Pharmacological blockade of HDAC3 accelerates diabetic wound healing by regulating macrophage activation

Aims: Here, we report the effect of histone deacetylase 3 (HDAC3) inhibition associated with macrophage activation, IL-1 beta expression, angiogenesis and wound healing in diabetic mice. Main methods: To determine the expression of HDAC3 in diabetic mice wounds, hyperglycemia was induced in C57BL/6 mice with streptozotocin followed by induction of 6 mm wounds. To understand the effect of HDAC3 selective inhibitor, BG45, wound tissues were isolated for analysing M1/M2 markers expression, immune cells infiltration, angiogenesis and healing factors expression. CD11b+F4/80+ cells were sorted from the wound tissues and analysed for the expression of M1/M2 markers using RT-qPCR and flow cytometer. In cell based assays, HDAC3 expression was measured in macrophages stimulated with high glucose (HG) plus LPS. Macrophages treated with BG45 and HG + LPS were analysed for the expression of pro-IL-1 beta, mature IL-1 beta, oxidative stress and pro-inflammatory (M1) and anti-inflammatory (M2) factors. Key findings: HDAC3 was found to be upregulated in impaired diabetic mice wounds and in macrophages stimulated with HG + LPS. Topical application of BG45 loaded gel accelerated the wound healing in diabetic mice and was evident by improved expression of Collagen-1A, IL-10, TGF-beta, and angiogenesis (CD31, VEGF). BG45 treatment decreased the expression of IL-1 beta, TNF-alpha, and IL-6 (M1 phenotype), reduced oxidative stress and promoted the expression of Arginase-1 and YM1/2 (M2 phenotype) in macrophages treated with HG + LPS. BG45 also improved the expression of CD11b+F4/80+CD206+ cells in wound tissues and reduced expression of inflammatory markers. Significance: HDAC3 is upregulated in diabetic mice wounds and HDAC3 selective inhibitor promotes the wound healing by regulating macrophage activation, angiogenesis and IL-1 beta.