Modification in Oxidative Stress, Inflammation, and Lipoprotein Assembly in Response to Hepatocyte Nuclear Factor 4α Knockdown in Intestinal Epithelial Cells
Modification in Oxidative Stress, Inflammation, and Lipoprotein Assembly in Response to Hepatocyte Nuclear Factor 4α Knockdown in Intestinal Epithelial Cells
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DOI：
10.1074/jbc.m110.155358
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发表时间：
2010-12-24
影响因子：
4.8
通讯作者：
Levy, Emile
中科院分区：
文献类型：
--
作者：
Marcil, Valerie;Seidman, Ernest;Levy, Emile
肝细胞核因子4 α（HNF 4 α）是一种主要在肝、肠、肾和胰腺中表达的核转录因子。它的许多肝脏和胰腺功能已被描述，但有限的信息是其在胃肠道中的作用。本研究的目的是评估HNF 4 α的抗炎和抗氧化功能以及其在肠道脂质转运和代谢中的意义。为此，通过用含有针对HNF 4 α的shRNA的pGFP-V-RS慢病毒载体转染Caco-2细胞来敲低HNF 4A基因。Caco-2细胞中HNF 4 α的失活导致以下结果：（a）氧化应激增加，如丙二醛和共轭二烯水平所示;（B）次级内源性抗氧化剂减少（过氧化氢酶、谷胱甘肽过氧化物酶和血红素加氧酶-1）;（c）核因子红细胞2相关因子的较低蛋白表达，所述核因子红细胞2相关因子控制抗氧化反应元件-调节的抗氧化酶;（d）核因子-κ B、白细胞介素-6、白细胞介素-8和白三烯B4的水平所示的细胞炎症活化的加重;（e）高密度脂蛋白及其抗炎和抗氧化组分载脂蛋白（apo）A-I和A-IV的输出的减少;（f）乳糜微粒及其apoB-48部分的较低细胞分泌揭示的细胞脂质转运减少;和（g）转录因子固醇调节元件结合蛋白2、过氧化物酶体增殖物激活受体α和肝X受体α和β的改变。总之，HNF 4 α似乎在肠道脂质代谢以及肠道抗氧化和抗炎防御机制中发挥关键作用。
Hepatocyte nuclear factor 4 alpha (HNF4 alpha) is a nuclear transcription factor mainly expressed in the liver, intestine, kidney, and pancreas. Many of its hepatic and pancreatic functions have been described, but limited information is available on its role in the gastrointestinal tract. The objectives of this study were to evaluate the anti-inflammatory and antioxidant functions of HNF4 alpha as well as its implication in intestinal lipid transport and metabolism. To this end, the HNF4A gene was knocked down by transfecting Caco-2 cells with a pGFP-V-RS lentiviral vector containing an shRNA against HNF4 alpha. Inactivation of HNF4 alpha in Caco-2 cells resulted in the following: (a) an increase in oxidative stress as demonstrated by the levels of malondialdehyde and conjugated dienes; (b) a reduction in secondary endogenous antioxidants (catalase, glutathione peroxidase, and heme oxygenase- 1); (c) a lower protein expression of nuclear factor erythroid 2-related factor that controls the antioxidant response elements- regulated antioxidant enzymes; (d) an accentuation of cellular inflammatory activation as shown by levels of nuclear factor-kappa B, interleukin-6, interleukin-8, and leukotriene B4; (e) a decrease in the output of high density lipoproteins and of their anti-inflammatory and anti-oxidative components apolipoproteins (apo) A-I and A-IV; (f) a diminution in cellular lipid transport revealed by a lower cellular secretion of chylomicrons and their apoB-48 moiety; and (g) alterations in the transcription factors sterol regulatory element-binding protein 2, peroxisome proliferator-activated receptor alpha, and liver X receptor alpha and beta. In conclusion, HNF4 alpha appears to play a key role in intestinal lipid metabolism as well as intestinal anti-oxidative and anti-inflammatory defense mechanisms.