Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA.
Gut Microbes. 2013 Jul-Aug;4(4):292-305. doi: 10.4161/gmic.24706. Epub 2013 Apr 15.
Failure of the intestinal barrier is a characteristic feature of cholestasis. We have previously observed higher mortality in C57BL/6J compared with A/J mice following common bile duct ligation (CBDL). We hypothesized the alteration in gut barrier function following cholestasis would vary by genetic background. Following one week of CBDL, jejunal TEER was significantly reduced in each ligated mouse compared with their sham counterparts; moreover, jejunal TEER was significantly lower in both sham and ligated C57BL/6J compared with sham and ligated A/J mice, respectively. Bacterial translocation to mesenteric lymph nodes was significantly increased in C57BL/6J mice vs. A/J mice. Four of 15 C57BL/6J mice were bacteremic; whereas, none of the 17 A/J mice were. Jejunal IFN-γ mRNA expression was significantly elevated in C57BL/6J compared with A/J mice. Western blot analysis demonstrated a significant decrease in occludin protein expression in C57BL/6J compared with A/J mice following both sham operation and CBDL. Only C57BL/6J mice demonstrated a marked decrease in ZO-1 protein expression following CBDL compared with shams. Pyrosequencing of the 16S rRNA gene in fecal samples showed a dysbiosis only in C57BL/6J mice following CBDL when compared with shams. This study provides evidence of strain differences in gut microbiota, tight junction protein expression, intestinal resistance and bacterial translocation which supports the notion of a genetic predisposition to exaggerated injury following cholestasis.
肠屏障功能衰竭是胆汁淤积的一个特征。我们之前观察到,在胆总管结扎(CBDL)后,C57BL/6J 小鼠的死亡率比 A/J 小鼠更高。我们假设,在胆汁淤积后,肠道屏障功能的改变将因遗传背景而异。在 CBDL 一周后,与假手术对照组相比,结扎组的空肠跨上皮电阻(TEER)显著降低;此外,与 sham 和 ligated A/J 小鼠相比,sham 和 ligated C57BL/6J 小鼠的空肠 TEER 分别显著降低。与 A/J 小鼠相比,C57BL/6J 小鼠的细菌易位至肠系膜淋巴结明显增加。15 只 C57BL/6J 小鼠中有 4 只发生菌血症;而 17 只 A/J 小鼠中无一例发生菌血症。与 A/J 小鼠相比,C57BL/6J 小鼠空肠 IFN-γ mRNA 表达显著升高。Western blot 分析表明,与 sham 手术和 CBDL 相比,C57BL/6J 小鼠的紧密连接蛋白 occludin 表达显著降低。只有 C57BL/6J 小鼠在 CBDL 后与 sham 相比,ZO-1 蛋白表达明显下降。粪便 16S rRNA 基因的焦磷酸测序显示,与 sham 相比,只有 C57BL/6J 小鼠在 CBDL 后出现肠道微生物群失调。本研究提供了证据表明,在肠道微生物群、紧密连接蛋白表达、肠道阻力和细菌易位方面存在菌株差异,这支持了遗传易感性在胆汁淤积后导致损伤加重的观点。