Regulation of c-fos gene expression by lipopolysaccharide and cycloheximide in C6 rat glioma cells

• Published in: Brain research 2000-07, Vol.872 (1), p.227-230
• Main Authors: Kim, Yung-Hi, Choi, Mi-Ran, Song, Dong-Keun, Huh, Sung-Oh, Jang, Choon-Gon, Suh, Hong-Won
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; c-fos; C6 rat glioma cells; Cell physiology; CREB; Cyclic AMP Response Element-Binding Protein - metabolism; Cycloheximide; Cycloheximide - pharmacology; Drug Synergism; extracellular signal-regulated kinase; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Neoplastic - drug effects; Glioma - genetics; Glioma - metabolism; Glioma - pathology; JNK Mitogen-Activated Protein Kinases; Lipopolysaccharide; Lipopolysaccharides - metabolism; Lipopolysaccharides - pharmacology; MAPK; Mitogen-Activated Protein Kinases - metabolism; Molecular and cellular biology; p38 Mitogen-Activated Protein Kinases; Phosphorylation - drug effects; Protein Synthesis Inhibitors - pharmacology; Proto-Oncogene Proteins c-fos - genetics; Proto-Oncogene Proteins c-fos - metabolism; Proto-Oncogene Proteins c-jun - genetics; Proto-Oncogene Proteins c-jun - metabolism; Rats; RNA, Messenger - metabolism; Signal transduction; Tumor Cells, Cultured
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/S0006-8993(00)02477-X

The effect of lipopolysaccharide (LPS) on the expression of immediate early genes, such as c-fos and c-jun, was examined in C6 rat glioma cells. LPS (1 μg/ml) alone did not affect c-fos mRNA level. LPS, however, transiently increased c-jun mRNA level. Cycloheximide (CHX, 20 μM), a protein synthesis inhibitor, alone caused increases of c-fos and c-jun mRNA levels. LPS showed a potentiating effect in the regulation of c-fos mRNA level, whereas LPS showed an additive action for the regulation of CHX-induced c-jun mRNA expression. To determine if CREB and mitogen-activated protein kinases (MAPKs) are involved in the regulation of c-fos mRNA expression by LPS and CHX, Western blot was carried out using the phosphorylated form of antibodies against ERK, JNK, p38, and CREB. LPS transiently increased the phosphorylation of p38-MAPK and CREB. In addition, LPS alone elevated phosphorylation of ERK (p44/p42) MAPK in a time-dependent manner. Furthermore, LPS plus CHX enhanced phosphorylation of ERK, p38, and CREB in a synergistic manner. Our results suggest that the phosphorylation of ERK, p38, and CREB may be involved in the regulation of synergistic c-fos mRNA expression induced by LPS plus CHX in C6 rat glioma cells.