目的 观察不同类型、不同剂量、同等剂量不同移植次数的间充质干细胞(MSCs)对肺纤维化的疗效.方法 72只雄性SD大鼠以随机数表法平均分为6组:A组于气管内注入0.1ml生理盐水;B、C、D、E、F组于气管内注入5 mg/kg博来霉素0.1ml.建模后1d,A、B组经尾静脉注射生理盐水1.0 ml,C组经尾静脉注射骨髓间充质干细胞(BMSCs)1×106,D组经尾静脉注射脐血间充质干细胞(UCB-MSCs)1×106,E组经尾静脉注射BMSCs 5 × 105,F组经尾静脉注射BMSCs 1×107.建模后8d,E组经尾静脉注射BMSCs 5×105.建模后28 d及42 d处死各组大鼠的一半,分别留取肺组织行病理学检查、测定大鼠肺组织转化生长因子-β1(TGF-β1)、羟脯氨酸(HYP)、基质金属蛋白酶-2(MMP-2)、基质金属蛋白酶组织抑制剂-1 (TIMP-1)水平.结果 B组可见大鼠肺泡结构严重紊乱,大量胶原纤维沉积,B、C、D、E、F、A组肺纤维化评分依次降低[28 d时为(3.00±0.00)、(2.17±0.75)、(1.60±0.89)、(1.33±0.52)、(1.00 ±0.00)、(0.00±0.00)分,42d时为(3.00±0.00)、(2.40±0.55)、(1.75±0.96)、(1.50±0.84)、(-)、(0.00±0.00)分],肺组织TGF-β1、HYP、MMP-2/TIMP-1水平依次下降.肺组织TGF-β1、HYP、MMP-2/TIMP-1分别与肺泡炎程度评分、肺纤维化程度评分呈正相关(P =0.000).结论 MSCs可延缓肺纤维化进展,其机制可能与下调TGF-β1水平、改善MMP/TIMP失衡有关,选择UCB-MSCs或分次移植可提高MSCs对肺纤维化的治疗效果.
Objective To investigate the effects of mesenchymal stem cells (MSCs) on pulmonary fibrosis under different conditions (different types,different doses and different transplantation times in the same dose).Methods Seventy-two male SD rats were equally divided into 6 groups by random number table method:Group A received intratracheal instillation of NS (0.1 ml).Group B,C,D,E and F received intratracheal instillation of bleomycin (5 mg/kg in 0.1 ml NS).On the 1st day after bleomycin administration,Group A and B received NS (1.0 ml) via the tail vein,while Group C received bone marrow mesenchymal stem ceils (BMSCs) 1 × 106,Group D received umbilical cord blood mesenchymal stem cells (UCB-MSCs) 1 × 106,Group E received BMSCs 5 × 105 and Group F received BMSCs 1 × 107 via the tail vein,respectively.On the 8th day after bleomycin administration,Group E received BMSCs 5 × 105 again.Half of rats in each group were sacrificed respectively on the 28th and 42nd day after bleomycin administration.The pathologic changes,transforming growth factor-β1 (TGF-β1),hydroxyproline (HYP),matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1) of the lung tissues were investigated.Results Alveolar structure was severely in disorder,and massive collagenous fiber was deposited in Group B.In Group B,C,D,E,F and A,the scores of pulmonary fibrosis were decreased in sequence [(3.00 ± 0.00),(2.17 ± 0.75),(1.60 ± 0.89),(1.33 ± 0.52),(1.00 ± 0.00),(0.00 ± 0.00) on the 28th day after bleomycin administration,and (3.00 ± 0.00),(2.40±0.55),(1.75±0.96),(1.50±0.84),(-),(0.00 ±0.00)on the42nd day after bleomycin administration],while the levels of TGF-β1,HYP and MMP-2/TIMP-1 were respectively decreased in sequence as above.The levels of TGF-β1,HYP and MMP-2/TIMP-1 were positively associated with pulmonary alveolitis and fibrosis scores respectively (P =0.000).Conclusion MSCs transplantation can suspend the progress of pulmonary fibrosis,and the mechanism may be related to reducing the level of TGF-β1 and improving the imbalance of MMP/TIMP.Choosing UCB-MSCs or multiple transplantation may improve the therapeutic effects of pulmonary fibrosis.