中文摘要：

目的研究缺氧对人肠上皮细胞Slingshot蛋白表达的影响及其与屏障功能变化的关系。方法建立人肠上皮细胞株Caco-2单层细胞培养模型。取细胞按照随机数字表法分为6部分，分别行缺氧处理0h（即刻）及1、2、6、12、24h，采用生物电阻测定仪测定细胞的跨上皮电阻（TER）。另取细胞同前行缺氧处理，采用蛋白质印迹法检测带状闭合蛋白1（ZO-1）、咬合蛋白、闭合蛋白1及Slingshot-1、Slingshot-2、Slingshot-3的蛋白表达。另取细胞同前行缺氧处理，采用荧光法检测纤维状肌动蛋白及球状肌动蛋白含量。3项检测中，各时相点样本数分别为10、10、18。对数据行单因素方差分析、Dunnett检验。结果（1）与缺氧0h比较，缺氧1—24h细胞的TER值均明显降低（P值均小于0．01）。（2）与缺氧0h（均为1．00）比较，缺氧1～24h细胞的ZO-1、咬合蛋白及闭合蛋白1表达量普遍降低，于缺氧12h或24h达到最低值（分别为0．69±0．20、0．47±0．15、0．474-0．22，P〈0．05或P〈0．01）。与缺氧0h比较，缺氧1～24h细胞的Slingshot-1、Slingshot-3蛋白表达量无明显变化（P值均大于0．05）；缺氧1～24h，细胞的Slingshot-2蛋白表达量呈先降低后上升的趋势，其中缺氧24h（1．544-0．57）明显高于缺氧0h（1．00，P〈0．05）。（3）与缺氧0h比较，缺氧1、6、12、24h细胞的纤维状肌动蛋白含量明显减少，缺氧6～24h细胞的球状肌动蛋白含量明显增加，P〈0．05或P〈0．01；其余时相点2项指标无明显变化（P值均大于0．05）。结论缺氧通过诱导人肠上皮细胞Slingshot-2表达，引起丝切蛋白去磷酸化而活化以及纤维状肌动蛋白解聚，从而影响细胞间紧密连接，导致细胞屏障功能受损。

英文摘要：

Objective To study the effect of hypoxia on Slingshot protein expression in human intestinal epithelial cell and its relation with changes in barrier function of the cells. Methods The human intestinal epithelial cell line Caeo-2 was used to reproduce monolayer-eells. One portion of the monolayer- cell specimens were divided into six parts according to the random number table, and they were respectively exposed to hypoxia for 0 （without hypoxia） , 1, 2, 6, 12, and 24 h. Transepithelial electrical resistance （TER） was determined with an ohmmeter. Another portion of the monolayer-cell specimens were exposed to hypoxia as above. Western blotting was used to detect the protein expressions of zonula occ]udens 1 （ZO-1） , occludin, claudin-1, Slingshot-1, Slingshot-2, and Slingshot-3. The remaining portion of the monolayer-eell specimens were also exposed to hypoxia as above. The content of fibrous actin （F-actin） and globular actin （G-actin） was determined by fluorescence method. The sample number of above-mentioned 3 experiments was respectively 10, 10, and 18 at each time point. Data were processed with one-way analysis of variance and Dunnett test. Results （ 1 ） Compared with that of cells exposed to hypoxia for 0 h, TER of cells exposed to hypoxia for 1 to 24 h was significantly reduced （ P values below 0.01 ）. （2） Compared with those of cells exposed to hypoxia for 0 h （all were 1.00） , the protein expressions of ZO-1, oceludin, and claudin- 1 of cells exposed to hypoxia for 1 to 24 h were generally lower, especially those of cells exposed to hypoxia for 12 hor24 h （respectively0.69 ±0.20, 0.47±0.15, and 0. 47 ± 0. 22 , P 〈0.05 orP 〈0.01）. Compared with those of cells exposed to hypoxia for 0 h, the protein expressions of Slingshot-1 and Slingshot-3 of cells exposed to hypoxia for 1 to 24 h were not obviously changed （ P values above 0.05）. The protein expression of Slingshot-2 of cells was decreased at first and then gradually increased from hypoxia hour 1 to 24.