The Role Of TLR4 On Vascular Injury Induced By Lower Limb Ischemia Reperfusion

Background and PurposeAcute limb ischemia is a highly dangerous arterial disease,after the urgent need to rebuild blood supply,restore blood perfusion,but blood recovery can lead to ischemia-reperfusion injury,not only can cause local tissue damage,but also can lead to damage to distant organs,multiple organ failure.TLRs identify the pathogen-associated molecular patterns through the LRRs domain,thereby stimulating the production of inflammatory factors and participating in the killing of pathogens.TLR4 receptor as a member of TLRs,widely distributed in the body,almost distributed in all cell lines,mainly expressed in the host of defense function cells,mediated a variety of diseases,mainly to the inflammatory response,induced a variety of inflammatory factor gene expression The TLR4 plays an important role in ischemia-reperfusion injury of various organs,such as liver,kidney,spinal cord,brain and other organs,can initiate immune response and cause inflammatory reaction,knockout TLR4 gene can significantly reduce ischemia-reperfusion injury.However,the role of TLR4 in ischemia-reperfusion injury is unclear.This study demonstrates the role of TLR4 in mouse lower limb ischemia-reperfusion injury.Study Contents1.The model of acute ischemia-reperfusion model of lower limb in mice was evaluated by laser Doppler flow imaging and hemodynamics was studied.2.The wild(WT)model group was used to detect the inflammation and apoptosis of the femoral artery.3.TLR4-knockout(TLR4-/-)model group was used to detect inflammation and apoptosis of femoral artery.Methods1.Hemodynamics experiments:in this study,the model of lower limb ischemia-reperfusion was established by rubber band wound method,C57BL/6J mice were randomly divided into model control group,Ischemia group(Ischemia)and reperfusion model(Reperfusion).Laser Doppler flow imaging were used to detect the perfusion of each group.2.Ischemia Reperfusion injury model:C57BL/6J mice were randomly divided into model control group(IR)and ischemia-reperfusion group(IR);The expression of TLR4,HMGB1,TNF-a and IL-6 were detected by immunohistochemistry.RT-PCR was used to detect the expression of TLR4,TNF-a and IL6.The apoptosis of vascular wall was detected by TUNEL.3.(TLR4-/-)model group:The mice models of lower limb ischemia reperfusion were divided into wild type(WT)model group and TLR4 knock out(TLR4-/-)model group.RT-PCR was used to detect the expression of TNF-a and IL6.The apoptosis of vascular wall was detected by TUNEL.Results1.A rubber band was used to establish the model of lower limbs ischemia reperfusion in the mice.The skin of the posterior hind paw was immediately pale and the temperature decreased,and the Flux decreased rapidly.After surgery,the lateral hind paw appeared swelling,the skin temperature increased,Flux gradually increased.2.The expression of TLR4,HMGB1,TNF-a,IL6 in the IR group was significantly higher than that in the control group(P<0.01).3.After TLR4 knockout,the expression of TNF-a,IL6 and apoptosis in TLR4 IR group was significantly reduced(P<0.01).Conclusion1.A rubber band can be used to establish the model of lower limbs ischemia reperfusion in the mice successful.The femoral artery was hypopnea after limb ligation,and the blood perfusion was gradually increased after reperfusion.2.Acute lower limb ischemia and reperfusion can lead to inflammatory reaction and apoptosis in vascular tissue.3.TLR4 mediates inflammatory response and induces apoptosis in lower limb ischemia reperfusion injury in mice.