SZC-6 Promotes Diabetic Wound Healing in Mice by Modulating the M1/M2 Macrophage Ratio and Inhibiting the MyD88/NF-χB Pathway

Abstract

Background/Objectives: The prolonged M1-like pro-inflammatory polarization of macrophages is a key factor in the delayed healing of diabetic ulcers (DU). SIRT3, a primary mitochondrial deacetylase, has been identified as a regulator of inflammation and represents a promising new therapeutic target for DU treatment. Nonetheless, the efficacy of existing SIRT3 agonists remains suboptimal. Methods: Here, we introduce a novel compound, SZC-6, demonstrating promising activity levels. Results: SZC-6 treatment down-regulated the expression of inflammatory factors in LPS-treated RAW264.7 cells and reduced the proportion of M1 macrophages. Mitosox, IF, and JC-1 staining revealed that SZC-6 preserved cellular mitochondrial homeostasis and reduced the accumulation of reactive oxygen species. In vivo experiments demonstrated that SZC-6 treatment accelerated wound healing in diabetic mice. Furthermore, HE and Masson staining revealed increased neovascularization at the wound site with SZC-6 treatment. Tissue immunofluorescence results indicated that SZC-6 effectively decreased the proportion of M1-like cells and increased the proportion of M2-like cells at the wound site. We also found that SZC-6 significantly reduced MyD88, p-IκBα, and NF-χB p65 protein levels and inhibited the nuclear translocation of P65 in LPS-treated cells. Conclusions: The study concluded that SZC-6 inhibited the activation of the NF-χB pathway, thereby reducing the inflammatory response and promoting skin healing in diabetic ulcers. SZC-6 shows promise as a small-molecule compound for promoting diabetic wound healing.