中文摘要：

目的探讨骨髓间质干细胞携带的血红素加氧酶-1（HO-1）基因于体外共培养体系中抑制肺动脉平滑肌细胞增殖的效果及机制。方法采用核转染技术将HO-1质粒转染至骨髓间质干细胞,共培养肺动脉平滑肌细胞和骨髓间质干细胞,评估5-羟色胺刺激后的平滑肌细胞增殖情况,检测5-羟色胺刺激后平滑肌细胞中RhoA的活性。结果 5-羟色胺可刺激肺动脉平滑肌细胞增殖,使单纯培养的平滑肌细胞总数较对照组增加2.40倍（P〈0.01）。野生型骨髓间质干细胞与肺动脉平滑肌细胞共培养并不能抑制平滑肌细胞的增殖,而携带HO-1基因的干细胞则可明显抑制5-羟色胺刺激的平滑肌细胞增殖,使平滑肌细胞总数降至对照组的1.56倍（P〈0.05）;5-羟色胺可引起肺动脉平滑肌细胞中RhoA活性增加2.90倍,野生型干细胞与肺动脉平滑肌细胞共培养并未能改变5-羟色胺刺激的RhoA激活,但在携带HO-1基因的干细胞共培养体系中5-羟色胺诱发的RhoA活性明显降低。结论骨髓间质干细胞携带的HO-1基因可以旁分泌的形式抑制平滑肌细胞的增殖,其作用的机制可能与其产生的CO通过激活cGMP信号通路进而抑制RhoA的激活有关。HO-1可作为外源基因导入体内治疗肺动脉高压。

英文摘要：

Objective To investigate the inhibitory effects and potential mechanisms of bone marrow mesenchymal stem cells transfected with HO-1 gene on the proliferation of co-cultured pulmonary artery smooth muscle cells.Methods Bone marrow mesenchymal stem cells were transfected with HO-1 plasmid using nucleofection and co-cultured with pulmonary artery smooth muscle cells.The proliferation and activation of RhoA of smooth muscle cells in response to serotoin were examined.Results Serotonin resulted in a 2.4 fold-increase in the proliferation of pulmonary artery smooth muscle cells（P0.01 vs.the control）.Co-culture of wild type mesenchymal stem cells did not affect the proliferation of smooth muscle cells in response to serotonin,while mesenchymal stem cells with over-expression of HO-1 gene significantly inhibited the proliferation of smooth muscle cells,which declined to 1.56 fold-increase over that of the control（P0.05）.Serotonin caused a 2.9 fold-increase in the proliferation and activation of RhoA of pulmonary artery smooth muscle cells.Co-culture of wild type mesenchyma stem cells did not alter the proliferation and activation of RhoA in response to serotoin.Bone marrow mesenchymal stem cells with over-expression of HO-1 gene significantly inhibited the proliferation of pulmonary artery smooth muscle cells in response to serotoin in co-culture.Conclusion Our study suggests that transplantation of bone marrow mesenchymal stem cells modified with HO-1 gene is an effective way of suppressing the proliferation of smooth muscle cells via paracrine secretion manner.The mechanism of HO-1 may be related to its inhibiting activation of RhoA through producing CO which can activate cGMP signaling pathway.Therefore,it may be used as an exogenic gene in treatment of pulmonary artery hypertension.