骨髓动员单个核细胞向血管内皮细胞和心肌样细胞的转化简

背景：目前骨髓动员能否归巢到心肌病心衰受损部位，分化成心肌样细胞和血管内皮细胞尚无定论。目的：观察骨髓动员剂粒细胞集落刺激因子对心肌病心衰大鼠心肌和血管的影响。方法：选取阿霉素心肌病心衰模型大鼠50只，分成2组，骨髓动员组30只皮下注射重组人粒细胞集落刺激因子，心衰组20只给予相同体积的生理盐水。骨髓动员组其中10只在动员第6天处死，留取心肌标本，行CD34免疫荧光检测。各组在治疗前及治疗后第5天剪尾取血，测量白细胞总数及单个核细胞百分比，同时提取外周血中单个核细胞行流式细胞仪检测。治疗第5天，腹腔注射Brdu 50 mg/kg，连续4周直至动物处死。留取心肌组织，通过心肌BrdU单染、BrdU与肌球蛋白重链双染及BrdU与肌动蛋白双染确定单个核细胞的归巢，评价移植的单个核细胞向心肌和血管内皮细胞的生成、分化。采用苏木精-伊红染色评价血管密度。结果与结论：骨髓动员组白细胞数及单个核细胞数较治疗前明显增高（P＜0.05）。流式细胞仪证实骨髓动员组外周血单个核细胞CD34阳性率显著高于心衰组（P＜0.05）。心肌CD34免疫荧光检测，心衰组阴性，骨髓动员组阳性。骨髓动员组心肌BrdU单染和肌球蛋白重链、肌动蛋白双染均呈阳性，心肌损伤处血管内皮细胞核呈BrdU阳性；心衰组均为阴性。骨髓动员组血管密度显著高于心衰组（P＜0.001）。提示骨髓动员出单个核细胞，归巢到心肌受损处，对心肌病心衰大鼠模型心肌和血管有明显修复作用。

Mononuclear cells isolated from mobilized bone marrow differentiate into vascular endothelial cells and cardiomyocyte-like cells

BACKGROUND：It is controversial whether bone marrow mobilization can retain in cardiac injured position in congestive cardiomyopathy or differentiate into cardiomyocytes and vascular endothelial cells. OBJECTIVE：To study the effects of granulocyte colony stimulating factor （G-GSF） on myocardium and angiogenesis in rats with congestive cardiomyopathy. METHODS：Fifty Wistar rats with heart failure caused by adriamycin-induced cardiomyopathy were divided into heart failure group （n=20） treated with normal saline and bone marrow mobilization （n=30） treated with subcutaneous injection of recombinant human G-GSF. Ten rats from the bone marrow mobilization were kil ed at day 6 of mobilization, and myocardial tissue was taken for CD43 immunofluorescent staining. Blood samples were＆amp;nbsp;taken from the rat tail in each group before and 5 days after treatment to count total number of white blood cells and percentage of mononuclear cells. Meanwhile, mononuclear cells extracted from the peripheral blood were used for flow cytometry detection. At day 5 after treatment, bromodeoxyuridine （BrdU, 50 mg/kg） was successively given to al rats for 4 weeks before they were sacrificed. Myocardial tissues were taken to determine the homing of mononuclear cells and evaluate differentiation of mononuclear cells into cardiomyocytes and vascular endothelial cells using BrdU staining, BrdU/myosin heavy chain double staining, and BrdU/actin double staining. Hematoxylin-eosin staining was used for determination of blood vessel density. RESULTS AND CONCLUSION：G-CSF mobilization increased the number of mononuclear cells that was significantly higher than before treatment （P〈0.05）. Flow cytometry showed that the number of CD34-positive mononuclear cells in the peripheral blood was higher in the bone marrow mobilization than in the heart failure group （P〈0.05）. Myocardial CD34 immunofluorescence showed that the heart failure group was negative and the bone marrow mobilization group was positive. In the bone marrow mobilization group, the myocardial tissue was positive for BrdU staining, BrdU/myosin heavy chain double staining and BrdU/actin double staining, while vascular endothelial cells in the region of myocardial injury was positive for BrdU;conversely, the heart failure group was negative. The density of blood vessels in the bone marrow mobilization group was significantly higher than that in the heart failure group （P〈0.001）. These findings indicate that bone marrow mobilization increases the number of mononuclear cells, and these cells are homing to myocardial injury, thereby playing a repair role in the myocardium and vascular tissue of heart failure rats with congestive cardiomyopathy.