肠上皮干细胞标志分子在小鼠放射性肠炎中的表达

The expression of intestinal epithelial stem cell markers in mouse radiation enteritis

目的探讨肠上皮干细胞标志分子Msil及Hesl在小鼠急性放射性肠炎（radiation enteritis，RE）模型中的表达情况。方法40只雌性BALB／c小鼠采用B射线进行以300cGy／min的速率一次性全腹部照射。选取30只小鼠于照射前（Od）及照射后第3、5、7、14天每天处死6只，分离小肠，截取小肠中段进行定量PCR、Western印迹及免疫组织化学法测定Msil及Hesl的表达，比较两者的表达差异。结果成功建立小鼠急性RE模型。定量PCR的结果显示，Msil和Hesl在第5天时表达的相对ACt值分别为15．17±0．47及15．83±0．24，Western印迹检测结果显示，Msil及Hesl于第5天表达的相对灰度分别为0．443±0．055和0．301±0．047，在RNA及蛋白质水平上两者均显著高于其他时间点（P值均〈0．05）。免疫组织化学检测结果显示，Msil和Hesl于第5、7天时在肠隐窝中大量表达。结论Msil及Hesl在RE的损伤修复前表达上调，提示肠干细胞的增殖与肠上皮修复有关。

Objective To investigate the expression of intestinal epithelial stem cell markers Msil and Hesl in mouse acute radiation enteritis（RE） model. Methods Forty female BALB/c mice were undergone one-time whole abdominal irradiation by 300 cGy/min D-ray. Thirty mice were selected before irradiation （Day 0） and every six mice were euthanized at day 3, 5, 7 and 14 after irradiation. The small intestinal were detached and the expression of Msil and Hesl were detected in middle part of small intestinal by quantitative RT-PCR, Western blots, and immunohistochemistry. Subsequently, the difference of Msil and Hesl expression was compared. Results The mouse acute RE model was successfully established. At the 5th day after radiation, the results of quantitative RT-PCR indicated that the relative △Ct value of Msil and Hesl expression were 15. 17±0. 47 and 15. 83±0. 24 respectively, the results of Western blot showed that the integrated intensity were 0. 443±0. 055 and 0. 301±0. 047 for Msil and Hesl. The expressions were significantly higher than other time points at RNA and protein levels （P〈0.05）. The results of immunohistochemistry revealed that Msil and Hesl were highly expressed in intestinal crypts at 5th day and 7th day. Conclusions The expression of Msil and Hesl, upregulated before wound repair in RE model, indicates that intestinal epithelial repair is related to intestinal stem celt proliferation.