Open AccessThe Human Inter‐α‐Trypsin Inhibitor Genes Respond Differently to Interleukin‐6 in HepG2 Cells
Author(s) -
Sarafan Nasrin,
Martin JeanPierre,
Bourguig Jeannette,
Borghi Hélè,
Callé Aleth,
Sesboüé Richard,
DiarraMehrpour Maryam
Publication year - 1995
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1995.0808p.x
Subject(s) - microbiology and biotechnology , inducer , messenger rna , transcription (linguistics) , gene expression , gene , trypsin , interleukin , biology , chemistry , cytokine , biochemistry , enzyme , immunology , philosophy , linguistics
The effects of interleukin 6 (IL‐6), the major inducer of the acute‐phase reaction, on the expression of inter‐α‐trypsin inhibitor (ITI) genes were examined using human HepG2 hepatoma cells. The three ITI heavy chain genes H1, H2 and H3 were transcriptionally regulated by IL‐6 in a dose‐ and time‐dependent manner. The treatment of HepG2 cells with IL‐6 resulted in an increase of H1 and H3 mRNA levels and a decrease of H2 and L mRNA levels. Actinomycin D blocked the action of IL‐6, suggesting that IL‐6 regulated the H1, H2, H3 gene expression. Moreover, the kinetics of the ITI mRNA degradation in untreated and IL‐6‐treated cells confirmed these data. The nuclear run‐on assay supports the regulatory effect of IL‐6 at the transcription level of the L and H2 genes. Primer extension experiments showed that the effect of IL‐6 on L, H2 and H3 mRNA synthesis was not related to the transcription starting point. Although H1, H2, H3 and L gene products are supposedly present in similar amounts in the ITI and pre‐α‐trypsin inhibitor molecules, the present work shows that these genes are regulated in a different manner, at least under the influence of IL‐6.