Molecular Mechanisms of Complement System Proteins and Matrix Metalloproteinases in the Pathogenesis of Age-Related Macular Degeneration

2019 ◽  
Vol 19 (10) ◽  
pp. 705-718 ◽  
Author(s):  
Naima Mansoor ◽  
Fazli Wahid ◽  
Maleeha Azam ◽  
Khadim Shah ◽  
Anneke I. den Hollander ◽  
...  
Keyword(s):  
Matrix Metalloproteinases ◽  
Macular Degeneration ◽  
Complement System ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Age Related Macular Degeneration ◽  
Genetic Changes ◽  
Complement System Proteins ◽  
Age Related ◽  
Common Genetic Variants

: Age-related macular degeneration (AMD) is an eye disorder affecting predominantly the older people above the age of 50 years in which the macular region of the retina deteriorates, resulting in the loss of central vision. The key factors associated with the pathogenesis of AMD are age, smoking, dietary, and genetic risk factors. There are few associated and plausible genes involved in AMD pathogenesis. Common genetic variants (with a minor allele frequency of >5% in the population) near the complement genes explain 40–60% of the heritability of AMD. The complement system is a group of proteins that work together to destroy foreign invaders, trigger inflammation, and remove debris from cells and tissues. Genetic changes in and around several complement system genes, including the CFH, contribute to the formation of drusen and progression of AMD. Similarly, Matrix metalloproteinases (MMPs) that are normally involved in tissue remodeling also play a critical role in the pathogenesis of AMD. MMPs are involved in the degradation of cell debris and lipid deposits beneath retina but with age their functions get affected and result in the drusen formation, succeeding to macular degeneration. In this review, AMD pathology, existing knowledge about the normal and pathological role of complement system proteins and MMPs in the eye is reviewed. The scattered data of complement system proteins, MMPs, drusenogenesis, and lipofusogenesis have been gathered and discussed in detail. This might add new dimensions to the understanding of molecular mechanisms of AMD pathophysiology and might help in finding new therapeutic options for AMD.

scholarly journals The complement system in age-related macular degeneration

2021 ◽  
Author(s):  
Angela Armento ◽  
Marius Ueffing ◽  
Simon J. Clark
Keyword(s):  
Risk Factors ◽  
Macular Degeneration ◽  
Complement System ◽  
Complement Activation ◽  
Molecular Mechanisms ◽  
Alternative Pathway ◽  
Disease Onset ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
The Complement System

AbstractAge-related macular degeneration (AMD) is a chronic and progressive degenerative disease of the retina, which culminates in blindness and affects mainly the elderly population. AMD pathogenesis and pathophysiology are incredibly complex due to the structural and cellular complexity of the retina, and the variety of risk factors and molecular mechanisms that contribute to disease onset and progression. AMD is driven by a combination of genetic predisposition, natural ageing changes and lifestyle factors, such as smoking or nutritional intake. The mechanism by which these risk factors interact and converge towards AMD are not fully understood and therefore drug discovery is challenging, where no therapeutic attempt has been fully effective thus far. Genetic and molecular studies have identified the complement system as an important player in AMD. Indeed, many of the genetic risk variants cluster in genes of the alternative pathway of the complement system and complement activation products are elevated in AMD patients. Nevertheless, attempts in treating AMD via complement regulators have not yet been successful, suggesting a level of complexity that could not be predicted only from a genetic point of view. In this review, we will explore the role of complement system in AMD development and in the main molecular and cellular features of AMD, including complement activation itself, inflammation, ECM stability, energy metabolism and oxidative stress.

scholarly journals Interactions between Apolipoprotein E Metabolism and Retinal Inflammation in Age-Related Macular Degeneration

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 635
Author(s):  
Monica L. Hu ◽  
Joel Quinn ◽  
Kanmin Xue
Keyword(s):  
Risk Factor ◽  
Apolipoprotein E ◽  
Macular Degeneration ◽  
Amyloid Beta ◽  
Complement System ◽  
Genetic Risk ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Retinal Inflammation ◽  
The Complement System

Age-related macular degeneration (AMD) is a multifactorial retinal disorder that is a major global cause of severe visual impairment. The development of an effective therapy to treat geographic atrophy, the predominant form of AMD, remains elusive due to the incomplete understanding of its pathogenesis. Central to AMD diagnosis and pathology are the hallmark lipid and proteinaceous deposits, drusen and reticular pseudodrusen, that accumulate in the subretinal pigment epithelium and subretinal spaces, respectively. Age-related changes and environmental stressors, such as smoking and a high-fat diet, are believed to interact with the many genetic risk variants that have been identified in several major biochemical pathways, including lipoprotein metabolism and the complement system. The APOE gene, encoding apolipoprotein E (APOE), is a major genetic risk factor for AMD, with the APOE2 allele conferring increased risk and APOE4 conferring reduced risk, in comparison to the wildtype APOE3. Paradoxically, APOE4 is the main genetic risk factor in Alzheimer's disease, a disease with features of neuroinflammation and amyloid-beta deposition in common with AMD. The potential interactions of APOE with the complement system and amyloid-beta are discussed here to shed light on their roles in AMD pathogenesis, including in drusen biogenesis, immune cell activation and recruitment, and retinal inflammation.

scholarly journals Complement System and Age-Related Macular Degeneration: Implications of Gene-Environment Interaction for Preventive and Personalized Medicine

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Andrea Maugeri ◽  
Martina Barchitta ◽  
Maria Grazia Mazzone ◽  
Francesco Giuliano ◽  
Antonella Agodi
Keyword(s):  
Public Health ◽  
Personalized Medicine ◽  
Macular Degeneration ◽  
Complement System ◽  
Genetic Variants ◽  
Age Related Macular Degeneration ◽  
Environment Interaction ◽  
Gene Environment Interaction ◽  
Age Related ◽  
Gene Environment

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.

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.

Age-related macular degeneration and the complement system

Immunobiology ◽  
2012 ◽  
Vol 217 (2) ◽  
pp. 127-146 ◽  
Author(s):  
S. Khandhadia ◽  
V. Cipriani ◽  
J.R.W. Yates ◽  
A.J. Lotery
Keyword(s):  
Macular Degeneration ◽  
Complement System ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
The Complement System

Role of complement system in autoimmune uveitis and age-related macular degeneration

2007 ◽  
Vol 44 (16) ◽  
pp. 3935
Author(s):  
Nalini S. Bora ◽  
Purushottam Jha ◽  
Sankarnarayanan Kaliappan ◽  
Puran S. Bora
Keyword(s):  
Macular Degeneration ◽  
Complement System ◽  
Age Related Macular Degeneration ◽  
Autoimmune Uveitis ◽  
Age Related

scholarly journals Semi-Quantitative Multiplex Profiling of the Complement System Identifies Associations of Complement Proteins with Genetic Variants and Metabolites in Age-Related Macular Degeneration

2021 ◽  
Vol 11 (12) ◽  
pp. 1256
Author(s):  
I. Erkin Acar ◽  
Esther Willems ◽  
Eveline Kersten ◽  
Jenneke Keizer-Garritsen ◽  
Else Kragt ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Complement System ◽  
Genetic Variants ◽  
Factor H ◽  
Age Related Macular Degeneration ◽  
Complement Protein ◽  
Complement Proteins ◽  
New Associations ◽  
Age Related ◽  
The Complement System

Age-related macular degeneration (AMD) is a major cause of vision loss among the elderly in the Western world. The complement system has been identified as one of the main AMD disease pathways. We performed a comprehensive expression analysis of 32 complement proteins in plasma samples of 255 AMD patients and 221 control individuals using mass spectrometry-based semi-quantitative multiplex profiling. We detected significant associations of complement protein levels with age, sex and body-mass index (BMI), and potential associations of C-reactive protein, factor H related-2 (FHR-2) and collectin-11 with AMD. In addition, we confirmed previously described associations and identified new associations of AMD variants with complement levels. New associations include increased C4 levels for rs181705462 at the C2/CFB locus, decreased vitronectin (VTN) levels for rs11080055 at the TMEM97/VTN locus and decreased factor I levels for rs10033900 at the CFI locus. Finally, we detected significant associations between AMD-associated metabolites and complement proteins in plasma. The most significant complement-metabolite associations included increased high density lipoprotein (HDL) subparticle levels with decreased C3, factor H (FH) and VTN levels. The results of our study indicate that demographic factors, genetic variants and circulating metabolites are associated with complement protein components. We suggest that these factors should be considered to design personalized treatment approaches and to increase the success of clinical trials targeting the complement system.

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