人脐血间充质干细胞预防博来霉素致大鼠肺纤维化效果

Preventive intervention effect of human umbilical cord blood mesenchymal stem cells on pulmonary interstitial fibrosis induced by bleomycin in rats

目的探讨人脐血间充质干细胞(HUCBMSC)对博来霉素所致大鼠肺纤维化的预防性干预效果及可能机制。方法取第2代HUCBMSC培养至第4代;取无特定病原体级5周龄雄性SD大鼠120只随机分为博来霉素组、干细胞干预组、地塞米松干预组和阴性对照组,每组30只。前3组分别经气管注入博来霉素建立肺纤维化模型,干细胞干预组造模后经鼠尾静脉注入5-溴-2-脱氧尿嘧啶核苷(Brdu)标记的HUCBMSC,地塞米松干预组造模后第1天开始连续腹腔注射地塞米松7 d,阴性对照组经气管注入等体积生理氯化钠溶液,在第7、14、28天分别处死各组中的10只动物,肺组织行苏木精-伊红、马松三色染色,碱水解法测定肺羟脯氨酸的水平。结果干细胞干预组第7、14、28天肺组织均可见Brdu标记的干细胞。3个时间点的博来霉素组肺羟脯氨酸水平呈逐渐升高的趋势,第28天达最高水平(P<0.01)。3个时间点干细胞干预组和地塞米松干预组的肺泡炎症及肺纤维化程度均分别较博来霉素组轻,差异均有统计学意义(P<0.05)。结论 HUCBMSC可以定植于受损的肺组织中,并可能在肺纤维化早期有效减轻肺泡炎及肺纤维化。

Objective To observe the preventive intervention effect and possible mechanism of human umbilical cord blood mesenchymal stem cells（HUCBMSC） on pulmonary fibrosis induced by bleomycin in rats.Methods The second generation of HUCBMSC were cultured to the fourth generation.One hundred and twenty specific pathogen free 5-week-old male rats were randomly divided into 4 groups： bleomycin group,stem cell intervention group,dexamethasone intervention group and negative control group.Pulmonary fibrosis was induced in the front 3 groups with bleomycin drop-in to trachea.Then 5-bromo-2-deoxyuridine（Brdu） marked stem cells were injected in stem cell intervention group immediately by tail vein.Dexamethasone was intraperitoneally injected in dexamethasone intervention group for 7 consecutive days.Sodium chloride was intraperitoneally injected in negative control group.At the 7th,14th,28th day,10 rats in each group were executed respectively.Lung tissue was examined with hematoxylin-eosin and Masson staining.Hydroxyproline contents were tested.Results In stem cell intervention group,there were Brdu marked stem cells at the 7th,14th,28th days in lung tissue.The lung hydroxyproline levels in the bleomycin groups at 3 time points showed a gradually rising trend,and reaching the highest at the 28th day（P ＆lt; 0.01）.Milder alveolitis and fibrosis were seen in stem cell intervention group and dexamethasone intervention group,compared with those in bleomycin group（P ＆lt; 0.05）.Conclusion HUCBMSC can colonize the damaged lung tissue,and may effectively reduce the early pulmonary alveolitis and pulmonary fibrosis.