Endomicroscopic and Transcriptomic Analysis of Impaired Barrier Function and Malabsorption in Environmental Enteropathy.
Endomicroscopic and Transcriptomic Analysis of Impaired Barrier Function and Malabsorption in Environmental Enteropathy.
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DOI：
10.1371/journal.pntd.0004600
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发表时间：
2016-04
影响因子：
3.8
通讯作者：
Watson A
中科院分区：
文献类型：
--
作者：
Kelly P;Besa E;Zyambo K;Louis-Auguste J;Lees J;Banda T;Soko R;Banda R;Amadi B;Watson A
环境性肠病 (EE) 与生长障碍、微量营养素吸收不良和口服疫苗反应受损有关。我们着手定义 EE 屏障功能受损的细胞机制并探索保护机制。我们使用共焦激光内窥镜 (CLE) 对赞比亚卢萨卡的 49 名患有环境性肠病的成年人进行了研究；小肠活检的组织学、免疫组织化学和 mRNA 测序；并将这些与血浆脂多糖（LPS）和锌摄取测试相关联。 CLE 图像（每项研究的中位数为 134）显示小肠损伤几乎无处不在。通过组织学和密蛋白 4 免疫染色成像，上皮缺陷主要出现在绒毛尖端，与 CLE 体内成像的渗漏相对应。在多变量分析中，循环对数转换 LPS 与细胞脱落事件（β = 0.83；P = 0.035）和血清胰高血糖素样肽-2（β = -0.13；P = 0.007）相关。 30/47 (64%) 个体中 25mg 测试剂量的锌摄取量减弱，并且在多变量分析中，HIV 导致锌摄取量减少，但与 GLP-2 呈正相关（β = 2.72；P = 0.03）。循环LPS与绒毛表面积之间存在U形关系。转录组分析鉴定出严重肠病中 23 个差异表达基因，包括保护性肽和蛋白质。共聚焦内窥镜检查、claudin 4 免疫染色和组织学可识别上皮缺陷，这些缺陷可能是细菌易位的部位，在存在这种缺陷的情况下，上皮表面积的增加会增加易位的负担。 GLP 2 和其他保护肽可能在 EE 的粘膜保护中发挥重要作用。环境性肠病是许多弱势群体中成人和儿童的普遍问题，特别是在热带地区。它不能归因于一种特定的传染源，而可能是由于环境造成的几种损害造成的。它与儿童生长障碍、口服疫苗反应受损以及导致微量营养素缺乏有关。其中许多问题可能与免疫激活有关，但免疫激活的途径尚不清楚。在这里，我们使用先进的内窥镜技术进行成像，表明肠道微生物及其分子成分的易位与肠道上皮衬里的缺陷有关。我们还报告了证据，表明这些缺陷与内分泌和旁分泌修复机制的失败有关，在健康情况下，这些机制应该恢复肠道屏障的完整性。这些观察结果可能会为治疗一种被忽视的热带疾病开辟新的方法，这种疾病损害了数百万成人和儿童的健康。
Environmental enteropathy (EE) is associated with growth failure, micronutrient malabsorption and impaired responses to oral vaccines. We set out to define cellular mechanisms of impaired barrier function in EE and explore protective mechanisms. We studied 49 adults with environmental enteropathy in Lusaka, Zambia using confocal laser endomicroscopy (CLE); histology, immunohistochemistry and mRNA sequencing of small intestinal biopsies; and correlated these with plasma lipopolysaccharide (LPS) and a zinc uptake test. CLE images (median 134 for each study) showed virtually ubiquitous small intestinal damage. Epithelial defects, imaged by histology and claudin 4 immunostaining, were predominantly seen at the tips of villi and corresponded with leakage imaged in vivo by CLE. In multivariate analysis, circulating log-transformed LPS was correlated with cell shedding events (β = 0.83; P = 0.035) and with serum glucagon-like peptide-2 (β = -0.13; P = 0.007). Zinc uptake from a test dose of 25mg was attenuated in 30/47 (64%) individuals and in multivariate analysis was reduced by HIV, but positively correlated with GLP-2 (β = 2.72; P = 0.03). There was a U-shaped relationship between circulating LPS and villus surface area. Transcriptomic analysis identified 23 differentially expressed genes in severe enteropathy, including protective peptides and proteins. Confocal endomicroscopy, claudin 4 immunostaining and histology identify epithelial defects which are probably sites of bacterial translocation, in the presence of which increased epithelial surface area increases the burden of translocation. GLP 2 and other protective peptides may play an important role in mucosal protection in EE. Environmental enteropathy is a widespread problem in adults and children in many disadvantaged populations, particularly in the tropics. It is not attributable to one specific infectious agent, but likely due to several insults of environmental origin. It is associated with growth failure in children, impaired responses to oral vaccines, and contributes to micronutrient deficiencies. Many of these problems can be related to immune activation, but the pathways of immune activation are unknown. Here we show that translocation of gut microbes and their molecular components is associated with defects in the epithelial lining of the gut, imaged using advanced endoscopic techniques. We also report evidence that these defects are associated with failure of endocrine and paracrine repair mechanisms which in health should restore the integrity of the intestinal barrier. These observations may open up new approaches for therapy for a neglected tropical disorder which impairs the health of millions of adults and children.