Specificity protein, Sp1-mediated increased expression of Prdx6 as a curcumin-induced antioxidant defense in lens epithelial cells against oxidative stress.
Specificity protein, Sp1-mediated increased expression of Prdx6 as a curcumin-induced antioxidant defense in lens epithelial cells against oxidative stress.
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DOI：
10.1038/cddis.2011.121
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发表时间：
2011-11-24
影响因子：
9
通讯作者：
中科院分区：
文献类型：
--
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Peroxiredoxin 6（Prdx 6）是一种多效性氧化应激反应蛋白，可保护细胞免受活性氧（ROS）诱导的损伤。姜黄素是一种天然存在的药物，具有多种有益作用，包括细胞保护作用。使用人透镜上皮细胞（hLEC）和Prdx 6缺陷细胞，我们显示的证据表明，姜黄素通过上调Prdx 6转录通过调用特异性蛋白1（Sp1）活性对促凋亡刺激保护细胞。姜黄素以浓度依赖性方式增强Sp1和Prdx 6 mRNA和蛋白表达，通过Western和实时PCR分析证明，从而通过钝化ROS表达和脂质过氧化来负调节ROS介导的细胞凋亡。生物信息学分析和DNA-蛋白质结合分析揭示了Prdx 6启动子中的三个活性Sp1位点（−19/27、−61/69和−82/89）。用Sp1和Prdx 6启动子-氯霉素乙酰转移酶（CAT）构建体的共转染实验表明，CAT活性在LEC或Sp1缺陷细胞（SL 2）中显著增加。姜黄素处理LEC增强Sp1结合到其网站，与姜黄素依赖性刺激Prdx 6启动子与Sp1网站和细胞保护一致。值得注意的是，通过点突变破坏Sp1位点废除了姜黄素对Prdx 6的反式激活。此外，姜黄素未能激活Prdx 6的表达在Sp1抑制剂的存在下，证明姜黄素介导的Prdx 6的表达增加依赖于Sp1活性。总的来说，这项研究可能为开发基于转录的诱导治疗提供基础，通过使用膳食补充剂来加强内源性抗氧化防御。
Peroxiredoxin 6 (Prdx6) is a pleiotropic oxidative stress-response protein that defends cells against reactive oxygen species (ROS)-induced damage. Curcumin, a naturally occurring agent, has diversified beneficial roles including cytoprotection. Using human lens epithelial cells (hLECs) and Prdx6-deficient cells, we show the evidence that curcumin protects cells by upregulating Prdx6 transcription via invoking specificity protein 1 (Sp1) activity against proapoptotic stimuli. Curcumin enhanced Sp1 and Prdx6 mRNA and protein expression in a concentration-dependent manner, as evidenced by western and real-time PCR analyses, and thereby negatively regulated ROS-mediated apoptosis by blunting ROS expression and lipid peroxidation. Bioinformatic analysis and DNA–protein binding assays disclosed three active Sp1 sites (−19/27, −61/69 and −82/89) in Prdx6 promoter. Co-transfection experiments with Sp1 and Prdx6 promoter–chloramphenicol acetyltransferase (CAT) constructs showed that CAT activity was dramatically increased in LECs or Sp1-deficient cells (SL2). Curcumin treatment of LECs enhanced Sp1 binding to its sites, consistent with curcumin-dependent stimulation of Prdx6 promoter with Sp1 sites and cytoprotection. Notably, disruption of Sp1 sites by point mutagenesis abolished curcumin transactivation of Prdx6. Also, curcumin failed to activate Prdx6 expression in the presence of Sp1 inhibitors, demonstrating that curcumin-mediated increased expression of Prdx6 was dependent on Sp1 activity. Collectively, the study may provide a foundation for developing transcription-based inductive therapy to reinforce endogenous antioxidant defense by using dietary supplements.
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影响因子：
7.4
作者：
Phelan, SA;Wang, X;Paigen, B
通讯作者：
Paigen, B
影响因子：
5.3
作者：
EMILI, A;GREENBLATT, J;INGLES, CJ
通讯作者：
INGLES, CJ
DOI：
10.1073/pnas.91.1.192
发表时间：
1994-01-04
影响因子：
11.1
作者：
GILL, G;PASCAL, E;TJIAN, R
通讯作者：
TJIAN, R
影响因子：
64.5
作者：
COUREY, AJ;TJIAN, R
通讯作者：
TJIAN, R
影响因子：
2.9
作者：
Fatma N;Kubo E;Sen M;Agarwal N;Thoreson WB;Camras CB;Singh DP
通讯作者：
Singh DP