Aim: determine whether mutations in innate immune cells in people with diabetic foot ulcers (DFUs) impact healing and target molecular pathways to improve outcomes.
Monocytes and macrophages (MM) are key innate immune cells. Dysfunctional MM can increase infection risk and impair healing. Clonal haematopoiesis (CH) involves mutations in haematopoietic stem progenitor cells (HSPCs) producing mutant MM. Common CH mutations occur in genes regulating DNA methylation (DNMT3A, TET2) and CH mutations are linked to higher type 2 diabetes risk. In the UK, one-third of 5.6 million people with diabetes develop DFUs. Half develop infections, and ~20% of moderate to severe cases result in amputation. Major amputations have a >70% five-year mortality, largely due to cardiovascular complications—exceeding that of many cancers.
We hypothesise that:
1. Clonal haematopoiesis (CH) is common in individuals with DFUs;
2. CH impairs DFU healing by disrupting innate immune responses;
3. CH is a key risk factor for diabetic foot disease and its cardiovascular complications.
WORKPLAN
i) Identify CH mutations in DFU patients and assess healing at 12 weeks (primary clinical endpoint). In pilot data, ~50% of DFU patients had CH mutations (Figure 1A). We will recruit and genotype 300 patients (CH and age-matched non-CH) over two years. We will assess correlations between CH status and ulcer healing at 12 weeks, and cardiovascular disease using age-matched non-CH patients as controls. As chronic inflammation may influence clonal expansion and healing, we will measure clone size and mutation burden at baseline and after 12 months comparing healed and non-healed CH patients (Figure 1B).
ii) Perform multi-omic analysis of healed and non-healed patients. Biobanked blood from selected patients (5 non-CH, 5 DNMT3A, 5 TET2 per group) will undergo single-cell RNA/CITE-seq (Figure 1C-D), serum cytokine profiling, and MM functional assays. This will reveal immune landscape differences between CH and non-CH patients, and between healed and non-healed DFUs, aiming to identify molecular markers and therapeutic targets for diabetic foot disease.
What to expect: You will join a supportive, well-funded team of postdocs and PhD students and gain experience in a wide range of experimental techniques and computational tools. You will collaborate with the clinical team, meet patients and analyse clinical data, and develop skills in hypothesis generation, experimental design, data analysis, project management, presentation, and scientific writing. We encourage students to present at conferences.
3 month project options: perform genotyping and variant calling to detect CH mutations or scRNAseq experiments and bioinformatic analysis. If student is already proficient in basic computational skills, they may be able to do some of both (genotyping and scRNAseq).
