scholarly journals Central Role of Oxidative Stress in Age-Related Macular Degeneration: Evidence from a Review of the Molecular Mechanisms and Animal Models

2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Samuel Abokyi ◽  
Chi-Ho To ◽  
Tim T. Lam ◽  
Dennis Y. Tse
Keyword(s):  
Oxidative Stress ◽  
Animal Models ◽  
Macular Degeneration ◽  
Molecular Mechanisms ◽  
The Elderly ◽  
Age Related Macular Degeneration ◽  
Related Factor ◽  
Vascular Endothelial ◽  
Age Related ◽  
Endothelial Growth Factor

Age-related macular degeneration (AMD) is a common cause of visual impairment in the elderly. There are very limited therapeutic options for AMD with the predominant therapies targeting vascular endothelial growth factor (VEGF) in the retina of patients afflicted with wet AMD. Hence, it is important to remind readers, especially those interested in AMD, about current studies that may help to develop novel therapies for other stages of AMD. This study, therefore, provides a comprehensive review of studies on human specimens as well as rodent models of the disease, to identify and analyze the molecular mechanisms behind AMD development and progression. The evaluation of this information highlights the central role that oxidative damage in the retina plays in contributing to major pathways, including inflammation and angiogenesis, found in the AMD phenotype. Following on the debate of oxidative stress as the earliest injury in the AMD pathogenesis, we demonstrated how the targeting of oxidative stress-associated pathways, such as autophagy and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, might be the futuristic direction to explore in the search of an effective treatment for AMD, as the dysregulation of these mechanisms is crucial to oxidative injury in the retina. In addition, animal models of AMD have been discussed in great detail, with their strengths and pitfalls included, to assist inform in the selection of suitable models for investigating any of the molecular mechanisms.

scholarly journals Age-Related Macular Degeneration: New Paradigms for Treatment and Management of AMD

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Luis Fernando Hernández-Zimbrón ◽  
Ruben Zamora-Alvarado ◽  
Lenin Ochoa-De la Paz ◽  
Raul Velez-Montoya ◽  
Edgar Zenteno ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Macular Degeneration ◽  
Vision Loss ◽  
Age Related Macular Degeneration ◽  
Related Factor ◽  
Visual Disability ◽  
Cellular Mechanisms ◽  
Cell Dysfunction ◽  
Age Related ◽  
Endothelial Growth Factor

Age-related macular degeneration (AMD) is a well-characterized and extensively studied disease. It is currently considered the leading cause of visual disability among patients over 60 years. The hallmark of early AMD is the formation of drusen, pigmentary changes at the macula, and mild to moderate vision loss. There are two forms of AMD: the “dry” and the “wet” form that is less frequent but is responsible for 90% of acute blindness due to AMD. Risk factors have been associated with AMD progression, and they are taking relevance to understand how AMD develops: (1) advanced age and the exposition to environmental factors inducing high levels of oxidative stress damaging the macula and (2) this damage, which causes inflammation inducing a vicious cycle, altogether causing central vision loss. There is neither a cure nor treatment to prevent AMD. However, there are some treatments available for the wet form of AMD. This article will review some molecular and cellular mechanisms associated with the onset of AMD focusing on feasible treatments for each related factor in the development of this pathology such as vascular endothelial growth factor, oxidative stress, failure of the clearance of proteins and organelles, and glial cell dysfunction in AMD.

scholarly journals Systemic Side Effects and Geographic Atrophy after Anti-VEGF Treatment in Wet-Form (Neovascular) Age-Related Macular Degeneration

2017 ◽  
pp. 256-261
Keyword(s):  
Side Effects ◽  
Macular Degeneration ◽  
The Elderly ◽  
Geographic Atrophy ◽  
Age Related Macular Degeneration ◽  
Vascular Endothelial ◽  
Anti Vegf ◽  
Age Related ◽  
Systemic Side Effects ◽  
Endothelial Growth Factor

Neovascular (wet-form) age-related macular degeneration (nARMD) is one of the leading causes of serious loss of vision in the elderly population. Intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents are commonly used in the treatment of nARMD. Systemic side effects and geographic atrophy following intravitreal administration of anti-VEGF agents in nARMD are mentioned in this review.

scholarly journals Crosstalk between Long-Term Sublethal Oxidative Stress and Detrimental Inflammation as Potential Drivers for Age-Related Retinal Degeneration

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 25
Author(s):  
Lara Macchioni ◽  
Davide Chiasserini ◽  
Letizia Mezzasoma ◽  
Magdalena Davidescu ◽  
Pier Luigi Orvietani ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Molecular Mechanisms ◽  
Age Related Macular Degeneration ◽  
Inflammasome Activation ◽  
Related Factor ◽  
Nuclear Factor ◽  
Rpe Cells ◽  
Age Related ◽  
Oxidative Insult

Age-related retinal degenerations, including age-related macular degeneration (AMD), are caused by the loss of retinal pigmented epithelial (RPE) cells and photoreceptors. The pathogenesis of AMD, deeply linked to the aging process, also involves oxidative stress and inflammatory responses. However, the molecular mechanisms contributing to the shift from healthy aging to AMD are still poorly understood. Since RPE cells in the retina are chronically exposed to a pro-oxidant microenvironment throughout life, we simulated in vivo conditions by growing ARPE-19 cells in the presence of 10 μM H2O2 for several passages. This long-term oxidative insult induced senescence in ARPE-19 cells without affecting cell proliferation. Global proteomic analysis revealed a dysregulated expression in proteins involved in antioxidant response, mitochondrial homeostasis, and extracellular matrix organization. The analyses of mitochondrial functionality showed increased mitochondrial biogenesis and ATP generation and improved response to oxidative stress. The latter, however, was linked to nuclear factor-κB (NF-κB) rather than nuclear factor erythroid 2–related factor 2 (Nrf2) activation. NF-κB hyperactivation also resulted in increased pro-inflammatory cytokines expression and inflammasome activation. Moreover, in response to additional pro-inflammatory insults, senescent ARPE-19 cells underwent an exaggerated inflammatory reaction. Our results indicate senescence as an important link between chronic oxidative insult and detrimental chronic inflammation, with possible future repercussions for therapeutic interventions.

scholarly journals The role of future treatments in the management of neovascular age-related macular degeneration in Europe

2021 ◽  
pp. 112067212110183
Author(s):  
Laurent Kodjikian ◽  
Carl Joe Mehanna ◽  
Salomon-Yves Cohen ◽  
François Devin ◽  
Sam Razavi ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Macular Degeneration ◽  
Age Related Macular Degeneration ◽  
Phase Iii ◽  
Vascular Endothelial ◽  
Real World Data ◽  
Phase Iii Clinical Trials ◽  
Age Related ◽  
Injection Frequency ◽  
Endothelial Growth Factor

Anti-vascular endothelial growth factor (VEGF) agents have transformed the management of patients with neovascular age-related macular degeneration (nAMD) over the past two decades. However, as more long-term real-world data become available, it is clear that treatment outcomes are inferior to those reported in large, controlled clinical trials. This is largely driven by undertreatment, that is, not maintaining a consistent injection frequency to achieve sustained VEGF suppression, whether due to patient non-compliance, an important injection burden, or non/incomplete anatomical response. Newer therapeutic advances under evaluation hold promise in achieving more, for less. We review the latest drugs currently in or having successfully finished phase III clinical trials, and determine their potential place in the management of patients with nAMD in Europe.

scholarly journals Neovascular Macular Degeneration: A Review of Etiology, Risk Factors, and Recent Advances in Research and Therapy

2021 ◽  
Vol 22 (3) ◽  
pp. 1170
Author(s):  
Arunbalaji Pugazhendhi ◽  
Margaret Hubbell ◽  
Pooja Jairam ◽  
Balamurali Ambati
Keyword(s):  
Risk Factors ◽  
Macular Degeneration ◽  
Kinase Inhibitors ◽  
Rho Kinase ◽  
The Elderly ◽  
Age Related Macular Degeneration ◽  
Gene Therapies ◽  
Rho Kinase Inhibitors ◽  
Age Related ◽  
Endothelial Growth Factor

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.

scholarly journals Oxidative Stress and Mitochondrial Damage in Dry Age-Related Macular Degeneration Like NFE2L2/PGC-1α -/- Mouse Model Evoke Complement Component C5a Independent of C3

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 622
Author(s):  
Iswariyaraja Sridevi Gurubaran ◽  
Hanna Heloterä ◽  
Stephen Marry ◽  
Ali Koskela ◽  
Juha M. T. Hyttinen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mouse Model ◽  
Macular Degeneration ◽  
Complement Component ◽  
Factor H ◽  
Age Related Macular Degeneration ◽  
Related Factor ◽  
Complement Factor ◽  
Age Related ◽  
Dry Amd

Aging-associated chronic oxidative stress and inflammation are known to be involved in various diseases, e.g., age-related macular degeneration (AMD). Previously, we reported the presence of dry AMD-like signs, such as elevated oxidative stress, dysfunctional mitophagy and the accumulation of detrimental oxidized materials in the retinal pigment epithelial (RPE) cells of nuclear factor erythroid 2-related factor 2, and a peroxisome proliferator-activated receptor gamma coactivator 1-alpha (NFE2L2/PGC1α) double knockout (dKO) mouse model. Here, we investigated the dynamics of inflammatory markers in one-year-old NFE2L2/PGC1α dKO mice. Immunohistochemical analysis revealed an increase in levels of Toll-like receptors 3 and 9, while those of NOD-like receptor 3 were decreased in NFE2L2/PGC1α dKO retinal specimens as compared to wild type animals. Further analysis showed a trend towards an increase in complement component C5a independent of component C3, observed to be tightly regulated by complement factor H. Interestingly, we found that thrombin, a serine protease enzyme, was involved in enhancing the terminal pathway producing C5a, independent of C3. We also detected an increase in primary acute phase C-reactive protein and receptor for advanced glycation end products in NFE2L2/PGC1α dKO retina. Our main data show C5 and thrombin upregulation together with decreased C3 levels in this dry AMD-like model. In general, the retina strives to mount an orchestrated inflammatory response while attempting to maintain tissue homeostasis and resolve inflammation.

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