scholarly journals Big DNA as a tool to dissect an age-related macular degeneration-associated haplotype

2018 ◽  
Author(s):  
Jon M Laurent ◽  
Xin Fu ◽  
Sergei German ◽  
Matthew T Maurano ◽  
Kang Zhang ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Association Studies ◽  
Genetic Association Studies ◽  
Cell Types ◽  
Difficult Problem ◽  
Age Related Macular Degeneration ◽  
Functional Sites ◽  
Functional Variants ◽  
Age Related ◽  
Aging Populations

AbstractAge-related Macular Degeneration (AMD) is a leading cause of blindness in the developed world, especially in aging populations, and is therefore an important target for new therapeutic development. Recently, there have been several studies demonstrating strong associations between AMD and sites of heritable genetic variation at multiple loci, including a highly significant association at 10q26. The 10q26 risk region contains two genes, HTRA1 and ARMS2, both of which have been separately implicated as causative for the disease, as well as dozens of sites of non-coding variation. To date, no studies have successfully pinpointed which of these variant sites are functional in AMD, nor definitively identified which genes in the region are targets of such regulatory variation. In order to efficiently decipher which sites are functional in AMD phenotypes, we describe a general framework for combinatorial assembly of large ‘synthetic haplotypes’ along with delivery to relevant disease cell types for downstream functional analysis. We demonstrate the successful and highly efficient assembly of a first-draft 119kb wild-type ‘assemblon’ covering the HTRA1/ARMS2 risk region. We further propose the parallelized assembly of a library of combinatorial variant synthetic haplotypes covering the region, delivery and analysis of which will identify functional sites and their effects, leading to an improved understanding of AMD development. We anticipate that the methodology proposed here is highly generalizable towards the difficult problem of identifying truly functional variants from those discovered via GWAS or other genetic association studies.

scholarly journals A Validated Phenotyping Algorithm for Genetic Association Studies in Age-related Macular Degeneration

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Joseph M. Simonett ◽  
Mahsa A. Sohrab ◽  
Jennifer Pacheco ◽  
Loren L. Armstrong ◽  
Margarita Rzhetskaya ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Genetic Association ◽  
Association Studies ◽  
Genetic Association Studies ◽  
Age Related Macular Degeneration ◽  
Age Related

scholarly journals Single-cell transcriptomic atlas of the human retina identifies cell types associated with age-related macular degeneration

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Madhvi Menon ◽  
Shahin Mohammadi ◽  
Jose Davila-Velderrain ◽  
Brittany A. Goods ◽  
Tanina D. Cadwell ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Single Cell ◽  
Association Studies ◽  
Enrichment Analysis ◽  
Cell Types ◽  
Age Related Macular Degeneration ◽  
Retinal Cell ◽  
Genome Wide Association Studies ◽  
Human Retina ◽  
Age Related

Abstract Genome-wide association studies (GWAS) have identified genetic variants associated with age-related macular degeneration (AMD), one of the leading causes of blindness in the elderly. However, it has been challenging to identify the cell types associated with AMD given the genetic complexity of the disease. Here we perform massively parallel single-cell RNA sequencing (scRNA-seq) of human retinas using two independent platforms, and report the first single-cell transcriptomic atlas of the human retina. Using a multi-resolution network-based analysis, we identify all major retinal cell types, and their corresponding gene expression signatures. Heterogeneity is observed within macroglia, suggesting that human retinal glia are more diverse than previously thought. Finally, GWAS-based enrichment analysis identifies glia, vascular cells, and cone photoreceptors to be associated with the risk of AMD. These data provide a detailed analysis of the human retina, and show how scRNA-seq can provide insight into cell types involved in complex, inflammatory genetic diseases.

scholarly journals New Technologies to Study Functional Genomics of Age-Related Macular Degeneration

2021 ◽  
Vol 8 ◽  
Author(s):  
Tu Nguyen ◽  
Daniel Urrutia-Cabrera ◽  
Roxanne Hsiang-Chi Liou ◽  
Chi D. Luu ◽  
Robyn Guymer ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Vision Loss ◽  
New Technologies ◽  
Cell Types ◽  
Developed Countries ◽  
Age Related Macular Degeneration ◽  
Retinal Cell ◽  
Functional Study ◽  
Age Related

Age-related macular degeneration (AMD) is the most common cause of irreversible vision loss in people over 50 years old in developed countries. Currently, we still lack a comprehensive understanding of the genetic factors contributing to AMD, which is critical to identify effective therapeutic targets to improve treatment outcomes for AMD patients. Here we discuss the latest technologies that can facilitate the identification and functional study of putative genes in AMD pathology. We review improved genomic methods to identify novel AMD genes, advances in single cell transcriptomics to profile gene expression in specific retinal cell types, and summarize recent development of in vitro models for studying AMD using induced pluripotent stem cells, organoids and biomaterials, as well as new molecular technologies using CRISPR/Cas that could facilitate functional studies of AMD-associated genes.

scholarly journals Identification of fluoxetine as a direct NLRP3 inhibitor to treat atrophic macular degeneration

2021 ◽  
Vol 118 (41) ◽  
pp. e2102975118
Author(s):  
Meenakshi Ambati ◽  
Ivana Apicella ◽  
Shao-bin Wang ◽  
Siddharth Narendran ◽  
Hannah Leung ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Vision Loss ◽  
Antidepressant Drugs ◽  
Drug Repurposing ◽  
Cell Types ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Dry Amd

The atrophic form of age-related macular degeneration (dry AMD) affects nearly 200 million people worldwide. There is no Food and Drug Administration (FDA)-approved therapy for this disease, which is the leading cause of irreversible blindness among people over 50 y of age. Vision loss in dry AMD results from degeneration of the retinal pigmented epithelium (RPE). RPE cell death is driven in part by accumulation of Alu RNAs, which are noncoding transcripts of a human retrotransposon. Alu RNA induces RPE degeneration by activating the NLRP3-ASC inflammasome. We report that fluoxetine, an FDA-approved drug for treating clinical depression, binds NLRP3 in silico, in vitro, and in vivo and inhibits activation of the NLRP3-ASC inflammasome and inflammatory cytokine release in RPE cells and macrophages, two critical cell types in dry AMD. We also demonstrate that fluoxetine, unlike several other antidepressant drugs, reduces Alu RNA–induced RPE degeneration in mice. Finally, by analyzing two health insurance databases comprising more than 100 million Americans, we report a reduced hazard of developing dry AMD among patients with depression who were treated with fluoxetine. Collectively, these studies identify fluoxetine as a potential drug-repurposing candidate for dry AMD.

scholarly journals Protective coding variants in CFH and PELI3 and a variant near CTRB1 are associated with age-related macular degeneration

2015 ◽  
Author(s):  
Erin K. Wagner ◽  
Yi Yu ◽  
Eric H. Souied ◽  
Sanna Seitsonen ◽  
Ilkka J. Immonen ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Rare Variants ◽  
Association Studies ◽  
Low Frequency ◽  
Density Lipoprotein ◽  
Age Related Macular Degeneration ◽  
European Ancestry ◽  
Genome Wide Association Studies ◽  
Age Related ◽  
Meta Analyses

ABSTRACTAlthough >20 common frequency age-related macular degeneration (AMD) alleles have been discovered with genome-wide association studies, substantial disease heritability remains unexplained. In this study we sought to identify additional variants, both common and rare, that have an association with advanced AMD. We genotyped 4,332 cases and 25,268 controls of European ancestry from three different populations using the Illumina Infinium HumanExome BeadChip. We performed meta-analyses to identify associations with common variants and performed single variant and gene-based burden tests to identify associations with rare variants. Two protective, low frequency, non-synonymous variants A307V in PELI3 (odds ratio [OR]=0.14, P=4.3×10−10) and N1050Y in CFH (OR=0.76, Pconditional=1.6×10−11) were significantly associated with a decrease in risk of AMD. Additionally, we identified an enrichment of protective alleles in PELI3 using a burden test (OR=0.14). The new variants have a large effect size, similar to rare mutations we reported previously in a targeted sequencing study, which remain significant in this analysis: CFH R1210C (OR=18.82, P=3.5×10−07), C3 K155Q (OR=3.27, P=1.5×10−10), and C9 P167S (OR=2.04, P=2.8×10−07). We also identified a strong protective signal for a common variant (rs8056814) near CTRB1 associated with a decrease in AMD risk (logistic regression: OR = 0.71, P = 1.8x10−07; Firth corrected OR = 0.64, P = 9.6x10−11). This study supports the involvement of both common and low frequency protective variants in AMD. It also may expand the role of the high-density lipoprotein pathway and branches of the innate immune pathway, outside that of the complement system, in the etiology of AMD.

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