Investigating age-dependent regulation of complement in human eye tissues: implications for Age-related Macular Degeneration

Lead Research Organisation: University of Manchester
Department Name: Life Sciences

Abstract

Over half of all cases of blindness in the UK are caused by Age-related Macular Degeneration (AMD), with about 50 million people affected worldwide. AMD is a disease that damages a part of the retina (called the macula) and leads to central vision loss. While there are associations with diet and environmental factors, there is clear evidence that the risk of developing this disease is strongly influenced by our genes. Recent studies revealed that a common variant of one particular gene (known as Complement Factor H or CFH for short) strongly increases the risk of developing AMD. This variant (called the Y402H polymorphism) is present in about 35% of people of European descent and it results in a small, but significant, change in the CFH protein that alters its functional properties. We have recently made an important discovery that the normal and disease-associated forms of CFH (referred to as '402H' and '402Y', respectively) differ in their ability to recognise a particular group of carbohydrate molecules (called GAGs) in the eye. This may influence the localisation of the CFH protein, which is likely to be important to the development of AMD since CFH controls part of our immune system that distinguishes healthy from diseased tissues. If the CFH protein is not present in the correct location (or if there is simply less of it), as we believe is the case for the 402H form of CFH, then the resulting disruption of the immune system would lead to inflammation and tissue damage; i.e. major features of AMD.
Based on our recent (MRC-funded) experiments we have preliminary evidence for age-related changes in the human eye that appear to influence CFH function. We think it likely that normal changes in the eye, which occur during ageing, may be important in the development of AMD, in particular for individuals with an 'at-risk' genetic profile (e.g. those having the 402H form of CFH). Therefore, one aim of this research project is to test this idea by analysing eye tissues from donors of different ages (i.e. ranging from 30 year olds to those over 80), which will be supplied by the Manchester Eye Bank. For example, we will characterise how the structure of GAGs change with age and how this influences the functions of the 402H and 402Y forms of CFH. To our knowledge, this is a unique approach that is not being pursued by other groups, who are mainly focusing on the later stages of AMD, i.e. when tissue damage has already occurred. We have also identified other changes that occur in healthy human eyes that might additionally contribute to the initiation and progression of AMD. We aim to investigate these important new discoveries in further detail to determine whether they might be useful in the design of improved treatments for AMD, which could potentially be targeted early in the disease process. If they do, we are well placed (i.e. with the necessary experience/facilities) to translate our findings from the laboratory to the clinic.
Our own expertise in Manchester, for example in AMD, the CFH protein and carbohydrate chemistry (along with the molecular tools we have developed over the last 8 years), will be supported by a network of scientific collaborators (both in the UK and abroad) providing access to specialised biochemicals and cutting-edge technologies.
Overall these unique and novel studies are likely to lead to a greater understanding of the causes of AMD and may allow the development of new therapeutic strategies for treating this devastating disease.

Technical Summary

Dysregulation of the complement system is thought to underlie Age-related Macular Degeneration (AMD), where the Y402H polymorphism in the complement factor H (CFH) gene is a major risk factor for this common form of blindness. Our previous studies have shown that this polymorphism adversely affects the interaction of the disease-associated 402H variant with sulphated glycosaminoglycans (e.g. heparan sulphate (HS) in the human Bruch's membrane), which might result in local chronic inflammation promoting the initiation and progression of tissue damage within the macula. More recently we have obtained preliminary evidence that age-related changes in Bruch's membrane (e.g. in HS composition) may specifically influence the binding of CFH 402H. On this basis, we have hypothesised that normal changes in the macula occurring during ageing contribute to the development of AMD, in particular in individuals carrying the CFH 402H allele. Therefore, the aim of this research is to test this new hypothesis by analysing human eye tissues from donors of different ages (i.e. 30-80+ years); we will characterise how the Bruch's membrane changes with age and how this influences the functions of CFH (in a 402H/402Y allotype-specific manner). This multidisciplinary project will involve immunofluorescent microscopy, HS compositional analysis, mass spectrometry, complement assays, affinity chromatography, microtitre plate-based binding assays and biophysical techniques; here we will utilize the human eye samples we have collected (over the last 3 years), with additional samples to be provided by the Manchester Eye Bank. The project is focused at understanding early changes in the human eye that may be responsible for the initiation/progression of AMD, rather than the later stages, i.e. once tissue damage has occurred. In this regard, our studies have the potential to facilitate the design of improved treatments for AMD, which could potentially be targeted early in the disease process.

Planned Impact

The aim of this project is to determine how normal age-related changes in the human eye contribute to the development of Age-related Macular Degeneration (AMD), i.e. in genetically predisposed individuals. Therefore, this work has the potential to have major impacts on the diagnosis, treatment and management of this devastating disease. AMD is the major cause of blindness in the developed world and its incidence is rising due to the demographic of the aging population; it imposes a large socioeconomic burden on the healthcare services (e.g. the NHS), AMD suffers themselves and their carers, both in the UK and throughout the Western world. Given that AMD affects reading, driving etc., this greatly reduces the ability of suffers to contribute to creative and work-related activities. Our research is focused on understanding age-related changes in the human eye that precede AMD and is aimed at facilitating the development of novel therapeutic strategies to slow the progression or indeed prevent the initiation of the disease. This could have direct commercial benefits (e.g. to the UK economy) through drug sales, licensing of IP, spinout companies etc. In addition, our findings could lead to new ways of identifying and treating individuals at risk from AMD (i.e. where preventative therapies and lifestyle changes could enable better management of this condition); currently AMD is not usually diagnosed until after visual changes (blurring/distortion) have occurred. Such changes in policy (e.g. within the NHS) could have a major impact on reducing the socioeconomic burden of AMD. Our public engagement programme (e.g. open days, museum events and press releases) is aimed at increasing the awareness of AMD within the general public, which might also facilitate early diagnosis.

Publications

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McHarg S (2015) Enrichment of Bruch's Membrane from Human Donor Eyes. in Journal of visualized experiments : JoVE

 
Description Fight for Sight PhD Studentship
Amount £98,768 (GBP)
Funding ID 2033 
Organisation Fight for Sight 
Sector Charity/Non Profit
Country United Kingdom
Start 09/2019 
End 09/2022
 
Description Fight for Sight/National Eye Research Centre Small Grant Award
Amount £14,547 (GBP)
Organisation Fight for Sight 
Sector Charity/Non Profit
Country United Kingdom
Start 11/2014 
End 08/2015
 
Description Fulbright Scholarship
Amount £75,000 (GBP)
Organisation Fight for Sight 
Sector Charity/Non Profit
Country United Kingdom
Start 09/2013 
End 08/2014
 
Description ISSF
Amount £5,000 (GBP)
Organisation Wellcome Trust 
Department Wellcome Trust Institutional Strategic Support Fund
Sector Charity/Non Profit
Country United Kingdom
Start 01/2015 
End 06/2015
 
Description MMPathIC Innovation and Technologies Pump Priming Award
Amount £23,287 (GBP)
Organisation University of Manchester 
Sector Academic/University
Country United Kingdom
Start 11/2018 
End 04/2019
 
Description MRC Career Development Award
Amount £664,961 (GBP)
Funding ID MR/K024418/1 
Organisation Medical Research Council (MRC) 
Sector Academic/University
Country United Kingdom
Start 09/2013 
End 08/2016
 
Description Macular Society Research Grant
Amount £169,318 (GBP)
Organisation Macular Society 
Sector Charity/Non Profit
Country United Kingdom
Start 01/2018 
End 12/2020
 
Description Project Grant
Amount £110,274 (GBP)
Organisation Fight for Sight 
Sector Charity/Non Profit
Country United Kingdom
Start 09/2016 
End 08/2018
 
Description Project grant
Amount £169,809 (GBP)
Organisation Fight for Sight 
Sector Charity/Non Profit
Country United Kingdom
Start 09/2014 
End 08/2017
 
Description Project grant
Amount £217,343 (GBP)
Organisation Macular Society 
Sector Charity/Non Profit
Country United Kingdom
Start 09/2014 
End 08/2017
 
Title Human eye collection 
Description We are building up a collection of human eye tissue (e.g. from donors of different ages) to support our work on Age-related Macular Degeneration. 
Type Of Material Biological samples 
Provided To Others? No  
Impact 6 primary papers (Clark et al., 2010 J. Biol. Chem.; Clark et al., 2011 IOVS; Keenan et al.., 2012 IOVS; Clark et al., 2013 J. Immunol.;Clark et al., 2014; Keenan et al., 2014 IOVS). Several papers are in preparation. Invited to speak at Complement UK Symposium (Newcastle, UK) 2013; Annual Meeting of Glycoren consortium 2013 (Leiden, The Netherlands); ARVO 2014 (Orlando, USA). 
 
Title Identification of novel disease mechanism for Age-related Macular Degeneration (AMD). 
Description We have identified a novel disease mechanism for Age-related Macular Degeneration (AMD). 
Type Of Material Model of mechanisms or symptoms - human 
Provided To Others? No  
Impact 3 primary papers (Clark et al., 2010 J. Biol. Chem; Clark et al. 2013 J. Immunol.; Keenan et al. 2014 IOVS), 4 review articles (Clark et al., 2010 Biochem. Soc. Trans; Day et al. Expert Reviews Ophthalmology; Clark et al., 2013 Frontiers in Immunology; Langford-Smith et al. 2014 J Innate Immunity) and 2 press releases. 
 
Description Development of a human choroidal endothelial cell line 
Organisation Radboud University Nijmegen Medical Center
Country Netherlands 
Sector Academic/University 
PI Contribution We supplied reagents that allowed testing of new cell line providing verification that this has characteristics in common with primary choroidal endothelial cells.
Collaborator Contribution They established the new cell line and performed testing.
Impact A primary publication in IOVS in 2018.
Start Year 2014
 
Description Role of complement factor H in AMD. 
Organisation University Hospital of Wales
Department Department of Medical Biochemistry and Immunology
Country United Kingdom 
Sector Hospitals 
PI Contribution We used reagents provided by these collaborators in our research.
Collaborator Contribution Provision of reagents to support our research.Provision of reagents to support our research.
Impact I primary paper in J. Biol. Chem. (2010). Abstract/poster at BSMB Spring Meeting: "Vascular Matrix in Health & Disease", Manchester, UK (2010). Abstract/poster at ARVO 2010 conference, Fort Lauderdale, Florida, USA (2010). Abstract/poster at BSMB Autumn Meeting "Inflammation meets matrix biology", UEA, Norwich (2010). Abstract/poster at 13th European Meeting on Complement in Human Disease, Leiden (2011). Abstract/poster at Get Connected 2, Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, UK (2011). Abstract/poster at 7th International Conference on Proteoglycans, Sydney, Australia (2011). Abstract/poster/talk presented at ARVO 2012, Fort Lauderdale, USA. Primary papers published in J. Biol. Chem. (2010) and J. Immunol. (2013).
Start Year 2008
 
Description Role of complement factor H in AMD. 
Organisation University of Oxford
Department Department of Pharmacology
Country United Kingdom 
Sector Academic/University 
PI Contribution We used reagents provided by these collaborators in our research.
Collaborator Contribution Provision of reagents to support our research.Provision of reagents to support our research.
Impact I primary paper in J. Biol. Chem. (2010). Abstract/poster at BSMB Spring Meeting: "Vascular Matrix in Health & Disease", Manchester, UK (2010). Abstract/poster at ARVO 2010 conference, Fort Lauderdale, Florida, USA (2010). Abstract/poster at BSMB Autumn Meeting "Inflammation meets matrix biology", UEA, Norwich (2010). Abstract/poster at 13th European Meeting on Complement in Human Disease, Leiden (2011). Abstract/poster at Get Connected 2, Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, UK (2011). Abstract/poster at 7th International Conference on Proteoglycans, Sydney, Australia (2011). Abstract/poster/talk presented at ARVO 2012, Fort Lauderdale, USA. Primary papers published in J. Biol. Chem. (2010) and J. Immunol. (2013).
Start Year 2008
 
Description The role of FHL-1 in AMD 
Organisation University of Ulm
Country Germany 
Sector Academic/University 
PI Contribution Used reagent supplied by collaborator.
Collaborator Contribution Collaborator provided research reagent.
Impact Clark et al. (2014) J. Immunol.
Start Year 2012
 
Description Art-Science Primary School Masterclass 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact A week-long Art-Science Masterclass took place at the Whitworth Art Gallery, Manchester, for local primary school pupils. Pupils were invited to look at art through a scientific lens to explore the world around us and discover how our cells respond to the world around them. This event was run by the Wellcome Trust Centre for Cell Matrix Research and Tony Day and his team participated during the week.
Year(s) Of Engagement Activity 2016,2017
URL https://www.wellcome-matrix.org/for-everyone/past-events/art-science-primary-school-masterclass/
 
Description Art-science collaboration on ageing 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact This is an ongoing collaboration between a local artist (see http://sallygilford.com/) and researchers at the Wellcome Trust Centre for Cell-Matrix Research. The artist is using images from our research into age-related diseases (including age-related macular degeneration and osteoarthritis) as the basis for art works using screen printing. The aim of this collaboration is to encourage awareness by the general public in the research we are doing by holding exhibitions, activities and workshops in and around Manchester. To date there has been:
A family screen printing workshop at the Manchester Museum as part of our annual Body Experience (21/3/15)
A work in progress exhibition, entitled Immortality, at Islington Mill, Salford (9-12/4/2015)
Premiere of Video at Celebrating Art/Science Engagement Event at Nowgen Centre, Manchester (13/5/15); video available on YouTube (see URL below).
Exhibition, entitled Immortality II, at The Wonder Inn, Manchester (26/11/15-6/12/15).
The Portico Print Fair, The Portico Library, Manchester (5/10/15).
Wellcome Trust Public Engagement Exhibition, Centre for Cell Matrix Research, Manchester (26/7/16).
Science Uncovered Manchester, European Researcher's Night, Manchester Museum, Manchester (25/9/16).
Ocula Bionica, Manchester Museum (20/10/16).
Primary School Masterclass, The Whitworth Art Gallery, Manchester (26/10/16).
Manchester Science Festival, The Whitworth Art Gallery, Manchester (18/11/16).
Primary School Masterclasses, The Whitworth Art Gallery, Manchester (2-6/10/17).
Who's That Girl, Salford Museum & Art Gallery, Manchester (from 29/11/18).


Attendees at the 'work in progress' exhibition at Islington Mill expressed their interest and excitement regarding the research work that the exhibition was based on; see short film in URL below.
Year(s) Of Engagement Activity 2015,2016,2017,2018
URL https://www.youtube.com/watch?v=FQUVhkX_Mq0
 
Description Article by Paul Bishop for Macular Society magazine Digest entitled "Establishing a national eye tissue archive" 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Patients, carers and/or patient groups
Results and Impact Article on the importance of donor eye tissue for research into AMD and the establishment of Manchester Eye Tissue Repository
Year(s) Of Engagement Activity 2016
 
Description Elizabeth Thomas Seminar 2016. Presentation by Paul Bishop entitled "Eye Banking/Repository - How does that contribute to Research in Macular Diseases in the UK?" 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Raised awareness of Manchester Eye tissue Repository and subsequently requests have been made for donor eye tissue for research.
Year(s) Of Engagement Activity 2016,2017
 
Description Invited speaker at Eyecare 2017, Glasgow. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Simon J Clark gave a talk about new treatments being developed for Dry AMD to eye care health professionals and patients. Official feedback was collected and provided (please see URL provided below). Briefly, the talk was the third highest attended talk of the two day conference (80); where 67% of the audience ranked it as "Excellent", and a further 30% as "Good". Dr. Clark also took part in the most attended session of the conference - the 'Ask the Experts' Q & A panel.
Year(s) Of Engagement Activity 2017
URL https://gallery.mailchimp.com/75705ffde3df8421f476475ac/files/94884fc5-64b5-49cb-9a55-ad0630a6b7ca/E...
 
Description Invited speaker at Macular Society Top Doctor event 2015 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Invited speaker at the Macular Society's 'Top Doctor' event 2015. There was much discussion with the lay audience of mainly elderly individuals, some of who suffer from AMD, and interaction both during and after the talks.
Year(s) Of Engagement Activity 2015
 
Description Invited speaker, Womens Institute Science Club, Grazely, Berkshire. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Simon J Clark was invited to talk about AMD, its affects on people and the economy and new treatments being developed that will make a difference in the future. He also raised money for the charity Fight for Sight.
Year(s) Of Engagement Activity 2016
 
Description Manchester schools outreach/widening participation 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Year-10 students, individually or in small groups, took part in lab shadowing events in our lab as part of work experience weeks at the University of Manchester; i.e. to give the students insights into scientific research. The visits in 2014/2015 were associated with the University of Manchester's Widening Participation Scheme.



Positive feedback from the students regarding their lab-based experience; this is pat of an on-going outreach programme that is proving effective at attracting underprivileged students to apply for University.
Year(s) Of Engagement Activity 2014,2015,2016,2017
URL http://www.ls.manchester.ac.uk/schoolsandcommunity/schooleventhighlights/workexperience/