Identification of c-Maf target genes in bone marrow-derived macrophages
Date Issued
2015
Date
2015
Author(s)
Li, Po-Yen
Abstract
c-Maf (v-maf musculoaponeurotic fibrosarcoma oncogene homolog), a member of the Maf family, is known to transactivate downstream target genes by binding to the Maf-recognition elements (MAREs). It is well known that c-Maf plays an important role in regulating the production of IL-4, IL-21 and IL-22 in TH cells. However, the role of c-Maf in the biology of macrophages remains unclear. In this study, I aimed to search for the possible c-Maf target genes in macrophages. Microarray data were analyzed for gene expression of classically activated (M1) and alternatively activated (M2) bone marrow-derived macrophages from WT and c-Maf KO mice. Two hundred and eighteen genes were selected as candidates based on differential expression with 2-fold change as cutoff. The promoter sequences of these genes in mice and human were analyzed with the MatInspector (Genometix) program and aligned with the ClustalW (GenomeNet) program. The sequences were compared with the sequences of all the known MARE sites. Based on their similarity and alignment analysis of the sequences in mice and human, there were 36 genes with conservative MARE-like sequences. Among them, Fabp4 was chosen for further study, because mRNA microarray analysis showed that the expression of Fabp4 was 8-fold higher in WT M2 than in M1 macrophages and the expression was reduced in c-Maf KO macrophages. Quantitative PCR (qPCR) assay confirmed the microarray results. Chromatin immunoprecipitation (ChIP) assay further revealed that c-Maf binds to Fabp4 promoter. Moreover, Fabp4 promoter reporter assay also showed that c-Maf transactivates Fabp4 gene. Taken together, these findings demonstrated that c-Maf binds to MARE site of Fabp4 promoter and transactivates Fabp4 gene expression in macrophages.
Subjects
macrophage
bone marrow derived macrophage
alternatively activated macrophage
Type
thesis