KLF4 promotes the expression, translocation, and release of HMGB1 IN RAW264.7 macrophages in response to LPS
KLF4 promotes the expression, translocation, and release of HMGB1 IN RAW264.7 macrophages in response to LPS
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KLF4 响应 LPS 促进 RAW264.7 巨噬细胞中 HMGB1 的表达、易位和释放
DOI：
10.1097/shk.0b013e318162bef7
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发表时间：
2008-09-01
期刊：
影响因子：
3.1
通讯作者：
Xiao, Xianzhong
中科院分区：
文献类型：
--
作者：
Liu, Junwen;Liu, Ying;Xiao, Xianzhong
Kruppel-like factor4(KLF4)是一种进化上保守的含锌指转录因子，在细胞生长、增殖、分化和胚胎发育中具有多种调节功能。我们在前期的研究中发现，内毒素刺激后，成年小鼠肺组织中KLF4的mRNA表达上调了10倍以上，并且KLF4可以调节早期炎症介质IL-10的表达。为确定KLF4是否影响晚期炎症介质高迁移率族蛋白1(HMGB1)的表达和释放，将其启动子中含有两个潜在的KLF4结合元件的真核表达载体pcDNA3.1-KLF4和KLF4反义寡核苷酸分别导入RAW264.7巨噬细胞，用逆转录聚合酶链式反应和Western印迹法检测HMGB1的表达和释放。用凝胶迁移率改变实验检测KLF4与HMGB1启动子的结合活性。结果表明，KLF4过表达导致HMGB1在胞浆和胞核的表达增加，而KLF4缺乏导致HMGB1表达下降。与对照组相比，KLF4高表达后HMGB1的释放增加，而KLF4缺乏时HMGB1的释放减少。凝胶迁移率改变分析结果表明，KLF4与根据HMGB1启动子设计的寡核苷酸结合，并且结合活性随内毒素刺激而增强。这些结果表明，KLF4在正常情况下调节HMGB1的表达，以及在内毒素刺激下调节HMGB1的转位和释放起重要作用。
Kruppel-like factor 4 (KLF4) is an evolutionarily conserved zinc finger-containing transcription factor with diverse regulatory functions in cell growth, proliferation, differentiation, and embryogenesis. In our previous study, we found that KLF4 mRNA was up-regulated more than 10-fold in adult mice lung tissues after endotoxin stimuli, and that KLF4 can regulate the expression of IL-10, an early inflammatory mediator. To determine whether KLF4 influences the expression and release of high-mobility group box 1 (HMGB1), an important late inflammatory mediator, which contains two potential KLF4-binding elements in its promoter, pcDNA3.1-KLF4 expression plasmid or KLF4 antisense oligonucleotide was transfected into RAW264.7 macrophages, the expression and release of HMGB1 were examined by reverse-transcriptase-polymerase chain reaction and Western blot, respectively. Electrophoretic mobility shift assay was performed to detect the binding activity of KLF4 to the HMGB1 promoter. The results showed that KLF4 overexpression led to an increased expression of HMGB1 in both cytoplasm and nucleus, whereas KLF4 deficiency led to a decrease in HMGB1. Moreover, compared with the control group, the release of HMGB1 was increased after KLF4 overexpression after LPS treatment, whereas the release of HMGB1 was decreased after KLF4 deficiency in response to LPS. Electrophoretic mobility shift assay results showed the binding of KLF4 to the oligonucleotides designed according to the HMGB1 promoter, and the binding activity was increased in response to LPS stimulation. These results indicate that KLF4 plays an important role in regulating the expression of HMGB1 in normal condition, as well as the translocation and release of HMGB1 in response to LPS.