O20 Microbial dysbiosis drives cutaneous wound senescence via the IL-1β pathway

Abstract Introduction and aims Chronic nonhealing wounds are devastating skin disease, costing the NHS over £8bn per year and leading to severe morbidity and mortality. Therefore, there is urgent clinical need to develop effective therapies to treat nonhealing wounds and restore patient quality of life. We previously showed that the microbiome and cellular senescence are two crucial factors linked to delayed healing. We demonstrated that the bacterial profile of a chronic wound upon presentation is predictive of whether it will heal, while our fundamental research in mice showed a mechanistic link between senescence and poor wound repair. We thus aimed to determine whether the microbiome critically drives senescence in cutaneous wound pathology. Methods Cutting-edge long-read shotgun sequencing was used to comprehensively profile the chronic wound microbiome (n = 60 donors), correlating microbial changes to clinical outcome measures and tissue senescence in patient-matched samples. Global RNA sequencing (RNAseq) identified a putative bacterial response pathway linked to senescence. This pathway was blocked in delayed healing db/db mice (n = 6 per group) to determine subsequent effects on senescence and wound repair. Results Long-read sequencing revealed HbA1c and senescence as clinical factors that significantly alter microbial composition (P < 0.05; beta diversity, Bray–Curtis dissimilarity) and correlate with dysregulation of Staphylococcus. Secreted products from clinically-isolated pathogenic Staphylococcus delayed healing and induced senescence in human wounds ex vivo (P < 0.001; one-way Anova, n = 6 donors). RNAseq identified senescence/bacterial response pathways elevated in diabetic human/mouse wounds (n = 24 per group). Finally, targeting a putative bacterial/senescence pathway (interleukin-1β) accelerated healing (P < 0.001) and dampened local (P < 0.01) and systemic (P < 0.05) senescence in diabetic mice. Conclusions Our data reveal microbial dysbiosis as a key driver of senescence and poor healing, while targeting a putative senescence-linked microbial pathway accelerated healing in diabetic mice. These studies highlight the potential of microbiome modulation to restore skin healing capacity, which could revolutionize future therapeutic pathways.