NF-kappaB and activator protein 1 response elements and the role of histone modifications in IL-1beta-induced TGF-beta1 gene transcription.
Abnormal expression of TGF-beta1 is believed to play an important role in the pathogenesis of a number of chronic inflammatory and immune lung diseases, including asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis. Gene activation in eukaryotes requires coordinated use of specific cell signals, chromatin modifications, and chromatin remodeling. We studied the roles of the ubiquitous inflammatory transcription factors, NF-kappaB and AP-1, in activation of the TGF-beta1 gene and histone acetylation at the TGF-beta1 promoter. IL-1beta-induced TGF-beta1 protein secretion and mRNA expression were prevented by actinomycin D and were attenuated by the inhibitor of kappaB kinase 2 inhibitor AS602868 and the JNK inhibitor SP600125, suggesting a degree of transcriptional regulation mediated by the NF-kappaB and AP-1 pathways. We demonstrated that IL-1beta activated the p65 subunit of NF-kappaB and the c-Jun subunit of AP-1. Using chromatin immunoprecipitation assays, we observed a sequential recruitment of p65 and c-Jun, accompanying ordered elevation of the levels of histone H4 and H3 acetylation and recruitment of RNA polymerase II at distinct regions in the native TGF-beta1 promoter. The specific NF-kappaB and AP-1 binding sites in the TGF-beta1 promoter were confirmed by an ELISA-based binding assay, and evidence for histone hyperacetylation in TGF-beta1 induction was supported by the observation that the histone deacetylase inhibitor trichostatin A enhanced basal and IL-1beta-induced TGF-beta1 mRNA expression. Our results suggest that IL-1beta-stimulated transcription of TGF-beta1 is temporally regulated by NF-kappaB and AP-1 and involves histone hyperacetylation at distinct promoter sites.
Lee
Kang-Yun
KY
Airways Disease Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom.
Ito
Kazuhiro
K
Hayashi
Ryuji
R
Jazrawi
Elen P I
EP
Barnes
Peter J
PJ
Adcock
Ian M
IM
D000107:Acetylation; D001483:Base Sequence; D001665:Binding Sites; D015153:Blotting, Western; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D007375:Interleukin-1 / Q000378:metabolism*; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D016755:Proto-Oncogene Proteins c-jun / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050863:Synaptotagmin I / Q000187:drug effects / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000187:drug effects / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects; D015533:Transcriptional Activation; D016212:Transforming Growth Factor beta / Q000235:genetics* / Q000378:metabolism*; D053773:Transforming Growth Factor beta1
D004791:Enzyme Inhibitors; D006657:Histones; D007375:Interleukin-1; D016328:NF-kappa B; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D050863:Synaptotagmin I; C508960:TGFB1 protein, human; D018808:Transcription Factor AP-1; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1