脐血间充质干细胞移植对大鼠肺动脉高压的治疗作用研究

目的:观察脐血间充质干细胞(mesenchymal stem cells,MSCs)移植对SD大鼠肺动脉高压(PAH)的治疗作用。方法:将60只健康雄性SD大鼠随机分为4组,每组15只(n=15),即①正常对照组:不做任何处理;②模型组:以腹主动脉-腔静脉瘘分流术(abdominal aortocaval fistula shuning,A-VF)+单野百合碱(monocrotaline,MCT)注射建立大鼠PAH模型,故也可称为A-VF+MCT组;③干细胞移植组:在建立PAH模型后4周,经尾静脉注射Ho-echst 33342荧光染料标记的脐血MSCs,故此组也可称A-VF+MCT+MSCs组;④培养液对照组:在建立PAH模型后4周,经尾静脉注射培养脐血MSCs的培养液,故此组也可称为A-VF+MCT+培养液组。4周后以右心导管法测定平均肺动脉压(mPAP)、右心室肥厚指数RVHI=RV/(LV+S)]、肺小动脉中层厚度占血管外径的百分比MA(%)]和血管壁中层横截面积占血管总横截面积的百分比MA(%)],观察肺小动脉重构情况。检测血流动力学、肺小动脉重塑及脐血MSCs的定植情况。结果:与正常对照组比较,造模实验证实,4周后A-VF+MCT组大鼠可形成典型的PAH,8周后mPAP明显增高,动脉中膜明显增厚,右心室出现明显肥厚;而A-VF+MCT+MSCs组大鼠mPAP、RV/(LV+S)、MT%和MA%均显著下降(P<0.01)。PAH大鼠死亡率从66.7%下降到13.3%。荧光显微镜观察显示脐血MSCs已成功定植到肺血管内膜。结论:以A-VF+MCT建立的大鼠PAH模型可形成重度PAH。脐血MSCs移植能显著降低肺动脉压力,减轻肺小动脉重构及右心室肥厚,显著降低PAH大鼠的死亡率。

Umbilical cord blood mesenchymal stem cell transplantation in treatment of pulmonary hypertension in rats

AIM: To establish a pulmonary arterial hypertension(PAH) animal model by arterial-vein shunting by combining with injection of monocrotaline(MCT) and to observe the therapeutic effects of mesenchymal stem cells(MSCs) from umbilical cord blood on PAH in Sprague Dawley(SD) rats.METHODS: For establishment of the animal model,60 healthy male SD rats were randomly divided into four groups: 1)normal control group(n=15): rats were given no treatment;2)A-VF+MCT group(n=15): rats were given a single s.c.injection of crotaline(50 mg/kg) after the A-VF operation to establish the PAH model;3)A-VF+MCT+MSCs group: 5×106 MSCs labeled with Hoechst 33342 were injected into rats through the tail vein 4 weeks after the shunting operation;4)A-VF+MCT+DMEM/F12 group: rats were injected a single s.c.cell culture medium 4 weeks after the shunting operation.Mean pulmonary arterial pressure(mPAP),right ventricle index(RVHI) and the microstructure and remodeling changes of small pulmonary vessels were determined 4 weeks after MSC transplantation.RESULTS: Compared with the normal control group,the PAH SD rat model was successfully established after 4 weeks of the A-VF+MCT method.Eight weeks after A-VF+MCT,mPAP and right ventricle index(RVI) were significantly enhanced,and pulmonary artery tunica media and right ventricular wall significantly thickened.The mPAP,RV/(LV+S),MT% and MA% decreased significantly in transplantation group compared to A-VF+MCT group(P<0.01).The mortality rate of PAH rats decreased from 66.7% to 13.3%.Fluorescence microscopy showed that MSCs labeled with Hoechst 33342 were permanently implanted in the tunica intima of the lung.CONCLUSION: MSC transplantation can significantly reduce pulmonary arterial pressure,alleviate pulmonary arterial remodeling,and lower the mortality rate of rats with PAH.