Delayed wound healing in diabetes is characterized by sustained activation of inflammasome and increased expression of IL-1β in macrophages. Identification and validation of novel pathways to regulate IL-1β expression will provide therapeutic targets for diabetic wounds. Here we report sustained over-expression of histone deacetylase 6 (HDAC6) in wounds of diabetic mice and its role in delayed wound healing. Topical application of HDAC6 inhibitor; Tubastatin A (TSA) gel promoted the wound healing in diabetic mice. TSA hydrogel reduced the infiltration of neutrophils, T-cells and macrophages in the early phase of wound healing. TSA treatment promoted the wound healing by inducing collagen deposition, angiogenesis (CD31) and fibrotic factors (TGF-β1) in the late phase of healing. Protein analysis of the diabetic wounds treated with TSA showed increased acetylated α-tubulin and decreased levels of mature IL-1β with no significant effect on the expression of pro-IL-1β, pro-caspase-1 and active caspase-1. In in vitro assays, macrophages exhibited upregulation of HDAC6, IL-1β and downregulation of IL-10 upon stimulation with high glucose and LPS. TSA inhibited the IL-1β secretion and promoted IL-10 in stimulated macrophages with high glucose and LPS. Further investigations showed that TSA inhibits IL-1β release by inhibiting tubulin dependent lysosomal exocytosis without affecting its transcription and maturation. Nocodazole (known acetylation inhibitor) pre-treatment inhibited TSA effect on IL-1β secretion in high glucose stimulated macrophages. Overall, our findings indicate that sustained HDAC6 expression in diabetic wounds contributes to impaired healing responses and HDAC6 may represent a new therapeutic target for diabetic wounds.

糖尿病中伤口愈合延迟的特征在于炎性体的持续活化和巨噬细胞中IL-1β表达的增加。鉴定和验证调节IL-1β表达的新途径将为糖尿病伤口提供治疗靶标。在这里，我们报道糖尿病小鼠伤口中组蛋白脱乙酰基酶6（HDAC6）的持续过度表达及其在伤口愈合延迟中的作用。HDAC6抑制剂的局部应用；Tubastatin A（TSA）凝胶可促进糖尿病小鼠的伤口愈合。在伤口愈合的早期，TSA水凝胶减少了中性粒细胞，T细胞和巨噬细胞的浸润。TSA治疗通过在愈合的后期诱导胶原沉积，血管生成（CD31）和纤维化因子（TGF-β1）促进伤口愈合。用TSA处理的糖尿病伤口的蛋白质分析显示乙酰化的α-微管蛋白增加，而成熟IL-1β的水平降低，对pro-IL-1β，pro-caspase-1和活性caspase-1的表达无明显影响。在体外测定中，巨噬细胞在高葡萄糖和LPS刺激下表现出HDAC6，IL-1β的上调和IL-10的下调。在具有高葡萄糖和LPS的刺激巨噬细胞中，TSA抑制IL-1β分泌并促进IL-10。进一步的研究表明，TSA通过抑制微管蛋白依赖性溶酶体胞吐作用来抑制IL-1β释放，而不会影响其转录和成熟。Nocodazole（已知的乙酰化抑制剂）预处理可抑制TSA对高葡萄糖刺激的巨噬细胞中IL-1β分泌的影响。总体，