脑心通胶囊促进后下肢缺血损伤小鼠内皮祖细胞动员与归巢

内皮祖细胞(endothelial progenitor cells,EPCs)是一种能分化为血管内皮细胞的前体细胞,组织缺血缺氧所产生的信号分子可促使骨髓EPCs动员至外周循环,并归巢于损伤组织参与新生血管的形成。脑心通胶囊(Naoxintong capsule,NXT)具有活血化瘀、行气止痛之功效,其多成分具有血管保护作用,可以有效改善组织缺血症状,但其对EPCs动员和归巢的作用尚不明确。该研究采用绿色荧光蛋白(green fluorescent protein,GFP)转基因小鼠骨髓移植(bone marrow transplantation,BMT)联合后下肢缺血损伤模型(unilateral hind limb ischemia,UHLI)研究脑心通胶囊对EPCs动员和归巢的作用。受体小鼠经CS137全身照射后,从目内眦静脉丛输注GFP标记的骨髓单个核细胞,建立BMT模型,经过4周骨髓重建后取外周血检测GFP阳性细胞比例。取BMT模型成功的小鼠,采用股动脉结扎复制UHLI模型,术后随机分为3组:模型组、NXT组(模型+NXT)和阳性对照组(模型+辛伐他汀)。采用流式细胞术检测骨髓重建4周后GFP阳性细胞比例,术前及术后第1,3,7,14天外周血中EPCs细胞数;采用免疫荧光组织化学染色检测给药3,7 d缺血腓肠肌组织EPCs细胞归巢数目。BMT小鼠与GFP基因鼠相比,GFP阳性细胞比例无显著性差异;术后1,3 d,NXT组和辛伐他汀组外周血EPCs数量显著性上调;术后3,7 d,NXT组和辛伐他汀组EPCs归巢数量显著高于模型组(P0.001),因此脑心通胶囊能显著促进EPCs的动员与归巢。

Effect of Naoxintong capsule on endothelial progenitor cell mobilization and homing following bone marrow transplantation in a mouse hind limb ischemia model

Endothelial progenitor cells (EPCs) are precursor cells of endothelial cells. Signal molecules produced by ischemia and hypoxia can promote mobilization of bone marrow EPCs to peripheral circulation and formation of novel blood vessels in tissues that are damaged during heart attack. Naoxintong capsule (NXT) has the functions of promoting blood circulation, removing blood stasis, promoting the circulation of qi and relieving pain. The various components in NXT have protective effects on blood vessels and can effectively improve the symptoms of ischemia. However, its effect on EPCs is not clear. To study the intervention effect of NXT on mobilization and homing of peripheral blood EPCs, green fluorescent protein (GFP) transgenic mice were used for bone marrow transplantation (BMT) and then unilateral hind limb ischemia model (UHLI) were constructed. For BMT, wild-type ICR mice were irradiated by CS¹³⁷ and then injected with 4×10⁶ bone marrow cells isolated from GFP mice. The bone marrow reconstitution of recipients was assessed by quantification of GFP bone marrow-derived cells (BMDC) from transplanted mice 4 weeks after BMT. The UHLI model was duplicated by ligating femoral artery and divided into three groups:the model group, the NXT group (model+NXT) and the positive control group (model+simvastatin). Flow cytometry was used to detect the proportion of GFP positive cells and the peripheral blood EPCs levels at 1, 3, 7, 14 days before and after surgery. Ischemic tissue of gastrocnemius muscle was excised at 3 and 7 days after operation for immunofluorescence staining to detect the number of GFP⁺ cells. The bone marrow chimerism was achieved at day 28 after BMT. There was no significant difference in the percentage of GFP positive cells between BMT mice and GFP transgenic mice. NXT and simvastatin could significantly increase the number of peripheral blood EPCs 1,3 days after surgery. Three and seven days after operation, the number of homing EPCs was significantly higher in NXT group and positive control group than that in model group (P<0.001). In conclusion, NXT can obviously promote the mobilization and homing of EPCs.