The let-7 microRNA enhances heme oxygenase-1 by suppressing Bach1 and attenuates oxidant injury in human hepatocytes.
The let-7 microRNA enhances heme oxygenase-1 by suppressing Bach1 and attenuates oxidant injury in human hepatocytes.
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DOI：
10.1016/j.bbagrm.2012.06.001
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发表时间：
2012-11
影响因子：
4.7
通讯作者：
Bonkovsky, Herbert L.
中科院分区：
文献类型：
--
作者：
Hou, Weihong;Tian, Qing;Steuerwald, Nury M.;Schrum, Laura W.;Bonkovsky, Herbert L.
let-7 microRNA（miRNA）在人类肝脏发育和疾病如肝细胞癌、肝纤维化和肝炎中起重要作用，其中氧化应激加速这些疾病的进展。到目前为止，let-7 miRNA家族在调节血红素加氧酶1（HMOX 1）（一种关键的细胞保护酶）中的作用仍然未知。我们的目的是确定let-7 miRNA是否直接调节Bach 1，HMOX 1基因的转录抑制因子，以及let-7 miRNA间接上调HMOX 1是否减弱人肝细胞的氧化损伤。通过实时荧光定量PCR、Western blot和荧光素酶报告基因分析来确定let-7 miRNA对Huh-7和HepG 2细胞中Bach 1和HMOX 1基因表达的影响。双荧光素酶报告基因分析显示，let-7 b、let-7 c或miR-98显著降低Bach 1 3 '-非翻译区（3'-UTR）依赖性荧光素酶活性，但不降低突变体Bach 1 3 '-UTR依赖性荧光素酶活性，而含有与突变体Bach 1 3'-UTR碱基互补性的突变体let-7 miRNA恢复了其对突变体报告基因活性的影响。与非特异性对照相比，let-7 b、let-7 c或miR-98下调Bach 1蛋白水平50- 70%，随后上调HMOX 1基因表达3-4倍。此外，Huh-7细胞转染let-7 b，let-7 c或miR-98模拟物表现出对叔丁基氢过氧化物（tBuOOH）诱导的氧化损伤的抵抗力增加，而Bach 1的过表达则消除了这种保护作用。总之，let-7 miRNA直接作用于Bach 1的3 '-UTR，并负调控该蛋白的表达，从而上调HMOX 1基因的表达。let-7 miRNA家族成员的过表达可能代表了一种保护人类肝细胞免受氧化损伤的新方法。
The let-7 microRNA (miRNA) plays important roles in human liver development and disease such as hepatocellular carcinoma, liver fibrosis and hepatitis wherein oxidative stress accelerates the progression of these diseases. To date, the role of the let-7 miRNA family in modulation of heme oxygenase 1 (HMOX1), a key cytoprotective enzyme, remains unknown. Our aims were to determine whether let-7 miRNA directly regulates Bach1, a transcriptional repressor of the HMOX1 gene, and whether indirect up-regulation of HMOX1 by let-7 miRNA attenuates oxidant injury in human hepatocytes. The effects of let-7 miRNA on Bach1 and HMOX1 gene expression in Huh-7 and HepG2 cells were determined by real-time qRT-PCR, Western blot, and luciferase reporter assays. Dual luciferase reporter assays revealed that let-7b, let-7c, or miR-98 significantly decreased Bach1 3’-untranslated region (3’-UTR)-dependent luciferase activity but not mutant Bach1 3’-UTR-dependent luciferase activity, whereas mutant let-7 miRNA containing base complementarity with mutant Bach1 3’-UTR restored its effect on mutant reporter activity. let-7b, let-7c, or miR-98 down-regulated Bach1 protein levels by 50–70%, and subsequently up-regulated HMOX1 gene expression by 3–4 fold, compared with non-specific controls. Furthermore, Huh-7 cells transfected with let-7b, let-7c or miR-98 mimic showed increased resistance against oxidant injury induced by tert-butyl-hydroperoxide (tBuOOH), whereas the protection was abrogated by over-expression of Bach1. In conclusion, let-7 miRNA directly acts on the 3’-UTR of Bach1 and negatively regulates expression of this protein, and thereby up-regulates HMOX1 gene expression. Over-expression of the let-7 miRNA family members may represent a novel approach to protecting human hepatocytes from oxidant injury.
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影响因子：
13.5
作者：
Hou, Weihong;Tian, Qing;Zheng, Jianyu;Bonkovsky, Herbert L.
通讯作者：
Bonkovsky, Herbert L.
影响因子：
56.9
作者：
Jopling, CL;Yi, MK;Sarnow, P
通讯作者：
Sarnow, P
影响因子：
4.8
作者：
Shan, Ying;Lambrecht, Richard W.;Bonkovsky, Herbert L.
通讯作者：
Bonkovsky, Herbert L.
影响因子：
4.8
作者：
Hintze, Korry J.;Katoh, Yasutake;Theil, Elizabeth C.
通讯作者：
Theil, Elizabeth C.
影响因子：
11.4
作者：
Ogawa, K;Sun, J;Igarashi, K
通讯作者：
Igarashi, K