Structural and functional changes of the duodenum in human norovirus infection
Structural and functional changes of the duodenum in human norovirus infection
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DOI：
10.1136/gut.2008.160150
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发表时间：
2008-11
期刊：
影响因子：
24.5
通讯作者：
H. Troeger;C. Loddenkemper;T. Schneider;E. Schreier;H. Epple;M. Zeitz;M. Fromm;J. Schulzke
中科院分区：
文献类型：
--
作者：
H. Troeger;C. Loddenkemper;T. Schneider;E. Schreier;H. Epple;M. Zeitz;M. Fromm;J. Schulzke
背景：诺沃克病毒感染是西方世界感染性腹泻最常见的原因。本研究旨在从功能和组织形态两个方面对人十二指肠病变进行研究。方法：用卡普兰标准诊断诺如病毒感染，并用粪便标本进行聚合酶链式反应(PCR)确诊。十二指肠活检均在内窥镜下进行。在微型Ussing小室中，进行了短路电流、磁通测量和阻抗频谱分析。进行组织学分析，包括细胞凋亡染色和上皮内淋巴细胞的特征。采用免疫印迹法对紧密连接蛋白进行定量。结果：在诺如病毒感染组，上皮阻力从对照组的24(2)Ωcm2下降到10(1)Ωcm2。甘露醇流量从对照组的113(24)nmolh−1 cm−2增加到242(29)nmolh−1 cm−2。显微解剖显示绒毛表面积减少47%(6.6%)。上皮内淋巴细胞增加到每100个肠细胞63(7)个，穿孔素阳性细胞毒性T细胞比率增加。紧密连接蛋白occludin、claudin-4和claudin-5的表达减少。诺如病毒感染组上皮细胞凋亡率增加一倍。此外，诺如病毒感染时基础短路电流增加，布美他尼和5-硝基-2-(3-苯丙氨基)苯甲酸(NPPB)可使其降低。结论：诺如病毒感染可导致上皮屏障功能障碍，其机制可能与细胞毒性上皮内淋巴细胞增多、紧密连接蛋白减少和上皮细胞凋亡增加有关。此外，显著刺激了活性阴离子的分泌。因此，诺沃克病毒感染中的腹泻是由渗漏通量和分泌成分共同驱动的。
Background: Norovirus infection is the most frequent cause of infectious diarrhoea in the western world. This study aimed to characterise functionally and histomorphologically the diseased duodenum in human biopsies. Methods: Norovirus infection was diagnosed by the Kaplan criteria and confirmed by PCR of stool samples. Duodenal biopsies were obtained endoscopically. In miniaturised Ussing chambers, short circuit current, flux measurements and impedance spectroscopy were performed. Histological analysis including apoptosis staining and characterisation of intraepithelial lymphocytes was performed. Tight junction proteins were quantified by immunoblotting. Results: In norovirus infection, epithelial resistance decreased from (mean (SEM)) 24 (2) Ω cm2 in controls to 10 (1) Ω cm2. Mannitol flux increased from 113 (24) nmol h−1 cm−2 in controls to 242 (29) nmol h−1 cm−2. Microdissection revealed a villus surface area reduced by 47% (6.6%). Intraepithelial lymphocytes were increased to 63 (7) per 100 enterocytes, with an increased rate of perforin-positive cytotoxic T cells. Expression of tight junctional proteins occludin, claudin-4 and claudin-5 was reduced. The epithelial apoptotic ratio was doubled in norovirus infection. Furthermore, the basal short circuit current was increased in norovirus infection and could be reduced by bumetanide and 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB). Conclusions: Norovirus infection leads to epithelial barrier dysfunction paralleled by a reduction of sealing tight junctional proteins and an increase in epithelial apoptosis, which may partly be mediated by increased cytotoxic intraepithelial lymphocytes. Furthermore, active anion secretion is markedly stimulated. Thus, the diarrhoea in norovirus infection is driven by both a leak flux and a secretory component.