The Mechanism Of Yiqi-Huoxue Decoction Promoting Angiogenesis In Ischemic Myocardium Through Calcium Signal Regulated By VEGFR2

ObjectiveYiqi Huoxue Decoction(YHD)promotes angiogenesis and improves ischemic environment of coronary heart disease,however,its mechanism is not clear.VEGFR2 and calcium ion concentration are closely related to angiogenesis.Therefore,the mechanism of YHD in promoting angiogenesis was explored using rat myocard ial ischemia model and endothelial cell hypoxia model.MethodsExperiment 1: The rats were divided into three groups: sham group,model group,and YHD group.1.The expressions of VEGF,VEGFR2 and KLF2 m RNA were detected using qRT-PCR.2.The expressions of VEGF,VEGFR2 and KLF2 protein were measured using Western blotting.Experiment 2: The hypoxia model was established,and the vascular endothelial growth factor receptor 2(VEGFR2)inhibitor Axitinib was used to treat endothelial cells.The cells were randomly divided into five groups: control group,model group,YHD group,Axitinib group,and YHD + Axitinib group.1.The expressions of VEGF,VEGFR2 and KLF2 m RNA were detected using qRT-PCR.2.The expressions of VEGF,VEGFR2 and KLF2 protein were measure d using Western blotting.3.The concentration of calcium in the cytoplasm of endothelial cells was detected using Fura 2-AM fluorescence dye.Results1.Compared with the sham group,the m RNA and protein expressions of VEGF,VEGFR2 and KLF2 in the model group significantly increased(P<0.05,or P<0.01).Compared with the model group,the m RNA and protein expressions of VEGF,VEGFR2 and KLF2 in the YHD group significantly increased(P<0.01).2.The results of hypoxia experiment showed that the expressions of VEGF,VEGFR2 and KLF2 increased in model group as well as calcium concentration in cytoplasm compared with those in the control group(P<0.05,or P<0.01).Compared with the control group,the expressions of VEGF,VEGFR2,KLF2 and the concentration of intracellular calcium in the model group significantly increased(P<0.05,or P<0.01).3.The results of Axitinib treatment showed that the expressions of VEGF,VEGFR2,KLF2 and the concentration of intracellular calcium in the YHD group significantly increased compared with those in the model group,while decreased in the Axitinib group(P<0.05,or P<0.01);compared with the YHD group,the expressions of VEGF,VEGFR2,and KLF2 in YHD + Axitinib group decreased as well as the concentration of intracellular calcium(P<0.01).ConclusionYHD promotes angiogenesis in ischemic myocardium,which is related to increasing intracellular calcium concentration through upregulating VEGFR2,suggesting that it may provide a new strategy for the treatment of ischemic diseases such as coronary heart disease.