Neutrophils Extracellualar Traps Caused Diabetic Impaired Wound Healing And Its Mechanism

Objective 1)To explore the mechanism of neurhophils extracellular traps excessive production in diabetic state.2)To explore the mechanism of neutrophils extracellular traps(NETs)induced macrophage phenotype transformation impairment.3)Try to promote diabetic wound healing through the regulation of neutrophils traps.Methods 1)Streptozotocin(STZ)was intraperitoneally injected to induce rat developing diabetes.2)NETs formation under diabetic state was detected using sytox and immunofluorescence.3)The mechanism of excessive production of NETs under diabetic state was explored using immunofluorescence and western blot.4)The mechanism of NETs induced macrophage phenotype transformation impairment was detected using immunofluorescence,western blot and immunochemistry.5)The production of NETs during wound healing was monitored in vivo.6)To check the effect of apoptosed neutrophils on macrophage phenotype transformation by synthesizing PS containing liposome to mimic apoptosed neutrophils and investigating whether PS containing liposome combined with DNAse 1 application promote diabetic wound healing Results:1)STZ injection induced rats developing diabetes.2)Significantly increased neutrophils extracellular traps formation was observed in neutrophils from diabetic rats and high-glucose cultured rat neutrophils,.3)PKC-ERK1 / 2-NADPH signaling pathway and over activated autophagy were involved in the neutrophils extracellular traps formation in diabetic state.The mechanism is related to the increase of DAG synthesis induced by high glucose and the increase of ROS production.4)NETs induced macrophages polarized to M1 phenotype,and the DNA in neutrophils extracellular traps plays a very important role in the M1 phenotype indction.The mechanism is mainly related to the activation of TLR9-MYD88-NF-?B/ AP-1 signaling pathway.5)The effect of promoting diabetic wound healing by DNAse 1 alone to remove NETs is limited.6)Apoptotic neutrophils promotes macrophage phenotype polarization from M1 phenotype to M2 phenotype.DNAse 1 combined with PS-containing liposomes as a analogue of apoptotic cells are capable significantly promote wound healing in diabetic rats.Conclusion 1.Neutrophils in diabetic state are likely to die through NETosis.2.NETs cause macrophage phenotype remaining in the M1 phenotype instead of switching to the M2 phenotype.3.The removal of neutrophils extracellular traps by DNAse 1 plus apoptotic cell analogues can improve wound healing in diabetic rats.