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目的探究人脐血间充质干细胞对大鼠肺纤维化及TNF-α、NO的影响。方法取清洁级健康雄性SD大鼠35只随机分为博来霉素组15只(P组)、干细胞治疗组15只(M组)和阴性对照组5只(N组),取第二代人脐血间充质干细胞培养至第四代;P组、M组分别经气管注入博来霉素制造肺纤维化模型,N组注入等量的生理盐水,M组造模后立即经鼠尾静脉注入5-溴-2-脱氧尿嘧啶核苷(Brdu)标记的干细胞。N组大鼠在造模后第7天全部处死,P组和M组大鼠在造模后第7、14、28天分别处死。取肺组织行HE、Masson染色,ELISA法检测肺泡灌洗液中TNF-α、NO的表达情况。结果 M组第7、14、28天肺组织均可见标记的干细胞;HE及Masson染色后观察,与N组相比,P组7 d时肺泡炎最明显,28 d肺纤维化程度最重,M组较P组肺泡炎及纤维化程度减轻;与N组相比,P组大鼠的TNF-α、NO水平明显升高,在7 d时达高峰,M组TNF-α、NO水平在各个时间段明显少于P组,组间差异有统计学意义。结论人脐血间充质干细胞可以定植于肺组织中,在肺纤维化早期可有效减轻肺泡炎及肺纤维化;抑制TNF-α、NO的表达,可能为其作用机制。
Objective To investigate the effects of human umbilical cord blood mesenchymal stem cells on pulmonary fibrosis and TNF-α and NO in rats. Methods Thirty-five healthy male Sprague Dawley rats were randomly divided into 15 groups (P group), 15 mice in the stem cell therapy group (Group M) and 5 mice in the negative control group (Group N) Human umbilical cord blood mesenchymal stem cells were cultured to the fourth generation. Pulmonary fibrosis model was established by injecting bleomycin into trachea and group M respectively. Rats in group N were injected with the same amount of saline, Intravenous injection of 5-bromo-2-deoxyuridine (Brdu) labeled stem cells. Rats in group N were sacrificed on the 7th day after the model was established. Rats in group P and group M were sacrificed on days 7, 14 and 28 respectively. The lung tissue was taken out for HE and Masson staining. The expression of TNF-α and NO in bronchoalveolar lavage fluid was detected by ELISA. RESULTS: The labeled stem cells were observed on the 7th, 14th and 28th days in M group. The staining of HE and Masson was observed. Compared with N group, the incidence of alveolitis in P group was the highest at 7th day, M group compared with P group alveolitis and fibrosis degree reduced; compared with N group, P group rats TNF-α, NO levels were significantly increased, reached its peak at 7 d, M group TNF-α, NO levels in Each time period was significantly less than the P group, the difference between the groups was statistically significant. Conclusion Human umbilical cord blood mesenchymal stem cells can be colonized in the lung tissue, which can effectively reduce alveolitis and pulmonary fibrosis in the early stage of pulmonary fibrosis. Inhibition of TNF-α and NO expression may be the mechanism.