Regulation of Spi 2.1 and 2.2 gene expression after turpentine inflammation: discordant responses to IL-6.
Regulation of Spi 2.1 and 2.2 gene expression after turpentine inflammation: discordant responses to IL-6.
复制标题
松节油炎症后 Spi 2.1 和 2.2 基因表达的调节：对 IL-6 的不一致反应。
DOI：
10.1152/ajpcell.1999.276.6.c1374
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
Schwarzenberg,SJ
中科院分区：
文献类型：
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作者：
Berry,SA;Bergad,PL;Stolz,AM;Towle,HC;Schwarzenberg,SJ
大鼠丝氨酸蛋白酶抑制剂（Spi）2基因家族包括阳性（Spi 2.2）和阴性（Spi 2.1）急性期反应物，促进肝脏急性期反应（APR）调节的建模。为了研究信号转导和转录激活（STAT）蛋白在诱导APR后这些模型基因的趋异调控中的作用，我们评估了基因的近端启动子，重点关注这些启动子元件中包含的STAT结合位点。通过注射姜黄素诱导APR包括激活STAT 3复合物，该复合物可以结合Spi 2.2基因启动子中的γ激活序列（GAS），尽管Spi 2.2 GAS位点也可以结合STAT 1或STAT 5。为了创建APR的体外模型，用细胞因子和激素的组合处理原代肝细胞以模拟APR诱导后整个动物的激素环境。用白细胞介素（IL）-6（一种关键的APR细胞因子）孵育原代大鼠肝细胞，可激活STAT 3，并诱导含有Spi 2.2启动子−319至+85区域的氯霉素乙酰转移酶报告基因构建体增加28倍。这表明松节油诱导的Spi 2.2增加主要由IL-6介导。相比之下，虽然turlycine治疗减少Spi 2.1 mRNA在体内和IL-6不增加Spi 2.1 mRNA在原代大鼠肝细胞，肝细胞与IL-6的治疗结果在5.4倍的诱导Spi 2.1启动子活性介导的配对GAS元件在这个启动子。Spi 2.1和2.2基因的差异调节部分是由于这些基因在GAS位点的启动子的差异。单独的IL-6不能再现由松节油诱导的炎症引起的大鼠Spi 2基因表达的模式。
The rat serine protease inhibitor (Spi) 2 gene family includes both positive (Spi 2.2) and negative (Spi 2.1) acute phase reactants, facilitating modeling of regulation of hepatic acute phase response (APR). To examine the role of signal transducer and activation of transcription (STAT) proteins in the divergent regulation of these model genes after induction of APR, we evaluated the proximal promoters of the genes, focusing on STAT binding sites contained in these promoter elements. Induction of APR by turpentine injection includes activation of a STAT3 complex that can bind to a γ-activated sequence (GAS) in the Spi 2.2 gene promoter, although the Spi 2.2 GAS site can bind STAT1 or STAT5 as well. To create an in vitro model of APR, primary hepatocytes were treated with combinations of cytokines and hormones to mimic the hormonal milieu of the whole animal after APR induction. Incubation of primary rat hepatocytes with interleukin (IL)-6, a critical APR cytokine, leads to activation of STAT3 and a 28-fold induction of a chloramphenicol acetyltransferase reporter construct containing the −319 to +85 region of the Spi 2.2 promoter. This suggests the turpentine-induced increase of Spi 2.2 is mediated primarily by IL-6. In contrast, although turpentine treatment reduces Spi 2.1 mRNA in vivo and IL-6 does not increase Spi 2.1 mRNA in primary rat hepatocytes, treatment of hepatocytes with IL-6 results in a 5.4-fold induction of Spi 2.1 promoter activity mediated through the paired GAS elements in this promoter. Differential regulation of Spi 2.1 and 2.2 genes is due in part to differences in the promoters of these genes at the GAS sites. IL-6 alone fails to reproduce the pattern of rat Spi 2 gene expression that results from turpentine-induced inflammation.