Cytokine-induced changes in chromatin structure and in vivo footprints in the inducible NOS promoter.

Document Type

Article

Abstract

Transcription of the human inducible nitric oxide synthase (iNOS) gene is regulated by inflammatory cytokines in a tissue-specific manner. To determine whether differences in cytokine-induced mRNA levels between pulmonary epithelial cells (A549) and hepatic biliary epithelial cells (AKN-1) result from different protein or DNA regulatory mechanisms, we identified cytokine-induced changes in DNase I-hypersensitive (HS) sites in 13 kb of the iNOS 5'-flanking region. Data showed both constitutive and inducible HS sites in an overlapping yet cell type-specific pattern. Using in vivo footprinting and ligation-mediated PCR to detect potential DNA or protein interactions, we examined one promoter region near -5 kb containing both constitutive and cytokine-induced HS sites. In both cell types, three in vivo footprints were present in both control and cytokine-treated cells, and each mapped within a constitutive HS site. The remaining footprint appeared only in response to cytokine treatment and mapped to an inducible HS site. These studies, performed on chromatin in situ, identify a portion of the molecular mechanisms regulating transcription of the human iNOS gene in both lung- and liver-derived epithelial cells.

Keywords

Base Sequence, Bile Ducts, Intrahepatic, Cell Line, Chromatin, Chromosome Mapping, Cytokines, DNA Footprinting, Epithelial Cells, Genes, Humans, Lung, Molecular Sequence Data, Nitric Oxide Synthase, Nitric Oxide Synthase Type II, Promoter Regions, Genetic, Reference Values

Medical Subject Headings

Base Sequence; Bile Ducts, Intrahepatic; Cell Line; Chromatin; Chromosome Mapping; Cytokines; DNA Footprinting; Epithelial Cells; Genes; Humans; Lung; Molecular Sequence Data; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Promoter Regions, Genetic; Reference Values

Publication Date

3-1-2001

Publication Title

American journal of physiology. Lung cellular and molecular physiology

ISSN

1040-0605

Volume

280

Issue

3

First Page

390

Last Page

399

PubMed ID

11159021

Digital Object Identifier (DOI)

10.1152/ajplung.2001.280.3.l390

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