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

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

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。

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.