Early molecular and functional changes in colonic epithelium that precede increased gut permeability during colitis development in mdrla(-/-) mice
Early molecular and functional changes in colonic epithelium that precede increased gut permeability during colitis development in mdrla(-/-) mice
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DOI：
10.1002/ibd.20375
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发表时间：
2008-05-01
影响因子：
4.9
通讯作者：
Warhurst, Geoffrey
中科院分区：
文献类型：
--
作者：
Collett, Andrew;Higgs, Norman B.;Warhurst, Geoffrey
背景：结肠炎粘膜炎症发生前的早期分子变化及其与肠道通透性的时间关系尚不清楚。这项研究研究了缺乏肠道转运蛋白P-糖蛋白的mdrla(-/-)小鼠在暴露于正常肠道菌群时自发发生结肠炎的功能和转录变化。方法：将mdrla(-/-)小鼠饲养在特定的无病原体条件下以减缓结肠炎的发展，并与同源对照进行比较。分析体外培养大鼠结肠粘膜通透性和细胞因子的分泌情况。用基因芯片和定量聚合酶链式反应分析结肠粘膜和上皮组织中的基因表达。结果：4-5周龄、无疾病的mdrla(-/-)小鼠的结肠组织学正常，与对照组相比没有证据表明通透性增加。然而，这些组织表现出一种独特的基因表达模式，涉及少数基因的显著变化。大多数上调的基因与细菌识别和泛素-蛋白酶体系统相关，并对干扰素(干扰素)有反应。抗炎因子胰腺炎相关蛋白(PAP)和相关基因RegIII-γ的表达明显降低。4-5周的mdrla(-/-)的集落细胞表现出相似的转录转录变化，伴随着基础趋化因子分泌增加和对内毒素的反应性增强。结肠通透性的显著增加与年龄较大(12-16周)的mdrla(-/-)小鼠表现出活动性炎症的分子和功能证据有关。结论：这些研究表明，在这种结肠炎模型中，与细菌反应性改变相关的早期上皮变化先于通透性和粘膜炎症，突显了P-糖蛋白在调节与共生微生物区系相互作用中的重要性。
Background: The early molecular changes preceding the onset of mucosal inflammation in colitis and their temporal relationship with gut permeability remain poorly defined. This study investigated functional and transcriptomic changes in mdrla(-/-) mice lacking the intestinal transporter P-glycoprotein, which develop colitis spontaneously when exposed to normal enteric flora.Methods: Mdrla(-/-) mice were housed in specific pathogen-free conditions to slow colitis development and compared to congenic controls. Mucosal permeability and cytokine secretion were analyzed in ex vivo colon. Gene expression in colonic mucosal and epithelial preparations was analyzed by microarray and qPCR. Colonocyte responsiveness to bacterial antigens was measured in short-term culture.Results: Colon from 4-5-week-old, disease-free mdrla(-/-) mice was histologically normal with no evidence of increased permeability compared to controls. However, these tissues display a distinctive pattern of gene expression involving significant changes in a small number of genes. The majority of upregulated genes were associated with bacterial recognition and the ubiquitin-proteasome system and were gamma-interferon (IFN-gamma) responsive. Expression of the antiinflammatory factor pancreatitis-associated protein (PAP) and the related gene RegIII gamma were markedly reduced. Colonocytes from 4-5-week mdrla(-/-) exhibit similar transcriptomic changes, accompanied by higher basal chemokine secretion and increased responsiveness to LPS. Significant increases in colonic permeability were associated with older (12-16-week) mdrla(-/-) mice displaying molecular and functional evidence of active inflammation.Conclusions: These studies show that early epithelial changes associated with altered responsiveness to bacteria precede increased permeability and mucosal inflammation in this model of colitis, highlighting the importance of P-glycoprotein in regulating interactions with the commensal microflora.