Inverse correlation between metallothioneins and hypoxia-inducible factor 1 alpha in colonocytes and experimental colitis
Inverse correlation between metallothioneins and hypoxia-inducible factor 1 alpha in colonocytes and experimental colitis
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DOI：
10.1016/j.bbrc.2011.11.031
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发表时间：
2011-12-16
影响因子：
3.1
通讯作者：
Laukens, Debby
中科院分区：
文献类型：
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作者：
Devisscher, Lindsey;Hindryckx, Pieter;Laukens, Debby
缺氧诱导因子1 α（HIF-1 α）和金属硫蛋白（MT）之间的正反馈机制已被确定在不同的疾病。这两种蛋白质已被独立地提出在炎症性肠病（IBD）的发病机制中;然而，它们的关系从未在肠道中进行过研究。在这项研究中，我们研究了结肠上皮细胞和实验性结肠炎中HIF-1 α和MTs之间的相互作用。在三种实验模型（体外、体内和离体）中，使用二甲基草酰甘氨酸（DMOG）使结肠细胞经受羟化酶抑制和HIF-1 α稳定化。利用靶向HIF-1 α（siRNA-HIF）和MT（siRNA-MT）的小干扰RNA以及锌介导的MT诱导来研究HT 29细胞中HIF-1 α和MT之间的相互作用。使用葡聚糖硫酸钠在C57 BL/6小鼠中诱导急性结肠炎。MT表达和HIF-1 α蛋白水平分别用实时定量PCR和ELISA测定。血管内皮生长因子（VEGF）的表达定量作为HIF-1转录活性的间接测量。DMOG下调HT 29细胞、新鲜分离的人结肠细胞和从用DMOG处理的小鼠分离的结肠细胞中的MT表达（p < 0.05）。SiRNA-HIF处理的细胞显示显著更高的基础MT水平（p < 0.05）和DMOG处理后减弱的MT下调。反过来，与用DMOG处理的siRNA-MT细胞相比，锌处理的对照细胞中的HIF-1 α稳定性显著较低，显示出高MT水平（p < 0.05）。在实验性结肠炎过程中，MT和VEGF mRNA表达呈负相关。MT在急性期被诱导，在恢复期下调。对于VEGF表达水平观察到相反的结果（p < 0.05）。本研究强调了结肠细胞和实验性结肠炎中HIF-1 α和MT表达之间的负相关关系。MT的操作可能代表了IBD患者的一种新的治疗策略。(C)2011 Elsevier Inc. All rights reserved.
A positive-feedback mechanism between hypoxia-inducible factor 1 alpha (HIF-1 alpha) and metallothioneins (MTs) has been identified in different diseases. Both proteins have been independently proposed in the pathogenesis of inflammatory bowel disease (IBD); however, their relation has never been studied in the gut. In this study, we investigated the interaction between HIF-1 alpha and MTs in colonic epithelial cells and during experimental colitis. Dimethyloxalylglycine (DMOG) was used to subject colonocytes to hydroxylase inhibition and HIF-1 alpha stabilization in three experimental models (in vitro, in vivo and ex vivo). Small interfering RNA targeting HIF-1 alpha (siRNA-HIF) and MT (siRNA-MT) together with zinc-mediated MT induction were used to study the interaction between HIF-1 alpha and MT in HT29 cells. Acute colitis was induced in C57BL/6 mice using dextran sulphate sodium. MT expression and HIF-1 alpha protein levels were measured using quantitative real-time PCR and ELISA, respectively. Vascular endothelial growth factor (VEGF) expression was quantified as an indirect measure of HIF-1 transcriptional activity. DMOG down-regulated MT expression in HT29 cells, in freshly isolated human colonocytes and in colonocytes isolated from mice treated with DMOG (p < 0.05). SiRNA-HIF-treated cells displayed significant higher basal MT levels (p < 0.05) and an attenuated MT down-regulation after DMOG treatment. In turn, HIF-1 alpha stabilization was significantly lower in zinc-treated control cells, displaying high MT levels, compared to siRNA-MT cells treated with DMOG (p < 0.05). In the course of experimental colitis, MT and VEGF mRNA expression were inversely related. MTs were induced in the acute phase and down-regulated during recovery. Opposing results were observed for VEGF expression levels (p < 0.05). The present study underscores the inverse relation between HIF-1 alpha and MT expression in colonocytes and during experimental colitis. The manipulation of MTs may represent a novel therapeutic strategy for patients suffering from IBD. (C) 2011 Elsevier Inc. All rights reserved.