Ac2–26 Hydrogel Modulates IL-1β-Driven Inflammation via Mast Cell-Associated and Immune Regulatory Pathways in Diabetic Wounds

Abstract

Chronic, non-resolving inflammation is a major contributor to impaired wound healing in diabetes. Annexin A1 (AnxA1), a pro-resolving mediator, and its mimetic peptide Ac_2-26 have demonstrated therapeutic potential in modulating inflammatory responses. In this study, we evaluated the effects of topical Ac_2-26 hydrogel in a streptozotocin-induced diabetic wound model. Treatment significantly accelerated wound closure, improved tissue architecture, and reduced leukocyte infiltration. Immunohistochemical analysis revealed diminished mast cell accumulation and IL-1β expression in treated wounds. Complementary transcriptomic profiling supported the downregulation of pro-inflammatory genes, including Il1b and mast cell-related mediators, confirming the peptide's regulatory effect on the wound immune landscape. Mounting evidence suggests that dysregulated mast cell activity plays a role in the heightened inflammatory tone and delayed tissue repair observed in diabetic wounds. In our model, Ac_2-26 hydrogel treatment attenuated IL-1β expression, suggesting an indirect downregulation of NLRP3 inflammasome activation, potentially mediated through mast cell modulation, though effects on other cell types within the wound microenvironment cannot be excluded. While definitive causality cannot be assigned, the integration of histological and transcriptomic data highlights mast cells as contributors to the IL-1β-driven inflammatory burden in diabetic wounds. These findings underscore the immunomodulatory capacity of Ac_2-26 and its potential to restore resolution pathways in chronic wound settings, positioning it as a promising candidate for future therapeutic development.