【摘要】  目的  研究肿瘤坏死因子α(TNF-α)对小鼠胰岛内皮(MSl)细胞胰岛素样生长因子结合蛋白7(IGFBPT)的mRNA和蛋白水平的影响，并探讨其机制。 方法  采用可溶性TNF受体I(sTNFRI)(50 ng/m1)和不同浓度TNF-a(o、10、50、100、200、500 ng/m1)作用MSl细胞，再收集TNF-α(100 rig/m1)作用MSl细胞12 h后的培养液，直接或加入sTNFR工(50 ng/mm1)后培养培养新鲜的MSl细胞，采用RT-PCR和Westernblot检测各组MSl细胞中IGFBP7的mRNA和蛋白水平。结果  与0 ng/ml TNF-a组相比，100、200、500 ng/ml TNF-α均可使MSl细胞中IGFBP7 mRNA和蛋白水平升高(P<0．05)，其中500 ng/ml TNF-a组最高(P<0.05)；TNF-α (100 ng/m1) 作用MSl细胞12 h后的培养液可明显提高IGFBP7的mRNA和蛋白水平(P< 0.05)，但该效应可被sT卜JF耐   (50 ng/m1)完全抑(P<0.05)。 结论  TNF-α可能是在转录水平促进MSl细胞IGFBP7表达的。

【Abstract】  Objective   To investigate the expression of mRNA and protein of insulin-like growth factor binding protein 7 (IGFBP7) in mouse islet endothelial MSI cells treated with TNF-α.   Methods   MS1 cells were treated with different concentrations of  TNF-α(0，10，50，100，200，500 ng/mol respectively) and sTNFR I (50ng/ml). MSI cells were exposed with TNF-α (100 ng/ml) for 12 h， and then the conditioned medium was harvested and added to fresh MS1 cells in the presence or absence of soluble tumor necrosis factor receptor I (sTNFR I) (50 ng/ml). The mRNA Level of IGFBP7 was detected by real-time PCR，and the protein level of IGFBP7 was measured by western blot.  Result  Compared with 0 ng/ml TNF-αgroup，the expression of IGFBP7 was up-regulated in MS1 cells with 100,200 and 500 ng/ml TNF-αgroups respectively (P＜0.05) and was increased most significantly in 500 ng/ml TNF-αgroup (P＜0.05). We incubated MS1 cells  for 24 h in conditioned medium harvested from cells exposed to TNF-α (100ng/ml) for 12 h. The expected increase in IGFBP7 expression occurred but was completely blocked when the conditioned medium was preincubated in the presence of sTNFR I (P＜0.05).  Conclusion  Up-regulation of IGFBP7  is transcriptionally mediated by TNF-α.

【Key  words】   Tumor necrosis factor-α （TNF-α） ; Insulin-like growth factor binfing protein 7 (IgFBP7); Soluble tumor necrosis factor receptor I (sTNFR I);Mouse islet endothelial (MS1) cells