目的:观察Transwell接触共培养促进单散人诱导多能干细胞(inducedpluripotentstemcells, iPSCs)生长及分化的作用。方法:将1~2代牛角膜内皮细胞(corneal endothelial cells, CECs)接种在Transwell 小室底面培养8 h后,应用Accutase消化及40μm过滤处理获得单散iPSCs,将其接种到已有CECs的Transwell小室内共培养14 d,前3 d使用mTeSR1培养基,第4天开始用含10%胎牛血清的低糖DMEM培养基。分别进行实时荧光定量聚合酶链式反应( real-time fluorescence quantitative polymerase chain reaction , qPCR )、免疫荧光、死活细胞染色及碱性磷酸酶( alkaline phosphatase , ALP)染色,对iPSCs多能特性表达及分化进行鉴定。设定单散iPSCs共培养组为实验组,常规培养iPSCs组为对照组(一),非共培养单散iPSCs组为对照组(二)。结果:培养牛CECs形态呈典型的六边形铺路石样外观。人iPSCs呈克隆样生长,共培养3 d后iPSCs贴壁呈单散细胞生长,免疫荧光检测未分化标志Nanog和Oct4呈阳性。 qPCR检测Nanog、Oct4和Sox2 mRNA表达,实验组与对照组(一)比较差异无统计学意义(P>0.05)。死活细胞染色显示,实验组死细胞明显减少,与对照组(二)比较差异有统计学意义(P<0.01)。共培养14 d后,人iPSCs形态比较均一,呈多边形,体积增大,无明显克隆团块;ALP染色阴性;免疫荧光染色ZO-1、AQP1和CD31表达阳性,CD34和CD133表达阴性。 qPCR检测Oct4、Nanog和Sox2 mRNA表达明显下调,与对照组(一)比较差异有统计学意义(P<0.01)。结论:与牛CECs共培养可增强人单散iPSCs活性,使iPSCs形态上向内皮样细胞转化,表达部分CECs的标志。 Transwell接触共培养模型可以促进单散iPSCs生长及分化。
AIM:ToinvestigatethepromotingroleofTranswellcontactco-culturesysteminthegrowthand differentiation of single-dissociated induced pluripotent stem cells (iPSCs).METHODS:Bovine corneal endothelial cells (CECs) at passage 1~2 (P1~2) were seeded on the underside of Transwell inserts placed into culture plates and were cultured in 37 ℃and 5%CO2 for 8 h.Accutase digestion and 40μm filter process disaggregated colony-aggregated iPSCs into single-dissociated iPSCs , and the cells were seeded on the inside of Transwell inserts with CECs in medium of mTeSR 1 for 3 d and then in low-glucose DMEM supplemented with 10% FBS for 2 weeks.The characteristics and differentiation markers were evaluated by real-time fluorescence quantitative polymerase chain reaction ( qPCR ) , immunofluorescence staining, live&dead cell staining and alkaline phosphatase (ALP) staining.The group of iPSCs cultured in conventional medium was used as control group 1.The group of single-dissociated iPSCs co-cultured with CECs was set as experimental group, while single-dissociated iPSCs without co-culture were as control group 2.RESULTS: The bovine CECs showed typical hexagonal cobblestone shape .iPSCs showed colony-like growth , while became single-dissociated cells after Tran-swell contact co-culture with bovine CECs for 3 d.The single-dissociated iPSCs positively expressed the undifferentiated markers, Nanog and Oct4.The mRNA expression levels of Nanog , Oct4 and Sox2 between experimental group and control group 1 were both positive and had no statistical significance difference (P>0.05).The dead cells in experimental group decreased significantly, and there was statistically significant difference compared to control group 2 (P<0.01).After 14 d of induced differentiation co-culture , the single-dissociated iPSCs showed rather uniform polygonal morphology , increased dimension and no obvious colony existence .Negative ALP staining, positive immunofluorescence staining for ZO-1, AQP1 and C