Background: Diabetic wounds represent a major clinical challenge due to persistent inflammation, oxidative stress, and impaired angiogenesis. Bone marrow mesenchymal stem cells (BMSCs) have strong regenerative potential, and their therapeutic effects and optimization strategies for diabetic wounds warrant further exploration. Objective: This study aimed to improve the therapeutic efficacy of BMSCs in diabetic wound healing via chrysin pretreatment, as well as to evaluate the healing capacity and molecular mechanisms of the derived chrysin-pretreated BMSC-conditioned medium (Chrysin-CM). Methods: BMSCs were pretreated with 1 μM chrysin for 48 h to generate Chrysin-CM. The therapeutic effects were evaluated in vitro by analyzing the proliferation, migration, and matrix synthesis of human umbilical vein endothelial cells (HUVECs) and human skin fibroblasts (HSFs) under high-glucose (HG) conditions. In vivo, a diabetic mouse model with full-thickness excisional wounds was established and treated topically with Chrysin-CM. Transcriptomic sequencing and immune infiltration analysis of wound tissues were performed on day 14 in order to investigate the underlying mechanisms. Results: Chrysin pretreatment significantly enhanced the functional activity of BMSCs, accompanied by increased proliferative capacity and accelerated cell cycle progression. In vitro, Chrysin-CM demonstrated superior efficacy, robustly protecting HUVECs and HSFs from HG-induced dysfunction. In vivo, Chrysin-CM significantly accelerated wound closure, re-epithelialization, and neovascularization compared to the control. Mechanistically, RNA sequencing (RNA-seq) revealed that Chrysin-CM induced multi-level remodeling, characterized by reduced inflammatory gene expression and immune cell infiltration, along with the upregulation of regenerative genes and alternative splicing events. Conclusions: Chrysin successfully improved the therapeutic efficacy of the BMSC secretome in wound healing. Chrysin-CM effectively accelerated diabetic wound healing by actively resolving chronic inflammation and promoting angiogenesis and structural remodeling, thus providing a potential strategy for stem cell-based cell-free treatment for chronic diabetic wounds.
Li et al. (Mon,) studied this question.