scholarly journals A widespread decrease of chromatin accessibility in age-related macular degeneration

2018 ◽  
Author(s):  
Jie Wang ◽  
Cristina Zibetti ◽  
Peng Shang ◽  
Srinivasa R. Sripathi ◽  
Pingwu Zhang ◽  
...  

AbstractAge-related macular degeneration (AMD) is a leading cause of blindness in the elderly. The extent to which epigenetic changes regulate AMD progression is unclear. Here we globally profiled chromatin accessibility in the retina and retinal pigmented epithelium (RPE) from AMD patients and controls. Global decreases in chromatin accessibility occurr in RPE in early AMD, and in the retina with advanced disease, suggesting that dysfunction in RPE cells drives disease progression. Footprints of photoreceptor and RPE-specific transcription factors are enriched in differentially accessible regions (DARs). Genes associated with DARs show altered expression in AMD. Cigarette smoke treatment of RPE cells recapitulates epigenomic changes seen in AMD, providing an epigenetic link between the known risk factors for AMD and AMD pathology. Finally, overexpression of HDAC11 is partially responsible for the reduction in chromatin accessibility, identifying potential new targets for treatment of AMD.

2020 ◽  
Vol 29 (15) ◽  
pp. 2611-2624
Author(s):  
Jennings Luu ◽  
Les Kallestad ◽  
Thanh Hoang ◽  
Dominik Lewandowski ◽  
Zhiqian Dong ◽  
...  

Abstract Age-related macular degeneration (AMD) is a chronic, multifactorial disorder and a leading cause of blindness in the elderly. Characterized by progressive photoreceptor degeneration in the central retina, disease progression involves epigenetic changes in chromatin accessibility resulting from environmental exposures and chronic stress. Here, we report that a photosensitive mouse model of acute stress-induced photoreceptor degeneration recapitulates the epigenetic hallmarks of human AMD. Global epigenomic profiling was accomplished by employing an Assay for Transposase-Accessible Chromatin using Sequencing (ATAC-Seq), which revealed an association between decreased chromatin accessibility and stress-induced photoreceptor cell death in our mouse model. The epigenomic changes induced by light damage include reduced euchromatin and increased heterochromatin abundance, resulting in transcriptional and translational dysregulation that ultimately drives photoreceptor apoptosis and an inflammatory reactive gliosis in the retina. Of particular interest, pharmacological inhibition of histone deacetylase 11 (HDAC11) and suppressor of variegation 3–9 homolog 2 (SUV39H2), key histone-modifying enzymes involved in promoting reduced chromatin accessibility, ameliorated light damage in our mouse model, supporting a causal link between decreased chromatin accessibility and photoreceptor degeneration, thereby elucidating a potential new therapeutic strategy to combat AMD.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Jiangyuan Gao ◽  
Ruozhou Tom Liu ◽  
Sijia Cao ◽  
Jing Z. Cui ◽  
Aikun Wang ◽  
...  

Age-related macular degeneration (AMD) is the leading cause of legal blindness in the elderly in industrialized countries. AMD is a multifactorial disease influenced by both genetic and environmental risk factors. Progression of AMD is characterized by an increase in the number and size of drusen, extracellular deposits, which accumulate between the retinal pigment epithelium (RPE) and Bruch’s membrane (BM) in outer retina. The major pathways associated with its pathogenesis include oxidative stress and inflammation in the early stages of AMD. Little is known about the interactions among these mechanisms that drive the transition from early to late stages of AMD, such as geographic atrophy (GA) or choroidal neovascularization (CNV). As part of the innate immune system, inflammasome activation has been identified in RPE cells and proposed to be a causal factor for RPE dysfunction and degeneration. Here, we will first review the classic model of inflammasome activation, then discuss the potentials of AMD-related factors to activate the inflammasome in both nonocular immune cells and RPE cells, and finally introduce several novel mechanisms for regulating the inflammasome activity.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zi-Yuan Zhang ◽  
Xiao-Li Bao ◽  
Yun-Yi Cong ◽  
Bin Fan ◽  
Guang-Yu Li

Age-related macular degeneration (AMD) is a leading cause of severe visual loss and irreversible blindness in the elderly population worldwide. Retinal pigment epithelial (RPE) cells are the major site of pathological alterations in AMD. They are responsible for the phagocytosis of shed photoreceptor outer segments (POSs) and clearance of cellular waste under physiological conditions. Age-related, cumulative oxidative stimuli contribute to the pathogenesis of AMD. Excessive oxidative stress induces RPE cell degeneration and incomplete digestion of POSs, leading to the continuous accumulation of cellular waste (such as lipofuscin). Autophagy is a major system of degradation of damaged or unnecessary proteins. However, degenerative RPE cells in AMD patients cannot perform autophagy sufficiently to resist oxidative damage. Increasing evidence supports the idea that enhancing the autophagic process can properly alleviate oxidative injury in AMD and protect RPE and photoreceptor cells from degeneration and death, although overactivated autophagy may lead to cell death at early stages of retinal degenerative diseases. The crosstalk among the NFE2L2, PGC-1, p62, AMPK, and PI3K/Akt/mTOR pathways may play a crucial role in improving disturbed autophagy and mitigating the progression of AMD. In this review, we discuss how autophagy prevents oxidative damage in AMD, summarize potential neuroprotective strategies for therapeutic interventions, and provide an overview of these neuroprotective mechanisms.


2021 ◽  
Author(s):  
Meenakshi Ambati ◽  
Ivana Apicella ◽  
Siddharth Narendran ◽  
Shao-bin Wang ◽  
Hannah Leung ◽  
...  

AbstractThe atrophic form of age-related macular degeneration (dry AMD) affects nearly 200 million people worldwide. There is no FDA-approved therapy for this disease, which is the leading cause of irreversible blindness among people over 50 years 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 that it inhibits activation of the NLRP3-ASC inflammasome in RPE cells and macrophages, two critical cell types in dry AMD. We also demonstrate that fluoxetine, unlike several other anti-depressant 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 triangulate to link fluoxetine as a potential drug repurposing candidate for a major unmet medical need that causes blindness in millions of people in the United States and across the world.Significance StatementDry age-related macular degeneration (AMD) affects the vision of millions of people worldwide. There is currently no FDA-approved treatment for dry AMD. The inflammasome components NLRP3 and ASC have been implicated in the pathogenesis of dry AMD. We report that fluoxetine, which is approved for the treatment of clinical depression, directly binds the NLRP3 protein and prevents the assembly and activation of the NLRP3-ASC inflammasome. As a result, it also blocks the degeneration of retinal pigmented epithelium (RPE) cells in an animal model of dry AMD. Furthermore, we demonstrate through an analysis of health insurance databases that use of this FDA-approved anti-depressant drug is associated with reduced incidence of dry AMD. These studies identify that fluoxetine is a potential repurposing candidate for AMD, a prevalent cause of blindness.


2018 ◽  
Vol 9 (4) ◽  
pp. 2171-2183 ◽  
Author(s):  
Jun Kim ◽  
Hong Lan Jin ◽  
Dae Sik Jang ◽  
Kwang Won Jeong ◽  
Se-Young Choung

Age-related macular degeneration (AMD) is a chronic degenerative disease that can lead to visual loss and blindness in the elderly.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shigeru Honda ◽  
Yasuo Yanagi ◽  
Hideki Koizumi ◽  
Yirong Chen ◽  
Satoru Tanaka ◽  
...  

AbstractThe chronic eye disorder, neovascular age-related macular degeneration (nAMD), is a common cause of permanent vision impairment and blindness among the elderly in developed countries, including Japan. This study aimed to investigate the disease burden of nAMD patients under treatment, using data from the Japan National Health and Wellness surveys 2009–2014. Out of 147,272 respondents, 100 nAMD patients reported currently receiving treatment. Controls without nAMD were selected by 1:4 propensity score matching. Healthcare Resource Utilisation (HRU), Health-Related Quality of Life (HRQoL), and work productivity loss were compared between the groups. Regarding HRU, nAMD patients had significantly increased number of visits to any healthcare provider (HCP) (13.8 vs. 8.2), ophthalmologist (5.6 vs. 0.8), and other HCP (9.5 vs. 7.1) compared to controls after adjusting for confounding factors. Additionally, nAMD patients had reduced HRQoL and work productivity, i.e., reduced physical component summary (PCS) score (46.3 vs. 47.9), increased absenteeism (18.14% vs. 0.24%), presenteeism (23.89% vs. 12.44%), and total work productivity impairment (33.57% vs. 16.24%). The increased number of ophthalmologist visits were associated with decreased PCS score, increased presenteeism and total work productivity impairment. The current study highlighted substantial burden for nAMD patients, requiring further attention for future healthcare planning and treatment development.


2021 ◽  
Vol 22 (3) ◽  
pp. 1170
Author(s):  
Arunbalaji Pugazhendhi ◽  
Margaret Hubbell ◽  
Pooja Jairam ◽  
Balamurali Ambati

Neovascular age-related macular degeneration (exudative or wet AMD) is a prevalent, progressive retinal degenerative macular disease that is characterized by neovascularization of the choroid, mainly affecting the elderly population causing gradual vision impairment. Risk factors such as age, race, genetics, iris color, smoking, drinking, BMI, and diet all play a part in nvAMD’s progression, with anti-vascular endothelial growth factor (anti-VEGF) therapy being the mainstay of treatment. Current therapeutic advancements slow the progression of the disease but do not cure or reverse its course. Newer therapies such as gene therapies, Rho-kinase inhibitors, and levodopa offer potential new targets for treatment.


2020 ◽  
Vol 77 (5) ◽  
pp. 779-780 ◽  
Author(s):  
Anu Kauppinen

AbstractProlonged life expectancies contribute to the increasing prevalence of age-related macular degeneration (AMD) that is already the leading cause of severe vision loss among the elderly in developed countries. In dry AMD, the disease culminates into vast retinal atrophy, whereas the wet form is characterized by retinal edema and sudden vision loss due to neovascularization originating from the choroid beneath the Bruch’s membrane. There is no treatment for dry AMD and despite intravitreal injections of anti-vascular endothelial growth factor (VEGF) that suppress the neovessel formation, also wet AMD needs new therapies to prevent the disease progression and to serve patients lacking of positive response to current medicines. Knowledge on disease mechanisms is a prerequisite for the drug development, which is hindered by the multifactorial nature of AMD. Numerous distinguished publications have revealed AMD mechanisms at the cellular and molecular level and in this multi-author review, we take a bit broader look at the topic with some novel aspects.


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