Post-transcriptional control of negative acute phase genes by transforming growth factor beta

Abstract

During the acute phase (AP) reaction the expression of a series of liver-specific genes coding for secretory proteins is either stimulated or suppressed by different cytokines released by activated monocytes. Transforming growth factor beta (TGF-beta) is a cytokine that, first identified for its ability to regulate cellular growth, has been gradually recognized to modulate several other functions. We have investigated the effect of TGF-beta on the expression of acute phase genes in liver cells. We found that TGF-beta selectively induces a specific decreases in the amount of mRNAs of genes negatively regulated during AP reaction, like albumin and apolipoprotein A-I (ApoA-I). The inhibitory effect of TGF-beta on the expression of negative AP genes is primarily post-transcriptional and it is very likely to be mediated via an enhancement of the turnover of both albumin and ApoA-I mRNAs.