骨髓间充质干细胞移植治疗肺动脉高压大鼠肺血管病变的研究

Changes of pulmonary vasculature of the rats with pulmonary arterial hypertension treated with bone marrow mesenchymal stem cell transplantation

目的探讨骨髓来源的间充质干细胞(mesenchymal stem cells,MSCs)移植对野百合碱诱导的实验性肺动脉高压大鼠肺血管病变的干预作用。方法体外分离、培养并纯化SD大鼠骨髓MSCs。健康雄性SD大鼠随机分为3组,肺动脉高压组(n=20)、MSCs移植组(n=20):2组大鼠均一次性向背部皮下注射野百合碱50 mg/kg,诱导肺动脉高压动物模型;正常对照组(n=15):注射同体积的生理盐水。同等条件饲养3周后,MSCs移植组大鼠经舌下静脉注射5×106/ml的经Hoechst33342荧光染料标记的MSCs细胞悬液1 ml,肺动脉高压组和正常对照组大鼠注射等量L-DMEM液。移植后观察4周,测定3组大鼠生存率、肺动脉平均压、肺小动脉的微观结构的改变。结果肺动脉高压大鼠移植MSCs 4周后,生存率由30%上升到90%,肺动脉平均压由(42.7±2.3)mmHg下降到(24.7±2.3)mmHg,下降了50%;右心指数由(45.30±3.13)%下降到(37.90±3.18)%(q=29.86,P<0.01),肺小动脉病变得到有效改善。荧光显微镜观察到Hoechst 33342标记的MSCs在肺内定植且分化成大量新生血管并形成侧枝循环,肺动脉重构得到有效逆转。结论MSCs移植可有效减轻并逆转肺动脉重构的进程,其作用机制是MSCs分化形成新生血管,建立了侧枝循环,从而修复野百合碱诱导的肺血管损伤。

Objective To study the effect of bone marrow mesenchymal stem cell transplantation on monoerotaline-induced pulmonary artery hypertension in rat model. Method MSCs obtained from bone marrow of Sprague-Dawleye （SD） rats were cultured, purified and propagated in vitro. Healthy male SD rats were randomly divided into 3 groups： normal control group （ n = 15 ） , pulmonary arterial hypertension （PAH） group （ n = 20）, MSCs transplantion group （ n = 20 ）. The rats of PAH group and MSCs transplantion group were injected with a single dose of subcutaneous Monoerotaline （ 50 mg/ kg） to establish the models of pulmonary artery hypertension. The 3 groups of rats were fed in the same condition. After 3 weeks, MSCs were labeled by Hoechst 33342 and then the labeled MSCs （5 × 10^6/ml） were infused into the rats in MSCs transplantation group by sublingual vein. PAH group and normal control group received a subcutaneous injection of 0.9% saline. The survival of rats, mean pulmonary artery pressure, right ventricle hypertrophy index, and the microstrueturo changes of small pulmonary vasculature were observed after 28 days. Results After the MSCs were transplanted into the rats for 28 days, the survival rate of rats in MSCs groups raised from 30% to 90%, while mean pulmonary artery pressure decreased by 50% , and the right ventricle hypertrophy index improved too（ P 〈 0. 01 ）. The pulmonary artery remodeling was improved signifieandy in MSCs transplantation group. MSCs labeled with Hoechst 33342, observed by fluorescence microscope, were permanently implanted and differentiated into plentiful collateral circulations in the lungs. The pulmonary artery remodeling was reversed effectively in MSCs transplantation group. Conclusions The results indicate that MSCs can reverse the progression of pulmonary arteries remodeling. MSCs cells can differentiate into plentiful new vessels, and even collateral circulation, then repair the monocrotaline-damaged lung.