Hirasawa Noriyasu, Torigoe Masashi, Kano Kuniyuki, Ohuchi Kazuo
Laboratory of Pathophysiological Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
Biochem Biophys Res Commun. 2006 Oct 20;349(2):833-7. doi: 10.1016/j.bbrc.2006.08.104. Epub 2006 Aug 24.
The involvement of Sp1 in the lipopolysaccharide (LPS)-induced transcription of HDC mRNA in the mouse macrophage-like cell line RAW 264 was analyzed. LPS increased the levels of HDC mRNA 4 h after the stimulation in a concentration-dependent manner. Mithramycin A, an inhibitor of the binding of the Sp family to the GC box, reduced the LPS-induced increase in the levels of HDC mRNA at 4 h and HDC protein at 8 h in a concentration-dependent manner. By conducting electrophoretic mobility shift assays, we found that one of the transcription factors binding to the DNA probe containing the GC box sequence of the mouse HDC gene promoter region was Sp1, and that levels of Sp1-DNA probe complexes were increased by stimulation with LPS although the protein levels of Sp1 were not changed. These results suggested that Sp1 is one of the transcription factors that regulate the LPS-induced expression of HDC in RAW 264 cells.
分析了Sp1在小鼠巨噬细胞样细胞系RAW 264中脂多糖（LPS）诱导的组氨酸脱羧酶（HDC）mRNA转录中的作用。刺激后4小时，LPS以浓度依赖的方式增加了HDC mRNA的水平。丝裂霉素A是一种Sp家族与GC盒结合的抑制剂，它以浓度依赖的方式降低了刺激4小时时LPS诱导的HDC mRNA水平的增加以及刺激8小时时HDC蛋白水平的增加。通过进行电泳迁移率变动分析，我们发现与包含小鼠HDC基因启动子区域GC盒序列的DNA探针结合的转录因子之一是Sp1，并且尽管Sp1的蛋白质水平没有变化，但LPS刺激会增加Sp1-DNA探针复合物的水平。这些结果表明，Sp1是调节RAW 264细胞中LPS诱导的HDC表达的转录因子之一。
