骨髓间充质干细胞移植对大鼠低氧性肺动脉高压的影响

The effect of bone marrow mesenchymal stem cell transplantation on hypoxic pulmonary hypertension in rats

目的:探讨骨髓间充质干细胞(MSCs)移植对大鼠低氧性肺动脉高压(HPH)的影响。方法:体外分离、培养、鉴定SD大鼠骨髓MSCs、绿色荧光蛋白腺病毒标记MSCs细胞。将健康雄性SD大鼠随机分为4组:正常对照组(NC组)8只、低氧性肺动脉高压组(HPH组)8只,低氧性肺动脉高压同时骨髓间充质干细胞移植组(MSCs组)24只,低氧性肺动脉高压同时携带血管内皮生长因子(VEGF)的MSCs移植组(VEGF+MSCs组)24只。采用常压间歇低氧法建立大鼠肺动脉高压模型,干细胞转染并行干细胞移植。观察大鼠平均肺动脉压力(mPAP),计算右心室肥厚指数(RVHI),显微镜下观察各组大鼠肺小动脉形态结构改变,并在荧光显微镜下观察干细胞移植7 d,14 d,28 d时腺病毒转染荧光标记的MSCs在肺小动脉分布及表现。结果:NC组28 d时mPAP(mmHg)为15.5±1.5,而HPH组、MSCs组及MSCs+VEGF组分别为26.1±1.9、21.6±2.7及20.1±2.9,均明显高于NC组(P<0.01),但MSCs组及MSCs+VEGF组较HPH组明显下降(P<0.01),MSCs组与MSCs+VEGF组无明显差别。NC组28 d时RVHI为0.28±0.02,而HPH组、MSCs组及MSCs+VEGF组RVHI分别为0.43±0.07、0.34±0.03及0.35±0.01,均明显高于NC组(P<0.01),但MSCs组及MSCs+VEGF组较HPH组明显下降(P<0.05),MSCs组与MSCs+VEGF组无明显差别。HPH组28 d时,肺小动脉管壁明显增厚,管腔明显狭窄、闭塞,内皮细胞不完整,而MSCs组血管壁较HPH组变薄,管腔通畅,内皮细胞完整性改善,MSCs组及MSCs+VEGF组的表现改变不明显。结论:骨髓间充质干细胞移植可改善肺小动脉血管重塑,从而部分逆转HPH的进程;而将VEGF与MSCs联合移植并未提高单纯MSCs移植的作用。

Objective： To study the influence of bone marrow mesenchymal stem cells （MSCs） transplantation on hypoxic pulmonary hypertension （HPH） in rats. Methods： SD rats MSCs were separated, cultivated, identified and labeled by the green fluorescence protein （GFP） gene virus and transplanted in vitro. Healthy male SD rats were randomly divided into four groups： Normal control group （NC group） and HPH group （eight rats respectively）, HPH ＋ MSCs transplantation group and HPH ＋ VEGF ＋ MSCs transplantation group （twenty-four respectively）. The test employed atmospheric intermittent low oxygen method to establish the rat model of pulmonary hypertension and stem cells were transferred and transplanted. The rats＇ mean pulmonary artery pressure （mPAP） was observed; right ventricular hypertrophy index （RVHI） was calculated; the morphological change of lung small artery in various groups of rats was observed under the microscope; the distribution of lung small artery and adenovirus transfection fluoreseenfly labeled MSCs was observed under a fluorescent microscope after 7, 14 and 28 days when stem cell was transplanted. Results： For NC group, the mPAP （mmHg） was 15.5 ± 1.5 after twenty-eight days while the mPAPs for HPH , MSCs and MSCs ＋ VEGF were 26.1 -± 1.9, 21.6 ± 2.7 and 20.1 ± 2.9 respectively which were apparently higher than that of NC group（ P 〈 0. 01 ）and compared with HPH group（ P 〈 O. O1 ）, which declined dearly. There was no significant difference between MSCs and MSCs ＋ VEGF. After twenty-eight days, RVHI for NC group was 0.28 ± 0.02 while the RVHI for HPH, MSCs and MSCs ＋ VEGF were 0.43 ± 0.07,0.34 ± 0.03 and 0.35 ± 0.01 respectively which was apparently higher than that of NC group （ P 〈 0.01 ） but which was clearly lower than that of MSCs and MSCs ＋ VEGF （ P 〈 0.05） and there was no significant difference between MSCs and MSCs ＋ VEGF. For HPH group, pulmonary arteriole wall became apparently thicker, the lumen became significantly narrow and nearly obstructed after twenty-eight days, the endothelial cells were incomplete; compared with HPH group, pulmonary arteriole wall of MSCs group became thin, the lumen was smooth and the completeness of endothelial cells was improved. Whereas for MSCs and MSCs ＋ VEGF, these changes were not significantly clear. Conclusion： After MSCs transplantation, mPAP and RVHI dechne sharply and lung small artery remedeling is improved which partially reverses HPH process; there is no significant difference between VEGF together with MSCs transplantation group and pure MSCs.