes because for the first time there is no need to define the position of the gene in the genome. The use of next generation sequencing in a diagnostic setting has allowed many more patients with an inherited retinal dystrophy to obtain a molecular diagnosis for their disease. The identification of novel genes that have a role in the development or maintenance of retinal function is opening up avenues of research which will lead to the development of new pharmacological and gene therapy approaches. Neither of which can be used unless the defective gene and protein is known. The continued development of sequencing technologies also holds great promise for the advent of truly personalised medicine. [ABSTRACT FROM AUTHOR]

The Age-Related Eye Disease Study (AREDS) and AREDS2 provided evidence for treating persons with age-related macular degeneration (AMD) with antioxidant vitamins and minerals to reduce the risk of development of late AMD. The AREDS2 data suggest that the beta-carotene in the original AREDS supplements be replaced by lutein and zeaxanthin, providing a safer drug for those who are smokers or former smokers. Even though consuming fish reduced the risk of AMD in observational studies, the AREDS2 results showed that omega-3 long-chain polyunsaturated fatty acids (docosahexaenoic acid/eicosapentaenoic acid) had no beneficial effect on AMD. Despite the major progress in the discovery of gene variants associated with AMD, the use of genetic testing to predict disease has not been clinically useful. The use of genetic testing prior to AMD therapies such as administering AREDS supplements is not recommended by the American Academy of Ophthalmology and other organizations. [ABSTRACT FROM AUTHOR]

Purpose: While the importance of risk polymorphisms for the pathogenesis of age-related macular degeneration (AMD) is well established, their impact on morphological and functional phenotypes is largely unclear. We aimed to characterize individual phenotypes in patients who were either homozygous for a risk allele in the CFH gene, ARMS2 gene, or both as compared to non-carriers. Methods: Patients with early AMD (n = 85) were assessed during a followup examination of a prospective study (MARS) with multimodal diagnostics including SD-OCT and microperimetry. Results: Compared to non-carriers, OCT scans revealed lower retinal thickness in patients homozygous for CFH or ARMS2, which was caused by a significantly reduced photoreceptor layer. The number and ultrastructure of drusen were also significantly different. Conclusions: These findings indicate that patients with risk alleles demonstrate distinct phenotypic differences of morphology and function as com-pared to non-carriers. In particular in the CFH group, a loss of photoreceptors occurred concomitantly with reduced retinal sensitivity. Further studies might help to better understand the pathophysiology. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Retinal detachment is an acute disorder in humans that is caused by trauma or disease, and it can often lead to permanent visual deficits that result from the death of photoreceptors in the retina. The final pathway for photoreceptor cell death is apoptosis and necroptosis. The X-linked inhibitor of apoptosis (XIAP) has been shown to block both of these cell death pathways. This study tested the effects of XIAP on photoreceptor survival in a feline model of retinal detachment. The study was performed in 12 cats, divided into two experimental groups. Six animals received a subretinal injection of adeno-associated virus (AAV) carrying XIAP, and six animals received AAV carrying green fluorescent protein ( GFP) as a control. Three weeks after viral delivery, retinas were detached by injecting C3F8 gas into the subretinal space. Optical coherence tomography revealed that the retinal detachments resolved within 3-6 weeks as the gas was slowly resorbed. Analysis of histological sections through the plane of the detachment showed significant preservation of the photoreceptor layer in AAV-XIAP-treated animals compared to AAV-GFP-treated animals at 9 weeks after the detachment. XIAP-treated detached retinas were similar to intact controls. These studies support the potential for XIAP therapy in the treatment of human retinal detachment. [ABSTRACT FROM AUTHOR]

Background: In this study, we present a juvenile retinoschisis patient with developmental delay, sensorineural hearing loss, and reduced axial tone. X-linked juvenile retinoschisis (XLRS) is a retinal dystrophy, most often not associated with systemic anomalies and also not showing any locus heterogeneity. Therefore it was of interest to understand the genetic basis of the condition in this patient. Materials and methods: RS1 gene screening for XLRS was performed by Sanger sequencing. Whole genome SNP 6.0 array analysis was carried out to investigate gross chromosomal aberrations that could result in systemic phenotype. In addition, targeted next generation sequencing (NGS) was employed to determine any possible involvement of X-linked syndromic and non-syndromic mental retardation genes. This NGS panel consisted of 550 genes implicated in several other rare inherited diseases. Results: RS1 gene screening revealed a pathogenic hemizygous splice site mutation (c.78+1G>T), inherited from the mother. SNP 6.0 array analysis did not indicate any significant chromosomal aberrations that could be disease-associated. Targeted resequencing did not identify any mutations in the X-linked mental retardation genes. However, variations in three other genes (NSD1, LARGE, and POLG) were detected, which were all inherited from the patient's unaffected father. Conclusions: Taken together, RS1 mutation was found to segregate with retinoschisis phenotype while none of the other identified variations were co-segregating with the systemic defects. Hereby, we infer that the multisystemic defects harbored by the patient are a rare coexistence of XLRS, developmental delay, sensorineural hearing loss, and reduced axial tone reported for the first time in the literature. [ABSTRACT FROM AUTHOR]

Age-related macular degeneration (AMD) is a leading cause of blindness in the developed world. While many AMD susceptibility variants have been identified, their influence on AMD progression has not been elucidated. Using data from two large clinical trials, Age-Related Eye Disease Study (AREDS) and AREDS2, we evaluated the effects of 34 known risk variants on disease progression. In doing so, we calculated the eye-level time-to-late AMD and modeled them using a bivariate survival analysis approach, appropriately accounting for between-eye correlation. We then derived a genetic risk score (GRS) based on these 34 risk variants, and analyzed its effect on AMD progression. Finally, we used the AREDS data to fit prediction models of progression based on demographic and environmental factors, eye-level AMD severity scores and the GRS and tested the models using the AREDS2 cohort. We observed that GRS was significantly associated with AMD progression in both cohorts, with a stronger effect in AREDS than in AREDS2 (AREDS: hazard ratio (HR) = 1.34, P = 1.6 X 10-22; AREDS2: HR = 1.11, P = 2.1 X 10-4). For prediction of AMD progression, addition of GRS to the demographic/environmental risk factors considerably improved the prediction performance. However, when the baseline eye-level severity scores were included as the predictors, any other risk factors including the GRS only provided small additional predictive power. Our model for predicting the disease progression risk demonstrated satisfactory performance in both cohorts, and we recommend its use with baseline AMD severity scores plus baseline age, education level, and smoking status, either with or without GRS. [ABSTRACT FROM AUTHOR]

Recessive Stargardt macular degeneration (STGD1) is caused by mutations in the gene for the ABCA4 transporter in photoreceptor outer segments. STGD1 patients and Abca4-/- (STGD1) mice exhibit buildup of bisretinoid-containing lipofuscin pigments in the retinal pigment epithelium (RPE), increased oxidative stress, augmented complement activation and slow degeneration of photoreceptors. A reduction in complement negative regulatory proteins (CRPs), possibly owing to bisretinoid accumulation, may be responsible for the increased complement activation seen on the RPE of STGD1 mice. CRPs prevent attack on host cells by the complement system, and complement receptor 1-like protein y (CRRY) is an important CRP in mice. Here we attempted to rescue the phenotype in STGD1 mice by increasing expression of CRRY in the RPE using a gene therapy approach. We injected recombinant adeno-associated virus containing the CRRY coding sequence (AAV-CRRY) into the subretinal space of 4-wk-old Abca4-/- mice. This resulted in sustained, several-fold increased expression of CRRY in the RPE, which significantly reduced the complement factors C3/C3b in the RPE. Unexpectedly, AAV-CRRY-treated STGD1 mice also showed reduced accumulation of bisretinoids compared with sham-injected STGD1 controlmice. Furthermore, we observed slower photoreceptor degeneration and increased visual chromophore in 1-y-old AAV-CRRY-treated STGD1 mice. Rescue of the STGD1 phenotype by AAV-CRRY gene therapy suggests that complement attack on the RPE is an important etiologic factor in STGD1. Modulation of the complement system by locally increasing CRP expression using targeted gene therapy represents a potential treatment strategy for STGD1 and other retinopathies associated with complement dysregulation. [ABSTRACT FROM AUTHOR]

X-linked juvenile retinoschisis ( XLRS) is a hereditary retinal dystrophy in young males, caused by mutations in the RS1 gene. The function of the encoded protein, termed retinoschisin, and the molecular mechanisms underlying XLRS pathogenesis are still unresolved, although a direct interaction partner of the secreted retinoschisin, the retinal Na/K- ATPase, was recently identified. Earlier gene expression studies in retinoschisin-deficient ( Rs1h −/Y) mice provided a first indication of pathological up-regulation of mitogen-activated protein ( MAP) kinase signalling in disease pathogenesis. To further investigate the role for retinoschisin in MAP kinase regulation, we exposed Y-79 cells and murine Rs1h −/Y retinae to recombinant retinoschisin and the XLRS-associated mutant RS1-C59S. Although normal retinoschisin stably bound to retinal cells, RS1-C59S exhibited a strongly reduced binding affinity. Simultaneously, exposure to normal retinoschisin significantly reduced phosphorylation of C- RAF and MAP kinases ERK1/2 in Y-79 cells and murine Rs1h −/Y retinae. Expression of MAP kinase target genes C- FOS and EGR1 was also down-regulated in both model systems. Finally, retinoschisin treatment decreased pro-apoptotic BAX-2 transcript levels in Y-79 cells and Rs1h −/Y retinae. Upon retinoschisin treatment, these cells showed increased resistance against apoptosis, reflected by decreased caspase-3 activity (in Y-79 cells) and increased photoreceptor survival (in Rs1h −/Y retinal explants). RS1-C59S did not influence C- RAF or ERK1/2 activation, C- FOS or EGR1 expression, or apoptosis. Our data imply that retinoschisin is a novel regulator of MAP kinase signalling and exerts an anti-apoptotic effect on retinal cells. We therefore discuss that disturbances of MAP kinase signalling by retinoschisin deficiency could be an initial step in XLRS pathogenesis. [ABSTRACT FROM AUTHOR]

Background: Age-related macular degeneration (AMD) is a common condition of vision loss with disease development strongly influenced by environmental and genetic factors. Recently, 34 loci were associated with AMD at genome-wide significance. So far, little is known about a genetic overlap between AMD and other complex diseases or disease-relevant traits. Methods: For each of 60 complex diseases/traits with publicly available genome-wide significant association data, the lead genetic variant per independent locus was extracted and a genetic score was calculated for each disease/ trait as the weighted sum of risk alleles. The association with AMD was estimated based on 16,144 AMD cases and 17,832 controls using logistic regression. Results: Of the respective disease/trait variance, the 60 genetic scores explained on average 4.8% (0.27-20.69%) and 16 of them were found to be significantly associated with AMD (Q-values < 0.01, p values from < 1.0 × 10-16 to 1.9 × 10-3). Notably, an increased risk for AMD was associated with reduced risk for cardiovascular diseases, increased risk for autoimmune diseases, higher HDL and lower LDL levels in serum, lower bone-mineral density as well as an increased risk for skin cancer. By restricting the analysis to 1824 variants initially used to compute the 60 genetic scores, we identified 28 novel AMD risk variants (Q-values < 0.01, p values from 1.1 × 10-7 to 3.0 × 10-4), known to be involved in cardiovascular disorders, lipid metabolism, autoimmune diseases, anthropomorphic traits, ocular disorders, and neurological diseases. The latter variants represent 20 novel AMD-associated, pleiotropic loci. Genes in the novel loci reinforce previous findings strongly implicating the complement system in AMD pathogenesis. Conclusions: We demonstrate a substantial overlap of the genetics of several complex diseases/traits with AMD and provide statistically significant evidence for an additional 20 loci associated with AMD. This highlights the possibility that so far unrelated pathologies may have disease pathways in common. [ABSTRACT FROM AUTHOR]

Retinal ganglion cell (RGC) injury is one of the important pathological features of diabetes-induced retinal neurodegeneration. Increasing attention has been paid to find strategies for protecting against RGC injury. Long noncoding RNAs (lncRNAs) have emerged as the key regulators of many cell functions. Here, we show that Sox2OT expression is significantly down-regulated in the retinas of STZ-induced diabetic mice and in the RGCs upon high glucose or oxidative stress. SOX2OT knockdown protects RGCs against high glucose-induced injury in vitro. Moreover, Sox2OT knockdown plays a neuroprotective role in diabetes-related retinal neurodegeneration in vivo. Sox2OT knockdown could regulate oxidative stress response in RGCs and diabetic mouse retinas. Sox2OT knockdown plays an anti-oxidative role via regulating NRF2/HO-1 signaling activity. Taken together, Sox2OT knockdown may be a therapeutic strategy for the prevention and treatment of diabetes-induced retinal neurodegeneration. [ABSTRACT FROM AUTHOR]

Background: Retinitis pigmentosa (RP) is the most common cause of inherited retinal degeneration and can occur in non-syndromic and syndromic forms. Syndromic RP is accompanied by other symptoms such as intellectual disability, hearing loss, or congenital abnormalities. Both forms are known to exhibit complex genetic interactions that can modulate the penetrance and expressivity of the phenotype. Materials and methods: In an individual with atypical RP, hearing loss, ataxia and cerebellar atrophy, whole exome sequencing was performed. The candidate pathogenic variants were tested by developing anin vivozebrafish model and assaying for retinal and cerebellar integrity. Results: Exome sequencing revealed a complex heterozygous protein-truncating mutation inRP1L1, p.[(Lys111Glnfs 27; Gln2373 )], and a heterozygous nonsense mutation inC2orf71, p.(Ser512 ). Mutations in both genes have previously been implicated in autosomal recessive non-syndromic RP, raising the possibility of a digenic model in this family. Functional testing in a zebrafish model for two key phenotypes of the affected person showed that the combinatorial suppression ofrp1l1andc2orf71linduced discrete pathology in terms of reduction of eye size with concomitant loss of rhodopsin in the photoreceptors, and disorganization of the cerebellum. Conclusions: We propose that the combination of heterozygous loss-of-function mutations in these genes drives syndromic retinal dystrophy, likely through the genetic interaction of at least two loci. Haploinsufficiency at each of these loci is insufficient to induce overt pathology. [ABSTRACT FROM AUTHOR]

Background: Infiltrating immune cells including monocytes/macrophages have been implicated in the pathogenesis of neovascular age-related macular degeneration (nAMD). The aim of this study was to investigate the cytokine and chemokine expression and secretion profile of peripheral blood mononuclear cells (PBMCs) from nAMD patients and the relationship between the cytokine/chemokine expression profile and clinical phenotype of nAMD, including macular fibrosis, macular atrophy or the responsiveness to anti-VEGF therapy.Methods: One hundred sixty-one nAMD patients and 43 controls were enrolled in this study. nAMD patients were divided into subgroups based on the presence/absence of (1) macular atrophy, (2) macular fibrosis and (3) responsiveness to anti-VEGF therapy; 25-30 ml of peripheral blood were obtained from all participants and 5 ml were used for serum collection, and the remaining were used for PBMC isolation using density gradient centrifugation. Intracellular cytokine expressions by PBMCs following phorbol 12-myristate 13-acetate (PMA) and ionomycin stimulation were examined using flow cytometry. Cytokine productions in lipopolysaccharides (LPS)-or 1% oxygen -treated PBMC were measured using cytometric bead array (CBA) assay. In addition, cytokine and chemokine levels in the serum were also measured by CBA assay.Results: PBMCs from nAMD patients secreted higher levels of IL-8, CCL2 and VEGF, especially following LPS and 1% oxygen stimulation, than those from controls. 60~80% of IL-8 producing cells were CD11b+CD3- monocytes. The percentage of CD11b+CD3- IL-8+ was significantly increased in nAMD patients compared to controls. PBMCs from nAMD patients without macular fibrosis produced the highest levels of IL-8 and CCL2, whilst PBMCs from nAMD patients with macular atrophy produced highest levels of VEGF. In addition, PBMCs from patients who partially responded to anti-VEGF produced higher levels of IL-8 compared to the cells from complete responders. Interestingly, serum level of CCL2 was not increased in nAMD patients although there was a trend of increased IL-8 in nAMD patients.Conclusions: PBMCs, in particular monocytes, may contribute to CNV development in nAMD through secreting elevated levels of IL-8, CCL2 and VEGF after they are recruited to the macula. Apart from VEGF, IL-8 and CCL2 may be additional targets for nAMD management. [ABSTRACT FROM AUTHOR]