title: NFκB- and AP-1-mediated DNA looping regulates matrix metalloproteinase-9 transcription in TNF-α-treated human leukemia U937 cells.
abstract: The aim of this study is to explore the spatial association of critical genomic elements in the effect of TNF-α on matrix metalloproteinase-9 (MMP-9) expression in human leukemia U937 cells. TNF-α up-regulated MMP-9 protein expression and mRNA level in U937 cells, and Akt-mediated-NFκB/p65 activation and JNK-mediated c-Jun activation were proven to be involved in TNF-α-induced MMP-9 up-regulation. Promoter luciferase activity assay revealed that NFκB (nt-600) and AP-1 (nt-79) binding sites were crucial for TNF-α-induced transcription of MMP-9 gene. The results of a chromatin immunoprecipitation assay indicated that TNF-α reduced histone deacetylase-1 (HDAC-1) recruitment but increased p300 (a histone acetyltransferase) recruitment to MMP-9 promoter regions surrounding NFκB and AP-1 binding sites. Consistently, TNF-α increased enrichment of the acetylated histone H3 mark on MMP-9 promoter regions. DNA affinity purification assay revealed that p300 and HDAC1 could bind oligonucleotides containing AP-1/c-Jun and NFκB/p65 binding sites. Chromosome conformation capture assay showed that TNF-α stimulated chromosomal loops in the MMP-9 promoter via NFκB/p65 and AP-1/c-Jun. The p300-associated acetyltransferase activity was crucial for p65/c-Jun-mediated DNA looping, and inhibition of HDAC activity increased the level of DNA looping. Reduction in the level of DNA looping eliminated all TNF-α-stimulated MMP-9 up-regulation. Taken together, our data suggest that p65/c-Jun-mediated DNA looping is involved in TNF-α-induced MMP-9 up-regulation and that the recruitment of p300 or HDAC1 to NFκB and AP-1 binding sites modifies the level of DNA looping.
authors.affiliation: Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan.
authors.forename: Ying-Jung
authors.initials: YJ
authors.lastname: Chen
authors.affiliation: Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan; Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan. Electronic address: lschang@mail.nsysu.edu.tw.
authors.forename: Long-Sen
authors.initials: LS
authors.lastname: Chang
mesh_terms: D001665:Binding Sites; D004247:DNA / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D050881:E1A-Associated p300 Protein / Q000235:genetics; D005786:Gene Expression Regulation; D056284:Histone Deacetylase 1 / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D007938:Leukemia / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis* / Q000235:genetics; D016328:NF-kappa B / Q000378:metabolism; D011401:Promoter Regions, Genetic; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics; D015398:Signal Transduction; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D051996:Transcription Factor RelA / Q000235:genetics* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage / Q000235:genetics / Q000378:metabolism*; D020298:U937 Cells
chemical_list: D004268:DNA-Binding Proteins; D016328:NF-kappa B; D018808:Transcription Factor AP-1; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D004247:DNA; D050881:E1A-Associated p300 Protein; C494360:EP300 protein, human; D051057:Proto-Oncogene Proteins c-akt; D048031:JNK Mitogen-Activated Protein Kinases; D020780:Matrix Metalloproteinase 9; C110550:HDAC1 protein, human; D056284:Histone Deacetylase 1
keywords: AP-1/c-Jun; DNA looping; Histone acetylation; MMP-9; NFκB/p65; TNF-α