Weber-Mzell D, Zaupa P, Petnehazy T, Kobayashi H, Schimpl G, Feierl G, Kotanko P, Höllwarth M
Department of Paediatric Surgery, Medical University Graz, Graz, Austria.
Pediatr Surg Int. 2006 Jan;22(1):43-9. doi: 10.1007/s00383-005-1599-y.
Xanthinoxidase (XO) derived radical species are involved in bacterial translocation (BT) in cholestatic rats. The mechanism by which XO influences remains unclear. It has been shown recently that nuclear factor-kappa B (NF-kappaB), a ubiquitous transcription factor, can be activated by oxidative stress and thereby promote the process of BT. We investigated the effects of NF-kappaB inactivation on the incidence of BT in cholestatic rats. Sprague-Dawley rats were randomly assigned to one of eight groups: groups 1-4 were sham laparotomized rats either untreated (S1) or treated for 5 days with thalidomide (S2), curcumin (S3), or Inchin-ko (ICK; S4); groups 5-8 underwent common bile duct ligation (CBDL) for 5 days and were either untreated (C1) or treated with thalidomide (C2), curcumin (C3), or ICK (C4). After 5 days bacteriological cultures were performed from portal blood and V. cava, from the central mesenteric lymph node complex (MLN), spleen, and liver. The intensity of the activated NF-kappaB-subunit p65/p50 in the ileum mucosa was estimated by light microscopy and a scoring system from 1 to 20. Malondialdehyde (MDA) and myeloperoxidase activity (MPO) in the ileum were evaluated and expressed as U/g dry weight. Thalidomide and ICK reduced in CBDL-rats significantly the BT rate (63% vs. 18%, 63% vs. 30%, P<0.01). Enzyme estimations (MDA, MPO, and GSH) in sham operated animals showed no significant changes in the untreated groups compared with the treated groups. CBDL-rats pre-treatment with all three compounds caused a significant increase of MDA levels if groups were compared with the untreated C1-group (C1 31.6+/-7.7, C2 54.5+/-12.2, C3 53.3+/-11.2, and C4 47.2+/-9.4). GSH was reduced after the pre-treatment by all compounds but only significantly after curcumin pre-treatment (C1 vs. C3: 13.9+/-1.8 vs. 7.1+/-1.8; P<0.05). MPO estimations were significantly higher in the untreated C1-group if compared with groups C2, C3, and C4 (C1 1036.4+/-340.9, C2 709.9+/-125.9, C3 545.2+/-136.6, and C4 556.7+/-247.4; P<0.05). Thalidomide inhibited significantly the activation of NF-kappaB (C2 vs. C1: 6.0+/-4.5 vs. 12.7+/-5.3; P<0.01). Likewise, Curcumin and ICK suppressed NF-kappaB activation, but this did not reach significance in this experiment. NF-kappaB is involved in the process of BT in cholestatic rats and may be activated by XO derived ROS. We assume that the activated NF-kappaB initiates transcription of target genes inducing cytokine production, which in turn disrupts the tight junctions leading to BT from the intestinal lumen to the MLNs and circulation.
黄嘌呤氧化酶（XO）衍生的自由基参与胆汁淤积大鼠的细菌移位（BT）。XO发挥影响的机制尚不清楚。最近研究表明，核因子-κB（NF-κB）作为一种普遍存在的转录因子，可被氧化应激激活，进而促进BT进程。我们研究了NF-κB失活对胆汁淤积大鼠BT发生率的影响。将Sprague-Dawley大鼠随机分为八组：第1 - 4组为假手术大鼠，未处理（S1）或用沙利度胺（S2）、姜黄素（S3）或茵陈蒿汤（ICK；S4）处理5天；第5 - 8组进行胆总管结扎（CBDL）5天，未处理（C1）或用沙利度胺（C2）、姜黄素（C3）或ICK（C4）处理。5天后，从门静脉血、腔静脉、肠系膜中央淋巴结复合体（MLN）、脾脏和肝脏进行细菌培养。通过光学显微镜和1至20的评分系统评估回肠黏膜中活化的NF-κB亚基p65/p50的强度。评估回肠中的丙二醛（MDA）和髓过氧化物酶活性（MPO），并以U/g干重表示。沙利度胺和ICK显著降低了CBDL大鼠的BT率（63%对18%，63%对30%，P<0.01）。假手术动物的酶测定（MDA、MPO和谷胱甘肽（GSH））显示，与处理组相比，未处理组无显著变化。与未处理的C1组相比，用这三种化合物预处理的CBDL大鼠导致MDA水平显著升高（C1 31.6±7.7，C2 54.5±12.2，C3 53.3±11.2，C4 47.2±9.4）。所有化合物预处理后GSH均降低，但仅姜黄素预处理后显著降低（C1对C3：13.9±1.8对7.1±1.8；P<0.05）。与C2、C3和C4组相比，未处理的C1组MPO测定值显著更高（C1 1036.4±340.9，C2 709.9±125.9，C3 545.2±136.6，C4 556.7±247.4；P<0.05）。沙利度胺显著抑制NF-κB的激活（C2对C1：6.0±4.5对12.7±5.3；P<o.01）。同样，姜黄素和ICK抑制NF-κB激活，但在本实验中未达到显著水平。NF-κB参与胆汁淤积大鼠的BT过程，可能被XO衍生的活性氧（ROS）激活。我们推测，活化的NF-κB启动靶基因转录，诱导细胞因子产生，进而破坏紧密连接，导致细菌从肠腔移位至MLN和循环系统。
