低氧条件下人脂肪间充质干细胞分泌多种细胞因子的水平

The secretion levels of various cytokines in human adipose mesenchymal stem cells under hypoxia

背景:脂肪间充质干细胞来源于脂肪组织,可分泌多种细胞因子,成为治疗各类缺血性疾病的热点种子细胞之一。目的:研究不同氧分压培养环境对人脂肪干细胞分泌细胞因子的影响,从而找出能使细胞因子高表达的最适氧分压。方法:利用酶消化法从人脂肪组织中分离脂肪干细胞,通过细胞形态学特征、体外分化功能及免疫表型对分离培养的细胞进行鉴定。人脂肪干细胞分别于3%,5%,21%的氧分压环境中培养48h,采用酶联免疫吸附实验检测血管内皮生长因子、脑源性神经营养因子、类胰岛素一号增长因子的分泌水平。结果与结论:①人脂肪干细胞呈长梭形或多角形,胞体丰满,胞浆均匀,呈漩涡状生长,体外诱导可进行成脂、成骨和成软骨分化;②流式细胞仪检测结果显示细胞高表达间充质表面标志物CD29、CD73、CD90和CD105,而几乎不表达造血干细胞表面标志物CD34和CD45,阴性表达HLA-DR;③人脂肪干细胞在低氧条件下(3%,5%氧分压)血管内皮生长因子的分泌量为常氧条件下的2.3倍(P<0.05)和1.5倍(P<0.05);低氧条件下(3%,5%氧分压)类胰岛素一号增长因子的分泌量分别为常氧条件下的2.4倍(P<0.05)和1.5倍(P<0.05);低氧条件下(3%,5%氧分压)脑源性神经营养因子的分泌量与常氧条件下差异无显著性意义(P>0.05);④结果表明,人脂肪干细胞在低氧环境中可显著提高血管内皮生长因子和类胰岛素一号增长因子的分泌量,而脑源性神经营养因子的分泌量并未受到影响。

BACKGROUND:Mesenchymal stem cells derived from adipose tissue can secrete a variety of cytokines.Therefore,these cells have become hot seed cells for treating various ischemic diseases.OBJECTIVE:To explore the effects of different oxygen partial pressures on the secretion of cytokines from human adipose mesenchymal stem cells,and to select the optimal oxygen partial pressures under which cytokines can highly express.METHODS:Adipose mesenchymal stem cells were isolated from human adipose tissue by enzymatic digestion,and were identified by morphological characteristics,differentiation function and immunophenotype.Human adipose mesenchymal stem cells were cultured at 3%,5%,and 21% partial oxygen pressures for 48 hours,respectively.The secretion levels of vascular endothelial growth factor,brain-derived neurotrophic factor,and insulin-like growth factor-1 in the cells were detected by enzyme-linked immunosorbent assay.RESULTS AND CONCLUSION:Human adipose mesenchymal stem cells grew spirally with a long fusiform or polygonal shape,plump cell body,and uniform cytoplasm.They could be induced for adipogenic,osteogenic and chondrogenic differentiation in vitro.The cultured cells highly expressed mesenchymal surface markers CD29,CD73,CD90,and CD105,scarcely expressed hematopoietic stem cell surface markers CD34 and CD45,and negatively expressed HLA-DR.The level of vascular endothelial growth factors secreted by human adipose mesenchymal stem cells under 3% or 5% partial pressure of oxygen(hypoxia)was 2.3 times(P<0.05)or 1.5 times(P<0.05)as high as that under normoxia,respectively.The secretion level of insulin-like growth factor-1 under 3% or 5% partial pressure of oxygen(hypoxia)was 2.4 times(P<0.05)or 1.5 times(P<0.05)higher than that under normoxia,respectively.However,there was no significant difference in the secretion levels of brain-derived neurotrophic factor between hypoxic and normoxic conditions(P>0.05).Therefore,human adipose mesenchymal stem cells significantly increase the secretion of vascular endothelial growth factor and insulin-like growth factor-1 under hypoxic conditions,while the secretion of brain-derived neurotrophic factor dose not change under hypoxic conditions.