Open AccessDNase I hypersensitive sites in the 5′ flanking region of the human plasminogen activator inhibitor type 2 (PAI‐2) gene are associated with basal and tumor necrosis factor‐α‐induced transcription in monocytes
Author(s) -
Mahony Donna,
Stringer Brett W.,
Dickinson Joanne L.,
Antalis Toni M.
Publication year - 1998
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.1998.2560550.x
Subject(s) - biology , microbiology and biotechnology , hypersensitive site , dnase i hypersensitive site , chromatin , serpin , transcription factor , intron , gene expression , plasminogen activator inhibitor 1 , plasminogen activator , gene , promoter , genetics
The plasminogen activator inhibitor type 2 (PAI‐2) gene encodes a serine proteinase inhibitor (serpin) which is rapidly induced in response to the inflammatory cytokine, tumour necrosis factor‐α (TNFα) in monocytes and macrophages. As an initial step towards understanding the molecular mechanisms underlying PAI‐2 gene regulation in monocytes, we report here the analysis of the chromatin structure of 9.6 kb of 5′ flanking region of the human PAI‐2 gene for potential cis ‐acting regulatory regions using DNase I hypersensitivity mapping. Sites sensitive to DNase I were mapped in two monocytic cell lines representative of early monocytic differentiation; U937 cells, which synthesise low constitutive levels of PAI‐2 that were induced following treatment with TNFα, and a MonoMac6 cell line which did not synthesise PAI‐2 even after treatment with TNFα. Six DNase I hypersensitive sites (DHS) were identified; three upstream of the transcription initiation site (DH1, DH2, DH3) and three downstream of the transcription initiation site which were contained within intron A (DH4, DH5) and the exon 2/intron B junction (DH6). Among these, one distally located DH site (DH2) disappeared in both cell lines following treatment with TNFα. Two DH sites (DH1, DH6) were absent in PAI‐2‐producing U937 cells, but were present in MonoMac6 cells, which did not produce PAI‐2, indicating the possible involvement of negative regulatory elements in the suppression of PAI‐2 gene expression. The results demonstrate the involvement of chromatin structure in transcriptional responsiveness of the PAI‐2 gene promoter and identify several loci which may be key control regions for PAI‐2 gene transcription.