Stead Family Department of Pediatrics, University of Iowa, Iowa City, IA.
Department of Pediatrics, Washington University School of Medicine, St Louis, MO.
J Pediatr Surg. 2019 Nov;54(11):2402-2407. doi: 10.1016/j.jpedsurg.2019.02.021. Epub 2019 Feb 23.
Necrotizing enterocolitis is associated with decreased intestinal perfusion and ischemia. Paneth cells, specialized epithelial cells, have been shown to regulate the intestinal vasculature and disruption of these cells has been associated with NEC. We hypothesized that Paneth cell disruption in immature mice intestine would decrease the perfusion of the intestinal microvasculature.
Paneth cells were disrupted in P14-16 mice using chemical (dithizone) and transgenic (diphtheria toxin) methodology. Six hours after Paneth cell disruption, Dylight 488 was injected directly into the left ventricle and allowed to perfuse for 5 minutes prior to intestinal harvesting. Tissue samples were evaluated with confocal fluorescence microscopy to quantify intestinal perfusion and samples were quantified by real time RT-PCR for gene expression.
Dithizone treatment significantly decreased intestinal perfusion compared to controls (p < 0.01). However, diphtheria toxin treatment demonstrated no significant difference in perfusion (p > 0.21). Intestines from all treatment groups had similar PECAM staining, but intestines treated with dithizone had significantly decreased nNOS and iNOS gene expression compared to controls (p < 0.007).
Paneth cell disruption significantly decreases the perfusion of the small intestinal microvasculature in a dithizone-specific manner. Dithizone has no effect on the amount of microvasculature, but does impact genes critical to nitric oxide signaling likely contributing to mesenteric vasoconstriction.
坏死性小肠结肠炎与肠道灌注减少和缺血有关。潘氏细胞是一种特殊的上皮细胞,已被证明可以调节肠道血管,这些细胞的破坏与 NEC 有关。我们假设不成熟小鼠肠道中潘氏细胞的破坏会降低肠道微血管的灌注。
使用化学(二硫代二氮杂菲)和转基因(白喉毒素)方法在 P14-16 小鼠中破坏潘氏细胞。潘氏细胞破坏后 6 小时,将 Dylight 488 直接注入左心室,在肠道收获前允许灌注 5 分钟。使用共聚焦荧光显微镜评估组织样本以量化肠道灌注,并用实时 RT-PCR 对样本进行定量以检测基因表达。
二硫代二氮杂菲处理与对照组相比,显著降低了肠道灌注(p<0.01)。然而,白喉毒素处理在灌注方面没有显示出显著差异(p>0.21)。所有治疗组的 PECAM 染色均相似,但与对照组相比,二硫代二氮杂菲处理的肠道中 nNOS 和 iNOS 基因表达显著降低(p<0.007)。
潘氏细胞破坏以二硫代二氮杂菲特异性的方式显著降低了小肠微血管的灌注。二硫代二氮杂菲对微血管数量没有影响,但会影响对一氧化氮信号至关重要的基因,可能导致肠系膜血管收缩。