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 Apolipoprotein E isoform-specific phase transitions in the retinal pigment epithelium drive disease phenotypes in age-related macular degeneration

2020 ◽  
Author(s):  
Nilsa La Cunza ◽  
Li Xuan Tan ◽  
Gurugirijha Rathnasamy ◽  
Thushara Thamban ◽  
Colin J. Germer ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Retinal Pigment Epithelium ◽  
Macular Degeneration ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Human Donor ◽  
Age Related ◽  
Histopathological Studies

AbstractThe retinal pigment epithelium (RPE) is the site of initial damage leading to photoreceptor degeneration and vision loss in age-related macular degeneration (AMD). Genetic and histopathological studies implicate cholesterol dysregulation in AMD; yet mechanisms linking cholesterol to RPE injury and drusen formation remain poorly understood. Especially enigmatic are allelic variants of the cholesterol transporter APOE, major risk modifiers in Alzheimer’s disease that show reversed risk associations with AMD. Here, we investigated how ApoE isoforms modulate RPE health using live-cell imaging of primary RPE cultures and high-resolution imaging of human donor tissue. We show that the AMD-protective ApoE4 efficiently transports cholesterol and safeguards RPE homeostasis despite cellular stress. In contrast, ApoE2-expressing RPE accumulate cholesterol, which promotes autophagic deficits and complement-mediated mitochondrial fragmentation. Redox-related order-disorder phase transitions in ApoE2 drive the formation of intracellular biomolecular condensates as potential drusen precursors. Drugs that restore mitochondrial function limit condensate formation in ApoE2-RPE. Autophagic and mitochondrial defects correlate with intracellular ApoE aggregates in AMD donor RPE. Our study elucidates how AMD risk variants act as tipping points to divert the RPE from normal aging towards AMD by disrupting critical metabolic functions, and identifies mitochondrial stress-mediated aberrant phase transitions as a novel mechanism of drusen biogenesis.

scholarly journals Cellular senescence in the aging retina and developments of senotherapies for age-related macular degeneration

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Keng Siang Lee ◽  
Shuxiao Lin ◽  
David A. Copland ◽  
Andrew D. Dick ◽  
Jian Liu
Keyword(s):  
Retinal Pigment Epithelium ◽  
Macular Degeneration ◽  
Cellular Senescence ◽  
Vision Loss ◽  
Inflammatory Responses ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
The Elderly ◽  
Age Related Macular Degeneration ◽  
Age Related

AbstractAge-related macular degeneration (AMD), a degenerative disease in the central macula area of the neuroretina and the supporting retinal pigment epithelium, is the most common cause of vision loss in the elderly. Although advances have been made, treatment to prevent the progressive degeneration is lacking. Besides the association of innate immune pathway genes with AMD susceptibility, environmental stress- and cellular senescence-induced alterations in pathways such as metabolic functions and inflammatory responses are also implicated in the pathophysiology of AMD. Cellular senescence is an adaptive cell process in response to noxious stimuli in both mitotic and postmitotic cells, activated by tumor suppressor proteins and prosecuted via an inflammatory secretome. In addition to physiological roles in embryogenesis and tissue regeneration, cellular senescence is augmented with age and contributes to a variety of age-related chronic conditions. Accumulation of senescent cells accompanied by an impairment in the immune-mediated elimination mechanisms results in increased frequency of senescent cells, termed “chronic” senescence. Age-associated senescent cells exhibit abnormal metabolism, increased generation of reactive oxygen species, and a heightened senescence-associated secretory phenotype that nurture a proinflammatory milieu detrimental to neighboring cells. Senescent changes in various retinal and choroidal tissue cells including the retinal pigment epithelium, microglia, neurons, and endothelial cells, contemporaneous with systemic immune aging in both innate and adaptive cells, have emerged as important contributors to the onset and development of AMD. The repertoire of senotherapeutic strategies such as senolytics, senomorphics, cell cycle regulation, and restoring cell homeostasis targeted both at tissue and systemic levels is expanding with the potential to treat a spectrum of age-related diseases, including AMD.

scholarly journals Classical, Micropulse and NanoSecond Laser Therapy in Dry-Form (Non-Neovascular) Age-Related Macular Degeneration

2017 ◽  
pp. 155-159
Keyword(s):  
Macular Degeneration ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Treatment Modalities ◽  
Nanosecond Laser ◽  
Laser Applications ◽  
Age Related ◽  
Neuroprotective Treatment

Age-related macular degeneration (AMD), which is a multifactorial, degenerative disease of the retina, is the most common reason for legal blindness over 50 years of age. Dry-form (non-neovascular) AMD is the common type, and frequently non-progressive to total vision loss. Epidemiological, histopathological, and biochemical data demonstrate that AMD is associated with oxidative damage, lipofuscin accumulation, chronic inflammation, and mutations in the complement system. Drusen, hyperpigmentation/hypopigmentation in retinal pigment epithelium, and geographical atrophy can also be observed in dry-form AMD. Various treatment modalities can be used according to the stages of the disease. Antioxidants, visual cycle inhibitors, anti-inflammatory agents, neuroprotective treatment, conventional, micropulse, and nano-second laser applications are intended to regulate the various mechanisms involved in the pathogenesis of the disease.

scholarly journals Epithelial phenotype restoring drugs suppress macular degeneration phenotypes in an iPSC model

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ruchi Sharma ◽  
Aman George ◽  
Malika Nimmagadda ◽  
Davide Ortolan ◽  
Barbosa-Sabanero Karla ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
High Throughput Screening ◽  
Vision Loss ◽  
Risk Allele ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Epithelial Phenotype ◽  
Rpe Atrophy

AbstractAge-related Macular Degeneration (AMD), a blinding eye disease, is characterized by pathological protein- and lipid-rich drusen deposits underneath the retinal pigment epithelium (RPE) and atrophy of the RPE monolayer in advanced disease stages - leading to photoreceptor cell death and vision loss. Currently, there are no drugs that stop drusen formation or RPE atrophy in AMD. Here we provide an iPSC-RPE AMD model that recapitulates drusen and RPE atrophy. Drusen deposition is dependent on AMD-risk-allele CFH(H/H) and anaphylatoxin triggered alternate complement signaling via the activation of NF-κB and downregulation of autophagy pathways. Through high-throughput screening we identify two drugs, L-745,870, a dopamine receptor antagonist, and aminocaproic acid, a protease inhibitor that reduce drusen deposits and restore RPE epithelial phenotype in anaphylatoxin challenged iPSC-RPE with or without the CFH(H/H) genotype. This comprehensive iPSC-RPE model replicates key AMD phenotypes, provides molecular insight into the role of CFH(H/H) risk-allele in AMD, and discovers two candidate drugs to treat AMD.

scholarly journals Implication of N-methyl-D-aspartate receptor In Homocysteine Induced Age related Macular Degeneration

2021 ◽  
Author(s):  
Yara A. Samra ◽  
Dina Kira ◽  
Pragya Rajpurohit ◽  
Riyaz Mohamed ◽  
Leah Owen ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Mice Model ◽  
Rpe Cells ◽  
Aspartate Receptor ◽  
Age Related ◽  
Retinal Structure

Abstract Background: Age related macular degeneration (AMD) is a leading cause of vision loss in old people. Elevated homocysteine (Hcy), known as Hyperhomocysteinemia (HHcy) was reported in association with AMD. We previously reported that HHcy induces AMD like features. The current study suggests activation of N-Methyl-D-aspartate receptor (NMDAR) in retinal pigment epithelium (RPE) cells as a mechanism for HHcy-induced AMD. Serum Hcy and cystathione-β-synthase enzyme (CBS) were assessed by ELISA in AMD patients. The involvement of NMDAR in Hcy’s induced AMD features were evaluated 1)-In-vitro using ARPE-19 cells, primary RPE isolated from mice model of HHcy (CBS) and mouse choroidal endothelial cells (MCEC). 2)-In-vivo using wild type mice and mice deficient in RPE cells NMDAR (NMDARR -/-) with/without intravitreal injection of Hcy. Expression of retinal isolectin-B4, Ki67, HIF-1α, VEGF, NMDAR1 and albumin were assessed by immunofluorescence (IF), Western blot (WB), Optical coherence tomography (OCT), and fluorescein angiography (FA) to evaluate retinal structure, fluorescein leakage and development of choroidal neovascularization (CNV) in living mice. Results: Serum of the neovascular AMD patients showed significant increase in Hcy and decrease in CBS levels. Moreover, Hcy significantly increased angiogenic markers; HIF-1α, VEGF and NMDAR in RPE cells and Ki67 in MCEC. Hcy-injected WT mice showed disrupted retinal morphology and development of CNV. Knocking down NMDAR in RPE improved retinal structure and CNV induction.Conclusion: Our findings underscore the potential role for NMDAR in RPE cells in mediating Hcy-induced features of AMD and CNV induction, thus NMDAR inhibition could provide a promising therapeutic target for AMD.

scholarly journals Progressive Photoreceptor Dysfunction and Age-Related Macular Degeneration-Like Features in rp1l1 Mutant Zebrafish

Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2214
Author(s):  
Nicole C. L. Noel ◽  
Nathan J. Nadolski ◽  
Jennifer C. Hocking ◽  
Ian M. MacDonald ◽  
W. Ted Allison
Keyword(s):  
Macular Degeneration ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Macular Dystrophy ◽  
Zebrafish Model ◽  
Photoreceptor Layer ◽  
Age Related ◽  
Subretinal Drusenoid Deposits

Photoreceptor disease results in irreparable vision loss and blindness, which has a dramatic impact on quality of life. Pathogenic mutations in RP1L1 lead to photoreceptor degenerations such as occult macular dystrophy and retinitis pigmentosa. RP1L1 is a component of the photoreceptor axoneme, the backbone structure of the photoreceptor’s light-sensing outer segment. We generated an rp1l1 zebrafish mutant using CRISPR/Cas9 genome editing. Mutant animals had progressive photoreceptor functional defects as determined by electrophysiological assessment. Optical coherence tomography showed gaps in the photoreceptor layer, disrupted photoreceptor mosaics, and thinner retinas. Mutant retinas had disorganized photoreceptor outer segments and lipid-rich subretinal drusenoid deposits between the photoreceptors and retinal pigment epithelium. Our mutant is a novel model of RP1L1-associated photoreceptor disease and the first zebrafish model of photoreceptor degeneration with reported subretinal drusenoid deposits, a feature of age-related macular degeneration.

scholarly journals Mitochondrial Dysfunction and Endoplasmic Reticulum Stress in Age Related Macular Degeneration, Role in Pathophysiology, and Possible New Therapeutic Strategies

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1170
Author(s):  
Valentina Bilbao-Malavé ◽  
Jorge González-Zamora ◽  
Miriam de la Puente ◽  
Sergio Recalde ◽  
Patricia Fernandez-Robredo ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Mitochondrial Dysfunction ◽  
Macular Degeneration ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Developed Countries ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Increased Risk

Age related macular degeneration (AMD) is the main cause of legal blindness in developed countries. It is a multifactorial disease in which a combination of genetic and environmental factors contributes to increased risk of developing this vision-incapacitating condition. Oxidative stress plays a central role in the pathophysiology of AMD and recent publications have highlighted the importance of mitochondrial dysfunction and endoplasmic reticulum stress in this disease. Although treatment with vascular endothelium growth factor inhibitors have decreased the risk of blindness in patients with the exudative form of AMD, the search for new therapeutic options continues to prevent the loss of photoreceptors and retinal pigment epithelium cells, characteristic of late stage AMD. In this review, we explain how mitochondrial dysfunction and endoplasmic reticulum stress participate in AMD pathogenesis. We also discuss a role of several antioxidants (bile acids, resveratrol, melatonin, humanin, and coenzyme Q10) in amelioration of AMD pathology.

scholarly journals Classical, Micropulse and NanoSecond Laser Therapy in Dry-Form (Non-Neovascular) Age-Related Macular Degeneration

2017 ◽  
pp. 155-159
Keyword(s):  
Macular Degeneration ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Treatment Modalities ◽  
Nanosecond Laser ◽  
Laser Applications ◽  
Age Related ◽  
Neuroprotective Treatment

Age-related macular degeneration (AMD), which is a multifactorial, degenerative disease of the retina, is the most common reason for legal blindness over 50 years of age. Dry-form (non-neovascular) AMD is the common type, and frequently non-progressive to total vision loss. Epidemiological, histopathological, and biochemical data demonstrate that AMD is associated with oxidative damage, lipofuscin accumulation, chronic inflammation, and mutations in the complement system. Drusen, hyperpigmentation/hypopigmentation in retinal pigment epithelium, and geographical atrophy can also be observed in dry-form AMD. Various treatment modalities can be used according to the stages of the disease. Antioxidants, visual cycle inhibitors, anti-inflammatory agents, neuroprotective treatment, conventional, micropulse, and nano-second laser applications are intended to regulate the various mechanisms involved in the pathogenesis of the disease.

Classical, Micropulse and NanoSecond Laser Therapy in Dry-Form (Non-Neovascular) Age-Related Macular Degeneration

2017 ◽  
pp. 155-159
Keyword(s):  
Macular Degeneration ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Treatment Modalities ◽  
Nanosecond Laser ◽  
Laser Applications ◽  
Age Related ◽  
Neuroprotective Treatment

Age-related macular degeneration (AMD), which is a multifactorial, degenerative disease of the retina, is the most common reason for legal blindness over 50 years of age. Dry-form (non-neovascular) AMD is the common type, and frequently non-progressive to total vision loss. Epidemiological, histopathological, and biochemical data demonstrate that AMD is associated with oxidative damage, lipofuscin accumulation, chronic inflammation, and mutations in the complement system. Drusen, hyperpigmentation/hypopigmentation in retinal pigment epithelium, and geographical atrophy can also be observed in dry-form AMD. Various treatment modalities can be used according to the stages of the disease. Antioxidants, visual cycle inhibitors, anti-inflammatory agents, neuroprotective treatment, conventional, micropulse, and nano-second laser applications are intended to regulate the various mechanisms involved in the pathogenesis of the disease.

Sign in / Sign up

Export Citation Format

Share Document