Goethe R, Phi-van L
Institut für Kleintierforschung (FAL), Celle, Germany.
J Leukoc Biol. 1997 Mar;61(3):367-74. doi: 10.1002/jlb.61.3.367.
C/EBPbeta has been shown to mediate the lipopolysaccharide (LPS)-induced expression of the lysozyme gene through enhanced binding to the -6.1-kb lysozyme enhancer. In this study, we describe the LPS regulation of the C/EBPbeta gene in myelomonocytic HD11 cells. Northern analysis showed that the steady state level of C/EBPbeta mRNA increased in response to LPS. The half life of C/EBPbeta mRNA of about 1 h in HD11 cells was not affected by exposure to LPS. Nuclear run-on transcription experiments with isolated nuclei revealed that the rate of C/EBPbeta gene transcription was enhanced by LPS, demonstrating that the C/EBPbeta gene in HD11 cells was regulated at the transcriptional level in response to LPS. Furthermore, the LPS-induced binding activity of C/EBPbeta to the -6.1-kb lysozyme enhancer was dependent not only on protein synthesis, but also on transcription. Thus, these results suggested that the LPS-induced binding activity to the -6.1-kb lysozyme enhancer in HD11 cells was regulated by an enhanced transcription-dependent de novo synthesis of C/EBPbeta.
C/EBPβ已被证明可通过增强与-6.1kb溶菌酶增强子的结合来介导脂多糖（LPS）诱导的溶菌酶基因表达。在本研究中，我们描述了髓单核细胞HD11细胞中C/EBPβ基因的LPS调节。Northern分析表明，C/EBPβ mRNA的稳态水平在LPS刺激下增加。HD11细胞中C/EBPβ mRNA约1小时的半衰期不受LPS暴露的影响。用分离的细胞核进行的核转录实验表明，LPS可增强C/EBPβ基因的转录速率，表明HD11细胞中的C/EBPβ基因在转录水平上受LPS调节。此外，LPS诱导的C/EBPβ与-6.1kb溶菌酶增强子的结合活性不仅依赖于蛋白质合成，还依赖于转录。因此，这些结果表明，HD11细胞中LPS诱导的与-6.1kb溶菌酶增强子的结合活性是由C/EBPβ转录依赖性从头合成增强所调节的。
