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Down‐regulation of negative acute‐phase response genes by hypotonic stress in HepG2 hepatoma cells
Author(s) -
Claeyssens Sophie,
Banine Fatima,
Rouet Philippe,
Lavoinne Alain,
Salier Jean-Philippe
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)00868-0
Subject(s) - tonicity , gene , chemistry , acute phase protein , microbiology and biotechnology , fight or flight response , biology , biochemistry , immunology , inflammation
An increased hepatocellular hydration state (HS) that can be induced by hypotonic stress or a high glutamine uptake modulates the transcription of given genes in liver. This could be important in the acute phase (AP) of a systemic inflammation where both HS and glutamine uptake transiently increase in liver. In HepG2 hepatoma cells cultured in conditions of hypotonic stress or a high extracellular glutamine availability, a specifically decreased expression of two human mRNAs, namely those of α1‐microglobulin/bikunin precursor (AMBP) and α2‐HS‐glycoprotein, that are also down‐regulated in liver by AP, could be seen. A functional analysis of the AMBP promoter indicated that this hypotonic stress‐induced down‐regulation takes place at a transcriptional level. In these experiments, the mRNA level and transcription of the glyceraldehyde‐3‐phosphate dehydrogenase gene that are known to be unmodified in AP did not exhibit any change. Given that hypotonic stress also up‐regulates the transcription of a liver gene that is also up‐regulated in AP [Meisse et al. (1998) FEBS Lett. 422, 346–348], the AP‐associated increase in hepatocellular HS now appears to participate in the transcriptional control of both sets of genes that are up‐ or down‐regulated in AP.