体外诱导人骨髓间充质干细胞向Ⅱ型肺泡上皮细胞分化

摘要

背景:Ⅱ型肺泡上皮细胞被证明在大鼠肺纤维化模型中直接参与肺的修复并可以减轻肺纤维化的程度.胚胎干细胞可以在体外诱导分化Ⅱ型肺泡上皮细胞,但是其应用受到多方面的限制.目的:探讨体外诱导骨髓间充质干细胞为Ⅱ型肺泡上皮细胞的方法及转化率.方法:取人胸骨骨髓细胞,体外分离培养骨髓间充质干细胞.采用无血清小气道生长液和改良无血清小气道生长液作为培养液,将骨髓间充质干细胞与人胚肺间质细胞共培养.观察骨髓间充质干细胞形态并用反转录PCR 检测表面活性蛋白C 的mRNA 以及免疫荧光检测表面活性蛋白C 表达.结果与结论:骨髓间充质干细胞与人胚肺间质细胞共培养10 d 后开始出现部分骨髓间充质干细胞由原先的长梭形变成和上皮细胞相似的形态.15d 后开始检测到表面活性蛋白C mRNA,但未随共培养时间延长而有所增加.改良无血清小气道生长液与无血清小气道生长液相比能增加表面活性蛋白C mRNA 表达(P < 0.05).说明采用无血清小气道生长液或改良无血清小气道生长液,并与胚肺间质细胞共培养可以将骨髓间充质干细胞在体外诱导分化为Ⅱ型肺泡上皮细胞,但其转化率较低,表面活性蛋白C 的阳性率仅为(3.15±0.69)%.%BACKGROUND: Al veolar epithelial type Ⅱ (AT Ⅱ) has been demonstrated to directly participate in liver recovery and can also alleviate the severity of pulmonary fibrosis in a rat model of pulmonary fibrosis. Embryonic stem cells (ESCs) can differentiate into AT Ⅱ in vitro, but the application of ESCs is confined by many factors. OBJECTIVE: To investigate the method and transformation rate of bone marrow mesenchymalstem cells (BMSCs) differentiation into AT Ⅱ. METHODS: The BMSCs were isolated from human bone marrow cells. BMSCs were co-cultured with human embryonic lung mesenchymal cells (MRC-5) in serum-free small ai rway growth medium (SAGM) and modi fied SAGM. The morphology of BMSCs was observed, and the expression of surfactant protein C (SPC) mRNA was detected by RT-PCR. In addition, the expression of SPC was also detected by immunofluorescence.RESULTS AND CONCLUSION: After the BMSCs were co-cultured with MRC-5 for 10 days, some of BMSCs began to turn into epithelioid cells in morphous. After 15 days, the expression of SPC mRNA was detected, but it was notincreased along with the prolongation of coculture days. Compared with SAGM, modified SAGM could significantly increase the expression of SPC mRNA (P < 0.05). BMSCs could differentiate into AT Ⅱ in SAGM or modi fied SAGM when co-culture with MRC-5 invitro at low transformation rate. Positive rate of SPC was only (3.15±0.69)%.