Dr Claire E. L. Smith

Profile

I was appointed as a Lecturer in Biomineralisation in Oral Health in 2024. My research focuses on identifying the disease mechanisms underlying amelogenesis imperfecta (AI) and using this knowledge to design and test potential therapeutics.

AI is a group of genetic conditions resulting in defective tooth enamel. It can also be part of syndromic diseases and have links to other organ systems and functions (hearing, sight, immunity, skin conditions to name just a few).

Currently pathogenic variants in many genes are known to cause AI, but very little is known about how these variants actually do cause disease. It is becoming clear that processes such as vesicle and ion transport, protein processing and removal, immune tolerance, ameloblast differentiation, metabolism and viability and likely many others, are critical to the formation of well mineralised enamel of appropriate thickness.

I use CRISPR-Cas9 gene editing and stem cell-derived ameloblast-like cells models to determine the critical processes that are affected by specific pathogenic AI variants. Models of disease are compared to wild-type using long-read RNA sequencing, followed by model-specific experiments to assess ameloblast function. Appropriate drugs or other reagents can then be tested in these models to determine whether disease can be avoided entirely or reduced in severity. Such treatments could be used to potentially prevent AI in the permanent adult dentition. The same CRISPR-Cas9 edited stem cell lines can be also used to study other cell types affected in syndromic disease.

Concurrently, I use whole genome sequencing of mutation-negative AI patients to try to identify novel pathogenic variants that may have been missed by the NHS’s R340 screening panels and research based whole exome sequencing. As a whole, this research will uncover the underlying genetics and disease mechanisms of AI.

Notably other more common, multi-factorial enamelopathies (diseases that affect enamel) such as Molar Incisor Hypomineralisation (MIH), dental caries and dental fluorosis may also have overlapping disease mechanisms, and some may even be treatable with the therapeutics identified for AI.

My previous role was as part of a collaborative, multi-centre £5.4 million project that aimed to increase understanding of the role of intrinsic disorder in protein-protein interactions and regulation of activity. This project used the cell signalling hub protein, aurora kinase A (AURKA), an important therapeutic target in cancer treatment, as a model protein to study intrinsic disorder.

AURKA has critical mitotic and non-mitotic cellular functions which make it essential to cells and important to many cellular processes, including cell division and inhibition of ciliogenesis. I designed various cell-based assays to study what happens in cells to the localisation and abundance of AURKA when interacting proteins were removed or interactions were perturbed by peptides or affimers. Specific peptides and AURKA binding affimers developed through collaboration with the Faculties of Chemistry and Biological Science. Production of effective affimers is the first step towards novel intelligent drug design to modulate AURKA binding and functions.

Another previous role aimed to identify lead compounds to treat ciliopathies affecting kidney function. This utilised high throughput screening methods and a variety of in vitro testing platforms. Two large chemical libraries (totalling 2,160 compounds) were the starting point to try to identify an effective starting chemical for downstream pre-clinical testing for a variety of ciliopathies. One class of compounds were highlighted by this research for further development. I also used CRISPR-Cas9 gene editing to make stem cell models of disease, differentiating them into kidney organoids for pre-clinical drug testing. This work resulted in the award of over £500,000 from Kidney Research UK as part of a collaborative project with the University of Sheffield.

Previous to these roles, I have had a long and diverse career in research both before and after the award of my PhD. After completing a degree in biology at the University of Nottingham in 2004, I started my research career as a research technician with the Centre for Plant Sciences, Faculty of Biological Sciences, at the University of Leeds. 

In 2009 I studied the expression of PLAGL1, a gene implicated in cancer, transient neonatal diabetes mellitus and intrauterine growth restriction. I then worked within Molecular Epidemiology, where I studied the detection of aflatoxin-albumin adducts as an epidemiological marker of aflatoxin exposure using ELISA and HPLC.

From 2010 to 2013 I worked as a research assistant on the EU FP7 project; Nuclease Immune Mediated Brain and Lupus-like conditions. My work specifically focused on producing various cell and animal models of Aicardi Goutières Syndrome and analysing them by RNA sequencing, co-immunoprecipitation, immunofluorescence, immunohistochemistry and western blotting.

In 2013 I began my PhD studying amelogenesis imperfecta (AI). My studies focused on a syndromic form of AI, Heimler syndrome. This condition also encompasses sensorineural hearing loss and often also retinal dystrophy. By whole exome sequencing of affected individuals, I identified mutations in the peroxisomal biogenesis factor genes, PEX1 and PEX6, as the cause of disease. I also studied a non-syndromic hypomineralised form of AI and identified a heterozygous multi-exon deletion in the amelotin gene in affected individuals. My thesis was entitled “Blindness, hearing loss and brown crumbly teeth; determining the molecular basis of Heimler and Heimler plus syndromes and other related conditions” and my PhD was awarded in November 2016.

In 2016 I was awarded Wellcome Trust Institutional Strategic Support funding for one year to complete research that followed on from my PhD. During my PhD, I identified AI-causing mutations in over 45 families. Where teeth were available from these families, enamel phenotyping of genotyped AI teeth and matched controls was carried out so that the effects of the mutations on the resulting enamel could be determined. Teeth analysed included those from patients with ACPT, KLK4 and LAMB3 mutations. With an aim to cataloguing all published AI mutations, I established a variant database for AI, which curated all published AI variants to provide a useful resource for fellow researchers and clinicians around the world and formed the basis of a well cited review on the genetics of AI published in 2017. To date, I have been involved in the discovery of seven new genes for which mutations cause AI and I retain a strong interest in this subject.

In 2017 I began research into inherited retinal disease as part of the UK Inherited Retinal Dystrophies Consortium team, jointly funded by charities RP Fighting Blindness and Fight For Sight. This project aimed to identify the human gene variants that underlie Inherited Retinal Dystrophies (IRDs). Methods used include targetted sequencing via capture by use of molecular inversion probe, whole exome sequencing, whole genome sequencing, transcriptomics and metabolomics.

This research was a UK wide collaboration to study a cohort of over 500 families and ultimately aimed to translate diagnostic protocols developed from this research to an NHS clinical setting. The research better catalogued the scope of variants (including structural, copy number and intronic variants) within known disease genes, as well as the range of phenotypes that they cause but also identified new genes for IRDs through the use of large, pre-screened cohorts. I used bioinformatics analyses including developing alignment, variant calling and filtering pipelines, to identify variants and assess their pathogenicity by in silico and in vitro analysis. This work led to new disease associations for RAX2 and CRX.

Responsibilities

• PhD supervisor: Jack Roberts
• Project Supervisor: MBiol
• Project Supervisor: BSc (Capstone)

Research interests

Amelogenesis Imperfecta (AI):

My research focus is amelogenesis imperfecta. I co-lead the Amelogenesis Research Group with Prof Alan Mighell. I am also part of the Biomineralisation Group, led by Dr Al-Jawad. I have also successfully supervised PhD student, Dr Georgios Nikolopoulos, who studied the genetics of AI. 

AI is a group of inherited defects in tooth enamel. Affected patients have either very thin enamel or very weak enamel, which in both cases does not function correctly. The impact of AI on affected individuals and their families is considerable since patients experience dental pain and sensitivity, poor aesthetics and are reported to experience a lower quality of life due to social anxiety. Treatment of AI is expensive since it requires ongoing clinical management to maintain function and aesthetics. The aim of the Biomineralisation and Amelogenesis Research groups is to increase our understanding of this disorder by studying the enamel structure and also by piecing together the molecular mechanisms involved in tooth enamel formation, a process known as amelogenesis. By identifying the causative mutation in a family, we can attempt to understand the underlying cause of the disorder and perhaps give an insight into potential treatments. Any mutations identified are fed back to patients, who by knowing their mutation can get access to accurate genetic counselling and may choose in future to participate in clinical trials of AI treatments or AI prevention for future generations.

My current research uses CRISPR-Cas9 gene editing and stem cell-derived ameloblast-like cells models to determine the critical processes that are affected by each pathogenic variant. I also continue to identify new variants and new genes for AI through various sequencing methodologies.

Combined, these studies may inform future treatments for AI by providing an appropriate preclinical testing platforms and providing information about which patient genotypes might most benefit (personalised medicine).

Drug screening to identify treatments for ciliopathies:

Ciliopathies are a heterogeneous collection of individually rare diseases that are collectively common, including Bardet-Biedl syndrome, Joubert syndrome, nephronophthisis, retinitis pigmentosa and polycystic kidney disease (PCKD). A major symptom of many ciliopathies is the development of polycystic kidneys which can result in end stage kidney disease, requiring regular dialysis or a kidney transplant to treat. Currently available treatments for PCKD are limited, mainly relying on treating on the secondary symptoms. Tolvaptan, a vasopressin V2 receptor antagonist is one treatment that does slow cyst progression, however it may not be appropriate to treat everyone, meaning that these is a clinical need for novel and more effective therapeutics. 

As part of the Ciliopathy Research group led by Prof. Colin Johnson, I screened 2,160 compounds to try to identify a compound for further development and refinement as a starting point for testing of a chemical hit series for preclinical studies. To do this, I used a high throughput cell-based screening method (Operetta high content imager) as well as a variety of model-based platforms to further test any chemicals passing primary screening. This study led to the award of further funding from Kidney Research UK as a collaborative project with the University of Sheffield.

Inherited Retinal Dystrophies (IRDs):

Inherited Retinal Dystrophies (IRDs) are a group of inherited defects affecting the retina, the part of the eye responsible for conversion of light to electrical signals that enables visual perception. IRDs affect up to 1 in 3000 people and include conditions such as retinitis pigmentosa, cone-rod dystrophies, macular dystrophies, Leber congenital amaurosis and congenital stationary nightblindness.

Sight loss has an immediate and obvious huge impact on the lives and wellbeing of affected individuals but is also estimated to cost the UK over £5 billion per year. Future treatments will be developed and their efficacy determined by the genetics of the conditions. This means that knowledge of the underlying mutation(s) will be the key to preventing sight loss and maintaining vision. Once identified, mutations are fed back to patients, who by knowing their mutation can get access to accurate genetic counselling and may choose in future to participate in clinical trials of treatments or prevention for future generations.

My research used a variety of different techniques to determine the underlying mutations responsible for IRDs, including molecular inversion probes, whole exome sequencing, whole genome sequencing, transcriptomics and metabolomics. The research aimed to better catalogue the scope of variants (including structural, copy number and intronic variants) within known disease genes but also aimed to identify new genes for IRDs through the use of large pre-screened cohorts. I used bioinformatics analyses including developing alignment, variant calling and filtering pipelines to identify variants and assess their pathogenicity by in silico and in vitro analysis. Research findings from a cohort of over 500 families were shared with colleagues at University College London, the University of Oxford, the University of Manchester and the University of Southampton. This means that even rare disease genes were more likely to be identified. The project ultimately aimed to translate diagnostic protocols developed from this research to an NHS clinical setting.

Other activities:

I am a member of the Genomics England Clinical Interpretation Partnership (GeCIP) Domain for Hearing and Sight and I am a curator for the Genomics England Amelogenesis Imperfecta R340 Panel.

I have reviewed submissions to many journals, including Clinical Genetics, Application of Clinical Genetics, Scientific Reports and PLOS ONE.

I am also active in patient and public involvement in research through the Leeds SMILE AIDER forum, through the Leeds University Be Curious festival and through hosting students in further education and lower years of higher education. I am also an International Friend of the D3 (Developmental Dental Defects) Group that aims to provide information to everyone: scientists, clinicians, adults and children on developmental dental defects: http://www.thed3group.org/international.html

Qualifications

• PhD Medicine (Genetics) - University of Leeds
• BSc (Hons) Biology - University of Nottingham
• UK Council for Graduate Education Recognised Research Supervisor

Professional memberships

• • Member of Leeds Centre for Disease Models
• • Genomics England Genome Clinical Interpretation panel member for Rare Disease domain, Hearing and Sight sub-domain. Curator for the Amelogenesis Imperfecta Panel App

Student education

I am a UK Council for Graduate Education (UKCGE) Recognised Research Supervisor.

I have taught undergraduates, postgraduates and visiting AS/A2 level students. This experience includes supervising PhD students, master’s degree and undergraduate degree student projects, giving seminars, practical demonstrating and marking assessed work on population and human genetics, evolution, biochemistry, microbiology, molecular biology, dental materials, biomedical science and molecular medicine.

Research groups and institutes

• Leeds Institute of Medical Research at St James's
• Amelogenesis Research Group
• Vision Research Group